Glasses-type electronic device

Abstract

An electronic device capable of accurately recognizing facial features of a user is provided. The eyeglass-type electronic device includes a first optical component, a second optical component, a frame, a camera device, a feature extraction unit, and an emotion inference unit. The frame contacts the sides of the first and second optical components. The camera device contacts the frame. The camera device has the function of detecting a portion of the user's face. The feature extraction unit has the function of extracting facial features from the detected portion of the face. The emotion inference unit has the function of inferring information about the user from the extracted features.

Description

Technical Field

[0001] One embodiment of the present invention relates to an eyeglasses-type electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above-described technical fields. Examples of technical fields within the scope of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting equipment, input devices, input / output devices, and methods for driving or manufacturing these devices. A semiconductor device refers to any device capable of operating by utilizing the characteristics of semiconductors. Prior Technology

[0003] Facial expression recognition technology based on captured images is known. This technology is used, for example, in digital cameras to automatically capture images when a smile appears on the subject's face or when the subject's gaze is directed at the camera.

[0004] As an expression recognition technology, for example, Patent Document 1 discloses a technology that detects facial features and recognizes expressions with high accuracy based on those features. [References] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2007-087346 Summary of the Invention

[0006] For example, facial expression recognition can be performed by shining infrared light on the face and detecting the reflected infrared light. However, if the light source emitting the infrared light and the sensor detecting the reflected infrared light are far from the face, especially the eyes, facial expressions may not be accurately recognized.

[0007] One objective of one embodiment of the present invention is to provide an electronic device capable of accurately recognizing facial features of a user. Furthermore, one objective of one embodiment of the present invention is to provide an electronic device capable of accurately inferring a user's emotions. Additionally, one objective of one embodiment of the present invention is to provide an electronic device capable of accurately inferring a user's level of fatigue. Furthermore, one objective of one embodiment of the present invention is to provide a novel electronic device.

[0008] Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device with a large number of pixels. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device with high resolution. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device capable of displaying high-definition images. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device capable of displaying high-quality images. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device capable of displaying immersive images. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device capable of displaying high-brightness images. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device with narrow bezels. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a small display device. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device operating at high speed. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a display device with low power consumption. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including an inexpensive display device. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a highly reliable display device. Furthermore, one objective of an embodiment of the present invention is to provide an electronic device including a novel display device.

[0009] Furthermore, one objective of one embodiment of the present invention is to provide a novel display device. Furthermore, one objective of one embodiment of the present invention is to provide a novel imaging device.

[0010] Note that the description of these objectives does not preclude the existence of other objectives. Note that one embodiment of the present invention does not need to achieve all of the above objectives. Furthermore, objectives other than those described above can be derived from the description in the specification, drawings, claims, etc.

[0011] One embodiment of the present invention is an eyeglass-type electronic device, which includes a first optical component, a second optical component, a frame, a camera device, a feature extraction unit, and an emotion inference unit. The frame contacts the side of the first optical component and the side of the second optical component. The camera device contacts the frame. The camera device has the function of detecting a portion of the user's face. The feature extraction unit has the function of extracting facial features from the detected portion of the face. The emotion inference unit has the function of inferring information about the user from the extracted features.

[0012] Furthermore, in the above embodiments, the information can be the user's level of fatigue or emotional state.

[0013] Furthermore, the above embodiments may also include a display device, which may also display images corresponding to the information.

[0014] Furthermore, in the above embodiments, the display device may also include a light-emitting element, which may also be an organic EL element.

[0015] Furthermore, in the above embodiments, the display device may also include a transistor, and the channel forming region of the transistor may also contain a metal oxide.

[0016] Furthermore, one embodiment of the present invention is an eyeglass-type electronic device, which includes a first optical component, a second optical component, a frame, a camera device, and a display device. The camera device includes a photoelectric conversion element with the function of detecting the amount of light received. The frame contacts the side of the first optical component and the side of the second optical component. The camera device contacts the frame. The display device is provided with a first layer and a second layer stacked together. The first layer has a gate driving circuit and a source driving circuit. The second layer has a pixel array with pixels arranged in a matrix shape. The gate driving circuit and the source driving circuit have regions overlapping with the pixels, and the gate driving circuit has a region overlapping with the source driving circuit.

[0017] Furthermore, in the above embodiments, the display device may also include a DA conversion circuit, which includes a potential generation circuit and a transmission transistor logic circuit. The potential generation circuit is disposed outside the source driving circuit, and the transmission transistor logic circuit is disposed in the source driving circuit. The potential generation circuit has the function of generating multiple potentials at different levels, and the transmission transistor logic circuit has the function of receiving image data and outputting any one of the multiple potentials generated by the potential generation circuit based on the digital value of the image data.

[0018] Furthermore, in the above embodiments, the pixel may also include a light-emitting element, which may also be an organic EL element.

[0019] Furthermore, in the above embodiments, the pixel may also include a transistor, and the channel forming region of the transistor may also contain a metal oxide.

[0020] According to one embodiment of the present invention, an electronic device capable of accurately recognizing facial features of a user can be provided. Furthermore, according to one embodiment of the present invention, an electronic device capable of accurately inferring a user's emotions can be provided. Furthermore, according to one embodiment of the present invention, an electronic device capable of accurately inferring a user's level of fatigue can be provided. Furthermore, according to one embodiment of the present invention, a novel electronic device can be provided.

[0021] Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device having a large number of pixels can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device with high resolution can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device capable of displaying high-resolution images can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device capable of displaying high-quality images can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device capable of displaying immersive images can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device capable of displaying high-brightness images can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device with narrow bezels can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a small display device can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a display device operating at high speed can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a low-power display device can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising an inexpensive display device can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a highly reliable display device can be provided. Furthermore, according to one embodiment of the present invention, an electronic device comprising a novel display device can be provided.

[0022] Furthermore, according to one embodiment of the present invention, a novel display device can be provided. Furthermore, according to one embodiment of the present invention, a novel imaging device can be provided.

[0023] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily require all of the above-described effects. Furthermore, effects other than those described above can be derived from the description in the specification, drawings, claims, etc. Simple Explanation of the Diagram

[0024] In the diagram: Figures 1A and 1B are diagrams illustrating structural examples of electronic devices; Figures 2A and 2B are diagrams illustrating structural examples of electronic devices; [Figures 3A to 3C] are diagrams illustrating structural examples of electronic devices; [Figure 4] is a block diagram showing a structural example of an electronic device; [Figure 5A] and [Figure 5B] are diagrams illustrating examples of neural network structures, while [Figure 5C] is a diagram illustrating emotion inference; [Figure 6A] is a diagram illustrating an example of how an electronic device is used, while [Figure 6B] is a diagram illustrating an example of the user's field of vision for an electronic device; [Figure 7] is a block diagram showing a structural example of an electronic device; [Figure 8] is a block diagram showing a structural example of a display device; [Figure 9] is a block diagram showing a structural example of a display device; [Figure 10] is a block diagram showing a structural example of a display device; [Figure 11] is a block diagram showing a structural example of a display device; [Figure 12] is a block diagram showing a structural example of a display device; [Figure 13] is a block diagram showing a structural example of a display device; [Figure 14] is a block diagram showing a structural example of a display device; [Figure 15] is a block diagram showing a structural example of a display device; [Figure 16] is a circuit diagram showing an example of the structure of a DA conversion circuit; [Figure 17] is a block diagram showing a structural example of a shift register; [Figure 18A] is a block diagram showing a structural example of a shift register, while [Figure 18B] is a circuit diagram showing a structural example of a shift register; [Figure 19] is a schematic diagram showing an example of the configuration of the gate drive circuit and the source drive circuit; [Figure 20] is a top view showing an example configuration of the gate drive circuit and the source drive circuit; [Figures 21A to 21G] are diagrams illustrating examples of pixel structures; [Figure 22A] and [Figure 22B] are circuit diagrams illustrating examples of pixel structures; [Figure 23A] is a circuit diagram showing an example of a pixel structure, while [Figure 23B] is a timing diagram showing an example of how a pixel works; [Figures 24A to 24E] are circuit diagrams illustrating examples of pixel structures; [Figure 25] is a block diagram showing a structural example of a display device; [Figure 26] is a diagram illustrating an example of the operation of the display device; [Figure 27] is a cross-sectional view showing a structural example of a display device; [Figure 28] is a cross-sectional view showing a structural example of a display device; [Figure 29] is a cross-sectional view showing a structural example of a display device; [Figure 30] is a cross-sectional view showing a structural example of a display device; [Figure 31A] and [Figure 31B] are top views showing an example of the structure of a pixel; [Figure 32] is a top view showing an example of the structure of a pixel; [Figure 33] is a cross-sectional view showing a structural example of a pixel; [Figure 34A] is a schematic diagram showing an example of a pixel structure, while [Figure 34B] is a top view showing an example of a pixel structure; [Figure 35A] and [Figure 35B] are top views showing examples of pixel structure; [Figure 36] is a top view showing an example of the structure of a pixel; [Figure 37] is a top view showing an example of the structure of a pixel; [Figure 38] is a cross-sectional view showing an example of the structure of a pixel; [Figures 39A to 39E] are diagrams illustrating structural examples of light-emitting elements; [Figure 40A] and [Figure 40B] are cross-sectional views showing a structural example of the camera device; [Figure 41A] is a top view showing an example of a transistor structure, while [Figure 41B] and [Figure 41C] are cross-sectional views showing examples of a transistor structure. [Figure 42A] is a top view showing an example of a transistor structure, while [Figure 42B] and [Figure 42C] are cross-sectional views showing examples of a transistor structure. [Figure 43A] is a top view showing an example of a transistor structure, while [Figure 43B] and [Figure 43C] are cross-sectional views showing examples of a transistor structure. Implementation

[0025] The embodiments will now be described with reference to the accompanying drawings. However, the embodiments can be implemented in many different ways, and those skilled in the art will readily understand that the methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the invention should not be construed as being limited to the contents described in the embodiments shown below.

[0026] Note that in the invention structure described below, the same symbols are used in different figures to represent the same parts or parts with the same function, and repeated descriptions are omitted. Furthermore, when representing parts with the same function, the same shading line is sometimes used without additional symbols.

[0027] Note that in the various figures described in this specification, the size of components, the thickness of layers, and areas are sometimes exaggerated for ease of understanding. Therefore, the present invention is not limited to the dimensions shown in the figures.

[0028] The ordinal numbers such as "first" and "second" used in this specification are appended to avoid confusion of components, and are not intended to limit the number of components.

[0029] In this specification, for convenience, terms such as "up," "down," "left," and "right" are used to indicate the positional relationships of components with reference to the diagrams. Furthermore, the positional relationships of the components may be appropriately changed depending on the orientation of each component being described. Therefore, the use of terms not limited to those described in the specification may be modified as appropriate.

[0030] A transistor is a type of semiconductor device that can amplify current or voltage, control the switching between conduction and non-conduction states, etc. The transistors discussed in this specification include insulated-gate field-effect transistors (IGFETs) and thin-film transistors (TFTs).

[0031] Furthermore, in this specification and other materials, the functions of the source and drain of a transistor may sometimes be interchanged depending on factors such as changes in the polarity of the transistor or the direction of current during circuit operation. Therefore, the terms "source" and "drain" may be used interchangeably.

[0032] In this specification, "electrical connection" includes both direct connection and connection via an "element having a certain electrical function." Here, the "element having a certain electrical function" is not particularly limited as long as it can transmit and receive electrical signals between connected objects. Therefore, even when described as "electrical connection," in actual circuits, there may be parts without physical connection and only wiring extensions. Furthermore, even when described as "direct connection," there may be cases where different conductors are connected via contacts. Moreover, as wiring, different conductors may sometimes contain more than one of the same element or sometimes different elements.

[0033] Furthermore, unless otherwise specified in this specification, the off-state current refers to the drain current when the transistor is in the off state (also known as the non-conducting state or the blocked state). Unless otherwise specified, in an n-channel transistor, the off state refers to the state where the gate-source voltage Vgs is lower than the critical voltage Vth (in a p-channel transistor, Vgs is higher than Vth).

[0034] Furthermore, in this specification and other materials, the terms "electrode" or "wiring" do not functionally limit the components. For example, sometimes "electrode" is used as part of "wiring," and vice versa. Moreover, "electrode" or "wiring" also includes cases where multiple "electrodes" or "wiring" are formed as a single unit.

[0035] Furthermore, in this specification, the resistance value of a "resistor" sometimes depends on the length of the wiring. Additionally, the resistance value is sometimes determined by connecting to a conductor having a resistivity different from that of the conductor used for wiring. Furthermore, the resistance value is sometimes determined by doping the semiconductor with impurities.

[0036] Furthermore, in this specification and other materials, a "terminal" in a circuit refers to a part that receives or outputs current or voltage, or receives or transmits signals. Therefore, a portion of wiring or electrodes is sometimes used as a terminal.

[0037] In this specification and the like, metal oxide refers to oxides of metals in a broad sense. Metal oxides are classified as oxide insulators, oxide conductors (including transparent oxide conductors), and oxide semiconductors (also simply referred to as OS). For example, when a metal oxide is used as the active layer of a transistor, the metal oxide is sometimes referred to as an oxide semiconductor. In other words, an OS FET can be referred to as a transistor that contains oxides or oxide semiconductors.

[0038] Implementation Method 1 In this embodiment, an electronic device according to one embodiment of the present invention will be described with reference to the drawings.

[0039] Figure 1A is a perspective view showing a structural example of an electronic device 10a as an embodiment of the present invention. The electronic device 10a is an eyeglass-type electronic device, which includes a pair of display devices 11 (display devices 11a and 11b), a pair of housings 12 (housings 12a and 12b), a pair of optical components 13 (optical components 13a and 13b), a pair of temples 14 (temples 14a and 14b), a pair of camera devices 15 (camera devices 15a and 15b), a pair of display areas 16 (display areas 16a and 16b), and a pair of nose pads 17 (nose pads 17a and 17b). Furthermore, the electronic device 10a also includes a frame 18 and a camera 19.

[0040] In electronic device 10a, display devices 11a and 11b can be disposed inside housings 12a and 12b, respectively. For example, housings 12a and 12b can contact the left and right sides of the eyeglass frame 18, respectively. Furthermore, housings 12a and 12b can also contact the right and left sides of the eyeglass frame 18, respectively.

[0041] Temples 14a and 14b can contact housings 12a and 12b respectively. Display areas 16a and 16b can overlap with optical components 13a and 13b respectively. Frame 18 can contact the sides of optical components 13a and 13b.

[0042] The camera 19 can contact the frame 18. For example, the camera 19 can be positioned on the bridge of the nose of the frame 18. That is, the camera 19 can be positioned between optical components 13a and 13b. Alternatively, the camera 19 can be positioned between nose pads 17a and 17b.

[0043] Display devices 11a and 11b have the function of displaying images. The image displayed by display device 11a can be projected onto display area 16a. The image displayed by display device 11b can be projected onto display area 16b. Thus, the user of electronic device 10a can see the image displayed by display device 11a through display area 16a and the image displayed by display device 11b through display area 16b.

[0044] Display device 11 preferably has the function of displaying high-definition images. For example, it is preferable to have the function of displaying images with a resolution of 1000ppi or higher, more preferably to have the function of displaying images with a resolution of 2000ppi or higher, and even more preferably to have the function of displaying images with a resolution of 5000ppi or higher. Because electronic device 10a is an eyeglass-type electronic device, the distance between the user's eyes and display area 16 is short. Therefore, if the resolution of the image displayed by display device 11 is not high, the user of electronic device 10a will experience a grainy appearance when viewing the image displayed on display area 16. Therefore, by improving the resolution of the image displayed by display device 11, the user can view the image displayed on display area 16 without a grainy appearance. Specific structural examples of display devices capable of displaying high-definition images will be described later.

[0045] The display device 11 has pixels. These pixels may include, for example, sub-pixels that emit red light, sub-pixels that emit green light, and sub-pixels that emit blue light. Furthermore, sub-pixels that emit infrared light may also be provided among the pixels of the display device 11. In this case, it can have the function of detecting the state of the user's eyes and surroundings by detecting infrared light through the camera device 15, the details of which will be described later.

[0046] Optical component 13 has the function of transmitting incident light. For example, optical component 13 has the function of transmitting incident visible light. Furthermore, optical component 13 has the function of refracting incident light. By enabling optical component 13 to refract incident light, refractive errors in the eyes of the user of electronic device 10a can be corrected. Therefore, optical component 13 can be, for example, a lens. Optical component 13 can be, for example, a concave lens, a convex lens, a progressive lens, or a multifocal lens. Furthermore, the material of optical component 13 can be, for example, plastic or glass.

[0047] Furthermore, the optical component 13 may not have the function of refracting incident light. In this case, for example, when a person without refractive errors in their eyes uses the electronic device 10a, fatigue, headaches, nausea, etc., can be suppressed.

[0048] Because the optical component 13 is light-transmitting and has a display area 16, the user of the electronic device 10a can see the image displayed on the display area 16 by superimposing the image seen through the optical component 13. Therefore, the electronic device 10a can be an electronic device capable of performing augmented reality (AR) displays.

[0049] Furthermore, the optical component 13 may also be opaque. In this case, the user of the electronic device 10a cannot see the external environment but only the image displayed on the display area 16. Therefore, the electronic device 10a can be an electronic device capable of virtual reality (VR) display. When the optical component 13 is opaque, for example, it is preferable to set the entire area occupied by the optical components 13a and 13b as the display area 16a and display area 16b respectively, thereby increasing the image that the user of the electronic device 10a can see.

[0050] The camera device 15 has a light detection function. Here, in addition to a sensor (photoelectric conversion element) that detects the amount of light received, a light source is preferably also provided in the camera device 15. Thus, light emitted by the light source, for example, shines on the face of the user of the electronic device 10a, and the sensor can detect the reflected light. For example, the camera device 15 may have the function of detecting the state of the user's eyes and their surroundings. Therefore, the electronic device 10a may have the function of recognizing facial features such as the user's expressions, and thus may have the function of inferring, for example, the user's level of fatigue, emotions, etc.

[0051] The light source provided in the camera device 15 is preferably one that emits infrared light, such as near-infrared light. In this case, the sensor provided in the camera device 15 is preferably one that detects infrared light, such as near-infrared light. Furthermore, the light source provided in the camera device 15 is preferably one that emits red light. In this case, the sensor provided in the camera device 15 is preferably one that detects red light. Thus, the electronic device 10a can accurately recognize facial features such as the user's facial expressions.

[0052] Furthermore, the sensor installed in the camera device 15 may, for example, have the function of detecting far-infrared light. Thus, the camera device 15 may, for example, have the function of detecting the temperature of the facial surface. Therefore, the electronic device 10a may, for example, have the function of inferring the user's health status, emotions, etc. For example, when the camera device 15 includes both a sensor that detects red light and a sensor that detects far-infrared light, the electronic device 10a can more accurately infer the user's emotions, etc.

[0053] In this specification, infrared light refers, for example, light with a wavelength of 0.7 μm or more and 1000 μm or less. Near-infrared light refers, for example, light with a wavelength of 0.7 μm or more and 2.5 μm or less, while mid-infrared light refers, for example, light with a wavelength of 2.5 μm or more and 4 μm or less. Furthermore, far-infrared light refers, for example, light with a wavelength of 4 μm or more and 1000 μm or less. Sometimes, near-infrared light, mid-infrared light, or far-infrared light are simply referred to as infrared light. Additionally, in this specification, red light refers, for example, light with a wavelength of 0.6 μm or more and 0.75 μm or less.

[0054] The camera device 15 is preferably in contact with the frame 18. In particular, it is preferred that the camera device 15a is arranged to surround the optical component 13a and the camera device 15b is arranged to surround the optical component 13b. As a result, the distance between the user's eyes and the camera device 15 can be shortened, so the electronic device 10a can accurately recognize the user's facial features such as expressions.

[0055] Although camera devices 15a and 15b completely surround optical components 13a and 13b respectively, one embodiment of the present invention is not limited thereto. Camera device 15a may be configured to surround only a portion of optical component 13a, or camera device 15b may be configured to surround only a portion of optical component 13b. Furthermore, two or more camera devices 15a and 15b may be provided respectively.

[0056] The light source may not be located within the imaging device 15. In this case, the light source is located outside the imaging device 15. For example, the light source may be located on the bridge of the nose of the eyeglass frame 18. Alternatively, the light source may be located between the housing 12a and the optical component 13a, or between the housing 12b and the optical component 13b. By not including a light source within the imaging device 15, photoelectric conversion elements can be arranged at a high density within the imaging device 15.

[0057] Furthermore, if the light source is not provided in the camera device 15, the photoelectric conversion element contained in the camera device 15 can be used to detect the light reflected after being emitted from the display device 11 and, for example, illuminating the face of the user in the electronic device 10a. In this case, the pixels provided in the display device 11 are preferably those that have the function of emitting infrared light.

[0058] The camera 19 has the function of shooting in front, that is, on the side opposite to the temple 14. The camera 19 can also be called a camera device.

[0059] Next, a method for projecting an image onto the display area 16 of the electronic device 10a will be described with reference to FIG1B. The display device 11, lens 21, and reflector 22 are disposed inside the housing 12. Furthermore, the portion of the display area 16 corresponding to the optical component 13 includes a reflective surface 23 that serves as a semi-reflective mirror.

[0060] The light 25 emitted by the display device 11 is reflected by the reflector 22 through the lens 21 to one side of the optical component 13. Inside the optical component 13, the light 25 undergoes repeated total internal reflection at the end face of the optical component 13, and when it reaches the reflective surface 23, the image is projected onto the reflective surface 23. Thus, the user can see both the light 25 reflected by the reflective surface 23 and the transmitted light 26 that passes through the optical component 13 (including the reflective surface 23).

[0061] Figure 1B shows an example where both the reflector 22 and the reflecting surface 23 are curved. This increases the flexibility of the optical design compared to cases where the reflector 22 and the reflecting surface 23 are planar, allowing for a reduction in the thickness of the optical component 13. Alternatively, the reflector 22 and the reflecting surface 23 can also be planar.

[0062] As the reflector 22, a component with a mirror surface can be used, and this component preferably has a high reflectivity. In addition, as the reflective surface 23, a semi-reflective mirror that utilizes the reflection of a metal film can also be used, but when a prism or the like that that utilizes total internal reflection is used, the transmittance of the transmitted light 26 can be increased.

[0063] Here, the housing 12 preferably has a mechanism for adjusting the distance and angle between the lens 21 and the display device 11. This allows for focus adjustment, image magnification, and reduction. For example, a structure that allows one or both of the lens 21 and the display device 11 to move along the optical axis can be used.

[0064] Furthermore, the housing 12 preferably has a mechanism capable of adjusting the angle of the reflector 22. By changing the angle of the reflector 22, the position of the display area 16 for displaying the image can be changed. Thus, the display area 16 can be positioned in the most suitable location according to the user's eye position.

[0065] Figures 2A and 2B are external views illustrating a structural example of an electronic device 10b as an embodiment of the present invention. The electronic device 10b can be a head-mounted display (HMD). Furthermore, the electronic device 10b can also be referred to as a goggle-type electronic device. Additionally, the electronic device 10b can also be referred to as an eyeglass-type electronic device.

[0066] The electronic device 10b includes a housing 31, a display device 33, a fixing component 34, a pair of optical components 35 (optical components 35a and 35b), a pair of eyeglass frames 36 (eyeglass frames 36a and 36b), a pair of camera devices 37 (camera devices 37a and 37b), and a light source 40.

[0067] Furthermore, an opening 32 is provided in the electronic device 10b, and an optical component 35, a frame 36, and a light source 40 are disposed in contact with the opening 32. The frame 36 contacts and surrounds the side of the optical component 35. The light source 40 may be disposed, for example, between optical components 35a and 35b. In addition, the display device 33 may be disposed inside the housing 31.

[0068] Display device 33 has the function of displaying images. The user of electronic device 10b can see the images displayed by display device 33 through optical component 35. Similar to display device 11 included in electronic device 10a, display device 33 preferably has the function of displaying high-definition images. For example, when the size of the display area is 8 inches, display device 33 preferably has the function of displaying images with a resolution of 8K or 4K.

[0069] Optical component 35 preferably has the same function as optical component 13 contained in electronic device 10a. In addition, the material, structure, etc. of optical component 35 can also be the same as those of optical component 13.

[0070] The user of electronic device 10b can see the image displayed on display device 33 through optical component 35. Electronic device 10b can be an electronic device capable of VR display.

[0071] The camera device 37 has a light detection function. A photoelectric conversion element is provided in the camera device 37. Because a light source 40 is provided in the electronic device 10b, a light source may not be provided in the camera device 37.

[0072] Electronic device 10b includes a camera device 37 and a light source 40. Light emitted by the light source 40, for example, shines on the face of the user of electronic device 10b, and the camera device 37 can detect the reflected light. For example, the camera device 37 may have the function of detecting the state of the user's eyes and their surroundings. Thus, similar to electronic device 10a, electronic device 10b may have the function of recognizing facial features such as the user's facial expressions, thereby enabling it to infer, for example, the user's level of fatigue, emotions, etc.

[0073] The light source 40 preferably has the function of emitting infrared light, such as near-infrared light. In this case, the camera device 37 preferably has the function of detecting infrared light, such as near-infrared light. Furthermore, the light source 40 preferably has the function of emitting red light. In this case, the camera device 37 preferably has the function of detecting red light. Thus, the electronic device 10b can accurately recognize facial features such as the user's expression. Furthermore, similar to the camera device 15 included in the electronic device 10a, the camera device 37 can also have the function of detecting far-infrared light.

[0074] Furthermore, the electronic device 10b may not have a light source 40. In this case, by providing pixels with the function of emitting infrared light in the display device 33, the camera device 37 can, for example, have the function of detecting the state of the user's eyes and the surroundings of the electronic device 10b.

[0075] The camera device 37a preferably contacts the eyeglass frame 36a. Furthermore, the camera device 37b preferably contacts the eyeglass frame 36b. This shortens the distance between the user's eyes and the camera device 37, allowing the electronic device 10b to accurately recognize facial features such as the user's expressions.

[0076] Although camera devices 37a and 37b completely surround optical components 35a and 35b respectively, one embodiment of the present invention is not limited thereto. Camera device 37a may be configured to surround only a portion of optical component 35a, or camera device 37b may be configured to surround only a portion of optical component 35b. Furthermore, two or more camera devices 37a and 37b may be provided respectively.

[0077] In Figures 2A and 2B, the camera device 37 is positioned in contact with the frame 36; however, one embodiment of the present invention is not limited to this. For example, the camera device 37 may also be positioned in contact with the opening 32. For example, as shown in Figure 3A, the camera device 37 may also be positioned to surround the optical component 35 and the frame 36. Furthermore, as shown in Figure 3B, one camera device 37 may be positioned to surround the optical component 35 and contact the frame 36, and another camera device 37 may be positioned to surround the frame 36 and contact the opening 32.

[0078] Furthermore, the electronic device 10b may also lack the camera device 37. In this case, for example, as shown in FIG3C, the light source 40a can be provided in contact with the frame 36a, and the light source 40b can be provided in contact with the frame 36b. That is, the light source 40 can be used instead of the camera device 37. In the case where the electronic device 10b does not have the camera device 37, for example, a photoelectric conversion element is provided in the display device 33. That is, by making the display device 33 have the function of a camera device, the electronic device 10b can have, for example, the function of detecting the state of the user's eyes and their surroundings.

[0079] Figure 4 is a block diagram illustrating a structural example of electronic device 10 (electronic device 10a and electronic device 10b). Electronic device 10 includes an information providing unit 51, an object detection unit 52, a feature extraction unit 53, an inference unit 54, and an information generation unit 55.

[0080] Note that the diagrams in this specification show components categorized according to their function in separate blocks. However, in reality, components are difficult to clearly classify according to their function. Sometimes a component has multiple functions, and sometimes a function is implemented by multiple components.

[0081] The information providing unit 51 has the function of stimulating the user's vision, smell, hearing, or touch. The information providing unit 51 can provide (output) information generated in the information generating unit 55 (described later) to the user of the electronic device 10. The display area 16 included in the electronic device 10a and the display device 33 included in the electronic device 10b can also be considered as part of the information providing unit 51 or the information providing unit 51.

[0082] As an information providing unit 51, various types of hardware can be used. For example, when stimulating the user's vision (or providing information to the user) of the electronic device 10, a display device capable of displaying images or a lighting device capable of changing illuminance or color temperature can be used. For example, as a device for stimulating the sense of smell, an aromatherapy diffuser that uses vibration or heat to emit fragrance can be used. For example, as a device for stimulating the sense of hearing, an audio output device such as a speaker, headphones, or earphones can be used. Furthermore, as a device for stimulating the sense of touch, a vibration device can be used.

[0083] The subject detection unit 52 has the function of acquiring information such as a portion of the face of the user of the electronic device 10 and outputting the information to the feature extraction unit 53. The camera device 15 included in the electronic device 10a and the camera device 37 included in the electronic device 10b can also be considered as part of the subject detection unit 52 or have the subject detection unit 52.

[0084] The feature extraction unit 53 has the function of extracting features from the face information output by the subject detection unit 52, extracting part or all of the face features according to the position of the features, and outputting the information of the extracted features to the inference unit 54.

[0085] When the facial information acquired by the subject detection unit 52 consists of the eyes and their surrounding area, features extracted by the feature extraction unit 53 may include, for example, the pupil, iris, cornea, conjunctiva (white of the eye), inner corner of the eye, outer corner of the eye, upper eyelid, lower eyelid, eyelashes, eyebrows, glabella, inner corner of the eyebrow, and outer corner of the eyebrow. Furthermore, features other than the eyes and their surrounding area may include the root of the nose, tip of the nose, columella, nostrils, lips (upper and lower lip), corners of the mouth, cleft of the mouth, teeth, cheeks, jaw, angle of the jaw, and forehead. The feature extraction unit 53 identifies the shape and position of these facial features and extracts their positional coordinates. Then, the extracted positional coordinate data is output as facial feature information to the inference unit 54.

