Electronic apparatus

Abstract

To provide an electronic apparatus capable of recognizing a user's emotions with high accuracy.SOLUTION: An electronic apparatus includes a detection device, a calculation device, and a housing. The housing has a space at a position overlapping with a user's nose when worn by the user. The detection device is located between the housing and the user's nose. The detection device has a function of acquiring user data related to the user's emotions and outputting the user data to the calculation device. The calculation device has a function of generating display data based on the user data and outputting the display data.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device, an input / output device, a driving method thereof, or a manufacturing method thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics. [Background technology]

[0003] As display devices for Augmented Reality (AR) or Virtual Reality (VR), wearable display devices and stationary display devices are becoming popular. Examples of wearable display devices include head mounted displays (HMDs) and glasses-type display devices. Examples of stationary display devices include head-up displays (HUDs).

[0004] Technologies are being considered that provide sensors, cameras, etc. in a head-mounted display to acquire the user's body movements and facial expressions and reflect this information in the display. Patent Documents 1 and 2 disclose configurations in which a camera is provided in a head-mounted display to recognize the user's facial expressions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 122299 [Patent Document 2] Special table number 2018-538593 Summary of the Invention [Problem to be solved by the invention]

[0006] When a detection device is provided in an electronic device to obtain information about a user's emotions, if the detection device is provided at a position far from the user, the detection accuracy will be low, and the user's emotions may not be recognized with high accuracy. Also, if the detection device protrudes from the housing of the electronic device, the detection device may be damaged by interference with the user or other objects, and the reliability of the electronic device may be reduced.

[0007] An object of one embodiment of the present invention is to provide an electronic device that can recognize a user's emotion with high accuracy.Another object of one embodiment of the present invention is to provide an electronic device that can estimate the type and degree of a user's emotion with high accuracy.Another object of one embodiment of the present invention is to provide an electronic device with high reliability.Another object of one embodiment of the present invention is to provide a novel electronic device.

[0008] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0009] One aspect of the present invention is an electronic device having a detection device, a calculation device, and a housing. The housing has a space at a position overlapping with a user's nose when worn by the user. The detection device is located between the housing and the user's nose. The detection device has a function of acquiring user data related to the user's emotions and outputting the user data to the calculation device. The calculation device has a function of generating display data based on the user data and outputting the display data.

[0010] One aspect of the present invention is an electronic device having a detection device, a calculation device, and a housing. The housing has a space at a position overlapping the user's nose when worn by the user. The detection device is located inside the housing so as to overlap the user's nose. The detection device has a function of acquiring user data related to the user's emotions and outputting the user data to the calculation device. The calculation device has a function of generating display data based on the user data and outputting the display data.

[0011] One aspect of the present invention is an electronic device having a detection device, a calculation device, a display device, and a housing. The housing has a space at a position overlapping with a user's nose when worn by the user. The detection device is located between the housing and the user's nose. The detection device has a function of acquiring user data related to the user's emotions and outputting the user data to the calculation device. The calculation device has a function of generating display data based on the user data and outputting the display data to the display device.

[0012] One aspect of the present invention is an electronic device having a detection device, a calculation device, a display device, and a housing. The housing has a space at a position overlapping with a user's nose when worn by the user. The detection device is located inside the housing so as to overlap with the user's nose. The detection device has a function of acquiring user data related to the user's emotions and outputting the user data to the calculation device. The calculation device has a function of generating display data based on the user data and outputting the display data to the display device.

[0013] In the electronic device described above, the detection device preferably has one or more of a temperature sensor, a humidity sensor, a microphone, and an imaging device.

[0014] In the above electronic device, the user data is preferably one or more of temperature, humidity, sound, and image.

[0015] In the electronic device described above, it is preferable that the electronic device further comprises an adjustment mechanism having a function of adjusting an angle of the detection device with respect to the housing.

[0016] In the electronic device described above, the detection device preferably includes an imaging device. The detection device has a function of outputting an image of the user captured as user data to the arithmetic device. The arithmetic device has a function of estimating an emotion of the user from the user data and generating display data based on the estimated emotion.

[0017] In the electronic device described above, the user data is preferably an image of a portion of the user including the nose.

[0018] In the electronic device described above, the user data is preferably an image of a portion of the user including a mouth.

[0019] In the electronic device described above, the estimation preferably uses a neural network. Effect of the Invention

[0020] According to one embodiment of the present invention, an electronic device capable of recognizing a user's emotion with high accuracy can be provided. Alternatively, according to one embodiment of the present invention, an electronic device capable of estimating the type and degree of a user's emotion with high accuracy can be provided. Alternatively, according to one embodiment of the present invention, an electronic device with high reliability can be provided. Alternatively, according to one embodiment of the present invention, a novel electronic device can be provided.

[0021] 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 have all of these effects. Note that effects other than these can be extracted from the description of the specification, drawings, claims, etc. [Brief description of the drawings]

[0022] [Figure 1] 1A and 1B are external views showing a configuration example of an electronic device. [Diagram 2] 2A and 2B are external views showing a configuration example of an electronic device. [Diagram 3] 3A and 3B are block diagrams showing configuration examples of electronic devices. [Figure 4] 4A to 4C are external views showing configuration examples of the housing. [Diagram 5] 5A and 5B are external views showing a configuration example of an electronic device. [Figure 6] 6A and 6B are external views showing a configuration example of an electronic device. [Figure 7] 7A and 7B are diagrams illustrating the housing and the detection device. [Figure 8] 8A and 8B are external views showing a configuration example of an electronic device. [Figure 9] 9A and 9B are external views showing a configuration example of an electronic device. [Figure 10] Fig. 10A is an external view showing a configuration example of an electronic device, and Fig. 10B is a block diagram showing a configuration example of an electronic device. [Figure 11] 11A and 11B are external views showing a configuration example of an electronic device. [Figure 12] FIG. 12 is a block diagram showing an example of the configuration of an electronic device. [Figure 13] FIG. 13 is an external view showing a configuration example of an electronic device. [Figure 14] 14A and 14B are external views showing a configuration example of an electronic device. [Figure 15] FIG. 15 is an external view showing a configuration example of an electronic device. [Figure 16] 16A and 16B are external views showing a configuration example of an electronic device. [Figure 17] FIG. 17 is a block diagram illustrating an example of the configuration of the arithmetic device. [Figure 18] 18A and 18B are diagrams illustrating an example of a neural network configuration, and Fig. 18C is a diagram illustrating emotion estimation. [Figure 19] 19A1 to 19A4 and 19B1 to 19B4 are diagrams showing examples of images including a mouth. [Figure 20] 20A and 20B are diagrams showing examples of a user's field of view. [Figure 21]21A and 21E are diagrams showing examples of a user's field of view. [Figure 22] 22A to 22C are diagrams showing configuration examples of the housing. [Figure 23] 23A and 23B are diagrams showing configuration examples of the housing. [Figure 24] 24A and 24B are external views showing configuration examples of the housing. [Diagram 25] FIG. 25 is a block diagram showing an example of the configuration of a display device. [Figure 26] FIG. 26 is a block diagram showing an example of the configuration of a display device. [Figure 27] 27A to 27G are diagrams showing examples of pixel configurations. [Figure 28] 28A and 28B are circuit diagrams showing examples of the configuration of a pixel. [Figure 29] Fig. 29A is a circuit diagram showing an example of a pixel configuration, and Fig. 29B is a timing chart showing an example of a pixel operation method. [Diagram 30] 30A to 30E are circuit diagrams showing examples of pixel configurations. [Diagram 31] FIG. 31 is a block diagram showing an example of the configuration of a display device. [Diagram 32] FIG. 32 is a diagram illustrating an example of the operation of the display device. [Diagram 33] FIG. 33 is a cross-sectional view showing a configuration example of a display device. [Diagram 34] FIG. 34 is a cross-sectional view showing a configuration example of a display device. [Diagram 35] FIG. 35 is a cross-sectional view showing a configuration example of a display device. [Diagram 36] FIG. 36 is a cross-sectional view showing a configuration example of a display device. [Figure 37] 37A to 37E are diagrams showing configuration examples of a light-emitting device. [Figure 38] 38A and 38B are cross-sectional views showing configuration examples of an imaging device. [Figure 39]Fig. 39A is a top view illustrating an example of the configuration of a transistor, and Fig. 39B and Fig. 39C are cross-sectional views illustrating an example of the configuration of a transistor. [Diagram 40] Fig. 40A is a top view illustrating an example of the configuration of a transistor, and Fig. 40B and Fig. 40C are cross-sectional views illustrating an example of the configuration of a transistor. [Diagram 41] Fig. 41A is a top view illustrating an example of the configuration of a transistor, and Fig. 41B and Fig. 41C are cross-sectional views illustrating an example of the configuration of a transistor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiments will be described with reference to the drawings. However, it will be easily understood by those skilled in the art that the embodiments can be implemented in many different ways, and that the modes and details can be changed in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the following embodiments.

[0024] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and the repeated explanations are omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be used.

[0025] In addition, in each figure described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0026] In addition, ordinal numbers such as "first" and "second" in this specification are used to avoid confusion of components and do not limit the numbers.

[0027] In this specification, the terms indicating the arrangement, such as "above," "below," "to the left," and "to the right," are used for convenience in describing the positional relationship between components with reference to the drawings. Furthermore, the positional relationship between components changes as appropriate depending on the direction in which each component is depicted. Therefore, the terms are not limited to those described in the specification, and can be rephrased appropriately depending on the situation.

[0028] A transistor is a type of semiconductor element and can realize a switching operation for amplifying a current or a voltage, controlling conduction or non-conduction, etc. In this specification, the term "transistor" includes an IGFET (Insulated Gate Field Effect Transistor) and a thin film transistor (TFT: Thin Film Transistor).

[0029] In this specification and the like, the functions of the source and drain of a transistor may be interchanged when the polarity of the transistor or the direction of current flow in a circuit operation is changed, etc. For this reason, the terms source and drain can be used interchangeably.

[0030] In this specification, "electrically connected" includes a direct connection and a connection via "something having some electrical action". Here, "something having some electrical action" is not particularly limited as long as it allows the transmission and reception of electrical signals between the connection objects. Therefore, even when it is expressed as "electrically connected", in an actual circuit, there may be no physical connection part and only wiring extending. In addition, even when it is expressed as "direct connection", it includes a case where different conductors are connected via contacts. Note that in the wiring, there are cases where different conductors contain one or more of the same element and cases where they contain different elements.

[0031] In this specification, unless otherwise specified, the off-state current refers to the drain current when the transistor is in an off state (also called a non-conducting state or a cut-off state). Unless otherwise specified, the off-state current refers to the voltage V between the gate and the source of an n-channel transistor. gs is the threshold voltage V th (For p-channel transistors, V th The term "higher" refers to a state of being.

[0032] In this specification and the like, the terms "electrode" and "wiring" do not limit the functionality of these components. For example, an "electrode" may be used as part of a "wiring", and vice versa. Furthermore, the terms "electrode" and "wiring" also include cases where multiple "electrodes" or "wirings" are formed integrally.

[0033] In this specification, the resistance value of a "resistor" may be determined by the length of the wiring. Alternatively, the resistance value may be determined by connecting a conductor having a different resistivity from the conductor used in the wiring. Alternatively, the resistance value may be determined by doping an impurity into a semiconductor.

[0034] In this specification and the like, a "terminal" in an electric circuit refers to a portion where a current or voltage is input or output, or a signal is received or transmitted. Therefore, a part of a wiring or an electrode may function as a terminal.

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

[0036] (Embodiment 1) In this embodiment, an electronic device of one embodiment of the present invention will be described with reference to drawings.

[0037] One embodiment of the present invention is an electronic device including a display device, a detection device, a calculation device, and a housing. The detection device has a function of acquiring data related to a user's emotion and outputting the data to the calculation device. The calculation device has a function of generating display data based on the data and outputting the display data to the display device.

[0038] For example, the temperature, humidity, or image around the nose or mouth can be used as data related to the user's emotions. When a user using an electronic device becomes excited, the temperature and humidity around the nose or mouth may increase. By acquiring the temperature or humidity around the nose or mouth, the degree of the user's excitement can be estimated. By acquiring an image of the mouth, the type and degree of the user's emotion can be estimated. In addition, by displaying the estimated user's emotion on the electronic device, the user can recognize his or her own condition and increase the sense of immersion.

[0039] An electronic device according to one aspect of the present invention has a space in a portion of the housing where the nose of the user is located, and the above-mentioned detection device is located in the space. By providing the detection device near the nose of the user, the user's emotions can be recognized with higher accuracy. Furthermore, by providing the detection device in the space and preventing the detection device from protruding from the housing, interference between the detection device and the user or other objects can be suppressed, and the reliability of the electronic device can be improved.

[0040] <Electronic device configuration example 1> 1A, 1B, 2A, 2B, and 3A show configuration examples of an electronic device according to one embodiment of the present invention. 1A, 1B, 2A, and 2B are perspective views illustrating the appearance of an electronic device 10. FIG. 3A is a block diagram showing the configuration of the electronic device 10.

[0041] In the drawings attached to this specification, the components are classified by function and shown in block diagrams as independent blocks. However, in reality, it is difficult to completely separate the components by function, and one component may be involved in multiple functions, or one function may be realized by multiple components.

[0042] The electronic device 10 has a function of displaying an image. The electronic device 10 can be used as a head mounted display (HMD). The electronic device 10 can be suitably used as a display device that displays images for augmented reality (AR) or virtual reality (VR). The electronic device 10 can also be called a goggle-type electronic device.

[0043] As shown in FIGS. 1A and 1B, the electronic device 10 has a housing 11 and a detection device 17. The housing 11 has a space 41 at the bottom, and the detection device 17 is provided in the space 41. The space 41 can also be called a recess in the housing 11. The space 41 is provided at a position where the space 41 overlaps with the user's nose when the user wears the electronic device 10. In FIG. 1B, the housing 11 is shown by a dashed line to clearly show the positional relationship between the housing 11 and the detection device 17. The electronic device 10 shown in FIGS. 1A and 1B can be used as an HMD by combining it with another electronic device having a display unit.

[0044] 2A and 2B, the electronic device 10 may include a housing 11, a display device 13, a detection device 17, a computing device 19, and a storage device 18. The electronic device 10 may further include an optical member 15L and an optical member 15R. In FIG. 2B, the housing 11 is shown by a dashed line in order to clearly show the positional relationship between the housing 11, the display device 13, the detection device 17, the computing device 19, the storage device 18, the optical member 15L, and the optical member 15R.

[0045] The display device 13 has pixels and has a function of displaying an image. For example, a liquid crystal display device, a light-emitting device (for example, a light-emitting device having a light-emitting device in each pixel), an electrophoretic display device, a DMD (Digital Micromirror Device), a PDP (Plasma Display Panel), an FED (Field Emission Display), etc. can be used as the display device 13.

[0046] As the light-emitting device, it is preferable to use an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of the light-emitting material that the light-emitting device has include a material that emits fluorescence (fluorescent material), a material that emits phosphorescence (phosphorescent material), a material that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF material), and an inorganic compound (such as a quantum dot material). Also, an LED such as a micro LED (Light Emitting Diode) can be used as the light-emitting device.

[0047] When the electronic device 10 is used as a head-mounted display, the distance between the user's eyes and the display device 13 is short, so that the user can easily see the pixels and feel a strong sense of graininess, which may reduce the immersive feeling and realism of AR or VR. For this reason, it is preferable that the display device 13 has high resolution so that the user cannot see the pixels. By using a display device 13 with high resolution, the user of the electronic device 10 can see the image displayed on the display device 13 without feeling a sense of graininess. The resolution of the display device 13 is preferably, for example, 1000 ppi or more, more preferably 2000 ppi or more, and even more preferably 5000 ppi or more. In addition, in AR applications, an image of a virtual space is displayed superimposed on a real space, so that the brightness of the display device 13 is desirably high, especially when the usage environment is bright.

[0048] The detection device 17 has a function of acquiring information on the environment surrounding the electronic device 10 or data on the user's emotions (hereinafter also referred to as user data) and outputting it to the calculation device 19. For example, temperature, humidity, sound, images, etc. can be used as the user data. For example, a temperature sensor, a humidity sensor, a microphone, or an imaging device can be used as the detection device 17. For example, a camera or a video camera can be used as the imaging device. Note that a combination of a plurality of these may be used as the detection device 17.

[0049] The arithmetic device 19 has a function of generating display data corresponding to the user's emotion by arithmetically processing the user data output from the detection device 17 , and outputting the display data to the display device 13 .

[0050] For example, a central processing unit (CPU), a digital signal processor (DSP), a graphics processing unit (GPU), etc. may be used as the arithmetic device 19. The arithmetic device 19 may also be configured to be realized by a programmable logic device (PLD) such as a field programmable gate array (FPGA) or a field programmable analog array (FPAA).

[0051] The storage device 18 has a function of storing programs executed by the arithmetic unit 19, data input to the arithmetic unit 19, data output from the arithmetic unit 19, and the like.

[0052] A storage device to which a nonvolatile storage element is applied can be suitably used as the storage device 18. For example, a flash memory, a Magnetoresistive Random Access Memory (MRAM), a Phase change RAM (PRAM), a Resistive RAM (ReRAM), a Ferroelectric RAM (FeRAM), or the like can be used as the storage device 18.

[0053] FIG. 3B shows a configuration different from that of electronic device 10 shown in FIG. 3A.

[0054] The electronic device 10 shown in Fig. 3A has an input / output device 21. The input / output device 21 has a function of acquiring information from outside the electronic device 10 and a function of outputting information to the outside. The input / output device 21 also has a function of acquiring information from the arithmetic device 19 and a function of outputting information to the arithmetic device 19. The information acquired from outside the electronic device 10 is, for example, content such as video, music, and games. The information output to outside the electronic device 10 is, for example, the user's emotions acquired by the electronic device 10.

[0055] The input / output device 21 can communicate with a wired or wireless network, and can input and output information with the server 23 via the network. When wireless communication is used in the network, various communication means can be used, such as short-range communication means such as Wi-Fi (registered trademark) and Bluetooth (registered trademark), communication means conforming to the third generation mobile communication system (3G), communication means conforming to LTE (sometimes called 3.9G), communication means conforming to the fourth generation mobile communication system (4G), or communication means conforming to the fifth generation mobile communication system (5G).

[0056] The housing 11 will be described with reference to Figures 4A to 4C. Figures 4A to 4C are external views showing the configuration of the housing 11. Figure 4B shows the display device 13 and the detection device 17 with dashed lines to show the positional relationship between the display device 13 and the detection device 17 and the housing 11.

[0057] The housing 11 has a first portion 12a, a second portion 12b, a third portion 12c, a fourth portion 12d, and a fifth portion 12e. Figures 4A and 4B show perspective views from the opposite side (user side) of the first portion 12a, and Figure 4C shows a perspective view from the first portion 12a side (opposite side to the user).

[0058] The second portion 12b is connected to the first portion 12a. The third portion 12c is connected to the second portion 12b via the first portion 12a. The third portion 12c has a space 41 shown by a dashed line in FIG. 4A and FIG. 4B. The fourth portion 12d is connected to the first portion 12a, the second portion 12b, and the third portion 12c. The fifth portion 12e is connected to the first portion 12a, the second portion 12b, and the third portion 12c. The first portion 12a to the fifth portion 12e may be detachable from each other. Note that FIG. 4A and the like show a configuration example in which the fourth portion 12d and the fifth portion 12e are not connected, but one embodiment of the present invention is not limited to this. The fourth portion 12d and the fifth portion 12e may be connected.

[0059] As shown in Fig. 4B, the display device 13 is located between the second portion 12b and the third portion 12c. The display device 13 may be fixed to one or more of the first portion 12a and the fifth portion 12e. The detection device 17 is provided in the space 41 of the third portion 12c.

[0060] The positional relationship between the housing 11, the display device 13, the detection device 17, the calculation device 19, the storage device 18, the optical members 15L and 15R will be described with reference to FIGS. 2A, 2B, 5A, 5B, 6A and 6B.

[0061] FIG. 5A is an external view of the electronic device 10 seen from the opposite side (user side) of the first portion 12a. FIG. 5B is an external view of the electronic device 10 seen from the fourth portion 12d side (user's left side). FIG. 6A is an external view of the electronic device 10 seen from the second portion 12b side (user's upper side). FIG. 6B is an external view of the electronic device 10 seen from the third portion 12c side (user's lower side). In FIG. 5A, FIG. 5B, FIG. 6A, and FIG. 6B, the first portion 12a, the second portion 12b, the third portion 12c, the fourth portion 12d, and the fifth portion 12e are shown by dashed lines. Also, FIG. 5B and FIG. 6A show an example when the electronic device 10 is worn by a user. In FIG. 5B, the detection device 17, the storage device 18, and the calculation device 19 are omitted for clarity.

[0062] It is preferable that the detection device 17 is fixed to the third portion 12c. Moreover, as shown in FIG. 5B and the like, it is preferable that the detection device 17 does not protrude from the housing 11. If the detection device 17 protrudes from the housing 11, there is a risk that the detection device 17 may interfere with the user or another object, resulting in damage to the detection device 17. By providing the detection device 17 in the space 41 and not protruding from the housing 11, it is possible to prevent damage to the detection device 17. Therefore, it is possible to improve the reliability of the electronic device 10. Moreover, it is possible to reduce the size of the electronic device 10, and to improve the convenience and design.

[0063] The space 41 will be described. An enlarged view of the space 41 as viewed from the fourth portion 12d side (the left side of the user) is shown in Fig. 7A. An enlarged view of the space 41 as viewed from the third portion 12c side (the lower side of the user) is shown in Fig. 7B.

[0064] 5B, 7A, and 7B, it is preferable that the space 41 has a shape that widens from the top to the bottom. In addition, it is preferable that the side of the space 41 is at an angle that allows the detection device 17 to easily obtain information about the user's nose or mouth.

[0065] The angle θ1 between the housing 11 and the lower bottom of the space 41 is preferably 120 degrees or more and 170 degrees or less, more preferably 130 degrees or more and 165 degrees or less, more preferably 135 degrees or more and 160 degrees or less, more preferably 140 degrees or more and 160 degrees or less, more preferably 145 degrees or more and 155 degrees or less, and more preferably 150 degrees or more and 155 degrees or less. The length LB of the space 41 is preferably 30 mm or more and 100 mm or less, more preferably 40 mm or more and 95 mm or less, more preferably 50 mm or more and 90 mm or less, more preferably 60 mm or more and 85 mm or less, and more preferably 70 mm or more and 80 mm or less. The length LH of the space 41 is preferably 30 mm or more and 100 mm or less, more preferably 40 mm or more and 95 mm or less, more preferably 50 mm or more and 90 mm or less, more preferably 60 mm or more and 85 mm or less, and even more preferably 70 mm or more and 80 mm or less. By making the space 41 into the above-mentioned shape, the detection device 17 can be provided at a position that does not interfere with the user's nose. Furthermore, the detection device 17 can be provided at an angle that makes it easy to obtain information about the user's nose or mouth.

