Display apparatus

Abstract

To provide a display apparatus with high definition or high resolution.SOLUTION: A display apparatus includes first light emitting devices and second light emitting devices. The first light emitting devices each include a first pixel electrode, a first hole injection layer, a first hole transport layer, a first light emitting layer, a first electron transport layer, a second electron transport layer, and a common electrode, which are laminated in this order. The second light emitting devices each include a second pixel electrode, a second hole injection layer, a second hole transport layer, a second light emitting layer, a third electron transport layer, a second electron transport layer, and the common electrode, which are laminated in this order. The first light emitting devices and the second light emitting devices have the function of emitting light of different colors each other. The second electron transport layer covers a side face of the first pixel electrode, a side face of the second pixel electrode, a side face of the first light emitting layer, and a side face of the second light emitting layer, at least.SELECTED DRAWING: Figure 1

Description

Technical Field

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

[0002] Note that one aspect of the present invention is not limited to the above technical field. Examples of the technical field of one aspect of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices (e.g., touch sensors, etc.), input / output devices (e.g., touch panels, etc.), their driving methods, or their manufacturing methods.

Background Art

[0003] In recent years, display devices are expected to be applied to various uses. For example, as uses of large display devices, there are home television sets (also referred to as TVs or television receivers), digital signage, and PIDs (Public Information Displays), etc. In addition, as portable information terminals, the development of smartphones and tablet terminals equipped with touch panels is in progress.

[0004] In addition, higher definition of display devices is required. As devices that require high-definition display devices, for example, devices for virtual reality (VR: Virtual Reality), augmented reality (AR: Augmented Reality), substitutional reality (SR: Substitutional Reality), and mixed reality (MR: Mixed Reality) are being actively developed.

[0005] As a display device, for example, a light-emitting device (also referred to as a light-emitting element) having a light-emitting device has been developed. A light-emitting device (also referred to as an EL device or an EL element) that utilizes the electroluminescence (hereinafter referred to as EL) phenomenon has characteristics such as being easily thinned and lightened, being able to respond quickly to an input signal, and being drivable using a DC constant voltage power supply, and is applied to display devices.

[0006] Patent Document 1 discloses a display device for VR using an organic EL device (also referred to as an organic EL element).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] When manufacturing a display device having a plurality of organic EL devices with different emission colors in the light-emitting layer, it is necessary to form the light-emitting layers with different emission colors in an island shape respectively.

[0009] For example, an island-shaped light-emitting layer can be formed by a vacuum deposition method using a metal mask (also referred to as a shadow mask). However, during deposition, the contour of the layer may be blurred and the thickness at the end may become thin. That is, the thickness of the island-shaped light-emitting layer may vary depending on the location. In addition, when manufacturing a large-sized, high-resolution, or high-definition display device, there is a concern that the manufacturing yield may be reduced due to the low dimensional accuracy of the metal mask and deformation due to heat or the like.

[0010] In addition, when manufacturing a display device using a metal mask in a vacuum evaporation method, there is a problem that a plurality of lines of manufacturing equipment are required. For example, since it is necessary to periodically clean the metal mask, it is necessary to prepare at least two or more lines of manufacturing equipment, and it is necessary to use the other manufacturing equipment while one manufacturing equipment is being maintained. Considering mass production, a plurality of lines of manufacturing equipment are required. Therefore, there is a problem that the initial investment for introducing the manufacturing equipment becomes extremely large.

[0011] One aspect of the present invention is to provide a method for manufacturing a high-definition display device as one of the problems. One aspect of the present invention is to provide a method for manufacturing a high-resolution display device as one of the problems. One aspect of the present invention is to provide a method for manufacturing a large-sized display device as one of the problems. One aspect of the present invention is to provide a method for manufacturing a highly reliable display device as one of the problems. One aspect of the present invention is to provide a method for manufacturing a display device with a high yield as one of the problems.

[0012] One aspect of the present invention is to provide a high-definition display device as one of the problems. One aspect of the present invention is to provide a high-resolution display device as one of the problems. One aspect of the present invention is to provide a large-sized display device as one of the problems. One aspect of the present invention is to provide a highly reliable display device as one of the problems.

[0013] Note that the description of these problems does not prevent the existence of other problems. One aspect of the present invention does not necessarily need to solve all of these problems. It is possible to extract other problems from the description of the specification, drawings, and claims.

Means for Solving the Problems

[0014] One aspect of the present invention is a display device having a first light-emitting device and a second light-emitting device. The first light-emitting device includes a first pixel electrode, a first hole injection layer on the first pixel electrode, a first hole transport layer on the first hole injection layer, a first light-emitting layer on the first hole transport layer, a first electron transport layer on the first light-emitting layer, a second electron transport layer on the first electron transport layer, an electron injection layer on the second electron transport layer, and a common electrode on the electron injection layer. The second light-emitting device includes a second pixel electrode, a second hole injection layer on the second pixel electrode, a second hole transport layer on the second hole injection layer, a second light-emitting layer on the second hole transport layer, a third electron transport layer on the second light-emitting layer, a second electron transport layer on the third electron transport layer, an electron injection layer on the second electron transport layer, and a common electrode on the electron injection layer. The first light-emitting device and the second light-emitting device have functions of emitting lights of different colors. The second electron transport layer covers at least the side surfaces of the first pixel electrode, the second pixel electrode, the first light-emitting layer, and the second light-emitting layer.

[0015] Preferably, the above display device has a protective layer on the common electrode.

[0016] The first light-emitting device and the second light-emitting device are preferably provided on an insulating layer. The insulating layer may have a recess. The second electron transport layer may be in contact with the recess.

[0017] There may be a gap between the second electron transport layer and the electron injection layer. Alternatively, there may be an insulator between the second electron transport layer and the electron injection layer.

[0018] One aspect of the present invention is a display module having a display device with any of the above configurations, to which a connector such as a Flexible Printed Circuit (hereinafter referred to as FPC) or a TCP (Tape Carrier Package) is attached, or a display module such as a display module in which an integrated circuit (IC) is mounted by a COG (Chip On Glass) method or a COF (Chip On Film) method.

[0019] One aspect of the present invention is an electronic device having the above display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0020] One aspect of the present invention is to form an insulating layer, form a conductive film on the insulating layer, form a first hole injection layer on the conductive film, form a first hole transport layer on the first hole injection layer, form a first light-emitting layer on the first hole transport layer, form a first electron transport layer on the first light-emitting layer, form a first sacrificial layer on the first electron transport layer, process the first hole injection layer, the first hole transport layer, the first light-emitting layer, the first electron transport layer, and the first sacrificial layer to expose a part of the conductive film, form a second hole injection layer on the first sacrificial layer and the conductive film, form a second hole transport layer on the second hole injection layer, form a second light-emitting layer on the second hole transport layer, form a second electron transport layer on the second light-emitting layer, form a second sacrificial layer on the second electron transport layer, process the second hole injection layer, the second hole transport layer, the second light-emitting layer, the second electron transport layer, and the second sacrificial layer to expose a part of the conductive film, and use the first sacrificial layer and the second sacrificial layer as a hard mask to process the conductive film, thereby forming a first pixel electrode overlapping the first sacrificial layer and a second pixel electrode overlapping the second sacrificial layer, removing the first sacrificial layer and the second sacrificial layer, forming a third electron transport layer on the first electron transport layer and the second electron transport layer, forming an electron injection layer on the third electron transport layer, and forming a common electrode on the electron injection layer, which is a method for manufacturing a display device.

[0021] Furthermore, it is preferable to form a protective layer on the common electrode.

[0022] In the method for manufacturing the above display device, the third electron transport layer is preferably provided so as to cover at least the side surfaces of the first pixel electrode, the side surfaces of the second pixel electrode, the side surfaces of the first light-emitting layer, and the side surfaces of the second light-emitting layer.

[0023] In the method for manufacturing the above display device, before forming the electron injection layer, the recesses of the third electron transport layer may be filled with an insulating material.

[0024] In the processing step of the conductive film, recesses may be formed in the insulating layer.

Advantages of the Invention

[0025] According to one aspect of the present invention, a method for manufacturing a high-definition display device can be provided. According to one aspect of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one aspect of the present invention, a method for manufacturing a large-sized display device can be provided. According to one aspect of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one aspect of the present invention, a method for manufacturing a high-yield display device can be provided.

[0026] According to one aspect of the present invention, a high-definition display device can be provided. According to one aspect of the present invention, a high-resolution display device can be provided. According to one aspect of the present invention, a large-sized display device can be provided. According to one aspect of the present invention, a highly reliable display device can be provided.

[0027] Note that the description of these effects does not prevent the existence of other effects. One aspect of the present invention does not necessarily have to have all of these effects. It is possible to extract other effects from the description of the specification, drawings, and claims.

Brief Description of the Drawings

[0028]

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[0029] 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 forms and details thereof can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below.

[0030] In the configuration of the invention described below, the same reference numerals are commonly used among different drawings for the same parts or parts having the same functions, and the repeated description thereof will be omitted. Also, when referring to the same function, the hatch patterns may be the same, and there may be cases where no particular reference numerals are attached.

[0031] In addition, the positions, sizes, ranges, etc. of the respective components shown in the drawings may not represent the actual positions, sizes, ranges, etc. for the sake of simplicity of understanding. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, ranges, etc. disclosed in the drawings.

[0032] In the present specification and the like, ordinal numbers such as "first" and "second" are used for convenience and do not limit the number of components or the order of components (for example, the process order or the stacking order). Also, the ordinal numbers attached to components in one part of the present specification may not match the ordinal numbers attached to the same components in other parts of the present specification or in the claims. Further, the terms "film" and "layer" can be interchanged with each other depending on the case or the 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".

[0033] In the present specification and the like, a device manufactured using a metal mask or an FMM (fine metal mask, high-definition metal mask) may be referred to as a device having an MM (metal mask) structure. Also, in the present specification and the like, a device manufactured without using a metal mask or an FMM may be referred to as a device having an MML (metal maskless) structure.

[0034] (Embodiment 1) In this embodiment, a display device and a manufacturing method thereof according to one aspect of the present invention will be described with reference to FIGS. 1 to 7.

[0035] In the method of manufacturing a display device according to an aspect of the present invention, a conductive film is formed, and after forming a first layer (which can be an EL layer or a part of the EL layer) including a light-emitting layer that emits light of a first color on one surface, a first sacrificial layer is formed on the first layer. Then, a first resist mask is formed on the first sacrificial layer, and by processing the first layer and the first sacrificial layer using the first resist mask, an island-shaped first layer is formed. Subsequently, in the same manner as the first layer, a second layer (which can be an EL layer or a part of the EL layer) including a light-emitting layer that emits light of a second color is formed in an island shape using a second sacrificial layer and a second resist mask.

[0036] Thus, in the method of manufacturing a display device according to an aspect of the present invention, the island-shaped EL layer is not formed using a fine metal mask, but is formed by processing after depositing the EL layer on one surface. Therefore, the island-shaped EL layer can be formed with a uniform thickness. Also, by providing a sacrificial layer on the EL layer, the damage received by the EL layer during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0037] After forming the EL layers that emit light of each color, the sacrificial layer remaining on each EL layer can be used as a hard mask to process the above-mentioned conductive film, thereby forming pixel electrodes. Since there is no need to separately provide a mask for forming the pixel electrodes in an island shape, the manufacturing cost of the display device can be reduced. Also, since there is no need to provide an insulating layer that covers the ends of the pixel electrodes between the pixel electrodes and the EL layer, the interval between adjacent light-emitting devices can be made extremely narrow. Therefore, high definition or high resolution of the display device can be achieved.

[0038] Here, the first layer and the second layer each contain at least a light-emitting layer and preferably consist of a plurality of layers. Specifically, it is preferable to have one or more layers on the light-emitting layer. By having other layers between the light-emitting layer and the sacrificial layer, it is possible to suppress the light-emitting layer from being exposed on the outermost surface during the manufacturing process of the display device and reduce the damage received by the light-emitting layer. Thereby, the reliability of the light-emitting device can be enhanced. Therefore, the first layer and the second layer each preferably have a light-emitting layer and a carrier transport layer on the light-emitting layer.

[0039] In addition, in a light-emitting device that emits light of different colors respectively, it is not necessary to separately fabricate all the layers constituting the EL layer, and some layers can be formed in the same process. In the method for manufacturing a display device according to one aspect of the present invention, after forming some of the layers constituting the EL layer in an island shape for each color, the sacrificial layer is removed, and the remaining layers constituting the EL layer and the common electrode (which can also be referred to as the upper electrode) are formed in common for each color light-emitting device. For example, the carrier injection layer and the common electrode can be formed in common for each color light-emitting device. On the other hand, the carrier injection layer is often a layer with relatively high conductivity among the EL layers. Therefore, there is a risk that the light-emitting device may short-circuit when the carrier injection layer contacts the side surface of some of the layers of the EL layer formed in an island shape or the side surface of the pixel electrode. In addition, even when the carrier injection layer is provided in an island shape and the common electrode is formed in common for each color light-emitting device, there is a risk that the light-emitting device may short-circuit when the common electrode contacts the side surface of the EL layer or the side surface of the pixel electrode.

[0040] Therefore, a display device according to one aspect of the present invention has two layers, namely, an island-shaped first carrier transport layer and a second carrier transport layer provided in common for each color light-emitting device, between the island-shaped light-emitting layer and the carrier injection layer provided in common for each color light-emitting device.

[0041] Thereby, it is possible to suppress some of the layers of the EL layer formed in an island shape and the pixel electrode from contacting the carrier injection layer. Therefore, short-circuiting of the light-emitting device can be suppressed, and the reliability of the light-emitting device can be enhanced.