[0086] As a method for feature extraction in feature extraction unit 53, various algorithms can be used to extract features from images acquired in object detection unit 52. For example, algorithms such as Scale Invariant Feature Transform (SIFT), Speeded Up Robust Features (SURF), and Histogram of Oriented Gradients (HOG) can be employed.

[0087] In particular, it is preferable to use neural network inference for feature extraction unit 53. The following describes the use of neural networks.

[0088] Figure 5A schematically illustrates a neural network NN1 that can be used for the feature extraction unit 53. The neural network NN1 includes an input layer 61, three intermediate layers 62, and an output layer 63. Furthermore, the number of intermediate layers 62 is not limited to three; it can also be one or more.

[0089] The neural network NN1 is input into the data 71 generated in the object detection unit 52. Data 71 includes coordinates and corresponding numerical values. Typically, it can be image data including coordinates and corresponding grayscale values. Data 72 is output from the neural network NN1. Data 72 is location coordinate data containing the aforementioned features.

[0090] The neural network NN1 has pre-learned the following: extracting the aforementioned features from data 71, such as image data, and outputting their coordinates. As part of the learning process of the neural network NN1, edge processing using various filters is performed in the intermediate layer 62 to improve the neuron values ​​of the output layer 63 corresponding to the coordinates where the aforementioned features exist.

[0091] The inference unit 54 has the function of inferring the user's fatigue level, health status, emotions, etc., based on facial feature information input by the feature extraction unit 53, and outputting the inferred information to the information generation unit 55. Preferably, the inference unit 54 has the function of inferring the degree (level) of fatigue level, health status, emotions, etc.

[0092] It is preferable to use neural network reasoning to perform inference for inference unit 54.

[0093] Figure 5B schematically illustrates the neural network NN2 that can be used in the inference unit 54. Figure 5B shows the inference unit 54 inferring the emotions of the user of the electronic device 10. Furthermore, an example is shown where the neural network NN2 has a structure substantially the same as that of the neural network NN1. Note that the number of neurons in the input layer 61 of the neural network NN2 can be less than that of the neural network NN1.

[0094] The neural network NN2 is input into the data 72 generated by the feature extraction unit 53. The data 72 contains information about the coordinates of the extracted features.

[0095] Furthermore, the data processed by data 72 can be used as input to neural network NN2. For example, a vector connecting any two features can be calculated, and this vector, which relates to all or some features, can be used as input to neural network NN2. Alternatively, data whose calculated vector has been normalized can also be used. Hereinafter, the data processed from the output of neural network NN1, data 72, will also be referred to as data 72.

[0096] Data 73 is output from the neural network NN2, which receives input data 72. Data 73 corresponds to the neuron values ​​output from each neuron in the output layer 63. Each neuron in the output layer 63 is associated with an emotion. As shown in Figure 5B, data 73 contains the neuron values ​​of neurons corresponding to specified emotions (joy, happiness, surprise, excitement, disgust, etc.).

[0097] The neural network NN2 has pre-learned the following: inferring the degree of each emotion based on data 72 and outputting neuron values. Based on the relative positions of multiple features on the user's face in the electronic device 10, the features of the user's face can be determined. Therefore, the neural network NN2 can be used to infer the user's emotions based on the features of the user's face.

[0098] Figure 5C shows a schematic diagram of data 73. The level of the neuron value corresponding to each emotion indicates the degree of the inferred emotion. The inference unit 54 can infer the degree of another emotion based on the degree of the inferred emotion. The data containing the degree of the other emotion is data 74. Figure 5C shows the case where the degree of interest is inferred based on the degree of emotions such as joy, happiness, surprise, excitement, and disgust.

[0099] For example, by inputting the levels of emotions such as joy, happiness, surprise, excitement, and disgust contained in data 73 into a predetermined formula, the level of interest contained in data 74 can be inferred. For example, the formula can be set such that the higher the level of joy, happiness, surprise, and excitement, the higher the level of interest, and the higher the level of disgust, the lower the level of interest.

[0100] Furthermore, fatigue levels, health status, and emotions can be inferred without using neural networks. For example, a template matching method can be used, which compares a portion of the user's face image acquired by the subject detection unit 52 with a template image to determine their similarity. In this case, the feature extraction unit 53 may not be required.

[0101] The information generation unit 55 has the function of determining or generating information for the user of the electronic device 10 based on the fatigue level, health status, emotions, etc. inferred by the inference unit 54, and outputting it to the information providing unit 51. Therefore, the information providing unit 51 can provide information corresponding to the information generated in the information generation unit 55.

[0102] For example, if the information providing unit 51 has the function of displaying images, the information generating unit 55 can generate or select the display images and output them to the information providing unit 51. Furthermore, if the information providing unit 51 functions as a lighting device, the information generating unit 55 can determine the brightness (illuminance) or chromaticity of the lighting and output it to the information providing unit 51. Furthermore, if the information providing unit 51 has the function of emitting fragrance, the information generating unit 55 can determine the type or intensity of the emitted fragrance and output a signal to control the operation of the information providing unit 51. Furthermore, if the information providing unit 51 has the function of outputting sound, the information generating unit 55 can generate or select the sound to be reproduced and output it along with volume information to the information providing unit 51. Furthermore, if the information providing unit 51 has the function of sensing vibration, the information generating unit 55 can generate or determine the vibration mode or intensity and output a signal to control the operation of the information providing unit 51.

[0103] This concludes the description of the structural example of electronic device 10.

[0104] Furthermore, the data 72 output from the feature extraction unit 53 can be directly input to the information generation unit 55 without going through the inference unit 54. For example, even without inference by the inference unit 54, features can be extracted by the feature extraction unit 53 to detect the user's facial expressions, etc., of the electronic device 10. In this case, by directly inputting the data 72 output from the feature extraction unit 53 to the information generation unit 55, the power consumption of the electronic device 10 can be reduced.

[0105] Figure 6A is a diagram illustrating an example of how electronic device 10 is used. Figure 6A shows a situation where a user 81 of one electronic device 10 and a user 82 of another electronic device 10 are talking. Specifically, user 82 is talking to user 81.

[0106] The electronic device 10 shown in Figure 6A adopts a structure in which a transmitter 56 and a receiver 57 are provided in the electronic device 10a shown in Figure 1A. Alternatively, a structure in which a transmitter 56 and a receiver 57 are provided in the electronic device 10b shown in Figure 2A can also be adopted.

[0107] Transmitter 56 and receiver 57 can be disposed inside housing 12. Transmitter 56 can function as a wireless transmitter, and receiver 57 can function as a wireless receiver. Alternatively, transmitter 56 and receiver 57 may not be disposed inside housing 12. For example, transmitter 56 and receiver 57 may be disposed outside housing 12 in contact with housing 12. Furthermore, transmitter 56 and receiver 57 may be integrated into one unit.

[0108] The transmitter 56 has the function of sending the information generated by the information generation unit 55 to the outside of the electronic device 10. Figure 6A shows the case where the information generated by the information generation unit 55 is sent to another electronic device 10.

[0109] The receiver 57 has the function of receiving information from outside the electronic device 10. For example, it has the function of receiving information transmitted from the transmitter 56 of another electronic device 10. For example, the received information can be displayed by the information providing unit 51.

[0110] In the scenario shown in Figure 6A, the electronic device 10 used by user 81 infers the feelings that user 81 experiences upon hearing the content spoken by user 82. For example, the electronic device 10 infers the degree of interest in the content spoken by user 82. Information indicating the degree of interest of user 81 is transmitted from the transmitter 56 located in the electronic device 10 used by user 81. The receiver 57 used by user 82 receives the information transmitted from the transmitter 56. Furthermore, the information received by the receiver 57 is displayed by the information providing unit 51.

[0111] Figure 6B shows the field of view of user 82. The field of view of user 82 includes not only user 81 but also information providing unit 51. Information providing unit 51 displays information received by receiver 57 in the electronic device 10 used by user 82. For example, it displays the level of interest of user 81. Thus, user 82 can know the level of interest of user 81. For example, if user 81 has little interest, user 82 can change the topic to find topics that user 81 might be interested in. Furthermore, when user 81 speaks, user 81 can know the level of interest of user 82.

[0112] Furthermore, the information providing unit 51 of the electronic device 10 displays the fatigue level, health status, etc. of the user of the other electronic device 10. Thus, a user of one electronic device 10 can know the fatigue level, health status, etc., of the user of another electronic device 10. Therefore, for example, a user of one electronic device 10 can suggest rest to someone with high fatigue or poor health. In addition, appropriate health management suggestions can be provided.

[0113] Figure 7 is a block diagram showing a structural example of the electronic device 10 shown in Figure 6A, and a modified example of the structure shown in Figure 4. The difference between the electronic device 10 shown in Figure 4 and Figure 7 is that the electronic device 10 of the structure shown in Figure 7 includes a transmitter 56 and a receiver 57.

[0114] As shown in Figure 7, the transmitter 56 supplies the information generated by the information generation unit 55. The transmitter 56 then sends this information to the outside of the electronic device 10.

[0115] The receiver 57 receives information from outside the electronic device 10. For example, it can receive information transmitted from another electronic device 10. Furthermore, it can also receive information transmitted from electronic devices other than the electronic device 10. Additionally, it can receive broadcasts, etc. The information received by the receiver 57 is displayed by the information providing unit 51. For example, an image corresponding to the information received by the receiver 57 can be displayed on the display area included in the information providing unit 51.

[0116] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification. Implementation Method 2

[0117] In this embodiment, a display device, a light source, a camera device, etc., that can be applied to an electronic device according to one embodiment of the present invention will be described.

[0118] <Example 1 of the structure of a display device> Figure 8 is a block diagram illustrating a structural example of a display device 810 as an embodiment of the present invention. The display device 810 includes a layer 820 and a layer 830 stacked on top of the layer 820. Layer 820 includes a gate drive circuit 821, a source drive circuit 822, and a circuit 840. Layer 830 includes pixels 834 arranged in a matrix shape to form a pixel array 833. An interlayer insulator may be disposed between layers 820 and 830. Alternatively, layer 820 may be stacked on top of layer 830.

[0119] Circuit 840 is electrically connected to source drive circuit 822. Alternatively, circuit 840 can also be electrically connected to other circuits.

[0120] Pixels 834 in the same row are electrically connected to the gate drive circuit 821 via wiring 831, and pixels 834 in the same column are electrically connected to the source drive circuit 822 via wiring 832. Wiring 831 functions as a scan line, while wiring 832 functions as a data line.

[0121] Although Figure 8 shows a structure in which a row of pixels 834 are electrically connected by a wiring 831 and a column of pixels 834 are electrically connected by wiring 832, one embodiment of the present invention is not limited thereto. For example, a row of pixels 834 may be electrically connected by two or more wirings 831, and a column of pixels 834 may be electrically connected by two or more wirings 832. That is, for example, a pixel 834 may be electrically connected to two or more scan lines and two or more data lines. Furthermore, for example, a wiring 831 may be electrically connected to two or more rows of pixels 834, and a wiring 832 may be electrically connected to two or more columns of pixels 834. That is, for example, two or more rows of pixels 834 may share a wiring 831, and two or more columns of pixels 834 may share a wiring 832.

[0122] The gate drive circuit 821 generates a signal to control the operation of the pixel 834 and supplies the signal to the pixel 834 via wiring 831. The source drive circuit 822 generates an image signal and supplies the image signal to the pixel 834 via wiring 832. The circuit 840, for example, receives image data as the basis for the image signal generated by the source drive circuit 822 and supplies the received image data to the source drive circuit 822. Furthermore, the circuit 840 also functions as a control circuit for generating start pulse signals and clock signals. Additionally, the circuit 840 can be a circuit with functions different from those of the gate drive circuit 821 and the source drive circuit 822.

[0123] The pixel array 833 has the function of displaying an image corresponding to the image signal supplied by the source drive circuit 822 to the pixel 834. Specifically, the image is displayed on the pixel array 833 by emitting light with a brightness corresponding to the aforementioned image signal from the pixel 834.

[0124] In Figure 8, the positional relationship between layer 820 and layer 830 is shown by a dashed line and a white circle. The white circles of layer 820 and layer 830, which are connected by the dashed line, overlap each other. This is also shown in other figures.

[0125] The display device 810 includes a gate driving circuit 821 and a source driving circuit 822 disposed in layer 820, with an area overlapping with the pixel array 833. For example, the gate driving circuit 821 and the source driving circuit 822 have areas overlapping with pixels 834. By stacking the gate driving circuit 821 and the source driving circuit 822 with the pixel array 833 in such a way that they have overlapping areas, the display device 810 can be made to have a narrow bezel and be miniaturized.

[0126] Furthermore, the gate driving circuit 821 and the source driving circuit 822 are not clearly separated, but have overlapping areas. This area is region 823. By having region 823, the area occupied by the gate driving circuit 821 and the source driving circuit 822 can be reduced. Therefore, even if the area of ​​the pixel array 833 is small, the gate driving circuit 821 and the source driving circuit 822 can be arranged without exceeding the pixel array 833. In addition, the area of ​​the gate driving circuit 821 and the source driving circuit 822 that does not overlap with the pixel array 833 can also be reduced. As described above, compared with the case without region 823, a narrower bezel and miniaturization can be further achieved.

[0127] Circuit 840 may not overlap with pixel array 833. Alternatively, circuit 840 may have a region that overlaps with pixel array 833.

[0128] Figure 8 shows a structural example where a gate drive circuit 821 and a source drive circuit 822 are provided in layer 820 and a pixel array 833 is provided in layer 830. However, multiple pixel arrays 833 can also be provided in layer 830. That is, the pixel arrays provided in layer 830 can be divided. Figure 9 is a modified example of the structure shown in Figure 8, showing a structural example of a display device 810 with a three-row, three-column pixel array 833 provided in layer 830. Furthermore, a two-row, two-column pixel array 833 or a four-row, four-column or more pixel array 833 can be provided in layer 830. In addition, the number of rows and columns of the pixel arrays 833 provided in layer 830 can also be different from each other. In the display device 810 with the structure shown in Figure 9, for example, an image is displayed using all the pixel arrays 833.

[0129] For ease of understanding, wiring 831 and wiring 832 are omitted in Figure 9, but wiring 831 and wiring 832 are actually provided in the display device 810 with the structure shown in Figure 9. Furthermore, the electrical connections of circuit 840 are omitted in Figure 9, but circuit 840 is actually electrically connected to the source drive circuit 822. Similar to Figure 9, other figures sometimes omit parts of components, etc.

[0130] For example, the same number of gate drive circuits 821 and source drive circuits 822 as the pixel array 833 can be provided in layer 820. In this case, the gate drive circuit 821 can be provided in a manner that overlaps with the pixel array 833 on which pixels 834 are provided with signals supplied by the gate drive circuit 821. Similarly, the source drive circuit 822 can be provided in a manner that overlaps with the pixel array 833 on which pixels 834 are provided with image signals supplied by the source drive circuit 822.

[0131] By setting up multiple pixel arrays 833 and configuring gate driving circuits 821 and source driving circuits 822 according to these multiple pixel arrays 833, the number of pixels 834 disposed in a single pixel array 833 can be reduced. The multiple gate driving circuits 821 can operate in parallel, and the multiple source driving circuits 822 can operate in parallel, thus shortening, for example, the time required to write an image signal corresponding to a frame image to the pixel 834. This shortens the frame time and enables high-speed operation of the display device 810. Therefore, the number of pixels 834 contained in the display device 810 can be increased to improve the clarity of the display device 810. Furthermore, compared to a display device where the gate driving circuit and source driving circuit do not overlap with the pixel array, the clarity of the image displayed by the display device according to one embodiment of the present invention is further improved. Moreover, the clock frequency can be reduced, thereby reducing the power consumption of the display device 810.

[0132] Here, when the gate driving circuit and the source driving circuit do not overlap with the pixel array, for example, the gate driving circuit and the source driving circuit are placed on the outer periphery of the pixel array. In this case, from the perspective of the placement position of the source driving circuit, it is difficult to set up a pixel array of more than two rows and two columns. On the other hand, in the display device 810, by placing the gate driving circuit and the source driving circuit in a layer different from the layer where the pixel array is placed, they can have an area that overlaps with the pixel array, thereby allowing a pixel array of more than two rows and two columns to be set up as shown in FIG. 9. That is to say, more than five gate driving circuits and source driving circuits can be respectively placed in the display device 810.

[0133] In summary, compared to display devices where the gate drive circuit and source drive circuit do not overlap with the pixel array, display device 810 can operate at, for example, a higher speed. Therefore, compared to display devices where the gate drive circuit and source drive circuit do not overlap with the pixel array, the resolution of display device 810 is further improved. For example, the pixel density of display device 810 can be set to 1000ppi or higher, 5000ppi or higher, or 10000ppi or higher. Therefore, display device 810 can display high-quality images without graininess and can display images with a strong sense of presence.

[0134] Furthermore, compared to display devices where the gate drive circuit and source drive circuit do not overlap with the pixel array, the resolution of the images that the display device 810 can display is further improved. For example, the display device 810 can display 4K2K, 8K4K, or higher resolution images. In addition, miniaturization of the display device is possible. For example, the size of the display area of ​​the display device 810 can be 8 inches or less.

[0135] Furthermore, even if multiple source drive circuits 822 are provided in layer 820 and multiple pixel arrays 833 are provided in layer 830, only one circuit 840 can be provided in the display device 810, just as shown in FIG. 8. Therefore, as shown in FIG. 9, the circuit 840 may not overlap with any of the pixel arrays 833. Alternatively, the circuit 840 may have an area that overlaps with any of the pixel arrays 833.

[0136] Although Figure 9 shows a structural example with the same number of gate drive circuits 821 as the pixel array 833, one embodiment of the present invention is not limited thereto. Figure 10 is a modified example of the structure shown in Figure 9, and shows a structural example of a display device 810 with the same number of gate drive circuits 821 as the number of columns of the pixel array 833. Because the display device 810 with the structure shown in Figure 10 has three columns of pixel array 833, three gate drive circuits 821 are provided. In addition, three rows of pixel array 833 are provided, and the three rows and one column of pixel array 833 share one gate drive circuit 821.

[0137] Figure 11 is a variation of the structure shown in Figure 9, illustrating a structural example of a display device 810 comprising multiple pixel arrays 833 and a gate drive circuit 821. In the display device 810 with the structure shown in Figure 11, the three-row, three-column pixel arrays 833 share a single gate drive circuit 821. Furthermore, in the display device 810 with the structure shown in Figure 11, the gate drive circuit 821 may not overlap with the pixel arrays 833.

[0138] Furthermore, although not shown, the same number of source drive circuits 822 as the pixel array 833 may not be provided. The number of source drive circuits 822 contained in the display device 810 may be greater than or less than the number of pixel arrays 833 provided in the display device 810.

[0139] Although Figure 8 shows a structural example with circuit 840 provided in layer 820, circuit 840 may not be provided in layer 820. Figure 12 is a modified example of the structure shown in Figure 8, and shows a structural example of a display device 810 with circuit 840 provided in layer 830. Furthermore, components of circuit 840 may be provided in both layer 820 and layer 830.

[0140] Although Figure 8 shows a structural example with one pixel array 833 and one gate drive circuit, it is also possible to provide more than one gate drive circuit for the pixel array 833. Figure 13 is a modified example of the structure shown in Figure 8, and shows a structural example of a display device 810 with two gate drive circuits (gate drive circuit 821a and gate drive circuit 821b) for one pixel array 833.

[0141] In the display device 810 with the structure shown in Figure 13, the pixels 834 in the odd-numbered rows are electrically connected to the gate drive circuit 821a via wiring 831a, while the pixels 834 in the even-numbered rows are electrically connected to the gate drive circuit 821b via wiring 831b. Like wiring 831, wiring 831a and wiring 831b function as scan lines.

[0142] Gate drive circuit 821a has the function of generating a signal to control the operation of pixel 834 in the odd-numbered row and supplying the signal to pixel 834 through wiring 831a. Gate drive circuit 821b has the function of generating a signal to control the operation of pixel 834 in the even-numbered row and supplying the signal to pixel 834 through wiring 831b.

[0143] Similar to gate driving circuit 821, gate driving circuits 821a and 821b have regions overlapping with pixel array 833. For example, similar to gate driving circuit 821, gate driving circuits 821a and 821b have regions overlapping with pixel 834. Furthermore, gate driving circuit 821a and source driving circuit 822 are not clearly separated, but have a region 823a where they overlap. Similarly, gate driving circuit 821b and source driving circuit 822 are not clearly separated, but have a region 823b where they overlap.

[0144] In the display device 810 with the structure shown in FIG13, image signals can be written to all pixels 834 of the odd-numbered rows by operating the gate drive circuit 821a, and then image signals can be written to all pixels 834 of the even-numbered rows by operating the gate drive circuit 821b. In other words, the display device 810 with the structure shown in FIG13 can operate in interlaced scanning mode. By operating the display device 810 in interlaced scanning mode, high-speed operation and increased frame frequency can be achieved. Furthermore, compared to operating the display device 810 in progressive scanning mode, the number of pixels 834 written with image signals during one frame can be reduced by half. Therefore, when the display device 810 operates in interlaced scanning mode, the clock frequency can be reduced compared to operating the display device 810 in progressive scanning mode, thereby reducing the power consumption of the display device 810.

[0145] Although Figure 8 shows a structural example where only one end of wiring 832 is connected to the source drive circuit 822, multiple portions of wiring 832 can also be connected to the source drive circuit 822. Figure 14 shows a structural example of a display device 810 with the source drive circuit 822 connected to both ends of wiring 832. By connecting multiple portions of wiring 832 to the source drive circuit 822, signal delays caused by wiring resistance, parasitic capacitance, etc., can be suppressed. Therefore, high-speed operation of the display device 810 can be achieved.

[0146] Alternatively, a portion of the wiring 832 other than one end and the other end can be connected to the source drive circuit 822. For example, the center portion of the wiring 832 can be connected to the source drive circuit 822. By increasing the connection portion between the wiring 832 and the source drive circuit 822, signal delay can be further suppressed, and high-speed operation of the display device 810 can be further achieved. Alternatively, for example, one end and the center portion of the wiring 832 can be connected to the source drive circuit 822, but the other end of the wiring 832 can be disconnected from the source drive circuit 822.

[0147] Furthermore, when a source driving circuit 822 is connected to multiple portions of wiring 832, as shown in FIG14, the area occupied by the source driving circuit 822 becomes larger. Because the source driving circuit 822 is also stacked in this case with an area overlapping with the pixel array 833, the enlargement of the display device 810 can be suppressed. Furthermore, although the entire gate driving circuit 821 and source driving circuit 822 are not clearly separated and overlap each other in FIG14, even when a source driving circuit 822 is connected to multiple portions of wiring 832, only a portion of the gate driving circuit 821 may overlap with the source driving circuit 822.

[0148] Furthermore, multiple portions of the wiring 831 can be connected to a single gate drive circuit 821. This can suppress signal delays and enable high-speed operation of the display device 810. In this case, similar to the source drive circuit 822 shown in FIG14, the area occupied is larger, but the gate drive circuit 821 is stacked in a manner that overlaps with the pixel array 833, thereby preventing the display device 810 from becoming too large.

[0149] The structures of the display device 810 shown in Figures 8 to 14 can be appropriately combined. For example, the structures shown in Figure 9 and Figure 13 can be combined. In this case, for example, multiple pixel arrays 833 can be provided in the display device 810, along with twice the number of gate drive circuits of the pixel arrays 833, and the same number of source drive circuits 822 as the pixel arrays 833.

[0150] <Structural Examples of Circuit 840 and Source Drive Circuit 822> Figure 15 is a block diagram showing a structural example of circuit 840 and source drive circuit 822. Furthermore, although only one source drive circuit 822 is shown in Figure 15, circuit 840 can also be electrically connected to multiple source drive circuits 822.

[0151] Circuit 840 includes a receiving circuit 841, a series-to-parallel conversion circuit 842, and a potential generation circuit 846a. Source drive circuit 822 includes a buffer circuit 843, a shift register circuit 844, a latch circuit 845, a transmission transistor logic circuit 846b, and an amplifier circuit 847. Here, the potential generation circuit 846a and the transmission transistor logic circuit 846b constitute a digital-to-analog conversion circuit (DA conversion circuit) 846.

[0152] The receiving circuit 841 is electrically connected to the series-parallel conversion circuit 842. The series-parallel conversion circuit 842 is electrically connected to the buffer circuit 843, and the buffer circuit 843 is electrically connected to the shift register circuit 844 and the latch circuit 845. The shift register circuit 844 is electrically connected to the latch circuit 845, and the latch circuit 845 and the potential generation circuit 846a are electrically connected to the transmission transistor logic circuit 846b. The transmission transistor logic circuit 846b is electrically connected to the input terminal of the amplifier circuit 847, and the output terminal of the amplifier circuit 847 is electrically connected to the wiring 832.

[0153] The receiving circuit 841 has the function of receiving image data as the basis for the image signal generated by the source drive circuit 822. This image data can be single-ended image data. When receiving image data using data transmission signals such as Low Voltage Differential Signaling (LVDS), the receiving circuit 841 can also have the function of converting the signal into a signal specification that can be internally processed.

[0154] The series-parallel conversion circuit 842 has the function of performing parallel conversion on the single-ended image data output by the receiving circuit 841. By setting the series-parallel conversion circuit 842 in the circuit 840, even if the load is large when transmitting image data from the circuit 840 to the source drive circuit 822, etc., the image data can still be transmitted from the circuit 840 to the source drive circuit 822, etc.

[0155] The buffer circuit 843 can be, for example, a unity-gain buffer. The buffer circuit 843 has the function of outputting the same image data as the image data output from the series-parallel conversion circuit 842. By providing the buffer circuit 843 in the source drive circuit 822, even if the potential corresponding to the image data output from the series-parallel conversion circuit 842 drops due to wiring resistance or the like when transmitted from circuit 840 to the source drive circuit 822, this drop can be compensated for. Therefore, even if the load when transmitting image data from circuit 840 to the source drive circuit 822 is large, the decrease in the driving capability of the source drive circuit 822 can be suppressed.

[0156] The shift register circuit 844 has the function of generating signals to control the operation of the latch circuit 845. The latch circuit 845 has the function of storing or outputting image data output from the buffer circuit 843. In the latch circuit 845, either the storage or output of image data is selected according to the signal supplied from the shift register circuit 844.

[0157] The DA conversion circuit 846 has the function of converting digital image data output from the latch circuit 845 into analog image signals. The potential generation circuit 846a has the function of generating potentials corresponding to the number of bits of the image data that can be DA converted and supplying these potentials to the transmission transistor logic circuit 846b. For example, when the DA conversion circuit 846 has the function of converting 8-bit image data into analog image signals, the potential generation circuit 846a can generate 256 different potentials.

[0158] The transmission transistor logic circuit 846b has the function of receiving image data from the latch circuit 845 and outputting any potential generated by the potential generation circuit 846a according to the digital value of the image data. For example, the larger the digital value of the image data, the higher the potential output by the transmission transistor logic circuit 846b. The potential output by the transmission transistor logic circuit 846b can be an image signal.

[0159] As shown in Figure 15, in the display device 810, the circuits constituting the DA conversion circuit 846 can be respectively arranged in the source driver circuit 822 and the circuit 840. Specifically, circuits such as the transmission transistor logic circuit 846b, which are preferably arranged in each source driver circuit, can be arranged in the source driver circuit 822, while circuits such as the potential generation circuit 846a, which do not necessarily need to be arranged in each source driver circuit, can be arranged in the circuit 840. For example, compared with the case where all the circuits constituting the DA conversion circuit 846 are arranged in the source driver circuit 822, the area occupied by the source driver circuit 822 can be reduced, thereby increasing the number of source driver circuits 822 arranged in layer 820. As a result, the number of pixel arrays 833 arranged in layer 830 can be increased, and the display device 810 can achieve high-speed operation, reduced power consumption, improved clarity, and improved resolution of the images that can be displayed. Here, components of circuits other than the DA conversion circuit 846 can also be arranged in the source driver circuit 822 and the circuit 840 respectively.

[0160] Furthermore, as shown in FIG15, when the circuit constituting the DA conversion circuit 846 is respectively arranged in the source drive circuit 822 and the circuit 840, the display device 810 may, for example, have a potential generation circuit 846a and the same number of transmission transistor logic circuits 846b as the source drive circuit 822.

[0161] The amplifier circuit 847 amplifies the image signal output from the transmission transistor logic circuit 846b and outputs the image signal to the wiring 832, which serves as a data line. By providing the amplifier circuit 847, the image signal can be stably supplied to the pixel 834. As the amplifier circuit 847, a voltage follower circuit, such as an operational amplifier, can be appropriately used. Furthermore, when using a circuit with a differential input circuit as the amplifier circuit, the offset voltage of the differential input circuit is preferably as close to 0V as possible.

[0162] In addition to the receiving circuit 841, the serial-parallel conversion circuit 842, and the potential generation circuit 846a, the circuit 840 may further include various circuits. For example, the circuit 840 may include a control circuit having functions such as generating a start pulse signal and a clock signal.

[0163] <Structural example of the DA conversion circuit 846> FIG. 16 is a circuit diagram showing a structural example of the potential generation circuit 846a and the transmission transistor logic circuit 846b constituting the DA conversion circuit 846. The DA conversion circuit 846 having the structure shown in FIG. 16 can convert 8-bit image data D<1> to image data D<8> into analog image data IS.

