Display device

Abstract

To provide a display device with high definition.SOLUTION: A display device includes a transistor, a light-emitting diode, a first conductive layer, a second conductive layer, a first insulating layer, and a second insulating layer. The transistor is electrically connected to the first conductive layer. The first conductive layer and the first insulating layer exist on the transistor. The second conductive layer exists on the first conductive layer. The second insulating layer exists on the first insulating layer. The light-emitting diode includes a first electrode on the second insulating layer, a light-emitting layer on the first electrode, and a second electrode on the light-emitting layer. The second electrode is electrically connected to the second conductive layer. A height of the first conductive layer on the second conductive layer side substantially coincides with a height of the first insulating layer on the second insulating layer side. The first insulating layer and the second insulating layer are bonded together directly. The second conductive layer exists inside an opening of the second insulating layer and is electrically connected to the first conductive layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One embodiment of the present invention relates to a display device, a display module, an electronic device, and a manufacturing method thereof.

[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 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 (e.g., a touch sensor), an input / output device (e.g., a touch panel), a driving method thereof, or a manufacturing method thereof. [Background technology]

[0003] In recent years, display devices using micro light emitting diodes (micro LEDs) as display devices (also called display elements) have been proposed (for example, Patent Document 1). Display devices using micro LEDs as display devices have advantages such as high brightness, high contrast, and long life, and are being actively researched and developed as next-generation display devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2014 / 0367705 Summary of the Invention [Problem to be solved by the invention]

[0005] Display devices that use micro LEDs as display devices require an extremely long time to mount LED chips, making it difficult to reduce manufacturing costs. For example, in the pick-and-place method, red (R), green (G), and blue (B) LEDs are fabricated on separate wafers, and the LEDs are cut out one by one and mounted on a circuit board. Therefore, the more pixels a display device has, the more LEDs it requires, and the longer it takes to mount them. Also, the higher the resolution of the display device, the more difficult it is to mount the LEDs.

[0006] An object of one embodiment of the present invention is to provide a display device with high definition.An object of one embodiment of the present invention is to provide a display device with high resolution.An object of one embodiment of the present invention is to provide a display device with high display quality.An object of one embodiment of the present invention is to provide a display device with low power consumption.An object of one embodiment of the present invention is to provide a display device with high reliability.

[0007] An object of one embodiment of the present invention is to reduce the manufacturing cost of a display device using a micro LED as a display device. An object of one embodiment of the present invention is to manufacture a display device using a micro LED as a display device with a high yield.

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

[0009] One embodiment of the present invention is a display device having a transistor, a light-emitting diode, a first conductive layer, a second conductive layer, a first insulating layer, and a second insulating layer. The transistor is electrically connected to the first conductive layer, and the first conductive layer and the first insulating layer are each located on the transistor. The second conductive layer is located on the first conductive layer. The second insulating layer is located on the first insulating layer. The light-emitting diode has a first electrode on the second insulating layer, a light-emitting layer on the first electrode, and a second electrode on the light-emitting layer. The second electrode is electrically connected to the second conductive layer. The height of the surface of the first conductive layer on the second conductive layer side is approximately equal to the height of the surface of the first insulating layer on the second insulating layer side. The first insulating layer and the second insulating layer are directly bonded to each other. The second conductive layer is located inside the opening of the second insulating layer and is electrically connected to the first conductive layer.

[0010] The display device of one embodiment of the present invention preferably further includes a third insulating layer and a fourth insulating layer. The third insulating layer is preferably located between the transistor and the first insulating layer. The fourth insulating layer is preferably located between the light-emitting diode and the second insulating layer. The first insulating layer and the second insulating layer each preferably include a silicon oxide film. The third insulating layer and the fourth insulating layer each preferably include at least one of an aluminum oxide film, a hafnium oxide film, and a silicon nitride film.

[0011] The display device of one embodiment of the present invention preferably further includes a fifth insulating layer. The transistor preferably includes a metal oxide layer and a gate electrode. The metal oxide layer preferably includes a channel formation region. The height of a top surface of the gate electrode is preferably approximately the same as the height of a top surface of the fifth insulating layer.

[0012] Alternatively, the transistor preferably has a metal oxide layer, a gate insulating layer, a gate electrode, a third conductive layer, and a fourth conductive layer. The metal oxide layer preferably has a channel formation region. The metal oxide layer preferably has a first region overlapping the third conductive layer, a second region overlapping the fourth conductive layer, and a third region between the first region and the second region. The third conductive layer and the fourth conductive layer are preferably located apart from each other on the metal oxide layer. The fifth insulating layer is preferably located on the third conductive layer and on the fourth conductive layer. The fifth insulating layer preferably has an opening overlapping the third region. The gate insulating layer is preferably located inside the opening and overlaps with a side surface of the fifth insulating layer and an upper surface of the third region. The gate electrode is preferably located inside the opening and overlaps with a side surface of the fifth insulating layer and an upper surface of the third region via the gate insulating layer.

[0013] The display device of one embodiment of the present invention preferably further includes a driver circuit. The driver circuit preferably includes a circuit transistor. The circuit transistor preferably includes a channel formation region in a semiconductor substrate. The transistor, the light-emitting diode, the first conductive layer, the second conductive layer, the first insulating layer, and the second insulating layer are preferably located over the semiconductor substrate.

[0014] Alternatively, the transistor preferably has a channel formation region in a semiconductor substrate, which is preferably a silicon substrate.

[0015] The light emitting diode is preferably a micro light emitting diode, and preferably comprises a compound containing a group 13 element and a group 15 element (also called a III-V compound), and preferably comprises gallium nitride.

[0016] The display device according to one embodiment of the present invention preferably further includes a functional layer. The functional layer is preferably located on the light-emitting diode. Light emitted by the light-emitting diode is preferably extracted to the outside of the display device via the functional layer. The functional layer preferably includes one or both of a coloring layer and a color conversion layer.

[0017] One embodiment of the present invention is an electronic device that includes the display device having the above structure, an optical member, a frame, and a housing, where the housing has a touch sensor.

[0018] One embodiment of the present invention is a display module having the display device having the above-described configuration. A connector such as a flexible printed circuit (hereinafter, referred to as FPC) or a TCP (Tape Carrier Package) may be attached to the display module. In addition, an integrated circuit (IC) may be mounted on the display module by a COG (Chip On Glass) method or a COF (Chip On Film) method.

[0019] One embodiment of the present invention is an electronic device including the above-described display module and at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button.

[0020] One embodiment of the present invention is to form a plurality of transistors over a first substrate, form a plurality of first conductive layers over the plurality of transistors, each of which is electrically connected to at least one of the plurality of transistors, form a first insulating layer over the plurality of transistors, form a conductive film, a first semiconductor film, a light-emitting body, a second semiconductor film, and a second insulating layer in this order over a second substrate, bond the first substrate and the second substrate together by directly bonding the first insulating layer to the second insulating layer, peel the second substrate from the first substrate, and remove the conductive film, the first semiconductor film, the light-emitting body, and the second semiconductor film. a plurality of first electrodes, a plurality of first semiconductor layers, a plurality of light-emitting layers, and a plurality of second semiconductor layers are formed in a matrix by processing a conductive film; a plurality of openings are formed in a second insulating layer, each of which reaches at least one of the plurality of first conductive layers; a plurality of second conductive layers are formed, each of which is located inside at least one of the plurality of openings; and a plurality of second electrodes are formed, each of which is electrically connected to at least one of the plurality of second semiconductor layers and at least one of the plurality of second conductive layers, thereby forming a plurality of light-emitting diodes.

[0021] The step of forming the plurality of transistors preferably uses at least one planarization process. At least one of the plurality of light-emitting diodes is preferably a micro light-emitting diode. At least one of the plurality of transistors preferably has a metal oxide in a channel formation region. At least one of the plurality of transistors preferably has silicon in a channel formation region.

[0022] In a method for manufacturing a display device according to one embodiment of the present invention, at least one of a coloring layer, a color conversion layer, and a touch sensor may be formed over a third substrate, and the third substrate may be attached over a plurality of light-emitting diodes.

[0023] Alternatively, in a method for manufacturing a display device according to one embodiment of the present invention, at least one of a colored layer, a color conversion layer, and a touch sensor may be formed over at least one of the plurality of light-emitting diodes. Effect of the Invention

[0024] According to one embodiment of the present invention, a display device with high definition can be provided. According to one embodiment of the present invention, a display device with high resolution can be provided. According to one embodiment of the present invention, a display device with high display quality can be provided. According to one embodiment of the present invention, a display device with low power consumption can be provided. According to one embodiment of the present invention, a display device with high reliability can be provided.

[0025] According to one embodiment of the present invention, the manufacturing cost of a display device using a micro LED as a display device can be reduced. According to one embodiment of the present invention, a display device using a micro LED as a display device can be manufactured with a high yield.

[0026] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description in the specification, drawings, and claims. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a display device. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of a display device. [Diagram 3] 3A and 3B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a method for manufacturing a display device. [Diagram 5] FIG. 5 is a cross-sectional view showing an example of a method for manufacturing a display device. [Figure 6] 6A and 6B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 7] 7A and 7B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 8] FIG. 8 is a cross-sectional view showing an example of a display device. [Figure 9]Fig. 9A is a top view illustrating an example of a transistor, and Figs. 9B to 9D are cross-sectional views illustrating an example of a transistor. [Figure 10] FIG. 10 is a circuit diagram showing an example of a pixel. [Figure 11] 11A and 11B are diagrams showing an example of an electronic device. [Figure 12] 12A and 12B are diagrams showing an example of an electronic device. [Figure 13] 13A and 13B are diagrams showing an example of an electronic device. [Figure 14] 14A to 14D are diagrams showing an example of an electronic device. [Figure 15] 15A to 15F are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that the modes and details of the present invention can be modified 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 embodiments shown below.

[0029] 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.

[0030] In addition, for ease of understanding, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

[0031] In addition, the words "film" and "layer" can be interchanged depending on the case or situation. For example, the term "conductive layer" can be changed to the term "conductive film". Or, for example, the term "insulating film" can be changed to the term "insulating layer".

[0032] (Embodiment 1) In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0033] The display device of this embodiment includes a plurality of light-emitting diodes as display devices and a plurality of transistors for driving the display devices. The plurality of light-emitting diodes are arranged in a matrix. Each of the plurality of transistors is electrically connected to at least one of the plurality of light-emitting diodes.

[0034] In the manufacturing method of the display device of this embodiment, a stacked film constituting a light-emitting diode and a plurality of transistors, which are formed on different substrates, are bonded together, and then the stacked film is processed to perform element separation (also called isolation) to form a plurality of light-emitting diodes.

[0035] In the method for manufacturing a display device according to the present embodiment, a substrate on which a laminated film constituting a light-emitting diode is formed and a substrate on which a transistor is formed are bonded together before processing the laminated film, so that high alignment accuracy is not required during bonding. Therefore, even when manufacturing a display device with a large number of pixels or a high-definition display device, the difficulty of bonding can be reduced, and the manufacturing yield of the display device can be increased.

[0036] In a method for manufacturing a display device according to one embodiment of the present invention, first, a plurality of transistors are formed in a matrix on a first substrate, and a first insulating layer and a plurality of first conductive layers are formed over the plurality of transistors. Here, the first insulating layer and the first conductive layer are formed so that the height of a top surface of the first insulating layer is equal to the height of a top surface of the first conductive layer. Each of the plurality of first conductive layers is electrically connected to at least one of the plurality of transistors. In addition, a conductive film, a first semiconductor film, a light-emitting body, a second semiconductor film, and a second insulating layer are formed in this order over a second substrate.

[0037] Next, the first and second insulating layers are directly bonded to each other to bond the first and second substrates together. The first and second insulating layers are preferably made of the same material, and it is particularly preferable to use silicon oxide films as the first and second insulating layers. Hydrophilic bonding via hydroxyl groups (OH groups) can be generated to increase the bonding strength between the first and second insulating layers. By bonding the first and second substrates together before processing the conductive film, the first semiconductor film, the light emitter, and the second semiconductor film (before element separation of the light-emitting diode), high alignment accuracy is not required, making it easier to bond and increasing the manufacturing yield of the display device.

[0038] Next, the second substrate is peeled off from the first substrate. Then, the conductive film, the first semiconductor film, the light emitter, and the second semiconductor film are each processed into a plurality of island patterns to form a plurality of first electrodes, a plurality of first semiconductor layers, a plurality of light emitting layers, and a plurality of second semiconductor layers in a matrix. The first electrodes, the first semiconductor layers, the light emitting layers, and the second semiconductor layers are each layers that constitute a light emitting diode.

[0039] Next, a plurality of openings are formed in the second insulating layer. Each of the plurality of openings reaches at least one of the plurality of first conductive layers. Next, a plurality of second conductive layers are formed. Each of the plurality of second conductive layers is located inside at least one of the plurality of openings. This allows the first conductive layer and the second conductive layer to be electrically connected to each other.

[0040] Then, a plurality of second electrodes are formed. The second electrodes are electrically connected to the second semiconductor layer and the second conductive layer. This allows the formation of a plurality of light-emitting diodes each having a first electrode, a first semiconductor layer, a light-emitting layer, a second semiconductor layer, and a second electrode. The second electrode is preferably formed so as to be in contact with an upper surface of the second semiconductor layer and an upper surface of the second conductive layer. In addition, the second electrode is electrically connected to the transistor through the first conductive layer and the second conductive layer. This allows each of the plurality of transistors to be electrically connected to at least one of the plurality of light-emitting diodes.

[0041] In the manufactured display device, the height of the surface of the first conductive layer facing the second conductive layer is approximately equal to the height of the surface of the first insulating layer facing the second insulating layer. In this specification, etc., "A and B approximately match" includes the case where A and B match, and also includes the case where a difference occurs between A and B due to a manufacturing error when A and B are manufactured to match.