[0042] A display device according to an aspect of the present invention includes a pixel electrode that functions as an anode, a hole injection layer, a hole transport layer, a light-emitting layer, and a first electron transport layer, each of which is island-shaped and provided in this order on the pixel electrode, and a second electron transport layer provided so as to cover the pixel electrode, the hole injection layer, the hole transport layer, the light-emitting layer, and the first electron transport layer, an electron injection layer provided on the second electron transport layer, and a common electrode provided on the electron injection layer and functioning as a cathode.

[0043] Alternatively, a display device according to an aspect of the present invention includes a pixel electrode that functions as a cathode, an electron injection layer, an electron transport layer, a light-emitting layer, and a first hole transport layer, each of which is island-shaped and provided in this order on the pixel electrode, a second hole transport layer provided so as to cover the pixel electrode, the electron injection layer, the electron transport layer, the light-emitting layer, and the first hole transport layer, a hole injection layer provided on the second hole transport layer, and a common electrode provided on the hole injection layer and functioning as an anode.

[0044] With such a configuration, a display device with high fineness or resolution and high reliability can be manufactured.

[0045] [Configuration Example of Display Device] FIGS. 1A and 1B show a display device according to an aspect of the present invention.

[0046] FIG. 1A shows a top view of the display device 100. The display device 100 includes a display unit in which a plurality of pixels 110 are arranged in a matrix, and a connection unit 140 outside the display unit. One pixel 110 is composed of three sub-pixels, namely sub-pixels 110a, 110b, and 110c. The connection unit 140 can also be called a cathode contact unit.

[0047] The top surface shape of the sub-pixel shown in FIG. 1A corresponds to the top surface shape of the light-emitting region.

[0048] In addition, the circuit layout constituting the sub-pixels is not limited to the range of the sub-pixels shown in FIG. 1A, and may be arranged outside thereof. For example, the transistors included in the sub-pixel 110a may be located within the range of the sub-pixel 110b shown in FIG. 1A, or part or all of them may be located outside the range of the sub-pixel 110a.

[0049] In FIG. 1A, the aperture ratios (which can also be said to be the sizes, the sizes of the light-emitting regions) of the sub-pixels 110a, 110b, and 110c are shown to be equal or approximately equal, but one aspect of the present invention is not limited thereto. The aperture ratios of the sub-pixels 110a, 110b, and 110c can be determined as appropriate respectively. The aperture ratios of the sub-pixels 110a, 110b, and 110c may be different from each other, or two or more of them may be equal or approximately equal.

[0050] In FIG. 1A, an example is shown in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may be arranged side by side in the Y direction, and sub-pixels of the same color may be arranged side by side in the X direction.

[0051] In FIG. 1A, an example is shown in which the connection portion 140 is located below the display portion in a top view, but it is not particularly limited. The connection portion 140 may be provided at at least one of the upper side, the right side, the left side, and the lower side of the display portion in a top view, or may be provided so as to surround the four sides of the display portion.

[0052] FIG. 1B shows a cross-sectional view between the dashed-dotted line X1-X2 in FIG. 1A.

[0053] As shown in FIG. 1B, in the display device 100, light-emitting devices 130a, 130b, and 130c are provided on a layer 101 including transistors, and protective layers 131 and 132 are provided so as to cover these light-emitting devices. A substrate 120 is bonded to the protective layer 132 by a resin layer 119.

[0054] The display device according to one aspect of the present invention may be a top emission type that emits light in a direction opposite to the substrate on which the light-emitting device is formed, a bottom emission type that emits light toward the substrate side on which the light-emitting device is formed, or a dual emission type that emits light from both sides.

[0055] For the layer 101 including transistors, for example, a stacked structure in which a plurality of transistors are provided on a substrate and an insulating layer is provided so as to cover these transistors can be applied. The layer 101 including transistors may have a recess between adjacent light-emitting devices. For example, a recess may be provided in the insulating layer located on the outermost surface of the layer 101 including transistors. A configuration example of the layer 101 including transistors will be described later in Embodiment 2.

[0056] The light-emitting devices 130a, 130b, and 130c each emit light of a different color. The light-emitting devices 130a, 130b, and 130c are preferably a combination that emits light of three colors, for example, red (R), green (G), and blue (B).

[0057] The light-emitting device has an EL layer between a pair of electrodes. In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other may be referred to as a common electrode.

[0058] Of the pair of electrodes of the light-emitting device, one electrode functions as an anode, and the other electrode functions as a cathode. Hereinafter, a case where the pixel electrode functions as an anode and the common electrode functions as a cathode will be described as an example.

[0059] The light-emitting device 130a includes a pixel electrode 111a on a layer 101 containing a transistor, an island-shaped first layer 113a on the pixel electrode 111a, a fourth electron transport layer 116 covering the upper surface and side surfaces of the island-shaped first layer 113a, an electron injection layer 114 on the fourth electron transport layer 116, and a common electrode 115 on the electron injection layer 114. The first layer 113a includes a first hole injection layer 181a on the pixel electrode 111a, a first hole transport layer 182a on the first hole injection layer 181a, a first light-emitting layer 183a on the first hole transport layer 182a, and a first electron transport layer 184a on the first light-emitting layer 183a. In the light-emitting device 130a, the first layer 113a, the fourth electron transport layer 116, and the electron injection layer 114 can be collectively referred to as an EL layer.

[0060] The light-emitting device 130b includes a pixel electrode 111b on a layer 101 containing a transistor, an island-shaped second layer 113b on the pixel electrode 111b, a fourth electron transport layer 116 covering the upper surface and side surfaces of the island-shaped second layer 113b, an electron injection layer 114 on the fourth electron transport layer 116, and a common electrode 115 on the electron injection layer 114. The second layer 113b includes a second hole injection layer 181b on the pixel electrode 111b, a second hole transport layer 182b on the second hole injection layer 181b, a second light-emitting layer 183b on the second hole transport layer 182b, and a second electron transport layer 184b on the second light-emitting layer 183b. In the light-emitting device 130b, the second layer 113b, the fourth electron transport layer 116, and the electron injection layer 114 can be collectively referred to as an EL layer.

[0061] The light-emitting device 130c includes a pixel electrode 111c on a layer 101 including a transistor, an island-shaped third layer 113c on the pixel electrode 111c, a fourth electron transport layer 116 covering the upper surface and side surfaces of the island-shaped third layer 113c, an electron injection layer 114 on the fourth electron transport layer 116, and a common electrode 115 on the electron injection layer 114. The third layer 113c includes a third hole injection layer 181c on the pixel electrode 111c, a third hole transport layer 182c on the third hole injection layer 181c, a third light-emitting layer 183c on the third hole transport layer 182c, and a third electron transport layer 184c on the third light-emitting layer 183c. In the light-emitting device 130c, the third layer 113c, the fourth electron transport layer 116, and the electron injection layer 114 can be collectively referred to as an EL layer.

[0062] The common electrode shared by the light-emitting devices of each color is electrically connected to a conductive layer provided in the connection portion 140.

[0063] Among the pixel electrode and the common electrode, a conductive film that transmits visible light is used for the electrode on the side where light is extracted. Further, it is preferable to use a conductive film that reflects visible light for the electrode on the side where light is not extracted.

[0064] As materials for forming a pair of electrodes (a pixel electrode and a common electrode) of a light-emitting device, metals, alloys, electroconductive compounds, and mixtures thereof can be appropriately used. Specifically, indium tin oxide (also referred to as In-Sn oxide or ITO), In-Si-Sn oxide (also referred to as ITSO), indium zinc oxide (In-Zn oxide), In-W-Zn oxide, alloys containing aluminum such as an alloy of aluminum, nickel, and lanthanum (Al-Ni-La), and an alloy of silver, palladium, and copper (also denoted as Ag-Pd-Cu or APC) can be mentioned. In addition, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these in appropriate combinations can also be used. In addition, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these in appropriate combinations, graphene, etc. can be used.

[0065] It is preferable that a microcavity structure is applied to the light-emitting device. Therefore, one of the pair of electrodes that the light-emitting device has preferably has an electrode (semi-transmissive and semi-reflective electrode) having transmissivity and reflectivity with respect to visible light, and the other preferably has an electrode (reflective electrode) having reflectivity with respect to visible light. By having a microcavity structure in the light-emitting device, the light emitted from the light-emitting layer can be resonated between the two electrodes, and the light emitted from the light-emitting device can be enhanced.

[0066] Note that the semi-transmissive and semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having transmissivity with respect to visible light (also referred to as a transparent electrode).

[0067] The light transmittance of the transparent electrode shall be 40% or more. For example, for a light-emitting device, it is preferable to use an electrode with a light transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The reflectance of visible light of the semi-transmissive / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of visible light of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. Also, the resistivity of these electrodes is preferably -2 1×10 Ωcm or less.

[0068] The first layer 113a, the second layer 113b, and the third layer 113c are each provided in an island shape. The first layer 113a, the second layer 113b, and the third layer 113c each have a light-emitting layer. Preferably, the first layer 113a, the second layer 113b, and the third layer 113c each have a light-emitting layer that emits light of a different color.

[0069] The light-emitting layer is a layer containing a light-emitting substance. The light-emitting layer can have one or more light-emitting substances. As the light-emitting substance, substances exhibiting light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red are appropriately used. Also, as the light-emitting substance, a substance that emits near-infrared light can be used.

[0070] Examples of the light-emitting substance include a fluorescent material, a phosphorescent material, a thermally activated delayed fluorescence (TADF) material, and a quantum dot material.

[0071] Examples of the fluorescent material include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0072] Examples of the phosphorescent material include an organometallic complex (especially an iridium complex) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton, an organometallic complex (especially an iridium complex) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, a platinum complex, a rare earth metal complex, and the like.

[0073] In addition to the light-emitting substance (guest material), the light-emitting layer may contain one or more organic compounds (host material, assist material, etc.). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Further, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0074] The light-emitting layer preferably has, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material which are a combination likely to form an exciplex. By adopting such a configuration, light emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the exciplex to the light-emitting substance (phosphorescent material), can be efficiently obtained. By selecting a combination that forms an exciplex that exhibits light emission overlapping with the wavelength of the absorption band on the lowest energy side of the light-emitting substance, energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, high efficiency, low-voltage driving, and long life of the light-emitting device can be achieved simultaneously.

[0075] As layers other than the light-emitting layer, the first layer 113a, the second layer 113b, and the third layer 113c may further have a layer containing a substance with high hole injection property, a substance with high hole transport property, a hole blocking material, a substance with high electron transport property, a substance with high electron injection property, an electron blocking material, or a bipolar substance (a substance with high electron transport property and high hole transport property).

[0076] The light-emitting device can use either a low-molecular compound or a high-molecular compound, and may contain an inorganic compound. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer method, printing method, inkjet method, coating method, etc.

[0077] For example, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0078] Among the EL layers, as the layers commonly formed in the light-emitting devices of each color, one or more of a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer can be applied.

[0079] In the display device 100 shown in FIG. 1B, the first layer 113a has a first light-emitting layer 183a and a first electron transport layer 184a on the first light-emitting layer 183a. Similarly, the second layer 113b has a second light-emitting layer 183b and a second electron transport layer 184b on the second light-emitting layer 183b, and the third layer 113c has a third light-emitting layer 183c and a third electron transport layer 184c on the third light-emitting layer 183c. Thereby, during the manufacturing process of the display device 100, it is possible to suppress the light-emitting layer from being exposed on the outermost surface and reduce the damage received by the light-emitting layer. Thereby, the reliability of the light-emitting device can be enhanced.

[0080] The first layer 113a, the second layer 113b, and the third layer 113c are covered by a fourth electron transport layer 116, and an electron injection layer 114 and a common electrode 115 are provided on the fourth electron transport layer 116. Thereby, it is possible to suppress the electron injection layer 114 or the common electrode 115 from contacting the side surface of any of the pixel electrodes 111a, 111b, 111c, and the first layer 113a, the second layer 113b, and the third layer 113c, and suppress a short circuit of the light-emitting device.

[0081] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection properties. Examples of materials with high hole injection properties include aromatic amine compounds and composite materials containing a hole transport material and an acceptor material (electron-accepting material).

[0082] The hole transport layer is a layer that transports the holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as the substance has higher hole transportability than electrons, other substances can also be used. As the hole transport material, hole transport materials with high hole transportability such as π-electron excess type heteroaromatic compounds (for example, carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton) are preferable.

[0083] The electron transport layer is a layer that transports the electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron transport material. As the electron transport material, a substance having an electron mobility of 1×10 -6 cm 2 / Vs or more is preferable. In addition, as long as the substance has higher electron transportability than holes, other substances can also be used. As the electron transport material, metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, etc., as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds, etc., can be used as electron transport materials with high electron transportability.

[0084] The electron injection layer is a layer that injects electrons from the cathode into the electron transport layer and is a layer containing a material with high electron injection properties. As materials with high electron injection properties, alkali metals, alkaline earth metals, or their compounds can be used. As materials with high electron injection properties, composite materials containing an electron transport material and a donor material (electron-donating material) can also be used.

[0085] As the electron injection layer, for example, lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolato lithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolato lithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolato lithium (abbreviation: LiPPP), lithium oxide (LiO x ), cesium carbonate, etc., such alkali metals, alkaline earth metals, or their compounds can be used.

[0086] Alternatively, as the electron injection layer, an electron transport material may be used. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring can be used as the electron transport material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used.

