Indication device

Abstract

To provide a display device with high display quality. To provide a high-definition display device. [Solution] A display device having a plurality of pixels, each pixel having a light-emitting device, a first transistor, a second transistor, a third transistor, a fourth transistor, and a first capacitive element. One electrode of the light-emitting device is electrically connected to either the source or drain of the first transistor, either the source or drain of the second transistor, and one electrode of the first capacitive element. The gate of the second transistor is The other electrode of the first capacitive element is electrically connected to either the source or drain of the third transistor, and either the source or drain of the fourth transistor. In addition, in each pixel, there is a period during one frame in which both the first transistor and the fourth transistor are conducting.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device and an electronic device.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. One aspect of the technology field is semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, Electronic equipment, lighting equipment, input devices, input / output devices, methods for driving them, or methods for manufacturing them. One example is semiconductor devices that function by utilizing semiconductor properties. This refers to all types of devices. [Background technology]

[0003] Oxide semiconductors, which use metal oxides, are attracting attention as semiconductor materials applicable to transistors. For example, Patent Document 1 describes stacking multiple oxide semiconductor layers, and the multiple oxide semiconductor layers are stacked. In the material semiconductor layer, the oxide semiconductor layer that forms the channel contains indium and gallium, and By making the proportion of indium greater than the proportion of gallium, the field effect mobility (simply move A semiconductor device with increased mobility (sometimes referred to as μFE or μ) is disclosed.

[0004] Metal oxides that can be used in semiconductor layers can be formed using methods such as sputtering. Therefore, it can be used in transistors that make up large display devices. It is possible to modify and utilize some of the production equipment for transistors using silicon or amorphous silicon. Because it is possible, capital investment can be kept down. Also, transistors using metal oxides are non Because it has a higher field-effect mobility compared to the case using crystalline silicon, a drive circuit is provided. This enables the creation of high-performance display devices.

[0005] By the way, Augmented Reality (AR) or Virtual Reality (V A wearable display device for R:Virtual Reality. , and stationary display devices are becoming widespread. As for wearable display devices, for example Head-mounted display (HMD) Examples include head-up displays and eyeglasses-type display devices. As for stationary display devices, for example, head-up displays Examples include displays (HUD: Head-Up Display).

[0006] In electronic devices having an imaging device such as a digital camera, the image to be captured can be confirmed before capturing. A viewfinder is used for confirmation. Also, as a viewfinder, An electronic viewfinder is used. The electronic viewfinder has a display unit. The image obtained by the imaging device can then be displayed as an image on the display unit. For example, Patent Document 2 describes how to obtain a good diopter state from the center to the periphery of an image. Electronic viewfinders capable of this are disclosed. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2014-7399 [Patent Document 2] Japanese Patent Publication No. 2012-42569 [Overview of the project] [Problems that the invention aims to solve]

[0008] In display devices such as HMDs, where the distance between the display unit and the user is close, it is important for the user to be able to see the pixels clearly. However, because the grainy texture is often strongly perceived, the sense of immersion and realism in AR and VR may be diminished. Yes. For this reason, it is equipped with fine pixels so that the user cannot see the pixels, that is, fineness A display device with high resolution is desired. However, the higher the resolution, the smaller the area of ​​each pixel. This results in a decrease in the number of elements such as transistors and capacitive elements provided in each pixel. In some cases, this may be the case. Therefore, in high-resolution display devices, pixels are composed of a small number of elements. It is desirable that this be done.

[0009] When you look at the light emitted from a display device, even after the light disappears, the light you were looking at remains. A phenomenon called afterimage may occur. When afterimage occurs, use For the user, previously displayed images are perceived as afterimages, which can degrade display quality. In the case of video, the afterimage phenomenon has a greater impact, which can significantly degrade the display quality. There is.

[0010] In view of the above, one aspect of the present invention aims to provide a display device with high resolution. Alternatively, one aspect of the present invention aims to provide a display device with minimal afterimages. Alternatively, one aspect of the present invention aims to provide a display device with high display quality. Alternatively, one aspect of the present invention aims to provide a display device with low power consumption. One aspect of the present invention is to provide a display device with a narrow bezel. Alternatively, one aspect of the present invention aims to provide a compact display device. Alternatively, one aspect of the present invention aims to provide a novel display device.

[0011] Furthermore, the description of these problems does not preclude the existence of other problems. One approach does not require that all of these issues be resolved. The title will become clear from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the drawings, claims, etc. [Means for solving the problem]

[0012] One aspect of the present invention is a pixel section having a plurality of pixels, a first wiring, a first scanning line, and This is a display device having two scan lines, a third scan line, and signal lines. The pixels are light-emitting devices. A chair, the first transistor, the second transistor, the third transistor, and the fourth It has a transistor and a first capacitive element. One electrode of the light-emitting device is the first transistor Either the source or drain of the transistor and the source or drain of the second transistor One side of the transistor is electrically connected to one electrode of the first capacitive element. The second transistor The gate of the transistor is connected to the other electrode of the first capacitive element and to the source or drain of the third transistor. One side of the input is electrically connected to either the source or drain of the fourth transistor. The other side of the source or drain of the first transistor, and the source of the fourth transistor. The other of the drain or the other has a first wiring that has the function of supplying a first potential and They are electrically connected. The gate of the first transistor is electrically connected to the first scan line. The gate of the third transistor is electrically connected to the second scan line. The fourth transistor The gate of the zista is electrically connected to the third scan line. The source of the third transistor... The other end of the drain is electrically connected to the signal line. Also, in each pixel, During the frame period, the first transistor and the fourth transistor are in a conductive state. It has a period of time.

[0013] In the aforementioned display device, it is preferable to have a second capacitive element. One electrode is electrically connected to the gate of the second transistor. One electrode is electrically connected to the other, either the source or drain, of the second transistor.

[0014] One aspect of the present invention is a pixel section having a plurality of pixels, a first wiring, a first scanning line, and This is a display device having two scan lines, a third scan line, and signal lines. The pixels are light-emitting devices. A chair, the first transistor, the second transistor, the third transistor, and the fourth It has a transistor and a first capacitive element. One electrode of the light-emitting device is the first transistor Either the source or drain of the transistor and the source or drain of the second transistor One side of the transistor, one side of the source or drain of the fourth transistor, and one side of the first capacitive element The electrode of the second transistor is electrically connected to the first capacitive element. The other electrode, one of the source or drain of the third transistor, and the fourth transistor The source or drain of the first transistor is electrically connected to the other side. The other end of the first transistor, either the drain or the other, is electrically connected to the first wiring. The gate is electrically connected to the first scan line. The gate of the third transistor is connected to the second scan line. The scan line is electrically connected. The gate of the fourth transistor is electrically connected to the third scan line. The connection continues. The source or drain of the third transistor is electrically connected to the signal line. In addition, in each pixel, during one frame period, the first transistor and The period when the three transistors are in a non-conducting state and the fourth transistor is in a conducting state. It has a gap.

[0015] One aspect of the present invention is a pixel section having a plurality of pixels, a first wiring, a second wiring, and a first This is a display device having a first scan line, a second scan line, a third scan line, and signal lines. The components are a light-emitting device, a first transistor, a second transistor, and a third transistor. It has a st, a fourth transistor, and a first capacitive element. One of the light-emitting devices The poles are either the source or drain of the first transistor and the source of the second transistor. One of the source or drain of the fourth transistor, and the first One electrode of the capacitive element is electrically connected to the second transistor. The gate of the second transistor is The other electrode of the capacitive element 1 and one of the source or drain of the third transistor, Electrically connected. The source or drain of the first transistor is connected to the first wiring. It is electrically connected to the second transistor. The source or drain of the fourth transistor is connected to the second transistor. The line is electrically connected. The gate of the first transistor is electrically connected to the first scan line. The gate of the third transistor is electrically connected to the second scan line. The gate of the transistor is electrically connected to the third scan line. The other end of the drain or the other is electrically connected to the signal line. Also, at each pixel During one frame period, the first transistor and the third transistor are each non-conductive. This state includes a period during which the fourth transistor is in a conductive state.

[0016] One aspect of the present invention is a pixel section having a plurality of pixels, a first wiring, a first scanning line, and This is a display device having two scan lines, a third scan line, and signal lines. The pixels are light-emitting devices. A chair, the first transistor, the second transistor, the third transistor, and the fourth It has a transistor and a first capacitive element. One electrode of the light-emitting device is a fourth transistor. It is electrically connected to either the source or drain of the transistor. The fourth transistor The other of the source or drain is connected to one of the source or drain of the first transistor. The source or drain of the second transistor and one electrode of the first capacitive element, It is electrically connected to the other electrode of the first capacitive element. The first transistor is electrically connected to either the source or drain of the third transistor. The source or drain of the transistor is electrically connected to the first wiring. The gate of the transistor is electrically connected to the first scan line. The gate of the third transistor The gate is electrically connected to the second scan line. The gate of the fourth transistor is connected to the third It is electrically connected to the scan line. The source or drain of the third transistor is connected to the signal. It is electrically connected to the line. Also, in each pixel, during one frame period, the first The transistor, the third transistor, and the fourth transistor are all in a non-conductive state. It has a duration.

[0017] One aspect of the present invention is a pixel section having a plurality of pixels, a first wiring, a first scanning line, and This is a display device having two scan lines, a third scan line, and signal lines. The pixels are light-emitting devices. A chair, the first transistor, the second transistor, the third transistor, and the fourth It has a transistor and a first capacitive element. One electrode of the light-emitting device is the first transistor Either the source or drain of the transistor and the source or drain of the second transistor One side of the transistor is electrically connected to one electrode of the first capacitive element. The second transistor The gate of the transistor is connected to the other electrode of the first capacitive element and to the source or drain of the third transistor. It is electrically connected to one side of the input and the other side of the source or drain of the second transistor. The first is electrically connected to either the source or the drain of the fourth transistor. The source or drain of the transistor is electrically connected to the first wiring. The gate of the transistor is electrically connected to the first scan line. The gate of the third transistor The gate is electrically connected to the second scan line. The gate of the fourth transistor is connected to the third It is electrically connected to the scan line. The source or drain of the third transistor is connected to the signal. It is electrically connected to the line. At each pixel, during one frame period, the first transistor The period during which the third and fourth transistors are each in a non-conductive state. To possess.

[0018] In the aforementioned display device, the second transistor preferably has a back gate. The back gate is electrically connected to either the source or drain of the second transistor. It will be done.

[0019] In the aforementioned display device, the second transistor preferably has a back gate. The back gate is electrically connected to the gate of the second transistor.

[0020] In the aforementioned display device, the other electrode of the light-emitting device is electrically connected to the third wiring. It is preferable that the first wiring is supplied with a first potential. The third wiring is supplied with a third potential. A potential is supplied, and it is preferable that the third potential is lower than the first potential.

[0021] In the aforementioned display device, the light-emitting device is preferably an organic light-emitting diode. .

[0022] In the aforementioned display device, a first drive circuit unit is provided, and the first drive circuit unit overlaps with the pixel unit. It is preferable that the region has a certain area and is electrically connected to the signal line.

[0023] In the aforementioned display device, it is preferable to have a first layer and a second layer on the first layer. The first layer has a first drive circuit section and a second drive circuit section, and the second layer is a drawing. It has an element section. The second drive circuit section is electrically connected to the first scan line.

[0024] In the aforementioned display device, the first transistor, the second transistor, and the third transistor The first and fourth transistors each have a metal oxide in the channel formation region. This is preferable. The metal oxide is indium, zinc, and element M (aluminum, titanium, gas). Rium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neo It has one or more selected from gymnastics or hafnium.

[0025] One aspect of the present invention is an electronic device having the aforementioned display device and a camera. [Effects of the Invention]

[0026] According to one aspect of the present invention, a display device with high resolution can be provided. Or, according to one aspect of the present invention This makes it possible to provide a display device with less afterimage. Alternatively, according to one aspect of the present invention, display quality A display device with high performance can be provided. Alternatively, according to one aspect of the present invention, a display device with low power consumption can be provided. This can provide a display device with a narrow bezel. According to one aspect of the present invention, a compact display device can be provided. Or, according to one aspect of the present invention This allows us to provide novel display devices.

[0027] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not necessarily have to possess all of these effects. Furthermore, other effects may be considered. This information can be extracted from descriptions in the specification, drawings, claims, etc. [Brief explanation of the drawing]

[0028] [Figure 1] Figures 1A and 1B are circuit diagrams showing examples of pixel configurations. [Figure 2] Figure 2 is a timing chart illustrating the operation of the pixel circuit. [Figure 3] Figure 3A is a circuit diagram showing an example of a pixel configuration. Figure 3B is a timing chart explaining the operation of the pixel circuit. [Figure 4] Figure 4A is a circuit diagram showing an example of a pixel configuration. Figure 4B is a timing chart explaining the operation of the pixel circuit. [Figure 5] Figures 5A and 5B are circuit diagrams showing examples of pixel configurations. [Figure 6] Figure 6 is a timing chart illustrating the operation of the pixel circuit. [Figure 7] Figure 7A is a circuit diagram showing an example of a pixel configuration. Figure 7B is a timing chart explaining the operation of the pixel circuit. [Figure 8] Figures 8A to 8C show the operation of the display device. [Figure 9]Figure 9A is a circuit diagram showing an example of pixel configuration. Figure 9B is a diagram showing the operation of the display device. [Figure 10] Figure 10 shows the operation of the display device. [Figure 11] Figures 11A and 11B show examples of pixel layouts. [Figure 12] Figures 12A and 12B are schematic diagrams showing examples of pixel configurations. [Figure 13] Figures 13A and 13B are schematic diagrams showing examples of pixel configurations. [Figure 14] Figure 14 is a block diagram showing an example of a display device configuration. [Figure 15] Figure 15A is a schematic diagram showing an example of the configuration of a display device. Figure 15B is a block diagram showing an example of the configuration of a display device. [Figure 16] Figure 16A is a schematic diagram showing an example of the configuration of a display device. Figure 16B is a block diagram showing an example of the configuration of a display device. [Figure 17] Figure 17 is a cross-sectional view showing an example of the configuration of a display device. [Figure 18] Figure 18 is a cross-sectional view showing an example of the configuration of a display device. [Figure 19] Figure 19 is a cross-sectional view showing an example of the configuration of a display device. [Figure 20] Figure 20 is a cross-sectional view showing an example of the configuration of a display device. [Figure 21] Figure 21 is a cross-sectional view showing an example of the configuration of a display device. [Figure 22] Figures 22A to 22E show examples of the configuration of a light-emitting device. [Figure 23] Figure 23A is a top view showing an example of a transistor configuration. Figures 23B and 23C are cross-sectional views showing an example of a transistor configuration. [Figure 24] Figure 24A is a top view showing an example of a transistor configuration. Figures 24B and 24C are cross-sectional views showing an example of a transistor configuration. [Figure 25]Figure 25A is a top view showing an example of a transistor configuration. Figures 25B and 25C are cross-sectional views showing an example of a transistor configuration. [Figure 26] Figure 26A is a top view showing an example of a transistor configuration. Figures 26B and 26C are cross-sectional views showing an example of a transistor configuration. [Figure 27] Figure 27A illustrates the classification of IGZO crystal structures. Figure 27B illustrates the XRD spectrum of a CAAC-IGZO film. Figure 27C illustrates the micro-electron diffraction pattern of a CAAC-IGZO film. [Figure 28] Figures 28A to 28E are perspective views showing examples of electronic devices. [Figure 29] Figures 29A to 29G are perspective views showing examples of electronic devices. [Figure 30] Figure 30 is a diagram illustrating the simulation results. [Figure 31] Figures 31A and 31B are photographs of the display device. [Figure 32] Figure 32A shows the correlation between the duty cycle and brightness of a display device. Figure 32B shows the change in brightness of a display device over time. [Modes for carrying out the invention]

[0029] The embodiments will be described below with reference to the drawings. However, many embodiments are described. It can be implemented in different ways, without deviating from its purpose and scope. It will be easily understood by those skilled in the art that the form and details can be changed in various ways. Therefore, The invention shall not be construed as being limited to the descriptions of the following embodiments.

[0030] In each figure described herein, the size of each component, the thickness of the layer, or the area are for clarity. Therefore, it may be exaggerated.

[0031] The ordinal numbers "1st," "2nd," and "3rd" used in this specification, etc., are intended to avoid confusion of constituent elements. This was added to avoid the issue of a numerical limitation.

[0032] In this specification, phrases indicating placement such as "above" and "below" refer to the positional relationship between components. This is used for convenience in explaining with reference to the diagram. Also, the positional relationships between the components are as follows: It changes appropriately depending on the direction in which each component is described. Therefore, as described in the specification It's not limited to specific words or phrases; it can be appropriately rephrased depending on the situation.

[0033] In this specification and elsewhere, the source and drain functions of a transistor are defined as follows: The polarity may change, or the direction of the current may change during circuit operation. Therefore, the terms source and drain may be used interchangeably.

[0034] In this specification, terms such as "electrode," "wiring," and "terminal" refer to these components functionally. It is not limited to that. For example, "electrode" can be used as part of "wiring". And the reverse is also true. Furthermore, the terms "electrode" and "wiring" can refer to multiple "electrodes" or This also includes cases where the "wiring" is formed as an integrated unit. Furthermore, for example, a "terminal" is considered part of the "wiring." It is sometimes used as part of an "electrode" or "end". Furthermore, it is sometimes used as part of an "end". The term "child" is used when multiple "electrodes," "wirings," "terminals," etc., are formed as a single unit. This also includes. Therefore, for example, an "electrode" can be part of a "wiring" or "terminal". Furthermore, for example, a "terminal" can be part of a "wire" or an "electrode." Terms such as "pole," "wiring," and "terminal" may be replaced with terms such as "area" depending on the context. be.

[0035] In this specification, the term "resistance" may be defined as the resistance value determined by the length of the wiring. Alternatively, the resistor may be connected to a conductor with lower efficiency than the conductor used in the wiring via contact. This also includes cases where connections are made to form the semiconductor. Alternatively, the resistance value can be increased by doping the semiconductor with impurities. There are times when a decision needs to be made.

[0036] In this specification, "electrically connected" refers to both a direct connection and "some kind of electrical connection". This includes cases where the connection is made via "some kind of electric" (or "some kind of electric"). "A device that has a gaseous effect" is one that enables the exchange of electrical signals between connected objects. There are no particular restrictions. Therefore, even when it is expressed as "electrically connected," in reality In some circuits, there are no physical connections, and only wiring extends. Furthermore, even when described as "direct connection," wiring is done via contacts to different conductors. This includes cases where a conductor is formed. Note that the wiring contains one or more different conductors of the same element. There are cases where it contains one element and cases where it contains different elements.

[0037] In this specification, the terms "membrane" and "layer" are interchangeable. It is possible. For example, the terms "conductive layer" and "insulating layer" are similar to "conductive film" and "insulating layer". In some cases, the term "membrane" can be used interchangeably.

[0038] In this specification, unless otherwise specified, off-current refers to the state in which the transistor is in the off state. This refers to the drain current when the device is in a non-conductive state or interrupted state. The off state is a special state. Unless otherwise specified, in an n-channel transistor, the voltage between the gate and source V gs but Threshold voltage V th Lower than (in p-channel transistors, V th (Higher than) To describe a state or attitude.

[0039] In drawings, size, layer thickness, or area may be exaggerated for clarity. Yes, it exists. Therefore, it is not necessarily limited to that scale. Note that the diagram is a schematic representation. Yes, and not limited to the shape or values ​​shown in the drawing. For example, in the actual manufacturing process, Due to processes such as chipping, layers and resist masks may be unintentionally reduced, but please understand. To facilitate this, some details may not be reflected in the drawings. Also, in the drawings, the same part or similar For parts with specific functions or materials, the same reference numeral is used consistently across different drawings, and its repetition is... The explanation of this may be omitted. Also, when referring to similar functions, materials, etc., the term "hatch pattern" may be used. The same character is used, and sometimes no specific symbol is added.

[0040] In this specification, metal oxide refers to metal in a broad sense. It is an oxide. Metal oxides are oxide insulators and oxide conductors (including transparent oxide conductors). ), oxide semiconductors (also called OS), etc. It is classified as follows. For example, when a metal oxide is used in the active layer of a transistor, the metal oxide The material is sometimes called an oxide semiconductor. In other words, when it is written as an OS transistor... Therefore, it can be rephrased as a transistor having an oxide or oxide semiconductor.

[0041] In this specification, a pixel refers, for example, to a single element whose brightness can be controlled. Therefore, as an example, one pixel is defined as representing one color element, and that color element Brightness is expressed using only one element. Therefore, a color consists of the color elements R (red), G (green), and B (blue). In the case of a display device, the smallest unit of an image consists of three pixels: a red pixel, a green pixel, and a blue pixel. It shall be assumed that this is done. In this case, each RGB pixel is called a subpixel. Sometimes, the sub-pixels of RGB are collectively referred to as pixels.

[0042] (Embodiment 1) In this embodiment, a display device that is one aspect of the present invention will be described.

[0043] A display device according to one aspect of the present invention has a pixel section. The pixel section has a plurality of pixels, Each of these consists of a light-emitting device and a drive transistor that controls the amount of current flowing through the light-emitting device. A display device having a starter and a light-emitting device during a frame period. One aspect of the present invention is a display device having a light-emitting device during a frame period. A period of time can be set during which the lights are turned off. By setting such a period and displaying black, the remaining Image density can be reduced, and display quality can be improved.

[0044] A display device according to one aspect of the present invention provides each pixel with image data from a source driver. The corresponding potential "Vdata" is supplied. Also, the light-emitting device is connected via a drive transistor. Current flows through the device, and the brightness of the light-emitting device is controlled by the amount of current. In other words, the display device The gradation of an image is expressed by the height of the potential "Vdata" supplied to the pixel. can.

[0045] As the resolution of a display device increases, the area of ​​each pixel becomes smaller, and therefore the light-emitting device also becomes smaller. As a result, the current required to make the light-emitting device emit light also decreases. In other words, the display device The higher the resolution, the smaller the current flowing from the drive transistor to the light-emitting device. The voltage required for the operation of the dynamic transistor also becomes lower. However, the potential supplied to the pixel... Reducing the range of "Vdata" reduces the potential per tone, that is, the potential between tones. Because the difference becomes smaller, controlling the gradation can sometimes become difficult.

[0046] A display device according to one aspect of the present invention has a potential lower than the potential "Vdata" supplied to the pixels. It has the function of applying to the drive transistor. Therefore, the range of the potential "Vdata" It is possible to display multi-tone images without reducing the size, thereby improving display quality. Cut.

[0047] <Example of pixel configuration 1> Figure 1A shows an example of the configuration of a pixel 10 that can be used in a display device according to one aspect of the present invention. Pixel 10 includes a light-emitting device 114, transistor 101, transistor 102, and It includes a transistor 103, a transistor 104, and a capacitive element 111.

[0048] One electrode of the light-emitting device 114 is connected to either the source or drain of the transistor 101. On one side, the source or drain of transistor 102 and the power supply of one side of capacitive element 111 The poles are electrically connected to each other. The gate of transistor 102 is connected to the other side of capacitive element 111. The electrodes, one of the source or drain of transistor 103, and the source of transistor 104 It is electrically connected to either the outlet or the drain.

[0049] The other of the source or drain of transistor 101, and the source of transistor 104 Alternatively, the other end of the drain is electrically connected to wiring 161. Transistor 10 The gate of transistor 1 is electrically connected to wiring 121. The gate of transistor 103 is connected to wiring It is electrically connected to 122. The gate of transistor 104 is electrically connected to wiring 123. The source or drain of transistor 103 is electrically connected to wiring 131. Connected.

[0050] Wiring 161 is connected to a specific potential (hereinafter also referred to as the first potential or reference potential) "Vref" It has the function of supplying transients. Wiring 121, wiring 122 and wiring 123 each have the function of supplying transients Scan lines for controlling the operation of transistor 101, transistor 103, and transistor 104 It functions as a switch within the pixel 10. The scanning signal applied to the scan line acts as a switch within the pixel 10. The conduction state of transistors 101, 103 and 104 that are capable of doing so This is a signal to control the non-conductive state (on or off). Wiring 131 is image data It functions as a data line that supplies the potential "Vdata" corresponding to the terminal.

[0051] The source or drain of transistor 102 is electrically connected to wiring 128. The wiring 128 preferably has the function of supplying a specific potential. The other electrode of chair 114 is electrically connected to wiring 129. Wiring 128 and wiring 1 Each of the 29s can function as a wire (power line) to which the power potential is supplied. For example, wiring 128 can function as a high-potential power line supplying a higher potential than wiring 129. Wiring 129 can be used as a low-potential power line supplying a lower potential than wiring 128. It can be made to work.

[0052] Transistor 102 is a drive transistor that controls the amount of current flowing to the light-emitting device 114. It functions as such. Transistor 103 functions as a selection transistor for selecting pixels. Transistors 101 and 104 each have a specific potential (reference potential). It functions as a switch to write "Vref" to pixel 10.

[0053] As the light-emitting device 114, a light-emitting diode (LED) is used. Diode), Organic Light Emitting Diode (OLED) Light-emitting diodes (QLEDs) that use quantum dots in the light-emitting layer. (uantum-dot Light Emitting Diode), semiconductor laser Examples of self-illuminating light-emitting devices include:

[0054] A display device according to one aspect of the present invention has a period during which the light-emitting device is turned off within one frame period. It is possible to set this up. By setting up this period and displaying black, afterimages can be reduced. This allows for improved display quality.

[0055] The pixel 10 preferably further has a capacitive element 112. The electrode is electrically connected to the gate of transistor 102. The other electrode of capacitive element 112 The pole is electrically connected to the other side of the source or drain of transistor 102. Pixel 1 Because 0 has a capacitive element 112, the potential "Vdata" supplied to the pixel 10 is A low potential can be applied to transistor 102, which functions as a driving transistor. Therefore, it is possible to display multi-tone images without reducing the range of the potential "Vdata". This allows for improved display quality.

[0056] Here, the gate of transistor 102, the source or drain of transistor 103 On the other hand, the wiring to which the other electrode of the capacitive element 111 and the other electrode of the capacitive element 112 are connected. This node is designated as node ND11. Node ND11 is a transistor that functions as a drive transistor. It has the function of maintaining the gate potential of Zistor 103. Depending on the potential of node ND11, The current flowing through the light-emitting device 114 can be controlled to control the light-emitting brightness of the light-emitting device 114. Either the source or drain of transistor 101, and the source of transistor 102 or The wiring to which one electrode of the drain and one electrode of the capacitive element 111 are connected is at node ND1 Let's assume it's 2. Node ND12 is the source of transistor 102, which functions as a drive transistor. It has the function of maintaining the potential of either the outlet or the drain.

[0057] In the pixel 10 shown in Figure 1A, via the capacitive element 111, the drive transistor is used as the mechanism The gate and source of the transistor 102 are electrically connected via the capacitive element 112. Then, the gate and drain of transistor 102 are electrically connected. Also, node ND The potential at 11 is determined by the capacitance between the gate and source of transistor 102 (capacitor element 111) and the transistor It is held by the capacitance between the gate and drain of the converter 102 (capacitive element 112).

[0058] By making transistor 103 conduct, the potential supplied to wiring 131 is transferred to node N It is possible to write to D11. Also, by making transistor 104 conductive, The potential supplied to line 161 can be written to node ND11. Transistor 10 By making transistors 3 and 104 non-conductive, the power written to node ND11 It can maintain its position.

[0059] By making transistor 101 conductive, the data supplied to wiring 161 is connected to the node It is possible to write to ND12. By making transistor 101 non-conductive, It can retain the data written to ND12.

[0060] Transistor 101, transistor 102, transistor 103 and transistor 10 It is preferable to use one or more transistors with extremely low off-currents from any one of the four. In addition, transistors 101, 103, and 104 receive extremely off-currents. By using small transistors, the potentials of nodes ND11 and ND12 can be extended. Time retention becomes possible. The transistor, for example, has a gold channel formation region. A transistor using a specific oxide (hereinafter referred to as an OS transistor) can be suitably used. .

[0061] Note that transistors 101, 102, 103 and It is even preferable to apply OS transistors to all of the TA104. Transistors other than 101, transistor 102, transistor 103 and transistor 104 An OS transistor may be used for the zista. Also, within an acceptable range for leakage current. When operating, a transistor (hereinafter referred to as Si-transistor) with silicon in the channel formation region is used. A transistor may be applied. Alternatively, OS transistors and Si transistors may be used in combination. This may be done. Furthermore, the above Si transistor may be a transistor having amorphous silicon. Zista has crystalline silicon (microcrystalline silicon, low-temperature polysilicon, monocrystalline silicon) Examples include transistors such as the one shown in Figure 1A. Although it is a channel-type transistor, a p-channel type transistor can also be used.

[0062] As a semiconductor material used in OS transistors, an energy gap of 2 eV or more is preferred. Alternatively, a metal oxide with a voltage of 2.2 eV or higher, more preferably 2.5 eV or higher, may be used. Yes, it is possible. Typical examples include indium-containing oxide semiconductors, such as CA, which will be discussed later. AC-OS(C-Axis Aligned Crystalline Oxide S emiconductor) or CAC-OS (Cloud-Aligned Com Posite oxide semiconductors can be used. CAAC-OS has a stable crystal structure and is suitable for transistors and other applications where reliability is important. Furthermore, because CAC-OS exhibits high mobility characteristics, it is suitable for transistors and other applications requiring high-speed operation. do.

[0063] OS transistors have a large energy gap in the semiconductor layer, resulting in a channel width of 1 μm. The off-current value per unit is several yA / μm (where y is 10 -24 ) an extremely small off-current characteristic This can demonstrate that OS transistors exhibit impact ionization and avalanche degradation. It has characteristics different from Si transistors, such as the absence of sagging and short-channel effects. This allows for the formation of highly reliable circuits. Furthermore, crystals, which are a problem in Si transistors, can be overcome. OS transistors are less prone to variations in electrical characteristics caused by non-uniformity of the material.