[0042] The display device of one embodiment of the present invention preferably further includes a third insulating layer and a fourth insulating layer. The third insulating layer is preferably located between the transistor and the first insulating layer. The fourth insulating layer is preferably located between the light-emitting diode and the second insulating layer. The third insulating layer and the fourth insulating layer are preferably formed using a film through which one or both of hydrogen and oxygen are less likely to diffuse than the first insulating layer and the second insulating layer. The third insulating layer and the fourth insulating layer each preferably include at least one of an aluminum oxide film, a hafnium oxide film, and a silicon nitride film. By using a film through which one or both of hydrogen and oxygen are less likely to diffuse than a silicon oxide film, it is possible to suppress diffusion of impurities from one of the stacked structures on the first substrate side and the stacked structures on the second substrate side to the other.

[0043] The display device of this embodiment has a function of displaying an image using light-emitting diodes. Since light-emitting diodes are self-emitting devices, when light-emitting diodes are used as display devices, the display device does not require a backlight and does not need to be provided with a polarizing plate. This makes it possible to reduce the power consumption of the display device and to make the display device thinner and lighter. Furthermore, a display device using light-emitting diodes as display devices can increase the luminance (for example, 5000 cd / m 2 More than 10,000 cd / m 2 The display device has a high display quality because of its high contrast and wide viewing angle. In addition, the use of inorganic materials for the light-emitting materials can extend the life of the display device and increase its reliability.

[0044] In this embodiment, in particular, an example in which a micro LED is used as a light emitting diode will be described. In this embodiment, a micro LED having a double heterojunction will be described. However, the light emitting diode is not particularly limited, and for example, a micro LED having a quantum well junction, an LED using a nanocolumn, etc. may be used.

[0045] The area of ​​the light-emitting diode that emits light is 1 mm 2 Less than 10000μm is preferable. 2 Less than 3000μm is more preferable. 2 Less than 700μm is more preferable. 2 In this specification, the area of ​​the light emitting region is more preferably 10,000 μm or less. 2 The following light-emitting diodes may be referred to as micro LEDs.

[0046] The transistors in the display device preferably have a metal oxide in the channel formation region. A transistor using a metal oxide can reduce power consumption. Therefore, by combining a transistor with a micro LED, a display device with extremely low power consumption can be realized.

[0047] In particular, the display device of this embodiment preferably has a transistor in which the height of the upper surface of the gate electrode is approximately equal to the height of the upper surface of the insulating layer. For example, by performing a planarization process using a CMP (Chemical Mechanical Polishing) method or the like, the upper surfaces of the gate electrode and the insulating layer can be planarized, and the heights of the upper surfaces of the gate electrode and the insulating layer can be made uniform.

[0048] The size of a transistor having such a structure can be easily reduced, and by reducing the size of the transistor, the size of a pixel can be reduced, thereby improving the resolution of a display device.

[0049] Alternatively, a transistor included in the display device preferably has silicon in a channel formation region, which enables high-speed operation of the circuit.

[0050] The display device may include both a transistor having silicon in a channel formation region and a transistor having metal oxide in a channel formation region. For example, a transistor having metal oxide in a channel formation region may be used in a pixel circuit and a gate driver, and a transistor having silicon in a channel formation region may be used in a source driver. Alternatively, a transistor having metal oxide in a channel formation region may be used in a pixel circuit, and a transistor having silicon in a channel formation region may be used in a source driver and a gate driver. Alternatively, a transistor having silicon in a channel formation region may be used in all of a pixel circuit, a gate driver, and a source driver. Alternatively, a transistor having metal oxide in a channel formation region may be used in all of a pixel circuit, a gate driver, and a source driver.

[0051] Since the display device of the present embodiment can increase the resolution, it can be suitably used in electronic devices having a relatively small display unit. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices). Other examples of such electronic devices include head-mounted wearable devices such as VR (Virtual Reality) devices, glasses-type AR (Augmented Reality) devices, and MR (Mixed Reality) devices.

[0052] [Display device configuration example 1] Fig. 1 shows a cross-sectional view of the display device 100A. Fig. 2 shows a cross-sectional view of the display device 100B. Figs. 3 to 7 show cross-sectional views illustrating a method for manufacturing the display device 100A and the display device 100B. The configurations and manufacturing methods of the display devices 100A and 100B will be described below.

[0053] The display device 100A and the display device 100B each include transistors 130a and 130b having silicon in a channel formation region, transistors 120a and 120b having metal oxide in a channel formation region, and light-emitting diodes 110a and 110b.

[0054] The light-emitting diode 110a has an electrode 112a, a semiconductor layer 113a, a light-emitting layer 114a, a semiconductor layer 115a, and an electrode 117a. The light-emitting diode 110b has an electrode 112b, a semiconductor layer 113b, a light-emitting layer 114b, a semiconductor layer 115b, and an electrode 117c. Each layer of the light-emitting diode may have a single-layer structure or a multilayer structure.

[0055] In the display device 100A and the display device 100B, the sub-pixels of each color have light-emitting diodes that emit light of the same color. In this embodiment, an example will be described in which the sub-pixels of each color have light-emitting diodes that emit blue light.

[0056] In the display device 100A and the display device 100B, a coloring layer CFR and a color conversion layer CCMR are provided in a region overlapping with the light emitting diode 110a of the red subpixel. The color conversion layer CCMR has a function of converting blue light into red light.

[0057] The light emitted by the light emitting diode 110a is converted from blue to red by the color conversion layer CCMR, the purity of the red light is increased by the colored layer CFR, and the light is emitted to the outside of the display device 100A or the display device 100B.

[0058] Although not shown, in the display device 100A and the display device 100B, a green colored layer and a color conversion layer that converts blue light into green are similarly provided in an area overlapping with the light emitting diode of the green subpixel. As a result, the light emitted by the light emitting diode of the green subpixel is converted from blue to green by the color conversion layer, and the purity of the green light is increased by the colored layer, and the light is emitted to the outside of the display device 100A or the display device 100B.

[0059] On the other hand, in the display device 100A or the display device 100B, a color conversion layer is not provided in a region overlapping with the light-emitting diode 110b of the blue subpixel. The blue light emitted from the light-emitting diode 110b is emitted to the outside of the display device 100A or the display device 100B without being color-converted.

[0060] In the display device 100A or 100B, a blue colored layer may be provided in a region overlapping with the light emitting diode 110b of the blue pixel. By providing a blue colored layer, the purity of blue light can be increased. Furthermore, if a blue colored layer is not provided, the manufacturing process can be simplified.

[0061] When manufacturing a display device having light-emitting diodes of the same configuration in the sub-pixels of each color, it is necessary to manufacture only one type of light-emitting diode on a substrate, which simplifies the manufacturing equipment and process compared to the case of manufacturing multiple types of light-emitting diodes.

[0062] In the display device of this embodiment, red light R and blue light B are extracted in the directions of the arrows shown in Figures 1 and 2. In the display device 100A, the light emitted by the light emitting diode 110a is extracted via the color conversion layer CCMR and the colored layer CFR formed on the light emitting diode 110a. On the other hand, in the display device 100B, a substrate 191 is attached onto the light emitting diode 110a, and the light emitted by the light emitting diode 110a is extracted via the color conversion layer CCMR and the colored layer CFR formed on the substrate 191.

[0063] In a method for producing the display device of the present embodiment, first, an LED substrate 150A shown in FIG. 3A and a circuit substrate 150B shown in FIG. 3B are produced.

[0064] FIG. 3A shows a cross-sectional view of an LED substrate 150A.

[0065] The LED substrate 150A includes a substrate 101, a semiconductor film 115, a light emitter 114, a semiconductor film 113, a conductive film 112, an insulating layer 103, and an insulating layer 104. The semiconductor film 115, the light emitter 114, the semiconductor film 113, the conductive film 112, the insulating layer 103, and the insulating layer 104 may each have a single-layer structure or a multilayer structure. The LED substrate 150A may further include a layer. For example, a base layer or the like may be provided between the substrate 101 and the semiconductor film 115.

[0066] The conductive film 112, the semiconductor film 113, the light emitter 114, and the semiconductor film 115 are processed in a later step to form a light emitting diode. The light emitter 114 is sandwiched between the semiconductor film 113 and the semiconductor film 115. In the light emitter 114, electrons and holes combine to emit light. One of the semiconductor film 113 and the semiconductor film 115 is an n-type semiconductor layer, and the other is a p-type semiconductor layer.

[0067] The stacked structure including the semiconductor film 113, the light emitter 114, and the semiconductor film 115 is formed to emit light of red, yellow, green, blue, ultraviolet light, or the like. For example, compounds including Group 13 elements and Group 15 elements (also called III-V group compounds) can be used in these stacked structures. Examples of Group 13 elements include aluminum, gallium, and indium. Examples of Group 15 elements include nitrogen, phosphorus, arsenic, and antimony. For example, a light-emitting diode can be manufactured using a gallium-phosphorus compound, a gallium-arsenic compound, a gallium-aluminum-arsenic compound, an aluminum-gallium-indium-phosphorus compound, gallium nitride (GaN), an indium-gallium nitride compound, a selenium-zinc compound, or the like.

[0068] A compound semiconductor substrate may be used as the substrate 101, for example, a compound semiconductor substrate containing elements of Group 13 and Group 15. In addition, a single crystal substrate such as a sapphire (Al2O3) substrate, a silicon carbide (SiC) substrate, a silicon (Si) substrate, or a gallium nitride (GaN) substrate may be used as the substrate 101.

[0069] The conductive film 112 is a film that will be processed in a later step to become an electrode of a light-emitting diode. Examples of materials that can be used for the conductive film 112 include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, tin, zinc, silver, platinum, gold, molybdenum, tantalum, and tungsten, and alloys containing these as main components (such as an alloy of silver, palladium, and copper (Ag-Pd-Cu(APC)). Oxides such as tin oxide and zinc oxide may also be used.

[0070] The insulating layer 103 and the insulating layer 104 can be formed using various inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, hafnium oxide, or titanium nitride.

[0071] In this specification and the like, silicon oxynitride refers to a material having a composition that contains more oxygen than nitrogen, and silicon nitride oxide refers to a material having a composition that contains more nitrogen than oxygen.

[0072] In particular, it is preferable to use a film in which hydrogen and / or oxygen are less likely to diffuse than in a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, for the insulating layer 103. It is preferable that the insulating layer 103 functions as a barrier layer that prevents impurities from diffusing from the LED substrate 150A to the circuit substrate 150B.

[0073] Moreover, it is preferable to use an oxide insulating film for the insulating layer 104. The insulating layer 104 is a layer that is directly bonded to an insulating layer of the circuit board 150B. By directly bonding the oxide insulating films to each other, the bonding strength (attachment strength) can be increased.

[0074] The display device of this embodiment mode may include a light-emitting diode that emits infrared light. The light-emitting diode that emits infrared light can be used as a light source for an infrared light sensor, for example.

[0075] FIG. 3B shows a cross-sectional view of circuit board 150B.

[0076] The circuit board 150B has a laminate of transistors (transistors 130a and 130b) having a channel formation region in a substrate 131 and transistors (transistors 120a and 120b) having a channel formation region in a metal oxide. Each layer of the circuit board 150B may have a single-layer structure or a laminate structure.

[0077] A single crystal silicon substrate is suitable as the substrate 131. The transistors 130a and 130b each have a conductive layer 135, an insulating layer 134, an insulating layer 136, and a pair of low-resistance regions 133. The conductive layer 135 functions as a gate. The insulating layer 134 is located between the conductive layer 135 and the substrate 131 and functions as a gate insulating layer. The insulating layer 136 is provided to cover the side surface of the conductive layer 135 and functions as a sidewall. The pair of low-resistance regions 133 are regions in the substrate 131 doped with impurities, one of which functions as the source of the transistor and the other functions as the drain of the transistor.

[0078] In addition, an element isolation layer 132 is provided between two adjacent transistors so as to be embedded in the substrate 131.

[0079] An insulating layer 139 is provided to cover the transistors 130a and 130b, and a conductive layer 138 is provided over the insulating layer 139. The conductive layer 138 is electrically connected to one of the pair of low-resistance regions 133 through a conductive layer 137 embedded in an opening in the insulating layer 139. An insulating layer 141 is provided to cover the conductive layer 138, and a conductive layer 142 is provided over the insulating layer 141. The conductive layer 138 and the conductive layer 142 each function as a wiring. An insulating layer 143 and an insulating layer 152 are provided to cover the conductive layer 142, and the transistors 120a and 120b are provided over the insulating layer 152.

[0080] At least one of the insulating layers (insulating layer 139, insulating layer 141, insulating layer 143, and insulating layer 152 in FIG. 3B) provided between the transistors 130a and 130b and the transistors 120a and 120b is preferably a layer that functions as a barrier layer. As the barrier layer, for example, a film in which one or both of hydrogen and oxygen are less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, is preferably used. In this embodiment, an example in which the insulating layer 152 functions as a barrier layer will be described. The insulating layer 152 functions as a barrier layer to prevent one or both of water and hydrogen from diffusing from the transistors 130a and 130b to the transistors 120a and 120b and to prevent oxygen from being released from the transistors 120a and 120b to the transistors 130a and 130b.

[0081] The transistors 120a and 120b each include a conductive layer 161, an insulating layer 163, an insulating layer 164, a metal oxide layer 165, a pair of conductive layers 166, an insulating layer 167, a conductive layer 168, and the like. One or more of the insulating layers, such as the insulating layer 162, the insulating layer 181, the insulating layer 182, the insulating layer 183, and the insulating layer 185, may be considered as components of a transistor; however, in this embodiment, they are not included in the components of the transistor in the description. Note that a specific example of a transistor that can be used in a display device of one embodiment of the present invention will be described in detail in Embodiment 2.

[0082] The metal oxide layer 165 has a channel formation region. The metal oxide layer 165 has a first region overlapping with one of the pair of conductive layers 166, a second region overlapping with the other of the pair of conductive layers 166, and a third region between the first region and the second region.

[0083] A conductive layer 161 and an insulating layer 162 are provided over the insulating layer 152, and an insulating layer 163 and an insulating layer 164 are provided to cover the conductive layer 161 and the insulating layer 162. A metal oxide layer 165 is provided over the insulating layer 164. The conductive layer 161 functions as a gate electrode, and the insulating layers 163 and 164 function as gate insulating layers. The conductive layer 161 overlaps with the metal oxide layer 165 with the insulating layers 163 and 164 interposed therebetween. The insulating layer 163 preferably functions as a barrier layer, similarly to the insulating layer 152. The insulating layer 164 in contact with the metal oxide layer 165 is preferably an oxide insulating film such as a silicon oxide film.