[0164] In this specification and the like, for example, the first-bit image data D is represented by the image data D<1>, the second-bit image data D is represented by the image data D<2>, and the eighth-bit image data D is represented by the image data D<8>.

[0165] The potential generation circuit 846a having the structure shown in FIG. 16 includes resistors 848[1] to resistor 848

[0256] , and the resistors 848[1] to resistor 848

[0256] are connected in series. That is, the DA conversion circuit 846 can be a resistor string type DA conversion circuit.

[0166] One terminal of the resistor 848[1] can be supplied with the potential VDD. One terminal of the resistor 848

[0256] can be supplied with the potential VSS. Thus, potentials V1 to V256 with different levels can be output from the respective terminals of the resistors 848[1] to resistor 848

[0256] . In addition, although FIG. 16 shows a structural example of the potential generation circuit 846a when the potential V1 is the potential VDD, a structure in which the potential V256 is the potential VSS can also be adopted. In addition, a structure in which the potential V1 is the potential VDD and the potential V256 is the potential VSS can be adopted without providing the resistor 848

[0256] .

[0167] In this specification and the like, for example, the potential VDD can be a high potential, and the potential VSS can be a low potential. Here, the low potential can be, for example, a ground potential. In addition, the high potential is a potential higher than the low potential, and when the low potential is the ground potential, the high potential can be a positive potential.

[0168] The transmission transistor logic circuit 846b shown in Figure 16 consists of eight stages of transmission transistors 849. Specifically, each stage has two branching paths, resulting in a total of 256 paths in the transmission transistor logic circuit 846b. That is, the transmission transistors 849 are electrically connected in a knockout diagram manner. An analog image signal IS can be output from either the source or drain of the eighth stage transmission transistor 849, which is the final stage.

[0169] For example, image data D <1> The image data D is supplied to the first-stage transmission transistor 849. <2> Supply to the second-stage transmission transistor 849, and transmit image data D <8> The signal is supplied to the eighth-level transmission transistor 849. With the above structure, the potential of the image signal IS can be any of potentials V1 to V256 depending on the image data D. Therefore, digital image data can be converted into an analog image signal IS.

[0170] Furthermore, the transmission transistor logic circuit 846b shown in Figure 16 includes both an n-channel transmission transistor 849 and a p-channel transmission transistor 849, but it is also possible to use only the n-channel transmission transistor 849. For example, in addition to image data D <1> To image data D <8> In addition, complementary data can be supplied to the gate of the transmission transistor 849 to configure all transmission transistors 849 in the transmission transistor logic circuit 846b as n-channel transistors.

[0171] The structure shown in Figure 16 can also be applied to a DA conversion circuit 846 that has the function of performing DA conversion on image data D with bits other than 8 bits. For example, by setting 1024 or 1023 resistors 848 in the potential generation circuit 846a and setting 10 levels of transmission transistors 849 in the transmission transistor logic circuit 846b, the DA conversion circuit 846 can have the function of performing DA conversion on 10-bit image data D.

[0172] <Structure Example of Gate Drive Circuit 821> Figure 17 is a block diagram showing a structural example of the gate drive circuit 821. The gate drive circuit 821 includes a shift register circuit SR composed of multiple set / reset flip-flops. The shift register circuit SR is electrically connected to the wiring 831, which serves as a scan line, and has the function of outputting signals to the wiring 831.

[0173] Signal RES is a reset signal. For example, by setting signal RES to a high potential, all outputs of the shift register circuit SR can be set to a low potential. Signal SP is a start pulse signal. By inputting this signal to the gate drive circuit 821, the shifting operation of the shift register circuit SR can be started. Signal PWC is a pulse width control signal and has the function of controlling the pulse width of the signal output by the shift register circuit SR to the wiring 831. Signals CLK[1], CLK[2], CLK[3] and CLK[4] are clock signals, and two of the signals CLK[1], CLK[2], CLK[3] and CLK[4] can be input to a shift register circuit SR.

[0174] Furthermore, in the structure shown in FIG17, by setting the wiring 831 electrically connected to the shift register circuit SR as another wiring, it can be applied to the shift register circuit 844 contained in the source drive circuit 822.

[0175] Figure 18A is a diagram showing the signals input to the shift register circuit SR and the signals output from the shift register circuit SR. Here, Figure 18A shows the cases where the clock signal input signals CLK[1] and CLK[3] are used as clock signals.

[0176] Signal FO is an output signal, for example, a signal output to wiring 831. Signal SROUT is a shift signal, which can be signal LIN input to the next stage shift register circuit SR. As mentioned above, in the signals shown in Figure 18A, signals RES, PWC, CLK[1], CLK[3] and LIN are signals input to the shift register circuit SR, while signals FO and SROUT are signals output from the shift register circuit SR.

[0177] Figure 18B is a circuit diagram illustrating a structural example of a shift register circuit SR with input and output signals as shown in Figure 18A. The shift register circuit SR includes transistors 851 to 863 and capacitors 864 to 866.

[0178] One of the source and drain terminals of transistor 851 is electrically connected to one of the source and drain terminals of transistor 852, one of the source and drain terminals of transistor 856, and one of the source and drain terminals of transistor 859. The gate terminal of transistor 852 is electrically connected to one of the source and drain terminals of transistor 853, one of the source and drain terminals of transistor 854, one of the source and drain terminals of transistor 855, the gate terminal of transistor 858, the gate terminal of transistor 861, and one electrode of capacitor 864. The other of the source and drain terminals of transistor 856 is electrically connected to the gate terminal of transistor 857 and one electrode of capacitor 865. The other of the source and drain terminals of transistor 859 is electrically connected to the gate terminal of transistor 860 and one electrode of capacitor 866. One of the source and drain electrodes of transistor 860 is electrically connected to one of the source and drain electrodes of transistor 861, the gate electrode of transistor 862, and the other electrode of capacitor 866.

[0179] The gate of transistor 851 and the gate of transistor 855 are input signals LIN. The gate of transistor 853 is input signal CLK[3]. The gate of transistor 854 is input signal RES. One of the source and drain of transistor 857 is input signal CLK[1]. The other of the source and drain of transistor 860 is input signal PWC.

[0180] One of the source and drain terminals of transistor 862 and one of the source and drain terminals of transistor 863 are electrically connected to a wiring 831, as described above, and a signal F0 is output from wiring 831. A signal SROUT is output from the other of the source and drain terminals of transistor 857, one of the source and drain terminals of transistor 858, and the other electrode of capacitor 865.

[0181] The other of the source and drain of transistor 851, the other of the source and drain of transistor 853, the other of the source and drain of transistor 854, the gate of transistor 856, the gate of transistor 859, and the other of the source and drain of transistor 862 are supplied with a potential VDD. The other of the source and drain of transistor 852, the other of the source and drain of transistor 855, the other of the source and drain of transistor 858, the other of the source and drain of transistor 861, the other of the source and drain of transistor 863, and the other electrode of capacitor 864 are supplied with a potential VSS.

[0182] The 863 transistor is a bias transistor used as a constant current source. The gate of the 863 transistor can be supplied with a potential Vbias as a bias potential.

[0183] A source follower circuit 867 is constructed from transistors 862 and 863. By incorporating the source follower circuit 867 within the shift register circuit SR, even if signal attenuation occurs within the shift register circuit SR due to wiring resistance, parasitic capacitance, etc., the potential drop of the signal FO caused by such attenuation can be suppressed. This enables high-speed operation of the display device 810. Furthermore, the source follower circuit 867 can be any circuit other than a source follower circuit, as long as it functions as a buffer.

[0184] <Structural Example of Region 823> Figure 19 is a diagram showing a structural example of region 823, which is the overlapping area of ​​gate drive circuit 821 and source drive circuit 822. As shown in Figure 19, in region 823, areas including elements constituting gate drive circuit 821 and areas including elements constituting source drive circuit 822 are arranged regularly. In Figure 19, transistor 871 is used as an element constituting gate drive circuit 821, and transistor 872 is used as an element constituting source drive circuit 822.

[0185] Figure 19 shows a case where the regions containing the elements constituting the gate drive circuit 821 are arranged in the first and third rows, and the regions containing the elements constituting the source drive circuit 822 are arranged in the second and fourth rows. In region 823, dummy elements are provided between the regions containing the elements constituting the gate drive circuit 821. Furthermore, dummy elements are provided between the regions containing the elements constituting the source drive circuit 822. Figure 19 shows a structural example of region 823 where dummy transistors 873, serving as dummy elements, are provided on the four sides of transistor 871 and transistor 872.

[0186] By placing dummy elements such as dummy transistors 873 in region 823 and having these dummy elements absorb impurities, the diffusion of impurities to transistors 871 and 872 can be suppressed. This improves the reliability of transistors 871 and 872, thereby improving the reliability of the display device 810. Furthermore, although transistors 871, 872, and dummy transistors 873 are arranged in a matrix shape in Figure 19, they can also be arranged in a non-matrix shape.

[0187] Figure 20 is a top view showing a structural example of region 870 as part of region 823. As shown in Figures 19 and 20, region 870 includes a transistor 871, a transistor 872, and two dummy transistors 873. As shown in Figure 20, transistor 871 includes a channel forming region 110, a source region 111, and a drain region 112. It also includes a gate electrode 113 having a region overlapping with the channel forming region 110.

[0188] In Figure 20, components such as the gate insulator are omitted. Furthermore, Figure 20 does not clearly show the channel formation region, source region, and drain region separately.

[0189] An opening 114 is provided in the source region 111, through which the source region 111 is electrically connected to the wiring 115. An opening 116 is provided in the drain region 112, through which the drain region 112 is electrically connected to the wiring 117.

[0190] An opening 118 is provided in the gate electrode 113, through which the gate electrode 113 is electrically connected to the wiring 121. An opening 119 is provided in the wiring 115, through which the wiring 115 is electrically connected to the wiring 122. An opening 120 is provided in the wiring 117, through which the wiring 117 is electrically connected to the wiring 123. That is, the source region 111 is electrically connected to the wiring 122 via the wiring 115, and the drain region 112 is electrically connected to the wiring 123 via the wiring 117.

[0191] Transistor 872 includes a channel forming region 130, a source region 131, and a drain region 132. It also includes a gate electrode 133 having a region overlapping with the channel forming region 130.

[0192] An opening 134 is provided in the source region 131, through which the source region 131 is electrically connected to the wiring 135. An opening 136 is provided in the drain region 132, through which the drain region 132 is electrically connected to the wiring 137.

[0193] An opening 138 is provided in the gate electrode 133, through which the gate electrode 133 is electrically connected to the wiring 141. An opening 139 is provided in the wiring 135, through which the wiring 135 is electrically connected to the wiring 142. An opening 140 is provided in the wiring 137, through which the wiring 137 is electrically connected to the wiring 143. That is, the source region 131 is electrically connected to the wiring 142 through the wiring 135, and the drain region 132 is electrically connected to the wiring 143 through the wiring 137.

[0194] Furthermore, channel forming region 110 and channel forming region 130 are disposed in the same layer. Additionally, source region 111 and drain region 112 are disposed in the same layer as source region 131 and drain region 132. Furthermore, gate electrode 113 and gate electrode 133 are disposed in the same layer. Furthermore, wiring 115 and wiring 117 are disposed in the same layer as wiring 135 and wiring 137. That is, transistor 871 and transistor 872 are disposed in the same layer. Therefore, compared to the case where transistor 871 and transistor 872 are disposed in different layers, the manufacturing process of display device 810 can be simplified, thereby providing a low-cost display device 810.

[0195] Wiring 121 to 123, which are electrically connected to the transistor 871 constituting the gate drive circuit 821, are disposed in the same layer. Similarly, wiring 141 to 143, which are electrically connected to the transistor 872 constituting the source drive circuit 822, are disposed in the same layer. Furthermore, wiring 121 to 123 are disposed in a different layer than wiring 141 to 143. With this structure, short circuits in the transistor 871 (constituting the gate drive circuit 821) and the transistor 872 (constituting the source drive circuit 822) can be suppressed. Therefore, even if the gate drive circuit 821 and the source drive circuit 822 are not clearly separated and have overlapping areas, malfunctions in both circuits can be suppressed. This improves the reliability of the display device 810.

[0196] In this specification, etc., "the same layer as A" means, for example, a layer containing the same material formed in the same process as A.

[0197] Although Figure 20 shows a structure in which wiring 141 to wiring 143 is provided above wiring 121 to wiring 123, wiring 141 to wiring 143 may also be provided below wiring 121 to wiring 123.

[0198] Furthermore, although Figure 20 shows a structure in which wirings 121 to 123 extend horizontally and wirings 141 to 143 extend vertically, one embodiment of the present invention is not limited thereto. For example, a structure in which wirings 121 to 123 extend vertically and wirings 141 to 143 extend horizontally may also be used. Alternatively, wirings 121 to 123 and wirings 141 to 143 may extend in either the horizontal or vertical direction.

[0199] The dummy transistor 873 includes a semiconductor 151 and a conductor 152. The conductor 152 has a region overlapping with the semiconductor 151. The semiconductor 151 may be formed in the same layer as the channel forming region of the transistor 871 and the transistor 872. Furthermore, the conductor 152 may be formed in the same layer as the gate electrode of the transistor 871 and the transistor 872. Alternatively, the dummy transistor 873 may not include either the semiconductor 151 or the conductor 152.

[0200] Semiconductor 151 and conductor 152 may not be electrically connected to other wiring. Semiconductor 151 and / or conductor 152 may be supplied with a constant potential. For example, they may be supplied with a ground potential.

[0201] <Structure example of 834 pixels> Figures 21A to 21E illustrate the colors displayed by the pixels 834 provided in the display device 810. As shown in Figure 21A, pixels 834 that emit red light (R), green light (G), and blue light (B) can be provided in the display device 810. Alternatively, as shown in Figure 21B, pixels 834 that emit cyan light (C), magenta light (M), and yellow light (Y) can be provided in the display device 810.

[0202] Furthermore, as shown in FIG21C, a pixel 834 having the function of emitting red light (R), a pixel 834 having the function of emitting green light (G), a pixel 834 having the function of emitting blue light (B), and a pixel 834 having the function of emitting white light (W) can be provided in the display device 810. Alternatively, as shown in FIG21D, a pixel 834 having the function of emitting red light (R), a pixel 834 having the function of emitting green light (G), a pixel 834 having the function of emitting blue light (B), and a pixel 834 having the function of emitting yellow light (Y) can be provided in the display device 810. Alternatively, as shown in FIG21E, a pixel 834 having the function of emitting cyan light (C), a pixel 834 having the function of emitting magenta light (M), a pixel 834 having the function of emitting yellow light (Y), and a pixel 834 having the function of emitting white light (W) can be provided in the display device 810.

[0203] As shown in Figures 21C and 21E, by placing a pixel 834 that emits white light (W) in the display device 810, the brightness of the displayed image can be improved. Furthermore, as shown in Figures 21D, etc., by increasing the variety of colors emitted by the pixel 834, the reproducibility of intermediate colors can be improved, thus enhancing the display quality.

[0204] Furthermore, as shown in FIG21F, in addition to pixels 834 that emit red light (R), green light (G), and blue light (B), the display device 810 may also include pixels 834 that emit infrared light (IR). As shown in FIG21G, in addition to pixels 834 that emit cyan light (C), magenta light (M), and yellow light (Y), the display device 810 may also include pixels 834 that emit infrared light (IR). Furthermore, in addition to the pixels 834 shown in FIG21F and FIG21G, the display device 810 may also include pixels 834 that emit white light (W).

[0205] Figures 22A and 22B are circuit diagrams illustrating a structural example of pixel 834. The pixel 834 shown in Figure 22A includes transistor 552, transistor 554, capacitor 562, and light-emitting element 572. As the light-emitting element 572, an electroluminescent (EL) element can be used. The EL element has a layer containing a light-emitting compound (hereinafter referred to as the EL layer) between a pair of electrodes. When a potential difference higher than the critical voltage of the EL element is generated between the pair of electrodes, holes are injected into the EL layer from the anode side, while electrons are injected into the EL layer from the cathode side. The injected electrons and holes recombine in the EL layer, thereby causing the light-emitting material contained in the EL layer to emit light.

[0206] EL elements are distinguished based on whether the light-emitting material is an organic compound or an inorganic compound. The former is usually called an organic EL element, while the latter is called an inorganic EL element.

[0207] In organic light-emitting diodes (EL) devices, by applying a voltage, electrons are injected into the EL layer from one electrode, while holes are injected into the EL layer from the other electrode. Through the recombination of these carriers (electrons and holes), the light-emitting organic compound forms an excited state, and emits light when it returns from the excited state to the ground state. Due to this mechanism, this type of light-emitting device is called a current-excited light-emitting device.

[0208] In addition to luminescent compounds, the EL layer can also include materials with high hole injection capacity, materials with high hole transport capacity, hole blocking materials, materials with high electron transport capacity, materials with high electron injection capacity, or bipolar materials (materials with both high electron transport capacity and high hole transport capacity).

[0209] EL layers can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, and coating.

[0210] Inorganic EL devices are classified into dispersed inorganic EL devices and thin-film inorganic EL devices based on their device structure. Dispersed inorganic EL devices include a light-emitting layer in which luminescent material particles are dispersed in a binder, and their luminescence mechanism utilizes donor-acceptor recombination luminescence based on donor and acceptor energy levels. Thin-film inorganic EL devices have a structure in which the light-emitting layer is sandwiched between dielectric layers, and these dielectric layers are sandwiched between electrodes; their luminescence mechanism utilizes localized luminescence based on inner-shell electron transitions of metal ions.

[0211] To extract light emission, at least one of the pair of electrodes of the light-emitting element is made transparent. A transistor and a light-emitting element are formed on a substrate. The light-emitting element can be a top-emitting structure that extracts light emission from a surface opposite to the substrate; a bottom-emitting structure that extracts light emission from a surface on one side of the substrate; or a double-sided emitting structure that extracts light emission from both surfaces.

[0212] Other light-emitting elements besides light-emitting element 572 can also use the same elements as light-emitting element 572.

[0213] One of the source and drain electrodes of transistor 552 is electrically connected to wiring 832. The other of the source and drain electrodes of transistor 552 is electrically connected to one electrode of capacitor 562 and the gate of transistor 554. The other electrode of capacitor 562 is electrically connected to wiring 835a. The gate of transistor 552 is electrically connected to wiring 831. One of the source and drain electrodes of transistor 554 is electrically connected to wiring 835a. The other of the source and drain electrodes of transistor 554 is electrically connected to one electrode of light-emitting element 572. The other electrode of light-emitting element 572 is electrically connected to wiring 835b. Wiring 835a is supplied with potential VSS, while wiring 835b is supplied with potential VDD. Wiring 835a and wiring 835b serve as power lines.

[0214] In pixel 834 of the structure shown in FIG22A, the current flowing through the light-emitting element 572 is controlled according to the potential of the gate supplied to the transistor 554, thereby controlling the light emission brightness from the light-emitting element 572.

[0215] Figure 22B shows a different structure for pixel 834 than that shown in Figure 22A. In pixel 834 of the structure shown in Figure 22B, one of the source and drain of transistor 552 is electrically connected to wiring 832. The other of the source and drain of transistor 552 is electrically connected to one electrode of capacitor 562 and the gate of transistor 554. The gate of transistor 552 is electrically connected to wiring 831. One of the source and drain of transistor 554 is electrically connected to wiring 835a. The other of the source and drain of transistor 554 is electrically connected to another electrode of capacitor 562 and one electrode of light-emitting element 572. The other electrode of light-emitting element 572 is electrically connected to wiring 835b. Wiring 835a is supplied with potential VDD, while wiring 835b is supplied with potential VSS.

[0216] Figure 23A shows a structural example of pixel 834, which differs from the pixel 834 structures shown in Figures 22A and 22B in that it includes memory. The pixel 834 structure shown in Figure 23A includes transistors 511, 513, and 521, capacitors 515 and 517, and a light-emitting element 572. Furthermore, pixel 834 is electrically connected to wiring 831_1 and wiring 831_2, which serve as scan lines, and to wiring 832-1 and wiring 832-2, which serve as data lines.

[0217] One of the source and drain electrodes of transistor 511 is electrically connected to wiring 832-1. The other of the source and drain electrodes of transistor 511 is electrically connected to one electrode of capacitor 515. The gate of transistor 511 is electrically connected to wiring 831_1. One of the source and drain electrodes of transistor 513 is electrically connected to wiring 832-2. The other of the source and drain electrodes of transistor 513 is electrically connected to another electrode of capacitor 515. The gate of transistor 513 is electrically connected to wiring 831_2. The other electrode of capacitor 515 is electrically connected to one electrode of capacitor 517. One electrode of capacitor 517 is electrically connected to the gate of transistor 521. One of the source and drain electrodes of transistor 521 is electrically connected to one electrode of light-emitting element 572. The other electrode of capacitor 517 is electrically connected to wiring 535. The other of the source and drain electrodes of transistor 521 is electrically connected to wiring 537. Another electrode in the light-emitting element 572 is electrically connected to wiring 539.

[0218] In this specification, the voltage supplied to the light-emitting element refers to the difference between the potential applied to one electrode of the light-emitting element and the potential applied to the other electrode of the light-emitting element.

[0219] The node that electrically connects one of the source and drain electrodes of transistor 511 to one electrode of capacitor 515 is called node N1. The node that electrically connects the other of the source and drain electrodes of transistor 513, one electrode of capacitor 517, and the gate electrode of transistor 521 is called node N2. In Figure 23A, the circuit consisting of capacitor 517, transistor 521, and light-emitting element 572 is circuit 401.

[0220] Wiring 535 can be a common wiring provided for all pixels 834 in the display device 810. In this case, the potential supplied to wiring 535 is a common potential. Furthermore, a constant potential can be supplied to wiring 537 and wiring 539. For example, wiring 537 and wiring 539 can be supplied with a high potential and a low potential, respectively. Wiring 537 and wiring 539 serve as power lines.

[0221] Transistor 521 has the function of controlling the current supplied to light-emitting element 572. Capacitor 517 is used as a storage capacitor. Capacitor 517 can also be omitted.

[0222] Furthermore, Figure 23A shows a structure in which the anode side of the light-emitting element 572 is electrically connected to the transistor 521, but the cathode side of the light-emitting element 572 can also be electrically connected to the transistor 521. In this case, the potential values ​​of wiring 537 and wiring 539 can be appropriately changed.

[0223] Pixel 834 can maintain the potential of node N1 by turning transistor 511 off. Furthermore, the potential of node N2 can be maintained by turning transistor 513 off. Moreover, by writing a predetermined potential to node N1 via transistor 511 while transistor 513 is off, the potential of node N2 can change in response to the potential change of node N1 due to the capacitive coupling of capacitor 515.

[0224] Here, transistors 511 and 513 can be transistors containing metal oxides in the channel formation region (hereinafter referred to as OS transistors). The band gap of the metal oxide can be 2 eV or more or 2.5 eV or more. Therefore, the leakage current (off-state current) of the OS transistor in the non-conducting state is extremely small. Therefore, by using OS transistors as transistors 511 and 513, the potentials of nodes N1 and N2 can be maintained for a long time.

[0225] For example, as a metal oxide, In-M-Zn oxide (where element M is selected from one or more of aluminum, gallium, yttrium, tin, copper, vanadium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is preferred. In particular, aluminum, gallium, yttrium, or tin can be used as element M. Furthermore, indium oxide, zinc oxide, In-Ga oxide, In-Zn oxide, Ga-Zn oxide, or gallium oxide can also be used as the metal oxide.

[0226] [An example of how the 834 pixel method works] Next, an example of the operation of pixel 834 of the structure shown in FIG23A will be described with reference to FIG23B. FIG23B is a timing diagram of the operation of pixel 834 of the structure shown in FIG23A. Note that, for ease of explanation, the effects of various resistors such as wiring resistors, parasitic capacitances of transistors or wiring, and the critical voltage of transistors are not considered here.

[0227] In the work shown in Figure 23B, one frame period is divided into period T1 and period T2. Period T1 is the period for writing potential to node N2, and period T2 is the period for writing potential to node N1.

[0228] During period T1, a potential that enables the transistor to conduct is supplied to both wiring 831_1 and wiring 831_2. Furthermore, a fixed potential Vref is supplied to wiring 832_1, and a potential Vw is supplied to wiring 832_2.

[0229] Node N1 is supplied with a potential Vref from wiring 832-1 via transistor 511. Furthermore, node N2 is supplied with a potential Vw from wiring 832-2 via transistor 513. Therefore, capacitor 515 maintains a potential difference Vw-Vref.

[0230] Next, during period T2, wiring 831_1 is supplied with a potential that turns transistor 511 on, and wiring 831_2 is supplied with a potential that turns transistor 513 off. Wiring 832-1 is supplied with a potential Vdata, and wiring 832-2 is supplied with a predetermined constant potential. Alternatively, wiring 832-2 can also be supplied with a floating potential.

[0231] Node N1 is supplied with a potential Vdata via transistor 511. At this time, due to capacitive coupling via capacitor 515, the potential of node N2 corresponding to potential Vdata changes by a value of potential dV. That is, circuit 401 is supplied with an input potential Vw plus a potential of potential dV. Note that although Figure 23B shows potential dV as a positive value, it can also be negative. That is, potential Vdata can also be lower than potential Vref.

[0232] Here, the potential dV is basically determined by the capacitance of capacitor 515 and the capacitance of circuit 401. When the capacitance of capacitor 515 is sufficiently greater than the capacitance of circuit 401, the potential dV becomes close to the potential difference Vdata-Vref.

[0233] As described above, since pixel 834 can combine two data signals to generate a potential supplied to node N2, the image displayed on pixel array 833 can be corrected within pixel 834. Here, one of the two data signals can be the image signal mentioned above. The other of the two data signals can be a correction signal. For example, by supplying a potential Vw corresponding to the correction signal to node N2 during period T1 and then supplying a potential Vdata corresponding to the image signal to node N1 during period T2, an image whose image signal has been corrected by the correction signal can be displayed on pixel array 833. Furthermore, the source drive circuit 822 of display device 810 can generate not only the image signal but also the correction signal, etc.

[0234] Furthermore, in pixel 834 of the structure shown in FIG23A, the potential of node N2 can be set to a potential exceeding the maximum potential that can be supplied to wirings 832-1 and 832-2. This allows a high voltage to be supplied to the light-emitting element 572. Specifically, for example, the potential of wiring 537 can be set to a high potential. Therefore, when the light-emitting element 572 is an organic EL element, the light-emitting element can have the series structure described later. This improves the current efficiency and external quantum efficiency of the light-emitting element 572. Therefore, the display device 810 can display high-brightness images. Furthermore, the power consumption of the display device 810 can be reduced.

[0235] Furthermore, the circuit is not limited to that shown in Figure 23A; additional transistors or capacitors can also be used. For example, by adding a transistor and a capacitor to the structure shown in Figure 23A, three nodes that maintain their potential can be provided. That is, in pixel 834, in addition to nodes N1 and N2, a node capable of maintaining its potential can be provided. This allows the potential of node N2 to be further increased. Therefore, a larger current can flow through the light-emitting element 572.

[0236] Figures 24A to 24E show examples of circuit 401 structures that differ from those in Figure 23A. Like the circuit 401 shown in Figure 23A, it includes a capacitor 517, a transistor 521, and a light-emitting element 572.

[0237] In circuit 401 shown in Figure 24A, node N2 is electrically connected to the gate of transistor 521 and one electrode of capacitor 517. One of the source and drain electrodes of transistor 521 is electrically connected to wiring 537. The other of the source and drain electrodes of transistor 521 is electrically connected to the other electrode of capacitor 517. The other electrode of capacitor 517 is electrically connected to one electrode of light-emitting element 572. The other electrode of light-emitting element 572 is electrically connected to wiring 539.

[0238] Similar to the circuit 401 with the structure shown in FIG23A, the circuit 401 with the structure shown in FIG24B includes a capacitor 517, a transistor 521 and a light-emitting element 572.

[0239] In circuit 401 shown in Figure 24B, node N2 is electrically connected to the gate of transistor 521 and one electrode of capacitor 517. One electrode of light-emitting element 572 is electrically connected to wiring 537. Another electrode of light-emitting element 572 is electrically connected to one of the source and drain of transistor 521. The other of the source and drain of transistor 521 is electrically connected to another electrode of capacitor 517. The other electrode of capacitor 517 is electrically connected to wiring 539.

[0240] Figure 24C shows a structural example of circuit 401 with the addition of a transistor 525 to the circuit 401 shown in Figure 24A. One of the source and drain terminals of transistor 525 is electrically connected to the other of the source and drain terminals of transistor 521 and the other of capacitor 517. The other of the source and drain terminals of transistor 525 is electrically connected to one electrode of light-emitting element 572. The gate of transistor 525 is electrically connected to wiring 541. Wiring 541 serves as a scan line for controlling the conduction of transistor 525.

[0241] In pixel 834 of circuit 401 with the structure shown in FIG24C, even if the potential of node N2 is above the critical voltage of transistor 521, current can only flow through light-emitting element 572 by turning on transistor 525. Thus, malfunction of display device 810 can be suppressed.

[0242] Figure 24D shows a structural example of circuit 401 with the addition of transistor 527 to the circuit 401 shown in Figure 24C. One of the source and drain terminals of transistor 527 is electrically connected to the other of the source and drain terminals of transistor 521. The other of the source and drain terminals of transistor 527 is electrically connected to wiring 543. The gate of transistor 527 is electrically connected to wiring 545. Wiring 545 serves as a scan line for controlling the conduction of transistor 527.

