Display device and electronic apparatus

Abstract

Provided is a small display device having a narrow bezel. A driving circuit and a pixel circuit are stacked on the display device, the display device is provided with a first layer, a second layer and a third layer, the driving circuit is arranged on the first layer and the second layer, and the pixel circuit is arranged on the third layer. The first layer includes a transistor including silicon in a semiconductor layer, and the second and third layers include a transistor including a metal oxide in the semiconductor layer. Further, the channel length of the transistor included in the second layer is shorter than the channel length of the transistor included in the third layer, and a structure suitable for high-speed operation of the circuit is provided.

Description

Technical Field

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

[0002] Note that one embodiment of the present invention is not limited to the above-mentioned technical field. As an example of the technical field of one embodiment of the present invention disclosed in this specification, a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, an electronic device, a lighting device, an input device, an input-output device, a driving method of these devices, or a manufacturing method of these devices can be cited.

[0003] Note that in this specification, etc., a semiconductor device refers to any device that can operate by utilizing semiconductor characteristics. A transistor, a semiconductor circuit, a computing device, a storage device, etc. are one form of a semiconductor device. In addition, an imaging device, an electro-optical device, a power generation device (including a thin-film solar cell, an organic thin-film solar cell, etc.), and an electronic device sometimes include a semiconductor device. Background Art

[0004] As electronic devices applied to virtual reality (VR) or augmented reality (AR), goggles-type or glasses-type devices have been developed.

[0005] In addition, as a small display device that can be applied to goggle-type or spectacles-type equipment, a display device including a liquid crystal element, a display device including an organic EL (Electro Luminescence) element or a light emitting diode (LED), etc. can be typically mentioned.

[0006] Since a display device including an organic EL element does not require a backlight source required for a liquid crystal display device, a thin, lightweight, high-contrast, and low-power display device can be realized. For example, Patent Document 1 discloses an example of a display device using an organic EL element.

[0007] Furthermore, Patent Document 2 discloses a technology in which a part of a circuit constituting a source driver is formed on a glass substrate similarly to a pixel circuit in order to reduce the production cost and mounting area of ​​a driver IC provided in a display device. [Prior technical literature] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2002-324673 [Patent Document 2] Japanese Patent Application Publication No. 2019-20687 Summary of the invention Technical problem to be solved by the invention

[0009] Electronic devices used in VR or AR are one type of wearable devices, and are preferably miniaturized and lightweight to improve portability and wearability. Therefore, the components that constitute the electronic devices need to be miniaturized while satisfying the required functions.

[0010] In order to achieve miniaturization of display devices, it is necessary to reduce the area outside the display area (frame) while increasing the pixel density.

[0011] The display device includes a driving circuit for driving a pixel circuit. As the driving circuit, in addition to the structure of installing an IC chip, a structure in which a part of the driving circuit is formed together with the pixel circuit on the same substrate in a monolithic manner is generally adopted. The above structures all use the area of ​​the frame, so there is a limitation in narrowing the frame.

[0012] In order to further achieve a narrow frame, it is preferred to configure the drive circuit and the display area in an overlapping manner. For example, by forming a pixel circuit using a thin film-formable transistor on a silicon substrate on which the drive circuit is formed, the frame can be made extremely narrow. In addition, by forming a part of the drive circuit using a thin film-formable transistor, the degree of freedom of the circuit provided on the silicon substrate can be increased.

[0013] Therefore, one of the purposes of one embodiment of the present invention is to provide a small display device. In addition, one of the purposes of one embodiment of the present invention is to provide a display device with a narrow frame. In addition, one of the purposes of one embodiment of the present invention is to provide a display device that can perform high-speed operations. In addition, one of the purposes of one embodiment of the present invention is to provide a low-power display device. In addition, one of the purposes of one embodiment of the present invention is to provide a high-performance display device. In addition, one of the purposes of one embodiment of the present invention is to provide a novel display device. In addition, one of the purposes of one embodiment of the present invention is to provide an electronic device including the above-mentioned display device. In addition, one of the purposes of one embodiment of the present invention is to provide a low-power electronic device. In addition, one of the purposes of one embodiment of the present invention is to provide a novel electronic device.

[0014] Note that the description of these purposes does not prevent the existence of other purposes. Note that one embodiment of the present invention does not necessarily achieve all of the above purposes. Note that purposes other than the above can be known and extracted from the description of the specification, drawings, claims, etc. Solutions to technical problems

[0015] One embodiment of the present invention is a display device having a structure in which a driver circuit and a pixel circuit are stacked. A transistor constituting part of the components of the driver circuit contains a metal oxide in a semiconductor layer and has a structure suitable for high-speed operation.

[0016] A first embodiment of the present invention is a display device, which includes a pixel circuit and a driving circuit having an area overlapping with the pixel circuit, the driving circuit including a first circuit and a second circuit, the second circuit having an area overlapping with the first circuit, the pixel circuit having an area overlapping with the second circuit, the first circuit including a first transistor containing silicon in a channel formation area, the second circuit including a second transistor containing metal oxide in a semiconductor layer, the pixel circuit including a third transistor containing metal oxide in the semiconductor layer, and the second transistor is a transistor in which the channel formation area is arranged along the side of an insulating layer.

[0017] In the first embodiment, the display device includes a first layer, a second layer and a third layer, the second layer can be provided between the first layer and the third layer, the pixel circuit can be provided in the third layer, the first circuit can be provided in the first layer, and the second circuit can be provided in the second layer.

[0018] A second embodiment of the present invention is a display device, which includes a first layer, a second layer and a third layer, the second layer is arranged between the first layer and the third layer, the third layer is provided with a pixel circuit, the first layer and the second layer are provided with a driving circuit for the pixel circuit, the first layer is provided with a first circuit as a constituent element of the driving circuit, the second layer is provided with a second circuit as a constituent element of the driving circuit, the first circuit includes a first transistor containing silicon in a channel formation region, the second circuit includes a second transistor containing metal oxide in a semiconductor layer, the pixel circuit includes a third transistor containing metal oxide in the semiconductor layer, and the second transistor is a transistor in which the channel formation region is arranged along the side of an insulating layer included in the second layer.

[0019] A third embodiment of the present invention is a display device, which includes a first layer, a second layer and a third layer, the second layer is arranged between the first layer and the third layer, the second layer and the third layer are provided with a pixel circuit, the first layer and the second layer are provided with a driving circuit for the pixel circuit, the first layer is provided with a first circuit as a constituent element of the driving circuit, the second layer is provided with a second circuit as a constituent element of the driving circuit and the first constituent element of the pixel circuit, the third layer is provided with the second constituent element of the pixel circuit, the first circuit includes a first transistor containing silicon in a channel formation region, the second circuit includes a second transistor containing metal oxide in a semiconductor layer, the pixel circuit includes a fourth transistor containing metal oxide in the semiconductor layer and a third transistor containing metal oxide in the semiconductor layer as the first constituent element and the second constituent element respectively, and the second transistor and the fourth transistor are transistors arranged along the side of the insulating layer included in the second layer in the channel formation region.

[0020] In the third embodiment, it is preferred that the driving transistor of the pixel circuit is formed using a third transistor, and the selection transistor of the pixel circuit is formed using a fourth transistor, the third transistor includes a first conductive layer used as a first gate electrode and a second conductive layer used as a second gate, the first conductive layer is electrically connected to the second conductive layer, and the second conductive layer is electrically connected to one of the source electrode and the drain electrode of the fourth transistor.

[0021] In the first to third aspects, in the stack in which the first conductive layer, the insulating layer, and the second conductive layer are stacked in this order, openings may be provided in the insulating layer and the second conductive layer so as to reach the first conductive layer.

[0022] A transistor in which a channel formation region is arranged along the side of an insulating layer may include a semiconductor layer containing metal oxide arranged in a manner to cover an opening, a second insulating layer arranged on the semiconductor layer containing metal oxide and the second conductive layer in a manner to cover a recess originating from the opening, and a third conductive layer arranged on the second insulating layer in a manner to fill the recess originating from the opening.

[0023] In the first to third aspects, the first circuit and the second circuit are components of a source driver, and the second circuit may include a pass transistor logic circuit. In addition, the second circuit may include a latch circuit.

[0024] In the first to third aspects, the driving circuit is provided in a rectangular region in plan view, and the driving circuit can drive a plurality of pixel circuits provided in the rectangular region. Alternatively, a plurality of rectangular regions may be arranged in a matrix.

[0025] In the first to third aspects, the pixel circuit preferably includes an organic EL element.

[0026] Note that an electronic device including the above-described display device, lens, and eyepiece focusing mechanism is also one embodiment of the present invention. Effects of the Invention

[0027] According to one embodiment of the present invention, a small display device can be provided. In addition, according to one embodiment of the present invention, a display device with a narrow frame can be provided. In addition, according to one embodiment of the present invention, a display device capable of high-speed operation can be provided. In addition, according to one embodiment of the present invention, a low-power display device can be provided. In addition, according to one embodiment of the present invention, a high-performance display device can be provided. In addition, according to one embodiment of the present invention, a novel display device can be provided. In addition, according to one embodiment of the present invention, an electronic device including the above-mentioned display device can be provided. In addition, according to one embodiment of the present invention, a low-power electronic device can be provided. In addition, according to one embodiment of the present invention, a novel electronic device can be provided.

[0028] Note that the description of these effects does not prevent the existence of other effects. One embodiment of the present invention does not necessarily have all of the above effects. Effects other than the above effects can be extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a diagram for explaining the structure of a display device. FIG. 2A to FIG. 2C It is a diagram for explaining the structure of a display device. Figure 3 is a block diagram illustrating a display device. Figure 4 This is a circuit diagram of a voltage generation circuit and a channel transistor logic circuit. FIG. 5A to FIG. 5C It is the circuit diagram of a latch circuit. FIG. 6A to FIG. 6D is a circuit diagram of a pixel circuit. Fig. 7A and Figure 7B A diagram illustrating a vertical transistor. FIG. 8A to FIG. 8C A diagram illustrating a structural example of a display panel. Fig. 9A and Fig. 9B A diagram illustrating a structural example of a display panel. FIG. 10A to FIG. 10F A diagram illustrating an example of the structure of a pixel. Fig.11A and Fig. 11B A diagram illustrating a structural example of a display panel. Fig.12 A diagram illustrating a structural example of a display panel. Fig.13 A diagram illustrating a structural example of a display panel. Fig.14 A diagram illustrating a structural example of a display panel. FIG. 15A to FIG. 15F is a diagram illustrating a structural example of a light emitting device. FIG. 16A to FIG. 16C is a diagram illustrating a structural example of a light emitting device. FIG. 17A to FIG. 17F It is a diagram for explaining an electronic device. Modes for Carrying Out the Invention

[0030] The embodiments are described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and a person of ordinary skill in the art can easily understand the fact that its methods and details can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the embodiments shown below. Note that in the structure of the invention described below, the same figure marks are used in different drawings to represent the same parts or parts with the same functions, and their repeated descriptions are omitted. Note that the shading of the same constituent elements is sometimes appropriately omitted or changed in different drawings.

[0031] In addition, even if there is one element in the circuit diagram, the element may be composed of multiple elements if there is no problem in terms of function. For example, sometimes multiple transistors used as switches may be connected in series or in parallel. Also, sometimes a capacitor is divided and arranged in multiple locations.

[0032] In addition, sometimes a conductor has multiple functions such as wiring, electrode and terminal, and in this specification, multiple names are sometimes used for the same element. In addition, even if the circuit diagram shows that the elements are directly connected, sometimes the elements are actually connected through more than one conductor, and this structure is also included in the category of direct connection in this specification.

[0033] In the accompanying drawings etc. of the explanation laminated structure, constituent elements other than the constituent elements possessed by each layer may also be included. In addition, in the structure where two layers contact each other, for the sake of convenience, the constituent elements disposed near the boundary of the two layers are illustrated as constituent elements of one layer, and may also be illustrated as constituent elements of the other layer.

[0034] (Implementation Method 1) In this embodiment, a display device which is one embodiment of the present invention is described.

[0035] One embodiment of the present invention is a display device with a narrow frame in which a driving circuit and a pixel circuit are stacked. The driving circuit is provided on a first layer and a second layer, and the pixel circuit is provided on a third layer. The second layer is located between the first layer and the third layer. Note that a part of the pixel circuit may also be provided on the second layer.

[0036] The first layer includes a transistor including silicon in the semiconductor layer, and the second and third layers include transistors including metal oxide in the semiconductor layer. In addition, the channel length of the transistor included in the second layer is shorter than the channel length of the transistor included in the third layer, and has a structure suitable for high-speed operation of the circuit.

[0037] By adopting this structure, the frame can be reduced and a small display device can be formed. In addition, a part of the driving circuit can be arranged on the second layer, so that the occupied area of ​​the driving circuit in the first layer can be reduced. Thus, circuits other than the driving circuit can be arranged on the first layer, so that the display device can be made high-performance.

[0038] In addition, the drive circuits provided in the first layer and the second layer are arranged to overlap with the pixel circuits, so that the wiring length can be shortened. Thus, the wiring resistance and wiring capacitance can be reduced, thereby realizing a low-power display device with less signal delay. In addition, by dividing the drive circuit into multiple pieces and making them work in parallel, high-speed operation of the display device can be realized.

[0039] In addition, in a structure where the drive circuit is divided into multiple parts, the amount of data transmission can be reduced by making the frame rate and display resolution of each display area different, thereby achieving high-speed operation and low power consumption. For example, the display near the line of sight can be performed with high resolution and high frame rate, while the display outside the line of sight can be performed with low resolution and low frame rate. This operation is also called foveated rendering.

[0040] Figure 1 1 is a diagram for explaining a display device according to one embodiment of the present invention. The display device 10 has a stacked structure including a layer 20, a layer 30a, and a layer 30b. Figure 1 Each layer is shown separately. Note that the layer 30a and the layer 30b may not be distinguished and may be collectively referred to as the layer 30. In addition, a wiring layer or the like may be provided between the layers.

[0041] The layer 20 is provided with components of a circuit for driving the pixel circuit PIX provided in the layer 30b. For example, a circuit 21a of a component of a gate driver 22 and a source driver 21 and a functional circuit 23 and the like can be provided in the layer 20. The gate driver 22 has a function of selecting a pixel circuit PIX to supply image data. The source driver 21 has a function of supplying image data to the pixel circuit PIX. As the functional circuit 23, a storage circuit for temporarily storing image data or correction data, a timing generation circuit, a power supply circuit, or an operation circuit and the like can be used.

[0042] For example, a pair of driving circuits (gate driver 22, source driver 21) can be arranged in a rectangular region 25 in a plan view. A plurality of regions 25 are arranged in a matrix, and by using the driving circuits in the region 25 to drive the divided pixel array 31 (a plurality of pixel circuits PIX) on the region 25, the entire display region can be divided into a plurality of regions for driving.

[0043] When the drive circuit is arranged in the frame, the freedom of arrangement of the drive circuit is limited, so the number of split drives is limited. On the other hand, in this structure, the drive circuit can be arranged overlapping with the pixel circuit, so the number of split drives can be increased.

[0044] For example, when the number of regions 25 in which a pair of driving circuits are provided is set to 32 (4×8), the display region can be divided into 32 and driven in parallel, so that the display operation can be performed at a high speed. In addition, the above-mentioned foveated point rendering can also be performed. Note that the number of divided drives is not limited to this, and can be appropriately determined according to the size of the display region, the resolution, the display function, etc.

[0045] The driving circuit and the functional circuit 23 need to operate at high speed, so the transistors constituting them are preferably capable of operating at high speed. As the transistor, for example, a transistor having high mobility and containing silicon in the channel formation region (hereinafter referred to as a Si transistor) can be used. In this case, the layer 20 may include a single crystal silicon substrate, an SOI (Silicon on Insulator) substrate, a glass substrate with polycrystalline silicon formed on the surface, and the like.

[0046] A circuit 21b as a component of the source driver 21 may be provided in the layer 30a. In addition, a split pixel array 31 may be provided in the layer 30b. The split pixel array 31 adopts a structure in which a plurality of pixel circuits PIX are arranged in a matrix. In addition, the display area adopts a structure in which the split pixel array 31 is arranged in a matrix. Note that a part of the transistor constituting the pixel circuit PIX may also be provided in the layer 30a.

[0047] The circuit included in layer 30 (layer 30a, layer 30b) is preferably formed using a transistor including a thin film semiconductor layer in a channel formation region. The thin film semiconductor layer can be formed using a deposition process, so it can be easily formed on a Si transistor through an insulating layer without using a bonding process or the like.

[0048] As the semiconductor layer that can be formed as a thin film, polycrystalline silicon, amorphous silicon, or metal oxide can be used. In particular, it is preferable to use a metal oxide that can form a transistor with high mobility without requiring a crystallization step or the like.

[0049] Here, the circuit 21b provided in the layer 30a is a component of the source driver 21, and is therefore preferably formed using a transistor suitable for high-speed operation of the circuit. In one embodiment of the present invention, a vertical transistor (hereinafter referred to as a first OS transistor) using a metal oxide for a semiconductor layer is used as the transistor.

[0050] Note that a vertical transistor refers to a transistor in which a channel forming region is provided in a semiconductor layer formed along the side of an insulating layer included in the layer, and the channel length depends on the thickness of the insulating layer. A vertical transistor has the advantage of being able to shorten the channel length without relying largely on photolithography accuracy. By shortening the channel length of the transistor, the on-state current can be increased. Therefore, it can be said that a vertical transistor is a transistor suitable for high-speed operation of a circuit.

[0051] It is preferable to use a light emitting element that does not require a light source for the display element included in the pixel circuit PIX. As the light emitting element, an organic EL element or a micro LED (Light Emitting Diode) can be used.

[0052] The pixel circuit PIX including the light emitting element preferably uses a plurality of transistors having different characteristics. Therefore, as the pixel circuit PIX provided in the layer 30b, transistors having different channel lengths are used, which are manufactured in a photolithography process.

[0053] In one embodiment of the present invention, the transistor is a transistor that uses a metal oxide in a channel formation region and has a structure different from that of the first OS transistor (hereinafter referred to as a second OS transistor). The structure of the second OS transistor may be a planar transistor, a staggered transistor, an inversely staggered transistor, a trench transistor, a fin transistor, or the like. In addition, a top-gate or bottom-gate transistor structure may also be used. Note that the first OS transistor provided in the layer 30a may also be used as a partial transistor included in the pixel circuit PIX.

[0054] FIG. 2A to FIG. 2C Shown in Figure 1The example configuration of a pair of driving circuits (source driver 21 and gate driver 22) and functional circuit 23 in the region 25 and a divided pixel array 31 provided thereon is shown. The pair of driving circuits can drive the divided pixel array 31 provided in the region 25.

[0055] Figure 2A This is an example in which a circuit 21b and a divided pixel array 31 (pixel circuit PIX) are provided on a pair of drive circuits and a functional circuit 23. The circuit 21b includes a first OS transistor provided on a layer 30a, and the pixel circuit PIX includes a second OS transistor provided on a layer 30b. Here, the circuit 21b has an area overlapping with one or more of the circuit 21a, the gate driver 22, and the functional circuit 23. In addition, the circuit 21b has an area overlapping with the pixel circuit PIX. This structure is effective for narrowing the frame.

[0056] Figure 2B yes Figure 2A A modified example. The circuit 21b includes a first OS transistor provided in the layer 30a, and the pixel circuit PIX includes a first OS transistor provided in the layer 30a and a second OS transistor provided in the layer 30b. Here, the circuit 21b has a region overlapping with any one of the circuit 21a, the gate driver 22, and the functional circuit 23. In addition, the circuit 21b has a region overlapping with the pixel circuit PIX.

[0057] This structure is not only easy to achieve narrow frame, but also easy to achieve high performance of pixels. In this structure, the components of the pixel circuit PIX can be formed in an overlapping manner, so the number of transistors per unit area of ​​the pixel circuit PIX can be increased. As a result, it is easy to add a correction circuit to the pixel circuit PIX.

[0058] Figure 2C An example is shown in which the circuit 21b and the divided pixel array 31 (pixel circuit PIX) are provided on a pair of driving circuits and functional circuits 23. Note that for the sake of clarity, Figure 2C Part of the content is shown in a segmented manner.

[0059] The circuit 21b and the pixel circuit PIX each include a first OS transistor provided in the layer 30a and a second OS transistor provided in the layer 30b. Here, the circuit 21b has an area overlapping with one or more of the circuit 21a, the gate driver 22, and the functional circuit 23, but does not have an area overlapping with the pixel circuit PIX. In other words, the circuit 21b has a structure formed in an area between pixels.

[0060] The circuit 21b also adopts a structure including a first OS transistor and a second OS transistor. Therefore, the above structure has Figure 2B In addition to the advantages, the degree of freedom of the structure of the circuit 21b can also be improved.

[0061] Figure 3 2 is a block diagram of the display device 10. The display device 10 includes a source driver 21 (circuits 21a and 21b), a gate driver 22, a functional circuit 23, a divided pixel array 31, and the like.

[0062] The circuit 21a as a component of the source driver 21 may include a receiving circuit 51, a serial-to-parallel conversion circuit 52, a shift register circuit 53, a latch circuit 54, a level shifting circuit 55, a voltage generating circuit 56 (R-DAC), a bandgap reference circuit 57 (BGR), a bias generating circuit 58 (BIAS-GEN) and a buffer amplifier circuit 59, etc.