[0087] Note that it is preferable that the lowest unoccupied molecular orbital (LUMO) of the organic compound having an unshared electron pair is -3.6 eV or more and -2.3 eV or less. Also, generally, the highest occupied molecular orbital (HOMO) level and LUMO level of the organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, etc.

[0088] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3’-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used for organic compounds having lone pairs. Note that NBPhen has a higher glass transition temperature (Tg) compared to BPhen and is excellent in heat resistance.

[0089] It is preferable that the light-emitting devices 130a, 130b, and 130c have the protective layers 131 and 132. By providing the protective layers 131 and 132, the reliability of the light-emitting device can be enhanced.

[0090] The conductivity of the protective layers 131 and 132 does not matter. As the protective layers 131 and 132, at least one of an insulating film, a semiconductor film, and a conductive film can be used.

[0091] By the protective layers 131 and 132 having an inorganic film, oxidation of the common electrode 115 is prevented, entry of impurities (such as moisture and oxygen) into the light-emitting devices 130a, 130b, and 130c is suppressed, etc., deterioration of the light-emitting device is suppressed, and the reliability of the display device can be enhanced.

[0092] For the protective layers 131 and 132, for example, inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitroxide insulating film can be used. Examples of the oxide insulating film include a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, a yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of the nitride insulating film include a silicon nitride film and an aluminum nitride film. Examples of the oxynitride insulating film include a silicon oxynitride film and an aluminum oxynitride film. Examples of the nitroxide insulating film include a silicon nitroxide film and an aluminum nitroxide film.

[0093] In addition, in this specification and the like, an oxynitride refers to a material having a higher oxygen content than nitrogen in its composition, and a nitride oxide refers to a material having a higher nitrogen content than oxygen in its composition.

[0094] The protective layers 131 and 132 preferably each have a nitride insulating film or a nitride oxide insulating film, and more preferably have a nitride insulating film.

[0095] Further, an inorganic film containing indium-tin oxide (also referred to as ITO), indium-zinc oxide, gallium-zinc oxide, aluminum-zinc oxide, or indium gallium zinc oxide (also referred to as In-Ga-Zn oxide, IGZO) can also be used for the protective layers 131 and 132. The inorganic film is preferably highly resistive, specifically, preferably more resistive than the common electrode 115. The inorganic film may further contain nitrogen.

[0096] When extracting the light emission of the light-emitting device through the protective layers 131 and 132, the protective layers 131 and 132 preferably have high transmittance to visible light. For example, ITO, IGZO, and aluminum oxide are each preferred because they are inorganic materials with high transmittance to visible light.

[0097] As the protective layers 131 and 132, for example, a laminated structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used. By using the laminated structure, it is possible to suppress the entry of impurities (such as water and oxygen) into the EL layer side.

[0098] Furthermore, the protective layers 131 and 132 may have an organic film. For example, the protective layer 132 may have both an organic film and an inorganic film.

[0099] Different film formation methods may be used for the protective layer 131 and the protective layer 132. Specifically, the protective layer 131 may be formed using the atomic layer deposition (ALD) method, and the protective layer 132 may be formed using the sputtering method.

[0100] The respective ends of the pixel electrodes 111a, 111b, and 111c are not covered by the insulating layer. Therefore, the interval between adjacent light-emitting devices can be made extremely narrow. Accordingly, a high-definition or high-resolution display device can be achieved.

[0101] In the display device of the present embodiment, light-emitting layers of different colors are provided in an island shape for each light-emitting device, and are manufactured by a so-called painting method (SBS (Side By Side) method). Therefore, a display device with high light extraction efficiency can be realized as compared with a configuration in which a white light-emitting device and a color filter are combined. In addition, since a light-emitting device having a single structure can be applied, a display device with a low driving voltage can be realized as compared with a configuration using a tandem structure light-emitting device. Further, by adopting the SBS method, a display device with low power consumption can be realized as compared with a configuration in which a white light-emitting device and a color filter are combined, and a configuration using a tandem structure light-emitting device.

[0102] The display device of the present embodiment can narrow the distance between the light-emitting devices. Specifically, the distance between the light-emitting devices can be 1 μm or less, preferably 500 nm or less, more preferably 200 nm or less, 100 nm or less, 90 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. In other words, it has a region where the interval between the side surface of the first layer 113a and the side surface of the second layer 113b, or the interval between the side surface of the second layer 113b and the side surface of the third layer 113c is 1 μm or less, preferably a region of 0.5 μm (500 nm) or less, and more preferably a region of 100 nm or less.

[0103] A light-shielding layer may be provided on the surface of the substrate 120 on the resin layer 119 side. In addition, various optical members can be arranged outside the substrate 120. Examples of the optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an antireflection layer, and a condensing film. Further, outside the substrate 120, an antistatic film for suppressing dust adhesion, a water-repellent film that is less likely to adhere dirt, a hard coat film for suppressing the occurrence of scratches during use, an impact absorption layer, etc. may be arranged.

[0104] For the substrate 120, glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, etc. can be used. For the substrate on the side of extracting light from the light-emitting device, a material that transmits the light is used. When a flexible material is used for the substrate 120, the flexibility of the display device can be enhanced, and a flexible display can be realized. Further, a polarizing plate may be used as the substrate 120.

[0105] As the substrate 120, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. can be used. Glass having a thickness that provides flexibility may be used for the substrate 120.

[0106] When a circular polarizing plate is overlaid on the display device, it is preferable to use a substrate having high optical isotropy for the substrate of the display device. A substrate having high optical isotropy has small birefringence (it can also be said that the birefringence amount is small).

[0107] The absolute value of the retardation (phase difference) value of the substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0108] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also known as cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic films.

[0109] Also, when using a film as a substrate, there is a risk of shape changes such as wrinkles occurring in the display panel due to the film absorbing water. Therefore, it is preferable to use a film with a low water absorption rate for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

[0110] As the resin layer 119, various curable adhesives such as photocurable adhesives such as ultraviolet curable types, reaction curable adhesives, thermosetting adhesives, and anaerobic adhesives can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. In particular, materials with low moisture permeability such as epoxy resins are preferable. Also, a two-component mixed resin may be used. Also, an adhesive sheet or the like may be used.

[0111] Note that there may be a gap between the fourth electron transport layer 116 and the electron injection layer 114. FIG. 1B shows an example in which an insulator 134 is filled in a portion that can become a gap. Note that depending on the distance between adjacent light-emitting devices, the thickness of the fourth electron transport layer 116, and the thickness of the electron injection layer 114, etc., the gap may not be formed and filling with the insulator 134 may not be necessary. In this case, the space between adjacent light-emitting devices has a structure filled with at least one of the fourth electron transport layer 116 and the electron injection layer 114.

[0112] The void has, for example, any one or more selected from air, nitrogen, oxygen, carbon dioxide, and Group 18 elements (typically, helium, neon, argon, xenon, krypton, etc.). Further, the void may contain, for example, a gas used when forming the electron injection layer 114. For example, when forming the electron injection layer 114 by vacuum evaporation, the void may be in a reduced-pressure atmosphere. When the void contains a gas, the gas can be identified by gas chromatography or the like.

[0113] Further, when the refractive index of the void is lower than that of the fourth electron transport layer 116, light emitted from the first layer 113a, the second layer 113b, or the third layer 113c is reflected at the interface between the fourth electron transport layer 116 and the void. Thereby, it is possible to suppress light emitted from the first layer 113a, the second layer 113b, or the third layer 113c from entering an adjacent pixel (or sub-pixel). Thereby, since mixing of light of different colors can be suppressed, the display quality of the display device can be improved.

[0114] As the material of the insulator 134 that can be filled in the portion that can become a void, one or both of an organic insulating material and an inorganic insulating material can be used. For the insulator 134, at least one of a solid substance, a gel substance, and a liquid substance can be used.

[0115] Examples of the organic insulating material include acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimide amide resin, polysiloxane resin, benzocyclobutene-based resin, and phenol resin. Further, various resins that can be used for the resin layer 119 may be used.

[0116] Examples of the inorganic insulating material include insulating oxide materials, insulating nitride materials, oxynitride insulating materials, and nitroxide insulating materials. Further, insulating materials that can be used for the protective layers 131 and 132 may be used.

[0117] In addition to the gate, source, and drain of a transistor, materials that can be used for conductive layers such as various wirings and electrodes constituting a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys mainly composed of such metals. Films containing these materials can be used as a single layer or in a laminated structure.

[0118] In addition, as the light-transmissive conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing the metal materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) may be used. When using a metal material, an alloy material (or their nitrides), it is preferably made thin enough to have light-transmittance. Also, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, and conductive layers (conductive layers functioning as pixel electrodes or common electrodes) of a light-emitting device.

[0119] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0120] [Example of manufacturing method of display device] Next, an example of a method for manufacturing a display device will be described with reference to FIGS. 2 to 7. FIGS. 2A to 2C are top views showing the method for manufacturing the display device. FIGS. 3A to 3C show a cross-sectional view between the dashed-dotted line X1 - X2 and a cross-sectional view between Y1 - Y2 in FIG. 1A side by side. The same applies to FIGS. 4 to 7 as in FIG. 3.

[0121] The thin films (such as insulating films, semiconductor films, and conductive films) constituting the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an ALD method, or the like. As the CVD method, there are a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. Further, one of the thermal CVD methods is a metal organic chemical vapor deposition (MOCVD) method.

[0122] Also, the thin films (such as insulating films, semiconductor films, and conductive films) constituting the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, and knife coating.

[0123] In particular, for manufacturing a light-emitting device, a vacuum process such as an evaporation method and a solution process such as a spin coating method and an inkjet method can be used. Examples of the evaporation method include physical vapor deposition (PVD) methods such as a sputtering method, an ion plating method, an ion beam evaporation method, a molecular beam evaporation method, and a vacuum evaporation method, and a chemical vapor deposition (CVD) method. In particular, for the functional layers (such as a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer) included in the EL layer, it can be formed by methods such as an evaporation method (such as a vacuum evaporation method), a coating method (such as a dip coating method, a die coating method, a bar coating method, a spin coating method, and a spray coating method), and a printing method (such as an inkjet method, a screen (stencil printing) method, an offset (lithographic printing) method, a flexo (letterpress printing) method, a gravure method, or a microcontact method).

[0124] In addition, when processing the thin film constituting the display device, a photolithography method or the like can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Further, an island-shaped thin film may be directly formed by a film forming method using a shielding mask such as a metal mask.

[0125] Typically, there are the following two methods as the photolithography method. One is a method of forming a resist mask on a thin film to be processed, processing the thin film by etching or the like, and removing the resist mask. The other is a method of forming a photosensitive thin film and then performing exposure and development to process the thin film into a desired shape.

[0126] In the photolithography method, as the light used for exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these can be used. In addition, ultraviolet light, KrF laser light, ArF laser light, or the like can also be used. Further, exposure may be performed by a liquid immersion exposure technique. In addition, as the light used for exposure, extreme ultraviolet (EUV) light or X-rays may be used. Instead of the light used for exposure, an electron beam can also be used. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because extremely fine processing becomes possible. Note that when exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0127] For the etching of the thin film, a dry etching method, a wet etching method, a sandblasting method, or the like can be used.

[0128] First, as shown in FIG. 3A, a conductive film 111 is formed on a layer 101 including a transistor.

[0129] Then, a first hole injection layer 181A, a first hole transport layer 182A, a first light-emitting layer 183A, and a first electron transport layer 184A are formed on the conductive film 111 in this order, and a first sacrificial layer 118A is formed on the first electron transport layer 184A. As shown in FIG. 3A, in the cross-sectional view between Y1 - Y2, the end portions of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A on the connection portion 140 side are located inside the end portion of the first sacrificial layer 118A. For example, by using a mask for defining the film-forming area (also referred to as an area mask or a rough metal mask, etc., distinguished from a fine metal mask), the film-forming areas of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A and the first sacrificial layer 118A can be changed. In one aspect of the present invention, a light-emitting device is formed using a resist mask, but by combining it with the area mask as described above, a light-emitting device can be manufactured by a relatively simple process.

[0130] The conductive film 111 becomes the pixel electrodes 111a, 111b, 111c and the layer that becomes the conductive layer 123 by being processed later. Therefore, the configurations applicable to the above-described pixel electrodes can be applied to the conductive film 111. For forming the conductive film 111, for example, a sputtering method or a vacuum evaporation method can be used.

[0131] The first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A are each a layer that will later become the first hole injection layer 181a, the first hole transport layer 182a, the first light-emitting layer 183a, and the first electron transport layer 184a. Therefore, the configurations applicable to the above-described first hole injection layer 181a, first hole transport layer 182a, first light-emitting layer 183a, and first electron transport layer 184a can be applied respectively. The first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A can each be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method. Further, the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A may each be formed using a premix material.

[0132] For the first sacrificial layer 118A, a film with high resistance to processing conditions such as the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, the first electron transport layer 184A, and the second hole injection layer 181B, the second hole transport layer 182B, the second light-emitting layer 183B, the second electron transport layer 184B, the third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, and the third electron transport layer 184C formed in subsequent processes is used. Specifically, a film with a large etching selectivity ratio is used. The first sacrificial layer 118A may have a single-layer structure or a laminated structure.

[0133] For the formation of the first sacrificial layer 118A, for example, a sputtering method, an ALD method (including a thermal ALD method and a PEALD method), or a vacuum vapor deposition method can be used. Note that a formation method with less damage to the EL layer is preferable, and it is preferable to form the first sacrificial layer 118A using the ALD method or the vacuum vapor deposition method rather than the sputtering method.