[0243] Wiring 543 can be electrically connected to a supply source at a specific potential, such as a reference potential. In other words, wiring 543 functions as a power supply line. By supplying another specific potential to the source and drain of transistor 521 from wiring 543, the writing of image data to pixel 834 can be stabilized.

[0244] Furthermore, wiring 543 can be electrically connected to circuit 520. Circuit 520 can have one or more of the following functions: supplying a specific potential, acquiring the electrical characteristics of transistor 521, and generating a correction signal.

[0245] The circuit 401 shown in Figure 24E includes a capacitor 517, a transistor 521, a transistor 529, and a light-emitting element 572.

[0246] In circuit 401 shown in Figure 24E, node N2 is electrically connected to the gate of transistor 521 and one of the electrodes of capacitor 517. One of the source and drain of transistor 521 is electrically connected to wiring 537. One of the source and drain of transistor 529 is electrically connected to wiring 543.

[0247] Another electrode in capacitor 517 is electrically connected to another of the source and drain electrodes of transistor 521. Another of the source and drain electrodes of transistor 521 is electrically connected to another of the source and drain electrodes of transistor 529. Another of the source and drain electrodes of transistor 529 is electrically connected to one electrode of light-emitting element 572.

[0248] The gate of transistor 529 is electrically connected to wiring 831_1. Another electrode in light-emitting element 572 is electrically connected to wiring 539.

[0249] <Example 2 of Display Device Structure> Figure 25 is a block diagram showing a structural example of a display device 810 when pixel 834 has the structure shown in Figure 23A. The display device 810 with the structure shown in Figure 25 includes, in addition to the components of the display device 810 shown in Figure 8, a demultiplexing circuit 824. As shown in Figure 25, the demultiplexing circuit 824 can, for example, be disposed in layer 820. Furthermore, the number of demultiplexing circuits 824 can, for example, be the same as the number of columns of pixels 834 disposed on the pixel array 833.

[0250] The gate drive circuit 821 is electrically connected to the pixel 834 via wiring 831_1. The gate drive circuit 821 is electrically connected to the pixel 834 via wiring 831_2. Wiring 831_1 and wiring 831_2 are used as scan lines.

[0251] The source drive circuit 822 is electrically connected to the input terminal of the demultiplexing circuit 824. The first output terminal of the demultiplexing circuit 824 is electrically connected to the pixel 834 via wiring 832-1. The second output terminal of the demultiplexing circuit 824 is electrically connected to the pixel 834 via wiring 832-2. Wiring 832-1 and wiring 832-2 are used as data lines.

[0252] Furthermore, the source drive circuit 822 and the demultiplexing circuit 824 can be collectively referred to as the source drive circuit. That is to say, the demultiplexing circuit 824 can also be included in the source drive circuit 822.

[0253] In the display device 810 with the structure shown in FIG25, the source driving circuit 822 has the function of generating image signal S1 and image signal S2. The demultiplexing circuit 824 has the function of supplying image signal S1 to pixel 834 through wiring 832-1, and supplying image signal S2 to pixel 834 through wiring 832-2. Here, it is assumed that the display device 810 with the structure shown in FIG25 is operated using the method shown in FIG23B, where potential Vdata corresponds to image signal S1 and potential Vw corresponds to image signal S2.

[0254] As shown in Figure 23B, by supplying potential Vw to node N2 and then supplying potential Vdata to node N1, the potential of node N2 becomes "Vw + dV". Here, as mentioned above, potential dV corresponds to potential Vdata. Therefore, image signal S1 can be added to image signal S2. That is, image signal S2 can be overlapped with image signal S1.

[0255] The magnitudes of the potential Vdata corresponding to image signal S1 and the potential Vw corresponding to image signal S2 are limited by factors such as the voltage withstand capability of the source drive circuit 822. Therefore, by overlapping image signal S2 with image signal S1, an image corresponding to an image signal whose potential is higher than that output by the source drive circuit 822 can be displayed on the pixel array 833. This allows a large current to flow through the light-emitting element 572, thereby enabling the display of a high-brightness image on the pixel array 833. Furthermore, the dynamic range of the brightness amplitude of the image that can be displayed by the pixel array 833 can be expanded.

[0256] The image corresponding to image signal S1 and the image corresponding to image signal S2 can be the same or different. When the image corresponding to image signal S1 and the image corresponding to image signal S2 are the same, an image whose brightness is higher than that of the image corresponding to image signal S1 and the image corresponding to image signal S2 can be displayed on the pixel array 833.

[0257] Figure 26 shows the case where image P1 corresponding to image signal S1 is an image containing only text, and image P2 corresponding to image signal S2 is an image containing both pictures and text. In this case, by overlaying image P1 and image P2, the brightness of the text can be increased, for example, the text can be emphasized. Furthermore, as shown in Figure 23B, since the potential of node N2 changes according to potential Vdata after potential Vw is written to node N2, when rewriting the potential Vw corresponding to image signal S2, it is necessary to write the potential Vdata of image signal S1 again. On the other hand, when rewriting potential Vdata, as long as the charge written to node N2 at time T1 shown in Figure 23B is maintained and does not leak from transistor 513, it is not necessary to rewrite potential Vw. Therefore, in the case shown in Figure 26, the brightness of the text can be adjusted by adjusting the value of potential Vdata.

[0258] Here, as described above, when rewriting the potential Vw corresponding to image signal S2, it is necessary to write the potential Vdata corresponding to image signal S1. On the other hand, when rewriting potential Vdata, it is not necessary to rewrite potential Vw. Therefore, the rewriting frequency of image P2 is preferably lower than the rewriting frequency of image P1. Note that image P1 is not limited to an image containing only text, and image P2 is not limited to an image containing both pictures and text.

[0259] <Example of a cross-sectional structure of a display device> Figure 27 is a cross-sectional view showing a structural example of the display device 810. The display device 810 includes a substrate 701 and a substrate 705, which are bonded together using a sealant 712.

[0260] As substrate 701, a single-crystal semiconductor substrate such as a single-crystal silicon substrate can be used. Alternatively, a semiconductor substrate other than a single-crystal semiconductor substrate can be used as substrate 701.

[0261] Transistors 441 and 601 are disposed on substrate 701. Transistor 441 may be a transistor disposed in circuit 840. Transistor 601 may be a transistor disposed in gate drive circuit 821 or source drive circuit 822. That is, transistors 441 and 601 may be disposed in layer 820 as shown in FIG8, etc.

[0262] Transistor 441 is composed of a conductor 443 serving as a gate electrode, an insulator 445 serving as a gate insulator, and a portion of substrate 701, and includes a semiconductor region 447 containing a channel forming region, a low-resistance region 449a serving as one of a source region and a drain region, and a low-resistance region 449b serving as the other of the source region and drain region. Transistor 441 can be p-channel or n-channel.

[0263] Transistor 441 is electrically separated from other transistors due to the device separation layer 403. Figure 27 shows the situation where transistor 441 and transistor 601 are electrically separated by the device separation layer 403. The device separation layer 403 can be formed using methods such as LOCOS (Local Oxidation of Silicon) or STI (Shallow Trench Isolation).

[0264] Here, in the transistor 441 shown in FIG27, the semiconductor region 447 has a convex shape. Furthermore, the sides and top surface of the semiconductor region 447 are covered by a conductor 443 via an insulator 445. Note that FIG27 does not show the appearance of the conductor 443 covering the sides of the semiconductor region 447. Furthermore, the conductor 443 can be made of a material with an adjustable work function.

[0265] Like transistor 441, a transistor with a convex shape in the semiconductor region can be called a finned transistor due to the use of a convex portion of the semiconductor substrate. Furthermore, an insulator used as a shield to form the convex portion can be provided in such a way that it contacts the top surface of the convex portion. Although FIG. 27 shows a case where a portion of the substrate 701 is processed to form the convex portion, a semiconductor with convex portions can also be formed by processing an SOI substrate.

[0266] Furthermore, the structure of transistor 441 shown in Figure 27 is only an example and is not limited to that structure. Suitable transistors can be used depending on the circuit structure or circuit operation method. For example, transistor 441 can be a planar transistor.

[0267] Transistor 601 can adopt the same structure as transistor 441.

[0268] In addition to the component separation layer 403, transistor 441, and transistor 601, insulators 405, 407, 409, and 411 are also provided on the substrate 701. A conductor 451 is embedded in insulators 405, 407, 409, and 411. Here, the height of the top surface of conductor 451 can be approximately the same as the height of the top surface of insulator 411.

[0269] Insulators 413 and 415 are provided on conductor 451 and insulator 411. Conductor 457 is embedded in insulators 413 and 415. Conductor 457 can be provided, for example, in the same layer as wiring 121 to wiring 123 shown in FIG. 20. Here, the height of the top surface of conductor 457 can be approximately the same as the height of the top surface of insulator 415.

[0270] Insulators 417 and 419 are provided on conductor 457 and insulator 415. Conductor 459 is embedded in insulators 417 and 419. Conductor 459 can be provided, for example, in the same layer as wiring 141 to wiring 143 shown in FIG. 20. Here, the height of the top surface of conductor 459 can be approximately the same as the height of the top surface of insulator 419.

[0271] Insulators 421 and 214 are provided on conductor 459 and insulator 419. Conductor 453 is embedded in insulator 421 and insulator 214. Here, the height of the top surface of conductor 453 can be made approximately the same as the height of the top surface of insulator 214.

[0272] An insulator 216 is provided on the conductor 453 and the insulator 214. The conductor 455 is embedded in the insulator 216. Here, the height of the top surface of the conductor 455 can be approximately the same as the height of the top surface of the insulator 216.

[0273] Insulators 222, 224, 254, 244, 280, 274, and 281 are provided on conductor 455 and insulator 216. Conductor 305 is embedded in insulators 222, 224, 254, 244, 280, 274, and 281. Here, the height of the top surface of conductor 305 can be approximately the same as the height of the top surface of insulator 281.

[0274] An insulator 361 is provided on the conductor 305 and the insulator 281. Conductors 317 and 337 are embedded in the insulator 361. Here, the height of the top surface of the conductor 337 can be made approximately the same as the height of the top surface of the insulator 361.

[0275] An insulator 363 is provided on the conductor 337 and the insulator 361. Conductors 347, 353, 355, and 357 are embedded in the insulator 363. Here, the height of the top surface of conductors 353, 355, and 357 can be made approximately the same as the height of the top surface of the insulator 363.

[0276] Connecting electrodes 760 are provided on conductors 353, 355, 357, and insulator 363. Furthermore, an anisotropic conductor 780 is provided in an electrically connected manner to the connecting electrodes 760, and an FPC (flexible printed circuit board) 716 is provided in an electrically connected manner to the anisotropic conductor 780. By using the FPC 716, various signals can be supplied to the display device 810 from outside.

[0277] As shown in Figure 27, the low-resistance region 449b of transistor 441, which serves as another of the source and drain regions, is electrically connected to FPC 716 by conductors 451, 457, 459, 453, 455, 305, 317, 337, 347, 353, 355, 357, connecting electrode 760, and anisotropic conductor 780. In Figure 27, three conductors—353, 355, and 357—are shown as conductors that function to electrically connect connecting electrode 760 and conductor 347; however, one embodiment of the invention is not limited to this. The number of conductors functioning to electrically connect connecting electrode 760 and conductor 347 can be one, two, or four or more. By providing multiple conductors functioning to electrically connect connecting electrode 760 and conductor 347, contact resistance can be reduced.

[0278] A transistor 750 is disposed on the insulator 214. The transistor 750 can be a transistor disposed in the pixel 834. That is, the transistor 750 can be disposed in layer 830 as shown in FIG8, etc. An OS transistor can be used as the transistor 750. OS transistors are characterized by extremely low off-state current. As a result, image signals can be maintained for a long time, thereby reducing the refresh rate. As a result, the power consumption of the display device 810 can be reduced.

[0279] Conductors 301a and 301b are embedded in insulators 254, 244, 280, 274, and 281. Conductor 301a is electrically connected to one of the source and drain electrodes of transistor 750, and conductor 301b is electrically connected to the other of the source and drain electrodes of transistor 750. Here, the height of the top surface of conductors 301a and 301b can be approximately the same as the height of the top surface of insulator 281.

[0280] Conductors 311, 313, 331, capacitor 790, conductor 333, and conductor 335 are embedded in insulator 361. Conductors 311 and 313 are electrically connected to transistor 750 and used for wiring. Conductors 333 and 335 are electrically connected to capacitor 790. Here, the height of the top surface of conductors 331, 333, and 335 can be approximately the same as the height of the top surface of insulator 361.

[0281] Conductors 341, 343, and 351 are embedded in insulator 363. Here, the height of the top surface of conductor 351 can be approximately the same as the height of the top surface of insulator 363.

[0282] Insulators 405, 407, 409, 411, 413, 415, 417, 419, 421, 214, 280, 274, 281, 361, and 363 are used as interlayer films, or as planarization films covering the uneven shapes beneath them. For example, to improve the flatness of the top surface of insulator 363, it can be planarized by a method such as chemical mechanical polishing (CMP).

[0283] As shown in Figure 27, the capacitor 790 includes a lower electrode 321 and an upper electrode 325. Furthermore, an insulator 323 is disposed between the lower electrode 321 and the upper electrode 325. That is, the capacitor 790 has a laminated structure in which an insulator 323 serving as a dielectric is sandwiched between a pair of electrodes. Although Figure 27 shows an example of a capacitor 790 disposed on an insulator 281, the capacitor 790 can also be disposed on an insulator different from the insulator 281.

[0284] Figure 27 shows an example where conductors 301a, 301b, and 305 are formed in the same layer. Furthermore, an example where conductors 311, 313, 317, and a lower electrode 321 are formed in the same layer is also shown. Additionally, an example where conductors 331, 333, 335, and 337 are formed in the same layer is also shown. Furthermore, an example where conductors 341, 343, and 347 are formed in the same layer is also shown. Furthermore, an example where conductors 351, 353, 355, and 357 are formed in the same layer is also shown. By forming multiple conductors in the same layer, the manufacturing process of the display device 810 can be simplified, thereby providing an inexpensive display device 810. Furthermore, they can also be formed in different layers and contain different types of materials.

[0285] The display device 810 shown in Figure 27 includes a light-emitting element 572. The light-emitting element 572 includes a conductor 772, an EL layer 786, and a conductor 788. The conductive layer 788 is disposed on one side of the substrate 705 and serves as a common electrode. Furthermore, the conductive layer 772 is electrically connected to another of the source and drain electrodes of the transistor 750 via conductors 351, 341, 331, 313, and 301b. The conductive layer 772 is formed on an insulator 363 and serves as a pixel electrode. Additionally, the EL layer 786 has an inorganic compound such as an organic compound or quantum dots.

[0286] Materials that can be used in organic compounds include fluorescent or phosphorescent materials. Furthermore, materials that can be used in quantum dots include colloidal quantum dots, alloy quantum dots, core-shell quantum dots, and nucleated quantum dots.

[0287] The display device 810 shown in Figure 27 has an insulator 730 disposed on an insulator 363. Here, the insulator 730 may cover a portion of the conductor 772. Furthermore, the light-emitting element 572 includes a light-transmitting conductor 788 and is a top-emitting type light-emitting element. Alternatively, the light-emitting element 572 may also employ a bottom-emitting structure that emits light to one side of the conductor 772, or a double-sided emitting structure that emits light to both sides of the conductor 772 and the conductor 788.

[0288] The light-emitting element 572 may have a microcavity structure, which will be described in detail later. Therefore, even without a color layer, light of a specified color (e.g., RGB) can be extracted, enabling the display device 810 to perform color display. By employing a structure without a color layer, light absorption by the color layer can be suppressed. Thus, the display device 810 can display high-brightness images and reduce power consumption. Furthermore, a structure without a color layer can also be used when the EL layer 786 is formed as islands in each pixel or as strips in each pixel column—that is, when the EL layer 786 is formed by separate coating.

[0289] Furthermore, the light-shielding layer 738 includes a region overlapping with the insulator 730. Additionally, the light-shielding layer 738 is covered by the insulator 734. Furthermore, the sealing layer 732 fills the space between the light-emitting element 572 and the insulator 734.

[0290] Furthermore, a structure 778 is provided between the insulator 730 and the EL layer 786. Additionally, a structure 778 is provided between the insulator 730 and the insulator 734. The structure 778 is a columnar spacer that functions to control the distance between the substrate 701 and the substrate 705. Alternatively, a spherical spacer can be used as the structure 778.

[0291] A light-shielding layer 738 and an insulator 734 in contact with it are provided on one side of the substrate 705. The light-shielding layer 738 has the function of blocking light emitted from the adjacent area. Alternatively, the light-shielding layer 738 has the function of preventing external light from reaching the transistor 750, etc.

[0292] Figure 28 is a modified example of the display device 810 shown in Figure 27, differing from the display device 810 shown in Figure 27 in that a color layer 736 is provided. By providing the color layer 736, the color purity of the light extracted from the light-emitting element 572 can be improved. Therefore, the display device 810 can display high-quality images. Furthermore, since all the light-emitting elements 572 in the display device 810 can be, for example, light-emitting elements that emit white light, it is not necessary to separately coat and form an EL layer 786, thus achieving a high-definition display device 810.

[0293] Although Figures 27 and 28 show a structure in which transistors 441 and 601, whose channel forming regions are formed inside substrate 701, are provided, and OS transistors are stacked on transistors 441 and 601, one embodiment of the present invention is not limited thereto. Figures 29 and 30 are variations of Figures 27 and 28, and differ from the display device 810 shown in Figures 27 and 28 in that transistors 750 are stacked on transistors 602 and 603, which are OS transistors, not on transistors 441 and 601. That is, the display device 810 with the structure shown in Figures 29 and 30 is provided with a stack of OS transistors.

[0294] An insulator 613 and an insulator 614 are provided on the substrate 701, and a transistor 602 and a transistor 603 are provided on the insulator 614. Alternatively, transistors or the like may be provided between the substrate 701 and the insulator 613. For example, transistors identical to those shown in FIG. 27 and FIG. 28 may be provided between the substrate 701 and the insulator 613.

[0295] Transistor 602 can be a transistor disposed in circuit 840. Transistor 603 can be a transistor disposed in gate drive circuit 821 or source drive circuit 822. That is, transistors 602 and 603 can be disposed in layer 820 as shown in FIG8, etc. Furthermore, as shown in FIG12, when circuit 840 is disposed in layer 830, transistor 602 can be disposed in layer 830.

[0296] Transistors 602 and 603 can be transistors with the same structure as transistor 750. Alternatively, transistors 602 and 603 can also be OS transistors with a different structure than transistor 750.

[0297] In addition to transistors 602 and 603, insulator 614 also includes insulators 616, 622, 624, 654, 644, 680, 674, and 681. Conductors 461 are embedded in insulators 654, 644, 680, 674, and 681. Here, the height of the top surface of conductor 461 can be approximately the same as the height of the top surface of insulator 681.

[0298] An insulator 501 is provided on the conductor 461 and the insulator 681. The conductor 463 is embedded in the insulator 501. Here, the height of the top surface of the conductor 463 can be made approximately the same as the height of the top surface of the insulator 501.

[0299] An insulator 503 is provided on the conductor 463 and the insulator 501. The conductor 465 is embedded in the insulator 503. Here, the height of the top surface of the conductor 465 can be made approximately the same as the height of the top surface of the insulator 503.

[0300] An insulator 505 is provided on the conductor 465 and the insulator 503. A conductor 467 is embedded in the insulator 505. The conductor 467 can, for example, be provided in the same layer as the wiring 121 to wiring 123 shown in FIG. 20. Here, the height of the top surface of the conductor 467 can be approximately the same as the height of the top surface of the insulator 505.

[0301] An insulator 507 is provided on the conductor 467 and the insulator 505. The conductor 469 is embedded in the insulator 507. Here, the height of the top surface of the conductor 469 can be made approximately the same as the height of the top surface of the insulator 507.

[0302] An insulator 509 is provided on the conductor 469 and the insulator 507. A conductor 471 is embedded in the insulator 509. The conductor 471 can be provided, for example, in the same layer as the wiring 141 to wiring 143 shown in FIG. 20. Here, the height of the top surface of the conductor 471 can be approximately the same as the height of the top surface of the insulator 509.

[0303] Insulators 421 and 214 are provided on conductor 471 and insulator 509. Conductor 453 is embedded in insulator 421 and insulator 214. Here, the height of the top surface of conductor 453 can be made approximately the same as the height of the top surface of insulator 214.

[0304] As shown in Figures 29 and 30, one of the source and drain electrodes of transistor 602 is electrically connected to FPC 716 via conductors 461, 463, 465, 467, 469, 471, 453, 455, 305, 317, 337, 347, 353, 355, 357, connecting electrode 760, and anisotropic conductor 780.

[0305] Insulators 613, 614, 680, 674, 681, 501, 503, 505, 507 and 509 are used as interlayer films, or as planarization films covering the uneven shapes below them respectively.

[0306] By adopting the structure of the display device 810 shown in Figures 29 and 30, OS transistors can be used for all transistors in the display device 810 while achieving narrow bezels and miniaturization. Therefore, for example, the transistors disposed in layer 820 and the transistors disposed in layer 830 can be manufactured using the same equipment. This reduces the manufacturing cost of the display device 810 and provides a low-cost display device 810.

[0307] <Example 3 of Display Device Structure> Figures 31A and 31B are top views illustrating a structural example of a sub-pixel 901 of a display device applicable to one embodiment of the present invention. The sub-pixel 901 can be the circuit structure shown in Figure 22B. Here, the transistor 552 includes a back gate in addition to a gate, which is electrically connected to wiring 831. Furthermore, the transistor 554 includes a back gate in addition to a gate, which is electrically connected to another of the source and drain electrodes of the transistor 554, another electrode in the capacitor 562, and one electrode of the light-emitting element 572.

[0308] Figure 31A shows the conductors and semiconductors, such as transistors, capacitors, and wiring, that constitute the sub-pixel 901. Figure 31B shows, in addition to the structure shown in Figure 31A, a conductor 772 that serves as one electrode in the light-emitting element 572. Furthermore, both Figures 31A and 31B omit the conductors that serve as the other electrode in the light-emitting element 572. Here, one electrode in the light-emitting element 572 serves as a pixel electrode, while the other electrode in the light-emitting element 572 serves as a common electrode.

[0309] As shown in Figures 31A and 31B, sub-pixel 901 includes conductor 911, conductor 912, semiconductor 913, semiconductor 914, conductor 915a, conductor 915b, conductor 916a, conductor 916b, conductor 917, conductor 918, conductor 919, conductor 920, conductor 921, conductor 922, conductor 923, conductor 924, conductor 925, conductor 926, conductor 927, conductor 928, conductor 929, conductor 930, conductor 931, and conductor 772.

[0310] Conductors 911 and 912 are formed using the same process. Semiconductors 913 and 914 are formed using the same process, and are formed after conductors 911 and 912. Conductors 915a and 915b, and conductors 916a and 916b are formed using the same process, and are formed after conductors 911 and 912. Conductors 917 and 918 are formed using the same process, and are formed after semiconductors 913 and 914, and conductors 915a, 915b, 916a, and 916b.

[0311] Conductors 919 to 923 are formed through the same process, and are formed after conductors 917 and 918. Conductor 924 is formed after conductors 919 to 923. Conductors 925 to 928 are formed through the same process, and are formed after conductor 924. Conductors 929 to 931 are formed through the same process, and are formed after conductors 925 to 928. Conductor 772 is formed after conductors 929 to 931.

[0312] In this specification, components formed through the same process are disposed in the same layer. For example, since conductors 911 and 912 can be formed through the same process, conductors 911 and 912 can be disposed in the same layer. Furthermore, components formed through a later process are disposed in a layer above components formed through a previous process. For example, since conductors 929 to 931 can be formed through a process following conductors 925 to 928, they can be disposed in a layer above conductors 925 to 928.

[0313] Conductor 911 serves as the back gate electrode of transistor 552. Semiconductor 913 contains a channel forming region for transistor 552. Conductor 915a serves as one of the source electrode and drain electrode of transistor 552. Conductor 915b serves as the other of the source electrode and drain electrode of transistor 552. Conductor 917 serves as the gate electrode of transistor 552.

[0314] Conductor 912 serves as the back gate electrode of transistor 554. Semiconductor 914 contains a channel forming region for transistor 554. Conductor 916a serves as one of the source and drain electrodes of transistor 554. Conductor 916b serves as the other of the source and drain electrodes of transistor 554. Conductor 918 serves as the gate electrode of transistor 554.

[0315] Conductor 919 serves as one electrode in capacitor 562. Conductor 924 serves as another electrode in capacitor 562. Conductor 925 corresponds to wiring 831, which serves as a scan line. Conductor 929 corresponds to wiring 832, which serves as a data line. Conductor 930 corresponds to wiring 835a, which serves as a power line. As described above, conductor 772 serves as one electrode in light-emitting element 572.

[0316] Conductor 911 is electrically connected to conductor 920. Conductor 912 is electrically connected to conductor 923. Conductor 915a is electrically connected to conductor 921. Conductor 915b is electrically connected to conductor 919. Conductor 916a is electrically connected to conductor 922.

[0317] Conductor 916b is electrically connected to conductor 923. That is, conductor 912, which serves as the back gate electrode of transistor 554, is electrically connected to conductor 916b, which serves as the other of the source and drain electrodes of transistor 554, via conductor 923.

[0318] Conductor 917 is electrically connected to conductor 920. That is, conductor 911, which serves as the back gate electrode of transistor 552, and conductor 917, which serves as the gate electrode of transistor 552, are electrically connected by conductor 920.

[0319] Conductor 920 is electrically connected to conductor 925. That is, conductor 917, which serves as the gate electrode of transistor 552, and conductor 925, which serves as the scan line, are electrically connected via conductor 920.

[0320] Conductors 918 and 919 are electrically connected. Conductors 921 and 926 are electrically connected. Conductors 922 and 927 are electrically connected. Conductors 923 and 928 are electrically connected. Conductors 924 and 928 are electrically connected.

[0321] Conductor 926 is electrically connected to conductor 929. That is, conductor 915a, which serves as one of the source and drain electrodes of transistor 552, is electrically connected to conductor 929, which serves as a data line, via conductor 921 and conductor 926.

[0322] Conductor 927 is electrically connected to conductor 930. That is, conductor 916a, which serves as one of the source and drain electrodes of transistor 554, is electrically connected to conductor 930, which serves as a power line, via conductor 922 and conductor 927.

[0323] Conductor 928 is electrically connected to conductor 931. Conductor 931 is electrically connected to conductor 772.

[0324] Semiconductors 913 and 914 may, for example, comprise metal oxides. Therefore, transistors 552 and 554 can be OS transistors.

[0325] Figure 32 is a top view showing a structural example of a pixel 902 composed of sub-pixels 901 having the structure shown in Figure 31B. In Figure 32, sub-pixel 901R represents a sub-pixel 901 that emits red light, sub-pixel 901G represents a sub-pixel 901 that emits green light, and sub-pixel 901B represents a sub-pixel 901 that emits blue light. As shown in Figure 32, pixel 902 is composed of sub-pixels 901R, 901G, and 901B. Specifically, a pixel 902 is composed of sub-pixels 901R and 901B located at a higher level and sub-pixels 901G located at a lower level. Furthermore, a pixel 902 is composed of sub-pixels 901G located at a higher level and sub-pixels 901R and 901B located at a lower level.

[0326] In Figure 32, sub-pixels 901R, 901G, and 901B in the upper level and sub-pixels 901R, 901G, and 901B in the lower level each have a left-right flipping structure. By employing this structure, sub-pixels 901 of the same color are alternately arranged in the extension direction of the conductor 925 used as a scan line. Thus, a data line can be electrically connected to a sub-pixel 901 that emits light of the same color. In other words, it is possible to prevent two or more sub-pixels 901 of 901R, 901G, and 901B from being electrically connected to a single data line.

[0327] Figure 33 is a cross-sectional view along the portion shown by the dashed line A1-A2 in Figure 31B. Transistors 552 and 554 are disposed on insulator 1021. Furthermore, insulator 1022 is disposed on transistors 552 and 554, and insulator 1023 is disposed on insulator 1022. A substrate is disposed in a layer below insulator 1021. Furthermore, an assembly of layer 820 (such as gate drive circuit 821, source drive circuit 822, and circuit 840) shown in Figure 8 can be disposed between the substrate and insulator 1021.

[0328] As shown in Figure 33, the conductors disposed in different layers are electrically connected by conductors 990, which serve as plugs. For example, conductor 915a and conductor 921 in the layer above conductor 915a are electrically connected by conductor 990. Conductor 990 can adopt the same structure as conductors 453, 305, 337, 353, 355, 357, 301a, 301b, 331, 351, 333, and 335 shown in Figure 27, etc.

[0329] An insulator 1024 is provided on conductors 919 to 923 and on insulator 1023. A conductor 924 is provided on insulator 1024. Capacitor 562 is composed of conductors 919, insulator 1024 and conductor 924.

[0330] An insulator 1025 is provided on the conductor 924 and the insulator 1024. An insulator 1026 is provided on the conductors 925 to 928 and the insulator 1025. An insulator 1027 is provided on the conductors 929 to 931 and the insulator 1026.

[0331] Conductor 772 and insulator 730 are disposed on insulator 1027. Here, insulator 730 may cover a portion of conductor 772. Light-emitting element 572 is composed of conductor 772, EL layer 786 and conductor 788.

[0332] An adhesive layer 991 is provided on the conductor 788, and an insulator 992 is provided on the adhesive layer 991. The insulator 992 on the adhesive layer 991 can be formed by the following process: First, the insulator 992 is formed on a substrate different from the substrate on which the light-emitting element 572 is formed. Next, the conductor 788 and the insulator 992 are bonded together using the adhesive layer 991. Then, the substrate on which the insulator 992 is formed is peeled off. Through the above process, the insulator 992 can be formed on the conductor 788.