[0064] The semiconductor layer of the OS transistor can be, for example, a film represented by an In-M-Zn-based oxide containing indium, zinc, and one or more elements M (M is aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium, or hafnium). When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn-based oxide, the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≥M and Zn≥M. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target.

[0065] When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn-based oxide, the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≥M and Zn≥M. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target. When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn-based oxide, the atomic ratio of the metal elements of the sputtering target used to form the In-M-Zn oxide preferably satisfies In≥M and Zn≥M. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 4G% of the atomic ratio of the metal elements contained in the above sputtering target. As such atomic ratios of the metal elements of the sputtering target, In:M:Zn = 1:1:1, In:M:Zn = 1:1:1.2, In:M:Zn = 3:1:2, In:M:Zn = 4:2:3, In:M:Zn = 4:2:4.1, In:M:Zn = 5:1:3, In:M:Zn = 5:1:6, In:M:Zn = 5:1:7, In:M:Zn = 5:1:8, In:M:Zn = 10:1:3, In:M:Zn = 10:1:6, In:M:Zn = 10:1:8, etc. are preferable. Note that the atomic ratio of the formed semiconductor layer includes fluctuations of plus or minus 40% of the atomic ratio of the metal elements contained in the above sputtering target.

[0066] An oxide semiconductor with a low carrier concentration is used as the semiconductor layer. For example, the carrier concentration of the semiconductor layer is 1×10 / cm or less, preferably 1×10 / cm or less, more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less. 17 3 As the semiconductor layer, an oxide semiconductor with a low carrier concentration is used. For example, the carrier concentration of the semiconductor layer is 1×10 / cm or less, preferably 1×10 / cm or less, more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less. 15 3 As the semiconductor layer, an oxide semiconductor with a low carrier concentration is used. For example, the carrier concentration of the semiconductor layer is 1×10 / cm or less, preferably 1×10 / cm or less, more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less. 13 3 As the semiconductor layer, an oxide semiconductor with a low carrier concentration is used. For example, the carrier concentration of the semiconductor layer is 1×10 / cm or less, preferably 1×10 / cm or less, more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less. 11 3 As the semiconductor layer, an oxide semiconductor with a low carrier concentration is used. For example, the carrier concentration of the semiconductor layer is 1×10 / cm or less, preferably 1×10 / cm or less, more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less, still more preferably 1×10 / cm or less. ​​​​​​​​​​​​Preferably 1 × 10 10 / cm 3 It is less than 1 × 10 -9 / cm 3 The above career details A high-purity or intrinsic oxide semiconductor can be used. Such an oxide semiconductor can be made high-purity or This is essentially a high-purity intrinsic oxide semiconductor. This oxide semiconductor has a low defect level density. It can be said that it is an oxide semiconductor with stable properties.

[0067] Furthermore, this is not limited to the semiconductor characteristics and electrical characteristics (electric field) of the transistor as needed. A suitable composition should be used depending on the effective mobility, threshold voltage, etc. To obtain the semiconductor characteristics of the transistor, the carrier concentration and impurity concentration of the semiconductor layer, and defects, It is preferable to set appropriate values ​​for depression density, the atomic ratio of metal elements to oxygen, interatomic distance, density, etc. It's nice.

[0068] In oxide semiconductors that constitute semiconductor layers, silicon and carbon are among the Group 14 elements. When silicon is present, oxygen vacancies increase, leading to n-type formation. Therefore, silicon in the semiconductor layer The concentration of carbon (concentration obtained by secondary ion mass spectrometry) is 2 × 10 18 ato ms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0069] Alkali metals and alkaline earth metals combine with components contained in oxide semiconductors to form k This can generate a carrier current, which can increase the transistor's off-current. Therefore, the concentration of alkali metals or alkaline earth metals in the semiconductor layer (secondary ion mass) The concentration obtained by the analytical method is 1 × 10⁻⁶. 18 atoms / cm3 The following is preferably 2× 10 16 atoms / cm 3 Do the following:

[0070] When nitrogen is present in the oxide semiconductor that makes up the semiconductor layer, carriers are present in the oxide semiconductor. As a result, electrons are generated, increasing the carrier concentration and making it easier to convert to n-type. Transistors using oxide semiconductors tend to exhibit normally-on characteristics. The nitrogen concentration in the conductive layer (concentration obtained by secondary ion mass spectrometry) is 5 × 10⁻⁶ 18 atoms / cm 3 The following is preferable:

[0071] If hydrogen is present in the oxide semiconductor that makes up the semiconductor layer, then the components in the oxide semiconductor Because it reacts with oxygen that bonds to metal atoms to form water, it creates oxygen vacancies in oxide semiconductors. In some cases, if oxygen vacancies are present in the channel formation region of an oxide semiconductor, transients may occur. Sta can exhibit normally-on properties. Furthermore, a defect where hydrogen is present in an oxygen vacancy is a d It functions as a charger, and sometimes electrons, which are carriers, are generated. Also, some of the hydrogen is gold It can combine with oxygen, which is bonded to a group atom, to generate electrons, which are carriers. Therefore Therefore, transistors using oxide semiconductors that contain a large amount of hydrogen exhibit normally-on characteristics. It is likely to happen.

[0072] Defects where hydrogen fills an oxygen vacancy can function as donors for oxide semiconductors. However, Therefore, it is difficult to quantitatively evaluate the defect. In oxide semiconductors, In some cases, the evaluation is based on the carrier concentration rather than the donor concentration. Therefore, in this specification, The parameters for oxide semiconductors are assumed to be those without an applied electric field, rather than the donor concentration. In some cases, the carrier concentration used is... This can sometimes be rephrased as "donor concentration."

[0073] Therefore, it is preferable that the hydrogen content in the oxide semiconductor be reduced as much as possible. Specifically In oxide semiconductors, secondary ion mass spectrometry (SIMS: Secondary I) is used. The hydrogen concentration obtained by on-mass spectrometry is 1 × 10⁻¹⁶ 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than, preferable kuha 5×10 18 atoms / cm 3 Less than 1 × 10 18 atom / cm 3 It shall be less than. Oxide semiconductors in which impurities such as hydrogen have been sufficiently reduced are used in transistors. By using it in the channel formation region, stable electrical characteristics can be imparted.

[0074] Oxide semiconductors (metal oxides) include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. They can be divided into conductors and non-single-crystal oxide semiconductors, for example, CAAC-OS and polycrystalline oxide. Solid semiconductor, nc-OS (nanocrystalline oxide semiconductor) ductor), pseudo-amorphous oxide semiconductor (a-like OS: amorphous- Examples include oxide semiconductors and amorphous oxide semiconductors. In non-single-crystal structures, the amorphous structure has the highest defect level density, and CAAC-OS This has the lowest defect level density.

[0075] Amorphous oxide semiconductor films, for example, have a disordered atomic arrangement and do not possess crystalline components. Alternatively, an amorphous oxide semiconductor film may have a completely amorphous structure, and the crystalline portion may be... It does not possess.

[0076] Furthermore, the semiconductor layer consists of regions with an amorphous structure, regions with a microcrystalline structure, regions with a polycrystalline structure, and CAA A mixed film may have two or more regions, including C-OS regions and single-crystal structures. The composite membrane is, for example, a monolayer structure containing two or more of the regions described above, or a compound membrane. It may have a layered structure.

[0077] The following describes the structure of CAC-OS, which is one form of a non-single-crystal semiconductor layer.

[0078] CAC-OS refers to, for example, an oxide semiconductor in which the elements constituting the semiconductor are between 0.5 nm and 10 nm. Preferably, the material is unevenly distributed with a size of 1 nm to 2 nm or near that size. This is the composition. In the following, in oxide semiconductors, one or more metal elements The elements are unevenly distributed, and the region containing the metal element is 0.5 nm to 10 nm, preferably 1 nm. A mixture of particles between 1 / 2nm and 2nm in size, or near that size, is described as a mosaic or patch. Also called form.

[0079] Furthermore, the oxide semiconductor preferably contains at least indium, particularly indium. It is preferable that it also contains aluminum, gallium, and zinc. Beryllium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, Germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium , one or more selected from tantalum, tungsten, magnesium, etc. may be contained.

[0080] For example, in In-Ga-Zn oxide, CAC-OS (among CAC-OS, In- Ga-Zn oxide may be particularly referred to as CAC-IGZO.) refers to indium oxide (hereinafter, InO X1 (let X1 be a real number greater than 0).), or indium zinc oxide (hereinafter, In X2 Zn Y2 O Z2 (let X2, Y2, and Z2 be real numbers greater than 0 ).), and gallium oxide (hereinafter, GaO X3 (let X3 be a real number greater than 0) ), or gallium zinc oxide (hereinafter, Ga X4 Zn Y4 O Z4 (let X4, Y4, and Z4 be real numbers greater than 0).) and other materials are separated to form a mosaic shape , and the mosaic InO X1 , or In X2 Zn Y2 O Z2 is uniformly distributed in the film in a configuration (hereinafter also referred to as cloud-like).

[0081] That is, CAC-OS is a composite oxide semiconductor X3 body having a configuration in which a region mainly composed of GaO X2 Zn Y2 O Z2 , or a region mainly composed of InO X1 is mixed. In this specification, for example, the atomic number ratio of In to element M in the first region is greater than the atomic number ratio of In to element M in the second region, and the first region is such that Assume that the concentration of In is high compared to the second region.

[0082] Note that IGZO is a common name and refers to a single compound of In, Ga, Zn, and O. There are cases. As a representative example, InGaO3(ZnO) m1 (m1 is a natural number), or In (1+x0) Ga (1-x0) O3(ZnO) m0 (-1 ≤ x0 ≤ 1, m0 is an arbitrary number). The crystalline compounds represented are as follows.

[0083] The above crystalline compound has a single crystal structure, polycrystalline structure, or CAAC structure. Note that The CAAC structure is a crystal structure in which a plurality of IGZO nanocrystals have c-axis orientation and are connected without orientation in the a-b plane. That is, it is a crystal structure in which they are connected without orientation in the a-b plane.

[0084] On the other hand, CAC-OS relates to the material composition of the oxide semiconductor. CAC-OS refers to a structure in which regions observed as nanoparticle-like with Ga as a main component and regions observed as nanoparticle-like with In as a main component are randomly dispersed in a mosaic pattern in a material composition containing In, Ga, Zn, and O. Therefore, in CAC-OS, the crystal structure is a secondary element. That is, it is a structure in which regions observed as nanoparticle-like with Ga as a main component and regions observed as nanoparticle-like with In as a main component are randomly dispersed in a mosaic pattern. Therefore, in CAC-OS, the crystal structure is a secondary element.

[0085] Note that CAC-OS does not include a laminated structure of two or more films with different compositions. For example, a structure composed of two layers of a film with In as a main component and a film with Ga as a main component is not included. That is, it does not include a structure composed of two layers of a film with In as a main component and a film with Ga as a main component.

[0086] Note that the region where GaO X3 is the main component and In X2 Zn Y2 O Z2 , or InO X1 In some cases, a clear boundary may not be observable in a region where [this component] is the main component.

[0087] Note that aluminum, yttrium, copper, vanadium, and beryllium can be used instead of gallium. Molybdenum, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum N, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If one or more species selected from Nesium etc. are included, CAC-OS will The region is observed to be in the form of nanoparticles mainly composed of the metal element, and the portion is mainly composed of In. The regions observed as nanoparticles are randomly dispersed in a mosaic-like manner. It refers to.

[0088] CAC-OS can be formed, for example, by sputtering under conditions where the substrate is not heated. This is possible. Also, when forming CAC-OS by sputtering, the deposition gas is Select from inert gases (typically argon), oxygen gas, and nitrogen gas. You may use one or more of them. Also, the oxygen gas amount relative to the total flow rate of the deposition gas during film formation. A lower flow rate ratio is preferable; for example, a flow rate ratio of 0% or more and less than 30% for oxygen gas is preferable. It is preferable that the percentage be between 0% and 10%.

[0089] CAC-OS is an X-ray diffraction (XRD) measurement method When measured using one method, the Out-of-Plane method with a θ / 2θ scan: It has the characteristic of not showing a clear peak. In other words, from X-ray diffraction measurements, It can be seen that no orientation is observed in the ab-plane direction or the c-axis direction within the defined region.

[0090] CAC-OS is irradiated with an electron beam having a probe diameter of 1 nm (also referred to as a nano-beam electron beam). In the electron diffraction pattern obtained by this irradiation, a region with high brightness in a ring shape (ring region) and a plurality of bright spots are observed in the ring region. Therefore, from the electron diffraction pattern, it can be seen that the crystal structure of CAC-OS has a non-oriented nc (nano-crystal) structure in the plane direction and the cross-sectional direction. For example, in CAC-OS in In-Ga-Zn oxide, by EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX), regions where GaO is the main component and regions where

[0091] In Zn O X3 or InO In X2 Zn Y2 O Z2 is the main component are unevenly distributed and mixed, and it can be confirmed that it has a structure. X1 That is, CAC-OS has a structure different from that of an IGZO compound in which metal elements are uniformly distributed and has properties different from those of the IGZO compound. In other words, CAC-OS has a structure in which regions where GaO and the like are the main components and regions where In

[0092] Zn O X3 or InO is the main component are phase-separated from each other and the regions with each element as the main component are mosaic-like. X2 Zn Y2 O Z2 or InO X1 is the main component are mutually phase-separated, and the regions with each element as the main component have a mosaic structure. Here, the regions where In

[0093] Zn X2 Zn Y2 O Z2 or InO X1 is the main component are regions where GaO X It is a region with high conductivity compared to a region where 3 etc. are the main components. That is, In X2 Zn Y2 O Z2 or a region where InO X1 is the main component exhibits conductivity as an oxide semiconductor when carriers flow through it. Therefore, a region where In Zn X2 Zn Y2 O Z2 or I nO X1 is the main component is distributed in a cloud-like manner in the oxide semiconductor, enabling a high field-effect mobility (μ) to be realized.

[0094] On the other hand, a region where GaO X3 etc. are the main components is a region with high insulation compared to a region where In X2 Zn Y2 O Z2 or InO X1 is the main component. That is, a region where GaO X3 etc. is the main component is distributed in the oxide semiconductor, suppressing the leakage current and enabling a good switching operation to be realized.

[0095] Therefore, when CAC-OS is used in a semiconductor device, the insulation X3 property caused by GaO etc. and the conductivity caused by In X2 Zn Y2 O Z2 or InO X1 act complementarily to realize a high on-current (I on ) and a high field-effect mobility (μ). can be achieved.

[0096] A semiconductor device using CAC-OS has high reliability. Therefore, CAC-OS is suitable as a constituent material for various semiconductor devices.

[0097] ​ A configuration different from the pixel 10 shown in FIG. 1A is shown in FIG. 1B.

[0098] As shown in FIG. 1B, the transistor 101, the transistor 102, and the transistor 103 and the transistor 104 may each have a back gate configuration. In particular, the transistor 102 that functions as the driving transistor of the light-emitting device 114 preferably has a back gate. FIG. 1B shows a configuration in which the back gate of the transistor 102 is electrically connected to one of the source or the drain, and has an effect of enhancing the saturation of the transistor characteristics. Also, FIG. 1B shows a configuration in which the back gates of the transistor 101, the transistor 103, and the transistor 104 are each electrically connected to the gate (sometimes referred to as the front gate), and has an effect of enhancing the on-current. The back gate of the transistor 102 may be electrically connected to the front gate. By adopting such a configuration, it has the effect of increasing the on-current of the transistor 102. Also, the back gate may be electrically connected to a wiring that can supply a fixed potential, and the threshold voltage of the transistor can be controlled. In FIG. 1B, although a configuration in which all transistors are provided with back gates is illustrated, one or more transistors without back gates may be provided.

[0099] The back gate of the transistor 102 may be electrically connected to the front gate. By adopting such a configuration, it has the effect of increasing the on-current of the transistor 102. Also, the back gate may be electrically connected to a wiring that can supply a fixed potential, and the threshold voltage of the transistor can be controlled. In FIG. 1B, although a configuration in which all transistors are provided with back gates is illustrated, one or more transistors without back gates may be provided. In FIG. 1B, a configuration in which all transistors are provided with back gates is illustrated, but one or more transistors without back gates may be provided.

[0100] An example of the operation of the pixel 10 will be described using the timing chart shown in FIG. 2. In FIG. 2, the variation of the potential V of the node ND11 and the potential V of the node ND12 are also shown. ND11 ND12

[0101] ​​​​​​​​​​In the following explanation, high potential will be represented as "High" and low potential as "Low". Image data Let "Vdata" be the potential corresponding to the terminal, and "Vref" be the potential of wiring 161. f'' can be, for example, 0V, GND potential, or a specific reference potential. Let the potential of line 128 be "Vano". "Vano" is, for example, the potential of light-emitting device 114 When the brightness is at its maximum, the potential of transistor 102 is set to operate in the saturation region. It is preferable to do so. Also, the potential of wiring 129 is set to “Vcath”. “Vcath” is When the potential of node ND12 is at its lowest potential, the light-emitting device 114 does not emit light. It is preferable to do so.

[0102] First, at time T31, set the potential of wire 121 to "High" and the potential of wire 122 to "High". h", the potential of wiring 123 is set to "Low", the potential of wiring 131 is set to "Vdata", wiring 161 If the potential is "Vref", then transistors 101 and 103 are in a conducting state. As a result, the potential "Vdata" of wiring 131 is connected to node ND11, and wiring 16 is connected to node ND12. A potential of 1, "Vref," is written.

[0103] At this time, if the potential difference across the capacitive element 111 is V1, then the potential difference V1 is given by equation (1 This can be shown as follows. Similarly, if the potential difference across the capacitive element 112 is V2, The potential difference V2 can be expressed by equation (2). Also, the gate and source of transistor 102. The voltage Vgs between them is the potential V at node ND11. ND11 and the potential V of node ND12 ND12 of The difference is given, and the voltage Vgs can be expressed by equation (3).

[0104] V1 = Vdata - Vref (1)

[0105] V2 = Vano - Vdata (2)

[0106] Vgs = Vdata - Vref (3)

[0107] Next, at time T32, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 The circuit becomes non-conductive. The gate-source voltage Vgs of transistor 102 is equal to the capacitance element 1 The voltage held in 11 and the capacitive element 112 becomes the current corresponding to the voltage Vgs, and the light-emitting device It flows into S114. Then the light-emitting device 114 lights up. The brightness of the light-emitting device 114 can be controlled by the amount of current applied.

[0108] At this time, the current flowing through the light-emitting device 114 and the current flowing through the transistor 102 are equal. Until it becomes, the potential V of node ND12 ND12 It will increase. Also, the potential of node ND12 V ND12 As the voltage increases, the potential V of node ND11 through the capacitive element 111 increases. ND11 High In one aspect of the present invention, in the pixel 10, the capacitance element 112 controls the power of node ND11. Place V ND11 The amount of increase can be reduced. Therefore, the potential V of node ND11 ND11 and the potential V of node ND12 ND12 The difference becomes smaller. In other words, transistor 1 The gate-source voltage Vgs of O2 can be reduced.

[0109] Potential V at node ND12 ND12 This is the movement between transistor 102 and light-emitting device 114. Determined by the point of creation. Potential V at node ND12 ND12 Vref changes to V0, The capacitance of the quantitative element 111 is C 111 The capacitance of the capacitive element 112 is C 112 Therefore, node ND Potential V of 11 ND11 This can be shown by equation (4). Also, the gauge of transistor 102 The voltage Vgs between the source and the capacitor can be expressed by equation (5). As shown in equation (5), the capacitance Capacitance C of element 111 111 and the capacitance C of the capacitive element 112 112 By changing the ratio, The gate-source voltage Vgs of the converter 102 can be changed.

[0110] V ND11 =Vdata+(C 111 / (C 111 +C 112 ))×(V0-Vref ) (4)

[0111] Vgs=Vdata-(C 111 / (C 111 +C 112 ))×Vref-(C 112 / (C 111 +C 112 )) × V0 (5)

[0112] The period P21a between time T31 and time T32 is used to cause the light-emitting device 114 to emit light. This is the period for writing the data, and the period P21b between time T32 and time T33 is This is the period during which the optical device 114 is emitting light. Also, the period between time T31 and time T33. In other words, the period P21, which is the sum of period P21a and period P21b, is the lighting period or light emission period. It can be said that... A ratio of 1 is sometimes referred to as "duty." Duty is the duration of one frame. In the FP, the period for writing data to cause the light-emitting device 114 to emit light, and This is the percentage of time during which the optical device 114 is emitting light.

[0113] Furthermore, during period P21a, the light-emitting device 114 may be configured to emit light. During period P21a, the light-emitting device 114 may not emit light. In configuration 1a, if the light-emitting device 114 does not emit light, the potential of the wiring 129 and the wiring The potential difference "Vref-Vcath" across line 161 exceeds the threshold voltage of the light-emitting device 114. If the potential of wiring 129 is "Vcath" and the potential of wiring 161 is "Vref", then good.

[0114] Next, at time T33, the potential of wiring 121 is set to "High" and the potential of wiring 122 is set to "Low" "If the potential of wiring 123 is set to "High", then transistor 101 and transistor 1 04 becomes conductive, and transistors 101 and 104 become conductive. The potential "Vref" of wiring 131 is set to node ND11, and the potential "Vref" of wiring 131 is set to node ND12. "Vref" is written, and the potential V of node ND11 is written. ND11 and the potential V of node ND12 N D12 Therefore, the gate-source voltage Vgs of transistor 102 becomes the same. The voltage becomes 0V, the light-emitting device 114 turns off, and black is displayed (hereinafter referred to as black display or black insertion). (It can be written down.)

[0115] Next, at time T34, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 and Transistor 104 becomes non-conductive. Also, light-emitting device 114 remains off. This is the resulting state.

[0116] Then, at time T35, one frame of operation ends. Time T35 is the time of the next frame. It is time T31, and the operation of the next frame will begin at time T35.

[0117] The period P22a between time T33 and time T34 is used to turn off the light-emitting device 114. This is the period for writing the data, and the period P22b between time T34 and time T35 is This is the period when the light device 114 is turned off. Also, the period between time T33 and time T35. In other words, the period P22, which is the sum of period P22a and period P22b, is the period of lights off or non-emitting period. It can be described as an interval.

[0118] A display device according to one aspect of the present invention includes a period of blackout (period P22) within one frame period. By displaying in black, afterimages can be reduced, and display quality can be improved. ru.

[0119] <Example of pixel configuration 2> Figure 3A shows a different configuration of pixel 10 from that shown in Figure 1B.

[0120] The pixel 10a shown in Figure 3A does not have a capacitive element 112, and the transistor 104 is One of the drains or the other of the light-emitting device 114 is connected to one of the electrodes of the light-emitting device 114 without going through the capacitive element 111. The point that is electrically connected to the transistor 104, and the other of the source or drain of the transistor It differs from pixel 10 shown in Figure 1B in that it is electrically connected to the gate of zistor 102. Oh, light-emitting device 114, transistor 101, transistor 102, transistor 10 Regarding 3 and the capacitive element 111, the connection relationships between these elements and the connection relationships with each wiring are described below. Since the description of pixel 10 shown in Figure 1B can be found there, a detailed explanation is omitted.

[0121] An example of the operation of pixel 10a will be explained using the timing chart shown in Figure 3B. Regarding wiring 161, please refer to the explanation in Figure 2, and therefore wiring 161 is omitted in Figure 3B. Yes, they are.

[0122] First, at time T31, set the potential of wire 121 to "High" and the potential of wire 122 to "High". h", the potential of wiring 123 is set to "Low", the potential of wiring 131 is set to "Vdata", wiring 161 If the potential is "Vref", then transistors 101 and 103 are in a conducting state. As a result, the potential "Vdata" of wiring 131 is connected to node ND11, and wiring 16 is connected to node ND12. A potential of 1, "Vref," is written.

[0123] Next, at time T32, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 The circuit becomes non-conductive. The gate-source voltage Vgs of transistor 102 is equal to the capacitance element 1 The voltage is maintained at 11, and a current corresponding to the voltage Vgs flows to the light-emitting device 114. Then, the light-emitting device 114 lights up. Also, depending on the amount of current flowing through the light-emitting device 114 This allows the brightness of the light-emitting device 114 to be controlled.

[0124] Next, at time T33, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "High", then transistors 101 and 10 3 becomes non-conductive, and transistor 104 becomes conductive. Transistor 104 is conductive When the power is supplied, nodes ND11 and ND12 are powered via transistor 104. Connected electrically, the potential V of node ND11 ND11 and the potential V of node ND12 ND12 but It becomes the same. In other words, the gate-source voltage Vgs of transistor 102 becomes 0V. As a result, the light-emitting device 114 can be turned off, and black can be displayed.

[0125] Next, at time T34, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 and Transistor 104 becomes non-conductive. Also, light-emitting device 114 remains off. This is the resulting state.

[0126] <Example of pixel configuration 3> Figure 4A shows a different configuration of pixel 10 from that shown in Figure 1B.

[0127] The pixel 10b shown in Figure 4A has the following characteristics: it does not have a capacitive element 112 and it has wiring 162. The source or drain of transistor 104 emits light without going through the capacitive element 111. One electrode of vise 114 is electrically connected to the point, and the source of transistor 104 is also It differs from pixel 10 shown in Figure 1B in that the other side of the drain is electrically connected to wiring 162. It is. Note that the light-emitting device 114, transistor 101, transistor 102, and transistor Regarding the sta 103 and the capacitive element 111, the connection relationships between these elements and each wiring The connection relationships can be seen by referring to the description of pixel 10 shown in Figure 1B, so a detailed explanation will be omitted.

[0128] Wiring 162 has the function of supplying a specific potential (hereinafter also referred to as the second potential). The potential of line 162 can be, for example, 0V, GND potential, or a specific reference potential. .

[0129] An example of the operation of pixel 10b will be explained using the timing chart shown in Figure 4B. Regarding wiring 161, please refer to the explanation in Figure 2, therefore wiring 161 is omitted in Figure 4B. Yes, they are.

[0130] First, at time T31, set the potential of wire 121 to "High" and the potential of wire 122 to "High". h", the potential of wiring 123 is set to "Low", the potential of wiring 131 is set to "Vdata", wiring 161 If the potential is "Vref", then transistors 101 and 103 are in a conducting state. As a result, the potential "Vdata" of wiring 131 is connected to node ND11, and wiring 16 is connected to node ND12. A potential of 1, "Vref," is written.

[0131] Next, at time T32, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 The circuit becomes non-conductive. The gate-source voltage Vgs of transistor 102 is equal to the capacitance element 1 The voltage is maintained at 11, and a current corresponding to the voltage Vgs flows to the light-emitting device 114, and The light device 114 lights up. Also, the amount of current flowing through the light-emitting device 114 determines the light emission. The brightness of Vice 114 can be controlled.

[0132] Next, at time T33, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "High", then transistors 101 and 10 3 becomes non-conductive, and transistor 104 becomes conductive. The potential of wiring 162 is It is preferable to set the potential of the optical device 114 so that it does not emit light. By setting the potential so that the lamp 114 does not emit light, the current flowing through the transistor 102 is controlled. Because the light flows into wiring 162 via inverter 104, the light-emitting device 114 turns off, and black appears. It can be displayed. Wiring 162 is connected to transistor 102 during period P22. It has the function of supplying current. Note that during the period when the potential of wiring 123 is "High" The light-emitting device 114 will then be turned off.

[0133] Note that in Figure 4A, the source or drain of transistor 101 is connected to wiring 161. Electrically connected, the source or drain of transistor 104 is connected to the wiring 162. The diagram shows a configuration that is electrically connected, but the present invention is not limited thereto. Wiring 162 Without providing a connection, the other side of the source or drain of transistor 101, and transistor 10 The other of either the source or drain of 4 may both be electrically connected to wiring 161.

[0134] <Example of pixel configuration 4> Figures 5A and 5B show a different configuration of pixel 10 from that shown in Figure 1B.

[0135] The pixel 10c shown in Figure 5A does not have a capacitive element 112, and the transistor 104 is One of the drains or the other of the light-emitting device 114 is connected to one of the electrodes of the light-emitting device 114 without going through the capacitive element 111. The point that is electrically connected to the transistor 104, and the other of the source or drain of the transistor As shown in Figure 1B, the point where it is electrically connected to either the source or drain of the zista 101. It is different from pixel 10.

[0136] The pixel 10d shown in Figure 5B does not have a capacitive element 112, and the transistor 104 is One of the source or drain of transistor 102 is electrically connected to the other of the source or drain. The point where it is connected, and the other of the source or drain of transistor 104 is connected to wiring 128 and power It differs from pixel 10 shown in Figure 1B in that it is electrically connected.

[0137] Note that the light-emitting device 114, transistor 101, transistor 102, transistor Regarding 103 and the capacitive element 111, the connection relationships between these elements and the connections to each wiring are as follows. The relationship can be understood by referring to the description of pixel 10 shown in Figure 1B, so a detailed explanation will be omitted.

[0138] An example of the operation of pixels 10c and 10d is explained using the timing chart shown in Figure 6. To clarify, please refer to the explanation in Figure 2 for wiring 161. It has been omitted.

[0139] First, at time T31, set the potential of wire 121 to "High" and the potential of wire 122 to "High". h", the potential of wiring 123 is set to "Low", the potential of wiring 131 is set to "Vdata", wiring 161 If the potential is "Vref", then transistors 101 and 103 are in a conducting state. As a result, the potential "Vdata" of wiring 131 is connected to node ND11, and wiring 16 is connected to node ND12. A potential of 1, "Vref," is written.

[0140] Next, at time T32, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "High", then transistors 101 and 10 3 becomes non-conductive, and transistor 104 becomes conductive. The voltage Vgs between the source and the capacitor becomes the voltage held by the capacitive element 111, and the voltage Vgs corresponds to The current flows to the light-emitting device 114, and the light-emitting device 114 lights up. The brightness of the light-emitting device 114 can be controlled by the amount of current flowing through the chair 114.