[0134] For the first sacrificial layer 118A, it is preferable to use a film that can be removed by a wet etching method. By using the wet etching method, compared with the case of using a dry etching method, damage to the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A during the processing of the first sacrificial layer 118A can be reduced.

[0135] In the processing steps of various sacrificial layers in the manufacturing method of the display device of the present embodiment, it is desirable that each layer (such as a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer) constituting the EL layer is difficult to process, and in the processing steps of each layer constituting the EL layer, it is desirable that various sacrificial layers are difficult to process. Regarding the material of the sacrificial layer, the processing method, and the processing method of the EL layer, it is desirable to select them in consideration of these.

[0136] As the first sacrificial layer 118A, for example, an inorganic film such as a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic insulating film can be used.

[0137] For the first sacrificial layer 118A, for example, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or an alloy material containing the metal material can be used.

[0138] In addition, a metal oxide such as In-Ga-Zn oxide can be used for the first sacrificial layer 118A. As the first sacrificial layer 118A, for example, an In-Ga-Zn oxide film can be formed by using a sputtering method. Furthermore, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Or indium tin oxide containing silicon can also be used.

[0139] In addition, instead of the above-mentioned gallium, an element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used.

[0140] Also, as the first sacrificial layer 118A, various inorganic insulating films that can be used for the protective layers 131 and 132 can be used. In particular, an oxide insulating film is preferable because it has a higher adhesion to the EL layer than a nitride insulating film. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the first sacrificial layer 118A. As the first sacrificial layer 118A, for example, an aluminum oxide film can be formed using the ALD method. Using the ALD method is preferable because it can reduce damage to the substrate (especially the EL layer, etc.).

[0141] Next, as shown in FIG. 3B, a resist mask 190a is formed on the first sacrificial layer 118A. The resist mask can be formed by applying a photosensitive resin (photoresist) and performing exposure and development.

[0142] As shown in FIG. 2A, the resist mask 190a is provided at a position overlapping the region that will later become the sub-pixel 110a. Furthermore, it is preferable that the resist mask 190a is also provided at a position overlapping the region that will later become the connection portion 140. Thereby, it is possible to suppress the region of the conductive film 111 that will later become the conductive layer 123 from being damaged during the manufacturing process of the display device. As the resist mask 190a, it is preferable that one island-shaped pattern is provided for one sub-pixel 110a. Alternatively, as the resist mask 190a, one strip-shaped pattern may be formed for a plurality of sub-pixels 110a arranged in a row (arranged in the Y direction in FIG. 2A).

[0143] Then, as shown in FIG. 3C, using the resist mask 190a, a part of the first hole injection layer 181A, a part of the first hole transport layer 182A, a part of the first light-emitting layer 183A, a part of the first electron transport layer 184A, and a part of the first sacrificial layer 118A are removed. As a result, the regions of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, the first electron transport layer 184A, and the first sacrificial layer 118A that do not overlap with the resist mask 190a can be removed. Therefore, a part of the conductive film 111 is exposed. In the region corresponding to the sub-pixel 110a, a stacked structure of the first hole injection layer 181a, the first hole transport layer 182a, the first light-emitting layer 183a, the first electron transport layer 184a, the first sacrificial layer 118a, and the resist mask 190a remains on the conductive film 111. Also, in the region corresponding to the connection portion 140, a stacked structure of the first sacrificial layer 118a and the resist mask 190a remains on the conductive film 111. Note that the stacked structure of the first hole injection layer 181a, the first hole transport layer 182a, the first light-emitting layer 183a, and the first electron transport layer 184a is also referred to as the first layer 113a. Then, the resist mask 190a is removed.

[0144] The first sacrificial layer 118A can be processed by a wet etching method or a dry etching method. The processing of the first sacrificial layer 118A is preferably performed by anisotropic etching.

[0145] By using the wet etching method, the damage applied to the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A during the processing of the first sacrificial layer 118A can be reduced compared to the case of using the dry etching method. When using the wet etching method, for example, it is preferable to use a chemical solution using a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof.

[0146] Also, when using the dry etching method, by not using a gas containing oxygen as the etching gas, deterioration of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A can be suppressed. When using the dry etching method, for example, it is preferable to use a gas containing a noble gas (also referred to as a rare gas) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He as the etching gas.

[0147] Note that in FIG. 3C, an example of processing the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, the first electron transport layer 184A, and the first sacrificial layer 118A while leaving the resist mask 190a is shown, but it is not limited thereto. For example, when the first sacrificial layer 118A has a stacked structure, some layers may be processed using the resist mask 190a, and after removing the resist mask 190a, the remaining layers may be processed using the processed part of the layer as a hard mask.

[0148] For example, after processing some layers of the first sacrificial layer 118A using the resist mask 190a, the resist mask 190a is removed by ashing using oxygen plasma or the like. At this time, since the remaining layers of the first sacrificial layer 118A are located on the outermost surface and the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A are not exposed, damage to the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A can be suppressed in the process of removing the resist mask 190a. Then, the processed part of the first sacrificial layer 118A can be used as a hard mask to process the remaining layers of the first sacrificial layer 118A and the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A, respectively.

[0149] The processing of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A is preferably performed by anisotropic etching. In particular, anisotropic dry etching is preferred. As the etching gas, it is preferable to use a gas containing nitrogen, a gas containing hydrogen, a gas containing a noble gas, a gas containing nitrogen and argon, or a gas containing nitrogen and hydrogen. By not using a gas containing oxygen as the etching gas, deterioration of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A can be suppressed.

[0150] Alternatively, a gas containing oxygen may be used as the etching gas. By the etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining the etching rate at a sufficient speed. As a result, damage to the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A can be suppressed. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0151] Next, as shown in FIG. 4A, on the first sacrificial layer 118a and the conductive film 111, a second hole injection layer 181B, a second hole transport layer 182B, a second light-emitting layer 183B, and a second electron transport layer 184B are formed in this order, and a second sacrificial layer 118B is formed on the second electron transport layer 184B. As shown in FIG. 4A, in the cross-sectional view between Y1 - Y2, the end portion on the connection portion 140 side of the second hole injection layer 181B, the second hole transport layer 182B, the second light-emitting layer 183B, and the second electron transport layer 184B is located inside the end portion of the second sacrificial layer 118B.

[0152] The second hole injection layer 181B, the second hole transport layer 182B, the second light-emitting layer 183B, and the second electron transport layer 184B are each layers that will later become the second hole injection layer 181b, the second hole transport layer 182b, the second light-emitting layer 183b, and the second electron transport layer 184b. The second light-emitting layer 183b emits light of a color different from that of the first light-emitting layer 183a. The configurations, materials, etc. applicable to the second hole injection layer 181b, the second hole transport layer 182b, the second light-emitting layer 183b, and the second electron transport layer 184b are the same as those of the first hole injection layer 181a, the first hole transport layer 182a, the first light-emitting layer 183a, and the first electron transport layer 184a, respectively. The second hole transport layer 182B, the second light-emitting layer 183B, and the second electron transport layer 184B can each be formed by the same method as the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A.

[0153] The second sacrificial layer 118B can be formed using a material applicable to the first sacrificial layer 118A.

[0154] Next, as shown in FIG. 4B, a resist mask 190b is formed on the second sacrificial layer 118B.

[0155] As shown in FIG. 2B, the resist mask 190b is provided at a position overlapping the region that will later become the sub-pixel 110b. Further, it is preferable that the resist mask 190b is also provided at a position overlapping the region that will later become the connection portion 140. Thereby, damage to the region that will later become the conductive layer 123 in the conductive film 111 can be suppressed during the manufacturing process of the display device. When the first sacrificial layer 118a is provided in the region that will later become the connection portion 140, the resist mask 190b may not be provided in that region. As the resist mask 190b, it is preferable that one island-shaped pattern is provided for one sub-pixel 110b. Alternatively, as the resist mask 190b, one strip-shaped pattern may be formed for a plurality of sub-pixels 110b arranged in a row.

[0156] Then, as shown in FIG. 4C, using the resist mask 190b, a part of the second hole injection layer 181B, a part of the second hole transport layer 182B, a part of the second light-emitting layer 183B, a part of the second electron transport layer 184B, and a part of the second sacrificial layer 118B are removed. As a result, regions of the second hole injection layer 181B, the second hole transport layer 182B, the second light-emitting layer 183B, the second electron transport layer 184B, and the second sacrificial layer 118B that do not overlap with the resist mask 190b can be removed. Therefore, a part of the conductive film 111 is exposed. And in the region corresponding to the sub-pixel 110b, a stacked structure of the second hole injection layer 181b, the second hole transport layer 182b, the second light-emitting layer 183b, the second electron transport layer 184b, the second sacrificial layer 118b, and the resist mask 190b remains on the conductive film 111. Also, in the region corresponding to the connection part 140, a stacked structure of the first sacrificial layer 118a, the second sacrificial layer 118b, and the resist mask 190b remains on the conductive film 111. Note that the stacked structure of the second hole injection layer 181b, the second hole transport layer 182b, the second light-emitting layer 183b, and the second electron transport layer 184b is also referred to as the second layer 113b. Then, the resist mask 190b is removed.

[0157] The second sacrificial layer 118B can be processed using a method applicable to the processing of the first sacrificial layer 118A. The second hole injection layer 181B, the second hole transport layer 182B, the second light-emitting layer 183B, and the second electron transport layer 184B can be processed using a method applicable to the processing of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A. The resist mask 190b can be removed by a method and timing applicable to the removal of the resist mask 190a.

[0158] Next, as shown in FIG. 5A, a third hole injection layer 181C, a third hole transport layer 182C, a third light-emitting layer 183C, and a third electron transport layer 184C are formed in this order on the first sacrificial layer 118a, the second sacrificial layer 118b, and the conductive film 111, and a third sacrificial layer 118C is formed on the third electron transport layer 184C. As shown in FIG. 5A, in the cross-sectional view between Y1 - Y2, the end portions on the connection portion 140 side of the third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, and the third electron transport layer 184C are located inside the end portions of the third sacrificial layer 118C.

[0159] The third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, and the third electron transport layer 184C are layers that will later become the third hole injection layer 181c, the third hole transport layer 182c, the third light-emitting layer 183c, and the third electron transport layer 184c, respectively. The third light-emitting layer 183c emits light of a color different from that of the first light-emitting layer 183a and the second light-emitting layer 183b. The configurations and materials applicable to the third hole injection layer 181c, the third hole transport layer 182c, the third light-emitting layer 183c, and the third electron transport layer 184c are the same as those of the first hole injection layer 181a, the first hole transport layer 182a, the first light-emitting layer 183a, and the first electron transport layer 184a, respectively. The third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, and the third electron transport layer 184C can be formed by using the same method as that of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A, respectively.

[0160] The third sacrificial layer 118C can be formed using a material applicable to the first sacrificial layer 118A.

[0161] Next, as shown in FIG. 5B, a resist mask 190c is formed on the third sacrificial layer 118C.

[0162] As shown in FIG. 2C, the resist mask 190c is provided at a position overlapping the region that will later become the sub-pixel 110c. As the resist mask 190c, it is preferable that one island-shaped pattern is provided for one sub-pixel 110c. Alternatively, as the resist mask 190c, one strip-shaped pattern may be formed for a plurality of sub-pixels 110c arranged in a row. Furthermore, the resist mask 190c is preferably also provided at a position overlapping the region that will later become the connection part 140. Note that when at least one of the first sacrificial layer 118a and the second sacrificial layer 118b is provided in the region that will later become the connection part 140, the resist mask 190c may not be provided in that region.

[0163] Then, as shown in FIG. 5C, using the resist mask 190c, a part of the third hole injection layer 181C, a part of the third hole transport layer 182C, a part of the third light-emitting layer 183C, a part of the third electron transport layer 184C, and a part of the third sacrificial layer 118C are removed. As a result, the regions of the third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, the third electron transport layer 184C, and the third sacrificial layer 118C that do not overlap with the resist mask 190c can be removed. And in the region corresponding to the sub-pixel 110c, on the conductive film 111, the laminated structure of the third hole injection layer 181c, the third hole transport layer 182c, the third light-emitting layer 183c, the third electron transport layer 184c, the third sacrificial layer 118c, and the resist mask 190c remains. Also, in the region corresponding to the connection part 140, on the conductive film 111, the laminated structure of the first sacrificial layer 118a, the second sacrificial layer 118b, the third sacrificial layer 118c, and the resist mask 190c remains. Note that the laminated structure of the third hole injection layer 181c, the third hole transport layer 182c, the third light-emitting layer 183c, and the third electron transport layer 184c is also denoted as the third layer 113c. Thereafter, as shown in FIG. 6A, the resist mask 190c is removed.

[0164] The third sacrificial layer 118C can be processed using a method applicable to the processing of the first sacrificial layer 118A. The third hole injection layer 181C, the third hole transport layer 182C, the third light-emitting layer 183C, and the third electron transport layer 184C can be processed using a method applicable to the processing of the first hole injection layer 181A, the first hole transport layer 182A, the first light-emitting layer 183A, and the first electron transport layer 184A. The resist mask 190c can be removed using a method and timing applicable to the removal of the resist mask 190a.

[0165] Next, as shown in FIG. 6B, the first sacrificial layer 118a, the second sacrificial layer 118b, and the third sacrificial layer 118c are used as a hard mask to process the conductive film 111, and the pixel electrodes 111a, 111b, 111c, and the conductive layer 123 are formed.

