Display device

Abstract

To provide a display device having high luminance.SOLUTION: The pixel includes a light-emitting device, a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, and a second capacitor. The one electrode of the light-emitting device is electrically connected to one of a source and a drain of the first transistor. A gate of the first transistor is electrically connected to one electrode of the first capacitor and one of a source and a drain of the second transistor. The other of the source and the drain of the first transistor is electrically connected to one electrode of the second capacitor. One electrode of the second capacitor is electrically connected to a first wiring having a function of supplying a first potential. The other electrode of the second capacitor is electrically connected to the other electrode of the first capacitor, one of a source and a drain of the third transistor, and one of a source and a drain of the fourth transistor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. In one embodiment of the technical field of the present invention, there are provided a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, Electronic device, lighting device, input device, input / output device, driving method thereof, or manufacturing method thereof For example, a semiconductor device functions by utilizing the semiconductor properties. This refers to all devices that can be used. [Background technology]

[0003] Oxide semiconductors using metal oxides are attracting attention as semiconductor materials that can be used in transistors. For example, in Patent Document 1, a plurality of oxide semiconductor layers are stacked, and the plurality of oxide semiconductor layers are Among the oxide semiconductor layers, an oxide semiconductor layer serving as a channel contains indium and gallium, and By increasing the ratio of indium to that of gallium, the field effect mobility (simply called mobility) can be improved. A semiconductor device is disclosed that has enhanced mobility, μFE, or μ.

[0004] Metal oxides that can be used for the semiconductor layer can be formed by sputtering or the like. Therefore, it can be used for transistors that make up large display devices. It is possible to improve and utilize some of the production equipment for transistors that use silicon or amorphous silicon. This allows for reduced capital investment. Since it has a higher field effect mobility than when using amorphous silicon, a drive circuit is provided. A highly functional display device can be realized.

[0005] By the way, Augmented Reality (AR) or Virtual Reality (VR) Wearable display devices for Virtual Reality (VR) Wearable display devices, such as For example, a head mounted display (HMD) ) and eyeglass-type display devices. Stationary display devices include, for example, head-up displays. Examples include HUD (Head-Up Display).

[0006] In an electronic device having an imaging device such as a digital camera, the image to be captured is confirmed before the image is captured. A viewfinder is used to check the image. An electronic viewfinder is used. The electronic viewfinder has a display. The image obtained by the imaging device can be displayed on the display unit as an image. For example, in Patent Document 2, a method for obtaining a good visibility state from the center of an image to the periphery of the image is disclosed. An electronic viewfinder capable of [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-7399 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-42569 Summary of the Invention [Problem to be solved by the invention]

[0008] In a display device such as an HMD where the display unit is close to the user, the pixels are easy for the user to see. This can lead to a sense of graininess, which can reduce the immersive and realistic feel of AR and VR. For this reason, HMDs are equipped with fine pixels so that the user cannot see the pixels. In other words, high-resolution display devices are desired. The pixel density of a display device is, for example, 1000p ppi or more is preferable, and 5000 ppi or more is more preferable, and 7000 ppi or more is even more preferable. In AR applications, it is preferable to display images of virtual space overlaid on real space. Therefore, a display device with high brightness is desired, especially when the usage environment is bright.

[0009] In view of the above, an object of one embodiment of the present invention is to provide a high-definition display device. Another object of one embodiment of the present invention is to provide a display device with high luminance. Another object of one embodiment of the present invention is to provide a display device with low power consumption. Another object of one embodiment of the present invention is to provide a display device with a narrow frame. Another object of one embodiment of the present invention is to provide a small-sized display device. Another object of one embodiment of the present invention is to provide a novel display device.

[0010] The description of these problems does not preclude the existence of other problems. It is not necessary for one embodiment to solve all of these problems. The subject matter can be extracted from the description, drawings, claims, etc. [Means for solving the problem]

[0011] One embodiment of the present invention is a pixel circuit including a pixel portion having a plurality of pixels, a first wiring, a second wiring, and a third wiring. The display device has a first wiring and a fourth wiring. a transistor, a second transistor, a third transistor, and a fourth transistor; The light-emitting device includes a first capacitor and a second capacitor. The first transistor is electrically connected to either the source or the drain of the second transistor. The gate of the first transistor is connected to one electrode of the first capacitance element and the source or drain of the second transistor. The other of the source and drain of the first transistor is electrically connected to , is electrically connected to one electrode of the second capacitor element. The second capacitor element is electrically connected to a first wiring having a function of supplying a first potential. The other electrode of the first capacitor element is connected to the source or drain of the third transistor. and one of the source and drain of the fourth transistor. The gate of the second transistor and the gate of the fourth transistor are connected to the second wiring. The gate of the third transistor is electrically connected to the third wiring. The other of the source and drain of the second transistor and the source of the third transistor are connected to each other. The other of the source and the drain is electrically connected to a fourth wiring.

[0012] In the display device, the first transistor has a back gate. is preferably electrically connected to one of the source and drain of the first transistor. It's nice.

[0013] In the display device, the first transistor has a back gate. is preferably electrically connected to the gate of the first transistor.

[0014] The display device further includes a fifth transistor, One of the source and drain may be electrically connected to one electrode of the light-emitting device. preferable.

[0015] In the display device, the other electrode of the light-emitting device has a function of supplying a second potential. and the second potential is preferably lower than the first potential. stomach.

[0016] In the above-described display device, the light-emitting device is preferably an organic light-emitting diode. .

[0017] The display device has a first driver circuit portion, and the first driver circuit portion overlaps with a pixel portion. The first driver circuit section preferably has a region electrically connected to the fourth wiring. It is preferable that

[0018] In the above-mentioned display device, it is preferable to have a first layer and a second layer on the first layer. The first layer preferably has a first drive circuit section and a second drive circuit section. The second layer preferably has a pixel portion. The second driver circuit portion includes a second wiring and It is preferable that the third wiring is electrically connected.

[0019] In the display device described above, the first transistor, the second transistor, and the third transistor The first and fourth transistors each have a metal oxide in a channel formation region. The metal oxide is preferably a mixture of indium, zinc, and an element M (aluminum, titanium, gallium). Sm, germanium, yttrium, zirconium, lanthanum, cerium, tin, neodymium It is preferred that the metal has one or more of: tungsten, tungsten or hafnium;

[0020] One embodiment of the present invention is an electronic device including the above-described display device and a camera. [Effects of the Invention]

[0021] According to one embodiment of the present invention, a display device with high definition can be provided. According to one embodiment of the present invention, a display device with high luminance can be provided. Alternatively, according to one embodiment of the present invention, a display device with a narrow frame can be provided. According to one embodiment of the present invention, a small-sized display device can be provided. According to one aspect of the present invention, a novel display device can be provided.

[0022] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have to have all of these effects. can be extracted from the description, drawings, claims, etc. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a circuit diagram showing an example of the configuration of a pixel. [Figure 2] FIG. 2 is a timing chart illustrating the operation of the pixel circuit. [Figure 3] 3A and 3B are circuit diagrams showing examples of pixel configurations. [Figure 4] FIG. 4 is a circuit diagram showing an example of the configuration of a pixel. [Figure 5] FIG. 5 is a circuit diagram showing an example of the configuration of a pixel. [Figure 6] FIG. 6 is a circuit diagram showing an example of the configuration of a pixel. [Figure 7] FIG. 7 is a timing chart illustrating the operation of the pixel circuit. [Figure 8]8A and 8B are diagrams showing examples of pixel layouts. [Figure 9] FIG. 9 is a diagram showing an example of a pixel layout. [Figure 10] FIG. 10 is a schematic diagram showing an example of the configuration of a pixel. [Figure 11] 11A and 11B are schematic diagrams showing examples of pixel configurations. [Figure 12] FIG. 12 is a block diagram showing an example of the configuration of a display device. [Figure 13] 13A and 13B are schematic and block diagrams showing an example of the configuration of a display device. [Figure 14] 14A and 14B are schematic and block diagrams showing an example of the configuration of a display device. [Figure 15] FIG. 15 is a cross-sectional view showing an example of the configuration of a display device. [Figure 16] FIG. 16 is a cross-sectional view showing an example of the configuration of a display device. [Figure 17] FIG. 17 is a cross-sectional view showing an example of the configuration of a display device. [Figure 18] FIG. 18 is a cross-sectional view showing an example of the configuration of a display device. [Figure 19] FIG. 19 is a cross-sectional view showing an example of the configuration of a display device. [Figure 20] 20A, 20B, 20C, 20D, and 20E are diagrams showing configuration examples of light-emitting devices. [Figure 21] 21A is a top view illustrating an example of the structure of a transistor, and FIGS. 21B and 21C are cross-sectional views illustrating an example of the structure of a transistor. [Figure 22] 22A is a top view illustrating an example of the structure of a transistor, and FIGS. 22B and 22C are cross-sectional views illustrating an example of the structure of a transistor. [Figure 23] 23A is a top view illustrating an example of the structure of a transistor, and FIGS. 23B and 23C are cross-sectional views illustrating an example of the structure of a transistor. [Figure 24]Fig. 24A is a diagram explaining the classification of IGZO crystal structures, Fig. 24B is a diagram explaining the XRD spectrum of a CAAC-IGZO film, and Fig. 24C is a diagram explaining the electron microbeam diffraction pattern of a CAAC-IGZO film. [Figure 25] 25A, 25B, 25C, 25D, and 25E are perspective views showing examples of electronic devices. [Figure 26] 26A, 26B, 26C, 26D, 26E, 26F, and 26G are perspective views showing examples of electronic devices. [Figure 27] FIG. 27 is a diagram illustrating the simulation results. [Figure 28] FIG. 28 is a diagram illustrating the simulation results. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments will be described with reference to the drawings. It is understood that the present invention may be embodied in various different forms without departing from its spirit and scope. It will be readily apparent to those skilled in the art that various modifications may be made to the mode and details of the present invention. The invention should not be construed as being limited to the following description of the embodiments.

[0025] In each figure described in this specification, the size of each component, layer thickness, or area is shown for clarity. may be exaggerated for this reason.

[0026] The ordinal numbers "first," "second," and "third" used in this specification are intended to avoid confusion of elements. The numbers are added to avoid confusion and are not intended to limit the number.

[0027] In this specification, terms indicating placement such as "above" and "below" refer to the positional relationship between components. are used for convenience in describing the drawings. The direction of each component changes accordingly. It is not limited to words and phrases, and can be rephrased appropriately depending on the situation.

[0028] In this specification and the like, the functions of the source and drain of a transistor are The polarity of the terminals may be reversed when the direction of current flow changes during circuit operation. For this reason, the terms source and drain can be used interchangeably.

[0029] In this specification, terms such as "electrode," "wiring," and "terminal" are used to refer to these components functionally. For example, an "electrode" may be used as part of a "wiring." Furthermore, the terms "electrode" and "wiring" are used interchangeably to refer to the plural "electrodes" and "wiring". This also includes cases where the "terminal" is integrally formed with the "wiring." " or part of "electrode", and vice versa. The term "electrode" is used when multiple "electrodes," "wiring," "terminals," etc. are integrally formed. Therefore, for example, an "electrode" can be a part of a "wiring" or a "terminal", Also, for example, a "terminal" can be a part of a "wiring" or an "electrode." Terms such as "pole," "wiring," and "terminal" may be replaced with terms such as "area" in some cases. be.

[0030] In this specification and the like, the resistance value of a "resistance" may be determined depending on the length of the wiring. Alternatively, the resistor may be connected to a conductor having a different resistance from that used in the wiring via a contact. This also includes cases where the resistance is increased by doping impurities into the semiconductor. There may be cases where this is decided.

[0031] In this specification, "electrically connected" refers to a direct connection and a connection by some kind of electrical This includes cases where the device is connected via "something that has an electrical effect." "Something with electrical action" means something that allows the transmission and reception of electrical signals between connected objects. Therefore, even if it is expressed as "electrically connecting," In some circuits, there are no physical connections, just wires running. Even if it is expressed as a "direct connection," it is not a case of wiring to different conductors via contacts. In addition, in wiring, different conductors containing one or more of the same elements may be formed. Some contain the same elements, while others contain different elements.

[0032] In this specification, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" and "insulating layer" can be used interchangeably with "conductive film" and "insulating film." The terms "membrane" and "membrane" may be interchangeable.

[0033] Unless otherwise specified, in this specification and the like, the off-state current is the current that flows when a transistor is in an off state ( The drain current when the device is in a non-conducting state (also called a cut-off state). Unless otherwise specified, for n-channel transistors, the voltage between the gate and source, V gs but Threshold voltage V th (For p-channel transistors, V th (higher than It refers to one's attitude.

[0034] In the drawings, the size, layer thickness, or area may be exaggerated for clarity. Therefore, the scale is not necessarily limited to that shown. For example, in the actual manufacturing process, It is possible that layers and resist masks may be unintentionally thinned out during processes such as chipping. In order to facilitate understanding, the same or similar parts may not be shown in the drawings. The same reference numerals are used in different drawings for parts having different functions, materials, etc., and the repetition of such reference numerals is In addition, when referring to similar functions, materials, etc., the same explanation may be omitted. In some cases, the same pattern is used and no particular symbol is assigned.

[0035] In this specification, the term "metal oxide" refers to a metal in a broad sense. Metal oxides are oxides of the following: oxide insulators, oxide conductors (including transparent oxide conductors), ), oxide semiconductors (also referred to as oxide semiconductors or simply OS), etc. For example, when a metal oxide is used in the active layer of a transistor, the metal oxide In other words, when an OS transistor is referred to as an oxide semiconductor, In other words, the transistor can be a transistor including an oxide or an oxide semiconductor.

[0036] (Embodiment 1) In this embodiment, a display device which is one embodiment of the present invention will be described.

[0037] One embodiment of the present invention is a display device having a pixel. It has the function of generating a voltage higher than the voltage corresponding to the image data supplied. A storage node is provided, and the storage node can store first data. The second data is further supplied to the first data input terminal, and the first data is attached to the second data by capacitive coupling. Then, the data obtained by adding the first data to the second data is provided to a light emitting device. Alternatively, the first data can be written to the storage node after the second data is written to the storage node. Data can also be added by capacitive coupling.

[0038] The same image data can be used as the first data and the second data. In this case, the pixels of the display device receive a voltage corresponding to image data supplied from the source driver. The driving transistor generates a voltage higher than the Therefore, the current flowing through the light-emitting device can be increased, resulting in high This makes it possible to provide a display device with high brightness.

[0039] For example, the display device according to one embodiment of the present invention may be used as a display device for AR, which requires high brightness. In addition, the output voltage of the source driver can be reduced. This makes it possible to provide a display device with low power consumption. Also, a high-voltage output driver is not required. A general-purpose driver IC can be used. It is also possible to operate light-emitting devices that are difficult to operate using a driver.

[0040] In this specification, generating a voltage higher than the supplied voltage is referred to as boosting. It may be noted.

[0041] A display device according to one embodiment of the present invention uses image data as first data, and The data for correction can be used as the data for 2. In this case, the display device is This correction allows the image to be up-converted. Or, you can correct a part or the whole image in the display area and achieve HDR (High Dynamic Range). Dynamic Range (Dynamic Range) display can be performed.

[0042] The display device according to one aspect of the present invention may include, for example, a display device that displays different first data and second data. By using image data such as the above, any images can be displayed in a superimposed manner.

[0043] A display device according to one embodiment of the present invention includes a pixel portion having a plurality of pixels and a source driver. By having an area where the pixel section and the source driver overlap, the pixels can be set Therefore, the area of ​​the frame, which is the area that is not covered by the frame, can be reduced. Furthermore, by narrowing the frame of the display device, it is possible to make a small display device. It can be placed.

[0044] In this specification, a pixel refers to, for example, one element whose brightness can be controlled. Therefore, as an example, one pixel indicates one color element, and the color element It expresses brightness with one element. Therefore, it is a color consisting of the color elements R (red), G (green), and B (blue). In the case of a display device, the smallest unit of an image is made up of three pixels: an R pixel, a G pixel, and a B pixel. In this case, each RGB pixel is called a sub-pixel, RGB subpixels are sometimes collectively called pixels.

[0045] <Pixel configuration example 1> FIG. 1 shows a structural example of a pixel 10 that can be used in a display device of one embodiment of the present invention. The element 10 includes a light emitting device 114, a transistor 101, a transistor 102, and a transistor The transistor 103, the transistor 104, the capacitor 111, and the capacitor 112 are included. do.

[0046] One electrode of the light-emitting device 114 is connected to one of the source and drain of the transistor 101. The gate of the transistor 101 is electrically connected to one electrode of the capacitor 111. The gate of the transistor 101 is electrically connected to the source of the transistor 102. The source or drain of the transistor 101 is electrically connected to the The other electrode of the capacitor 112 is electrically connected to one electrode of the capacitor 112. The electrode is electrically connected to the other electrode of the capacitor 111. The electrode is electrically connected to one of the source and drain of the transistor 103. The other electrode of the transistor 112 is electrically connected to either the source or the drain of the transistor 104. Connected.

[0047] In the pixel 10 shown in FIG. 1, the capacitance element 111 and the capacitance element 112 are connected in series. The gate of the transistor 101 functioning as a driving transistor is connected to the The other of the source and the drain is electrically connected.

[0048] The light-emitting device 114 is a light-emitting diode (LED). Diode, Organic Light Emitting Diode (OLED) Quantum dot light-emitting diode (QLED), and quantum dot light-emitting diode (QLED) uantum-dot Light Emitting Diode), semiconductor laser, etc. Self-luminous light-emitting devices such as shutter-type or optical interference-type devices are also available. MEMS (Micro Electro Mechanical Systems) elements or microcapsules, electrophoresis, electrowetting, or electronic It is also possible to use an element that employs a liquid powder (registered trademark) method or the like.

[0049] Here, the gate of the transistor 101, the source or drain of the transistor 102 A wiring to which one electrode of the capacitor 111 is connected is referred to as a node ND1. The potential of the node ND1 controls the current flowing through the light emitting device 114, and the potential of the light emitting device 11 The light emission brightness of the transistor 4 can be controlled. One of the source and drain of the transistor 104, the other electrode of the capacitor element 111, and the capacitor The wiring to which the other electrode of the element 112 is connected is referred to as a node ND2.

[0050] The transistor 101 is a driving transistor that controls the amount of current flowing through the light-emitting device 114. The transistors 102 and 103 function as a selection transistor for selecting a pixel. The transistor 104 functions as a transistor. It functions as a switch for writing the reference potential "Vref" to the pixel.

[0051] The gate of the transistor 102 is electrically connected to the wiring 121. The gate of the transistor 4 is electrically connected to a wiring 121. The other of the source and drain of the transistor 102 is electrically connected to the transistor 122. The other of the source and drain of the transistor 103 is electrically connected to the line 131. It is electrically connected to the wiring 131 .

[0052] One electrode of the capacitor 112 is electrically connected to a wiring 128. The wiring 128 is It is preferable that the capacitor 112 has a function of supplying a constant potential. 28, the potential of one electrode of the capacitor 112 is connected to the wiring 128. It is possible to fix the voltage to a specific potential supplied from the The other electrode of the light-emitting device 114 is electrically connected to the wiring 129. 28 and the wiring 129 are each made to function as a wiring (power supply line) to which a power supply potential is applied. For example, the wiring 128 can be a high potential power supply line that supplies a higher potential than the wiring 129. The wiring 129 can be supplied with a lower potential than the wiring 128. It can function as a low-potential power supply line.

[0053] The wiring 121 and the wiring 122 are connected to the transistor 102, the transistor 103, and the transistor 104. The scanning lines have the function of controlling the operation of the scanning sensor 104. The scan signal is applied to the select transistor (transistor 102) which acts as a switch within the pixel 10. , transistor 103 and transistor 104) in a conducting or non-conducting state (on or off). The wiring 131 is a signal for controlling the first data and the second data. The wiring 127 functions as a data line that supplies a specific voltage to drive the pixel 10. It has the function of supplying a reference potential "Vref."

[0054] The node ND1 is a storage node, and when the transistor 102 is turned on, The first data supplied to the transistor 131 can be written to the node ND1. By making 102 non-conductive, the first data written to the node ND1 is retained. It is possible.

[0055] The node ND2 is a storage node, and when the transistor 103 is turned on, The second data supplied to the transistor 131 can be written to the node ND2. By turning on the wiring 104, the second data supplied to the wiring 127 is transmitted to the node ND2. In addition, the transistors 103 and 104 can be turned off. By doing so, the second data written to the node ND2 can be held.

[0056] Transistor 101, transistor 102, transistor 103 and transistor 10 It is preferable to use a transistor with extremely low off-state current in at least one of the above four transistors. In addition, the transistors 102, 103, and 104 have extremely low off-state currents. By using a transistor with a small capacitance, the potentials of the nodes ND1 and ND2 can be maintained for a long time. The transistor may have a metal oxide film in the channel formation region, for example. A transistor using an oxide (hereinafter referred to as an OS transistor) can be preferably used.

[0057] The transistors 101, 102, 103 and It is more preferable to use OS transistors for all of the transistors 104. Transistors other than 101, 102, 103 and 104 An OS transistor may be used for the transistor (not shown). To operate to the best of our ability, we use transistors with silicon in the channel formation region (hereafter referred to as Alternatively, an OS transistor and a Si transistor may be used. The Si transistor may be made of amorphous silicon. Transistors with crystalline silicon (microcrystalline silicon, low-temperature polysilicon, single-crystal silicon) The transistor shown in FIG. Although both are n-channel transistors, p-channel transistors are used. It is also possible.

[0058] The semiconductor material used in the OS transistor has an energy gap of 2 eV or more. It is possible to use a metal oxide having a refractive index of 2.2 eV or more, more preferably 2.5 eV or more. A typical example is an oxide semiconductor containing indium, for example, the CA AC-OS(C-Axis Aligned Crystalline Oxide S emiconductor) or CAC-OS (Cloud-Aligned Com Posite Oxide Semiconductor) can be used. CAAC-OS has a stable crystal structure and is suitable for transistors where reliability is important. In addition, CAC-OS exhibits high mobility characteristics, making it suitable for high-speed transistors. do.

[0059] The OS transistor has a large energy gap in the semiconductor layer, so the channel width is 1 μm. The off-state current per -24 ) extremely small off-state current In addition, the OS transistor can be used for impact ionization, avalanche breakdown, and other It has features that are different from Si transistors, such as no short channel effect or insufficiency. It is possible to form highly reliable circuits. In addition, there is no crystallinity problem with Si transistors. OS transistors are also less susceptible to variations in electrical characteristics due to non-uniformity of the conductivity type.

[0060] The semiconductor layer of the OS transistor contains, for example, indium, zinc, and an element M (M is Aluminum, titanium, gallium, germanium, yttrium, zirconium, lanthanum In-M-Zn oxide containing one or more of: silicon, cerium, tin, neodymium, or hafnium It can be a membrane expressed as an object.

[0061] When the oxide semiconductor constituting the semiconductor layer is an In-M-Zn oxide, The atomic ratio of the metal elements in the sputtering target used to form the oxide film is In≧ It is preferable that M and Zn satisfy the condition M. The metal elements of such a sputtering target The atomic ratios of In:M:Zn=1:1:1, In:M:Zn=1:1:1.2, I n: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:Z Preferably, n=10:1:6, In:M:Zn=10:1:8, etc. The atomic ratio of each layer is the atomic ratio of the metal elements contained in the sputtering target. This includes a variation of plus or minus 40% in numerical ratios.

[0062] The semiconductor layer is made of an oxide semiconductor with a low carrier concentration. Carrier concentration is 1×10 17 / cm 3 Less than 1 × 10 15 / cm3 Further details are as follows: Preferably 1 x 10 13 / cm 3 Less than or equal to 1×10 11 / cm 3 Below, further Preferably 1 x 10 10 / cm 3 Less than 1 x 10 -9 / cm 3 More than a rich career Such an oxide semiconductor can be a highly pure intrinsic or The oxide semiconductor is called a substantially high-purity intrinsic oxide semiconductor. The oxide semiconductor has a low density of defect states and It can be said that this is an oxide semiconductor with stable characteristics.