[0141] Next, at time T33, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". If the potential of wiring 123 is set to "Low", then transistors 101 and 103 and Transistor 104 becomes non-conductive. As a result, current stops flowing to the light-emitting device 114, the light-emitting device 114 turns off, and displays black. It is possible to display it in black (also known as black insertion).

[0142] <Pixel configuration example 5> Figure 7A shows a different configuration of pixel 10 from that shown in Figure 1B.

[0143] The pixel 10e shown in Figure 7A has a transistor 104, a capacitive element 112, and wiring 123. It differs from pixel 10 shown in Figure 1B in that it does not use light-emitting device 114, transistor Regarding transistors 101, 102, 103 and 111, The connection relationships between these elements, and the connection relationships with each wire, are described in the description of pixel 10 shown in Figure 1B. Since it can be referenced, a detailed explanation will be omitted.

[0144] An example of the operation of pixel 10e will be explained using the timing chart shown in Figure 7B. Regarding wiring 161, please refer to the explanation in Figure 2, and therefore wiring 161 is omitted in Figure 7B. Yes, they are.

[0145] First, at time T31, set the potential of wire 121 to "High" and the potential of wire 122 to "High". If we let h'', the potential of wiring 131 be "Vdata", and the potential of wiring 161 be "Vref", then Transistors 101 and 103 become conductive, and wiring 1 to node ND11 The potential "Vdata" of 31 and the potential "Vref" of wiring 161 are written to node ND12. It can be done.

[0146] Next, at time T32, set the potential of wiring 121 to "Low" and the potential of wiring 122 to "Low". As a result, transistors 101 and 103 become non-conductive. The gate-source voltage Vgs of the terminal 102 becomes the voltage held by the capacitive element 111, and A current corresponding to the voltage Vgs flows through the light-emitting device 114, causing the light-emitting device 114 to light up. Furthermore, the brightness of the light-emitting device 114 is controlled by the amount of current flowing through the light-emitting device 114. It is possible.

[0147] Next, at time T33, the potential of wiring 121 is set to "High" and the potential of wiring 122 is set to "Low" "In that case, transistor 101 will be in a conductive state, and transistor 103 will be in a non-conductive state." Yes. The potential "Vref" of wiring 161 is written to node ND12, and the light-emitting device 11 4 can be turned off and black can be displayed. Here, the potential of wiring 129 and the potential of wiring 161 The position difference "Vref-Vcath" does not exceed the threshold voltage of the light-emitting device 114. It is preferable to set the potential of wiring 129 to "Vcath" and the potential of wiring 161 to "Vref". Furthermore, during the period when the potential of wiring 121 is "High", the light-emitting device 114 remains off. To become.

[0148] Pixel 10e shown in Figure 7A is a transistor compared to pixels 10 to 10d mentioned above. Because it has a small number of capacitive elements and wiring, it is suitable for use in high-definition display devices with small pixels. It is possible.

[0149] <Example of display device operation> An example of the operation of a display device according to one aspect of the present invention will be explained with reference to Figures 8A to 8C. .

[0150] A display device according to one aspect of the present invention has m rows and n columns (where m and n are independent integers of 1 or more). It has multiple pixels arranged in a matrix. The pixels include the aforementioned pixel 10, Pixels 10a, 10b, 10c, 10d, or 10e can be used. ru.

[0151] Figure 8A shows an overview diagram illustrating the operation of the display device. In Figure 8A, the vertical axis represents the number of pixel rows i (i is The x-axis represents an integer between 1 and m (inclusive), and the x-axis represents time. Also, in Figure 8A, 1f The frames from the first frame (FL=1) to the fourth frame (FL=4) are shown as excerpts.

[0152] A display device according to one aspect of the present invention includes a period P22 within a frame period and displays black. It is possible to do so. Also, as shown in Figure 8A, it is possible to configure the system to display each row in black. In this specification, the method of driving pixels row by row may be referred to as line-sequential driving. In one aspect of the present invention, a display device performs black display by sequential line driving, thereby enabling all Compared to the case where all pixels are displayed in black at once, the amount of data per line for writing image data is The selection time (also called the horizontal period) can be lengthened. Therefore, the image data to the pixels can be extended. Because data can be written reliably, the display quality of the display device can be improved. For example, even during high-speed operation with increased frame rate, image data writing is not possible. It can protect your feet.

[0153] The duty cycle can be any value. Figure 8A shows a configuration where the duty cycle is 80%. Examples are shown. Figure 8B shows an example configuration with a duty cycle of 50%. Figure 8C is The example shows a configuration with a duty cycle of 20%. By increasing the duty cycle, the light will turn on. The duration ratio increases, allowing the brightness of the display device to be increased. The duty cycle is reduced. This increases the proportion of time the screen is off and black, further reducing afterimages. ru.

[0154] <Pixel configuration example 6> A different configuration of pixel 10 from that shown in Figure 1B is shown in Figure 9A.

[0155] The pixel 10f shown in Figure 9A consists of a transistor 104, a capacitive element 112, wiring 122 and wiring In that it does not have wire 123, the gate of transistor 103 is electrically connected to wiring 121. In this respect, it differs from pixel 10 shown in Figure 1B. In pixel 10f, the gate of transistor 101 The gates of the transistor 102 and the terminal of the transistor 102 are electrically connected to the wiring 121, respectively.

[0156] Pixel 10f shown in Figure 9A is a transistor compared to pixels 10 to 10e mentioned above. Because it has a small number of capacitive elements and wiring, it is suitable for use in high-definition display devices with small pixels. It is possible.

[0157] An example of the operation of pixel 10f will be explained using the timing chart shown in Figure 9B. Regarding wiring 161, please refer to the explanation in Figure 2, and therefore wiring 161 is omitted in Figure 9B. Yes, they are.

[0158] First, at time T31, set the potential of wiring 121 to "High" and the potential of wiring 131 to "Vda If we let "ta_1" and the potential of wiring 161 be "Vref", then transistor 101 and transistor 161 and When zista 103 becomes conductive, the potential of wiring 131 "Vdata_1" is connected to node ND11. The potential "Vref" of wiring 161 is written to node ND12. The potential of wiring 131 is "Vdata_1" will be the potential corresponding to the image data.

[0159] Next, at time T32, if the potential of wiring 121 is set to "Low", then transistor 101 and Transistor 103 becomes non-conductive. The voltage between the gate and source of transistor 102 The voltage Vgs is the voltage held by the capacitive element 111, and a current corresponding to the voltage Vgs is generated in the light-emitting device. The fluid flows to chair 114, and the light-emitting device 114 lights up. The brightness of the light-emitting device 114 can be controlled by the amount of current.

[0160] Next, at time T33, the potential of wiring 121 is set to “High” and the potential of wiring 131 is set to “Vda If we set it to ta_2", transistors 101 and 103 will be in a conductive state, The potential of wire 131 “Vdata_2” is set to node ND11, and the potential of wire 161 is set to node ND12. The position "Vref" is written. The potential "Vdata_2" is, for example, the smallest gradation. By setting the potential to correspond to the black image data, the light-emitting device 114 turns off, displaying black. It can be done.

[0161] Next, at time T34, if the potential of wiring 121 is set to "Low", then transistor 101 and Transistor 103 becomes non-conductive. Also, the light-emitting device 114 remains off. This is the resulting state.

[0162] Note that during period P21, the potential of wiring 131 is set to "Vdata_1", and during period P22, wiring 131 It is preferable to set the potential of this to "Vdata_2".

[0163] An example of the operation of pixel 10f, which differs from the timing chart shown in Figure 9B, will be explained. An example of a timing chart for 10f is shown in Figure 10. Wiring 131 has a potential "Vdat "a_1" and the potential "Vdata_2" are supplied alternately. Regarding wiring 161, see Figure Since explanation 2 is available, wiring 161 is omitted in Figure 10.

[0164] The period P21c between time T31a and time T32 is used to make the light-emitting device 114 emit light. This is the period (1 horizontal period) for selecting the row on which to write the data. Also, period P21c is The period during which the potential "Vdata_1" is supplied from wiring 131 and the period during which the potential "Vdata_2" is Divide it into periods of supply.

[0165] At time T31a, if the potential of wiring 121 is set to "Low", then transistor 101 and The transistor 103 becomes non-conductive, and the light-emitting device 114 does not emit light.

[0166] Next, at time T31, the potential of wiring 121 is set to “High” and the potential of wiring 131 is set to “Vda If we let "ta_1" and the potential of wiring 161 be "Vref", then transistor 101 and transistor 161 and When zista 103 becomes conductive, the potential of wiring 131 "Vdata_1" is connected to node ND11. The potential "Vref" of wiring 161 is written to node ND12.

[0167] Next, at time T32, if the potential of wiring 121 is set to "Low", then transistor 101 and Transistor 103 becomes non-conductive. The voltage between the gate and source of transistor 102 The voltage Vgs is the voltage held by the capacitive element 111, and a current corresponding to the voltage Vgs is generated in the light-emitting device. The fluid flows to chair 114, and the light-emitting device 114 lights up. The brightness of the light-emitting device 114 can be controlled by the amount of current. Time T31 and time T During the period P21a between 32 and 32, data is written to cause the light-emitting device 114 to emit light. It is a period of time.

[0168] The period P22c between time T33 and time T34a is used to turn off the light-emitting device 114. This is the period for selecting the row on which to write the data. Also, period P22c is set from wiring 131. The period during which the potential "Vdata_1" is supplied and the period during which the potential "Vdata_2" is supplied. Divide into.

[0169] Next, at time T33, the potential of wiring 121 is set to “High” and the potential of wiring 131 is set to “Vda If we set it to ta_2", transistors 101 and 103 will be in a conductive state, The potential of wire 131 “Vdata_2” is set to node ND11, and the potential of wire 161 is set to node ND12. When the value "Vref" is written, the light-emitting device 114 turns off and displays black. It is possible.

[0170] Next, at time T34, if the potential of wiring 121 is set to "Low", then transistor 101 and Transistor 103 becomes non-conductive. Also, the light-emitting device 114 remains off. This is the resulting state.

[0171] <Example of pixel layout> The following describes an example layout for pixel 10.

[0172] An example of the layout of pixel 10 shown in Figure 1B is shown in Figures 11A and 11B.

[0173] Figure 11A shows transistors 101, 102, 103, and Transistor 104, Capacitive element 111, Capacitive element 112, Wiring 121, Wiring 122, Wiring 12 3. Wiring 128, wiring 131, and wiring 161 are shown. Note that in Figure 11A, the diagram is For clarity, the light-emitting device 114 and wiring 129 have been omitted.

[0174] Figure 11B shows the configuration when a pixel electrode 53 is added in addition to the configuration shown in Figure 11A. The pixel electrode 53 is electrically connected to the light-emitting device 114. 14 can be provided on the pixel electrode 53.

[0175] In Figure 11B, the pixel electrode 53 is connected to the transistor 101, the capacitive element 111, etc. It is installed overlapping with some of the elements and wiring that make up 0. This configuration is particularly noticeable on the top surface This is effective when using light-emitting devices of the top-emission type. By arranging the transistor 101 etc. below the pixel electrode 53, the occupied area of ​​the pixel 10 is reduced. Even if the size is reduced, a large aperture ratio can be achieved.

[0176] As shown in Figure 11B, the pixel electrode 53 does not overlap with the wiring 131 which functions as a signal line. It is preferable that the pixel electrode 53 and the wiring 131 do not overlap, so that the potential of the wiring 131 This can suppress the effect of the change on the potential of the pixel electrode 53. If it is necessary to place 53 in overlap with wiring 131, then, relative to the area of ​​pixel electrode 53, The percentage of overlapping area should be 10% or less, preferably 5% or less.

[0177] <Example of sub-pixel configuration> An example of a sub-pixel configuration that can be applied to a display device according to one aspect of the present invention is shown in Figures 12A and 1. 2B, as shown in Figures 13A and 13B.

[0178] Pixel 10 shown in Figure 12A is a sub-pixel 10R that emits red light, and a sub-pixel 10R that emits green light. It has subpixels 10G and subpixels 10B that emit blue light, and these three subpixels make up one pixel An example of what constitutes 10 is shown. The pixel 10 shown in Figure 12A is located in the direction of extension of the wiring 131. The pixels have a long, strip-like shape, and the extension method of wiring 121, wiring 122 and wiring 123 They are arranged in a striped pattern in the direction of travel.

[0179] In Figure 12B, subpixels (two pixels 10) arranged in a 2x3 matrix are shown together Wiring 121, 122, 123, and 131 are also shown. (See Figure 12A) And in Figure 12B, wiring 121, wiring 122, and wiring 123 in row i are, respectively, Line 121[i], wiring 122[i], wiring 123[i] are indicated. (i-1)th line Wiring 121, wiring 122, and wiring 123 are respectively wired as wiring 121[i-1], wiring 122 [i-1], is labeled as wiring 123[i-1]. Wiring 13 in columns (j-6) through j. Each of the 1s is denoted as wiring 131[j-6] to wiring 131[j].

[0180] The sub-pixel 10R has a pixel electrode 53a, and the display area 51a of the sub-pixel 10R is the pixel electrode 53 It is located inside a. The sub-pixel 10G has a pixel electrode 53b, and the display area of ​​the sub-pixel 10G is 5 1b is located inside the pixel electrode 53b. Sub-pixel 10B has a pixel electrode 53c, and sub-pixel The display area 51c of 10B is located inside the pixel electrode 53c. Note that in Figure 12B, the pixel This example shows that electrode 53a, pixel electrode 53b, and pixel electrode 53c have the same area, but They may each have different areas. Also, display area 51a, display area 51b and display area 5 Each of the 1c areas may be different.

[0181] Pixel 10 shown in Figure 12B is a sub-pixel of the same color in the direction of extension of wiring 121 and wiring 122. This shows an example where the position is misaligned. In other words, pixel 10 is located between wiring 121 and wiring 1 In the extension direction of 22, subpixels of the same color are arranged in a zigzag pattern.

[0182] The pixel 10 shown in Figure 13A has a strip-like shape with the sub-pixel length being longer in the direction of extension of the wiring 131. It has and is arranged in a stripe pattern in the direction of extension of wiring 121 and wiring 122. Sub-pixels 10R, 10G, and 10B are located in the direction of extension of line 121 and wiring 122. This shows an example of how they are aligned.

[0183] Pixel 10 shown in Figure 13B has subpixels arranged in a stripe pattern, with wiring 121 and wiring 12 This shows an example where the positions of subpixels of the same color are shifted in the extension direction of 2. In other words, In element 10, subpixels of the same color are arranged in a zigzag pattern in the direction of extension of wiring 121 and wiring 122. It is.

[0184] Figures 12A, 12B, 13A, and 13B show the color combinations of light emitted by the subpixels. The example shown uses three colors: red (R), green (G), and blue (B). The number of subpixels and colors is not limited thereto. The combination of colors of light emitted by the subpixel is red (R), The four colors are green (G), blue (B), and white (W), or red (R), green (G), and blue. (B), yellow (Y) may also be used as the four colors. The color elements applied to the subpixels are not limited to those mentioned above. Alternatively, you may combine cyan (C) and magenta (M), etc.

[0185] In this specification, the blue wavelength range is defined as 400 nm or more and less than 490 nm. The blue emission has at least one emission spectral peak in that wavelength region. The wavelength range for green light is between 490 nm and 580 nm, and green light emission occurs within this wavelength range. It has at least one emission spectral peak. Also, the red wavelength region is 580 nm. The above wavelength is 680 nm or less, and the red emission is at least one emission spectrum in the wavelength range. It has a rupee.

[0186] <Example of display device configuration 1> The following describes in detail a display device according to one embodiment of the present invention.

[0187] Figure 14 shows a block diagram illustrating an example configuration of the display device 100. The display device 100 is a multiple A pixel section 150 having pixels 10, a drive circuit section 130, a drive circuit section 140a, and drive It has a circuit section 140b, wiring 121, wiring 122, wiring 123, and wiring 131. ru.

[0188] The pixel section 150 has a plurality of pixels 10, and each pixel 10 is arranged in a matrix. The drive circuit unit 130 is electrically connected to the pixel 10 via the wiring 121. The drive circuit unit 130 is electrically connected to the pixel 10 via wiring 122. The drive circuit section 130 is electrically connected to the pixel 10 via wiring 123. 0 functions as a gate line drive circuit (also called a gate driver). Multiple pixels 10 are A signal is supplied from the drive circuit unit 130 via wiring 121 and wiring 122, respectively. The movement is controlled. Drive circuit section 140a and drive circuit section 140b each have wiring 131 It is electrically connected to the pixel 10 via the drive circuit 140a and drive circuit 140b Each functions as a source line driving circuit (also called a source driver). Multiple pixels 10 Each of these transmits a signal via wiring 131 from either the drive circuit unit 140a or the drive circuit unit 140b. The drive is controlled by the given parameters. In Figure 14, the odd-numbered pixels 10 are driven by the drive circuit section 140a. An example is shown where the pixels 10 in even-numbered rows are electrically connected to the drive circuit section 140b. They are doing it.

[0189] A display device according to one aspect of the present invention has a plurality of drive circuit units that function as source drivers. This enables high-speed operation even on displays with a large number of pixels. One manifestation of a display device is, for example, one with a resolution of 1000 ppi or more, 2000 ppi or more, and This can be suitably used in high-definition display devices with a resolution of 5000 ppi or higher.

[0190] Note that in Figure 14, the drive circuit section 140 functions as a source driver. Although an example has been shown in which both a and the drive circuit section 140b are provided, the present invention is not limited to this. No. You may provide three or more drive circuit sections that function as source drivers. Also, source A drive circuit section that functions as a driver may be provided.

[0191] Figure 15 shows a schematic diagram illustrating an example configuration of the display device 100. The display device 100 has a first layer It has a laminated structure of 20 and a second layer 30 on the first layer 20. In Figure 15A, the first Although the diagram shows a configuration in which a second layer 30 is provided on layer 20, one aspect of the present invention is not limited thereto. i. The first layer 20 may be placed on the second layer 30. Between the first layer 20 and the second layer 30 One or more interlayer insulating layers and wiring layers may be provided. Also, the first layer 20 and the second layer 30 The interlayer insulating layer and wiring layer provided between the layers may each be multiple.

[0192] The first layer 20 has drive circuit section 140a and drive circuit section 140b. Second layer 30 It has a drive circuit section 130 and a pixel section 150.

[0193] Figure 15B shows an example of the configuration of the first layer 20 and the second layer 30 shown in Figure 15A. The positional relationship between the first layer 20 and the second layer 30 is shown by white circles and dashed lines. The white circle in the first layer 20 and the white circle in the second layer 30, connected by a dashed line, overlap. It is present. The same notation will be used in other figures as well. Furthermore, to clearly show the figure, Figure 15 B omits all wiring except for wiring 121, 122, 123, and 131.

[0194] The display device 100 includes a drive circuit section 140a and a drive circuit section 14 provided on the first layer 20. It is preferable that each of 0b has a region that overlaps with the pixel portion 150. The drive circuit section 140a and the drive circuit section 140b are stacked and provided so that they have an overlapping region. By doing so, the area of ​​the frame, which is the region where the pixel portion 150 is not provided, can be reduced. Therefore, the bezel of the display device 100 can be narrowed. Also, the display device 100 By narrowing the bezel, the display device 100 can be made smaller.

[0195] Figure 15B shows an example where the size of the first layer 20 and the second layer 30 are approximately the same, but The outline of the invention is not limited thereto. The sizes of the first layer 20 and the second layer 30 may be different. For example, the first layer 20 may be larger than the second layer 30. Also, the first layer 20 may be larger than the second layer 30. It may be smaller than layer 30.

[0196] After forming the first layer 20, the second layer 30 is formed on the first layer 20 to create the display device 1 00 can be produced. By forming a second layer 30 on the first layer 20, the first The alignment accuracy of layer 20 and the second layer 30 can be improved. Therefore, the display device 1 It can increase the productivity of 00.

[0197] After forming the first layer 20 and the second layer 30 respectively, the first layer 20 and the second layer 30 The display device 100 may be manufactured by bonding the first layer 20 and the second layer 30 together. When manufacturing the display device 100, the sizes of the first layer 20 and the second layer 30 are different. This is also possible. Therefore, the first layer 20 and the second layer 30 are influenced by each other in terms of their size. It can be formed without [having any problems]. For example, multiple first layers 20 can be formed on a substrate to which the first layer 20 is formed. Then, after dividing into individual first layers 20, they are bonded together with the second layer 30 to form a display device 1 00 can be fabricated. Similarly, for the second layer 30, multiple second layers can be fabricated on the substrate on which the second layer 30 is formed. A layer 30 is formed, and after dividing it into each second layer 30, it is bonded to the first layer 20. The display device 100 may be manufactured in conjunction with the first layer 20 and the second layer 30. This can improve the efficiency and increase the productivity of the display device 100.

[0198] <Example of display device configuration 2> Figures 16A and 16B show a configuration example different from the display device 100 shown in Figures 15A and 15B. As shown in Figures 16A and 16B, the display device 100 has a first layer 20 which is the drive circuit section 13 The main difference from the display device 100 shown in Figures 15A and 15B is that it has 0. The 130 is provided on the same first layer 20 as the drive circuit section 140a and the drive circuit section 140b. This allows for the manufacturing process of the drive circuit section 130, drive circuit section 140a, and drive circuit section 140b. It can be standardized, which can increase productivity.

[0199] Figure 16B shows an example in which the pixel section 150 does not overlap with the drive circuit section 130. However, the present invention is not limited to this. The pixel section 150 overlaps with the drive circuit section 130. It may have a region. Also, the pixel section 150 is connected to the drive circuit section 130, the drive circuit section 140a and It may have an area that overlaps with either the drive circuit section 140b. This makes it possible to narrow the bezel of the display device 100. By doing so, the display device 100 can be made smaller.

[0200] <Example of cross-sectional configuration of a display device 1> Figure 17 shows a cross-sectional view illustrating an example configuration of the display device 100. The display device 100 is a substrate 70 It has a substrate 701 and a substrate 705, and the substrate 701 and the substrate 705 are bonded together by a sealing material 712. It is.

[0201] As the substrate 701, a single-crystal semiconductor substrate such as a single-crystal silicon substrate can be used. Note that a semiconductor substrate other than a single-crystal semiconductor substrate may be used as the substrate 701.

[0202] Transistors 441 and 601 are provided on the substrate 701. The transistors 441 and 601 are transistors provided in the first layer 20. This is possible. For example, in the display device 100 shown in Figures 15A and 15B, Stat 441 and transistor 601 are connected to drive circuit section 140a or drive circuit section 140b It can be a transistor provided. For example, the table shown in Figures 16A and 16B In the device 100, transistors 441 and 601 are located in the drive circuit section 13 0. A transistor provided in the drive circuit section 140a or drive circuit section 140b. It is possible.

[0203] Transistor 441 has a conductor 443 that functions as a gate electrode and a gate insulating It consists of an insulator 445 that has the function of a body and a part of the substrate 701, forming a channel. A semiconductor region 447 containing a region, which functions as either a source region or a drain region. Low resistance region 449a, and low resistance having the other function as source region or drain region. It has an anti-region 449b. Transistor 441 is either p-channel or n-channel. That's fine too.

[0204] Transistor 441 is electrically isolated from other transistors by the element isolation layer 403. In Figure 17, the element isolation layer 403 separates transistor 441 and transistor 601. This shows the case where they are electrically isolated. The element isolation layer 403 is LOCOS(LOCal Oxidation of Silicon (STI) method, or STI (Shallow Tr It can be formed using methods such as ench isolation.

[0205] Here, the transistor 441 shown in Figure 17 has a convex shape in the semiconductor region 447. The sides and top surface of the semiconductor region 447 are covered by the conductor 443 via the insulator 445. It is provided there. Note that in Figure 17, the conductor 443 covers the side surface of the semiconductor region 447. The child is not shown in the diagram. Also, the conductor 443 can be made of a material that adjusts the work function. Cut.

[0206] Transistors with a convex semiconductor region, such as transistor 441, are found on a semiconductor substrate. Because it utilizes the convex part, it can be called a fin-type transistor. It has an insulator that is in contact with the upper part and functions as a mask for forming a protrusion. This is also acceptable. Figure 17 also shows a configuration in which a portion of the substrate 701 is processed to form a protrusion. However, the SOI substrate may be processed to form a semiconductor having a convex shape.

[0207] Note that the configuration of transistor 441 shown in Figure 17 is just one example and is not limited to this configuration. The appropriate configuration should be chosen depending on the circuit configuration or the way the circuit operates. For example, a transistor 441 may also be a planar transistor.

[0208] Transistor 601 can have the same configuration as transistor 441.

[0209] On the substrate 701 are an element isolation layer 403, as well as transistors 441 and 6 In addition to 01, insulators 405, 407, 409, and 411 are provided. Conductor 45 in insulator 405, insulator 407, insulator 409, and insulator 411 1 is buried. Here, the height of the top surface of the conductor 451 and the height of the top surface of the insulator 411 They can be done to a similar degree.

[0210] Insulators 413 and 415 are provided on the conductor 451 and on the insulator 411, respectively. Furthermore, a conductor 457 is embedded in the insulator 413 and the insulator 415. Here, The height of the top surface of the conductor 457 and the height of the top surface of the insulator 415 can be made to be approximately the same.

[0211] Insulators 417 and 419 are provided on the conductor 457 and on the insulator 415, respectively. Furthermore, the conductor 459 is embedded in the insulator 417 and the insulator 419. Here, The height of the top surface of the conductor 459 and the height of the top surface of the insulator 419 can be made to be approximately the same.

[0212] Insulators 421 and 214 are provided on the conductor 459 and on the insulator 419, respectively. A conductor 453 is embedded in the insulator 421 and in the insulator 214. Here, the conductor The height of the top surface of 453 and the height of the top surface of the insulator 214 can be made to be approximately the same.

[0213] An insulator 216 is provided on the conductor 453 and on the insulator 214. A conductor 455 is embedded. Here, the height of the top surface of the conductor 455 and the insulator 216 The height of the top surface can be made to be approximately the same.

[0214] On the conductor 455, and on the insulator 216, insulators 222, 224, and 254, Insulators 244, 280, 274, and 281 are provided. Insulator 2 22, insulator 224, insulator 254, insulator 244, insulator 280, insulator 2 A conductor 305 is embedded in 74 and in the insulator 281. Here, the conductor 305 The height of the top surface and the height of the top surface of the insulator 281 can be made to be approximately the same.

[0215] An insulator 361 is provided on the conductor 305 and on the insulator 281. Conductors 317 and 337 are embedded. Here, the height of the upper surface of conductor 337 This allows the height of the top surface of the insulator 361 to be approximately the same.

[0216] An insulator 363 is provided on the conductor 337 and on the insulator 361. Conductors 347, 353, 355, and 357 are embedded here. Therefore, the height of the upper surfaces of the conductor 353, conductor 355, and conductor 357, and the upper surface of the insulator 363 The surface height can be made to be approximately the same.

[0217] Connecting electrodes 7 are placed on the conductor 353, the conductor 355, the conductor 357, and the insulator 363. 60 is provided. Also, an anisotropic conductor 78 is electrically connected to the connecting electrode 760. A 0 is provided, and an FPC (Flexible Printed Circuit) is electrically connected to the anisotropic conductor 780. A Printed Circuit (FPC) 716 is provided. The FPC 716 allows the table to be displayed. Various signals and the like are supplied to the display device 100 from outside the display device 100.

[0218] As shown in Figure 17, the source region or drain region of transistor 441 is the other of the two. The low-resistance region 449b, which has the function of conductor 451, conductor 457, conductor 459, conductor Electromagnetic material 453, conductor 455, conductor 305, conductor 317, conductor 337, conductor 347 , conductor 353, conductor 355, conductor 357, connecting electrode 760, and anisotropic conductor 78 It is electrically connected to FPC716 via 0. Here, in Figure 17, the connecting electrode 76 Conductors that have the function of electrically connecting 0 and conductor 347 include conductor 353 and conductor Although three elements are shown, 355 and the conductor 357, the present invention is not limited to these. There may be one conductor that has the function of electrically connecting electrode 760 and conductor 347. There may be two, or four or more. The connecting electrode 760 and the conductor 347 are electrically connected. By providing multiple conductors that have the function of connecting to each other, the contact resistance can be reduced. .

[0219] A transistor 750 is provided on the insulator 214. The transistor 750 is second It can be a transistor provided in layer 30. For example, Figures 15A and 15B, In the display device 100 shown in Figures 16A and 16B, the transistor 750 is a pixel It can be a transistor provided at 150. Transistor 750 is an OS transistor A transistor can be suitably used. OS transistors have an extremely small off-current. It has the following characteristics. Therefore, the retention time of image signals, etc. can be extended, The frequency of the flashing operation can be reduced. Therefore, the power consumption of the display device 100 can be reduced. can.

[0220] Insulator 254, insulator 244, insulator 280, insulator 274, and insulator 28 Conductors 301a and 301b are embedded in 1. Conductor 301a is tra The conductor 301b is electrically connected to either the source or drain of the inverter 750. It is electrically connected to the other side of the source or drain of the transistor 750. Here, conductive The height of the upper surfaces of body 301a and conductor 301b is approximately the same as the height of the upper surface of insulator 281. can.

[0221] Insulator 361 contains conductor 311, conductor 313, conductor 331, capacitive element 790, conductive Body 333 and conductor 335 are embedded. Conductors 311 and 313 are trans It is electrically connected to the ZISTA 750 and functions as wiring. Conductor 333 and conductor 335 is electrically connected to the capacitive element 790. Here, conductor 331, conductor 3 The height of the upper surface of the conductor 335 and the height of the upper surface of the insulator 361 can be made to be approximately the same.

[0222] Conductors 341, 343, and 351 are embedded in the insulator 363. Here, the height of the top surface of the conductor 351 and the height of the top surface of the insulator 363 can be made to be approximately the same.

[0223] Insulator 405, Insulator 407, Insulator 409, Insulator 411, Insulator 413, Insulator 4 15, Insulator 417, Insulator 419, Insulator 421, Insulator 214, Insulator 280, Insulator Body 274, insulator 281, insulator 361, and insulator 363 have the function of interlayer films. Furthermore, it may function as a planarizing film that covers the uneven shape below each of them. The upper surface of the insulator 363 is chemically mechanically polished (CMP) to improve flatness. Planarization is performed using methods such as mechanical polishing. It's fine if it is done.