[0084] Here, the height of the upper surface of the conductive layer 161 is approximately the same as the height of the upper surface of the insulating layer 162. This allows the size of the transistors 120a and 120b to be reduced.

[0085] The display device of this embodiment employs at least one structure in which the height of the top surface of the insulating layer is approximately the same as the height of the top surface of the conductive layer. An example of a method for manufacturing this structure is to first form an insulating layer, provide an opening in the insulating layer, form a conductive layer so as to fill the opening, and then perform a planarization process using a CMP method or the like. This allows the height of the top surface of the conductive layer to be aligned with the height of the top surface of the insulating layer.

[0086] The pair of conductive layers 166 are provided on the metal oxide layer 165 with a space therebetween. The pair of conductive layers 166 function as a source and a drain. An insulating layer 181 is provided to cover the metal oxide layer 165 and the pair of conductive layers 166, and an insulating layer 182 is provided on the insulating layer 181. An opening reaching the metal oxide layer 165 is provided in the insulating layer 181 and the insulating layer 182, and the insulating layer 167 and the conductive layer 168 are embedded in the opening. The opening overlaps with the third region. The insulating layer 167 overlaps with a side surface of the insulating layer 181 and a side surface of the insulating layer 182. The conductive layer 168 overlaps with a side surface of the insulating layer 181 and a side surface of the insulating layer 182 with the insulating layer 167 interposed therebetween. The conductive layer 168 functions as a gate electrode, and the insulating layer 167 functions as a gate insulating layer. The conductive layer 168 overlaps with the metal oxide layer 165 with the insulating layer 167 interposed therebetween.

[0087] Here, the height of the upper surface of the conductive layer 168 is approximately the same as the height of the upper surface of the insulating layer 182. This allows the size of the transistors 120a and 120b to be reduced.

[0088] An insulating layer 183 and an insulating layer 185 are provided to cover top surfaces of the insulating layer 182, the insulating layer 167, and the conductive layer 168. The insulating layer 181 and the insulating layer 183 preferably function as a barrier layer, similar to the insulating layer 152. Covering the pair of conductive layers 166 with the insulating layer 181 can prevent the pair of conductive layers 166 from being oxidized by oxygen contained in the insulating layer 182.

[0089] A plug electrically connected to one of the pair of conductive layers 166 and the conductive layer 189a is embedded in an opening provided in the insulating layers 181, 182, 183, and 185. The plug preferably has a conductive layer 184b in contact with a side surface of the opening and an upper surface of one of the pair of conductive layers 166, and a conductive layer 184a embedded inwardly of the conductive layer 184b. In this case, the conductive layer 184b is preferably made of a conductive material through which hydrogen and oxygen are unlikely to diffuse.

[0090] A conductive layer 189a and an insulating layer 186 are provided on an insulating layer 185, a conductive layer 189b is provided on the conductive layer 189a, and an insulating layer 187 is provided on the insulating layer 186. An insulating layer 188, a conductive layer 190a, a conductive layer 190b, a conductive layer 190c, and a conductive layer 190d are provided on the insulating layer 187. The insulating layer 186 preferably has a planarization function. Here, the height of the upper surface of the conductive layer 189b is approximately equal to the height of the upper surface of the insulating layer 187. The insulating layer 187 and the insulating layer 186 are provided with an opening that reaches the conductive layer 189a, and the conductive layer 189b is embedded inside the opening. The conductive layer 189b functions as a plug that electrically connects the conductive layer 189a to the conductive layer 190a or the conductive layer 190c. The height of the upper surface of the insulating layer 188 is approximately the same as the height of the upper surfaces of the conductive layers 190a, 190b, 190c, and 190d.

[0091] One of the pair of conductive layers 166 of the transistor 120a is electrically connected to the conductive layer 190a through the conductive layer 184a, the conductive layer 184b, the conductive layer 189a, and the conductive layer 189b.

[0092] Similarly, one of the pair of conductive layers 166 of the transistor 120b is electrically connected to the conductive layer 190c through the conductive layer 184a, the conductive layer 184b, the conductive layer 189a, and the conductive layer 189b.

[0093] The insulating layer 186 is preferably formed using an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, hafnium oxide, or titanium nitride.

[0094] The insulating layer 187 may be a film in which hydrogen and / or oxygen are less likely to diffuse than silicon oxide films, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film. The insulating layer 187 preferably functions as a barrier layer that prevents impurities (hydrogen, water, etc.) from diffusing from the LED substrate 150A to the transistors. The insulating layer 187 also preferably functions as a barrier layer that prevents impurities from diffusing from the circuit substrate 150B to the LED substrate 150A.

[0095] The insulating layer 188 is a layer that is directly bonded to the insulating layer 104 of the LED substrate 150A. The insulating layer 188 is preferably formed of the same material as the insulating layer 104. An oxide insulating film is preferably used for the insulating layer 188. By directly bonding the oxide insulating films together, the bonding strength (bonding strength) can be increased. When one or both of the insulating layer 104 and the insulating layer 188 have a laminated structure, the layers that are in contact with each other (surface layers, layers including bonding surfaces) are preferably formed of the same material.

[0096] Examples of materials that can be used for the various conductive layers of the circuit board 150B include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, tin, zinc, silver, platinum, gold, molybdenum, tantalum, and tungsten, or alloys containing these as main components (such as APC). Also, oxides such as tin oxide and zinc oxide may be used.

[0097] The circuit board 150B may have one or both of a reflective layer that reflects light from the light emitting diode and a light blocking layer that blocks the light.

[0098] The transistors 120a and 120b can be used as transistors that form a pixel circuit. The transistors 130a and 130b can be used as transistors that form a pixel circuit or a driver circuit (either a gate driver or a source driver, or both) for driving the pixel circuit. The transistors 120a, 120b, 130a, and 130b can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0099] With this configuration, not only the pixel circuits but also the driving circuits can be formed directly under the light-emitting diodes, so the display device can be made smaller than when the driving circuits are provided outside the display section. Also, a display device with a narrow frame (narrow non-display area) can be realized.

[0100] Next, as shown in Fig. 4, the LED substrate 150A and the circuit substrate 150B are bonded together. Here, the insulating layer 104 provided on the LED substrate 150A and the insulating layer 188 provided on the circuit substrate 150B are directly bonded together. The insulating layer 104 and the insulating layer 188 are preferably made of the same component.

[0101] At the joining surfaces of the LED substrate 150A and the circuit substrate 150B, layers of the same material are in contact with each other, so that a connection having sufficient mechanical strength can be obtained.

[0102] For bonding between insulating layers, a hydrophilic bonding method can be used in which high flatness is obtained by polishing, etc., and then surfaces that have been hydrophilically treated with oxygen plasma or the like are brought into contact with each other to form a temporary bond, and then dehydrated by heat treatment to perform the actual bond. The hydrophilic bonding method also produces bonds at the atomic level, so mechanically excellent bonds can be obtained. When an oxide insulating film is used, hydrophilic treatment can be performed to further increase the bonding strength, which is preferable. Note that when an oxide insulating film is used, a separate hydrophilic treatment does not need to be performed.

[0103] Here, when a plurality of light-emitting diodes are fabricated on an LED substrate and a plurality of transistors are fabricated on a circuit substrate in advance, and then the LED substrate and the circuit substrate are bonded together, high alignment accuracy is required. The higher the definition and resolution of the display device to be manufactured, the more difficult the bonding becomes, and the lower the manufacturing yield of the display device becomes.

[0104] On the other hand, in the manufacturing of the display device of this embodiment, the LED substrate 150A is bonded to the circuit substrate 150B in a state where the film constituting the light emitting diode is formed but no processing such as patterning is performed. Therefore, high alignment accuracy is not required, and the degree of difficulty of bonding can be reduced. This makes it possible to increase the manufacturing yield even for display devices with high definition and resolution.

[0105] Next, the substrate 101 is peeled off (FIGS. 5 and 6A).

[0106] There is no limitation on the method for peeling off the substrate 101, and for example, as shown in Fig. 5, a method of irradiating the entire surface of the substrate 101 with a laser beam can be used. In this way, the substrate 101 can be peeled off to expose the semiconductor film 115 (Fig. 6A).

[0107] The laser may be an excimer laser, a solid-state laser, etc. For example, a diode-pumped solid-state laser (DPSS) may be used.

[0108] A release layer may be provided between the substrate 101 and the light emitting diode (between the substrate 101 and the semiconductor film 115 in FIG. 6A).

[0109] The release layer can be formed using an organic material or an inorganic material.

[0110] Examples of organic materials that can be used for the release layer include polyimide resins, acrylic resins, epoxy resins, polyamide resins, polyimideamide resins, siloxane resins, benzocyclobutene-based resins, and phenol resins.

[0111] Examples of inorganic materials that can be used for the peeling layer include metals containing an element selected from tungsten, molybdenum, titanium, tantalum, niobium, nickel, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, and silicon, alloys containing the element, and compounds containing the element, etc. The crystal structure of the silicon-containing layer may be amorphous, microcrystalline, or polycrystalline.

[0112] 6B, the conductive film 112, the semiconductor film 113, the light-emitting body 114, and the semiconductor film 115 are processed to form electrodes 112a, 112b, semiconductor layers 113a, 113b, light-emitting layers 114a, 114b, and semiconductor layers 115a and 115b. Furthermore, an insulating layer 102 is formed on the insulating layer 103. Here, it is preferable that the height of the upper surface of the insulating layer 102 is approximately equal to the height of the upper surfaces of the semiconductor layers 115a and 115b.

[0113] The insulating layer 102 is preferably formed using an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, hafnium oxide, or titanium nitride. The insulating layer 102 preferably has a function of blocking visible light. When the insulating layer 102 has a function of blocking visible light, light emitted from the light-emitting diode is prevented from reaching an adjacent subpixel, and the display quality of the display device can be improved.

[0114] 7A, openings reaching the conductive layer 190a, the conductive layer 190b, the conductive layer 190c, the electrode 112a, and the electrode 112b are provided in the insulating layer 102. Although not shown, an opening reaching the conductive layer 190d is also provided in the insulating layer 102.

[0115] Next, the conductive layers 116a, 116b, 116c, 116d, and 116e are formed to fill these openings. Although not shown, the opening reaching the conductive layer 190d is also filled with a conductive layer.

[0116] Examples of materials that can be used for the conductive layers 116a to 116d include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, tin, zinc, silver, platinum, gold, molybdenum, tantalum, and tungsten, and alloys containing these as main components (such as APC). Also, oxides such as tin oxide and zinc oxide may be used.

[0117] Then, over the insulating layer 102, the electrode 117a, the conductive layer 117b, the electrode 117c, and the conductive layer 117d are formed.

[0118] This makes it possible to form a light-emitting diode 110a having the electrode 112a, the semiconductor layer 113a, the light-emitting layer 114a, the semiconductor layer 115a, and the electrode 117a. Also, it is possible to form a light-emitting diode 110b having the electrode 112b, the semiconductor layer 113b, the light-emitting layer 114b, the semiconductor layer 115b, and the electrode 117c.

[0119] The electrode 117a electrically connects the semiconductor layer 115a and the conductive layer 116a. The electrode 117a is electrically connected to the conductive layer 190a through the conductive layer 116a. By electrically connecting the electrode 117a and the conductive layer 190a, the transistor 120a and the light-emitting diode 110a can be electrically connected. The electrode 117a functions as a pixel electrode of the light-emitting diode 110a. Note that the electrode 117a is preferably formed so as to be in contact with an upper surface of the semiconductor layer 115a and an upper surface of the conductive layer 116a.

[0120] In addition, the conductive layer 117b is electrically connected to the electrode 112a through the conductive layer 116b, and is electrically connected to the conductive layer 190b through the conductive layer 116c. The electrode 112a is electrically connected to the conductive layer 190b through the conductive layer 116b, the conductive layer 117b, and the conductive layer 116c. The electrode 112b functions as a common electrode for the light-emitting diode 110a.

[0121] Similarly, the electrode 117c electrically connects the semiconductor layer 115b and the conductive layer 116d. The electrode 117c is electrically connected to the conductive layer 190c through the conductive layer 116d. By electrically connecting the electrode 117c and the conductive layer 190c, the transistor 120b and the light-emitting diode 110b can be electrically connected. The electrode 117c functions as a pixel electrode of the light-emitting diode 110b. Note that the electrode 117c is preferably formed so as to be in contact with an upper surface of the semiconductor layer 115b and an upper surface of the conductive layer 116d.

[0122] Moreover, the conductive layer 117d is electrically connected to the electrode 112b through the conductive layer 116e, and is also electrically connected to the conductive layer 190d through a conductive layer (not shown). The electrode 112b is electrically connected to the conductive layer 190d through the conductive layers 116e and 117d, etc. The electrode 112b functions as a common electrode for the light-emitting diode 110b.

[0123] As shown in Fig. 7B, an opening surrounding the light-emitting diode may be provided in the insulating layer 102, and a light-shielding layer BM may be embedded in the opening. This prevents the light emitted by the light-emitting diode from reaching adjacent sub-pixels, improving the display quality of the display device. The material of the light-shielding layer BM is not particularly limited, and may be, for example, an inorganic material such as a metal material, or an organic material such as a resin material containing a pigment (carbon black, etc.) or a dye.

[0124] Thereafter, the color conversion layer CCMR and the colored layer CFR are formed in the region overlapping with the light emitting diode 110a. Furthermore, a blue colored layer may be formed in the region overlapping with the light emitting diode 110b.

[0125] When forming the display device 100A shown in Fig. 1, a color conversion layer CCMR is formed on the light emitting diode 110a, and a colored layer CFR is formed on the color conversion layer CCMR. The color conversion layer CCMR may be formed directly on the light emitting diode 110a. Alternatively, as shown in Fig. 1, an insulating layer may be formed on the light emitting diode 110a, and the color conversion layer CCMR may be formed on the insulating layer.

