Display device and display device production method

Abstract

Provided is a display device with which high definition is easily achieved. The provided display device combines high display quality and high definition. The display device comprises pixel electrodes, EL layers, upper electrodes, first insulating layers, and partition walls. Each first insulating layer comprises a first portion, a second portion, and a third portion therebetween. The height of the second portion from a formation target surface is shorter than that of the first portion. The height of the upper surface of the third portion changes from the first portion to the second portion. Each partition wall has conductivity, is positioned on top of a first portion of a first insulating layer, and has a reverse tapered shape in a cross-sectional view. Each EL layer contains a light-emitting compound and is in contact with an upper surface of a pixel electrode and a second portion of a first insulating layer. Each upper electrode covers an upper surface and an end portion of an EL layer and is in contact with a side surface of a partition wall.

Description

Display device and method for manufacturing a display device

[0001] One aspect of the present invention relates to a display device. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, methods for driving them, or methods for manufacturing them. A semiconductor device refers to any device that can function by utilizing semiconductor properties.

[0003] In recent years, there has been a growing demand for higher resolution display panels. Devices requiring high-resolution display panels include, for example, smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors are also required to have higher resolutions. In addition, devices that require the highest level of resolution include, for example, devices for virtual reality (VR) or augmented reality (AR).

[0004] Furthermore, typical examples of display devices applicable to display panels include liquid crystal displays, organic EL (Electroluminescence) elements, light-emitting devices equipped with light-emitting elements such as light-emitting diodes (LEDs), and electronic paper that displays information using electrophoretic methods.

[0005] For example, the basic structure of an organic EL element consists of a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light can be obtained from the light-emitting organic compound. Because a display device using such an organic EL element does not require a backlight, which is necessary for liquid crystal displays and the like, it is possible to realize a thin, lightweight, high-contrast, and low-power display device. For example, an example of a display device using an organic EL element is described in Patent Document 1.

[0006] Furthermore, while a method using a metal mask is known for fabricating different organic EL elements, it has limitations in terms of aperture ratio, resolution, and substrate size. Patent document 2 describes a method for fabricating different organic EL elements using photolithography without using a metal mask.

[0007] Japanese Patent Publication No. 2002-324673, International Publication No. 2023 / 285907

[0008] One aspect of the present invention aims to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Another aspect of the present invention aims to provide a display device that combines high display quality and high resolution. Another aspect of the present invention aims to provide a display device with high contrast. Another aspect of the present invention aims to provide a highly reliable display device.

[0009] One aspect of the present invention aims to provide a display device having a novel configuration, or a method for manufacturing a display device. Another aspect of the present invention aims to provide a method for manufacturing the above-mentioned display device with a high yield. Another aspect of the present invention aims to mitigate at least one of the problems of the prior art.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. Moreover, one aspect of the present invention does not need to solve all of these problems. Other problems can be identified from the description in the specification, drawings, claims, etc.

[0011] One aspect of the present invention comprises a pixel electrode, an EL layer, an upper electrode, a first insulating layer, and a partition wall. The first insulating layer has a first portion, a second portion, and a third portion between them. The height of the second portion from the surface to be formed is lower than that of the first portion. The height of the upper surface of the third portion changes from the first portion to the second portion. The partition wall is conductive, located on the first portion of the first insulating layer, and has an inverse tapered shape in cross-section. The EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the second portion of the first insulating layer. The upper electrode covers the upper surface and edges of the EL layer and is in contact with the side surface of the partition wall.

[0012] Furthermore, in the above, it is preferable that the first insulating layer has a corner at the boundary between the first portion and the third portion in a cross-sectional view. It is also preferable that the corner overlaps with the side surface of the partition wall. Alternatively, it is preferable that the corner is located on the pixel electrode side rather than the most protruding end of the partition wall.

[0013] Furthermore, in the above, it is preferable that the angle between the contact surface between the partition wall and the first insulating layer and the side surface of the partition wall is 105 degrees or more and 175 degrees or less.

[0014] Furthermore, in the above, it is preferable that the partition wall contains one or more of the following: molybdenum, silver, copper, aluminum, tungsten, and titanium.

[0015] Another aspect of the present invention is a method for manufacturing a display device, comprising the following steps: 1. Form a first insulating layer covering the pixel electrodes. 2. Form a first conductive film on the first insulating layer. 3. Form a resist mask on the first conductive film. 4. Etch the portion of the first conductive film not covered by the resist mask to form a reverse tapered partition wall. 5. Etch a portion of the first insulating layer not covered by the resist mask to form a first portion, a second portion whose upper surface height from the surface to be formed is lower than that of the first portion, and a third portion located between the first and second portions, where the height of the upper surface changes from the first portion to the second portion. 6. Remove the resist mask. 7. Remove a portion of the second portion of the first insulating layer to expose a portion of the pixel electrodes. 8. Form a first EL layer in contact with the upper surface of the pixel electrodes and the upper surface of the second portion, and a second EL layer on the partition wall that is physically separated from the first EL layer. 9. Form an upper electrode covering the first EL layer and in contact with the side surface of the partition wall.

[0016] Furthermore, in the above, it is preferable to form a first conductive film by sputtering, comprising a first layer and a second layer on the first layer. In this case, it is preferable to form the second layer under conditions that satisfy lower pressure, higher power supply voltage, or both, than the conditions for forming the first layer.

[0017] Furthermore, in the above, it is preferable that the first conductive film and the first insulating layer are processed by dry etching.

[0018] Furthermore, in the above, it is preferable that the first conductive film is formed to contain one or more of the following: molybdenum, silver, copper, aluminum, tungsten, and titanium.

[0019] According to one aspect of the present invention, it is possible to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Alternatively, it is possible to provide a display device that combines high display quality and high resolution. Alternatively, it is possible to provide a display device with high contrast. Alternatively, it is possible to provide a highly reliable display device.

[0020] Furthermore, according to one aspect of the present invention, a display device having a novel configuration, or a method for manufacturing a display device, can be provided. Alternatively, a method for manufacturing the above-mentioned display device with a high yield can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be mitigated.

[0021] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description in the specification, drawings, claims, etc.

[0022] Figures 1A and 1B show examples of the configuration of a display device. Figures 2A and 2B show examples of the configuration of a display device. Figure 3 shows an example of the configuration of a display device. Figure 4 shows an example of the configuration of a display device. Figures 5A, 5B, 5C, and 5D show examples of the configuration of a display device. Figure 6 shows an example of the configuration of a display device. Figures 7A, 7B, 7C, 7D, 7E, 7F, 7G, 7H, and 7I show examples of the configuration of a display device. Figures 8A and 8B show examples of the configuration of a display device. Figures 9A and 9B show examples of the configuration of a display device. Figures 10A and 10B show examples of the configuration of a display device. Figure 11 shows an example of the configuration of a display device. Figures 12A, 12B, and 12C show examples of the configuration of a display device. Figures 13A, 13B, 13C, 13D, 13E, and 13F are diagrams illustrating examples of methods for manufacturing a display device. Figures 14A, 14B, 14C, 14D, and 14E illustrate examples of methods for manufacturing a display device. Figures 15A, 15B, 15C, 15D, 15E, and 15F illustrate examples of methods for manufacturing a display device. Figures 16A and 16B illustrate examples of methods for manufacturing a display device. Figures 17A and 17B illustrate examples of methods for manufacturing a display device. Figures 18A, 18B, 18C, 18D, and 18E illustrate examples of methods for manufacturing a display device. Figures 19A, 19B, and 19C show examples of the configuration of a display device manufacturing apparatus. Figures 20A and 20B show examples of the configuration of a display device manufacturing apparatus. Figure 21 shows an example of the configuration of a display device. Figure 22 shows an example of the configuration of a display device. Figures 23A and 23B show examples of the configuration of a display device. Figures 24A and 24B show examples of the configuration of a display device. Figure 25 shows an example of a display device configuration. Figure 26 shows an example of a display device configuration. Figure 27 shows an example of a display device configuration. Figures 28A, 28B, 28C, 28D, 28E, and 28F show examples of a light-emitting device configuration. Figures 29A, 29B, and 29C show examples of a light-emitting device configuration. Figures 30A, 30B, 30C, and 30D show examples of an electronic device configuration. Figures 31A, 31B, 31C, 31D, 31E, and 31F show examples of an electronic device configuration. Figures 32A, 32B, 32C, 32D, 32E, 32F, and 32G show examples of an electronic device configuration. Figures 33A and 33B show examples of an electronic device configuration.FIG. 33C is a diagram showing how an electronic device is used. FIGS. 34A and 34B are cross-sectional observation images according to an example.

[0023] Embodiments will be described below with reference to the drawings. However, it will be readily appreciated by those skilled in the art that the embodiments can be implemented in many different forms, and that the forms and details thereof can be variously changed without departing from the spirit and scope thereof. Therefore, the present invention should not be construed as being limited to the content described in the following embodiments.

[0024] In the configuration of the invention described below, the same reference numerals are commonly used for the same parts or parts having similar functions between different drawings, and repeated description thereof will be omitted. In addition, when referring to similar functions, the same hatching pattern is used, and in some cases, no particular reference numeral is assigned.

[0025] In each drawing described in this specification, the size, layer thickness, or region of each component may be exaggerated for clarity. Therefore, the scale is not necessarily limited.

[0026] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion between constituent elements, and are not intended to be numerically limiting.