[0063] The circuit 21b as a component of the source driver 21 may include a latch circuit 34, a pass transistor logic circuit 35, etc. Note that the latch circuit 34 may also be a component of the circuit 21a.

[0064] In the circuit 21a, first, serial video data (digital data) is input to the receiving circuit 51, and is converted into parallel video data in the serial-to-parallel conversion circuit 52. The parallel video data is distributed to and held by a plurality of latch circuits 54 by the shift register circuit 53. Each video data held by the plurality of latch circuits is boosted by the level shift circuit 55 and output to the circuit 21b.

[0065] The boosted parallel video data is input to the channel transistor logic circuit 35 through the plurality of latch circuits 34 included in the circuit 21b. In the channel transistor logic circuit 35, the parallel video data (digital data) is converted into analog data and output to the buffer amplifier circuit 59. The analog data is amplified in the buffer amplifier circuit 59 and output as analog video data to the pixel circuit PIX included in the divided pixel array 31.

[0066] Here, the channel transistor logic circuit 35 is a circuit having a function of converting input digital data into analog data. The channel transistor logic circuit 35 requires a large number of transistors according to the number of grayscales of the video data, so the occupied area becomes larger. In addition, in order to increase the output current of the channel transistor logic circuit 35, the transistors constituting the circuit are preferably high-voltage transistors.

[0067] Therefore, the channel transistor logic circuit 35 is not necessarily suitable for being formed in layer 20 using Si transistors like other circuits that process digital data. In addition, the channel transistor logic circuit 35 can be formed not only using a CMOS circuit but also using a unipolar circuit. Therefore, in one embodiment of the present invention, the channel transistor logic circuit 35 is formed in layer 30 as a component of the circuit 21b using the first OS transistor.

[0068] Compared with transistors using silicon, transistors using metal oxides have lower off-state currents, so data value changes due to the influence of transistor leakage currents, etc., when transmitting analog data or temporarily holding the analog data are almost nonexistent. In addition, compared with transistors using silicon, the withstand voltage of transistors using metal oxides can be improved. In addition, the first OS transistor has a structure with a short channel length and an easy increase in on-state current, which is suitable for high-speed operation of the circuit. Therefore, by using the first OS transistor in the channel transistor logic circuit 35, processing and transmission of analog signals with higher voltages can be performed at high speed with high reliability.

[0069] Furthermore, by providing the pass transistor logic circuit 35 in the layer 30, the area for arranging the functional circuit 23 and the like in the layer 20 can be increased. This also contributes to the improvement of the performance of the display device.

[0070] In addition, preferably, the latch circuit 34 is also formed in layer 30 using the first OS transistor as a component of the circuit 21b. The first OS transistor adopts a structure in which a semiconductor layer, an insulating layer and a conductive layer are formed in an overlapping manner along the bottom and side surfaces of the groove. This structure can also be used as a trench MOS capacitor with a small occupation area by changing the connection form of the conductive layer. In addition, by removing the semiconductor layer, a trench MIM capacitor with a small occupation area can be formed. Thereby, the occupation area of ​​the latch circuit 34 using the structure of the transistor and the capacitor can be reduced. Note that the latch circuit 34 can also be set in layer 20 as a component of the circuit 21a.

[0071] Figure 4 2 shows a configuration example of the pass transistor logic circuit 35. Figure 4 A configuration example of a voltage generating circuit 56 (R-DAC) connected to the pass transistor logic circuit 35 is also shown.

[0072] The channel transistor logic circuit 35 is a circuit having a function of converting input digital data into analog data. In addition, the voltage generating circuit 56 is a circuit having a function of generating a voltage of the analog data output from the channel transistor logic circuit 35. It can be said that the channel transistor logic circuit 35 and the voltage generating circuit 56 constitute a D / A (digital / analog) conversion circuit.

[0073] Figure 4 The illustrated pass transistor logic circuit 35 is a circuit that outputs analog data corresponding to 8-bit digital data to an output terminal (OUT). Note that the number of bits of the input digital data is not limited to this.

[0074] First, the voltage generating circuit 56 will be described. Figure 4An example of a circuit of a voltage generating circuit 56 of a resistor voltage division method (resistance string method) is shown. The voltage generating circuit 56 is a circuit for generating a plurality of voltages (256 voltages in this case), and has a structure in which a plurality of resistor elements RES are connected in series.

[0075] exist Figure 4 In the voltage generating circuit 56 shown in FIG. 1 , one end of a string of series-connected resistor elements RES is supplied with a potential V 255 , the other end is supplied with potential V0. Voltage V 255 -V0 is divided into 256 voltages by a plurality of resistor elements RES and output as an output voltage to the pass transistor logic circuit 35. 255 The potential V0 corresponds to the output potential corresponding to the grayscale value 255, and the potential V0 corresponds to the output potential corresponding to the grayscale value 0.

[0076] Note that V is used as a reference potential (reference potential) in this example. 255 and V0, but as the potential V 255 More than one reference potential may be used as a potential between the potential V0. The greater the number of reference potentials, the more stable the output potential of the voltage generating circuit 56 can be.

[0077] Note that the configuration of the voltage generating circuit 56 is not limited to this, and various configurations may be adopted as long as the circuit is capable of generating a plurality of potentials.

[0078] in addition, Figure 4 Although the configuration in which one voltage generating circuit 56 is connected to one pass transistor logic circuit 35 is shown, a configuration in which one voltage generating circuit 56 is connected to a plurality of pass transistor logic circuits 35 to supply a potential may be adopted.

[0079] Next, the channel transistor logic circuit 35 is described. The channel transistor logic circuit 35 includes a plurality of switches SW whose conduction states are controlled by input data DATA(0) to DATA(7) and their inverted data DATA_B(0) to DATA_B(7). Here, for example, DATA(0) is the first bit of 8-bit data, and DATA_B(7) is the inverted eighth bit of data.

[0080] By controlling the conduction state of the switch SW included in the pass transistor logic circuit 35 , the voltage of the data converted from digital data to analog data and output from the output terminal (OUT) becomes a voltage equivalent to the grayscale voltage supplied to the divided pixel array 31 .

[0081] Here, first OS transistors are used as the plurality of switches SW. In order to increase the output current, the digital data amplified by the level shift circuit 55 is input to the pass transistor logic circuit 35. Therefore, the transistor used for the pass transistor logic circuit 35 preferably has a high withstand voltage.

[0082] Compared with transistors using silicon in the channel formation region, transistors using metal oxides have a high withstand voltage characteristic and are therefore suitable for use in circuits with high drive voltages. In addition, by using a transistor with a short channel length and a large on-state current such as the first OS transistor, the operating frequency and output characteristics of the channel transistor logic circuit 35 can be improved.

[0083] Figure 5A A circuit diagram of a latch circuit 34 that may be used for latch circuit 34 is shown. Figure 5A The latch circuit 34 shown is a sample-and-hold circuit that can hold 1 bit of digital data.

[0084] The latch circuit 34 includes two transistors and two capacitors. SAMP and latch signal S LAT The function of sampling the data DATA(i) (i is the number of bits) and holding the output data of the channel transistor logic circuit 35. In addition, the latch circuit 34 can be configured to receive the precharge signal S PRE Precharge the output potential to voltage V PRE .

[0085] Figure 5B An example of forming two capacitors using transistors is shown. Each capacitor adopts a structure in which the source and drain of the transistor are connected. Thus, two transistors and two capacitors can be formed by the same process. Note that when the first OS transistor is used as a capacitor, it is easy to increase the capacity.

[0086] Figure 5C FIG. 2 shows a configuration example of a latch circuit 34 including two holding nodes. By adopting this configuration, the node closer to the output side of the two holding nodes can hold output data, and in this state, the data of the next frame can be written to the node closer to the input side. Specifically, according to the latch signal S LAT2 and latch signal S LAT2B The data held by the node close to the input side is sampled, and the data is held by the node close to the output side. During the data holding period, the sampling signal S SAMP and latch signal S LAT1 The data DATA(i) which is the data of the next frame is sampled and held at a node close to the input side. Figure 5B same, Figure 5CThe capacitors shown may also be formed using transistors.

[0087] FIG. 6A to FIG. 6C 1 is a diagram for explaining an example of a circuit that can be applied to the pixel circuit PIX included in the divided pixel array 31 .

[0088] Fig. 6A The circuit PIX1 shown includes a light emitting device EL1, a transistor M1, a transistor M2, a transistor M3, and a capacitor C1. Here, an example using a light emitting diode as the light emitting device EL1 is shown. An organic EL element that emits visible light is preferably used for the light emitting device EL1.

[0089] The gate of the transistor M1 is electrically connected to the wiring G1, one of the source and the drain is electrically connected to the wiring S1, and the other of the source and the drain is electrically connected to one electrode of the capacitor C1 and the gate of the transistor M2. One of the source and the drain of the transistor M2 is electrically connected to the wiring V2, and the other of the source and the drain is electrically connected to the anode of the light-emitting device EL1 and one of the source and the drain of the transistor M3. The gate of the transistor M3 is electrically connected to the wiring G2, and the other of the source and the drain is electrically connected to the wiring V0. The cathode of the light-emitting device EL1 is electrically connected to the wiring V1.

[0090] The wiring V1 and the wiring V2 are each supplied with a constant potential. By setting the anode side and the cathode side of the light emitting device EL1 to a high potential and a low potential, respectively, light can be emitted. The transistor M1 is controlled by a signal supplied to the wiring G1 and serves as a selection transistor for controlling the selection state of the circuit PIX1. In addition, the transistor M2 serves as a driving transistor for controlling the current flowing through the light emitting device EL1 according to the potential supplied to the gate.

[0091] When the transistor M1 is in the on state, the potential supplied to the wiring S1 is supplied to the gate of the transistor M2, and the light luminance of the light emitting device EL1 can be controlled according to the potential. The transistor M3 is controlled by the signal supplied to the wiring G2. Thus, the potential between the transistor M3 and the light emitting device EL1 can be reset to a fixed potential supplied from the wiring V0, and the potential writing to the gate of the transistor M2 can be performed in a state where the source potential of the transistor M2 is stabilized.

[0092] Note that Figure 6B As shown, two gates may be provided in each transistor included in the circuit PIX1. In this specification, one of the two gates is referred to as a first gate or a front gate, and the other of the two gates is referred to as a second gate or a back gate.

[0093] Figure 6BThe structure in which the front gate and the back gate are connected and the same signal is supplied to both is shown. This structure can increase the on-state current. Note that a structure in which the two gates are not connected and the back gate is supplied with a constant potential can also be adopted. This structure can control the threshold voltage of the transistor.

[0094] Note that a configuration in which a back gate is provided in a transistor may also be applied to the circuit PIX2 described below. In addition, the circuits PIX1 and PIX2 may contain a mixture of transistors without a back gate and transistors with a back gate.

[0095] Figure 6C An example of a circuit PIX2 different from the circuit PIX1 is shown. The circuit PIX2 has a voltage boosting function. The circuit PIX2 includes a light emitting device EL2, a transistor M4, a transistor M5, a transistor M6, a transistor M7, a capacitor C2, and a capacitor C3.

[0096] The gate of the transistor M4 is electrically connected to the wiring G1, one of the source and the drain is electrically connected to the wiring S4, and the other of the source and the drain is electrically connected to one electrode of the capacitor C2, one electrode of the capacitor C3, and the gate of the transistor M6. The gate of the transistor M5 is electrically connected to the wiring G6, one of the source and the drain is electrically connected to the wiring S5, and the other of the source and the drain is electrically connected to the other electrode of the capacitor C3.

[0097] One of the source and drain of the transistor M6 is electrically connected to the wiring V2, and the other of the source and drain is electrically connected to the anode of the light emitting device EL2 and one of the source and drain of the transistor M7. The gate of the transistor M7 is electrically connected to the wiring G2, and the other of the source and drain is electrically connected to the wiring V0. The cathode of the light emitting device EL2 is electrically connected to the wiring V1.

[0098] The transistor M4 is controlled by a signal supplied to the wiring G1, and the transistor M5 is controlled by a signal supplied to the wiring G6. The transistor M6 functions as a driving transistor that controls a current flowing through the light emitting device EL2 according to a potential supplied to a gate.

[0099] The light luminance of the light emitting device EL2 can be controlled according to the potential supplied to the gate of the transistor M6. The transistor M7 is controlled by the signal supplied to the wiring G2. The potential between the transistor M6 and the light emitting device EL2 can be reset to a fixed potential supplied from the wiring V0, and the potential writing to the gate of the transistor M6 can be performed in a state where the source potential of the transistor M6 is stabilized. In addition, by setting the potential supplied from the wiring V0 to the same potential as the wiring V1 or a potential lower than it, the light emission of the light emitting device EL2 can be suppressed.

[0100] Next, the voltage boosting function of the circuit PIX2 will be described.

[0101] First, the potential “D1” of the wiring S4 is supplied to the gate of the transistor M6 via the transistor M4, and at the same time, the reference potential “V ref At this time, capacitor C3 maintains "D1-V ref Then, the gate of the transistor M6 is placed in a floating state, and the potential “D2” of the wiring S5 is supplied to the other electrode of the capacitor C3 through the transistor M5. Here, the potential “D2” is a combining potential.

[0102] At this time, if the capacitance value of capacitor C3 is set to C3, the capacitance value of capacitor C2 is set to C2, and the capacitance value of the gate of transistor M6 is set to C M6 When the gate potential of transistor M6 is D1+(C3 / (C3+C2+C M6 ))×(D2-V ref )). Here, assuming that the value of C3 is greater than C2+C M6 When the value of is large enough, C3 / (C3+C2+C M6 ) is close to 1. Therefore, it can be said that the potential of the gate of transistor M6 is close to "D1+(D2-V ref )". And, if D1=D2 and V ref =0, then "D1+(D2-V ref ))” = “2D1”.

[0103] In other words, if the circuit is designed appropriately, a potential approximately twice the potential that can be input from the wiring S4 or S5 can be supplied to the gate of the transistor M6.

[0104] This action can generate a high voltage in the pixel circuit, thereby reducing the voltage input to the pixel circuit and thus reducing the power consumption of the drive circuit.

[0105] In addition, the circuit PIX2 can also have Fig.6D The structure shown. Fig.6D The circuit shown in PIX2 is Figure 6C The circuit PIX2 shown is different in that it includes a transistor M8. The gate of the transistor M8 is electrically connected to the wiring G1, one of the source and the drain is electrically connected to the other of the source and the drain of the transistor M5 and the other electrode of the capacitor C3, and the other of the source and the drain is electrically connected to the wiring V0. In addition, one of the source and the drain of the transistor M5 is connected to the wiring S4.

[0106] As mentioned above, in Figure 6CIn the circuit PIX2 shown, the reference potential and the combining potential are supplied to the other electrode of the capacitor C3 via the transistor M5. In this case, two wirings S4 and S5 are required, and the reference potential and the combining potential need to be alternately rewritten in the wiring S5.

[0107] exist Fig.6D In the pixel circuit PIX2 shown, although the transistor M8 is added, a dedicated path for supplying the reference potential is provided, so the wiring S5 can be omitted. In addition, since the gate of the transistor M8 can be connected to the wiring G1, and the wiring V0 can be used as the wiring for supplying the reference potential, the wiring connected to the transistor M8 is not increased. In addition, since the reference potential and the merging potential are not alternately rewritten in one wiring, high-speed operation can be performed with low power consumption.

[0108] Note that Figure 6C and Fig.6D In the reference potential "V ref "An inverted potential "D1B" of "D1" may also be used. In this case, a potential approximately three times the potential that can be input from wiring S4 or S5 can be supplied to the gate of transistor M6. Note that "inverted potential" refers to a potential that is the same (or approximately the same) as the absolute value of the difference with a certain reference potential and is different from the original potential. If the original potential is set to "D1", the inverted potential is set to "D1B", and the reference potential is set to V0, then the relationship V0=(D1+D1B) / 2 is achieved.

[0109] In the display device of this embodiment, the light emitting device can also emit light in a pulsed manner to display an image. By shortening the driving time of the light emitting device, the power consumption of the display device can be reduced and heat generation can be suppressed.

[0110] Here, it is preferable that the transistors included in the circuits PIX1 to PIX2 are transistors whose semiconductor layers forming channels contain metal oxide (oxide semiconductor).

[0111] Transistors using metal oxides, which have a wider band gap than silicon and a lower carrier density, can achieve extremely low off-state current. Since the off-state current is low, the charge stored in the capacitor connected in series with the transistor can be retained for a long period of time.

[0112] That is, since data can be retained for a long time, image display can be maintained even when the frame rate is reduced to, for example, below 1 Hz. By reducing the frame rate, the power consumption required to rewrite data can be suppressed, so low power consumption of the display device can be achieved. In addition, the ability to reduce the frame rate is also effective for foveated rendering technology.

[0113] Note that although FIG. 6A to FIG. 6DAlthough an example using an n-channel transistor is shown, a p-channel transistor may also be used.

[0114] By manufacturing a display device using one embodiment of the present invention, it is possible to achieve a narrow frame and high functionality of the display device and to achieve high-speed operation of the display device.

[0115] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate.

[0116] (Implementation Method 2) In this embodiment, a vertical transistor corresponding to the first OS transistor described in Embodiment 1 will be described.

[0117] Fig. 7A and Figure 7B A diagram illustrating a vertical transistor. Fig. 7A It is a top view. Figure 7B It is shown Fig. 7A A cross-sectional stereogram of the depth direction of the region d indicated by the hatched line in FIG. Fig. 7A Some components are omitted. Figure 7B Conductive layer 104 is shown in dashed lines.

[0118] The vertical transistor 100 can be provided over the substrate 102. Note that when the transistor 100 is formed in the layer 30a described in Embodiment 1, the substrate 102 corresponds to the layer 20.

[0119] The transistor 100 includes a conductive layer 104, a conductive layer 104e, an insulating layer 106, a semiconductor layer 108, a conductive layer 112a, and a conductive layer 112b. The conductive layer 104 is a gate wiring and is electrically connected to the conductive layer 104e used as a gate electrode. A portion of the insulating layer 106 is used as a gate insulating layer. The conductive layer 112a is used as one of a source electrode and a drain electrode. The conductive layer 112b is used as the other of the source electrode and the drain electrode.

[0120] In the semiconductor layer 108, the entire region overlapping the gate electrode with the gate insulating layer between the source electrode and the drain electrode is used as a channel formation region. In addition, in the semiconductor layer 108, the region in contact with the source electrode is used as a source region, and the region in contact with the drain electrode is used as a drain region.

[0121] The conductive layer 112a is provided on the substrate 102, the insulating layer 110 is provided on the conductive layer 112a, and the conductive layer 112b is provided on the insulating layer 110. The insulating layer 110 includes a region sandwiched by the conductive layer 112a and the conductive layer 112b. The conductive layer 112a includes a region overlapping with the conductive layer 112b via the insulating layer 110. The insulating layer 110 and the conductive layer 112b include an opening 141 that reaches the conductive layer 112a.

[0122] Each of the conductive layer 112a and the conductive layer 112b may have a stacked-layer structure. Figure 7B The example in which the conductive layer 112a has a stacked structure of the conductive layer 112a_1 and the conductive layer 112a_2 is shown. Figure 7B Although an example is shown in which a region where the conductive layer 112a_2 is not provided on the conductive layer 112a_1 and the conductive layer 112a_1 is in contact with the semiconductor layer 108 in the region is included, a structure in which the conductive layer 112a_2 is in contact with the semiconductor layer 108 may also be employed.

[0123] The top surface shape of the opening 141 may be, for example, circular or elliptical. Since the top surface shape of the opening 141 is circular, the processing accuracy when forming the opening 141 can be improved, so that a fine opening 141 can be formed. In addition, the top surface shape of the opening 141 may also be a polygon such as a triangle, a quadrangle (including a rectangle, a rhombus, a square), a pentagon, or a shape in which the corners of these polygons are rounded. The opening 141 may be formed, for example, using a resist mask.

[0124] The semiconductor layer 108 covers the opening 141. The semiconductor layer 108 includes a region in contact with the top surface and the side surface of the conductive layer 112b, the side surface of the insulating layer 110, and the top surface of the conductive layer 112a. The semiconductor layer 108 is electrically connected to the conductive layer 112a through the opening 141. The semiconductor layer 108 has a shape along the top surface and the side surface of the conductive layer 112b, the side surface of the insulating layer 110, and the top surface of the conductive layer 112a.

[0125] In addition, Figure 7B Although the semiconductor layer 108 has a single-layer structure, one embodiment of the present invention is not limited thereto. The semiconductor layer 108 may have a stacked-layer structure of two or more layers.

[0126] The insulating layer 106 used as a gate insulating layer of the transistor 100 is provided over the semiconductor layer 108 , the conductive layer 112 b , and the insulating layer 110 so as to cover the recessed portion derived from the opening 141 .

[0127] The conductive layer 104e of the transistor 100 is provided over the insulating layer 106 so as to fill the recess formed from the opening 141. Here, over the insulating layer 106, an insulating layer 150 including the opening 141 and an opening 151 reaching the insulating layer 106 is preferably provided.