[0126] FIG. 1 shows an example in which an insulating layer 193 is formed over the insulating layer 102, and an insulating layer 194 is formed over the electrode 117a, the conductive layer 117b, the electrode 117c, the conductive layer 117d, and the insulating layer 193. Various insulating materials can be used for the insulating layer 193 and the insulating layer 194. The insulating layer provided between the light-emitting diode 110a and the color conversion layer CCMR preferably has at least one layer of a film in which one or both of hydrogen and oxygen are less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film. FIG. 1 shows an example in which an oxide insulating film (such as a silicon oxide film) is used for the insulating layer 193, and a film in which one or both of hydrogen and oxygen are less likely to diffuse than a silicon oxide film is used for the insulating layer 194.

[0127] 1 shows an example in which the top surfaces of electrode 117a, conductive layer 117b, electrode 117c, and conductive layer 117d are approximately flush with the top surface of insulating layer 193.

[0128] It is preferable to use one or both of phosphors and quantum dots (QDs) as the color conversion layer. In particular, quantum dots have a narrow peak width of the emission spectrum, and can emit light with good color purity. This can improve the display quality of the display device.

[0129] The color conversion layer can be formed by using a droplet discharge method (for example, an inkjet method), a coating method, an imprint method, various printing methods (screen printing, offset printing), etc. A color conversion film such as a quantum dot film may also be used.

[0130] The material constituting the quantum dots is not particularly limited, and examples thereof include Group 14 elements, Group 15 elements, Group 16 elements, compounds consisting of multiple Group 14 elements, compounds of elements belonging to Groups 4 to 14 and Group 16 elements, compounds of Group 2 elements and Group 16 elements, compounds of Group 13 elements and Group 15 elements, compounds of Group 13 elements and Group 17 elements, compounds of Group 14 elements and Group 15 elements, compounds of Group 11 elements and Group 17 elements, iron oxides, titanium oxides, chalcogenide spinels, and various semiconductor clusters.

[0131] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, terbium Indium sulfide, Indium sulfide, Gallium selenide, Arsenic sulfide, Arsenic selenide, Arsenic telluride, Antimony sulfide, Antimony selenide, Antimony telluride, Bismuth sulfide, Bismuth selenide, Bismuth telluride, Silicon, Silicon carbide, Germanium, Tin, Selenium, Tellurium, Boron, Carbon, Phosphorus, Boron nitride, Boron phosphide, Boron arsenide, Aluminum nitride, Aluminum sulfide, Barium sulfide, Barium selenide, Barium telluride, Calcium sulfide, Selenide Calcium, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tungsten oxide Examples of the quantum dots include talc, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, a compound of selenium, zinc, and cadmium, a compound of indium, arsenic, and phosphorus, a compound of cadmium, selenium, and sulfur, a compound of cadmium, selenium, and tellurium, a compound of indium, gallium, and arsenic, a compound of indium, gallium, and selenium, a compound of indium, selenium, and sulfur, a compound of copper, indium, and sulfur, and combinations thereof. In addition, so-called alloy-type quantum dots whose composition is expressed in any ratio may be used.

[0132] Examples of the structure of quantum dots include core type, core-shell type, and core-multishell type. In addition, quantum dots have a high proportion of surface atoms, so they are highly reactive and prone to aggregation. Therefore, it is preferable that a protective agent is attached to the surface of the quantum dots or a protective group is provided. By attaching the protective agent or providing the protective group, aggregation can be prevented and solubility in a solvent can be increased. It is also possible to reduce reactivity and improve electrical stability.

[0133] The smaller the size of the quantum dot, the larger the band gap becomes, so the size is adjusted appropriately to obtain light of the desired wavelength. As the size of the crystal becomes smaller, the emission of the quantum dot shifts to the blue side, that is, to the high energy side, so that the emission wavelength can be adjusted over the wavelength range of the spectrum of the ultraviolet region, the visible region, and the infrared region by changing the size of the quantum dot. The size (diameter) of the quantum dot is, for example, 0.5 nm or more and 20 nm or less, preferably 1 nm or more and 10 nm or less. The narrower the size distribution of the quantum dot, the narrower the emission spectrum becomes, and light emission with good color purity can be obtained. In addition, the shape of the quantum dot is not particularly limited, and may be spherical, rod-shaped, disk-shaped, or other shapes. A quantum rod, which is a rod-shaped quantum dot, has the function of exhibiting light with directionality.

[0134] The colored layer is a colored layer that transmits light in a specific wavelength range. For example, a color filter that transmits light in a red, green, blue, or yellow wavelength range can be used. Examples of materials that can be used for the colored layer include metal materials, resin materials, and resin materials containing pigments or dyes.

[0135] On the other hand, when forming the display device 100B shown in FIG. 2, a substrate 191 on which a colored layer CFR and a color conversion layer CCMR are provided is prepared.

[0136] Since the substrate 191 is located on the side where light from the light emitting diode is extracted, it is preferable to use a material that is highly transparent to visible light. Examples of materials that can be used for the substrate 191 include glass, quartz, sapphire, and resin. A film such as a resin film may be used for the substrate 191. This allows the display device to be made lighter and thinner.

[0137] Then, the substrate 191 is attached using the adhesive layer 192 so that the colored layer CFR and the color conversion layer CCMR overlap the light emitting diode 110a. In this manner, the display device 100B can be fabricated.

[0138] For the adhesive layer 192, various types of curing adhesives such as a light curing adhesive such as an ultraviolet curing adhesive, a reaction curing adhesive, a heat curing adhesive, an anaerobic adhesive, etc. may be used. Also, an adhesive sheet or the like may be used.

[0139] Although Figure 2 shows an example in which the adhesive layer 192 is in contact with the insulating layer 102 and the electrode 117a, an insulating layer (for example, one or both of the insulating layer 193 and the insulating layer 194 shown in Figure 1) may be provided on one or both of the insulating layer 102 and the electrode 117a, and the insulating layer and the adhesive layer 192 may be in contact with each other.

[0140] Note that in the display device of this embodiment, a plurality of light-emitting diodes may be electrically connected to one transistor.

[0141] In addition, at least one of the size, channel length, channel width, and structure of the transistor driving the light-emitting diode may be different for each color of the subpixel. Specifically, one or both of the channel length and channel width of the transistor may be changed for each color according to the amount of current required for emitting light at a desired luminance.

[0142] Further, the display device of one embodiment of the present invention may be a display device equipped with a touch sensor (also referred to as an input / output device or a touch panel).

[0143] There is no limitation on a sensing device (also referred to as a sensor device, a sensing element, or a sensor element) included in the touch panel of one embodiment of the present invention. Various sensors capable of detecting the proximity or contact of a sensing object such as a finger or a stylus can be used as the sensing device.

[0144] As the sensor type, various types can be used, such as a capacitance type, a resistive film type, a surface acoustic wave type, an infrared type, an optical type, and a pressure sensitive type.

[0145] The capacitance type includes a surface capacitance type, a projected capacitance type, etc. The projected capacitance type includes a self-capacitance type, a mutual capacitance type, etc. The mutual capacitance type is preferable because it enables simultaneous multi-point detection.

[0146] The touch panel of one embodiment of the present invention can have various configurations, such as a configuration in which a display device and a detection device that are separately manufactured are bonded to each other, or a configuration in which electrodes that constitute a detection device are provided on one or both of a substrate supporting a display device and an opposing substrate.

[0147] [Display device configuration example 2] The display device 100C shown in FIG. 8 differs from the display device 100A shown in FIG. 1 mainly in that the display device 100C does not include the transistors 120a and 120b.

[0148] In the display device 100C, a pixel circuit is formed using transistors (transistors 130a and 130b) having a channel formation region in the substrate 131. Furthermore, various circuits such as a driver circuit (one or both of a gate driver and a source driver) for driving the pixel circuit, an arithmetic circuit, and a memory circuit may be formed using transistors having a channel formation region in the substrate 131.

[0149] The display device 100C can be fabricated in the same manner as the display device 100A, except for the configuration of the circuit board to be fabricated. The configuration of the circuit board will be described below.

[0150] In the display device 100C, the configuration from the substrate 131 to the conductive layer 138 is the same as that of the circuit board 150B (FIG. 3B). Furthermore, an insulating layer 186 is provided on the conductive layer 138, a conductive layer 189 is provided on the conductive layer 138, and an insulating layer 187 is provided on the insulating layer 186. On the insulating layer 187, an insulating layer 188, a conductive layer 190a, a conductive layer 190b, a conductive layer 190c, and a conductive layer 190d are provided. The insulating layer 186 preferably has a planarizing function. Here, the height of the upper surface of the conductive layer 189 is approximately equal to the height of the upper surface of the insulating layer 187. The insulating layer 187 and the insulating layer 186 are provided with an opening that reaches the conductive layer 138, and the conductive layer 189 is embedded inside the opening. The conductive layer 189 functions as a plug that electrically connects the conductive layer 138 to the conductive layer 190a or the conductive layer 190c. The height of the upper surface of the insulating layer 188 is approximately the same as the height of the upper surfaces of the conductive layers 190a, 190b, 190c, and 190d.

[0151] As described above, in the display device of the present embodiment, the substrate on which the laminated film constituting the light-emitting diode is formed and the substrate on which the transistor is formed are bonded together before processing the laminated film constituting the light-emitting diode, so that high alignment accuracy is not required during bonding. Therefore, even when manufacturing a display device with a large number of pixels or a high-definition display device, the difficulty of bonding can be reduced, and the manufacturing yield of the display device can be increased.

[0152] In the display device of the present embodiment, a film of the same material (preferably an oxide insulating film, more preferably a silicon oxide film) is used for the first insulating layer on the plurality of transistors and the second insulating layer on the stacked film constituting the light-emitting diode. The first insulating layer and the second insulating layer are directly bonded to each other, thereby increasing the bonding strength. Furthermore, a third insulating layer is provided between the plurality of transistors and the first insulating layer, and a fourth insulating layer is provided between the stacked film constituting the light-emitting diode and the second insulating layer. As the third insulating layer and the fourth insulating layer, a film in which one or both of hydrogen and oxygen are less likely to diffuse than the first insulating layer and the second insulating layer is used. Specifically, as the third insulating layer and the fourth insulating layer, at least one of an aluminum oxide film, a hafnium oxide film, and a silicon nitride film is preferably used, and a silicon nitride film is particularly preferably used. This makes it possible to suitably suppress impurities from entering the transistor and the light-emitting diode.

[0153] In addition, since the size of a transistor can be reduced in the display device of this embodiment mode, the resolution can be increased and the display device can be easily applied to electronic devices having a relatively small display portion.

[0154] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in the case where a plurality of configuration examples are shown in one embodiment mode in this specification, the configuration examples can be combined as appropriate.

[0155] (Embodiment 2) In this embodiment, a transistor that can be used in a display device of one embodiment of the present invention will be described.

[0156] The structure of the transistor included in the display device is not particularly limited. For example, the transistor may be a planar type transistor, a staggered type transistor, or an inverted staggered type transistor. In addition, the transistor may have either a top gate structure or a bottom gate structure. Alternatively, gate electrodes may be provided above and below a channel.

[0157] For example, a transistor in which a channel formation region is formed using a metal oxide can be used as a transistor included in a display device, whereby a transistor with an extremely small off-state current can be realized.

[0158] A transistor having silicon in a channel formation region may be used as a transistor included in a display device. Examples of such a transistor include a transistor having amorphous silicon, a transistor having crystalline silicon (typically, low-temperature polysilicon), a transistor having single crystal silicon, etc. For example, a transistor using a metal oxide in a channel formation region and a transistor having silicon in a channel formation region may be used in combination.

[0159] In this specification, a transistor is an element having at least three terminals including a gate, a drain, and a source. A region where a channel is formed between the drain (drain terminal, drain region, or drain electrode) and the source (source terminal, source region, or source electrode) (hereinafter, also referred to as a channel formation region) is provided, and a current can flow between the source and the drain through the channel formation region. In this specification, a channel formation region refers to a region through which a current mainly flows.

[0160] Furthermore, the functions of the source and drain may be interchanged when transistors of different polarities are used, or when the direction of current changes during circuit operation, etc. For this reason, in this specification and the like, the terms source and drain may be used interchangeably.

[0161] The channel length refers to, for example, a region where the semiconductor (or a portion in the semiconductor through which current flows when the transistor is on) and the gate electrode overlap in a top view of a transistor, or a distance between the source (source region or source electrode) and the drain (drain region or drain electrode) in a channel formation region. Note that the channel length of one transistor does not necessarily have the same value in all regions. That is, the channel length of one transistor may not be fixed to one value. Therefore, in this specification, the channel length is defined as any one value, maximum value, minimum value, or average value in the channel formation region.

[0162] The channel width refers to, for example, the length of a channel formation region in a vertical direction based on the channel length direction in a region where a semiconductor (or a portion in the semiconductor through which current flows when the transistor is on) and a gate electrode overlap in a top view of a transistor, or in a channel formation region. Note that the channel width does not necessarily have the same value in all regions in one transistor. In other words, the channel width of one transistor may not be determined to a single value. Therefore, in this specification, the channel width is defined as any one value, maximum value, minimum value, or average value in the channel formation region.

[0163] In this specification and the like, depending on the structure of a transistor, the channel width in a region where a channel is actually formed (hereinafter also referred to as an "effective channel width") may differ from the channel width shown in a top view of the transistor (hereinafter also referred to as an "apparent channel width"). For example, when a gate electrode covers a side surface of a semiconductor, the effective channel width may be larger than the apparent channel width, and the influence of this may not be negligible. For example, in a fine transistor in which a gate electrode covers a side surface of a semiconductor, the proportion of a channel formation region formed on the side surface of the semiconductor may be large. In that case, the effective channel width is larger than the apparent channel width.

[0164] In such a case, it may be difficult to estimate the effective channel width by actual measurement. For example, in order to estimate the effective channel width from the design value, it is necessary to assume that the shape of the semiconductor is known. Therefore, if the shape of the semiconductor is not precisely known, it is difficult to accurately measure the effective channel width.

[0165] In this specification, when simply referred to as a channel width, it may refer to an apparent channel width. Alternatively, when simply referred to as a channel width, it may refer to an effective channel width. Note that the values ​​of the channel length, channel width, effective channel width, apparent channel width, etc. can be determined by analyzing a cross-sectional TEM (Transmission Electron Microscope) image, etc.