[0063] However, the semiconductor characteristics and electrical characteristics (electric field characteristics) of the required transistors are not limited to these. It is sufficient to use an appropriate composition depending on the characteristics (effective mobility, threshold voltage, etc.). In order to obtain the semiconductor characteristics of the transistor, the carrier concentration, impurity concentration, and defect density of the semiconductor layer are determined. It is preferable to appropriately set the recess density, atomic ratio of metal elements to oxygen, interatomic distance, density, etc. It's nice.

[0064] In the oxide semiconductor that makes up the semiconductor layer, silicon and carbon, which are group 14 elements, If oxygen is contained, oxygen vacancies increase and the semiconductor layer becomes n-type. The concentrations of corn and carbon (obtained by secondary ion mass spectrometry) were 2 × 10 18 ato ms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0065] Alkali metals and alkaline earth metals react with the components contained in oxide semiconductors to form catalytic compounds. This may generate carriers, which may increase the off-state current of the transistor. Therefore, the concentration of alkali metals or alkaline earth metals in the semiconductor layer (secondary ion mass (concentration obtained by analytical method) is 1 x 10 18 atoms / cm 3 Below, preferably 2x 10 16 atoms / cm 3 Do the following:

[0066] When nitrogen is contained in the oxide semiconductor that constitutes the semiconductor layer, carriers As a result, electrons that become ions are generated, the carrier concentration increases, and the material becomes more likely to become n-type. A transistor using an oxide semiconductor containing such a semiconductor tends to be normally on. The nitrogen concentration in the conductor layer (obtained by secondary ion mass spectrometry) is 5×10 18 atoms / cm 3 It is preferable to do the following:

[0067] When hydrogen is contained in the oxide semiconductor constituting the semiconductor layer, It reacts with oxygen that bonds with metal atoms to form water, creating oxygen vacancies in the oxide semiconductor. When oxygen vacancies are present in the channel formation region of an oxide semiconductor, Furthermore, defects in which hydrogen enters oxygen vacancies can cause damage to the driver. It functions as a donor and generates electrons as carriers. It may bond with oxygen, which bonds with a metal atom, to generate electrons, which are carriers. Therefore, a transistor using an oxide semiconductor containing a lot of hydrogen has normally-on characteristics. It is easy to become.

[0068] The defect where hydrogen has entered the oxygen vacancy can function as a donor in the oxide semiconductor. Therefore, it is difficult to quantitatively evaluate the defects in oxide semiconductors. In some cases, the carrier concentration is used for evaluation instead of the donor concentration. As a parameter of the oxide semiconductor, we assume a state in which no electric field is applied, rather than the donor concentration. In other words, the "carrier concentration" described in this specification is This can sometimes be rephrased as "donor concentration."

[0069] Therefore, it is preferable that the amount of hydrogen in the oxide semiconductor be reduced as much as possible. In oxide semiconductors, secondary ion mass spectrometry (SIMS) The hydrogen concentration obtained by mass spectrometry was calculated as 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 Less than, more preferred Kuha 5 x 10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 The oxide semiconductor in which impurities such as hydrogen are sufficiently reduced is used for the transistor. By using it in a channel formation region, stable electrical characteristics can be imparted.

[0070] Oxide semiconductors (metal oxides) are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Non-single-crystal oxide semiconductors are classified into conductive and non-conductive oxide semiconductors, such as CAAC-OS and polycrystalline oxide semiconductors. Semiconductor, nc-OS (nanocrystalline oxide semiconductor) conductor), pseudo-amorphous oxide semiconductor (a-like OS: amorphous- like oxide semiconductor), and amorphous oxide semiconductor, etc. Among non-single crystal structures, the amorphous structure has the highest defect level density, and CAAC-OS has the lowest defect level density.

[0071] An oxide semiconductor film with an amorphous structure has, for example, a disordered atomic arrangement and does not contain crystalline components. Alternatively, the amorphous oxide semiconductor film may have a completely amorphous structure and may have a crystalline portion. does not have.

[0072] The semiconductor layer may have an amorphous structure region, a microcrystalline structure region, a polycrystalline structure region, a CAA region, or a crystalline structure region. The film may be a mixed film having two or more of the C-OS region and the single crystal structure region. The composite film may have a single layer structure including two or more of the above-mentioned regions, or a laminate structure. It may have a layer structure.

[0073] The structure of a CAC-OS, which is one mode of a non-single-crystal semiconductor layer, will be described below.

[0074] CAC-OS is, for example, an oxide semiconductor in which elements constituting the oxide semiconductor are 0.5 nm to 10 nm thick. Preferably, the size of the material is 1 nm or more and 2 nm or less, or a size of the material is unevenly distributed in the vicinity of the size. In the following, it is assumed that one or more metal elements are contained in an oxide semiconductor. The region having the metal element is unevenly distributed, and the region having the metal element is 0.5 nm or more and 10 nm or less, preferably 1n A mixture of particles with sizes between 1 m and 2 nm or close to that size is called a mosaic or patch. It is also called a state.

[0075] Note that the oxide semiconductor preferably contains at least indium. and zinc. In addition to these, aluminum, gallium, iridium, tritium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, Germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium tantalum, tungsten, magnesium, or the like. It may be included.

[0076] For example, CAC-OS in In-Ga-Zn oxide (In- Ga-Zn oxide may be specifically referred to as CAC-IGZO. (hereinafter referred to as InO X1 (X1 is a real number greater than 0.) or Indium Zinc oxide (hereinafter referred to as In X2 Zn Y2 O Z2 (X2, Y2, and Z2 are real numbers greater than 0. ) and gallium oxide (GaO X3 (X3 is a real number greater than 0) ), or gallium zinc oxide (hereinafter referred to as Ga X4 Zn Y4 O Z4 (X4, Y4, and Z1 and Z2 are real numbers greater than 0.) The material is separated into mosaics. The mosaic-like InO X1 , or In X2 Zn Y2 O Z2 is uniformly distributed in the film This is a cloud-like configuration (hereinafter also referred to as a cloud-like configuration).

[0077] In other words, CAC-OS is X3 The region where In is the main component and X2 Zn Y2 O Z2 , or InOX1 A composite oxide semiconductor having a structure in which a region in which In this specification, for example, the number of In atoms relative to the element M in the first region is The ratio of the number of atoms of In to the element M in the first region is greater than the ratio of the number of atoms of In to the element M in the second region. It is assumed that the concentration of In is higher than that of the second region.

[0078] IGZO is a common name and refers to a compound made of In, Ga, Zn, and O. A typical example is 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) Examples of the crystalline compounds include those represented by the formula:

[0079] The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC structure. The CAAC structure is a structure in which multiple IGZO nanocrystals have a c-axis orientation and are aligned in the ab plane. The crystal structure is non-oriented and connected.

[0080] On the other hand, CAC-OS refers to the material structure of an oxide semiconductor. In a material composition containing Ga, Zn, and O, some of the nanoparticles are mainly composed of Ga. The region where In is observed as a nanoparticle and the region where In is observed as a nanoparticle are mainly composed of In are shown in Fig. Therefore, in CAC-OS, , the crystal structure is a secondary factor.

[0081] Note that CAC-OS does not include a laminated structure of two or more films with different compositions. For example, a structure consisting of two layers, one containing In as the main component and the other containing Ga as the main component, Not at all.

[0082] In addition, GaO X3 The region where In is the main component and X2 Zn Y2 O Z2 , or InO X1 In some cases, a clear boundary between the region where the main component is the chromatic aberration and the region where the chromatic aberration is the main component may not be observed.

[0083] Instead of gallium, aluminum, yttrium, copper, vanadium, and beryllium can be used. Aluminum, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If one or more selected elements such as cesium are included, CAC-OS will In the region, nanoparticles containing the metal element as the main component are observed, and in the region, In is the main component. The nanoparticle-like regions are randomly dispersed in a mosaic pattern. This refers to...

[0084] CAC-OS can be formed by, for example, a sputtering method without heating the substrate. When the CAC-OS is formed by a sputtering method, the following gas is used as the deposition gas: Any one selected from the group consisting of an inert gas (typically argon), oxygen gas, and nitrogen gas. In addition, the ratio of oxygen gas to the total flow rate of film-forming gas during film formation can be The lower the flow rate ratio, the more preferable. For example, the flow rate ratio of oxygen gas is set to 0% or more and less than 30%, preferably It is preferable to set it to 0% or more and 10% or less.

[0085] CAC-OS is an X-ray diffraction (XRD) measurement method. When measured using one of the out-of-plane θ / 2θ scans In other words, from the X-ray diffraction measurement, no clear peaks are observed. It can be seen that no orientation in the ab plane direction or the c axis direction is observed in the fixed region.

[0086] CAC-OS irradiates electron beams with a probe diameter of 1 nm (also called nanobeam electron beams). In the electron diffraction pattern obtained by this method, a ring-shaped area with high brightness (ring region) The electron diffraction pattern shows that the ring region is dominated by a single bright spot. The crystal structure of CAC-OS has no orientation in the planar direction and the cross-sectional direction. It can be seen that it has a c (nano-crystal) structure.

[0087] For example, in the case of CAC-OS in In-Ga-Zn oxide, energy dispersive X-ray diffraction (EDX) Optical method (EDX:Energy Dispersive X-ray spectrosc) EDX mapping obtained using a microscope (microscope) revealed that GaO X3 and a region where In X2 Zn Y2 O Z2 , or InO X1 The area where the main component is unevenly distributed and mixed. It can be confirmed that the compound has the structure shown in Fig.

[0088] CAC-OS has a structure different from that of IGZO compounds, in which metal elements are uniformly distributed. CAC-OS has different properties from GZO compounds. X3 The main components are and the region where In X2 Zn Y2 O Z2 , or InO X1 The region where is the main component and the region where is The phases are separated into individual elements, resulting in a mosaic structure of regions each consisting of a different element as the main component.

[0089] Here, In X2 Zn Y2 O Z2 , or InO X1 The region where is the main component is GaO X This is a region with high conductivity compared to the region where In is the main component. X2 Zn Y2 O Z2 , or InO X1 The carriers flow through the area where the main component is Therefore, the conductivity of In is exhibited as a semiconductor. X2 Zn Y2 O Z2 , or I nO X1 The regions where the main component is distributed in a cloud-like shape in the oxide semiconductor produce high electric current. Field-effect mobility (μ) can be achieved.

[0090] On the other hand, GaO X3 The region where the main components are In X2 Zn Y2 O Z2 , or InO X1 This region has higher insulating properties than the region where GaO is the main component. X3 etc. The distribution of the region in which the main component is Switching operation can be achieved.

[0091] Therefore, when CAC-OS is used in a semiconductor device, GaO X3 Insulation due to Sex and In X2 Zn Y2 O Z2 , or InO X1 The conductivity caused by the This allows for a high on-state current (Ion ), and high field-effect mobility (μ) It is possible.

[0092] Semiconductor devices using CAC-OS are highly reliable. It is suitable as a constituent material for various semiconductor devices.

[0093] <Pixel operation example 1> An example of the voltage boosting operation of the pixel 10 will be described using the timing chart shown in FIG. In this example, the same image data is used as the first data and the second data, and the first data is By adding data 2, a voltage higher than the voltage corresponding to the image data is generated. An example is shown below.

[0094] In the following explanation, high potential is represented by "High" and low potential is represented by "Low". Let the image data be "Vdata" and the specific potential be "Vref". For example, 0V, GND potential, or a specific reference potential can be used. "Vano" is, for example, the maximum brightness of the light-emitting device 114. In this case, it is preferable to set the potential at which the transistor 101 operates in a saturation region. The potential of the wiring 129 is defined as "Vcath." It is preferable that the light emitting device 114 does not emit light when the potential of the .

[0095] First, the image data "Vdata" is written to the node ND1 as the first data. In this section, we will explain the distribution, coupling, and loss of potential, taking into account the circuit configuration and operation type. It does not take into account detailed changes due to factors such as timing.

[0096] At time T1, the potential of the wiring 121 is set to "High", the potential of the wiring 122 is set to "Low", If the potential of 131 is "Vdata" and the potential of wiring 127 is "Vref", The transistor 102 and the transistor 104 are turned on, and the potential of the wiring 131 is applied to the node ND1. The potential "Vref" of the wiring 127 is written to the node ND1 and the node ND2.

[0097] At this time, if the potential difference across both ends of the capacitance element 111 is V1, the potential difference V1 is expressed by the formula (1 ) can be shown as

[0098] V1=Vdata-Vref (1)

[0099] Similarly, if the potential difference across the capacitive element 112 is V2, the potential difference V2 is expressed by the following equation (2): This can be shown as:

[0100] V2=Vano-Vref (2)

[0101] At time T2, if the potential of the wiring 121 is set to "Low" and the potential of the wiring 122 is set to "Low", , the transistor 102 and the transistor 104 are turned off.

[0102] At this time, the potential V of the node ND1 ND1 can be expressed by equation (3). potential V ND2 can be expressed by equation (4).

[0103] V ND1 =Vdata-a (3)

[0104] V ND2 =Vref-b (4)

[0105] At this time, the potential difference V1 across the capacitive element 111 can be expressed by equation (5). The potential difference V2 across the capacitive element 112 can be expressed by equation (6).

[0106] V1=(Vdata-a)-(Vref-b) (5)

[0107] V2=Vano-(Vref-b) (6)

[0108] Note that a is a constant and is the feedthrough when the transistor 102 is in a non-conducting state. indicates the amount of potential fluctuation due to the influence of the charge injection, etc. b is a constant, Feedthrough, charge injection, etc. when the transistor 104 is in a non-conductive state This shows the amount of potential fluctuation due to the influence of

[0109] Next, the image data "Vdata" is written to node ND2 as the second data. The operation of boosting the potential of the node ND1 will now be described.

[0110] At time T3, the potential of the wiring 121 is set to "Low" and the potential of the wiring 122 is set to "High." Then, the transistor 103 is turned on, and the potential of the wiring 131 “Vdat a" is written.

[0111] At this time, the potential difference V1 across the capacitive element 111 is maintained at the potential difference V1 shown in equation (5). Therefore, the potential V ND1 can be expressed by equation (7). 2 potential V ND2 can be expressed by equation (8).

[0112] V ND1 =2Vdata-Vref-a+b (7)

[0113] V ND2 =Vdata (8)

[0114] At time T4, if the potential of the wiring 121 is set to "Low" and the potential of the wiring 122 is set to "Low", , the transistor 103 is turned off, and the gate-source voltage of the transistor 101 Vgs is the sum of the voltages held by the capacitance elements 111 and 112, and Vgs A current corresponding to this flows through the light emitting device 114.

[0115] At this time, the potential V of the node ND1 ND1 can be expressed by equation (9). potential V ND2 can be expressed by equation (10).

[0116] V ND1 =2Vdata-Vref-a+bc (9)

[0117] V ND2 =Vdata-c (10)

[0118] Note that c is a constant and is the feedthrough when the transistor 103 is in a non-conducting state. This shows the amount of potential fluctuation due to the influence of factors such as charge injection.

[0119] In equation (9), Vref is set to "0V" and constants a, b, and c are set to zero. Then, V ND1 can be expressed as "2Vdata", and the potential "V data” is obtained at a value higher than the image data “data” supplied to the pixel 10. The transistor that functions as a drive transistor is boosted to a voltage higher than the voltage (Vdata). Therefore, the current flowing through the light emitting device 114 can be increased. This allows for a high level of brightness to be achieved.

[0120] The operation of FIG. 2 can be performed continuously within one horizontal period.

[0121] A display device according to one embodiment of the present invention generates a high voltage even when a general-purpose driver IC is used. For example, the power supplied from a driver IC to drive a light-emitting device can be Since the voltage can be reduced to about half, the power consumption of the display device can be reduced. For example, by writing the same image data twice, the current flowing through the light-emitting device can be increased. This allows for increased brightness of the display.

[0122] By combining such first data and second data, upconversion is performed. , HDR display, correction of display irregularities inherent in display devices, threshold voltage of transistors in pixels It is possible to perform pressure correction, etc. Or, it is possible to perform a combination of these.

[0123] In the up-conversion operation, for example, each of four adjacent pixels (two rows and two columns) has a different The image data is then supplied to the pixel array. The data is corrected (converted) into different image data for each pixel, and the display at each pixel For example, 4K can be displayed on specific 4 pixels of a display device having 8K4K pixels. Input data that is applied to a specific pixel of the K2K data, and then apply different values ​​to each of the four pixels. By inputting the correction data, it is possible to display with improved resolution.

[0124] The display device according to one embodiment of the present invention corrects image data in a broad sense, but For example, the first image consisting of image data "Vdata" can be displayed as It is possible to display a composite image by superimposing a second image composed of the correction data "Vw" on the first image. In such a combination of image data and correction data, a composite table of different images can be obtained. In addition to the display, it is possible to improve the brightness of the entire displayed image. For example, it is possible to insert text and It can be applied to displays, etc.

[0125] <Pixel configuration example 2> Configurations different from the pixel 10 shown in FIG. 1 are shown in FIGS. 3A, 3B, and 4. FIG.

[0126] As shown in FIG. 3A, transistor 101, transistor 102, and transistor 103 and the transistor 104 may each have a back gate. The transistor 101 functioning as a driving transistor preferably has a back gate. 3A shows a case where the back gate of the transistor 101 is connected to either the source or the drain. This shows a configuration in which the transistor is electrically connected to the In addition, the transistors 102, 103, and 104 are The back gate is electrically connected to the gate (sometimes called the front gate). This shows a structure that has the effect of increasing the on-current.

[0127] As shown in FIG. 3B, the back gate of the transistor 101 is electrically connected to the front gate. With this structure, the on-state current of the transistor 101 can be increased. It has the effect of

[0128] As shown in Figure 4, the back gate is electrically connected to a wiring that can supply a constant potential, and It is also possible to configure the device to control the threshold voltage of the transistor. In FIG. 4, a configuration in which all transistors are provided with back gates is shown. It is also possible to have a transistor without a lock gate.

[0129] <Pixel configuration example 3> FIG. 5 shows a configuration different from that of pixel 10 shown in FIG. 3A.

[0130] The pixel 10 shown in FIG. 5 differs from the pixel 10 shown in FIG. 3A in that it includes a transistor 105. One of the source and drain of the transistor 105 is connected to one of the light-emitting devices 114. The other of the source and drain of the transistor 105 is electrically connected to The gate of the transistor 105 is electrically connected to the wiring 141. The wiring 141 is connected as a scan line for controlling the operation of the transistor 105. It has the following functions.

[0131] The transistor 105 connects the potential of one electrode of the light-emitting device 114 to the potential of the wiring 143. The potential of one electrode of the light-emitting device 114 can be reset to By setting it, problems such as unintended current flowing through the light-emitting device 114 can be prevented. It has the function of

[0132] The transistor 105 is connected to a circuit (see FIG. This allows the transistor 10 to be electrically connected to the The current that flows when a predetermined potential is applied to the gate of the transistor 105 and the wiring 14 is By passing the current through the circuit via 1, the electrical characteristics of the transistor 101 can be monitored. The current flowing through the circuit can be used to determine the variation in the threshold voltage of the transistor 101. The variation in the capacitance and mobility is calculated, and the data for correcting the threshold voltage is input to the transistor 101. By providing the above, it is possible to provide a display device with less display unevenness.

[0133] The transistor 105 may have a back gate. The back gate of the gate electrode 105 is electrically connected to the gate (front gate). The back gate of the transistor 105 is connected to either the source or the drain. Alternatively, the transistor 105 may have a back gate. It may be configured without this.

[0134] <Pixel configuration example 4> FIG. 6 shows a configuration different from that of the pixel 10 shown in FIG.

[0135] In the pixel 10A shown in FIG. 6, a transistor 101, a transistor 102, a transistor The light emitting device 103 and the transistor 104 are p-channel transistors. The connections of the device 114, the transistors, the capacitance elements, and the wiring are the same as those shown in FIG. Since the description of element 10 can be referred to, detailed explanation will be omitted.

[0136] <Pixel operation example 2> An example of the boosting operation of the pixel 10A shown in FIG. 6 will be described with reference to the timing chart shown in FIG. "Vref" can be a high potential. For example, The potential can be set to the same potential as the potential “Vano” of the wiring 128.

[0137] First, the image data "Vdata" is written to the node ND1 as the first data. In this section, we will explain the distribution, coupling, and loss of potential, taking into account the circuit configuration and operation type. It does not take into account detailed changes due to factors such as timing.

[0138] At time T11, the potential of the wiring 121 is set to "Low", the potential of the wiring 122 is set to "High", If the potential of the line 131 is "Vdata" and the potential of the wiring 127 is "Vref", then the transistor The transistor 102 and the transistor 104 are turned on, and the potential of the wiring 131 is applied to the node ND1. The potential "Vref" of the wiring 127 is written to the node ND1 and the potential "Vdata" of the wiring 127 is written to the node ND2.

[0139] At this time, the potential difference V1 across the capacitive element 111 can be expressed by equation (11): The potential difference V2 across the capacitive element 112 can be expressed by equation (12).

[0140] V1=Vref-Vdata (11)

[0141] V2=Vref-Vano (12)

[0142] At time T12, the potential of the wiring 121 is set to "High" and the potential of the wiring 122 is set to "High." As a result, the transistor 102 and the transistor 104 are turned off.

[0143] At this time, the potential V of the node ND1 ND1 can be expressed by equation (13). 2 potential V ND2 can be expressed by equation (14).

[0144] V ND1 =Vdata+a (13)

[0145] V ND2 =Vref+b (14)

[0146] At this time, the potential difference V1 across the capacitive element 111 can be expressed by equation (15): The potential difference V2 across the capacitive element 112 can be expressed by equation (16).

[0147] V1=(Vref+b)-(Vdata+a) (15)

[0148] V2=(Vref+b)-Vano (16)

[0149] Next, the image data "Vdata" is written to node ND2 as the second data. The operation of boosting the potential of the node ND1 will now be described.

[0150] At time T13, the potential of the wiring 121 is set to "High" and the potential of the wiring 122 is set to "Low." Then, the transistor 103 is turned on, and the potential of the wiring 131 “Vda ta” is written.

[0151] At this time, the potential difference across the capacitive element 111 is maintained at V1 shown in equation (15). Therefore, the potential V ND1 can be expressed by equation (17). 2 potential V ND2 can be shown by equation (18).

[0152] V ND1 =2Vdata-Vref+ab (17)

[0153] V ND2 =Vdata (18)

[0154] At time T14, the potential of the wiring 121 is set to "High" and the potential of the wiring 122 is set to "High." Then, the transistor 103 becomes non-conductive, and the gate-source The voltage Vgs between the capacitors 111 and 112 is the sum of the voltages held by the capacitors 111 and 112, A current corresponding to Vgs flows through the light emitting device 114 .

[0155] At this time, the potential V of the node ND1 ND1 can be expressed by equation (19). 2 potential V ND2 can be expressed by equation (20).

[0156] V ND1 =2Vdata-Vref+a-b+c (19)

[0157] V ND2 =Vdata+c (20)

[0158] As described above, the pixel 10A receives a voltage (Vdata) corresponding to the supplied image data. The voltage is boosted to a voltage higher than the voltage at the time of the power supply voltage Vcc, and the voltage is applied to the transistor 101 functioning as a driving transistor. Therefore, the current flowing through the light-emitting device 114 can be increased. This makes it possible to provide a display device with high brightness.

[0159] <Pixel layout example> An example of the layout of the pixel 10 will be described below.

[0160] An example of the layout of the pixel 10 shown in FIG. 3A is shown in FIG. 8A.

[0161] FIG. 8A shows a transistor 101, a transistor 102, a transistor 103, and a transistor 104. A resistor 104, a capacitor 111, a capacitor 112, a wiring 121, a wiring 122, and a wiring 131 8B shows the wiring 127 and the wiring 128. 8A and 8B, for clarity, the light emitting The device 114 and the wiring 129 are omitted.