[0224] For example, in the display device 100 shown in Figures 15 and 16, the capacitive element 790 is a pixel This can be a capacitive element 111 or a capacitive element 112 provided in part 150.

[0225] As shown in Figure 17, the capacitive element 790 has a lower electrode 321 and an upper electrode 325. Furthermore, an insulator 323 is provided between the lower electrode 321 and the upper electrode 325. In other words, the capacitive element 790 has an insulator 323 that functions as a dielectric sandwiched between a pair of electrodes. This is a laminated structure. Figure 17 shows an example where a capacitive element 790 is placed on an insulator 281. Although this is shown, the capacitive element 790 may be provided on an insulator different from the insulator 281.

[0226] In Figure 17, conductors 301a, 301b, and 305 are formed in the same layer. An example of this is shown. Also, conductor 311, conductor 313, conductor 317, and the lower This shows an example where electrode 321 is formed in the same layer. Also, conductor 331, conductor 333 This shows an example in which conductors 335 and 337 are formed in the same layer. This shows an example in which body 341, conductor 343, and conductor 347 are formed in the same layer. Furthermore, conductors 351, 353, 355, and 357 are formed in the same layer. An example is shown. By forming multiple conductors in the same layer, the display device 100 This simplifies the manufacturing process, thereby reducing the manufacturing cost of the display device 100. This can be achieved. Furthermore, these may be formed in different layers and may contain different types of materials. You may do so.

[0227] The display device 100 shown in Figure 17 has a light-emitting device 782. The light-emitting device 782 is It has a conductor 772, an EL layer 786, and a conductor 788. The EL layer 786 is an organic compound It contains a substance or an inorganic compound such as a quantum dot.

[0228] Examples of materials that can be used with organic compounds include fluorescent materials or phosphorescent materials. Furthermore, colloidal quantum dot materials and composite materials can be used as materials for quantum dots. Examples include mold quantum dot materials, core-shell type quantum dot materials, and core type quantum dot materials. It can be done.

[0229] Conductor 772 is composed of conductor 351, conductor 341, conductor 331, conductor 313, and Electrically connected to the other side of the source or drain of transistor 750 via the electrical body 301b. The conductor 772 is formed on the insulator 363 and functions as a pixel electrode. .

[0230] The conductor 772 can be made of a material that is transparent to visible light or a material that is reflective to visible light. It is possible. As a translucent material, for example, an oxide material containing indium, zinc, tin, etc. can be used. It would be good to do so. As a reflective material, it is good to use a material containing, for example, aluminum or silver. .

[0231] Although not shown in Figure 17, the display device 100 includes a polarizing member, a phase difference member, an anti-reflective member, etc. Optical components (optical substrates), etc., can be provided.

[0232] On the substrate 705 side, a light-shielding layer 738 and an insulator 734 in contact with them are provided. The light-shielding layer 738 has the function of blocking light emitted from adjacent areas. Alternatively, the light-shielding layer 73 8 has the function of blocking external light from reaching transistor 750, etc.

[0233] In the display device 100 shown in Figure 17, an insulator 730 is provided on the insulator 363. The insulator 730 can be configured to cover a portion of the conductor 772. Vice 782 has a translucent conductor 788 and is a top-emission type light-emitting device. This is possible. The light-emitting device 782 emits light towards the conductor 772. A dual emitter that emits light to both the mission structure or conductors 772 and 788. It can also be used as a cushion structure.

[0234] Furthermore, the light-shielding layer 738 is provided so as to have an area that overlaps with the insulator 730. The light-shielding layer 738 is covered with an insulator 734. Also, the light-emitting device 782 and the insulator 7 The space between 34 is filled with a sealing layer 732.

[0235] Furthermore, the structure 778 is provided between the insulator 730 and the EL layer 786. The structure 778 is provided between the insulator 730 and the insulator 734.

[0236] A modified version of the display device 100 shown in Figure 17 is shown in Figure 18. Display device 100 shown in Figure 18 This differs from the display device 100 shown in Figure 17 in that it has a colored layer 736. 736 is provided so as to have an area that overlaps with the light-emitting device 782. Colored layer 73 By providing 6, the color purity of the light extracted from the light-emitting device 782 can be increased. Yes, it is possible. This allows the display device 100 to display high-quality images. For example, all light-emitting devices 782 of the display device 100 are light-emitting devices that emit white light. Therefore, the EL layer 786 does not need to be formed by painting, and the display device 100 This allows for high-definition rendering.

[0237] The light-emitting device 782 can have a micro-optical resonator (microcavity) structure. This allows for the extraction of light of a predetermined color (e.g., RGB) without the need for a colored layer. This allows the display device 100 to display in color. The configuration does not include a colored layer. This makes it possible to suppress light absorption by the colored layer. 0 allows for the display of high-brightness images and reduces the power consumption of the display device 100. This can be done. Furthermore, the EL layer 786 is formed in an island-like pattern for each pixel or in a striped pattern for each row of pixels, that is Even when formed by painting in different colors, it is possible to create a structure without a colored layer.

[0238] In Figures 17 and 18, transistors 441 and 601 are located on substrate 701. A channel formation region is formed inside, and transistor 441 and transistor Although a configuration in which transistor 750 is provided by stacking on top of 601 has been shown, one aspect of the present invention is This is not the only example. A modified example of Figure 18 is shown in Figure 19. The display device 100 shown in Figure 19 is Instead of transistors 441 and 601, the OS transistor is The main difference from the display device 100 shown in Figure 18 is that it has a sta 602 and a transistor 603. Yes. Also, transistor 750 can use an OS transistor. In other words, The display device 100 shown in Figure 19 has OS transistors arranged in a stack.

[0239] Insulators 613 and 614 are provided on the substrate 701, and a trap is placed on the insulator 614. A transistor 602 and a transistor 603 are provided. The substrate 701 and the insulator 61 A transistor or the like may be provided between 3 and 6. For example, a substrate 701 and an insulator 6 Between 13 and , a structure similar to that of transistors 441 and 601 shown in Figure 18 is used. A transistor may be provided.

[0240] Transistors 602 and 603 are provided in the first layer 20 It can be set to . For example, in the display device 100 shown in Figures 15A and 15B Transistors 602 and 603 are located in the drive circuit section 140a or the drive circuit section This can be a transistor located at 140b. For example, see Figures 16A and 16B. In the display device 100 shown, transistors 602 and 603 drive Transistors provided in circuit section 130, drive circuit section 140a, or drive circuit section 140b It can be done this way.

[0241] Transistors 602 and 603 have the same configuration as transistor 750. It can be made into a transistor. Note that transistors 602 and 603 are An OS transistor with a different configuration from transistor 750 may also be used.

[0242] In addition to transistors 602 and 603, insulator 616 is located on insulator 614. Insulator 622, Insulator 624, Insulator 654, Insulator 644, Insulator 680, Insulator 6 74 and an insulator 681 are provided. Among the insulators 654, among the insulators 644, insulator 680 Conductors 461 are embedded in the insulator 674 and in the insulator 681. The height of the top surface of the electrical body 461 and the height of the top surface of the insulator 681 can be made to be approximately the same.

[0243] An insulator 501 is provided on the conductor 461 and on the insulator 681. A conductor 463 is embedded. Here, the height of the upper surface of the conductor 463 and the insulator 501 The height of the top surface can be made to be approximately the same.

[0244] An insulator 503 is provided on the conductor 463 and on the insulator 501. A conductor 465 is embedded. Here, the height of the top surface of the conductor 465 and the insulator 503 The height of the top surface can be made to be approximately the same.

[0245] An insulator 505 is provided on the conductor 465 and on the insulator 503. Also, insulator 50 A conductor 467 is embedded in 5. Here, the height of the upper surface of the conductor 467 and the insulator 5 The height of the top surface of 05 can be made to be about the same.

[0246] An insulator 507 is provided on the conductor 467 and on the insulator 505. A conductor 469 is embedded. Here, the height of the upper surface of the conductor 469 and the insulator 507 The height of the top surface can be made to be approximately the same.

[0247] An insulator 509 is provided on the conductor 469 and on the insulator 507. Also, insulator 50 A conductor 471 is embedded in 9. Here, the height of the upper surface of the conductor 471 and the insulator 5 The height of the top surface of 09 can be made to be about the same.

[0248] Insulators 421 and 214 are provided on the conductor 471 and on the insulator 509, respectively. A conductor 453 is embedded in the insulator 421 and in the insulator 214. Here, the conductor The height of the top surface of 453 and the height of the top surface of the insulator 214 can be made to be approximately the same.

[0249] As shown in Figure 19, either the source or drain of transistor 602 is connected to conductor 46 1. Conductor 463, Conductor 465, Conductor 467, Conductor 469, Conductor 471, Conductor 453, Conductor 455, Conductor 305, Conductor 317, Conductor 337, Conductor 347, Conductor The electric body 353, conductor 355, conductor 357, connecting electrode 760, and anisotropic conductor 780 are It is electrically connected to the FPC716 via this.

[0250] Insulator 613, Insulator 614, Insulator 680, Insulator 674, Insulator 681, Insulator 5 01, insulator 503, insulator 505, insulator 507, and insulator 509 are interlayer films It may have the function of a planarizing film that covers the uneven shape below each of them. stomach.

[0251] By configuring the display device 100 as shown in Figure 19, the display device 100 can be made smaller. While standardizing the design, all transistors in the display device 100 are to be OS transistors. This makes it possible to, for example, a transistor provided in the first layer 20 and the second layer 30 The transistors provided in and can be manufactured using the same apparatus. Therefore, the table This reduces the manufacturing cost of the display device 100, making the display device 100 inexpensive. It is possible.

[0252] <Example of cross-sectional configuration of a display device 2> Figure 20 is a cross-sectional view showing an example configuration of the display device 100, which has a transistor 750. Between the layer and the layer having transistors 441 and 601, transistor 8 The main difference from the display device 100 shown in Figure 18 is that it has a layer containing 00. In this, transistor 601, transistor 750, transistor 800, and The diagram shows a configuration in which each region overlaps with the others, but one aspect of the present invention is not limited thereto. It is not determined. For example, transistor 601 and transistor 750 have an overlapping region. And transistor 800, transistor 601 and transistor 750, respectively They do not need to have overlapping regions. Alternatively, transistor 601 and transistor Transistor 800 and transistor 750 and transistor 601 have overlapping regions, and transistor 750 and transistor 601 and The transistors 800 and 800 do not necessarily have overlapping regions.

[0253] As shown in Figure 15A, the first layer 20 is the first circuit layer, and the second circuit layer is on the first circuit layer. A stacked structure can be formed. For example, transistors 441 and 601 are It can be a transistor provided in the first circuit layer. Transistor 800 is the It can be a transistor provided in the second circuit layer. Transistor 750 is the second This can be a transistor located in layer 30.

[0254] Insulators 821 and 814 are provided on the conductor 459 and on the insulator 419, respectively. A conductor 853 is embedded in the insulator 821 and in the insulator 814. Here, the conductor The height of the top surface of 853 and the height of the top surface of the insulator 814 can be made to be approximately the same.

[0255] An insulator 816 is provided on the conductor 853 and on the insulator 814. A conductor 855 is embedded. Here, the height of the upper surface of the conductor 855 and the insulator 816 The height of the top surface can be made to be approximately the same.

[0256] Insulators 822, 824, and 854 are placed on the conductor 855 and on the insulator 816. Insulators 844, 880, 874, and 881 are provided. 22, insulator 824, insulator 854, insulator 844, insulator 880, insulator 8 Conductor 805 is embedded in 74 and in insulator 881. Here, conductor 805 The height of the top surface and the height of the top surface of the insulator 881 can be made to be approximately the same.

[0257] Insulators 421 and 214 are provided on the conductor 817 and on the insulator 881, respectively.

[0258] As shown in Figure 20, the source region or drain region of transistor 441 is the other of the two. The low-resistance region 449b, which has the function of conductor 451, conductor 457, conductor 459, conductor Electrical element 853, conductor 855, conductor 805, conductor 817, conductor 453, conductor 455 Conductor 305, Conductor 317, Conductor 337, Conductor 347, Conductor 353, Conductor 3 FPC716 via 55, conductor 357, connecting electrode 760, and anisotropic conductor 780 It is electrically connected to it.

[0259] A transistor 800 is provided on the insulator 814. Transistor 800 is the first This can be a transistor provided in layer 20. For example, see Figures 15A and 15B. In the display device 100 shown, the transistor 800 is driven by the drive circuit section 140a or This can be a transistor provided in the dynamic circuit section 140b. For example, as shown in Figure 16A and In the display device 100 shown in Figure 16B, the transistor 800 is in the drive circuit section 130. This can be a transistor provided in the drive circuit section 140a or the drive circuit section 140b. It is possible. Transistor 800 is preferably an OS transistor.

[0260] Insulator 854, insulator 844, insulator 880, insulator 874, and insulator 88 Conductors 801a and 801b are embedded in 1. Conductor 801a is tra Electrically connected to either the source or drain of the converter 800, the conductor 801b is It is electrically connected to the other side of the source or drain of the transistor 800. Here, conductive The height of the upper surfaces of body 801a and conductor 801b is approximately the same as the height of the upper surface of insulator 881. can.

[0261] The transistor 750 can be a transistor provided in the second layer 30. For example, in the display device 100 shown in Figures 15A, 15B, 16A, and 16B, The transistor 750 can be a transistor provided in the pixel section 150. It is preferable to use an OS transistor for the Rangista 750.

[0262] Furthermore, the layer on which transistors 441 and 601, etc. are provided, and An OS transistor or the like may be provided between the layer where 800 etc. is provided. Between the layer on which transistors such as the zista 800 are provided and the layer on which transistors such as the transistor 750 are provided, S transistors, etc., may be provided. Furthermore, above the layer in which transistor 750, etc., is provided. OS transistors or the like may be provided in the layer.

[0263] Insulator 405, Insulator 407, Insulator 409, Insulator 411, Insulator 413, Insulator 4 15, Insulator 417, Insulator 419, Insulator 821, Insulator 814, Insulator 880, Insulator Body 874, insulator 881, insulator 421, insulator 214, insulator 280, insulator 274, Insulators 281, 361, and 363 have the function of interlayer films, and each It may also function as a planarizing film that covers the uneven shape below it.

[0264] In Figure 20, conductors 801a, 801b, and 805 are formed in the same layer. An example of this is shown. Also, conductors 811, 813, and 817 are the same. This shows an example of formation in the layer.

[0265] In Figure 20, transistors 441 and 601 are placed inside the substrate 701. A layer is provided so as to form a Nell formation region, above transistors 441 and 601. The configuration shown involves stacking transistors 800 and 750, but this development The present invention is not limited to this. A modified example of Figure 20 is shown in Figure 21. Display device shown in Figure 21 100 is an OS transistor instead of transistors 441 and 601. The display device 1 shown in Figure 20 has transistors 602 and 603. It is different from 00. In other words, the display device 100 shown in Figure 21 has three layers of OS transistors stacked together. It is provided as such.

[0266] A layer on which transistors 602 and 603 are provided, and transistor 800 OS transistors, etc., may be provided between the layer on which the etc. are provided. A layer in which transistors such as 800 are provided, and a layer in which transistors 750 or transistors such as 750 are provided. An OS transistor or the like may be provided between the layers. Furthermore, a transistor 750 or the like may be provided. OS transistors or the like may be provided in the layer above the layer being cut.

[0267] For example, transistors 602 and 603 are located in the first circuit layer of the first layer 20. A transistor can be provided in the first layer 20. Transistor 800 is a transistor provided in the first layer 20 It can be a transistor provided in the second circuit layer. Transistor 750 is the This can be a transistor located in layer 30 of layer 2.

[0268] Insulators 821 and 814 are provided on the conductor 471 and on the insulator 509, respectively. A conductor 853 is embedded in the insulator 821 and in the insulator 814. Here, the conductor The height of the top surface of 853 and the height of the top surface of the insulator 814 can be made to be approximately the same.

[0269] As shown in Figure 21, either the source or drain of transistor 602 is connected to conductor 46 1. Conductor 463, Conductor 465, Conductor 467, Conductor 469, Conductor 471, Conductor 853, Conductor 855, Conductor 805, Conductor 817, Conductor 453, Conductor 455, Conductor Electrode 305, Conductor 317, Conductor 337, Conductor 347, Conductor 353, Conductor 355 The FPC 716 and electricity are connected via the conductor 357, connecting electrode 760, and anisotropic conductor 780. They are connected by energy.

[0270] By configuring the display device 100 as shown in Figure 21, a narrow-bezel and compact display device 10 It can be set to 0. Also, all transistors in the display device 100 are OS transistors. By using a standard transistor, it becomes unnecessary to manufacture different types of transistors, thus displaying This reduces the manufacturing cost of the device 100 and makes the display device 100 inexpensive. It is possible.

[0271] <Example of light-emitting device configuration> As the light-emitting device 572, for example, an EL element that utilizes electroluminescence It can be applied. An EL element has a layer containing a light-emitting compound between a pair of electrodes (hereinafter, It also has an EL layer. Between the pair of electrodes, there is an electric current greater than the threshold voltage of the EL element. When a positional difference is created, holes are injected into the EL layer from the anode side and electrons are injected from the cathode side. The injected electrons and holes recombine in the EL layer, causing the light-emitting material contained in the EL layer to emit light. ru.

[0272] EL elements are distinguished by whether the light-emitting material is an organic compound or an inorganic compound. Generally, the former are called organic EL elements, and the latter are called inorganic EL elements.

[0273] Organic EL elements, when a voltage is applied, emit electrons from one electrode and positive electrons from the other electrode. Each pore is injected into the EL layer. Then, these carriers (electrons and holes) recombine. This causes the luminescent organic compound to form an excited state, and then that excited state returns to the ground state. It emits light at that time. Due to this mechanism, such light-emitting devices are current-excited type These are called optical devices.

[0274] In this specification, the voltage supplied to a display element such as a light-emitting device or liquid crystal element is the same as the voltage supplied to the display element. The potential applied to one electrode of the display element and the potential applied to the other electrode of the display element It shows the difference between the rank and the position.

[0275] In addition to luminescent compounds, the EL layer also contains materials with high hole injection potential and high hole transport potential. Materials, hole-blocking materials, materials with high electron transport properties, materials with high electron injection properties, or bipolar It may contain substances with high electron transport and hole transport properties.

[0276] The EL layer is produced by vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating methods. It can be formed by methods such as those listed above.

[0277] Inorganic EL elements are classified into dispersed inorganic EL elements and thin-film inorganic EL elements based on their device configuration. They are classified into two types. Dispersed inorganic EL elements are light-emitting devices in which particles of light-emitting material are dispersed in a binder. It has layers, and the luminescence mechanism utilizes donor and acceptor levels. --This is acceptor-recombination type light emission. Thin-film inorganic EL elements sandwich the light-emitting layer between dielectric layers. Furthermore, it has a structure in which it is sandwiched between electrodes, and the light emission mechanism is the inner-shell electron transition of metal ions. This is a localized type of light emission that utilizes movement.

[0278] A light-emitting device only needs to have at least one of its pair of electrodes transparent in order to extract light. Then, a transistor and a light-emitting device are formed on the substrate, and from the side opposite to the substrate... Top emission structure for extracting light, bottom emission structure for extracting light from the substrate side Surface emission (bottom emission) structure, and double-sided emission (dual emission) structure that extracts light from both sides. There is a light-emitting device with a mission structure, and any light-emitting device with an injection structure can be applied. can.

[0279] Figures 22A to 22E show examples of the configuration of the light-emitting device 572. Figure 22A shows This shows a structure (single structure) in which an EL layer 786 is sandwiched between conductors 772 and 788. As mentioned above, the EL layer 786 contains a light-emitting material, for example, an organic compound that emits light. It contains ingredients.

[0280] Figure 22B shows the stacked structure of the EL layer 786. Here, the structure shown in Figure 22B In the light-emitting device 572, the conductor 772 functions as the anode, and the conductor 788 functions as the cathode. It functions as such.

[0281] The EL layer 786 consists of a hole injection layer 721, a hole transport layer 722, and an emissive layer on top of the conductor 772. The structure has a sequential stacking of 723, an electron transport layer 724, and an electron injection layer 725. If the electrode 772 functions as a cathode and the conductor 788 functions as an anode, The stacking order will be reversed.

[0282] The light-emitting layer 723 has a combination of light-emitting materials and other materials as appropriate, and emits a desired light color. A configuration can be made that produces fluorescence or phosphorescence exhibiting the same characteristics. Furthermore, the light-emitting layer 723 A laminated structure with different light-emitting colors may also be used. In this case, the light used in each laminated light-emitting layer may vary. Light-emitting materials and other substances can each be made from different materials.

[0283] In the light-emitting device 572, for example, the conductor 772 shown in Figure 22B is used as a reflective electrode. Conductor 788 is used as a semi-transmissive / semi-reflective electrode, forming a micro-optical resonator (microcavity) structure. By doing so, the light emitted from the light-emitting layer 723 contained in the EL layer 786 resonates between the two electrodes. This allows for an increase in the amount of light emitted through the conductor 788.

[0284] Furthermore, the conductor 772 of the light-emitting device 572 is a conductive material that has reflectivity and transmittance. In the case of a reflective electrode consisting of a laminated structure with a conductive material (transparent conductive film), the transparent conductive film Optical adjustments can be made by controlling the film thickness. Specifically, from the light-emitting layer 723 For the wavelength λ of the resulting light, the distance between the electrodes of conductor 772 and conductor 788 is mλ / 2 (where m is a natural number) It is preferable to adjust it so that it is in a neighborhood.

[0285] In order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 723, the conductor 772 is used. The optical distance from the light-emitting layer to the region where the desired light can be obtained (light-emitting region), and the distance from the conductor 788. The optical distance to the region (emission region) where the desired light is obtained in the optical layer 723, and (2m) It is preferable to adjust it so that it is in the vicinity of '+1)λ / 4 (where m' is a natural number). In this context, the light-emitting region refers to the recombination region between holes and electrons in the light-emitting layer 723. This indicates.

[0286] By performing such optical adjustments, the spectrum of a specific monochromatic light obtained from the light-emitting layer 723 is achieved. By narrowing the duct, it is possible to obtain emission with good color purity.

[0287] However, in the above case, the optical distance between conductor 772 and conductor 788 is strictly speaking conductor 77 This can be described as the total thickness from the reflective region in 2 to the reflective region in the conductor 788. However, it is difficult to precisely determine the reflection region in conductors 772 and 788. Therefore, by assuming that any position on the conductor 772 and conductor 788 is a reflection region, it is sufficient to... The effects described above can be obtained. In addition, the conductor 772 and the generator that produces the desired light The optical distance to the light layer is, strictly speaking, the reflection region in the conductor 772 and the emission region from which the desired light is obtained. It can be said that this is the optical distance to the light-emitting region in the light layer. However, in conductor 772 Precisely determining the reflective region and the light-emitting region in the light-emitting layer from which the desired light can be obtained is difficult. Because it is difficult, any position on the conductor 772 is designated as a reflection region, and the light-emitting layer is designated as the source of the desired light. The above-mentioned effect can be sufficiently obtained by assuming that the location of the intention is the luminescent region.

[0288] The light-emitting device 572 shown in Figure 22B has a microcavity structure, therefore the same E Even with an L layer, it is possible to extract light of different wavelengths (monochromatic light). Therefore, different This eliminates the need for color separation (e.g., RGB) to obtain the desired emission color. Therefore, higher resolution is achieved. It is easy to do. It can also be combined with a colored layer. Furthermore, specific wavelengths This allows for increased light emission intensity in the forward direction, thus enabling lower power consumption.

[0289] Furthermore, the light-emitting device 572 shown in Figure 22B does not have a microcavity structure. This may also be done by having a structure in which the light-emitting layer 723 emits white light and a colored layer is provided. This allows for the extraction of light of a predetermined color (e.g., RGB). Furthermore, the EL layer 786 is formed When creating the product, if different colors of light are applied using a coloring process, the desired color can be achieved without the need for a separate colored layer. It is possible to extract light from it.

[0290] At least one of the conductor 772 and the conductor 788 is a light-transmitting electrode (transparent electrode, semi-transparent electrode). It can be a transparent electrode (transmissive / semi-reflective electrode, etc.). If the electrode with light-transmitting properties is a transparent electrode, it is transparent The visible light transmittance of the electrode shall be 40% or higher. In the case of semi-transparent and semi-reflective electrodes, semi-transparent The reflectance of the semi-reflective electrode in visible light is 20% to 80%, preferably 40% to 70%. The following applies. Furthermore, the resistivity of these electrodes is 1 × 10⁻⁶. -2 A value of Ωcm or less is preferable.

[0291] If the conductor 772 or conductor 788 is a reflective electrode (reflecting electrode), then reflection The visible light reflectance of the electrode having properties is 40% or more and 100% or less, preferably 70% or more. The resistivity of this electrode should be 00% or less. -2 A value of Ωcm or less is preferable.

[0292] The configuration of the light-emitting device 572 may be as shown in Figure 22C. Figure 22C shows conductive There are two EL layers (EL layer 786a and EL layer 786b) between the body 772 and the conductor 788. A laminated structure is provided, having a charge generation layer 792 between the EL layer 786a and the EL layer 786b. The light-emitting device 572 is shown in a tandem structure. This makes it possible to increase the current efficiency and external quantum efficiency of the light-emitting device 572. This allows a high-brightness image to be displayed on the display device 100. Also, the display device 100's power Power consumption can be reduced. Here, EL layer 786a and EL layer 786b are shown in Figure 22 The same configuration as the EL layer 786 shown in B can be used.

[0293] When a voltage is supplied between the conductor 772 and the conductor 788, the charge generation layer 792 generates E In the L layer 786a and EL layer 786b, electrons are injected into one and holes are created in the other. It has an injection function. Therefore, the potential of conductor 772 is higher than the potential of conductor 788. When a voltage is supplied in this manner, electrons are injected from the charge generation layer 792 to the EL layer 786a. Holes will be injected from the charge generation layer 792 into the EL layer 786b.

[0294] Furthermore, the charge generation layer 792 transmits visible light (specifically, in terms of light extraction efficiency). It is preferable that the transmittance of visible light in the charge generation layer 792 is 40% or more. The conductivity of the charge generation layer 792 is lower than that of the conductor 772 or the conductor 788. That's fine.

[0295] The configuration of the light-emitting device 572 may be as shown in Figure 22D. Figure 22D shows conductive Between body 772 and conductor 788 are three EL layers (EL layer 786a, EL layer 786b, and An EL layer 786c) is provided, between EL layer 786a and EL layer 786b, and EL layer 78 Light-emitting device 5 with a tandem structure having a charge generation layer 792 between 6b and EL layer 786c Figure 22 shows 72. Here, EL layer 786a, EL layer 786b, and EL layer 786c are shown in Figure 22. The EL layer 786 shown in B can have a similar configuration. The light-emitting device 572 is shown in Figure 22D. By adopting the configuration shown, the current efficiency and external quantum efficiency of the light-emitting device 572 can be further improved. This can be increased. Therefore, it is possible to display even higher brightness images on the display device 100. This allows for further reduction of the power consumption of the display device 100.

[0296] The configuration of the light-emitting device 572 may be as shown in Figure 22E. Figure 22E shows conductive Between body 772 and conductor 788 is an n-layer EL layer (EL layer 786(1) to EL layer 786( n)) is provided, and a tandem structure having a charge generation layer 792 between each EL layer 786 The light-emitting device 572 is shown. Here, the EL layers 786(1) to 786(n) are The same configuration as the EL layer 786 shown in Figure 22B can be used. Note that Figure 22E shows, Of the EL layer 786, EL layer 786(1), EL layer 786(m), and EL layer 786(m+1) ), and EL layer 786(n) are shown. Here, m is an integer between 2 and n, and n is Let n be an integer greater than or equal to m. The larger the value of n, the higher the current efficiency of the light-emitting device 572 and the external quantum efficiency. Efficiency can be increased. Therefore, a high-brightness image can be displayed on the display device 100. This also allows for a reduction in the power consumption of the display device 100.

[0297] The constituent materials that can be used in the light-emitting device 572 will be described below.

[0298] [Conductors 772 and 788] Conductors 772 and 788 can fulfill the functions of an anode and a cathode, respectively, as follows: The materials shown can be used in appropriate combinations. For example, metals, alloys, and electrically conductive materials. Compounds and mixtures thereof can be used as appropriate. Specifically, In-Sn oxides (Also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide Examples include In-W-Zn oxide. Other examples include aluminum (Al) and titanium (Ti). Chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni ), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn) Molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), Gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc. The genera and alloys containing them in appropriate combinations can also be used. Other examples include those shown above. Elements that do not belong to Group 1 or Group 2 of the periodic table (e.g., lithium (Li), cesium) (Cs), calcium (Ca), strontium (Sr), europium (Eu), i Rare earth metals such as terberbium (Yb) and alloys containing them in appropriate combinations, and other materials Rafen and the like can be used.

[0299] [Hole injection layer 721 and hole transport layer 722] The hole injection layer 721 is connected to the conductor 772 which is the anode or the charge generation layer 792 to the EL layer 786. This is a layer into which holes are injected, and it is a layer containing a material with high hole injection potential. Here, EL layer 78 6 is EL layer 786a, EL layer 786b, EL layer 786c, and EL layer 786(1) to It shall include EL layer 786(n).

[0300] Materials with high hole injection potential include molybdenum oxide, vanadium oxide, and ruthenium oxide. Examples include transition metal oxides such as tungsten oxide and manganese oxide. In addition, Talocyanine compounds, aromatic amine compounds, or polymers can be used.