[0166] During the processing of the conductive film 111, a part of the layer 101 including the transistor (specifically, the insulating layer located on the outermost surface) may be processed to form a recess. In the following description, the case where a recess is provided in the layer 101 including the transistor will be described as an example, but a recess may not be provided.

[0167] Here, in order to form the conductive layer 123, it is sufficient that at least the third sacrificial layer 118c is provided at the connection portion 140. On the other hand, as described above, by providing the laminated structure of the second sacrificial layer 118b and the third sacrificial layer 118c, or the laminated structure of the first sacrificial layer 118a, the second sacrificial layer 118b, and the third sacrificial layer 118c at the connection portion 140, it is possible to suppress the region of the conductive film 111 that becomes the conductive layer 123 from being damaged during the manufacturing process of the display device, which is preferable.

[0168] The conductive film 111 can be processed by a wet etching method or a dry etching method. The processing of the conductive film 111 is preferably performed by anisotropic etching.

[0169] Next, as shown in FIG. 6C, the first sacrificial layer 118a, the second sacrificial layer 118b, and the third sacrificial layer 118c are removed. As a result, the first electron transport layer 184a is exposed on the pixel electrode 111a, the second electron transport layer 184b is exposed on the pixel electrode 111b, the third electron transport layer 184c is exposed on the pixel electrode 111c, and at the connection portion 140, the conductive layer 123 is exposed.

[0170] For the sacrificial layer removal step, the same method as the sacrificial layer processing step can be used. In particular, by using the wet etching method, compared with the case of using the dry etching method, when removing the first sacrificial layer 118a, the second sacrificial layer 118b, and the third sacrificial layer 118c, the damage applied to the first layer 113a, the second layer 113b, and the third layer 113c can be reduced.

[0171] Next, as shown in FIG. 7A, a fourth electron transport layer 116 is formed so as to cover the first layer 113a, the second layer 113b, and the third layer 113c. As shown in FIG. 7A, in the cross-sectional view between Y1 - Y2, the end portion of the fourth electron transport layer 116 on the connection portion 140 side is located inside the connection portion 140, and the conductive layer 123 remains exposed.

[0172] The material that can be used as the fourth electron transport layer 116 is as described above. The fourth electron transport layer 116 can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer method, printing method, inkjet method, coating method, etc. Also, the fourth electron transport layer 116 may be formed using a premix material.

[0173] The fourth electron transport layer 116 is formed using a material that is more insulating than the electron injection layer 114 to be formed next. Since the fourth electron transport layer 116 is provided so as to cover the upper surfaces and side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, and the side surfaces of the pixel electrodes 111a, 111b, and 111c, it is possible to suppress the highly conductive electron injection layer 114 from coming into contact with these layers, and suppress the short circuit of the light-emitting device. Thereby, the reliability of the light-emitting device can be enhanced.

[0174] In particular, when a concave portion is provided in a part of the layer 101 including the transistor (specifically, the insulating layer located on the outermost surface), it is preferable that the entire side surfaces of the pixel electrodes 111a, 111b, and 111c can be covered with the fourth electron transport layer 116.

[0175] Next, as shown in FIG. 7B, an electron injection layer 114 is formed on the fourth electron transport layer 116. As shown in FIG. 7B, in the cross-sectional view between Y1 - Y2, the end portion on the connection portion 140 side of the electron injection layer 114 is located inside the connection portion 140, and the conductive layer 123 remains exposed.

[0176] The materials that can be used as the electron injection layer 114 are as described above. The electron injection layer 114 can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer method, printing method, inkjet method, coating method, etc. Also, the electron injection layer 114 may be formed using a premix material.

[0177] Here, an example is shown in which voids 133 are formed by the film formation of the electron injection layer 114, but the voids 133 may not be formed. In this case, between the two light-emitting devices, it has a structure filled with the electron injection layer 114. Or, before the film formation of the electron injection layer 114, the space between the two light-emitting devices may have a structure filled with the fourth electron transport layer 116.

[0178] Also, as shown in FIG. 7C, the portion that can become voids 133 may be filled with an insulator 134 in advance. Details of the voids 133 and the insulator 134 are as described above.

[0179] Then, a common electrode 115 is formed on the electron injection layer 114.

[0180] The materials that can be used as the common electrode 115 are as described above. For the formation of the common electrode 115, for example, a sputtering method or a vacuum vapor deposition method can be used.

[0181] Thereafter, a protective layer 131 is formed on the common electrode 115, and a protective layer 132 is formed on the protective layer 131. Further, by using the resin layer 119 to bond the substrate 120 onto the protective layer 132, the display device 100 shown in FIG. 1B can be fabricated.

[0182] The materials and film-forming methods that can be used for the protective layers 131 and 132 are as described above. Examples of the film-forming methods for the protective layers 131 and 132 include a vacuum evaporation method, a sputtering method, a CVD method, and an ALD method. The protective layer 131 and the protective layer 132 may be films formed using different film-forming methods. Also, each of the protective layers 131 and 132 may have a single-layer structure or a laminated structure.

[0183] As described above, in the method for fabricating the display device according to the present embodiment, the island-shaped EL layer is not formed using a fine metal mask, but is formed by processing after depositing the EL layer on one surface. Therefore, the island-shaped EL layer can be formed with a uniform thickness.

[0184] The first layer, the second layer, and the third layer constituting the light-emitting devices of each color are formed in separate steps. Therefore, each EL layer can be fabricated with a configuration (such as materials and film thickness) suitable for the light-emitting devices of each color. Thereby, a light-emitting device with good characteristics can be fabricated.

[0185] The display device according to one aspect of the present invention has an island-shaped first electron transport layer on the light-emitting layer, and further has a second electron transport layer that covers the side surfaces of the pixel electrode, the light-emitting layer, and the first electron transport layer. In the manufacturing process of the display device, since the EL layer is processed in a state where the light-emitting layer and the first electron transport layer are laminated, the display device has a configuration in which the damage to the light-emitting layer is reduced. Also, the second electron transport layer suppresses the contact between the pixel electrode and the electron injection layer or the common electrode, and has a configuration in which the light-emitting device is prevented from short-circuiting.

[0186] This embodiment can be appropriately combined with other embodiments. Also, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

[0187] (Embodiment 2) In this embodiment, a display device according to one aspect of the present invention will be described with reference to FIGS. 8 to 11.

[0188] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, in information terminals (wearable devices) such as wristwatch type and bracelet type, and in display units of wearable devices that can be worn on the head, such as VR devices like head-mounted displays and AR devices like glasses-type devices.

[0189] [Display module] FIG. 8A shows a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be the display device 100B or the display device 100C described later.

[0190] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display unit 281. The display unit 281 is an area for displaying an image in the display module 280, and is an area where light from each pixel provided in the pixel unit 284 described later can be visually recognized.

[0191] FIG. 8B shows a perspective view schematically showing the configuration on the substrate 291 side. On the substrate 291, a circuit unit 282, a pixel circuit unit 283 on the circuit unit 282, and a pixel unit 284 on the pixel circuit unit 283 are laminated. Also, a terminal unit 285 for connecting to the FPC 290 is provided in a portion that does not overlap with the pixel unit 284 on the substrate 291. The terminal unit 285 and the circuit unit 282 are electrically connected by a wiring unit 286 formed of a plurality of wirings.

[0192] The pixel section 284 has a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of FIG. 8B. The pixel 284a has light-emitting devices 130a, 130b, and 130c that emit light of different colors. In the present embodiment, a case where the pixel 284a is configured by the light-emitting device 130a that emits red light, the light-emitting device 130b that emits green light, and the light-emitting device 130c that emits blue light will be described as an example. The plurality of light-emitting devices can be arranged in a stripe pattern as shown in FIG. 8B. Also, various light-emitting device arrangement methods such as a delta arrangement or a pentile arrangement can be applied.

[0193] Here, when a pixel of the display device has three sub-pixels having light-emitting devices that emit light of different colors, examples of the three sub-pixels include sub-pixels of three colors R, G, and B, and sub-pixels of three colors yellow (Y), cyan (C), and magenta (M). When the display device has four sub-pixels, examples of the four sub-pixels include sub-pixels of four colors R, G, B, and white (W), and sub-pixels of four colors R, G, B, and Y.

[0194] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0195] One pixel circuit 283a is a circuit that controls the light emission of the three light-emitting devices included in one pixel 284a. One pixel circuit 283a may be configured to include three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to include at least one selection transistor, one current control transistor (drive transistor), and a capacitive element for each light-emitting device. At this time, a gate signal is input to the gate of the selection transistor, and a source signal is input to one of the source or drain. Thereby, an active matrix type display device is realized.

[0196] The structure of the transistor included in the display device of the present embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Also, either a top gate type or a bottom gate type transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0197] The crystallinity of the semiconductor material used for the transistor is also not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity other than a single crystal (microcrystalline semiconductor, polycrystalline semiconductor, or a semiconductor having a crystal region in part) may be used. Using a single crystal semiconductor or a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0198] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). That is, the display device of the present embodiment preferably uses a transistor (hereinafter, an OS transistor) using a metal oxide for the channel formation region. Alternatively, the semiconductor layer of the transistor preferably contains silicon. Examples of the silicon include amorphous silicon, crystalline silicon (such as low-temperature polysilicon and single crystal silicon).

[0199] The semiconductor layer preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0200] In particular, it is preferable to use an oxide (also referred to as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0201] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of the atomic ratio of the metal elements in such an In-M-Zn oxide include a composition of In:M:Zn = 1:1:1 or in the vicinity thereof, a composition of In:M:Zn = 1:1:1.2 or in the vicinity thereof, a composition of In:M:Zn = 2:1:3 or in the vicinity thereof, a composition of In:M:Zn = 3:1:2 or in the vicinity thereof, a composition of In:M:Zn = 4:2:3 or in the vicinity thereof, a composition of In:M:Zn = 4:2:4.1 or in the vicinity thereof, a composition of In:M:Zn = 5:1:3 or in the vicinity thereof, a composition of In:M:Zn = 5:1:6 or in the vicinity thereof, a composition of In:M:Zn = 5:1:7 or in the vicinity thereof, a composition of In:M:Zn = 5:1:8 or in the vicinity thereof, a composition of In:M:Zn = 6:1:6 or in the vicinity thereof, a composition of In:M:Zn = 5:2:5 or in the vicinity thereof, and the like. The composition in the vicinity means a range including ±30% of the desired atomic ratio.

[0202] For example, when the atomic ratio is described as In:Ga:Zn = 4:2:3 or in the vicinity thereof, when In is 4, it includes cases where Ga is 1 or more and 3 or less, and Zn is 2 or more and 4 or less. Also, when the atomic ratio is described as In:Ga:Zn = 5:1:6 or in the vicinity thereof, when In is 5, it includes cases where Ga is greater than 0.1 and 2 or less, and Zn is 5 or more and 7 or less. Also, when the atomic ratio is described as In:Ga:Zn = 1:1:1 or in the vicinity thereof, when In is 1, it includes cases where Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0203] The transistor included in the circuit unit 282 and the transistor included in the pixel circuit unit 283 may have the same structure or different structures. The structures of the plurality of transistors included in the circuit unit 282 may all be the same or there may be two or more types. Similarly, the structures of the plurality of transistors included in the pixel circuit unit 283 may all be the same or there may be two or more types.

[0204] The circuit section 282 has a circuit for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably has one or both of a gate line driving circuit and a source line driving circuit. In addition, it may have at least one of an arithmetic circuit, a memory circuit, a power supply circuit, etc.

[0205] The FPC 290 functions as a wiring for supplying a video signal, a power supply potential, etc. from the outside to the circuit section 282. Also, an IC (integrated circuit) may be mounted on the FPC 290.

[0206] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are provided overlapping below the pixel section 284, so that the aperture ratio (effective display area ratio) of the display section 281 can be made extremely high. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, more preferably 60% or more and 95% or less. Also, the pixels 284a can be arranged extremely densely, and the fineness of the display section 281 can be made extremely high. For example, in the display section 281, the pixels 284a are preferably arranged with a fineness of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, still more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0207] Since such a display module 280 is extremely high-definition, it can be suitably used for VR devices such as head-mounted displays or glasses-type AR devices. For example, even in the case of a configuration where the display section of the display module 280 is viewed through a lens, since the display module 280 has an extremely high-definition display section 281, no pixels can be seen even if the display section is enlarged by the lens, and a highly immersive display can be performed. Also, the display module 280 is not limited to this, and can be suitably used for electronic devices having a relatively small display section. For example, it can be suitably used for the display section of wearable electronic devices such as wristwatches.

[0208] [Display device 100A] The display device 100A shown in FIG. 9 includes a substrate 301, light-emitting devices 130a, 130b, 130c, a capacitor 240, and a transistor 310.

[0209] The substrate 301 corresponds to the substrate 291 in FIGS. 8A and 8B. The stacked structure from the substrate 301 to the insulating layer 255 corresponds to the layer 101 including the transistor in Embodiment 1.

[0210] The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as one of a source or a drain. The insulating layer 314 is provided to cover the side surface of the conductive layer 311.

[0211] Also, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0212] Also, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0213] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as a dielectric of the capacitor 240.

[0214] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 via the insulating layer 243.

[0215] An insulating layer 255 is provided to cover the capacitor 240, and light-emitting devices 130a, 130b, 130c, etc. are provided on the insulating layer 255. In the present embodiment, an example is shown in which the light-emitting devices 130a, 130b, 130c have the same structure as the stacked structure shown in FIG. 1B. Further, a protective layer 131 is provided on each of the light-emitting devices 130a, 130b, 130c. A protective layer 132 is provided on the protective layer 131, and the substrate 120 is bonded by a resin layer 119 on the protective layer 132. An insulator 134 is filled between the fourth electron transport layer 116 and the electron injection layer 114. Details of the components from the light-emitting device to the substrate 120 can be referred to in Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 8A.