[0162] FIG. 9 shows a configuration in which a pixel electrode 53 is provided in addition to the configuration of FIG. 8A. The electrode 53 is electrically connected to the light emitting device 114. The light emitting device 114 is , can be provided on the pixel electrode 53.

[0163] In FIG. 9, the pixel electrode 53 includes a pixel 10 including a transistor 101 and a capacitor element 111. The light emitting element is provided so as to overlap with a part of the constituting elements and wiring. This is effective when using a top-emission type light-emitting device. By arranging the transistor 101 and the like below the electrode 53, the area occupied by the pixel 10 can be reduced. Even if the size is reduced, a large aperture ratio can be achieved.

[0164] As shown in FIG. 9, the pixel electrode 53 does not overlap with the wiring 131 that functions as a signal line. It is preferable that the pixel electrode 53 and the wiring 131 do not overlap each other. It is possible to suppress the influence of the pixel electrode 53 on the potential of the pixel electrode 53. When it is necessary to arrange the wiring 131 so as to overlap with the pixel electrode 53, the area of ​​the wiring 131 is The ratio of the overlapping area between them may be 10% or less, preferably 5% or less.

[0165] <Example of sub-pixel configuration> Configuration examples of subpixels that can be applied to a display device of one embodiment of the present invention are shown in FIGS. 10 and 11. A and 11B.

[0166] The pixel 10 shown in FIG. 10 has a sub-pixel 10R that emits red light and a sub-pixel 10B that emits green light. 10B, which emits blue light, and a sub-pixel 10G, which emits blue light. These three sub-pixels form one pixel 10B. 10 shows an example of forming a matrix of sub-pixels arranged in two rows and three columns. In addition to the two pixels 10, the wiring 121, the wiring 122, and the wiring 131 are also shown. The lines 121 and the wirings 122 may each have an area overlapping with the pixel electrodes 53 .

[0167] The sub-pixel 10R has a pixel electrode 53a, and the display area 51a of the sub-pixel 10R has the pixel electrode 53 The subpixel 10G has a pixel electrode 53b, and is located inside the display region 5a of the subpixel 10G. The sub-pixel 10B has a pixel electrode 53c, and the sub-pixel 10B is located inside the pixel electrode 53b. The display area 51c of 10B is located inside the pixel electrode 53c. 1 shows an example in which the pixel electrode 53a, the pixel electrode 53b, and the pixel electrode 53c have the same area. The display areas 51a, 51b, and 51c may have different areas. c. Each may have a different area.

[0168] The pixel 10 shown in FIG. 10 has sub-pixels of the same color arranged in the extending direction of the wiring 121 and the wiring 122. In other words, the pixel 10 is connected to the wiring 121 and the wiring 12 Sub-pixels of the same color are arranged in a zigzag pattern in the extension direction of 2.

[0169] In Figure 10, the combination of colors emitted by the sub-pixels is red (R), green (G), and blue (C). Although an example in which there are three colors (B) is shown, the combination of colors and the number of colors are not limited to this. The combination of colors emitted by the sub-pixels is red (R), green (G), blue (B), and white (W). or as four colors: red (R), green (G), blue (B), and yellow (Y) The color elements applied to the sub-pixels are not limited to the above, and may include cyan (C) and magenta (M). ) may be combined.

[0170] The pixel 10 shown in FIG. 11A has a rectangular shape in which the length of the subpixel is long in the direction in which the wiring 131 extends. and are arranged in stripes in the direction in which the wiring 121 and the wiring 122 extend. In the extending direction of the line 121 and the wiring 122, the subpixels 10R, 10G, and 10B This shows an example where

[0171] In the pixel 10 shown in FIG. 11B, sub-pixels are arranged in a stripe pattern, and wiring 121 and wiring 12 In other words, the positions of the sub-pixels of the same color are shifted in the direction of extension of the pixel 2. In the pixel 10, sub-pixels of the same color are arranged in a zigzag pattern in the direction in which the wiring 121 and the wiring 122 extend. are.

[0172] In this specification, the blue wavelength range is 400 nm or more and less than 490 nm. The blue light emission has at least one emission spectrum peak in the wavelength region. The green wavelength region is 490 nm or more and less than 580 nm, and green light is emitted in this wavelength region. It has at least one emission spectrum peak. The red wavelength region is 580 nm. The red light has at least one emission spectrum in the wavelength range of 680 nm or more and 680 nm or less. It has a peak.

[0173] <Display device configuration example 1> A display device according to one embodiment of the present invention will be described in detail below.

[0174] A block diagram showing a configuration example of the display device 100 is shown in FIG. a pixel section 150 having the pixel 10, a drive circuit section 130, a drive circuit section 140a, and a drive The circuit portion 140b includes a wiring 121, a wiring 122, and a wiring 131.

[0175] The pixel section 150 has a plurality of pixels 10, and the pixels 10 are arranged in a matrix. The driving circuit unit 130 is electrically connected to the pixel 10 via the wiring 121. The driving circuit unit 130 is electrically connected to the pixel 10 via the wiring 122. The driving circuit section 130 functions as a gate line driving circuit (also called a gate driver). The pixels 10 receive signals from the driving circuit unit 130 via wirings 121 and 122. The driving circuit unit 140a is connected to the pixel 10 via the wiring 131 and controls the driving. The drive circuit section 140b is electrically connected to the drive circuit section 140a via the wiring 131. The driving circuit unit 14 is electrically connected to a pixel 10 different from the pixel 10 to which it is electrically connected. The driver circuit portion 140a and the driver circuit portion 140b are source line driver circuits (also called source drivers). Each of the pixels 10 functions as a driving circuit unit 140a or a driving circuit unit 14 0b is given a signal through the wiring 131 to control the driving. The pixels 10 are electrically connected to the drive circuit unit 140a, and the pixels 10 in the even-numbered columns are connected to the drive circuit unit 14 0b.

[0176] A display device according to one embodiment of the present invention includes a plurality of driver circuit units each functioning as a source driver. By doing so, it is possible to operate a display device with a large number of pixels at high speed. The display device according to one embodiment has a resolution of, for example, 1000 ppi or more, 2000 ppi or more, or can be suitably used in high-resolution display devices with a resolution of 5000 ppi or more.

[0177] In FIG. 12, the driving circuit section 140 functions as a source driver. However, one embodiment of the present invention is not limited to this. Three or more drive circuit units that function as source drivers may be provided. One drive circuit unit may be provided to function as a driver.

[0178] A schematic diagram showing a configuration example of the display device 100 is shown in FIG. 13A. The display device 100 includes a first 13A, the first layer 20 is laminated with the second layer 30 on the first layer 20. However, one embodiment of the present invention is not limited to this. The first layer 20 may be provided on the second layer 30. In addition, the first layer 20 and the second layer 30 may be provided with one or more interlayer insulating layers and wiring layers. The number of interlayer insulating layers and wiring layers provided between the first and second wiring layers may be plural.

[0179] The first layer 20 includes a driving circuit section 140a and a driving circuit section 140b. The LCD device includes a driver circuit section 130 and a pixel section 150 .

[0180] An example of the configuration of the first layer 20 and the second layer 30 shown in Figure 13A is shown in Figure 13B. In the figure, the positional relationship between the first layer 20 and the second layer 30 is shown by the open circle and the dashed line. In plan view, the white circle of the first layer 20 and the white circle of the second layer 30 are connected by a dashed line. The same notation is used in other figures. For clarity, FIG. 13B omits wiring other than wiring 121, wiring 122, and wiring 131. .

[0181] The display device 100 includes a driving circuit section 140a and a driving circuit section 14 0b preferably have an area overlapping with the pixel section 150. The drive circuit section 140a and the drive circuit section 140b are stacked so as to have an overlapping area. By doing so, it is possible to reduce the area of ​​the frame, which is an area where the pixel section 150 is not provided. Therefore, the frame of the display device 100 can be narrowed. By narrowing the frame, the display device 100 can be made smaller.

[0182] In FIG. 13B, an example in which the first layer 20 and the second layer 30 are approximately the same size is shown. The outline of the invention is not limited to this. The first layer 20 and the second layer 30 may have different sizes. For example, the first layer 20 may be larger than the second layer 30. It may be smaller than the layer 30.

[0183] After forming the first layer 20, the second layer 30 is formed on the first layer 20 to form the display device 1. 00 can be fabricated. By forming the second layer 30 on the first layer 20, the first This can improve the accuracy of alignment between the first layer 20 and the second layer 30. 00's productivity can be increased.

[0184] After the first layer 20 and the second layer 30 are formed, the first layer 20 and the second layer 30 are The first layer 20 and the second layer 30 may be bonded together to produce the display device 100. When the display device 100 is manufactured in combination, the first layer 20 and the second layer 30 have different sizes. Therefore, the first layer 20 and the second layer 30 are not affected by each other in size. For example, a plurality of first layers 20 can be formed on a substrate on which the first layers 20 are to be formed. Then, after dividing into each first layer 20, they are bonded to the second layer 30 to form the display device 1. Similarly, the second layer 30 can be formed by forming a plurality of second The layer 30 is formed, and after dividing into each second layer 30, it is laminated with the first layer 20. In other words, the productivity of the first layer 20 and the second layer 30 can be improved. This can improve productivity of the display device 100 as well.

[0185] <Configuration example 2 of the display device> 14A and 14B show examples of a configuration different from that of the display device 100 shown in FIGS. 13A and 13B. The display device 100 shown in FIGS. 14A and 14B has a first layer 20 including a drive circuit section 13. 13A and 13B in that the display device 100 has a driving circuit section 130 is provided on the same first layer 20 as the driving circuit section 140a and the driving circuit section 140b. Thus, the manufacturing process of the drive circuit section 130, the drive circuit section 140a, and the drive circuit section 140b is completed. This allows for commonality, thereby improving productivity.

[0186] 14B shows an example in which the pixel section 150 does not have an area overlapping with the driver circuit section 130. However, one embodiment of the present invention is not limited to this. The pixel section 150 may have a driving circuit section 130, a driving circuit section 140a, and a It is also possible to have an area overlapping both the drive circuit section 140b and the drive circuit section 140c. This allows the frame of the display device 100 to be narrowed. By reducing the width, the display device 100 can be made smaller.

[0187] <Example 1 of cross-sectional configuration of display device> A cross-sectional view showing a configuration example of the display device 100 is shown in FIG. The substrate 701 and the substrate 705 are bonded together with a sealing material 712. are.

[0188] The substrate 701 can be a single crystal semiconductor substrate such as a single crystal silicon substrate. Note that the substrate 701 may be a semiconductor substrate other than a single crystal semiconductor substrate.

[0189] The transistor 441 and the transistor 601 are provided on a substrate 701. The transistor 441 and the transistor 601 are transistors provided in the first layer 20. For example, in the display device 100 shown in FIGS. 13A and 13B, The transistor 441 and the transistor 601 are connected to the drive circuit unit 140a or the drive circuit unit 140b. For example, the transistors shown in FIGS. 14A and 14B can be used. In the display device 100, the transistor 441 and the transistor 601 are connected to the driver circuit unit 13. 0. The transistor is provided in the drive circuit unit 140a or the drive circuit unit 140b. can be done.

[0190] The transistor 441 includes a conductor 443 that functions as a gate electrode and a gate insulating film 444. The insulator 445 functions as a dielectric, and a part of the substrate 701. The semiconductor region 447 includes a region that functions as either a source region or a drain region. The low-resistance region 449a and the low-resistance region 449b functioning as the other of the source region and the drain region The transistor 441 is either a p-channel or n-channel transistor. This is also fine.

[0191] The transistor 441 is electrically isolated from other transistors by an element isolation layer 403. In FIG. 15, the transistor 441 and the transistor 601 are separated by the element isolation layer 403. The element isolation layer 403 is formed by LOCOS (LOCal Oxidation of Silicon (STI) method or Shallow Transition (STI) method The insulating layer can be formed by using a method such as a annealing isolation method.

[0192] Here, the semiconductor region 447 of the transistor 441 shown in FIG. The conductor 443 covers the side and top surfaces of the semiconductor region 447 with the insulator 445 interposed therebetween. 15, the conductor 443 is provided so as to cover the side surface of the semiconductor region 447. The conductor 443 can be made of a material that can adjust the work function. Cut.

[0193] A transistor having a convex semiconductor region such as the transistor 441 is formed by Since the protrusions of the fin transistor are used, it can be called a fin transistor. and an insulator that functions as a mask for forming the protrusions is provided in contact with the upper portion of the 15 shows a configuration in which a part of the substrate 701 is processed to form a convex portion. However, a semiconductor having a convex shape may be formed by processing an SOI substrate.

[0194] Note that the configuration of the transistor 441 shown in FIG. 15 is an example, and the present invention is not limited to this configuration. An appropriate configuration may be used depending on the circuit configuration or the operation method of the circuit. For example, 441 may be a planar transistor.

[0195] The transistor 601 can have a structure similar to that of the transistor 441 .

[0196] On the substrate 701, an element isolation layer 403, a transistor 441, and a transistor 6 In addition to the insulating film 401, an insulator 405, an insulator 407, an insulator 409, and an insulator 411 are provided. Conductors 45 are disposed in the insulators 405, 407, 409, and 411. Here, the height of the upper surface of the conductor 451 and the height of the upper surface of the insulator 411 are can be done to the same extent.

[0197] An insulator 413 and an insulator 415 are provided over the conductor 451 and the insulator 411 . In addition, a conductor 457 is embedded in the insulator 413 and the insulator 415. The height of the upper surface of the conductor 457 and the height of the upper surface of the insulator 415 can be made approximately the same.

[0198] An insulator 417 and an insulator 419 are provided over the conductor 457 and the insulator 415 . In addition, a conductor 459 is embedded in the insulator 417 and the insulator 419. The height of the top surface of the conductor 459 and the height of the top surface of the insulator 419 can be made approximately the same.

[0199] An insulator 421 and an insulator 214 are provided over the conductor 459 and the insulator 419 . The conductor 453 is embedded in the insulator 421 and the insulator 214. The height of the upper surface of 453 and the height of the upper surface of the insulator 214 can be made to be approximately the same.

[0200] An insulator 216 is provided on the conductor 453 and on the insulator 214. The conductor 455 is buried. Here, the height of the upper surface of the conductor 455 and the height of the insulator 216 are The height of the top surface can be made the same.

[0201] On the conductor 455 and on the insulator 216, the insulator 222, the insulator 224, the insulator 254, Insulator 244, insulator 280, insulator 274, and insulator 281 are provided. 22, Insulator 224, Insulator 254, Insulator 244, Insulator 280, Insulator 2 The conductor 305 is embedded in the insulating material 281 and the insulating material 74. The height of the upper surface can be made approximately the same as the height of the upper surface of the insulator 281.

[0202] An insulator 361 is provided on the conductor 305 and on the insulator 281. The conductor 317 and the conductor 337 are buried. The height of the upper surface of the insulator 361 can be made approximately the same.

[0203] An insulator 363 is provided on the conductor 337 and on the insulator 361. Conductor 347, conductor 353, conductor 355, and conductor 357 are embedded. The height of the upper surfaces of the conductors 353, 355, and 357 and the upper surface of the insulator 363 are The height of the surfaces can be made the same.

[0204] The connection electrode 7 is formed on the conductor 353, the conductor 355, the conductor 357, and the insulator 363. 60 is provided. Anisotropic conductor 78 is provided so as to be electrically connected to connection electrode 760. 0 is provided, and an FPC (Flexible Printed Circuit) is provided so as to be electrically connected to the anisotropic conductor 780. The FPC 716 is provided with a FPC (Fiber Printed Circuit) 716. Various signals and the like are supplied to the display device 100 from outside the display device 100 .

[0205] As shown in FIG. 15, the other of the source region and the drain region of the transistor 441 is The low resistance region 449b having the function of Conductor 453, Conductor 455, Conductor 305, Conductor 317, Conductor 337, Conductor 347 , the conductor 353, the conductor 355, the conductor 357, the connection electrode 760, and the anisotropic conductor 78 15, the connecting electrode 76 is electrically connected to the FPC 716 via the connecting electrode 76. Conductor 353 and conductor 347 are conductors having the function of electrically connecting 355 and the conductor 357 are shown, one embodiment of the present invention is not limited to this. There may be one conductor that has the function of electrically connecting the electrode 760 and the conductor 347. The number of the connection electrodes 760 and the conductors 347 may be two, four, or more. By providing a plurality of conductors each having the function of connecting to the .

[0206] A transistor 750 is provided on the insulator 214. The transistor 750 is a second For example, the transistors shown in FIGS. 13A and 13B can be provided in the layer 30. In the display device 100 shown in FIGS. 14A and 14B, the transistor 750 is The transistor 750 may be the transistor provided in the OS transistor 150. An OS transistor can be preferably used. Therefore, the retention time of image signals etc. can be extended, Therefore, the power consumption of the display device 100 can be reduced. can.

[0207] Insulator 254, insulator 244, insulator 280, insulator 274, and insulator 28 The conductor 301a and the conductor 301b are embedded in the conductive layer 1. The conductor 301b is electrically connected to either the source or the drain of the transistor 750. The transistor 750 is electrically connected to the other of the source and drain. The height of the upper surfaces of the conductive body 301a and the conductive body 301b is approximately equal to the height of the upper surface of the insulator 281. can.

[0208] In the insulator 361, the conductor 311, the conductor 313, the conductor 331, the capacitance element 790, the conductor The conductor 311 and the conductor 313 are buried in the The conductor 333 is electrically connected to the resistor 750 and functions as a wiring. 335 is electrically connected to the capacitor element 790. Here, the conductor 331, the 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.

[0209] Conductor 341 , conductor 343 , and conductor 351 are embedded in insulator 363 . Here, the height of the upper surface of the conductor 351 and the height of the upper surface of the insulator 363 can be made to be approximately the same.

[0210] Insulator 405, insulator 407, insulator 409, insulator 411, insulator 413, insulator 4 15, insulator 417, insulator 419, insulator 421, insulator 214, insulator 280, insulation The insulator 274, the insulator 281, the insulator 361, and the insulator 363 function as an interlayer film. In addition, it may also have a function as a planarizing film that covers the underlying uneven shapes. The top surface of the insulator 363 is polished by chemical mechanical polishing (CMP) to improve flatness. l Flattening by flattening process using mechanical polishing method etc. It may be done.

[0211] For example, in the display device 100 shown in FIGS. 13 and 14, the capacitance element 790 is The capacitor 111 or the capacitor 112 provided in the circuit 150 can be used.

[0212] As shown in FIG. 15, the capacitance element 790 has a lower electrode 321 and an upper electrode 325. In addition, an insulator 323 is provided between the lower electrode 321 and the upper electrode 325. That is, the capacitor 790 has an insulator 323 sandwiched between a pair of electrodes, which functions as a dielectric. 15 shows an example in which a capacitor 790 is provided on an insulator 281. 7, the capacitor 790 may be provided over an insulator different from the insulator 281.

[0213] In FIG. 15, the conductor 301a, the conductor 301b, and the conductor 305 are formed in the same layer. In addition, the conductor 311, the conductor 313, the conductor 317, and the lower In this example, the conductor 331 and the conductor 333 are formed in the same layer. 10 shows an example in which the conductor 335 and the conductor 337 are formed in the same layer. In this example, the conductive material 341, the conductive material 343, and the conductive material 347 are formed in the same layer. Furthermore, the conductor 351, the conductor 353, the conductor 355, and the conductor 357 are formed in the same layer. By forming a plurality of conductors in the same layer, the display device 100 Since the manufacturing process can be simplified, the manufacturing cost of the display device 100 can be reduced. These may be formed in different layers and may be made of different types of materials. You may do so.

[0214] The display device 100 shown in FIG. 15 includes a light-emitting device 782. The light-emitting device 782 is The EL layer 786 includes an organic compound. or inorganic compounds such as quantum dots.

[0215] Materials that can be used for the organic compound include fluorescent materials and phosphorescent materials. In addition, materials that can be used for quantum dots include colloidal quantum dot materials, Examples include mold quantum dot materials, core-shell quantum dot materials, and core quantum dot materials. can be.

[0216] The conductor 772 includes the conductor 351, the conductor 341, the conductor 331, the conductor 313, and the conductor The other of the source and drain of the transistor 750 is electrically connected via the conductive body 301b. The conductor 772 is formed on the insulator 363 and functions as a pixel electrode. .

[0217] The conductor 772 can be made of a material that is transparent to visible light or a material that is reflective to visible light. As the light-transmitting material, for example, an oxide material containing indium, zinc, tin, etc. is used. As the reflective material, for example, a material containing aluminum, silver, etc. may be used. .

[0218] Although not shown in FIG. 15, the display device 100 may include a polarizing member, a phase difference member, an anti-reflection member, etc. An optical member (optical substrate) or the like can be provided.

[0219] On the substrate 705 side, a light-shielding layer 738 and an insulator 734 in contact with the light-shielding layer 738 are provided. The light-shielding layer 738 has a function of blocking light emitted from the adjacent region. 8 has the function of blocking external light from reaching the transistor 750 and the like.

[0220] In the display device 100 shown in FIG. 15, an insulator 730 is provided on the insulator 363. The insulator 730 can be configured to cover part of the conductor 772. The device 782 has a light-transmitting conductor 788 and is a top-emission light-emitting device. The light-emitting device 782 can be a bottom emitter that emits light to the conductor 772 side. A mission structure or a dual emitter that emits light to both conductor 772 and conductor 788. A cushion structure may also be used.

[0221] The light-shielding layer 738 is provided so as to have a region overlapping with the insulator 730. The light-shielding layer 738 is covered with an insulator 734. The gap between the holes 34 is filled with a sealing layer 732.

[0222] Furthermore, the structure 778 is disposed between the insulator 730 and the EL layer 786. Structure 778 is disposed between insulator 730 and insulator 734 .

[0223] A modified example of the display device 100 shown in FIG. 15 is shown in FIG. 16. 15 in that a colored layer 736 is provided. The coloring layer 736 is provided to have an area overlapping with the light-emitting device 782. By providing the light emitting device 782 with the light emitting element 6, the color purity of the light extracted from the light emitting device 782 can be improved. This allows the display device 100 to display a high-quality image. For example, all the 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 separate coating, and the display device 100 can be made highly precise.

[0224] The light emitting device 782 may have a micro-optical resonator (microcavity) structure. This makes it possible to extract light of a specific color (for example, RGB) without providing a colored layer. This allows the display device 100 to perform color display. This makes it possible to suppress the absorption of light by the colored layer. 0 can display a high brightness image and reduce the power consumption of the display device 100. The EL layer 786 can be formed in an island shape for each pixel or in a stripe shape for each pixel column, that is, Even when forming the layers by coloring, it is possible to adopt a configuration in which no colored layer is provided.

[0225] 15 and 16, the transistor 441 and the transistor 601 are connected to the substrate 701. The transistor 441 and the transistor 442 are provided so as to form a channel formation region therein. Although the structure in which an OS transistor is stacked on the semiconductor substrate 601 is shown, one embodiment of the present invention is A modification of FIG. 16 is shown in FIG. 17. The display device 100 shown in FIG. 17 is Instead of the transistor 441 and the transistor 601, a transistor that is an OS transistor is used. 16 in that it has a capacitor 602 and a transistor 603. The transistor 750 can be an OS transistor. The display device 100 shown in FIG. 17 includes stacked OS transistors.

[0226] An insulator 613 and an insulator 614 are provided on the substrate 701, and a transistor is provided on the insulator 614. The transistor 602 and the transistor 603 are provided. For example, a transistor or the like may be provided between the substrate 701 and the insulator 6 13, a transistor having a structure similar to the transistor 441 and the transistor 601 shown in FIG. A transistor of the same configuration may be provided.

[0227] The transistor 602 and the transistor 603 are transistors provided in the first layer 20. For example, in the display device 100 shown in FIGS. 13A and 13B, The transistor 602 and the transistor 603 are connected to the driver circuit unit 140a or the driver circuit unit 140b. 140b. For example, the transistors shown in FIGS. 14A and 14B In the display device 100 shown in FIG. Transistors provided in the circuit section 130, the drive circuit section 140a, or the drive circuit section 140b It can be said that:

[0228] The transistor 602 and the transistor 603 have the same configuration as the transistor 750. The transistors 602 and 603 can be transistors. An OS transistor having a different structure from the transistor 750 may be used.