[0128] The insulating layer 150 may be used as an insulating layer for forming an embedded electrode by a damascene process. That is, the conductive layer 104e is provided on the insulating layer 106 in a manner that fills the recessed portion from the opening 141 and the opening 151 included in the insulating layer 150. The conductive layer 104 may be formed on the conductive layer 104e and the insulating layer 150 that are planarized by the damascene process.

[0129] In the opening 141, the conductive layer 104e includes a region overlapping with the semiconductor layer 108 via the insulating layer 106. In addition, the conductive layer 104e includes a region overlapping with the conductive layer 112a and a region overlapping with the conductive layer 112b via the insulating layer 106 and the semiconductor layer 108. The conductive layer 104e preferably covers the end of the conductive layer 112b on the side of the opening 141. By adopting such a structure, the entire region overlapping with the gate electrode via the gate insulating layer between the source electrode and the drain electrode in the semiconductor layer 108 can be used as a channel formation region.

[0130] The transistor 100 is a so-called top-gate transistor having a gate electrode above the semiconductor layer 108. Since the bottom surface of the semiconductor layer 108 is in contact with the source electrode or the drain electrode, it can be said to be a TGBC (Top Gate Bottom Contact) type transistor.

[0131] The conductive layer 112a, the conductive layer 112b, and the conductive layer 104 can all be used as wiring, and the transistor 100 can be provided in a region where these wirings overlap. That is, in a circuit including the transistor 100 and the wiring, the occupied area of ​​the transistor 100 and the wiring can be reduced. Therefore, the occupied area of ​​the circuit can be reduced.

[0132] In the transistor of one embodiment of the present invention, the conductive layer 112a, the conductive layer 112b, and the conductive layer 104 used as wiring can be formed by processing different conductive films. Therefore, any conductive layer can be arranged to overlap with one or more other conductive layers, thereby increasing the degree of freedom of layout and reducing the area occupied by the circuit.

[0133] Next, the channel length and channel width of the transistor 100 are described. In the semiconductor layer 108, the region in contact with the conductive layer 112a is used as one of the source region and the drain region, the region in contact with the conductive layer 112b is used as the other of the source region and the drain region, and the region between the source region and the drain region is used as a channel formation region.

[0134] The channel length of transistor 100 is the distance between the source region and the drain region. Figure 7BA dotted double arrow indicates a channel length L100 of the transistor 100. The channel length L100 is a distance between an end portion of a region where the semiconductor layer 108 contacts the conductive layer 112a and an end portion of a region where the semiconductor layer 108 contacts the conductive layer 112b in a cross section.

[0135] That is, the channel length L100 is determined by the thickness of the insulating layer 110 and the angle formed by the side surface of the opening 141 of the insulating layer 110 and the top surface of the conductive layer 112a, and is not affected by the performance of the exposure device used to manufacture the transistor. Therefore, the channel length L100 can be set to a value smaller than the limiting resolution of the exposure device, and a fine transistor can be realized.

[0136] By reducing the channel length L100, the on-state current of the transistor 100 can be increased. By using the transistor 100, a circuit capable of high-speed operation can be manufactured. Furthermore, the transistor can be miniaturized, thereby reducing the area occupied by the circuit.

[0137] Note that Figure 7B The structure in which the shape of the side surface of the opening 141 side of the insulating layer 110 in the cross section is a straight line is shown in the figure, but one embodiment of the present invention is not limited to this. The shape of the side surface of the opening 141 side of the insulating layer 110 in the cross section may also be a curve, or may include both a straight line region and a curve region.

[0138] The channel width of the transistor 100 is the width of the source region or the width of the drain region in the direction perpendicular to the channel length direction. In other words, the channel width is the width of the region where the semiconductor layer 108 contacts the conductive layer 112a or the width of the region where the semiconductor layer 108 contacts the conductive layer 112b in the direction perpendicular to the channel length direction. Here, the width of the region where the semiconductor layer 108 contacts the conductive layer 112b in the direction perpendicular to the channel length direction is described as the channel width of the transistor 100. Fig. 7A and Figure 7B A solid double-ended arrow indicates a channel width W100 of the transistor 100. The channel width W100 is the length of the bottom end of the conductive layer 112b on the opening 141 side in a plan view.

[0139] Channel width W100 is determined by the top surface shape of opening 141. Note that when the top surface shape of opening 141 is circular, when the diameter of opening 141 is D141 and the thickness of conductive layer 112b can be ignored, channel width W100 can be calculated as "D141×π".

[0140] That is, the transistor 100 can be said to be a transistor having a large channel width relative to the occupied area. By increasing the channel width W100, the on-state current of the transistor 100 can be increased, so that a circuit capable of high-speed operation can be manufactured.

[0141] The components included in the transistor 100 of this embodiment will be described below.

[0142] [Components of a transistor] [Semiconductor layer 108] There is no particular limitation on the semiconductor material that can be used for the semiconductor layer 108. For example, a single-material semiconductor or a compound semiconductor can be used. As a single-material semiconductor, for example, silicon or germanium can be used. As a compound semiconductor, for example, gallium arsenide and silicon germanium can be cited. As a compound semiconductor, an organic substance having semiconductor characteristics or a metal oxide having semiconductor characteristics (also referred to as an oxide semiconductor) can be used. Note that these semiconductor materials may also contain impurities as dopants.

[0143] There is no particular limitation on the crystallinity of the semiconductor material used for the semiconductor layer 108, and an amorphous semiconductor or a crystalline semiconductor (a single crystal semiconductor, a polycrystalline semiconductor, a microcrystalline semiconductor, or a semiconductor having a crystalline region in part thereof) can be used. When a crystalline semiconductor is used, degradation of transistor characteristics can be suppressed, so it is preferred.

[0144] The semiconductor layer 108 preferably includes a metal oxide (oxide semiconductor). Examples of metal oxides that can be used for the semiconductor layer 108 include indium oxide, gallium oxide, and zinc oxide. The metal oxide preferably includes at least indium (In) or zinc (Zn). In addition, the metal oxide preferably includes two or three selected from indium, element M, and zinc. Note that element M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, antimony, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, cobalt, and magnesium. In particular, element M is preferably one or more selected from aluminum, gallium, yttrium, and tin. Element M is more preferably gallium.

[0145] The semiconductor layer 108 may be made of, for example, indium oxide, indium gallium oxide (In-Ga oxide), indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), gallium zinc oxide (Ga-Zn oxide), indium aluminum zinc oxide (In-Al-Zn oxide, also referred to as IAZO), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide, also referred to as IGZTO), indium gallium aluminum zinc oxide (In-Ga-Al-Zn oxide, also referred to as IGAZO or IAGZO), etc. Alternatively, silicon-containing indium tin oxide, etc. may be used.

[0146] Here, the composition of the metal oxide included in the semiconductor layer 108 greatly affects the electrical characteristics and reliability of the transistor 100. For example, by increasing the ratio of the number of indium atoms to the total number of atoms of all metal elements included in the metal oxide, a transistor with a large on-state current can be realized.

[0147] When In-Zn oxide is used as the semiconductor layer 108, it is preferable to use a metal oxide in which the atomic ratio of indium is greater than the atomic ratio of zinc. For example, a metal oxide in which the atomic ratio of the metal elements is In:Zn=1:1, In:Zn=2:1, In:Zn=3:1, In:Zn=4:1, In:Zn=5:1, In:Zn=7:1, In:Zn=10:1 or a metal oxide in the vicinity thereof can be used.

[0148] When In-Sn oxide is used as the semiconductor layer 108, it is preferable to use a metal oxide in which the atomic ratio of indium is greater than the atomic ratio of tin. For example, a metal oxide in which the atomic ratio of the metal elements is In:Sn=1:1, In:Sn=2:1, In:Sn=3:1, In:Sn=4:1, In:Sn=5:1, In:Sn=7:1, In:Sn=10:1 or a metal oxide in the vicinity thereof can be used.

[0149] When In-Sn-Zn oxide is used as the semiconductor layer 108, a metal oxide in which the atomic ratio of indium is higher than the atomic ratio of tin can be used. Furthermore, a metal oxide in which the atomic ratio of zinc is higher than the atomic ratio of tin is preferably used. For example, the atomic ratios of the metal elements that can be used are In:Sn:Zn=2:1:3, In:Sn:Zn=3:1:2, In:Sn:Zn=4:2:3, In:Sn:Zn=4:2:4.1, In:Sn:Zn=5:1:3, In:Sn:Zn=5:1:6, In:Sn:Zn=5:1:7, In:Sn:Zn=5:1:8, In:Sn:Zn=5:1:9, In:Sn:Zn=5:1:10, In:Sn:Zn=5:1:11, In:Sn:Zn=5:1:12, In:Sn:Zn=5:1:13, In:Sn:Zn=5:1:14, In:Sn:Zn=5:1:15, In:Sn:Zn=5:1:16, In:Sn:Zn=5:1:17, In:Sn:Zn=5:1:18, In:Sn:Zn=5:1:19, In:Sn:Zn=5:1:10, In:Sn:Zn=5:1:11, In:Sn:Zn=5:1:12, In:Sn:Zn=5:1:13, In:Sn:Zn=5:1:14, In:Sn:Zn=5:1:15 n=6:1:6、In:Sn:Zn=10:1:3、In:Sn:Zn=10:1:6、In:Sn:Zn=10:1:7、In:Sn:Zn=10:1:8、In :Sn:Zn=5:2:5, In:Sn:Zn=10:1:10, In:Sn:Zn=20:1:10, In:Sn:Zn=40:1:10 or metal oxides in their vicinity.

[0150] When In-Al-Zn oxide is used as the semiconductor layer 108, a metal oxide in which the atomic ratio of indium is higher than the atomic ratio of aluminum can be used. Furthermore, a metal oxide in which the atomic ratio of zinc is higher than the atomic ratio of aluminum is preferably used. For example, the atomic ratios of the metal elements that can be used are In:Al:Zn=2:1:3, In:Al:Zn=3:1:2, In:Al:Zn=4:2:3, In:Al:Zn=4:2:4.1, In:Al:Zn=5:1:3, In:Al:Zn=5:1:6, In:Al:Zn=5:1:7, In:Al:Zn=5:1:8, In:Al:Zn=5:1:9, In:Al:Zn=5:1:10, In:Al:Zn=5:1:11, In:Al:Zn=5:1:12, In:Al:Zn=5:1:13, In:Al:Zn=5:1:14, In:Al:Zn=5:1:15, In:Al:Zn=5:1:16, In:Al:Zn=5:1:17, In:Al:Zn=5:1:18, In:Al:Zn=5:1:19, In:Al:Zn=5:1:1 n=6:1:6, In:Al:Zn=10:1:3, In:Al:Zn=10:1:6, In:Al:Zn=10:1:7, In:Al:Zn=10:1:8, In:Al:Zn=5:2:5, In:Al:Zn=10:1:10, In:Al:Zn=20:1:10, In:Al:Zn=40:1:10 or metal oxides thereabouts.

[0151] When In-Ga-Zn oxide is used as the semiconductor layer 108, a metal oxide in which the atomic number ratio of indium to the sum of the atomic numbers of all metal elements contained therein is higher than that of gallium can be used. Furthermore, it is more preferable to use a metal oxide in which the atomic number ratio of zinc is higher than that of gallium. For example, the semiconductor layer 108 can use metal element atomic ratios of In:Ga:Zn=2:1:3, In:Ga:Zn=3:1:2, In:Ga:Zn=4:2:3, In:Ga:Zn=4:2:4.1, In:Ga:Zn=5:1:3, In:Ga:Zn=5:1:6, In:Ga:Zn=5:1:7, In:Ga:Zn=5:1:8, In:Ga:Zn=5:1:9, In:Ga:Zn=5:1:10, In:Ga:Zn=5:1:11, In:Ga:Zn=5:1:12, In:Ga:Zn=5:1:13, In:Ga:Zn=5:1:14, In:Ga:Zn=5:1:15, In:Ga:Zn=5:1:16, In:Ga:Zn=5:1:17, In:Ga:Zn=5:1:18, In:Ga:Zn=5:1:19, In:Ga:Zn=5:1:19, In:Ga:Zn=5:1:10 a:Zn=6:1:6, In:Ga:Zn=10:1:3, In:Ga:Zn=10:1:6, In:Ga:Zn=10:1:7, In:Ga:Zn=10:1:8, In:Ga:Zn=5:2:5, In:Ga:Zn=10:1:10, In:Ga:Zn=20:1:10, In:Ga:Zn=40:1:10 or metal oxides thereabouts.

[0152] When In-M-Zn oxide is used as the semiconductor layer 108, a metal oxide in which the atomic number ratio of indium relative to the sum of the atomic numbers of all metal elements contained is higher than the atomic number ratio of element M can be used. Furthermore, it is more preferable to use a metal oxide in which the atomic number ratio of zinc is higher than the atomic number ratio of element M. For example, the semiconductor layer 108 can use metal element atomic ratios of In:M:Zn=2:1:3, In:M:Zn=3:1:2, In:M:Zn=4:2:3, In:M:Zn=4:2:4.1, In:M:Zn=5:1:3, In:M:Zn=5:1:6, In:M:Zn=5:1:7, In:M:Zn=5:1:8, In: M:Zn=6:1:6, In:M:Zn=10:1:3, In:M:Zn=10:1:6, In:M:Zn=10:1:7, In:M:Zn=10:1:8, In:M:Zn=5:2:5, In:M:Zn=10:1:10, In:M:Zn=20:1:10, In:M:Zn=40:1:10 or metal oxides thereabouts.

[0153] By increasing the indium content of the metal oxide, a transistor with a large on-state current can be realized. By using this transistor for a transistor requiring a large on-state current, a circuit with excellent electrical characteristics can be formed.

[0154] The composition of metal oxides can be analyzed, for example, using energy dispersive X-ray analysis (EDX: Energy Dispersive X-ray Spectrometry), X-ray photoelectron spectroscopy (XPS: X-ray Photoelectron Spectrometry), inductively coupled plasma mass spectrometry (ICP-MS: Inductively Coupled Plasma-Mass Spectrometry) or inductively coupled plasma atomic emission spectrometry (ICP-AES: Inductively Coupled Plasma-Atomic Emission Spectrometry). Alternatively, multiple of the above methods can be combined for analysis. Note that the actual content of elements with low content is sometimes different from the content obtained by analysis due to the influence of analysis accuracy. For example, when the content of element M is low, the content of element M obtained by analysis is sometimes lower than the actual content.

[0155] In this specification, etc., the nearby composition includes a range of ±30% of the desired atomic number ratio. For example, when the atomic number ratio is described as In:M:Zn=4:2:3 or a composition nearby, the following cases are included: when the atomic number ratio of indium is 4, the atomic number ratio of M is greater than 1 and less than 3, and the atomic number ratio of zinc is greater than 2 and less than 4. In addition, when the atomic number ratio is described as In:M:Zn=5:1:6 or a composition nearby, the following cases are included: when the atomic number ratio of indium is 5, the atomic number ratio of M is greater than 0.1 and less than 2, and the atomic number ratio of zinc is greater than 5 and less than 7. In addition, when the atomic number ratio is described as In:M:Zn=1:1:1 or a composition nearby, the following cases are included: when the atomic number ratio of indium is 1, the atomic number ratio of M is greater than 0.1 and less than 2, and the atomic number ratio of zinc is greater than 0.1 and less than 2.

[0156] The metal oxide can be formed by sputtering or atomic layer deposition (ALD) as appropriate. Note that when the metal oxide is formed by sputtering, the atomic number ratio of the target material is sometimes different from the atomic number ratio of the metal oxide. In particular, the atomic number ratio of zinc in the metal oxide is sometimes smaller than the atomic number ratio of zinc in the target material. Specifically, the atomic number ratio of zinc is sometimes about 40% or more and 90% or less of the atomic number ratio of zinc in the target material.

[0157] The semiconductor layer 108 may also have a stacked structure including two or more metal oxide layers. The compositions of the two or more metal oxide layers included in the semiconductor layer 108 may also be the same or substantially the same as each other. By adopting a stacked structure of metal oxide layers with the same composition, for example, the same sputtering target can be used to form them, thereby reducing manufacturing costs.

[0158] The compositions of the two or more metal oxide layers included in the semiconductor layer 108 may also be different from each other. For example, a stacked structure of a first metal oxide layer having a composition of In:M:Zn=1:3:4 [atomic ratio] or a composition close thereto and a second metal oxide layer having a composition of In:M:Zn=1:1:1 [atomic ratio] or a composition close thereto disposed on the first metal oxide layer may be appropriately used. In addition, gallium or aluminum is particularly preferably used as the element M. For example, a stacked structure of any one selected from indium oxide, indium gallium oxide, and IGZO and any one selected from IAZO, IAGZO, and ITZO (registered trademark) may be used.

[0159] A crystalline metal oxide layer is preferably used as the semiconductor layer 108. For example, a metal oxide layer having a CAAC (c-axis aligned crystal) structure, a polycrystalline structure, a microcrystalline (nc: nano-crystal) structure, or the like can be used. By using a crystalline metal oxide layer for the semiconductor layer 108, the defect state density in the semiconductor layer 108 can be reduced, thereby realizing a transistor with high reliability.

[0160] The higher the crystallinity of the metal oxide layer used for the semiconductor layer 108, the lower the defect state density in the semiconductor layer 108. On the other hand, by using a metal oxide layer with low crystallinity, a transistor capable of passing a large current can be realized.

[0161] The semiconductor layer 108 may also have a stacked structure of two or more metal oxide layers with different crystallinity. For example, a stacked structure may have a first metal oxide layer and a second metal oxide layer disposed on the first metal oxide layer, and the second metal oxide layer may include a region whose crystallinity is higher than that of the first metal oxide layer. Alternatively, the second metal oxide layer may include a region whose crystallinity is lower than that of the first metal oxide layer. The compositions of the two or more metal oxide layers included in the semiconductor layer 108 may also be the same or substantially the same as each other. By adopting a stacked structure of metal oxide layers with the same composition, for example, the same sputtering target can be used to form them, thereby reducing manufacturing costs. For example, by using the same sputtering target to make the oxygen flow ratio different, a stacked structure of two or more metal oxide layers with different crystallinity can be formed. Note that the compositions of the two or more metal oxide layers included in the semiconductor layer 108 may also be different from each other.

[0162] When an oxide semiconductor is used as the semiconductor layer 108, the carrier concentration of the oxide semiconductor in a region serving as a channel formation region is preferably 1×10 18 cm -3 Below, more preferably below 1×10 17 cm -3 , more preferably less than 1×10 16 cm -3 , more preferably less than 1×10 13 cm -3 , and more preferably less than 1×10 12 cm -3 The lower limit of the carrier concentration of the oxide semiconductor in the region serving as the channel formation region is not particularly limited, and can be set to 1×10 -9 cm -3 .

[0163] Compared with transistors using amorphous silicon, transistors using oxide semiconductors (hereinafter referred to as OS transistors) have very high field effect mobility. In addition, the leakage current between the source and the drain in the off state of the OS transistor (hereinafter also referred to as the off-state current) is extremely small, and the charge stored in the capacitor connected in series with the transistor can be maintained for a long time. In addition, by using OS transistors, the power consumption of semiconductor devices can be reduced.

[0164] [Insulating layer 110] When an oxide semiconductor is used for the semiconductor layer 108, an inorganic insulating material can be used as appropriate for the insulating layer 110 (the insulating layer 110a, the insulating layer 110b, and the insulating layer 110c). Alternatively, the insulating layer 110 may have a stacked-layer structure of an inorganic insulating material and an organic insulating material.

[0165] As the inorganic insulating material, one or more of oxides, oxynitrides, nitride oxides and nitrides can be used. For example, the insulating layer 110 can use one or more of silicon oxide, silicon oxynitride, aluminum oxide, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, silicon nitride, silicon oxynitride and aluminum nitride.

[0166] Note that in this specification and the like, oxynitride refers to a material containing more oxygen than nitrogen in its composition. Nitride oxide refers to a material containing more nitrogen than oxygen in its composition. For example, silicon oxynitride refers to a material containing more oxygen than nitrogen in its composition, and silicon nitride oxide refers to a material containing more nitrogen than oxygen in its composition.

[0167] The insulating layer 110b is preferably made of oxide or oxynitride. The insulating layer 110b is preferably made of a film that releases oxygen by heating. For example, silicon oxide or silicon oxynitride can be used for the insulating layer 110b.

[0168] Oxygen is released by the insulating layer 110b, and oxygen can be supplied from the insulating layer 110b to the semiconductor layer 108. By supplying oxygen from the insulating layer 110b to the semiconductor layer 108, especially to the channel formation region of the semiconductor layer 108, oxygen vacancies (V O ) and V O H (hydrogen enters the defect in the oxygen vacancy), a transistor with good electrical characteristics and high reliability can be realized. The insulating layer 110b preferably has a high oxygen diffusion coefficient. By increasing the oxygen diffusion coefficient of the insulating layer 110b, oxygen can be easily diffused into the insulating layer 110b, and oxygen can be efficiently supplied from the insulating layer 110b to the semiconductor layer 108. Note that as a process for supplying oxygen to the semiconductor layer 108, there is also a heat treatment in an oxygen-containing atmosphere or a plasma treatment in an oxygen-containing atmosphere.