[0027] In this specification, "the top surface shapes are substantially the same" means that at least a part of the outline overlaps between stacked layers. For example, it includes the case where the upper layer and the lower layer are processed by the same mask pattern, or partially by the same mask pattern. However, strictly speaking, the outlines do not overlap, the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer, and this case may also be referred to as "the top surface shapes are substantially the same".

[0028] In this specification, the top surface shape of a component refers to the contour shape of the component in plan view. Plan view refers to viewing from the normal direction of the surface on which the component is formed, or the surface of a support (for example, a substrate) on which the component is formed.

[0029] It should be noted that, hereinafter, expressions indicating orientations such as "upper" and "lower" are basically used in accordance with the orientation in the drawings. However, for the purpose of facilitating description and other purposes, the orientation meant by "upper" or "lower" in the specification may not match that in the drawings. As an example, when describing the stacking order (or formation order) of a laminate or the like, even if the surface on which the laminate is provided (a surface to be formed, a support surface, an adhesive surface, a flat surface, etc.) is located above the laminate in the drawings, the surface to be formed side may be expressed as lower and the laminate side as upper in some cases.

[0030] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable with each other. For example, the term "insulating layer" may be interchangeable with the term "insulating film" in some cases.

[0031] In this specification, the EL layer refers to a layer (also referred to as a light-emitting layer) that is provided between a pair of electrodes of a light-emitting element and contains at least a light-emitting substance, or a laminate including the light-emitting layer.

[0032] In addition, in this specification and the like, a display panel substrate with a connector such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached thereto, or a substrate with an IC mounted by a COG (Chip On Glass) method or the like may be referred to as a display panel module, a display module, or simply a display panel in some cases.

[0033] (Embodiment 1) In this embodiment, a structural example of a display device according to one embodiment of the present invention and an example of a manufacturing method thereof are described.

[0034] One aspect of the present invention is a display device having light-emitting elements (also called light-emitting devices). The display device has at least two light-emitting elements with different emission colors. Each light-emitting element has a pair of electrodes and an EL layer between them. Preferably, the light-emitting elements are organic EL elements (organic electroluminescent elements). Two or more light-emitting elements with different emission colors each have an EL layer containing a different material. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light, respectively.

[0035] Here, when differentiating between light-emitting elements of different emission colors by creating part or all of the EL layer, it is known that this is done by deposition using a shadow mask such as a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-like organic film due to various influences such as the precision of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spreading of the film's outline due to vapor scattering, making it difficult to increase the resolution and aperture ratio of the display device. Therefore, measures are taken to artificially increase the resolution (also called pixel density) by applying special pixel arrangement methods such as pentile arrangements.

[0036] One aspect of the present invention involves processing the EL layer into a fine pattern without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high resolution and a large aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be differentiated, it is possible to realize a display device with extremely vivid colors, high contrast, and high display quality.

[0037] One aspect of the present invention involves providing a partition wall between two adjacent light-emitting elements (a first light-emitting element and a second light-emitting element) to physically divide the EL layer. The partition wall is a conductive structure with an inverse tapered shape. The partition wall can also be described as having a shape in which its upper part protrudes laterally more than its lower part. The partition wall is formed so as to be located between two adjacent pixel electrodes when viewed from above. The partition wall is also provided so as to surround one pixel electrode. When the EL layer of the first light-emitting element is deposited, a step is created by the partition wall, and an island-shaped EL layer is formed in the region surrounded by the partition wall.

[0038] In this specification, "step breakage" refers to the phenomenon in which a layer, film, electrode, etc., is divided due to the shape of the surface on which it is formed (for example, a step or other difference in height).

[0039] Next, a sacrificial layer is formed by covering the EL layer. The sacrificial layer functions as a protective layer to protect the EL layer in subsequent etching processes. The sacrificial layer is preferably formed by atomic layer deposition (ALD), which provides extremely high step coverage. This makes it possible to obtain a good protective film with few defects such as pinholes.

[0040] Next, a resist mask is formed to cover the target pixel electrode and a portion of the partition wall, and the sacrificial layer and EL layer located in the areas not covered by the resist mask are removed by etching. At this time, it is preferable to leave the partition wall intact so that the process of creating the partition wall does not need to be repeated.

[0041] By repeating the process from the formation of the EL layer to the etching process, it is possible to create different types of EL layers. This method allows for the creation of different light-emitting elements using photolithography, which enables microfabrication, without the need for a metal mask. As a result, it is possible to manufacture display devices with extremely high resolution and a high aperture ratio.

[0042] Next, after removing the sacrificial layer covering each EL layer, the upper electrode is formed by covering the EL layer and the partition wall. At this time, the upper electrode is formed using a film formation method that provides higher step coverage than the EL layer. This allows a configuration in which a portion of the upper electrode covers the edge of the EL layer and also contacts a portion of the partition wall.

[0043] Here, the conductive partition wall can be provided on an insulating layer (first insulating layer). Preferably, this insulating layer also serves as an insulating layer covering the ends of the pixel electrodes. Furthermore, when etching to form the partition wall, it is preferable to etch (also called half-etch) a part of the upper part of the insulating layer to form a stepped portion in the insulating layer. The insulating layer thus formed has a region in contact with the partition wall, a region covered by the partition wall, and a portion in the vicinity of these regions that is not half-etched, and a region away from the partition wall that is half-etched. In other words, the insulating layer has a first portion and a second portion whose upper surface height (height from the surface on which the insulating layer is formed) is lower than that of the first portion. This makes it possible to substantially increase the height of the partition wall by the height of the step. Therefore, it becomes possible to more reliably create a stepped cut in the EL layer, and the manufacturing yield of the display device can be improved.

[0044] Furthermore, it is preferable that the height changes continuously between the first and second parts. That is, it is preferable to have a third part between the first and second parts in which the height of the upper surface changes from the first part to the second part. This prevents the upper electrode from being cut off by the step.

[0045] This allows for the fabrication of a light-emitting element having a pixel electrode, an island-shaped EL layer, and an upper electrode in contact with the partition wall, within a region surrounded by a partition wall. A protective layer may also be formed to cover the light-emitting element. The partition wall in contact with the upper electrode can function as wiring for supplying potential to the upper electrode.

[0046] While it is difficult to reduce the spacing between different colored EL layers to less than 10 μm using, for example, a metal mask formation method, the above method allows for narrowing the spacing to 3 μm or less, 2 μm or less, or even 1 μm or less. For example, by using an exposure apparatus for LSIs, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting elements, making it possible to approach an aperture ratio of 100%. For example, an aperture ratio of 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, can be achieved, and even less than 100%.

[0047] Furthermore, the size of the EL layer itself can be made significantly smaller compared to when a metal mask is used. Also, for example, when a metal mask is used to create different EL layers, variations in thickness occur between the center and edges of the island-shaped EL layer, resulting in a smaller effective area usable as an emitting region relative to the total area of ​​the EL layer. On the other hand, with the above manufacturing method, island-shaped EL layers are formed by processing a film deposited to a uniform thickness, so the thickness can be made uniform, and even if the size of the EL layer is fine, almost the entire area can be used as an emitting region. Therefore, the above manufacturing method can achieve both high resolution and a high aperture ratio.

[0048] Thus, according to the above manufacturing method, a display device with integrated fine light-emitting elements can be realized. Therefore, there is no need to apply a special pixel arrangement method such as the PenTile method to artificially increase the resolution. Thus, a display device can be realized with a configuration in which each pixel has three colored light-emitting elements, and with a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, 5000 ppi or more, and even 8000 ppi or more.

[0049] Below, we will explain more specific examples with reference to the diagrams.

[0050] [Configuration Example] Figure 1A shows a schematic top view of the display device 100. The display device 100 has multiple red light-emitting elements 110R, multiple green light-emitting elements 110G, and multiple blue light-emitting elements 110B. In Figure 1A, the mutually orthogonal X and Y directions are indicated by arrows.

[0051] The light-emitting elements 110R, 110G, and 110B are each arranged in a matrix. Figure 1A shows a so-called stripe arrangement in which light-emitting elements of the same color are arranged in the Y direction. Note that the arrangement method of the light-emitting elements is not limited to this, and arrangement methods such as S-stripe arrangement, delta arrangement, zigzag arrangement may be applied, or a pentile arrangement may be used. Figure 1B shows an example in which an S-stripe arrangement is used.

[0052] It is preferable to use EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes) as the light-emitting elements 110R, 110G, and 110B. Examples of light-emitting materials for EL elements include fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. Not only organic compounds but also inorganic compounds (such as quantum dot materials) can be used as light-emitting materials for EL elements.

[0053] In this embodiment, when describing matters common to components distinguished by letters or numbers attached to their reference numerals (such as light-emitting element 110R and light-emitting element 110G), the reference numerals (such as light-emitting element 110) may be used without further explanation.

[0054] Furthermore, partition walls 120 are provided between each light-emitting element 110. The partition walls 120 have a grid-like upper surface shape. It can also be said that the light-emitting elements 110 are provided in the region surrounded by the partition walls 120.

[0055] As shown in Figure 1A, in a plan view, a gap is provided between the partition wall 120 and the light-emitting element 110. Figure 1A shows the gap Sx in the X direction and the gap Sy in the Y direction between the light-emitting element 110 and the partition wall 120.