[0166] The following insulators, conductors, oxides, and semiconductors can be formed by sputtering, chemical vapor deposition (CVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD), atomic layer deposition (ALD), or the like. In this specification and the like, the term "insulator" can be replaced with an insulating film or an insulating layer. The term "conductor" can be replaced with a conductive film or a conductive layer. The term "oxide" can be replaced with an oxide film or an oxide layer. The term "semiconductor" can be replaced with a semiconductor film or a semiconductor layer.

[0167] FIG. 9A shows a top view of transistor 200. Note that in FIG. 9A, some elements are omitted for clarity. FIG. 9B shows a cross-sectional view taken along dashed lines A1-A2 in FIG. 9A. FIG. 9B can be considered a cross-sectional view of transistor 200 in the channel length direction. FIG. 9C shows a cross-sectional view taken along dashed lines A3-A4 in FIG. 9A. FIG. 9C can be considered a cross-sectional view of transistor 200 in the channel width direction. FIG. 9D shows a cross-sectional view taken along dashed lines A5-A6 in FIG. 9A.

[0168] The semiconductor device shown in FIGS. 9A to 9D includes an insulator 212 on a substrate (not shown), an insulator 214 on the insulator 212, a transistor 200 on the insulator 214, an insulator 280 on the transistor 200, an insulator 282 on the insulator 280, an insulator 283 on the insulator 282, and an insulator 285 on the insulator 283. The insulators 212, 214, 280, 282, 283, and 285 function as interlayer insulating films. The semiconductor device also includes a conductor 240 (conductor 240a and conductor 240b) that is electrically connected to the transistor 200 and functions as a plug. An insulator 241 (insulator 241a and insulator 241b) is provided in contact with a side surface of the conductor 240 that functions as a plug. In addition, a conductor 246 (conductor 246a and conductor 246b) that is electrically connected to the conductor 240 and functions as wiring is provided over the insulator 285 and the conductor 240.

[0169] The insulator 241a is provided in contact with the inner walls of the openings of the insulators 280, 282, 283, and 285, the first conductor of the conductor 240a is provided in contact with the side surface of the insulator 241a, and the second conductor of the conductor 240a is provided further inside. The insulator 241b is provided in contact with the inner walls of the openings of the insulators 280, 282, and 283, the first conductor of the conductor 240b is provided in contact with the side surface of the insulator 241b, and the second conductor of the conductor 240b is provided further inside. Here, the height of the top surface of the conductor 240 and the height of the top surface of the insulator 285 in the region overlapping with the conductor 246 can be made approximately the same. Note that, in the transistor 200, a configuration in which a first conductor and a second conductor are stacked as the conductor 240 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.

[0170] [Transistor 200] As shown in FIGS. 9A to 9D , the transistor 200 includes an insulator 216 on an insulator 214, conductors 205 (conductors 205a, 205b, and 205c) disposed so as to be embedded in the insulator 216, an insulator 222 on the insulator 216 and on the conductor 205, an insulator 224 on the insulator 222, an oxide 230a on the insulator 224, an oxide 230b on the oxide 230a, an oxide 243 (oxide 243a and oxide 243b) on the oxide 230b, a conductor 242a on the oxide 243a, and a conductor 242a on the oxide 243a. The oxide 243b has an insulator 271a on the oxide 243b, a conductor 242b on the oxide 243b, an insulator 271b on the conductor 242b, an insulator 250 (insulator 250a and insulator 250b) on the oxide 230b, a conductor 260 (conductor 260a and conductor 260b) located on the oxide 250 and overlapping with a portion of the oxide 230b, and an insulator 275 arranged to cover the insulator 222, the insulator 224, the oxide 230a, the oxide 230b, the oxide 243a, the oxide 243b, the conductor 242a, the conductor 242b, the insulator 271a, and the insulator 271b.

[0171] In the following, the oxide 230a and the oxide 230b may be collectively referred to as the oxide 230. Furthermore, the conductor 242a and the conductor 242b may be collectively referred to as the conductor 242. Furthermore, the insulator 271a and the insulator 271b may be collectively referred to as the insulator 271.

[0172] The insulator 280 and the insulator 275 have openings that reach the oxide 230b. The insulator 250 and the conductor 260 are disposed in the openings. In addition, in the channel length direction of the transistor 200, the conductor 260 and the insulator 250 are provided between the insulator 271a, the conductor 242a, and the oxide 243a and the insulator 271b, the conductor 242b, and the oxide 243b. The insulator 250 has a region in contact with a side surface of the conductor 260 and a region in contact with a bottom surface of the conductor 260.

[0173] The oxide 230 preferably has an oxide 230a disposed on the insulator 224 and an oxide 230b disposed on the oxide 230a. By having the oxide 230a below the oxide 230b, it is possible to suppress the diffusion of impurities from a structure formed below the oxide 230a to the oxide 230b.

[0174] Note that, in the transistor 200, the oxide 230 has a structure in which two layers of the oxide 230a and the oxide 230b are stacked, but the present invention is not limited to this. For example, the oxide 230b may have a single layer or a stacked structure of three or more layers, or each of the oxide 230a and the oxide 230b may have a stacked structure.

[0175] The conductor 260 functions as a first gate (also referred to as a top gate) electrode, and the conductor 205 functions as a second gate (also referred to as a back gate) electrode. The insulator 250 functions as a first gate insulating film, and the insulators 224 and 222 function as second gate insulating films. The conductor 242a functions as one of a source electrode or a drain electrode, and the conductor 242b functions as the other of the source electrode or the drain electrode. At least a part of a region of the oxide 230 overlapping with the conductor 260 functions as a channel formation region.

[0176] The oxide 230b has one of a source region and a drain region in a region overlapping with the conductor 242a, and has the other of the source region and the drain region in a region overlapping with the conductor 242b. The oxide 230b also has a channel formation region (the region indicated by the shaded area in FIG. 9B) between the source region and the drain region.

[0177] The channel formation region is a high-resistance region having a low carrier concentration because it has fewer oxygen vacancies or a lower impurity concentration than the source and drain regions. 18 cm -3 It is preferable that the value is less than 1×10 17 cm -3 More preferably, it is less than 1×10 16 cm -3 More preferably, it is less than 1×10 13 cm -3 More preferably, it is less than 1×10 12 cm -3 The lower limit of the carrier concentration in the channel formation region is not particularly limited, but is preferably, for example, 1×10 -9 cm -3 It can be said that:

[0178] In the above, the channel formation region, the source region, and the drain region are formed in the oxide 230b, but the present invention is not limited to this. For example, the channel formation region, the source region, and the drain region may be formed in the oxide 230a in a similar manner.

[0179] In the transistor 200, a metal oxide that functions as a semiconductor (also referred to as an oxide semiconductor) is preferably used for the oxide 230 (the oxide 230a and the oxide 230b) including a channel formation region.

[0180] The metal oxide functioning as a semiconductor preferably has a band gap of 2 eV or more, more preferably 2.5 eV or more. By using a metal oxide having such a large band gap, the off-state current of a transistor can be reduced.

[0181] As the oxide 230, for example, a metal oxide such as an In-M-Zn oxide having indium, an element M, and zinc (the 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.) may be used. Alternatively, as the oxide 230, an In-Ga oxide, an In-Zn oxide, or an indium oxide may be used.

[0182] Here, it is preferable that the atomic ratio of In to element M in the metal oxide used for oxide 230b is greater than the atomic ratio of In to element M in the metal oxide used for oxide 230a.

[0183] Specifically, the oxide 230a may be a metal oxide having a composition of In:M:Zn=1:3:4 [atomic ratio] or a composition close thereto, or In:M:Zn=1:1:0.5 [atomic ratio] or a composition close thereto. The oxide 230b may be a metal oxide having a composition of In:M:Zn=1:1:1 [atomic ratio] or a composition close thereto, or In:M:Zn=4:2:3 [atomic ratio] or a composition close thereto. The composition close thereto includes a range of ±30% of the desired atomic ratio. The element M is preferably gallium.

[0184] In addition, when a metal oxide film is formed by a sputtering method, the above atomic ratio is not limited to the atomic ratio of the formed metal oxide film, but may be the atomic ratio of a sputtering target used to form the metal oxide film.

[0185] In this manner, by disposing the oxide 230a below the oxide 230b, it is possible to suppress the diffusion of impurities and oxygen from structures formed below the oxide 230a into the oxide 230b.

[0186] In addition, since the oxide 230a and the oxide 230b have a common element other than oxygen (as a main component), the defect state density at the interface between the oxide 230a and the oxide 230b can be reduced. Since the defect state density at the interface between the oxide 230a and the oxide 230b can be reduced, the effect of interface scattering on carrier conduction is small, and a high on-current can be obtained.

[0187] It is preferable that the oxide 230b has crystallinity, and it is particularly preferable to use c-axis aligned crystalline oxide semiconductor (CAAC-OS) as the oxide 230b.

[0188] CAAC-OS has a highly crystalline and dense structure and is free of impurities and defects (e.g., oxygen vacancies (V OIn particular, by subjecting the metal oxide to heat treatment at a temperature at which the metal oxide does not polycrystallize (for example, 400° C. or higher and 600° C. or lower) after formation of the metal oxide, the CAAC-OS can have a dense structure with higher crystallinity. In this way, the density of the CAAC-OS can be increased, thereby further reducing the diffusion of impurities or oxygen in the CAAC-OS.

[0189] On the other hand, it is difficult to identify clear grain boundaries in CAAC-OS, so it is unlikely that the electron mobility will decrease due to grain boundaries. Therefore, metal oxides with CAAC-OS have stable physical properties. Therefore, metal oxides with CAAC-OS are resistant to heat and highly reliable.

[0190] At least one of the insulators 212, 214, 271, 275, 282, and 283 preferably functions as a barrier insulating film that suppresses diffusion of impurities such as water and hydrogen from the substrate side or from above the transistor 200 to the transistor 200. Therefore, at least one of the insulators 212, 214, 271, 275, 282, and 283 is preferably made of an insulating material that has a function of suppressing diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (NO, NO, NO, etc.), and copper atoms (through which the above impurities are unlikely to permeate). Alternatively, it is preferable to use an insulating material that has a function of suppressing diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.) (through which the above oxygen is unlikely to permeate).

[0191] In this specification, a barrier insulating film refers to an insulating film having a barrier property. In this specification, the barrier property means a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing and fixing a corresponding substance (also referred to as gettering).

[0192] For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulators 212, 214, 271, 275, 282, and 283. For example, it is preferable to use silicon nitride or the like, which has a higher hydrogen barrier property, for the insulators 212, 275, and 283. For example, it is preferable to use aluminum oxide or magnesium oxide, which has a high function of capturing and fixing hydrogen, for the insulators 214, 271, and 282. This can suppress impurities such as water and hydrogen from diffusing from the substrate side to the transistor 200 side through the insulators 212 and 214. Alternatively, it is possible to suppress impurities such as water and hydrogen from diffusing from an interlayer insulating film disposed outside the insulator 283 to the transistor 200 side. Alternatively, oxygen contained in the insulator 224 or the like can be suppressed from diffusing toward the substrate side through the insulator 212 and the insulator 214. Alternatively, oxygen contained in the insulator 280 or the like can be suppressed from diffusing upward from the transistor 200 through the insulator 282 or the like. In this manner, it is preferable to have a structure in which the transistor 200 is surrounded by the insulators 212, 214, 271, 275, 282, and 283, which have a function of suppressing the diffusion of impurities such as water and hydrogen, and oxygen.

[0193] Here, it is preferable to use an oxide having an amorphous structure as the insulators 212, 214, 271, 275, 282, and 283. For example, AlO x (x is any number greater than 0), or MgO yIt is preferable to use a metal oxide such as y (y is any number greater than 0). In such a metal oxide having an amorphous structure, oxygen atoms have dangling bonds, and the dangling bonds may have a property of capturing or fixing hydrogen. By using such a metal oxide having an amorphous structure as a component of the transistor 200 or providing it around the transistor 200, hydrogen contained in the transistor 200 or hydrogen present around the transistor 200 can be captured or fixed. In particular, it is preferable to capture or fix hydrogen contained in the channel formation region of the transistor 200. By using a metal oxide having an amorphous structure as a component of the transistor 200 or providing it around the transistor 200, a transistor 200 and a semiconductor device having good characteristics and high reliability can be manufactured.

[0194] Note that the insulators 212, 214, 271, 275, 282, and 283 preferably have an amorphous structure, but may have a polycrystalline structure region in a portion thereof. The insulators 212, 214, 271, 275, 282, and 283 may have a multilayer structure in which a layer of an amorphous structure and a layer of a polycrystalline structure are stacked. For example, they may have a stacked structure in which a layer of a polycrystalline structure is formed on a layer of an amorphous structure.

[0195] The insulators 212, 214, 271, 275, 282, and 283 may be formed by, for example, a sputtering method. Because the sputtering method does not require the use of hydrogen as a film formation gas, the hydrogen concentration of the insulators 212, 214, 271, 275, 282, and 283 can be reduced. Note that the film formation method is not limited to the sputtering method, and a CVD method, an MBE method, a PLD method, an ALD method, or the like may be used as appropriate.

[0196] The insulators 216, 280, and 285 preferably have a lower dielectric constant than the insulator 214. By using a material with a low dielectric constant as an interlayer insulating film, parasitic capacitance 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 vacancies, or the like may be used as appropriate for the insulators 216, 280, and 285.

[0197] The conductor 205 is disposed so as to overlap the oxide 230 and the conductor 260. Here, the conductor 205 is preferably provided by being embedded in an opening formed in the insulator 216.

[0198] The conductor 205 includes a conductor 205a, a conductor 205b, and a conductor 205c. The conductor 205a is provided in contact with the bottom surface and the side wall of the opening. The conductor 205b is provided so as to be embedded in a recess formed in the conductor 205a. Here, the upper surface of the conductor 205b is lower than the upper surface of the conductor 205a and the upper surface of the insulator 216. The conductor 205c is provided in contact with the upper surface of the conductor 205b and the side surface of the conductor 205a. Here, the height of the upper surface of the conductor 205c is approximately equal to the height of the upper surface of the conductor 205a and the height of the upper surface of the insulator 216. In other words, the conductor 205b is configured to be wrapped in the conductor 205a and the conductor 205c.