[0301] Materials with high hole injection potential include hole transport materials and acceptor materials (electron-accepting materials). ) can also be used as a composite material. In this case, hole transport is performed by the acceptor material. Electrons are extracted from the material, generating holes in the hole injection layer 721, and then through the hole transport layer 722. Then holes are injected into the light-emitting layer 723. The hole injection layer 721 is made of a hole transportable material and It may be formed as a single layer of composite material containing a receptor material (electron-accepting material), By stacking hole transport materials and acceptor materials (electron-accepting materials) in separate layers... It may be formed.

[0302] The hole transport layer 722 receives holes injected from the conductor 772 by the hole injection layer 721. This is the layer that transports to the light-emitting layer 723. The hole transport layer 722 is a layer containing a hole-transporting material. Therefore, the hole transport material used in the hole transport layer 722 is particularly the HOMO of the hole injection layer 721. It is preferable to use a device that has the same or a similar HOMO level as the current level.

[0303] As the acceptor material used in the hole injection layer 721, elements from Group 4 of the periodic table to Oxides of metals belonging to Group 8 can be used. Specifically, molybdenum oxide, oxide Vanadium, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide Rhenium oxide is one example. In particular, molybdenum oxide is stable even in the atmosphere and absorbs It is preferable because it has low moisture content and is easy to handle. Other options include quinodimethane derivatives and chloranil derivatives. Organic acceptors such as hexaazatriphenylene derivatives can be used.

[0304] The hole transport material used in the hole injection layer 721 and the hole transport layer 722 is 10 -6 cm 2 / A material having a hole mobility of Vs or higher is preferred. Furthermore, a material with higher hole transport than electron transport is preferred. If quality is the priority, other materials can be used.

[0305] Hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives and ion compounds). Doll derivatives and aromatic amine compounds are preferred.

[0306] However, the hole transport material is not limited to the above, and may be one or more of various known materials. The combined material is used as a hole transport material in the hole injection layer 721 and the hole transport layer 722. This can be achieved. Furthermore, the hole transport layer 722 may be formed from multiple layers. For example, a first hole transport layer and a second hole transport layer may be stacked on top of each other.

[0307] [Emitting layer 723] The light-emitting layer 723 is a layer containing light-emitting material. The light-emitting material can be blue, purple, or blue-violet. Substances that emit light in various colors such as green, yellow-green, yellow, orange, and red are used as appropriate. Here, Figure As shown in Figures 22C, 22D and 22E, the light-emitting device 572 has multiple EL layers. In this case, by using different light-emitting materials in the light-emitting layer 723 provided in each EL layer, and configurations that exhibit different emission colors (for example, obtained by combining emission colors that are complementary to each other) It can be made to emit white light. For example, if the light-emitting device 572 has the configuration shown in Figure 22C In some cases, the light-emitting material used in the light-emitting layer 723 provided on the EL layer 786a, and the EL layer 7 By making the light-emitting material used in the light-emitting layer 723 provided in 86b different from E The emission color exhibited by the L layer 786a and the emission color exhibited by the EL layer 786b are made different. Yes, it is possible. Furthermore, a layered structure in which one of the light-emitting layers has a different light-emitting material may also be used.

[0308] The light-emitting layer 723 contains one or more organic compounds (H) in addition to the light-emitting substance (guest material). It may also contain a starter material, an assisting material, etc. Furthermore, it may contain one or more types of organic compounds. Therefore, hole-transporting materials, electron-transporting materials, or both can be used.

[0309] The light-emitting material that can be used in the light-emitting layer 723 is not particularly limited, and the singlet excitation energy - A light-emitting material that converts light into visible light, or a triplet excitation energy that converts light into visible light. A light-emitting substance that can be changed to the following can be used. For example, the above light-emitting substance may be the following: Some examples can be listed.

[0310] As a light-emitting material that converts singlet excitation energy into light emission, it is a substance that emits fluorescence (fluorescent material). Examples include pyrene derivatives, anthracene derivatives, triphenylene derivatives, and ful Orene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives Dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives Examples include pyrene derivatives, phenanthrene derivatives, naphthalene derivatives, etc. In particular, pyrene derivatives are This is preferable because it yields a high photon quantum yield.

[0311] As a light-emitting material that converts triplet excitation energy into light emission, for example, phosphorescent material (phosphorescent Photomaterials) and thermally activated delayed fluorescence (TADF) exhibiting thermally activated delayed fluorescence. Examples include activated delayed fluorescence materials.

[0312] Examples of phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. These exhibit different emission colors (emission peaks) depending on the substance, so select as appropriate as needed. Select and use.

[0313] Note that blue light-emitting materials have a photoluminescence peak wavelength of 430 nm or higher, up to 470 nm. A material with a wavelength of 430 nm or less, more preferably 430 nm to 460 nm, may be used. Green light-emitting materials have a photoluminescence peak wavelength between 500 nm and 540 nm. More preferably, a material with a wavelength of 500 nm to 530 nm should be used. (Red light-emitting material) The photoluminescence peak wavelength is preferably between 610 nm and 680 nm. For this, a material with a wavelength between 620 nm and 680 nm should be used. The solution can be either a solution or a thin film.

[0314] By using such compounds in combination with the microcavity effect, the above can be more easily achieved. Chromaticity can be achieved. At this time, the semi-transparent material necessary to obtain the microcavity effect is The film thickness of the semi-reflective electrode (metal thin film portion) is preferably 20 nm to 40 nm. The minimum wavelength is greater than 25 nm and less than or equal to 40 nm. Note that efficiency decreases above 40 nm. There's a possibility of diarrhea.

[0315] The organic compounds (host material, assist material) used in the light-emitting layer 723 are light-emitting substances (guest material). A material having an energy gap larger than the energy gap of the material, Multiple types can be selected and used. Furthermore, the hole transport material mentioned above and the electron transport material described later... Each material can also be used as either a host material or an assist material.

[0316] When the light-emitting material is a fluorescent material, the host material has a large singlet excited state energy level. Therefore, it is preferable to use organic compounds with low energy levels in their triplet excited states. For example In this case, it is preferable to use anthracene derivatives or tetracene derivatives.

[0317] If the luminescent material is a phosphorescent material, the triplet excitation energy of the luminescent material is used as the host material. (The energy difference between the ground state and the triplet excited state) is greater than the triplet excitation energy. You should select the appropriate compound. In this case, in addition to zinc and aluminum-based metal complexes, Oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxali Dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives Conductors, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, fer In addition to nanthroline derivatives, aromatic amines and carbazole derivatives can also be used. .

[0318] When multiple organic compounds are used in the light-emitting layer 723, the compound that forms the excitation complex is the light-emitting substance. It is preferable to use it in a mixture with [another substance]. In this case, various organic compounds can be used in appropriate combinations. However, in order to efficiently form an excited complex, a compound that readily accepts holes is needed. Combining a hole-transporting material with a compound that readily accepts electrons (an electron-transporting material) It is particularly preferable to do so. Specific examples of hole-transporting materials and electron-transporting materials are as follows: The materials shown in this embodiment can be used.

[0319] TADF materials are materials that can be excited from a triplet excited state to a singlet excited state with only a small amount of thermal energy. Upconversion (reverse intersystem crossing) is possible, and emission (fluorescence) from singlet excited states can be efficiently performed. It refers to a material that exhibits a certain characteristic. Furthermore, the conditions under which thermally activated delayed fluorescence can be efficiently obtained are three The energy difference between the doublet excited level and the singlet excited level is 0 eV or more and 0.2 eV or less, preferably. One example is that the voltage is between 0 eV and 0.1 eV. Also, regarding delayed fluorescence in TADF materials... Light refers to emission that has a spectrum similar to ordinary fluorescence but with a significantly longer lifetime. Its lifespan is 10 -6 10 seconds or more, preferably 10 -3 It is more than a second.

[0320] Examples of TADF materials include fullerenes and their derivatives, and acridines such as proflavin. Examples include derivatives and eosin. Also, magnesium (Mg), zinc (Zn), cadmium Um (Cd), tin (Sn), platinum (Pt), indium (In), or palladium Examples include metal-containing porphyrins, such as those containing (Pd).

[0321] In addition, heterocyclic compounds having π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings. It is possible to use materials. Furthermore, π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings The directly bonded substance has the characteristics of a donor of a π-electron-rich heteroaromatic ring and an a of a π-electron-deficient heteroaromatic ring. The xceptor properties become stronger in both states, and the energy difference between the singlet excited state and the triplet excited state becomes smaller. Therefore, it is particularly preferable.

[0322] Furthermore, when using TADF materials, they can also be used in combination with other organic compounds. .

[0323] [Electron transport layer 724] The electron transport layer 724 receives electrons injected from the conductor 788 by the electron injection layer 725. This layer transports electrons to the light-emitting layer 723. The electron transport layer 724 is a layer containing an electron-transporting material. The electron transport material used in the electron transport layer 724 is 1 × 10⁻⁶. -6 cm 2 / Vs or higher A material with electron mobility is preferred. In addition, any material with higher electron transport capabilities than hole transport is preferred. Other materials can be used.

[0324] As electron transport materials, quinoline ligands, benzoquinoline ligands, and oxazole ligands. , or metal complexes having thiazole ligands, oxadiazole derivatives, triazoles Examples include derivatives, phenanthroline derivatives, pyridine derivatives, and bipyridine derivatives. In addition, π-electron-deficient heteroaromatic compounds, such as nitrogen-containing heteroaromatic compounds, can also be used. can.

[0325] The electron transport layer 724 is not only a single layer, but also a layer in which two or more layers made of the above material are stacked. The structure is also acceptable.

[0326] [Electron injection layer 725] The electron injection layer 725 is a layer containing a material with high electron injection potential. Lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2) , lithium oxide (LiO x Alkali metals, alkaline earth metals, or similar materials such as ) Compounds such as erbium fluoride (ErF3) can be used. Compounds of this group can be used. Alternatively, electrides may be used in the electron injection layer 725. As an electride, for example, a mixed oxide of calcium and aluminum can be used to increase electron density. Examples include substances added in concentration. Furthermore, the substances constituting the electron transport layer 724 described above are used. It is possible to stay there.

[0327] A composite material, which is a mixture of an organic compound and an electron donor, is placed in the electron injection layer 725. It may be used. Such composite materials generate electrons in the organic compound through the action of an electron donor. Therefore, it has excellent electron injection and electron transport properties. In this case, as an organic compound, It is preferable that the material is excellent in electron transport, specifically, for example, the electron transport layer described above. Electron transport materials (such as metal complexes and heteroaromatic compounds) can be used in 724. Any substance that exhibits electron-donating properties towards organic compounds can be used as an electron donor. Specifically, Alkali metals, alkaline earth metals, and rare earth metals are preferred, as are lithium, cesium, and magnesium. Examples include nesium, calcium, erbium, and ytterbium. Also, alkali gold Metal oxides and alkaline earth metal oxides are preferred, as are lithium oxides, calcium oxides, and barium oxides. Examples include magnesium oxides. Additionally, using Lewis bases such as magnesium oxide is also an option. It is also possible to use organic compounds such as tetrathiafulvalene (abbreviated as TTF). can.

[0328] [Charge generation layer 792] The charge generation layer 792, when a voltage is applied between the conductor 772 and the conductor 788, Of the two EL layers 786 in contact with the charge generation layer 792, the EL layer closer to the conductor 772 It has the function of injecting electrons into 786 and injecting holes into the EL layer 786 on the opposite side of the conductor 788. For example, in the light-emitting device 572 with the configuration shown in Figure 22C, the charge generation layer 792 is It has the function of injecting electrons into EL layer 786a and holes into EL layer 786b. The charge generation layer 792 has a configuration in which electron acceptors are added to a hole transport material. However, the configuration may also include an electron donor added to the electron transport material. Furthermore, both of these configurations may be stacked. By forming the raw layer 792, the drive of the display device 100 when the EL layer is stacked This can suppress the rise in dynamic voltage.

[0329] In the charge generation layer 792, when an electron acceptor is added to the hole transport material: As an electron acceptor, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoro Examples include quinodimethane (abbreviation: F4-TCNQ) and chloranil. Examples include oxides of metals belonging to groups 4 through 8 of the periodic table. Specifically These are vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, and tartium oxide. Examples include ngsten, manganese oxide, and rhenium oxide.

[0330] In the case where the charge generation layer 792 has a configuration in which an electron donor is added to the electron transport material. , as electron donors, alkali metals or alkaline earth metals or rare earth metals or elements from the periodic table Metals belonging to groups 2 and 13 in the region, as well as their oxides and carbonates, can be used. Physically, lithium (Li), cesium (Cs), magnesium (Mg), calcium ( Ca, ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc. It is preferable to use an organic compound such as tetrathianaphthalene as an electron donor. It may be used as such.

[0331] Furthermore, the fabrication of the light-emitting device 572 involved vacuum processes such as vapor deposition, as well as spin coating and Solution processes such as inkjet methods can be used. When using vapor deposition methods, Putter method, ion plating method, ion beam deposition method, molecular beam deposition method, vacuum deposition method, etc. Physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods can be used. Functional layers included in the EL layer of an optical device (hole injection layer, hole transport layer, light emission layer, electron transport layer, For the electron injection layer and charge generation layer, deposition methods (such as vacuum deposition) and coating methods (such as dip coating) are used. (e.g., die coating, bar coating, spin coating, spray coating), printing methods (Inkjet method, screen printing method, offset printing method, flexographic printing) Formed by methods such as (relief printing), gravure printing, microcontact printing, etc. can.

[0332] In this embodiment, each functional layer (hole injection layer, positive) that constitutes the EL layer of the light-emitting device is shown. The pore transport layer, light-emitting layer, electron transport layer, electron injection layer, and charge generation layer are limited to the materials described above. It is not necessary to use other materials, and if they can fulfill the function of each layer, they can be combined. It can be used as an example. - etc.), medium-molecular-weight compounds (compounds in the intermediate region between low-molecular-weight and high-molecular-weight compounds: molecular weight 400-4000) Inorganic compounds (such as quantum dot materials) can be used. colloidal quantum dot materials, alloy quantum dot materials, core-shell quantum dot materials Core-type quantum dot materials and the like can be used.

[0333] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., are at least a part of them. This can be implemented by combining it with other configuration examples or drawings as appropriate.

[0334] This embodiment may be appropriately combined with other embodiments described herein, at least in part. They can be implemented in combination.

[0335] (Embodiment 2) In this embodiment, a transistor that can be used in a display device according to one aspect of the present invention. I will explain this.

[0336] <Transistor Configuration Example 1> Figures 23A, 23B, and 23C show a display device that is one embodiment of the present invention. Transistor 200A, and a top view and a cross view of the area around transistor 200A. A transistor 200A can be applied to a display device according to one aspect of the present invention.

[0337] Figure 23A is a top view of transistor 200A. Also, Figures 23B and 23C are This is a cross-sectional view of transistor 200A. Here, Figure 23B is a cross-sectional view of A1-A2 in Figure 23A. This is a cross-sectional view of the area indicated by the dashed line, and is a cross-sectional view of transistor 200A in the channel length direction. There is also Figure 23C, which is a cross-sectional view of the area shown by the dashed line A3-A4 in Figure 23A. This is also a cross-sectional view of transistor 200A in the channel width direction. Note that in Figure 23A, the top view is shown. Some elements have been omitted from the diagram for clarity.

[0338] As shown in Figure 23B, transistor 200A is placed on a substrate (not shown). A metal oxide 230a and a metal oxide 230b placed on top of the metal oxide 230a , conductors 242a and conductor 2 are arranged on the metal oxide 230b at a distance from each other. 42b and the conductor 242a and the conductor 242b are arranged on the conductor 242a and the conductor 2 An insulator 280 having an opening formed between 42b, and a conductor 260 placed inside the opening, Metal oxide 230b, conductor 242a, conductor 242b, and insulator 280, and conductor 2 60, an insulator 250, a metal oxide 230b, a conductor 242a, and a conductive element are positioned between them. Body 242b, and metal oxide 230 disposed between insulator 280 and insulator 250 It has c and . Here, as shown in Figures 23B and 23C, the upper surface of the conductor 260 is The upper surfaces of insulator 250, insulator 254, metal oxide 230c, and insulator 280 are approximately in line with each other. It is preferable to do so. In the following, metal oxide 230a, metal oxide 230b, and Sometimes, metal oxides 230c are collectively referred to as metal oxide 230. Also, conductor 24 Sometimes, conductors 2a and conductor 242b are collectively referred to as conductor 242.

[0339] In the transistor 200A shown in Figure 23, the conductors 242a and 242b The side of the 260 has a roughly vertical shape. Note that the transistor 20 shown in Figure 23 0A is not limited to the side and bottom surfaces of conductors 242a and 242b. The angle formed may be 10° or more and 80° or less, preferably 30° or more and 60° or less. Furthermore, the opposing sides of the conductor 242a and the conductor 242b may have multiple surfaces. stomach.

[0340] As shown in Figure 23, the insulator 224, metal oxide 230a, metal oxide 230b, and conductive Insulation between body 242a, conductor 242b, and metal oxide 230c and insulator 280. It is preferable that the body 254 is positioned. Here, the insulator 254 is shown in Figures 23B and 23C. As shown, the side surface of metal oxide 230c, the top and side surfaces of conductor 242a, and conductor 242 The top and side surfaces of b, the side surfaces of metal oxide 230a and metal oxide 230b, and the insulator 22 It is preferable that it be in contact with the upper surface of 4.

[0341] In transistor 200A, the region where the channel is formed (hereinafter referred to as the channel formation region) Also called the region.) and in its vicinity, metal oxide 230a, metal oxide 230b, and The present invention is not limited to a configuration in which three layers of metal oxide 230c are stacked. It is not the case that... For example, a two-layer structure of metal oxide 230b and metal oxide 230c, or 4 A configuration with a stacked structure of more than one layer may also be used. In addition, in transistor 200A, the conductor Although 260 is shown as a two-layer laminated structure, the present invention is not limited thereto. For example, the conductor 260 may have a single-layer structure or a multilayer structure of three or more layers. Furthermore, each of the metal oxides 230a, 230b, and 230c It may have a laminated structure of two or more layers.

[0342] For example, metal oxide 230c is a first metal oxide and a second metal on the first metal oxide In the case of having a layered structure made of oxides, the first metal oxide is the same as metal oxide 230b. The second metal oxide has the same composition as metal oxide 230a, and it is preferable that the second metal oxide has the same composition as metal oxide 230a. It seems so.

[0343] Here, the conductor 260 functions as the gate electrode of the transistor, and the conductor 242a and The conductor 242b functions as either a source electrode or a drain electrode, respectively. Furthermore, the conductor 260 is sandwiched between the opening of the insulator 280 and the conductors 242a and 242b. It is formed to be embedded in the region. Here, conductor 260, conductor 242a and The arrangement of the conductor 242b is self-aligned with the opening of the insulator 280. In transistor 200A, the gate electrode is placed between the source electrode and the drain electrode. It can be positioned in a self-aligning manner. Therefore, the conductor 260 has a margin for alignment. Because it can be formed without the need for additional components, the occupied area of ​​transistor 200A is reduced. This makes it possible to make the display device high-resolution. Also, the display device It is possible to have a narrow bezel.

[0344] As shown in Figure 23, the conductor 260 is provided inside the insulator 250. It comprises a and a conductor 260b which is provided to be embedded inside the conductor 260a. It is preferable to do so.

[0345] Transistor 200A has an insulator 214 placed on a circuit board (not shown), and An insulator 216 is placed on top of the edge 214, and is placed so as to be embedded in the insulator 216. A conductive material 205, an insulator 216, and an insulator 222 placed on top of the conductive material 205, Preferably, the insulator 224 is disposed on the edge 222. It is preferable that a metal oxide 230a is placed on top.

[0346] An insulator 274 and an insulator 281, which function as interlayer films, are placed on top of the transistor 200A. It is preferable that the insulator 274 is arranged such that the conductor 260 and the insulator 250 are The insulator 254, the metal oxide 230c, and the insulator 280 are arranged in contact with the upper surface of the insulator 254, the metal oxide 230c, and the insulator 280. preferable.

[0347] Insulators 222, 254, and 274 contain hydrogen (e.g., hydrogen atoms, hydrogen components). It is preferable that it has the function of suppressing the diffusion of at least one of the children. For example, insulator 2 22, insulator 254, and insulator 274 are insulator 224, insulator 250, and insulator 2 It is preferable that the hydrogen permeability is lower than 80. Also, insulators 222 and 254 are It has the function of suppressing the diffusion of at least one of the oxygen molecules (e.g., oxygen atoms, oxygen molecules, etc.). This is preferable. For example, insulator 222 and insulator 254 are insulator 224, insulator 25 It is preferable that the oxygen permeability is lower than that of 0 and insulator 280.

[0348] Here, insulator 224, metal oxide 230, and insulator 250 are insulator 280 and insulator The edge 281 is separated from the insulator 254 and the insulator 274. Therefore, insulation Body 224, metal oxide 230, and insulator 250, and insulator 280 and insulator 281 contain Impurities such as hydrogen and excess oxygen are present in the insulator 224, metal oxide 230a, and metal oxide. This prevents the material 230b from being mixed into the insulator 250.

[0349] Conductor 240 (conductor) is electrically connected to transistor 200A and functions as a plug. It is preferable that 240a and conductor 240b) are provided. Insulator 241 (insulator 241a and insulator 241b) is in contact with the side surface of the conductor 240. These are provided. That is, insulator 254, insulator 280, insulator 274, and insulator 281 An insulator 241 is provided in contact with the inner wall of the opening. Also, a guide is provided in contact with the side surface of the insulator 241. A first conductor of the electric body 240 is provided, and a second conductor of the electric body 240 is provided further inside. A configuration in which the height of the upper surface of the conductor 240 and the upper surface of the insulator 281 may be used. The height can be made to be about the same. Note that in transistor 200A, the first conductor of conductor 240 The present invention also shows a configuration in which a second conductive material of the conductive material 240 is laminated, but the present invention does not It is not limited to this. For example, the conductor 240 can be configured as a single layer or a laminated structure of three or more layers. It may also be configured in such a way. If the structure has a layered structure, an ordinal number may be assigned to distinguish it according to the order of formation. There are cases where this occurs.

[0350] Transistor 200A contains a metal oxide 230 (metal oxide 23) which includes a channel formation region. 0a, metal oxide 230b, and metal oxide 230c) function as oxide semiconductors. It is preferable to use metal oxides (hereinafter also referred to as oxide semiconductors). For example, metal acids As a metal oxide that forms the channel-forming region of ion 230, the band gap is 2 eV or greater. Preferably, a voltage of 2.5 eV or higher is used.

[0351] The above metal oxide may include at least indium (In) or zinc (Zn). Preferably. In particular, it is preferable that it contains indium (In) and zinc (Zn). In addition to these, it is preferable that element M is included. As element M, aluminum (A l), gallium (Ga), yttrium (Y), tin (Sn), boron (B), titanium ( Ti (Ti), iron (Fe), nickel (Ni), germanium (Ge), zirconium (Zr) Molybdenum (Mo), lanthanum (La), cerium (Ce), neodymium (Nd), HAF Nium (Hf), tantalum (Ta), tungsten (W), magnesium (Mg), or corn One or more elements of balth (Co) can be used. In particular, element M is aluminum (Al). It is preferable that it be one or more of gallium (Ga), yttrium (Y), or tin (Sn). Furthermore, it is preferable that element M contains either Ga or Sn, or both. It seems so.

[0352] As shown in Figure 23B, the metal oxide 230b has a film thickness in the region that does not overlap with the conductor 242. However, the film thickness may be thinner than the film thickness in the region overlapping with conductor 242a. Furthermore, when forming the conductor 242b, a portion of the upper surface of the metal oxide 230b is removed. A conductive film, which becomes a conductor 242, is formed on the upper surface of the metal oxide 230b. In such cases, a region of low resistance may be formed near the interface with the conductive film. Located between the conductors 242a and 242b on the upper surface of the metal oxide 230b, with low resistance By removing the unwanted region, it is possible to prevent the formation of channels in that region. .

[0353] According to one aspect of the present invention, a display device having a small transistor and high resolution is provided. It can be provided. Alternatively, a display device with a transistor that has a large on-current and high brightness. It can provide a device with fast transistors and a fast display device. It can provide a transistor with stable electrical characteristics and high reliability. A display device can be provided. Alternatively, a transistor with a small off-current and low power consumption can be provided. It is possible to provide a display device with low power output.

[0354] Detailed structure of transistor 200A that can be used in a display device according to one aspect of the present invention Let me explain about the formation.

[0355] The conductor 205 has an overlapping region with the metal oxide 230 and the conductor 260. They are arranged in such a way. Furthermore, it is preferable that the conductor 205 is embedded in the insulator 216.

[0356] The conductor 205 comprises conductor 205a, conductor 205b, and conductor 205c. The conductor 205a is provided in contact with the bottom surface and side wall of the opening provided in the insulator 216. The conductor 205b is provided so as to be embedded in a recess formed in the conductor 205a. Here, the upper surface of the conductor 205b is above the upper surface of the conductor 205a and the upper surface of the insulator 216. The temperature becomes lower. Conductor 205c is on the upper surface of conductor 205b and the side surface of conductor 205a. They are provided in contact with each other. Here, the height of the upper surface of the conductor 205c is the height of the upper surface of the conductor 205a. The height of the conductor 205b is approximately equal to the height of the top surface of the insulator 216. The configuration will consist of being enclosed between 05a and the conductive material 205c.

[0357] Conductors 205a and 205c are composed of hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, and nitrogen It suppresses the diffusion of impurities such as elementary molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms. It is preferable to use a conductive material that has the function of doing so. Alternatively, oxygen (for example, oxygen atoms Using a conductive material that has the function of suppressing the diffusion of at least one of the following: oxygen molecules. It is preferable.

[0358] Conductive material having the function of reducing hydrogen diffusion in conductor 205a and conductor 205c By using this material, impurities such as hydrogen contained in the conductor 205b are removed from the insulator 224, etc. Diffusion into the metal oxide 230 can be suppressed via this. Also, conductor 205a and By using a conductive material that has the function of suppressing oxygen diffusion in the conductor 205c, This can suppress the oxidation of the conductor 205b, which reduces its conductivity. Examples of conductive materials that have the function of suppressing [something] include titanium, titanium nitride, tantalum, and nitrogen. It is preferable to use tantalum oxide, ruthenium oxide, etc. The conductive body 205a may be made of the above conductive material in a single layer or in a multilayer form. For example, conductive body 205 For 'a', titanium nitride can be used.

[0359] Conductor 205b is a conductive material whose main components are tungsten, copper, or aluminum. It is preferable to use [a specific material]. For example, tungsten may be used for the conductor 205b.

[0360] Here, the conductor 260 functions as the first gate (also called the top gate) electrode. In some cases, this may occur. Also, the conductor 205 is connected to the second gate (also called the bottom gate) electrode. In some cases, it may function in this way. In that case, the potential applied to the conductor 205 is marked on the conductor 260. By changing the voltage independently of the applied potential, the V of the 200A transistor can be controlled. th of It can be controlled. In particular, by applying a negative potential to the conductor 205, the transient V of Sta200A th By making it greater than 0V, it becomes possible to reduce the off-current. Therefore, applying a negative potential to the conductor 205 is more effective than not applying a negative potential to the conductor 2 The drain current can be reduced when the potential applied to 60 is 0V.

[0361] If the conductor 205 is made larger than the channel formation region in the metal oxide 230 Good. In particular, as shown in Figure 23C, the conductor 205 is the channel width of the metal oxide 230. It is preferable that the extension extends even in the region outside the end where it intersects with the direction. On the outer side of the side surface in the channel width direction of the group oxide 230, the conductor 205 and the conductor 260 is preferably superimposed via an insulator.

[0362] Having the above configuration, the electric field of the conductor 260, which functions as the first gate electrode Then, due to the electric field of the conductor 205 which functions as a second gate electrode, the metal oxide 2 Thirty channel-forming regions can be electrically enclosed.

[0363] As shown in Figure 23C, the conductor 205 is extended and also functions as wiring. Furthermore, without being limited to this, a conductor that functions as wiring can be provided beneath the conductor 205. It is also acceptable to use this configuration.

[0364] The insulator 214 prevents impurities such as water or hydrogen from entering the transistor 200A from the substrate side. It is preferable that it functions as a barrier insulating film that suppresses the following. Therefore, insulator 21 4 consists of a hydrogen atom, a hydrogen molecule, a water molecule, a nitrogen atom, a nitrogen molecule, and a nitrogen oxide molecule (N2O, NO). It has the function of suppressing the diffusion of impurities such as NO2, copper atoms, etc. (the above impurities do not permeate) It is preferable to use an insulating material. Alternatively, oxygen (for example, oxygen atoms, oxygen molecules) Insulating material having the function of suppressing the diffusion of at least one of the above-mentioned substances (such as oxygen) (the above-mentioned oxygen is less permeable). It is preferable to use materials.

[0365] For example, aluminum oxide or silicon nitride may be used as the insulator 214. This is because impurities such as water or hydrogen can pass through the substrate side of the insulator 214. This can suppress diffusion to the 200A side. Alternatively, oxygen contained in the insulator 224, etc. Diffusion can be suppressed towards the substrate side of the edge 214.

[0366] The insulators 216, 280, and 281, which function as interlayer films, are insulator 21 A dielectric constant lower than 4 is preferable. By using a material with a low dielectric constant as the interlayer film, the wiring space The parasitic capacitance that occurs in can be reduced. For example, insulator 216, insulator 280, and As insulator 281, silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride N, silicon oxide with added fluorine, silicon oxide with added carbon, carbon and nitrogen added Silicon oxide, or silicon oxide with voids, may be used as appropriate.

[0367] Insulators 222 and 224 function as gate insulators.

[0368] Here, the insulator 224 in contact with the metal oxide 230 can deoxygenate by heating. Preferred. In this specification, oxygen released by heating may be referred to as excess oxygen. For example. The insulator 224 may be silicon oxide or silicon oxide nitride, etc., as appropriate. By providing an insulator in contact with the metal oxide 230, oxygen deficiencies in the metal oxide 230 are eliminated. This can reduce the noise and improve the reliability of the 200A transistor.