[0169] The oxygen vacancies (V O ) and V O H is preferably small. In particular, when the channel length L100 is short, the oxygen vacancies (V O ) and V O H has a greater impact on electrical characteristics and reliability. For example, sometimes V O H diffuses from the source region or the drain region to the channel formation region, increasing the carrier concentration in the channel formation region, thereby causing the threshold voltage of the transistor 100 to vary or the reliability to decrease. The shorter the channel length L100 of the transistor 100, the greater the V O The greater the effect of H diffusion on electrical characteristics and reliability. By supplying oxygen from the insulating layer 110b to the semiconductor layer 108, especially to the channel formation region of the semiconductor layer 108, oxygen vacancies (V O ) and V O H. Therefore, a short-channel transistor having good electrical characteristics and high reliability can be realized.

[0170] The insulating layer 110a and the insulating layer 110c are each preferably not easily permeable to oxygen. The insulating layer 110a and the insulating layer 110c are used as a barrier film for suppressing the separation of oxygen from the insulating layer 110b. Furthermore, the insulating layer 110a and the insulating layer 110c are each preferably not easily permeable to hydrogen. The insulating layer 110a and the insulating layer 110c are used as a barrier film for suppressing the diffusion of hydrogen from the outside of the transistor through the insulating layer 110 to the semiconductor layer 108. The film density of the insulating layer 110a and the insulating layer 110c is preferably high. By increasing the film density of the insulating layer 110a and the insulating layer 110c, the barrier property of oxygen and hydrogen can be improved. The film density of the insulating layer 110a and the insulating layer 110c is each preferably higher than the film density of the insulating layer 110b. In the case of using silicon oxide or silicon oxynitride for the insulating layer 110b, the insulating layer 110a and the insulating layer 110c can appropriately use silicon nitride, silicon nitride oxide, or aluminum oxide, for example. The insulating layer 110a and the insulating layer 110c each preferably include a region containing more nitrogen than the insulating layer 110b. The insulating layer 110a and the insulating layer 110c each may use a material containing more nitrogen than the insulating layer 110b. The insulating layer 110a and the insulating layer 110c each preferably use a nitride or a nitride oxide. The insulating layer 110a and the insulating layer 110c each may use silicon nitride or silicon nitride oxide, for example.

[0171] When oxygen included in the insulating layer 110b diffuses upward from a region of the insulating layer 110b that is not in contact with the semiconductor layer 108 (for example, the top surface of the insulating layer 110b), the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 may decrease. By providing the insulating layer 110c on the insulating layer 110b, it is possible to suppress the diffusion of oxygen included in the insulating layer 110b from a region of the insulating layer 110 that is not in contact with the semiconductor layer 108. Similarly, by providing the insulating layer 110a under the insulating layer 110b, it is possible to suppress the diffusion of oxygen from a region of the insulating layer 110 that is not in contact with the semiconductor layer 108 to the bottom. Therefore, the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 is increased, and thus the oxygen vacancies (V in the semiconductor layer 108) in the semiconductor layer 108 can be reduced. O ) and V O H. Therefore, a transistor having good electrical characteristics and high reliability can be realized.

[0172] Sometimes, the conductive layer 112a and the conductive layer 112b are oxidized due to oxygen contained in the insulating layer 110b, thereby increasing the resistance. In addition, sometimes, the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 is reduced because the conductive layer 112a and the conductive layer 112b are oxidized due to oxygen contained in the insulating layer 110b. By providing the insulating layer 110a between the insulating layer 110b and the conductive layer 112a, it is possible to suppress the conductive layer 112a from being oxidized and the resistance from being increased. Similarly, by providing the insulating layer 110c between the insulating layer 110b and the conductive layer 112b, it is possible to suppress the conductive layer 112b from being oxidized and the resistance from being increased. At the same time, the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 is increased, and the oxygen vacancies (V O ) and V O H, thereby achieving a transistor with good electrical characteristics and high reliability.

[0173] When hydrogen diffuses into the semiconductor layer 108, it reacts with oxygen atoms contained in the oxide semiconductor to form water, and oxygen vacancies (V O ). Furthermore, V O H, sometimes the carrier density becomes high. By providing the insulating layer 110a and the insulating layer 110c, the oxygen vacancies (V O ) and V O H, thereby achieving a transistor with good electrical characteristics and high reliability.

[0174] The insulating layer 110a and the insulating layer 110c preferably have a thickness that allows them to function as a barrier film for oxygen and hydrogen. When the thickness of the insulating layer 110a and the insulating layer 110c is small, the function as a barrier film may be reduced. On the other hand, when the thickness of the insulating layer 110a and the insulating layer 110c is large, the region of the semiconductor layer 108 in contact with the insulating layer 110b becomes narrower, and the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 may be reduced. The thickness of the insulating layer 110a and the insulating layer 110c may be smaller than the thickness of the insulating layer 110b.

[0175] In the transistor 100, oxygen is supplied from the insulating layer 110 to the semiconductor layer 108, thereby reducing oxygen vacancies (V O ) and V O H. Therefore, a transistor having good electrical characteristics and high reliability can be realized.

[0176] In addition, either or both of the insulating layer 110 a and the insulating layer 110 c may not be provided.

[0177] [Conductive layer 112a, conductive layer 112b, conductive layer 104e] The conductive layer 112a, the conductive layer 112b, and the conductive layer 104e used as the source electrode, the drain electrode, or the gate electrode can be formed using one or more of chromium, copper, aluminum, gold, silver, zinc, tantalum, titanium, tungsten, manganese, nickel, iron, cobalt, molybdenum, and niobium, or an alloy containing one or more of the above metals. The conductive layer 112a, the conductive layer 112b, and the conductive layer 104e can appropriately use a low-resistance conductive material containing one or more of copper, silver, gold, and aluminum. Among them, copper or aluminum is particularly advantageous in mass productivity and is therefore preferred.

[0178] The conductive layer 112a, the conductive layer 112b, and the conductive layer 104e can each use a metal oxide film (also referred to as an oxide conductor). Examples of the oxide conductor (OC) include In-Sn oxide (ITO), In-W oxide, In-W-Zn oxide, In-Ti oxide, In-Ti-Sn oxide, In-Zn oxide, In-Sn-Si oxide (ITSO), and In-Ga-Zn oxide.

[0179] Here, an oxide conductor (OC) is described. For example, oxygen vacancies are formed in a metal oxide having semiconductor properties, and hydrogen is added to the oxygen vacancies to form a donor energy level near the conduction band. As a result, the conductivity of the metal oxide increases, and it becomes a conductor. A metal oxide that can become a conductor is called an oxide conductor.

[0180] The conductive layers 112a, 112b, and 104e may have a stacked-layer structure of a conductive film containing the above-mentioned oxide conductor (metal oxide) and a conductive film containing a metal or an alloy. By using a conductive film containing a metal or an alloy, wiring resistance can be reduced.

[0181] As the conductive layer 112a, the conductive layer 112b, and the conductive layer 104e, each may be applied with a Cu-X alloy film (X is Mn, Ni, Cr, Fe, Co, Mo, Ta, or Ti). By using the Cu-X alloy film, processing can be performed by a wet etching process, thereby reducing manufacturing costs.

[0182] Note that the conductive layer 112a, the conductive layer 112b, and the conductive layer 104e can be made of the same material or different materials from each other.

[0183] Here, taking a structure in which a metal oxide is used as the semiconductor layer 108 as an example, the conductive layer 112a and the conductive layer 112b are specifically described.

[0184] When an oxide semiconductor is used as the semiconductor layer 108, the conductive layers 112a and 112b may be oxidized by oxygen contained in the semiconductor layer 108, and the resistance may be increased. The conductive layers 112a and 112b may be oxidized by oxygen contained in the insulating layer 110b, and the resistance may be increased. The conductive layers 112a and 112b may be oxidized by oxygen contained in the semiconductor layer 108, and the oxygen vacancies (V O ) increases. The conductive layer 112a and the conductive layer 112b are oxidized by oxygen contained in the insulating layer 110b, and the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108 is sometimes reduced.

[0185] The conductive layer 112a and the conductive layer 112b are preferably made of materials that are not easily oxidized. The conductive layer 112a and the conductive layer 112b are preferably made of oxide conductors. For example, In-Sn oxide (ITO) or In-Sn-Si oxide (ITSO) can be used appropriately. The conductive layer 112a can also use a nitride conductor. Examples of nitride conductors include tantalum nitride and titanium nitride. The conductive layer 112a can also have a stacked structure of the above materials.

[0186] By using a material that is not easily oxidized for the conductive layer 112a and the conductive layer 112b, an increase in resistance due to oxidation of oxygen contained in the semiconductor layer 108 or oxygen contained in the insulating layer 110b can be suppressed. O ) is suppressed while increasing the amount of oxygen supplied from the insulating layer 110b to the semiconductor layer 108. Therefore, the oxygen vacancies (V O ) and V O H, thereby achieving a transistor having good electrical characteristics and high reliability.

[0187] Similarly, by using a material that is not easily oxidized for the conductive layer 112b, an increase in resistance can be suppressed. Note that the conductive layer 112a and the conductive layer 112b may be made of the same material or different materials.

[0188] The conductive layer 112b includes a region in contact with the transistor 100. By using a material that is not easily oxidized for the conductive layer 112b, oxygen vacancies (V O ) and V O H.

[0189] As described above, as the conductive layers 112a and 112b in contact with the semiconductor layer 108, it is preferable to use a material that is not easily oxidized. However, when a material that is not easily oxidized is used, the resistance sometimes increases. Preferably, the conductive layers 112a and 112b have low resistance because they are used as wiring. Therefore, by using a material that is not easily oxidized for the conductive layer 112a_1 including the area in contact with the semiconductor layer 108 and using a low-resistance material for the conductive layer 112a_2 in the area not in contact with the semiconductor layer 108, the resistance of the conductive layer 112a can be reduced. Furthermore, the oxygen vacancies (V O ) and V O H, thereby achieving a transistor with good electrical characteristics and high reliability.

[0190] As described above, especially when the channel length L100 is short, the oxygen vacancies (V O ) and V O H has a greater influence on electrical characteristics and reliability. By using a material that is not easily oxidized for the conductive layer 112a_1, oxygen vacancies (V O ) and V O H increases. Therefore, a short-channel transistor having good electrical characteristics and high reliability can be realized.

[0191] As the conductive layer 112a_1, one or more of an oxide conductor and a nitride conductor can be appropriately used. As the conductive layer 112a_2, it is preferable to use a material whose resistance is lower than that of the conductive layer 112a_1. As the conductive layer 112a_2, for example, one or more of copper, aluminum, titanium, tungsten, and molybdenum or an alloy containing one or more of the above metals as components can be appropriately used. Specifically, it is preferable to use In-Sn-Si oxide (ITSO) for the conductive layer 112a_1 and tungsten for the conductive layer 112a_2.

[0192] In addition, the structure of the conductive layer 112a can be determined according to the wiring resistance required for the conductive layer 112a. For example, when the length of the wiring (conductive layer 112a) is short and the required wiring resistance is relatively high, the conductive layer 112a can have a single-layer structure and a material that is not easily oxidized can be used. On the other hand, when the length of the wiring (conductive layer 112a) is long and the required wiring resistance is relatively low, the conductive layer 112a preferably has a stacked structure of a material that is not easily oxidized and a low-resistance material.

[0193] Furthermore, the structure of the conductive layer 112 a may be applied to other conductive layers.

[0194] [Insulating layer 106] The insulating layer 106 used as a gate insulating layer preferably has a low defect density. When the defect density of the insulating layer 106 is low, a transistor having good electrical characteristics can be realized. Furthermore, the insulating layer 106 preferably has a high dielectric strength voltage. Since the dielectric strength voltage of the insulating layer 106 is high, a transistor with high reliability can be formed.

[0195] The insulating layer 106 may be made of, for example, one or more of an oxide, an oxynitride, an oxynitride, and a nitride having insulating properties. The insulating layer 106 may be made of, for example, one or more of silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum oxynitride, aluminum nitride oxide, aluminum nitride, hafnium oxide, hafnium oxynitride, gallium oxide, gallium oxynitride, yttrium oxide, yttrium oxynitride, and Ga-Zn oxide. The insulating layer 106 may also be a single layer or a stacked layer. The insulating layer 106 may also have, for example, a stacked layer structure of an oxide and a nitride.

[0196] Note that in a fine transistor, when the thickness of the gate insulating layer is small, the leakage current sometimes increases. By using a material with a high relative dielectric constant (also called a high-k material) for the gate insulating layer, it is possible to achieve a low voltage when the transistor is operating while maintaining the physical thickness. Examples of high-k materials include gallium oxide, hafnium oxide, zirconium oxide, oxides containing aluminum and hafnium, oxynitrides containing aluminum and hafnium, oxides containing silicon and hafnium, oxynitrides containing silicon and hafnium, or nitrides containing silicon and hafnium.

[0197] It is preferable that a small amount of impurities (for example, water and hydrogen) is released from the insulating layer 106 itself. Since a small amount of impurities is released from the insulating layer 106, diffusion of impurities into the semiconductor layer 108 can be suppressed, thereby achieving a transistor having good electrical characteristics and high reliability.

[0198] Here, the insulating layer 106 is specifically described by taking a structure in which the semiconductor layer 108 is made of metal oxide as an example.

[0199] In order to improve the interface characteristics between the insulating layer 106 and the semiconductor layer 108, an oxide is preferably used for at least one side of the insulating layer 106 that is in contact with the semiconductor layer 108. For example, one or more of silicon oxide and silicon oxynitride can be used for the insulating layer 106. In addition, the insulating layer 106 is preferably made of a film that releases oxygen by heating.

[0200] Note that the insulating layer 106 may have a stacked-layer structure. The insulating layer 106 may have a stacked-layer structure of an oxide film in contact with the semiconductor layer 108 side and a nitride film in contact with the conductive layer 104e side. As the oxide film, for example, one or more of silicon oxide and silicon oxynitride can be appropriately used. As the nitride film, silicon nitride can be appropriately used.

[0201] [Insulation layer 150] The insulating layer 150 can be formed using the same material as the insulating layer 110. Preferably, the insulating layer 150 is formed using a material that has a large etching selectivity ratio with the insulating layer 106 and is easier to etch than the insulating layer 106. Figure 7B Although an example in which the insulating layer 150 is formed of a single layer is shown, a two-layer structure may be used.

[0202] [Substrate 102] Although there is no particular limitation on the material of the substrate 102, it is at least necessary to have heat resistance sufficient to withstand subsequent heat treatment. For example, a single crystal semiconductor substrate or polycrystalline semiconductor substrate made of silicon or silicon carbide, a compound semiconductor substrate such as silicon germanium, an SOI substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, or an organic resin substrate can be used as the substrate 102. In addition, a substrate having a semiconductor element provided thereon can also be used as the substrate 102. Note that the shape of the semiconductor substrate and the insulating substrate can be circular or angular.

[0203] As the substrate 102, a flexible substrate may be used, and the transistor 100 and the like may be directly formed on the flexible substrate. Alternatively, a peeling layer may be provided between the substrate 102 and the transistor 100 and the like. The peeling layer may be used when a part or all of a semiconductor device is manufactured on the peeling layer, and then separated from the substrate 102 and transferred to another substrate. In this case, the transistor 100 and the like may also be transferred to a substrate with low heat resistance or a flexible substrate.

[0204] The above is the description of the transistor 100 .

[0205] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate.

[0206] (Implementation 3) In this embodiment, a structural example of a display panel that can be used for an electronic device according to one embodiment of the present invention is described. The display panel described below can be used as the display device 10 according to Embodiment 1.

[0207] One embodiment of the present invention is a display panel including a light-emitting element (also referred to as a light-emitting device). The display panel includes two or more pixels with different luminous colors. Each pixel includes a light-emitting element. Each light-emitting element includes a pair of electrodes and an EL layer between the pair of electrodes. The light-emitting element is preferably an organic EL element (organic electroluminescent element). The two or more light-emitting elements with different luminous colors each include an EL layer containing different luminescent materials. For example, a full-color display panel can be achieved by including three light-emitting elements that emit red (R), green (G) or blue (B) light, respectively.

[0208] When manufacturing a display panel including a plurality of light-emitting elements with different luminous colors, it is necessary to form at least a layer containing a light-emitting material (light-emitting layer) into an island shape. Here, a method of forming an island-shaped organic film by a vapor deposition method using a shadow mask such as a metal mask is known when forming a part or all of the EL layer separately. However, this method is difficult to achieve high definition and high aperture ratio of the display panel because the shape and position of the island-shaped organic film deviate from the shape and position at the time of design due to various influences such as the accuracy of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the enlargement of the outline of the deposited film caused by vapor scattering. In addition, during vapor deposition, the film thickness at the end is sometimes reduced due to the blurred outline of the layer. That is, the film thickness of the island-shaped light-emitting layer is sometimes different depending on the position. In addition, when manufacturing a large-scale and high-resolution or high-definition display panel, there is the following concern: due to the low dimensional accuracy of the metal mask and deformation caused by heat, etc., the manufacturing yield is reduced. Therefore, the following measures have been taken: the definition (also called pixel density) is simulated by adopting a special pixel arrangement such as a Pentile arrangement.

[0209] Note that in this specification, etc., "island-shaped" means a state in which two or more layers formed using the same material in the same process are physically separated. For example, an island-shaped light-emitting layer means a state in which the light-emitting layer is physically separated from an adjacent light-emitting layer.

[0210] In one embodiment of the present invention, the EL layer is processed into a fine pattern by photolithography without using a shadow mask such as a fine metal mask (FMM). Therefore, a display panel with high definition and high aperture ratio, which is difficult to achieve at present, can be realized. In addition, since the EL layer can be manufactured separately, a display panel with a very clear and high contrast display quality can be realized. In addition, for example, the EL layer can be processed into a fine pattern by using both a metal mask and photolithography.

[0211] In addition, part or all of the EL layer can be physically separated. Thus, leakage current between light-emitting elements through a layer (also referred to as a common layer) commonly used by adjacent light-emitting elements can be suppressed. Therefore, crosstalk caused by unintentional light emission can be suppressed, thereby realizing a display panel with very high contrast. In particular, a display panel with high current efficiency at low brightness can be realized.

[0212] One embodiment of the present invention can also realize a display panel that combines a white light-emitting light-emitting element and a color filter. In this case, light-emitting elements of the same structure can be used for each light-emitting element in a pixel (sub-pixel) that emits light of different colors, and all layers in each light-emitting element can be used as a common layer. Furthermore, a part or all of each EL layer can be separated by a process utilizing a photolithography method. Thus, the leakage current through the common layer can be suppressed and a display panel with high contrast can be realized. In particular, in an element having a series structure in which a plurality of light-emitting layers are stacked with an intermediate layer having high conductivity, the leakage current through the intermediate layer can be effectively prevented, so a display panel with high brightness, high definition and high contrast can be realized.

[0213] When the EL layer is processed by photolithography, degradation is sometimes caused by the exposure of a portion of the light-emitting layer. Therefore, it is preferred to provide an insulating layer that covers at least the side of the island-shaped light-emitting layer. The insulating layer may also cover a portion of the top surface of the island-shaped EL layer. The insulating layer is preferably made of a material that has a barrier property against water and oxygen. For example, an inorganic insulating film that does not easily diffuse water or oxygen can be used. Thus, the degradation of the EL layer can be suppressed and a display panel with high reliability can be realized.

[0214] In addition, there is an area (recess) between two adjacent light-emitting elements where the EL layer of each light-emitting element is not provided. When a common electrode or a common electrode and a common layer are formed in a manner covering the recess, the common electrode is sometimes broken due to a step at the end of the EL layer (also called disconnection), resulting in the insulation of the common electrode on the EL layer. Therefore, it is preferable to adopt a structure (also called LFP: Local Filling Planarization) in which a resin layer used as a planarization film is used to fill the local step between two adjacent light-emitting elements. The resin layer is used as a planarization film. As a result, the disconnection of the common layer or the common electrode can be suppressed, and a display panel with high reliability can be achieved.

[0215] Hereinafter, a more specific structural example of a display panel according to one embodiment of the present invention will be described with reference to the drawings.

[0216] [Structural example 1] Fig. 8A FIG. 2 is a schematic top view of a display panel 200 according to one embodiment of the present invention. The display panel 200 includes a plurality of red light emitting elements 210R, a plurality of green light emitting elements 210G, and a plurality of blue light emitting elements 210B on a layer 201. Fig. 8A In order to distinguish each light-emitting element, symbols “R”, “G”, and “B” are added to the light-emitting region of each light-emitting element. Note that the layer 201 may be a component included in the layer 30 b in Embodiment Mode 1.

[0217] The light-emitting elements 210R, 210G, and 210B are all arranged in a matrix. Fig. 8A The so-called stripe arrangement in which light-emitting elements of the same color are arranged in one direction is shown. Note that the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as S stripe arrangement, Delta arrangement, Bayer arrangement, zigzag arrangement, etc. can also be used, and Pentile arrangement, Diamond arrangement, etc. can also be used.