[0229] The transistor 602 and the transistor 603 are disposed on the insulator 614, and the insulator 616 is disposed on the insulator 614. , insulator 622, insulator 624, insulator 654, insulator 644, insulator 680, insulator 6 74, and insulator 681 are provided. The conductor 461 is embedded in the insulating material 674 and the insulating material 681. The height of the top surface of the conductive body 461 and the height of the top surface of the insulator 681 can be made to be approximately the same.

[0230] An insulator 501 is provided on the conductor 461 and the insulator 681. The conductor 463 is buried. Here, the height of the upper surface of the conductor 463 and the height of the insulator 501 are The height of the top surface can be made the same.

[0231] An insulator 503 is provided on the conductor 463 and the insulator 501. The conductor 465 is buried. Here, the height of the upper surface of the conductor 465 and the height of the insulator 503 are The height of the top surface can be made the same.

[0232] An insulator 505 is provided on the conductor 465 and the insulator 503. A conductor 467 is embedded in the insulator 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.

[0233] An insulator 507 is provided on the conductor 467 and on the insulator 505. The conductor 469 is buried. Here, the height of the upper surface of the conductor 469 and the height of the insulator 507 are The height of the top surface can be made the same.

[0234] An insulator 509 is provided on the conductor 469 and the insulator 507. A conductor 471 is embedded in the insulating layer 9. Here, the height of the upper surface of the conductor 471 and the height of the insulator 5 are The height of the top surface of 09 can be made to be about the same.

[0235] An insulator 421 and an insulator 214 are provided over the conductor 471 and the insulator 509 . The conductor 453 is embedded in the insulator 421 and the insulator 214. The height of the upper surface of 453 and the height of the upper surface of the insulator 214 can be made to be approximately the same.

[0236] As shown in FIG. 17, one of the source and 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 conductor 353, the conductor 355, the conductor 357, the connection electrode 760, and the anisotropic conductor 780 are It is electrically connected to the FPC716 via a

[0237] Insulator 613, insulator 614, insulator 680, insulator 674, insulator 681, insulator 5 01, the insulator 503, the insulator 505, the insulator 507, and the insulator 509 are interlayer films. and may also function as a planarizing film that covers the underlying uneven shapes. stomach.

[0238] By configuring the display device 100 as shown in FIG. 17, the frame of the display device 100 can be narrowed and the display device can be made small. While achieving a smaller size, all transistors in the display device 100 are OS transistors. This allows, for example, a transistor provided in the first layer 20 and a transistor provided in the second layer 30 The transistors provided in the first and second gate electrodes can be manufactured using the same device. The manufacturing cost of the display device 100 can be reduced, making the display device 100 low-priced. It is possible.

[0239] <Example 2 of cross-sectional configuration of display device> 18 is a cross-sectional view showing a configuration example of the display device 100. Between the layer having the transistor 601 and the layer having the transistor 441, the transistor 8 The main difference from the display device 100 shown in FIG. 16 is that it has a layer having 00.

[0240] The first layer 20 shown in FIG. 13A and the like is a first circuit layer and a second circuit layer on the first circuit layer. For example, the transistor 601 and the transistor 441 may have a stacked structure. The transistor 800 may be a transistor provided in the first circuit layer. The transistor 750 may be a transistor provided in the second circuit layer. It may be a transistor provided in layer 30.

[0241] An insulator 821 and an insulator 814 are provided over the conductor 459 and the insulator 419 . The conductor 853 is embedded in the insulator 821 and the insulator 814. The height of the upper surface of 853 and the height of the upper surface of insulator 814 can be made to be approximately the same.

[0242] An insulator 816 is provided on the conductor 853 and the insulator 814. The conductor 855 is buried. Here, the height of the upper surface of the conductor 855 and the height of the insulator 816 are The height of the top surface can be made the same.

[0243] On the conductor 855 and on the insulator 816, an insulator 822, an insulator 824, an insulator 854, Insulator 844, insulator 880, insulator 874, and insulator 881 are provided. 22 in, insulator 824 in, insulator 854 in, insulator 844 in, insulator 880 in, insulator 8 The conductor 805 is embedded in the insulating material 881 and the insulating material 74. The height of the upper surface can be made to be approximately the same as the height of the upper surface of the insulator 881 .

[0244] An insulator 421 and an insulator 214 are provided over the conductor 817 and the insulator 881 .

[0245] As shown in FIG. 18, the other of the source region and the drain region of the transistor 441 is The low resistance region 449b having the function of Conductor 853, Conductor 855, Conductor 805, Conductor 817, Conductor 453, Conductor 455 , Conductor 305, Conductor 317, Conductor 337, Conductor 347, Conductor 353, Conductor 3 55, the conductor 357, the connection electrode 760, and the anisotropic conductor 780, and the FPC 716 and is electrically connected.

[0246] The transistor 800 is provided on the insulator 814. The transistor 800 is a second For example, the transistors shown in FIGS. 13A and 13B can be provided in the layer 30. In the display device 100 shown in FIG. 1, the transistor 800 is For example, the transistors shown in FIGS. In the display device 100 shown in FIG. 14B, the transistor 800 is connected to the drive circuit unit 130, The transistor may be provided in the drive circuit unit 140a or the drive circuit unit 140b. The transistor 800 is preferably an OS transistor.

[0247] Insulator 854, insulator 844, insulator 880, insulator 874, and insulator 88 The conductor 801a and the conductor 801b are embedded in the conductive layer 1. The conductor 801b is electrically connected to either the source or the drain of the transistor 800. The transistor 800 is electrically connected to the other of the source and drain. The height of the upper surfaces of the body 801a and the conductor 801b is approximately the same as the height of the upper surface of the insulator 881. can.

[0248] The transistor 750 may be a transistor provided in the second layer 30 . For example, in the display device 100 shown in FIGS. 13A, 13B, 14A, and 14B, The transistor 750 can be a transistor provided in the pixel portion 150. Transistor 750 is preferably an OS transistor.

[0249] Note that the layer in which the transistor 441, the transistor 601, and the like are provided and the An OS transistor or the like may be provided between the layer on which the transistor 800 or the like is provided. Between the layer in which the transistor 800 and the like are provided and the layer in which the transistor 750 and the like are provided, Furthermore, a layer above the layer where the transistor 750 is provided may be provided. An OS transistor or the like may be provided in the layer.

[0250] Insulator 405, insulator 407, insulator 409, insulator 411, insulator 413, insulator 4 15, insulator 417, insulator 419, insulator 821, insulator 814, insulator 880, insulation Insulator 874, insulator 881, insulator 421, insulator 214, insulator 280, insulator 274, The insulator 281, the insulator 361, and the insulator 363 function as interlayer films. It may also function as a planarizing film that covers the underlying unevenness.

[0251] In FIG. 18, a conductor 801a, a conductor 801b, and a conductor 805 are formed in the same layer. In addition, the conductor 811, the conductor 813, and the conductor 817 are the same. 1 shows an example in which the layer

[0252] In FIG. 18, the transistor 441 and the transistor 601 are placed inside the substrate 701. A channel forming region is formed on the transistor 441 and the transistor 601. However, one embodiment of the present invention is not limited to this. A modification of FIG. 18 is shown in FIG. 19. The display device 100 shown in FIG. 19 has four transistors. Instead of transistor 41 and transistor 601, transistors 602 and 603, which are OS transistors, are used. 18 in that it has a transistor 603. The display device 100 shown in FIG. 19 includes three stacked OS transistor layers.

[0253] A layer in which the transistor 602, the transistor 603, etc. are provided, and a layer in which the transistor 800 An OS transistor or the like may be provided between the layer where the transistor or the like is provided and the layer where the transistor or the like is provided. The layer in which the transistor 800 or the like is provided and the layer in which the transistor 750 or the like is provided are An OS transistor or the like may be provided between the layer. An OS transistor or the like may be provided above the layer where the gate is blocked.

[0254] For example, the transistor 602 and the transistor 603 are transistors provided on the first circuit layer. The transistor 800 can be a transistor provided in the second circuit layer. The transistor 750 can be a transistor provided in the second layer 30. It can be a star.

[0255] An insulator 821 and an insulator 814 are provided over the conductor 471 and the insulator 509 . The conductor 853 is embedded in the insulator 821 and the insulator 814. The height of the upper surface of 853 and the height of the upper surface of insulator 814 can be made to be approximately the same.

[0256] As shown in FIG. 19, one of the source and 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 Conductor 305, Conductor 317, Conductor 337, Conductor 347, Conductor 353, Conductor 355 , the FPC 716 and the electric power are connected via the electric conductor 357, the connection electrode 760, and the anisotropic electric conductor 780. are electrically connected.

[0257] By configuring the display device 100 as shown in FIG. 19, the display device 100 can be made smaller with a narrower frame. While achieving a smaller size, all transistors in the display device 100 are OS transistors. This eliminates the need to fabricate different types of transistors, allowing for The manufacturing cost of the display device 100 can be reduced, and the display device 100 can be made inexpensive. This can be done.

[0258] <Example of light-emitting device configuration> As the light-emitting device 572, for example, an EL element that utilizes electroluminescence is used. The EL element can be applied to a device that includes a layer containing a light-emitting compound between a pair of electrodes (hereinafter, A voltage higher than the threshold voltage of the EL element is applied between a pair of electrodes. When a potential 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 luminescent material contained in the EL layer to emit light. do.

[0259] EL elements are classified according to whether the light-emitting material is an organic compound or an inorganic compound. Generally, the former is called an organic EL element, and the latter is called an inorganic EL element.

[0260] When a voltage is applied to an organic EL element, electrons are emitted from one electrode and positive electrons are emitted from the other electrode. The holes are injected into the EL layer, and the carriers (electrons and holes) recombine. By this, the light-emitting organic compound forms an excited state, and the excited state returns to the ground state. Due to this mechanism, such a light-emitting device is a current-excited light-emitting device. These are called optical devices.

[0261] In this specification, the voltage supplied to a display element such as a light-emitting device or a liquid crystal element is A potential applied to one electrode of the display element and a potential applied to the other electrode of the display element Indicates the difference between the two places.

[0262] In addition to the light-emitting compound, the EL layer may contain a material with high hole injection properties and a material with high hole transport properties. materials, hole blocking materials, materials with high electron transport properties, materials with high electron injection properties, or bipolar The layer may contain a highly functional substance (a substance having high electron-transporting and hole-transporting properties), or the like.

[0263] The EL layer can be produced by a variety of methods, including vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating. It can be formed by the following method.

[0264] Inorganic EL elements are classified into dispersed inorganic EL elements and thin-film inorganic EL elements depending on the device configuration. Dispersion-type inorganic EL elements are luminescent elements in which particles of luminescent material are dispersed in a binder. The light emission mechanism is a donor layer that utilizes the donor level and the acceptor level. Thin-film inorganic EL devices sandwich the light-emitting layer between dielectric layers. The light-emitting mechanism is the transition of inner electrons of metal ions. This is a localized emission that utilizes electron transfer.

[0265] A light-emitting device only requires that at least one of the pair of electrodes is transparent in order to extract light. Then, a transistor and a light-emitting device are formed on the substrate, and the substrate is Top emission structure that extracts light from the top surface, and bottom emission structure that extracts light from the surface on the substrate side Bottom emission structure and dual emission structure that emits light from both sides There are light-emitting devices with a mission structure, and any light-emitting device with an injection structure can be applied. can.

[0266] 20A to 20E are diagrams showing examples of the configuration of a light-emitting device 572. 7 shows a structure (single structure) in which an EL layer 786 is sandwiched between a conductor 772 and a conductor 788. As mentioned above, the EL layer 786 contains a light-emitting material, for example, an organic compound light-emitting Materials included.

[0267] FIG. 20B is a diagram showing the laminated structure of the EL layer 786. Here, the structure shown in FIG. In light-emitting device 572, conductor 772 functions as an anode, and conductor 788 functions as a cathode. It has the function as.

[0268] The EL layer 786 is formed by stacking a hole injection layer 721, a hole transport layer 722, a light-emitting layer 723, and a conductor 772 thereon. The conductive layer 723, the electron transport layer 724, and the electron injection layer 725 are laminated in this order. When the conductor 772 functions as a cathode and the conductor 788 functions as an anode, , the stacking order is reversed.

[0269] The light-emitting layer 723 has a light-emitting material or a combination of materials, and emits light of a desired color. The light-emitting layer 723 can have a structure in which fluorescent light or phosphorescent light can be emitted. It is also possible to use a laminated structure in which different luminescent colors are emitted. The optical material and other materials may be different materials.

[0270] In the light-emitting device 572, for example, the conductor 772 shown in FIG. 20B 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 this, light emitted from the light-emitting layer 723 included in the EL layer 786 is resonated between both electrodes. This can intensify the light emitted through the conductor 788.

[0271] The conductor 772 of the light-emitting device 572 is made of a conductive material having reflectivity and a light-transmitting material. When the reflective electrode has a laminated structure with a conductive material (transparent conductive film) that By controlling the film thickness, optical adjustment can be performed. The distance between the electrodes of the conductor 772 and the conductor 788 is mλ / 2, where λ is the wavelength of the light to be obtained. (where m is a natural number)

[0272] In order to amplify the desired light (wavelength: λ) obtained from the light emitting layer 723, The optical distance from the conductor 788 to the region (light emitting region) where desired light is obtained from the light emitting layer is and the optical distance to the region (light emitting region) of the optical layer 723 where the desired light is obtained (2 m It is preferable to adjust the wavelength to be in the vicinity of m'+1)λ / 4 (where m' is a natural number). The light-emitting region here refers to a recombination region of holes and electrons in the light-emitting layer 723. Shows.

[0273] By performing such optical adjustment, the specific monochromatic light spectrum obtained from the light emitting layer 723 can be adjusted. It is possible to narrow the spectrum and obtain light emission with good color purity.

[0274] However, in the above case, the optical distance between the conductor 772 and the conductor 788 is, strictly speaking, 2 to the reflective area of ​​the conductor 788. However, it is difficult to precisely determine the reflection area of ​​the conductor 772 or the conductor 788. Therefore, it is sufficient to assume that any position of the conductor 772 and the conductor 788 is a reflection area. In addition, the conductor 772 and the light emitting element 773 that can obtain the desired light can be obtained. Strictly speaking, the optical distance between the reflective area of ​​the conductor 772 and the light emitting area where the desired light is obtained is However, the conductor 772 is It is difficult to strictly determine the reflection region in the light emitting layer and the light emitting region in the light emitting layer where the desired light is obtained. Therefore, any position of the conductor 772 may be set as a reflection region, and any position of the light-emitting layer from which desired light can be obtained may be set as a reflection region. The above-mentioned effect can be sufficiently obtained by assuming any position as the light-emitting region.

[0275] The light-emitting device 572 shown in FIG. 20B has a microcavity structure, so it has the same E Even if the L layer is included, light of different wavelengths (monochromatic light) can be extracted. There is no need to paint different colors (e.g., RGB) to obtain different luminous colors. This allows for high definition. It is also possible to combine it with a colored layer. Since it is possible to increase the light emission intensity in the front direction, it is possible to reduce power consumption.

[0276] It should be noted that the light-emitting device 572 shown in FIG. 20B does not have a microcavity structure. In this case, the light-emitting layer 723 may be configured to emit white light, and a colored layer may be provided. By this, it is possible to extract light of a predetermined color (for example, RGB). When forming the LED, if different colors are applied to obtain different luminescent colors, the desired color can be obtained without providing a colored layer. It is possible to extract light from

[0277] At least one of the conductor 772 and the conductor 788 is a light-transmitting electrode (a transparent electrode, a semiconductor When the electrode having light transmission is a transparent electrode, the transparent electrode can be The visible light transmittance of the electrode is 40% or more. In the case of a semi-transparent / semi-reflective electrode, the semi-transparent The reflectance of the semi-reflective electrode for visible light is 20% or more and 80% or less, preferably 40% or more and 70% or less. The resistivity of these electrodes is 1×10 -2 Ωcm or less is preferable.

[0278] When the conductor 772 or the conductor 788 is an electrode having reflectivity (a reflective electrode), the reflective The reflectance of the electrode having the property of visible light is 40% or more and 100% or less, preferably 70% or more and 100% or less. 00% or less. The resistivity of this electrode is 1×10 -2 Ωcm or less is preferable.

[0279] The light emitting device 572 may have a configuration as shown in FIG. Two EL layers (EL layer 786a and EL layer 786b) are provided between the substrate 772 and the conductor 788. a stacked structure having a charge generating layer 792 between the EL layer 786a and the EL layer 786b; The light emitting device 572 has a tandem structure. This can increase the current efficiency and external quantum efficiency of the light-emitting device 572. This allows the display device 100 to display a high-brightness image. Here, the EL layer 786a and the EL layer 786b are The EL layer 786 may have the same structure as that of the EL layer 786 shown in FIG.

[0280] The charge generating layer 792 generates a charge when a voltage is applied between the conductor 772 and the conductor 788. Electrons are injected into one of the L layer 786a and the EL layer 786b, and holes are injected into the other. Therefore, the potential of the conductor 772 is higher than the potential of the conductor 788. When a voltage is applied so that the charge generation layer 792 is turned on, electrons are injected into the EL layer 786a. Holes are injected from the charge generating layer 792 into the EL layer 786b.

[0281] In addition, the charge generation layer 792 transmits visible light from the viewpoint of light extraction efficiency (specifically, It is preferable that the visible light transmittance of the charge generation layer 792 is 40% or more. The conductivity of the charge generating layer 792 is lower than the conductivity of the conductor 772 or the conductivity of the conductor 788. That's fine.

[0282] The light emitting device 572 may have a configuration as shown in FIG. Three EL layers (EL layer 786a, EL layer 786b, and EL layer 786c) is provided between EL layer 786a and EL layer 786b and between EL layer 78 7. Tandem light-emitting device 5 having a charge generation layer 792 between EL layer 786b and EL layer 786c. 72. Here, the EL layer 786a, the EL layer 786b, and the EL layer 786c are the same as those in FIG. The light-emitting device 572 can have a configuration similar to that of the EL layer 786 shown in FIG. By adopting the configuration shown in FIG. 1, the current efficiency and external quantum efficiency of the light-emitting device 572 can be further improved. Therefore, the display device 100 can display an image with even higher brightness. Moreover, the power consumption of the display device 100 can be further reduced.

[0283] The light emitting device 572 may have a configuration as shown in FIG. Between the substrate 772 and the conductor 788, n EL layers (EL layer 786(1) to EL layer 786( n)) are provided, and a charge generation layer 792 is provided between each EL layer 786. 7 shows a light-emitting device 572 having an EL layer 786(1) through an EL layer 786(n). 20E, the EL layer 786 can have the same structure as the EL layer 786 shown in FIG. Among the EL layers 786, the EL layer 786(1), the EL layer 786(m), and the EL layer 786(n ) where m is an integer greater than or equal to 2 and less than n, and n is an integer greater than or equal to m. The higher the value, the higher the current efficiency and external quantum efficiency of the light-emitting device 572 can be. Therefore, a high brightness image can be displayed on the display device 100. 0 power consumption can be reduced.

[0284] The constituent materials that can be used for the light-emitting device 572 will now be described.

[0285] [Conductor 772 and Conductor 788] The conductor 772 and the conductor 788 may have the following functions as an anode and a cathode. The materials shown in the table below can be used in appropriate combination. For example, metals, alloys, electrically conductive materials, etc. In-Sn oxides and mixtures thereof can be used as appropriate. (also called ITO), In-Si-Sn oxide (also called ITSO), In-Zn oxide , In-W-Zn oxide. Other examples include aluminum (Al), 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. In addition, the above-exemplified metals and alloys containing them in appropriate combination can also be used. Elements belonging to Group 1 or 2 of the Periodic Table (e.g., lithium (Li), cesium) (Cs), calcium (Ca), strontium (Sr), europium (Eu), Rare earth metals such as tterbium (Yb) and alloys containing these in appropriate combinations, and other group Lafene and the like can be used.

[0286] [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 through the EL layer 786. The EL layer 78 is a layer that injects holes into the EL layer 78 and contains a material with high hole injection properties. 6 includes an EL layer 786a, an EL layer 786b, an EL layer 786c, and EL layers 786(1) to 786(6). It is assumed that the EL layer 786(n) is included.

[0287] Materials with high hole injection properties include molybdenum oxide, vanadium oxide, and ruthenium oxide. Examples of oxides of transition metals include oxides of tungsten, manganese, and the like. Phthalocyanine compounds, aromatic amine compounds, polymers, etc. can be used.

[0288] As materials with high hole injection properties, hole transport materials and acceptor materials (electron acceptor materials) ) can also be used. In this case, the hole transport is performed by the acceptor material. Electrons are extracted from the conductive material, generating holes in the hole injection layer 721. The holes are then transported through the hole transport layer 722. The hole injection layer 721 is made of a hole transporting material and an arsenic compound. It may be formed as a single layer made of a composite material containing an acceptor material (electron-accepting material), The hole transport material and the acceptor material (electron acceptor material) are laminated in separate layers. It may be formed.

[0289] The hole transport layer 722 transports holes injected from the conductor 772 by the hole injection layer 721. The hole transport layer 722 is a layer that transports electrons to the light-emitting layer 723. The hole transport layer 722 is a layer containing a hole transport material. The hole transporting material used for the hole transport layer 722 is particularly It is preferable to use a compound having a HOMO level that is the same as or close to the HOMO level.

[0290] The acceptor material used for the hole injection layer 721 is a material of Group 4 to 5 in the periodic table. Oxides of metals belonging to Group 8 can be used. Specifically, molybdenum oxide, Vanadium, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide Among them, molybdenum oxide is particularly stable in the atmosphere and is easily absorbed. It is preferred because it has low moisture resistance and is easy to handle. Other examples include quinodimethane derivatives and chloranil derivatives. Organic acceptors such as hexaazatriphenylene derivatives can be used.

[0291] The hole transporting material used in the hole injection layer 721 and the hole transporting layer 722 is 10 -6 cm 2 / A material having a hole mobility of Vs or higher is preferred. Other materials can be used as long as they are of the same quality.

[0292] Hole transport materials are π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives and indium ions). dhole derivatives) and aromatic amine compounds are preferred.

[0293] However, the hole transport material is not limited to the above, and one or more of various known materials may be used. The hole-transporting material may be used in combination in the hole injection layer 721 and the hole transport layer 722. The hole transport layer 722 may be formed of a plurality of layers. For example, a first hole transport layer and a second hole transport layer may be laminated.

[0294] [Light-emitting layer 723] The light-emitting layer 723 is a layer containing a light-emitting substance. A substance that emits light of a color such as red, green, yellow-green, yellow, orange, or red is appropriately used. 20C, 20D, and 20E, a light-emitting device 572 may have multiple EL layers. In this case, different light-emitting materials are used for the light-emitting layers 723 provided in the respective EL layers. and a configuration that exhibits different luminescent colors (for example, a configuration that can be obtained by combining luminescent colors that are complementary to each other). For example, if the light-emitting device 572 has the configuration shown in FIG. 20C, In some cases, the luminescent material used in the luminescent layer 723 provided in the EL layer 786a and the luminescent material used in the EL layer 786b are By making the luminescent material used in the luminescent layer 723 provided in the luminescent layer 86b different from that of the luminescent material used in the luminescent layer 723 provided in the luminescent layer 86b, The color of light emitted by the L layer 786a can be made different from the color of light emitted by the EL layer 786b. It is also possible to use a laminated structure in which one light-emitting layer contains different light-emitting materials.

[0295] The light-emitting layer 723 contains one or more organic compounds (phosphatides) in addition to a light-emitting substance (guest material). The organic compound may contain one or more organic compounds (e.g., a support material, an assist material). In this case, one or both of a hole transporting material and an electron transporting material can be used.