[0216] The pixel electrode of the light-emitting device is electrically connected to one of the source or drain of the transistor 310 by a plug 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261.

[0217] [Display device 100B] The display device 100B shown in FIG. 10 is mainly different from the display device 100A in that the configuration of the transistor is different. Note that the description of the same parts as those of the display device 100A may be omitted.

[0218] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is applied to a semiconductor layer in which a channel is formed.

[0219] Transistor 320 includes a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0220] Substrate 331 corresponds to substrate 291 in FIGS. 8A and 8B. The stacked structure from substrate 331 to insulating layer 255 corresponds to layer 101 including the transistor in Embodiment 1. As substrate 331, an insulating substrate or a semiconductor substrate can be used.

[0221] An insulating layer 332 is provided on substrate 331. Insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from substrate 331 into transistor 320 and oxygen from desorbing from semiconductor layer 321 to the insulating layer 332 side. As insulating layer 332, a film in which hydrogen or oxygen diffuses less easily than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, can be used.

[0222] Conductive layer 327 is provided on insulating layer 332, and insulating layer 326 is provided so as to cover conductive layer 327. Conductive layer 327 functions as the first gate electrode of transistor 320, and a part of insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film such as a silicon oxide film for at least the portion of insulating layer 326 that contacts semiconductor layer 321. The upper surface of insulating layer 326 is preferably flattened.

[0223] Semiconductor layer 321 is provided on insulating layer 326. Semiconductor layer 321 preferably has a metal oxide (also referred to as an oxide semiconductor) film having semiconductor characteristics. Details of materials that can be suitably used for semiconductor layer 321 will be described later.

[0224] A pair of conductive layers 325 are provided in contact with semiconductor layer 321 and function as source and drain electrodes.

[0225] Further, an insulating layer 328 is provided to cover the upper surface and side surfaces of a pair of conductive layers 325 and the side surface of the semiconductor layer 321, etc., and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264, etc. into the semiconductor layer 321, and prevents oxygen from desorbing from the semiconductor layer 321. As the insulating layer 328, an insulating film similar to the above-mentioned insulating layer 332 can be used.

[0226] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 in contact with the upper surface of the semiconductor layer 321, the side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325, and a conductive layer 324 are embedded. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0227] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are substantially the same, and an insulating layer 329 and an insulating layer 265 are provided to cover them.

[0228] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265, etc. into the transistor 320. As the insulating layer 329, an insulating film similar to the above-mentioned insulating layer 328 and insulating layer 332 can be used.

[0229] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided so as to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably has a conductive layer 274a that covers the side surfaces of the respective openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b in contact with the upper surface of the conductive layer 274a. At this time, it is preferable to use a conductive material in which hydrogen and oxygen hardly diffuse as the conductive layer 274a.

[0230] In addition, the layer 101 containing transistors may have various inorganic insulating films. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, etc. can be used. Further, a hafnium oxide film, a yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, etc. may be used. Also, two or more of the above-described insulating films may be laminated and used.

[0231] The structure from the insulating layer 254 to the substrate 120 in the display device 100B is the same as that of the display device 100A.

[0232] [Display device 100C] The display device 100C shown in FIG. 11 has a structure in which a transistor 310 having a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in a semiconductor layer where a channel is formed are laminated. Note that descriptions of the same parts as those of the display devices 100A and 100B may be omitted.

[0233] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. Further, an insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layer 251 and the conductive layer 252 each function as a wiring. Also, an insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. Further, an insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0234] The transistor 320 can be used as a transistor constituting a pixel circuit. Further, the transistor 310 can be used as a transistor constituting a pixel circuit or a transistor constituting a driving circuit (gate line driving circuit, source line driving circuit) for driving the pixel circuit. Further, the transistor 310 and the transistor 320 can be used as transistors constituting various circuits such as an arithmetic circuit or a memory circuit.

[0235] With such a configuration, not only the pixel circuit but also the driving circuit and the like can be formed directly under the light-emitting device, so that the display device can be downsized compared to the case where the driving circuit is provided around the display area.

[0236] This embodiment can be appropriately combined with other embodiments.

[0237] (Embodiment 3) In this embodiment, a light-emitting device that can be used in a display device according to an aspect of the present invention will be described.

[0238] The light-emitting device shown in FIG. 12A has an electrode 772, an EL layer 786, and an electrode 788. Of the electrode 772 and the electrode 788, one functions as an anode and the other functions as a cathode. Further, of the electrode 772 and the electrode 788, one functions as a pixel electrode and the other functions as a common electrode. Further, the electrode on the light extraction side of the electrode 772 and the electrode 788 has transparency to visible light, and the other electrode preferably reflects visible light.

[0239] As shown in FIG. 12A, the EL layer 786 included in the light-emitting device can be composed of a plurality of layers such as layer 4420, light-emitting layer 4411, and layer 4430. Layer 4420 can have, for example, a layer containing a substance with high electron injection property (electron injection layer) and a layer containing a substance with high electron transport property (electron transport layer). The light-emitting layer 4411 has, for example, a light-emitting compound. Layer 4430 can have, for example, a layer containing a substance with high hole injection property (hole injection layer) and a layer containing a substance with high hole transport property (hole transport layer).

[0240] The configuration having layer 4420, light-emitting layer 4411, and layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and in this specification, the configuration of FIG. 12A is referred to as a single structure.

[0241] Further, FIG. 12B shows a modified example of the EL layer 786 included in the light-emitting device shown in FIG. 12A. Specifically, the light-emitting device shown in FIG. 12B has layer 4431 on electrode 772, layer 4432 on layer 4431, light-emitting layer 4411 on layer 4432, layer 4421 on light-emitting layer 4411, layer 4422 on layer 4421, and electrode 788 on layer 4422. For example, when electrode 772 is an anode and electrode 788 is a cathode, layer 4431 functions as a hole injection layer, layer 4432 functions as a hole transport layer, layer 4421 functions as an electron transport layer, and layer 4422 functions as an electron injection layer. Or, when electrode 772 is a cathode and electrode 788 is an anode, layer 4431 functions as an electron injection layer, layer 4432 functions as an electron transport layer, layer 4421 functions as a hole transport layer, and layer 4422 functions as a hole injection layer. By adopting such a layer structure, carriers can be efficiently injected into the light-emitting layer 4411, and the efficiency of carrier recombination in the light-emitting layer 4411 can be increased.

[0242] Note that a configuration in which a plurality of light-emitting layers (light-emitting layers 4411, 4412, 4413) are provided between layer 4420 and layer 4430 as shown in FIG. 12C is also a variation of the single structure.

[0243] Also, as shown in FIG. 12D, a configuration in which a plurality of light-emitting units (EL layers 786a and 786b) are connected in series via an intermediate layer 4440 (also referred to as a charge generation layer) is referred to as a tandem structure in this specification. Note that the present invention is not limited to this, and for example, the tandem structure may be referred to as a stack structure. By adopting the tandem structure, a light-emitting device capable of high-brightness emission can be obtained.

[0244] Note that also in FIGS. 12C and 12D, as shown in FIG. 12B, the layer 4420 and the layer 4430 can each have a stacked structure composed of two or more layers.

[0245] The emission color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, white, or the like depending on the material constituting the EL layer 786. Further, by providing a microcavity structure to the light-emitting device, the color purity can be further enhanced.

[0246] A light-emitting device that emits white light preferably has a configuration in which the light-emitting layer contains two or more types of light-emitting substances. To obtain white light emission, light-emitting substances can be selected such that the emissions of the two or more light-emitting substances are in a complementary color relationship. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer be in a complementary color relationship, a light-emitting device that emits white light as a whole can be obtained. The same applies to a light-emitting device having three or more light-emitting layers. For example, if the emission colors of the light-emitting layers 4411, 4412, and 4413 shown in FIG. 12C are in a complementary color relationship, a single-structure white light-emitting device can be realized.

[0247] The light-emitting layer preferably contains two or more light-emitting substances that exhibit emissions such as R (red), G (green), B (blue), Y (yellow), and O (orange). Alternatively, it has two or more light-emitting substances, and the emission of each light-emitting substance preferably contains spectral components of two or more colors among R, G, and B.

[0248] This embodiment can be appropriately combined with other embodiments.

[0249] (Embodiment 4) In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the OS transistor described in the above embodiment will be described.

[0250] The metal oxide preferably contains at least indium or zinc. In particular, it preferably contains indium and zinc. In addition to these, it is preferable that aluminum, gallium, yttrium, tin, etc. are contained. Further, one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc. may be contained.

[0251] The metal oxide can be formed by a sputtering method, a chemical vapor deposition (CVD) method such as a metal organic chemical vapor deposition (MOCVD) method, or an atomic layer deposition (ALD) method.

[0252] <Classification of Crystal Structure> Examples of the crystal structure of the oxide semiconductor include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0253] Note that 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 the XRD spectrum obtained by grazing-incidence XRD (GIXD) measurement. Note that the GIXD method is also referred to as the thin film method or the Seemann-Bohlin method.

[0254] For example, in a quartz glass substrate, the shape of the peak in the XRD spectrum is almost symmetric about the left and right. On the other hand, in an IGZO film having a crystal structure, the shape of the peak in the XRD spectrum is asymmetric about the left and right. The fact that the shape of the peak in the XRD spectrum is asymmetric about the left and right indicates the presence of crystals in the film or the substrate. In other words, if the shape of the peak in the XRD spectrum is not symmetric about the left and right, it cannot be said that the film or the substrate is in an amorphous state.

[0255] In addition, the crystal structure of the film or the substrate can be evaluated by the diffraction pattern (also referred to as the nano beam electron diffraction pattern) observed by the nano beam electron diffraction method (NBED). For example, in the diffraction pattern of a quartz glass substrate, a halo is observed, and it can be confirmed that the quartz glass is in an amorphous state. Also, in the diffraction pattern of an IGZO film formed at room temperature, a spot-like pattern is observed instead of a halo. Therefore, it is presumed that the IGZO film formed at room temperature is in an intermediate state that is neither a crystalline state nor an amorphous state, and it cannot be concluded that it is in an amorphous state.

[0256] [Structure of Oxide Semiconductor] Note that when focusing on the structure, the oxide semiconductor may be classified differently from the above. For example, the oxide semiconductor can be divided into a single crystal oxide semiconductor and other non-single crystal oxide semiconductors. Examples of the non-single crystal oxide semiconductor include the above-mentioned CAAC-OS and nc-OS. In addition, the non-single crystal oxide semiconductor includes a polycrystalline oxide semiconductor, an amorphous-like oxide semiconductor (a-like OS), an amorphous oxide semiconductor, and the like.

[0257] Here, the details of the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described.

[0258] [CAAC-OS] CAAC-OS is an oxide semiconductor having a plurality of crystal regions, and the c-axis of the plurality of crystal regions is oriented in a specific direction. Here, the specific direction means 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. Also, the crystal region is a region having periodicity in the atomic arrangement. When the atomic arrangement is regarded as a lattice arrangement, the crystal region is also a region where the lattice arrangements are aligned. Further, CAAC-OS has a region where a plurality of crystal regions are connected in the a-b plane direction, and this region may have strain. Here, the strain refers to a portion where the direction of the lattice arrangement changes between a region where the lattice arrangements are aligned and another region where the lattice arrangements are aligned in the region where a plurality of crystal regions are connected. That is, CAAC-OS is an oxide semiconductor in which the c-axis is oriented and there is no obvious orientation in the a-b plane direction.

[0259] Each of the plurality of crystal regions is composed of one or more minute crystals (crystals having a maximum diameter of less than 10 nm). When a crystal region is composed of one minute crystal, the maximum diameter of the crystal region is less than 10 nm. Also, when a crystal region is composed of a number of minute crystals, the size of the crystal region may be about several tens of nm.

[0260] Also, in In-M-Zn oxide (element M is one or more selected from aluminum, gallium, yttrium, tin, titanium, etc.), 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 laminated. Here, indium and element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. Also, the In layer may contain element M. Note that the In layer may also contain Zn. The layered structure is observed as a lattice image, for example, in a high-resolution TEM (Transmission Electron Microscope) image.

[0261] When performing a structural analysis on the CAAC-OS film using, for example, an XRD apparatus, in the out-of-plane XRD measurement using θ / 2θ scan, a peak indicating c-axis orientation is detected at 2θ = 31° or in its vicinity. Note that the position (the value of 2θ) of the peak indicating c-axis orientation may vary depending on the type and composition of the metal elements constituting CAAC-OS.

[0262] Also, for example, in the electron diffraction pattern of the CAAC-OS film, a plurality of bright spots (spots) are observed. Note that one spot and another spot are observed at point-symmetric positions with the spot of the incident electron beam transmitted through the sample (also referred to as the direct spot) as the center of symmetry.

[0263] When observing the crystal region from the above specific direction, the lattice arrangement within the crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, in the above distortion, there may be a lattice arrangement such as a pentagon or a heptagon. Note that in CAAC-OS, even in the vicinity of the distortion, a clear grain boundary cannot be confirmed. That is, it can be seen that the formation of grain boundaries is suppressed due to the distortion of the lattice arrangement. This is presumably because CAAC-OS can tolerate distortion due to the fact that the arrangement of oxygen atoms is not dense in the a-b plane direction and the interatomic bond distance changes due to the substitution of metal atoms.