[0218] As the light-emitting elements 210R, 210G, and 210B, OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode) is preferably used. As the light-emitting substances contained in the EL element, substances that emit fluorescence (fluorescent materials), substances that emit phosphorescence (phosphorescent materials), and substances that exhibit thermally activated delayed fluorescence (Thermally activated delayed fluorescence: TADF materials) can be cited. As the light-emitting substances contained in the EL element, inorganic compounds (such as quantum dot materials) can also be used in addition to organic compounds.

[0219] In addition, Fig. 8A The connection electrode 211C electrically connected to the common electrode 213 is shown. The connection electrode 211C is supplied with the potential (for example, anode potential or cathode potential) supplied to the common electrode 213. The connection electrode 211C is provided outside the display area where the light-emitting elements 210R, etc. are arranged.

[0220] The connection electrode 211C can be provided along the outer periphery of the display area. For example, it can be provided along one side of the outer periphery of the display area, or it can span two or more sides of the outer periphery of the display area. That is, when the top surface shape of the display area is rectangular, the top surface shape of the connection electrode 211C can be strip-shaped (rectangular), L-shaped, "冂"-shaped (bracket-shaped), or quadrangular, etc.

[0221] Figure 8B , Figure 8C respectively are cross-sectional schematic views corresponding to Fig. 8A the dash-dotted lines A1 - A2 and A3 - A4 in Figure 8B The cross-sectional schematic views of the light-emitting elements 210R, 210G, and 210B are shown, Figure 8C The cross-sectional schematic view of the connection portion 230 where the connection electrode 211C is connected to the common electrode 213 is shown.

[0222] The light-emitting element 210R includes a pixel electrode 211R, an organic layer 212R, a common layer 214, and a common electrode 213. The light-emitting element 210G includes a pixel electrode 211G, an organic layer 212G, a common layer 214, and a common electrode 213. The light-emitting element 210B includes a pixel electrode 211B, an organic layer 212B, a common layer 214, and a common electrode 213. The light-emitting element 210R, the light-emitting element 210G, and the light-emitting element 210B share the common layer 214 and the common electrode 213.

[0223] The organic layer 212R included in the light-emitting element 210R includes a light-emitting organic compound that emits at least red light. The organic layer 212G included in the light-emitting element 210G includes a light-emitting organic compound that emits at least green light. The organic layer 212B included in the light-emitting element 210B includes a light-emitting organic compound that emits at least blue light. The organic layer 212R, the organic layer 212G, and the organic layer 212B can each also be referred to as an EL layer, and at least includes a layer (light-emitting layer) having a light-emitting substance.

[0224] Hereinafter, when describing the common contents among the light-emitting element 210R, the light-emitting element 210G, and the light-emitting element 210B, they are sometimes referred to as the light-emitting element 210. Similarly, when describing the common contents among the constituent elements distinguished by letters, such as the organic layer 212R, the organic layer 212G, and the organic layer 212B, the symbols without letters are sometimes used for description.

[0225] The organic layer 212 and the common layer 214 may independently include one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, the organic layer 212 has a stacked structure of a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer from one side of the pixel electrode 211, and the common layer 214 includes an electron injection layer.

[0226] The pixel electrode 211R, the pixel electrode 211G and the pixel electrode 211B are all arranged in each light-emitting element. In addition, the common electrode 213 and the common layer 214 are set as a layer commonly used by each light-emitting element. A conductive film that is translucent to visible light is used as one of the pixel electrodes and the common electrode 213, and a conductive film that is reflective is used as the other. By making each pixel electrode translucent and the common electrode 213 reflective, a bottom emission type (bottom emission structure) display panel can be realized. On the contrary, by making each pixel electrode reflective and the common electrode 213 translucent, a top emission type (top emission structure) display panel can be realized. In addition, by making both the pixel electrode and the common electrode 213 translucent, a double-sided emission type (double-sided emission structure) display panel can also be realized.

[0227] A protective layer 221 is provided on the common electrode 213 so as to cover the light emitting element 210R, the light emitting element 210G, and the light emitting element 210B. The protective layer 221 has a function of preventing impurities such as water from diffusing from above to each light emitting element.

[0228] The end of the pixel electrode 211 preferably has a tapered shape. When the end of the pixel electrode 211 has a tapered shape, the organic layer 212 provided along the end of the pixel electrode 211 may also have a tapered shape. By making the side of the pixel electrode 211 have a tapered shape, the coverage of the organic layer 212 provided across the end of the pixel electrode 211 can be improved. In addition, by making the side of the pixel electrode 211 have a tapered shape, foreign matter (for example, dust or particles, etc.) in the manufacturing process can be easily removed by washing treatment, etc., so it is preferred.

[0229] Note that in this specification, etc., a tapered shape means a shape in which at least a portion of the side surface of a component is inclined relative to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also referred to as a taper angle) is less than 90 degrees.

[0230] The organic layer 212 is processed into an island shape by photolithography. Therefore, the organic layer 212 has a shape at its end where the angle between the top surface and the side surface is close to 90°. On the other hand, the film thickness of the organic film formed using FMM or the like tends to become thinner as it approaches the end, for example, the top surface is formed in a slope shape within a range of 1 μm to 10 μm, so it is difficult to distinguish the top surface from the side surface.

[0231] An insulating layer 225 , a resin layer 226 , and a layer 228 are provided between two adjacent light emitting elements.

[0232] Between two adjacent light-emitting elements, the side surfaces of each organic layer 212 face each other via the resin layer 226. The resin layer 226 is located between two adjacent light-emitting elements and is provided in a manner to fill the end of each organic layer 212 and the area between the two organic layers 212. The top surface of the resin layer 226 has a smooth convex shape, and the common layer 214 and the common electrode 213 are provided in a manner to cover the top surface of the resin layer 226.

[0233] The resin layer 226 is used as a planarization film for filling the step between two adjacent light-emitting elements. By providing the resin layer 226, it is possible to prevent the common electrode 213 from being disconnected (also called disconnected) due to the step at the end of the organic layer 212, thereby preventing the common electrode on the organic layer 212 from being insulated. The resin layer 226 may also be referred to as LFP (Local Filling Planarization).

[0234] As the resin layer 226, an insulating layer containing an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimide amide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin and precursors of the above resins can be used as the resin layer 226. In addition, as the resin layer 226, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose or alcohol-soluble polyamide resin can also be used.

[0235] In addition, a photosensitive resin may be used as the resin layer 226. A photoresist may be used as the photosensitive resin. A positive type material or a negative type material may be used as the photosensitive resin.

[0236] The resin layer 226 may also contain a material that absorbs visible light. For example, the resin layer 226 itself may be composed of a material that absorbs visible light, or the resin layer 226 may contain a pigment that absorbs visible light. As the resin layer 226, for example, the following resins may be used: a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light; or a resin that contains carbon black as a pigment and is used as a black matrix; etc.

[0237] The insulating layer 225 is in contact with the side surface of the organic layer 212. In addition, the insulating layer 225 covers the upper end portion of the organic layer 212. In addition, a portion of the insulating layer 225 is in contact with the top surface of the layer 201.

[0238] The insulating layer 225 is located between the resin layer 226 and the organic layer 212 and is used as a protective film to prevent the resin layer 226 from contacting the organic layer 212. When the organic layer 212 and the resin layer 226 are in contact, the organic layer 212 may be dissolved by an organic solvent or the like used when forming the resin layer 226. Therefore, by providing the insulating layer 225 between the organic layer 212 and the resin layer 226, the side surface of the organic layer 212 can be protected.

[0239] The insulating layer 225 may be an insulating layer containing an inorganic material. As the insulating layer 225, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film may be used. The insulating layer 225 may be a single-layer structure or a stacked-layer structure. As the oxide insulating film, a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film may be cited. As the nitride insulating film, a silicon nitride film and an aluminum nitride film may be cited. As the oxynitride insulating film, an oxynitride silicon film and an oxynitride aluminum film may be cited. As the nitride oxide insulating film, a nitride oxide silicon film and an oxynitride aluminum film may be cited. In particular, by using a metal oxide film such as an aluminum oxide film or a hafnium oxide film or an inorganic insulating film such as a silicon oxide film formed by an ALD method for the insulating layer 225, the insulating layer 225 can have fewer pinholes and have an excellent function of protecting the EL layer.

[0240] In this specification, etc., "oxynitride" refers to a material whose composition contains more oxygen than nitrogen, and "nitride oxide" refers to a material whose composition contains more nitrogen than oxygen. For example, "silicon oxynitride" refers to a material whose composition contains more oxygen than nitrogen, and "silicon nitride oxide" refers to a material whose composition contains more nitrogen than oxygen.

[0241] The insulating layer 225 can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, etc. The insulating layer 225 is preferably formed by an ALD method having good coverage.

[0242] In addition, a reflective film (for example, a metal film including one or more selected from silver, palladium, copper, titanium, and aluminum) may be provided between the insulating layer 225 and the resin layer 226 so that the reflective film reflects the light emitted by the light-emitting layer. In this way, the light extraction efficiency can be further improved.

[0243] The layer 228 is a portion of a protective layer (also referred to as a mask layer or a sacrificial layer) that is used to protect the organic layer 212 when etching the organic layer 212. The layer 228 can use a material that can be used for the insulating layer 225. In particular, the layer 228 and the insulating layer 225 are preferably made of the same material, so that the same equipment for processing can be used.

[0244] In particular, metal oxide films such as aluminum oxide films and hafnium oxide films and inorganic insulating films such as silicon oxide films formed by the ALD method have fewer pinholes and are therefore excellent in the function of protecting the EL layer and can be preferably used for the insulating layer 225 and the layer 228 .

[0245] The protective layer 221 may have, for example, a single-layer structure or a stacked-layer structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as silicon oxide films, silicon oxynitride films, silicon nitride oxide films, silicon nitride films, aluminum oxide films, aluminum oxynitride films, and hafnium oxide films. Alternatively, a semiconductor material or conductive material such as indium gallium oxide, indium zinc oxide, indium tin oxide, and indium gallium zinc oxide may be used as the protective layer 221.

[0246] As the protective layer 221, a laminated film of an inorganic insulating film and an organic insulating film can also be used. For example, it is preferred to sandwich an organic insulating film between a pair of inorganic insulating films. In addition, the organic insulating film is preferably used as a planarizing film. Therefore, the top surface of the organic insulating film can be made flat, so the coverage of the inorganic insulating film thereon is improved, thereby improving the barrier property. In addition, the top surface of the protective layer 221 becomes flat, so when a structure (for example, a color filter, an electrode or a lens array of a touch sensor, etc.) is set above the protective layer 221, the influence of the concave-convex shape caused by the lower structure can be reduced, so it is preferred.

[0247] Figure 8C The connecting portion 230 that electrically connects the connecting electrode 211C and the common electrode 213 is shown. In the connecting portion 230, an opening is provided in the insulating layer 225 and the resin layer 226 above the connecting electrode 211C. The connecting electrode 211C and the common electrode 213 are electrically connected in the opening.

[0248] Notice, Figure 8C The connection portion 230 electrically connecting the connection electrode 211C and the common electrode 213 is shown, but the common electrode 213 may be provided on the connection electrode 211C via the common layer 214. In particular, when a carrier injection layer is used as the common layer 214, the resistivity of the material used for the common layer 214 is sufficiently low and the film thickness is also thin, so in many cases there is no problem in positioning the common layer 214 at the connection portion 230. Thus, the common electrode 213 and the common layer 214 can be formed using the same shadow mask, so that the manufacturing cost can be reduced.

[0249] [Structural example 2] Hereinafter, a display panel having a partially different structure from that of the above-described Structural Example 1 will be described. Note that, regarding the same parts as those of the above-described Structural Example 1, the above-described Structural Example 1 may be referred to and the description thereof may be omitted.

[0250] Fig. 9A 2 is a schematic cross-sectional view of a display panel 200a. The main differences between the display panel 200a and the display panel 200 are: the structure of the light emitting element; and the former includes a coloring layer.

[0251] The display panel 200a includes a light-emitting element 210W that emits white light. The light-emitting element 210W includes a pixel electrode 211, an organic layer 212W, a common layer 214, and a common electrode 213. The organic layer 212W emits white light. For example, the organic layer 212W may include two or more light-emitting materials whose luminescent colors are in a complementary color relationship. For example, the organic layer 212W may include a light-emitting organic compound that emits red light, a light-emitting organic compound that emits green light, and a light-emitting organic compound that emits blue light. In addition, it may also include a light-emitting organic compound that emits blue light and a light-emitting organic compound that emits yellow light.

[0252] Each organic layer 212W is separated between two adjacent light emitting elements 210W. Thus, leakage current flowing between adjacent light emitting elements 210W through the organic layer 212W can be suppressed, and crosstalk caused by the leakage current can be suppressed. Therefore, a display panel with high contrast and color reproducibility can be realized.

[0253] An insulating layer 222 serving as a planarization film is provided on the protective layer 221 , and a colored layer 216R, a colored layer 216G, and a colored layer 216B are provided on the insulating layer 222 .

[0254] As the insulating layer 222, an organic resin film or an inorganic insulating film with a flat top surface can be used. Since the insulating layer 222 is the surface on which the coloring layer 216R, the coloring layer 216G, and the coloring layer 216B are formed, the thickness of the coloring layer 216R and the like can be made uniform when the top surface of the insulating layer 222 is flat, thereby improving the color purity of light extracted from each light-emitting element. Note that when the thickness of the coloring layer 216R and the like is not uniform, the amount of light absorption varies depending on the position in the coloring layer 216R, which may cause a decrease in color purity.

[0255] [Structural example 3] Fig. 9B is a schematic cross-sectional view of the display panel 200 b.

[0256] The light emitting element 210R includes a pixel electrode 211, a conductive layer 215R, an organic layer 212W, and a common electrode 213. The light emitting element 210G includes a pixel electrode 211, a conductive layer 215G, an organic layer 212W, and a common electrode 213. The light emitting element 210B includes a pixel electrode 211, a conductive layer 215B, an organic layer 212W, and a common electrode 213. The conductive layer 215R, the conductive layer 215G, and the conductive layer 215B are all light-transmissive and are used as optical adjustment layers.

[0257] A microcavity resonator (microcavity) structure can be realized by using a film that reflects visible light as the pixel electrode 211 and using a film that is both reflective and transmissive to visible light as the common electrode 213. At this time, by adjusting the thickness of the conductive layer 215R, the conductive layer 215G, and the conductive layer 215B so as to realize the most appropriate optical path length, even when using the organic layer 212 that emits white light, it is possible to extract light of different wavelengths from the light-emitting element 210R, the light-emitting element 210G, and the light-emitting element 210B, respectively, and to enhance the light.

[0258] Furthermore, by providing the colored layer 216R, the colored layer 216G, and the colored layer 216B on the optical paths of the light emitting element 210R, the light emitting element 210G, and the light emitting element 210B, respectively, light with high color purity can be extracted.

[0259] In addition, an insulating layer 223 is provided to cover the ends of the pixel electrode 211 and the optical adjustment layer. The ends of the insulating layer 223 preferably have a tapered shape. By providing the insulating layer 223, the coverage of the organic layer 212W, the common electrode 213, and the protective layer 221 formed thereon can be improved.

[0260] The organic layer 212W and the common electrode 213 are respectively provided as a continuous film in each light emitting element. By adopting this structure, the manufacturing process of the display panel can be greatly simplified, so it is preferred.

[0261] Here, the end of the pixel electrode 211 preferably has a shape that is almost perpendicular to the top surface of the layer 201. Thus, a steeply inclined portion can be formed on the surface of the insulating layer 223, and a thin portion can be formed on a portion of the organic layer 212W covering the portion, or a portion of the organic layer 212W can be separated. Thus, the leakage current generated between adjacent light-emitting elements through the organic layer 212W can be suppressed without processing the organic layer 212W using photolithography or the like.

[0262] The above is a description of the structural example of the display panel.

[0263] [Pixel layout] The following mainly describes Fig. 8A Different pixel layouts: There is no particular restriction on the arrangement of light-emitting elements (sub-pixels), and various arrangements can be used.

[0264] As the top surface shape of the sub-pixel, for example, there can be cited polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, shapes with rounded corners of these polygons, ellipses, circles, etc. Here, the top surface shape of the sub-pixel is equivalent to the top surface shape of the light-emitting region of the light-emitting element.

[0265] Fig. 10AThe pixels 250 are shown in an S-stripe arrangement. Fig. 10A The pixel 250 shown is composed of three sub-pixels, namely, light emitting elements 210a, 210b, and 210c. For example, the light emitting element 210a, the light emitting element 210b, and the light emitting element 210c may be a blue light emitting element, a red light emitting element, and a green light emitting element, respectively.

[0266] Fig. 10B The pixel 250 shown includes a light-emitting element 210a having a top surface shape of a trapezoid or a triangle with rounded corners, a light-emitting element 210b having a top surface shape of a trapezoid or a triangle with rounded corners, and a light-emitting element 210c having a top surface shape of a quadrangular or a hexagonal with rounded corners. In addition, the light-emitting area of ​​the light-emitting element 210a is larger than that of the light-emitting element 210b. In this way, the shape and size of each light-emitting element can be determined independently. For example, the size of a light-emitting element with high reliability can be smaller. For example, the light-emitting element 210a, the light-emitting element 210b, and the light-emitting element 210c can be a green light-emitting element, a red light-emitting element, and a blue light-emitting element, respectively.

[0267] Fig. 10C The pixels 224a and 224b shown are arranged in a Pentile arrangement. Fig. 10C The example of alternately arranging pixel 224a including light emitting element 210a and light emitting element 210b and pixel 224b including light emitting element 210b and light emitting element 210c is shown. For example, light emitting element 210a, light emitting element 210b and light emitting element 210c may be a red light emitting element, a green light emitting element and a blue light emitting element, respectively.

[0268] Fig. 10D and Fig. 10E The pixels 224a and 224b shown are arranged in Delta. Pixel 224a includes two light-emitting elements (light-emitting elements 210a and 210b) in the upper row (first row) and one light-emitting element (light-emitting element 210c) in the lower row (second row). Pixel 224b includes one light-emitting element (light-emitting element 210c) in the upper row (first row) and two light-emitting elements (light-emitting elements 210a and 210b) in the lower row (second row). For example, light-emitting element 210a, light-emitting element 210b, and light-emitting element 210c may also be a red light-emitting element, a green light-emitting element, and a blue light-emitting element, respectively.

[0269] Fig. 10D An example is shown in which each light emitting element has a top surface shape that is approximately quadrangular with rounded corners. Fig. 10E An example is shown in which each light emitting element has a circular top surface shape.

[0270] Fig.10FAn example in which the light-emitting elements of each color are arranged in a zigzag shape is shown. Specifically, in the top view, the positions of the upper sides of two light-emitting elements arranged in the column direction (for example, the light-emitting element 210a and the light-emitting element 210b or the light-emitting element 210b and the light-emitting element 210c) are inconsistent. For example, the light-emitting element 210a, the light-emitting element 210b, and the light-emitting element 210c may be a red light-emitting element, a green light-emitting element, and a blue light-emitting element, respectively.

[0271] In photolithography, the finer the pattern being processed, the more important it is to not ignore the effect of light diffraction. Therefore, when the pattern of the photomask is transferred by exposure, its fidelity decreases, and it is difficult to process the resist mask into a desired shape. Therefore, even if the pattern of the photomask is rectangular, it is easy to form a pattern with rounded corners. Therefore, the top surface shape of the light-emitting element is sometimes a polygonal shape with rounded corners, an ellipse, or a circle.

[0272] Furthermore, in a method for manufacturing a display panel according to one embodiment of the present invention, an EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the material of the EL layer and the curing temperature of the resist material, the curing of the resist film is sometimes insufficient. The insufficiently cured resist film sometimes has a shape that is far from the desired shape when processed. As a result, the top surface shape of the EL layer is sometimes a polygonal shape with rounded corners, an ellipse, or a circle. For example, when a resist mask having a square top surface shape is to be formed, a resist mask having a circular top surface shape is sometimes formed and the top surface shape of the EL layer is circular.

[0273] In order to make the top surface shape of the EL layer a desired shape, a technique (OPC (Optical Proximity Correction) technique) of pre-correcting the mask pattern so that the design pattern and the transfer pattern coincide with each other can be used. Specifically, in the OPC technique, correction patterns are added to the pattern corners on the mask pattern.

[0274] The above describes the layout of pixels.

[0275] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate.

[0276] (Implementation 4) In this embodiment, another structural example of a display panel that can be used for an electronic device according to one embodiment of the present invention is described.

[0277] The display panel of this embodiment is a high-definition display panel, and is particularly suitable for use in the display portion of wearable devices such as head-mounted displays and VR devices and glasses-type AR devices that can be worn on the head. As the display panel of this embodiment, the structure of the display device 10 shown in Embodiment 1 can be used.

[0278] [Display module] Fig.11A FIG. 2 is a perspective view of a display module 280. The display module 280 includes a display panel 200A and an FPC 290. The display panel 200A may have the structure of the display device 10 described in Embodiment 1.

[0279] The display module 280 includes a substrate 291, a substrate 292, and a display unit 281. The display unit 281 is a region where an image is displayed. The substrate 291 corresponds to the layer 20 described in Embodiment 1, and a layer 30 including a light-emitting element is provided between the substrate 291 and the substrate 292. The substrate 292 can use a glass substrate with high transmittance of light emitted by the light-emitting element.