[0296] The light-emitting material that can be used for the light-emitting layer 723 is not particularly limited. luminescent material that converts triplet excitation energy into visible light emission, or triplet excitation energy into visible light emission The above-mentioned luminescent material can be, for example, the following: Some examples include:

[0297] Fluorescent materials are luminescent materials that convert singlet excitation energy into light. Examples thereof include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, and the like. Olene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives , dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives In particular, pyrene derivatives are This is preferred because of its high light quantum yield.

[0298] As a luminescent material that converts triplet excitation energy into luminescence, for example, a phosphorescent material (phosphor and thermally activated delayed fluorescence (TADF) activated delayed fluorescence) materials.

[0299] Phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. These emit different colors (emission peaks) depending on the substance, so they should be selected appropriately as needed. Select and use.

[0300] The blue luminescent material has a photoluminescence peak wavelength of 430 nm or more and 470 nm or more. It is preferable to use a substance having a wavelength of 430 nm or less and more preferably 460 nm or more. Green luminescent materials have a photoluminescence peak wavelength of 500 nm or more and 540 nm or less. More preferably, a substance with a wavelength of 500 nm or more and 530 nm or less may be used. The photoluminescence peak wavelength is preferably 610 nm or more and 680 nm or less. The wavelength of the photoluminescence measurement material should be between 620 nm and 680 nm. The measurement may be in the form of a solution or a thin film.

[0301] By using such a compound in combination with the microcavity effect, the above-mentioned The color can be achieved at this time, and the semi-transparent color required to achieve the microcavity effect can be achieved. The thickness of the semi-reflective electrode (metal thin film portion) is preferably 20 nm or more and 40 nm or less. Preferably, it is greater than 25 nm and equal to or less than 40 nm. However, if it exceeds 40 nm, the efficiency will decrease. There is a possibility that it will go down.

[0302] The organic compounds (host material, assist material) used in the light-emitting layer 723 are light-emitting materials (guest A substance that has an energy gap larger than the energy gap of a material is called a kind or In addition, the hole transport material and the electron transport material described later may be used in combination. Each of the materials can also be used as a host material or an assist material.

[0303] When the light-emitting substance is a fluorescent material, the host material has a high energy level in the singlet excited state. Therefore, it is preferable to use an organic compound with a small energy level in the triplet excited state. For example, it is preferable to use an anthracene derivative or a tetracene derivative.

[0304] When the emitting material is a phosphorescent material, the host material is a material that can absorb the triplet excitation energy of the emitting material. (energy difference between the ground state and the triplet excited state) In this case, in addition to zinc and aluminum-based metal complexes, Oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives Conductors, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, In addition to anthroline derivatives, aromatic amines and carbazole derivatives can also be used. .

[0305] When a plurality of organic compounds are used in the light-emitting layer 723, a compound that forms an exciplex is used as a light-emitting material. In this case, various organic compounds are used in appropriate combination. However, to efficiently form an exciplex, a compound that readily accepts holes is required. (hole transport material) and a compound that easily accepts electrons (electron transport material) Specific examples of the hole transporting material and the electron transporting material are as follows: The materials shown in this embodiment mode can be used.

[0306] TADF materials are materials that convert triplet excited states into singlet excited states using a small amount of thermal energy. Upconversion (reverse intersystem crossing) is possible, and light emission (fluorescence) from the singlet excited state is efficiently In addition, the conditions for efficiently obtaining thermally activated delayed fluorescence are three The energy difference between the doublet excitation level and the singlet excitation level is 0 eV or more and 0.2 eV or less, preferably The delayed fluorescence in TADF materials is between 0 eV and 0.1 eV. The light is an emission that has a spectrum similar to that of normal fluorescence, but has a significantly longer lifespan. The lifespan of -6 seconds or more, preferably 10 -3 More than a second.

[0307] TADF materials include fullerenes and their derivatives, and acridines such as proflavine. Derivatives, eosin, etc. Also, magnesium (Mg), zinc (Zn), cadmium Cd, Sn, Pt, In, or Palladium Examples of metal-containing porphyrins include those containing Pd.

[0308] In addition, heterocyclic compounds having π-electron rich heteroaromatic rings and π-electron deficient heteroaromatic rings are also available. In addition, a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring can be used. The directly bonded materials exhibit the donor properties of the π-electron rich heteroaromatic ring and the alkane properties of the π-electron deficient heteroaromatic ring. The acceptor property is strong, and the energy difference between the singlet excited state and the triplet excited state is small. This is particularly preferable.

[0309] When using TADF materials, they can also be used in combination with other organic compounds. .

[0310] [Electron transport layer 724] The electron transport layer 724 transports electrons injected from the conductor 788 by the electron injection layer 725. The electron transport layer 724 is a layer that transports electrons to the light-emitting layer 723. The electron transport layer 724 is a layer containing an electron transporting material. The electron transporting material used in the electron transport layer 724 is 1×10 -6 cm 2 / Vs or more A substance having electron mobility is preferred. , and other than these may be used.

[0311] Electron transport materials include quinoline, benzoquinoline, and oxazole ligands. or metal complexes having thiazole ligands, oxadiazole derivatives, triazoles derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, etc. In addition, π-electron deficient heteroaromatic compounds such as nitrogen-containing heteroaromatic compounds can also be used. can.

[0312] The electron transport layer 724 may be a single layer or a stack of two or more layers made of the above-mentioned materials. It may be a structure.

[0313] [Electron injection layer 725] The electron injection layer 725 is a layer containing a substance with a high electron injection property. Lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2) , lithium oxide (LiO x ) and the like, alkali metals, alkaline earth metals, or the like Compounds such as erbium fluoride (ErF3) can also be used. Alternatively, an electride may be used for the electron injection layer 725. For example, a mixed oxide of calcium and aluminum is used as an electride. The above-mentioned substance constituting the electron transport layer 724 may be used. You can also be there.

[0314] The electron injection layer 725 is made of a composite material obtained by mixing an organic compound and an electron donor (donor). Such a composite material may be used in which electrons are generated in an organic compound by an electron donor. Therefore, it has excellent electron injection and electron transport properties. It is preferable that the material has excellent electron transport properties. Specifically, for example, the above-mentioned electron transport layer Electron transport materials (metal complexes, heteroaromatic compounds, etc.) used in 724 can be used. The electron donor may be any substance that exhibits electron donating properties to organic compounds. Alkali metals, alkaline earth metals and rare earth metals are preferred, and lithium, cesium, magnesium Examples include nesium, calcium, erbium, and ytterbium. Metal oxides and alkaline earth metal oxides are preferred, and lithium oxide, calcium oxide, barium oxide, etc. Also, Lewis bases such as magnesium oxide can be used. It is also possible to use organic compounds such as tetrathiafulvalene (TTF). can.

[0315] [Charge generation layer 792] When a voltage is applied between the conductor 772 and the conductor 788, the charge generating layer 792 generates a charge. Of the two EL layers 786 in contact with the charge generating layer 792, the EL layer closer to the conductor 772 786 and the conductor 788 has a function of injecting holes into the EL layer 786 on the other side. For example, in the light-emitting device 572 having the configuration shown in FIG. 20C, the charge generation layer 792 is The EL layer 786a has a function of injecting electrons into the EL layer 786a and injecting holes into the EL layer 786b. The charge generation layer 792 is made of a hole transport material to which an electron acceptor is added. Alternatively, an electron donor (donor) may be added to the electron transporting material. In addition, both of these structures may be laminated. By forming the green layer 792, the driving of the display device 100 when the EL layer is laminated can be improved. The increase in dynamic voltage can be suppressed.

[0316] In the charge generation layer 792, when an electron acceptor is added to a hole transport material , 7,7,8,8-tetracyano-2,3,5,6-tetrafluoro as an electron acceptor Examples include quinodimethane (abbreviation: F4-TCNQ), chloranil, etc. Examples include oxides of metals belonging to groups 4 to 8 of the periodic table. are vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tantalum oxide Examples of suitable oxides include rhenium oxide, manganese oxide, and rhenium oxide.

[0317] In the charge generation layer 792, when an electron donor is added to an electron transporting material , as an electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, or an element of the periodic table Metals belonging to Groups 2 and 13 of the above, as well as their oxides and carbonates, can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium ( Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc. It is also preferable to use an organic compound such as tetrathianaphthacene as an electron donor. It may also be used as.

[0318] The light-emitting device 572 can be fabricated by a vacuum process such as vapor deposition, a spin coating method, or the like. A solution process such as an inkjet method can be used. When using a vapor deposition method, Sputtering, ion plating, ion beam deposition, molecular beam deposition, vacuum deposition, etc. Physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods can be used. The functional layers included in the EL layer of the optical device (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, For the electron injection layer and charge generation layer, deposition methods (vacuum deposition, etc.), coating methods (dip coating, etc.) coating method, die coating method, bar coating method, spin coating method, spray coating method, etc.), printing method (Inkjet method, Screen (Stencil printing) method, Offset (Lithographic printing) method, Flexo (relief printing) method, gravure method, microcontact method, etc. can.

[0319] Note that each functional layer (hole injection layer, The materials for the hole transport layer, light emitting layer, electron transport layer, electron injection layer, and charge generation layer are not limited to the materials mentioned above. Other materials can be combined as long as they fulfill the functions of each layer. As an example, a polymer compound (oligomer, dendrimer, polymer) can be used. -, etc.), medium molecular weight compounds (compounds in the intermediate range between low molecular weight and high molecular weight: molecular weight 400 to 4000) Inorganic compounds (quantum dot materials, etc.) can be used. Colloidal quantum dot materials, alloy quantum dot materials, core-shell quantum dot materials , core-type quantum dot materials, etc. can be used.

[0320] The configuration examples exemplified in this embodiment and the corresponding drawings etc. are at least partly The above can be implemented in appropriate combination with other configuration examples or drawings, etc.

[0321] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0322] (Embodiment 2) In this embodiment, a transistor that can be used in a display device according to one embodiment of the present invention will be described. This article explains:

[0323] <Transistor configuration example 1> 21A, 21B, and 21C show a display device that can be used in one embodiment of the present invention. 1A and 1B are a top view and a cross-sectional view of a transistor 200A and the periphery of the transistor 200A. The transistor 200A can be applied to the display device of one embodiment of the present invention.

[0324] 21A is a top view of the transistor 200A. 21B is a cross-sectional view of the transistor 200A. 1 is a cross-sectional view of a portion indicated by a dashed line, and is a cross-sectional view of a transistor 200A in the channel length direction. FIG. 21C is a cross-sectional view of the area indicated by the dashed line A3-A4 in FIG. 21A. 21A is also a cross-sectional view of the transistor 200A in the channel width direction. In the drawings, some elements are omitted for clarity of illustration.

[0325] As shown in FIG. 21, the transistor 200A is disposed on a substrate (not shown). a metal oxide 230a, a metal oxide 230b disposed on the metal oxide 230a, On the metal oxide 230b, a conductor 242a and a conductor 24 are disposed at a distance from each other. 2b, and is disposed on the conductor 242a and the conductor 242b, and the conductor 242a and the conductor 24 2b, an opening is formed between the insulator 280, a conductor 260 is disposed in the opening, and a gold Metal oxide 230b, conductor 242a, conductor 242b, and insulator 280, and conductor 26 0 and an insulator 250 disposed between the metal oxide 230b, the conductor 242a, and the conductor 242b, and a metal oxide 230c disposed between the insulator 280 and the insulator 250. 21B and 21C, the upper surface of the conductor 260 is an insulating Approximately coincident with the top surfaces of the edge 250, the insulator 254, the metal oxide 230c, and the insulator 280 In the following, the metal oxide 230a, the metal oxide 230b, and The metal oxide 230c may be collectively referred to as the metal oxide 230. The conductor 242a and the conductor 242b may be collectively referred to as the conductor 242.

[0326] In the transistor 200A shown in FIG. 21, the conductors 242a and 242b The side surface on the 260 side has a substantially vertical shape. OA is not limited to this, and may be the side and bottom surfaces of the conductor 242a and the conductor 242b. The angle formed by the two may be 10° or more and 80° or less, and preferably 30° or more and 60° or less. Furthermore, the opposing side surfaces of the conductor 242a and the conductor 242b may have multiple surfaces. stomach.

[0327] As shown in FIG. 21, the insulating layer 224, the metal oxide layer 230a, the metal oxide layer 230b, and the conductive layer 230b are The insulating material 280 is provided between the body 242a, the conductor 242b, and the metal oxide 230c. Preferably, an insulator 254 is disposed on the insulating body 254. Here, the insulating body 254 is shown in FIGS. 21B and 21C. As shown in FIG. 1, the side surface of the metal oxide 230c, the top and side surfaces of the conductor 242a, and the conductor 242 the top and side surfaces of the metal oxide 230a and the metal oxide 230b, and the insulator 22 It is preferable that the upper surface of the substrate 4 is in contact with the substrate 4.

[0328] In the transistor 200A, a region where a channel is formed (hereinafter, referred to as a channel forming region) ) and in the vicinity thereof, metal oxide 230a, metal oxide 230b, and Although a configuration in which three layers of metal oxide 230c are stacked is shown, the present invention is not limited to this. For example, a two-layer structure of metal oxide 230b and metal oxide 230c, or a four-layer structure The transistor 200A may have a stacked structure of more than one layer. Although 260 is shown as a two-layer laminated structure, the present invention is not limited to this. For example, the conductor 260 may have a single layer structure or a laminated structure of three or more layers. In addition, each of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c The film may have a laminated structure of two or more layers.

[0329] For example, metal oxide 230c may be a first metal oxide and a second metal oxide on the first metal oxide. In the case of a laminated structure made of oxides, the first metal oxide is the same as the metal oxide 230b. The second metal oxide preferably has a composition similar to that of the metal oxide 230a. I wish.

[0330] Here, the conductor 260 functions as the gate electrode of the transistor, and the conductors 242a and The conductor 242b functions as a source electrode and a drain electrode, respectively. The conductor 260 is sandwiched between the opening of the insulator 280 and the conductors 242a and 242b. The conductor 260, the conductor 242a, and the The placement of the conductor 242b is selected to be self-aligned with the opening of the insulator 280. In the transistor 200A, the gate electrode is disposed between the source electrode and the drain electrode. Therefore, the conductor 260 can be positioned in a self-aligned manner. Since the transistor 200A can be formed without providing a gate, the area occupied by the transistor 200A can be reduced. This allows the display device to have high definition. It is possible to make the frame narrower.

[0331] As shown in FIG. 21, the conductor 260 is provided inside the insulator 250. a and a conductor 260b provided so as to be embedded inside the conductor 260a. It is preferable that

[0332] The transistor 200A includes an insulator 214 disposed on a substrate (not shown) and an insulator 215. An insulator 216 is disposed on the edge 214, and a conductive material is disposed so as to be embedded in the insulator 216. The insulator 222 is disposed on the conductor 205 and the insulator 216. and an insulator 224 disposed on the edge 222. Preferably, metal oxide 230a is disposed thereon.

[0333] An insulator 274 and an insulator 281 are provided on the transistor 200A, and the insulator 281 functions as an interlayer film. Here, the insulator 274 is preferably arranged between the conductor 260, the insulator 250, The insulating material 254, the metal oxide 230c, and the insulating material 280 may be disposed on the upper surface thereof. preferable.

[0334] The insulators 222, 254, and 274 are made of hydrogen (e.g., hydrogen atoms, hydrogen molecules, etc.). It is preferable that the insulator 2 has a function of suppressing the diffusion of at least one of the following: 22, insulator 254, and insulator 274 are insulators 224, 250, and 274. It is preferable that the hydrogen permeability is lower than that of the insulator 80. It has a function of suppressing at least one diffusion of oxygen (for example, oxygen atoms, oxygen molecules, etc.). For example, the insulator 222 and the insulator 254 are preferably 0, and preferably has lower oxygen permeability than insulator 280.

[0335] Here, the insulator 224, the metal oxide 230, and the insulator 250 are insulator 280 and The insulating material 254 and the insulating material 274 separate the insulating material 281. The metal oxide 224, the metal oxide 230, and the insulator 250 are included in the insulator 280 and the insulator 281. Impurities such as hydrogen contained in the insulator 224, the metal oxide 230a, and the metal oxide 230b are mixed. This can prevent the particles from getting mixed into the object 230b and the insulator 250.

[0336] A conductor 240 (conductor It is preferable that the conductive material 240a and the conductive material 240b are provided. The insulators 241 (insulators 241a and 241b) are in contact with the side surfaces of the conductors 240. That is, the insulator 254, the insulator 280, the insulator 274, and the insulator 281 are provided. An insulator 241 is provided in contact with the inner wall of the opening. A first conductor of the conductor 240 is provided, and a second conductor of the conductor 240 is further provided inside. Here, the height of the upper surface of the conductor 240 and the height of the upper surface of the insulator 281 may be The heights can be made to be approximately the same. The present invention is not limited to this configuration, but may be applied to a configuration in which the second conductor of the conductor 240 is laminated. For example, the conductor 240 may be configured as a single layer or a laminated structure of three or more layers. When the structure has a laminated structure, ordinal numbers are assigned to indicate the order of formation to distinguish them. This may be the case.

[0337] The transistor 200A includes a metal oxide 230 (metal oxide 23 0a, metal oxide 230b, and metal oxide 230c) functioning as oxide semiconductors. It is preferable to use a metal oxide (hereinafter also referred to as an oxide semiconductor). The metal oxide that will be the channel forming region of the oxide 230 has a band gap of 2 eV or more. It is preferable to use one having an energy of 2.5 eV or more.

[0338] The metal oxide may contain at least indium (In) or zinc (Zn). It is particularly preferable that the alloy contains indium (In) and zinc (Zn). In addition to these, it is preferable that the element M is contained. As the element M, aluminum (A l), gallium (Ga), yttrium (Y), tin (Sn), boron (B), titanium ( Ti), iron (Fe), nickel (Ni), germanium (Ge), zirconium (Zr) , Molybdenum (Mo), Lanthanum (La), Cerium (Ce), Neodymium (Nd), Huff Hf, tantalum (Ta), tungsten (W), magnesium (Mg) or copper In particular, the element M can be one or more of aluminum (Al), It is preferred that the metal is one or more of gallium (Ga), yttrium (Y), or tin (Sn). It is more preferable that the element M contains either or both of Ga and Sn. I wish.

[0339] 21B, the metal oxide 230b is formed in the region that does not overlap with the conductor 242. The film thickness may be thinner than the film thickness in the area overlapping with the conductor 242. When forming the metal oxide film 230b and the conductor 242b, a part of the upper surface of the metal oxide film 230b is removed. On the upper surface of the metal oxide 230b, a conductive film that becomes the conductor 242 is formed. When the conductive film is heated, a region with low resistance may be formed near the interface with the conductive film. and a resistor located between the conductor 242a and the conductor 242b on the upper surface of the metal oxide 230b. By removing the low-energy region, it is possible to prevent the formation of a channel in that region. Cut.

[0340] According to one embodiment of the present invention, a display device having a small-sized transistor and high resolution can be provided. Alternatively, a display device having a transistor with large on-state current and high luminance can be provided. Alternatively, a display device having a high-speed transistor and a high-speed operation can be provided. Alternatively, a transistor having stable electrical characteristics and high reliability can be provided. Alternatively, a display device having a transistor with low off-state current and low power consumption can be provided. A low force display device can be provided.

[0341] FIG. 1 shows a detailed structure of a transistor 200A that can be used in a display device according to one embodiment of the present invention. This section explains the composition of the system.

[0342] The conductor 205 is formed so as to have an overlapping area with the metal oxide 230 and the conductor 260. In addition, the conductor 205 is preferably embedded in the insulator 216. Here, it is preferable to improve the flatness of the upper surface of the conductor 205. For example, 5. The average surface roughness (Ra) of the upper surface is 1 nm or less, preferably 0.5 nm or less, more preferably This allows the insulator 22 formed on the conductor 205 to be 0.3 nm or less. 4 and improves the crystallinity of the metal oxide 230b and the metal oxide 230c. It is possible.

[0343] Here, the conductor 260 functions as a first gate (also called a top gate) electrode. The conductor 205 may also serve as a second gate (also called a bottom gate) electrode. In this case, the potential applied to the conductor 205 may be changed to the potential applied to the conductor 260. By changing the voltage independently of the applied voltage, the V th of In particular, by applying a negative potential to the conductor 205, the transistor Star 200A V th It is possible to make the off-state current smaller by increasing the voltage to be higher than 0V. Therefore, applying a negative potential to the conductor 205 increases the current density of the conductor 205 compared to when no negative potential is applied. The drain current when the potential applied to 60 is 0V can be reduced.

[0344] The conductor 205 is formed to be larger than the channel forming region in the metal oxide 230. In particular, as shown in FIG. 21C, the conductor 205 is formed in the width direction of the channel of the metal oxide 230. It is preferable that the metal film is also elongated in the region outside the end portion intersecting with the direction of the metal film. The metal oxide 230 is provided on the outer side of the side surface in the channel width direction with a conductor 205 and a conductor It is preferable that the wiring 260 overlaps with an insulator therebetween.

[0345] With the above configuration, the electric field of the conductor 260 that functions as the first gate electrode Then, the metal oxide 2 is formed by the electric field of the conductor 205 which functions as the second gate electrode. The channel forming region 30 can be electrically surrounded.

[0346] As shown in FIG. 21C, the conductor 205 is extended to function as wiring. However, the present invention is not limited to this, and a conductor that functions as a wiring may be provided under the conductor 205. It may be configured as follows.

[0347] The conductor 205 is made of a conductive material mainly composed of tungsten, copper, or aluminum. Although the conductor 205 is illustrated as a single layer, it may have a laminated structure. For example, a laminate of titanium or titanium nitride and the above conductive material may be used.

[0348] Under the conductor 205, hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules are (N2O, NO, NO2, etc.), and has the function of suppressing the diffusion of impurities such as copper atoms (the above impurities Alternatively, a conductor that is impervious to oxygen (e.g., oxygen atoms, oxygen molecules) may be used. The conductive material has a function of suppressing the diffusion of at least one of the oxygen atoms (the oxygen is less likely to permeate). It is preferable to use a material that suppresses the diffusion of impurities or oxygen. The function of suppressing the diffusion of either or both of the above impurities and the above oxygen is referred to as the function of suppressing the diffusion of either or both of the above impurities and the above oxygen. do.

[0349] By using a conductor having a function of suppressing oxygen diffusion under the conductor 205, It is possible to prevent the conductor 205 from being oxidized and the conductivity from decreasing. Examples of the conductive material having the function of controlling the temperature include tantalum, tantalum nitride, ruthenium, and oxide. Therefore, it is preferable to use ruthenium chloride or the like as the first conductor of the conductor 205. The conductive material may be a single layer or a multilayer.

[0350] The insulator 214 prevents impurities such as water or hydrogen from entering the transistor 200A from the substrate side. Therefore, the insulator 214 preferably functions as a barrier insulating film that suppresses the are hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules (NO, NO, It has the function of suppressing the diffusion of impurities such as NO2 and copper atoms (the above impurities are less likely to penetrate). It is preferable to use an insulating material. Alternatively, oxygen (for example, oxygen atoms, oxygen molecules, etc.) ) an insulating material having a function of suppressing the diffusion of at least one of the above (i.e., the material is difficult for the oxygen to permeate) It is preferable to use a material.

[0351] For example, the insulator 214 is preferably made of aluminum oxide or silicon nitride. This allows impurities such as water or hydrogen to flow from the substrate side to the transistor rather than the insulator 214. Alternatively, the oxygen contained in the insulator 224 and the like can be prevented from diffusing to the side of the capacitor 200A. This can prevent the element from diffusing toward the substrate side of the insulator 214.

[0352] The insulators 216, 280, and 281, which function as interlayer films, are It is preferable that the dielectric constant is lower than that of 4. By using a material with a low dielectric constant as the interlayer film, For example, the parasitic capacitance occurring in the insulators 216, 280, and As the insulator 281, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride fluorine-doped silicon oxide, carbon-doped silicon oxide, carbon and nitrogen-doped silicon oxide Silicon oxide having holes, silicon oxide having holes, or the like may be used as appropriate.

[0353] The insulators 222 and 224 function as gate insulators.