[0264] Note that a crystal structure in which a clear grain boundary is confirmed is called a so-called polycrystal. Grain boundaries can become recombination centers, and there is a high possibility of causing a decrease in the on-current of the transistor and a decrease in the field-effect mobility due to the capture of carriers. Therefore, CAAC-OS in which a clear grain boundary is not confirmed is one of the crystalline oxides having a crystal structure suitable for the semiconductor layer of the transistor. Note that for forming CAAC-OS, a configuration having Zn is preferable. For example, In-Zn oxide and In-Ga-Zn oxide are preferable because they can suppress the generation of grain boundaries more than In oxide.

[0265] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly identified crystal grain boundaries. Therefore, it can be said that CAAC-OS is less likely to have a reduction in electron mobility due to crystal grain boundaries. Also, since the crystallinity of an oxide semiconductor may decrease due to the incorporation of impurities, the generation of defects, etc., CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen deficiencies). Therefore, the physical properties of the oxide semiconductor having CAAC-OS are stable. For this reason, the oxide semiconductor having CAAC-OS is heat-resistant and highly reliable. Also, CAAC-OS is stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, when CAAC-OS is used for an OS transistor, it becomes possible to expand the degree of freedom in the manufacturing process.

[0266] [nc-OS] nc-OS has periodicity in the atomic arrangement in a minute region (for example, a region of 1 nm or more and 10 nm or less, particularly a region of 1 nm or more and 3 nm or less). In other words, nc-OS has minute crystals. Note that since the size of the minute crystal is, for example, 1 nm or more and 10 nm or less, particularly 1 nm or more and 3 nm or less, the minute crystal is also referred to as a nano crystal. Also, nc-OS does not show regularity in the crystal orientation between different nano crystals. Therefore, no orientation is seen in the entire film. Therefore, depending on the analysis method, nc-OS may not be distinguishable from a-like OS or an amorphous oxide semiconductor. For example, when structural analysis is performed on an nc-OS film using an XRD apparatus, no peak indicating crystallinity is detected in the Out-of-plane XRD measurement using θ / 2θ scan. Also, when electron beam diffraction (also referred to as limited field electron beam diffraction) using an electron beam with a probe diameter larger than the nano crystal (for example, 50 nm or more) is performed on an nc-OS film, a diffraction pattern like a halo pattern is observed. On the other hand, when electron beam diffraction (also referred to as nano beam electron beam diffraction) using an electron beam with a probe diameter close to or smaller than the nano crystal (for example, 1 nm or more and 30 nm or less) is performed on an nc-OS film, an electron beam diffraction pattern in which a plurality of spots are observed in a ring-shaped region centered on a direct spot may be obtained.

[0267] [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 loose or low-density region. That is, the a-like OS has lower crystallinity compared to the nc-OS and the CAAC-OS. Also, the a-like OS has a higher hydrogen concentration in the film compared to the nc-OS and the CAAC-OS.

[0268] [[Configuration of Oxide Semiconductor]] Next, the details of the above-described CAC-OS will be described. Note that the CAC-OS relates to the material composition.

[0269] [CAC-OS] The CAC-OS is, for example, a configuration of a material in which the elements constituting the metal oxide are unevenly distributed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof. In the following, in the metal oxide, one or more metal elements are unevenly distributed, and the region having the metal element is in a state of being mixed in a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof, which is also referred to as a mosaic state or a patch state.

[0270] Furthermore, the CAC-OS is a configuration in which the material is separated into a first region and a second region to form a mosaic state, and the first region is distributed in the film (hereinafter also referred to as a cloud state). That is, the CAC-OS is a composite metal oxide having a configuration in which the first region and the second region are mixed.

[0271] 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. Also, the second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS. 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.

[0272] 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.

[0273] In addition, there are cases where a clear boundary between the first region and the second region cannot be observed.

[0274] 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.

[0275] CAC-OS can be formed by sputtering, for example, under the condition of not heating the substrate. Also, when forming CAC-OS by sputtering, any one or more selected from an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the film-forming gas. Further, the lower the flow rate ratio of oxygen gas to the total flow rate of the film-forming gas during film formation, the more preferable. For example, it is preferable that the flow rate ratio of oxygen gas to the total flow rate of the film-forming gas during film formation is 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0276] Also, for example, in CAC-OS in In-Ga-Zn oxide, it can be confirmed by EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) that the region mainly composed of In (the first region) and the region mainly composed of Ga (the second region) are unevenly distributed and have a mixed structure.

[0277] Here, the first region is a region with higher conductivity compared to the second region. That is, when carriers flow through the first region, the conductivity as a metal oxide is exhibited. Therefore, when the first region is distributed in a cloud-like manner in the metal oxide, a high field-effect mobility (μ) can be realized.

[0278] On the other hand, the second region is a region with higher insulation compared to the first region. That is, by distributing the second region in the metal oxide, the leakage current can be suppressed.

[0279] Therefore, when using CAC-OS in a transistor, the conductivity caused by the first region and the insulating property caused by the second region act complementarily, enabling the function of switching (turning on / off) to be imparted to the CAC-OS. That is, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and has a semiconductor function as a whole. By separating the conductive function and the insulating function, both functions can be enhanced to the maximum extent. Therefore, by using CAC-OS in a transistor, a high on-current (I on )、high field-effect mobility (μ), and good switching operation can be realized.

[0280] In addition, a transistor using CAC-OS has high reliability. Therefore, CAC-OS is optimal for various semiconductor devices including display devices.

[0281] Oxide semiconductors have various structures and each has different characteristics. The oxide semiconductor according to one aspect of the present invention may have two or more of amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0282] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0283] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. In addition, a highly reliable transistor can be realized.

[0284] For a transistor, it is preferable to use an oxide semiconductor with a low carrier concentration. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 or less, preferably 1×10 15 cm -3 or less, more preferably 1×10 13 cm -3Hereinafter, more preferably 1×10 11 cm -3 or less, still more preferably 1×10 10 cm -3 or less, and 1×10 -9 cm -3 or more. When reducing the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be decreased, and the density of defect levels may be decreased. In this specification and the like, the fact that the impurity concentration is low and the density of defect levels is low is referred to as highly pure intrinsic or substantially highly pure intrinsic. Note that an oxide semiconductor with a low carrier concentration may be referred to as a highly pure intrinsic or substantially highly pure intrinsic oxide semiconductor.

[0285] In addition, since an oxide semiconductor film that is highly pure intrinsic or substantially highly pure intrinsic has a low density of defect levels, the density of trap levels may also be low.

[0286] In addition, the time required for the charges trapped in the trap levels of the oxide semiconductor to disappear may be long, and they may behave as if they were fixed charges. Therefore, the electrical characteristics of a transistor in which a channel formation region is formed in an oxide semiconductor with a high trap level density may become unstable.

[0287] Therefore, in order to stabilize the electrical characteristics of the transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. In addition, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to reduce the impurity concentration in the adjacent film. Examples of the impurity include hydrogen, nitrogen, an alkali metal, an alkaline earth metal, iron, nickel, and silicon.

[0288] <Impurity> Here, the influence of each impurity in the oxide semiconductor will be described.

[0289] In an oxide semiconductor, when silicon or carbon, which is one of the Group 14 elements, is included, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (the concentration obtained by secondary ion mass spectrometry (SIMS)) are set to 2×10 18 atoms / cm 3 or less, preferably 2×10 17 atoms / cm 3 or less.

[0290] Further, when an alkali metal or an alkaline earth metal is included in the oxide semiconductor, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal tends to have normally-on characteristics. For this reason, the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is set to 1×10 18 atoms / cm 3 or less, preferably 2×10 16 atoms / cm 3 or less.

[0291] Moreover, in an oxide semiconductor, when nitrogen is included, electrons, which are carriers, are generated, the carrier concentration increases, and the semiconductor tends to be n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as the semiconductor tends to have normally-on characteristics. Or, when nitrogen is included in the oxide semiconductor, trap levels may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to less than 5×10 19 atoms / cm 3 , preferably less than 5×10 18 atoms / cm 3 , more preferably 1×10 18 atoms / cm 3 , even more preferably 5×10 17 atoms / cm 3 or less.

[0292] In addition, since hydrogen contained in the oxide semiconductor reacts with oxygen bonded to metal atoms to form water, oxygen vacancies may be formed. When hydrogen enters these oxygen vacancies, electrons, which are carriers, may be generated. Also, a part of hydrogen may bond with oxygen bonded to metal atoms to generate electrons, which are carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen tends to have normally-on characteristics. For this reason, it is preferable that hydrogen in the oxide semiconductor be reduced as much as possible. Specifically, in the oxide semiconductor, the hydrogen concentration obtained by SIMS is less than 1×10 20 atoms / cm 3 less than, preferably less than 1×10 19 atoms / cm 3 less than, more preferably less than 5×10 18 atoms / cm 3 less than, even more preferably less than 1×10 18 atoms / cm 3 less than.

[0293] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0294] This embodiment can be appropriately combined with other embodiments.

[0295] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to FIGS. 13 to 17.

[0296] The electronic device of this embodiment has a display device according to one aspect of the present invention in a display unit. The display device according to one aspect of the present invention can be easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0297] Examples of electronic devices include relatively large-screen electronic devices such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, and large game machines such as pachinko machines. In addition, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, audio playback devices, and the like can be mentioned.

[0298] In particular, since the display device according to one aspect of the present invention can enhance the definition, it can be suitably used for electronic devices having a relatively small display unit. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), VR devices such as head-mounted displays, glasses-type AR devices, and MR devices, and other wearable devices that can be worn on the head.

[0299] The display device according to one aspect of the present invention preferably has an extremely high resolution such as HD (number of pixels: 1280 × 720), FHD (number of pixels: 1920 × 1080), WQHD (number of pixels: 2560 × 1440), WQXGA (number of pixels: 2560 × 1600), 4K (number of pixels: 3840 × 2160), 8K (number of pixels: 7680 × 4320). In particular, it is preferably 4K, 8K, or a higher resolution. Also, the pixel density (definition) in the display device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 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 one or both of such high resolution and high definition, it is possible to enhance the sense of presence and depth in personal-use electronic devices such as portable or home-use devices. Also, there is no particular limitation on the screen ratio (aspect ratio) of the display device according to one aspect of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0300] The electronic device according to this embodiment may have a sensor (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, voice, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays).

[0301] The electronic device according to this embodiment can have various functions. For example, it can have functions such as displaying various information (such as still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date or time, a function of executing various software (programs), a wireless communication function, a function of reading programs or data recorded on a recording medium, etc.

[0302] An example of a wearable device wearable on the head will be described with reference to FIGS. 13A, 13B, 14A, and 14B. These wearable devices have one or both of a function of displaying AR content and a function of displaying VR content. Note that these wearable devices may have a function of displaying SR or MR content in addition to AR and VR. By having a function of displaying content such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0303] The electronic device 700A shown in FIG. 13A and the electronic device 700B shown in FIG. 13B each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting parts 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0304] The display device according to one aspect of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of extremely high-precision display can be obtained.

[0305] The electronic device 700A and the electronic device 700B can each project the image displayed on the display panel 751 onto the display area 756 of the optical member 753. Since the optical member 753 has translucency, the user can view the image displayed in the display area superimposed on the transmitted image viewed through the optical member 753. Therefore, the electronic device 700A and the electronic device 700B are each an electronic device capable of AR display.

[0306] The electronic device 700A and the electronic device 700B may each be provided with a camera capable of imaging the front as an imaging unit. In addition, the electronic device 700A and the electronic device 700B can each detect the orientation of the user's head by including an acceleration sensor such as a gyro sensor, and display an image corresponding to the orientation in the display area 756.

[0307] The communication unit has a wireless communication device, and can supply a video signal or the like by the wireless communication device. In addition to or instead of the wireless communication device, a connector to which a cable for supplying a video signal and a power potential can be connected may be provided.

[0308] In addition, the electronic device 700A and the electronic device 700B are each provided with a battery and can be charged by one or both of wireless and wired methods.

[0309] The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting that the outer surface of the housing 721 is touched. By the touch sensor module, it is possible to detect a tap operation or a slide operation of the user and execute various processes. For example, it is possible to execute processes such as pausing or resuming a video by a tap operation, and it is possible to execute a fast forward or rewind process by a slide operation. In addition, by providing a touch sensor module on each of the two housings 721, the range of operations can be widened.

[0310] As the touch sensor module, various touch sensors can be applied. For example, various methods such as the capacitance method, the resistive film method, the infrared method, the electromagnetic induction method, the surface acoustic wave method, and the optical method can be adopted. In particular, it is preferable to apply a capacitance method or an optical method sensor to the touch sensor module.

[0311] When using an optical touch sensor, a photoelectric conversion device (also referred to as a photoelectric conversion element) can be used as the light receiving device (also referred to as a light receiving element). One or both of an inorganic semiconductor and an organic semiconductor can be used for the active layer of the photoelectric conversion device.

[0312] The electronic device 800A shown in FIG. 14A and the electronic device 800B shown in FIG. 14B each have a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0313] The display device according to one aspect of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of extremely high-precision display can be obtained. As a result, a high sense of immersion can be given to the user.

[0314] The display unit 820 is provided at a position inside the housing 821 where it can be visually recognized through the lens 832. Also, by displaying different images on the pair of display units 820, three-dimensional display using parallax can be performed.

[0315] The electronic device 800A and the electronic device 800B can each be referred to as an electronic device for VR. A user wearing the electronic device 800A or the electronic device 800B can visually recognize the image displayed on the display unit 820 through the lens 832.