[0369] Specifically, as the insulator 224, an oxide material is used from which some oxygen is desorbed by heating. It is preferable to do so. Oxides that desorb oxygen upon heating are TDS (Thermal D Oxygen converted to oxygen atoms by esorption spectroscopy analysis The amount of detachment is 1.0 × 10 18 atoms / cm 3 Preferably 1.0 × 10 19 at oms / cm 3 More preferably 2.0 × 10 19 atoms / cm 3 The above, or 3.0×10 20 atoms / cm 3 The above describes the oxide film. Furthermore, the above TDS analysis... The surface temperature of the film at that time is between 100°C and 700°C, or between 100°C and 400°C. A range of [specified range] is preferred.

[0370] As shown in Figure 23C, the insulator 224 does not overlap with the insulator 254, and the metal oxide 2 The film thickness in areas that do not overlap with 30b may be thinner than the film thickness in other areas. (Insulation) In body 224, there is a region that does not overlap with the insulator 254 and does not overlap with the metal oxide 230b. The film thickness is preferably such that it allows sufficient diffusion of the above-mentioned oxygen.

[0371] Insulator 222, like insulator 214, allows impurities such as water or hydrogen to enter from the substrate side. It is preferable that it functions as a barrier insulating film to suppress contamination of the 200A. For example, it is preferable that insulator 222 has lower hydrogen permeability than insulator 224. 222, insulator 254, and insulator 274, insulator 224, metal oxide 230, And by surrounding the insulator 250 etc., impurities such as water or hydrogen from the outside are prevented from entering the transistor 2 This can prevent intrusion into 00A.

[0372] Furthermore, the insulator 222 provides at least one expansion of oxygen (e.g., oxygen atoms, oxygen molecules, etc.). It is preferable that it has a function to suppress dispersion (i.e., the above oxygen does not easily permeate). For example, insulation It is preferable that body 222 has lower oxygen permeability than insulator 224. By having the function of suppressing the diffusion of impurities, the oxygen contained in the metal oxide 230 is contained in the substrate This reduces diffusion to the side, which is preferable. Also, the conductor 205 is insulator 224 and metal This can suppress the reaction of oxide 230 with oxygen.

[0373] The insulator 222 is an oxide of one or both of the insulating materials aluminum and hafnium. It is preferable to use an insulator containing a substance. Oxides of aluminum and hafnium, or one or both. The insulators include aluminum oxide, hafnium oxide, aluminum, and hafnium. It is preferable to use oxides containing such materials (hafnium aluminate, etc.). When an insulator 222 is formed, the insulator 222 releases oxygen from the metal oxide 230. Also, to suppress the ingress of impurities such as hydrogen from the peripheral area of ​​transistor 200A into the metal oxide 230. They function as the dominant force.

[0374] Alternatively, these insulators may contain, for example, aluminum oxide, bismuth oxide, or germanium oxide. M, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, acid Zirconium oxide may be added. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxide nitride, or silicon nitride may be laminated onto the edge body.

[0375] The insulator 222 can be, for example, aluminum oxide, hafnium oxide, tantalum oxide, or dioxide. Zirconium, lead zirconate titanate (PZT), strontium titanate (SrTiO3) ) or an insulator containing so-called high-k materials such as (Ba,Sr)TiO3 (BST) It may be used in single-layer or multi-layer configurations. As transistors become smaller and more integrated, gate insulation becomes more important. Thinning of the edge material may cause problems such as leakage current. (Functions as a gate insulator) By using a high-k material as the insulator, the physical film thickness is maintained while the transistor movement This allows for a reduction in the gate potential during operation.

[0376] Furthermore, the insulators 222 and 224 may have a laminated structure of two or more layers. In that case, it is not limited to a laminated structure made of the same material, but can also be a laminated structure made of different materials. For example, an insulator similar to the insulator 224 may be provided below the insulator 222. .

[0377] Metal oxide 230 consists of metal oxide 230a and metal oxide 23 on metal oxide 230a. It comprises 0b and a metal oxide 230c on the metal oxide 230b. Having metal oxide 230a below, the structure formed below metal oxide 230a The diffusion of impurities from the material to the metal oxide 230b can be suppressed. Having metal oxide 230c on the oxide 230b, above the metal oxide 230c The diffusion of impurities from the formed structure to the metal oxide 230b can be suppressed.

[0378] Furthermore, metal oxide 230 has a layered structure of multiple oxide layers with different atomic ratios of each metal atom. It is preferable that the metal oxide 230 has at least indium (In) And, if element M is included, the number of atoms of all elements constituting the metal oxide 230a is, The proportion of atoms of element M contained in the group oxide 230a is the total proportion of atoms of element M that make up the metal oxide 230b. This is higher than the ratio of the number of atoms of element M contained in metal oxide 230b to the total number of atoms of the element. This is preferable. Also, the atomic ratio of element M contained in the metal oxide 230a to In is It is preferable that the atomic ratio of element M in metal oxide 230b to In is greater than that of In. Here, metal oxide 230c is used in metal oxide 230a or metal oxide 230b. Metal oxides that can be used can be employed.

[0379] The energy at the lower end of the conduction band of metal oxide 230a and metal oxide 230c is It is preferable that the energy is higher than the energy at the lower end of the conduction band at 230b. In other words, The electron affinity of metal oxide 230a and metal oxide 230c is such that the electron affinity of metal oxide 230b It is preferable that it is smaller than the affinity. In this case, metal oxide 230c is metal oxide 230 It is preferable to use a metal oxide that can be used for a. Specifically, metal oxide 2 The number of atoms of element M contained in metal oxide 230c relative to the total number of atoms of all elements that make up 30c. The ratio of the number of atoms is the ratio of the total number of atoms of the elements that make up metal oxide 230b to the total number of atoms of metal oxide 230b It is preferable that the ratio of the number of atoms of element M contained in b is higher than that of b. Also, metal oxide 230c The atomic ratio of element M contained in to In is the same as the atomic ratio of element M contained in metal oxide 230b. Preferably, the atomic ratio is greater than that of In.

[0380] Here, the joint between metal oxide 230a, metal oxide 230b, and metal oxide 230c In this case, the energy level at the lower end of the conduction band changes smoothly. In other words, metal oxides The lower end of the conduction band at the junction of 230a, metal oxide 230b, and metal oxide 230c Energy levels can also be described as continuously changing or continuously joining. In order to do so, the interface between metal oxide 230a and metal oxide 230b, and metal oxide 230 Lowering the defect level density of the mixed layer formed at the interface between b and metal oxide 230c good.

[0381] Specifically, metal oxide 230a and metal oxide 230b, metal oxide 230b and metal acid The compound 230c has a common element other than oxygen (which is the main component), resulting in a dense defect level. A mixed layer with a low degree of saturation can be formed. For example, if metal oxide 230b is In-Ga-Z In the case of n oxides, metal oxide 230a and metal oxide 230c are In-Ga-Zn. Oxides, Ga-Zn oxide, gallium oxide, etc. may also be used. Furthermore, metal oxide 230c The layers may be arranged in a stacked structure. For example, an In-Ga-Zn oxide and the In-Ga-Zn acid A layered structure with Ga-Zn oxide on a phosphate, or In-Ga-Zn oxide and the In-G A layered structure with gallium oxide on α-Zn oxide can be used. In other words, In - A layered structure of Ga-Zn oxide and an in-free oxide is defined as metal oxide 230c. It may also be used in this way.

[0382] Specifically, for metal oxide 230a, the ratio of atoms is In:Ga:Zn = 1:3:4. Alternatively, a metal oxide in an atomic ratio of 1:1:0.5 may be used. Also, metal oxide 23 As 0b, In:Ga:Zn = 4:2:3 [atomic ratio] or 3:1:2 [atomic ratio] You can use the following metal oxide. Also, as metal oxide 230c, In:Ga:Zn=1 :3:4 [atomic ratio], In:Ga:Zn=4:2:3 [atomic ratio], Ga:Zn=2: You can use metal oxides with an atomic ratio of 1, or Ga:Zn = 2:5. Furthermore, as a specific example of a layered structure of metal oxide 230c, In:Ga:Zn=4: Layered structures of 2:3 [atomic ratio] and Ga:Zn=2:1 [atomic ratio], In:Ga:Z Layered structure of n=4:2:3 [atomic ratio] and Ga:Zn=2:5 [atomic ratio], In: Examples include a layered structure with Ga:Zn=4:2:3 [atomic ratio] and gallium oxide.

[0383] In this case, the main carrier pathway is metal oxide 230b. Metal oxide 230a, By configuring the metal oxide 230c as described above, metal oxide 230a and metal oxide 230 Defect level density at the interface with b, and at the interface between metal oxide 230b and metal oxide 230c. The degree can be reduced. Therefore, the influence of interfacial scattering on carrier conduction becomes smaller. Therefore, the 200A transistor can achieve high on-current and high frequency characteristics. Oh, when metal oxide 230c is made into a layered structure, the above metal oxide 230b and metal oxide In addition to the effect of lowering the defect level density at the interface with material 230c, the metal oxide 230c It is expected that the constituent elements will be suppressed from diffusing to the insulator 250 side. In terms of structure, the metal oxide 230c is layered, with an in-free oxide on top of the layered structure. In order to position it, it is possible to suppress In which may diffuse towards the insulator 250. Since 50 acts as a gate insulator, if In diffuses, the transistor's characteristics will be affected. This is good. Therefore, by using a layered structure of metal oxide 230c, a highly reliable display can be achieved. It will become possible to provide the device.

[0384] On the metal oxide 230b, there is a conductor 24 that functions as a source electrode and a drain electrode. 2 (conductors 242a and 242b) are provided. As the conductor 242, aluminum nium, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tung Stainless steel, hafnium, vanadium, niobium, manganese, magnesium, zirconium, be Selected from lylium, indium, ruthenium, iridium, strontium, and lanthanum. A metal element, or an alloy containing the above-mentioned metal elements, or a combination of the above-mentioned metal elements It is preferable to use alloys such as tantalum nitride, titanium nitride, and tungsten. Titanium and aluminum nitrides, tantalum and aluminum nitrides, ruthenium oxide Um, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel It is preferable to use oxides containing [the specified substance]. Also, tantalum nitride, titanium nitride, titanium and [the specified substance] Nitrides containing luminium, nitrides containing tantalum and aluminum, ruthenium oxide, nitrides Ruthenium, oxides containing strontium and ruthenium, oxides containing lanthanum and nickel. The material is a conductive material that is resistant to oxidation, or a material that maintains its conductivity even when it absorbs oxygen. That's good.

[0385] By providing the conductor 242 in contact with the metal oxide 230, the metal oxide 230 In the vicinity of the conductor 242, the oxygen concentration may decrease. Also, the metal oxide 230 In the vicinity of the conductor 242, the metal contained in the conductor 242 and the components of the metal oxide 230 A metal compound layer containing may be formed. In such cases, the deposition of the metal oxide 230 In the region near the current body 242, the carrier density increases, and this region becomes a low-resistance region. .

[0386] Here, the region between the conductor 242a and the conductor 242b is superimposed on the opening of the insulator 280. This is formed by creating a self-contained conductor 260 between conductor 242a and conductor 242b. It can be arranged in a consistent manner.

[0387] Insulator 250 functions as a gate insulator. Insulator 250 is metal oxide 230c It is preferable to place it in contact with the upper surface. The insulator 250 is silicon oxide, silicon oxidnitride Cone, silicon nitride oxide, silicon nitride, fluorine-added silicon oxide, carbon-added Silicon oxide, silicon oxide with added carbon and nitrogen, and porous silicon oxide are used. It is possible. In particular, silicon oxide and silicon oxide-nitride are stable to heat. It is preferable.

[0388] The insulator 250, like the insulator 224, has an impurity concentration of water or hydrogen in the insulator 250. It is preferable that the amount is reduced. The film thickness of the insulator 250 is 1 nm or more and 20 nm or less. It is preferable to do so.

[0389] A metal oxide may be provided between the insulator 250 and the conductor 260. The metal oxide is It is preferable to suppress oxygen diffusion from the insulator 250 to the conductor 260. This can suppress the oxidation of the conductor 260 by oxygen in the edge body 250.

[0390] The metal oxide in question may function as part of the gate insulator. Therefore, When silicon oxide or silicon oxide nitride is used for the insulator 250, the metal oxide is It is preferable to use a metal oxide, which is a high-k material with a high dielectric constant. Gate insulation By making the body a laminated structure of the insulator 250 and the metal oxide, it is stable against heat, A laminated structure with a high dielectric constant can be achieved. Therefore, the physical film thickness of the gate insulator can be maintained. While maintaining this, it becomes possible to reduce the gate potential applied during transistor operation. This makes it possible to reduce the equivalent oxide film thickness (EOT) of an insulator that functions as an insulator.

[0391] Specifically, hafnium, aluminum, gallium, yttrium, zirconium, t Select from sten, titanium, tantalum, nickel, germanium, or magnesium, etc. Metal oxides containing one or more of the specified types can be used. In particular, aluminum Aluminum oxide, an insulator containing an oxide of either or both of um or hafnium. Hafnium oxide, aluminum, and hafnium-containing oxides (hafnium aluminate) It is preferable to use the like.

[0392] Although the conductor 260 is shown as a two-layer structure in Figure 23, it may also be a single-layer or three-layer structure. The above layered structure is also acceptable.

[0393] Conductor 260a contains the above-mentioned hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and oxides. It has the function of suppressing the diffusion of impurities such as nitrogen molecules (N2O, NO, NO2, etc.) and copper atoms. It is preferable to use a conductor. Alternatively, a low amount of oxygen (e.g., oxygen atoms, oxygen molecules, etc.) It is preferable to use a conductive material that has the function of suppressing diffusion.

[0394] Because the conductor 260a has the function of suppressing oxygen diffusion, it is contained in the insulator 250. The presence of oxygen can suppress the oxidation of the conductor 260b, which would otherwise reduce its conductivity. Conductive materials that have the function of suppressing oxygen diffusion include, for example, tantalum and tantalum nitride. It is preferable to use ruthenium, ruthenium oxide, or the like.

[0395] Conductor 260b is a conductive material mainly composed of tungsten, copper, or aluminum. It is preferable to use it. Also, since the conductor 260 also functions as wiring, high conductivity is desirable. It is preferable to use a conductive material. For example, tungsten, copper, or aluminum as the main component. A conductive material can be used. Furthermore, the conductor 260b may also be in a laminated structure. For example, a laminated structure of titanium or titanium nitride and the above-mentioned conductive material may be used.

[0396] As shown in Figures 23A and 23C, the metal oxide 230b does not overlap with the conductor 242. In the region, or in other words, the channel-forming region of the metal oxide 230, The sides of the device are arranged to be covered with the conductive material 260. This allows the first gate electrode to be formed This makes it easier to apply the electric field of the functional conductor 260 to the side surface of the metal oxide 230. This increases the on-current of the 200A transistor and improves its frequency characteristics. ru.

[0397] Insulator 254, like insulator 214, contains impurities such as water or hydrogen on the insulator 280 side. It functions as a barrier insulating film that prevents contamination of transistor 200A. Preferably, the insulator 254 has lower hydrogen permeability than the insulator 224. Furthermore, as shown in Figures 23B and 23C, the insulator 254 is made of metal oxide 230c Side view, top and side view of conductor 242a, top and side view of conductor 242b, metal oxide 230a It is preferable that it is in contact with the side surface of the metal oxide 230b and the upper surface of the insulator 224. By using such a configuration, the hydrogen contained in the insulator 280 will be absorbed by the conductor 242a and the conductor 2 From the top or side surface of 42b, metal oxide 230a, metal oxide 230b and insulator 224 This can suppress penetration into the metal oxide 230.

[0398] Furthermore, the insulator 254 provides at least one expansion of oxygen (e.g., oxygen atoms, oxygen molecules, etc.). It is preferable that it has a function to suppress dispersion (i.e., the above oxygen does not easily permeate). For example, insulation Body 254 preferably has lower oxygen permeability than insulator 280 or insulator 224.

[0399] The insulator 254 is preferably formed using a sputtering method. The insulating film of the insulator 224 is formed by depositing it using the sputtering method in an oxygen-containing atmosphere. Oxygen can be added to the vicinity of the region in contact with body 254. This allows oxygen to be released from that region. Oxygen can be supplied into the metal oxide 230 via the insulator 224. Here, the insulation Body 254 has the function of suppressing the upward diffusion of oxygen, so that oxygen does not penetrate the metal oxide 23 This prevents diffusion from 0 to the insulator 280. Also, the insulator 222 downwards By having the function of suppressing the diffusion of oxygen, oxygen diffuses from the metal oxide 230 to the substrate side. This prevents the formation of a channel in the channel formation region of the metal oxide 230. Oxygen is supplied. This reduces the oxygen deficiency of metal oxide 230, and the transistor This can suppress the normalization process.

[0400] As the insulator 254, for example, an oxide of one or both of aluminum and hafnium It is preferable to form a film containing an insulator. Note that the oxidation of one or both aluminum and hafnium As insulators containing materials, aluminum oxide, hafnium oxide, aluminum and hafnium It is preferable to use an oxide containing um (such as hafnium aluminate).

[0401] The insulator 254, which has barrier properties against hydrogen, provides a barrier to the insulator 224 and the insulator 250. And, covered by the metal oxide 230, the insulator 280 is covered by the insulator 254, and the insulator 2 24, metal oxide 230, and insulator 250 are separated. This allows the transistor Because it can suppress the intrusion of impurities such as hydrogen from the outside of the 200A, transistor 2 This can provide good electrical characteristics and reliability to the 00A.

[0402] The insulator 280, through the insulator 254, is connected to the insulator 224, the metal oxide 230, and the conductive It is provided on the body 242. For example, as the insulator 280, silicon oxide, silicon oxide nitride N, silicon dioxide, silicon dioxide with added fluorine, silicon dioxide with added carbon, The material may have silicon oxide with added carbon and nitrogen, or silicon oxide with voids, etc. Preferred. In particular, silicon oxide and silicon oxide nitride are preferred because they are thermally stable. In particular, materials such as silicon oxide, silicon oxide nitride, and silicon oxide with voids are heated This is preferable because it allows for the easy formation of a region containing oxygen that is removed.

[0403] It is preferable that the concentration of impurities such as water or hydrogen in the insulator 280 is reduced. The upper surface of the insulator 280 may be flattened.

[0404] Insulator 274, like insulator 214, etc., is susceptible to impurities such as water or hydrogen from above. It is preferable that it functions as a barrier insulating film to suppress mixing with 280. Insulator 2 For example, an insulator that can be used for insulator 214, insulator 254, etc., can be used as 74. That's all you need to do.

[0405] It is preferable to provide an insulator 281 that functions as an interlayer film on top of the insulator 274. The edge body 281, like the insulator 224, has a reduced concentration of impurities such as water or hydrogen in the film. It is preferable that they be present.

[0406] In the openings formed in insulators 281, 274, 280, and 254, Conductors 240a and 240b are arranged. Conductors 240a and 240b are, They are provided opposite each other with the conductor 260 in between. Note that the upper surfaces of the conductors 240a and 240b The height of the insulator may be on the same plane as the upper surface of the insulator 281.

[0407] Furthermore, on the inner walls of the openings of insulators 281, 274, 280, and 254 An insulator 241a is provided in contact with the side surface of the insulator 241a, and the first conductor of the conductor 240a is in contact with the side surface of the insulator 241a. It is formed. At least a portion of the bottom of the opening is located in the conductor 242a. Conductor 240a is in contact with conductor 242a. Similarly, insulator 281, insulator 274, and insulator An insulator 241b is provided in contact with the inner wall of the opening of the body 280 and the insulator 254, and on its side The first conductive material of the conductive material 240b is formed in contact with the surface. At least the bottom of the opening In some parts, the conductor 242b is located, and the conductor 240b is in contact with the conductor 242b.

[0408] Conductors 240a and 240b are mainly composed of tungsten, copper, or aluminum. It is preferable to use a conductive material that is as follows. Furthermore, conductors 240a and 240b are A laminated structure is also acceptable.

[0409] When the conductive material 240 has a layered structure, metal oxide 230a, metal oxide 230b, conductive Conductors in contact with body 242, insulator 254, insulator 280, insulator 274, and insulator 281 This involves using a conductor that has the function of suppressing the diffusion of impurities such as water or hydrogen, as described above. Preferred. For example, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or acid It is preferable to use ruthenium ionide or the like. Furthermore, it suppresses the diffusion of impurities such as water or hydrogen. The functional conductive material may be used in a single layer or in a laminated form. Then, the oxygen added to the insulator 280 is absorbed by the conductors 240a and 240b. This can suppress impurities such as water or hydrogen from the layer above the insulator 281, and the conductor 24 This prevents contamination of the metal oxide 230 through 0a and the conductor 240b.

[0410] Insulators 241a and 241b can be used, for example, as insulator 254, etc. Any suitable insulator should be used. Insulators 241a and 241b are in contact with insulator 254. Because it is provided in such a way, impurities such as water or hydrogen can be released from the insulator 280, etc., into the conductor 240a and the conductor The mixing of the electric material 240b into the metal oxide 230 can be suppressed. Also, the insulator 28 This prevents oxygen contained in 0 from being absorbed by conductors 240a and 240b.

[0411] Although not shown in the diagram, the wiring is connected to the upper surface of the conductor 240a and the upper surface of the conductor 240b. Functional conductors may be placed. Conductors that function as wiring may be tungsten, copper, or It is preferable to use a conductive material whose main component is aluminum. Furthermore, the conductor is It may also be a laminated structure, for example, a laminate of titanium or titanium nitride and the above conductive material. The conductor may be formed to be embedded in an opening provided in the insulator.

[0412] <Example of transistor configuration 2> Figures 24A, 24B, and 24C show a display device that can be used in one aspect of the present invention. A top view and a cross-sectional view of the transistor 200B and the area around it. Transistor 200B is a modified version of transistor 200A.

[0413] Figure 24A is a top view of transistor 200B. Also, Figures 24B and 24C are This is a cross-sectional view of transistor 200B. Here, Figure 24B is a cross-sectional view of A1-A2 in Figure 24A. This is a cross-sectional view of the area indicated by the dashed line, and is a cross-sectional view of transistor 200B in the channel length direction. There is also Figure 24C, which is a cross-sectional view of the area shown by the dashed line A3-A4 in Figure 24A. This is also a cross-sectional view of transistor 200B in the channel width direction. Note that in the top view of Figure 24A... Some elements have been omitted from the diagram for clarity.

[0414] The transistor 200B has insulators 212 and 283, which is a characteristic of the transistor. It is different from the Ta200A.

[0415] Transistor 200B has an insulator 212 provided on a substrate (not shown). An insulator 283 is provided on the insulator 212 and on the insulator 271.

[0416] In transistor 200B, insulators 214, 216, 222, and 22 4. The insulator 244, insulator 280, and insulator 274 are covered by insulator 283. The insulator 283 is located on the top surface of the insulator 274, the side surface of the insulator 274, and the insulator 280. Side, side of insulator 244, side of insulator 224, side of insulator 222, insulator 216 It is in contact with the side surface, the side surface of insulator 214, and the top surface of insulator 212, respectively. This allows the metal acid to be in contact with the side surface, the side surface of insulator 214, and the top surface of insulator 212. The material 230, etc., is isolated from the outside by the insulators 283 and 212.

[0417] Insulators 283 and 212 contain hydrogen (for example, hydrogen atoms, hydrogen molecules, etc.) 1) It is preferable that the insulator 281 and have a high function of suppressing the diffusion of water molecules. As the insulator 212, a material with high hydrogen barrier properties is used, such as silicon nitride or silicon nitride oxide. It is preferable to use n. This suppresses the diffusion of hydrogen and other substances into the metal oxide 230. Because it can be controlled, the degradation of the characteristics of the 200B transistor can be suppressed. Therefore, this This can improve the reliability of semiconductor devices in one aspect.

[0418] For example, silicon nitride can be used as the insulator 283. When using silicon dioxide, the film is deposited by sputtering, resulting in a high density and porosity. It is possible to form a silicon nitride film that is difficult to form. Also, as the insulator 283, On top of silicon nitride film deposited by the puttering method, further silicon nitride film deposited by the ALD method Recon may be stacked. With this structure, the film can be deposited by sputtering. Even if defects, such as voids, occur in the silicon nitride, the film can be deposited using the ALD method, which offers good coverage. The void can be filled with silicon nitride to improve sealing performance. As 212, a material that can be used for the insulator 214 can be used. For example, an insulating material Silicon nitride can be used for body 212, and aluminum oxide can be used for insulator 214. .

[0419] <Transistor Configuration Example 3> Figures 25A, 25B, and 25C show a display device that can be used in one aspect of the present invention. Transistor 200C, and a top view and a cross view of the area around transistor 200C. Transistor 200C is a modified version of transistor 200A.

[0420] Figure 25A is a top view of transistor 200C. Also, Figures 25B and 25C are This is a cross-sectional view of transistor 200C. Here, Figure 25B is a cross-sectional view of B1-B2 in Figure 25A. This is a cross-sectional view of the area indicated by the dashed line, and is a cross-sectional view of transistor 200C in the channel length direction. There is also Figure 25C, which is a cross-sectional view of the area shown by the dashed line B3-B4 in Figure 25A. This is also a cross-sectional view of transistor 200C in the channel width direction. Note that in Figure 25A, the top view is shown. Some elements have been omitted from the diagram for clarity.

[0421] In transistor 200C, conductors 242a and 242b are metal oxide 230 c has a region that overlaps with the insulator 250 and the conductor 260. This results in a transistor 200C can be a transistor with a high on-current. Also, transistor 200 C can be a transistor that is easy to control.

[0422] The conductor 260, which functions as a gate electrode, consists of a conductor 260a and a conductive material on the conductor 260a. It has an electric body 260b and a conductor 260a. The conductor 260a is composed of hydrogen atoms, hydrogen molecules, water molecules, copper atoms, etc. It is preferable to use a conductive material that has the function of suppressing the diffusion of impurities. Alternatively, oxygen A conductive material having the function of suppressing the diffusion of at least one (for example, an oxygen atom, an oxygen molecule, etc.) It is preferable to use materials.

[0423] The conductor 260a has the function of suppressing the diffusion of oxygen, thus the material of the conductor 260b Material selectivity can be improved. In other words, by having the conductor 260a, the conductor 26 This suppresses the oxidation of 0b and prevents a decrease in conductivity.

[0424] The top and side surfaces of the conductor 260, the side surfaces of the insulator 250, and the side surfaces of the metal oxide 230c It is preferable to provide an insulator 254 so as to cover it. The insulator 254 may be water or hydrogen, etc. It is preferable to use an insulating material that has the function of suppressing the diffusion of impurities and oxygen.

[0425] By providing the insulator 254, oxidation of the conductor 260 can be suppressed. By having the edge body 254, impurities such as water and hydrogen present in the insulator 280 are absorbed into the transistor 2 This can suppress diffusion into 00C.

[0426] <Transistor Configuration Example 4> Figures 26A, 26B, and 26C show a display device that can be used in one aspect of the present invention. Transistor 200D, and a top view and cross-sectional view of the area around transistor 200D. Transistor 200D is a modified version of transistor 200A.

[0427] Figure 26A is a top view of transistor 200D. Also, Figures 26B and 26C are This is a cross-sectional view of transistor 200D. Here, Figure 26B shows the same circuit as C1-C2 in Figure 26A. This is a cross-sectional view of the area indicated by the dashed line, and is a cross-sectional view of transistor 200D in the channel length direction. There is also Figure 26C, which is a cross-sectional view of the area shown by the dashed line C3-C4 in Figure 26A. This is also a cross-sectional view of transistor 200D in the channel width direction. Note that in the top view of Figure 26A... Some elements have been omitted from the diagram for clarity.

[0428] In transistor 200D, an insulator 250 is present on the metal oxide 230c, and insulator 25 It has a metal oxide 252 on top of 0. It also has a conductor 260 on top of the metal oxide 252. The electric body 260 has an insulator 270 on it. Furthermore, the insulator 271 has an insulator 271 on the insulator 270.

[0429] The metal oxide 252 preferably has the function of suppressing oxygen diffusion. Insulator 250 By providing a metal oxide 252 that suppresses oxygen diffusion between the conductive material and the conductive material 260, The diffusion of oxygen into body 260 is suppressed. In other words, the amount of oxygen supplied to metal oxide 230 is reduced. It can suppress the amount of oxidation. In addition, it can suppress the oxidation of the conductor 260 by oxygen. ru.

[0430] Furthermore, the metal oxide 252 may also function as part of the gate electrode. For example, An oxide semiconductor that can be used as metal oxide 230 is used as metal oxide 252 It is possible. In that case, by depositing the conductor 260 using the sputtering method, the metal The electrical resistance of oxide 252 can be reduced to make it a conductor. This is called OC(Oxi It can be called a (de Conductor) electrode.

[0431] Metal oxide 252 may function as part of the gate insulator. Therefore When silicon oxide or silicon oxide nitride is used for the insulator 250, metal oxide 252 It is preferable to use a metal oxide, which is a high-k material with a high dielectric constant. By creating a layered structure, it is possible to create a laminated structure that is stable against heat and has a high dielectric constant. Therefore, while maintaining the physical film thickness, the gate potential applied during transistor operation is reduced. This makes reduction possible. Also, the equivalent oxide film thickness (EOT) of the insulating layer that functions as a gate insulator. This makes it possible to create thin films.

[0432] In transistor 200D, metal oxide 252 is shown as a single layer, but stacking of two or more layers is possible. It may also be a structure. For example, a metal oxide that functions as part of the gate electrode and a gate insulator. A metal oxide that functions as part of the body may be layered and provided.

[0433] If the metal oxide 252 is present and it functions as a gate electrode, then the conductor 260 or The goal is to improve the on-current of transistor 200D without weakening the effects of the electric field. Yes, it is possible. Or, if it functions as a gate insulator, insulator 250 and metal oxide 252 The physical thickness maintains the distance between the conductor 260 and the metal oxide 230, The leakage current between the conductor 260 and the metal oxide 230 can be suppressed. Therefore, By providing a laminated structure of insulator 250 and metal oxide 252, the conductor 260 and metal The physical distance between the oxide 230 and the conductor 260, and the electrical charge from the conductor 260 to the metal oxide 230. The field strength can be easily adjusted.