[0280] Fig. 11B 2 is a perspective view schematically showing a structure on one side of a substrate 291. A circuit portion 282, a circuit portion 283 on the circuit portion 282, and a circuit portion 284 on the circuit portion 283 are stacked on the substrate 291. Here, the circuit portion 282 is provided with the circuit 21a described in Embodiment Mode 1. The circuit portion 283 is provided with the circuit 21b described in Embodiment Mode 1. The circuit portion 284 is provided with the pixel circuit PIX described in Embodiment Mode 1.

[0281] Furthermore, a terminal portion 285 for connecting to the FPC 290 is provided on the substrate 291. The terminal portion 285 and the circuit portion 282 are electrically connected via a wiring portion 286 composed of a plurality of wirings.

[0282] The circuit portion 284 includes a plurality of pixels 284 a arranged periodically. Fig. 11B An enlarged view of one pixel 284a is shown on the right side of FIG. The pixel 284a includes a light-emitting element 210R that emits red light, a light-emitting element 210G that emits green light, and a light-emitting element 210B that emits blue light.

[0283] In addition, the circuit unit 284 includes a plurality of pixel circuits PIX arranged periodically. One pixel circuit PIX controls the light emission of three light-emitting devices included in one pixel 284a. One pixel circuit PIX may include three circuits for controlling the light emission of one light-emitting device. For example, the pixel circuit PIX may adopt a structure having at least one selection transistor, one current control transistor (driving transistor) and a capacitor for one light-emitting device. At this time, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. Thus, an active matrix display panel can be realized.

[0284] The circuit section 282 and the circuit section 283 include a circuit for driving each pixel circuit PIX. The FPC 290 is used as wiring for supplying video data, power supply potential, etc. from the outside to the circuit section 282. In addition, an IC may be mounted on the FPC 290.

[0285] The display module 280 can adopt a structure in which the circuit unit 283 and the circuit unit 282 are stacked on the lower side of the circuit unit 284, so that the display unit 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display unit 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. In addition, the pixels 284a can be arranged at an extremely high density, thereby making the display unit 281 have an extremely high definition. For example, the display unit 281 preferably arranges the pixels 284a with a definition of 2000ppi or more, more preferably 3000ppi or more, more preferably 5000ppi or more, and more preferably 6000ppi or more and 20000ppi or less or 30000ppi or less.

[0286] This display module 280 is very clear, so it is suitable for use in VR devices such as head-mounted displays or glasses-type AR devices. For example, because the display module 280 has a display unit 281 with extremely high clarity, in the structure of viewing the display unit of the display module 280 through a lens, even if the display unit is magnified by a lens, the user cannot see the pixels, thereby achieving a highly immersive display. In addition, the display module 280 can also be applied to electronic devices with a relatively small display unit. For example, it is suitable for use in the display unit of wearable electronic devices such as watch-type devices.

[0287] exist Fig.12 In the display panel 200A shown, a transistor 310 having a channel formed on a substrate 301, and transistors 320A and 320B having a semiconductor layer containing a metal oxide forming a channel are stacked. Fig.12 The stacked structure shown is Figure 2A An example of the structure shown.

[0288] Here, the substrate 301 corresponds to Fig.11A and Fig. 11B The substrate 291 in the substrate 291. The transistor 310, the transistor 320A, and the transistor 320B correspond to the Si transistor provided in the layer 20, the first OS transistor provided in the layer 30a, and the second OS transistor provided in the layer 30b described in Embodiment 1, respectively.

[0289] The transistor 310 and the transistor 320A can be used as transistors constituting a driving circuit (gate driver, source driver) or a functional circuit for driving a pixel circuit. The transistor 320B can be used as a transistor constituting a pixel circuit.

[0290] The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. Note that Fig.12 Although a planar transistor is shown as the transistor 310 , a fin-type transistor may also be used.

[0291] The transistor 310 includes a portion of a substrate 301, a conductive layer 311, a low resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 is used as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311, and is used as a gate insulating layer. The low resistance region 312 is a region doped with impurities in the substrate 301, and is used as one of a source and a drain. The insulating layer 314 covers the side of the conductive layer 311.

[0292] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0293] An insulating layer 261 is provided so as to cover the transistor 310, and a conductive layer 251 and a conductive layer 252 are provided over the insulating layer 261. In addition, an insulating layer 262 is provided so as to cover the conductive layers 251 and 252. The conductive layers 251 and 252 are used as wiring. In addition, an insulating layer 332 is provided over the insulating layer 262, and a transistor 320A is provided over the insulating layer 332.

[0294] The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 301 side to the transistor 320A. As the insulating layer 332, for example, a film such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, in which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, can be used.

[0295] The transistor 320A is a vertical transistor, and the details thereof can be referred to the description of the first OS transistor described in Embodiment 1.

[0296] The transistor 320A is electrically connected to the transistor 310 via the plug 272, the conductive layer 251, and the plug 271. In addition, as needed, the transistor 320A may be provided with an insulating layer 333, an insulating layer 335, an insulating layer 336, a plug 275 electrically connected to the transistor 320A, and a conductive layer 253 electrically connected to the plug 275.

[0297] An insulating layer 334 is provided over the transistor 320A, and a transistor 320B is provided over the insulating layer 334. The insulating layer 334 can be an insulating film similar to the insulating layer 332.

[0298] The transistor 320B is a transistor in which a semiconductor layer forming a channel is formed using a metal oxide (also referred to as an oxide semiconductor), and corresponds to the second OS transistor described in Embodiment 1. The transistor 320B corresponds to Fig. 6A or Figure 6B The driving transistor of the pixel circuit shown is the transistor M2 or the transistor M6.

[0299] The transistor 320B includes a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .

[0300] A conductive layer 327 is provided on the insulating layer 334, and an insulating layer 326 is provided so as to cover the conductive layer 327. The conductive layer 327 serves as a first gate electrode of the transistor 320B, and a portion of the insulating layer 326 serves as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that contacts the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0301] The semiconductor layer 321 is provided on the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film exhibiting semiconductor characteristics. A pair of conductive layers 325 are in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0302] An insulating layer 328 is provided so as to cover the top surface and side surfaces of the pair of conductive layers 325 and the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 is used as a barrier layer that prevents impurities such as water and hydrogen from diffusing from the insulating layer 264 to the semiconductor layer 321 and oxygen from being released from the semiconductor layer 321. As the insulating layer 328, an insulating film similar to the insulating layer 332 described above can be used.

[0303] The insulating layer 328 and the insulating layer 264 are provided with openings reaching the semiconductor layer 321. The insulating layer 323 and the conductive layer 324 are embedded in the openings and are in contact with the top surface of the semiconductor layer 321. The conductive layer 324 is used as a second gate electrode, and the insulating layer 323 is used as a second gate insulating layer.

[0304] The top surfaces of the conductive layer 324 , the insulating layer 323 , and the insulating layer 264 are planarized so that their heights are uniform or substantially uniform, and the insulating layer 329 and the insulating layer 265 are provided to cover them.

[0305] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water and hydrogen from diffusing from the insulating layer 265 and the like into the transistor 320B. The insulating layer 329 can use an insulating film similar to the insulating layer 332.

[0306] The plug 274 electrically connected to one of the pair of conductive layers 325 is embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably includes a first conductive layer covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and a portion of the top surface of the conductive layer 325, and a second conductive layer in contact with the top surface of the first conductive layer. At this time, it is preferable to use a conductive material that does not easily diffuse hydrogen and oxygen as the first conductive layer.

[0307] Note that the structure of the transistor 320B may be a planar transistor, a staggered transistor, an inversely staggered transistor, a trench transistor, a fin transistor, etc. Alternatively, a top-gate transistor or a bottom-gate transistor may be used.

[0308] As transistor 320B, a structure in which two gates sandwich a semiconductor layer forming a channel is adopted. Alternatively, two gates may be connected and the transistor may be driven by supplying the same signal to the two gates. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and applying a potential for driving to the other.

[0309] There is no particular limitation on the crystallinity of the semiconductor material used for the semiconductor layer of the transistor 320B, and an amorphous semiconductor, a single crystal semiconductor, or a semiconductor other than a single crystal semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystallized region in part thereof) can be used. When a single crystal semiconductor or a semiconductor having crystallinity is used, it is preferred because it can suppress the degradation of the characteristics of the transistor.

[0310] The band gap of the metal oxide used for the semiconductor layer of the transistor 320B is preferably 2 eV or more, more preferably 2.5 eV or more. By using a metal oxide with a wider band gap, the off-state current of the OS transistor can be reduced. Note that the transistor 320B (second OS transistor) can use the same metal oxide as the metal oxide that can be used for the first OS transistor described in Embodiment 2.

[0311] Compared with transistors using amorphous silicon, the field effect mobility of OS transistors is very high. In addition, the leakage current between the source and the drain in the off state of the OS transistor (hereinafter also referred to as the off-state current) is extremely low, and the charge stored in the capacitor connected in series with the transistor can be maintained for a long period of time. In addition, by using OS transistors, the power consumption of the display panel can be reduced.

[0312] In addition, when the luminance of the light-emitting device included in the pixel circuit is increased, it is necessary to increase the amount of current flowing through the light-emitting device. To this end, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Because the source-drain withstand voltage of the OS transistor is higher than that of the Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Therefore, by using the OS transistor as the driving transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased to improve the luminance of the light-emitting device.

[0313] In addition, when the transistor operates in the saturation region, the change in source-drain current of the OS transistor for the change in gate-source voltage is smaller than that of the Si transistor. Therefore, by using the OS transistor as the driving transistor included in the pixel circuit, the current flowing through the source-drain can be determined in detail according to the change in gate-source voltage, so the amount of current flowing through the light-emitting device can be controlled. As a result, the number of grayscales of the pixel circuit can be increased.

[0314] In addition, regarding the saturation characteristics of the current flowing when the transistor operates in the saturation region, compared with the Si transistor, the OS transistor can make a stable current (saturation current) flow even if the source-drain voltage is gradually increased. Therefore, by using the OS transistor as a driving transistor, even if, for example, the current-voltage characteristics of the EL device are uneven, a stable current can flow through the light-emitting device. That is, when the OS transistor operates in the saturation region, even if the source-drain voltage is increased, the source-drain current is almost unchanged, so the light-emitting brightness of the light-emitting device can be stabilized.

[0315] As described above, by using an OS transistor as a driving transistor included in a pixel circuit, “reduction in power consumption”, “increase in light emission brightness”, “multi-gradation”, “suppression of unevenness in light emitting devices”, etc. can be achieved.

[0316] An insulating layer 265 is provided on the insulating layer 329, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 is electrically connected to the transistor 320B via a plug 274. The capacitor 240 is equivalent to FIG. 6A to FIG. 6D The transistor capacitor C1 or capacitor C2 is shown.

[0317] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 therebetween. The conductive layer 241 serves as one electrode of the capacitor 240, the conductive layer 245 serves as the other electrode of the capacitor 240, and the insulating layer 243 serves as a dielectric of the capacitor 240.

[0318] The conductive layer 241 is provided on the insulating layer 265 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and the drain of the transistor 320B through the plug 256 embedded in the insulating layer 255a. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 via the insulating layer 243.

[0319] The cover capacitor 240 is provided with an insulating layer 255 a , an insulating layer 255 b is provided on the insulating layer 255 a , and an insulating layer 255 c is provided on the insulating layer 255 b .

[0320] Inorganic insulating films can be used as appropriate for the insulating layers 255a, 255b, and 255c. For example, it is preferable to use silicon oxide films as the insulating layers 255a and 255c, and to use a silicon nitride film as the insulating layer 255b. Thus, the insulating layer 255b can be used as an etching protection film. Although an example in which a portion of the insulating layer 255c is etched to provide a recess is shown in this embodiment, the recess may not be provided in the insulating layer 255c.

[0321] The light emitting element 210R, the light emitting element 210G, and the light emitting element 210B are provided on the insulating layer 255c. The structures of the light emitting element 210R, the light emitting element 210G, and the light emitting element 210B can refer to Embodiment 3.

[0322] The display panel 200A forms light-emitting devices for each light-emitting color, so the chromaticity change between low-brightness light and high-brightness light is small. In addition, the organic layers 212R, 212G, and 212B are separated from each other, so even if a high-definition display panel is used, crosstalk between adjacent sub-pixels can be suppressed. Therefore, a high-definition display panel with high display quality can be realized.

[0323] An insulating layer 225 , a resin layer 226 , and a layer 228 are provided in a region between adjacent light emitting elements.

[0324] The pixel electrode 211R, the pixel electrode 211G, and the pixel electrode 211B of the light emitting element are electrically connected to one of the source and the drain of the transistor 320B through the plug 256 embedded in the insulating layer 255a, the insulating layer 255b, and the insulating layer 255c, the conductive layer 241 embedded in the insulating layer 254, and the plug 274 embedded in the insulating layer 265. The height of the top surface of the insulating layer 255c is the same or substantially the same as the height of the top surface of the plug 256. Various conductive materials can be used as the plug.

[0325] In addition, a protective layer 221 is provided on the light emitting elements 210R, 210G, and 210B. A substrate 270 is bonded to the protective layer 221 via an adhesive layer 276. The substrate 270 corresponds to Fig.11AThe substrate 292 in FIG.

[0326] No insulating layer covering the top end of the pixel electrode 211 is provided between two adjacent pixel electrodes 211. Therefore, the interval between adjacent light emitting elements can be made very small. Therefore, a high-definition or high-resolution display panel can be realized.

[0327] Note that the above description describes a structure in which the first OS transistor is formed on the Si transistor via an insulating layer and the two are electrically connected via a plug, but the Si transistor and the first OS transistor may be electrically connected by bonding.

[0328] Fig.13 The structure shown is that the transistor 310 (Si transistor) formed on the substrate 301 and the transistor 320A (first OS transistor) are electrically connected by bonding. Note that the structure of the layer above the transistor 320A is omitted.

[0329] The transistor 320A is formed as a supporting substrate on a silicon substrate 302. An insulating layer 266 is formed on a first surface of the silicon substrate 302, and a conductive layer 258 is provided on the insulating layer 266. One of the source and drain of the transistor 320A is electrically connected to the conductive layer 258 via an insulating layer 262 provided on the insulating layer 266 and the conductive layer 258 and a plug 272 embedded in the insulating layer 332.

[0330] In addition, an insulating layer 267 is formed on the second surface opposite to the first surface of the silicon substrate 302, and an insulating layer 268 and a conductive layer 259 are provided on the insulating layer 267. Here, the insulating layer 268 and the conductive layer 259 are also used as bonding layers, and the conductive layer 259 has a region embedded in the insulating layer 268, and the top surfaces of both are flattened.

[0331] Furthermore, a through hole is formed in the silicon substrate 302 , and the conductive layer 258 and the conductive layer 259 are electrically connected via a through electrode 257 formed in the through hole via an insulating layer.

[0332] An insulating layer 261 is provided over the transistor 310 provided on the substrate 301, and an insulating layer 269 and a conductive layer 251 are provided over the insulating layer 261. Here, the insulating layer 269 and the conductive layer 251 function as bonding layers, and the conductive layer 251 has a region embedded in the insulating layer 269, and both top surfaces are planarized.

[0333] The surfaces of the insulating layer 268 and the insulating layer 269 can be brought into contact with each other, and the surfaces of the conductive layer 259 and the conductive layer 251 can be brought into contact with each other. Thus, the transistor 310 and the transistor 320A can be electrically connected to each other by bonding.

[0334] Note that the insulating layer 268 and the insulating layer 269 are preferably inorganic insulating layers formed of the same material. The same conductive material is preferably used as the conductive layer 259 and the conductive layer 251. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) containing the above elements as components can be used. From the viewpoint of easy bonding, copper is particularly preferably used for the conductive layer 259 and the conductive layer 251.

[0335] In the above description, the transistor 320A is used as an example of a transistor constituting a driving circuit or a functional circuit. However, the transistor 320A may be used as a transistor constituting a pixel circuit.

[0336] Fig.14 An example of transistor 320A being used as a selection transistor for a pixel circuit is shown. The selection transistor for the pixel circuit is preferably capable of high-speed driving, and thus a vertical transistor with a high on-state current may be used to constitute the selection transistor. On the other hand, the driving transistor preferably has good saturation characteristics, and thus a transistor with a long channel length is preferably used, and thus, as the driving transistor, a transistor whose channel length can be determined by a photolithography process is preferably used.

[0337] Here, the transistor 320B and Figure 6B When the transistor M2 (driving transistor) shown also adopts a structure in which the front gate and the back gate are electrically connected, one of the source and the drain of the transistor 320A can be electrically connected to the conductive layer 327 serving as the back gate of the transistor 320B.

[0338] That is, the gate of the transistor 320A can electrically connect one of the source and the drain of the transistor 320A to the gate of the transistor 320B by a simpler structure than a structure using only the conductive layer 324 (without a back gate).

[0339] Notice, Fig.14 Although the structure in which the transistor 320A and the transistor 320B are electrically connected via the plug 275 , the conductive layer 253 , and the plug 273 is shown, the transistor 320A and the transistor 320B may be electrically connected via only one of the plug 275 and the plug 273 .

[0340] in addition, Fig.14 The transistor 320A, which is a component of the driving circuit, is not shown. Figure 2B or Figure 2C In the structure shown, the transistor 320A can be used as a constituent element of both the pixel circuit and the driver circuit.

[0341] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate.

[0342] (Implementation method 5) In this embodiment, a light-emitting device (light-emitting element) that can be used for a display panel which is one embodiment of the present invention is described.

[0343] In this specification, a device manufactured using a metal mask or FMM is sometimes referred to as a device having an MM (Metal Mask) structure. In addition, in this specification, a device manufactured without using a metal mask or FMM is sometimes referred to as a device having an MML (Metal Mask Less) structure.

[0344] In this specification, etc., a structure in which at least the light-emitting layers are manufactured separately in light-emitting devices with different emission wavelengths is sometimes referred to as an SBS (Side By Side) structure. Since the SBS structure can optimize the materials and structures for each light-emitting device, the freedom of choice of materials and structures is increased, and it is easy to achieve improved brightness and reliability.

[0345] In this specification, holes or electrons are sometimes referred to as "carriers". Specifically, a hole injection layer or an electron injection layer is sometimes referred to as a "carrier injection layer", a hole transport layer or an electron transport layer is sometimes referred to as a "carrier transport layer", and a hole blocking layer or an electron blocking layer is sometimes referred to as a "carrier blocking layer". Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer are sometimes not clearly distinguishable based on cross-sectional shapes or characteristics. In addition, sometimes one layer has two or three functions of a carrier injection layer, a carrier transport layer, and a carrier blocking layer.

[0346] In this specification, etc., a light-emitting device (also referred to as a light-emitting element) includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. Here, as layers included in the EL layer (also referred to as functional layers), a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer) can be cited.

[0347] As light-emitting devices, for example, OLED (Organic Light Emitting Diode) and QLED (Quantum-dot Light Emitting Diode) are preferably used. As the light-emitting substances contained in the light-emitting device, for example, substances that emit fluorescence (fluorescent materials), substances that emit phosphorescence (phosphorescent materials), substances that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) materials) and inorganic compounds (quantum dot materials, etc.) can be cited. In addition, LEDs such as Micro LEDs can also be used as light-emitting devices.

[0348] The light emitting color of the light emitting device may be infrared, red, green, blue, cyan, magenta, yellow or white, etc. In addition, when the light emitting device has a microcavity structure, the color purity can be further improved.

[0349] like Fig.15A As shown in FIG. 1 , the light-emitting device includes an EL layer 763 between a pair of electrodes (a lower electrode 761 and an upper electrode 762). The EL layer 763 may be composed of a plurality of layers such as a layer 780, a light-emitting layer 771, and a layer 790.

[0350] The light-emitting layer 771 includes at least a light-emitting substance (also referred to as a light-emitting material).

[0351] In the case where the lower electrode 761 and the upper electrode 762 are respectively the anode and the cathode, the layer 780 includes one or more of a layer containing a substance with high hole injection property (hole injection layer), a layer containing a substance with high hole transport property (hole transport layer), and a layer containing a substance with high electron blocking property (electron blocking layer). In addition, the layer 790 includes one or more of a layer containing a substance with high electron injection property (electron injection layer), a layer containing a substance with high electron transport property (electron transport layer), and a layer containing a substance with high hole blocking property (hole blocking layer). In the case where the lower electrode 761 and the upper electrode 762 are respectively the cathode and the anode, the structures of the layers 780 and 790 are reversed from the above.

[0352] The structure including the layer 780 disposed between a pair of electrodes, the light-emitting layer 771, and the layer 790 can be used as a single light-emitting unit. Fig.15A The structure is called a simple structure.

[0353] in addition, Fig. 15B Show Fig.15A 1 is a modified example of the EL layer 763 included in the light-emitting device shown in FIG. Fig. 15BThe light-emitting device shown includes a layer 781 on a lower electrode 761 , a layer 782 on layer 781 , a light-emitting layer 771 on layer 782 , a layer 791 on light-emitting layer 771 , a layer 792 on layer 791 , and an upper electrode 762 on layer 792 .