[0056] Figure 2A is a schematic cross-sectional view of the display device 100 corresponding to the cutting line A-B shown in Figure 1A. The display device 100 has a plurality of transistors 150, a light-emitting element 110R, a light-emitting element 110G, and a light-emitting element 110B.

[0057] Multiple transistors 150 are provided on the substrate 101. Each transistor 150 has a semiconductor layer 151 on which a channel is formed, an insulating layer 152 that functions as a gate insulating layer, a conductive layer 153 that functions as a gate electrode, and a pair of conductive layers 154 that are in contact with the semiconductor layer 151 and function as a source electrode and a drain electrode. The conductive layers 154 are provided on an insulating layer 131 that covers the semiconductor layer 151, the insulating layer 152, and the conductive layers 153, and are in contact with the semiconductor layer 151 at an opening provided in the insulating layer 131.

[0058] It is preferable to use a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties as the semiconductor layer 151. As the oxide semiconductor, an oxide semiconductor such as indium oxide or In-Ga-Zn oxide (IGZO) can be used. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0059] In addition, metal oxides that can be used in the semiconductor layer 151 include tin oxide, zinc oxide, indium tin oxide, indium titanium oxide, indium gallium oxide, indium tungsten oxide, indium zinc oxide, indium gallium aluminum oxide, indium gallium tin oxide, gallium zinc oxide, aluminum zinc oxide, indium aluminum zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, indium gallium zinc oxide, indium gallium tin zinc oxide, and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, aluminum tin oxide, etc., can also be used.

[0060] In this example, transistor 150 is shown as a so-called top-gate type transistor, where the gate electrode is located on the upper side of the semiconductor layer, but it is not limited to this. For example, a bottom-gate type transistor, where the gate electrode is located below the semiconductor layer, can also be used.

[0061] An insulating layer 132 is provided covering the conductive layer 154 and the insulating layer 131, and light-emitting elements 110R, 110G, and 110B are provided on the insulating layer 132.

[0062] The light-emitting element 110R has an EL layer 112R between the pixel electrode 111R and the upper electrode 113. The light-emitting element 110G has an EL layer 112G between the pixel electrode 111G and the upper electrode 113. The light-emitting element 110B has an EL layer 112B between the pixel electrode 111B and the upper electrode 113. The upper electrode 113 is provided in common to each light-emitting element 110. Note that the upper electrode 113 provided on each light-emitting element 110 may be physically separated by a partition wall 120.

[0063] The EL layer 112R of the light-emitting element 110R has a light-emitting compound that emits at least red light. The EL layer 112G of the light-emitting element 110G has a light-emitting compound that emits at least green light. The EL layer 112B of the light-emitting element 110B has a light-emitting compound that emits at least blue light.

[0064] Each of the EL layers 112R, 112G, and 112B may have, in addition to a layer containing a light-emitting compound (light-emitting layer), one or more of the following: an electron injection layer, an electron transport layer, an electron blocking layer, a hole injection layer, a hole transport layer, and a hole blocking layer.

[0065] A conductive film that is transparent to visible light is used on either each pixel electrode 111 or the upper electrode 113, and a conductive film that is reflective is used on the other. By making each pixel electrode 111 transparent and the upper electrode 113 reflective, a bottom-emission type light-emitting element can be created. Conversely, by making each pixel electrode 111 reflective and the upper electrode 113 transparent, a top-emission type light-emitting element can be created. Furthermore, by making both each pixel electrode 111 and the upper electrode 113 transparent, a dual-emission type display device can also be created.

[0066] A protective layer 135 is provided covering the upper electrode 113 and the partition wall 120. The protective layer 135 can be a single-layer structure or a multi-layer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 135. Aluminum oxide and silicon nitride are particularly preferred due to their high barrier properties against water.

[0067] In this specification, the term "oxidogenic nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and the term "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content.

[0068] Furthermore, a laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 135. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films.

[0069] An insulating layer 133 is provided to cover the ends of each pixel electrode 111. The portion of the pixel electrode 111 that is not covered by the insulating layer 133 functions as the light-emitting region of the light-emitting element 110. The ends of the insulating layer 133 are preferably tapered.

[0070] In this specification, an object is said to have a tapered shape if the angle between the side surface of the object and the contact surface between the object and the surface to be formed (also called the taper angle) is greater than 0 degrees and less than 90 degrees, and the cross-sectional shape has a thickness that increases continuously from the end. On the other hand, an object is said to have an inverse tapered shape if the angle between the side surface of the object and the contact surface between the object and the surface to be formed is greater than 90 degrees and less than 180 degrees.

[0071] The upper surface of the insulating layer 133 forms the surface to which the partition wall 120 is formed. The insulating layer 133 can be an inorganic insulating film or an organic insulating film.

[0072] It is preferable to use an inorganic insulating film for the insulating layer 133. Since inorganic insulating films are suitable for microfabrication, they are suitable for high-resolution display devices. When an inorganic insulating film is used for the insulating layer 133, it is preferable that its edges have a tapered shape. As inorganic insulating materials that can be used for the insulating layer 133, silicon oxide, silicon nitride, silicon oxide nitride, aluminum oxide, aluminum nitride, etc. may also be used. Furthermore, two or more of the above insulating films may be laminated and used.

[0073] Alternatively, an organic insulating film containing an organic resin can be used for the insulating layer 133. In particular, using an organic resin on the outermost surface of the insulating layer 133 can improve adhesion with the EL layer 112, which contains the same organic material, thereby improving the manufacturing yield. Especially when each EL layer is processed by etching, it is preferable to use an organic resin with high adhesion to the EL layer on the surface of the insulating layer 133 that is in contact with the EL layer, as this reduces the problem of the EL layer peeling off after etching. Furthermore, by using an organic resin for the insulating layer 133, its surface can be made flat or gently curved. Therefore, the coverage of the film formed on the insulating layer 133 can be improved.

[0074] Examples of organic resins that can be used in the insulating layer 133 include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0075] A partition wall 120 is provided on the insulating layer 133. The partition wall 120 is conductive and has a tapered shape.

[0076] Figure 2B shows an enlarged view of the light-emitting element 110R, the light-emitting element 110G, the partition wall 120 located between them, and the vicinity thereof.

[0077] The insulating layer 133 has a shape in which a portion of the upper part is removed by etching at both ends in cross-sectional view, and there is a step between the central part and both ends. In other words, the insulating layer 133 has portions R1 and R2 with different heights on the upper surface. Furthermore, it is preferable that the insulating layer 133 has a portion R3 located between portions R1 and R2. When the height of the upper surface of portion R1 (for example, the height relative to the upper surface of the insulating layer 132) is height h1 and the height of the upper surface of portion R2 is height h2, height h2 is lower than height h1.

[0078] Part R1 includes the region in contact with the partition wall 120. Part R2 includes both ends of the insulating layer 133 and the region overlapping with the pixel electrode 111. In addition, the height of the upper surface of part R3 changes from part R1 to part R2. In part R3, it is preferable that the height of the upper surface changes continuously. However, the inclination of the upper surface may be discontinuous at the boundary (corner R) between part R1 and part R3.

[0079] In this way, the insulating layer 133 has steps that reduce the height of the upper surfaces at both ends, so that in the region where the EL layer 112R is formed, the height from the upper surface of the insulating layer 133 to the upper surface of the partition wall 120 can be substantially increased by the amount of the steps. Therefore, even if the height of the partition wall 120 is insufficient for the EL layer 112R to be stepped, the EL layer 112R can be reliably stepped. This improves the manufacturing yield of the display device 100.

[0080] The EL layer 112R and EL layer 112B are stepped by the partition wall 120, and their respective ends are located on the insulating layer 133. Figure 2B shows an example where the EL layer 112R and EL layer 112G are in contact with the upper surfaces of portions R2 and R3, and are not located on portion R1.

[0081] The upper electrode 113 covers the end of the EL layer 112R or EL layer 112G and is in contact with the upper surface of portion R1 of the insulating layer 133 and the side surface of the partition wall 120. The protective layer 135 is provided covering the upper electrode 113. Note that, as shown in Figure 2B, the upper electrode 113 may be physically separated into a portion that covers the EL layer 112 and a portion located above the partition wall 120. On the partition wall 120, EL layers 112Ra and EL layers 112Ga may be provided between the upper electrode 113 and the partition wall 120. EL layer 112Ra contains the same material as EL layer 112R, and EL layer 112Ga contains the same material as EL layer 112G.

[0082] The upper electrode 113 is in contact with a conductive partition wall 120. Even if the upper electrode 113 is divided into two by the partition wall 120, the two upper electrodes 113 are connected via the partition wall 120. As shown in Figure 1A, the partition wall 120 is arranged in a grid pattern so as to weave between the light-emitting elements 110, so the upper electrodes 113 of all light-emitting elements 110 are connected via the partition wall 120. The partition wall 120 also functions as wiring that supplies potential to the upper electrodes 113 of each light-emitting element 110.

[0083] Figure 3 shows a perspective view of the display device 100. In Figure 3, some components such as the upper electrode and protective layer 135 are omitted. As shown in Figure 3, the partition wall 120 has a grid-like shape. Island-shaped EL layers 112 are provided in the area surrounded by the partition wall 120.

[0084] Figure 3 shows an example where the EL layers 112Ra, 112Ga, and 112Ba are separated on the partition wall 120 between adjacent light-emitting elements 110 of the same color in the Y direction. Figure 4 shows an example where they are not separated. In Figure 4, the upper part of the partition wall 120 is provided with ladder-shaped EL layers 112Ra, 112Ga, and 112Ba.