[0333] A color layer 993 is provided on the insulator 992. In FIG33, color layers 993a and 993b are shown as color layers 993. The substrate 995 is attached to the color layer 993 by an adhesive layer 994.

[0334] Color layer 993b has the function of transmitting light of a different color than color layer 993a. For example, if pixel 902 is composed of sub-pixel 901R which has the function of emitting red light, sub-pixel 901G which has the function of emitting green light, and sub-pixel 901B which has the function of emitting blue light, and color layer 993a has the function of transmitting red light, then color layer 993b has the function of transmitting green light or blue light.

[0335] By forming a color layer 993 on the insulator 992, the positions of the color layer 993 and the light-emitting element 572 can be easily aligned. This improves the clarity of the display device according to one embodiment of the present invention.

[0336] <Example 4 of Display Device Structure> Figure 34A shows a schematic diagram of a structural example of a sub-pixel 940 of a display device applicable to one embodiment of the present invention. The sub-pixel 940 can employ a stacked structure of sub-pixels 940_1 and 940_2. The sub-pixel 940 can be the circuit structure shown in Figure 24E. Here, transistors 511 and 529 include a back gate in addition to a gate, which is electrically connected to wiring 831_1. Furthermore, transistor 513 includes a back gate electrically connected to wiring 831_2. Moreover, transistor 521 includes a back gate electrically connected to another electrode in capacitor 517 and one electrode in light-emitting element 572.

[0337] Figure 34B is a top view showing a structural example of sub-pixel 940_1. Figure 34B shows the conductors and semiconductors, such as transistors, capacitors, and wiring, that constitute sub-pixel 940_1.

[0338] As shown in Figure 34B, sub-pixel 940_1 includes conductor 951, semiconductor 952, semiconductor 953, conductor 954a, conductor 954b, conductor 955a, conductor 955b, conductor 956, conductor 957, conductor 958, conductor 959, conductor 960, conductor 961, conductor 962, conductor 963, conductor 964, conductor 965, conductor 966 and conductor 967.

[0339] Semiconductor 952 and semiconductor 953 are formed in the same process and are formed after conductor 951. Conductors 954a and 954b, conductors 955a and 955b are formed in the same process and are formed after conductor 951. Conductors 956 and 957 are formed in the same process and are formed after semiconductor 952 and semiconductor 953, conductors 954a, conductor 954b, conductors 955a and 955b.

[0340] Conductors 958 to 962 are formed in the same process and are formed in the process following conductors 956 and 957. Conductor 963 is formed in the process following conductors 958 to 962. Conductors 964 to 967 are formed in the same process and are formed in the process following conductor 963.

[0341] Conductor 951 serves as the back gate electrode of transistors 511 and 529. Conductor 951 is equivalent to wiring 831_1 used as a scan line.

[0342] Semiconductor 952 contains a channel forming region for transistor 511. Conductor 954a serves as one of the source electrode and drain electrode of transistor 511. Conductor 954b serves as the other of the source electrode and drain electrode of transistor 511. Conductor 956 serves as the gate electrode of transistor 511.

[0343] Semiconductor 953 contains a channel forming region for transistor 529. Conductor 955a serves as one of the source electrode and drain electrode of transistor 529. Conductor 955b serves as the other of the source electrode and drain electrode of transistor 529. Conductor 957 serves as the gate electrode of transistor 529.

[0344] Conductor 958 serves as one electrode in capacitor 515. Conductor 963 serves as the other electrode in capacitor 515. Conductor 964 corresponds to wiring 832-1 used as a data line. Conductor 965 corresponds to wiring 543 used as a power line.

[0345] Conductor 951 is electrically connected to conductor 962. Conductor 954a is electrically connected to conductor 959. Conductor 954b is electrically connected to conductor 958. Conductor 955a is electrically connected to conductor 960. Conductor 955b is electrically connected to conductor 961.

[0346] Conductors 956 and 957 are electrically connected to conductor 962. That is, conductor 951, which serves as the back gate electrode of transistors 511 and 529 and is equivalent to wiring 831_1 used as a scan line, is electrically connected to conductor 956, which serves as the gate electrode of transistor 511, and conductor 957, which serves as the gate electrode of transistor 529, via conductor 962.

[0347] Conductor 959 is electrically connected to conductor 964. That is, conductor 954a, which serves as one of the source and drain electrodes of transistor 511, is electrically connected to conductor 964, which serves as a data line, via conductor 959.

[0348] Conductor 960 is electrically connected to conductor 965. That is, conductor 955a, which serves as one of the source electrode and drain electrode of transistor 529, is electrically connected to conductor 965, which serves as a power line, via conductor 960.

[0349] Conductor 961 is electrically connected to conductor 967. Conductor 963 is electrically connected to conductor 966.

[0350] Semiconductors 952 and 953 may, for example, comprise metal oxides. Therefore, transistors 511 and 529 can be OS transistors.

[0351] Figure 35A shows the conductors and semiconductors, such as transistors, capacitors, and wiring, that constitute sub-pixel 940_2. Figure 35B shows the structure shown in Figure 35A, as well as the conductor 772, which serves as one electrode in the light-emitting element 572. Furthermore, both Figures 35A and 35B omit the conductors, etc., that serve as the other electrode in the light-emitting element 572.

[0352] As shown in Figures 35A and 35B, sub-pixel 940_2 includes conductor 968, conductor 969, conductor 970, semiconductor 971, semiconductor 972, conductor 973a, conductor 973b, conductor 974a, conductor 974b, conductor 975, conductor 976, conductor 977, conductor 978, conductor 979, conductor 980, conductor 981, conductor 982, conductor 983, conductor 984, conductor 985, conductor 986, conductor 987, and conductor 772.

[0353] Conductors 968 to 970 are formed using the same process. Semiconductors 971 and 972 are formed using the same process and are formed after conductors 968 to 970. Conductors 973a and 973b, conductors 974a and 974b are formed using the same process and are formed after conductors 968 to 970. Conductors 975 and 976 are formed using the same process and are formed after semiconductors 971 and 972, conductors 973a, 973b, 974a, and 974b.

[0354] Conductors 977 to 981 are formed through the same process, and are formed after conductors 975 and 976. Conductor 982 is formed after conductors 977 to 981. Conductors 983 to 985 are formed through the same process, and are formed after conductor 982. Conductors 986 and 987 are formed through the same process, and are formed after conductors 983 to 985. Conductor 772 is formed after conductors 986 and 987.

[0355] Conductor 968 serves as the back gate electrode of transistor 513 and corresponds to wiring 831_2 used as a scan line. Semiconductor 971 contains a channel forming region for transistor 513. Conductor 973a serves as one of the source and drain electrodes of transistor 513. Conductor 973b serves as the other of the source and drain electrodes of transistor 513. Conductor 975 serves as the gate electrode of transistor 513.

[0356] Conductor 970 serves as the back gate electrode of transistor 521. Semiconductor 972 contains a channel forming region for transistor 521. Conductor 974a serves as one of the source and drain electrodes of transistor 521. Conductor 974b serves as the other of the source and drain electrodes of transistor 521. Conductor 976 serves as the gate electrode of transistor 521.

[0357] Conductor 977 serves as one electrode in capacitor 517. Conductor 982 serves as the other electrode in capacitor 517. Conductor 983 corresponds to wiring 832-2 used as a data line. Conductor 986 corresponds to wiring 537 used as a power line. As described above, conductor 772 serves as one electrode in light-emitting element 572.

[0358] Conductor 968 is electrically connected to conductor 978. Conductor 969 is electrically connected to conductor 977. Conductor 970 is electrically connected to conductor 981. Conductor 973a is electrically connected to conductor 979. Conductor 973b is electrically connected to conductor 977. Conductor 974a is electrically connected to conductor 980.

[0359] Conductor 974b is electrically connected to conductor 981. That is, conductor 970, which serves as the back gate electrode of transistor 521, is electrically connected to conductor 974b, which serves as the other of the source and drain electrodes of transistor 521, via conductor 981.

[0360] Conductor 975 is electrically connected to conductor 978. That is, conductor 968, which serves as the back gate electrode of transistor 513, and conductor 975, which serves as the gate electrode of transistor 513, are electrically connected via conductor 978. In addition, conductor 976 is electrically connected to conductor 977.

[0361] Conductor 979 is electrically connected to conductor 983. That is, conductor 973a, which serves as one of the source electrode and drain electrode of transistor 513, is electrically connected to conductor 983, which serves as a data line, via conductor 979.

[0362] Conductor 980 is electrically connected to conductor 984. Conductor 981 is electrically connected to conductor 985. Conductor 982 is electrically connected to conductor 985.

[0363] Conductor 984 is electrically connected to conductor 986. That is, conductor 974a, which serves as one of the source and drain electrodes of transistor 521, is electrically connected to conductor 986, which serves as a data line, via conductor 980 and conductor 984.

[0364] Conductor 985 is electrically connected to conductor 987. Conductor 987 is electrically connected to conductor 772.

[0365] Semiconductors 971 and 972 may, for example, comprise metal oxides. Therefore, transistors 513 and 521 can be OS transistors.

[0366] Figure 36 is a top view showing the stacked structure of sub-pixels 940_1 and 940_2, and illustrating the electrical connection between sub-pixels 940_1 and 940_2. For ease of understanding, the conductor 772, which serves as a pixel electrode, disposed in sub-pixel 940_2, is not shown.

[0367] As shown in Figure 36, conductor 966 in sub-pixel 940_1 and conductor 969 in sub-pixel 940_2 are electrically connected. Therefore, the other electrode of capacitor 515 in sub-pixel 940_1 can be electrically connected to the other electrode of source and drain of transistor 513 in sub-pixel 940_2, the gate of transistor 521, and one electrode of capacitor 517. Furthermore, conductor 967 in sub-pixel 940_1 and conductor 970 in sub-pixel 940_2 are electrically connected. Therefore, the other electrode of source and drain of transistor 529 in sub-pixel 940_1 can be electrically connected to the other electrode of capacitor 517 in sub-pixel 940_2, the other electrode of source and drain of transistor 521, and one electrode of light-emitting element 572.

[0368] Figure 37 is a top view showing a structural example of a pixel 941 composed of sub-pixels 940 having the structures shown in Figures 34B and 35B. In Figure 37, sub-pixel 940R represents a sub-pixel 940 that emits red light, sub-pixel 940G represents a sub-pixel 940 that emits green light, and sub-pixel 940B represents a sub-pixel 940 that emits blue light. As shown in Figure 37, pixel 941 is composed of sub-pixels 940R, 940G, and 940B. Specifically, a pixel 941 is composed of sub-pixels 940R and 940B located at a higher level and sub-pixels 940G located at a lower level. Furthermore, a pixel 941 is composed of sub-pixels 940G located at a higher level and sub-pixels 940R and 940B located at a lower level.

[0369] In Figure 37, sub-pixels 940R, 940G, and 940B in the upper level and sub-pixels 940R, 940G, and 940B in the lower level each have a left-right flipping structure. By employing this structure, sub-pixels 940 of the same color are alternately arranged in the extending directions of the conductors 951 and 968, which serve as scan lines. Thus, a data line can be electrically connected to a sub-pixel 940 that emits light of the same color. In other words, it is possible to prevent two or more sub-pixels 940R, 940G, and 940B from being electrically connected to a single data line.

[0370] Figure 38 is a cross-sectional view along the portion shown by the dotted lines A3-A4 in Figures 34B and 35B. A transistor 511 and a transistor 529, which are transistors disposed in sub-pixel 940_1, are disposed on the insulator 1031. Furthermore, an insulator 1032 is disposed on the transistors 511 and 529, and an insulator 1033 is disposed on the insulator 1032. A substrate is disposed in a layer below the insulator 1031. Furthermore, components of layer 820 shown in Figure 8 (gate drive circuit 821, source drive circuit 822, circuit 840, etc.) can be disposed between the substrate and the insulator 1031.

[0371] As shown in Figure 38, the conductors disposed in different layers are electrically connected by the conductor 990, which is used as a plug.

[0372] An insulator 1034 is provided on conductors 958 to 962 and an insulator 1033. A conductor 963 is provided on the insulator 1034. The capacitor 515 is composed of conductors 958, insulator 1034, and conductor 963.

[0373] An insulator 1035 is provided on the conductor 963 and the insulator 1034. An insulator 1036 is provided on the conductors 964 to 967.

[0374] A transistor 513 and a transistor 521, which are transistors disposed in sub-pixel 940_2, are disposed on an insulator 1036. Furthermore, an insulator 1042 is disposed on the transistors 513 and 521, and an insulator 1043 is disposed on the insulator 1042.

[0375] An insulator 1044 is provided on conductors 977 to 981 and on insulator 1043. A conductor 982 is provided on insulator 1044. Capacitor 517 is composed of conductors 977, insulator 1044 and conductor 982.

[0376] An insulator 1045 is provided on the conductor 982 and the insulator 1044. An insulator 1046 is provided on the conductors 983 to 985 and the insulator 1045. An insulator 1047 is provided on the conductors 986, 987 and the insulator 1046.

[0377] Conductors 772 and insulator 730 are disposed on insulator 1047. Here, similar to the case shown in FIG33, insulator 730 may cover a portion of conductor 772. Light-emitting element 572 is composed of conductor 772, EL layer 786 and conductor 788.

[0378] Similar to the case shown in Figure 33, an adhesive layer 991 is provided on the conductor 788, and an insulator 992 is provided on the adhesive layer 991. Furthermore, a color layer 993 is provided on the insulator 992, and the substrate 995 is attached to the color layer 993 by the adhesive layer 994.

[0379] <Structure Examples of Light-Emitting Elements> Figures 39A to 39E show structural examples of the light-emitting element 572. Figure 39A shows a structure (single-layer structure) with an EL layer 786 sandwiched between conductor 772 and conductor 788. As described above, the EL layer 786 contains a light-emitting material, for example, an organic compound as the light-emitting material.

[0380] Figure 39B is a diagram showing the stacked structure of the EL layer 786. Here, in the light-emitting element 572 having the structure shown in Figure 39B, the conductor 772 serves as the anode and the conductor 788 serves as the cathode.

[0381] The EL layer 786 has a structure in which a hole injection layer 721, a hole transport layer 722, a light-emitting layer 723, an electron transport layer 724, and an electron injection layer 725 are sequentially stacked on the conductor 772. Furthermore, when the conductor 772 is used as the cathode and the conductor 788 is used as the anode, the stacking order is reversed.

[0382] The luminescent layer 723, by appropriately combining luminescent materials and multiple materials, has a structure capable of achieving fluorescent and phosphorescent emission with the desired emission color. Furthermore, the luminescent layer 723 can also be a stacked structure with different emission colors. In this case, the luminescent material or other substances used for each luminescent layer can be different materials.

[0383] In the light-emitting element 572, for example, by using the conductor 772 shown in FIG39B as a reflective electrode, the conductor 788 as a transmissive and reflective electrode, and employing an optical microcavity resonator (microcavity) structure, the light obtained from the light-emitting layer 723 in the EL layer 786 can resonate between the electrodes, thereby enhancing the light emitted through the conductor 788.

[0384] When the conductor 772 of the light-emitting element 572 is a reflective electrode composed of a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by adjusting the thickness of the transparent conductive film. Specifically, it is preferable to adjust it in such a way that the distance between the electrodes of the conductor 772 and the conductor 788 is approximately mλ / 2 (note that m is a natural number) relative to the wavelength λ of the light obtained from the light-emitting layer 723.

[0385] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 723, it is preferable to adjust the optical distances as follows: the optical distance from the conductor 772 to the region (light-emitting area) where the desired light from the light-emitting layer 723 can be obtained, and the optical distance from the conductor 788 to the region (light-emitting area) where the desired light from the light-emitting layer 723 can be obtained, are both approximately (2m'+1)λ / 4 (note that m' is a natural number). Note that the "light-emitting area" explained here refers to the recombination region of holes and electrons in the light-emitting layer 723.

[0386] By making the above optical adjustments, the spectrum of specific monochromatic light that can be obtained from the light-emitting layer 723 can be narrowed, thereby obtaining light emission with good color purity.

[0387] Furthermore, in the above-described case, strictly speaking, the optical distance between conductor 772 and conductor 788 can be considered as the total thickness from the reflective region in conductor 772 to the reflective region in conductor 788. However, since it is difficult to accurately determine the position of the reflective region in conductor 772 or conductor 788, the aforementioned effect can be sufficiently obtained by assuming any position in conductor 772 or conductor 788 as the reflective region. Furthermore, strictly speaking, the optical distance between conductor 772 and the light-emitting layer from which the desired light is obtained can be considered as the optical distance between the reflective region in conductor 772 and the light-emitting region in the light-emitting layer from which the desired light is obtained. However, since it is difficult to accurately determine the position of the reflective region in conductor 772 or the light-emitting region in the light-emitting layer from which the desired light is obtained, the aforementioned effect can be sufficiently obtained by assuming any position in conductor 772 as the reflective region and any position in the light-emitting layer from which the desired light is obtained as the light-emitting region.

[0388] The light-emitting element 572 shown in Figure 39B has a microcavity structure, so it can extract light of different wavelengths (monochromatic light) even with the same EL layer. Therefore, it is not necessary to separately coat the layers (e.g., R, G, B) to obtain different emission colors. This facilitates the achievement of high resolution. Furthermore, it can be combined with a color layer. Moreover, the emission intensity in the front direction with a specific wavelength can be enhanced, thereby achieving low power consumption.

[0389] The light-emitting element 572 shown in Figure 39B may also not have a microcavity structure. In this case, by emitting white light through the light-emitting layer 723 and providing a color layer, light of a specified color (such as RGB) can be extracted. Alternatively, when forming the EL layer 786, by coating it separately to obtain different emission colors, light of a specified color can be extracted without providing a color layer.

[0390] At least one of conductors 772 and 788 is a light-transmitting electrode (transparent electrode, transmissive / reflective electrode, etc.). When the light-transmitting electrode is a transparent electrode, its visible light transmittance is 40% or more. Furthermore, when the electrode is a transmissive / reflective electrode, its visible light reflectance is 20% or more and 80% or less, preferably 40% or more and 70% or less. Additionally, the resistivity of these electrodes is preferably 1 × 10⁻² Ωcm or less.

[0391] When conductor 772 or conductor 788 is a reflective electrode (reflective electrode), 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. Furthermore, the resistivity of the electrode is preferably 1 × 10⁻² Ωcm or less.

[0392] The structure of the light-emitting element 572 can be as shown in FIG. 39C. FIG. 39C shows a light-emitting element 572 with a stacked structure (series structure) having two EL layers (EL layer 786a and EL layer 786b) disposed between conductor 772 and conductor 788, and a charge generating layer 792 disposed between EL layer 786a and EL layer 786b. By having the light-emitting element 572 have a series structure, the current efficiency and external quantum efficiency of the light-emitting element 572 can be improved. As a result, high-brightness images can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be reduced. Here, EL layer 786a and EL layer 786b can have the same structure as EL layer 786 shown in FIG. 39B.

[0393] The charge generation layer 792 has the function of injecting electrons into one of the EL layers 786a and 786b and injecting holes into the other when a voltage is supplied to the conductors 772 and 788. Therefore, when a voltage is supplied such that the potential of the conductor 772 is higher than that of the conductor 788, electrons are injected into the EL layer 786a and holes are injected into the EL layer 786b from the charge generation layer 792.

[0394] Furthermore, from the viewpoint of light extraction efficiency, the charge generation layer 792 is preferably designed to allow visible light to pass through (specifically, the visible light transmittance of the charge generation layer 792 is 40% or higher). Additionally, the electrical conductivity of the charge generation layer 792 can be lower than that of the conductor 772 or the conductor 788.

[0395] The structure of the light-emitting element 572 can be as shown in FIG. 39D. FIG. 39D shows a light-emitting element 572 with a series structure in which three EL layers (EL layer 786a, EL layer 786b, and EL layer 786c) are disposed between the conductor 772 and the conductor 788, and a charge generation layer 792 is disposed between EL layer 786a and EL layer 786b and between EL layer 786b and EL layer 786c. Here, EL layer 786a, EL layer 786b, and EL layer 786c can have the same structure as EL layer 786 shown in FIG. 39B. By making the light-emitting element 572 have the structure shown in FIG. 39D, the current efficiency and external quantum efficiency of the light-emitting element 572 can be further improved. As a result, a brighter image can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be further reduced.

[0396] The structure of the light-emitting element 572 can be as shown in FIG39E. FIG39E shows a light-emitting element 572 with a series structure in which n EL layers (EL layers 786(1) to EL layers 786(n)) are disposed between conductors 772 and conductors 788, and charge generating layers 792 are disposed between each EL layer 786. Here, EL layers 786(1) to EL layers 786(n) can have the same structure as EL layer 786 shown in FIG39B. In addition, FIG39E shows EL layer 786(1), EL layer 786(m), EL layer 786(m+1) and EL layer 786(n) in EL layer 786. Here, m is an integer greater than or equal to 2 and less than n, and n is an integer greater than m. The larger the value of n, the higher the current efficiency and external quantum efficiency of the light-emitting element 572 can be. As a result, high-brightness images can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be reduced.

[0397] <Materials Constituting Light-Emitting Elements> Next, the constituent materials that can be used in the light-emitting element 572 will be described.

[0398] Conductor 772 and Conductor 788 As conductors 772 and 788, the following materials can be appropriately combined if they can satisfy the functions of the two electrodes described above. For example, metals, alloys, conductive compounds, and mixtures thereof can be appropriately used. Specifically, examples include In-Sn oxide (also known as ITO), In-Si-Sn oxide (also known as ITSO), In-Zn oxide, and In-W-Zn oxide. In addition to the above, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), and neodymium (Nd), as well as alloys appropriately combined therein, can also be used. In addition to the above, elements belonging to Group 1 or Group 2 of the periodic table (e.g., rare earth metals such as lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), alloys of them appropriately combined, and graphene, etc.) can be used.

[0399] Hole Injection Layer 721 and Hole Transport Layer 722 The hole injection layer 721 is a layer in which holes are injected from the conductor 772 of the anode or the charge generation layer 792 into the EL layer 786, and contains a material with high hole injection capability. Here, the EL layer 786 includes EL layers 786a, EL layers 786b, EL layers 786c, EL layers 786(1) to EL layers 786(n).

[0400] Materials with high hole injection properties include transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. In addition to the above, phthalocyanine compounds such as phthalocyanine (H2Pc) and copper phthalocyanine (CuPc) can be used; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB) and N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (DNTPD) can be used; or polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) can be used.

[0401] As a material with high hole injection capability, a composite material containing a hole transport material and an acceptor material (electron acceptor material) can also be used. In this case, electrons are extracted from the hole transport material by the acceptor material to generate a hole in the hole injection layer 721, and the hole is injected into the light-emitting layer 723 through the hole transport layer 722. Furthermore, the hole injection layer 721 can be a single layer composed of a composite material containing a hole transport material and an acceptor material (electron acceptor material), or it can be a stack of layers formed using hole transport materials and acceptor materials (electron acceptor materials) respectively.

[0402] The hole transport layer 722 is a layer that transports holes injected from the conductor 772 through the hole injection layer 721 to the light-emitting layer 723. Furthermore, the hole transport layer 722 is a layer containing a hole-transporting material. As the hole-transporting material for the hole transport layer 722, it is particularly preferred to use a material having a HOMO level that is the same as or similar to the HOMO level of the hole injection layer 721.

[0403] As the acceptor material for the hole injection layer 721, oxides of metals belonging to Groups 4 to 8 of the periodic table can be used. Specifically, examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition to the above, organic acceptors such as quinone dimethyl derivatives, tetrachlorobenzoquinone derivatives, and hexaazatribenzene derivatives can be used. Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethyl (abbreviated: F4-TCNQ), chloroquinone, and 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatribenzene (abbreviated: HAT-CN) can be used.

[0404] The hole transport material used in the hole injection layer 721 and the hole transport layer 722 is preferably a material having a hole mobility of 10⁻⁶ cm² / Vs or higher. Furthermore, any material other than those mentioned above can be used as long as its hole transportability is higher than its electron transportability.

[0405] As hole-transporting materials, π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives or indole derivatives) or aromatic amine compounds are preferred. Specific examples include: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviated as TPD), 4,4'-bis[N-(spiro-9,9'-bifuran-2-yl)-N-phenylamino]biphenyl (abbreviated as BSPB), 4-phenyl-4'-(9-phenyl) 4-Phenylacetyl-9-yl)triphenylamine (abbreviated as: BPAFLP), 4-Phenylacetyl-3'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: mBPAFLP), 4-Phenylacetyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), 3-[4-(9-phenanthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as: PCPPn), N-(4-biphenyl)-N-(9,9-dimethyl-9H-phenanthyl)-9-phenyl-9H-carbazole-3-amine (abbreviated as: PCPiF), N-(1,1'-biphenyl-4-yl)-N -[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-enazol-2-amine (abbreviation: PCBBiF), 4,4'-diphenyl-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4”-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCNBB), 9,9-dimethyl-N-phenyl-N-[4-( Compounds with aromatic amine skeletons include 9-phenyl-9H-carbazole-3-yl)phenyl]enzo-2-amine (PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]spiro-9,9'-dienzo-2-amine (PCBASF), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), 4,4',4”-tris(N,N-diphenylamino)triphenylamine (TDATA), and 4,4',4”-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (MTDATA).1,3-Bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9H-carbazole) Compounds with a carbazole skeleton, such as PCCP, 3-[N-(9-phenylcarbazole-3-yl)-N-anilino]-9-phenylcarbazole (PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-anilino]-9-phenylcarbazole (PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (PCzPCN1), 1,3,5-tris[4-(N-carbazole-3-yl)phenyl]benzene (TCPB), and 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (CzPA); 4,4',4”-(benzene-1,3, Compounds with a thiophene skeleton, such as 5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-prostaglandin-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-prostaglandin-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV); and compounds with a furan skeleton, such as 4,4',4”-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-prostaglandin-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II).

[0406] Furthermore, other polymers such as poly(N-vinylcarbazole) (PVK), poly(4-vinyltriphenylamine) (PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (Poly-TPD) can also be used.

[0407] Note that the hole transport material is not limited to the materials mentioned above; one or more of a variety of known materials can be combined to serve as the hole transport material for both the hole injection layer 721 and the hole transport layer 722. Furthermore, the hole transport layer 722 can also be composed of multiple layers. That is, for example, a first hole transport layer and a second hole transport layer can be stacked.

[0408] "Emitting Layer 723" The light-emitting layer 723 is a layer containing a light-emitting material. Furthermore, as the light-emitting material, materials exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used. Here, as shown in Figures 39C to 39E, when the light-emitting element 572 has multiple EL layers, by using different light-emitting materials in the light-emitting layer 723 disposed in each EL layer, a structure exhibiting different light-emitting colors can be achieved (for example, white light emission can be obtained by combining light-emitting colors that are complementary colors). For example, when the light-emitting element 572 has the structure shown in Figure 39C, by using different light-emitting materials between the light-emitting layer 723 disposed in EL layer 786a and the light-emitting layer 723 disposed in EL layer 786b, the light emission color of EL layer 786a can be different from the light emission color of EL layer 786b. Furthermore, a stacked structure with different light-emitting materials in one light-emitting layer is also possible.

[0409] In addition to the luminescent material (guest material), the luminescent layer 723 may also contain one or more organic compounds (host material, auxiliary material). Furthermore, one or both of hole transport materials and electron transport materials may be used as one or more organic compounds.

[0410] When the light-emitting element 572 has the structure shown in FIG. 39C, it is preferable to use a blue-emitting material (blue emitting material) as the guest material in either EL layer 786a or EL layer 786b, and to use a green-emitting material (green emitting material) and a red-emitting material (red emitting material) in the other. This method is effective when the luminous efficiency and lifespan of the blue emitting material (blue emitting layer) are lower or shorter than those of other colors. Furthermore, here, when a emitting material that converts single excitation energy into light in the visible light region is used as the blue emitting material, and a emitting material that converts triple excitation energy into light in the visible light region is used as the green and red emitting materials, the RGB spectrum is well balanced, which is preferable.

[0411] There are no particular limitations on the luminescent material that can be used in the luminescent layer 723. A luminescent material that converts single excitation energy into light in the visible light region or a luminescent material that converts triple excitation energy into light in the visible light region can be used. Furthermore, examples of such luminescent materials include the following:

[0412] As luminescent substances that convert singlet excitation energy into light emission, examples include fluorescent materials, such as pyrene derivatives, anthracene derivatives, triphenylene derivatives, fenestration derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoline derivatives, quinoline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives, in particular, exhibit high luminescence quantum yield and are therefore preferred. Specific examples of pyrene derivatives include N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-en-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6mMemFLPAPrn), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-en-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviated as: 1,6FrAPrn), and N,N'-bis(dibenzothiophene-2-yl)-N,N' 1,6-Diphenylpyrene-1,6-diamine (abbreviated as: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviated as: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviated as: 1,6BnfAPrn-03), etc. Furthermore, pyrene derivatives are a group of compounds effective in achieving the blue hue in one embodiment of the present invention.

[0413] In addition to the above, 5,6-bis[4-(10-phenyl-9-anthrayl)phenyl]-2,2'-bipyridine (abbreviated as: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthrayl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as: PAPP2BPy), and N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviated as: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), 4-(10) 4-[4-(10-phenyl-9-anthrayl)phenyl]-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCPAPA), 4-[4-(10-phenyl-9-anthrayl)phenyl]-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCPABA), perylene, 2,5,8,11-tetra(tertiary butyl)perylene (abbreviation: TBP), N,N”-(2-tertiary butylanthracene-9,10-diyldi-4-yl) Examples of N,N',N'-triphenyl-1,4-phenylenediamine include: DPABPA (N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (2PCAPPA), and 2DPAPPA (N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine).