[0066] As shown in Fig. 5B, it is preferable that the housing 11 does not cover the mouth of the user. If the housing is configured to cover the mouth, the user may feel discomfort or pressure. The electronic device 10 according to one embodiment of the present invention can obtain information about the user's mouth without the housing 11 covering the user's mouth.

[0067] Although FIG. 2A and the like show a configuration in which the detection device 17 is located outside the housing 11, one embodiment of the present invention is not limited to this. As shown in FIG. 8A, the detection device 17 may be provided inside the housing 11. By providing the detection device 17 inside the housing 11, interference between the user and the detection device 17 can be suppressed, and the reliability of the electronic device can be improved. In addition, the housing 11 may have an opening (not shown) located between the detection device 17 and the user. By having the opening in the housing 11, the detection accuracy of the detection device 17 can be improved.

[0068] 8B shows an enlarged view of space 41. It is preferable that angle θ1 between housing 11 and the lower bottom of space 41 be within the above-mentioned range.

[0069] The electronic device 10 may have an adjustment mechanism for adjusting the position and angle of the detection device 17. Figures 9A and 9B show a configuration in which the electronic device 10 has an adjustment mechanism 45. The adjustment mechanism 45 has a function of adjusting the position and angle of the detection device 17, and can easily acquire the state of each nose and mouth according to the user. The adjustment mechanism 45 is preferably fixed to the housing 11.

[0070] It is preferable that the angle θ2 between the housing 11 and the detection device 17 is in the range of the angle θ1 described above. By setting the angle θ2 in the range described above, the detection device 17 can be provided at a position that does not interfere with the user's nose. Furthermore, the detection device 17 can be provided at an angle that makes it easy to obtain information about the user's nose or mouth. For example, by making the angle 2θ smaller, it is easy to obtain information about the user's nose. For example, by making the angle 2θ larger, it is easy to obtain information about the user's mouth.

[0071] In FIG. 2A and other figures, a configuration in which one detection device 17 is provided in the space 41 is shown, but one aspect of the present invention is not limited to this. A plurality of detection devices 17 may be provided in the space 41. FIG. 10A shows an external view of the electronic device 10 in which the detection device 17L and the detection device 17R are provided in the space 41. FIG. 10B shows a block diagram showing the configuration of the electronic device 10. FIG. 10A is an external view of the electronic device 10 as seen from the opposite side (user side) of the first portion 12a. In FIG. 10A, the first portion 12a, the second portion 12b, the third portion 12c, the fourth portion 12d, and the fifth portion 12e are indicated by dashed lines.

[0072] For example, in space 41, detection device 17L can be provided on the left side of the user, and detection device 17R can be provided on the right side of the user. In this case, detection device 17L can obtain information on the left side of the user's nose, and detection device 17R can obtain information on the right side of the nose. Also, the angles at which detection devices 17L and 17R are provided may be adjusted so that detection device 17L can obtain information on the right side of the user's mouth, and detection device 17R can obtain information on the left side of the user's mouth.

[0073] The user data acquired by the detection device 17L and the detection device 17R are output to the calculation device 19. By using a plurality of detection devices, the emotion of the user can be acquired with higher accuracy.

[0074] The arithmetic device 19 and the storage device 18 are each located between the second portion 12b and the third portion 12c. The arithmetic device 19 and the storage device 18 may each be fixed to one or more of the first portion 12a, the second portion 12b, the third portion 12c, the fourth portion 12d, and the fifth portion 12e. Note that, although an example in which the arithmetic device 19 and the storage device 18 are located on the fifth portion 12e side is shown in FIG. 2A and the like, one embodiment of the present invention is not limited thereto.

[0075] The optical member 15L and the optical member 15R are each located between the second portion 12b and the third portion 12c. The optical member 15L and the optical member 15R may each be fixed to one or more of the first portion 12a, the second portion 12b, the third portion 12c, the fourth portion 12d, and the fifth portion 12e.

[0076] As shown in FIG. 5B and other figures, the detection device 17 is provided in the space 41. When the electronic device 10 is in use, the user's nose is located in the space 41. The space 41 preferably has a shape that widens from the top to the bottom. In other words, the space 41 preferably has a shape that widens from the second portion 12b side to the third portion 12c side. By having the space 41 have such a shape, the detection device 17 provided in the space 41 can easily obtain information about the area around the user's nose or mouth.

[0077] When a user becomes excited while using the electronic device 10, the user's body temperature rises, and the temperature of the nasal breath and exhaled air also rises, which may cause the temperature of the environment around the nose and mouth to rise. By using a temperature sensor as the detection device 17 to obtain the temperature of the environment around the nose or mouth, the degree of the user's excitement can be estimated. For example, it can be estimated that the higher the temperature of the environment around the nose or mouth, the higher the degree of the user's excitement.

[0078] When a user becomes excited while using the electronic device 10, the body temperature may rise and the skin temperature around the nose or mouth may also rise. By using a temperature sensor as the detection device 17 to obtain the skin temperature around the nose and mouth, the degree of the user's excitement can be estimated. For example, it can be estimated that the higher the skin temperature around the nose and mouth, the higher the degree of the user's excitement.

[0079] When a user becomes excited while using the electronic device 10, breathing may become faster and the humidity of the environment around the nose or mouth may increase due to breathing and exhalation. By using a humidity sensor as the detection device 17 to obtain the humidity of the environment around the nose and mouth, the degree of excitement of the user can be estimated. For example, it can be estimated that the higher the humidity of the environment around the nose and mouth, the higher the degree of excitement of the user.

[0080] When a user becomes excited while using the electronic device 10, the user may become louder. The degree of excitement of the user can be estimated by acquiring the user's voice using a microphone as the detection device 17. For example, it can be estimated that the louder the volume of the user's voice is, the higher the degree of excitement of the user.

[0081] When a user becomes excited while using the electronic device 10, the user's body temperature may rise and sweat may occur. The degree of excitement of the user can be estimated by capturing an image of the nose or under the nose using an imaging device as the detection device 17 and acquiring the state of sweating on the nose or under the nose. For example, it can be estimated that the greater the amount of sweating on the nose or under the nose, the higher the degree of excitement of the user.

[0082] The type and degree of emotion of the user may change while using the electronic device 10. By capturing an image of the mouth using an imaging device as the detection device 17 and acquiring the shape of the mouth, it is possible to estimate the type and degree of emotion of the user.

[0083] In addition, when an imaging device is used as the detection device 17, the detection device 17 may have a light source (not shown). By having a light source, light emitted from the light source is reflected by the user's face, and the detection device 17 can detect the reflected light. For example, it is preferable that the light source has a function of emitting red light, and the imaging device has a function of detecting red light. For example, it is preferable that the light source has a function of emitting near-infrared light, and the imaging device has a function of detecting near-infrared light. For example, it is preferable that the light source has a function of emitting mid-infrared light, and the imaging device has a function of detecting mid-red light. For example, it is preferable that the light source has a function of emitting far-infrared light, and the imaging device has a function of detecting far-infrared light. This allows the electronic device 10 to accurately acquire the sweating state and mouth shape of the user.

[0084] In this specification, infrared light refers to light having a wavelength of, for example, 0.7 μm or more and 1000 μm or less. Near-infrared light refers to light having a wavelength of, for example, 0.7 μm or more and 2.5 μm or less, and mid-infrared light refers to light having a wavelength of, for example, 2.5 μm or more and 4 μm or less. Far-infrared light refers to light having a wavelength of, for example, 4 μm or more and 1000 μm or less. Note that near-infrared light, mid-infrared light, or far-infrared light may simply be referred to as infrared light. In this specification, red light refers to light having a wavelength of, for example, 0.6 μm or more and 0.75 μm or less.

[0085] The electronic device 10 according to one embodiment of the present invention has a detection device 17, and can acquire the degree of excitement of the user and the type and degree of the user's emotion. In this specification and the like, the degree of excitement of the user and the type and degree of the user's emotion may be collectively referred to as the user's emotion. The electronic device 10 according to one embodiment of the present invention can display information according to the user's emotion on the display device 13. A character (also called an avatar) representing the user may be made to have a facial expression according to the user's emotion and displayed on the display device 13. The user can recognize his / her own emotion, and the sense of immersion can be enhanced. The user can also make a choice, such as taking a break, by recognizing his / her own emotion.

[0086] 5B, the detection device 17 may be configured to be located outside the housing 11. In this case, the detection device 17 is located between the housing 11 and the nose of the user. By configuring the detection device 17 to be located outside the housing 11, there is no housing 11 between the user and the detection device 17, so that the detection accuracy of the detection device 17 can be improved.

[0087] The area of ​​the second portion 12b opposite to the first portion 12a is a portion that contacts the forehead of the user. The area of ​​the third portion 12c opposite to the first portion 12a is a portion that contacts the cheek of the user. Each of the areas preferably has a curved shape, and in particular, preferably has an arc shape toward the first portion 12a. By having the area have a curved or arc shape, the second portion 12b can be closely attached to the forehead or cheek of the user. Therefore, light leakage from the outside of the electronic device 10 is suppressed, and the user can further enhance the sense of immersion. The shape of the housing 11 of the electronic device 10 is not limited to the configuration shown in FIG. 2A and the like.

[0088] The optical member 15L and the optical member 15R each have an area overlapping with the display device 13, and are located between the display device 13 and the user. The user can view the image displayed on the display device 13 through the optical member 15L and the optical member 15R. FIG. 2A and other figures show the optical member 15L for the left eye and the optical member 15R for the right eye. The optical member 15L and the optical member 15R each have a function of enlarging and projecting the image displayed on the display device 13 to the user. For example, a convex lens can be used as the optical member 15L and the optical member 15R. Note that, in FIG. 2A and other figures, the optical member 15L and the optical member 15R are each shown as a single convex lens, but the shape is not particularly limited, and a combination of multiple optical members may be used.

[0089] The optical members 15L and 15R may be made of, for example, plastic or glass. The plastic is preferably a material with high transparency to visible light, and may be, for example, urethane resin, acrylic resin, carbon resin, or allyl resin. In addition, the refractive index of the optical members 15L and 15R may be increased by using a material in which a halogen, an aromatic ring, or sulfur with a large atomic refraction is added to these plastics. As the halogen, it is preferable to use at least one of chlorine, bromine, and iodine.

[0090] <Electronic device configuration example 2> FIG. 2A and other figures show a configuration example in which the electronic device 10 has one display device, but one embodiment of the present invention is not limited thereto. The electronic device according to one embodiment of the present invention may have a plurality of display devices. FIGS. 11A and 11B show a configuration example of an electronic device 10a having two display devices. FIG. 11A is a perspective view illustrating the appearance of the electronic device 10a. FIG. 11B shows the appearance of the electronic device 10a as viewed from the second portion 12b side. In FIGS. 11A and 11B, the housing 11 is shown by a dashed line. Also, FIG. 11B shows an example of the electronic device 10a when worn by a user.

[0091] The electronic device 10a shown in Figures 11A and 11B has a display device 13L and a display device 13R. By having the display device 13L and the display device 13R, the user can see an image displayed on one display device per one eye. This makes it possible to display a high-resolution image even when performing 3D display using parallax.

[0092] A block diagram showing an example of the configuration of the electronic device 10a is shown in Fig. 12. Display data generated by the arithmetic device 19 is output to the display device 13L and the display device 13R as different data.

[0093] As shown in Fig. 13, the electronic device 10a may further include a separator 29. The separator 29 is preferably provided so as to be perpendicular to the display surfaces of the display devices 13L and 13R. The separator 29 is preferably provided closer to the user than the display devices 13L and 13R. The separator 29 separates the fields of view of the left and right eyes, thereby making it possible to make the displays seen by the left and right eyes different, thereby generating binocular parallax. This binocular parallax allows the user to feel a stereoscopic view.

[0094] FIG. 2A and other figures show a configuration example in which the display device of the electronic device is flat, but one embodiment of the present invention is not limited thereto. The display device of the electronic device according to one embodiment of the present invention may be curved. FIGS. 14A and 14B show a configuration example of an electronic device 10b having a curved display device. FIG. 14A is a perspective view illustrating the appearance of the electronic device 10b. FIG. 14B shows the appearance of the electronic device 10b as viewed from the second portion 12b side. In FIGS. 14A and 14B, the housing 11 is shown by a dashed line. Also, FIG. 14B shows an example of the electronic device 10b when worn by a user.

[0095] 14A and 14B show a configuration in which the display device 13L and the display device 13R are curved in an arc shape with the user's eyes approximately at the center. This makes the distance from the user's eyes to the display surface of the display unit constant, allowing the user to view more natural images. Even if the brightness or chromaticity of the light from the display unit changes depending on the viewing angle, the user's eyes are positioned in the normal direction to the display surface of the display unit, so that the effect can be substantially ignored, allowing a more realistic image to be displayed.

[0096] <Electronic device configuration example 3> An example of a configuration different from the above-described electronic device 10 and electronic device 10a is shown in Fig. 15. Fig. 15 is a perspective view illustrating the external appearance of electronic device 10b.

[0097] 15, the electronic device 10b has a housing 11, a detection device 17, a computing device 19, and a storage device 18. The housing 11 has a space 41 in the lower part, in which the detection device 17 is provided. The electronic device 10b differs from the above-described electronic device 10 and electronic device 10a mainly in that the electronic device 10b does not have a display device 13. The electronic device 10b may further have an optical member 15L and an optical member 15R.

[0098] As shown in Fig. 16A and Fig. 16B, the electronic device 10b can be used in combination with another electronic device having a display unit. For example, a smartphone, a portable game machine, or other electronic device can be used as the other electronic device. The other electronic device is connected to the arithmetic device 19 via a connector (not shown) of the electronic device 10b.

[0099] 16A and 16B show a configuration example of a smartphone that can be used as the electronic device 31. The electronic device 31 has a display unit 33, and can function in the same manner as the display device 13 in FIG. 2A by being attached to the inside of the electronic device 10b through the opening 43.

[0100] 15 and 16A show a configuration in which the second portion 12b has the opening 43, but one embodiment of the present invention is not limited thereto. The opening 43 may be provided in any one or more of the first portion 12a to the fifth portion 12e. The electronic device 10b may not have the opening 43. A part of the electronic device 10b may be configured to be detachable, and the electronic device 31 can be attached to the inside of the electronic device 10b by removing the part. For example, the first portion 12a may be configured to be detachable, and the user can attach the electronic device 31 to the inside of the electronic device 10b by removing the first portion 12a. Not having the opening 43 can prevent external light from entering the electronic device 10b.

[0101] <User Emotion Estimation> A method for estimating the emotion of a user will be described below. Here, an example will be described in which an image of the part including the user's mouth is used.

[0102] 17 is a block diagram showing an example of the configuration of the arithmetic unit 19. The arithmetic unit 19 has a feature extraction unit 53, an estimation unit 54, and an information generation unit 55.

[0103] The feature extraction unit 53 has the function of extracting feature points from the image of the area including the user's mouth output from the detection device 17, calculating feature amounts from the positions of the feature points, and outputting the feature amounts to the estimation unit 54.

[0104] When the information acquired by the detection device 17 is an image of a portion including the mouth, for example, the upper end of the upper lip, the lower end of the lower lip, the right corner of the mouth, and the left corner of the mouth can be used as feature points.

[0105] Various algorithms can be applied as a method for extracting features by the feature extraction unit 53. The feature extraction unit 53 can use algorithms such as Scaled Invariant Feature Transform (SIFT), Speeded Up Robust Features (SURF), and Histograms of Oriented Gradients (HOG), for example.

[0106] A neural network can be used for the feature extraction by the feature extraction unit 53. FIG. 18A shows a schematic diagram of a neural network NN1 that can be used in the feature extraction unit 53. The neural network NN1 has an input layer 61, an intermediate layer 62, and an output layer 63. Note that, although FIG. 18A shows a configuration in which the feature extraction unit 53 has three intermediate layers 62, one embodiment of the present invention is not limited to this. The feature extraction unit 53 may have one or more intermediate layers 62.

[0107] Data 71 is input to the neural network NN1. For example, image data captured by the detection device 17 can be used as the data 71. The data 71 includes coordinates and gradation values ​​of each pixel. Data 72 is output from the neural network NN1. The data 72 includes the feature points described above.

[0108] The neural network NN1 is trained in advance to extract the above-mentioned feature points from data 71 such as image data and output their coordinates. The neural network NN1 is trained to perform edge processing using various filters in the intermediate layer 62 so that the neuron values ​​in the output layer 63 corresponding to the coordinates where the above-mentioned feature points exist become high.

[0109] The estimation unit 54 has a function of estimating the emotion of the user of the electronic device 10 from the information of the feature points input from the feature extraction unit 53, and outputting the estimated information to the information generation unit 55. The estimation by the estimation unit 54 can use a neural network.

[0110] FIG. 18B shows a schematic diagram of the neural network NN2 that can be used in the estimation unit 54. FIG. 18B shows a case where the estimation unit 54 estimates the emotion of the user of the electronic device 10. Also, an example is shown in which the neural network NN2 has a configuration generally similar to that of the neural network NN1. Note that the number of neurons in the input layer 61 of the neural network NN2 can be smaller than that of the neural network NN1.

[0111] The neural network NN2 receives data 72 generated by the feature extraction unit 53. The data 72 includes information related to the coordinates of the extracted feature points.

[0112] Data obtained by processing the data 72 may be used as data to be input to the neural network NN2. For example, a vector connecting any two feature points may be calculated, and the vector may be calculated for all or some of the feature points and used as data to be input to the neural network NN2. The calculated vector may also be normalized as data. In the following, data obtained by processing the data 72 output by the neural network NN1 is also referred to as data 72.

[0113] Data 73 is output from the neural network NN2 to which data 72 is input. The data 73 corresponds to a neuron value output from each neuron in the output layer 63. Each neuron in the output layer 63 is associated with one emotion. As shown in FIG. 18B, the data 73 is data including neuron values ​​of neurons corresponding to a predetermined emotion (joy, enjoyment, surprise, disgust, etc.).

[0114] The neural network NN2 is trained in advance to estimate the degree of each emotion from the data 72 and output it as a neuron value. The neural network NN2 can estimate the emotion of the user from the shape of the user's mouth.

[0115] FIG. 18C is a diagram showing data 73. The level of the neuron value corresponding to each emotion indicates the level of the estimated emotion. The estimation unit 54 may estimate the level of another emotion from the level of the estimated emotion. The data including the level of the other emotion is called data 74. FIG. 18C shows a case where the level of interest is estimated from the levels of emotions such as joy, fun, surprise, and disgust.

[0116] The degree of the emotion of interest contained in the data 74 can be estimated by inputting the degrees of emotions such as joy, pleasure, surprise, and disgust contained in the data 73 into a predetermined formula. For example, the formula can be set so that the greater the degree of the emotion of joy, pleasure, or surprise, the greater the degree of the emotion of interest, and the greater the degree of the emotion of disgust, the smaller the degree of the emotion of interest.

[0117] Incidentally, the estimation of emotions can be performed without using a neural network. For example, the estimation can be performed by a template matching method or a pattern matching method that uses the similarity between an image of the part including the user's mouth acquired by the detection device 17 and a template image. In that case, the configuration can be one without the feature extraction unit 53.

[0118] The information generation unit 55 has a function of determining or generating information to be presented to the user based on the emotion estimated by the estimation unit 54, and outputting the information to the display device 13. This enables the display device 13 to present information corresponding to the information generated by the information generation unit 55.

[0119] It should be noted that the data 72 output from the feature extraction unit 53 may be directly input to the information generation unit 55 without being input to the estimation unit 54. For example, even without estimation by the estimation unit 54, the user's emotion can be detected by extraction of feature points by the feature extraction unit 53. In such a case, by directly inputting the data 72 output from the feature extraction unit 53 to the information generation unit 55, it is possible to reduce the power consumption of the electronic device 10.

[0120] Examples of images including the user's mouth that can be used as data 71 are shown in Figs. 19A1 to 19A4. Figs. 19A1 to 19A4 respectively show examples of images including the mouth when the user's emotions are high in "happiness", high in "fun", high in "surprise" and high in "disgust". Figs. 19B1 to 19B4 respectively show examples of extracted feature points from the images including the mouth shown in Figs. 19A1 to 19A4. In Figs. 19B1 to 19B4, the upper end LP of the upper lip TL , L.P. T , L.P. TR , Lower end of lower lip LP BL , L.P. B , L.P. BR , Right corner of mouth LP R , and left corner of mouth LP L 1 shows an example in which the following are extracted as feature points. The feature extraction unit 53 extracts these feature points, and outputs information on the feature points to the estimation unit 54. The estimation unit 54 estimates the user's emotion from the information on the feature points, and outputs the information on the user's emotion to the information generation unit 55. The information estimation unit determines or generates information to be presented to the user from the information on the user's emotion, and outputs the information to be presented to the user to the display device 13. Then, the display device 13 can display the information to be presented to the user.

[0121] <Examples of information presented to users> An example of user information presented on the electronic device will be described below.

[0122] Examples of the field of view of a user when using an electronic device according to one embodiment of the present invention are shown in Figures 20A, 20B, 21A, and 21B. Figures 20A, 20B, 21A, and 21B show examples of the field of view when a user is viewing an image of a tourist spot.

[0123] In Fig. 20A and Fig. 20B, information 81 and information 82 simulating the user's level of excitement are presented at the bottom left of the field of vision, respectively, superimposed on the displayed image.

[0124] 20A shows an example in which the user's level of excitement is determined to be high based on the user data. For example, if the temperature of the environment around the user's nose or mouth is equal to or higher than a predetermined temperature, the skin temperature around the nose or mouth is equal to or higher than a predetermined temperature, the humidity of the environment around the nose or mouth is equal to or higher than a predetermined humidity, the volume of the voice is equal to or higher than a predetermined volume, or the amount of sweating around the nose or under the nose is equal to or higher than a predetermined amount, the user's level of excitement can be determined to be high.

[0125] User data may be presented as the information 81. For example, the temperature of the environment around the user's nose or mouth can be presented as the information 81. For example, the volume of a voice can be presented as the information 81.