[0085] As shown in Figure 2B, the insulating layer 133 has its ends in portion R2 positioned on the pixel electrode 111R and on the pixel electrode 111G, respectively. The gap Sx corresponds to the space between the end of the insulating layer 133 and the end of the most protruding portion of the partition wall 120. The presence of this gap Sx allows the EL layer 112 to be formed such that, during deposition, the stepped end of the EL layer 112, separated by the partition wall 120, is positioned on the insulating layer 133 and not on the pixel electrode 111. For example, if the end of the EL layer 112 is positioned on the pixel electrode 111, the upper electrode covering the EL layer may come into contact with the pixel electrode 111, potentially causing an electrical short circuit. Therefore, it is important to provide a gap Sx between the end of the insulating layer 133 and the partition wall 120 to ensure that the end of the EL layer 112 is reliably positioned on the insulating layer 133. The same applies to the gap Sy.

[0086] Preferably, the height h (also called thickness) of the partition wall 120 is greater than the thickness of the thickest film among the EL layers 112R, EL layer 112G, and EL layer 112B. Furthermore, it is preferable that the sum of the height difference between the upper surfaces of portions R1 and R2 of the insulating layer 133 (h1-h2) and the height h of the partition wall 120 (h+(h1-h2)) is greater than the thickness of the thickest film among the EL layers 112.

[0087] Furthermore, the taper angle θ of the partition wall 120 can be greater than 90 degrees and less than 180 degrees. The closer the taper angle θ is to 90 degrees, the easier it is for the partition wall 120 and the upper electrode 113 to come into contact when the upper electrode 113 is formed. However, the gap between the end of the EL layer 112 and the partition wall 120 becomes narrower, and there is a risk that sufficient space cannot be secured for the upper electrode 113 and the partition wall 120 to come into contact. Also, the closer the taper angle θ is to 180 degrees, the easier it is for the EL layer 112 to break in steps, while it becomes difficult to bring the upper electrode 113 and the partition wall 120 into contact. For this reason, the taper angle θ can be, for example, 95 degrees or more and 150 degrees or less, preferably 100 degrees or more and 135 degrees or less. Furthermore, if the coverage of the upper electrode 113 is sufficiently high, an even larger taper angle θ can be used. For example, the taper angle θ can be 105 degrees or more and 175 degrees or less, preferably 120 degrees or more and 170 degrees or less.

[0088] Here, the taper angle θ is used as the angle between the bottom and side surfaces of the partition wall 120. However, as shown in Figure 2B, it can also be expressed as the angle (taper angle θ') between the side surface of the partition wall 120 and the upper surface of the underlayment (insulating layer 133 in this case) that does not come into contact with the partition wall 120. In that case, it can be expressed as θ' ​​= 180 degrees - θ (both θ and θ' are between 0 and 180 degrees). That is, the preferred range for the taper angle θ' can be expressed as 30 degrees to 85 degrees, preferably 45 degrees to 80 degrees, or 5 degrees to 75 degrees, preferably 10 degrees to 60 degrees. The choice of which angle to use to express the taper angle can be made by considering the surface shape of the underlayment (e.g., insulating layer 133) and selecting the one that is easier to measure.

[0089] The partition wall 120 can be made of various conductive materials. For example, metals, alloys, oxide conductive materials, nitride conductive materials, etc., can be used. For example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used.

[0090] Furthermore, it is preferable that the partition wall 120 contains an oxide conductive material containing indium. This is preferable because it can reduce the contact resistance with the upper electrode 113. For example, an oxide conductive material such as indium tin oxide can be used. Other materials that can be used include indium oxide, indium zinc oxide, indium titanium oxide, indium gallium zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, and indium gallium tin zinc oxide. Alternatively, indium tin oxide containing silicon can also be used. In addition, an oxide conductive material that does not contain indium, such as zinc oxide, may be used.

[0091] In particular, it is preferable that the partition wall 120 and the insulating layer 133 be a combination that can be processed continuously by the same etching process. This can reduce processing costs. For example, when an insulating film containing silicon, such as silicon oxide, silicon oxynitride, or silicon nitride, is used as the insulating layer 133, SF ６ CF ４ CHF ３ It is preferable to use etching gases containing fluorine, such as those mentioned above. Therefore, it is preferable to use a material that can be etched with the same fluorine-containing etching gas as the partition wall 120, and it is preferable to use metallic materials such as molybdenum, tungsten, chromium, and titanium.

[0092] Alternatively, it is preferable to use a combination of materials for the partition wall 120 and the insulating layer 133 that allows for a high selectivity ratio of etching rates. This allows the etching of the partition wall 120 and the insulating layer 133 to be carried out separately under different conditions, thereby increasing the controllability of each process and enabling highly accurate processing. For example, if the partition wall 120 is made of the above-mentioned metal material such as molybdenum, the insulating layer 133 can be made of an insulating film that does not contain silicon, such as aluminum oxide.

[0093] In this configuration, a conductive partition wall 120 having an inverse taper shape is provided between adjacent pixels, and an insulating layer 133 having a stepped shape is placed below the partition wall 120. This allows for the creation of different EL layers 112 between adjacent light-emitting elements, substantially eliminating leakage current through the EL layers 112 compared to cases where the EL layers 112 are in contact with each other or where a common EL layer 112 is used. This prevents unintended light emission and enables the realization of a display device with high contrast and high display quality. Furthermore, since the EL layer 112 is covered by the upper electrode 113 and protective layer 135 within the region surrounded by the partition wall 120, it prevents the diffusion of impurities such as moisture into the EL layer 112, enabling the realization of a highly reliable display device. In addition, this configuration does not require the use of a metal mask, and all processing of the EL layer 112, etc., can be performed using photolithography, making it easier to achieve high resolution and high aperture ratio compared to cases where a metal mask is used.

[0094] The stepped shape of the insulating layer 133 can be formed by etching (half-etching) a portion of the insulating layer 133 after the partition wall 120 has been formed. At this time, the relative position of the area of ​​the insulating layer 133 that is half-etched and the partition wall 120 may change depending on the etching conditions. More specifically, the relative position of the corner R shown in Figure 2B and the partition wall 120 may change depending on the processing conditions of the insulating layer 133.

[0095] Figure 5A is a schematic cross-sectional view extracted from a portion of Figure 2B. Figure 5A shows a straight line P passing through the outermost protruding point of the partition wall 120 and perpendicular to the surface to be formed, and a straight line Q passing through the lower end of the side surface of the partition wall 120 and perpendicular to the surface to be formed. The region of the upper surface of the insulating layer 133 located between the straight line P and the straight line Q can be said to be the region that overlaps with the side surface of the partition wall 120.

[0096] Figure 5A shows an example where the corner R coincides with the straight line P. In other words, the portion of the insulating layer 133 that overlaps with the partition wall 120 is not half-etched, while the portion of the insulating layer 133 outside the portion that overlaps with the partition wall 120, i.e., the portion that does not overlap with the partition wall 120, is half-etched.

[0097] Figure 5B shows an example where corner R is located between line P and line Q. That is, an example where corner R is located in a region that overlaps with the side surface of partition wall 120. Figure 5C shows an example where corner R overlaps with line Q. Figure 5D shows an example where corner R is located inside line Q and overlaps with the bottom surface of partition wall 120.

[0098] In all of Figures 5A to 5D, the end of the EL layer 112, which is stepped by the partition wall 120, tends to be located outside the corner radius R. When a highly conductive material is used for the EL layer 112, if the end of the EL layer 112 comes into contact with the partition wall 120, unintended leakage current may occur. Therefore, as shown in Figures 5A to 5D, it is preferable that the end of the EL layer 112 is located outside the corner radius R (towards the pixel electrode 111).

[0099] Furthermore, depending on the processing conditions of the insulating layer 133, as shown in Figure 6, the corner R may be located outside the straight line P (on the pixel electrode 111R side), and a part of the EL layer 112 may cover the corner R and reach part R1. In a cross-sectional view, the corner R can be said to be located on the pixel electrode 111R side of the most protruding end of the partition wall 120.

[0100] The partition wall 120 shown in Figure 2B, etc., is an example having an inverse tapered shape. The shape of the partition wall 120 exemplified in Figure 2B, etc., can also be described as having a roughly trapezoidal shape in cross-section, where the length of the upper base is longer than the length of the lower base. However, the shape of the partition wall 120 is not limited to this, and various shapes can be taken if the EL layer 112 can be stepped. The partition wall 120 can also have a symmetrical shape in cross-section. If the upper surface of the partition wall 120 is flat, the shape of the partition wall 120 in cross-section will be a polygon with an even number of corners. Examples of other cross-sectional shapes of the partition wall 120 will be described below.

[0101] The examples shown in Figures 7A and 7B are examples in which the side surface of the partition wall 120 has a curved shape. In Figure 7A, it has a concave curved surface, and in Figure 7B, it has a convex curved surface.

[0102] When the side surface of the partition wall 120 has a curved shape, it is difficult to uniquely determine the taper angle θ. In such cases, as shown in Figures 7A and 7B, a straight line connecting the point of the widest part of the partition wall 120 in a cross-sectional view and the point of the end of the contact surface between the partition wall 120 and the underlayment (insulating layer 133) can be assumed to be a hypothetical side surface of the partition wall 120, and the angle between this straight line and the contact surface between the partition wall 120 and the underlayment (insulating layer 133) can be defined as the taper angle θ.