[0414] Examples of luminescent materials that convert triple excitation energy into light emission include phosphorescent materials that emit phosphorescence or thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0415] Examples of phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare-earth metal complexes. Each of these materials exhibits a different emission color (emission peak), thus requiring appropriate selection based on specific needs.

[0416] Examples of phosphorescent materials that exhibit blue or green color and whose emission spectrum has a peak wavelength of 450 nm or higher and 570 nm or lower include the following substances.

[0417] Examples include tri{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as: [Ir(mpptz-dmp)3]), tri(5-methyl-3,4-diphenyl-4H-1,2,4-triazol(triazolato))iridium(III) (abbreviated as: [Ir(Mptz)3]), and tri[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazol(triazolato)]iridium(III) (abbreviated as: [Ir(iPrptz- 3b)3]), tri[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazol(triazolato)]iridium(III) (abbreviated as: [Ir(iPr5btz)3]), and other organometallic complexes with a 4H-triazole skeleton; tri[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazol(triazolato)]iridium(III) (abbreviated as: [Ir(Mptz1-mp)3]), tri(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazol(triazolato) ... Organometallic complexes with a 1H-triazole skeleton, such as [Ir(Prptz1-Me)3]; organometallic complexes with an imidazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazolium]iridium(III) (abbreviated as [Ir(iPrpmi)3]) and tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as [Ir(dmpimpt-Me)3]); and bis[2-(4',6'-difluorophenyl)pyridinium-N,C2'] Organometallic complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands include iridium(III) tetratetra(1-pyrazolyl)borate (abbreviated as Fir6), bis[2-(4',6'-difluorophenyl)pyridin-N,C2']iridium(III)pyridinecarboxylate (abbreviated as Firpic), bis[2-(3,5-bistrifluoromethyl-phenyl)pyridin-N,C2']iridium(III)pyridinecarboxylate (abbreviated as [Ir(CF3ppy)2(pic)]), and bis[2-(4',6'-difluorophenyl)pyridin-N,C2']iridium(III)acetoacetone (abbreviated as Fir(acac)).

[0418] Examples of phosphorescent materials that exhibit green or yellow color and whose emission spectrum has a peak wavelength of 495 nm or higher and 590 nm or lower include the following substances.

[0419] Examples include tris(4-methyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)3]), acetyl acetone bis(6-methyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)2(acac)]), acetyl acetone bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)2 (acac)]), acetyl acetone bis[6-(2-norborneol)-4-phenylpyrimidine]iridium(III) (abbreviated as [Ir(nbppm)2(acac)]), and acetyl acetone bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidine]iridium(III) (abbreviated as [Ir(mpmppm)2]). (acac)]), (acetylacetone)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviated as: [Ir(dmppm-dmp)2(acac)]), (acetylacetone)bis(4,6-diphenylpyrimidine)iridium(III) (abbreviated as: [Ir(dppm)2(acac)]), etc., organometallic iridium complexes with a pyrimidine skeleton, (acetylacetone)bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-Me)2(acac)]), (acetylacetone)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviated as: [Ir(mppr-iPr)2(acac)]), tri(2-phenyl Tris(2-phenylpyridinium-N,C2')iridium(III) (abbreviated as [Ir(ppy)3]), bis(2-phenylpyridinium-N,C2')iridium(III)acetone (abbreviated as [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium(III)acetone (abbreviated as [Ir(bzq)2(acac)]), tris(benzo[h]quinoline)iridium(III) (abbreviated as [Ir(bzq)3]), tris(2-phenylquinoline-N,C2')iridium(III) Organometallic iridium complexes with a pyridine skeleton, such as [Ir(pq)3], bis(2-phenylquinoline-N,C2')iridium(III)acetoacetone (abbreviated as [Ir(pq)2(acac)]), bis(2,4-diphenyl-1,3-acetazole-N,C2')iridium(III)acetoacetone (abbreviated as [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridine-N,C2'}iridium(III)acetoacetone (abbreviated as [Ir(p-PF-ph)2(acac)], and bis(2-phenylbenzothiazole-N,Organometallic complexes such as C2'-iridium(III)acetophenone (abbreviated as [Ir(bt)2(acac)]) and rare earth metal complexes such as tri(acetophenone)(monoporphyrin)bium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0420] Among the above substances, organometallic iridium complexes having a pyridine skeleton (especially a phenylpyridine skeleton) or a pyrimidine skeleton are an effective group of compounds for achieving the green hue in one embodiment of the present invention.

[0421] Examples of phosphorescent materials that exhibit yellow or red color and whose emission spectrum has a peak wavelength of 570 nm or higher and 750 nm or lower include the following substances.

[0422] Examples include organometallic complexes with a pyrimidine skeleton such as (diisobutylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinium]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and bis[4,6-bis(naphthyl-1-yl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]); and bis(acetylacetone)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as: [Ir(tppr)2(acac)]). (Di-neoptidomylmethane)iridium(III) (abbreviated as: [Ir(tppr)2(dpm)]), bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedione-κ2O,O')iridium(III) (abbreviated as: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedione-κ2O,O')iridium(III) (abbreviated as: [Ir(dmdppr-dmCP)2)2 (dpm)]), (acetylene)bis[2-methyl-3-phenylquinoxalinato]-N,C2']iridium(III) (abbreviated as: [Ir(mpq)2(acac)]), (acetylene)bis(2,3-diphenylquinoxalinato)-N,C2']iridium(III) (abbreviated as: [Ir(dpq)2(acac)]), (acetylene)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviated as: [Ir(Fdpq)2) Organometallic complexes with pyrazine skeletons, such as [Ir(piq)3] and [Ir(piq)2(acac)]; organometallic complexes with pyridine skeletons, such as tris(1-phenylisoquinoline-N,C2')iridium(III) (abbreviated as [Ir(piq)3]) and bis(1-phenylisoquinoline-N,C2')iridium(III)acetone (abbreviated as [Ir(piq)2(acac)]); platinum complexes, such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as [PtOEP]);And rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato) (monoporphyrin) europium(III) (abbreviated as: [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenemethyl)-3,3,3-trifluoroacetone] (monoporphyrin) europium(III) (abbreviated as: [Eu(TTA)3(Phen)]).

[0423] Among the aforementioned substances, organometallic iridium complexes with a pyrazine skeleton are an effective group of compounds for achieving a red hue in one embodiment of the present invention. In particular, organometallic iridium complexes with a cyano group, such as [Ir(dmdppr-dmCP)2(dpm)], are preferred due to their high stability.

[0424] Furthermore, as a blue luminescent material, a material with a photoluminescence peak wavelength of 430 nm or higher and 470 nm or lower, preferably 430 nm or higher and 460 nm or lower, can be used. As a green luminescent material, a material with a photoluminescence peak wavelength of 500 nm or higher and 540 nm or lower, preferably 500 nm or higher and 530 nm or lower, can be used. As a red luminescent material, a material with a photoluminescence peak wavelength of 610 nm or higher and 680 nm or lower, preferably 620 nm or higher and 680 nm or lower, can be used. Furthermore, photoluminescence can be measured using either a solution or a thin film.

[0425] By simultaneously using the aforementioned compounds and the microcavity effect, the aforementioned chromaticity can be achieved more easily. In this case, the thickness of the transmissive and reflective electrodes (metal thin film portion) required to obtain the microcavity effect is preferably 20 nm or more and 40 nm or less, more preferably greater than 25 nm and 40 nm or less. When the thickness exceeds 40 nm, the efficiency may decrease.

[0426] As organic compounds (host material, auxiliary material) used for the luminescent layer 723, one or more materials whose band gap is larger than that of the luminescent material (guest material) can be used. Furthermore, the aforementioned hole-transporting material and the electron-transporting material described later can be used as host materials or auxiliary materials, respectively.

[0427] When the luminescent material is a fluorescent material, it is preferable to use an organic compound with a high energy level in the singlet excited state and a low energy level in the triplet excited state as the host material. For example, anthracene derivatives or condensed tetraphenyl derivatives are preferred. Specifically, examples include 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated as CzPA), and 7-[4-(10-phenyl-9-anthrayl)phenyl]-7H-dibenzo[ c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthrayl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviated as 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-furo-9-yl)biphenyl-4'-yl}anthracene (abbreviated as FLPPA), 5,12-diphenyltetraphenyl, 5,12-bis(biphenyl-2-yl)tetraphenyl, etc.

[0428] When the luminescent material is a phosphorescent material, an organic compound whose triplet excitation energy is greater than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the luminescent material can be selected as the host material. In this case, zinc or aluminum metal complexes, acediazole derivatives, triazole derivatives, benzimidazole derivatives, quinoline derivatives, dibenzoquinoline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenobarbital derivatives, and other heteroaromatic compounds, or aromatic amines, carbazole derivatives, etc., can be used.

[0429] Specifically, the following are listed: tris(8-hydroxyquinoline)aluminum(III) (abbreviated as Alq), tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), and bis[2-(2-benzo[azolyl]phenol]zinc(II) (Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviation: ZnBTZ) and other metal complexes; 2-(4-biphenyl)-5-(4-tributylphenyl)-1,3,4-diazole (abbreviation: PBD), 1,3-bis[5-(p-tributylphenyl)-1,3,4-diazole-2-yl]phenyl (abbreviation: OXD-7), 3-(4-biphenyl)-4-phenyl-5-(4-tributylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2 Heterocyclic compounds such as 2',2”-(1,3,5-phenyltriyl)-tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), ruberin (abbreviated as BPhen), copper oxychloride (abbreviated as BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenerin (abbreviated as NBphen), 9-[4-(5-phenyl-1,3,4-diazol-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), and aromatic amine compounds such as NPB, TPD, and BSPB.

[0430] In addition, examples include anthracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives, which are condensed polycyclic aromatic compounds. Specifically, examples include 9,10-diphenylanthracene (DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (CzA1PA), 4-(10-phenyl-9-anthrayl)triphenylamine (DPhPA), YGAPA, PCAPA, and N,9-diphenyl-N-{4-[4-(10-phenyl- 9-Anthracene]phenyl]phenyl}-9H-carbazole-3-amine (abbreviation: PCAPBA), 9,10-diphenyl-2-[N-phenyl-N-(9-phenyl-9H-carbazole-3-yl)amino]anthracene (abbreviation: 2PCAPA), 6,12-dimethoxy-5,11-diphenylamine, N,N,N',N',N”,N”,N”',N”'-octaphenyldibenzo[g,p]phenyl-2,7, 10,15-Tetraamine (abbreviated as DBC1), 9-[4-(10-phenyl-9-anthracene)phenyl]-9H-carbazole (abbreviated as CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthracene)phenyl]-9H-carbazole (abbreviated as DPCzPA), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated as DPPA), 9,10-bis(2-naphthyl)anthracene (abbreviated as DNA), 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviated as t-BuDNA), 9,9'-bianthracene (abbreviated as BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviated as DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviated as DPNS2), and 1,3,5-tris(1-pyrene)benzene (abbreviated as TPB3), etc.

[0431] Furthermore, when using multiple organic compounds in the light-emitting layer 723, it is preferable to use a combination of compounds that form excited-state complexes and light-emitting materials. In this case, various organic compounds can be used in combination, but for efficient formation of excited-state complexes, it is particularly preferable to combine compounds that readily accept holes (hole-transporting materials) and compounds that readily accept electrons (electron-transporting materials). Furthermore, as specific examples of hole-transporting materials and electron-transporting materials, the materials shown in this embodiment can be used.

[0432] TADF materials are materials capable of efficiently upconverting a triplet excited state to a singlet excited state using minimal thermal energy (inverse intersystem crossing) and exhibiting fluorescence from the singlet excited state. The conditions for efficiently obtaining thermally activated delayed fluorescence are as follows: the energy difference between the triplet and singlet excited states is greater than 0 eV and less than 0.2 eV, preferably greater than 0 eV and less than 0.1 eV. The delayed fluorescence exhibited by TADF materials refers to luminescence with a spectrum similar to ordinary fluorescence but with a very long lifetime. This lifetime is greater than 10⁻⁶ seconds, preferably greater than 10⁻³ seconds.

[0433] Examples of TADF materials include fullerenes or their derivatives, acridine derivatives such as proflavin, and eosin. Additionally, examples include metalloporphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metalloporphyrins include protoporphyrin-tin fluoride complexes (SnF2(Proto IX)), mesoporphyrin-tin fluoride complexes (SnF2(Meso IX)), hematoporphyrin-tin fluoride complexes (SnF2(Hemato IX)), tetramethyl coprophyrin-tin fluoride complexes (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complexes (SnF2(OEP)), protoporphyrin-tin fluoride complexes (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complexes (PtCl2OEP).

[0434] In addition to the above, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (PCCzPTzn), 2-[4-(10H-phenanthro-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (PXZ-TRZ), 3-[4-(5-phenylene]... Heterocyclic compounds with π-electron-rich and π-electron-deficient aromatic heterocycles include [4-(9,9-dimethyl-9H-acridin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl] ion (DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (ACRSA). Furthermore, in substances where π-electron-rich aromatic heterocycles and π-electron-deficient aromatic heterocycles are directly bonded, the donor nature of the π-electron-rich aromatic heterocycle and the acceptor nature of the π-electron-deficient aromatic heterocycle are both strong, and the energy difference between the singlet excited state and the triplet excited state becomes smaller, making it particularly superior.

[0435] Furthermore, when using TADF materials, they can be combined with other organic compounds.

[0436] Electron Transport Layer 724 The electron transport layer 724 is a layer that transports electrons injected from the conductor 788 through the electron injection layer 725 to the light-emitting layer 723. Furthermore, the electron transport layer 724 is a layer containing an electron transport material. Preferably, the electron transport material used for the electron transport layer 724 is a material having an electron mobility of 1 × 10⁻⁶ cm² / Vs or higher. However, any material other than those described above can be used, as long as its electron transport capability is higher than its hole transport capability.

[0437] Examples of materials used for electron transport include metal complexes with quinoline ligands, benzoquinoline ligands, acetazole ligands, thiazole ligands, acediazole derivatives, triazole derivatives, phenoline derivatives, pyridine derivatives, and bipyridine derivatives. In addition to the above, π-electron-deficient heteroaromatic compounds, such as nitrogen-containing heteroaromatic compounds, can also be used.

[0438] To be specific, Alq3, tris(4-methyl-8-hydroxyquinoline)aluminum(III) (abbreviated as Almq3), bis(10-hydroxybenzo[h]-quinoline)beryllium (abbreviated as BeBq2), BAlq, Zn(BOX)2, bis[2-(2-hydroxyphenyl)-benzothiazole]zinc (abbreviated as Zn(BTZ)2)(II) and other metal complexes, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-diazole (abbreviated as PB) D), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-diazol-2-yl]phenyl (abbreviation: OXD-7), 3-(4'-biphenyl)-4-phenyl-5-(4”-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (abbreviation: p-EtTAZ), and Bphen (abbreviation: Bphen) Heteroaromatic compounds such as copper hydroxide (BCP), 4,4'-bis(5-methylbenzoxazo-2-yl)stilbene (BzOs), 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoline (2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoline (2mDBTBPDBq-II), 2-[4-( Quinoline derivatives or dibenzoquinoline derivatives, such as 3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as: 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoline (abbreviated as: 6mDBTPDBq-II).

[0439] In addition, polymers such as poly(2,5-pyridinediyl) (abbreviated as PPy), poly[(9,9-dihexylfuran-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviated as PF-Py), and poly[(9,9-dioctylfuran-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviated as PF-BPy) can also be used.

[0440] Furthermore, the electron transport layer 724 can be composed of a single layer or of two or more layers composed of the aforementioned material.

[0441] Electron Injection Layer 725 The electron injection layer 725 is a layer containing a material with high electron injection capability. Alkali metals, alkaline earth metals, or compounds of these metals, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), and lithium oxide (LiOx), can be used as the electron injection layer 725. Furthermore, rare earth metal compounds such as erbium fluoride (ErF3) can be used. Additionally, an electron salt can be used in the electron injection layer 725. Examples of such an electron salt include, for instance, a mixture of calcium and aluminum oxides to which electrons are added at a high concentration. Furthermore, the material constituting the electron transport layer 724 as described above can also be used.

[0442] Furthermore, a composite material formed by mixing an organic compound with an electron donor (donor) can be used for the electron injection layer 725. This composite material exhibits excellent electron injection and electron transport properties because electrons are generated in the organic compound through the electron donor. In this case, the organic compound is preferably a material with excellent performance in transporting the generated electrons; specifically, for example, an electron transport material (metal complex, heteroaromatic compound, etc.) used in the electron transport layer 724 as described above can be used. As the electron donor, any substance that exhibits electron donor properties to the organic compound is acceptable. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, such as lithium, cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides or alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Additionally, Lewisite such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiofulvalene (TTF) can also be used.

[0443] Charge Generation Layer 792 The charge generation layer 792 has the following function: when a voltage is applied to the conductors 772 and 788, it injects electrons into the EL layer 786 closer to the conductor 772 and injects holes into the EL layer 786 closer to the conductor 788. For example, in the light-emitting element 572 having the structure shown in FIG. 39C, the charge generation layer 792 has the function of injecting electrons into EL layer 786a and injecting holes into EL layer 786b. The charge generation layer 792 can have a structure in which an electron acceptor is added to the hole transport material, or it can have a structure in which an electron donor is added to the electron transport material. Alternatively, both of these structures can be stacked. Furthermore, by using the above-described material to form the charge generation layer 792, the increase in the driving voltage of the display device 810 when EL layers are stacked can be suppressed.

[0444] When the charge-generating layer 792 has a structure that adds electron acceptors to the hole-transporting material, examples of electron acceptors include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethane (F4-TCNQ) and chloroquinone. Furthermore, oxides of metals belonging to groups 4 through 8 of the periodic table can be cited. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0445] When the charge-generating layer 792 has a structure in which an electron donor is added to the electron-transporting material, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to Groups 2 and 13 of the periodic table, as well as their oxides or carbonates, can be used as electron donors. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc., are preferred. In addition, organic compounds such as tetrathianaphthacene can also be used as electron donors.

[0446] Furthermore, when manufacturing the light-emitting element 572, vacuum processes such as vapor deposition or solution processes such as spin coating and inkjet printing can be used. As for vapor deposition methods, physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam vapor deposition, molecular beam vapor deposition, and vacuum vapor deposition, or chemical vapor deposition (CVD) methods can be used. In particular, functional layers (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer), and charge generation layer included in the EL layer of the light-emitting element can be formed using methods such as vapor deposition (vacuum vapor deposition), coating methods (dip coating, dye coating, rod coating, spin coating, spray coating), and printing methods (inkjet printing, screen printing, lithography, flexographic printing, photogravure printing, micro-contact printing, etc.).

[0447] Furthermore, the materials used for the functional layers (hole injection layer, hole transport layer, light emission layer, electron transport layer, electron injection layer) and charge generation layer constituting the EL layer of the light-emitting element shown in this embodiment are not limited to these; any materials that can satisfy the functions of each layer can be used in combination. As an example, polymeric compounds (oligomers, dendritic polymers, polymers, etc.), medium-molecular-weight compounds (compounds between low and high molecular weight: molecular weight 400 to 4000), and inorganic compounds (quantum dot materials, etc.) can be used. As quantum dot materials, colloidal quantum dot materials, alloy-type quantum dot materials, core-shell quantum dot materials, and core-type quantum dot materials can be used.

[0448] The display device 810 shown in this embodiment can be applied to the light source shown in Embodiment 1. By applying the display device 810 to the light source shown in Embodiment 1, light-emitting elements can be arranged in the light source at a high density. As a result, the electronic device of one embodiment of the present invention can accurately recognize facial features such as expressions of the user of the electronic device.

[0449] Figure 40A is a cross-sectional view showing a structural example of an imaging device according to an embodiment of the present invention. As shown in Figure 40A, a transistor 1003, a light-emitting element 572, a photoelectric conversion element 1010, and a color layer 993 may be sandwiched between a substrate 1001 and a substrate 995. Here, for example, the transistor 1003 may be an OS transistor. Figure 40A shows four transistors 1003.

[0450] An insulator 1002 is disposed on a substrate 1001, and a transistor 1003 is disposed on the insulator 1002. An insulator 1004 is disposed on the transistor 1003, and an insulator 1005 is disposed on the insulator 1004. A light-emitting element 572 and a photoelectric conversion element 1010 are disposed on the insulator 1005, and a color layer 993 is disposed in such a way that it includes a region overlapping with the light-emitting element 572 or the photoelectric conversion element 1010. FIG40A shows two light-emitting elements 572 (light-emitting element 572_1, light-emitting element 572_2) and two photoelectric conversion elements 1010 (photoelectric conversion element 1010_1, photoelectric conversion element 1010_2), which are electrically connected to different transistors 1003 respectively. Furthermore, in Figure 40A, a color layer 993R, which functions as a color layer 993 that transmits red light, is provided in a manner that includes a region overlapping with the light-emitting element 572_1, and a color layer 993IR, which functions as a color layer 993 that transmits infrared light, is provided in a manner that includes a region overlapping with the light-emitting element 572_2. Also, a color layer 993R is provided in a manner that includes a region overlapping with the photoelectric conversion element 1010_1, and a color layer 993IR is provided in a manner that includes a region overlapping with the photoelectric conversion element 1010_2.

[0451] The photoelectric conversion element 1010 has the function of receiving light Lex irradiated from outside the camera device and converting it into an electrical signal corresponding to the illuminance of the light Lex.

[0452] The light-emitting element 572 preferably has the function of emitting white light and infrared light. Thus, the light emitted from the light-emitting element 572_1 passes through the color layer 993R and is emitted as red light R to the outside of the imaging device. Furthermore, the light emitted from the light-emitting element 572_2 passes through the color layer 993IR and is emitted as infrared light IR to the outside of the imaging device. The red light R and infrared light IR emitted to the outside of the imaging device are reflected by an object and irradiate the photoelectric conversion element 1010. For example, when the imaging device having the structure shown in FIG40A is applied to the glasses-type electronic device shown in Embodiment 1, the red light R and infrared light IR irradiate the face of the user of the glasses-type electronic device and are reflected, and this light (Lex) can be detected by the photoelectric conversion element 1010.

[0453] Because the camera device has the function of detecting both red light and infrared light, compared to a device that only detects one of the two, this camera device can, for example, accurately detect the state of the user's eyes and surrounding area in the electronic device according to one embodiment of the present invention. Therefore, for example, it can accurately identify facial features such as expressions of the user of the electronic device according to one embodiment of the present invention, and thus the electronic device according to one embodiment of the present invention can, for example, have the function of accurately inferring the user's level of fatigue, emotions, etc.

[0454] Furthermore, in one embodiment of the present invention, when the display device has a photoelectric conversion element, the display device may have the structure shown in FIG40A. In this case, in addition to the light-emitting element 572 including a region overlapping with the color layer 993 which has the function of transmitting red light and the light-emitting element 572 including a region overlapping with the color layer 993 which has the function of transmitting infrared light, the display device may also have a light-emitting element 572 including a region overlapping with the color layer 993 which has the function of transmitting green light and a light-emitting element 572 including a region overlapping with the color layer 993 which has the function of transmitting blue light.

[0455] The light-emitting element 572 is formed of a conductor 772, an EL layer 786, and a conductor 788. Furthermore, the photoelectric conversion element 1010 is formed of a conductor 772, an active layer 1011, and a conductor 788. Here, the transistor 1003 is electrically connected to the conductor 772.

[0456] As the active layer 1011, it can be a stacked structure of pn junction with p-type semiconductors and n-type semiconductors stacked together, or a stacked structure of pin junction with p-type semiconductors, i-type semiconductors and n-type semiconductors stacked together.

[0457] As the semiconductor used for the active layer 1011, inorganic semiconductors such as silicon or organic semiconductors containing organic compounds can be used. In particular, by using organic semiconductor materials, the EL layer 786 of the light-emitting element 572 and the active layer 1011 can be easily formed by the same vacuum evaporation method, and the manufacturing equipment can be used together, which is preferable.

[0458] When using an organic semiconductor material as the active layer 1011, examples of electron-accepting organic semiconductor materials include fullerenes (e.g., C60, C70, etc.) or their derivatives, which are n-type semiconductors. Examples of electron-donating organic semiconductor materials include copper(II) phthalocyanine (CuPc) and tetraphenyldibenzoperiflanthene (DBP), which are p-type semiconductors. The active layer 1011 can be a stacked structure of electron-accepting and electron-donating semiconductor materials (pn stacked structure) or a stacked structure of a bulk heterostructure layer formed by co-depositing electron-accepting and electron-donating semiconductor materials (pin stacked structure). Furthermore, layers serving as hole barrier layers or electron barrier layers can be provided around the periphery (upper or lower side) of the pn stacked structure or pin stacked structure to suppress dark currents in the absence of light irradiation.

[0459] In the light-emitting element 572, an EL layer 786 is provided on the conductor 772. Furthermore, in the photoelectric conversion element 1010, an active layer 1011 is provided on the conductor 772. Additionally, a conductor 788 is provided covering the EL layer 786 and the active layer 1011. Thus, the conductor 788 can serve as both an electrode of the light-emitting element 572 and an electrode of the photoelectric conversion element 1010.

[0460] Figure 40B is a cross-sectional view showing a structural example of a camera device according to one embodiment of the present invention, and is a modified example of the structure shown in Figure 40A. The camera device having the structure shown in Figure 40B differs from that in Figure 40A in that it does not have a light-emitting element 572.

[0461] In one embodiment of the present invention, when the electronic device includes a camera device having the structure shown in FIG40B, by providing a light source outside the camera device, the light emitted from the light source can be detected by the camera device. For example, when the camera device having the structure shown in FIG40B is applied to the eyeglass-type electronic device shown in Embodiment 1, red light and infrared light emitted from the light source illuminate the face of the user of the eyeglass-type electronic device and are reflected, and this light Lex can be detected by the photoelectric conversion element 1010.

[0462] By having the camera device included in an electronic device according to one embodiment of the present invention have the structure shown in FIG40B, photoelectric conversion elements 1010 can be arranged in the camera device with high density.

[0463] The structural examples shown in this embodiment and at least a portion of the corresponding diagrams can be implemented in appropriate combinations with other structural examples or diagrams.

[0464] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification. Implementation Method 3

[0465] In this embodiment, a transistor that can be used in a display device according to one embodiment of the present invention is described.

[0466] <Example 1 of transistor structure> Figures 41A, 41B, and 41C are top and cross-sectional views of a transistor 200A and its surroundings in a display device that can be used in one embodiment of the present invention. The transistor 200A can be used as the transistor included in the pixel array 833, gate drive circuit 821, source drive circuit 822, and circuit 840 shown in Embodiment 1, etc.

[0467] Figure 41A is a top view of transistor 200A. Furthermore, Figures 41B and 41C are cross-sectional views of transistor 200A. Here, Figure 41B is a cross-sectional view along the dashed line A1-A2 in Figure 41A, which corresponds to a cross-sectional view along the channel length direction of transistor 200A. Figure 41C is a cross-sectional view along the dashed line A3-A4 in Figure 41A, which corresponds to a cross-sectional view along the channel width direction of transistor 200A. Note that for ease of understanding, some components are omitted in the top view of Figure 41A.

[0468] [Transistor 200A] Transistor 200A includes: a metal oxide 230a disposed on a substrate (not shown); a metal oxide 230b disposed on the metal oxide 230a; a conductor 242a and a conductor 242b disposed on the metal oxide 230b and separated from each other; an insulator 280 disposed on the conductors 242a and 242b and having an opening formed between the conductors 242a and 242b; a conductor 260 disposed in the opening; an insulator 250 disposed between the metal oxide 230b, the conductors 242a and 242b and between the insulators 280 and 260; and a metal oxide 230c disposed between the metal oxide 230b, the conductors 242a and 242b and between the insulators 280 and 250. Here, as shown in Figures 41B and 41C, the top surface of conductor 260 preferably coincides substantially with the top surfaces of insulator 250, insulator 254, metal oxide 230c, and insulator 280. Hereinafter, metal oxides 230a, 230b, and 230c are sometimes collectively referred to as oxide 230. Furthermore, conductors 242a and 242b are sometimes collectively referred to as conductor 242.

[0469] In the transistor 200A shown in FIG. 41B, the side surfaces of conductors 242a and 242b located on the side of conductor 260 are substantially perpendicular to the bottom surface. Furthermore, the transistor 200A shown in FIGS. 41A to 41C is not limited to this; a structure in which the angle formed by the side surfaces of conductors 242a and 242b and the bottom surface is 10˚ or more and 80˚ or less, preferably 30˚ or more and 60˚ or less, may also be used. Additionally, a structure in which the opposing side surfaces of conductors 242a and 242b have multiple surfaces may also be used.

[0470] Furthermore, as shown in Figures 41B and 41C, it is preferable that an insulator 254 is disposed between the insulator 224, metal oxide 230a, metal oxide 230b, conductor 242a, conductor 242b, and metal oxide 230c and the insulator 280. Here, as shown in Figures 41B and 41C, the insulator 254 is preferably in contact with the side surface of the metal oxide 230c, the top and side surface of the conductor 242a, the top and side surface of the conductor 242b, the side surfaces of the metal oxides 230a and 230b, and the top surface of the insulator 224.