[0126] 20B shows an example in which the user's level of excitement is determined to be low based on the user data. For example, if the temperature of the environment around the user's nose or mouth is below a predetermined temperature, the skin temperature around the nose or mouth is below a predetermined temperature, the humidity of the environment around the nose or mouth is below a predetermined humidity, the volume of the voice is below a predetermined volume, or the amount of sweating on or under the nose is below a predetermined amount, the user's level of excitement can be determined to be low.

[0127] As described above, by presenting the user with the degree of excitement, the user can recognize the degree of his / her own excitement, and the sense of immersion can be enhanced. Alternatively, by recognizing the degree of his / her own excitement, the user can make a choice such as taking a break.

[0128] In Fig. 21A and Fig. 21B, information 91 and information 92 in the shape of a character are presented at the bottom left of the field of view, respectively, superimposed on the displayed image.

[0129] FIG. 21A shows an example in which the user's emotion is judged to be high in "fun." For example, this corresponds to the case in FIG. 18C where the neuron value of "fun" is the highest. FIG. 21A also shows an example in which the user's interest is judged to be high. For example, this corresponds to the case in FIG. 18C where the value exceeds the threshold value Th2.

[0130] FIG. 21B shows an example in which the user's emotions of "joy," "fun," "surprise," and "disgust" are all judged to be low. For example, this corresponds to the case in FIG. 18C where none of the neuron values ​​exceed the threshold value Th1. FIG. 21B also shows an example in which the user's interest is judged to be low. For example, this corresponds to the case in FIG. 18C where none of the values ​​exceed the threshold value Th2.

[0131] In Fig. 18C, if the user's emotion is determined to be high in "happiness", for example, information 93 shown in Fig. 21C can be presented. If the user's emotion is determined to be high in "surprise", for example, information 94 shown in Fig. 21D can be presented. If the user's emotion is determined to be high in "disgust", for example, information 95 shown in Fig. 21E can be presented.

[0132] 21A and 21B show an example of presenting one piece of information, but one aspect of the present invention is not limited to this. A plurality of pieces of information may be presented by superimposing them on a displayed image. For example, in FIG. 18C, when the neuron values ​​of "fun" and "surprise" exceed the threshold value Th1, the corresponding pieces of information can be presented. For example, one or more of information 91 and information 94 can be presented.

[0133] As described above, by presenting a character having a facial expression that reflects the estimated emotion of the user to the user, the user can recognize his / her own emotion, and the sense of immersion can be enhanced. Alternatively, the user can become aware of an emotion that the user does not recognize. Note that, although a method of presenting emotional information to the user using the character's facial expression has been described here, the present invention is not limited to this, and various images that visualize the type and degree of emotion can be used.

[0134] <Example of case configuration> In the electronic device according to one aspect of the present invention, the housing 11 only needs to have a space 41 positioned at the nose of the user, and the configuration and shape of the portions other than the space 41 are not particularly limited.

[0135] The housing 11 may be configured by connecting a plurality of housings. Configuration examples of the housing 11 are shown in Figures 22A, 22B, 22C, 23A, and 23B.

[0136] Fig. 22A shows an example in which the housing 11 has a first part 11a to a fifth part 11e. Fig. 22A shows a configuration in which the first part 12a to the fifth part 12e shown in Figs. 4A to 4C correspond to the first part 11a to the fifth part 11e, respectively. The first part 11a to the fifth part 11e are connected to each other to form the housing 11. In addition, any one or more of the first part 11a to the fifth part 11e may be detachable from the housing 11.

[0137] 22B shows an example in which the housing 11 has a fourth part 11d, a fifth part 11e, and a sixth part 11f. FIG. 22B shows a configuration in which the sixth part 11f is formed by integrating the first part 12a to the third part 12c shown in FIGS. 4A to 4C. The fourth part 11d, the fifth part 11e, and the sixth part 11f are connected to each other to form the housing 11. In addition, any one or more of the fourth part 11d, the fifth part 11e, and the sixth part 11f may be detachable from the housing 11.

[0138] Fig. 22C shows an example in which the housing 11 has a first part 11a and a seventh part 11g. Fig. 22C shows a configuration in which the seventh part 11g is formed by integrating the second part 12b to the fifth part 12e shown in Figs. 4A to 4C. The first part 11a and the seventh part 11g are connected to each other to form the housing 11. Either the first part 11a or the seventh part 11g may be detachable from the housing 11.

[0139] 23A shows an example in which the housing 11 has a second part 11b, a third part 11c, and an eighth part 11h. FIG. 23A shows a configuration in which the eighth part 11h is formed by integrating the first part 12a, the fourth part 12d, and the fifth part 12e shown in FIGS. 4A to 4C. The second part 11b, the third part 11c, and the eighth part 11h are connected to each other to form the housing 11. In addition, any one or more of the second part 11b, the third part 11c, and the eighth part 11h may be detachable from the housing 11.

[0140] Fig. 23B shows an example in which the housing 11 has a third part 11c and a ninth part 11i. Fig. 23B shows a configuration in which the seventh part 11g is formed by integrating the first part 12a, the second part 12b, the fourth part 12d, and the fifth part 12e shown in Figs. 4A to 4C. The third part 11c and the ninth part 11i are connected to each other to form the housing 11. Either the third part 11c or the ninth part 11i may be detachable from the housing 11.

[0141] In addition, in Figs. 22A to 22C, 23A and 23B, the respective parts are shown separated for clarity of the drawings.

[0142] By configuring the housing 11 by connecting a plurality of parts, it is possible to easily load components (such as the computing device 19) to be provided in the electronic device 10. For example, in the case of the housing 11 having the first part 11a to the fifth part 11e, it is possible to load components into each of the first part 11a to the fifth part 11e and then connect the first part 11a to the fifth part 11e, which can improve productivity compared to the case where the first part 11a to the fifth part 11e are connected and then the components are loaded. In addition, by making some of the parts detachable from the housing 11, it is possible to easily replace the components in the event of a malfunction, for example.

[0143] The shape of the housing 11 is not particularly limited to the shape shown in FIG. 2A and the like. Each part constituting the housing 11 may have a curved surface. An example of the housing 11 having a curved surface is shown in FIG. 24A. The housing 11 having a curved surface can improve the design of the electronic device according to one embodiment of the present invention. Furthermore, the housing 11 having a curved surface and fewer corners can prevent a user from being injured even if he or she comes into contact with the housing 11, thereby improving the safety of the electronic device according to one embodiment of the present invention.

[0144] An electronic device according to an embodiment of the present invention may have a fixing device 25 as shown in FIG. 24B. By having the fixing device 25, the housing 11 can be fixed to the head of the user. Note that, although the fixing device 25 is shown in a band-like shape in FIG. 24B, the embodiment of the present invention is not limited to this. Also, although FIG. 24B shows a configuration in which one end of the fixing device 25 is fixed to the housing 11 by a fastener 27, another configuration may be used. For example, a configuration without the fastener 27 may be used.

[0145] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0146] (Embodiment 2) In this embodiment, a display device, a light source, an imaging device, and the like that can be applied to the electronic devices of one embodiment of the present invention will be described.

[0147] <Display device configuration example 1> FIG. 25 is a block diagram illustrating a structural example of a display device that can be used in an electronic device of one embodiment of the present invention. A display device 810 illustrated in FIG. 25 includes a layer 820 and a layer 830 stacked above the layer 820. The layer 820 includes a gate driver circuit 821, a source driver circuit 822, and a circuit 840. The layer 830 includes pixels 834, and the pixels 834 are arranged in a matrix to form a pixel array 833. An interlayer insulator can be provided between the layer 820 and the layer 830. Note that the layer 820 may be stacked above the layer 830.

[0148] The circuit 840 is electrically connected to the source driver circuit 822. Note that the circuit 840 may be electrically connected to other circuits, etc.

[0149] The pixels 834 in the same row are electrically connected to the gate driver circuit 821 via a wiring 831, and the pixels 834 in the same column are electrically connected to the source driver circuit 822 via a wiring 832. The wiring 831 functions as a scan line, and the wiring 832 functions as a data line.

[0150] 25 shows a configuration in which pixels 834 in one row are electrically connected by one wiring 831 and pixels 834 in one column are electrically connected by one wiring 832, but one embodiment of the present invention is not limited thereto. For example, pixels 834 in one row may be electrically connected by two or more wirings 831, and pixels 834 in one column may be electrically connected by two or more wirings 832. That is, for example, one pixel 834 may be electrically connected to two or more scan lines or to two or more data lines. For example, one wiring 831 may be electrically connected to pixels 834 in two or more rows, and one wiring 832 may be electrically connected to pixels 834 in two or more columns. That is, for example, one wiring 831 may be shared by pixels 834 in two or more rows, and one wiring 832 may be shared by pixels 834 in two or more columns.

[0151] The gate driver circuit 821 has a function of generating a signal for controlling the operation of the pixel 834 and supplying the signal to the pixel 834 through a wiring 831. The source driver circuit 822 has a function of generating an image signal and supplying the signal to the pixel 834 through a wiring 832. The circuit 840 has a function of receiving image data that is a basis of an image signal generated by the source driver circuit 822 and supplying the received image data to the source driver circuit 822. The circuit 840 also has a function as a control circuit that generates a start pulse signal, a clock signal, and the like. In addition, the circuit 840 can be a circuit having a function that the gate driver circuit 821 and the source driver circuit 822 do not have.

[0152] The pixel array 833 has a function of displaying an image corresponding to an image signal supplied to the pixels 834 by the source driver circuit 822. Specifically, an image is displayed on the pixel array 833 by emitting light of a luminance corresponding to the image signal from the pixels 834.

[0153] 25, the positional relationship between the layer 820 and the layer 830 is indicated by a dashed line and a white circle, and the white circle of the layer 820 and the white circle of the layer 830, which are connected by the dashed line, overlap each other. Note that similar notations are used in other figures.

[0154] In the display device 810, a gate driver circuit 821 and a source driver circuit 822 provided in a layer 820 have an overlapping region with a pixel array 833. For example, the gate driver circuit 821 and the source driver circuit 822 have an overlapping region with a pixel 834. By stacking the gate driver circuit 821 and the source driver circuit 822, and the pixel array 833 so as to have an overlapping region with each other, the frame of the display device 810 can be narrowed and the size can be reduced.

[0155] The gate driver circuit 821 and the source driver circuit 822 are not clearly separated, but have an overlapping region. This region is referred to as a region 823. By including the region 823, the area occupied by the gate driver circuit 821 and the source driver circuit 822 can be reduced. Therefore, even if the area of ​​the pixel array 833 is small, the gate driver circuit 821 and the source driver circuit 822 can be provided without protruding from the pixel array 833. Alternatively, the area of ​​the region of the gate driver circuit 821 and the source driver circuit 822 that does not overlap with the pixel array 833 can be reduced. As described above, the frame can be made narrower and the size can be reduced compared to the case where the region 823 is not included.

[0156] The circuit 840 can be provided so as not to overlap with the pixel array 833. Note that the circuit 840 may be provided so as to have a region overlapping with the pixel array 833.

[0157] 25 shows a configuration example in which one gate driver circuit 821 and one source driver circuit 822 are provided in the layer 820, and one pixel array 833 is provided in the layer 830, but a plurality of pixel arrays 833 may be provided in the layer 830. In other words, the pixel array provided in the layer 830 may be divided.

[0158] 25 shows a configuration example in which the circuit 840 is provided in the layer 820, but the circuit 840 does not have to be provided in the layer 820. Fig. 26 shows a configuration example of a display device 810 in which the circuit 840 is provided in the layer 830, which is a modification of the configuration shown in Fig. 25. Note that elements constituting the circuit 840 may be provided in a distributed manner in the layer 820 and the layer 830.

[0159] <Configuration example of pixel 834> 27A to 27E are diagrams illustrating colors exhibited by a pixel 834 provided in a display device 810. As shown in Fig. 27A, a pixel 834 having a function of emitting red light (R), a pixel 834 having a function of emitting green light (G), and a pixel 834 having a function of emitting blue light (B) can be provided in the display device of the electronic device which is one embodiment of the present invention. Alternatively, as shown in Fig. 27B, a pixel 834 having a function of emitting cyan (C) light, a pixel 834 having a function of emitting magenta (M) light, and a pixel 834 having a function of emitting yellow (Y) light may be provided in the display device 810.

[0160] As shown in Fig. 27C, a pixel 834 having a function of emitting red light (R), a pixel 834 having a function of emitting green light (G), a pixel 834 having a function of emitting blue light (B), and a pixel 834 having a function of emitting white light (W) may be provided in the display device 810. Alternatively, as shown in Fig. 27D, a pixel 834 having a function of emitting red light (R), a pixel 834 having a function of emitting green light (G), a pixel 834 having a function of emitting blue light (B), and a pixel 834 having a function of emitting yellow (Y) light may be provided in the display device 810. Alternatively, as shown in Fig. 27E, a pixel 834 having a function of emitting cyan (C) light, a pixel 834 having a function of emitting magenta (M) light, a pixel 834 having a function of emitting yellow (Y) light, and a pixel 834 having a function of emitting white light (W) may be provided in the display device 810.

[0161] 27C and 27E, the brightness of the displayed image can be increased by providing the pixels 834 having a function of emitting white light (W) in the display device 810. Also, as shown in Fig. 27D etc., the reproducibility of intermediate colors can be improved by increasing the number of colors emitted by the pixels 834, thereby improving the display quality.

[0162] As shown in FIG. 27F, the display device 810 may have a pixel 834 having a function of emitting red light (R), a pixel 834 having a function of emitting green light (G), and a pixel 834 having a function of emitting blue light (B), as well as a pixel 834 having a function of emitting infrared light (IR). Alternatively, as shown in FIG. 27G, the display device 810 may have a pixel 834 having a function of emitting cyan (C) light, a pixel 834 having a function of emitting magenta (M), and a pixel 834 having a function of emitting yellow (Y) light, as well as a pixel 834 having a function of emitting infrared light (IR). Furthermore, the display device 810 may have a pixel 834 having a function of emitting white light (W) in addition to the pixels 834 shown in FIG. 27F and FIG. 27G.

[0163] 28A and 28B are circuit diagrams showing a configuration example of a pixel 834. The pixel 834 shown in FIG. 28A includes a transistor 552, a transistor 554, a capacitor 562, and a light-emitting device 572. For example, an EL device using electroluminescence can be used as the light-emitting device 572. The EL device includes a layer (hereinafter also referred to as an EL layer) containing a light-emitting compound between a pair of electrodes. When a potential difference larger than the threshold voltage of the EL device is generated between the pair of electrodes, holes are injected into the EL layer from the anode side, and electrons are injected into the EL layer from the cathode side. The injected electrons and holes are recombined in the EL layer, and the light-emitting material contained in the EL layer emits light.

[0164] EL devices are classified according to whether the light-emitting material is an organic compound or an inorganic compound. The former are generally called organic EL devices, and the latter are generally called inorganic EL devices.

[0165] In an organic EL device, when a voltage is applied, electrons are injected from one electrode and holes are injected from the other electrode into the EL layer. Then, when these carriers (electrons and holes) recombine, the light-emitting organic compound forms an excited state, and light is emitted when the excited state returns to the ground state. Due to this mechanism, this type of light-emitting device is called a current-excited light-emitting device.

[0166] In addition to the light-emitting compound, the EL layer may contain a substance with high hole injection property, a substance with high hole transport property, a hole blocking material, a substance with high electron transport property, a substance with high electron injection property, a bipolar substance (a substance with high electron transport property and high hole transport property), or the like.

[0167] The EL layer can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0168] Inorganic EL devices are classified into dispersion-type inorganic EL devices and thin-film inorganic EL devices based on their device structure. Dispersion-type inorganic EL devices have an emitting layer in which particles of emitting material are dispersed in a binder, and the emitting mechanism is donor-acceptor recombination-type luminescence that utilizes donor and acceptor levels. Thin-film inorganic EL devices have a structure in which an emitting layer is sandwiched between dielectric layers, which are further sandwiched between electrodes, and the emitting mechanism is localized luminescence that utilizes the inner-shell electron transition of metal ions.

[0169] A light-emitting device only requires that at least one of a pair of electrodes is transparent in order to extract light. A transistor and a light-emitting device are formed on a substrate, and light-emitting devices can be of a top emission structure in which light is extracted from the surface opposite the substrate, a bottom emission structure in which light is extracted from the surface on the substrate side, or a dual emission structure in which light is extracted from both sides, and any light-emitting device of any emission structure can be used.

[0170] As for light-emitting devices other than the light-emitting device 572, devices similar to the light-emitting device 572 can be used.

[0171] One of the source and the drain of the transistor 552 is electrically connected to the wiring 832. The other of the source and the drain of the transistor 552 is electrically connected to one electrode of the capacitor 562 and the gate of the transistor 554. The other electrode of the capacitor 562 is electrically connected to the wiring 835a. The gate of the transistor 552 is electrically connected to the wiring 831. One of the source and the drain of the transistor 554 is electrically connected to the wiring 835a. The other of the source and the drain of the transistor 554 is electrically connected to one electrode of the light-emitting device 572. The other electrode of the light-emitting device 572 is electrically connected to the wiring 835b. A potential VSS is supplied to the wiring 835a, and a potential VDD is supplied to the wiring 835b. The wiring 835a and the wiring 835b function as power supply lines.

[0172] In pixel 834 having the configuration shown in FIG. 28A, the current flowing through light-emitting device 572 is controlled in accordance with the potential supplied to the gate of transistor 554, thereby controlling the luminance of light emitted from light-emitting device 572.

[0173] FIG. 28B shows a structure different from that of the pixel 834 shown in FIG. 28A. In the pixel 834 shown in FIG. 28B, one of the source and the drain of the transistor 552 is electrically connected to the wiring 832. The other of the source and the drain of the transistor 552 is electrically connected to one electrode of the capacitor 562 and the gate of the transistor 554. The gate of the transistor 552 is electrically connected to the wiring 831. One of the source and the drain of the transistor 554 is electrically connected to the wiring 835a. The other of the source and the drain of the transistor 554 is electrically connected to the other electrode of the capacitor 562 and one electrode of the light-emitting device 572. The other electrode of the light-emitting device 572 is electrically connected to the wiring 835b. A potential VDD is supplied to the wiring 835a, and a potential VSS is supplied to the wiring 835b.

[0174] 29A shows an example of the configuration of a pixel 834, which differs from the pixel 834 shown in FIGS. 28A and 28B in that it has a memory. The pixel 834 shown in FIG. 29A includes a transistor 511, a transistor 513, a transistor 521, a capacitor 515, a capacitor 517, and a light-emitting device 572. In addition, wirings 831_1 and 831_2 are electrically connected to the pixel 834 as a wiring 831 having a function as a scan line, and wirings 832_1 and 832_2 are electrically connected to the pixel 834 as a wiring 832 having a function as a data line.

[0175] One of the source or drain of the transistor 511 is electrically connected to a wiring 832_1. The other of the source or drain of the transistor 511 is electrically connected to one electrode of the capacitor 515. The gate of the transistor 511 is electrically connected to a wiring 831_1. One of the source or drain of the transistor 513 is electrically connected to a wiring 832_2. The other of the source or drain of the transistor 513 is electrically connected to the other electrode of the capacitor 515. The gate of the transistor 513 is electrically connected to a wiring 831_2. The other electrode of the capacitor 515 is electrically connected to one electrode of the capacitor 517. The one electrode of the capacitor 517 is electrically connected to a gate of the transistor 521. One of the source or drain of the transistor 521 is electrically connected to one electrode of the light-emitting device 572. The other electrode of the capacitor 517 is electrically connected to a wiring 535. The other of the source and the drain of the transistor 521 is electrically connected to a wiring 537. The other electrode of the light-emitting device 572 is electrically connected to a wiring 539.

[0176] In this specification and the like, the voltage supplied to a light-emitting device refers to the difference between a potential applied to one electrode of the light-emitting device and a potential applied to the other electrode of the light-emitting device.

[0177] A node N1 is a node where the other of the source and the drain of the transistor 511 is electrically connected to one electrode of the capacitor 515. A node N2 is a node where the other of the source and the drain of the transistor 513, one electrode of the capacitor 517, and a gate of the transistor 521 are electrically connected to each other. In FIG. 29A, a circuit including the capacitor 517, the transistor 521, and the light-emitting device 572 is a circuit 401.

[0178] The wiring 535 can be a common wiring for, for example, all the pixels 834 provided in the display device 810. In this case, a potential supplied to the wiring 535 is a common potential. A constant potential can be supplied to the wiring 537 and the wiring 539. For example, a high potential can be supplied to the wiring 537, and a low potential can be supplied to the wiring 539. The wiring 537 and the wiring 539 function as power supply lines.

[0179] The transistor 521 has a function of controlling a current supplied to the light-emitting device 572. The capacitor 517 has a function as a storage capacitor. The capacitor 517 may be omitted.

[0180] 29A illustrates a configuration in which the anode side of the light-emitting device 572 is electrically connected to the transistor 521, the transistor 521 may be electrically connected to the cathode side. In this case, the potential value of the wiring 537 and the potential value of the wiring 539 can be changed as appropriate.

[0181] In the pixel 834, the potential of the node N1 can be held by turning off the transistor 511. Also, the potential of the node N2 can be held by turning off the transistor 513. Furthermore, by turning off the transistor 513 and writing a predetermined potential to the node N1 through the transistor 511, the potential of the node N2 can be changed in response to a change in the potential of the node N1 due to capacitive coupling through the capacitor 515.

[0182] Here, a transistor having a metal oxide in a channel formation region (hereinafter also referred to as an OS transistor) can be used as the transistor 511 and the transistor 513. The band gap of the metal oxide can be 2 eV or more, or 2.5 eV or more. Thus, the leakage current (off-state current) of the OS transistor is extremely small in a non-conducting state. Thus, by using OS transistors as the transistors 511 and 513, the potentials of the nodes N1 and N2 can be held for a long period of time.

[0183] As the metal oxide, it is preferable to use a metal oxide such as In-M-Zn oxide (element M is one or more selected from aluminum, gallium, yttrium, tin, copper, vanadium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc.). In particular, it is preferable to use aluminum, gallium, yttrium, or tin as the element M. Indium oxide, zinc oxide, In-Ga oxide, In-Zn oxide, Ga-Zn oxide, or gallium oxide may also be used as the metal oxide.

[0184] An example of how pixel 834 operates Next, an example of an operation method of pixel 834 having the configuration shown in Fig. 29A will be described with reference to Fig. 29B. Fig. 29B is a timing chart relating to the operation of pixel 834 having the configuration shown in Fig. 29A. Note that, for ease of explanation, the influence of various resistances such as wiring resistance, parasitic capacitance of transistors and wiring, threshold voltage of transistors, etc. is not taken into consideration here.