[0103] Here, the partition wall 120 only needs to have a tapered shape in a portion including at least the part that is in contact with the substrate film, and the shape of the part above that is not specified. As shown in Figure 7C, the partition wall 120 can be divided into a lower part 120B (also called the first part) which has a tapered shape, and an upper part 120T (also called the second part) which is located above the lower part 120B. Since the upper part 120T can take various shapes, its shape is not explicitly shown here and is indicated by a dashed line. Below, examples of upper parts 120T with different shapes will be described.

[0104] Figure 7D shows an example where the upper part 120T has a rectangular shape in cross-section. Figures 7E and 7F show examples where the upper part 120T has a trapezoidal shape in cross-section, where the length of the upper side (also called the upper base) is shorter than the length of the lower side (also called the lower base). Figure 7E shows an example where the thickness of the upper part 120T is thinner than the lower part 120B, and Figure 7F shows an example where the thicknesses of the upper part 120T and the lower part 120B are roughly the same. The partition walls 120 shown in Figures 7D, 7E, and 7F can also be said to have a hexagonal shape in cross-section.

[0105] Figure 7G shows an example where the partition wall 120 has an octagonal shape in cross-sectional view. In Figure 7G, a portion of the side surface of the partition wall 120 is approximately perpendicular to the surface to be formed.

[0106] Figures 7H and 7I are modified examples of Figures 7A and 7B, respectively, and are examples having a curved lower part 120B and an upper part 120T that has a trapezoidal shape in cross-sectional view.

[0107] Although the above shows that the side surface of the partition wall 120 has corners, depending on the processing method of the partition wall 120, the corners may be rounded. In particular, when the partition wall 120 is formed by an isotropic etching method such as wet etching, the corners tend to be rounded.

[0108] [Modified Version] The following describes an example of a display device with some configuration differences from the above. Note that parts that overlap with the above configuration example will be omitted from the explanation.

[0109] [Modification 1] Figures 8A and 8B show an example where the insulating layer 133 has a laminated structure. The insulating layer 133 has an insulating layer 133a and an insulating layer 133b on top of it.

[0110] It is preferable that the insulating layer 133a and insulating layer 133b be a combination with a high selectivity ratio for etching rate. For example, insulating layer 133b is a film that can be etched under the same etching conditions as the partition wall 120, and insulating layer 133a is a film that is not etched under those etching conditions, or has an etching rate lower than that of insulating layer 133b. When insulating layer 133 has a single-layer structure, variations in the size of the step may occur in the half-etching process for forming the step shape. On the other hand, by making insulating layer 133 a laminated structure, insulating layer 133a functions as an etching stopper when insulating layer 133b is etched, thereby reducing processing variations.

[0111] [Modification 2] Figure 9A shows an example where there is no insulating layer 133. The partition wall 120 and the pixel electrode 111 are provided in contact with the upper surface of the insulating layer 132. The insulating layer 132 also has recesses in the portion not covered by the pixel electrode 111 and the partition wall 120. The EL layer 112 is in contact with the upper and side surfaces of the pixel electrode 111 and has a portion located in the recess of the insulating layer 132. The upper electrode 113 covers the end of the EL layer 112 and is provided in contact with a part of the upper surface of the insulating layer 132 and the side surface of the partition wall 120. In this way, even when the insulating layer 133 is not provided, the EL layer 112 can be easily cut in steps by providing a region with a lower upper surface height between the partition wall 120 and the pixel electrode 111 of the insulating layer 132 that forms the surface to be formed on the partition wall 120.

[0112] [Modification 3] A common layer 114 that can be used in common for each light-emitting element may be provided between the EL layer 112 and the upper electrode 113. Figure 9B is a schematic cross-sectional view when a common layer 114 is provided. It is preferable to form the common layer 114 by a film deposition method that has higher coverage than each EL layer 112. This allows the edges of the EL layer 112 to be covered by the common layer 114, and even if a highly conductive film is used for the EL layer 112, it is possible to prevent the highly conductive film from coming into contact with the upper electrode 113. It is also preferable to form the common layer 114 by a film deposition method that has lower coverage than the upper electrode 113. This is preferable because it makes it easier to create a stepped common layer 114 and provide a portion where the partition wall 120 and the upper electrode 113 come into direct contact. If the electrical conductivity in the thickness direction of the common layer 114 is sufficiently high, the common layer 114 may be provided between the partition wall 120 and the upper electrode 113.

[0113] [Modification 4] Figures 10A and 10B show an example where not only each EL layer 112, but also the upper electrode 113 and protective layer 135 are separated for each pixel. Each light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B has an upper electrode 113R, upper electrode 113G, or upper electrode 113B and a protective layer 135R, protective layer 135G, or protective layer 135B. With this configuration, during the process of processing the EL layer 112, the EL layer 112 can be processed while covered by the upper electrode 113 and protective layer 135, thereby suppressing damage during processing and preventing the diffusion of impurities such as moisture into the EL layer 112, thus realizing a highly reliable display device.

[0114] [Modification 5] In the above, a configuration in which EL layers 112 with different emission colors are made separately for each pixel was shown, but as shown in Figure 11, a configuration combining a white-emitting light-emitting element and a color filter may also be used. In the example shown in Figure 11, there are multiple white light-emitting elements 110W. The light-emitting element 110 has a pixel electrode 111, an EL layer 112W, and an upper electrode 113. The EL layer 112W can be configured to have two or more light-emitting layers. For example, white light emission can be obtained by combining two light-emitting layers so that their emission colors are complementary. Alternatively, a configuration with three or more light-emitting layers may also be used.

[0115] One of the following color filters is provided on the light-emitting element 110W: a red color filter 115R, a green color filter 115G, and a blue color filter 115B. Alternatively, no color filters may be provided, and in addition to red, green, and blue pixels, there may be white pixels.

[0116] Although this example uses a white light-emitting element, a configuration using a light-emitting element that emits blue or ultraviolet light and a wavelength conversion filter is also possible. In this case, the wavelength conversion filter uses a material that converts short-wavelength light to long-wavelength light. For example, a fluorescent material or a resin in which quantum dots are dispersed can be used as the wavelength conversion filter.

[0117] [Modification 6] In the above example, the display device 100 was shown to have three colored light-emitting elements 110 (light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B), but it may have further elements.

[0118] Figures 12A and 12B show an example in which a white light-emitting element 110W is included in addition to the red, green, and blue light-emitting elements 110. Figure 12A is a top view, and Figure 12B is a schematic cross-sectional view along the cutting line C-D in Figure 12A.

[0119] The light-emitting element 110W has a pixel electrode 111W, an EL layer 112W, and an upper electrode 113. A protective layer 135 is also provided covering the light-emitting element 110W.

[0120] The EL layer 112W can have a configuration having two or more light-emitting layers. For example, white light can be obtained by combining two light-emitting layers such that their light-emitting colors are complementary. Alternatively, it may have a configuration having three or more light-emitting layers.

[0121] By using white light-emitting elements in addition to red, green, and blue light-emitting elements, it is possible to improve contrast and reliability.

[0122] Figure 12C shows an example where a light-receiving element 110S is used instead of the light-emitting element 110W.

[0123] The light-receiving element 110S functions as a photoelectric conversion element and can output an electrical signal corresponding to the amount of incident light. This allows an image sensor to be incorporated into the display device 100. In Figure 12C, the directions of the light R, light G, and light B emitted by the light-emitting elements 110R, 110G, and 110B, respectively, and the direction of the light Lex incident on the light-receiving element 110S from the outside are indicated by arrows.

[0124] The light-receiving element 110S includes a pixel electrode 111S, a sensor layer 112S, and an upper electrode 113. A protective layer 135 is also provided covering the light-receiving element 110S.

[0125] The sensor layer 112S preferably has an organic layer common to the EL layer 112R, etc. For example, the light-emitting layer of the EL layer 112R can be replaced with a light-receiving layer (also called an active layer or photoelectric conversion layer).

[0126] The light-receiving layer of the sensor layer 112S can be a stacked structure in which a p-type semiconductor and an n-type semiconductor are stacked to realize a pn junction, or a stacked structure in which a p-type semiconductor, an i-type semiconductor, and an n-type semiconductor are stacked to realize a pin junction.

[0127] As the semiconductor used for the light-receiving layer, an inorganic semiconductor such as silicon or an organic semiconductor containing an organic compound can be used. In particular, using an organic semiconductor material is preferable because it makes it easy to form the EL layer 112R and the light-receiving layer using the same vacuum deposition method, and the manufacturing equipment can be shared.

[0128] When using an organic semiconductor material as the light-receiving layer, the n-type semiconductor material can be fullerene (for example, C ６０ , C ７０ Electron-accepting organic semiconductor materials such as (etc.) or their derivatives can be used. In addition, as the p-type semiconductor material, electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc) and tetraphenyldibenzoperifuranthene (DBP) can be used. The light-receiving layer may be a stacked structure of an electron-accepting semiconductor material and an electron-donating semiconductor material (p-n stacked structure), or a stacked structure in which a bulk heterostructure layer of an electron-accepting semiconductor material and an electron-donating semiconductor material is co-deposited between them (p-i-n stacked structure). Furthermore, in order to suppress dark current when light is not irradiated, a layer that functions as a hole-blocking layer, a layer that functions as an electron-blocking layer, etc. may be provided around (above or below) the above-mentioned p-n stacked structure or p-i-n stacked structure.