[0471] Note that in transistor 200A, three layers of metal oxides 230a, 230b, and 230c are stacked in and around the channel-forming region (hereinafter also referred to as the channel-forming region), but the present invention is not limited to this. For example, it can be a two-layer structure of metal oxides 230b and 230c, or a stacked structure of four or more layers. Furthermore, in transistor 200A, conductor 260 has a two-layer structure, but the present invention is not limited to this. For example, conductor 260 can also have a single-layer structure or a stacked structure of three or more layers. Furthermore, metal oxides 230a, 230b, and 230c can each have a stacked structure of two or more layers.

[0472] For example, when metal oxide 230c has a stacked structure consisting of a first metal oxide and a second metal oxide on the first metal oxide, the first metal oxide may have the same composition as metal oxide 230b, while the second metal oxide preferably has the same composition as metal oxide 230a.

[0473] Here, conductor 260 is used as the gate electrode of the transistor, and conductors 242a and 242b are each used as the source electrode or drain electrode. As described above, conductor 260 is formed by embedding itself in the opening of insulator 280 and being sandwiched in the region between conductors 242a and 242b. Here, the arrangement of conductors 260, 242a, and 242b is self-aligned relative to the opening of insulator 280. That is, in transistor 200A, the gate electrode can be self-aligned between the source electrode and the drain electrode. Therefore, conductor 260 can be formed without providing room for alignment, thus reducing the occupied area of ​​transistor 200A. This allows for high resolution of the display device. Furthermore, a display device with a narrow bezel can be realized.

[0474] Furthermore, as shown in Figures 41A to 41C, the conductor 260 preferably includes a conductor 260a disposed inside the insulator 250 and a conductor 260b disposed in a manner embedded inside the conductor 260a.

[0475] Furthermore, as shown in Figures 41A to 41C, the transistor 200A preferably includes an insulator 214 disposed on a substrate (not shown), an insulator 216 disposed on the insulator 214, a conductor 205 disposed in a manner embedded in the insulator 216, an insulator 222 disposed on the insulator 216 and the conductor 205, and an insulator 224 disposed on the insulator 222. Preferably, a metal oxide 230a is disposed on the insulator 224.

[0476] Furthermore, it is preferable to have insulators 274 and 281, which serve as interlayer films, disposed on transistor 200A. Here, insulator 274 is preferably in contact with the top surface of conductor 260, insulator 250, insulator 254, metal oxide 230c, and insulator 280.

[0477] Furthermore, insulators 222, 254, and 274 preferably have the function of suppressing the diffusion of hydrogen (e.g., at least one of hydrogen atoms, hydrogen molecules, etc.). For example, the hydrogen permeability of insulators 222, 254, and 274 is preferably lower than that of insulators 224, 250, and 280. Furthermore, insulators 222 and 254 preferably have the function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.). For example, the oxygen permeability of insulators 222 and 254 is preferably lower than that of insulators 224, 250, and 280.

[0478] Here, insulator 224, oxide 230, and insulator 250 are separated from insulator 280 and insulator 281 by insulator 254 and insulator 274. This prevents impurities such as hydrogen or excess oxygen contained in insulator 280 and insulator 281 from mixing into insulator 224, metal oxide 230, and insulator 250.

[0479] Furthermore, it is preferable to include a conductor 240 (conductor 240a and conductor 240b) that is electrically connected to the transistor 200A and serves as a plug. It also includes an insulator 241 (insulator 241a and insulator 241b) that contacts the side of the conductor 240 used as a plug. That is, the insulator 241 is formed in contact with the inner wall of the openings of the insulators 254, 280, 274, and 281. Furthermore, a first conductor of the conductor 240 may be provided in contact with the side of the insulator 241, and a second conductor may be provided inside it. Here, the height of the top surface of the conductor 240 and the height of the top surface of the insulator 281 may be approximately the same. Furthermore, a structure in the transistor 200A in which the first conductor and the second conductor of the conductor 240 are stacked is shown, but the present invention is not limited to this. For example, the conductor 240 may also have a single-layer structure or a stacked structure of three or more layers. In cases where a structure has a layered structure, ordinal numbers are sometimes assigned according to the order in which they are formed to distinguish them.

[0480] Furthermore, it is preferable that the metal oxide (hereinafter also referred to as oxide semiconductor) to be used as an oxide semiconductor in the transistor 200A is used in the oxide 230 (metal oxide 230a, metal oxide 230b, and metal oxide 230c) containing the channel forming region. For example, as the metal oxide that will become the channel forming region of the oxide 230, it is preferable to use a metal oxide with a band gap of 2 eV or more, preferably 2.5 eV or more.

[0481] Furthermore, as shown in Figure 41B, the thickness of the region in the metal oxide 230b that does not overlap with the conductor 242 is sometimes thinner than the thickness of the region that overlaps with the conductor 242. This is because a portion of the top surface of the metal oxide 230b is removed when the conductors 242a and 242b are formed. When a conductive film serving as the conductor 242 is formed on the top surface of the metal oxide 230b, a low-resistance region is sometimes formed near the interface with the conductive film. Thus, by removing the low-resistance region on the top surface of the metal oxide 230b located between the conductors 242a and 242b, the formation of channels in that region can be suppressed.

[0482] According to one embodiment of the present invention, a display device comprising a small transistor and having high resolution can be provided. Furthermore, a display device comprising a transistor with a large on-state current and having high brightness can be provided. Furthermore, a display device comprising a transistor with high operating speed can be provided. Furthermore, a display device comprising a transistor with stable electrical characteristics and having high reliability can be provided. Furthermore, a display device comprising a transistor with low off-state current and having low power consumption can be provided.

[0483] The detailed structure of the transistor 200A, which can be used in one embodiment of the present invention, is described below.

[0484] The conductor 205 is configured to include a region overlapping with the oxide 230 and the conductor 260. Furthermore, the conductor 205 is preferably embedded within the insulator 216. Here, the flatness of the top surface of the conductor 205 is preferably high. For example, the average surface roughness (Ra) of the top surface of the conductor 205 is 1 nm or less, preferably 0.5 nm or less, and more preferably 0.3 nm or less. This improves the flatness of the insulator 224 formed on the conductor 205 and enhances the crystallinity of the metal oxides 230b and 230c.

[0485] Here, conductor 260 is sometimes used as the first gate electrode (also called the top gate electrode). Furthermore, conductor 205 is sometimes used as the second gate electrode (also called the back gate electrode). In this case, the Vth of transistor 200A can be controlled by independently changing the potential supplied to conductor 205 without linking it to the potential supplied to conductor 260. In particular, by supplying a negative potential to conductor 205, the Vth of transistor 200A can be made greater than 0V, and the off-state current can be reduced. Therefore, compared to not applying a negative potential to conductor 205, applying a negative potential to conductor 205 can reduce the drain current of transistor 200A when the potential supplied to conductor 260 is 0V.

[0486] Furthermore, the conductor 205 is preferably larger than the channel forming region in the metal oxide 230. In particular, as shown in FIG41C, the conductor 205 is preferably a region extending to the outside of the end of the metal oxide 230 that intersects with the channel width direction. That is, preferably, the conductor 205 and the conductor 260 overlap with an insulator on the outside of the side of the metal oxide 230 in the channel width direction.

[0487] That is to say, by having the above structure, a region can be formed around the channel of the metal oxide 230 by the electric field of the conductor 260 used as the first gate electrode and the electric field of the conductor 205 used as the second gate electrode.

[0488] Furthermore, as shown in FIG41C, the conductor 205 is extended to serve as wiring. However, the present invention is not limited thereto, and the conductor used as wiring may also be provided under the conductor 205.

[0489] Furthermore, it is preferable to use a conductive material with tungsten, copper, or aluminum as the main components as conductor 205. In the figure, conductor 205 is illustrated as a single layer, but conductor 205 may also have a multilayer structure, for example, a multilayer structure of titanium, titanium nitride, and the aforementioned conductive materials may be used.

[0490] Furthermore, a conductor that suppresses the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms (making it difficult for the aforementioned impurities to pass through) can also be used under conductor 205. Moreover, it is preferable to use a conductor that suppresses the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (making it difficult for the aforementioned oxygen to pass through). In this specification, "the function of suppressing the diffusion of impurities or oxygen" refers to the function of suppressing the diffusion of any one or all of the aforementioned impurities and oxygen.

[0491] Furthermore, when a conductor with the function of inhibiting oxygen diffusion is used under the conductor 205, the decrease in conductivity caused by oxidation of the conductor 205 can be suppressed. For example, tantalum, tantalum nitride, ruthenium, or ruthenium oxide are preferably used as the conductor with the function of inhibiting oxygen diffusion. Therefore, a single layer or a stack of the above-mentioned conductive materials can be used as the conductor 205.

[0492] The insulator 214 is preferably a barrier insulating film used to prevent impurities such as water or hydrogen from entering the transistor 200A from the substrate side. Therefore, the insulator 214 is preferably an insulating material that has the function of inhibiting the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms (making it difficult for the aforementioned impurities to permeate). Furthermore, it is preferable to use an insulating material that has the function of inhibiting the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (making it difficult for the aforementioned oxygen to permeate).

[0493] For example, it is preferable to use aluminum oxide or silicon nitride as the insulator 214. This suppresses the diffusion of impurities such as water or hydrogen from the side closer to the substrate than the insulator 214 to the transistor 200A side. Furthermore, it suppresses the diffusion of oxygen contained in the insulator 224, etc., to the side closer to the substrate than the insulator 214.

[0494] Furthermore, the relative permittivity of insulators 216, 280, and 281, which are used as interlayer films, is preferably lower than that of insulator 214. By using materials with low relative permittivity as interlayer films, parasitic capacitance generated between wirings can be reduced. For example, silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, fluorine-added silicon oxide, carbon-added silicon oxide, silicon oxide with added carbon and nitrogen, or porous silicon oxide are appropriately used as insulators 216, 280, and 281.

[0495] Insulators 222 and 224 are used as gate insulators.

[0496] Here, in the insulator 224 that is in contact with the metal oxide 230, it is preferable to remove the oxygen by heating. In this specification, the oxygen removed by heating is sometimes referred to as excess oxygen. For example, silicon oxide or silicon oxynitride can be appropriately used as the insulator 224. By providing an insulator containing oxygen in a manner that allows it to contact the metal oxide 230, oxygen vacancies in the metal oxide 230 can be reduced, thereby improving the reliability of the transistor 200A.

[0497] Specifically, as the insulator 224, it is preferable to use an oxide material in which a portion of the oxygen is removed by heating. The oxide in which oxygen is removed by heating refers to an oxide film in which the amount of oxygen removed, converted to oxygen atoms in TDS (Thermal Desorption Spectroscopy) analysis, is 1.0 × 10¹⁸ atoms / cm³ or more, preferably 1.0 × 10¹⁹ atoms / cm³ or more, further preferably 2.0 × 10¹⁹ atoms / cm³ or more, or 3.0 × 10²⁰ atoms / cm³ or more. Furthermore, the surface temperature of the film during the above TDS analysis is preferably in the range of 100°C or higher and 700°C or lower, or 100°C or higher and 400°C or lower.

[0498] Furthermore, as shown in Figure 41C, sometimes the thickness of the region in insulator 224 that does not overlap with insulator 254 or metal oxide 230b is thinner than the thickness of other regions. Preferably, the region in insulator 224 that does not overlap with insulator 254 or metal oxide 230b has a thickness sufficient to allow for the diffusion of the aforementioned oxygen.

[0499] Similar to insulator 214, insulator 222 is preferably used as a barrier insulating film to prevent impurities such as water or hydrogen from mixing into transistor 200A from the substrate side. For example, the hydrogen permeability of insulator 222 is preferably lower than that of insulator 224. By surrounding insulator 224, metal oxide 230, and insulator 250 with insulator 222, insulator 254, and insulator 274, impurities such as water or hydrogen can be prevented from entering transistor 200A from the outside.

[0500] Furthermore, insulator 222 preferably has the function of inhibiting the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (making it difficult for the aforementioned oxygen to permeate). For example, the oxygen permeability of insulator 222 is preferably lower than that of insulator 224. By enabling insulator 222 to inhibit the diffusion of oxygen or impurities, the diffusion of oxygen present in metal oxide 230 to the substrate side can be reduced, which is therefore preferable. In addition, the reaction between conductor 205 and oxygen present in insulator 224 and metal oxide 230 can be suppressed.

[0501] The insulator 222 is preferably an insulator containing an oxide of one or both of aluminum and hafnium as the insulating material. As an insulator containing an oxide of one or both of aluminum and hafnium, aluminum oxide, hafnium oxide, or an oxide containing aluminum and hafnium (hafnium aluminate) are preferred. When this material is used to form the insulator 222, the insulator 222 serves as a layer to suppress the release of oxygen from the metal oxide 230 or the entry of impurities such as hydrogen from the periphery of the transistor 200A into the metal oxide 230.

[0502] Alternatively, aluminum oxide, bismuth oxide, germanium oxide, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, or zirconium oxide can be added to the insulator. Furthermore, the insulator can be nitrided. Silicon oxide, silicon oxynitride, or silicon nitride can also be laminated onto the insulator.

[0503] Furthermore, as the insulator 222, insulators containing so-called high-k materials such as alumina, hafnium oxide, tantalum oxide, zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrTiO3), or (Ba,Sr)TiO3 (BST) can be used, either as a single layer or in a multilayer. When miniaturizing and hyper-integrating transistors, problems such as leakage current sometimes occur due to the thinning of the gate insulator. By using a high-k material as the gate insulator, the gate potential during transistor operation can be reduced while maintaining the physical thickness.

[0504] Furthermore, insulators 222 and 224 may also have a multilayered structure. In this case, it is not limited to a multilayered structure made of the same material, but may also be a multilayered structure made of different materials. For example, an insulator identical to insulator 224 may be provided under insulator 222.

[0505] The metal oxide 230 includes metal oxide 230a, metal oxide 230b on metal oxide 230a, and metal oxide 230c on metal oxide 230b. When metal oxide 230a is disposed under metal oxide 230b, the diffusion of impurities from the structure formed under metal oxide 230a to metal oxide 230b can be suppressed. When metal oxide 230c is disposed on metal oxide 230b, the diffusion of impurities from the structure formed above metal oxide 230c to metal oxide 230b can be suppressed.

[0506] Furthermore, metal oxide 230 is preferably a layered structure of oxides having different atomic ratios of each metal atom. Specifically, in the metal oxide used for metal oxide 230a, the atomic ratio of element M among the constituent elements is preferably greater than that of element M among the constituent elements of the metal oxide used for metal oxide 230b. Furthermore, in the metal oxide used for metal oxide 230a, the atomic ratio of element M to In is preferably greater than that of element M to In in the metal oxide used for metal oxide 230b. Furthermore, in the metal oxide used for metal oxide 230b, the atomic ratio of In to element M is preferably greater than that of In to element M in the metal oxide used for metal oxide 230a. Additionally, metal oxide 230c can be any metal oxide that can be used for metal oxide 230a or metal oxide 230b.

[0507] Metal oxides 230a, 230b, and 230c are preferably crystalline, and in particular, CAAC-OS is preferred. Crystalline oxides such as CAAC-OS have a highly crystalline and dense structure with few impurities and defects (such as oxygen vacancies). Therefore, oxygen extraction from the source or drain electrode of the metal oxide 230b can be suppressed. Thus, even with heat treatment, oxygen extraction from the metal oxide 230b can be reduced, and the transistor 200A is also stable at high temperatures (so-called thermal budget) during the process.

[0508] Preferably, the conduction band bottom energies of metal oxides 230a and 230c are higher than those of metal oxide 230b. In other words, the electron affinity of metal oxides 230a and 230c is preferably lower than that of metal oxide 230b. In this case, metal oxide 230c is preferably a metal oxide that can be used for metal oxide 230a. Specifically, in the metal oxide used for metal oxide 230c, the number of atoms of element M in the constitutive elements is preferably greater than the ratio of the number of atoms of element M in the constitutive elements of the metal oxide used for metal oxide 230b. Furthermore, in the metal oxide used for metal oxide 230c, the ratio of the number of atoms of element M to In is preferably greater than the ratio of the number of atoms of element M to In in the metal oxide used for metal oxide 230b. Furthermore, in the metal oxide used for metal oxide 230b, the ratio of the number of In atoms to the number of M atoms is preferably greater than that in the metal oxide used for metal oxide 230c.

[0509] Here, at the junction of metal oxides 230a, 230b, and 230c, the energy level of the conduction band bottom changes gradually. In other words, the above situation can also be expressed as the energy level of the conduction band bottom at the junction of metal oxides 230a, 230b, and 230c changing continuously or continuously joining. For this purpose, it is preferable to reduce the defect state density of the mixed layer formed at the interface between metal oxides 230a and 230b, and at the interface between metal oxides 230b and 230c.

[0510] Specifically, by including a common element (as the main component) in addition to oxygen in metal oxides 230a and 230b, and in metal oxides 230b and 230c, a mixed layer with low defect state density can be formed. For example, when metal oxide 230b is an In-Ga-Zn oxide, In-Ga-Zn oxide, Ga-Zn oxide, and gallium oxide can be used as metal oxides 230a and 230c. Furthermore, metal oxide 230c can have a stacked structure. For example, a stacked structure of In-Ga-Zn oxide and Ga-Zn oxide on the In-Ga-Zn oxide can be used, or a stacked structure of In-Ga-Zn oxide and gallium oxide on the In-Ga-Zn oxide can be used. In other words, a stacked structure of In-Ga-Zn oxide and an oxide not containing In can also be used as metal oxide 230c.

[0511] Specifically, for metal oxide 230a, an In:Ga:Zn ratio of 1:3:4 or 1:1:0.5 is acceptable. Furthermore, for metal oxide 230b, an In:Ga:Zn ratio of 4:2:3 or 3:1:2 is acceptable. Additionally, for metal oxide 230c, an In:Ga:Zn ratio of 1:3:4, 4:2:3, 2:1, or 2:5 is acceptable. Furthermore, as specific examples of metal oxide 230c having a stacked structure, we can cite stacked structures with In:Ga:Zn=4:2:3 [atomic ratio] and Ga:Zn=2:1 [atomic ratio], stacked structures with In:Ga:Zn=4:2:3 [atomic ratio] and Ga:Zn=2:5 [atomic ratio], and stacked structures with In:Ga:Zn=4:2:3 [atomic ratio] and gallium oxide, etc.

[0512] At this point, the primary carrier pathway is metal oxide 230b. By giving metal oxides 230a and 230c the aforementioned structure, the defect state density at the interface between metal oxides 230a and 230b, and at the interface between metal oxides 230b and 230c, can be reduced. Therefore, the influence of interface scattering on carrier conduction is reduced, resulting in high on-state current and high frequency characteristics for transistor 200A. Furthermore, when metal oxide 230c has a stacked structure, it is expected to reduce the defect state density at the interface between metal oxides 230b and 230c and suppress the diffusion of constituent elements from metal oxide 230c to the insulator 250 side. More specifically, when metal oxide 230c has a stacked structure, because the oxides that do not contain In are located on top of the stacked structure, the diffusion of In to the insulator 250 side can be suppressed. Since the insulator 250 is used as a gate insulator, the diffusion of In within it leads to poor transistor characteristics. Therefore, by giving the metal oxide 230c a multilayer structure, a highly reliable display device can be provided.

[0513] The metal oxide 230 is preferably a metal oxide used as an oxide semiconductor. For example, the metal oxide that will form the channel formation region of the metal oxide 230 is preferably a metal oxide with a band gap of 2 eV or more, more preferably 2.5 eV or more. In this way, by using a metal oxide with a wider band gap, the off-state current of the transistor can be reduced. By using such a transistor, a low-power display device can be provided.

[0514] Conductors 242 (conductors 242a and 242b) serving as source and drain electrodes are provided on the metal oxide 230b. Preferably, conductor 242 is a metal element selected from aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium, beryllium, indium, ruthenium, iridium, strontium, and lanthanum, an alloy containing the aforementioned metal elements, or an alloy combining the aforementioned metal elements. For example, tantalum nitride, titanium nitride, tungsten, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel are preferred. In addition, tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel are conductive materials that are not easily oxidized or that maintain conductivity even when absorbing oxygen, so they are preferred.

[0515] By forming the conductor 242 in contact with the metal oxide 230, the oxygen concentration near the conductor 242 in the metal oxide 230 sometimes decreases. Furthermore, a metal compound layer comprising the metal contained in the conductor 242 and components of the metal oxide 230 sometimes forms near the conductor 242 in the metal oxide 230. In this case, the carrier density in the region near the conductor 242 of the metal oxide 230 increases, and the resistance of that region decreases.

[0516] Here, the region between conductors 242a and 242b is formed in a manner that overlaps with the opening of insulator 280. Therefore, conductor 260 can be self-aligned between conductors 242a and 242b.

[0517] Insulator 250 is used as a gate insulator. Insulator 250 is preferably configured to contact the top surface of metal oxide 230c with ground. Insulator 250 can be made of silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, fluorine-added silicon oxide, carbon-added silicon oxide, silicon oxide with both carbon and nitrogen, or porous silicon oxide. In particular, silicon oxide and silicon oxynitride are preferred due to their thermal stability.

[0518] Similar to insulator 224, it is preferable to reduce the concentration of impurities such as water or hydrogen in insulator 250. The thickness of insulator 250 is preferably 1 nm or more and 20 nm or less.

[0519] Alternatively, a metal oxide can be disposed between the insulator 250 and the conductor 260. This metal oxide is preferably one that suppresses oxygen diffusion from the insulator 250 to the conductor 260. This suppresses oxidation of the conductor 260 caused by oxygen in the insulator 250.

[0520] Furthermore, this metal oxide is sometimes used as part of the gate insulator. Therefore, when silicon oxide or silicon oxynitride is used for the insulator 250, it is preferable to use a high-k metal oxide, which is a material with a high relative permittivity, as the metal oxide. By giving the gate insulator a laminated structure of the insulator 250 and the metal oxide, a transistor 200A with thermal stability and a high relative permittivity can be formed. Therefore, the gate potential applied during transistor operation can be reduced while maintaining the physical thickness of the gate insulator. In addition, the equivalent oxide thickness (EOT) of the insulator used as the gate insulator can be reduced.

[0521] Specifically, one or more metal oxides selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, and magnesium can be used. In particular, it is preferred to use aluminum oxide, hafnium oxide, or oxides containing aluminum and hafnium (hafnium aluminate) as insulators containing one or both of aluminum and hafnium.

[0522] Although the conductor 260 has a two-layer structure in Figures 41A to 41C, it can also have a single-layer structure or a stacked structure of three or more layers.

[0523] As the conductor 260a, it is preferable to use the above-mentioned conductor that has the function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms. Furthermore, it is preferable to use a conductive material that has the function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.).

[0524] Furthermore, when the conductor 260a has the function of inhibiting oxygen diffusion, it can prevent the oxygen contained in the insulator 250 from oxidizing the conductor 260b and causing a decrease in the conductivity of the conductor 260b. As a conductive material with the function of inhibiting oxygen diffusion, tantalum, tantalum nitride, ruthenium, or ruthenium oxide are preferably used, for example.

[0525] Furthermore, it is preferable to use a conductive material with tungsten, copper, or aluminum as the main component as the conductor 260b. Also, since the conductor 260 is also used for wiring, it is preferable to use a conductor with high conductivity. For example, a conductive material with tungsten, copper, or aluminum as the main component can be used. Furthermore, the conductor 260b can have a multilayer structure, for example, a multilayer structure of titanium, titanium nitride, and the aforementioned conductive material.

[0526] Furthermore, as shown in Figures 41A and 41C, in the region of the metal oxide 230b that does not overlap with the conductor 242, i.e., in the channel-forming region of the metal oxide 230, the side surface of the metal oxide 230 is covered by the conductor 260. Therefore, the electric field of the conductor 260, which is used as the first gate electrode, can easily influence the side surface of the metal oxide 230. This improves the on-state current and frequency characteristics of the transistor 200A.

[0527] Insulator 254, like insulator 214, is preferably used as a barrier insulating film to prevent impurities such as water or hydrogen from mixing into transistor 200A from the insulator 280 side. For example, the hydrogen permeability of insulator 254 is preferably lower than that of insulator 224. Furthermore, as shown in Figures 41B and 41C, insulator 254 is preferably in contact with the side surface of metal oxide 230c, the top and side surface of conductor 242a, the top and side surface of conductor 242b, the side surface of metal oxide 230a, the side surface of metal oxide 230b, and the top surface of insulator 224. By adopting this structure, hydrogen contained in insulator 280 can be prevented from penetrating metal oxide 230 from the top or side surface of conductor 242a, conductor 242b, metal oxide 230a, metal oxide 230b, and insulator 224.

[0528] Furthermore, insulator 254 also has the function of inhibiting the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (making it difficult for the aforementioned oxygen to permeate). For example, the oxygen permeability of insulator 254 is preferably lower than that of insulator 280 or insulator 224.

[0529] The insulator 254 is preferably formed by sputtering. By forming the insulator 254 using sputtering in an oxygen-containing atmosphere, oxygen can be added to the vicinity of the region where the insulator 224 contacts the insulator 254. This allows oxygen to be supplied from this region to the metal oxide 230 via the insulator 224. Furthermore, by enabling the insulator 254 to suppress oxygen diffusion upwards, oxygen diffusion from the metal oxide 230 to the insulator 280 can be prevented. Additionally, by enabling the insulator 222 to suppress oxygen diffusion downwards, oxygen diffusion from the metal oxide 230 to the substrate side can be prevented. Thus, oxygen is supplied to the channel-forming region in the metal oxide 230. This reduces oxygen vacancies in the metal oxide 230 and suppresses the constant-on state of the transistor.

[0530] As insulator 254, for example, an insulator containing one or more oxides of aluminum and hafnium can be formed. Note that as an insulator containing one or both of aluminum and hafnium, aluminum oxide, hafnium oxide, oxides containing aluminum and hafnium (hafnium aluminate), etc. are preferred.

[0531] In this way, by means of an insulator 254 that blocks hydrogen and covering insulators 224, 250, and metal oxide 230, insulator 280 is separated from insulator 254, insulator 224, metal oxide 230, and insulator 250. Thus, impurities such as hydrogen can be suppressed from entering the transistor 200A from the outside, thereby imparting good electrical characteristics and reliability to the transistor 200A.

[0532] The insulator 280 is preferably disposed on the insulator 224, the metal oxide 230, and the conductor 242, with the insulator 254 as a separator. For example, the insulator 280 is preferably made of silicon oxide, silicon oxynitride, silicon oxynitride, fluorine-added silicon oxide, carbon-added silicon oxide, silicon oxide with carbon and nitrogen added, or porous silicon oxide. In particular, silicon oxide and silicon oxynitride are preferred because they have thermal stability. In particular, materials such as silicon oxide, silicon oxynitride, and porous silicon oxide are preferred because they readily form regions containing oxygen that is released by heating.

[0533] Furthermore, it is preferable that the concentration of impurities such as water or hydrogen in the insulator 280 is reduced. Additionally, the top surface of the insulator 280 can also be planarized.

[0534] Insulator 274 is preferably a barrier insulating film used in the same way as insulator 214 to prevent impurities such as water or hydrogen from mixing into insulator 280 from above. As insulator 274, for example, an insulator that can be used for insulator 214, insulator 254, etc. can be used.

[0535] Furthermore, it is preferable to provide an insulator 281, which serves as an interlayer film, on the insulator 274. Similar to the insulator 224, it is preferable that the concentration of impurities such as water or hydrogen in the insulator 281 is reduced.

[0536] Furthermore, conductors 240a and 240b are disposed in openings formed in insulators 281, 274, 280, and 254. Conductors 240a and 240b are arranged such that conductor 260 is sandwiched between them. Additionally, the top surfaces of conductors 240a and 240b can be on the same plane as the top surface of insulator 281.

[0537] Furthermore, an insulator 241a is provided in contact with the inner wall of the openings of insulators 281, 274, 280, and 254, and a first conductor 240a is formed in contact with its side surface. A conductor 242a is located at least a portion of the bottom of the opening, and the conductor 240a is in contact with the conductor 242a. Similarly, an insulator 241b is provided in contact with the inner wall of the openings of insulators 281, 274, 280, and 254, and a first conductor 240b is formed in contact with its side surface. A conductor 242b is located at least a portion of the bottom of the opening, and the conductor 240b is in contact with the conductor 242b.

[0538] Conductors 240a and 240b are preferably made of conductive materials with tungsten, copper, or aluminum as the main components. Alternatively, conductors 240a and 240b may also have a laminated structure.

[0539] When the conductor 240 is constructed using a multilayer structure, the conductor in contact with the metal oxide 230a, metal oxide 230b, conductor 242, insulator 254, insulator 280, insulator 274, and insulator 281 is preferably a conductor that has the function of suppressing the diffusion of impurities such as water or hydrogen. For example, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or ruthenium oxide are preferably used. The conductive material with the function of suppressing the diffusion of impurities such as water or hydrogen can be used as a single layer or in multilayers. By using this conductive material, oxygen added to the insulator 280 can be prevented from being absorbed by the conductors 240a and 240b. Furthermore, impurities such as water or hydrogen can be prevented from entering the metal oxide 230 from the layer above the insulator 281 via the conductors 240a and 240b.

[0540] As insulators 241a and 241b, insulators suitable for insulators 254, for example, can be used. Because insulators 241a and 241b are disposed in contact with insulator 254 and ground, it is possible to suppress the introduction of impurities such as water or hydrogen from insulator 280 into the metal oxide 230 via conductors 240a and 240b. Furthermore, it is possible to prevent the absorption of oxygen contained in insulator 280 by conductors 240a and 240b.

[0541] Although not shown, the conductor used for wiring can be configured to contact the top surfaces of conductors 240a and 240b. Preferably, the conductor used for wiring is a conductive material primarily composed of tungsten, copper, or aluminum. Furthermore, the conductor can have a multilayer structure, for example, a multilayer structure of titanium, titanium nitride, and the aforementioned conductive material. Additionally, the conductor can also be formed by embedding it within an opening in an insulator.