[0185] 29B, one frame period is divided into a period T1 and a period T2. The period T1 is a period in which a potential is written to the node N2, and the period T2 is a period in which a potential is written to the node N1.

[0186] In the period T1, a potential for turning on the transistor is supplied to both the wiring 831_1 and the wiring 831_2. In addition, a fixed potential V ref is supplied to the wiring 832_2, and a potential V w supplies.

[0187] The node N1 is supplied with a potential V ref The node N2 is supplied with a potential V w Therefore, the capacitance element 515 has a potential difference V w -V ref is held.

[0188] Next, in the period T2, a potential for turning on the transistor 511 is supplied to the wiring 831_1, and a potential for turning off the transistor 513 is supplied to the wiring 831_2. data A predetermined constant potential is supplied to the wiring 832_2. Note that the potential of the wiring 832_2 may be floating.

[0189] The node N1 is supplied with a potential V data At this time, the potential V data In response to this, the potential of the node N2 changes by a potential dV. w The potential obtained by adding the potential V to the potential dV is input. Note that although dV is shown to be a positive value in FIG. 29B, it may be a negative value. data is the potential V ref It may be lower.

[0190] Here, the potential dV is roughly determined by the capacitance of the capacitor 515 and the capacitance of the circuit 401. When the capacitance of the capacitor 515 is sufficiently larger than the capacitance of the circuit 401, the potential dV is a potential difference V data -V ref The potential becomes close to

[0191] In this way, the pixel 834 can generate a potential to be supplied to the node N2 by combining two types of data signals, and therefore the image displayed on the pixel array 833 can be corrected inside the pixel 834. Here, one of the two types of data signals can be the image signal described above, and the other of the two types of data signals can be, for example, a correction signal. For example, a potential V corresponding to the correction signal during the period T1 w is supplied to node N2, and then during period T2, a potential V data to the node N1, an image displayed on the pixel array 833 can be an image signal corrected by the correction signal. Note that not only the image signal but also the correction signal and the like can be generated by the source driver circuit 822 included in the display device 810.

[0192] In the pixel 834 having the configuration shown in FIG. 29A, the potential of the node N2 can be set to a potential exceeding the maximum potential that can be supplied to the wirings 832_1 and 832_2. This allows a high voltage to be supplied to the light-emitting device 572. Specifically, for example, the potential of the wiring 537 can be increased. Therefore, when the light-emitting device 572 is an organic EL device, the light-emitting device can have a tandem structure described later. This allows the current efficiency and external quantum efficiency of the light-emitting device 572 to be increased. Therefore, a high-luminance image can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be reduced.

[0193] 29A, a configuration in which a transistor, a capacitor, or the like is added may be used. For example, by adding one transistor and one capacitor to the configuration shown in FIG. 29A, the number of nodes capable of holding a potential can be three. That is, a configuration can be provided in which, in addition to the nodes N1 and N2, another node capable of holding a potential is provided in the pixel 834. This can further increase the potential of the node N2. Therefore, a larger current can flow through the light-emitting device 572.

[0194] 30A to 30E are diagrams showing examples of a configuration of a circuit 401 different from that shown in Fig. 30A. The circuit 401 shown in Fig. 30A includes a capacitor 517, a transistor 521, and a light-emitting device 572, similar to the circuit 401 shown in Fig. 29A.

[0195] In the circuit 401 having the configuration shown in FIG. 30A, a gate of a transistor 521 and one electrode of a capacitor 517 are electrically connected to a node N2. One of a source or a drain of the transistor 521 is electrically connected to a wiring 537. The other of the source or the drain of the transistor 521 is electrically connected to the other electrode of the capacitor 517. The other electrode of the capacitor 517 is electrically connected to one electrode of a light-emitting device 572. The other electrode of the light-emitting device 572 is electrically connected to a wiring 539.

[0196] The circuit 401 having the configuration shown in FIG. 30B also includes a capacitor 517, a transistor 521, and a light-emitting device 572, like the circuit 401 having the configuration shown in FIG. 29A.

[0197] In the circuit 401 having the configuration shown in FIG. 30B, a gate of a transistor 521 and one electrode of a capacitor 517 are electrically connected to a node N2. One electrode of a light-emitting device 572 is electrically connected to a wiring 537. The other electrode of the light-emitting device 572 is electrically connected to one of a source or a drain of the transistor 521. The other of the source or the drain of the transistor 521 is electrically connected to the other electrode of the capacitor 517. The other electrode of the capacitor 517 is electrically connected to a wiring 539.

[0198] 30C shows a configuration example of the circuit 401 in which a transistor 525 is added to the circuit 401 shown in FIG. 30A. One of the source and the drain of the transistor 525 is electrically connected to the other of the source and the drain of the transistor 521 and the other electrode of the capacitor 517. The other of the source and the drain of the transistor 525 is electrically connected to one electrode of the light-emitting device 572. A gate of the transistor 525 is electrically connected to a wiring 541. The wiring 541 functions as a scan line for controlling the conduction of the transistor 525.

[0199] 30C, even if the potential of the node N2 becomes equal to or higher than the threshold voltage of the transistor 521, no current flows through the light-emitting device 572 unless the transistor 525 is turned on. Therefore, malfunction of the display device 810 can be suppressed.

[0200] 30D shows a configuration example of the circuit 401 in which a transistor 527 is added to the circuit 401 shown in FIG. 30C. One of the source and the drain of the transistor 527 is electrically connected to the other of the source and the drain of the transistor 521. The other of the source and the drain of the transistor 527 is electrically connected to a wiring 543. A gate of the transistor 527 is electrically connected to a wiring 545. The wiring 545 functions as a scan line that controls the conduction of the transistor 527.

[0201] The wiring 543 can be electrically connected to a supply source of a specific potential such as a reference potential. That is, the wiring 543 functions as a power supply line. By supplying a specific potential to the other of the source and the drain of the transistor 521 from the wiring 543, writing of an image signal to the pixel 834 can be stabilized.

[0202] The wiring 543 can be electrically connected to the circuit 520. The circuit 520 can have one or more of the following functions: a source of the specific potential described above, a function of acquiring electrical characteristics of the transistor 521, and a function of generating a correction signal.

[0203] The circuit 401 having the configuration shown in FIG. 30E includes a capacitor 517, a transistor 521, a transistor 529, and a light-emitting device 572.

[0204] 30E, a gate of a transistor 521 and one electrode of a capacitor 517 are electrically connected to a node N2. One of a source or a drain of the transistor 521 is electrically connected to a wiring 537. One of a source or a drain of the transistor 529 is electrically connected to a wiring 543.

[0205] The other electrode of the capacitor 517 is electrically connected to the other of the source and the drain of the transistor 521. The other of the source and the drain of the transistor 521 is electrically connected to the other of the source and the drain of the transistor 529. The other of the source and the drain of the transistor 529 is electrically connected to one electrode of the light-emitting device 572.

[0206] A gate of the transistor 529 is electrically connected to the wiring 831_1. The other electrode of the light-emitting device 572 is electrically connected to the wiring 539.

[0207] <Display device configuration example 2> Fig. 31 is a block diagram showing a configuration example of a display device 810 when the pixel 834 has the configuration shown in Fig. 29A. In addition to the components of the display device 810 shown in Fig. 25, the display device 810 having the configuration shown in Fig. 31 is provided with a demultiplexer circuit 824. The demultiplexer circuit 824 can be provided in, for example, a layer 820 as shown in Fig. 31. The number of demultiplexer circuits 824 can be the same as the number of columns of the pixels 834 provided in the pixel array 833, for example.

[0208] The gate driver circuit 821 is electrically connected to the pixels 834 through a wiring 831-1. The gate driver circuit 821 is electrically connected to the pixels 834 through a wiring 831-2. The wiring 831-1 and the wiring 831-2 function as scan lines.

[0209] The source driver circuit 822 is electrically connected to an input terminal of a demultiplexer circuit 824. A first output terminal of the demultiplexer circuit 824 is electrically connected to a pixel 834 via a wiring 832-1. A second output terminal of the demultiplexer circuit 824 is electrically connected to a pixel 834 via a wiring 832-2. The wiring 832-1 and the wiring 832-2 function as data lines.

[0210] The source driver circuit 822 and the demultiplexer circuit 824 may be collectively referred to as a source driver circuit. That is, the demultiplexer circuit 824 may be included in the source driver circuit 822.

[0211] In the display device 810 having the configuration shown in Fig. 31, the source driver circuit 822 has a function of generating an image signal S1 and an image signal S2. The demultiplexer circuit 824 has a function of supplying the image signal S1 to the pixel 834 via a wiring 832-1, and a function of supplying the image signal S2 to the pixel 834 via a wiring 832-2. Here, if the display device 810 having the configuration shown in Fig. 31 is operated by the method shown in Fig. 29B, the potential V data can be set as a potential corresponding to the image signal S1, and the potential V w can be set as a potential corresponding to the image signal S2.

[0212] As shown in FIG. 29B, a potential V w After supplying the potential V data By supplying w +dV”. Here, as mentioned above, the potential dV is the potential V dataTherefore, the image signal S1 can be added to the image signal S2. That is, the image signal S1 can be superimposed on the image signal S2.

[0213] Potential V corresponding to image signal S1 data , and the potential V corresponding to the image signal S2 w The size of is limited depending on the withstand voltage of the source driver circuit 822, etc. Therefore, by overlapping the image signal S1 and the image signal S2, an image corresponding to an image signal having a higher potential than the potential that the source driver circuit 822 can output can be displayed on the pixel array 833. This allows a large current to flow through the light emitting device 572, so that a high-luminance image can be displayed on the pixel array 833. In addition, the dynamic range, which is the range of luminance of an image that the pixel array 833 can display, can be expanded.

[0214] The image corresponding to the image signal S1 and the image corresponding to the image signal S2 may be the same or different. When the image corresponding to the image signal S1 and the image corresponding to the image signal S2 are the same, the pixel array 833 can display an image with a luminance higher than the luminance of the image corresponding to the image signal S1 and the luminance of the image corresponding to the image signal S2.

[0215] 32 shows a case where an image P1 corresponding to an image signal S1 contains only text, and an image P2 corresponding to an image signal S2 contains pictures and text. In this case, by superimposing the images P1 and P2, the luminance of the text can be increased, for example, the text can be emphasized. Also, as shown in FIG. 29B, when a potential V w After the potential of node N2 is changed to the potential V data Therefore, the potential V corresponding to the image signal S2 w When rewriting, the potential V of the image signal S1 data On the other hand, the potential V dataIn the case where the potential V w Therefore, in the case shown in FIG. data By adjusting the value of , you can adjust the brightness of the characters.

[0216] As described above, the potential V corresponding to the image signal S2 w When rewriting the image signal S1, the potential V data On the other hand, the potential V data If you rewrite it, the potential V w It is not necessary to rewrite the image P2. Therefore, it is preferable that the image P2 is an image that is rewritten less frequently than the image P1. Note that, although an example in which the image P1 includes only text and the image P2 includes pictures and text is shown in FIG. 32, one embodiment of the present invention is not limited to this.

[0217] <Example of cross-sectional configuration of a display device> 33 is a cross-sectional view showing a configuration example of a display device 810. The display device 810 has a substrate 701 and a substrate 705, and the substrate 701 and the substrate 705 are attached to each other with a sealant 712.

[0218] A single crystal semiconductor substrate such as a single crystal silicon substrate can be used as the substrate 701. Note that the substrate 701 may be a semiconductor substrate other than a single crystal semiconductor substrate.

[0219] The transistor 441 and the transistor 601 are provided over a substrate 701. The transistor 441 can be provided in the circuit 840. The transistor 601 can be provided in the gate driver circuit 821 or the source driver circuit 822. That is, the transistor 441 and the transistor 601 can be provided in the layer 820 shown in FIG. 25 and the like.

[0220] The transistor 441 includes a conductor 443 having a function as a gate electrode, an insulator 445 having a function as a gate insulator, and a part of the substrate 701, and includes a semiconductor region 447 including a channel formation region, a low-resistance region 449a having a function as one of a source region and a drain region, and a low-resistance region 449b having a function as the other of the source region and the drain region. The transistor 441 may be either a p-channel type or an n-channel type.

[0221] The transistor 441 is electrically isolated from other transistors by the element isolation layer 403. Fig. 33 shows a case where the transistor 441 and the transistor 601 are electrically isolated by the element isolation layer 403. The element isolation layer 403 can be formed by a LOCOS (LOCal Oxidation of Silicon) method, an STI (Shallow Trench Isolation) method, or the like.

[0222] 33 has a convex semiconductor region 447. A conductor 443 is provided to cover the side and top surfaces of the semiconductor region 447 with an insulator 445 interposed therebetween. Note that the conductor 443 covering the side surfaces of the semiconductor region 447 is not illustrated in FIG. The conductor 443 can be formed using a material that adjusts a work function.

[0223] A transistor having a convex semiconductor region such as the transistor 441 can be called a fin transistor because it uses a convex portion of a semiconductor substrate. Note that an insulator that is in contact with the upper portion of the convex portion and functions as a mask for forming the convex portion may be provided. In addition, although a configuration in which the convex portion is formed by processing a part of the substrate 701 is shown in FIG. 33, a semiconductor having a convex portion may be formed by processing an SOI substrate.

[0224] 33 is just an example, and is not limited to that configuration, and may be an appropriate configuration depending on the circuit configuration, the operation method of the circuit, etc. For example, the transistor 441 may be a planar transistor.

[0225] The transistor 601 can have a structure similar to that of the transistor 441 .

[0226] Over the substrate 701, in addition to the element isolation layer 403, the transistor 441, and the transistor 601, an insulator 405, an insulator 407, an insulator 409, and an insulator 411 are provided. A conductor 451 is embedded in the insulator 405, the insulator 407, the insulator 409, and the insulator 411. Here, the height of the top surface of the conductor 451 and the height of the top surface of the insulator 411 can be made approximately the same.

[0227] An insulator 413 and an insulator 415 are provided over the conductor 451 and the insulator 411. A conductor 457 is embedded in the insulator 413 and the insulator 415.

[0228] An insulator 417 and an insulator 419 are provided over the conductor 457 and the insulator 415. In addition, a conductor 459 is embedded in the insulator 417 and the insulator 419.

[0229] An insulator 421 and an insulator 214 are provided on the conductor 459 and the insulator 419. A conductor 453 is embedded in the insulator 421 and the insulator 214. Here, the height of the top surface of the conductor 453 and the height of the top surface of the insulator 214 can be made approximately the same.

[0230] An insulator 216 is provided on the conductor 453 and the insulator 214. A conductor 455 is embedded in the insulator 216. Here, the height of the top surface of the conductor 455 and the height of the top surface of the insulator 216 can be approximately the same.

[0231] Insulators 222, 224, 254, 244, 280, 274, and 281 are provided on conductor 455 and insulator 216. Conductor 305 is embedded in insulator 222, insulator 224, insulator 254, insulator 244, insulator 280, insulator 274, and insulator 281. Here, the height of the upper surface of conductor 305 and the height of the upper surface of insulator 281 can be made approximately the same.

[0232] An insulator 361 is provided on the conductor 305 and on the insulator 281. A conductor 317 and a conductor 337 are embedded in the insulator 361. Here, the height of the upper surface of the conductor 337 and the height of the upper surface of the insulator 361 can be made to be approximately the same.

[0233] An insulator 363 is provided on the conductor 337 and on the insulator 361. The conductors 347, 353, 355, and 357 are embedded in the insulator 363. Here, the height of the top surfaces of the conductors 353, 355, and 357 can be made approximately the same as the height of the top surface of the insulator 363.

[0234] A connection electrode 760 is provided on the conductor 353, the conductor 355, the conductor 357, and the insulator 363. An anisotropic conductor 780 is provided so as to be electrically connected to the connection electrode 760, and an FPC (Flexible Printed Circuit) 716 is provided so as to be electrically connected to the anisotropic conductor 780. Various signals and the like are supplied to the display device 810 from outside the display device 810 by the FPC 716.

[0235] 33, the low-resistance region 449b having a function as the other of the source region and the drain region of the transistor 441 is electrically connected to the FPC 716 through the conductor 451, the conductor 457, the conductor 459, the conductor 453, the conductor 455, the conductor 305, the conductor 317, the conductor 337, the conductor 347, the conductor 353, the conductor 355, the conductor 357, the connection electrode 760, and the anisotropic conductor 780. Here, in FIG. 33, the conductor 353, the conductor 355, and the conductor 357 are shown as the conductors having a function of electrically connecting the connection electrode 760 and the conductor 347, but one embodiment of the present invention is not limited thereto. The number of conductors having a function of electrically connecting the connection electrode 760 and the conductor 347 may be one, two, or four or more. By providing a plurality of conductors each having the function of electrically connecting the connection electrode 760 and the conductor 347, the contact resistance can be reduced.

[0236] A transistor 750 is provided over the insulator 214. The transistor 750 can be a transistor provided in the pixel 834. That is, the transistor 750 can be provided in the layer 830 illustrated in FIG. 25 and the like. The transistor 750 can be an OS transistor. An OS transistor has a characteristic of having an extremely low off-state current. Thus, the retention time of an image signal or the like can be extended, and therefore the frequency of a refresh operation can be reduced. Thus, the power consumption of the display device 810 can be reduced.

[0237] Conductor 301a and conductor 301b are embedded in insulator 254, insulator 244, insulator 280, insulator 274, and insulator 281. Conductor 301a is electrically connected to one of the source and drain of transistor 750, and conductor 301b is electrically connected to the other of the source and drain of transistor 750. Here, the height of the top surfaces of conductor 301a and conductor 301b and the top surface of insulator 281 can be made approximately the same.

[0238] The conductor 311, the conductor 313, the conductor 331, the capacitor 790, the conductor 333, and the conductor 335 are embedded in the insulator 361. The conductor 311 and the conductor 313 are electrically connected to the transistor 750 and function as wirings. The conductor 333 and the conductor 335 are electrically connected to the capacitor 790. Here, the height of the top surface of the conductor 331, the conductor 333, and the conductor 335 can be made approximately the same as the height of the top surface of the insulator 361.

[0239] Conductor 341, conductor 343, and conductor 351 are embedded in insulator 363. Here, the height of the top surface of conductor 351 and the height of the top surface of insulator 363 can be made approximately the same.

[0240] The insulators 405, 407, 409, 411, 413, 415, 417, 419, 421, 214, 280, 274, 281, 361, and 363 each function as an interlayer film and may also function as a planarizing film that covers the uneven shapes below the insulators. For example, the top surface of the insulator 363 may be planarized by planarization treatment using a chemical mechanical polishing (CMP) method or the like to improve the planarity.

[0241] 33, the capacitor 790 has a lower electrode 321 and an upper electrode 325. An insulator 323 is provided between the lower electrode 321 and the upper electrode 325. That is, the capacitor 790 has a layered structure in which the insulator 323 functioning as a dielectric is sandwiched between a pair of electrodes. Note that while an example in which the capacitor 790 is provided over the insulator 281 is shown in FIG. 33, the capacitor 790 may be provided over an insulator different from the insulator 281.

[0242] FIG. 33 shows an example in which the conductor 301a, the conductor 301b, and the conductor 305 are formed in the same layer. Also, an example in which the conductor 311, the conductor 313, the conductor 317, and the lower electrode 321 are formed in the same layer is shown. Also, an example in which the conductor 331, the conductor 333, the conductor 335, and the conductor 337 are formed in the same layer is shown. Also, an example in which the conductor 341, the conductor 343, and the conductor 347 are formed in the same layer is shown. Furthermore, an example in which the conductor 351, the conductor 353, the conductor 355, and the conductor 357 are formed in the same layer is shown. By forming a plurality of conductors in the same layer in this way, the manufacturing process of the display device 810 can be simplified, and therefore the display device 810 can be made inexpensive. Note that these may be formed in different layers, and may have different types of materials.

[0243] A display device 810 shown in FIG. 33 includes a light-emitting device 572. The light-emitting device 572 includes a conductor 772, an EL layer 786, and a conductor 788. The conductor 788 is provided on the substrate 705 side and functions as a common electrode. The conductor 772 is electrically connected to the other of the source and the drain of the transistor 750 through the conductor 351, the conductor 341, the conductor 331, the conductor 313, and the conductor 301b. The conductor 772 is formed over the insulator 363 and functions as a pixel electrode. The EL layer 786 includes an organic compound or an inorganic compound such as quantum dots.

[0244] Examples of materials that can be used for the organic compound include fluorescent materials and phosphorescent materials, etc. Examples of materials that can be used for the quantum dot include colloidal quantum dot materials, alloy type quantum dot materials, core-shell type quantum dot materials, core type quantum dot materials, etc.

[0245] 33 includes an insulator 730 over an insulator 363. The insulator 730 can be configured to cover a part of a conductor 772. The light-emitting device 572 can have a light-transmitting conductor 788 and can be a top-emission light-emitting device. The light-emitting device 572 can have a bottom-emission structure in which light is emitted to the conductor 772 side, or a dual-emission structure in which light is emitted to both the conductor 772 and the conductor 788.

[0246] The light emitting device 572 may have a microcavity structure, the details of which will be described later. This allows light of a predetermined color (for example, RGB) to be extracted without providing a colored layer, and the display device 810 can perform color display. By adopting a configuration without providing a colored layer, it is possible to suppress absorption of light by the colored layer. This allows the display device 810 to display a high-luminance image and reduce the power consumption of the display device 810. Note that even when the EL layer 786 is formed in an island shape for each pixel or in a striped shape for each pixel row, that is, formed by painting, it is possible to adopt a configuration without providing a colored layer.

[0247] The light-shielding layer 738 is provided to have a region overlapping with the insulator 730. The light-shielding layer 738 is covered with the insulator 734. The space between the light-emitting device 572 and the insulator 734 is filled with the sealing layer 732.

[0248] Furthermore, a structure 778 is provided between the insulator 730 and the EL layer 786. A structure 778 is provided between the insulator 730 and the insulator 734. The structure 778 is a columnar spacer and has a function of controlling the distance (cell gap) between the substrate 701 and the substrate 705. Note that a spherical spacer may be used as the structure 778.

[0249] A light-shielding layer 738 and an insulator 734 in contact with the light-shielding layer 738 are provided on the substrate 705 side. The light-shielding layer 738 has a function of blocking light emitted from an adjacent region. Alternatively, the light-shielding layer 738 has a function of blocking external light from reaching the transistor 750 and the like.