[0129] The above is an explanation of the variations.

[0130] [Example of Manufacturing Method] Below, an example of a manufacturing method for a display device according to one aspect of the present invention will be described with reference to the drawings. Here, the display device 100 exemplified in the above configuration example will be used as an example. Figures 13A to 15F are schematic cross-sectional views of each step in the example of the manufacturing method for the display device exemplified below.

[0131] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD).

[0132] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, and knife coating.

[0133] Sputtering methods include RF sputtering, which uses a high-frequency power supply for sputtering; DC sputtering, which uses a DC power supply; and pulsed DC sputtering, which changes the voltage applied to the electrodes in pulses. For film deposition using insulating targets, RF sputtering is preferable. DC sputtering is mainly used when depositing films using conductive targets. In addition to forming conductive films, DC sputtering can also be used to form insulating films by reactive sputtering using pulsed DC sputtering. Specifically, pulsed DC sputtering can be used when depositing compounds such as oxides, nitrides, and carbides using reactive sputtering.

[0134] CVD methods can be classified into plasma-enhanced CVD (PECVD), which utilizes plasma; thermal CVD (TCD), which utilizes heat; and photo-CVD, which utilizes light. Furthermore, depending on the source gas used, they can be divided into metal CVD (MCCVD) and metal-organic CVD (MOCVD).

[0135] Plasma CVD allows for the production of high-quality films at relatively low temperatures. Thermal CVD, on the other hand, does not use plasma, thus minimizing plasma damage to the workpiece. Furthermore, thermal CVD avoids plasma damage during film formation, resulting in films with fewer defects.

[0136] As ALD methods, thermal ALD, which carries out the reaction of the precursor and reactant using only thermal energy, and PEALD, which uses plasma-excited reactants, can be used.

[0137] Unlike sputtering, CVD and ALD are film deposition methods that are less affected by the shape of the workpiece and provide good step-level coverage. In particular, the ALD method is suitable for coating the surface of openings with high aspect ratios due to its excellent step-level coverage and excellent thickness uniformity. However, since the ALD method has a relatively slow deposition rate, it is sometimes preferable to use it in combination with other film deposition methods that have a faster deposition rate, such as the CVD method.

[0138] In CVD (Chemical Vapor Deposition), films of any composition can be deposited by changing the flow rate ratio of the raw material gases. For example, in CVD, by changing the flow rate ratio of the raw material gases while the film is being deposited, films with continuously changing compositions can be deposited. When depositing films while changing the flow rate ratio of the raw material gases, the time required for film deposition can be shortened compared to depositing films using multiple deposition chambers, because time spent on transport or pressure adjustment is eliminated. Therefore, it may be possible to increase the productivity of semiconductor devices.

[0139] In the ALD method, films of any composition can be deposited by simultaneously introducing multiple different types of precursors. Alternatively, when introducing multiple different types of precursors, films of any composition can be deposited by controlling the number of cycles for each precursor. Furthermore, similar to the CVD method, films with continuously changing compositions can be deposited.

[0140] Furthermore, the thin films constituting the display device can be processed using photolithography or other methods. Alternatively, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off methods, etc. Island-like thin films may also be directly formed using a film deposition method with a shielding mask such as a metal mask. Induced self-assembly (DSA) methods may also be used.

[0141] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0142] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as the above-mentioned light or an electron beam.

[0143] Thin films can be etched using methods such as dry etching, wet etching, and sandblasting. Dry etching allows for isotropic or anisotropic etching by controlling the conditions. Wet etching allows for isotropic etching.

[0144] First, a substrate 101 is prepared, and transistors 150, insulating layer 131, insulating layer 132, etc. are formed. Next, a conductive film is deposited on the insulating layer 132, and unnecessary parts are removed by etching to form pixel electrodes 111R, pixel electrode 111G, and pixel electrode 111B.

[0145] When using a conductive film that is reflective to visible light as each pixel electrode 111, it is preferable to use a material (for example, silver or aluminum) that has the highest possible reflectivity across the entire wavelength range of visible light. This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0146] Next, an insulating layer 133 is formed to cover each pixel electrode 111 (Figure 13A). As the insulating layer 133, the inorganic insulating film or organic insulating film described above can be used. In Figure 13A, the upper surface of the insulating layer 133 is shown to be flat, but it may have an uneven shape that reflects the shape of the pixel electrode 111.

[0147] Next, a conductive film 120f, which will later become a partition wall 120, is formed on the insulating layer 133. The conductive film 120f can be made from the conductive material described above.

[0148] The conductive film 120f is a film that will later be processed into an inverse tapered shape. Here, not limited to conductive films, the etching rate when etching thin films tends to be slower as the density of the film increases. Therefore, it is preferable to use a laminated structure of a low-density film and a high-density film for the conductive film 120f, as this allows the etching rate of the lower part to be faster than that of the upper part, making it easier to process into an inverse tapered shape. For example, when depositing the conductive film 120f by sputtering, the higher the deposition pressure (i.e., the lower the vacuum) and the lower the power supply, the more likely it is to result in a low-density film.

[0149] For example, when forming a metal film (e.g., molybdenum film, tungsten film, chromium film, titanium film, etc.) as a conductive film 120f by sputtering, a laminated structure consisting of a low-density first layer and a high-density second layer can be formed. In this case, it is preferable to form the second layer under conditions that satisfy lower pressure, higher power supply voltage, or both, than the conditions for forming the first layer. In particular, it is preferable to form the second layer under conditions that satisfy lower pressure and higher power supply than the first layer. This makes it easier to process the conductive film 120f into an inverse tapered shape, as the etching rate of the low-density first layer becomes faster than that of the second layer during subsequent etching of the conductive film 120f.

[0150] Next, a resist mask 141 is formed on the conductive film 120f (Figure 13B).

[0151] Next, the portion of the conductive film 120f not covered by the resist mask is removed by etching to form a reverse-tapered partition wall 120, and then a portion of the upper part of the insulating layer 133 is etched (half-etched). After that, the resist mask 141 is removed (Figure 13C). At this time, it is important to process the insulating layer 133 to the extent that the upper surface of each pixel electrode 111 is not exposed. In this way, after forming the partition wall 120, an insulating layer 133 can be formed having a portion R1 that is in contact with the partition wall 120, a portion R2 whose upper surface height from the surface to be formed is lower than that of portion R1, and a portion R3 located between portions R1 and R2, where the height of the upper surface changes from portion R1 to portion R2, as shown in Figure 2B, etc.

[0152] Etching of the conductive film 120f is preferably performed by a dry etching method. This allows for continuous etching of the conductive film 120f and half-etching of the insulating layer 133, thereby shortening the process. Etching of the conductive film 120f and the insulating layer 133 is preferably performed continuously, for example, using the same etching gas and in the same processing chamber of the same etching apparatus. For example, etching of the conductive film 120f and the insulating layer 133 is performed by a dry etching method. ６ CF ４ CHF ３ The process can be carried out continuously using etching gases containing fluorine, such as those mentioned above.

[0153] In this case, when etching the conductive film 120f and the insulating layer 133, as shown in Figure 16A, the side surface of the partition wall 120 may be etched so that the most protruding end of the partition wall 120 is inside the edge of the resist mask 141. In this case, the corner R of the insulating layer 133 is formed in a position that roughly overlaps with the edge of the resist mask 141, and as a result, the corner R and the partition wall 120 may separate.

[0154] In that case, as shown in Figure 16B, additional etching can be performed on the insulating layer 133 so that the corner R overlaps with the partition wall 120. Additional etching can be performed before removing the resist mask 141 by isotropic etching (dry etching or wet etching) to etch the insulating layer 133 under conditions of high selectivity between the partition wall 120 and the etching rate. Alternatively, after removing the resist mask 141, the insulating layer 133 can be etched by isotropic or anisotropic etching under conditions of high selectivity between the partition wall 120 and the etching rate.

[0155] The conductive film 120f and the insulating layer 133 can also be etched separately. In that case, the conductive film 120f can be processed by a wet etching method and the insulating layer 133 can be processed by a dry etching method. Alternatively, the conductive film 120f and the insulating layer 133 can each be processed by a wet etching method.

[0156] Next, a resist mask (not shown) is formed to cover the partition wall 120 and the insulating layer 133. A portion of the insulating layer 133 is etched to expose a portion of the upper surface of each pixel electrode 111, and then the resist mask is removed (Figure 13D).

[0157] Next, an EL layer 112R is formed on each pixel electrode 111 and the partition wall 120 (Figure 13E). At this time, the EL layer 112R is stepped by the partition wall 120, and is formed in the region surrounded by the partition wall 120 and on top of the partition wall 120. The EL layer 112R can be formed using, for example, vacuum deposition, sputtering, or both.

[0158] A method for forming an EL layer 112R will be described with reference to FIGS. 17A and 17B. The EL layer 112R is preferably formed by a film deposition method with high anisotropy. That is, as shown in FIG. 17A, film deposition is performed such that the flight direction of a film deposition material 121 is substantially perpendicular to the upper surface of a substrate 101. Accordingly, as shown in FIG. 17B, disconnection can be caused by a partition wall 120. In this case, an end portion of the EL layer 112R is preferably positioned closer to a pixel electrode 111 than a corner portion R of an insulating layer 133. In addition, in this case, it is preferable that a sufficient space for an upper electrode 113 to enter is secured between the EL layer 112R and the partition wall 120.