[0354] Here, the insulator 224 in contact with the metal oxide 230 can release oxygen by heating. In this specification, the oxygen released by heating may be referred to as excess oxygen. For example, The insulator 224 may be made of silicon oxide, silicon oxynitride, or the like as appropriate. By providing an insulator containing the metal oxide 230 in contact with the metal oxide 230, oxygen vacancies in the metal oxide 230 can be eliminated. This can reduce the resistance and improve the reliability of the transistor 200A.

[0355] Specifically, the insulator 224 is made of an oxide material from which part of the oxygen is released by heating. The oxides that release oxygen by heating are called TDS (Thermal Dissociation Oxygen converted to oxygen atoms in the ion absorption spectroscopy analysis The amount of desorption is 1.0×10 18 atoms / cm 3 or more, preferably 1.0 × 10 19 at oms / cm 3 More preferably, 2.0 × 10 19 atoms / cm 3 or more, or 3.0×10 20 atoms / cm 3 The oxide film is as described above. The surface temperature of the film at this time is 100°C or more and 700°C or less, or 100°C or more and 400°C or less. The range is preferred.

[0356] As shown in FIG. 21C, the insulator 224 does not overlap with the insulator 254 and the metal oxide 2 The film thickness of the region that does not overlap with 30b may be thinner than the film thickness of the other region. In the region of the body 224, the region that does not overlap with the insulator 254 and the metal oxide 230b The thickness of the film is preferably a thickness that allows sufficient diffusion of the oxygen.

[0357] The insulator 222, like the insulator 214, prevents impurities such as water or hydrogen from traversing from the substrate side. It is preferable that the insulating film functions as a barrier insulating film that prevents the metal from being mixed into the transistor 200A. For example, insulator 222 preferably has a lower hydrogen permeability than insulator 224. 22, insulator 254, and insulator 274, which insulates insulator 224, metal oxide 230, and By surrounding the transistor 20 with the insulating material 250, impurities such as water or hydrogen from the outside can be prevented from entering the transistor 20. It is possible to prevent the voltage from entering 0A.

[0358] Furthermore, the insulator 222 may include at least one diffusion region of oxygen (e.g., oxygen atoms, oxygen molecules, etc.). It is preferable that the insulating material has a function of suppressing the diffusion of oxygen (i.e., the oxygen is less likely to permeate). Preferably, the body 222 has a lower oxygen permeability than the insulator 224. The metal oxide 230 has a function of suppressing the diffusion of impurities and oxygen contained in the metal oxide 230. In addition, the conductor 205 is preferably made of an insulator 224 or a metal. This can prevent the oxide 230 from reacting with oxygen.

[0359] The insulator 222 is an oxide of one or both of aluminum and hafnium, which are insulating materials. It is advisable to use an insulator containing oxides of either or both aluminum and hafnium. Insulators containing aluminum oxide, hafnium oxide, aluminum and hafnium It is preferable to use oxides containing hafnium (hafnium aluminate). When the insulator 222 is formed using the metal oxide 230, the insulator 222 is In addition, the incorporation of impurities such as hydrogen into the metal oxide 230 from the periphery of the transistor 200A is suppressed. It functions as a controlling layer.

[0360] Alternatively, for example, aluminum oxide, bismuth oxide, or germanium oxide may be added to these insulators. Niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, Alternatively, zirconium oxide may be added to these insulators. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxynitride, or silicon nitride may be laminated on the edge.

[0361] The insulator 222 may be, for example, aluminum oxide, hafnium oxide, tantalum oxide, or zinc oxide. lead zirconate titanate (PZT), strontium titanate (SrTiO3 ) or (Ba,Sr)TiO3 (BST), which are so-called high-k materials. As transistors become smaller and more highly integrated, the gate insulating layer Thinning of the insulator may cause problems such as leakage current. Functions as a gate insulator By using a high-k material as the insulator, the transistor behavior can be improved while maintaining the physical thickness. This makes it possible to reduce the gate potential during operation.

[0362] The insulator 222 and the insulator 224 may have a stacked structure of two or more layers. In this case, the laminate structure is not limited to the same material, but may be a laminate structure made of different materials. For example, an insulator similar to the insulator 224 may be provided below the insulator 222. .

[0363] The metal oxide 230 is a metal oxide 230a and a metal oxide 23 on the metal oxide 23a. 0b and a metal oxide 230c on the metal oxide 230b. By having the metal oxide 230a below, the structure formed below the metal oxide 230a It is possible to suppress the diffusion of impurities from the structure to the metal oxide 230b. By having the metal oxide 230c on the oxide 230b, the metal oxide 230c is The diffusion of impurities from the formed structure into the metal oxide 230b can be suppressed.

[0364] The metal oxide 230 has a laminated structure of a plurality of oxide layers with different atomic ratios of each metal atom. For example, the metal oxide 230 preferably has at least indium (In). and element M, the number of atoms of the metal oxide 230a relative to the number of atoms of all elements constituting the metal oxide 230a is The ratio of the number of atoms of element M contained in metal oxide 230a to the total number of atoms constituting metal oxide 230b is The ratio of the number of atoms of element M contained in metal oxide 230b to the number of atoms of the element is higher than the ratio of the number of atoms of element M contained in metal oxide 230b to the number of atoms of the element. In addition, it is preferable that the atomic ratio of the element M contained in the metal oxide 230a to In is The atomic ratio of the element M contained in the metal oxide 230b is preferably greater than that of In. Here, the metal oxide 230c is used for the metal oxide 230a or the metal oxide 230b. Metal oxides that can be used can be used.

[0365] The energy of the conduction band minimum of the metal oxide 230a and the metal oxide 230c is It is preferable that the energy level is higher than the energy level of the bottom of the conduction band of 230b. The electron affinity of the metal oxide 230a and the metal oxide 230c is smaller than that of the metal oxide 230b. In this case, the metal oxide 230c is preferably smaller than the affinity of the 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 number of atoms of all elements that make up 30c The ratio of the number of atoms of the metal oxide 230 to the number of atoms of all elements constituting the metal oxide 230b is b) is preferably higher than the ratio of the number of atoms of element M contained in metal oxide 230c. The atomic ratio of the element M contained in the metal oxide 230b to In is , preferably greater than the atomic ratio to In.

[0366] Here, the junction of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c In other words, the energy level of the conduction band minimum changes smoothly. The conduction band minimum at the junction of 230a, metal oxide 230b, and metal oxide 230c The energy levels can be said to change continuously or to be in a continuous junction. In order to achieve this, the interface between the metal oxide 230a and the metal oxide 230b and the metal oxide 230 When the defect level density of the mixed layer formed at the interface between b and the metal oxide 230c is reduced, good.

[0367] Specifically, the metal oxide 230a and the metal oxide 230b, the metal oxide 230b and the metal oxide The oxide 230c has a common element other than oxygen (as a main component), so that the defect level density For example, a mixed layer with a low degree of In-Ga-Z In the case of n-oxide, In-Ga-Zn is used as the metal oxide 230a and the metal oxide 230c. Oxide, Ga-Zn oxide, gallium oxide, etc. may also be used. For example, a laminated structure of In-Ga-Zn oxide and the In-Ga-Zn oxide may be used. A laminated structure of Ga-Zn oxide on an In-Ga-Zn oxide, or a laminated structure of In-Ga-Zn oxide and the In-Ga A layered structure of gallium oxide on a-Zn oxide can be used. A laminated structure of Ga-Zn oxide and an oxide not containing In is used as the metal oxide 230c. It may also be used.

[0368] Specifically, the metal oxide 230a is composed of In:Ga:Zn=1:3:4 [atomic ratio] or 1:1:0.5 [atomic ratio] of metal oxide may be used. 0b: In:Ga:Zn=4:2:3 [atomic ratio] or 3:1:2 [atomic ratio] The metal oxide 230c may be a metal oxide of In:Ga:Zn=1. :3:4 [atomic ratio], In:Ga:Zn=4:2:3 [atomic ratio], Ga:Zn=2: It is possible to use a metal oxide having an atomic ratio of Ga:Zn=1:1 or an atomic ratio of Ga:Zn=2:5. In addition, as a specific example of a case where the metal oxide 230c has a laminated structure, 2:3 [atomic ratio] and Ga:Zn=2:1 [atomic ratio] stacked structure, In:Ga:Z Layer structure of n=4:2:3 [atomic ratio] and Ga:Zn=2:5 [atomic ratio], In: Examples include a laminated structure of Ga:Zn=4:2:3 [atomic ratio] and gallium oxide.

[0369] At this time, the main carrier path is the metal oxide 230b. By configuring the metal oxide 230c as described above, the metal oxide 230a and the metal oxide 230 The defect density at the interface between the metal oxide 230b and the metal oxide 230c is Therefore, the influence of interface scattering on carrier conduction is reduced. As a result, the transistor 200A can achieve a high on-state current and high frequency characteristics. When the metal oxide 230c has a laminated structure, the metal oxide 230b and the metal oxide In addition to the effect of reducing the defect level density at the interface with the metal oxide 230c, It is expected that the constituent elements contained therein are prevented from diffusing to the insulator 250 side. Specifically, the metal oxide 230c is formed into a laminated structure, and an oxide not containing In is formed above the laminated structure. Therefore, it is possible to suppress In that may diffuse toward the insulator 250. Since 0 functions as a gate insulator, if In diffuses, the transistor characteristics will be poor. Therefore, by forming the metal oxide 230c into a laminated structure, a highly reliable display device can be obtained. It will be possible to provide a place for

[0370] On the metal oxide 230b, a conductor 24 is formed, which functions as a source electrode and a drain electrode. 2 (conductor 242a and conductor 242b). Aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tungsten Stainless steel, hafnium, vanadium, niobium, manganese, magnesium, zirconium, Selected from the group consisting of lilium, indium, ruthenium, iridium, strontium, and lanthanum. 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, tungsten, Nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide Ruthenium, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum and nickel It is preferable to use oxides containing tantalum nitride, titanium nitride, titanium and tantalum nitride, etc. Aluminum nitride, tantalum and aluminum nitride, ruthenium oxide, nitride 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 after absorbing oxygen. Therefore, it is preferable.

[0371] By providing the conductor 242 so as to be in contact with the metal oxide 230, the metal oxide 230 The oxygen concentration may decrease in the vicinity of the conductor 242. In the vicinity of the conductor 242, the metal contained in the conductor 242 and the component of the metal oxide 230 In such a case, a metal compound layer containing the metal oxide 230 may be formed. The carrier density increases in the region near the conductor 242, and the region becomes a low-resistance region. .

[0372] Here, the region between the conductor 242a and the conductor 242b overlaps the opening of the insulator 280. As a result, the conductor 260 is formed between the conductor 242a and the conductor 242b. It can be arranged in a consistent manner.

[0373] The insulator 250 functions as a gate insulator. The insulator 250 is preferably arranged in contact with the upper surface of the insulating layer 250. Silicon nitride oxide, silicon nitride, silicon oxide with fluorine, silicon oxide with carbon silicon oxide containing no carbon and nitrogen, silicon oxide containing vacancies, In particular, silicon oxide and silicon oxynitride are stable to heat, This is preferable.

[0374] The insulator 250, like the insulator 224, has an impurity concentration of water or hydrogen in the insulator 250. The thickness of the insulator 250 is preferably 1 nm or more and 20 nm or less. It is preferable to do so.

[0375] A metal oxide may be provided between the insulator 250 and the conductor 260. The metal oxide may be: It is preferable to suppress the diffusion of oxygen from the insulator 250 to the conductor 260. Oxidation of the conductor 260 due to oxygen in the insulator 250 can be suppressed.

[0376] The metal oxide may function as part of the gate insulator. When silicon oxide, silicon oxynitride, or the like is used for the insulator 250, the metal oxide is It is preferable to use metal oxides, which are high-k materials with high dielectric constants. By making the body a laminated structure of the insulator 250 and the metal oxide, it is stable against heat and Therefore, the physical thickness of the gate insulator can be maintained. This makes it possible to reduce the gate potential applied during transistor operation while maintaining the gate potential. This allows the equivalent oxide thickness (EOT) of the insulator that functions as a gate insulator to be made thinner.

[0377] Specifically, hafnium, aluminum, gallium, yttrium, zirconium, Select from tungsten, titanium, tantalum, nickel, germanium, magnesium, etc. Metal oxides containing one or more of the above metals can be used. aluminum oxide, which is an insulator containing oxides of either or both of aluminum and hafnium; Hafnium oxide, oxides containing aluminum and hafnium (hafnium aluminate) It is preferable to use the following.

[0378] Although the conductor 260 is shown as having a two-layer structure in FIG. 21, it may have a single-layer structure or a three-layer structure. The above laminated structure may also be used.

[0379] The conductor 260a is composed of the above-mentioned hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and oxides. 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 material containing a small amount of oxygen (for example, oxygen atoms, oxygen molecules, etc.) It is preferable to use a conductive material that has the function of suppressing both diffusion.

[0380] The conductor 260a has a function of suppressing the diffusion of oxygen, and thus the conductor 260a is contained in the insulator 250. The oxygen in the conductive material 260b can prevent oxidation of the conductive material 260b and decrease in conductivity. Examples of conductive materials that have the function of suppressing oxygen diffusion include tantalum and tantalum nitride. It is preferable to use ruthenium, ruthenium oxide, or the like.

[0381] The conductor 260b is made of a conductive material mainly composed of tungsten, copper, or aluminum. In addition, the conductor 260 also functions as a wiring, so it is preferable to use a highly conductive material. For example, a material mainly composed of tungsten, copper, or aluminum is preferably used. The conductor 260b may have a laminated structure. For example, a laminated structure of titanium or titanium nitride and the above conductive material may be used.

[0382] As shown in FIGS. 21A and 21C, the metal oxide 230b does not overlap with the conductor 242. In other words, in the channel forming region of the metal oxide 230, the metal oxide 230 The side surface of the first gate electrode is covered with the conductor 260. This makes it easier for the electric field of all the functioning conductors 260 to act on the side surfaces of the metal oxide 230. This increases the on-state current of the transistor 200A, thereby improving the frequency characteristics. do.

[0383] The insulator 254, like the insulator 214, is designed to prevent impurities such as water or hydrogen from penetrating the insulator 280 side. It is preferable that the insulating film functions as a barrier insulating film that prevents foreign matter from entering the transistor 200A. For example, it is preferable that the insulator 254 has a lower hydrogen permeability than the insulator 224. Furthermore, as shown in FIGS. 21B and 21C, the insulator 254 is disposed on the side of the metal oxide 230c. the upper and side surfaces of the conductor 242a, the upper and side surfaces of the conductor 242b, the metal oxide 230a, and It is preferable that the metal oxide 230b contacts the side surface of the insulating material 224 and the upper surface of the insulating material 224. With this configuration, hydrogen contained in the insulator 280 is absorbed by the conductor 242a, the conductor 24 2b, metal oxide 230a, metal oxide 230b, and insulator 224 from the top or side thereof. This can prevent the metal oxide 230 from penetrating.

[0384] Additionally, the insulator 254 may include at least one diffusion region of oxygen (e.g., oxygen atoms, oxygen molecules, etc.). It is preferable that the insulating material has a function of suppressing the diffusion of oxygen (i.e., the oxygen is less likely to permeate). Preferably, body 254 has a lower oxygen permeability than insulator 280 or insulator 224 .

[0385] The insulator 254 is preferably formed by sputtering. The insulating film of the insulator 224 is formed by sputtering in an atmosphere containing oxygen. Oxygen can be added to the area adjacent to the body 254. This allows oxygen to be released from the area. Oxygen can be supplied into the metal oxide 230 through the insulator 224. The metal oxide 23 is formed on the surface of the metal oxide 23. 0 to the insulator 280. By having the function of suppressing the diffusion of oxygen, oxygen is diffused from the metal oxide 230 to the substrate side. In this way, the metal oxide 230 in the channel forming region can be prevented from being Oxygen is supplied to the metal oxide 230. This reduces the oxygen vacancies in the metal oxide 230, and Normally-on state can be suppressed.

[0386] The insulator 254 may be, for example, an oxide of one or both of aluminum and hafnium. It is preferable to form an insulator containing aluminum and / or hafnium oxide. Insulators containing aluminum oxide, hafnium oxide, aluminum and hafnium It is preferable to use an oxide containing hafnium (hafnium aluminate) or the like.

[0387] The insulator 254 has a barrier property against hydrogen, and the insulator 224, the insulator 250, and metal oxide 230 covers insulator 280, which is insulated by insulator 254. 24, metal oxide 230, and insulator 250. Since impurities such as hydrogen are prevented from entering from the outside of the transistor 200A, 00A can be given good electrical characteristics and reliability.

[0388] The insulator 280 is connected to the insulator 224, the metal oxide 230, and the conductive layer 240 via the insulator 254. The insulator 280 is formed on the insulating layer 242. For example, the insulating layer 280 may be silicon oxide or silicon oxynitride. silicon nitride oxide, silicon oxide doped with fluorine, silicon oxide doped with carbon, It may contain silicon oxide to which carbon and nitrogen are added, or silicon oxide having vacancies. Silicon oxide and silicon oxynitride are particularly preferred because they are thermally stable. In particular, materials such as silicon oxide, silicon oxynitride, and silicon oxide with pores can be easily heated. This is preferable because it is possible to easily form a region containing oxygen that is released by the reaction.

[0389] It is preferable that the concentration of impurities such as water or hydrogen in the insulator 280 is reduced. The top surface of the insulator 280 may be planarized.

[0390] The insulator 274, like the insulator 214, is configured such that impurities such as water or hydrogen are absorbed from above. It is preferable that the insulator 27 functions as a barrier insulating film that prevents the insulator 27 from being mixed into the insulator 280. For example, an insulator that can be used for the insulator 214, the insulator 254, etc. is used as the insulator 4. That's fine.

[0391] It is preferable to provide an insulator 281 that functions as an interlayer film on the insulator 274. The insulator 281 has a reduced concentration of impurities such as water or hydrogen in the film, similar to the insulator 224. It is preferable that

[0392] In the openings formed in the insulators 281, 274, 280, and 254, The conductors 240a and 240b are arranged. The conductors 240a and 240b are The conductors 240a and 240b are provided facing each other with the conductor 260 in between. The height of the insulating member 281 may be flush with the upper surface of the insulating member 281.

[0393] In addition, the inner walls of the openings of the insulators 281, 274, 280, and 254 An insulator 241a is provided adjacent to the first conductor of the conductor 240a, and the first conductor of the conductor 240a is provided adjacent to the side surface of the insulator 241a. A conductor 242a is located on at least a portion of the bottom of the opening, The conductor 240a contacts the conductor 242a. Similarly, the insulator 281, the insulator 274, the insulator An insulator 241b is provided in contact with the inner wall of the opening of the body 280 and the insulator 254. The first conductor of the conductor 240b is formed in contact with the surface. A conductor 242b is located in the other part, and the conductor 240b contacts the conductor 242b.

[0394] The conductors 240a and 240b are made of tungsten, copper, or aluminum. It is preferable to use a conductive material that satisfies the above condition. A laminated structure may also be used.

[0395] When the conductor 240 has a laminated structure, the metal oxide 230a, the metal oxide 230b, the conductor Conductors in contact with the body 242, the insulator 254, the insulator 280, the insulator 274, and the insulator 281 In the case of the above, a conductor having the function of suppressing the diffusion of impurities such as water or hydrogen can be used. For example, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or oxide is preferred. It is preferable to use ruthenium dioxide or the like. In addition, it is preferable to suppress the diffusion of impurities such as water or hydrogen. The functional conductive material may be used in a single layer or a multilayer structure. The oxygen added to the insulator 280 is absorbed by the conductors 240a and 240b. In addition, impurities such as water or hydrogen can be prevented from entering the conductor from above the insulator 281. 240a and the conductor 240b, it is possible to prevent the metal oxide 230 from being mixed therein. Cut.

[0396] The insulator 241a and the insulator 241b can be used as the insulator 254, for example. The insulators 241a and 241b are in contact with the insulator 254. Therefore, impurities such as water or hydrogen from the insulator 280 and the like can be absorbed into the conductor 240a and the conductor The insulator 240b can prevent the metal oxide 230 from being mixed therein. This can prevent oxygen contained in the conductor 240a from being absorbed by the conductor 240b. do.

[0397] Although not shown, the upper surface of the conductor 240a and the upper surface of the conductor 240b are in contact with each other as wiring. A functional conductor may be disposed. The conductor that functions as a wiring may be made of tungsten, copper, or It is preferable to use a conductive material containing aluminum as the main component. Alternatively, it may have a laminated structure, for example, a laminate of titanium or titanium nitride and the above conductive material. The conductor may be formed so as to be embedded in an opening provided in the insulator.

[0398] <Transistor configuration example 2> 22A, 22B, and 22C show a display device that can be used in one embodiment of the present invention. 1A and 1B are a top view and a cross-sectional view of a transistor 200B and the periphery of the transistor 200B. Transistor 200B is a variation of transistor 200A.

[0399] 22A is a top view of the transistor 200B. 22B is a cross-sectional view of transistor 200B. Here, FIG. 22B is a cross-sectional view of transistor 200B along line B1-B2 in FIG. 22A. FIG. 10 is a cross-sectional view of the portion indicated by the dashed line, showing the channel length direction of the transistor 200B. FIG. 22C is a cross-sectional view of the portion indicated by the dashed line B3-B4 in FIG. 22A. 22A is also a cross-sectional view of the transistor 200B in the channel width direction. In the drawings, some elements are omitted for clarity of illustration.

[0400] In the transistor 200B, the conductor 242a and the conductor 242b are formed on the metal oxide 230. c, the insulator 250, and the conductor 260. The transistor 200B can be a transistor with a high on-state current. B can be a transistor that is easy to control.

[0401] The conductor 260 functioning as the gate electrode is made up of a conductor 260a and a conductor on the conductor 260a. The conductor 260a includes 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 such as oxygen. Conductive material that has the function of suppressing the diffusion of (for example, at least one of oxygen atoms, oxygen molecules, etc.) It is preferable to use materials.

[0402] The conductor 260a has a function of suppressing the diffusion of oxygen, and therefore the material of the conductor 260b In other words, by having the conductor 260a, the material selectivity can be improved. Oxidation of 0b is suppressed, and a decrease in electrical conductivity can be prevented.

[0403] The top and side surfaces of the conductor 260, the side surface of the insulator 250, and the side surface of the metal oxide 230c are It is preferable to provide an insulator 254 so as to cover the electrode. The insulator 254 is made of water, hydrogen, or the like. It is preferable to use an insulating material that has a function of suppressing the diffusion of impurities and oxygen.

[0404] By providing the insulator 254, oxidation of the conductor 260 can be suppressed. By providing the insulator 254, impurities such as water and hydrogen contained in the insulator 280 can be absorbed into the transistor 2. This can prevent the spread to 00B.

[0405] <Transistor configuration example 3> 23A, 23B, and 23C show a display device that can be used in one embodiment of the present invention. 1A and 1B are a top view and a cross-sectional view of a transistor 200C and the periphery of the transistor 200C. Transistor 200C is a variation of transistor 200A.

[0406] 23A is a top view of the transistor 200C. 23B is a cross-sectional view of transistor 200C. Here, FIG. 23B shows the cross-sectional view of transistor 200C, where C1-C2 in FIG. 23A is a cross-sectional view of transistor 200C. FIG. 10 is a cross-sectional view of the portion indicated by the dashed dotted line, showing the transistor 200C in the channel length direction. FIG. 23C is a cross-sectional view of the area indicated by the dashed line C3-C4 in FIG. 23A. 23A is also a cross-sectional view of the transistor 200C in the channel width direction. In the drawings, some elements are omitted for clarity of illustration.

[0407] The transistor 200C has an insulator 250 on the metal oxide 230c. 2. A metal oxide 252 is provided on the metal oxide 252. A conductor 260 is provided on the metal oxide 252. An insulator 270 is provided on the insulator 260. An insulator 271 is provided on the insulator 270.