[0199] The conductor 205a and the conductor 205c may be made of a conductive material that can be used for the conductor 260a, which will be described later. The conductor 205b may be made of a conductive material that can be used for the conductor 260b, which will be described later. Although the conductor 205 in the transistor 200 has a stacked structure of the conductor 205a, the conductor 205b, and the conductor 205c, the present invention is not limited to this. For example, the conductor 205 may be provided as a single layer, a two-layer, or a four or more layer stacked structure.

[0200] The insulators 222 and 224 function as gate insulating films.

[0201] The insulator 222 preferably has a function of suppressing the diffusion of hydrogen (e.g., at least one of hydrogen atoms, hydrogen molecules, etc.). The insulator 222 preferably has a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.). For example, the insulator 222 preferably can suppress the diffusion of one or both of hydrogen and oxygen more effectively than the insulator 224.

[0202] The insulator 222 may be an insulator containing an oxide of one or both of insulating materials, aluminum and hafnium. As the insulator, it is preferable to use aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), or the like. Alternatively, the insulator 222 may be a barrier insulating film that can be used for the insulator 214 described above, or the like.

[0203] The insulator 224 may be made of silicon oxide, silicon oxynitride, or the like as appropriate. By providing the insulator 224 containing oxygen in contact with the oxide 230, oxygen vacancies in the oxide 230 can be reduced and the reliability of the transistor 200 can be improved. The insulator 224 is preferably processed into an island shape so as to overlap with the oxide 230a. In this case, the insulator 275 is configured to be in contact with the side surface of the insulator 224 and the top surface of the insulator 222. This allows the insulator 224 and the insulator 280 to be separated from each other by the insulator 275, so that the oxygen contained in the insulator 280 is diffused into the insulator 224, and the oxygen in the insulator 224 can be prevented from becoming excessive.

[0204] 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 being made of the same material, and may be made of different materials. Although FIG. 9B and other figures show a configuration in which the insulator 224 is formed in an island shape by overlapping with the oxide 230a, the present invention is not limited to this. If the amount of oxygen contained in the insulator 224 can be appropriately adjusted, the insulator 224 may be configured not to be patterned, similar to the insulator 222.

[0205] The oxide 243a and the oxide 243b are provided on the oxide 230b. The oxide 243a and the oxide 243b are provided to be separated from each other with the conductor 260 interposed therebetween. The oxide 243 (the oxide 243a and the oxide 243b) preferably has a function of suppressing oxygen permeation. By disposing the oxide 243 having a function of suppressing oxygen permeation between the conductor 242 functioning as a source electrode or a drain electrode and the oxide 230b, the electrical resistance between the conductor 242 and the oxide 230b is reduced, which is preferable. Note that if the electrical resistance between the conductor 242 and the oxide 230b can be sufficiently reduced, the oxide 243 may not be provided.

[0206] A metal oxide having element M may be used as the oxide 243. In particular, the element M may be aluminum, gallium, yttrium, or tin. The oxide 243 preferably has a higher concentration of element M than the oxide 230b. Gallium oxide may be used as the oxide 243. A metal oxide such as In-M-Zn oxide may be used as the oxide 243. Specifically, in the metal oxide used for the oxide 243, the atomic ratio of element M to In is preferably greater than the atomic ratio of element M to In in the metal oxide used for the oxide 230b. The thickness of the oxide 243 is preferably 0.5 nm or more and 5 nm or less, more preferably 1 nm or more and 3 nm or less, and even more preferably 1 nm or more and 2 nm or less.

[0207] It is preferable that the conductor 242a be provided in contact with an upper surface of the oxide 243a, and the conductor 242b be provided in contact with an upper surface of the oxide 243b. The conductor 242a and the conductor 242b function as a source electrode and a drain electrode of the transistor 200, respectively.

[0208] As the conductor 242 (conductor 242a and conductor 242b), for example, a nitride containing tantalum, a nitride containing titanium, a nitride containing molybdenum, a nitride containing tungsten, a nitride containing tantalum and aluminum, a nitride containing titanium and aluminum, or the like is preferably used. In one embodiment of the present invention, a nitride containing tantalum is particularly preferable. Also, for example, ruthenium oxide, ruthenium nitride, an oxide containing strontium and ruthenium, an oxide containing lanthanum and nickel, or the like may be used. These materials are preferable because they are conductive materials that are difficult to oxidize, or materials that maintain their conductivity even when they absorb oxygen.

[0209] Moreover, it is preferable that no curved surface is formed between the side surface of the conductor 242 and the top surface of the conductor 242. By forming the conductor 242 without such a curved surface, it is possible to increase the cross-sectional area of ​​the conductor 242 in the cross section in the channel width direction as shown in Fig. 9D. This can increase the conductivity of the conductor 242 and the on-current of the transistor 200.

[0210] The insulator 271a is provided in contact with the upper surface of the conductor 242a, and the insulator 271b is provided in contact with the upper surface of the conductor 242b.

[0211] The insulator 275 is provided in contact with the upper surface of the insulator 222, the side surface of the insulator 224, the side surface of the oxide 230a, the side surface of the oxide 230b, the side surface of the oxide 243, the side surface of the conductor 242, and the side surface and upper surface of the insulator 271. The insulator 275 has openings formed in the regions where the insulator 250 and the conductor 260 are provided.

[0212] By providing insulators 214, 271, and 275, which have the function of capturing impurities such as hydrogen, in a region sandwiched between insulators 212 and 275, impurities such as hydrogen contained in insulator 224 or insulator 216 can be captured and the amount of hydrogen in the region can be kept constant. In this case, it is preferable that insulators 214, 271, and 275 contain aluminum oxide with an amorphous structure.

[0213] The insulator 250 has an insulator 250a and an insulator 250b on the insulator 250a, and functions as a gate insulating film. The insulator 250a is preferably disposed in contact with the top surface of the oxide 230b, the side of the oxide 243, the side of the conductor 242, the side of the insulator 271, the side of the insulator 275, and the side of the insulator 280. The thickness of the insulator 250 is preferably 1 nm or more and 20 nm or less.

[0214] The insulator 250a may 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, silicon oxide having vacancies, or the like. Silicon oxide and silicon oxynitride are particularly preferred because they are stable against heat. As with the insulator 224, the insulator 250a is preferably made of insulator 250 having a reduced concentration of impurities such as water and hydrogen.

[0215] It is preferable that the insulator 250a is formed using an insulator that releases oxygen when heated, and the insulator 250b is formed using an insulator that has a function of suppressing the diffusion of oxygen. With such a configuration, it is possible to suppress the diffusion of oxygen contained in the insulator 250a into the conductor 260. In other words, it is possible to suppress a decrease in the amount of oxygen supplied to the oxide 230. In addition, it is possible to suppress the oxidation of the conductor 260 due to the oxygen contained in the insulator 250a. For example, the insulator 250b can be provided using the same material as the insulator 222.

[0216] Specifically, the insulator 250b may be a metal oxide containing one or more of hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, magnesium, or a metal oxide that can be used as the oxide 230. In particular, it is preferable to use an insulator containing an oxide of one or both of aluminum and hafnium. It is preferable to use aluminum oxide, hafnium oxide, or an oxide containing aluminum and hafnium (hafnium aluminate) as the insulator. The thickness of the insulator 250b is preferably 0.5 nm or more and 3.0 nm or less, and more preferably 1.0 nm or more and 1.5 nm or less.

[0217] 9B and 9C, the insulator 250 is illustrated as having a two-layer laminated structure, but the present invention is not limited to this. The insulator 250 may have a single layer structure or a laminated structure of three or more layers.

[0218] The conductor 260 is provided on the insulator 250b and functions as a first gate electrode of the transistor 200. The conductor 260 preferably includes a conductor 260a and a conductor 260b disposed on the conductor 260a. For example, the conductor 260a is preferably disposed so as to surround the bottom and side surfaces of the conductor 260b. As shown in FIGS. 9B and 9C, the top surface of the conductor 260 is substantially flush with the top surface of the insulator 250. Note that, although the conductor 260 is shown in FIGS. 9B and 9C as having a two-layer structure of the conductor 260a and the conductor 260b, the conductor 260 may have a single-layer structure or a stacked structure of three or more layers.

[0219] 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, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules, copper atoms, etc. 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, etc.).

[0220] Furthermore, since the conductor 260a has a function of suppressing oxygen diffusion, it is possible to suppress a decrease in conductivity due to oxidation of the conductor 260b caused by oxygen contained in the insulator 250. As a conductive material having a function of suppressing oxygen diffusion, it is preferable to use, for example, titanium, titanium nitride, tantalum, tantalum nitride, ruthenium, ruthenium oxide, or the like.

[0221] In addition, since the conductor 260 also functions as wiring, it is preferable to use a conductor with high conductivity. For example, the conductor 260b can be a conductive material mainly composed of tungsten, copper, or aluminum. The conductor 260b may also have a laminated structure, for example, a laminated structure of titanium or titanium nitride and the above-mentioned conductive material.

[0222] Moreover, in the transistor 200, the conductor 260 is formed in a self-aligned manner so as to fill an opening formed in the insulator 280 or the like. By forming the conductor 260 in this manner, the conductor 260 can be reliably disposed in the region between the conductor 242a and the conductor 242b without alignment.

[0223] 9C, in the channel width direction of the transistor 200, the height of the bottom surface of the conductor 260 in the region where the oxide 230b does not overlap with the oxide 230b is preferably lower than the height of the bottom surface of the oxide 230b when the bottom surface of the insulator 222 is used as a reference. The conductor 260, which functions as a gate electrode, is configured to cover the side and top surfaces of the channel formation region of the oxide 230b via the insulator 250 or the like, so that the electric field of the conductor 260 can be easily applied to the entire channel formation region of the oxide 230b. This makes it possible to increase the on-current of the transistor 200 and improve the frequency characteristics. When the bottom surface of the insulator 222 is used as a reference, the difference between the height of the bottom surface of the conductor 260 in the region where the oxide 230a and the oxide 230b do not overlap with the conductor 260 and the height of the bottom surface of the oxide 230b is 0 nm or more and 100 nm or less, preferably 3 nm or more and 50 nm or less, and more preferably 5 nm or more and 20 nm or less.

[0224] The insulator 280 is provided on the insulator 275, and openings are formed in the regions where the insulator 250 and the conductor 260 are provided. The upper surface of the insulator 280 may be flattened. In this case, it is preferable that the upper surface of the insulator 280 is roughly aligned with the upper surfaces of the insulator 250 and the conductor 260.

[0225] The insulator 282 is provided in contact with the upper surface of the insulator 280, the upper surface of the insulator 250, and the upper surface of the conductor 260. The insulator 282 preferably functions as a barrier insulating film that suppresses the diffusion of impurities such as water and hydrogen from above into the insulator 280, and preferably has a function of capturing impurities such as hydrogen. The insulator 282 preferably functions as a barrier insulating film that suppresses the transmission of oxygen. For example, an insulator such as aluminum oxide may be used as the insulator 282. By providing the insulator 282 in contact with the insulator 280 in a region sandwiched between the insulator 212 and the insulator 283 and having a function of capturing impurities such as hydrogen, the impurities such as hydrogen contained in the insulator 280 can be captured, and the amount of hydrogen in the region can be made constant. In particular, it is preferable to use aluminum oxide having an amorphous structure or aluminum oxide having an amorphous structure as the insulator 282, because hydrogen can be more effectively captured or fixed. As a result, a transistor 200 and a semiconductor device having favorable characteristics and high reliability can be manufactured.

[0226] 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. When the conductor 240 has a layered structure, the conductor in contact with the insulator 241 is preferably made of a conductive material that has a function of suppressing the permeation of impurities such as water and hydrogen. For example, the conductive material that can be used for the conductor 260a described above may be used.

[0227] The insulators 241a and 241b may be, for example, insulators such as silicon nitride, aluminum oxide, and silicon nitride oxide. The insulators 241a and 241b are provided in contact with the insulators 283, 282, and 271, and therefore can prevent impurities such as water and hydrogen contained in the insulator 280 from being mixed into the oxide 230 through the conductors 240a and 240b.

[0228] Conductors 246 (conductors 246a and 246b) functioning as wiring may be disposed in contact with the upper surface of conductor 240a and the upper surface of conductor 240b. Conductor 246 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.

[0229] As a result, a semiconductor device having good electrical characteristics can be provided. A semiconductor device having good reliability can be provided. A semiconductor device that can be miniaturized or highly integrated can be provided. A semiconductor device with low power consumption can be provided.

[0230] [Metal oxides] Next, a metal oxide (also referred to as an oxide semiconductor) that can be used for a transistor will be described.

[0231] 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, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0232] Moreover, the metal oxide can be formed by a sputtering method, a CVD method such as a metal organic chemical vapor deposition (MOCVD) method, or an ALD method.

[0233] <Classification of crystal structures> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0234] The crystal structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by a GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0235] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is almost symmetric. On the other hand, in the case of an IGZO film having a crystalline structure, the peak shape of the XRD spectrum is asymmetric. The asymmetric peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetric, the film or substrate cannot be said to be in an amorphous state.

[0236] The crystal structure of a film or substrate can be evaluated by a diffraction pattern (also called a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is presumed that an IGZO film formed at room temperature is in an intermediate state that is neither crystalline nor amorphous, and therefore it cannot be concluded that it is in an amorphous state.

[0237] <<Structure of oxide semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0238] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0239] [[CAAC-OS]] CAAC-OS is an oxide semiconductor having a plurality of crystalline regions, each of which has a c-axis aligned in a specific direction. The specific direction is the thickness direction of the CAAC-OS film, the normal direction of the surface on which the CAAC-OS film is formed, or the normal direction of the surface of the CAAC-OS film. The crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, the crystalline region is also a region with a uniform lattice arrangement. CAAC-OS has a region in which a plurality of crystalline regions are connected in the ab-plane direction, and the region may have distortion. The distortion refers to a portion in which the direction of the lattice arrangement changes between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement in the region in which the plurality of crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor having a c-axis aligned and no clear orientation in the ab-plane direction.