[0159] Subsequently, a sacrificial layer 134R is formed to cover the EL layer 112R, the insulating layer 133, and the partition wall 120 (FIG. 13F). The sacrificial layer 134R functions as a protective layer for protecting the EL layer 112R from damage during the process, and is a film to be removed later. The sacrificial layer 134R is preferably formed by a film deposition method with high step coverage, and is preferably deposited by a CVD method or an ALD method. In particular, the ALD method is preferable because it causes small film deposition damage to a layer to be formed.

[0160] For example, an aluminum oxide film can be formed as the sacrificial layer 134R by the ALD method. In this case, as an aluminum-containing precursor, it is preferable to use trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum hydride, tris(dimethylamino)aluminum, tris(diethylamino)aluminum, aluminum trichloride, or the like. In addition, as an oxidant serving as a reactant, for example, ozone (O ３ ), oxygen (O ２ ), water (H ２ O), nitrogen dioxide (NO ２ ), dinitrogen monoxide (N ２ O), hydrogen peroxide (H ２ O ２ ), or the like can be used, and two or more of these may be used.

[0161] Furthermore, the sacrificial layer 134R may be a laminated structure consisting of a film deposited by the ALD method and a film deposited by a film deposition method other than the ALD method (e.g., CVD method, sputtering method, etc.). While the ALD method has extremely high step coverage, its deposition rate is relatively slow compared to other film deposition methods. Therefore, by first depositing a film with very few defects using the ALD method, and then forming a thick insulating film using the CVD method or the like, the time required for the deposition process of the sacrificial layer 134R can be shortened.

[0162] Next, a resist mask 142a is formed (Figure 14A). The resist mask 142a is formed such that its end is located above the portion of the partition wall 120 that surrounds the pixel electrode 111R.

[0163] Next, the portions of the sacrificial layer 134R and EL layer 112R that are not covered by the resist mask 142a are removed by etching (Figure 14B). After that, the resist mask 142a is removed (Figure 14C). At this point, a portion of the sacrificial layer 134R and EL layer 112R remains on the upper part of the partition wall 120. Note that a portion of the EL layer 112R on the partition wall 120 may have disappeared.

[0164] As a result, an island-shaped EL layer 112R protected by the sacrificial layer 134R can be formed in the region surrounded by the partition wall 120.

[0165] Next, the EL layer 112G and the sacrificial layer 134G are deposited in sequence (Figure 14D). The deposition methods for the EL layer 112G and the sacrificial layer 134G can be found by referring to the deposition methods for the EL layer 112R and the sacrificial layer 134R, respectively.

[0166] Next, the resist mask 142b is formed (Figure 14E). The resist mask 142b is formed such that its end is located at the top of the portion of the partition wall 120 that surrounds the pixel electrode 111G.

[0167] Next, the portions of the sacrificial layer 134G and the EL layer 112G that are not covered by the resist mask 142b are removed by etching, and then the resist mask 142b is removed (Figure 15A). During etching of the EL layer 112G, the EL layer 112R and the pixel electrode 111R are covered by the sacrificial layer 134R and are therefore not damaged. As a result, an island-shaped EL layer 112G protected by the sacrificial layer 134G can be formed in the region surrounded by the partition wall 120.

[0168] As shown in Figures 14D and 14E, before etching the sacrificial layer 134G and the EL layer 112G, there may be areas near the partition wall 120 where the sacrificial layer 134R and the sacrificial layer 134G are in contact. In this case, when etching the sacrificial layer 134G, the sacrificial layer 134R may also be etched, potentially exposing a portion of the EL layer 112R. Therefore, it is preferable to laminate two or more films with different etching rates for the sacrificial layer 134R and the sacrificial layer 134G. This prevents a portion of the sacrificial layer 134R located below from disappearing when etching the sacrificial layer 134G.

[0169] Next, the EL layer 112B and the sacrificial layer 134B are deposited in sequence. The deposition methods for the EL layer 112R and the sacrificial layer 134R can be referred to, respectively.

[0170] Next, the resist mask 142c is formed (Figure 15B). The resist mask 142c is formed such that its end is located above the portion of the partition wall 120 that surrounds the pixel electrode 111B.

[0171] Next, the portions of the sacrificial layer 134B and the EL layer 112B that are not covered by the resist mask 142c are removed by etching. After that, the resist mask 142c is removed (Figure 15C). As a result, an island-shaped EL layer 112B protected by the sacrificial layer 134B can be formed in the region surrounded by the partition wall 120.

[0172] Next, sacrificial layers 134R, 134G, and 134B are removed by etching to expose the surfaces of EL layers 112R, 112G, and 112B (Figure 15D). At this time, it is preferable to remove each sacrificial layer 134 by wet etching. In particular, it is preferable to use wet etching with an aqueous solution of acid or alkali as the etching solution.

[0173] Next, the upper electrode 113 is formed by covering each EL layer 112 and the partition wall 120 (Figure 15E). The upper electrode 113 can be formed using one or more of the following methods: vacuum deposition, sputtering, and CVD.

[0174] The method for forming the upper electrode 113 will be explained using Figures 18A to 18E. It is preferable to form the upper electrode 113 using a film formation method that has lower anisotropy than each EL layer 112. That is, it is preferable to use a film formation method in which the flight direction of the film formation material for the upper electrode 113 has components not only in the direction perpendicular to the upper surface of the substrate, but also in the oblique direction. For example, a film formation method with low anisotropy can be achieved by reducing the distance between the deposition source (or sputtering target) and the substrate, using multiple deposition sources (or sputtering targets), or increasing the area of ​​the deposition source (or sputtering target).

[0175] Furthermore, as shown in Figure 18A, a film deposition apparatus can be used that has a mechanism for launching the film deposition material 122 from an oblique direction onto the upper surface of the substrate 101 and rotating the substrate 101 on a rotation axis 125 perpendicular to the upper surface. In Figure 18A, an example is shown in which the rotation axis 125 passes through the center of the substrate 101, but it may pass anywhere on the substrate 101, or the rotation axis 125 may be located off-center from the substrate 101. Also, the rotation axis 125 does not have to be perpendicular to the upper surface of the substrate 101.

[0176] Alternatively, as shown in Figure 18B, a film deposition apparatus may be used that has a mechanism in which the substrate 101 rotates (or oscillates) on a rotation axis 125 parallel to its upper surface. In this case, the flight direction of the film deposition material 122 can be perpendicular to the rotation axis 125.

[0177] By using a film deposition apparatus having a mechanism like those shown in Figures 18A and 18B, as shown in Figure 18C, during the film deposition process of the upper electrode 113, it is possible to provide a period in which the deposition material 122 flies from an oblique direction relative to the substrate surface of the substrate 101, and a period in which it flies from an oblique direction in the opposite direction, as shown in Figure 18D. Therefore, as shown in Figure 18E, the upper electrode 113 can be deposited so as to be in contact with the side surface of the partition wall 120 which has an inverse tapered shape.

[0178] In addition, the above example shows a case where the substrate 101 moves, but the configuration may also be such that only the deposition source moves, or both the substrate 101 and the deposition source move.

[0179] Next, a protective layer 135 is formed to cover the upper electrode 113 (Figure 15F). The protective layer 135 is preferably formed by a film formation method that provides high step coverage, similar to the sacrificial layers 134 described above. In particular, the protective layer 135 is preferably formed by the ALD method. For the method of forming the protective layer 135, refer to the description of the sacrificial layer 134 above.

[0180] The display device 100 can be manufactured through the above process.

[0181] [Example of a deposition apparatus configuration] Here, we will describe a deposition apparatus configuration suitable for a large substrate 101. The deposition apparatus exemplified below can be used for both each EL layer 112 and the upper electrode 113.

[0182] When uniformly depositing a film on a large substrate 101, using multiple deposition sources makes it possible to shorten the time required for film deposition and to deposit a film with uniform thickness without unevenness.

[0183] For example, as shown in Figure 19A, a unit 127a can be used in which a plurality of nozzles 128 are arranged at equal intervals in one direction. A deposition source is placed in each nozzle 128, and a film-forming material 123 is injected from the nozzles 128 in a roughly conical shape. The spread of the film-forming material 123 is determined by the shape of the nozzles 128, the distance between the substrate 101 and the nozzles 128, etc. The unit 127a can be moved in a direction intersecting the direction of arrangement of the nozzles 128 (for example, a perpendicular direction), as indicated by the arrows. A movable unit 127a is preferable because it can reduce the footprint of the film-forming chamber. Alternatively, the unit 127a may be fixed and the substrate 101 may be moved.

[0184] The configuration shown in Figure 19B has multiple units 127b. Each unit 127b is provided with a nozzle 128. Each unit 127b has a long shape in one direction and has a mechanism that allows the nozzle 128 to move in that longitudinal direction. Multiple units 127b are arranged in directions that intersect the longitudinal direction (for example, perpendicular directions). With the positions of the substrate 101 and the units 127b fixed, the nozzle 128 of each unit 127b moves as indicated by the arrows, allowing a film to be formed on the entire surface of the substrate 101. With this configuration, there is no need to move large units 127b, so the apparatus configuration can be simplified.