[0408] The metal oxide 252 preferably has a function of suppressing oxygen diffusion. By providing a metal oxide 252 that suppresses the diffusion of oxygen between the conductive material 260 and the conductive material 260, In other words, the amount of oxygen supplied to the metal oxide 230 is reduced. In addition, oxidation of the conductor 260 due to oxygen can be suppressed. do.

[0409] The metal oxide 252 may function as a part of the gate electrode. For example, The oxide semiconductor that can be used as the metal oxide 230 is used as the metal oxide 252. In this case, the conductor 260 can be formed by sputtering to form a metal film. The electrical resistance of the oxide 252 can be reduced to make it a conductor. The electrode can be called a de Conductor electrode.

[0410] The metal oxide 252 may function as part of the gate insulator. When silicon oxide or silicon oxynitride is used for the insulator 250, the metal oxide 252 It is preferable to use a metal oxide, which is a high-k material having a high dielectric constant. By using a layered structure, it is possible to create a laminated structure that is stable against heat and has a high relative dielectric constant. Therefore, while maintaining the physical film thickness, the gate potential applied during transistor operation can be reduced. In addition, the equivalent oxide thickness (EOT) of the insulating layer that functions as the gate insulator can be reduced. This makes it possible to make the film thinner.

[0411] In the transistor 200C, the metal oxide 252 is shown as a single layer, but it may be a stack of two or more layers. For example, a metal oxide that functions as a part of the gate electrode and a gate insulating film may be used. It may also be provided by laminating a metal oxide that functions as a part of the body.

[0412] When the metal oxide 252 functions as a gate electrode, the conductor 260 It is possible to improve the on-current of the transistor 200C without weakening the influence of these electric fields. Alternatively, the insulator 250 and the metal oxide 252 may be used as a gate insulator. By maintaining the distance between the conductor 260 and the metal oxide 230 due to the physical thickness of The leakage current between the conductor 260 and the metal oxide 230 can be suppressed. By providing a laminated structure of the insulator 250 and the metal oxide 252, the conductor 260 and the metal The physical distance between the conductor 260 and the metal oxide 230 and the electric current applied from the conductor 260 to the metal oxide 230 The field strength can be easily adjusted.

[0413] Specifically, the metal oxide 252 may be an oxide that can be used for the metal oxide 230. A semiconductor with reduced resistance can be used. Alternatively, hafnium, aluminum, gallium Sodium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, Metal oxide containing one or more metals selected from ruthenium, magnesium, etc. can be used.

[0414] In particular, an insulating layer containing oxides of either or both of aluminum and hafnium is used. Aluminum oxide, hafnium oxide, oxides containing aluminum and hafnium (hafnium It is preferable to use hafnium aluminate. In particular, hafnium aluminate is a It has higher heat resistance than fluorine film, so it is less likely to crystallize during heat treatment in the subsequent process. It is preferable because the metal oxide 252 is not an essential component. The design should be appropriate depending on the characteristics of the capacitor.

[0415] The insulator 270 is an insulating material having a function of suppressing the permeation of impurities such as water or hydrogen, and oxygen. For example, aluminum oxide or hafnium oxide can be used. This is preferable because the conductor 260 is prevented from being oxidized by oxygen from above the insulator 270. In addition, impurities such as water or hydrogen from above the insulator 270 can be prevented. , and the conductor 260 and the insulator 250 are used to prevent the metal oxide 230 from being mixed therein. It is possible.

[0416] The insulator 271 functions as a hard mask. When processing 60, the side of the conductor 260 is approximately perpendicular, specifically, the side of the conductor 260 and the substrate 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. This can be done.

[0417] The insulator 271 has a function of suppressing the permeation of impurities such as water or hydrogen, and oxygen. By using an insulating material, the layer may also function as a barrier layer. The edge 270 may not be provided.

[0418] The insulator 271 is used as a hard mask to form the insulator 270, the conductor 260, and the metal oxide 252, insulator 250, and metal oxide 230c are selectively removed. The side surfaces of the metal oxide 230b can be made to be substantially flush with each other, and a part of the surface of the metal oxide 230b can be exposed. do.

[0419] Transistor 200C has regions 243a and 243b on the exposed metal oxide surface of metal oxide 230b. One of the regions 243a and 243b functions as a source region. The other of the region 243a and the region 243b functions as a drain region.

[0420] The regions 243a and 243b are formed by, for example, an ion implantation method or an ion doping method. , plasma immersion ion implantation, or plasma treatment to remove the exposed metal oxide. This can be achieved by introducing impurity elements such as phosphorus or boron into the surface of the substrate 230b. In the embodiments and the like, the term "impurity elements" refers to elements other than the main component elements.

[0421] After exposing a portion of the surface of the metal oxide 230b, a metal film is formed, and then a heat treatment is performed. By this, the elements contained in the metal film are diffused into the metal oxide 230b, and the regions 243a and A region 243b can also be formed.

[0422] The region of the metal oxide 230b into which the impurity element is introduced has a reduced electrical resistivity. Therefore, the regions 243a and 243b may be called "impurity regions" or "low resistance regions." do.

[0423] By using the insulator 271 and / or the conductor 260 as a mask, the regions 243a and The region 243b can be formed in a self-aligned manner. The area 243a and / or the area 243b do not overlap with the conductor 260, thereby reducing the parasitic capacitance. In addition, the channel forming region and the source / drain region (region 243a or region 24 3b), no offset region is formed between the regions 243a and 243b. (Self-aligned) formation increases on-current and reduces threshold voltage , and an improvement in the operating frequency can be realized.

[0424] The transistor 200C includes an insulator 271, an insulator 270, a conductor 260, a metal oxide 2 52, the insulator 250, and the insulator 272 on the side of the metal oxide 230c. 72 is preferably an insulator with a low relative dielectric constant, such as silicon oxide or oxynitride. Silicon, silicon oxynitride, silicon nitride, silicon oxide doped with fluorine, and carbon doped silicon oxide doped with carbon and nitrogen, silicon oxide with vacancies It is preferable that the material is a silicon oxide, a silicon oxynitride, a silicon nitride oxide, or a resin. When silicon or silicon oxide having vacancies is used for the insulator 272, the insulator 27 In addition, silicon oxide and oxynitride are preferable because they can easily form an excess oxygen region in the silicon dioxide. Silicon is preferred because it is thermally stable. Also, the insulator 272 has a function of diffusing oxygen. It is preferable that the compound has the ability to

[0425] In order to further reduce the off-current, a gate insulating film is formed between the channel formation region and the source / drain region. An offset region may be provided. The offset region is a region with high electrical resistivity. The offset region is a region where the impurity element described above is not introduced. This can be achieved by introducing the impurity element described above after forming the insulator 72. The insulating layer 72 functions as a mask in the same manner as the insulating layer 271. Impurity elements are not introduced into the region overlapping with the insulator 272, and the electrical resistivity of the region remains high. It is possible.

[0426] Transistor 200C has insulator 272 and insulator 254 on metal oxide 230. The insulator 254 is preferably formed by sputtering. By using this method, an insulator with little impurities such as water or hydrogen can be formed.

[0427] In addition, the oxide film formed by the sputtering method may extract hydrogen from the structure on which the film is formed. Therefore, the insulator 254 absorbs hydrogen and water from the metal oxide 230 and the insulator 272. By absorbing hydrogen, the hydrogen concentration in the metal oxide 230 and the insulator 272 can be reduced.

[0428] <Transistor constituent materials> The constituent materials that can be used for the transistor will be described.

[0429] 〔substrate〕 Forming transistor 200A, transistor 200B, or transistor 200C The substrate may be, for example, an insulating substrate, a semiconductor substrate, or a conductive substrate. The substrate may be, for example, a glass substrate, a quartz substrate, a sapphire substrate, or a stabilized zirconia substrate ( yttria-stabilized zirconia substrates, resin substrates, etc. In addition, semiconductor substrates, e.g. For example, semiconductor substrates such as silicon and germanium, or silicon carbide and silicon germanium Compound semiconductor base consisting of zinc, gallium arsenide, indium phosphide, zinc oxide, and gallium oxide Furthermore, there are semiconductor substrates having an insulator region inside the semiconductor substrate, such as and SOI (Silicon On Insulator) substrates. Examples of substrates include graphite substrates, metal substrates, alloy substrates, and conductive resin substrates. There are also substrates with metal oxides, etc. Furthermore, there are substrates with conductors or semiconductors on insulating substrates. a substrate on which a conductor or an insulator is provided, a substrate on which a semiconductor substrate is provided, Substrates with conductors or insulators, or those with elements mounted on these substrates The elements provided on the substrate may include a capacitance element, a resistance element, a switch element, a light emitting element, and the like. Examples include optical devices and memory elements.

[0430] [Insulator] Insulators include oxides, nitrides, oxynitrides, nitride oxides, and metal oxides that have insulating properties. , metal oxide nitride, metal nitride oxide, etc.

[0431] For example, as transistors become smaller and more highly integrated, the gate insulator becomes thinner. However, problems such as leakage current may occur. By using gh-k materials, it is possible to reduce the voltage required for transistor operation while maintaining the physical film thickness. On the other hand, by using a material with a low relative dielectric constant for the insulator that functions as the interlayer film, Therefore, depending on the function of the insulator, the parasitic capacitance between the wirings can be reduced. , it is advisable to select the material.

[0432] Insulators with high dielectric constants include gallium oxide, hafnium oxide, zirconium oxide, and aluminum. Oxides containing aluminum and hafnium, oxynitrides containing aluminum and hafnium oxides containing silicon and hafnium, and oxynitrides containing silicon and hafnium hafnium nitrides, or silicon and hafnium nitrides.

[0433] Insulators with low dielectric constants include silicon oxide, silicon oxynitride, silicon nitride oxide, Silicon nitride, fluorine-doped silicon oxide, carbon-doped silicon oxide, carbon and Examples of the material include silicon oxide doped with nitrogen, silicon oxide having pores, and resin.

[0434] A transistor using an oxide semiconductor has the function of suppressing the permeation of impurities such as hydrogen and oxygen. Insulators (insulator 214, insulator 222, insulator 254, insulator 274, etc.) having By enclosing the transistor, the electrical characteristics of the transistor can be stabilized. Examples of insulators that have the function of suppressing oxygen permeation include boron, carbon, nitrogen, and oxygen. silicon, fluorine, magnesium, aluminum, silicon, phosphorus, chlorine, argon, gallium , germanium, yttrium, zirconium, lanthanum, neodymium, hafnium, or An insulator containing tantalum may be used in a single layer or a multilayer. Aluminum oxide and magnesium oxide are used as insulators that have the function of suppressing the permeation of substances and oxygen. Sium oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, Metal oxides such as lanthanum, neodymium oxide, hafnium oxide, or tantalum oxide, aluminum nitride aluminum, titanium aluminum nitride, titanium nitride, silicon nitride oxide, silicon nitride, etc. The following metal nitrides can be used.

[0435] The insulator that functions as the gate insulator is an insulator having a region containing oxygen that is desorbed by heating. For example, an oxide silicon dioxide having a region containing oxygen that is released by heating is preferable. By forming a structure in which silicon or silicon oxynitride is in contact with the metal oxide 230, the metal oxide The oxygen deficiency of 230 can be compensated for.

[0436] 〔conductor〕 Conductors include aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, and titanium. Niobium, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium Sodium, zirconium, beryllium, indium, ruthenium, iridium, strontium A metal element selected from the group consisting of ruthenium, lanthanum, etc., or an alloy containing the above-mentioned metal element, or It is preferable to use an alloy or the like that combines metal elements such as tantalum nitride, nitride, etc. titanium dioxide, tungsten, nitrides containing titanium and aluminum, tantalum and aluminum Nitrides containing strontium, ruthenium oxide, ruthenium nitride, and oxides containing strontium and ruthenium It is preferable to use tantalum nitride, lanthanum nitride, or oxide containing lanthanum and nickel. , titanium nitride, nitride containing titanium and aluminum, nitride containing tantalum and aluminum Ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, lanthanum Oxides containing tungsten and nickel are conductive materials that are resistant to oxidation, or that absorb oxygen but remain conductive. It is preferable because it is a material that maintains its properties. Highly conductive semiconductors such as silicon and silicides such as nickel silicide It may be used.

[0437] A plurality of conductors made of the above materials may be stacked. Alternatively, a laminated structure may be used in which a material containing oxygen and a conductive material containing oxygen are combined. a laminated structure combining a material containing the above-mentioned metal element and a conductive material containing nitrogen; In addition, the material containing the metal element, the conductive material containing oxygen, and the conductive material containing nitrogen may be used. A laminated structure may be formed by combining a conductive material containing

[0438] When a metal oxide is used for the channel formation region of a transistor, The conductors that function as electrodes include materials containing the above-mentioned metal elements and conductive materials containing oxygen. In this case, it is preferable to use a laminated structure in which the conductive material containing oxygen is combined. It is preferable to provide a conductive material containing oxygen on the channel formation region side. By doing so, oxygen released from the conductive material is easily supplied to the channel formation region. .

[0439] In particular, the metal oxide in which the channel is formed is used as a conductor that functions as a gate electrode. It is preferable to use a conductive material containing the metal element and oxygen contained in the metal. Conductive materials containing elements such as titanium nitride and tantalum nitride may also be used. A conductive material containing nitrogen may also be used. Indium tin oxide and tungsten oxide may also be used. Indium oxide containing tungsten oxide, indium zinc oxide containing titanium oxide Indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, silicon dioxide Silicon-doped indium tin oxide may also be used. The channel can be formed by using such a material. It may be possible to capture hydrogen contained in metal oxides, or to capture hydrogen from the outer insulator, etc. In some cases, it may be possible to capture hydrogen that is mixed in from the

[0440] The configuration examples exemplified in this embodiment and the corresponding drawings etc. are at least partly The above can be implemented in appropriate combination with other configuration examples or drawings, etc.

[0441] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0442] (Embodiment 3) In this embodiment, the semiconductor device can be used for the OS transistor described in the above embodiment. The metal oxide (hereinafter also referred to as an oxide semiconductor) will be described.

[0443] <Classification of crystal structures> First, the classification of crystal structures in oxide semiconductors will be explained with reference to FIG. 24A. FIG. 24A shows an oxide semiconductor, typically IGZO (a metal oxide containing In, Ga, and Zn). FIG. 1 is a diagram illustrating the classification of crystal structures of metal oxides.

[0444] As shown in FIG. 24A, oxide semiconductors are broadly divided into "amorphous" and "non-amorphous" oxide semiconductors. ) and "Crystalline" and "Crystal" Also, among "Amorphous" there are those that are completely amorphous. Also, "Crystalline" contains CAAC (ca xis-aligned crystalline), nc(nanocrystall ine), and CAC (cloud-aligned composite) The classification of "Crystalline" includes single crystal, po Completely crystalline and completely amorphous are excluded. "Crystal" includes single crystal and poly crystal. Includes ystal.

[0445] The structures within the bold frame in Figure 24A are "Amorphous" and "Cr It is an intermediate state between "crystal" and "new crystal" In other words, the structure is in the It is completely different from the unstable "Amorphous" and "Crystal" This can be rephrased as a structure in which:

[0446] The crystal structure of the film or substrate can be determined by X-ray diffraction (XRD). It can be evaluated using the "Crystalline" spectrum. CAAC-IGZO films classified as The XRD spectrum obtained by the GIXD measurement is shown in Figure 24B. This is also called the Seemann-Bohlin method. The obtained XRD spectrum is simply referred to as the XRD spectrum. The composition of the AC-IGZO film is approximately In:Ga:Zn=4:2:3 [atomic ratio]. The thickness of the CAAC-IGZO film shown in FIG. 24B is 500 nm.

[0447] As shown in Figure 24B, the XRD spectrum of the CAAC-IGZO film shows clear crystalline Specifically, in the XRD spectrum of the CAAC-IGZO film, A peak indicating the c-axis orientation is detected near 2θ=31°. The peak around 2θ=31° is asymmetrical with respect to the angle at which the peak intensity is detected. .

[0448] The crystalline structure of the film or substrate was analyzed by nanobeam electron diffraction (NBED). Diffraction patterns observed by electron diffraction (ultrafine electron beam diffraction) The diffraction pattern of the CAAC-IGZO film can be evaluated by the diffraction pattern. The electron beam is incident parallel to the substrate using NBED. The diffraction pattern observed is shown in Fig. 24C. The atomic ratio is approximately In:Ga:Zn=4:2:3. Electron diffraction is performed using a probe diameter of 1 nm.

[0449] As shown in Figure 24C, the diffraction pattern of the CAAC-IGZO film shows multiple patterns indicating c-axis orientation. Several spots are observed.

[0450] [Structure of oxide semiconductor] In addition, when focusing on the crystal structure, oxide semiconductors may be classified differently from those shown in FIG. 24A. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS, Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors and pseudo-non-crystalline oxide semiconductors. amorphous-like oxide semiconductor (a-like OS) semiconductor), amorphous oxide semiconductor, etc.

[0451] Here, for details on the above-mentioned CAAC-OS, nc-OS, and a-like OS, , and provide an explanation.

[0452] [CAAC-OS] The CAAC-OS has multiple crystalline regions, each of which has a c-axis aligned in a specific direction. The specific direction is the thickness direction of the CAAC-OS film. , a normal direction to the surface on which the CAAC-OS film is formed, or a normal direction to the surface of the CAAC-OS film. The crystalline region is a region in which the atomic arrangement has periodicity. When viewed as an arrangement, the crystalline region is also a region with a uniform lattice arrangement. S has a region where multiple crystalline regions are connected in the ab-plane direction, and this region has strain. The distortion is a distortion of the lattice arrangement in the region where multiple crystal regions are connected. A place where the orientation of the lattice arrangement changes between a uniform area and a uniform area with a different lattice arrangement. In other words, the CAAC-OS has a c-axis orientation and no clear orientation in the ab-plane direction. It is an oxide semiconductor that does not contain

[0453] Each of the plurality of crystalline regions is made up of one or more minute crystals (maximum diameter 10n If a crystalline region is made up of a single microcrystal, The maximum diameter of the crystalline region is less than 10 nm. When the crystallized region is formed, the size of the crystallized region may be approximately several tens of nanometers.

[0454] In-M-Zn oxide (element M is aluminum, gallium, yttrium, tin, or titanium) In the CAAC-OS, indium (In ), and a layer having oxygen (hereinafter referred to as In layer), and a layer having element M, zinc (Zn), and oxygen It has a layered crystal structure (also called a layered structure) in which a layer (hereinafter referred to as an (M, Zn) layer) is stacked. Indium and element M can be substituted for each other. The n) layer may contain indium, and the In layer may contain the element M. The In layer may contain Zn. This layered structure is useful for, for example, high resolution In a TEM image, it is observed as a lattice pattern.

[0455] For example, when the structure of the CAAC-OS film is analyzed using an XRD device, the θ / 2θ phase In the out-of-plane XRD measurement using a can, two peaks indicating the c-axis orientation were observed. The peak position (2θ value) indicating the c-axis orientation is detected at or near θ=31°. may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0456] For example, in the electron diffraction pattern of the CAAC-OS film, several bright spots are observed. Note that one spot and another spot are the spots of the incident electron beam that have passed through the sample. The beams are observed at positions symmetrical with respect to the point (also called the direct spot) as the center of symmetry.

[0457] When the crystalline region is observed from the specific direction, the lattice arrangement within the crystalline region is a hexagonal lattice. However, the unit cell is not necessarily a regular hexagon, and may be a non-regular hexagon. The above distortion may have a lattice arrangement such as a pentagon or heptagon. In the OS, clear grain boundaries were confirmed even near the strain. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is because the arrangement of oxygen atoms in the CAAC-OS is dense in the ab-plane direction. The metal atoms are replaced by other atoms, which causes the bond distance between the atoms to change. This is thought to be because it can tolerate the

[0458] The crystal structure in which clear grain boundaries are observed is called polycrystal. The grain boundaries act as recombination centers, trapping carriers and forming transistors. It is highly likely that this will cause a decrease in on-state current and a decrease in field effect mobility. CAAC-OS, which has no visible grain boundaries, has a crystal structure suitable for the semiconductor layer of a transistor. It is one of the crystalline oxides that can be used to form CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are preferable. This is preferable because it can suppress the occurrence of grain boundaries more effectively than the material.

[0459] CAAC-OS is an oxide semiconductor with high crystallinity and no clear grain boundaries. Therefore, the CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. In addition, the crystallinity of oxide semiconductors may be reduced due to the incorporation of impurities or the generation of defects. Therefore, CAAC-OS is also called an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, the physical properties of an oxide semiconductor having a CAAC-OS are stable. Therefore, oxide semiconductors having CAAC-OS are heat-resistant and highly reliable. The OS is stable even under high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS for OS transistors increases the flexibility of the manufacturing process. This becomes possible.

[0460] [nc-OS] nc-OS is a material that can be used in microscopic areas (e.g., areas between 1 nm and 10 nm, especially areas between 1 nm and 10 nm). In other words, nc-OS has a periodic atomic arrangement in the region of 3 nm or less. It has small crystals. The size of the minute crystals is, for example, 1 nm or more and 10 nm or less. Since the size of these tiny crystals is between 1 nm and 3 nm, they are also called nanocrystals. In nc-OS, there is no regularity in the crystal orientation between different nanocrystals. Therefore, depending on the analytical method, nc-OS may be considered as a-like In some cases, it is difficult to distinguish between an OS and an amorphous oxide semiconductor. For example, in the case of an nc-OS film, , Structural analysis was performed using an XRD instrument, and out-of-plane analysis using θ / 2θ scan was performed. In the XRD measurement, no peaks indicating crystallinity were detected. However, electron beam circuits using electron beams with probe diameters larger than nanocrystals (e.g., 50 nm or larger) are being used. When electron diffraction (also called selected area electron diffraction) is performed, a diffraction pattern resembling a halo pattern is observed. On the other hand, for the nc-OS film, the size of the nanocrystals is close to or smaller than that of the nanocrystals. Electron beam diffraction (nanobeam) using an electron beam with a probe diameter (for example, 1 nm to 30 nm) When electron diffraction is performed, a ring-shaped region is formed around the direct spot. An electron diffraction pattern may be obtained in which multiple spots are observed.

[0461] [a-like OS] The a-like OS is an oxide semiconductor with a structure between the nc-OS and amorphous oxide semiconductor. A-like OS has pores or low density regions. The OS has lower crystallinity than the nc-OS and CAAC-OS. The OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0462] [Configuration of oxide semiconductor] Next, the details of the above-mentioned CAC-OS will be explained. Regarding the formation of

[0463] [CAC-OS] CAC-OS is a type of metal oxide in which the elements constituting the metal oxide are 0.5 nm to 10 nm in size. Preferably, the material is unevenly distributed in a size range of 1 nm to 3 nm or less, or in the vicinity thereof. In the following, it is assumed that one or more metal elements are unevenly distributed in a metal oxide, and the metal The region having the metal element has a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less. A state in which the size of the mixed area is below or close to the mixed area is also called a mosaic or patch state.

[0464] Furthermore, CAC-OS is a material that is separated into a first region and a second region. The first regions are in a shape similar to a cloud, and the first regions are distributed throughout the film (hereinafter also referred to as a cloud shape). ) In other words, the CAC-OS is a mixture of the first area and the second area. It is a composite metal oxide having a structure in which

[0465] Here, the I ratio of the metal elements constituting the CAC-OS in the In-Ga-Zn oxide is The atomic ratios of n, Ga, and Zn are expressed as [In], [Ga], and [Zn], respectively. For example, in a CAC-OS made of In-Ga-Zn oxide, the first region is This is the region where [In] is larger than [In] in the composition of the CAC-OS film. In the region 2, [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region has a larger [In] than the second region. The first region is a region in which [Ga] is smaller than [Ga] in the second region. In the second region, [Ga] is larger than [Ga] in the first region, and [In] is , which is a region smaller than [In] in the first region.

[0466] Specifically, the first region is mainly composed of indium oxide, indium zinc oxide, etc. The second region is a region where gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region in which In is the main component. The second region can be rephrased as a region containing Ga as the main component. can be done.