[0542] <Example 2 of Transistor Structure> Figures 42A, 42B, and 42C are top and cross-sectional views of a transistor 200B and its surrounding area in a display device that can be used in one embodiment of the present invention. The transistor 200B is a modified example of the transistor 200A.

[0543] Figure 42A is a top view of transistor 200B. Furthermore, Figures 42B and 42C are cross-sectional views of transistor 200B. Here, Figure 42B is a cross-sectional view along the dashed line B1-B2 in Figure 42A, which corresponds to a cross-sectional view along the channel length direction of transistor 200B. Figure 42C is a cross-sectional view along the dashed line B3-B4 in Figure 42A, which corresponds to a cross-sectional view along the channel width direction of transistor 200B. Note that for ease of understanding, some components are omitted in the top view of Figure 42A.

[0544] In transistor 200B, conductors 242a and 242b have regions overlapping with metal oxide 230c, insulator 250, and conductor 260. Therefore, transistor 200B can be a transistor with high on-state current. Furthermore, transistor 200B can be a transistor that is easily controlled.

[0545] The conductor 260 used as the gate electrode includes a conductor 260a and a conductor 260b on the conductor 260a. The conductor 260a is preferably made of a conductive material that has the function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. Furthermore, it is preferable to use a conductive material that has the function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms and oxygen molecules).

[0546] By giving conductor 260a the function of inhibiting oxygen diffusion, the material selectivity of conductor 260b can be improved. In other words, by including conductor 260a, the oxidation of conductor 260b can be inhibited, thereby inhibiting the decrease in conductivity.

[0547] Furthermore, it is preferable to provide the insulator 254 in such a way that it covers the top and side surfaces of the conductor 260, the side surfaces of the insulator 250, and the side surfaces of the metal oxide 230c. Preferably, the insulator 254 is made of an insulating material that has the function of suppressing the diffusion of impurities such as water or hydrogen and oxygen.

[0548] By providing insulator 254, oxidation of conductor 260 can be suppressed. In addition, by including insulator 254, impurities such as water and hydrogen contained in insulator 280 can be suppressed from diffusing into transistor 200B.

[0549] <Example 3 of transistor structure> Figures 43A, 43B, and 43C are top and cross-sectional views of a transistor 200C and its surroundings in a display device that can be used in one embodiment of the present invention. The transistor 200C is a modified example of the transistor 200A.

[0550] Figure 43A is a top view of transistor 200C. Furthermore, Figures 43B and 43C are cross-sectional views of transistor 200C. Here, Figure 43B is a cross-sectional view along the dashed line C1-C2 in Figure 43A, which corresponds to a cross-sectional view along the channel length direction of transistor 200C. Figure 43C is a cross-sectional view along the dashed line C3-C4 in Figure 43A, which corresponds to a cross-sectional view along the channel width direction of transistor 200C. Note that for ease of understanding, some components are omitted in the top view of Figure 43A.

[0551] In transistor 200C, an insulator 250 is included on metal oxide 230c, and a metal oxide 252 is included on insulator 250. Furthermore, a conductor 260 is included on metal oxide 252, and an insulator 270 is included on conductor 260. Additionally, an insulator 271 is included on insulator 270.

[0552] The metal oxide 252 preferably has the function of suppressing oxygen diffusion. By providing the oxygen-suppressing metal oxide 252 between the insulator 250 and the conductor 260, oxygen diffusion to the conductor 260 is suppressed. In other words, the reduction in the amount of oxygen supplied to the metal oxide 230 can be suppressed. In addition, the oxidation of the conductor 260 can be suppressed.

[0553] Furthermore, metal oxide 252 can be used as part of the gate electrode. For example, an oxide semiconductor that can be used as metal oxide 230 can be used as metal oxide 252. In this case, by forming conductor 260 using sputtering, the resistance of metal oxide 252 can be reduced, making it a conductor. This can be referred to as an OC (Oxide Conductor) electrode.

[0554] Furthermore, metal oxide 252 is sometimes used as part of the gate insulator. Therefore, when silicon oxide or silicon oxynitride, which are materials with high thermal stability, are used as the insulator 250, it is preferable to use a high-k metal oxide, which is a material with a high relative permittivity, as the metal oxide 252. By employing this stacked structure, a transistor 200C with both thermal stability and a high relative permittivity can be formed. Therefore, the gate potential applied during transistor operation can be reduced while maintaining the physical thickness. In addition, the equivalent oxide thickness (EOT) of the insulator used as the gate insulator can be reduced.

[0555] Although the metal oxide 252 in the transistor 200C is shown as a single layer, a stacked structure of two or more layers can also be used. For example, a metal oxide used as part of the gate electrode can be stacked with a metal oxide used as part of the gate insulator.

[0556] When the transistor 200C has a metal oxide 252 and uses the metal oxide 252 as a gate electrode, the on-state current of the transistor 200C can be increased without weakening the influence of the electric field from the conductor 260. Furthermore, when the metal oxide 252 is used as a gate insulator, the distance between the conductor 260 and the metal oxide 230 can be maintained by utilizing the physical thickness of the insulator 250 and the metal oxide 252. This suppresses leakage current between the conductor 260 and the metal oxide 230. Therefore, by having the transistor 200C have a stacked structure of insulator 250 and metal oxide 252, the physical distance between the conductor 260 and the metal oxide 230, as well as the electric field strength applied from the conductor 260 to the metal oxide 230, can be easily adjusted.

[0557] Specifically, the metal oxide 252 can be used by making the oxide semiconductor suitable for the metal oxide 230 low-resistivity. Alternatively, one or more metal oxides selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, and magnesium can be used.

[0558] In particular, it is preferable to use alumina, hafnium oxide, or oxides containing aluminum and hafnium (hafnium aluminate) as insulating layers containing one or both of aluminum and hafnium. Hafnium aluminate, in particular, has higher heat resistance than hafnium oxide. Therefore, it is less prone to crystallization during subsequent heat treatment processes, making it preferable. Note that metal oxide 252 is not a necessary component and can be appropriately designed according to the required transistor characteristics.

[0559] The insulator 270 is preferably made of an insulating material that inhibits the permeation of impurities such as water or hydrogen, as well as oxygen. For example, alumina or hafnium oxide is preferred. This prevents the conductor 260 from oxidizing due to oxygen from above the insulator 270. Furthermore, it inhibits impurities such as water or hydrogen from above the insulator 270 from entering the metal oxide 230 through the conductor 260 and the insulator 250.

[0560] Insulator 271 is used as a hard shield. By providing insulator 271, conductor 260 can be processed in such a way that the side of conductor 260 is substantially perpendicular to the substrate surface. Specifically, the angle formed between the side of conductor 260 and the substrate surface can be 75 degrees or more and 100 degrees or less, preferably 80 degrees or more and 95 degrees or less.

[0561] Alternatively, the insulator 271 can also function as a barrier layer by using an insulating material that inhibits the permeation of impurities such as water or hydrogen and oxygen. In this case, the insulator 270 may not be required.

[0562] By using insulator 271 as a hard mask, selectively removing a portion of insulator 270, conductor 260, metal oxide 252, insulator 250 and metal oxide 230c can make their sides roughly the same and expose a portion of the surface of metal oxide 230b.

[0563] Furthermore, the transistor 200C has regions 243a and 243b on a portion of the exposed metal oxide 230b surface. One of regions 243a and 243b is used as a source region, and the other is used as a drain region.

[0564] For example, regions 243a and 243b can be formed by introducing impurity elements such as phosphorus or boron onto the surface of the exposed metal oxide 230b using methods such as ion implantation, ion doping, plasma immersion ion implantation, or plasma treatment. Note that in this embodiment, "impurity element" refers to an element other than the main component element.

[0565] Alternatively, a metal film can be formed after a portion of the surface of the metal oxide 230b is exposed, followed by a heat treatment to diffuse the elements contained in the metal film into the metal oxide 230b, thereby forming regions 243a and 243b.

[0566] The resistivity decreases in a portion of the metal oxide 230b where the impurity element is introduced. Therefore, regions 243a and 243b are sometimes referred to as "impurity regions" or "low-resistance regions".

[0567] By using insulator 271 and / or conductor 260 as a shield, regions 243a and 243b can be formed in a self-aligned manner. Therefore, regions 243a and / or 243b do not overlap with conductor 260, reducing parasitic capacitance. Furthermore, the bias region is not formed between the channel formation region and the source / drain regions (region 243a or region 243b). By forming regions 243a and 243b in a self-aligned manner, it is possible to achieve increased on-state current, reduced threshold voltage, and increased operating frequency.

[0568] Transistor 200C includes insulator 272 on the sides of insulator 271, insulator 270, conductor 260, metal oxide 252, insulator 250, and metal oxide 230c. Insulator 272 is preferably an insulator with a low relative permittivity. For example, silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, fluorine-added silicon oxide, carbon-added silicon oxide, silicon oxide with carbon and nitrogen added, porous silicon oxide, or resin are preferred. In particular, when silicon oxide, silicon oxynitride, silicon oxynitride, or porous silicon oxide is used for insulator 272, excess oxygen regions can easily form in insulator 272 during subsequent processes, which is preferred. Furthermore, silicon oxide and silicon oxynitride have thermal stability, which is also preferred. Additionally, insulator 272 preferably has oxygen-diffusing properties.

[0569] Furthermore, to further reduce the off-state current, a bias region can be provided between the channel formation region and the source / drain regions. The bias region is a region with high resistivity and is a region where the aforementioned impurity elements are not introduced. This bias region can be formed by introducing the aforementioned impurity elements after forming the insulator 272. In this case, the insulator 272 is also used as a shield, similar to the insulator 271. Therefore, the region of the metal oxide 230b overlapping with the insulator 272 is not subject to impurity elements, thereby maintaining a high resistivity in this region.

[0570] Furthermore, the transistor 200C includes an insulator 254 on the insulator 272 and the metal oxide 230. The insulator 254 is preferably formed using a sputtering method. By using a sputtering method, an insulator with few impurities such as water or hydrogen can be formed.

[0571] Sometimes, hydrogen is extracted from the structure formed by sputtering of an oxide film. Therefore, when insulator 254 is formed by sputtering, insulator 254 extracts hydrogen and water from metal oxide 230 and insulator 272. This reduces the hydrogen concentration in metal oxide 230 and insulator 272.

[0572] <Materials that make up transistors> The following describes the constituent materials that can be used in transistors.

[0573] 《Substrate》 Substrates for forming transistors can be, for example, insulator substrates, semiconductor substrates, or conductive substrates. Examples of insulator substrates include glass substrates, quartz substrates, sapphire substrates, stabilized zirconia substrates (yttrium-stabilized zirconia substrates, etc.), and resin substrates. Examples of semiconductor substrates include semiconductor substrates made of silicon or germanium, or compound semiconductor substrates made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, or gallium oxide. Furthermore, semiconductor substrates having insulating regions within the aforementioned semiconductor substrates can also be used, such as SOI (Silicon On Insulator) substrates. Examples of conductive substrates include graphite substrates, metal substrates, alloy substrates, and conductive resin substrates. Alternatively, substrates containing metal nitrides or metal oxides can be used. Furthermore, examples of insulator substrates with conductors or semiconductors, semiconductor substrates with conductors or insulators, and conductive substrates with semiconductors or insulators can also be used. Alternatively, substrates with components mounted on them can be used. Examples of components mounted on the substrate include capacitors, resistors, switching elements, and memory elements.

[0574] Insulators As insulators, there are oxides, nitrides, oxynitrides, nitrogen oxides, metal oxides, metal oxynitrides, and metal nitrogen oxides, etc., which have insulating properties.

[0575] For example, when miniaturizing and hyper-integrating transistors, problems such as leakage current sometimes occur due to the thinning of the gate insulator. By using high-k materials as the gate insulator, it is possible to achieve low voltage operation of the transistor while maintaining the physical thickness. On the other hand, by using materials with relatively low permittivity in the insulator used as the interlayer film, parasitic capacitance generated between wirings can be reduced. Therefore, it is preferable to select materials based on the function of the insulator.

[0576] In addition, examples of insulators with relatively high permittivity 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.

[0577] In addition, examples of insulators with relatively low permittivity include silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, silicon oxide with added fluorine, silicon oxide with added carbon, silicon oxide with added carbon and nitrogen, and porous silicon oxide or resin.

[0578] Furthermore, by surrounding a transistor using an oxide semiconductor with an insulator (such as insulator 214, insulator 222, insulator 254, and insulator 274) that has the function of suppressing the permeation of impurities such as hydrogen and oxygen, the electrical characteristics of the transistor can be stabilized. For example, insulators containing boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium, zirconium, lanthanum, neodymium, hafnium, or tantalum can be used in single layers or in layers to suppress the permeation of impurities such as hydrogen and oxygen. Specifically, as insulators that suppress the permeation of impurities such as hydrogen and oxygen, metal oxides such as aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, or tantalum oxide, as well as metal nitrides such as aluminum nitride, titanium aluminum nitride, titanium nitride, silicon oxynitride, or silicon nitride can be used.

[0579] Furthermore, the insulator used as the gate insulator is preferably an insulator having a region containing oxygen that is removed by heating. For example, by employing a structure in which silicon oxide or silicon oxynitride having a region containing oxygen that is removed by heating is contacted with the metal oxide 230, the oxygen vacancies contained in the metal oxide 230 can be filled.

[0580] <<Conductors>> As a conductor, it is preferable to use a metallic element selected from aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, titanium, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium, zirconium, beryllium, indium, ruthenium, iridium, strontium, and lanthanum, an alloy containing the above-mentioned metallic elements, or an alloy combining the above-mentioned metallic elements. For example, it is preferable to use tantalum nitride, titanium nitride, tungsten, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel. In addition, tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, nitrides containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, oxides containing strontium and ruthenium, and oxides containing lanthanum and nickel are conductive materials that are not easily oxidized or that maintain conductivity even when absorbing oxygen, so they are preferred. In addition, semiconductors with high conductivity, such as polycrystalline silicon containing impurity elements such as phosphorus, and silicides such as nickel silicates can also be used.

[0581] Furthermore, multiple conductive layers formed from the above-described materials can be stacked. For example, a stacked structure combining materials containing the aforementioned metallic elements and conductive materials containing oxygen can also be used. Furthermore, a stacked structure combining materials containing the aforementioned metallic elements and conductive materials containing nitrogen can also be used. Additionally, a stacked structure combining materials containing the aforementioned metallic elements, conductive materials containing oxygen, and conductive materials containing nitrogen can also be used.

[0582] Furthermore, when using metal oxides in the channel forming region of a transistor, it is preferable to employ a laminated structure combining a material containing the aforementioned metal element and an oxygen-containing conductive material as the conductor used as the gate electrode. In this case, it is preferable to place the oxygen-containing conductive material on one side of the channel forming region. By placing the oxygen-containing conductive material on one side of the channel forming region, oxygen detached from the conductive material can be easily supplied to the channel forming region.

[0583] In particular, as the conductor used as the gate electrode, it is preferable to use a conductive material containing a metal element and oxygen contained in the metal oxide forming the channel. Alternatively, a conductive material containing the aforementioned metal element and nitrogen can also be used. For example, conductive materials containing nitrogen, such as titanium nitride and tantalum nitride, can also be used. Furthermore, indium tin oxide, indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, and silicon-added indium tin oxide can be used. Additionally, indium gallium zinc oxide containing nitrogen can also be used. By using the above materials, hydrogen contained in the metal oxide forming the channel can sometimes be trapped. Or, hydrogen entering from external insulators or the like can sometimes be trapped.

[0584] Metal Oxides The metal oxide preferably contains at least indium or zinc. More preferably, it contains both indium and zinc. Furthermore, it preferably also contains aluminum, gallium, yttrium, or tin. Alternatively, it may contain one or more of boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium.

[0585] Here, we consider the case where the metal oxide is an In-M-Zn oxide containing indium, element M, and zinc. Note that element M can be aluminum, gallium, yttrium, or tin, etc. Other elements that can be used as element M include boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium. Note that multiple of the above elements can sometimes be combined as element M.

[0586] Note that in this specification and other materials, nitrogen-containing metal oxides are sometimes referred to as metal oxides. Furthermore, nitrogen-containing metal oxides may also be referred to as metal oxynitrides.

[0587] [Structure of metal oxides] Oxide semiconductors (metal oxides) are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include CAAC-OS, polycrystalline oxide semiconductors, nc-OS (nanocrystalline oxide semiconductor), a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors.

[0588] [Impurities] Here, the influence of various impurities in metal oxides is explained. When metal oxides contain alkali metals or alkaline earth metals, defect energy levels can sometimes be formed, thus creating carriers. Therefore, transistors using metal oxides containing alkali metals or alkaline earth metals as channel formation regions tend to have always-on characteristics. Consequently, it is preferable to reduce the concentration of alkali metals or alkaline earth metals in the metal oxide. Specifically, the concentration of alkali metals or alkaline earth metals in the metal oxide, as measured by secondary ion mass spectrometry (SIMS), is 1 × 10¹⁸ atoms / cm³ or less, preferably 2 × 10¹⁶ atoms / cm³ or less.

[0589] Hydrogen contained in metal oxides reacts with oxygen bonded to the metal atom to form water. Therefore, hydrogen contained in metal oxides can sometimes lead to the formation of oxygen vacancies within the metal oxide. When hydrogen enters this oxygen vacancy, it can sometimes generate electrons as carriers. Furthermore, sometimes a portion of the hydrogen bonds with oxygen bonded to the metal atom, generating electrons as carriers. Therefore, transistors using hydrogen-containing metal oxides tend to have always-on characteristics.

[0590] Therefore, it is preferable to minimize the hydrogen content in the metal oxide. Specifically, the hydrogen concentration in the metal oxide, as measured by SIMS analysis, is set to be below 1 × 10²⁰ atoms / cm³, preferably below 1 × 10¹⁹ atoms / cm³, more preferably below 5 × 10¹⁸ atoms / cm³, and even more preferably below 1 × 10¹⁸ atoms / cm³. By using metal oxides with sufficiently reduced impurities in the channel formation region of the transistor, the transistor can possess stable electrical properties.

[0591] Metal oxides used as semiconductors in transistors are preferably thin films with high crystallinity. Using such films can improve the stability or reliability of the transistor. Examples of such films include, for instance, single-crystal metal oxide films or polycrystalline metal oxide films. However, forming single-crystal or polycrystalline metal oxide films on a substrate requires high-temperature or laser heating processes. Therefore, the process cost increases and throughput decreases.

[0592] The structural examples shown in this embodiment and at least a portion of the corresponding diagrams can be implemented in appropriate combinations with other structural examples or diagrams.

[0593] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0594] 10: Electronic devices 10a: Electronic devices 10b: Electronic devices 11: Display device 11a: Display device 11b: Display device 12: Outer shell 12a: Outer shell 12b: Outer shell 13: Optical components 13a: Optical components 13b: Optical components 14: Temples 14a: Temples 14b: Temples 15: Camera device 15a: Camera device 15b: Camera device 16: Display area 16a: Display area 16b: Display area 17a: Nose pad 17b: Nose pad 18: Eyeglass frames 19: Camera 21: Lens 22: Reflector 23: Reflective surface 25: Light 26: Through the light 31: Outer shell 32: Opening 33: Display device 34: Fixed components 35: Optical components 35a: Optical components 35b: Optical components 36: Eyeglass frames 36a: Eyeglass frames 36b: Eyeglass frames 37: Camera device 37a: Camera device 37b: Camera device 40: Light source 40a: Light source 40b: Light source 51: Information Provider Unit 52: Subject Detection Unit 53: Feature Extraction Unit 54: Inference Unit 55: Information Generation Unit 56: Transmitter 57: Receiver 61: Input Layer 62: Intermediate layer 63: Output Layer 71: Data 72: Data 73: Data 74: Data 81: User 82: User 110: Channel Formation Area 111: Source Region 112: Duji Zone 113: Gate electrode 114: Opening 115: Wiring 116: Opening 117: Wiring 118: Opening 119: Opening 120: Opening 121: Wiring 122: Wiring 123: Wiring 130: Channel Formation Area 131: Source Region 132: Dublin Region 133: Gate electrode 134: Opening 135: Wiring 136: Opening 137: Wiring 138: Opening 139: Opening 140: Opening 141: Wiring 142: Wiring 143: Wiring 151: Semiconductors 152: Conductor 200A: Transistor 200B: Transistor 200C: Transistor 205: Conductor 214: Insulator 216: Insulator 222: Insulator 224: Insulator 230: Metal oxides 230a: Metal oxide 230b: Metal oxide 230c: Metal Oxide 240: Conductor 240a: Conductor 240b: Conductor 241: Insulator 241a: Insulator 241b: Insulator 242: Conductor 242a: Conductor 242b: Conductor 243a: Area 243b: Area 244: Insulator 250: Insulator 252: Metal Oxides 254: Insulator 260: Conductor 260a: Conductor 260b: Conductor 270: Insulator 271: Insulator 272: Insulator 274: Insulator 280: Insulator 281: Insulator 301a: Conductor 301b: Conductor 305: Conductor 311: Conductor 313: Conductor 317: Conductor 321: Lower electrode 323: Insulator 325: Upper electrode 331: Conductor 333: Conductor 335: Conductor 337: Conductor 341: Conductor 343: Conductor 347: Conductor 351: Conductor 353: Conductor 355: Conductor 357: Conductor 361: Insulator 363: Insulator 401: Circuit 403: Component Separation Layer 405: Insulator 407: Insulator 409: Insulator 411: Insulator 413: Insulator 415: Insulator 417: Insulator 419: Insulator 421: Insulator 441: Transistor 443: Conductor 445: Insulator 447: Semiconductor Region 449a: Low resistance region 449b: Low resistance region 451: Conductor 453: Conductor 455: Conductor 457: Conductor 459: Conductor 461: Conductor 463: Conductor 465: Conductor 467: Conductor 469: Conductor 471: Conductor 501: Insulator 503: Insulator 505: Insulator 507: Insulator 509: Insulator 511: Transistor 513: Transistor 515: Capacitor 517: Capacitor 520: Circuit 521: Transistor 525: Transistor 527: Transistor 529: Transistor 535: Wiring 537: Wiring 539: Wiring 541: Wiring 543: Wiring 545: Wiring 552: Transistor 554: Transistor 562: Capacitor 572: Light-emitting element 572_1: Light-emitting element 572_2: Light-emitting element 601: Transistor 602: Transistor 603: Transistor 613: Insulator 614: Insulator 616: Insulator 622: Insulator 624: Insulator 644: Insulator 654: Insulator 674: Insulator 680: Insulator 681: Insulator 701:Substrate 705:Substrate 712: Sealant 716:FPC 721: Hole Injection Layer 722: Electric Void Transport Layer 723: Emissive Layer 724: Electron Transport Layer 725: Electron Injection Layer 730: Insulator 732: Sealing layer 734: Insulator 736: Color Layer 738: Light-shielding layer 750: Transistor 760: Connecting electrodes 772: Conductor 778: Structure 780: Anisotropic conductor 786: EL layer 786a: EL layer 786b: EL layer 786c: EL layer 788: Conductor 790: Capacitor 792: Charge Generation Layer 810: Display device 820: Floor 821: Gate drive circuit 821a: Gate drive circuit 821b: Gate drive circuit 822: Source drive circuit 823: Area 823a: Area 823b: Area 824: Demultiplexing circuit 830: Floor 831: Wiring 831-1: Wiring 831-2: Wiring 831a: Wiring 831b: Wiring 832: Wiring 832-1: Wiring 832-2: Wiring 833: Pixel Array 834: pixels 835a: Wiring 835b: Wiring 840: Circuit 841: Receiver Circuit 842: Series-Parallel Conversion Circuit 843: Buffer Circuit 844: Shift Register Circuit 845: Latch circuit 846: DA Conversion Circui...

Claims

1. A glasses-type electronic device, comprising: a camera device; a feature extraction unit; and an inference unit; Information generation unit; The information providing unit includes: a camera device configured to detect a portion of a user's face; a feature extraction unit configured to extract features of the user's face from information of the portion detected on the user's face; an inference unit configured to infer the user's fatigue level from the features extracted by the feature extraction unit; an information generation unit configured to generate information to be provided to the user based on the fatigue level inferred by the inference unit; and an information providing unit configured to provide the information generated by the information generation unit to the user.

2. A glasses-type electronic device, comprising: a camera device; a feature extraction unit; an inference unit; an information generation unit; an information providing unit; optical elements; and a frame, wherein: The camera device is configured to detect a portion of a user's face. The feature extraction unit is configured to extract features of the user's face from information of the portion detected on the user's face. The inference unit is configured to infer the user's fatigue level from the features extracted by the feature extraction unit. The information generation unit is configured to generate information to be provided to the user based on the fatigue level inferred by the inference unit. The information providing unit is configured to provide the information generated by the information generation unit to the user. The frame is in contact with the side of the optical element, and the camera device is in contact with the frame.

3. A glasses-type electronic device, comprising: a camera device; a feature extraction unit including a neural network; an inference unit; an information generation unit; and an information providing unit, wherein: The camera device is configured to detect portions of a user's face. The camera device is configured to output first data, including information from the detected portions of the user's face, to the neural network. The neural network is configured to extract facial features from the first data. The neural network is configured to output these features as second data to the inference unit. The inference unit is configured to infer the user's physical condition or emotions from the second data. The inference unit is configured to output third data, including the inferred physical condition or emotions, to the information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred physical condition or emotions from the third data, and the information providing unit provides the fourth data to the user in the form of an image or sound.

4. A glasses-type electronic device, comprising: a camera device; a feature extraction unit including a neural network; an inference unit; an information generation unit; and an information providing unit, wherein: The camera device is configured to detect a portion of a user's face, including the user's eyes and the area surrounding the eyes. The camera device is configured to output first data, including information on the detected portion of the user's face, to the neural network. The neural network is configured to extract features of the user's face from the first data. The neural network is configured to output these features as second data to the inference unit. The inference unit is configured to infer the user's physical condition or emotion from the second data. The inference unit is configured to output third data, including the inferred physical condition or emotion, to the information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred physical condition or emotion from the third data, and the information providing unit provides the fourth data to the user in the form of an image or sound.

5. A glasses-type electronic device, comprising: a camera device; a feature extraction unit including a neural network; an inference unit; an information generation unit; and an information providing unit, wherein: The camera device is configured to detect a portion of a user's face, including the user's eyes and the area surrounding the eyes. The camera device is configured to output first data, including information on the detected portion of the user's face, to the neural network. The neural network is configured to extract features of the user's face from the first data. The neural network is configured to output the features as second data to the inference unit. The inference unit is configured to infer the user's physical condition or multiple emotions from the second data. The inference unit is configured to output third data, including the inferred physical condition or multiple emotions, to the information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred physical condition or multiple emotions from the third data, and the information providing unit provides the fourth data to the user in the form of an image or sound.

6. A glasses-type electronic device, comprising: a camera device; a feature extraction unit including a first neural network; an inference unit; an information generation unit; and an information providing unit, wherein: The camera device is configured to detect a portion of a user's face, including the user's eyes and the area surrounding the eyes. The camera device is configured to output first data, including information from the detected portion of the user's face, to a first neural network. The first neural network is configured to extract facial features from the first data. The first neural network is configured to output these features as second data to an inference unit. The inference unit is configured to infer the user's physical condition or emotions from the second data through reasoning by the second neural network. The inference unit is configured to output third data, including the inferred physical condition or emotions, to an information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred physical condition or emotions from the third data, and the information providing unit provides the fourth data to the user in the form of an image or sound.

7. A glasses-type electronic device, comprising: a camera device; a feature extraction unit including a first neural network; an inference unit including a second neural network; an information generation unit; and an information providing unit, wherein: The camera device is configured to detect a portion of a user's face, including the user's eyes and the area surrounding the eyes. The camera device is configured to output first data, including information from the detected portion of the user's face, to a first neural network. The first neural network is configured to extract facial features from the first data. The first neural network is configured to output these features as second data to a second neural network. The second neural network is configured to infer the user's physical condition or emotional state from the second data through reasoning. The second neural network is configured to output third data, including the inferred level of the physical condition or emotional state, to an information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred level of the physical condition or emotional state from the third data, and the information providing unit provides the fourth data to the user in the form of an image or sound.

8. A glasses-type electronic device, comprising: a camera device including a first light-emitting element; a feature extraction unit including a neural network; an inference unit; an information generation unit; and an information providing unit including a second light-emitting element, wherein: The camera device is configured to detect a portion of a user's face, including the user's eyes and the area surrounding the eyes. The camera device is configured to output first data, including information from the detected portion of the user's face, to a neural network. The neural network is configured to extract facial features from the first data. The neural network is configured to output these features as second data to an inference unit. The inference unit is configured to infer the user's physical condition or multiple emotions from the second data. The inference unit is configured to output third data, including the inferred physical condition or multiple emotions, to an information generation unit. The information generation unit is configured to generate fourth data to be provided to the user based on the inferred physical condition or multiple emotions from the third data, and to an information providing unit. The information providing unit provides the fourth data to the user in the form of an image or sound. The first light-emitting element and the second light-emitting element are disposed on the same insulating layer. The first light-emitting element is configured to emit infrared light onto the user's face, and the image provided to the user includes light emitted from the second light-emitting element.

9. An eyeglass-type electronic device according to any one of claims 3 to 8, wherein, The first data is image data containing coordinates and grayscale values ​​corresponding to those coordinates.

10. An eyeglass-style electronic device, comprising: a camera device; a feature extraction unit including a first neural network; an inference unit including a second neural network; an information generation unit; and an information providing unit.

Images