[0250] Fig. 34 is a modified example of the display device 810 shown in Fig. 33, and differs from the display device 810 shown in Fig. 33 in that a colored layer 736 is provided. By providing the colored layer 736, the color purity of the light extracted from the light-emitting device 572 can be increased. This allows the display device 810 to display a high-quality image. In addition, since, for example, all of the light-emitting devices 572 of the display device 810 can be light-emitting devices that emit white light, it is not necessary to form the EL layer 786 by different colors, and the display device 810 can have high definition.

[0251] 33 and 34 show a structure in which the transistor 441 and the transistor 601 are provided so that a channel formation region is formed inside the substrate 701 and the OS transistor is stacked over the transistor 441 and the transistor 601, but one embodiment of the present invention is not limited to this. Fig. 35 shows a modification of Fig. 33, and Fig. 36 shows a modification of Fig. 34, which differ from the display device 810 shown in Figs. 33 and 34 in that the transistor 750 is stacked over the OS transistors 602 and 603 instead of the transistors 441 and 601. That is, the display device 810 shown in Figs. 35 and 36 has OS transistors stacked.

[0252] An insulator 613 and an insulator 614 are provided over a substrate 701, and a transistor 602 and a transistor 603 are provided over the insulator 614. Note that a transistor or the like may be provided between the substrate 701 and the insulator 613. For example, a transistor having a structure similar to that of the transistor 441 and the transistor 601 shown in FIGS. 33 and 34 may be provided between the substrate 701 and the insulator 613.

[0253] The transistor 602 can be a transistor provided in the circuit 840. The transistor 603 can be a transistor provided in the gate driver circuit 821 or a transistor provided in the source driver circuit 822. That is, the transistors 602 and 603 can be provided in the layer 820 shown in FIG. 25 and the like. Note that when the circuit 840 is provided in the layer 830 as shown in FIG. 26, the transistor 602 can be provided in the layer 830.

[0254] The transistor 602 and the transistor 603 can have a structure similar to that of the transistor 750. Note that the transistor 602 and the transistor 603 may be OS transistors having a different structure from that of the transistor 750.

[0255] In addition to the transistor 602 and the transistor 603, insulators 616, 622, 624, 654, 644, 680, 674, and 681 are provided over the insulator 614. The conductor 461 is embedded in the insulator 654, the insulator 644, the insulator 680, the insulator 674, and the insulator 681. Here, the height of the top surface of the conductor 461 can be made approximately the same as the height of the top surface of the insulator 681.

[0256] 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 and the height of the top surface of the insulator 501 can be made approximately the same.

[0257] An insulator 503 is provided on the conductor 463 and on the insulator 501. A conductor 465 is embedded in the insulator 503. Here, the height of the top surface of the conductor 465 and the height of the top surface of the insulator 503 can be made approximately the same.

[0258] An insulator 505 is provided over the conductor 465 and the insulator 503. In addition, a conductor 467 is embedded in the insulator 505.

[0259] An insulator 507 is provided on the conductor 467 and on the insulator 505. A conductor 469 is embedded in the insulator 507. Here, the height of the top surface of the conductor 469 and the height of the top surface of the insulator 507 can be made approximately the same.

[0260] An insulator 509 is provided over the conductor 469 and the insulator 507. In addition, a conductor 471 is embedded in the insulator 509.

[0261] An insulator 421 and an insulator 214 are provided on the conductor 471 and the insulator 509. A conductor 453 is embedded in the insulator 421 and the insulator 214. Here, the height of the top surface of the conductor 453 and the height of the top surface of the insulator 214 can be made approximately the same.

[0262] As shown in Figures 35 and 36, one of the source or drain of transistor 602 is electrically connected to FPC 716 via conductor 461, conductor 463, conductor 465, conductor 467, conductor 469, conductor 471, conductor 453, conductor 455, conductor 305, conductor 317, conductor 337, conductor 347, conductor 353, conductor 355, conductor 357, connection electrode 760, and anisotropic conductor 780.

[0263] Insulator 613, insulator 614, insulator 680, insulator 674, insulator 681, insulator 501, insulator 503, insulator 505, insulator 507, and insulator 509 function as interlayer films and may also function as planarizing films covering the uneven shapes underneath.

[0264] 35 and 36, the display device 810 can have a narrow frame and be small in size, and all of the transistors in the display device 810 can be OS transistors. This allows, for example, the transistors provided in the layer 820 and the transistors provided in the layer 830 to be manufactured using the same device. Thus, the manufacturing cost of the display device 810 can be reduced, and the display device 810 can be manufactured at a low price.

[0265] <Example of light-emitting device configuration> 37A to 37E are diagrams showing a configuration example of a light-emitting device 572. Fig. 37A shows a structure (single structure) in which an EL layer 786 is sandwiched between a conductor 772 and a conductor 788. As described above, the EL layer 786 includes a light-emitting material, for example, a light-emitting material that is an organic compound.

[0266] Fig. 37B is a diagram showing the laminated structure of the EL layer 786. Here, in the light-emitting device 572 having the structure shown in Fig. 37B, the conductor 772 functions as an anode, and the conductor 788 functions as a cathode.

[0267] 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 a conductor 772. Note that when the conductor 772 functions as a cathode and the conductor 788 functions as an anode, the stacking order is reversed.

[0268] The light-emitting layer 723 has a light-emitting material or a combination of a plurality of materials, and can have a structure that can obtain fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 723 may have a stacked structure that emits light of different colors. In this case, different materials may be used as the light-emitting substance and other substances for each stacked light-emitting layer.

[0269] In the light-emitting device 572, for example, by making the conductor 772 shown in FIG. 37B a reflective electrode and the conductor 788 a semi-transparent and semi-reflective electrode, and forming a micro-optical resonator (microcavity) structure, the light emitted from the light-emitting layer 723 included in the EL layer 786 can be resonated between the two electrodes, and the light emitted through the conductor 788 can be enhanced.

[0270] When the conductor 772 of the light-emitting device 572 is a reflective electrode having a laminated structure of a conductive material having reflectivity and a conductive material having light transmission (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the inter-electrode distance between the conductor 772 and the conductor 788 to be approximately mλ / 2 (where m is a natural number) for the wavelength λ of the light obtained from the light-emitting layer 723.

[0271] In order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 723, it is preferable to adjust the optical distance from the conductor 772 to the region (light-emitting region) in the light-emitting layer where the desired light is obtained, and the optical distance from the conductor 788 to the region (light-emitting region) in the light-emitting layer 723 where the desired light is obtained, to be approximately (2m'+1)λ / 4 (where m' is a natural number). Note that the light-emitting region here refers to a recombination region of holes and electrons in the light-emitting layer 723.

[0272] By carrying out such optical adjustment, it is possible to narrow the spectrum of the specific monochromatic light obtained from the light-emitting layer 723, and obtain light emission with good color purity.

[0273] However, in the above case, the optical distance between the conductor 772 and the conductor 788 can be said to be the total thickness from the reflection region of the conductor 772 to the reflection region of the conductor 788, strictly speaking. However, since it is difficult to determine the reflection region of the conductor 772 and the conductor 788 strictly, it is assumed that the above-mentioned effect can be sufficiently obtained by assuming any position of the conductor 772 and the conductor 788 as the reflection region. Furthermore, the optical distance between the conductor 772 and the light-emitting layer from which the desired light is obtained can be said to be the optical distance between the reflection region of the conductor 772 and the light-emitting region of the light-emitting layer from which the desired light is obtained, strictly speaking. However, since it is difficult to determine the reflection region of the conductor 772 and the light-emitting region of the light-emitting layer from which the desired light is obtained strictly, it is assumed that the above-mentioned effect can be sufficiently obtained by assuming any position of the conductor 772 as the reflection region and any position of the light-emitting layer from which the desired light is obtained as the light-emitting region.

[0274] The light-emitting device 572 shown in FIG. 37B has a microcavity structure, so that even if it has the same EL layer, it can extract light of different wavelengths (monochromatic light). Therefore, it is not necessary to paint different colors (e.g., RGB) to obtain different luminescent colors. Therefore, it is easy to achieve high definition. It can also be combined with a colored layer. Furthermore, it is possible to increase the luminescent intensity of a specific wavelength in the front direction, which can reduce power consumption.

[0275] The light-emitting device 572 shown in Fig. 37B does not need to have a microcavity structure. In this case, the light-emitting layer 723 may be structured to emit white light, and a colored layer may be provided to extract light of a desired color (e.g., RGB). When forming the EL layer 786, if different colors are applied to obtain different luminescent colors, light of a desired color may be extracted without providing a colored layer.

[0276] At least one of the conductor 772 and the conductor 788 can be a light-transmitting electrode (transparent electrode, semi-transparent / semi-reflective electrode, etc.). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. When the electrode is a semi-transparent / semi-reflective electrode, the visible light reflectance of the semi-transparent / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. The resistivity of these electrodes is 1×10 -2 Ωcm or less is preferable.

[0277] When the conductor 772 or the conductor 788 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is set to 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of this electrode is 1×10 -2 Ωcm or less is preferable.

[0278] The light-emitting device 572 may have a structure shown in FIG. 37C. FIG. 37C shows a light-emitting device 572 having a stacked structure (tandem structure) in which two EL layers (EL layer 786a and EL layer 786b) are provided between the conductor 772 and the conductor 788, and a charge generating layer 792 is provided between the EL layer 786a and the EL layer 786b. By forming the light-emitting device 572 into a tandem structure, the current efficiency and external quantum efficiency of the light-emitting device 572 can be improved. Thus, a high-luminance image can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be reduced. Here, the EL layer 786a and the EL layer 786b can have the same structure as the EL layer 786 shown in FIG. 37B.

[0279] The charge generation layer 792 has a function of injecting electrons into one of the EL layer 786a and the EL layer 786b and injecting holes into the other when a voltage is supplied between the conductor 772 and the conductor 788. Therefore, when a voltage is supplied so that the potential of the conductor 772 is higher than the potential of the conductor 788, electrons are injected from the charge generation layer 792 to the EL layer 786a and holes are injected from the charge generation layer 792 to the EL layer 786b.

[0280] From the viewpoint of light extraction efficiency, the charge generation layer 792 preferably transmits visible light (specifically, the visible light transmittance of the charge generation layer 792 is preferably 40% or more). The conductivity of the charge generation layer 792 may be lower than the conductivity of the conductor 772 or the conductivity of the conductor 788.

[0281] The light-emitting device 572 may have a configuration shown in FIG. 37D. FIG. 37D shows a light-emitting device 572 having a tandem structure in which three EL layers (EL layer 786a, EL layer 786b, and EL layer 786c) are provided between the conductor 772 and the conductor 788, and a charge generation layer 792 is provided between the EL layer 786a and the EL layer 786b, and between the EL layer 786b and the EL layer 786c. Here, the EL layer 786a, the EL layer 786b, and the EL layer 786c can have the same configuration as the EL layer 786 shown in FIG. 37B. By configuring the light-emitting device 572 as shown in FIG. 37D, the current efficiency and external quantum efficiency of the light-emitting device 572 can be further increased. Therefore, an image with higher brightness can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be further reduced.

[0282] The light-emitting device 572 may have a configuration shown in FIG. 37E. FIG. 37E shows a light-emitting device 572 having a tandem structure in which n EL layers (EL layer 786(1) to EL layer 786(n)) are provided between a conductor 772 and a conductor 788, and a charge generating layer 792 is provided between each of the EL layers 786. Here, the EL layers 786(1) to EL layer 786(n) can have the same configuration as the EL layer 786 shown in FIG. 37B. Note that FIG. 37E shows the EL layer 786(1), EL layer 786(m), EL layer 786(m+1), and EL layer 786(n) among the EL layers 786. Here, m is an integer equal to or greater than 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 device 572 can be. Therefore, a high-luminance image can be displayed on the display device 810. In addition, the power consumption of the display device 810 can be reduced.

[0283] <Materials for light-emitting devices> Next, constituent materials that can be used for the light emitting device 572 will be described.

[0284] <<Conductor 772 and Conductor 788>> The conductor 772 and the conductor 788 may be made of any of the following materials in combination, provided that they fulfill the functions of an anode and a cathode. For example, metals, alloys, electrically conductive compounds, and mixtures thereof may be used as appropriate. Specific examples include In-Sn oxide (also called ITO), In-Si-Sn oxide (also called ITSO), In-Zn oxide, and In-W-Zn oxide. In addition, 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 containing any of these metals in combination as appropriate, may also be used. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium (Li), cesium (Cs), calcium (Ca), and strontium (Sr)) that are not listed above, rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing appropriate combinations of these, as well as graphene.

[0285] <<Hole Injection Layer 721 and Hole Transport Layer 722>> The hole-injection layer 721 is a layer that injects holes from the conductor 772, which is an anode, or the charge generation layer 792 to the EL layer 786, and is a layer that contains a material with a high hole-injection property. Here, the EL layer 786 includes an EL layer 786a, an EL layer 786b, an EL layer 786c, and EL layers 786(1) to 786(n).

[0286] Examples of materials with high hole injection properties include transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. In addition, phthalocyanine-based compounds, aromatic amine compounds, polymer compounds, etc. can be used.

[0287] A composite material containing a hole transport material and an acceptor material (electron accepting material) can also be used as a material with high hole injection properties. In this case, electrons are extracted from the hole transport material by the acceptor material, generating holes in the hole injection layer 721, and the holes are injected into the light emitting layer 723 via the hole transport layer 722. Note that the hole injection layer 721 may be formed as a single layer made of a composite material containing a hole transport material and an acceptor material (electron accepting material), or may be formed by laminating the hole transport material and the acceptor material (electron accepting material) in separate layers.

[0288] The hole transport layer 722 is a layer that transports holes injected from the conductor 772 by the hole injection layer 721 to the light emitting layer 723. Note that the hole transport layer 722 is a layer containing a hole transport material. It is particularly preferable to use a hole transport material used for the hole transport layer 722 that has a HOMO level that is the same as or close to the HOMO level of the hole injection layer 721.

[0289] As an acceptor material used for the hole-injection layer 721, an oxide of a metal belonging to Groups 4 to 8 of the periodic table can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among them, molybdenum oxide is particularly preferable because it is stable in the air, has low hygroscopicity, and is easy to handle. In addition, organic acceptors such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can be used.

[0290] As a hole transporting material used for the hole injection layer 721 and the hole transport layer 722, -6 cm 2 A substance having a hole mobility of / Vs or more is preferable. Note that other substances can be used as long as they have a higher hole transporting property than an electron transporting property.

[0291] As the hole transporting material, a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative or an indole derivative) or an aromatic amine compound can be suitably used. As the hole transporting material, for example, a compound having an aromatic amine skeleton, a compound having a carbazole skeleton, a compound having a thiophene skeleton, or a compound having a furan skeleton can be used. In addition, a polymer compound can also be used as the hole transporting material.

[0292] However, the hole transport material is not limited to the above, and one or a combination of various known materials can be used as the hole transport material for the hole injection layer 721 and the hole transport layer 722. The hole transport layer 722 may be formed of a plurality of layers. That is, the hole transport layer 722 may be formed by laminating, for example, a first hole transport layer and a second hole transport layer.

[0293] <<Light-emitting layer 723>> The light-emitting layer 723 is a layer containing a light-emitting substance. Note that, as the light-emitting substance, a substance exhibiting an emission color of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, or the like is appropriately used. Here, as shown in FIG. 37C, FIG. 37D, and (E), when the light-emitting device 572 has a plurality of EL layers, a structure exhibiting different emission colors (for example, white light emission obtained by combining emission colors that are complementary colors) can be obtained by using different light-emitting substances for the light-emitting layers 723 provided in the respective EL layers. For example, when the light-emitting device 572 has the structure shown in FIG. 37C, the light-emitting layer 723 provided in the EL layer 786a and the light-emitting layer 723 provided in the EL layer 786b are made different from each other in the emission color of the EL layer 786a and the emission color of the EL layer 786b can be made different from each other. Note that a stacked structure in which one light-emitting layer has different light-emitting substances may be used.

[0294] The light-emitting layer 723 may contain one or more organic compounds (host materials, assist materials) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used.

[0295] When the light-emitting device 572 has the structure shown in Fig. 37C, it is preferable to use a light-emitting substance that emits blue light (blue light-emitting substance) as a guest material in one of the EL layers 786a and 786b, and to use a substance that emits green light (green light-emitting substance) and a substance that emits red light (red light-emitting substance) in the other. This method is effective when the luminous efficiency and life of the blue light-emitting substance (blue light-emitting layer) are inferior to the others. Note that, here, it is preferable to use a light-emitting substance that converts singlet excitation energy into light in the visible light region as the blue light-emitting substance, and to use light-emitting substances that convert triplet excitation energy into light in the visible light region as the green and red light-emitting substances, because this improves the RGB spectral balance.

[0296] There is no particular limitation on the light-emitting substance that can be used for the light-emitting layer 723, and a light-emitting substance that converts singlet excitation energy into light emission in the visible light region or a light-emitting substance that converts triplet excitation energy into light emission in the visible light region can be used. Note that, for example, the following light-emitting substances can be given as the light-emitting substance.

[0297] Examples of luminescent materials that convert singlet excitation energy into luminescence include fluorescent materials, such as pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives are particularly preferred because they have a high luminescence quantum yield. Pyrene derivatives are a group of compounds useful for achieving the blue chromaticity in one embodiment of the present invention.

[0298] Examples of luminescent materials that convert triplet excitation energy into luminescence include phosphorescent materials and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0299] Examples of phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), rare earth metal complexes, etc. Since each substance exhibits a different emission color (emission peak), they are appropriately selected and used as needed.

[0300] Examples of phosphorescent materials that exhibit blue or green color and have an emission spectrum with a peak wavelength of 450 nm or more and 570 nm or less include organometallic complexes having a 4H-triazole skeleton, organometallic complexes having a 1H-triazole skeleton, organometallic complexes having an imidazole skeleton, and organometallic complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand.

[0301] Examples of phosphorescent materials that exhibit green or yellow color and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include organometallic iridium complexes having a pyrimidine skeleton, organometallic iridium complexes having a pyrazine skeleton, organometallic iridium complexes having a pyridine skeleton, organometallic complexes, and rare earth metal complexes.

[0302] Among the above, organometallic iridium complexes having a pyridine skeleton (particularly a phenylpyridine skeleton) or a pyrimidine skeleton are a group of compounds useful for achieving green chromaticity in one embodiment of the present invention.

[0303] Examples of phosphorescent materials that exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570 nm or more and 750 nm or less include organometallic complexes having a pyrimidine skeleton, organometallic complexes having a pyrazine skeleton, organometallic complexes having a pyridine skeleton, platinum complexes, and rare earth metal complexes.

[0304] Among the above, organometallic iridium complexes having a pyrazine skeleton are a group of compounds useful for achieving the red chromaticity in one embodiment of the present invention. In particular, organometallic iridium complexes having a cyano group, such as [Ir(dmdppr-dmCP)2(dpm)], are highly stable and are preferred.

[0305] The blue light-emitting material may have a photoluminescence peak wavelength of 430 nm or more and 470 nm or less, more preferably 430 nm or more and 460 nm or less. The green light-emitting material may have a photoluminescence peak wavelength of 500 nm or more and 540 nm or less, more preferably 500 nm or more and 530 nm or less. The red light-emitting material may have a photoluminescence peak wavelength of 610 nm or more and 680 nm or less, more preferably 620 nm or more and 680 nm or less. The photoluminescence measurement may be performed using either a solution or a thin film.

[0306] By using such a compound in combination with the microcavity effect, the above-mentioned chromaticity can be more easily achieved. In this case, the film thickness of the semi-transmissive / semi-reflective electrode (metal thin film portion) required to obtain the microcavity effect is preferably 20 nm or more and 40 nm or less. More preferably, it is more than 25 nm and 40 nm or less. However, if it exceeds 40 nm, there is a possibility that the efficiency will decrease.

[0307] One or more substances having an energy gap larger than the energy gap of the light-emitting substance (guest material) may be selected and used as the organic compound (host material, assist material) used in the light-emitting layer 723. Note that the above-mentioned hole-transporting material and the later-described electron-transporting material can also be used as the host material or the assist material.

[0308] When the light-emitting substance is a fluorescent material, it is preferable to use an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state as the host material, such as an anthracene derivative or a tetracene derivative.

[0309] When the light-emitting material is a phosphorescent material, an organic compound having a triplet excitation energy larger than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting material may be selected as the host material. In this case, in addition to zinc or aluminum-based metal complexes, oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives, bipyridine derivatives, phenanthroline derivatives, aromatic amines, carbazole derivatives, etc. may be used.

[0310] When a plurality of organic compounds are used in the light-emitting layer 723, it is preferable to use a compound that forms an exciplex in a mixed state with a light-emitting substance. In this case, various organic compounds can be used in appropriate combination, but in order to efficiently form an exciplex, it is particularly preferable to combine a compound that easily receives holes (hole transporting material) with a compound that easily receives electrons (electron transporting material). As specific examples of the hole transporting material and the electron transporting material, the materials shown in this embodiment mode can be used.

[0311] A TADF material is a material that can upconvert a triplet excited state to a singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and efficiently emits light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited level and the singlet excited level of 0 eV or more and 0.2 eV or less, and preferably 0 eV or more and 0.1 eV or less. Delayed fluorescence in TADF materials refers to light emission that has a spectrum similar to that of normal fluorescence, but has a significantly long lifetime. The lifetime is approximately 10 -6 seconds or more, preferably 10 -3 More than seconds.

[0312] Examples of TADF materials include fullerene and its derivatives, acridine derivatives such as proflavine, eosin, etc. Also included are metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. Also, heterocyclic compounds having π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings can be used as TADF materials. In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded to each other is particularly preferable because the donor property of the π-electron-rich heteroaromatic ring and the acceptor property of the π-electron-deficient heteroaromatic ring are both strong, and the energy difference between the singlet excited state and the triplet excited state is small.

[0313] In addition, when using a TADF material, it can also be used in combination with other organic compounds.

[0314] <<Electron transport layer 724>> The electron transport layer 724 transports electrons injected from the conductor 788 by the electron injection layer 725 to the light-emitting layer 723. Note that the electron transport layer 724 is a layer containing an electron transport material. The electron transport material used for the electron transport layer 724 has a conductivity of 1×10 -6 cm 2 A substance having an electron mobility of 1 / Vs or more is preferable. Note that other substances can be used as long as they have a higher electron transporting property than a hole transporting property.

[0315] Examples of the electron transporting material include metal complexes having a quinoline ligand, a benzoquinoline ligand, an oxazole ligand, or a thiazole ligand, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, etc. In addition, a π-electron deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound can also be used.

[0316] The electron transport layer 724 may have not only a single layer structure, but also a stacked structure of two or more layers made of the above substances.