[0240] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be about several tens of nm.

[0241] In addition, in an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter, In layer) and a layer containing element M, zinc (Zn), and oxygen (hereinafter, (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Thus, the (M, Zn) layer may contain indium. Also, the In layer may contain element M. Note that the In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution TEM image, for example.

[0242] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD device, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0243] For example, a plurality of bright points (spots) are observed in the electron diffraction pattern of the CAAC-OS film, and the two spots are observed at positions symmetrical to each other with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0244] When the crystal region is observed from the specific direction, the lattice arrangement in the crystal region is based on a hexagonal lattice, but the unit lattice is not necessarily a regular hexagon, and may be a non-regular hexagon. The above distortion may have a lattice arrangement such as a pentagon or heptagon. In addition, in the CAAC-OS, no clear grain boundary can be confirmed even in the vicinity of the distortion. That is, it can be seen that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is considered to be because the CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms in the ab-plane direction is not dense, and the bond distance between atoms changes due to the substitution of metal atoms.

[0245] A crystal structure in which clear grain boundaries are observed is called a polycrystal. The grain boundaries are likely to become recombination centers and capture carriers, causing a decrease in the on-current of a transistor and a decrease in field effect mobility. Therefore, CAAC-OS in which clear grain boundaries are not observed is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. In order to form a CAAC-OS, a structure containing Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the occurrence of grain boundaries more than In oxide.

[0246] The CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. In addition, since the crystallinity of an oxide semiconductor can be decreased by the inclusion of impurities and the generation of defects, the CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, the physical properties of an oxide semiconductor having the CAAC-OS are stable. Therefore, an oxide semiconductor having the CAAC-OS is resistant to heat and has high reliability. In addition, the CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of the CAAC-OS in an OS transistor can increase the degree of freedom in the manufacturing process.

[0247] [[nc-OS]] The nc-OS has periodic atomic arrangement in a minute region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has minute crystals. Note that the size of the minute crystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the minute crystals are also called nanocrystals. In addition, the nc-OS does not show regularity in crystal orientation between different nanocrystals. Therefore, no orientation is seen in the entire film. Therefore, the nc-OS may be indistinguishable from an a-like OS and / or an amorphous oxide semiconductor depending on the analysis method. For example, when the structure of the nc-OS film is analyzed using an XRD device, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. In addition, when the nc-OS film is subjected to electron diffraction (also called selected area electron diffraction) using an electron beam with a probe diameter larger than that of the nanocrystals (for example, 50 nm or more), a diffraction pattern like a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter (e.g., 1 nm to 30 nm) that is close to the size of a nanocrystal or smaller than the nanocrystal, an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on the direct spot may be obtained.

[0248] [[a-like OS]] The a-like OS is an oxide semiconductor having a structure between the nc-OS and the amorphous oxide semiconductor. The a-like OS has a void or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Moreover, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0249] <<Oxide semiconductor structure>> Next, the above-mentioned CAC-OS will be described in detail, with reference to its material composition.

[0250] [[CAC-OS]] CAC-OS is, for example, a material configuration in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide and the regions having the metal elements are mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0251] Furthermore, CAC-OS is a composite metal oxide in which the material is separated into a first region and a second region, forming a mosaic structure, and the first region is distributed throughout the film (hereinafter, also referred to as a cloud structure). In other words, CAC-OS is a composite metal oxide in which the first region and the second region are mixed together.

[0252] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are represented as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. Also, the second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. Also, the second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0253] Specifically, the first region is a region mainly composed of indium oxide, indium zinc oxide, etc., and the second region is a region mainly composed of gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region mainly composed of In, and the second region can be rephrased as a region mainly composed of Ga.

[0254] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0255] In addition, the CAC-OS in In-Ga-Zn oxide refers to a structure in which some regions mainly composed of Ga and some regions mainly composed of In are arranged randomly in a mosaic pattern in a material structure containing In, Ga, Zn, and O. Therefore, it is presumed that the CAC-OS has a structure in which metal elements are distributed non-uniformly.

[0256] CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not heated. When CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the film formation gas. The lower the flow rate ratio of oxygen gas to the total flow rate of film formation gas during film formation, the more preferable it is. For example, the flow rate ratio of oxygen gas to the total flow rate of film formation gas during film formation is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0257] Furthermore, for example, in the case of a CAC-OS of an In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) can confirm that the CAC-OS has a structure in which a region mainly composed of In (first region) and a region mainly composed of Ga (second region) are unevenly distributed and mixed.

[0258] Here, the first region is a region with higher conductivity than the second region. In other words, the first region exhibits conductivity as a metal oxide when carriers flow through the first region. Therefore, the first region is distributed in a cloud-like shape in the metal oxide, thereby realizing a high field-effect mobility (μ).

[0259] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, so that leakage current can be suppressed.

[0260] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act in a complementary manner, giving the CAC-OS a switching function (On / Off function). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, it is possible to maximize both functions. Therefore, by using CAC-OS in a transistor, it is possible to achieve a high on-current (I on ), high field effect mobility (μ), and good switching operation can be achieved.

[0261] In addition, a transistor using CAC-OS has high reliability, making it ideal for various semiconductor devices such as display devices.

[0262] Oxide semiconductors have a variety of structures and have different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0263] This embodiment mode can be combined with other embodiment modes as appropriate.

[0264] (Embodiment 3) In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0265] The display device of this embodiment has a plurality of pixels arranged in a matrix of m rows and n columns (m and n are each an integer equal to or greater than 1). Fig. 10 shows an example of a circuit diagram of a pixel PIX(i,j) (i is an integer equal to or greater than 1 and equal to or less than m, and j is an integer equal to or greater than 1 and equal to or less than n).

[0266] 10 includes a light-emitting device 110 (also referred to as a light-emitting element), a switch SW21, a transistor M, and a capacitance C1. The pixel PIX(i,j) may further include a switch SW22. Here, an example is shown in which a light-emitting diode is used as the light-emitting device 110. In particular, it is preferable to use a micro light-emitting diode as the light-emitting device 110.

[0267] In this embodiment, an example in which a transistor is used as the switch SW21 will be described. The gate of the switch SW21 is electrically connected to the scan line GL1(i). One of the source and drain of the switch SW21 is electrically connected to the signal line SL(j), and the other is electrically connected to the gate of the transistor M.

[0268] In this embodiment, an example in which a transistor is used as the switch SW22 will be described. A gate of the switch SW22 is electrically connected to the scan line GL2(i). One of the source and drain of the switch SW22 is electrically connected to the wiring COM, and the other is electrically connected to the gate of the transistor M.

[0269] The gate of the transistor M is electrically connected to one electrode of the capacitor C1, the other of the source and drain of the switch SW21, and the other of the source and drain of the switch SW22. One of the source and drain of the transistor M is electrically connected to the wiring CATHODE, and the other is electrically connected to the cathode of the light-emitting device 110.

[0270] The other electrode of the capacitor C1 is electrically connected to the wiring CATHODE.

[0271] The anode of the light emitting device 110 is electrically connected to the wiring ANODE.

[0272] The scanning line GL1(i) has a function of supplying a selection signal. The scanning line GL2(i) has a function of supplying a control signal. The signal line SL(j) has a function of supplying an image signal. A constant potential is supplied to the wiring COM, the wiring CATHODE, and the wiring ANODE. The anode side of the light emitting device 110 can be set to a high potential, and the cathode side can be set to a lower potential than the anode side.

[0273] The switch SW21 is controlled by a selection signal and functions as a selection transistor for controlling the selection state of the pixel PIX(i,j).

[0274] The transistor M functions as a drive transistor that controls the current flowing through the light emitting device 110 according to the potential supplied to the gate. When the switch SW21 is in a conductive state, an image signal supplied to the signal line SL(j) is supplied to the gate of the transistor M, and the light emission brightness of the light emitting device 110 can be controlled according to the potential.

[0275] The switch SW22 has a function of controlling, based on a control signal, the gate potential of the transistor M. Specifically, the switch SW22 can supply, to the gate of the transistor M, a potential that puts the transistor M into a non-conductive state.

[0276] The switch SW22 can be used to control, for example, a pulse width, and can supply a current from the transistor M to the light emitting device 110 during a period based on the control signal. Alternatively, the light emitting device 110 can express a gray scale based on the image signal and the control signal.

[0277] Here, it is preferable that the transistors included in the pixel PIX(i,j) are transistors using a metal oxide (oxide semiconductor) for a semiconductor layer in which a channel is formed.

[0278] A transistor using a metal oxide having a wider band gap than silicon and a lower carrier concentration can achieve an extremely small off-state current. Therefore, the small off-state current allows the charge stored in the capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use transistors using an oxide semiconductor for the switches SW21 and SW22 connected in series with the capacitor C1 in particular. In addition, by using transistors using an oxide semiconductor for the other transistors as well, the manufacturing cost can be reduced.

[0279] Furthermore, a transistor in which silicon is used as a semiconductor in which a channel is formed can also be used as the transistor in the pixel PIX(i,j). In particular, by using one or more types of silicon with high crystallinity such as single crystal silicon and polycrystalline silicon, high field effect mobility can be realized, which is preferable since it enables faster operation.

[0280] Alternatively, a structure may be used in which at least one of the transistors included in the pixel PIX(i,j) is a transistor using an oxide semiconductor and the rest are transistors using silicon.

[0281] Although the transistors are shown as n-channel transistors in FIG. 10, p-channel transistors can also be used.

[0282] This embodiment mode can be combined with other embodiment modes as appropriate.

[0283] (Embodiment 4) In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0284] The electronic devices of this embodiment include the display device of one embodiment of the present invention in a display portion. The display device of one embodiment of the present invention has high display quality and low power consumption. In addition, the display device of one embodiment of the present invention can easily have high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portion of various electronic devices.

[0285] Examples of electronic devices include electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and audio playback devices.

[0286] In particular, the display device of one embodiment of the present invention can be suitably used in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices). Other examples of such electronic devices include wearable devices that can be worn on the head, such as head-mounted displays and other VR devices, glasses-type AR devices, and MR devices.

[0287] The display device of one embodiment of the present invention preferably has an extremely high resolution such as HD (1280×720 pixels), FHD (1920×1080 pixels), WQHD (2560×1440 pixels), WQXGA (2560×1600 pixels), 4K (3840×2160 pixels), or 8K (7680×4320 pixels). In particular, a resolution of 4K, 8K, or more is preferable. The pixel density (resolution) of the display device of one embodiment of the present invention is preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display device having such a high resolution and / or high resolution, it is possible to further improve the sense of realism and the sense of depth in electronic devices for personal use such as portable and home use.

[0288] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0289] The electronic device of the present embodiment can have various functions, such as a function of displaying various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, time, etc., a function of executing various software (programs), a wireless communication function, a function of reading out a program or data recorded on a recording medium, etc.

[0290] 11A shows a perspective view of glasses-type electronic device 700. Electronic device 700 has a pair of display panels 701, a pair of housings 702, a pair of optical members 703, a pair of mounting parts 704, a frame 707, nose pads 708, and the like.

[0291] The electronic device 700 can project an image displayed on the display panel 701 onto a display area 706 of the optical member 703. Since the optical member 703 is translucent, the user can see the image displayed in the display area 706 superimposed on a transmitted image visually recognized through the optical member 703. Therefore, the electronic device 700 is an electronic device capable of AR display.

[0292] One or both of the housings 702 may be provided with a camera capable of capturing an image of the front. The housing 702 may have a wireless communication device, and a video signal or the like can be supplied to the housing 702 through the wireless communication device. Note that instead of or in addition to the wireless communication device, a connector to which a cable through which a video signal and / or a power supply potential can be connected may be provided. The housing 702 may be provided with an acceleration sensor such as a gyro sensor to detect the orientation of the user's head and display an image corresponding to the orientation in the display region 706.

[0293] A processor may be provided in one or both of the housings 702. The processor has a function of controlling various components of the electronic device 700, such as a camera, a wireless communication device, and a pair of display panels 701, and a function of generating an image. The processor may have a function of generating a composite image for AR display.

[0294] In addition, the wireless communication device can communicate data with external devices. For example, data transmitted from the outside can be output to the processor, and the processor can generate image data for AR display based on the data. Examples of data transmitted from the outside include image data and data including bioinformation transmitted from a biosensor device.

[0295] 11B, a method of projecting an image onto display area 706 of electronic device 700 will be described. A display panel 701 is provided inside housing 702. A reflector 712 is provided on optical member 703, and a reflecting surface 713 functioning as a half mirror is provided on a portion of optical member 703 that corresponds to display area 706.

[0296] Light 715 emitted from the display panel 701 is reflected by the reflector 712 towards the optical member 703. Inside the optical member 703, the light 715 is repeatedly totally reflected by the end face of the optical member 703, and reaches the reflecting surface 713, whereby an image is projected onto the reflecting surface 713. This allows the user to visually recognize both the light 715 reflected by the reflecting surface 713 and the transmitted light 716 that has transmitted through the optical member 703 (including the reflecting surface 713).

[0297] 11 shows an example in which the reflector 712 and the reflecting surface 713 each have a curved surface. This allows for greater freedom in optical design compared to when these surfaces are flat, and allows for a thinner optical member 703. The reflector 712 and the reflecting surface 713 may also be flat.

[0298] A member having a mirror surface can be used as the reflector 712, and it is preferable that the reflector has a high reflectance. Also, a half mirror utilizing the reflection of a metal film may be used as the reflector surface 713, but the transmittance of the transmitted light 716 can be increased by using a prism utilizing total reflection.

[0299] Here, the housing 702 may have a lens between the display panel 701 and the reflector 712. In this case, it is preferable that the housing 702 has a mechanism for adjusting the distance between the lens and the display panel 701 and the angle therebetween. This makes it possible to adjust the focus and enlarge or reduce the image. For example, the lens or the display panel 701 or both may be configured to be movable in the direction of the optical axis.

[0300] Moreover, it is preferable that the housing 702 has a mechanism capable of adjusting the angle of the reflector 712. It is possible to change the position of the display area 706 where the image is displayed by changing the angle of the reflector 712. This makes it possible to position the display area 706 at an optimal position according to the position of the user's eyes.