[0354] In the case where the lower electrode 761 and the upper electrode 762 are respectively an anode and a cathode, for example, the layers 781, 782, 791, and 792 may be respectively a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. In addition, in the case where the lower electrode 761 and the upper electrode 762 are respectively a cathode and an anode, the layers 781, 782, 791, and 792 may be respectively an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer. By adopting such a layer structure, carriers can be efficiently injected into the light-emitting layer 771 and the recombination efficiency of carriers in the light-emitting layer 771 can be improved.

[0355] In addition, if Fig. 15C and Fig.15D As shown in FIG. 1 , a structure in which a plurality of light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a modified example of a single structure. Fig. 15C and Fig.15D Although an example including three light-emitting layers is shown, the light-emitting layer in the light-emitting device having a single structure may be two layers, or may be four or more layers. In addition, the light-emitting device having a single structure may include a buffer layer between two light-emitting layers.

[0356] In addition, if Fig.15E and Fig.15F As shown, in this specification, etc., a structure in which multiple light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785 (also referred to as an intermediate layer) is referred to as a series structure. In addition, the series structure may also be referred to as a stacked structure. By adopting a series structure, a light-emitting device capable of emitting light with high brightness can be realized. In addition, the series structure can improve reliability because the current required to obtain the same brightness can be reduced compared to a single structure.

[0357] Fig.15D and Fig.15F An example is shown in which the display panel includes a layer 764 overlapping the light emitting device. Fig.15D Layer 764 is shown overlapping Fig. 15C The example of the light emitting device shown, Fig.15F Layer 764 is shown overlapping Fig.15E Examples of light emitting devices are shown.

[0358] As the layer 764, one or both of a color conversion layer and a color filter (coloring layer) can be used.

[0359] exist Fig. 15C and Fig.15D In the embodiment, a luminescent material that emits light of the same color, or even the same luminescent material, may be used for the luminescent layer 771, the luminescent layer 772, and the luminescent layer 773. For example, a luminescent material that emits blue light may be used for the luminescent layer 771, the luminescent layer 772, and the luminescent layer 773. For a sub-pixel that emits blue light, the blue light emitted by the light-emitting device may be extracted. For a sub-pixel that emits red light and a sub-pixel that emits green light, the blue light emitted by the light-emitting device may be extracted. Fig.15D The layer 764 shown is provided as a color conversion layer, which can convert the blue light emitted by the light-emitting device into light with a longer wavelength and extract it as red light or green light.

[0360] In addition, light-emitting materials having different luminescent colors may be used for the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. When the light emitted by the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 is in a complementary color relationship, white light emission can be obtained. For example, a light-emitting device having a single structure preferably includes a light-emitting layer containing a light-emitting material that emits blue light and a light-emitting layer containing a light-emitting material that emits visible light having a longer wavelength than blue.

[0361] For example, in the case where a light-emitting device having a single structure includes three light-emitting layers, it is preferred to include a light-emitting layer containing a light-emitting substance that emits red (R) light, a light-emitting layer containing a light-emitting substance that emits green (G) light, and a light-emitting layer containing a light-emitting substance that emits blue (B) light. As the stacking order of the light-emitting layers, the order of stacking R, G, and B in sequence from the anode side or the order of stacking R, B, and G in sequence from the anode side can be adopted. At this time, a buffer layer can also be provided between R and G or B.

[0362] In addition, for example, when a light-emitting device having a single structure includes two light-emitting layers, it is preferable to include a light-emitting layer containing a light-emitting substance emitting blue (B) light and a light-emitting layer containing a light-emitting substance emitting yellow light. This structure is sometimes called a BY single structure.

[0363] As Fig.15D The layer 764 shown may also be provided with a color filter, so that when white light passes through the color filter, light of a desired color can be obtained.

[0364] A light-emitting device that emits white light preferably includes two or more light-emitting substances. In order to obtain white light emission, two or more light-emitting substances whose light emission is in a complementary color relationship may be selected. For example, by making the light emission color of the first light-emitting layer and the light emission color of the second light-emitting layer in a complementary color relationship, a light-emitting device that emits white light as a whole can be obtained. In addition, the same is true for a light-emitting device including three or more light-emitting layers.

[0365] exist Fig.15E and Fig.15F In the present invention, a light-emitting material that emits light of the same color, or even the same light-emitting material, can be used for the light-emitting layer 771 and the light-emitting layer 772.

[0366] For example, in the light-emitting device included in the sub-pixel that presents light of each color, a light-emitting substance that emits blue light can also be used for the light-emitting layer 771 and the light-emitting layer 772. For the sub-pixel that presents blue light, the blue light emitted by the light-emitting device can be extracted. In addition, for the sub-pixel that presents red light and the sub-pixel that presents green light, by using Fig.15F The layer 764 shown is provided as a color conversion layer, which can convert the blue light emitted by the light-emitting device into light with a longer wavelength and extract it as red light or green light.

[0367] In addition, Fig.15E or Fig.15F When the light-emitting device of the structure shown is used to present sub-pixels of each color, different light-emitting materials can be used according to the sub-pixels. Specifically, in the light-emitting device included in the sub-pixel presenting red light, the light-emitting material that emits red light can also be used for the light-emitting layer 771 and the light-emitting layer 772. Similarly, in the light-emitting device included in the sub-pixel presenting green light, the light-emitting material that emits green light can also be used for the light-emitting layer 771 and the light-emitting layer 772. In the light-emitting device included in the sub-pixel presenting blue light, the light-emitting material that emits blue light can also be used for the light-emitting layer 771 and the light-emitting layer 772. It can be said that the display panel with such a structure uses a light-emitting device with a series structure and has an SBS structure. Thus, it has the advantages of both the series structure and the SBS structure. Thus, a light-emitting device with high brightness and high reliability can be realized.

[0368] In addition, Fig.15E and Fig.15F In the embodiment, light-emitting materials with different luminescent colors may be used for the light-emitting layer 771 and the light-emitting layer 772. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are in a complementary color relationship, white light emission can be obtained. Fig.15F The layer 764 shown may also be provided with a color filter. By passing white light through the color filter, light of a desired color may be obtained.

[0369] Note that although Fig.15E and Fig.15F The example in which the light-emitting unit 763a includes one light-emitting layer 771 and the light-emitting unit 763b includes one light-emitting layer 772 is shown, but the present invention is not limited thereto. The light-emitting unit 763a and the light-emitting unit 763b may each include two or more light-emitting layers.

[0370] Although Fig.15E and Fig.15FThe light emitting device includes two light emitting units, but the present invention is not limited thereto and the light emitting device may include three or more light emitting units.

[0371] Specifically, we can cite FIG. 16A to FIG. 16C The structure of the light emitting device shown.

[0372] Fig.16A Note that the structure including two light emitting units and the structure including three light emitting units may also be referred to as a two-stage series structure and a three-stage series structure, respectively.

[0373] like Fig.16A As shown, a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series with each other via a charge generation layer 785. In addition, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a, light-emitting unit 763b includes layer 780b, light-emitting layer 772, and layer 790b, and light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c.

[0374] exist Fig.16A In the structure shown, the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 preferably each contain a light-emitting substance that emits light of the same color. Specifically, the following structures can be adopted: a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a red (R) light-emitting substance (so-called R\R\R three-stage tandem structure); a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a green (G) light-emitting substance (so-called G\G\G three-stage tandem structure); or a structure in which the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 all contain a blue (B) light-emitting substance (so-called B\B\B three-stage tandem structure).

[0375] Note that the structure including light-emitting substances each emitting the same color is not limited to the above structure. Fig. 16B As shown in FIG. 1 , a tandem light-emitting device in which a plurality of light-emitting units including a plurality of light-emitting substances are stacked may also be used. Fig. 16B In the embodiment, a plurality of light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge generation layer 785. In addition, light-emitting unit 763a includes layer 780a, light-emitting layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b includes layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0376] exist Fig. 16BIn the structure shown, the luminescent materials of the luminescent layers 771a, 771b, and 771c are selected in such a way that they emit light in a complementary color relationship to realize white luminescence (W). In addition, the luminescent materials of the luminescent layers 772a, 772b, and 772c are selected in such a way that they emit light in a complementary color relationship to realize white luminescence (W). That is, Fig. 16C The structure shown is a W\W two-stage series structure. Note that there is no particular restriction on the stacking order of the luminescent materials in the luminescent layer 771a, the luminescent layer 771b, and the luminescent layer 771c in a complementary color relationship. The implementer can appropriately select the most appropriate stacking order. Although not shown in the figure, a W\W\W three-stage series structure or a series structure of four or more stages can also be used.

[0377] In addition, when using a light-emitting device with a series structure, examples include: a B\Y two-stage series structure including a light-emitting unit emitting yellow (Y) light and a light-emitting unit emitting blue (B) light; an R·G\B two-stage series structure including a light-emitting unit emitting red (R) light and green (G) light and a light-emitting unit emitting blue (B) light; a B\Y\B three-stage series structure including, in sequence, a light-emitting unit emitting blue (B) light, a light-emitting unit emitting yellow (Y) light, and a light-emitting unit emitting blue (B) light; a B\YG\B three-stage series structure including, in sequence, a light-emitting unit emitting blue (B) light, a light-emitting unit emitting yellow-green (YG) light, and a light-emitting unit emitting blue (B) light; and a B\G\B three-stage series structure including, in sequence, a light-emitting unit emitting blue (B) light, a light-emitting unit emitting green (G) light, and a light-emitting unit emitting blue (B) light, etc.

[0378] like Fig. 16C As shown, a light-emitting unit including one light-emitting substance and a light-emitting unit including a plurality of light-emitting substances may be combined.

[0379] Specifically, in Fig. 16C In the structure shown, a plurality of light-emitting units (light-emitting unit 763a, light-emitting unit 763b, and light-emitting unit 763c) are connected in series with each other via a charge generation layer 785. In addition, light-emitting unit 763a includes layer 780a, light-emitting layer 771, and layer 790a, light-emitting unit 763b includes layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b, and light-emitting unit 763c includes layer 780c, light-emitting layer 773, and layer 790c.

[0380] For example, in Fig. 16CThe structure shown can adopt a B\R·G·YG\B three-stage series structure, wherein the light-emitting unit 763a is a light-emitting unit that emits blue (B) light, the light-emitting unit 763b is a light-emitting unit that emits red (R) light, green (G) light and yellow-green (YG) light, and the light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0381] For example, as the number of layers and color sequence of the light-emitting unit, there can be cited a two-stage structure in which B and Y are stacked from the anode side, a two-stage structure in which B and the light-emitting unit X are stacked, a three-stage structure in which B, Y and B are stacked, and a three-stage structure in which B, X and B are stacked. As the number of layers and color sequence of the light-emitting layer in the light-emitting unit X, there can be adopted a two-stage structure in which R and Y are stacked from the anode side, a two-stage structure in which R and G are stacked, a two-stage structure in which G and R are stacked, a three-stage structure in which G, R and G are stacked, or a three-stage structure in which R, G and R are stacked. In addition, another layer may be provided between two light-emitting layers.

[0382] Notice, Fig. 15C , Fig.15D The layers 780 and 790 in the embodiment may also be independently selected. Fig. 15B The laminated structure shown is composed of two or more layers.

[0383] exist Fig.15E and Fig.15F In the embodiment, the light emitting unit 763a includes a layer 780a, a light emitting layer 771, and a layer 790a, and the light emitting unit 763b includes a layer 780b, a light emitting layer 772, and a layer 790b.

[0384] In the case where the lower electrode 761 and the upper electrode 762 are respectively an anode and a cathode, the layers 780a and 780b each include one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. In addition, the layers 790a and 790b each include one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. In the case where the lower electrode 761 and the upper electrode 762 are respectively a cathode and an anode, the structures of the layers 780a and 790a are reversed from the above, and the structures of the layers 780b and 790b are also reversed from the above.

[0385] In the case where the lower electrode 761 and the upper electrode 762 are respectively the anode and the cathode, for example, the layer 780a includes a hole injection layer and a hole transport layer on the hole injection layer, and may also include an electron blocking layer on the hole transport layer. In addition, the layer 790a includes an electron transport layer, and may also include a hole blocking layer between the light-emitting layer 771 and the electron transport layer. In addition, the layer 780b includes a hole transport layer, and may also include an electron blocking layer on the hole transport layer. In addition, the layer 790b includes an electron transport layer and an electron injection layer on the electron transport layer, and may also include a hole blocking layer between the light-emitting layer 772 and the electron transport layer. In the case where the lower electrode 761 and the upper electrode 762 are respectively the cathode and the anode, for example, the layer 780a includes an electron injection layer and an electron transport layer on the electron injection layer, and may also include a hole blocking layer on the electron transport layer. In addition, the layer 790a includes a hole transport layer, and may also include an electron blocking layer between the light-emitting layer 771 and the hole transport layer. In addition, layer 780b includes an electron transport layer and may also include a hole blocking layer on the electron transport layer. In addition, layer 790b includes a hole transport layer and a hole injection layer on the hole transport layer and may also include an electron blocking layer between the light emitting layer 772 and the hole transport layer.

[0386] When manufacturing a light-emitting device having a tandem structure, two light-emitting units are stacked via a charge generation layer 785. The charge generation layer 785 has at least a charge generation region. The charge generation layer 785 has a function of injecting electrons into one of the two light-emitting units and injecting holes into the other when a voltage is applied between a pair of electrodes.

[0387] Next, materials that can be used for the light-emitting device are described.

[0388] A conductive film that transmits visible light is used as the electrode on the light extraction side of the lower electrode 761 and the upper electrode 762. In addition, a conductive film that reflects visible light is preferably used as the electrode on the side that does not extract light. In addition, when the display panel includes a light-emitting device that emits infrared light, it is preferred that a conductive film that transmits visible light and infrared light is used as the electrode on the light extraction side, and a conductive film that reflects visible light and infrared light is used as the electrode on the side that does not extract light.

[0389] Alternatively, a conductive film that transmits visible light may be used as the electrode on the side that does not extract light. In this case, the electrode is preferably arranged between the reflective layer and the EL layer 763. In other words, light emitted from the EL layer 763 can also be reflected by the reflective layer and extracted from the display panel.

[0390] As the material for forming a pair of electrodes of the light-emitting device, metals, alloys, conductive compounds and mixtures thereof can be appropriately used. As the material, specifically, metals such as aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium and neodymium and alloys appropriately combined therewith can be cited. In addition, as the material, indium tin oxide (In-Sn oxide, also known as ITO), In-Si-Sn oxide (also known as ITSO), indium zinc oxide (In-Zn oxide) and In-W-Zn oxide can be cited. In addition, as the material, aluminum alloys (aluminum alloys) such as alloys of aluminum, nickel and lanthanum (Al-Ni-La) and alloys of silver, palladium and copper (Ag-Pd-Cu, also known as APC) can be cited. In addition, examples of the material include elements belonging to Group 1 or Group 2 of the periodic table that are not listed above (e.g., lithium, cesium, calcium, and strontium), rare earth metals such as europium and ytterbium, alloys of appropriately combined elements, and graphene.

[0391] The light-emitting device preferably adopts an optical microcavity resonator (microcavity) structure. Therefore, one of a pair of electrodes included in the light-emitting device preferably includes an electrode that is transmissive and reflective to visible light (transflective electrode), and the other preferably includes an electrode that is reflective to visible light (reflective electrode). When the light-emitting device has a microcavity structure, the light emitted from the light-emitting layer can be resonated between the two electrodes, and the light emitted from the light-emitting device can be increased.

[0392] The transflective electrode may have a stacked-layer structure of a conductive layer that can function as a reflective electrode and a conductive layer that can function as an electrode that is transmissive to visible light (also referred to as a transparent electrode).

[0393] The light transmittance of the transparent electrode is 40% or more. For example, an electrode having a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm) is preferably used as a transparent electrode for a light-emitting device. The reflectivity of the transflective electrode to visible light is 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectivity of the reflective electrode to visible light is 40% or more and 100% or less, preferably 70% or more and 100% or less. In addition, the resistivity of these electrodes is preferably 1×10 -2 Ωcm or less.

[0394] The light-emitting device includes at least a light-emitting layer. In addition, as a layer other than the light-emitting layer, the light-emitting device may also include a layer containing a substance with high hole injection property, a substance with high hole transport property, a hole blocking material, a substance with high electron transport property, an electron blocking material, a substance with high electron injection property, or a bipolar substance (a substance with high electron transport property and hole transport property). For example, the light-emitting device may include one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer in addition to the light-emitting layer.

[0395] The light emitting device may use a low molecular weight compound or a high molecular weight compound, and may also contain an inorganic compound. The layers constituting the light emitting device may be formed by a method such as evaporation (including vacuum evaporation), transfer, printing, inkjet, or coating.

[0396] The light-emitting layer contains one or more light-emitting substances. As the light-emitting substance, a substance that emits light in a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange or red is appropriately used. In addition, as the light-emitting substance, a substance that emits near-infrared light can also be used.

[0397] Examples of the light-emitting substance include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0398] Examples of the fluorescent material include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0399] As phosphorescent materials, for example, there can be mentioned organic metal complexes (especially iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, a pyridine skeleton, organic metal complexes (especially iridium complexes) with phenylpyridine derivatives having electron-withdrawing groups as ligands, platinum complexes, rare earth metal complexes, and the like.

[0400] In addition to the luminescent material (guest material), the light-emitting layer may also include one or more organic compounds (host material, auxiliary material, etc.) as one or more organic compounds, and one or both of a substance with high hole transport (hole transport material) and a substance with high electron transport (electron transport material) can be used. As a hole transport material, the following materials with high hole transport that can be used for a hole transport layer can be used. As an electron transport material, the following materials with high electron transport that can be used for an electron transport layer can be used. In addition, as one or more organic compounds, a bipolar material or a TADF material can also be used.

[0401] For example, the light-emitting layer preferably includes a combination of a phosphorescent material, a hole transport material that easily forms an exciplex, and an electron transport material. By adopting such a structure, light emission by ExTET (Exciplex-Triplet Energy Transfer) utilizing energy transfer from the exciplex to the luminescent substance (phosphorescent material) can be efficiently obtained. In addition, by selecting a combination in a manner that forms an exciplex that emits light with a wavelength overlapping with the absorption band on the lowest energy side of the luminescent substance, energy transfer can be smoothed, thereby efficiently obtaining light emission. By adopting the above structure, high efficiency, low voltage drive, and long life of the light-emitting device can be achieved simultaneously.

[0402] The hole injection layer is a layer containing a material with high hole injection properties and injects holes from the anode into the hole transport layer. Examples of materials with high hole injection properties include aromatic amine compounds and composite materials containing a hole transport material and an acceptor material (electron acceptor material).

[0403] As the hole transport material, the following materials having high hole transport properties that can be used in the hole transport layer can be used.

[0404] As the acceptor material, for example, an oxide of a metal belonging to Group 4 to Group 8 in the periodic table can be used. Specifically, molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide can be cited. Molybdenum oxide is particularly preferably used because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition, an organic acceptor material containing fluorine can also be used. In addition, organic acceptor materials such as quinone dimethane derivatives, tetrachlorobenzoquinone derivatives, and hexaazatriphenylene derivatives can also be used.

[0405] For example, as the material having a high hole injecting property, a material containing a hole transport material and an oxide of the metal belonging to Group 4 to Group 8 of the periodic table (typically molybdenum oxide) can be used.

[0406] The hole transport layer is a layer that transports holes injected from the anode through the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole transport material. As the hole transport material, preferably a hole transport material having a hole mobility of 1×10 -6 cm 2 / Vs or more. Note that as long as the hole transport property is higher than the electron transport property, substances other than the above can be used. As hole transport materials, it is preferred to use materials with high hole transport properties such as π-electron-rich aromatic hetero compounds (such as carbazole derivatives, thiophene derivatives, furan derivatives, etc.) or aromatic amines (compounds containing aromatic amine skeletons).

[0407] The electron blocking layer is provided in contact with the light emitting layer. The electron blocking layer is a layer including a material having hole transport properties and capable of blocking electrons. The electron blocking material among the hole transport materials can be used for the electron blocking layer.

[0408] The electron blocking layer has a hole transporting property, so it can also be called a hole transporting layer. In addition, the layer having an electron blocking property in the hole transporting layer can also be called an electron blocking layer.

[0409] The electron transport layer is a layer that transports electrons injected from the cathode through the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron transport material. As the electron transport material, it is preferred to use an electron transport material with an electron mobility of 1×10 -6 cm 2 / Vs or above. Note that as long as the electron transport property is higher than the hole transport property, substances other than the above can be used. As electron transport materials, metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, or metal complexes having a thiazole skeleton can be used. Materials with high electron transport properties such as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives with quinoline ligands, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, or nitrogen-containing aromatic hetero compounds and other π-electron-deficient aromatic hetero compounds can also be used.

[0410] The hole blocking layer is provided in contact with the light emitting layer. The hole blocking layer is a layer including a material having electron transport properties and capable of blocking holes. The hole blocking material among the above-mentioned electron transport materials can be used for the hole blocking layer.

[0411] The hole blocking layer has an electron transporting property, so it may also be called an electron transporting layer. In addition, the layer having a hole blocking property in the electron transporting layer may also be called a hole blocking layer.

[0412] The electron injection layer is a layer containing a material with high electron injection property that injects electrons from the cathode into the electron transport layer. As a material with high electron injection property, an alkali metal, an alkaline earth metal or a compound thereof can be used. As a material with high electron injection property, a composite material containing an electron transport material and a donor material (electron donor material) can also be used.