[0317] <<Electron injection layer 725>> The electron injection layer 725 is a layer containing a substance with high electron injection properties. The electron injection layer 725 may contain any of a variety of materials, including lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), lithium oxide (LiO x ) or an alkaline earth metal, or a compound thereof, can be used. Also, a rare earth metal compound, such as erbium fluoride (ErF3), can be used. Also, an electride can be used for the electron injection layer 725. For example, an electride can be a substance in which electrons are highly doped into a mixed oxide of calcium and aluminum. Note that the above-mentioned substance constituting the electron transport layer 724 can also be used.

[0318] A composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer 725. Such a composite material has excellent electron injection and electron transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent in transporting the generated electrons, and specifically, for example, the above-mentioned electron transport material (metal complex, heteroaromatic compound, etc.) used for the electron transport layer 724 can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferred, and examples of such materials include lithium, cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides and alkaline earth metal oxides are preferred, and examples of such materials include lithium oxide, calcium oxide, and barium oxide. Furthermore, a Lewis base such as magnesium oxide can also be used. Furthermore, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can also be used.

[0319] <<Charge generation layer 792>> When a voltage is applied between the conductor 772 and the conductor 788, the charge generation layer 792 has a function of injecting electrons into the EL layer 786 closer to the conductor 772 and injecting holes into the EL layer 786 closer to the conductor 788, among the two EL layers 786 in contact with the charge generation layer 792. For example, in the light-emitting device 572 having the configuration shown in FIG. 37C, the charge generation layer 792 has a function of injecting electrons into the EL layer 786a and injecting holes into the EL layer 786b. The charge generation layer 792 may have a configuration in which an electron acceptor is added to a hole transporting material, or a configuration in which an electron donor is added to an electron transporting material. In addition, both of these configurations may be laminated. By forming the charge generation layer 792 using the above-mentioned material, it is possible to suppress an increase in the driving voltage of the display device 810 when EL layers are laminated.

[0320] In the case where the charge generation layer 792 has a structure in which an electron acceptor is added to a hole transporting material, examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, and the like. Examples of the electron acceptor include oxides of metals belonging to Groups 4 to 8 of the periodic table. Specific examples of the oxides include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

[0321] In the charge generation layer 792, when an electron donor is added to an electron transporting material, an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Groups 2 and 13 of the periodic table, and an oxide or carbonate thereof can be used as the electron donor. Specifically, it is preferable to use lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, or the like. An organic compound such as tetrathianaphthacene may also be used as the electron donor.

[0322] In addition, the light-emitting device 572 can be manufactured by a vacuum process such as a deposition method, or a solution process such as a spin coating method or an inkjet method. When a deposition method is used, a physical deposition method (PVD method) such as a sputtering method, an ion plating method, an ion beam deposition method, a molecular beam deposition method, or a vacuum deposition method, or a chemical deposition method (CVD method) can be used. In particular, the functional layers (hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer) and the charge generation layer included in the EL layer of the light-emitting device can be formed by a deposition method (vacuum deposition method, etc.), a coating method (dip coating method, die coating method, bar coating method, spin coating method, spray coating method, etc.), a printing method (inkjet method, screen (screen printing) method, offset (lithographic printing) method, flexo (relief printing) method, gravure method, microcontact method, etc.), etc.

[0323] The functional layers (hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer) and the charge generation layer constituting the EL layer of the light emitting device shown in this embodiment are not limited to the above-mentioned materials, and other materials can be used in combination as long as they fulfill the functions of each layer. As an example, a polymer compound (oligomer, dendrimer, polymer, etc.), a medium molecular compound (a compound in the intermediate range between a low molecular weight and a high molecular weight: molecular weight 400 to 4000), an inorganic compound (quantum dot material, etc.), etc. can be used. As the quantum dot material, a colloidal quantum dot material, an alloy type quantum dot material, a core-shell type quantum dot material, a core type quantum dot material, etc. can be used.

[0324] The display device 810 described in this embodiment can also be used as a light source included in the detection device 17 described in Embodiment 1. By using the display device 810 as the light source described in Embodiment 1, the light sources can be arranged at high density. In this manner, the electronic device of one embodiment of the present invention can obtain information about a user of the electronic device with higher accuracy.

[0325] FIG. 38A shows a configuration example of an imaging device that can be used in the detection device 17 shown in Embodiment 1. FIG. 38A is a cross-sectional view showing the configuration of the imaging device. As shown in FIG. 38A, a transistor 1003, a light-emitting device 572, a photoelectric conversion device 1010, a colored layer 993R, a colored layer 993IR, and the like can be sandwiched between a substrate 1001 and a substrate 995. Here, the transistor 1003 can be, for example, an OS transistor. Four transistors 1003 are shown in FIG. 38A.

[0326] An insulator 1002 is provided on a substrate 1001, and a transistor 1003 is provided on the insulator 1002. An insulator 1004 is provided on the transistor 1003, and an insulator 1005 is provided on the insulator 1004. A light-emitting device 572 and a photoelectric conversion device 1010 are provided on the insulator 1005, and a coloring layer 993R and a coloring layer 993IR are provided so as to have an area overlapping with the light-emitting device 572 or the photoelectric conversion device 1010. FIG. 38A shows a configuration in which two light-emitting devices 572 (light-emitting device 572_1, light-emitting device 572_2) and two photoelectric conversion devices 1010 (photoelectric conversion device 1010_1, photoelectric conversion device 1010_2) are electrically connected to different transistors 1003, respectively. 38A shows a configuration in which a colored layer 993R having a function of transmitting red light is provided so as to have a region overlapping with the light-emitting device 572_1, and a colored layer 993IR having a function of transmitting infrared light is provided so as to have a region overlapping with the light-emitting device 572_2. Also, a configuration in which a colored layer 993R is provided so as to have a region overlapping with the photoelectric conversion device 1010_1, and a colored layer 993IR is provided so as to have a region overlapping with the photoelectric conversion device 1010_2 is shown.

[0327] The photoelectric conversion device 1010 converts light L irradiated from outside the imaging device into ex The received light L ex The device has the function of converting the reflected light into an electrical signal corresponding to the illuminance of the light.

[0328] The light emitting device 572 preferably has a function of emitting white light and infrared light. As a result, the light emitted from the light emitting device 572_1 passes through the colored layer 993R and is emitted to the outside of the imaging device as red light R. Also, the light emitted from the light emitting device 572_2 passes through the colored layer 993IR and is emitted to the outside of the imaging device as infrared light IR. The red light R and infrared light IR emitted to the outside of the imaging device are reflected by an object and irradiated to the photoelectric conversion device 1010. For example, when the imaging device having the configuration shown in FIG. 38A is applied to the eyeglass-type electronic device shown in the first embodiment, the red light R and infrared light IR are irradiated to the face of the user of the eyeglass-type electronic device, and the reflected light L is reflected by the object. ex can be detected by the photoelectric conversion device 1010.

[0329] Since the imaging device has a function of detecting both red light and infrared light, the imaging device can detect the eyes and the surrounding conditions of the user of the electronic device of one embodiment of the present invention with higher accuracy than a device having a function of detecting only one of red light or infrared light. As a result, the facial features of the user of the electronic device of one embodiment of the present invention, such as the facial expression of the user, can be recognized with high accuracy, and the electronic device of one embodiment of the present invention can have a function of estimating, for example, the fatigue level, emotions, etc. of the user with high accuracy.

[0330] Note that when the display device of one embodiment of the present invention includes a photoelectric conversion device, the display device can have a structure as shown in Fig. 38A. In this case, the display device includes a light-emitting device 572 having a region overlapping with a colored layer 993R having a function of transmitting red light, a light-emitting device 572 having a region overlapping with a colored layer 993IR having a function of transmitting infrared light, a light-emitting device 572 having a region overlapping with a colored layer having a function of transmitting green light, and a light-emitting device 572 having a region overlapping with a colored layer having a function of transmitting blue light.

[0331] The conductor 772, the EL layer 786, and the conductor 788 form a light-emitting device 572. The conductor 772, the active layer 1011, and the conductor 788 form a photoelectric conversion device 1010. Here, the transistor 1003 is electrically connected to the conductor 772.

[0332] The active layer 1011 may have a layered structure in which a p-type semiconductor and an n-type semiconductor are stacked to form a pn junction, or a layered structure in which a p-type semiconductor, an i-type semiconductor, and an n-type semiconductor are stacked to form a pin junction.

[0333] An inorganic semiconductor such as silicon or an organic semiconductor containing an organic compound can be used as the semiconductor used in the active layer 1011. In particular, by using an organic semiconductor material, it becomes easy to form the EL layer 786 of the light-emitting device 572 and the active layer 1011 by the same vacuum deposition method, and it is preferable because the manufacturing equipment can be shared.

[0334] When an organic semiconductor material is used for the active layer 1011, fullerene (e.g., C 60 , C 70 An electron-accepting organic semiconductor material such as phthalocyanine (Pc) or a derivative thereof can be used. An electron-donating organic semiconductor material such as copper (II) phthalocyanine (CuPc) or tetraphenyldibenzoperiflanthene (DBP) can be used as a p-type semiconductor material. The active layer 1011 may have a laminated structure (pn laminated structure) of an electron-accepting semiconductor material and an electron-donating semiconductor material, or a laminated structure (pin laminated structure) in which a bulk heterostructure layer is provided between the pn laminated structure and the electron-donating semiconductor material by co-evaporation. In order to suppress dark current when light is not irradiated, a layer functioning as a hole blocking layer or a layer functioning as an electron blocking layer may be provided around (upper or lower side of) the pn laminated structure or the pin laminated structure.

[0335] In the light-emitting device 572, an EL layer 786 is provided on the conductor 772. In the photoelectric conversion device 1010, an active layer 1011 is provided on the conductor 772. Furthermore, a conductor 788 is provided to cover the EL layer 786 and the active layer 1011. This allows the conductor 788 to function as both an electrode of the light-emitting device 572 and an electrode of the photoelectric conversion device 1010.

[0336] Fig. 38B is a cross-sectional view illustrating a configuration example of an imaging device of one embodiment of the present invention, which is a modification of the configuration illustrated in Fig. 38A. The imaging device having the configuration illustrated in Fig. 38B differs from the imaging device having the configuration illustrated in Fig. 38A in that a light-emitting device 572 is not provided.

[0337] When the electronic device according to one embodiment of the present invention has an imaging device having the configuration shown in FIG. 38B, a light source is provided outside the imaging device, so that the imaging device can detect light emitted from the light source. For example, when the imaging device having the configuration shown in FIG. 38B is applied to the glasses-type electronic device described in embodiment 1, red light and infrared light emitted from the light source are irradiated onto the face of a user of the glasses-type electronic device, and reflected light L ex can be detected by the photoelectric conversion device 1010.

[0338] When an imaging device included in an electronic device of one embodiment of the present invention has the structure shown in FIG. 38B, the imaging device can be provided with photoelectric conversion devices 1010 at high density.

[0339] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be implemented in appropriate combination with other configuration examples or drawings.

[0340] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification.

[0341] (Embodiment 3) In this embodiment, a transistor that can be used in a display device which is one embodiment of the present invention will be described.

[0342] <Transistor configuration example 1> 39A, 39B, and 39C are a top view and a cross-sectional view of a transistor 200A that can be used in a display device which is one embodiment of the present invention, and a periphery of the transistor 200A. The transistor 200A can be used as a transistor included in the pixel array 833, the gate driver circuit 821, the source driver circuit 822, and the circuit 840 described in Embodiment 1 and the like.

[0343] FIG. 39A is a top view of the transistor 200A. Also, FIG. 39B and FIG. 39C are cross-sectional views of the transistor 200A. Here, FIG. 39B is a cross-sectional view of a portion indicated by a dashed line A1-A2 in FIG. 39A, and is also a cross-sectional view of the transistor 200A in the channel length direction. Also, FIG. 39C is a cross-sectional view of a portion indicated by a dashed line A3-A4 in FIG. 39A, and is also a cross-sectional view of the transistor 200A in the channel width direction. Note that in the top view of FIG. 39A, some elements are omitted for clarity.

[0344] The transistor 200A has a metal oxide 230a arranged on a substrate (not shown), a metal oxide 230b arranged on the metal oxide 230a, a conductor 242a and a conductor 242b arranged on the metal oxide 230b and spaced apart from each other, an insulator 280 arranged on the conductor 242a and the conductor 242b and having an opening formed between the conductor 242a and the conductor 242b, a conductor 260 arranged in the opening, an insulator 250 arranged among the metal oxide 230b, the conductor 242a, the conductor 242b, and the insulator 280, and the conductor 260, and a metal oxide 230c arranged among the metal oxide 230b, the conductor 242a, the conductor 242b, the insulator 280, and the insulator 250. 39B and 39C, it is preferable that the top surface of the conductor 260 approximately coincides with the top surfaces of the insulator 250, the insulator 254, the metal oxide 230c, and the insulator 280. In the following, the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c may be collectively referred to as the metal oxide 230. Furthermore, the conductor 242a and the conductor 242b may be collectively referred to as the conductor 242.

[0345] As shown in Fig. 39B, in the transistor 200A, the side surfaces of the conductor 242a and the conductor 242b facing the conductor 260 have a generally vertical shape. Note that the transistor 200A shown in Fig. 39 is not limited to this, and the angle formed between the side surface and the bottom surface of the conductor 242a and the conductor 242b may be 10° or more and 80° or less, preferably 30° or more and 60° or less. Furthermore, the opposing side surfaces of the conductor 242a and the conductor 242b may have multiple surfaces.

[0346] 39B and 39C, it is preferable that an insulator 254 is disposed between the insulator 224, the metal oxide 230a, the metal oxide 230b, the conductor 242a, the conductor 242b, and the metal oxide 230c and the insulator 280. Here, it is preferable that the insulator 254 has an area in contact with the side surface of the metal oxide 230c, the top surface and side surface of the conductor 242a, the top surface and side surface of the conductor 242b, the side surface of the metal oxide 230a, the side surface of the metal oxide 230b, and the top surface of the insulator 224, as shown in FIG.

[0347] In the transistor 200A, a three-layer structure of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c is shown in the region where a channel is formed (hereinafter also referred to as a channel formation region) and in the vicinity thereof, but the present invention is not limited to this. For example, a two-layer structure of the metal oxide 230b and the metal oxide 230c or a stacked structure of four or more layers may be provided. In addition, in the transistor 200A, the conductor 260 is shown as having a two-layer stacked structure, but the present invention is not limited to this. For example, the conductor 260 may have a single-layer structure or a stacked structure of three or more layers. In addition, each of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c may have a stacked structure of two or more layers.

[0348] For example, when metal oxide 230c has a layered structure consisting of a first metal oxide and a second metal oxide on the first metal oxide, it is preferable that the first metal oxide has a composition similar to that of metal oxide 230b, and the second metal oxide has a composition similar to that of metal oxide 230a.

[0349] Here, the conductor 260 functions as a gate electrode of the transistor, and the conductor 242a and the conductor 242b function as a source electrode or a drain electrode, respectively. As described above, the conductor 260 is formed so as to be embedded in the opening of the insulator 280 and in the region sandwiched between the conductor 242a and the conductor 242b. Here, the arrangement of the conductor 260, the conductor 242a, and the conductor 242b is selected in a self-aligned manner with respect to the opening of the insulator 280. That is, in the transistor 200A, the gate electrode can be arranged in a self-aligned manner between the source electrode and the drain electrode. Therefore, the conductor 260 can be formed without providing a margin for alignment, so that the occupied area of ​​the transistor 200A can be reduced. This allows the display device to have a high resolution. In addition, the display device can have a narrow frame.

[0350] As shown in FIG. 39, it is preferable that the conductor 260 has a conductor 260a provided inside the insulator 250 and a conductor 260b provided so as to be embedded inside the conductor 260a.

[0351] 39A, 39B, and 39C, the transistor 200A preferably has an insulator 214 disposed on a substrate (not shown), an insulator 216 disposed on the insulator 214, a conductor 205 disposed so as to be 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. In addition, a metal oxide 230a is preferably disposed on the insulator 224.

[0352] An insulator 274 functioning as an interlayer film and an insulator 281 are preferably disposed over the transistor 200A. Here, the insulator 274 is preferably disposed in contact with top surfaces of the conductor 260, the insulator 250, the insulator 254, the metal oxide 230c, and the insulator 280.

[0353] It is preferable that the insulators 222, 254, and 274 have a function of suppressing the diffusion of hydrogen (e.g., at least one of hydrogen atoms, hydrogen molecules, etc.). For example, it is preferable that the insulators 222, 254, and 274 have lower hydrogen permeability than the insulators 224, 250, and 280. It is also preferable that the insulators 222 and 254 have a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.). For example, it is preferable that the insulators 222 and 254 have lower oxygen permeability than the insulators 224, 250, and 280.

[0354] Here, the insulator 224, the metal oxide 230, and the insulator 250 are separated by the insulators 280 and 281, and the insulators 254 and 274. Therefore, impurities such as hydrogen contained in the insulators 280 and 281, and excess oxygen can be prevented from being mixed into the insulators 224, the metal oxide 230, and the insulator 250.

[0355] It is preferable that the conductor 240 (conductor 240a and conductor 240b) is provided, electrically connected to the transistor 200A and functioning as a plug. Note that the insulator 241 (insulator 241a and insulator 241b) is provided in contact with the side surface of the conductor 240 functioning as a plug. That is, the insulator 241 is provided in contact with the inner wall of the opening of the insulator 254, the insulator 280, the insulator 274, and the insulator 281. Also, a configuration may be adopted in which the first conductor of the conductor 240 is provided in contact with the side surface of the insulator 241, and the second conductor of the conductor 240 is provided further inside. Here, the height of the upper surface of the conductor 240 and the height of the upper surface of the insulator 281 can be made approximately the same. Note that, in the transistor 200A, a configuration in which the first conductor of the conductor 240 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 be provided as a single layer or a laminated structure of three or more layers. When the structure has a laminated structure, the layers may be distinguished by giving ordinal numbers in the order of formation.

[0356] In the transistor 200A, a metal oxide that functions as an oxide semiconductor (hereinafter also referred to as an oxide semiconductor) is preferably used for the metal oxide 230 (metal oxide 230a, metal oxide 230b, and metal oxide 230c) including the channel formation region. For example, as the metal oxide that becomes the channel formation region of the metal oxide 230, it is preferable to use a metal oxide having a band gap of 2 eV or more, preferably 2.5 eV or more, as described above.

[0357] As shown in FIG. 39B, the thickness of the metal oxide 230b in a region not overlapping with the conductor 242 may be thinner than the thickness of the region overlapping with the conductor 242. This is formed by removing a part of the upper surface of the metal oxide 230b when forming the conductors 242a and 242b. When a conductive film that becomes the conductor 242 is formed on the upper surface of the metal oxide 230b, a low resistance region may be formed near the interface with the conductive film. In this way, by removing the low resistance region located between the conductors 242a and 242b on the upper surface of the metal oxide 230b, it is possible to suppress the formation of a channel in that region.

[0358] According to one embodiment of the present invention, a display device having a small transistor and high definition can be provided. Alternatively, a display device having a transistor with high on-state current and high luminance can be provided. Alternatively, a display device having a transistor with high speed operation can be provided. Alternatively, a display device having a transistor with stable electrical characteristics and high reliability can be provided. Alternatively, a display device having a transistor with low off-state current and low power consumption can be provided.

[0359] The detailed structure of the transistor 200A that can be used in the display device of one embodiment of the present invention will be described.

[0360] The conductor 205 is disposed so as to have an overlapping region with the metal oxide 230 and the conductor 260. The conductor 205 is preferably embedded in the insulator 216. Here, it is preferable to improve the flatness of the upper surface of the conductor 205. For example, the average surface roughness (Ra) of the upper surface of the conductor 205 may be set to 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 improves the crystallinity of the metal oxide 230b and the metal oxide 230c.

[0361] Here, the conductor 260 may function as a first gate (also referred to as a top gate) electrode. The conductor 205 may function as a second gate (also referred to as a back gate) electrode. In this case, the potential applied to the conductor 205 is changed independently of the potential applied to the conductor 260, thereby making it possible to control the V th In particular, applying a negative potential to conductor 205 can control the V th The off-state current can be reduced by making the potential higher than 0 V. Therefore, when a negative potential is applied to the conductor 205, the drain current of the transistor 200A when the potential applied to the conductor 260 is 0 V can be made smaller than when no potential is applied.

[0362] The conductor 205 is preferably provided to be larger than the channel formation region in the metal oxide 230. In particular, as shown in Fig. 39C, the conductor 205 preferably extends also in a region outside the end portion intersecting with the channel width direction of the metal oxide 230. In other words, the conductor 205 and the conductor 260 preferably overlap with each other via an insulator on the outside of the side surface of the metal oxide 230 in the channel width direction.

[0363] With the above structure, the channel formation region of the metal oxide 230 can be electrically surrounded by the electric field of the conductor 260 functioning as a first gate electrode and the electric field of the conductor 205 functioning as a second gate electrode.

[0364] 39C, the conductor 205 is extended to function as wiring. However, the present invention is not limited to this, and a conductor functioning as wiring may be provided below the conductor 205.

[0365] It is preferable to use a conductive material containing tungsten, copper, or aluminum as a main component for the conductor 205. Although the conductor 205 is illustrated as a single layer, it may have a laminated structure, for example, a laminate of titanium or titanium nitride and the above conductive material.

[0366] A conductor having a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (NO, NO, NO, etc.), copper atoms, etc. (the impurities are less likely to permeate) may be provided under the conductor 205. Alternatively, it is preferable to provide a conductor having a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (the oxygen is less likely to permeate). Note that 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 impurities or the oxygen.

[0367] By providing a conductor having a function of suppressing oxygen diffusion under the conductor 205, it is possible to suppress the conductor 205 from being oxidized and its conductivity from decreasing. As the conductor having a function of suppressing oxygen diffusion, it is preferable to use, for example, tantalum, tantalum nitride, ruthenium, ruthenium oxide, or the like. Therefore, the conductor 205 may be formed as a single layer or a multilayer structure of the above-mentioned conductive materials.

[0368] The insulator 214 preferably functions as a barrier insulating film that suppresses impurities such as water or hydrogen from entering the transistor 200A from the substrate side. Therefore, the insulator 214 is preferably made of an insulating material that has a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (NO, NO, NO, etc.), copper atoms, etc. (the impurities are less likely to permeate through the material). Alternatively, it is preferably made of an insulating material that has a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.) (the oxygen is less likely to permeate through the material).