[0301] The housing 702 is preferably provided with a battery 717 and a wireless power supply module 718. By providing the battery 717, the electronic device 700 can be used without connecting a separate battery, thereby improving convenience. Furthermore, by providing the wireless power supply module 718, charging can be performed wirelessly, thereby improving convenience and design. Furthermore, compared to charging by wire using a connector or the like, the risk of failure such as poor contact can be reduced, and the reliability of the electronic device 700 can be improved.

[0302] The housing 702 is provided with a touch sensor module 719. The touch sensor module 719 has a function of detecting that the outer surface of the housing 702 is touched. FIG. 11B shows a state where the surface of the housing 702 is touched with a finger 720. The touch sensor module 719 detects a tap operation and / or a slide operation of the user, and can execute various processes. For example, a tap operation can execute processes such as pausing and resuming a video, and a slide operation can execute processes such as fast forwarding and rewinding. In addition, by providing the touch sensor module 719 on each of the two housings 702, the range of operations can be expanded.

[0303] Various touch sensors can be applied as the touch sensor module 719. For example, various types can be adopted, such as a capacitance type, a resistive film type, an infrared type, an electromagnetic induction type, a surface acoustic wave type, an optical type, etc. In particular, it is preferable to apply a capacitance type or an optical type sensor to the touch sensor module 719.

[0304] When an optical touch sensor is used, a photoelectric conversion device (also called a photoelectric conversion element) can be used as a light receiving device (also called a light receiving element). Photoelectric conversion devices include those that use inorganic semiconductors or those that use organic semiconductors in the active layer.

[0305] The display device of one embodiment of the present invention can be applied to the display panel 701. Thus, the electronic device 700 can provide an extremely high-definition display.

[0306] 12A and 12B show perspective views of a goggle-type electronic device 950. Fig. 12A is a perspective view showing the front, top, and left side of the electronic device 950, and Fig. 12B is a perspective view showing the back, bottom, and right side of the electronic device 950.

[0307] The electronic device 950 includes a pair of display panels 951, a housing 952, a pair of mounting portions 954, a cushioning member 955, and a pair of lenses 956. The pair of display panels 951 are provided inside the housing 952 at positions viewable through the lenses 956.

[0308] The electronic device 950 is an electronic device for VR. A user wearing the electronic device 950 can view an image displayed on a display panel 951 through a lens 956. In addition, by displaying different images on a pair of display panels 951, a three-dimensional display using parallax can be performed.

[0309] An input terminal 957 and an output terminal 958 are provided on the rear side of the housing 952. A cable for supplying a video signal from a video output device or the like and power for charging a battery provided in the housing 952 can be connected to the input terminal 957. The output terminal 958 can function as, for example, an audio output terminal, and can be connected to earphones, headphones, or the like. Note that when a configuration is used in which audio data can be output by wireless communication, or when audio is output from an external video output device, the audio output terminal does not need to be provided.

[0310] The electronic device 950 preferably has a mechanism for adjusting the left-right positions of the lens 956 and the display panel 951 so that the lens 956 and the display panel 951 are positioned optimally according to the position of the user's eyes. Also, the electronic device 950 preferably has a mechanism for adjusting the focus by changing the distance between the lens 956 and the display panel 951.

[0311] The display device of one embodiment of the present invention can be applied to the display panel 951. Therefore, the electronic device 950 can display images with extremely high definition. This allows the user to feel a strong sense of immersion.

[0312] The cushioning member 955 is a portion that comes into contact with the user's face (forehead, cheeks, etc.). The cushioning member 955 comes into close contact with the user's face, thereby preventing light leakage and enhancing the sense of immersion. The cushioning member 955 is preferably made of a soft material so that it comes into close contact with the user's face when the user wears the electronic device 950. For example, materials such as rubber, silicone rubber, urethane, and sponge can be used. In addition, if a material such as sponge with a surface covered with cloth or leather (natural leather or synthetic leather) is used as the cushioning member 955, a gap is unlikely to occur between the user's face and the cushioning member 955, and light leakage can be suitably prevented. It is preferable that the members that come into contact with the user's skin, such as the cushioning member 955 and the mounting portion 954, are each configured to be removable, which makes cleaning and replacement easy.

[0313] Electronic device 6500 shown in FIG. 13A is a portable information terminal that can be used as a smartphone.

[0314] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508. The display portion 6502 has a touch panel function.

[0315] The display device of one embodiment of the present invention can be applied to the display portion 6502.

[0316] FIG. 13B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0317] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0318] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0319] In an area outside the display unit 6502, a part of the display panel 6511 is folded back, and the folded back part is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0320] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while suppressing the thickness of the electronic device. In addition, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0321] 14A shows an example of a television device. In a television device 7100, a display unit 7000 is incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0322] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0323] 14A can be operated using an operation switch provided on the housing 7101 and a separate remote control 7111. Alternatively, a touch sensor may be provided on the display unit 7000, and the television unit 7100 may be operated by touching the display unit 7000 with a finger or the like. The remote control 7111 may have a display unit that displays information output from the remote control 7111. Using operation keys or a touch panel provided on the remote control 7111, it is possible to operate the channel and volume, and to operate the video displayed on the display unit 7000.

[0324] The television device 7100 includes a receiver and a modem. The receiver can receive general television broadcasts. By connecting to a wired or wireless communication network via the modem, one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers) information communication can be performed.

[0325] 14B shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. A display unit 7000 is incorporated in the housing 7211.

[0326] The display device of one embodiment of the present invention can be applied to the display portion 7000.

[0327] 14C and 14D show an example of digital signage.

[0328] 14C includes a housing 7301, a display unit 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, an operation key (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0329] 14D shows a digital signage 7400 attached to a cylindrical pole 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pole 7401.

[0330] 14C and 14D, the display device of one embodiment of the present invention can be applied to the display portion 7000.

[0331] The larger the display unit 7000, the more information can be provided at one time. Also, the larger the display unit 7000, the more easily it catches people's attention, which can increase the advertising effect of, for example, advertisements.

[0332] Applying a touch panel to the display unit 7000 is preferable because it not only displays images or videos on the display unit 7000 but also allows the user to intuitively operate it. Furthermore, when used for providing information such as route information or traffic information, usability can be improved by intuitive operation.

[0333] 14C and 14D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked to an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user via wireless communication. For example, advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. Furthermore, the display on the display unit 7000 can be switched by operating the information terminal 7311 or the information terminal 7411.

[0334] In addition, a game can be executed on the digital signage 7300 or the digital signage 7400 using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller). This allows an unspecified number of users to participate in and enjoy the game at the same time.

[0335] The electronic device shown in Figures 15A to 15F has a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0336] The electronic device shown in Fig. 15A to Fig. 15F has various functions. For example, it can have a function of displaying various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date or time, a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing a program or data recorded on a recording medium, etc. The functions of the electronic device are not limited to these, and it can have various functions. The electronic device may have multiple display units. In addition, the electronic device may have a function of providing a camera or the like to capture still images and / or videos and store them on a recording medium (external or built-in to the camera), a function of displaying the captured images on the display unit, etc.

[0337] The electronic device shown in FIGS. 15A to 15F will be described in detail below.

[0338] FIG. 15A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used as, for example, a smartphone. The mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like. The mobile information terminal 9101 can display text and / or image information on a plurality of surfaces. FIG. 15A shows an example in which three icons 9050 are displayed. Information 9051 shown in a dashed rectangle can also be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming e-mail, SNS, phone calls, etc., titles of e-mail, SNS, etc., sender names, date and time, time, remaining battery power, radio wave strength, and the like. Alternatively, the icon 9050, etc. may be displayed at the position where the information 9051 is displayed.

[0339] 15B is a perspective view showing a mobile information terminal 9102. The mobile information terminal 9102 has a function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053 displayed in a position that can be observed from above the mobile information terminal 9102 while holding the mobile information terminal 9102 in a breast pocket of clothes. The user can check the display without taking the mobile information terminal 9102 out of the pocket and decide, for example, whether or not to answer a call.

[0340] FIG. 15C is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used as, for example, a smart watch. The display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. The mobile information terminal 9200 can also perform hands-free conversation by communicating with, for example, a headset capable of wireless communication. The mobile information terminal 9200 can also perform data transmission and / or charging with another information terminal through a connection terminal 9006. Note that charging may be performed by wireless power supply.

[0341] 15D to 15F are perspective views showing a foldable mobile information terminal 9201. FIG. 15D is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 15F is a perspective view of the mobile information terminal 9201 in a folded state, and FIG. 15E is a perspective view of the mobile information terminal 9201 in a state in the middle of changing from one of FIG. 15D and FIG. 15F to the other. The mobile information terminal 9201 has excellent portability in a folded state, and has excellent viewability of the display due to a seamless wide display area in an unfolded state. The display unit 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm or more and 150 mm or less.

[0342] This embodiment mode can be appropriately combined with other embodiment modes and examples. [Explanation of symbols]

[0343] ANODE: wiring, CATHODE: wiring, COM: wiring, CCMR: color conversion layer, CFR: colored layer, C1: capacitance, GL1: scanning line, GL2: scanning line, M: transistor, PIX: pixel, SL: signal line, SW21: switch, SW22: switch, 100A: display device, 100B: display device, 100C: display device, 101: substrate, 102: insulating layer, 103: insulating layer, 104: insulating layer, 110: light emitting device, 110a: light emitting diode, 110b: light emitting diode, 112: conductive film, 112a: electrode, 112b: electrode, 113: semiconductor film, 113a: semiconductor layer, 113b: semiconductor layer, 114: light emitter, 114a: light emitting layer, 114b: light emitting layer, 115: semiconductor film, 115a: semiconductor layer, 115b: semiconductor layer, 116a: conductive layer, 116b: conductive layer, 116c: conductive layer, 116d: conductive layer, 116e: conductive layer, 117a: electrode, 117b: conductive layer, 117c: electrode, 117d: conductive layer, 120a: transistor, 120b: transistor, 130a: transistor, 130b: transistor, 131: substrate, 132: element isolation layer, 133: low resistance region, 134: insulating layer, 135: conductive layer, 136: insulating layer, 137 : Conductive layer, 138: Conductive layer, 139: Insulating layer, 141: Insulating layer, 142: Conductive layer, 143: Insulating layer, 150A: LED board, 150B: Circuit board, 152: Insulating layer, 161: Conductive layer, 162: Insulating layer, 163: Insulating layer, 164: Insulating layer, 165: Metal oxide layer, 166: Conductive layer, 167: Insulating layer, 168: Conductive layer, 181: Insulating layer, 182: Insulating layer, 183: Insulating layer, 184a: Conductive layer, 184b: Conductive layer, 185: Insulating layer, 186: Insulating layer, 187: Insulating layer, 188: Insulating layer, 189: Conductive layer, 189a: Conductive layer, 189b: Conductive layer, 190a: Conductive layer , 190b: conductive layer, 190c: conductive layer, 190d: conductive layer, 191: substrate, 192: adhesive layer, 193: insulating layer, 194: insulating layer, 200: transistor, 205: conductor, 205a: conductor, 205b: conductor, 205c: conductor, 212: insulator, 214: insulator, 216: insulator, 222: insulator, 224: insulator, 230: oxide, 230a: oxide, 230b: oxide, 240: conductor, 240a: conductor, 240b: conductor, 241: insulator, 241a: insulator, 241b: insulator, 242: conductor, 242a: conductor, 242b: conductor,243: oxide, 243a: oxide, 243b: oxide, 246: conductor, 246a: conductor, 246b: conductor, 250: insulator, 250a: insulator, 250b: insulator, 260: conductor, 260a: conductor, 260b: conductor, 271: insulator, 271a: insulator, 271b: insulator, 275: insulator, 280: insulator, 282: insulator, 283: insulator, 285: insulator, 700: electronic device, 701: display panel, 702: housing, 703: optical member, 704: mounting portion, 706: display area, 707: frame ,708: nose pad, 712: reflector, 713: reflecting surface, 715: light, 716: transmitted light, 717: battery, 718: wireless power supply module, 719: touch sensor module, 720: finger, 950: electronic device, 951: display panel, 952: housing, 954: mounting part, 955: cushioning material, 956: lens, 957: input terminal, 958: output terminal, 6500: electronic device, 6501: housing, 6502: display part, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: camera, 6509: camera, 6510: camera, 6511: camera, 6512: camera, 6513: camera, 6514: camera, 6515: camera, 6516: camera, 6517: camera, 6518: camera, 6519: camera, 6520: camera, 6521: camera, 6522: camera, 6523: camera, 6524: camera, 6525: camera, 6526: camera, 6527: camera, 6528: camera, 6529: camera, 6530: camera, 6531: camera, 6532: camera, 6533: camera, 6534: camera, 6535: camera, 6536: camera, 6537: camera, 6538: camera, 6539: camera, 6540: camera, 6541: camera, 6542: camera, 6543: camera, 6544: camera, 6545: camera, 65 508: light source, 6510: protective member, 6511: display panel, 6512: optical member, 6513: touch sensor panel, 6515: FPC, 6516: IC, 6517: printed circuit board, 6518: battery, 7000: display unit, 7100: television device, 7101: housing, 7103: stand, 7111: remote control device, 7200: notebook personal computer, 7211: housing, 7212: keyboard, 7213: pointing device, 7214: external connection port, 7300: digital signage ,7301: Housing, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 9000: Housing, 9001: Display unit, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

[Claim 1] a transistor, a light emitting diode, a first conductive layer, a second conductive layer, a first insulating layer, and a second insulating layer; the transistor is electrically connected to the first conductive layer; the first conductive layer overlies the transistor; the first insulating layer overlies the transistor; the second conductive layer is located on the first conductive layer; the second insulating layer is located on the first insulating layer; the light emitting diode has a first electrode on the second insulating layer, a light emitting layer on the first electrode, and a second electrode on the light emitting layer; the second electrode is electrically connected to the second conductive layer; a height of a surface of the first conductive layer on the side of the second conductive layer is approximately equal to a height of a surface of the first insulating layer on the side of the second insulating layer, the first insulating layer and the second insulating layer are directly bonded to each other, The second conductive layer is located inside the opening of the second insulating layer and is electrically connected to the first conductive layer.

Images