[0413] In addition, it is preferable that the difference between the LUMO level of the material having a high electron injectability and the work function value of the material used for the cathode is small (specifically, 0.5 eV or less).

[0414] The electron injection layer can be made of, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaFx , X is an arbitrary number), 8-(hydroxyquinoline) lithium (abbreviated as Liq), 2-(2-pyridyl) phenol lithium (abbreviated as LiPP), 2-(2-pyridyl)-3-hydroxypyridine (pyridinolato) lithium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl) phenol lithium (abbreviated as LiPPP), lithium oxide (LiO x ) or alkali metals such as cesium carbonate, alkaline earth metals or their compounds. In addition, the electron injection layer can also have a stacked structure of more than two layers. As this stacked structure, for example, a structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be cited.

[0415] The electron injection layer may also contain an electron transport material. For example, a compound having a non-shared electron pair and an electron-deficient heteroaromatic ring may be used as the electron transport material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring) and a triazine ring may be used.

[0416] The lowest unoccupied molecular orbital (LUMO) energy level of an organic compound having an unshared electron pair is preferably greater than -3.6 eV and less than -2.3 eV. Generally, the highest occupied molecular orbital (HOMO) energy level and the LUMO energy level of an organic compound can be estimated using CV (cyclic voltammetry), photoelectron spectroscopy, absorption spectroscopy, or inverse photoelectron spectroscopy.

[0417] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as organic compounds having non-shared electron pairs. In addition, NBPhen has a high glass transition point (Tg) compared to BPhen, thereby having high heat resistance.

[0418] As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably includes an acceptor material, for example, preferably includes a hole transport material and an acceptor material that can be used in the hole injection layer.

[0419] In addition, the charge generation layer preferably includes a layer containing a material with high electron injection. This layer may also be referred to as an electron injection buffer layer. The electron injection buffer layer is preferably disposed between the charge generation region and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be relaxed, so that the electrons generated in the charge generation region are easily injected into the electron transport layer.

[0420] The electron injection buffer layer preferably comprises an alkali metal or an alkaline earth metal, for example, a compound of an alkali metal or a compound of an alkaline earth metal. Specifically, the electron injection buffer layer preferably comprises an inorganic compound containing an alkali metal and oxygen or an inorganic compound containing an alkaline earth metal and oxygen, more preferably an inorganic compound containing lithium and oxygen (lithium oxide (Li2O) etc.). In addition, as the electron injection buffer layer, a material applicable to the above-mentioned electron injection layer can be appropriately used.

[0421] The charge generation layer preferably includes a layer containing a material with high electron transport properties. This layer may also be referred to as an electron relay layer. The electron relay layer is preferably disposed between the charge generation region and the electron injection buffer layer. When the charge generation layer does not include an electron injection buffer layer, the electron relay layer is preferably disposed between the charge generation region and the electron transport layer. The electron relay layer has the function of suppressing the interaction between the charge generation region and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0422] As the electron relay layer, it is preferable to use a phthalocyanine material such as copper (II) phthalocyanine (abbreviation: CuPc) or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0423] Note that the charge generation region, the electron injection buffer layer, and the electron relay layer may not be clearly distinguished from each other due to their cross-sectional shape, characteristics, or the like.

[0424] In addition, the charge generation layer may include a donor material instead of an acceptor material. For example, the charge generation layer may include a layer containing an electron transport material applicable to the electron injection layer and a donor material.

[0425] When stacking light-emitting units, by providing a charge generation layer between two light-emitting units, an increase in driving voltage can be suppressed.

[0426] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate.

[0427] (Implementation 6) In this embodiment, electronic equipment to which a display device according to one embodiment of the present invention can be applied is described.

[0428] The display device of one embodiment of the present invention can be used in the display part of an electronic device. Thus, an electronic device with high display quality can be realized. Alternatively, an electronic device with extremely high precision can be realized. Alternatively, an electronic device with high reliability can be realized.

[0429] Examples of electronic devices using a display device according to one embodiment of the present invention include display devices such as televisions and monitors, lighting devices, desktop or notebook personal computers, word processors, and computers that reproduce and store data stored on DVDs. Disc: digital versatile disc) and other recording media such as a still image or a moving image reproducing device, a portable CD player, a radio, a tape recorder, a headphone stereo, a stereo, a table clock, a wall clock, a cordless telephone handset, a radio transceiver, a car phone, a mobile phone, a portable information terminal, a tablet terminal, a portable game console, a fixed game console such as a pinball machine, a calculator, an electronic notebook, an e-book reader terminal, an electronic translator, a voice input device, a video camera, a digital still camera, an electric scraper, a microwave oven and other high-frequency heating device, an electric rice cooker, an electric washing machine, an electric vacuum cleaner, a water heater, an electric fan, an electric hair dryer, air conditioning equipment such as an air conditioner, a humidifier, a dehumidifier, etc., a dishwasher, a dishwashing machine, a dryer, a dryer, a quilt dryer, an electric refrigerator, an electric freezer, an electric freezer for storing DNA, tools such as a flashlight and a chain saw, and medical equipment such as a smoke detector and a dialysis device. Furthermore, industrial equipment such as guide lights, signal lights, conveyor belts, elevators, escalators, industrial robots, power storage systems, power storage devices for power equalization and smart grids, etc. can also be cited. In addition, mobile bodies propelled by engines using fuel or electric motors using power from power storage bodies are sometimes included in the category of electronic equipment. As the above-mentioned mobile bodies, for example, electric vehicles (EV), hybrid vehicles (HV) with both internal combustion engines and electric motors, plug-in hybrid vehicles (PHV), tracked vehicles using tracks instead of wheels, bicycles with engines including electric-assisted bicycles, motorcycles, electric wheelchairs, golf carts, small or large ships, submarines, helicopters, airplanes, rockets, artificial satellites, space probes, planetary probes and spacecraft can be cited.

[0430] The electronic device according to one embodiment of the present invention may include a secondary battery (battery), and the secondary battery is preferably charged by contactless power transmission.

[0431] Examples of the secondary battery include lithium ion secondary batteries, nickel hydrogen batteries, nickel cadmium batteries, organic radical batteries, lead storage batteries, air secondary batteries, nickel zinc batteries, and silver zinc batteries.

[0432] The electronic device according to one embodiment of the present invention may also include an antenna. By receiving a signal with the antenna, an image or data can be displayed on the display unit. In addition, when the electronic device includes an antenna and a secondary battery, the antenna can be used for contactless power transmission.

[0433] An electronic device according to one embodiment of the present invention may also include a sensor (the sensor has the function of sensing, detecting, and measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, inclination, vibration, smell, or infrared).

[0434] An electronic device according to one embodiment of the present invention may have various functions. For example, it may have the following functions: a function of displaying various information (static images, dynamic images, text images, etc.) on a display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of executing various software (programs); a function of wireless communication; a function of reading programs or data stored in a storage medium; etc.

[0435] In addition, an electronic device including a plurality of display units may have a function of mainly displaying image information on a part of the display unit and mainly displaying text information on other parts of the display unit, or a function of displaying a three-dimensional image by displaying an image taking parallax into consideration on a plurality of display units, etc. Furthermore, an electronic device having an image receiving unit may have the following functions: capturing a still image; capturing a moving image; automatically or manually correcting the captured image; storing the captured image in a recording medium (external or built into the electronic device); displaying the captured image on the display unit; etc. In addition, the functions of an electronic device according to one embodiment of the present invention are not limited thereto, and the electronic device may have various functions.

[0436] A display device according to one embodiment of the present invention can display high-definition images. Therefore, it can be particularly suitably used in portable electronic devices, wearable electronic devices, and e-book readers. For example, it can be suitably used in xR devices such as VR devices or AR devices.

[0437] Fig.17A FIG. 8 is an external view of a camera 8000 equipped with a viewfinder 8100 .

[0438] The camera 8000 includes a housing 8001, a display portion 8002, operation buttons 8003, a shutter button 8004, and the like. In addition, the camera 8000 is provided with a detachable lens 8006. In the camera 8000, the lens 8006 and the housing may be formed integrally.

[0439] The camera 8000 can capture an image by pressing a shutter button 8004 or touching a display portion 8002 serving as a touch panel.

[0440] The housing 8001 includes an embedder having electrodes, and can be connected to a flash device or the like in addition to the viewfinder 8100 .

[0441] The viewfinder 8100 includes a housing 8101 , a display portion 8102 , a button 8103 , and the like.

[0442] The housing 8101 is attached to the camera 8000 via an inserter that fits into the camera 8000. The viewfinder 8100 can display an image received from the camera 8000 on the display portion 8102.

[0443] Button 8103 is used as a power button or the like.

[0444] The display device according to one embodiment of the present invention can be used for the display portion 8002 of the camera 8000 and the display portion 8102 of the viewfinder 8100. Alternatively, the viewfinder 8100 may be built in the camera 8000.

[0445] Fig. 17B This is an appearance diagram of the head mounted display 8200.

[0446] The head mounted display 8200 includes a mounting portion 8201 , a lens 8202 , a main body 8203 , a display portion 8204 , a cable 8205 , and the like. In addition, a battery 8206 is built in the mounting portion 8201 .

[0447] Power is supplied from a battery 8206 to a main body 8203 via a cable 8205. The main body 8203 includes a wireless receiver and the like, and can display received image information on a display portion 8204. In addition, the main body 8203 includes a camera, thereby making it possible to use information on the movement of the user's eyeballs or eyelids as an input method.

[0448] In addition, multiple electrodes may be provided at the position of the mounting portion 8201 touched by the user to detect the current flowing through the electrodes according to the movement of the user's eyeballs, thereby realizing the function of recognizing the user's line of sight. In addition, it may also have a function of monitoring the user's pulse according to the current flowing through the electrodes. The mounting portion 8201 may also have various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, and may also have a function of displaying the user's biological information on the display portion 8204 or a function of changing the image displayed on the display portion 8204 in synchronization with the movement of the user's head.

[0449] The display device according to one embodiment of the present invention can be used for the display portion 8204 .

[0450] FIG. 17C to FIG. 17E 8300 is an external view of a head mounted display 8300. The head mounted display 8300 includes a housing 8301, a display portion 8302, a belt-shaped fixing tool 8304, and a pair of lenses 8305.

[0451] The user can see the display on the display unit 8302 through the lens 8305. Preferably, the display unit 8302 is arranged in a curved manner. This is because the user can experience a high sense of reality. In addition, the images displayed on different areas of the display unit 8302 are respectively seen through the lens 8305, so that three-dimensional display using parallax can be performed. In addition, one embodiment of the present invention is not limited to a structure in which one display unit 8302 is provided, and two display units 8302 can also be provided so that one display unit is respectively provided for a pair of eyes of the user.

[0452] A display device according to one embodiment of the present invention can be used for the display portion 8302. A display device according to one embodiment of the present invention can also achieve extremely high definition. Fig.17E As shown, even if the display is magnified and viewed using the lens 8305, the pixels are not easily visible to the user. That is, the display portion 8302 can be used to allow the user to see an image with a higher sense of reality.

[0453] Fig.17F 8400. The head mounted display 8400 includes a pair of housings 8401, a mounting portion 8402, and a buffer member 8403. A display portion 8404 and a lens 8405 are provided in each of the pair of housings 8401. By making the pair of display portions 8404 display different images, a three-dimensional display using parallax can be performed.

[0454] The user can see the display on the display unit 8404 through the lens 8405. The lens 8405 has an eyepiece focusing mechanism, which can adjust the position of the lens 8405 according to the user's vision. The display unit 8404 is preferably a square or a horizontally long rectangle. This can improve the sense of reality.

[0455] The mounting portion 8402 preferably has plasticity and elasticity so that it can be adjusted according to the size of the user's face and does not fall off. In addition, a part of the mounting portion 8402 preferably has a vibration mechanism used as a bone conduction headset. Thus, you can enjoy images and sounds just by installing it, without the need for audio equipment such as headphones and speakers. In addition, it can also have a function of outputting sound data to the frame 8401 through wireless communication.

[0456] The mounting portion 8402 and the buffer member 8403 are parts that come into contact with the user's face (forehead, cheek, etc.). By making the buffer member 8403 in close contact with the user's face, light leakage can be prevented, thereby further improving the sense of immersion. The buffer member 8403 preferably uses a soft material to be in close contact with the user's face when the user puts on the head-mounted display 8400. For example, materials such as rubber, silicone rubber, polyurethane, and sponge can be used. In addition, when a member that covers the surface of a sponge or the like with cloth or leather (natural leather or synthetic leather) is used, it is not easy to produce a gap between the user's face and the buffer member 8403, so that light leakage can be appropriately prevented. In addition, when such a material is used, it not only makes the user feel skin-friendly, but also does not make the user feel cold when it is installed in colder seasons, so it is preferred. When the member that contacts the user's skin, such as the buffer member 8403 or the mounting portion 8402, adopts a detachable structure, it is easy to clean and replace, so it is preferred.

[0457] At least a part of this embodiment mode can be implemented in combination with other embodiment modes described in this specification as appropriate. [Explanation of symbols]

[0458] PIX: pixel circuit, RES: resistor element, SW: switch, 10: display device, 20: layer, 21a: circuit, 21b: circuit, 21: source driver, 22: gate driver, 23: functional circuit, 25: region, 30a: layer, 30b: layer, 30: layer, 31: divided pixel array, 34: latch circuit, 35: channel transistor logic circuit, 51: receiving circuit, 52: serial-to-parallel conversion circuit, 53: shift register circuit, 54: latch circuit, 55: level shift circuit, 56: voltage generation circuit, 57: bandgap reference circuit, 58: bias generation circuit, 59: buffer amplifier circuit, 100: transistor, 102: substrate, 104e: conductive layer, 104: conductive layer, 106: insulating layer, 108: semiconductor layer, 110a: insulating layer, 110b: insulating layer, 110c: insulating layer, 110: insulating layer, 112a: conductive layer, 112a_1: conductive layer, 112a_2: conductive layer, 112b: conductive layer, 141: opening, 150: insulating layer, 151: opening, 200A: display panel, 200a: display panel, 200b: display panel, 200: display panel, 201: layer, 210a: light emitting element, 210B: light emitting element, 210b: light emitting element, 210c: light emitting element, 210G: light emitting element, 210R: light emitting element, 210: light emitting element, 211B: pixel electrode, 211C: connecting electrode, 211G: pixel electrode, 211R: pixel electrode, 211: pixel electrode, 212b: conductive layer, 212B: organic layer, 212G: organic layer, 212R: organic layer, 212W: organic layer, 212: organic layer, 213: common electrode, 214: common layer, 215B: conductive layer, 215G: conductive layer, 215R: conductive layer, 216B: coloring layer, 216G: coloring layer, 216R: coloring layer, 221: protective layer, 222: insulating layer, 223: insulating layer, 224a: pixel, 224b: pixel, 225: insulating layer, 226: resin layer, 228: layer, 230: connecting portion, 240: capacitor, 241: conductive layer, 243: insulating layer, 245 : conductive layer, 250: pixel, 251: conductive layer, 252: conductive layer, 253: conductive layer, 254: insulating layer, 255a: insulating layer, 255b: insulating layer, 255c: insulating layer, 256: plug, 257: through electrode, 258: conductive layer, 259: conductive layer, 261: insulating layer, 262: insulating layer, 264: insulating layer, 265: insulating layer, 266: insulating layer, 267: insulating layer, 268: insulating layer, 270: substrate, 271: plug, 272: plug, 273: plug, 274: plug, 275: plug, 276: adhesive layer, 280: display module, 281: display unit, 282: circuit unit, 283: circuit unit, 284a: pixel,284: Circuit portion, 285: Terminal portion, 286: Wiring portion, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element separation layer, 320A: Transistor, 320B: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: insulating layer, 332: insulating layer, 333: insulating layer, 334: insulating layer, 335: insulating layer, 336: insulating layer, 761: lower electrode, 762: upper electrode, 763a: light-emitting unit, 763b: light-emitting unit, 763c: light-emitting unit, 763: EL layer, 764: layer, 771a: light-emitting layer, 771b: light-emitting layer, 771c: light-emitting layer, 771: light-emitting layer, 772a: light-emitting layer, 772b: light-emitting layer, 772c: light-emitting layer, 7 72: light-emitting layer, 773: light-emitting layer, 780a: layer, 780b: layer, 780c: layer, 780: layer, 781: layer, 782: layer, 785: charge generation layer, 790a: layer, 790b: layer, 790c: layer, 790: layer, 791: layer, 792: layer, 8000: camera, 8001: housing, 8002: display unit, 8003: operation button, 8004: shutter button, 8006: lens, 8100: viewfinder, 8101: housing, 8102: display unit, 02: Display unit, 8103: Button, 8200: Head-mounted display, 8201: Mounting unit, 8202: Lens, 8203: Main body, 8204: Display unit, 8205: Cable, 8206: Battery, 8300: Head-mounted display, 8301: Frame, 8302: Display unit, 8304: Fixing tool, 8305: Lens, 8400: Head-mounted display, 8401: Frame, 8402: Mounting unit, 8403: Buffer member, 8404: Display unit, 8405: Lens,

Claims

1. A display device, comprising: Pixel circuit; as well as a driving circuit having an area overlapping with the pixel circuit, Wherein, the driving circuit includes a first circuit and a second circuit, the second circuit has an area overlapping with the first circuit, The pixel circuit has an area overlapping with the second circuit, The first circuit includes a first transistor including silicon in a channel formation region, The second circuit includes a second transistor including a metal oxide in a semiconductor layer, The pixel circuit includes a third transistor including a metal oxide in a semiconductor layer, Furthermore, the second transistor is a transistor in which a channel formation region is provided along a side surface of an insulating layer.

2. The display device according to claim 1, comprising: First floor; Second floor; as well as The third floor, The second layer is disposed between the first layer and the third layer, The pixel circuit is arranged on the third layer, The first circuit is arranged on the first layer, And the second circuit is arranged on the second layer.

3. A display device, comprising: First floor; Second floor; as well as The third floor, wherein the second layer is disposed between the first layer and the third layer, The third layer is provided with a pixel circuit, The first layer and the second layer are provided with a driving circuit of the pixel circuit. The first layer is provided with a first circuit as a constituent element of the driving circuit. The second layer is provided with a second circuit as a component of the driving circuit. The first circuit includes a first transistor including silicon in a channel formation region, The second circuit includes a second transistor including a metal oxide in a semiconductor layer, The pixel circuit includes a third transistor including a metal oxide in a semiconductor layer, Furthermore, the second transistor is a transistor in which a channel formation region is provided along a side surface of the insulating layer included in the second layer.

4. A display device, comprising: First floor; Second floor; as well as The third floor, wherein the second layer is disposed between the first layer and the third layer, The second layer and the third layer are provided with pixel circuits, The first layer and the second layer are provided with a driving circuit of the pixel circuit. The first layer is provided with a first circuit as a constituent element of the driving circuit. The second layer includes a second circuit as a component of the driving circuit and a first component of the pixel circuit. The third layer is provided with a second component of the pixel circuit. The first circuit includes a first transistor including silicon in a channel formation region, The second circuit includes a second transistor including a metal oxide in a semiconductor layer, The pixel circuit includes, as the first component and the second component, a fourth transistor including a metal oxide in a semiconductor layer and a third transistor including a metal oxide in a semiconductor layer, respectively. Furthermore, the second transistor and the fourth transistor are transistors in which a channel formation region is provided along a side surface of the insulating layer included in the second layer.

5. The display device according to claim 4, wherein the driving transistor of the pixel circuit is formed using the third transistor, The selection transistor of the pixel circuit is formed using the fourth transistor, The third transistor includes a first conductive layer used as a first gate electrode and a second conductive layer used as a second gate electrode, The first conductive layer is electrically connected to the second conductive layer, And the second conductive layer is electrically connected to one of a source electrode and a drain electrode of the fourth transistor.

6. The display device according to any one of claims 1 to 5, In the stack of the third conductive layer, the insulating layer and the fourth conductive layer stacked in sequence, openings are provided in the insulating layer and the second conductive layer so as to reach the first conductive layer.

7. The display device according to claim 6, The transistor in which the channel formation region is arranged along the side of the insulating layer includes a semiconductor layer containing metal oxide arranged in a manner to cover the opening, a second insulating layer arranged on the semiconductor layer containing metal oxide and the second conductive layer in a manner to cover the recess originating from the opening, and a third conductive layer arranged on the second insulating layer in a manner to fill the recess originating from the opening.

8. The display device according to any one of claims 1 to 5, The first circuit and the second circuit are components of a source driver. And the second circuit includes a pass transistor logic circuit.

9. The display device according to claim 7, The second circuit includes a latch circuit.

10. The display device according to any one of claims 1 to 5, The driving circuit is arranged in a rectangular region when viewed from above. And the driving circuit drives the plurality of pixel circuits arranged in the rectangular area.

11. The display device according to claim 10, A plurality of the rectangular regions are arranged in a matrix.

12. The display device according to any one of claims 1 to 5, The pixel circuit includes an organic EL element.

13. An electronic device comprising: The display device according to any one of claims 1 to 5; lens; as well as Eyepiece focusing mechanism.

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