[0369] For example, it is preferable to use aluminum oxide, silicon nitride, or the like as the insulator 214. This can prevent impurities such as water or hydrogen from diffusing from the substrate side of the insulator 214 to the transistor 200A side. Alternatively, it can prevent oxygen contained in the insulator 224, etc. from diffusing to the substrate side of the insulator 214.

[0370] The insulator 216, insulator 280, and insulator 281, which function as interlayer films, preferably have a lower dielectric constant than the insulator 214. By using a material with a low dielectric constant as the interlayer film, the parasitic capacitance generated between wirings can be reduced. For example, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide to which fluorine has been added, silicon oxide to which carbon has been added, silicon oxide to which carbon and nitrogen have been added, silicon oxide having voids, or the like may be used as appropriate for the insulator 216, insulator 280, and insulator 281.

[0371] The insulators 222 and 224 function as gate insulators.

[0372] Here, the insulator 224 in contact with the metal oxide 230 preferably releases oxygen when heated. In this specification and the like, oxygen released by heating is sometimes referred to as excess oxygen. For example, the insulator 224 may be made of silicon oxide, silicon oxynitride, or the like as appropriate. By providing an insulator containing oxygen in contact with the metal oxide 230, oxygen vacancies in the metal oxide 230 can be reduced and the reliability of the transistor 200A can be improved.

[0373] Specifically, it is preferable to use an oxide material from which a portion of oxygen is released by heating as the insulator 224. The oxide material from which oxygen is released by heating is an oxide material from which the amount of released oxygen converted into oxygen atoms is 1.0×10 18 atoms / cm 3 More than 1.0×10 19 atoms / cm 3 More preferably, 2.0×10 19 atoms / cm 3 or more than 3.0 x 10 20 atoms / cm 3 The oxide film is preferably an oxide film having a surface temperature of 100° C. or more and 700° C. or less, or 100° C. or more and 400° C. or less, during the TDS analysis.

[0374] 39C, the thickness of the region of insulator 224 that does not overlap with insulator 254 and does not overlap with metal oxide 230b may be thinner than the thickness of the other regions. It is preferable that the thickness of the region of insulator 224 that does not overlap with insulator 254 and does not overlap with metal oxide 230b is a thickness that allows the oxygen to diffuse sufficiently.

[0375] Like the insulator 214, etc., the insulator 222 preferably functions as a barrier insulating film that suppresses impurities such as water or hydrogen from entering the transistor 200A from the substrate side. For example, the insulator 222 preferably has lower hydrogen permeability than the insulator 224. By surrounding the insulator 224, the metal oxide 230, the insulator 250, etc. with the insulators 222, 254, and 274, it is possible to suppress impurities such as water or hydrogen from entering the transistor 200A from the outside.

[0376] Furthermore, it is preferable that the insulator 222 has a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (the oxygen is less likely to permeate). For example, it is preferable that the insulator 222 has lower oxygen permeability than the insulator 224. The insulator 222 is preferable because it has a function of suppressing the diffusion of oxygen and impurities, thereby reducing the diffusion of oxygen contained in the metal oxide 230 toward the substrate side. Also, it is possible to suppress the reaction of the conductor 205 with the oxygen contained in the insulator 224 and the oxygen contained in the metal oxide 230.

[0377] The insulator 222 may be an insulator containing an oxide of one or both of aluminum and hafnium, which are insulating materials. As the insulator containing an oxide of one or both of aluminum and hafnium, it is preferable to use aluminum oxide or hafnium oxide. Alternatively, it is preferable to use an oxide containing aluminum and hafnium (hafnium aluminate), etc. When the insulator 222 is formed using such a material, the insulator 222 functions as a layer that suppresses the release of oxygen from the metal oxide 230 and the intrusion of impurities such as hydrogen into the metal oxide 230 from the periphery of the transistor 200A.

[0378] Alternatively, for example, aluminum oxide, bismuth oxide, germanium oxide, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, or zirconium oxide may be added to these insulators. Alternatively, these insulators may be nitrided. Silicon oxide, silicon oxynitride, or silicon nitride may be stacked on the above insulators.

[0379] The insulator 222 may be a single layer or a multilayer of an insulator containing a so-called high-k material, such as aluminum oxide, hafnium oxide, tantalum oxide, zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrTiO3), or (Ba,Sr)TiO3 (BST). As transistors become smaller and more highly integrated, problems such as leakage current may occur due to the thinning of the gate insulator. By using a high-k material for the insulator that functions as the gate insulator, it is possible to reduce the gate potential during transistor operation while maintaining the physical film thickness.

[0380] The insulator 222 and the insulator 224 may have a laminated structure of two or more layers. In that case, the laminated structure is not limited to a laminated structure made of the same material, and may be a laminated structure made of different materials. For example, a configuration in which an insulator similar to the insulator 224 is provided under the insulator 222 may be used.

[0381] The metal oxide 230 includes a metal oxide 230a, a metal oxide 230b on the metal oxide 230a, and a metal oxide 230c on the metal oxide 230b. By having the metal oxide 230a below the metal oxide 230b, it is possible to suppress the diffusion of impurities from structures formed below the metal oxide 230a to the metal oxide 230b. Furthermore, by having the metal oxide 230c on the metal oxide 230b, it is possible to suppress the diffusion of impurities from structures formed above the metal oxide 230c to the metal oxide 230b.

[0382] The metal oxide 230 preferably has a laminated structure of a plurality of oxide layers with different atomic ratios of each metal atom. Specifically, in the metal oxide used for the metal oxide 230a, the atomic ratio of element M among the constituent elements is preferably larger than the atomic ratio of element M among the constituent elements in the metal oxide used for the metal oxide 230b. In addition, in the metal oxide used for the metal oxide 230a, the atomic ratio of element M to In is preferably larger than the atomic ratio of element M to In in the metal oxide used for the metal oxide 230b. In addition, in the metal oxide used for the metal oxide 230b, the atomic ratio of In to element M is preferably larger than the atomic ratio of In to element M in the metal oxide used for the metal oxide 230a. In addition, the metal oxide 230c can be a metal oxide that can be used for the metal oxide 230a or the metal oxide 230b.

[0383] The metal oxide 230a, the metal oxide 230b, and the metal oxide 230c are preferably crystalline, and in particular, it is preferable to use CAAC-OS (c-axis aligned crystalline oxide semiconductor). Crystalline oxides such as CAAC-OS have few impurities and defects (oxygen deficiency, etc.), and have a dense structure with high crystallinity. Therefore, it is possible to suppress the extraction of oxygen from the metal oxide 230b by the source electrode or the drain electrode. As a result, even when a heat treatment is performed, it is possible to suppress the extraction of oxygen from the metal oxide 230b. Therefore, the transistor 200A is stable against high temperatures (so-called thermal budget) in the manufacturing process.

[0384] It is preferable that the energy of the conduction band minimum of the metal oxide 230a and the metal oxide 230c is higher than the energy of the conduction band minimum of the metal oxide 230b. In other words, it is preferable that the electron affinity of the metal oxide 230a and the metal oxide 230c is smaller than the electron affinity of the metal oxide 230b. In this case, it is preferable that the metal oxide 230c is a metal oxide that can be used for the metal oxide 230a. Specifically, it is preferable that the atomic ratio of the element M among the constituent elements in the metal oxide used for the metal oxide 230c is larger than the atomic ratio of the element M among the constituent elements in the metal oxide used for the metal oxide 230b. It is also preferable that the atomic ratio of the element M to In in the metal oxide used for the metal oxide 230c is larger than the atomic ratio of the element M to In in the metal oxide used for the metal oxide 230b. In addition, in the metal oxide used for the metal oxide 230b, the atomic ratio of In to the element M is preferably larger than the atomic ratio of In to the element M in the metal oxide used for the metal oxide 230c.

[0385] Here, at the junction of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c, the energy level of the conduction band minimum changes gradually. In other words, it can be said that the energy level of the conduction band minimum at the junction of the metal oxide 230a, the metal oxide 230b, and the metal oxide 230c changes continuously or is continuously junctioned. To achieve this, it is preferable to reduce the defect level density of the mixed layer formed at the interface between the metal oxide 230a and the metal oxide 230b and the interface between the metal oxide 230b and the metal oxide 230c.

[0386] Specifically, the metal oxide 230a and the metal oxide 230b, and the metal oxide 230b and the metal oxide 230c have a common element other than oxygen (as a main component), so that a mixed layer with a low defect level density can be formed. For example, when the metal oxide 230b is an In-Ga-Zn oxide, the metal oxide 230a and the metal oxide 230c may be made of In-Ga-Zn oxide, Ga-Zn oxide, gallium oxide, or the like. The metal oxide 230c may also have a laminated structure. For example, a laminated structure of In-Ga-Zn oxide and Ga-Zn oxide on the In-Ga-Zn oxide, or a laminated structure of In-Ga-Zn oxide and gallium oxide on the In-Ga-Zn oxide can be used. In other words, a laminated structure of In-Ga-Zn oxide and an oxide not containing In may be used as the metal oxide 230c.

[0387] Specifically, the metal oxide 230a may be a metal oxide having an atomic ratio of In:Ga:Zn=1:3:4 or 1:1:0.5. The metal oxide 230b may be a metal oxide having an atomic ratio of In:Ga:Zn=4:2:3 or 3:1:2. The metal oxide 230c may be a metal oxide having an atomic ratio of In:Ga:Zn=1:3:4, In:Ga:Zn=4:2:3, Ga:Zn=2:1, or Ga:Zn=2:5. Specific examples of the metal oxide 230c having a layered structure include a layered structure of In:Ga:Zn=4:2:3 [atomic ratio] and Ga:Zn=2:1 [atomic ratio], a layered structure of In:Ga:Zn=4:2:3 [atomic ratio] and Ga:Zn=2:5 [atomic ratio], and a layered structure of In:Ga:Zn=4:2:3 [atomic ratio] and gallium oxide.

[0388] At this time, the main path of the carriers is the metal oxide 230b. By configuring the metal oxide 230a and the metal oxide 230c as described above, the defect level density at the interface between the metal oxide 230a and the metal oxide 230b and at the interface between the metal oxide 230b and the metal oxide 230c can be reduced. Therefore, the influence of the interface scattering on the carrier conduction is reduced, and the transistor 200A can obtain a high on-current and high frequency characteristics. When the metal oxide 230c has a stacked structure, in addition to the effect of reducing the defect level density at the interface between the metal oxide 230b and the metal oxide 230c, it is expected that the constituent elements of the metal oxide 230c can be suppressed from diffusing to the insulator 250 side. More specifically, the metal oxide 230c has a stacked structure, and an oxide that does not contain In is positioned above the stacked structure, so that In that may diffuse to the insulator 250 side can be suppressed. Since the insulator 250 functions as a gate insulator, if In diffuses, the transistor characteristics will be poor. Therefore, by forming the metal oxide 230c into a laminated structure, it is possible to provide a highly reliable display device.

[0389] The metal oxide 230 is preferably a metal oxide that functions as an oxide semiconductor. For example, a metal oxide having a band gap of 2 eV or more, preferably 2.5 eV or more, is preferably used as the metal oxide that becomes the channel formation region of the metal oxide 230. By using a metal oxide having a wide band gap in this manner, the off-state current of the transistor can be reduced. By using such a transistor, a display device with low power consumption can be provided.

[0390] Conductors 242 (conductors 242a and 242b) functioning as a source electrode and a drain electrode are provided on the metal oxide 230b. As the conductor 242, it is preferable to use 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 above-mentioned metal elements as a component, or an alloy combining the above-mentioned metal elements. For example, it is preferable to use tantalum nitride, titanium nitride, tungsten, a nitride containing titanium and aluminum, a nitride containing tantalum and aluminum, ruthenium oxide, ruthenium nitride, an oxide containing strontium and ruthenium, an oxide containing lanthanum and nickel, or the like. 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 preferred because they are conductive materials that are difficult to oxidize or materials that maintain their conductivity even when they absorb oxygen.

[0391] By providing the conductor 242 so as to be in contact with the metal oxide 230, the oxygen concentration may be reduced in the vicinity of the conductor 242 of the metal oxide 230. Furthermore, a metal compound layer containing a metal contained in the conductor 242 and a component of the metal oxide 230 may be formed in the vicinity of the conductor 242 of the metal oxide 230. In such a case, the carrier density increases in the region of the metal oxide 230 in the vicinity of the conductor 242, and the region becomes a low-resistance region.

[0392] Here, the region between the conductor 242a and the conductor 242b is formed so as to overlap the opening of the insulator 280. This allows the conductor 260 to be disposed in a self-aligned manner between the conductor 242a and the conductor 242b.

[0393] The insulator 250 functions as a gate insulator. The insulator 250 is preferably disposed in contact with the upper surface of the metal oxide 230c. The insulator 250 can be made of silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide doped with fluorine, silicon oxide doped with carbon, silicon oxide doped with carbon and nitrogen, or silicon oxide having vacancies. In particular, silicon oxide and silicon oxynitride are preferable because they are stable against heat.

[0394] The insulator 250 preferably has a reduced concentration of impurities such as water or hydrogen, similar to the insulator 224. The thickness of the insulator 250 is preferably 1 nm or more and 20 nm or less.

[0395] A metal oxide may be provided between the insulator 250 and the conductor 260. The metal oxide preferably has a function of suppressing oxygen diffusion from the insulator 250 to the conductor 260. This can suppress oxidation of the conductor 260 due to oxygen contained in the insulator 250.

[0396] The metal oxide may function as a part of the gate insulator. Therefore, when silicon oxide, silicon oxynitride, or the like is used for the insulator 250, it is preferable to use a metal oxide that is a high-k material with a high relative dielectric constant. By forming the gate insulator into a stacked structure of the insulator 250 and the metal oxide, the transistor 200A can be made stable against heat and have a high relative dielectric constant. Therefore, it is possible to reduce the gate potential applied during the transistor operation while maintaining the physical thickness of the gate insulator. In addition, it is possible to reduce the equivalent oxide thickness (EOT) of the insulator that functions as the gate insulator.

[0397] Specifically, it is possible to use a metal oxide containing one or more selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, magnesium, etc. In particular, it is preferable to use aluminum oxide, hafnium oxide, or an oxide containing aluminum and hafnium (hafnium aluminate), which is an insulator containing an oxide of either or both of aluminum and hafnium.

[0398] Although the conductor 260 is shown as having a two-layer structure in FIG. 39, it may have a single-layer structure or a laminated structure of three or more layers.

[0399] The conductor 260a is preferably made of a conductor having a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (NO, NO, NO, etc.), copper atoms, etc. Alternatively, it is preferable to use a conductive material having a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.).

[0400] The conductor 260a has a function of suppressing the diffusion of oxygen, and thus it is possible to suppress a decrease in the conductivity of the conductor 260b caused by the oxidation of the conductor 260b due to the oxygen contained in the insulator 250. As a conductive material having a function of suppressing the diffusion of oxygen, it is preferable to use, for example, tantalum, tantalum nitride, ruthenium, ruthenium oxide, or the like.

[0401] The conductor 260b is preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. Since the conductor 260 also functions as wiring, it is preferable to use a conductor having high conductivity. For example, a conductive material containing tungsten, copper, or aluminum as a main component can be used. The conductor 260b may have a layered structure, for example, a layered structure of titanium or titanium nitride and the above-mentioned conductive material.

[0402] 39A and 39C, in a region of the metal oxide 230b that does not overlap with the conductor 242, in other words, in a channel formation region of the metal oxide 230, the side surface of the metal oxide 230 is arranged to be covered with the conductor 260. This makes it easier for the electric field of the conductor 260, which functions as a first gate electrode, to act on the side surface of the metal oxide 230. This increases the on-current of the transistor 200A, and improves the frequency characteristics of the transistor 200A.

[0403] Like the insulator 214, the insulator 254 preferably functions as a barrier insulating film that suppresses impurities such as water or hydrogen from entering the transistor 200A from the insulator 280 side. For example, the insulator 254 preferably has lower hydrogen permeability than the insulator 224. Furthermore, as shown in FIG. 39B and FIG. 39C, the insulator 254 preferably has a region in contact with the side of the metal oxide 230c, the upper surface and side of the conductor 242a, the upper surface and side of the conductor 242b, the side of the metal oxide 230a, the side of the metal oxide 230b, and the upper surface of the insulator 224. With this configuration, it is possible to suppress hydrogen contained in the insulator 280 from entering the metal oxide 230 from the upper surfaces or side of the conductor 242a, the conductor 242b, the metal oxide 230a, the metal oxide 230b, and the insulator 224.

[0404] Furthermore, it is preferable that the insulator 254 has a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (i.e., the oxygen is less likely to permeate). For example, it is preferable that the insulator 254 has lower oxygen permeability than the insulator 280 or the insulator 224.

[0405] The insulator 254 is preferably formed by a sputtering method. By forming the insulator 254 by a sputtering method in an atmosphere containing oxygen, oxygen can be added to the vicinity of a region of the insulator 224 that is in contact with the insulator 254. This allows oxygen to be supplied from this region to the metal oxide 230 through the insulator 224. Here, the insulator 254 has a function of suppressing upward diffusion of oxygen, thereby suppressing diffusion of oxygen from the metal oxide 230 to the insulator 280. In addition, the insulator 222 has a function of suppressing downward diffusion of oxygen, thereby suppressing diffusion of oxygen from the metal oxide 230 to the substrate side. In this manner, oxygen is supplied to the channel formation region of the metal oxide 230. This reduces oxygen vacancies in the metal oxide 230, and suppresses the transistor from becoming normally on.

[0406] For example, an insulator containing one or both of an oxide of aluminum and hafnium may be formed as the insulator 254. Note that as the insulator containing one or both of an oxide of aluminum and hafnium, it is preferable to use aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), or the like.

[0407] By covering the insulator 224, the insulator 250, and the metal oxide 230 with the insulator 254 having a barrier property against hydrogen, the insulator 280 is separated from the insulator 224, the metal oxide 230, and the insulator 250 by the insulator 254. This makes it possible to suppress the intrusion of impurities such as hydrogen from the outside of the transistor 200A, thereby improving the electrical characteristics and reliability of the transistor 200A.

[0408] The insulator 280 is provided on the insulator 224, the metal oxide 230, and the conductor 242 via the insulator 254. For example, the insulator 280 preferably includes silicon oxide, silicon oxynitride, silicon nitride oxide, silicon oxide to which fluorine has been added, silicon oxide to which carbon has been added, silicon oxide to which carbon and nitrogen have been added, silicon oxide having vacancies, or the like. In particular, silicon oxide and silicon oxynitride are preferable because they are thermally stable. In addition, materials such as silicon oxide, silicon oxynitride, and silicon oxide having vacancies are preferable because they can easily form a region containing oxygen that is desorbed by heating.

[0409] It is preferable that the concentration of impurities such as water or hydrogen is reduced in the insulator 280. In addition, the top surface of the insulator 280 may be flattened.

[0410] Like the insulator 214, the insulator 274 preferably functions as a barrier insulating film that suppresses impurities such as water or hydrogen from entering the insulator 280. As the insulator 274, for example, an insulator that can be used for the insulator 214, the insulator 254, etc. can be used.

[0411] An insulator 281 functioning as an interlayer film is preferably provided over the insulator 274. Like the insulator 224 and the like, the insulator 281 preferably has a reduced concentration of impurities such as water or hydrogen.

[0412] The conductor 240a and the conductor 240b are disposed in openings formed in the insulator 281, the insulator 274, the insulator 280, and the insulator 254. The conductor 240a and the conductor 240b are disposed opposite each other with the conductor 260 interposed therebetween. Note that the height of the upper surfaces of the conductor 240a and the conductor 240b may be flush with the upper surface of the insulator 281.

[0413] In addition, insulator 241a is provided in contact with the inner walls of the openings of insulators 281, 274, 280, and 254, and a first conductor of conductor 240a is formed in contact with the side surface of insulator 241a. Conductor 242a is located at least in a part of the bottom of the opening, and conductor 240a is in contact with conductor 242a. Similarly, insulator 241b is provided in contact with the inner walls of the openings of insulators 281, 274, 280, and 254, and a first conductor of conductor 240b is formed in contact with the side surface of insulator 241b. Conductor 242b is located at least in a part of the bottom of the opening, and conductor 240b is in contact with conductor 242b.

[0414] The conductor 240a and the conductor 240b are preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. The conductor 240a and the conductor 240b may have a layered structure.

[0415] When the conductor 240 has a laminated structure, it is preferable to use the above-mentioned conductor having the function of suppressing the diffusion of impurities such as water or hydrogen for the conductor in contact with the metal oxide 230a, the metal oxide 230b, the conductor 242, the insulator 254, the insulator 280, the insulator 274, and the insulator 281. For example, it is preferable to use tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or ruthenium oxide. In addition, the conductive material having the function of suppressing the diffusion of impurities such as water or hydrogen may be used in a single layer or a laminate. By using the conductive material, it is possible to suppress the oxygen added to the insulator 280 from being absorbed by the conductor 240a and the conductor 240b. In addition, it is possible to suppress the impurities such as water or hydrogen from the layer above the insulator 281 from being mixed into the metal oxide 230 through the conductor 240a and the conductor 240b.

[0416] As the insulator 241a and the insulator 241b, for example, an insulator that can be used for the insulator 254 or the like may be used. Since the insulator 241a and the insulator 241b are provided in contact with the insulator 254, impurities such as water or hydrogen from the insulator 280 or the like can be prevented from being mixed into the metal oxide 230 through the conductor 240a and the conductor 240b. In addition, oxygen contained in the insulator 280 can be prevented from being absorbed by the conductor 240a and the conductor 240b.

[0417] Although not shown, a conductor functioning as wiring may be disposed in contact with the upper surface of the conductor 240a and the upper surface of the conductor 240b. The conductor functioning as wiring is preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. The conductor may have a laminated structure, for example, a laminate of titanium or titanium nitride and the above-mentioned conductive material. The conductor may be formed so as to be embedded in an opening provided in an insulator.

[0418] <Transistor configuration example 2> 40A, 40B, and 40C are a top view and a cross-sectional view of a transistor 200B that can be used in a display device of one embodiment of the present invention and the periphery of the transistor 200B. The transistor 200B is a variation of the transistor 200A.

[0419] FIG. 40A is a top view of the transistor 200B. Also, FIG. 40B and FIG. 40C are cross-sectional views of the transistor 200B. Here, FIG. 40B is a cross-sectional view of a portion indicated by a dashed line B1-B2 in FIG. 40A, and is also a cross-sectional view of the transistor 200B in the channel length direction. Also, FIG. 40C is a cross-sectional view of a portion indicated by a dashed line B3-B4 in FIG. 40A, and is also a cross-sectional view of the transistor 200B in the channel width direction. Note that in the top view of FIG. 40A, some elements are omitted for clarity.