[0467] Note that there are cases where a clear boundary between the first region and the second region cannot be observed. .

[0468] For example, in the case of CAC-OS in In-Ga-Zn oxide, energy dispersive X-ray diffraction (EDX) Optical method (EDX:Energy Dispersive X-ray spectrosc) The EDX mapping obtained using the opy revealed a region containing In as the main component (the first region). The structure has a structure in which a first region (a first region) and a region (a second region) mainly composed of Ga are unevenly distributed and mixed. It can be confirmed that

[0469] When CAC-OS is used in a transistor, the conductivity due to the first region and the conductivity due to the second region are The insulating properties due to the region act complementary to each other to provide a switching function (On In other words, the CAC-OS and has a conductive function in a part of the material and an insulating function in a part of the material, and By separating the conductive function from the insulating function, Therefore, by using CAC-OS in transistors, This allows for a high on-state current (I on ), high field-effect mobility (μ), and good switching This allows for realizing a locking operation.

[0470] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductors in Two or more of AC-OS, nc-OS, and CAAC-OS may be included.

[0471] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0472] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility can be realized. Furthermore, a highly reliable transistor can be realized.

[0473] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. , the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 c m -3 or less, more preferably 1 × 10 13 cm -3 Less than or equal to 1×10 11 cm -3or less, more preferably 1 × 10 10 cm -3 Less than 1 x 10 -9 cm - 3 In order to reduce the carrier concentration of the oxide semiconductor film, The impurity concentration in the semiconductor film may be reduced to reduce the defect state density. A low impurity concentration and a low defect level density are called high purity intrinsic or substantially high purity intrinsic. The oxide semiconductor having a low carrier concentration is preferably a high-purity intrinsic or substantially high-purity intrinsic oxide. These are sometimes called compound semiconductors.

[0474] A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states. , the trap state density may also be reduced.

[0475] Charges trapped in the trap levels of the oxide semiconductor take a long time to disappear, Therefore, oxides with high trap level density can behave as if they are fixed charges. In transistors where the channel formation region is formed in a semiconductor, the electrical characteristics may become unstable. There is.

[0476] Therefore, in order to stabilize the electrical characteristics of a transistor, the impurity concentration in the oxide semiconductor In order to reduce the impurity concentration in the oxide semiconductor, it is effective to reduce It is preferable to also reduce the impurity concentration in the adjacent film. Metals, alkaline earth metals, iron, nickel, silicon, etc.

[0477] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0478] When oxide semiconductors contain silicon or carbon, which are elements of Group 14, they are oxidized. Defect levels are formed in semiconductors, which is why defects in silicon and carbon in oxide semiconductors The concentration of silicon and carbon near the interface with the oxide semiconductor (obtained by SIMS) concentration) is 2 x 10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0479] When an alkali metal or an alkaline earth metal is contained in an oxide semiconductor, defect levels are formed, Therefore, alkali metals or alkaline earth metals may be included. A transistor using an oxide semiconductor having such a structure tends to be normally on. The concentration of alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 below To do so.

[0480] When nitrogen is contained in an oxide semiconductor, electrons are generated as carriers, and the carrier concentration As a result, when an oxide semiconductor containing nitrogen is used as a semiconductor, In addition, a transistor having a nitrogen-containing oxide semiconductor is likely to be normally on. If the ions are contained, trap levels may be formed. As a result, the electrical characteristics of the transistor may deteriorate. Therefore, the nitrogen in the oxide semiconductor obtained by SIMS may become unstable. Concentration: 5 x 10 19 atoms / cm 3 Less than 5 x 10 18 atoms / c m 3 Less than or equal to 1×10 18 atoms / cm 3 Below, more preferably 5x 10 17 atoms / cm 3 Do the following:

[0481] The hydrogen contained in the oxide semiconductor reacts with the oxygen that bonds with the metal atoms to form water, so the acid When hydrogen enters the oxygen vacancy, electrons, which act as carriers, are generated. In addition, some of the hydrogen atoms may bond with oxygen atoms that bond with metal atoms, forming carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen can generate electrons. Therefore, hydrogen in the oxide semiconductor is not generated. Specifically, in an oxide semiconductor, SIMS The hydrogen concentration obtained from 20 atoms / cm 3 Less than 1 x 10 1 9 atoms / cm 3 less than 5 × 10 18 atoms / cm 3 Less than, more Preferably 1 x 10 18 atoms / cm 3 Make it less than.

[0482] By using an oxide semiconductor with sufficiently reduced impurities for a channel formation region of a transistor, This makes it possible to impart stable electrical properties.

[0483] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0484] (Fourth embodiment) In this embodiment, an electronic device including a display device according to one embodiment of the present invention will be described. .

[0485] FIG. 25A is a diagram showing the appearance of the camera 8000 with the viewfinder 8100 attached. The camera 8000 is provided with an imaging device. In FIG. 25A, the camera 8000 and the finder The camera 8000 and the camera 8100 are separate electronic devices that can be detached. The housing 8001 may have a built-in finder equipped with a display device.

[0486] The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, and a shutter. The camera 8000 has a button 8004 and the like. The camera 8000 also has a detachable lens 8006. It is attached.

[0487] Here, the camera 8000 is assumed to have a lens 8006 that is detached from the housing 8001 and replaced. However, the lens 8006 and the housing may be integrated.

[0488] The camera 8000 can capture an image by pressing the shutter button 8004. The display unit 8002 also functions as a touch panel. It is also possible to take an image by

[0489] The housing 8001 of the camera 8000 has a mount with electrodes, and a finder 810 In addition to the 0, strobe devices etc. can also be connected.

[0490] The finder 8100 includes a housing 8101, a display unit 8102, buttons 8103, etc. The viewfinder 8100 may be an electronic viewfinder.

[0491] The housing 8101 has a mount that engages with the mount of the camera 8000, The mount can be attached to the camera 8000. and an image received from a camera 8000 via the electrode is displayed on a display unit 8102. It can be done.

[0492] The button 8103 functions as a power button. The 8102 display can be switched on and off.

[0493] The display unit 8002 of the camera 8000 and the display unit 8102 of the viewfinder 8100 are The display device of one embodiment of the present invention can be applied. Because of its high resolution, even if the user is close to the display unit 8002 or the display unit 8102, The user can see the pixels, and the image with a higher sense of realism can be displayed on the display unit 8002 or the display In particular, the display unit 8102 provided in the finder 8100 can display the The image displayed on the viewfinder 102 is displayed by bringing the user's eye close to the eyepiece of the viewfinder 8100. Therefore, the distance between the user and the display unit 8102 becomes very short. Therefore, it is particularly preferable to use the display device of one embodiment of the present invention for the display portion 8102. When the display device of one embodiment of the present invention is applied to the display portion 8102, The resulting image resolution can be 4K, 5K, or even higher.

[0494] The resolution of the image that can be captured by the imaging device provided in the camera 8000 is The resolution must be equal to or greater than the resolution of the image that can be displayed on the 8002 or display unit 8102. For example, if the display unit 8102 can display an image with a 4K resolution, It is preferable to equip the 8000 with an imaging device capable of capturing images of 4K or higher. For example, if the display unit 8102 can display an image with a resolution of 5K, the camera 8000 It is preferable to provide an imaging device capable of capturing the above images.

[0495] FIG. 25B is a diagram showing the appearance of the head mounted display 8200.

[0496] The head-mounted display 8200 includes a mounting part 8201, a lens 8202, and a main body 82 8203, a display unit 8204, a cable 8205, etc. It has a built-in 8206 battery.

[0497] A cable 8205 supplies power from a battery 8206 to the main body 8203. 03 is provided with a wireless receiver and the like, and displays an image corresponding to the received image data on a display unit 8204. In addition, the camera installed in the main body 8203 can capture the user's eyeballs and eyelids. By capturing the movement of the user's eyes and calculating the coordinates of the user's line of sight based on that information, A line can be used as an input means.

[0498] The wearing part 8201 may be provided with a plurality of electrodes at positions that come into contact with the user. The 8203 detects the current flowing through the electrodes in response to the user's eye movements, The electrode may have a function of detecting the line of sight of the wearer. The attachment unit 8201 may have a function of monitoring the pulse of the user. The device may have various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, etc. The device may have a function to display biological information on the display unit 8204. The image displayed on the display unit 8204 may be changed in accordance with the movement.

[0499] The display device of one embodiment of the present invention can be applied to the display portion 8204. The head-mounted display 8200 has a narrow frame, and a high-quality image is displayed on the display unit 8204. It is possible to display highly realistic images.

[0500] 25C, 25D, and 25E show the appearance of the head mounted display 8300. The head-mounted display 8300 includes a housing 8301 and a display unit 8302. , a band-shaped fixture 8304, and a pair of lenses 8305.

[0501] A user can view the display on the display unit 8302 through the lens 8305 . It is preferable to arrange the display portion 8302 in a curved manner. By placing the device in this position, the user can feel a high sense of realism. Although the example shows a configuration in which one display unit 8302 is provided, the present invention is not limited to this. For example, Two display units 8302 may be provided. In this case, one display is provided for each eye of the user. If the display unit is arranged in such a way that it is possible to perform 3D display using parallax, etc. do.

[0502] Note that the display device of one embodiment of the present invention can be applied to the display portion 8302. The display device of this embodiment has extremely high definition, so it uses a lens 8305 as shown in FIG. 25E. Even if the image is enlarged, the pixels will not be visible to the user, and a more realistic image will be displayed. It can be shown.

[0503] Next, an example of an electronic device different from the electronic device shown in FIGS. 25A to 25E will be described with reference to FIGS. 26A to 26E. Shown in Figure 26G.

[0504] The electronic device shown in FIGS. 26A to 26G includes a housing 9000, a display unit 9001, a speaker 9002, and a 003, operation keys 9005 (including a power switch or an operation switch), connection terminal 900 6. Sensor 9007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, Magnetic, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity (including functions to measure degree, gradient, vibration, smell, or infrared rays), microphone 90 It has 08 etc.

[0505] The electronic devices shown in FIGS. 26A to 26G have various functions. For example, Functions for displaying still images, videos, text images, etc. on the display, touch panel function, calendar - Function to display date or time, etc., processed by various software (programs) Functions for controlling various computer networks using wireless communication functions a function to connect to a computer, a function to send or receive various data using wireless communication functions, a function to connect to a computer using a recording medium, It has the function of reading out the programs or data stored in the body and displaying them on the display unit, etc. The electronic devices shown in FIGS. 26A to 26G can have the following functions: The functions are not limited to these, and may have various functions. Although not shown in the figure, the electronic device may have a configuration having multiple display units. The electronic device is provided with a camera or the like, and has a function of taking still images, a function of taking videos, and a function of recording the taken images. The camera has the function of saving the image to a recording medium (external or built-in), and displaying the captured image on the display. The function may be, for example,

[0506] The electronic device shown in FIGS. 26A to 26G will be described in detail below.

[0507] 26A is a perspective view showing a television device 9100. 0 is equipped with a large screen, for example, a display unit 9001 of 50 inches or more, or 100 inches or more. It is possible to include

[0508] The display device of one embodiment of the present invention is applied to a display portion 9001 of a television set 9100. This allows the television device 9100 to have a narrower frame, and the display unit 90 01 can display high-quality images, allowing for highly realistic images.

[0509] FIG. 26B is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 is, for example, For example, it has one or more functions selected from a telephone, a notebook, an information viewing device, etc. In practice, it can be used as a smartphone. A speaker 9003, a connection terminal 9006, a sensor 9007, etc. may be provided. The terminal 9101 can display text and images on multiple surfaces. For example, An operation button 9050 (also called an operation icon or simply an icon) is provided on one side of the display unit 9001. Also, information 9051 shown in a dashed rectangle can be displayed on other parts of the display unit 9001. Examples of information 9051 include emails and SNS (Social Networking Services). Displays to notify you of incoming calls, e-mails, etc. Subject of SNS, sender name of email or SNS, date and time, remaining battery level, The strength of the radar reception, etc. Or, the information 9051 is displayed at the position where the information 9051 is displayed. Instead, operation buttons 9050 and the like may be displayed.

[0510] The display device of one embodiment of the present invention is applied to a display portion 9001 included in a portable information terminal 9101. This allows the portable information terminal 9101 to be miniaturized and the display portion 9001 to be high-quality. Therefore, it is possible to display an image with a high sense of realism.

[0511] FIG. 26C is a perspective view showing a mobile information terminal 9102. The mobile information terminal 9102 has a display. The display unit 9001 has a function of displaying information on three or more surfaces. 9053 and information 9054 are displayed on different surfaces. The user of the information terminal 9102 carries the mobile information terminal 9102 in the breast pocket of his / her clothes. In this case, the display (information 9053) can be confirmed. The telephone number or name of the caller is displayed in a position where it can be seen from above the mobile information terminal 9102. The user can check the display without taking the mobile information terminal 9102 out of his pocket. You can then decide whether to accept the call.

[0512] The display device of one embodiment of the present invention is applied to a display portion 9001 included in a portable information terminal 9102. This allows the portable information terminal 9101 to be miniaturized and the display portion 9001 to be high-quality. Therefore, it is possible to display an image with a high sense of realism.

[0513] 26D is a perspective view showing a wristwatch-type mobile information terminal 9200. 00 is a mobile phone, e-mail, document viewing and writing, music playback, internet communication, It is possible to execute various applications such as computer games. The display surface of the display device 001 is curved, and the display can be performed along the curved display surface. In addition, the portable information terminal 9200 is capable of performing short-distance wireless communication according to a communication standard. For example, by communicating with a wireless headset, hands-free operation is possible. The mobile information terminal 9200 also has a connection terminal 9006. It is possible to exchange data directly with other information terminals via a connector. Charging can also be performed via the terminal 9006. Note that the charging operation is performed via the connection terminal 9006. Alternatively, power may be supplied wirelessly without using the power supply.

[0514] The display device of one embodiment of the present invention is applied to a display portion 9001 included in a portable information terminal 9200. This allows the frame of the portable information terminal 9200 to be narrowed, and the display portion 9001 to be It is possible to display high-quality images and highly realistic images.

[0515] 26E, 26F, and 26G are perspective views showing a foldable mobile information terminal 9201. 26E is a perspective view of the mobile information terminal 9201 in an unfolded state, and FIG. 6F changes the portable information terminal 9201 from one of the unfolded state and the folded state to the other. FIG. 26G is a perspective view of the portable information terminal 9201 in a folded state. The portable information terminal 9201 is highly portable when folded and easy to carry when unfolded. The mobile information terminal 9201 has a seamless, wide display area, making it easy to see the display. The display unit 9001 is supported by three housings 9000 connected by hinges 9055. The hinge 9055 allows the two housings 9000 to bend, making it portable. The information terminal 9201 can be reversibly transformed from an unfolded state to a folded state. For example, the portable information terminal 9201 can be bent with a radius of curvature of 1 mm or more and 150 mm or less. can be done.

[0516] The display device of one embodiment of the present invention is applied to a display portion 9001 included in a portable information terminal 9201. This allows the frame of the portable information terminal 9201 to be narrowed, and the display portion 9001 to be It is possible to display high-quality images and highly realistic images.

[0517] The configuration examples exemplified in this embodiment and the corresponding drawings etc. are at least partly The above can be implemented in appropriate combination with other configuration examples or drawings, etc.

[0518] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. [Example]

[0519] In this example, a circuit simulation was used to determine the pixel circuit configuration shown in FIG. The boost operation was confirmed using the timing chart shown in 2.

[0520] In the simulation, the transistors 101 and 102 are The OS transistor had a channel length of 200 μm and a channel width of 60 μm. The transistor 103 and the transistor 104 each have a channel length of 60 μm and a channel width of 6 μm. The capacitance values ​​of the capacitors 111 and 112 were The voltages applied to the wiring 121 and the wiring 122 are set to High The wiring 131 is set to 0.5V, 1.0V, 1.0V, and 5V. Simulation was performed at each of the following voltages: 0.5V, 2.0V, 2.5V, 3.0V, 3.5V, and 4.0V. The circuit simulation software used was Silvaco's Smart Spice was used. Wire 127 is "Vref" 0.5V, wire 128 is "Vano" was set to 8.0V, and the "Vcath" of wiring 129 was set to -1.5V.

[0521] The simulation results are shown in FIG. 27. In FIG. 27, the horizontal axis represents the timing chart The vertical axis represents the potential V of the node ND1 after time T4. ND1 of The potential V of the node ND1 is also shown. ND1 Ideal values ​​and simulations of The results are shown in Table 1.

[0522] In addition, the potential V shown in Table 1 ND1 The ideal value of is the constant a, constant b and The values ​​shown are those where the constant c is set to zero.

[0523] [Table 1]

[0524] As shown in FIG. 27 and Table 1, the potential V of the node ND1 obtained by the simulation ND It was confirmed that 1 is equivalent to the ideal value. The difference from the ideal value is due to the constants a, b, and The transistor 102, the transistor 103, and the transistor 104 shown by the number c are This is thought to be due to the effects of feedthrough or charge injection when the device is in a non-conductive state. The display device according to one aspect of the present invention is configured such that the voltage corresponding to the image data supplied to the pixel 10 is The voltage is boosted to a voltage higher than the voltage at the time of the power supply voltage Vcc, and the voltage is applied to the transistor 101 that functions as a driving transistor. Therefore, it is possible to increase the current flowing through the light-emitting device 114. I found that it is possible. [Example]

[0525] In this example, the results of a simulation performed under conditions different from those in Example 1 are shown. Please refer to Figure 1 for the configuration and Figure 2 for the timing chart.

[0526] In the simulation, the transistors 101 and 102 are The OS transistor had a channel length of 200 μm and a channel width of 60 μm. The transistor 103 and the transistor 104 each have a channel length of 60 μm and a channel width of 6 μm. The capacitance values ​​of the capacitors 111 and 112 were The voltages applied to the wiring 121 and the wiring 122 are set to High The wire 131 is set to "Vdata" at 4.3V, and the wire 127 is set to " Vref” to 1.1V, wire 128 to “Vano” to 8.0V, and wire 129 to “Vcat The simulation was carried out with h” set to -1.5V. SPICE was used for the analysis.

[0527] The simulation results are shown in FIG. 28. In FIG. 28, the horizontal axis represents the timing chart The vertical axis represents the time (Time) according to the wiring 121, wiring 122, wiring 131, and node The potentials V of the nodes ND1 and ND2 are shown.

[0528] As shown in Figure 28, the potential V of the node ND1 obtained by simulation is 6.1 V. It was confirmed that the potential was higher than the given potential (potential of the wiring 131). [Explanation of symbols]

[0529] 10: pixel, 10A: pixel, 10B: sub-pixel, 10G: sub-pixel, 10R: sub-pixel, 20: First layer, 30: second layer, 51a: display area, 51b: display area, 51c: display area, 53: pixel electrode, 53a: pixel electrode, 53b: pixel electrode, 53c: pixel electrode, 100: surface Display device, 101: transistor, 102: transistor, 103: transistor, 104 : transistor, 105: transistor, 111: capacitance element, 112: capacitance element, 114 : Light emitting device, 121: Wiring, 122: Wiring, 127: Wiring, 128: Wiring, 129: Wiring, 130: drive circuit section, 131: wiring, 140a: drive circuit section, 140b: drive circuit part, 141: wiring, 143: wiring, 150: pixel part, 200A: transistor, 200B : transistor, 200C: transistor, 205: conductor, 214: insulator, 216: Insulator, 222: insulator, 224: insulator, 230a: metal oxide, 230b: metal oxide substance, 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, 243b: region, 244 : insulator, 250: insulator, 252: metal oxide, 254: insulator, 260a: conductor, 260b: conductor, 260: conductor, 270: insulator, 271: insulator, 272: insulator , 274: insulator, 280: insulator, 281: insulator, 301a: conductor, 301b: conductor Conductor, 305: Conductor, 311: Conductor, 313: Conductor, 317: Conductor, 321: Bottom Lower electrode, 323: insulator, 325: upper electrode, 331: conductor, 333: conductor, 335 : conductor, 337: conductor, 341: conductor, 343: conductor, 347: conductor, 351 : conductor, 353: conductor, 355: conductor, 357: conductor, 361: insulator, 363 : insulator, 403: element isolation layer, 405: insulator, 407: insulator, 409: insulator, 4 11: Insulator, 413: Insulator, 415: Insulator, 417: Insulator, 419: Insulator, 4 21: insulator, 441: transistor, 443: conductor, 445: insulator, 447: semiconductor body region, 449a: low resistance region, 449b: low resistance region, 451: conductor, 453: conductive body, 455: conductor, 457: conductor, 459: conductor, 461: conductor, 463: conductor body, 465: conductor, 467: conductor, 469: conductor, 471: conductor, 501: insulator body, 503: insulator, 505: insulator, 507: insulator, 509: insulator, 572: light-emitting Device, 601: transistor, 602: transistor, 603: transistor, 61 3: Insulator, 614: Insulator, 616: Insulator, 622: Insulator, 624: Insulator, 64 4: Insulator, 654: Insulator, 674: Insulator, 680: Insulator, 681: Insulator, 70 1: substrate, 705: substrate, 712: sealing material, 716: FPC, 721: hole injection layer, 7 22: Hole transport layer, 723: Light emitting layer, 724: Electron transport layer, 725: Electron injection layer, 730 : insulator, 732: sealing layer, 734: insulator, 736: coloring layer, 738: light-shielding layer, 750 : transistor, 760: connection electrode, 772: conductor, 778: structure, 780: anisotropy Conductor, 782: Light-emitting device, 786a: EL layer, 786b: EL layer, 786c: EL layer, 786: EL layer, 788: conductor, 790: capacitance element, 792: charge generation layer, 800 : transistor, 801a: conductor, 801b: conductor, 805: conductor, 811: conductor body, 813: conductor, 814: insulator, 816: insulator, 817: conductor, 821: insulator body, 822: insulator, 824: insulator, 844: insulator, 853: conductor, 854: insulator 855: Conductor, 874: Insulator, 880: Insulator, 881: Insulator, 8000: Camera, 8001: Housing, 8002: Display, 8003: Operation buttons, 8004: Shutter - Button, 8006: Lens, 8100: Finder, 8101: Housing, 8102: Surface display unit, 8103: buttons, 8200: head-mounted display, 8201: wearing unit, 8202: Lens, 8203: Main unit, 8204: Display unit, 8205: Cable, 8206 : Battery, 8300: Head-mounted display, 8301: Housing, 8302: Display part, 8304: fixture, 8305: lens, 9000: housing, 9001: display part, 900 3: Speaker, 9005: Operation keys, 9006: Connection terminal, 9007: Sensor, 9008 : Microphone, 9050: Operation button, 9051: Information, 9052: Information, 9053 : information, 9054: information, 9055: hinge, 9100: television device, 9101: Mobile information terminal, 9102: Mobile information terminal, 9200: Mobile information terminal, 9201: Mobile information Terminal

Claims

[Claim 1] a first wiring, a second wiring, a third wiring, a fourth wiring, a fifth wiring, a pixel electrode, a first transistor, a second transistor, a third transistor, a fourth transistor, a first capacitor, and a second capacitor; the pixel electrode is electrically connected to one of the source and the drain of the first transistor; the pixel electrode has an area that overlaps with the fourth wiring of 10% or less in a top view; a gate of the first transistor is electrically connected to one electrode of the first capacitor element and one of the source and drain of the second transistor; the other of the source and the drain of the first transistor is electrically connected to one electrode of the second capacitor element; one electrode of the second capacitor is electrically connected to the first wiring having a function of supplying a first potential; the other electrode of the second capacitor is electrically connected to the other electrode of the first capacitor, one of the source and the drain of the third transistor, and one of the source and the drain of the fourth transistor; a gate of the second transistor electrically connected to the second wiring; a gate of the fourth transistor is electrically connected to the second wiring; a gate of the third transistor electrically connected to the third wiring; the other of the source and the drain of the second transistor is electrically connected to the fourth wiring; the other of the source and the drain of the third transistor is electrically connected to the fourth wiring; the other of the source and the drain of the fourth transistor is electrically connected to the fifth wiring; Display device.

Images