[0316] It is preferable that each of the electronic devices 800A and 800B has a mechanism capable of adjusting the left and right positions of the lens 832 and the display unit 820 so that they are in optimal positions according to the position of the user's eyes. Further, it is preferable that it has a mechanism for adjusting focus by changing the distance between the lens 832 and the display unit 820.

[0317] With the mounting unit 823, the user can mount the electronic device 800A or the electronic device 800B on the head. In FIG. 14A and the like, it is exemplified as having a shape like a temple of glasses (also referred to as a joint or a temple), but it is not limited to this. The mounting unit 823 only needs to be mountable by the user, and may have, for example, a helmet type or a band type shape.

[0318] The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Further, a plurality of cameras may be provided so as to be capable of corresponding to a plurality of viewing angles such as telephoto and wide angle.

[0319] Here, an example having the imaging unit 825 is shown, but a distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object may be provided. That is, the imaging unit 825 is one aspect of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as a lidar (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired and a more accurate gesture operation can be enabled.

[0320] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having the vibration mechanism can be applied to any one or more of the display unit 820, the housing 821, and the mounting unit 823. As a result, there is no need for a separate acoustic device such as headphones, earphones, or a speaker, and images and sound can be enjoyed simply by wearing the electronic device 800A.

[0321] The electronic device 800A and the electronic device 800B may each have an input terminal. A cable for supplying a video signal from a video output device or the like and power for charging a battery provided in the electronic device can be connected to the input terminal.

[0322] The electronic device according to one aspect of the present invention may have a function of performing wireless communication with the earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (for example, audio data) from the electronic device by the wireless communication function. For example, the electronic device 700A shown in FIG. 13A has a function of transmitting information to the earphone 750 by the wireless communication function. Also, for example, the electronic device 800A shown in FIG. 14A has a function of transmitting information to the earphone 750 by the wireless communication function.

[0323] Also, the electronic device may have an earphone unit. The electronic device 700B shown in FIG. 13B has an earphone unit 727. For example, the earphone unit 727 and the control unit can be configured to be wired to each other. A part of the wiring connecting the earphone unit 727 and the control unit may be arranged inside the housing 721 or the mounting unit 723.

[0324] Similarly, the electronic device 800B shown in FIG. 14B has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be configured to be wired to each other. A part of the wiring connecting the earphone unit 827 and the control unit 824 may be disposed inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. Thereby, the earphone unit 827 can be fixed to the mounting unit 823 by magnetic force, which is preferable because it facilitates storage.

[0325] In addition, the electronic device may have an audio output terminal to which an earphone or a headphone can be connected. Further, the electronic device may have one or both of an audio input terminal and an audio input mechanism. As the audio input mechanism, for example, a sound collecting device such as a microphone can be used. By the electronic device having the audio input mechanism, a so-called headset function may be imparted to the electronic device.

[0326] As described above, as the electronic device according to one aspect of the present invention, both the glasses type (such as the electronic devices 700A and 700B) and the goggle type (such as the electronic devices 800A and 800B) are suitable.

[0327] Also, the electronic device according to one aspect of the present invention can transmit information to an earphone by wire or wirelessly.

[0328] The electronic device 6500 shown in FIG. 15A is a portable information terminal that can be used as a smartphone.

[0329] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display unit 6502 has a touch panel function.

[0330] The display device according to one aspect of the present invention can be applied to the display unit 6502.

[0331] FIG. 15B is a schematic cross-sectional view including the end portion of the housing 6501 on the side of the microphone 6506.

[0332] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 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.

[0333] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0334] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0335] A flexible display according to an aspect of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding back a part of the display panel 6511 and arranging the connection portion with the FPC 6515 on the back side of the pixel portion, a narrow-bezel electronic device can be realized.

[0336] An example of a television device is shown in FIG. 16A. The television device 7100 has a display unit 7000 incorporated in a housing 7101. Here, a configuration in which the housing 7101 is supported by a stand 7103 is shown.

[0337] A display device according to an aspect of the present invention can be applied to the display unit 7000.

[0338] The operation of the television apparatus 7100 shown in FIG. 16A can be performed by an operation switch provided in the housing 7101 and a separate remote control operation unit 7111. Alternatively, the display unit 7000 may be provided with a touch sensor, and the television apparatus 7100 may be operated by touching the display unit 7000 with a finger or the like. The remote control operation unit 7111 may have a display unit for displaying information output from the remote control operation unit 7111. Channel and volume operations can be performed by operation keys or a touch panel provided in the remote control operation unit 7111, and the video displayed on the display unit 7000 can be operated.

[0339] Note that the television apparatus 7100 has a configuration including a receiver and a modem, etc. General television broadcasts can be received by the receiver. Also, 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, etc.) information communication is also possible.

[0340] FIG. 16B shows an example of a notebook personal computer. The notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. The display unit 7000 is incorporated in the housing 7211.

[0341] The display device according to one aspect of the present invention can be applied to the display unit 7000.

[0342] FIGS. 16C and 16D show an example of digital signage.

[0343] The digital signage 7300 shown in FIG. 16C has a housing 7301, a display unit 7000, a speaker 7303, etc. Furthermore, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0344] FIG. 16D shows a digital signage 7400 attached to a cylindrical column 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the column 7401.

[0345] In FIGS. 16C and 16D, the display device according to an aspect of the present invention can be applied to the display unit 7000.

[0346] The larger the display unit 7000 is, the more information can be provided at once. Also, the larger the display unit 7000 is, the easier it is to catch people's eyes, and for example, the advertising effect can be enhanced.

[0347] By applying a touch panel to the display unit 7000, not only can an image or video be displayed on the display unit 7000, but also the user can operate it intuitively, which is preferable. Also, when used for applications such as providing route information or traffic information, the usability can be enhanced by intuitive operation.

[0348] Also, as shown in FIGS. 16C and 16D, it is preferable that the digital signage 7300 or the digital signage 7400 can be linked by wireless communication with an information terminal 7311 such as a smartphone or an information terminal 7411 held by the user. For example, the information of the advertisement displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. Also, by operating the information terminal 7311 or the information terminal 7411, the display of the display unit 7000 can be switched.

[0349] Also, 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). Thereby, an unspecified number of users can participate in the game and enjoy it at the same time.

[0350] The electronic device shown in FIGS. 17A to 17F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (including a function of measuring 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.

[0351] In FIGS. 17A to 17F, the display device according to an aspect of the present invention can be applied to the display unit 9001.

[0352] The electronic device shown in FIGS. 17A to 17F has various functions. For example, it can have a function of displaying various information (such as still images, moving images, text images, etc.) on the display unit, a touch panel function, a function of displaying a calendar, date or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, etc. Note that the functions of the electronic device are not limited to these and can have various functions. The electronic device may have a plurality of display units. Also, the electronic device may be provided with a camera or the like and have a function of taking a still image or a moving image and storing it in a recording medium (external or built-in to the camera), a function of displaying the taken image on the display unit, etc.

[0353] Details of the electronic device shown in FIGS. 17A to 17F will be described below.

[0354] FIG. 17A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 can be used, for example, as a smartphone. Note that the mobile information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, etc. Further, the mobile information terminal 9101 can display character and image information on its plurality of surfaces. FIG. 17A shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mail, SNS, and telephone, titles such as e-mail or SNS, sender names, dates, times, remaining battery levels, radio wave intensities, etc. Alternatively, an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.

[0355] FIG. 17B 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 surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces. For example, the user can also confirm the information 9053 displayed at a position where it can be observed from above the mobile information terminal 9102 in a state where the mobile information terminal 9102 is stored in the breast pocket of the clothes. The user can check the display without taking the mobile information terminal 9102 out of the pocket and can determine, for example, whether to answer a call.

[0356] FIG. 17C is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can be used, for example, as a smartwatch (registered trademark). Also, the display surface of the display unit 9001 is provided to be curved, and display can be performed along the curved display surface. Further, the mobile information terminal 9200 can also make a hands-free call by communicating with, for example, a wirelessly communicable headset. Also, the mobile information terminal 9200 can perform mutual data transmission with other information terminals and charging by the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0357] Figs. 17D to 17F are perspective views showing the foldable mobile information terminal 9201. Further, Fig. 17D shows the state where the mobile information terminal 9201 is unfolded, Fig. 17F shows the folded state, and Fig. 17E is a perspective view of the state in the middle of changing from one of Fig. 17D and Fig. 17F to the other. The mobile information terminal 9201 has excellent portability in the folded state and excellent display comprehensibility due to a seamless wide display area in the unfolded state. The display unit 9001 included in the mobile information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0358] This embodiment can be appropriately combined with other embodiments.

Description of Reference Numerals

[0359] 100A: Display device, 100B: Display device, 100C: Display device, 100: Display device, 101: Layer containing transistors, 110a: Sub-pixel, 110b: Sub-pixel, 110c: Sub-pixel, 110: Pixel, 111a: Pixel electrode, 111b: Pixel electrode, 111c: Pixel electrode, 111: Conductive film, 113a: First layer, 113b: Second layer, 113c: Third layer, 114: Electron injection layer, 115: Common electrode, 116: Fourth electron transport layer, 118A: First sacrificial layer, 118a: First sacrificial layer, 118B: Second sacrificial layer, 118b: Second sacrificial layer, 118C: Third sacrificial layer, 118c: Third sacrificial layer, 119: Resin layer, 120: Substrate, 123: Conductive layer, 130a: Light-emitting device, 130b: Light-emitting device, 130c: Light-emitting device, 131: Protection layer, 132: Protection layer, 133: Void, 134: Insulator, 140: Connection part, 181A: First hole injection layer, 181a: First hole injection layer, 181B: Second hole injection layer, 181b: Second hole injection layer, 181C: Third hole injection layer, 181c: Third hole injection layer, 182A: First hole transport layer, 182a: First hole transport layer, 182B: Second hole transport layer, 182b: Second hole transport layer, 182C: Third hole transport layer, 182c: Third hole transport layer, 183A: First light-emitting layer, 183a: First light-emitting layer, 183B: Second light-emitting layer, 183b: Second light-emitting layer, 183C: Third light-emitting layer, 183c: Third light-emitting layer, 184A: First electron transport layer, 184a: First electron transport layer, 184B: Second electron transport layer, 184b: Second electron transport layer, 184C: Third electron transport layer, 184c: Third electron transport layer, 190a: Resist mask, 190b: Resist mask, 190c: Resist mask, 240: Capacitance, 241: Conductive layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255: Insulating layer, 256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 271: Plug, 274a: Conductive layer, 274b: Conductive layer, 274: Plug, 280: Display module, 281: Display part, 282: Circuit part, 283a: Pixel circuit, 283: Pixel circuit part, 284a: Pixel, 284: Pixel part, 285: Terminal part, 286: Wiring part, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer312: Low-resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 700A: Electronic device, 700B: Electronic device, 721: Housing, 723: Mounting part, 727: Earphone part, 750: Earphone, 751: Display panel, 753: Optical member, 756: Display area, 757: Frame, 758: Nose pad, 772: Electrode, 786a: EL layer, 786b: EL layer, 786: EL layer, 788: Electrode, 800A: Electronic device, 800B: Electronic device, 820: Display unit, 821: Housing, 822: Communication part, 823: Mounting part, 824: Control part, 825: Imaging part, 827: Earphone part, 832: Lens, 4411: Light-emitting layer, 4412: Light-emitting layer, 4413: Light-emitting layer, 4420: Layer, 4421: Layer, 4422: Layer, 4430: Layer, 4431: Layer, 4432: Layer, 4440: Intermediate layer, 6500: Electronic device, 6501: Housing, 6502: Display unit, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protection 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 unit, 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 device, 7400: Digital signage, 7401: Column, 7411: Information terminal device, 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

1. An insulating layer, a first pixel electrode having a region in contact with the upper surface of the insulating layer, a second pixel electrode having a region in contact with the upper surface of the insulating layer, a first layer having a region in contact with the upper surface of the first pixel electrode, a second layer having a region in contact with the upper surface of the second pixel electrode, an electron transport layer having a region in contact with the upper surface of the first layer and a region in contact with the upper surface of the second layer, an electron injection layer having a region in contact with the upper surface of the electron transport layer, a common electrode having a region in contact with the upper surface of the electron injection layer, and the first layer and the second layer each have a function of emitting light of different colors, the electron transport layer has at least a region in contact with the upper surface of the insulating layer, a region in contact with the side surface of the insulating layer, a region in contact with the side surface of the first pixel electrode, a region in contact with the side surface of the second pixel electrode, a region in contact with the side surface of the first layer, and a region in contact with the side surface of the second layer. A display device.

2. An insulating layer, a first pixel electrode having a region in contact with the upper surface of the insulating layer, a second pixel electrode having a region in contact with the upper surface of the insulating layer, a first layer having a region in contact with the upper surface of the first pixel electrode, a second layer having a region in contact with the upper surface of the second pixel electrode, an electron transport layer having a region in contact with the upper surface of the first layer and a region in contact with the upper surface of the second layer, an electron injection layer having a region in contact with the upper surface of the electron transport layer, a common electrode having a region in contact with the upper surface of the electron injection layer, and the first layer and the second layer each have a function of emitting light of different colors, the electron transport layer has at least a region in contact with the upper surface of the insulating layer, a region in contact with the side surface of the insulating layer, a region in contact with the side surface of the first pixel electrode, a region in contact with the side surface of the second pixel electrode, a region in contact with the side surface of the first layer, and a region in contact with the side surface of the second layer, a display device having an insulator in contact with the upper surface of the electron transport layer in a region where the electron transport layer is in contact with the upper surface of the insulating layer.

Images