[0434] Specifically, metal oxide 252 is an oxide that can be used in metal oxide 230. A semiconductor with reduced resistance can be used. Alternatively, hafnium, aluminum, gas can be used. Tium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, A metal oxide containing one or more elements selected from rumanium, magnesium, etc. You can use it.

[0435] In particular, an insulating layer containing an oxide of aluminum or hafnium, or both, is acid Aluminum oxide, hafnium oxide, aluminum and hafnium oxide (hafnium It is preferable to use hafnium aluminate, etc. In particular, hafnium aluminate is a type of hafnium oxide. It has higher heat resistance than a humic acid film. Therefore, it does not crystallize during subsequent heat treatment processes. It is preferable for the trapping. Note that metal oxide 252 is not an essential component. Desired transient The design should be adjusted according to the characteristics.

[0436] The insulator 270 has the function of suppressing the permeation of impurities such as water or hydrogen, and oxygen. It is preferable to use a material with properties such as aluminum oxide or hafnium oxide. This is preferable. As a result, the conductor 260 is oxidized by oxygen from above the insulator 270. This can be suppressed. Also, impurities such as water or hydrogen coming from above the insulator 270 can be prevented from conducting. The body 260 and the insulator 250 are used to suppress contamination of the metal oxide 230. can.

[0437] The insulator 271 functions as a hard mask. By providing the insulator 271, the conductor 2 During the processing of 60, the side surface of the conductor 260 is approximately perpendicular, specifically, the side surface of the conductor 260 and the base The angle formed by the plate surface is 75 degrees or more and 100 degrees or less, preferably 80 degrees or more and 95 degrees or less. It is possible.

[0438] Furthermore, the insulator 271 has a function to suppress the permeation of impurities such as water or hydrogen, and oxygen. By using an insulating material, it may also function as a barrier layer. In that case, The edge body 270 does not need to be provided.

[0439] Using insulator 271 as a hard mask, insulator 270, conductor 260, metal oxide By selectively removing 252, the insulator 250, and a portion of the metal oxide 230c, this These sides are made to roughly coincide, and a portion of the metal oxide 230b surface is exposed. ru.

[0440] Transistor 200D has a region 243a and a portion of the exposed metal oxide 230b surface. It has region 243b. Either region 243a or region 243b functions as the source region. The other of region 243a or region 243b functions as a drain region.

[0441] The formation of regions 243a and 243b can be achieved, for example, by ion implantation or ion doping. Using plasma immersion ion implantation or plasma treatment, exposed metal oxides This can be achieved by introducing impurity elements such as phosphorus or boron to the surface of material 230b. In the embodiments, "impurity elements" refers to elements other than the main component elements.

[0442] A metal film is deposited after a portion of the surface of metal oxide 230b is exposed, and then heat treatment is performed. By doing so, the elements contained in the metal film are diffused into the metal oxide 230b, and region 243a and It can also form region 243b.

[0443] In the region where impurity elements of metal oxide 230b are introduced, the electrical resistivity decreases. Therefore, regions 243a and 243b are sometimes referred to as the "impurity region" or the "low resistance region." ru.

[0444] By using the insulator 271 and / or the conductor 260 as a mask, region 243a and Region 243b can be formed in a self-aligned manner. Therefore, Regions 243a and / or 243b do not overlap with the conductor 260, thereby reducing parasitic capacitance. This is possible. Also, the channel formation region and the source-drain region (region 243a or region 24 No offset region is formed between 3b). Regions 243a and 243b are self-aligned. By forming in a (self-aligned) manner, the on-current increases and the threshold voltage decreases. This enables improvements such as increased operating frequency.

[0445] Transistor 200D consists of insulator 271, insulator 270, conductor 260, and metal oxide 2. 52, insulator 250, and insulator 272 on the side surface of metal oxide 230c. Insulator 2 72 is preferably an insulator with a low dielectric constant. For example, silicon oxide, silicon oxide, silicon nitride. Silicon, silicon nitride oxide, silicon nitride, fluorine-added silicon oxide, carbon-added Silicon oxide with added carbon and nitrogen, silicon oxide with added carbon and nitrogen, porous silicon oxide Preferably, it is silicon oxide, silicon oxide nitride, silicon nitride When silicon or porous silicon oxide is used as the insulator 272, in a later process the insulator 27 It is preferable because an excess oxygen region can be easily formed in 2. Also, silicon oxide and nitridation Silicon is preferred because it is thermally stable. In addition, the insulator 272 is an oxygen diffusing device. It is preferable that it has the ability.

[0446] Furthermore, in order to further reduce the off-current, between the channel formation region and the source-drain region An offset region may be provided. An offset region is a region with high electrical resistivity, and the front This is the region where the impurity elements described above are not introduced. The formation of the offset region occurs in insulator 2 This can be achieved by introducing the aforementioned impurity elements after the formation of 72. In this case, insulator 2 72 also functions as a mask, similar to insulator 271, etc. Therefore, the insulation of metal oxide 230b No impurity elements are introduced into the region overlapping with edge body 272, and the electrical resistivity of that region remains high. It is possible.

[0447] The transistor 200D has an insulator 272 and an insulator 254 on a metal oxide 230. The insulator 254 is preferably deposited using the sputtering method. By using this method, it is possible to form an insulating film with low levels of impurities such as water or hydrogen.

[0448] Furthermore, oxide films produced by sputtering may extract hydrogen from the structure to which the film is deposited. Therefore, the insulator 254 absorbs hydrogen and water from the metal oxide 230 and the insulator 272. By doing so, the hydrogen concentration of the metal oxide 230 and the insulator 272 can be reduced.

[0449] <Materials used in transistors> This section describes the constituent materials that can be used in transistors.

[0450] 〔substrate〕 Transistor 200A, Transistor 200B, Transistor 200C or Transistor For example, the substrate used to form the STA200D is an insulating substrate, a semiconductor substrate, or a conductive substrate. You can use this. As an insulating substrate, for example, a glass substrate, a quartz substrate, a sapphire substrate, Examples include stabilized zirconia substrates (such as yttria-stabilized zirconia substrates) and resin substrates. For example, semiconductor substrates such as silicon, germanium, or silicon carbide. N, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, gallium oxide There are compound semiconductor substrates made of the same material. Furthermore, there are semiconductor substrates with insulating regions inside the aforementioned semiconductor substrate. Semiconductor substrates, such as SOI (Silicon On Insulator) substrates, etc. There are conductive substrates such as graphite substrates, metal substrates, alloy substrates, and conductive resin substrates. Alternatively, there are substrates having metallic nitrides, substrates having metallic oxides, etc. Furthermore, insulation A substrate in which a conductor or semiconductor is provided on the substrate, and a semiconductor substrate in which a conductor or insulator is provided. There are substrates, conductive substrates, and substrates on which semiconductors or insulators are provided. A substrate with elements provided on it may also be used. Elements provided on the substrate include capacitive elements and resistors. Examples include elements, switch elements, light-emitting devices, and memory elements.

[0451] [Insulator] As insulators, insulating oxides, nitrides, oxidized nitrides, nitride oxides, and metal oxides are used. Examples include metal oxides and nitrides, and metal nitride oxides.

[0452] For example, as transistors become smaller and more integrated, the gate insulator becomes thinner. Problems such as leakage current may occur in the insulator that functions as a gate insulator. By using gh-k material, it is possible to lower the voltage during transistor operation while maintaining the physical film thickness. This is possible. On the other hand, for the insulator that functions as an interlayer film, a material with a low dielectric constant is used. This reduces parasitic capacitance between wires. Therefore, depending on the function of the insulator... Selecting materials is a good idea.

[0453] As insulators with high dielectric constant, gallium oxide, hafnium oxide, zirconium oxide, and Oxides containing luminium and hafnium, and nitrogen oxides containing aluminum and hafnium. Oxides having silicon and hafnium, silicon and hafnium oxides having nitrogen Examples include nitrides, or nitrides containing silicon and hafnium.

[0454] As insulators with low dielectric constant, silicon oxide, silicon oxide nitride, silicon nitride oxide, silicon nitride, silicon oxide with added fluorine, silicon oxide with added carbon, carbon and Examples include silicon oxide with added nitrogen, silicon oxide with voids, or resins.

[0455] Transistors using oxide semiconductors have the function of suppressing the permeation of impurities such as hydrogen and oxygen. Insulators having (insulator 214, insulator 222, insulator 254, and insulator 274, etc.) By enclosing it, the electrical characteristics of the transistor can be stabilized. (Impurities such as hydrogen) And as an insulator that has the function of suppressing oxygen permeation, for example, boron, carbon, nitrogen, acid Fluorine, magnesium, aluminum, silicon, phosphorus, chlorine, argon, gallium Germanium, yttrium, zirconium, lanthanum, neodymium, hafnium, or A tantalum-containing insulator can be used in a single layer or in a multilayer configuration. Specifically, impurities such as hydrogen can be used. As an insulator that has the function of suppressing the permeation of substances and oxygen, aluminum oxide, magnesium oxide Zium, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, oxide Metal oxides such as lanthanum, neodymium oxide, hafnium oxide, or tantalum oxide, aluminum nitride Aluminum, titanium aluminum nitride, titanium nitride, silicon oxide nitride, or silicon nitride, etc. Metal nitrides can be used.

[0456] An insulator that functions as a gate insulator has an area containing oxygen that is released by heating. It is preferable that it be a related body. For example, an oxide having a region containing oxygen that is removed by heating. By making silicon oxide or silicon nitride into a structure that is in contact with the metal oxide 230, This can compensate for the oxygen deficiency present in 230.

[0457] 〔conductor〕 As conductors, aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium Molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium Indium, zirconium, beryllium, indium, ruthenium, iridium, strontium A metallic element selected from lanthanum, etc., or an alloy containing the aforementioned metallic elements, or the above It is preferable to use an alloy or the like that, which is a combination of the metal elements. For example, tantalum nitride, nitriding Titanium oxides, tungsten, nitrides containing titanium and aluminum, tantalum and aluminum Nitrides containing ruthenium oxide, ruthenium nitride, strontium and ruthenium-containing acids It is preferable to use oxides containing lanthanum and nickel, or similar compounds. Tantalum nitride is also preferable. Titanium nitride, titanium and aluminum nitrides, tantalum and aluminum nitrides substances, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, ran Oxides containing tungsten and nickel are conductive materials that are resistant to oxidation, or that remain conductive even after absorbing oxygen. It is preferable because it is a material that maintains its properties. Furthermore, it is a polycrystalline material containing impurity elements such as phosphorus. Semiconductors with high electrical conductivity, such as silicon, and silicides such as nickel silicide. You may use it.

[0458] Multiple conductive materials formed from the above materials may be stacked and used. For example, the aforementioned metal base A laminated structure may be formed by combining a material containing an element with a conductive material containing oxygen. a laminated structure combining the aforementioned metal element-containing material and a nitrogen-containing conductive material. It is also possible to use a material containing the aforementioned metal element, a conductive material containing oxygen, and a material containing nitrogen. A laminated structure combining conductive material and may also be used.

[0459] Furthermore, when a metal oxide is used in the channel formation region of a transistor, the gate electric current The conductor that functions as an electrode includes a material containing the aforementioned metal element and a conductive material containing oxygen. It is preferable to use a laminated structure that combines these elements. In this case, an oxygen-containing conductive material is used. It is preferable to provide it on the channel formation region side. Provide an oxygen-containing conductive material on the channel formation region side. This makes it easier for oxygen released from the conductive material to be supplied to the channel-forming region. .

[0460] In particular, as a conductor that functions as a gate electrode, it is included in the metal oxide in which the channel is formed. It is preferable to use a conductive material containing metallic elements and oxygen. Conductive materials containing elements and nitrogen may be used. For example, titanium nitride, tantalum nitride, etc. A conductive material containing nitrogen may be used. In addition, indium tin oxide and tungsten oxide may be used. Contains indium oxide, indium zinc oxide containing tungsten oxide, and titanium oxide. Indium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, Indium tin oxide with added chlorine may also be used. Alternatively, indium gallium oxide containing nitrogen may be used. Zinc oxide may also be used. Using such a material allows for the formation of channels. It may be possible to capture hydrogen contained in metal oxides. Alternatively, the outer insulator, etc. In some cases, it is possible to capture the hydrogen that is mixed in.

[0461] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., are at least a part of them. This can be implemented by combining it with other configuration examples or drawings as appropriate.

[0462] This embodiment may be appropriately combined with other embodiments described herein, at least in part. They can be implemented in combination.

[0463] (Embodiment 3) In this embodiment, it can be used in the OS transistor described in the above embodiment. This section will explain metal oxides (hereinafter also referred to as oxide semiconductors).

[0464] <Classification of crystal structures> First, we will explain the classification of crystal structures in oxide semiconductors using Figure 27A. Figure 27A shows an oxide semiconductor, typically IGZO (containing In, Ga, and Zn). This is a diagram illustrating the classification of the crystal structures of oxides.

[0465] As shown in Figure 27A, oxide semiconductors can be broadly classified into "Amorphous" )」 and 「Crystalline」 and 「Crystal」 and, It is classified. Also, within "Amorphous," there are completely amor It includes phous. Also, within "Crystalline" there is CAAC(ca xis-aligned crystalline), nc(nanocrystall This includes ine, and CAC (cloud-aligned composite). Note that the classification of "Crystalline" includes single crystal, po Ly crystals and completely amorphous molecules are excluded. Furthermore, "Crystal" includes single crystal and poly crystal. It includes ystal.

[0466] The structures within the thick frame shown in Figure 27A are "Amorphous" and "Cr It is an intermediate state between "crystal" and a new boundary region (New crystal This structure belongs to the (linear phase). In other words, this structure is energetically It is completely different from the unstable "Amorphous" or "Crystal" forms. This can be rephrased as a structure.

[0467] The crystal structure of the film or substrate is determined by X-ray diffraction (XRD). It can be evaluated using the (on) spectrum. Here, "Crystalline" GIXD (Grazing-Incidence) of CAAC-IGZO film, which is classified as such. The XRD spectrum obtained by the XRD measurement is shown in Figure 27B. Note that the GIXD method is used for thin films. This method is also called the Seemann-Bohlin method. Hereafter, the GIXD measurement shown in Figure 27B will be used. The resulting XRD spectrum will simply be referred to as the XRD spectrum. Note that the CA shown in Figure 27B The composition of the AC-IGZO film is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. Furthermore, the thickness of the CAAC-IGZO film shown in Figure 27B is 500 nm.

[0468] As shown in Figure 27B, the XRD spectrum of the CAAC-IGZO film shows clear crystallinity. A peak indicating this is detected. In Figure 27B, the horizontal axis represents 2θ [deg.] and the vertical axis represents It indicates the intensity [au] of the CAAC-IGZO film. In the XRD spectrum, a peak indicating c-axis orientation is detected near 2θ=31°. As shown in Figure 27B, the peak near 2θ = 31° is the angle at which the peak intensity was detected. It is asymmetrical with respect to the axis.

[0469] The crystal structure of the film or substrate is determined by nano-beam electron diffraction (NBED). Diffraction patterns observed by (ctron diffraction) (microelectron beam diffraction) Diffraction pattern of CAAC-IGZO film (also called folding pattern) can be evaluated. The NBED is shown in Figure 27C. Figure 27C shows the NBED with an electron beam incident parallel to the substrate. This is the diffraction pattern that is observed. The composition of the CAAC-IGZO film shown in Figure 27C is also shown. The ratio is approximately In:Ga:Zn=4:2:3 [atomic ratio]. Furthermore, by microelectron diffraction... Electron diffraction is performed with a probe diameter of 1 nm.

[0470] As shown in Figure 27C, the diffraction pattern of the CAAC-IGZO film shows a complex c-axis orientation. A number of spots are observed.

[0471] [Structure of oxide semiconductors] Note that oxide semiconductors may be classified differently from those shown in Figure 27A when considering their crystal structure. For example, oxide semiconductors include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. It can be divided into conductors and non-single-crystal oxide semiconductors, for example, the aforementioned CAAC-OS. And there is nc-OS. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors and pseudo-non-crystalline oxide semiconductors. crystalline oxide semiconductor (a-like OS: amorphous-like oxide) This includes semiconductors, amorphous oxide semiconductors, etc.

[0472] Here, we will provide details on the CAAC-OS, nc-OS, and a-like OS mentioned above. Then, I will give an explanation.

[0473] [CAAC-OS] CAAC-OS has multiple crystalline regions, and these multiple crystalline regions have their c-axis oriented in a specific direction. It is an oriented oxide semiconductor. The specific direction refers to the thickness direction of the CAAC-OS film. , in the direction normal to the surface on which the CAAC-OS film is formed, or in the direction normal to the surface of the CAAC-OS film. Furthermore, a crystalline region is a region in which the atomic arrangement has periodicity. If considered as an arrangement, a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-O S has a region in the ab-plane direction where multiple crystalline regions are connected, and this region is strained. This can sometimes occur. Note that strain refers to the deformation of the lattice arrangement in a region where multiple crystal regions are connected. Areas where the orientation of the grid arrangement changes between aligned regions and aligned regions with a different grid arrangement. This refers to the fact that CAAC-OS is c-axis oriented and has a clear orientation in the ab-plane direction. It is an oxide semiconductor that does not exist.

[0474] Each of the above multiple crystalline regions is composed of one or more minute crystals (with a maximum diameter of 10n It is composed of crystals that are less than m in size. If the crystalline region is composed of one minute crystal, The maximum diameter of the crystalline region is less than 10 nm. Furthermore, the crystalline region is composed of numerous tiny crystals. If this is the case, the size of the crystalline region may be around several tens of nanometers.

[0475] In-M-Zn oxide (element M is aluminum, gallium, yttrium, tin, cysteine) In one or more types selected from tan, etc., CAAC-OS is indium (In A layer having ), and oxygen (hereinafter referred to as the In layer), and a layer having element M, zinc (Zn), and oxygen It has a layered crystalline structure (also called a layered structure) in which layers (hereinafter referred to as (M,Zn) layers) are stacked. There is a tendency for this to happen. Furthermore, indium and element M are mutually substitutable. Therefore, (M,Z The n) layer may contain indium. Also, the In layer may contain element M. Yes, it exists. Note that the In layer may also contain Zn. This layered structure is, for example, high resolution. In TEM images, it is observed as a grid pattern.

[0476] For example, when structural analysis of a CAAC-OS film is performed using an XRD device, the θ / 2θ scale is obtained. Out-of-plane XRD measurements using the CANR showed two peaks indicating c-axis orientation. It is detected at θ = 31° or nearby. Note that the position of the peak indicating c-axis orientation (value of 2θ) This may vary depending on the type and composition of the metal elements that make up CAAC-OS.

[0477] For example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots are Observed. Note that one spot and another spot are the spots of the incident electron beam that passed through the sample. It is observed at a point-symmetric position with respect to the spot (also called a direct spot) as the center of symmetry.

[0478] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is a hexagonal lattice. While this is the basic principle, the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, In the above distortion, there may be a grid arrangement such as a pentagon or heptagon. Note that CAAC- In OS, clear grain boundaries can be observed even near strain. It is not possible. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This can be seen. This is because CAAC-OS has a dense arrangement of oxygen atoms in the ab-plane direction. Due to the absence of certain elements, or because the bond distance between atoms changes due to the substitution of metal atoms, strain occurs. This is thought to be because it allows for tolerance.

[0479] Furthermore, a crystal structure in which clear grain boundaries can be observed is known as a polycrystalline structure. It is called al(al). The grain boundaries become recombination centers, trapping carriers and forming transistors. This is highly likely to cause a decrease in on-current, a decrease in field-effect mobility, etc. Therefore, a clear conclusion is reached. CAAC-OS, which lacks visible grain boundaries, has a crystal structure suitable for the semiconductor layer of transistors. It is one of the crystalline oxides. Note that CAAC-OS requires the presence of Zn. The configuration is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are In oxide It is preferable because it can suppress the generation of grain boundaries more effectively than other materials.

[0480] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less prone to a decrease in electron mobility caused by grain boundaries. Furthermore, the crystallinity of oxide semiconductors can decrease due to the inclusion of impurities or the formation of defects. Therefore, CAAC-OS is also an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors expands the degree of freedom in the manufacturing process. This becomes possible.

[0481] [nc-OS] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially regions larger than 1 nm). It has periodicity in the atomic arrangement in the region of 3 nm or less. In other words, nc-OS is micro It has small crystals. The size of these minute crystals is, for example, between 1 nm and 10 nm. In particular, because they are between 1 nm and 3 nm in size, these minute crystals are also called nanocrystals. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, the entire film... No orientation is observed. Therefore, nc-OS is a-like depending on the analytical method. It can sometimes be indistinguishable from OS or amorphous oxide semiconductors. For example, compared to nc-OS films When performing structural analysis using an XRD device, out-of-pl using θ / 2θ scans is obtained. In ane XRD measurements, no peak indicating crystallinity was detected. Furthermore, for nc-OS films... Furthermore, electron beam blasts using electron beams with probe diameters larger than those of nanocrystals (e.g., 50 nm or more) When diffraction (also called limited-field electron diffraction) is performed, a diffraction pattern similar to a halo pattern is obtained. Observed. On the other hand, compared to the nc-OS film, the size is close to or smaller than that of nanocrystals. Electron diffraction (nanobeam) using electron beams with probe diameters (e.g., 1 nm to 30 nm). Also called electron diffraction, when this is performed, a ring-shaped region centered on the direct spot appears. In some cases, electron diffraction patterns with multiple spots observed may be obtained.

[0482] [a-like OS] a-like OS is an oxide having a structure between nc-OS and amorphous oxide semiconductors. It is a semiconductor. an a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, it has a-like properties. OS has a higher hydrogen concentration in the membrane compared to nc-OS and CAAC-OS.

[0483] [Oxide semiconductor composition] Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS is a material composition. Regarding achievement.

[0484] [CAC-OS] CAC-OS refers to, for example, metal oxides in which the elements constituting the metal oxide are between 0.5 nm and 10 nm. Below, preferably, a composition of material with a size of 1 nm to 3 nm, or close to that size. In addition, in the following, in metal oxides, one or more metal elements are unevenly distributed, and the metal The region containing the group element is 0.5 nm to 10 nm, preferably 1 nm to 3 nm. A mixture of sizes below or near that size is also called a mosaic or patchy appearance.

[0485] Furthermore, CAC-OS is a material that separates into a first region and a second region. This results in a zigzag-like structure, where the first region is distributed within the film (hereinafter also referred to as a cloud-like structure). ) In other words, CAC-OS is a mixture of the first region and the second region. It is a composite metal oxide having the following composition.

[0486] Here, I for the metal elements constituting CAC-OS in In-Ga-Zn oxide The atomic ratios of n, Ga, and Zn are denoted as [In], [Ga], and [Zn], respectively. For example, in CAC-OS in In-Ga-Zn oxide, the first region is This is the region where [In] is greater than the [In] in the composition of the CAC-OS film. Region 2 is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Alternatively, for example, in the first region, [In] is greater than [In] in the second region. Furthermore, the region where [Ga] is smaller than the region where [Ga] is smaller. In region 2, [Ga] is greater than [Ga] in region 1, and [In] is This is a region smaller than [In] in the first region.

[0487] Specifically, the first region mentioned above is mainly composed of indium oxide, indium zinc oxide, etc. This is the region. Furthermore, the second region mentioned above contains gallium oxide, gallium zinc oxide, etc. This is the region of the principal component. In other words, the first region described above can be rephrased as the region with In as its principal component. It is possible to obtain this. Also, the second region mentioned above can be rephrased as the region with Ga as the main component. It is possible.

[0488] Note that a clear boundary may not be observed between the first region and the second region described above. .

[0489] For example, in CAC-OS in In-Ga-Zn oxide, the energy-dispersive X-ray segment Optical method (EDX:Energy Dispersive X-ray spectrosc) EDX mapping obtained using opy revealed the region with In as its main component (the first region) It has a structure in which a region (the second region) and a region mainly composed of Ga are unevenly distributed and mixed. This can be confirmed.

[0490] When CAC-OS is used in a transistor, the conductivity is due to the first region and the second region The insulating properties due to the region work complementarily to enable the switching function (On The function to turn off CAC-OS can be added to it. In other words, CAC-OS and The material has both conductive and insulating properties in parts, and the entire material Then it has the function of a semiconductor. By separating the conductive function and the insulating function, This allows for the maximum enhancement of both functions. Therefore, CAC-OS is used in transistors. This results in a high on-current (I on ), high field-effect mobility (μ), and good switching This enables the implementation of a specific action.

[0491] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and C It may have two or more of the following: AC-OS, nc-OS, and CAAC-OS.

[0492] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0493] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility is obtained. This can be achieved. Furthermore, highly reliable transistors can be realized.

[0494] It is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. The carrier concentration of oxide semiconductors is 1 × 10⁻⁶ 17 cm -3 The following is preferably 1 × 10 15 c m -3 More preferably 1 × 10 13 cm -3 More preferably 1 × 10 11 cm -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm - 3 That concludes the explanation. Furthermore, when lowering the carrier concentration of the oxide semiconductor film, the oxide... The impurity concentration in the semiconductor film can be reduced to lower the defect level density. High-purity intrinsic or substantially high-purity intrinsic refers to a product with a low impurity concentration and a low defect level density. Furthermore, an oxide semiconductor with a low carrier concentration is subjected to high-purity intrinsic or substantially high-purity intrinsic acid. They are sometimes called monstrous semiconductors.

[0495] High-purity intrinsic or substantially high-purity intrinsic oxide semiconductor films have a low defect level density. In some cases, the trap level density may also be low.

[0496] Charges trapped in the trap levels of oxide semiconductors take a long time to disappear. It can sometimes behave as if it were a fixed charge. Therefore, oxidation with a high trap level density In transistors where a channel formation region is formed in a semiconductor material, the electrical characteristics become unstable. There is.

[0497] Therefore, in order to stabilize the electrical characteristics of a transistor, the impurity concentration in the oxide semiconductor is Reducing it is effective. Furthermore, in order to reduce the impurity concentration in oxide semiconductors, It is also preferable to reduce the concentration of impurities in the adjacent membrane. These impurities include hydrogen, nitrogen, and alkali. Examples include metals, alkaline earth metals, iron, nickel, silicon, etc.

[0498] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0499] In oxide semiconductors, if silicon or carbon, which are among the Group 14 elements, are present, oxidation occurs. Defect levels are formed in silicon semiconductors. Therefore, in oxide semiconductors, silicon and carbon The concentration of the element and the concentrations of silicon and carbon near the interface with the oxide semiconductor (obtained by SIMS). (The concentration) is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 1017 atoms / cm 3 The following applies:

[0500] When alkali metals or alkaline earth metals are present in oxide semiconductors, they form defect levels. Carriers may be generated. Therefore, alkali metals or alkaline earth metals are present. Transistors using oxide semiconductors tend to exhibit normally-on characteristics. Therefore, The concentration of alkali metals or alkaline earth metals in oxide semiconductors obtained by SIMS is determined as follows: 1 x 10 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 below I'll do that.

[0501] In oxide semiconductors, when nitrogen is present, electrons, which act as carriers, are generated, and the carrier concentration... The nitrogen content increases, making it easier to create an n-type semiconductor. As a result, oxide semiconductors containing nitrogen are used as semiconductors. Transistors tend to exhibit normally-on characteristics. Alternatively, in oxide semiconductors, nitrogen If present, trap levels may be formed. As a result, the electrical characteristics of the transistor may be affected. The properties may become unstable. Therefore, nitrogen in oxide semiconductors obtained by SIMS The concentration is 5 × 10 19 atoms / cm 3 Less than 5 × 10 18 ate / c m 3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5× 10 17 atoms / cm 3 Do the following:

[0502] Hydrogen contained in oxide semiconductors reacts with oxygen bonded to metal atoms to form water, so acid In some cases, an elementary defect may form. When hydrogen enters this oxygen defect, an electron, which acts as a carrier, is produced. This can occur. Also, some of the hydrogen combines with oxygen that is bonded to a metal atom, forming a carrier. It can generate electrons. Therefore, using an oxide semiconductor containing hydrogen... Lampistors tend to exhibit normally-on characteristics. Therefore, hydrogen in oxide semiconductors is formed. It is preferable that it be reduced as much as possible. Specifically, in oxide semiconductors, SIMS The hydrogen concentration obtained is 1 × 10 20 atoms / cm 3 Less than 1 × 10 1 9 atoms / cm 3 Less than 5x10 18 atoms / cm 3 less than, further Preferably 1 × 10 18 atoms / cm 3 Make it less than.

[0503] Using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor. This allows for the provision of stable electrical characteristics.

[0504] This embodiment may be appropriately combined with other embodiments described herein, at least in part. They can be implemented in combination.

[0505] (Embodiment 4) This embodiment describes an electronic device equipped with a display device, which is one aspect of the present invention. .

[0506] Figure 28A shows the external appearance of the camera 8000 with the viewfinder 8100 attached. The camera 8000 is equipped with an imaging device. The camera 8000 is, for example, a It can be used as a digital camera. Note that in Figure 28A, the camera 8000 and the viewfinder The 8100 is treated as a separate electronic device, and these are configured to be detachable, but the camera 8000 The housing 8001 may also have a viewfinder equipped with a display device built into it.

[0507] The camera 8000 consists of a housing 8001, a display unit 8002, operation buttons 8003, and a shutter. It has buttons 8004, etc. The camera 8000 also has a detachable lens 8006. It is attached.

[0508] Here, we'll use camera 8000 and replace lens 8006 by removing it from housing 8001. The configuration allows for this, but the lens 8006 and the housing may be integrated.

[0509] Camera 8000 can take an image by pressing the shutter button 8004. Furthermore, the display unit 8002 also functions as a touch panel, and touching the display unit 8002... This also makes it possible to take images.