[0420] In the transistor 200B, the conductor 242a and the conductor 242b have regions that overlap with the metal oxide 230c, the insulator 250, and the conductor 260. This enables the transistor 200B to have a high on-state current. Furthermore, the transistor 200B can be easily controlled.

[0421] The conductor 260 functioning as a gate electrode includes a conductor 260a and a conductor 260b on the conductor 260a. The conductor 260a is preferably made of a conductive material having a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, and copper atoms. Alternatively, it is preferably made of a conductive material having a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, and the like).

[0422] The conductor 260a has a function of suppressing oxygen diffusion, which improves the material selectivity of the conductor 260b. In other words, the presence of the conductor 260a suppresses oxidation of the conductor 260b, thereby suppressing a decrease in electrical conductivity.

[0423] It is preferable to provide an insulator 254 so as to cover the top surface and side surfaces of the conductor 260, the side surfaces of the insulator 250, and the side surfaces of the metal oxide 230c. Note that the insulator 254 is preferably made of an insulating material having a function of suppressing diffusion of impurities such as water or hydrogen, and oxygen.

[0424] Providing the insulator 254 can suppress oxidation of the conductor 260. Furthermore, including the insulator 254 can suppress diffusion of impurities such as water and hydrogen contained in the insulator 280 to the transistor 200B.

[0425] <Transistor configuration example 3> 41A, 41B, and 41C are a top view and a cross-sectional view of a transistor 200C that can be used in a display device of one embodiment of the present invention and the periphery of the transistor 200C. The transistor 200C is a variation of the transistor 200A.

[0426] FIG. 41A is a top view of the transistor 200C. Also, FIG. 41B and FIG. 41C are cross-sectional views of the transistor 200C. Here, FIG. 41B is a cross-sectional view of a portion indicated by a dashed line C1-C2 in FIG. 41A, and is also a cross-sectional view of the transistor 200C in the channel length direction. Also, FIG. 41C is a cross-sectional view of a portion indicated by a dashed line C3-C4 in FIG. 41A, and is also a cross-sectional view of the transistor 200C in the channel width direction. Note that in the top view of FIG. 41A, some elements are omitted for clarity.

[0427] The transistor 200C includes an insulator 250 over the metal oxide 230c and a metal oxide 252 over the insulator 250. The transistor 200C also includes a conductor 260 over the metal oxide 252 and an insulator 270 over the conductor 260. The transistor 200C also includes an insulator 271 over the insulator 270.

[0428] The metal oxide 252 preferably has a function of suppressing oxygen diffusion. By providing the metal oxide 252, which suppresses oxygen diffusion, between the insulator 250 and the conductor 260, the diffusion of oxygen to the conductor 260 is suppressed. In other words, it is possible to suppress a decrease in the amount of oxygen supplied to the metal oxide 230. In addition, it is possible to suppress oxidation of the conductor 260.

[0429] The metal oxide 252 may function as a part of the gate electrode. For example, an oxide semiconductor that can be used as the metal oxide 230 can be used as the metal oxide 252. In this case, the electric resistance value of the metal oxide 252 can be reduced by forming the conductor 260 by a sputtering method, thereby making the metal oxide 252 a conductor. This can be called an OC (Oxide Conductor) electrode.

[0430] The metal oxide 252 may function as a part of the gate insulator. Therefore, when the insulator 250 is made of a material with high thermal stability, such as silicon oxide or silicon oxynitride, it is preferable to use a metal oxide, which is a high-k material with a high relative dielectric constant, as the metal oxide 252. By using such a stacked structure, the transistor 200C can be a transistor that is stable against heat and has a high relative dielectric constant. Therefore, it is possible to reduce the gate potential applied during the transistor operation while maintaining the physical film thickness. In addition, it is possible to reduce the equivalent oxide thickness (EOT) of the insulator that functions as the gate insulator.

[0431] Although the metal oxide 252 in the transistor 200C is illustrated as a single layer, it may have a stacked structure of two or more layers. For example, a metal oxide functioning as part of a gate electrode and a metal oxide functioning as part of a gate insulator may be stacked.

[0432] Since the transistor 200C has the metal oxide 252, when the metal oxide 252 functions as a gate electrode, the on-current of the transistor 200C can be improved without weakening the effect of the electric field from the conductor 260. Furthermore, when the metal oxide 252 functions as a gate insulator, the physical thickness of the insulator 250 and the metal oxide 252 can maintain a distance between the conductor 260 and the metal oxide 230. This can suppress the leakage current between the conductor 260 and the metal oxide 230. Therefore, when the transistor 200C has a stacked structure of the insulator 250 and the metal oxide 252, the physical distance between the conductor 260 and the metal oxide 230 and the electric field strength applied from the conductor 260 to the metal oxide 230 can be easily adjusted.

[0433] Specifically, the metal oxide 252 may be an oxide semiconductor that can be used for the metal oxide 230 and has a reduced resistance. Alternatively, a metal oxide containing one or more elements selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, magnesium, and the like may be used.

[0434] In particular, it is preferable to use an insulator containing an oxide of either or both of aluminum and hafnium, such as aluminum oxide, hafnium oxide, or an oxide containing aluminum and hafnium (hafnium aluminate). In particular, hafnium aluminate has higher heat resistance than hafnium oxide. Therefore, it is preferable because it is less likely to crystallize in a heat treatment in a later process. Note that the metal oxide 252 is not an essential component. It may be appropriately designed depending on the desired transistor characteristics.

[0435] The insulator 270 may be made of an insulating material that has a function of suppressing the permeation of impurities such as water or hydrogen, and oxygen. For example, it is preferable to use aluminum oxide or hafnium oxide. This can suppress the conductor 260 from being oxidized by oxygen from above the insulator 270. In addition, it can suppress impurities such as water or hydrogen from being mixed into the metal oxide 230 from above the insulator 270 through the conductor 260 and the insulator 250.

[0436] The insulator 271 functions as a hard mask. By providing the insulator 271, when the conductor 260 is processed, the side surface of the conductor 260 can be approximately vertical, specifically, the angle between the side surface of the conductor 260 and the substrate surface can be set to 75 degrees or more and 100 degrees or less, preferably 80 degrees or more and 95 degrees or less.

[0437] Note that the insulator 271 may also function as a barrier layer by using an insulating material that has a function of suppressing permeation of impurities such as water or hydrogen and oxygen. In that case, the insulator 270 is not necessarily provided.

[0438] By using insulator 271 as a hard mask to selectively remove portions of insulator 270, conductor 260, metal oxide 252, insulator 250, and metal oxide 230c, their sides can be made substantially coincident and a portion of the surface of metal oxide 230b can be exposed.

[0439] The transistor 200C has a region 243a and a region 243b on a portion of the exposed surface of the metal oxide 230b. One of the region 243a or the region 243b functions as a source region, and the other of the region 243a or the region 243b functions as a drain region.

[0440] The formation of the regions 243a and 243b can be achieved by introducing an impurity element such as phosphorus or boron into the exposed surface of the metal oxide 230b by, for example, ion implantation, ion doping, plasma immersion ion implantation, plasma treatment, etc. In the present embodiment and the like, the term "impurity element" refers to an element other than the main component element.

[0441] It is also possible to form the regions 243a and 243b by forming a metal film after exposing a portion of the surface of the metal oxide 230b and then performing a heat treatment, thereby diffusing elements contained in the metal film into the metal oxide 230b.

[0442] The region of the metal oxide 230b into which the impurity element has been introduced has a reduced electrical resistivity, and therefore the region 243a and the region 243b are sometimes referred to as an "impurity region" or a "low resistance region."

[0443] By using the insulator 271 and / or the conductor 260 as a mask, the regions 243a and 243b can be formed in a self-aligned manner. Therefore, the regions 243a and / or 243b do not overlap with the conductor 260, and parasitic capacitance can be reduced. In addition, an offset region is not formed between the channel formation region and the source / drain region (region 243a or region 243b). By forming the regions 243a and 243b in a self-aligned manner, it is possible to realize an increase in on-current, a reduction in threshold voltage, an improvement in operating frequency, and the like.

[0444] The transistor 200C has an insulator 272 on the side surface of the insulator 271, the insulator 270, the conductor 260, the metal oxide 252, the insulator 250, and the metal oxide 230c. The insulator 272 is preferably an insulator with a low dielectric constant. For example, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide to which fluorine has been added, silicon oxide to which carbon has been added, silicon oxide to which carbon and nitrogen have been added, silicon oxide having voids, or a resin is preferable. In particular, when silicon oxide, silicon oxynitride, silicon nitride oxide, or silicon oxide having voids is used for the insulator 272, it is preferable because an excess oxygen region can be easily formed in the insulator 272 in a later step. In addition, silicon oxide and silicon oxynitride are preferable because they are thermally stable. In addition, the insulator 272 preferably has a function of diffusing oxygen.

[0445] In order to further reduce the off-current, an offset region may be provided between the channel formation region and the source / drain region. The offset region is a region with high electrical resistivity, into which the above-mentioned impurity element is not introduced. The offset region can be formed by introducing the above-mentioned impurity element after the formation of the insulator 272. In this case, the insulator 272 also functions as a mask, similar to the insulator 271 and the like. Therefore, the impurity element is not introduced into the region of the metal oxide 230b that overlaps with the insulator 272, and the electrical resistivity of the region can be kept high.

[0446] The transistor 200C includes an insulator 272 and an insulator 254 over the metal oxide 230. The insulator 254 is preferably formed by a sputtering method. By using a sputtering method, an insulator containing few impurities such as water or hydrogen can be formed.

[0447] Note that an oxide film formed by a sputtering method may extract hydrogen from a target structure. Therefore, when the insulator 254 is formed by a sputtering method, the insulator 254 absorbs hydrogen and water from the metal oxide 230 and the insulator 272. This allows the hydrogen concentrations in the metal oxide 230 and the insulator 272 to be reduced.

[0448] <Transistor constituent materials> The constituent materials that can be used for the transistor will be described.

[0449] <<Substrate>> For example, an insulating substrate, a semiconductor substrate, or a conductive substrate may be used as a substrate for forming the transistor 200A, the transistor 200B, or the transistor 200C. Examples of insulating substrates include a glass substrate, a quartz substrate, a sapphire substrate, a stabilized zirconia substrate (such as an yttria stabilized zirconia substrate), and a resin substrate. Examples of semiconductor substrates include semiconductor substrates such as silicon and germanium, and compound semiconductor substrates made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, and gallium oxide. Examples of semiconductor substrates include a semiconductor substrate having an insulating region inside the semiconductor substrate, such as an SOI (Silicon On Insulator) substrate. Examples of conductive substrates include a graphite substrate, a metal substrate, an alloy substrate, and a conductive resin substrate. Examples of substrates include a substrate having a metal nitride, a substrate having a metal oxide, and the like. Examples of substrates include a substrate having a conductor or semiconductor provided on an insulating substrate, a substrate having a conductor or insulator provided on a semiconductor substrate, and a substrate having a semiconductor or insulator provided on a conductive substrate. Alternatively, a substrate provided with elements may be used. The elements provided on the substrate include a capacitor element, a resistor element, a switch element, a memory element, and the like.

[0450] A flexible substrate may be used as the substrate, and the transistor 200A, the transistor 200B, or the transistor 200C may be formed directly on the flexible substrate. Alternatively, a peeling layer may be provided between the substrate and the transistor. The peeling layer can be used to separate the transistor from the substrate after forming a part or the whole of the transistor thereon, and transfer the transistor to another substrate. In this case, the transistor can be transferred to a substrate having poor heat resistance or a flexible substrate.

[0451] <<Insulators>> Examples of the insulator include oxides, nitrides, oxynitrides, nitride oxides, metal oxides, metal oxynitrides, and metal nitride oxides, each of which has insulating properties.

[0452] For example, as transistors become smaller and more highly integrated, problems such as leakage current can occur due to thinner gate insulators. By using a high-k material for the insulator that functions as the gate insulator, it is possible to reduce the voltage required for transistor operation while maintaining the physical film thickness. On the other hand, by using a material with a low relative dielectric constant for the insulator that functions as the interlayer film, it is possible to reduce the parasitic capacitance that occurs between wiring. Therefore, it is advisable to select materials according to the functions of the insulator.

[0453] Examples of insulators with a high relative dielectric constant include gallium oxide, hafnium oxide, zirconium oxide, oxides having aluminum and hafnium, oxynitrides having aluminum and hafnium, oxides having silicon and hafnium, oxynitrides having silicon and hafnium, and nitrides having silicon and hafnium.

[0454] Examples of insulators with a low dielectric constant include silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide with fluorine added, silicon oxide with carbon added, silicon oxide with carbon and nitrogen added, silicon oxide having voids, or resin.

[0455] A transistor using an oxide semiconductor can have stable electrical characteristics by being surrounded by an insulator (insulator 214, insulator 222, insulator 254, insulator 274, etc.) having a function of suppressing the transmission of impurities such as hydrogen and oxygen. As an insulator having a function of suppressing the transmission of impurities such as hydrogen and oxygen, for example, an insulator containing boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium, zirconium, lanthanum, neodymium, hafnium, or tantalum may be used in a single layer or a stacked layer. Specifically, as an insulator having a function of suppressing the transmission of impurities such as hydrogen and oxygen, a metal oxide such as aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, or tantalum oxide, or a metal nitride such as aluminum nitride, aluminum titanium nitride, titanium nitride, silicon nitride oxide, or silicon nitride may be used.

[0456] The insulator that functions as the gate insulator is preferably an insulator having a region containing oxygen that is released by heating. For example, by using a structure in which silicon oxide or silicon oxynitride having a region containing oxygen that is released by heating is in contact with the metal oxide 230, oxygen vacancies in the metal oxide 230 can be compensated for.

[0457] <<Conductors>> As the conductor, it is preferable to use 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, lanthanum, etc., or an alloy containing the above-mentioned metal elements as a component, or an alloy combining the above-mentioned metal 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, oxides containing lanthanum and nickel, etc. 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 preferable because they are conductive materials that are difficult to oxidize, or materials that maintain conductivity even when oxygen is absorbed. Furthermore, a semiconductor having high electrical conductivity, typified by polycrystalline silicon containing an impurity element such as phosphorus, or a silicide such as nickel silicide may be used.

[0458] A plurality of conductors formed of the above-mentioned materials may be stacked. For example, a stacked structure may be formed by combining the above-mentioned material containing a metal element and a conductive material containing oxygen. A stacked structure may be formed by combining the above-mentioned material containing a metal element and a conductive material containing nitrogen. A stacked structure may be formed by combining the above-mentioned material containing a metal element, a conductive material containing oxygen, and a conductive material containing nitrogen.

[0459] In addition, when a metal oxide is used for the channel formation region of a transistor, it is preferable to use a stacked structure in which a material containing the above-mentioned metal element and a conductive material containing oxygen are combined for a conductor functioning as a gate electrode. In this case, it is preferable to provide the conductive material containing oxygen on the channel formation region side. By providing the conductive material containing oxygen on the channel formation region side, oxygen released from the conductive material is easily supplied to the channel formation region.

[0460] In particular, it is preferable to use a conductive material containing oxygen and a metal element contained in the metal oxide in which the channel is formed as a conductor functioning as a gate electrode. The conductive material containing the metal element and nitrogen described above may also be used. For example, a conductive material containing nitrogen, such as titanium nitride or tantalum nitride, may also be used. 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, or indium tin oxide to which silicon is added may also be used. Indium gallium zinc oxide containing nitrogen may also be used. By using such a material, hydrogen contained in the metal oxide in which the channel is formed may be captured. Or, hydrogen mixed in from an external insulator or the like may be captured.

[0461] <<Metal oxides>> The metal oxide preferably contains at least indium or zinc. In particular, it is preferable that the metal oxide contains indium and zinc. In addition to these, it is preferable that the metal oxide contains aluminum, gallium, yttrium, tin, etc. Furthermore, the metal oxide may contain one or more elements selected from boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc.

[0462] Here, the case where the metal oxide is an In-M-Zn oxide having indium, an element M, and zinc is considered. The element M is aluminum, gallium, yttrium, tin, or the like. Other elements applicable to the element M include boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and the like. However, there are cases where the element M may be a combination of a plurality of the above-mentioned elements.

[0463] In this specification and the like, metal oxides containing nitrogen may also be collectively referred to as metal oxides. Furthermore, metal oxides containing nitrogen may also be referred to as metal oxynitrides.

[0464] [Metal oxide structures] Oxide semiconductors (metal oxides) are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors, such as CAAC-OS, polycrystalline oxide semiconductors, nanocrystalline oxide semiconductors (nc-OS), amorphous-like oxide semiconductors (a-like OS), and amorphous oxide semiconductors.

[0465] [impurities] The influence of each impurity in the metal oxide will be described. When an alkali metal or alkaline earth metal is contained in a metal oxide, defect levels may be formed and carriers may be generated. Therefore, a transistor using a metal oxide containing an alkali metal or alkaline earth metal in a channel formation region is likely to have normally-on characteristics. For this reason, it is preferable to reduce the concentration of the alkali metal or alkaline earth metal in the metal oxide. Specifically, the concentration of the alkali metal or alkaline earth metal in the metal oxide obtained by secondary ion mass spectrometry (SIMS) is set to 1×10 18 atoms / cm 3 Less than or equal to 2×10 16 atoms / cm 3 To the following:

[0466] Hydrogen contained in a metal oxide reacts with oxygen that is bonded to a metal atom to form water. Therefore, the hydrogen contained in the metal oxide may form an oxygen vacancy in the metal oxide. When hydrogen enters the oxygen vacancy, electrons that serve as carriers may be generated. In addition, some of the hydrogen may bond with oxygen that is bonded to a metal atom to generate electrons that serve as carriers. Therefore, a transistor using a metal oxide that contains hydrogen is likely to have normally-on characteristics.

[0467] For this reason, it is preferable to reduce hydrogen in the metal oxide as much as possible. Specifically, the hydrogen concentration in the metal oxide obtained by SIMS is set to 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 less than 5×10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 By using a metal oxide with sufficiently reduced impurities for a channel formation region of a transistor, the transistor can have stable electrical characteristics.

[0468] It is preferable to use a highly crystalline thin film as the metal oxide used as the semiconductor of the transistor. By using the thin film, the stability or reliability of the transistor can be improved. Examples of the thin film include a thin film of a single crystal metal oxide or a thin film of a polycrystalline metal oxide. However, a high temperature or laser heating process is required to form a thin film of a single crystal metal oxide or a thin film of a polycrystalline metal oxide on a substrate. This increases the cost of the manufacturing process and also reduces the throughput.

[0469] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be implemented in appropriate combination with other configuration examples or drawings.

[0470] This embodiment mode can be implemented by appropriately combining at least a part of it with other embodiment modes described in this specification. [Explanation of symbols]

[0471] : 10: electronic device, 10a: electronic device, 10b: electronic device, 11: housing, 11a: first part, 11b: second part, 11c: third part, 11d: fourth part, 11e: fifth part, 11f: sixth part, 11g: seventh part, 11h: eighth part, 11i: ninth part, 12a: first part, 12b: second part, 12c: third part, 12d: fourth part, 12e: fifth part, 13: display device, 13L: display device, 13R: display device, 15L: optical member, 15R: optical member, 17: detection device, 17L: detection device, 17R: detection device device, 18: storage device, 19: computing device, 21: input / output device, 23: server, 25: fixture, 27: fastener, 29: separator, 31: electronic device, 33: display unit, 41: space, 43: opening, 45: adjustment mechanism, 53: feature extraction unit, 54: estimation unit, 55: information generation unit, 61: input layer, 62: intermediate layer, 63: output layer, 71: data, 72: data, 73: data, 74: data, 81: information, 82: information, 91: information, 92: information, 93: information, 94: information, 95: information, 200A: transistor, 200B: transistor, 200C: transistor, 205: conductor conductor, 214: insulator, 216: insulator, 222: insulator, 224: insulator, 230: metal oxide, 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: region, 243b: region, 244: insulator, 250: insulator, 252: metal oxide, 254: insulator, 260: conductor, 260a: conductor, 260b: conductor, 270: insulator, 271: insulator, 27 2: 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: element isolation layer, 405: insulator, 407: insulator, 409: insulator,411: insulator, 413: insulator, 415: insulator, 417: insulator, 419: insulator, 421: insulator, 441: transistor, 443: conductor, 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: Capacitive element, 517: Capacitive element, 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: Capacitive element, 572: Light emitting device, 572_1: Light emitting device, 572_2: Light emitting device, 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: hole transport layer, 723: light emitting layer, 724: electron transport layer, 725: electron injection layer, 730: insulator, 732: sealing layer, 734: insulator, 736: colored layer, 738: light shielding layer, 750: transistor, 760: connection electrode, 772: conductor, 778: structure, 780: anisotropic conductor, 786: EL layer, 786a: EL layer, 786b: EL layer, 786c: EL layer, 788: conductor, 790: capacitance element, 792: charge generation layer, 810: display device, 820: layer, 821: gate driver circuit, 822: source driver circuit, 823: region, 824: demultiplexer circuit, 830: layer, 831: wiring, 831-1: wiring, 831-2: wiring, 831_1: wiring, 831_2: wiring, 832: wiring, 832-1: wiring, 832-2: wiring, 832_1: wiring, 832_2: wiring, 833: pixel array, 834: pixel, 835a: wiring, 835b: wiring, 840: circuit, 993IR: colored layer, 993R: colored layer, 995: substrate,1001: substrate, 1002: insulator, 1003: transistor, 1004: insulator, 1005: insulator, 1010: photoelectric conversion device, 1010_1: photoelectric conversion device, 1010_2: photoelectric conversion device, 1011: active layer,

Claims

[Claim 1] The optical system includes a detection device, a calculation device, a display device, a housing, a first optical member, a second optical member, and an adjustment mechanism, the display device has a first region overlapping the first optical member and a second region overlapping the second optical member, the housing has a recess at a position that overlaps with the user's nose when the user wears the headset; the detection device is disposed in the recess so as to be sandwiched between the housing in a first direction connecting the first optical member and the second optical member, the housing has a region that is disposed above the detection device when worn by the user, the housing does not have a region that is disposed below the detection device when worn by the user, The detection device is not in contact with the user when worn by the user, the adjustment mechanism is fixed to the housing and has a function of changing an angle between the detection device and the housing; the detection device has a function of acquiring first data related to the emotion of the user and outputting the first data to the arithmetic device; The arithmetic device has a function of generating display data based on the user data and outputting the display data to the display device. electronic equipment.

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