[0510] The camera 8000's housing 8001 has a mount with electrodes, and the viewfinder 810 In addition to the above, a strobe device and other equipment can be connected.

[0511] The viewfinder 8100 has a housing 8101, a display unit 8102, buttons 8103, etc. The 8100 viewfinder can be used as an electronic viewfinder.

[0512] The housing 8101 has a mount that engages with the mount of the camera 8000, and The mount 8100 can be attached to the camera 8000. The mount also has electrodes. The electrode has the ability to display images and other data received from the camera 8000 on the display unit 8102. It can be done.

[0513] Button 8103 functions as a power button. Button 8103 controls the display. You can switch the display of 8102 on or off.

[0514] The display unit 8002 of the camera 8000 and the display unit 8102 of the viewfinder 8100 are equipped with this A display device according to one aspect of the invention can be applied. The display device according to one aspect of the present invention is extremely Because of its high resolution, even if the distance between the display unit 8002 or the display unit 8102 and the user is short The display unit 8002 or display unit displays an image with a higher sense of realism without the user being able to see the pixels. It can be displayed in section 8102. In particular, the display section 8 provided in the viewfinder 8100 The image displayed in 102 is obtained by bringing the user's eye close to the eyepiece of the Finder 8100. Because it is visible, the distance between the user and the display unit 8102 becomes very close. Therefore, it is particularly preferable to apply a display device according to one embodiment of the present invention to the display unit 8102. When a display device according to one aspect of the present invention is applied to the display unit 8102, the display unit 8102 displays The image resolution can be 4K, 5K, or higher.

[0515] Furthermore, the resolution of the image that can be captured by the imaging device provided in camera 8000 is displayed on the display unit. The resolution must be equivalent to or greater than the resolution of the image that can be displayed on the 8002 or the display unit 8102. This is preferable. For example, if the display unit 8102 can display an image with a resolution of 4K, the camera It is preferable to provide an imaging device capable of capturing images of 4K or higher resolution in the 8000. Also, for example, If the display unit 8102 can display an image with a resolution of 5K, then the camera 8000 will be able to display a 5K image. It is preferable to provide an imaging device capable of capturing the above images.

[0516] Figure 28B shows the external appearance of the head-mounted display 8200.

[0517] The head-mounted display 8200 consists of a mounting part 8201, lenses 8202, and a main body 82 03, it has a display unit 8204, a cable 8205, etc. Also, the mounting part 8201 has It has a built-in 8206 battery.

[0518] Cable 8205 supplies power from battery 8206 to main unit 8203. Main unit 82 03 is equipped with a wireless receiver, etc., and displays the image corresponding to the received image data etc. on the display unit 8204. It can also display the user's eyeballs and eyelids using a camera located on the main unit 8203. By capturing the user's movements and calculating the user's line of sight coordinates based on that information, the user's vision Lines can be used as input means.

[0519] The attachment portion 8201 may have multiple electrodes positioned in a location that comes into contact with the user. The 8203 detects the current flowing through the electrodes in response to the user's eye movements, thereby enabling the user It may also have a function to recognize the gaze. Furthermore, it may detect the current flowing through the electrode. The device may also have a function to monitor the user's pulse. It may also have various sensors such as temperature sensors, pressure sensors, and acceleration sensors, and the user The system may also have a function to display biometric information on the display unit 8204. The system may detect movements such as 'ki' and change the image displayed on the display unit 8204 to match those movements.

[0520] A display device according to one aspect of the present invention can be applied to the display unit 8204. This allows, The head-mounted display 8200 has a narrow bezel, and the display unit 8204 displays high-quality images. It can display highly immersive images.

[0521] Figures 28C, 28D, and 28E show the appearance of the head-mounted display 8300. This is a diagram. The head-mounted display 8300 consists of a housing 8301 and a display unit 8302 It also includes a band-shaped fastener 8304 and a pair of lenses 8305.

[0522] The user can view the display on the display unit 8302 through the lens 8305. Furthermore, it is preferable to arrange the display unit 8302 in a curved shape. By placing it there, the user can experience a high level of realism. The example given is one configuration with a single display unit 8302, but it is not limited to this, for example, The system may also be configured to have two display units 8302. In this case, one display is shown to one eye of the user. If the display unit is arranged in such a configuration, it becomes possible to perform 3D displays using parallax, etc. ru.

[0523] Furthermore, a display device according to one embodiment of the present invention can be applied to the display unit 8302. One embodiment of the display device has extremely high resolution, and therefore uses lens 8305 as shown in Figure 28E. Even when enlarged, the user cannot perceive individual pixels, resulting in a more immersive image. It can be shown.

[0524] Next, Figures 28A to 28E show electronic devices, and Figures 29A to 28E show examples of different electronic devices. This is shown in Figure 29G.

[0525] The electronic device shown in Figures 29A to 29G consists of a housing 9000, a display unit 9001, and a speaker 9 003, Operation key 9005 (including power switch or operation switch), Connection terminal 900 6. Sensor 9007 (force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, Magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power, radiation, flow rate, humidity (Including functions for measuring degrees, incline, vibration, odor, or infrared radiation), Microphone 90 It has 08, etc.

[0526] The electronic devices shown in Figures 29A to 29G have various functions. For example, various information ( Functions to display still images, videos, text images, etc. on the display unit, touch panel function, calendar - A function to display the date or time, etc., processed by various software (programs). Functions to control, wireless communication functions, and various computer networks using wireless communication functions Functions for connecting, functions for transmitting or receiving various data using wireless communication, recording media It has functions such as reading programs or data recorded in the body and displaying them on a display unit. It is possible to have the functions of the electronic devices shown in Figures 29A to 29G. These are not limited to these, and can have a variety of functions. Also, see Figures 29A to 29G. Although not shown in the diagram, the electronic device may have a configuration with multiple display units. The electronic device is equipped with a camera, etc., and has functions for taking still images, taking videos, and capturing images. Functions to save images to a recording medium (external or built into the camera), and to display captured images on the display unit. It may have functions such as [specific functions].

[0527] Details of the electronic equipment shown in Figures 29A to 29G will be explained below.

[0528] Figure 29A is a perspective view showing the television equipment 9100. 0 incorporates a large screen, for example, a display unit 9001 of 50 inches or more, or 100 inches or more. It is possible to include it.

[0529] A display device according to one aspect of the present invention is applied to the display unit 9001 of the television device 9100. This allows for a narrower bezel for the television device 9100 and the display unit 90 01 can display high-quality images, allowing for the display of highly immersive images.

[0530] Figure 29B is a perspective view showing a personal digital assistant (PDA) 9101. For example, For example, it has one or more functions selected from a telephone, notebook, or information viewing device. In terms of functionality, it can be used as a smartphone. Note that the mobile information terminal 9101 is a smartphone. A speaker 9003, connection terminal 9006, sensor 9007, etc. may be provided. Terminal 9101 can display text and images on multiple sides. For example, three operations The operation button 9050 (also called the operation icon or simply the icon) is on one side of the display unit 9001. It can be displayed on the other of the display unit 9001. In addition, the information 9051 shown by the dashed rectangle can be displayed on the other of the display unit 9001. It can be displayed on the surface. For example, information 9051 can be sent via email or social networking services (SNS). A display that notifies you of incoming calls (such as those from social networking services) and telephones, as well as emails and Subject of SNS etc., sender name of email or SNS etc., date and time, time, battery level, There is a signal strength, etc. Alternatively, at the location where information 9051 is displayed, information 9051 Alternatively, you could display operation buttons such as 9050.

[0531] A display device according to one aspect of the present invention is applied to the display unit 9001 of the portable information terminal 9101. This makes it possible to miniaturize the portable information terminal 9101 and to provide high quality to the display unit 9001. It can display images of various positions, and can display highly immersive images.

[0532] Figure 29C is a perspective view showing the personal digital assistant 9102. The personal digital assistant 9102 is a table The display unit 9001 has the function of displaying information on three or more sides. Here, information 9052, information This shows an example where 9053 and information 9054 are displayed on different sides. For example, mobile information The user of the information terminal 9102 has the information terminal 9102 stored in the breast pocket of their clothing. And you can check the display (information 9053 in this case). Specifically, the incoming call The phone number or name of the caller is positioned so that it can be observed from above the mobile information terminal 9102. The user can view the information without taking the portable information terminal 9102 out of their pocket. It can acknowledge the call and decide whether or not to answer it.

[0533] A display device according to one aspect of the present invention is applied to the display unit 9001 of the portable information terminal 9102. This makes it possible to miniaturize the portable information terminal 9101 and to provide high quality to the display unit 9001. It can display images of various positions, and can display highly immersive images.

[0534] Figure 29D is a perspective view showing a wristwatch-type personal information terminal 9200. Personal information terminal 92 00 is mobile phone, email, document viewing and creation, music playback, internet communication, It can run various applications such as computer games. Also, the display unit 9 001 has a curved display surface, and can display along the curved display surface. Furthermore, the portable information terminal 9200 is capable of performing standardized short-range wireless communication. It is possible. For example, by communicating with a wireless headset, hands-free —It can also be used for making calls. Furthermore, the mobile information terminal 9200 has a connection terminal 9006, It is possible to directly exchange data with other information terminals via a connector. Charging can also be performed via terminal 9006. Note that the charging operation is performed via connection terminal 9006. It may also be done by wireless power transfer.

[0535] A display device according to one aspect of the present invention is applied to the display unit 9001 of the portable information terminal 9200. This makes it possible to narrow the bezel of the mobile information terminal 9200 and to display high quality on the display unit 9001. It can display high-quality images and images that convey a strong sense of realism.

[0536] Figures 29E, 29F, and 29G are perspective views showing a foldable portable information terminal 9201. Figure 29E is a perspective view of the mobile information terminal 9201 in an unfolded state, and Figure 2 9F changes from either the unfolded or folded state of the mobile information terminal 9201 to the other state. This is a perspective view of the device in the process of being folded, and Figure 29G is a perspective view of the mobile information terminal 9201 in the folded state. This is a diagram. The portable information terminal 9201 is highly portable when folded, and when unfolded... It offers excellent readability due to its seamless, wide display area. The mobile information terminal 9201 has The display unit 9001 is supported by three housings 9000 connected by hinges 9055. It is made portable by bending the two housings 9000 via the hinge 9055. The information terminal 9201 can be reversibly transformed from an unfolded state to a folded state. For example, the mobile information terminal 9201 can be bent with a radius of curvature of 1 mm or more and 150 mm or less. It is possible.

[0537] A display device according to one aspect of the present invention is applied to the display unit 9001 of the portable information terminal 9201. This makes it possible to narrow the bezel of the mobile information terminal 9201 and to display high quality on the display unit 9001. It can display high-quality images and images that convey a strong sense of realism.

[0538] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., are at least a part of them. This can be implemented by combining it with other configuration examples or drawings as appropriate.

[0539] This embodiment may be appropriately combined with other embodiments described herein, at least in part. They can be implemented in combination. [Examples]

[0540] In this embodiment, circuit simulation is used to describe a display device that is one aspect of the present invention. The operation of the pixel that can do this was confirmed. The simulation involved the structure of pixel 10 shown in Figure 1B. The timing chart shown in Figure 2 was used.

[0541] In the simulation, transistor 101, transistor 102, transistor Transistors 103 and 104 each have a channel length of 200 nm and a channel width of 60 An nm OS transistor was used. The capacitance value of the capacitive element 111 was set to 17.0 fF. The capacitance value of 2 was set to 3.4 fF. The potential applied to wiring 121 and wiring 122 was H High was set to 5V and Low to 0V. Wiring 131 has "Vdata" set to 4.0V, Wiring 16 Wire 1 is “Vref” set to 0.5V, wire 128 is “Vano” set to 11.0V, wire 129 is “ The simulation was performed with Vcath set to -5.0V. SPICE was used for the software.

[0542] The simulation results are shown in Figure 30. Figure 30 shows the timing chart on the horizontal axis. The graph shows the time (Time), with the potential V of node ND11 on the vertical axis. ND11 , and node ND1 Potential V ND12 This indicates that.

[0543] As shown in Figure 30, the potential V ND11 and potential V ND12 The difference is 3.2 in period P21a. The voltage was 3V, 0.92V during period P21b, and 0.00V during period P22a. Therefore, the potential V ND11 and potential V ND12 The difference is smaller than the 4.0V of "Vdata". We were able to confirm that this was the case. Also, during period P22, the potential V ND11 and potential V ND12 of We were able to confirm that the difference was 0V. [Examples]

[0544] In this embodiment, the display device shown in the embodiment was manufactured.

[0545] The manufactured display panel has a diagonal size of 0.66 inches and a resolution of 1440 x 1 440 pixels, resolution (pixel density) of 3078 ppi, pixel size of 2.75 μm × 8.25 μm (2.75μm × RGB × 8.25μm), aperture ratio 33.7%, frame rate It is 90Hz. Furthermore, the gate driver and source driver are built-in, and the gate driver The source driver uses CMOS with OS transistors, while the source driver uses CMOS with Si transistors.

[0546] A photograph of the fabricated display device is shown in Figure 31A. A magnified photograph of the pixel area is shown in Figure 31B. As shown in Figures 31A and 31B, it can be confirmed that the entire pixel area can be displayed well. Ta.

[0547] The brightness was evaluated using the aforementioned display device with different duty cycles. The relationship is shown in Figure 32A. In Figure 32A, the horizontal axis represents duty cycle. The vertical axis represents brightness L. Note that Figure 32A shows the brightness when the entire pixel area is displayed in white. Yes, they are.

[0548] At a duty cycle of 100%, the brightness is 5040 cd / m². 2 At a duty cycle of 50%, the brightness is 2520 cd / m² 2 At a duty cycle of 20%, the brightness is 1008 cd / m². 2 , duty At 0%, the brightness is 0 cd / m². 2 Thus, we can confirm that duty cycle and brightness are proportional. In addition, Figure 32A shows plots for a 100% duty cycle and plots for a 0% duty cycle. The straight line connecting these points is shown as a dashed line.

[0549] Figure 32B shows the time variation of the displayed brightness. In Figure 32B, the horizontal axis is time (Tim Figure e) shows the luminance L on the vertical axis. Note that Figure 32B shows a white line with a width of 1 pixel. This shows the brightness measured with a spectroluminometer when the display is set to 20% brightness.

[0550] During the illumination period (P21) within a single frame period (FP), the brightness increases, and from black display... I was able to confirm that it switched to a white display. [Explanation of Symbols]

[0551] ND11: node, ND12: node, 10a: pixel, 10B: sub-pixel, 10b: pixel 10c: pixel, 10d: pixel, 10e: pixel, 10f: pixel, 10G: sub-pixel, 10R: Subpixel, 10: Pixel, 20: First layer, 30: Second layer, 51a: Display area, 51b: Surface Display area, 51c: display area, 53a: pixel electrode, 53b: pixel electrode, 53c: pixel electrode, 53: Pixel electrode, 100: Display device, 101: Transistor, 102: Transistor, 1 03: Transistor, 104: Transistor, 111: Capacitive element, 112: Capacitive element, 1 14: Light-emitting device, 121: Wiring, 122: Wiring, 123: Wiring, 128: Wiring, 12 9: Wiring, 130: Drive circuit section, 131: Wiring, 140a: Drive circuit section, 140b: Drive Circuit section, 150: Pixel section, 161: Wiring, 162: Wiring, 200A: Transistor, 20 0B: Transistor, 200C: Transistor, 200D: Transistor, 205a: Conductor Electrical material, 205b: Conductor, 205c: Conductor, 205: Conductor, 212: Insulator, 214 : insulator, 216: insulator, 222: insulator, 224: insulator, 230a: metal oxide, 230b: Metal oxide, 230c: Metal oxide, 230: Metal oxide, 240a: Conductor , 240b: conductor, 240: conductor, 241a: insulator, 241b: insulator, 241: Insulator, 242a: Conductor, 242b: Conductor, 242: Conductor, 243a: Region, 24 3b: region, 244: insulator, 250: insulator, 252: metal oxide, 254: insulator, 260a: Conductor, 260b: Conductor, 260: Conductor, 270: Insulator, 271: Insulator Body, 272: Insulator, 274: Insulator, 280: Insulator, 281: Insulator, 283: Insulator Body, 301a: Conductor, 301b: Conductor, 305: Conductor, 311: Conductor, 313: Conductor, 317: Conductor, 321: Lower electrode, 323: Insulator, 325: Upper electrode, 33 1: Conductor, 333: Conductor, 335: Conductor, 337: Conductor, 341: Conductor, 34 3: Conductor, 347: Conductor, 351: Conductor, 353: Conductor, 355: Conductor, 35 7: Conductor, 361: Insulator, 363: Insulator, 403: Element isolation layer, 405: Insulator, 407: Insulator, 409: Insulator, 411: Insulator, 413: Insulator, 415: Insulator, 417: Insulator, 419: Insulator, 421: Insulator, 441: Transistor, 443: Conductor Electromagnetic material, 445: Insulator, 447: Semiconductor region, 449a: Low resistance region, 449b: Low resistance Region, 451: Conductor, 453: Conductor, 455: Conductor, 457: Conductor, 459: Conductor Electric body, 461: Conductor, 463: Conductor, 465: Conductor, 467: Conductor, 469: Conductor Electrical body, 471: Conductor, 501: Insulator, 503: Insulator, 505: Insulator, 507: Insulator Edge body, 509: insulator, 572: light-emitting device, 601: transistor, 602: transistor 603: Transistor, 613: Insulator, 614: Insulator, 616: Insulator, 6 22: insulator, 624: insulator, 644: insulator, 654: insulator, 674: insulator, 6 80: Insulator, 681: Insulator, 701: Substrate, 705: Substrate, 712: Sealing material, 71 6: FPC, 721: Hole injection layer, 722: Hole transport layer, 723: Emitting layer, 724: Electron Transport layer, 725: Electron injection layer, 730: Insulator, 732: Sealing layer, 734: Insulator, 73 6: Colored layer, 738: Light-shielding layer, 750: Transistor, 760: Connecting electrode, 772: Conductive Body, 778: Structure, 780: Anisotropic conductor, 782: Light-emitting device, 786a: EL layer , 786b: EL layer, 786c: EL layer, 786: EL layer, 788: Conductor, 790: Capacitor Quantitative element, 792: Charge generation layer, 800: Transistor, 801a: Conductor, 801b: Conductor Electrical material, 805: Conductor, 811: Conductor, 813: Conductor, 814: Insulator, 816: Insulator Edge material, 817: Conductor, 821: Insulator, 822: Insulator, 824: Insulator, 844: Insulator Edge material, 853: Conductor, 854: Insulator, 855: Conductor, 874: Insulator, 880: Insulator Edge body, 881: insulator, 8000: camera, 8001: housing, 8002: display unit, 800 3: Operation button, 8004: Shutter button, 8006: Lens, 8100: Fine Dar, 8101: enclosure, 8102: display unit, 8103: buttons, 8200: head mount Display, 8201: Mounting part, 8202: Lens, 8203: Main body, 8204: Front Display unit, 8205: Cable, 8206: Battery, 8300: Head-mounted display I, 8301: Housing, 8302: Display unit, 8304: Fixing device, 8305: Lens, 900 0: Enclosure, 9001: Display unit, 9003: Speaker, 9005: Operation keys, 9006: Connection Connection terminals, 9007: Sensor, 9008: Microphone, 9050: Operation button, 905 1: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 91 00: Television equipment, 9101: Personal digital assistant, 9102: Personal digital assistant, 9200 : Mobile information terminal, 9201: Mobile information terminal

Claims

1. A pixel having a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, a second capacitor, and a light-emitting device, The channel formation region of the first transistor, the channel formation region of the third transistor, and the channel formation region of the fourth transistor each have a metal oxide. The first transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The second transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The third transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The fourth transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The first gate and the second gate of the first transistor are electrically connected. The first gate of the first transistor is electrically connected to the first wiring, Either the source or the drain of the first transistor is electrically connected to the sixth wiring. The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The second gate of the second transistor is electrically connected to either the source or the drain of the second transistor. The first gate of the second transistor is electrically connected to either the source or the drain of the third transistor. Either the source or the drain of the second transistor is electrically connected to the pixel electrode of the light-emitting device. The source or drain of the second transistor, the other of which is electrically connected to the fifth wiring, The first gate and the second gate of the third transistor are electrically connected. The first gate of the third transistor is electrically connected to the second wiring. The source or drain of the third transistor, the other of which is electrically connected to the fourth wiring, The first gate and the second gate of the fourth transistor are electrically connected. The first gate of the fourth transistor is electrically connected to the third wiring. Either the source or the drain of the fourth transistor is electrically connected to the sixth wiring. The source or drain of the fourth transistor is electrically connected to the source or drain of the third transistor. One electrode of the first capacitor is electrically connected to either the source or the drain of the second transistor. The other electrode of the first capacitor is electrically connected to the first gate of the second transistor. One electrode of the second capacitor is electrically connected to the first gate of the second transistor. The other electrode of the second capacitance is electrically connected to the other source or drain of the second transistor. The first wiring has the function of transmitting a potential that selects the conduction state or non-conduction state of the first transistor. The second wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the third transistor. The third wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the fourth transistor. The fourth wiring has the function of transmitting an electric potential corresponding to the image data, The fifth wiring has the function of transmitting the first potential, The first potential is the potential at which the second transistor operates in the saturation region when the brightness of the light-emitting device is at its maximum. The sixth wiring is a display device having the function of transmitting a second potential, In a plan view of the pixel, the first wiring, the second wiring, the third wiring, and the fifth wiring are arranged to extend along the first direction. In a plan view of the pixel, the fourth wiring and the sixth wiring are arranged to extend along a second direction intersecting the first direction. In a plan view of the pixel, the wiring width of the fifth wiring is greater than the wiring width of the first wiring, greater than the wiring width of the second wiring, and greater than the wiring width of the third wiring. A display device wherein, in a plan view of the pixel, the fourth wiring does not overlap with the conductive layer that functions as the pixel electrode.

2. A pixel having a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, a second capacitor, and a light-emitting device, The channel formation region of the first transistor, the channel formation region of the third transistor, and the channel formation region of the fourth transistor each have a metal oxide. The first transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The second transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The third transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The fourth transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The first gate and the second gate of the first transistor are electrically connected. The first gate of the first transistor is electrically connected to the first wiring, Either the source or the drain of the first transistor is electrically connected to the sixth wiring. The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The second gate of the second transistor is electrically connected to either the source or the drain of the second transistor. The first gate of the second transistor is electrically connected to either the source or the drain of the third transistor. Either the source or the drain of the second transistor is electrically connected to the pixel electrode of the light-emitting device. The source or drain of the second transistor, the other of which is electrically connected to the fifth wiring, The first gate and the second gate of the third transistor are electrically connected. The first gate of the third transistor is electrically connected to the second wiring. The source or drain of the third transistor, the other of which is electrically connected to the fourth wiring, The first gate and the second gate of the fourth transistor are electrically connected. The first gate of the fourth transistor is electrically connected to the third wiring. Either the source or the drain of the fourth transistor is electrically connected to the sixth wiring. The source or drain of the fourth transistor is electrically connected to the source or drain of the third transistor. One electrode of the first capacitor is electrically connected to either the source or the drain of the second transistor. The other electrode of the first capacitor is electrically connected to the first gate of the second transistor. One electrode of the second capacitor is electrically connected to the first gate of the second transistor. The other electrode of the second capacitance is electrically connected to the other source or drain of the second transistor. The first wiring has the function of transmitting a potential that selects the conduction state or non-conduction state of the first transistor. The second wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the third transistor. The third wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the fourth transistor. The fourth wiring has the function of transmitting an electric potential corresponding to the image data, The fifth wiring has the function of transmitting the first potential, The first potential is the potential at which the second transistor operates in the saturation region when the brightness of the light-emitting device is at its maximum. The sixth wiring has the function of transmitting a second potential, The display device wherein the second potential is 0V or GND potential, In a plan view of the pixel, the first wiring, the second wiring, the third wiring, and the fifth wiring are arranged to extend along the first direction. In a plan view of the pixel, the fourth wiring and the sixth wiring are arranged to extend along a second direction intersecting the first direction. In a plan view of the pixel, the wiring width of the fifth wiring is greater than the wiring width of the first wiring, greater than the wiring width of the second wiring, and greater than the wiring width of the third wiring. A display device wherein, in a plan view of the pixel, the fourth wiring does not overlap with the conductive layer that functions as the pixel electrode.

3. A pixel having a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, a second capacitor, and a light-emitting device, The channel formation region of the first transistor, the channel formation region of the third transistor, and the channel formation region of the fourth transistor each have a metal oxide. The first transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The second transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The third transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The fourth transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The first gate and the second gate of the first transistor are electrically connected. The first gate of the first transistor is electrically connected to the first wiring, Either the source or the drain of the first transistor is electrically connected to the sixth wiring. The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The second gate of the second transistor is electrically connected to either the source or the drain of the second transistor. The first gate of the second transistor is electrically connected to either the source or the drain of the third transistor. Either the source or the drain of the second transistor is electrically connected to the pixel electrode of the light-emitting device. The source or drain of the second transistor, the other of which is electrically connected to the fifth wiring, The first gate and the second gate of the third transistor are electrically connected. The first gate of the third transistor is electrically connected to the second wiring. The source or drain of the third transistor, the other of which is electrically connected to the fourth wiring, The first gate and the second gate of the fourth transistor are electrically connected. The first gate of the fourth transistor is electrically connected to the third wiring. Either the source or the drain of the fourth transistor is electrically connected to the sixth wiring. The source or drain of the fourth transistor is electrically connected to the source or drain of the third transistor. One electrode of the first capacitor is electrically connected to either the source or the drain of the second transistor. The other electrode of the first capacitor is electrically connected to the first gate of the second transistor. One electrode of the second capacitor is electrically connected to the first gate of the second transistor. The other electrode of the second capacitance is electrically connected to the other source or drain of the second transistor. The first wiring has the function of transmitting a potential that selects the conduction state or non-conduction state of the first transistor. The second wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the third transistor. The third wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the fourth transistor. The fourth wiring has the function of transmitting an electric potential corresponding to the image data, The fifth wiring has the function of transmitting the first potential, The first potential is the potential at which the second transistor operates in the saturation region when the brightness of the light-emitting device is at its maximum. The sixth wiring is a display device having the function of transmitting a second potential, In a plan view of the pixel, the channel length direction of the first transistor, the channel length direction of the third transistor, and the channel length direction of the fourth transistor are directions along the first direction. In a plan view of the pixel, the channel length direction of the second transistor is along a second direction that intersects with the first direction. In a plan view of the pixel, the first wiring, the second wiring, the third wiring, and the fifth wiring are arranged to extend along the first direction. In a plan view of the pixel, the fourth wiring and the sixth wiring are arranged to extend along the second direction. In a plan view of the pixel, the wiring width of the fifth wiring is greater than the wiring width of the first wiring, greater than the wiring width of the second wiring, and greater than the wiring width of the third wiring. A display device wherein, in a plan view of the pixel, the fourth wiring does not overlap with the conductive layer that functions as the pixel electrode.

4. A pixel having a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, a second capacitor, and a light-emitting device, The channel formation region of the first transistor, the channel formation region of the third transistor, and the channel formation region of the fourth transistor each have a metal oxide. The first transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The second transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The third transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The fourth transistor has a first gate having a region above the channel formation region and a second gate having a region below the channel formation region. The first gate and the second gate of the first transistor are electrically connected. The first gate of the first transistor is electrically connected to the first wiring, Either the source or the drain of the first transistor is electrically connected to the sixth wiring. The source or drain of the first transistor is electrically connected to the source or drain of the second transistor. The second gate of the second transistor is electrically connected to either the source or the drain of the second transistor. The first gate of the second transistor is electrically connected to either the source or the drain of the third transistor. Either the source or the drain of the second transistor is electrically connected to the pixel electrode of the light-emitting device. The source or drain of the second transistor, the other of which is electrically connected to the fifth wiring, The first gate and the second gate of the third transistor are electrically connected. The first gate of the third transistor is electrically connected to the second wiring. The source or drain of the third transistor, the other of which is electrically connected to the fourth wiring, The first gate and the second gate of the fourth transistor are electrically connected. The first gate of the fourth transistor is electrically connected to the third wiring. Either the source or the drain of the fourth transistor is electrically connected to the sixth wiring. The source or drain of the fourth transistor is electrically connected to the source or drain of the third transistor. One electrode of the first capacitor is electrically connected to either the source or the drain of the second transistor. The other electrode of the first capacitor is electrically connected to the first gate of the second transistor. One electrode of the second capacitor is electrically connected to the first gate of the second transistor. The other electrode of the second capacitance is electrically connected to the other source or drain of the second transistor. The first wiring has the function of transmitting a potential that selects the conduction state or non-conduction state of the first transistor. The second wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the third transistor. The third wiring has the function of transmitting a potential that selects the conduction or non-conduction state of the fourth transistor. The fourth wiring has the function of transmitting an electric potential corresponding to the image data, The fifth wiring has the function of transmitting the first potential, The first potential is the potential at which the second transistor operates in the saturation region when the brightness of the light-emitting device is at its maximum. The sixth wiring has the function of transmitting a second potential, The display device wherein the second potential is 0V or GND potential, In a plan view of the pixel, the channel length direction of the first transistor, the channel length direction of the third transistor, and the channel length direction of the fourth transistor are directions along the first direction. In a plan view of the pixel, the channel length direction of the second transistor is along a second direction that intersects with the first direction. In a plan view of the pixel, the first wiring, the second wiring, the third wiring, and the fifth wiring are arranged to extend along the first direction. In a plan view of the pixel, the fourth wiring and the sixth wiring are arranged to extend along the second direction. In a plan view of the pixel, the wiring width of the fifth wiring is greater than the wiring width of the first wiring, greater than the wiring width of the second wiring, and greater than the wiring width of the third wiring. A display device wherein, in a plan view of the pixel, the fourth wiring does not overlap with the conductive layer that functions as the pixel electrode.

5. In any one of claims 1 to 4, The aforementioned metal oxide contains indium, and is used in display devices.

Images