[0185] Although a configuration using multiple nozzles was described above, a configuration using only one nozzle is also possible. The configuration shown in Figure 19C has one unit 127c equipped with one nozzle 128. The unit 127c has a mechanism that allows it to move in two orthogonal directions. By fixing the position of the substrate 101 and scanning the unit 127c in a zigzag pattern, a film can be formed over the entire surface of the substrate 101.

[0186] Next, we will explain the relationship between the film deposition method and the incident angle of the deposition material.

[0187] Figure 20A schematically shows a method of film deposition (also called the point source method) in which the positions of both the substrate 101 and the nozzle 128 are fixed. Above the nozzle 128, at a distance D ＴＳA substrate 101 is placed at a distance of D, and a film-forming material 123 is injected upward from the nozzle. The film-forming material 123 does not travel in a straight line upward from the nozzle, but diffuses at a predetermined solid angle. Here, the distance D ＴＳ At position D, the minimum angle of incidence of the film-forming material 123, that is, the angle of incidence when the inclination from the straight direction is greatest, is defined as angle a. In order to uniformly form a film on the substrate 101, distance D ＴＳ It is important to increase the distance D and position the substrate 101 within the range where the film deposition material 123 reaches the same height as the substrate surface. At this time, the minimum angle of incidence of the film deposition material 123 reaching the substrate 101 will be an angle greater than angle a (angle b). Thus, the point source method has high straightness of propagation for the film deposition material 123 and is a method in which the film deposition material 123 is less likely to wrap around. Note that even with the point source method, the distance D can be increased by increasing the number of nozzles 128. ＴＳ It is also possible to bring them closer.

[0188] Figure 20B schematically shows a method of depositing a film while moving the nozzle 128 parallel to the substrate surface (also called the moving cell method). Because the nozzle 128 can be moved, the distance D is greater than that of the point source method. ＴＳ This can reduce the amount of radiation. The minimum angle of incidence of the deposition material 123 reaching the substrate 101 is equal to angle a. Thus, the moving cell method is a method in which the deposition material 123 has lower straightness of propagation and is more likely to wrap around than the point source method. ＴＳ By widening the nozzle, it is possible to improve the straight-line propagation of the film-forming material 123. The same applies when the substrate 101 is moved instead of the nozzle 128.

[0189] In the above-described example of a method for manufacturing a display device, when forming each EL layer 112, it is preferable to form the film using a film formation method that has high linearity of the film formation material, and when forming the upper electrode 113, it is preferable to form the film using a film formation method that has low linearity of the film formation material.

[0190] Furthermore, when a metal material such as silver is deposited as the upper electrode 113 by vacuum deposition, the temperature of the crucible rises to over 1000°C, and the distance D between the substrate 101 and the nozzle 128 increases. ＴＳ In some cases, it is difficult to bring the materials close together. In such cases, it is preferable to combine a film deposition method with high linearity of the film deposition material and a film deposition method with low linearity (for example, sputtering) to form a layered structure. For example, the upper electrode 113 can be a two-layer structure in which an alloy film containing silver and magnesium is deposited by vacuum deposition, and then an oxide conductive film containing indium is deposited by sputtering.

[0191] The above is a description of an example configuration of a vapor deposition apparatus.

[0192] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0193] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0194] The display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, smartphones, smartwatches, tablet devices, personal digital assistants, and audio playback devices.

[0195] [Display device 400A] Figure 21 shows a perspective view of the display device 400A, and Figure 22 shows a cross-sectional view of the display device 400A.

[0196] The display device 400A has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 21, substrate 452 is clearly indicated by a dashed line.

[0197] The display device 400A includes a display unit 462, a circuit 464, wiring 465, etc. Figure 21 shows an example in which IC 473 and FPC 472 are mounted on the display device 400A. Therefore, the configuration shown in Figure 21 can also be described as a display module having the display device 400A, an IC (integrated circuit), and an FPC.

[0198] For example, a scan line drive circuit can be used as circuit 464.

[0199] The wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to the wiring 465 from an external source via the FPC 472, or from the IC 473.

[0200] Figure 21 shows an example in which IC 473 is provided on the substrate 451 using the COG (Chip On Glass) method or the COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400A and the display module may be configured without an IC. Alternatively, the IC may be mounted on the FPC using the COF method or the like.

[0201] Figure 22 shows an example of a cross-section obtained by cutting a portion of the area including the FPC 472, a portion of the circuit 464, a portion of the display unit 462, and a portion of the area including the end portion of the display device 400A.

[0202] The display device 400A shown in Figure 22 has a transistor 201, a transistor 205, a light-emitting element 430a that emits red light, a light-emitting element 430b that emits green light, and a light-emitting element 430c that emits blue light, etc., between substrates 451 and 452.

[0203] The light-emitting elements 430a, 430b, and 430c can be the light-emitting elements exemplified in Embodiment 1. Each light-emitting element 430 has a pixel electrode 411a, a pixel electrode 411b, or a pixel electrode 411c, an island-shaped EL layer having a different light-emitting layer, and an island-shaped upper electrode.

[0204] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting element with a different emission color, examples of such three subpixels include subpixels of three colors: R, G, and B; and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of such four subpixels include subpixels of four colors: R, G, B, and white (W); and subpixels of four colors: R, G, B, and Y.

[0205] Each protective layer 416 and the substrate 452 are bonded together via an adhesive layer 442. For sealing the light-emitting element, a solid sealing structure or a hollow sealing structure can be applied. In Figure 22, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 is filled with an inert gas (such as nitrogen or argon), indicating a hollow sealing structure. The adhesive layer 442 may be provided overlapping the light-emitting element. Alternatively, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 may be filled with a resin different from the adhesive layer 442.

[0206] The light-emitting elements 430a, 430b, and 430c have an optical adjustment layer between the pixel electrode and the EL layer. Light-emitting element 430a has an optical adjustment layer 426a, light-emitting element 430b has an optical adjustment layer 426b, and light-emitting element 430c has an optical adjustment layer 426c. Details of the light-emitting elements can be found in Embodiment 1. Each optical adjustment layer 426 has a different thickness. It is also preferable that each optical adjustment layer 426 is made of the same material that is transparent and conductive. It is preferable to use a conductive metal oxide film containing indium or zinc as the optical adjustment layer 426.

[0207] The pixel electrodes 411a, 411b, and 411c are each connected to the conductive layer 222b of the transistor 205 through openings provided in the insulating layer 214.

[0208] The edges of the pixel electrodes and the optical adjustment layer are covered by an insulating layer 421. The pixel electrodes contain a material that reflects visible light, and the counter electrodes contain a material that transmits visible light.

[0209] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transparency to visible light for the substrate 452.

[0210] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the partition wall 120 shown in Embodiment 1. The partition wall 420 is provided in a region that overlaps with the light-shielding layer 417. On the partition wall 420, a layer is provided which includes a part of the upper electrodes of two adjacent light-emitting elements on either side of the partition wall 420, and the same material as the EL layer. In addition, a protective layer 416 is provided covering the partition wall 420.

[0211] Both transistors 201 and 205 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0212] On the substrate 451, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0213] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0214] It is preferable to use inorganic insulating films for insulating layers 211, 213, and 215. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0215] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400A. This prevents impurities from entering through the organic insulating film from the edge of the display device 400A. Alternatively, the organic insulating film may be formed so that its edge is inward from the edge of the display device 400A, so that the organic insulating film is not exposed at the edge of the display device 400A.

[0216] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0217] In the region 228 shown in Figure 22, an opening is formed in the insulating layer 214. This prevents impurities from entering the display unit 462 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. Therefore, the reliability of the display device 400A can be improved.

[0218] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0219] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0220] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0221] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0222] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0223] The semiconductor layer preferably contains a metal oxide containing indium. In particular, it is especially preferable that it contains indium oxide.

[0224] Furthermore, the semiconductor layer preferably comprises, 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.

[0225] In particular, it is preferable to use an oxide (also written as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0226] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is equal to or greater than the atomic ratio of M. Examples of such In-M-Zn oxide atomic ratios of metal elements include compositions where In:M:Zn = 1:1:1 or nearby, In:M:Zn = 1:1:1.2 or nearby, In:M:Zn = 2:1:3 or nearby, In:M:Zn = 3:1:2 or nearby, In:M:Zn = 4:2:3 or nearby, In:M:Zn = 4:2:4.1 or nearby, In:M:Zn = 5:1:3 or nearby, In:M:Zn = 5:1:6 or nearby, In:M:Zn = 5:1:7 or nearby, In:M:Zn = 5:1:8 or nearby, In:M:Zn = 6:1:6 or nearby, In:M:Zn = 5:2:5 or nearby, and so on. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0227] For example, when the atomic ratio is stated as In:Ga:Zn = 4:2:3 or nearby, it includes cases where, with In set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when the atomic ratio is stated as In:Ga:Zn = 5:1:6 or nearby, it includes cases where, with In set to 5, Ga is greater than 0.5 and 2 or less, and Zn is between 5 and 7. Furthermore, when the atomic ratio is stated as In:Ga:Zn = 1:1:1 or nearby, it includes cases where, with In set to 1, Ga is greater than 0.5 and 2 or less, and Zn is greater than 0.5 and 2 or less.

[0228] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0229] A connection portion 204 is provided in the region of substrate 451 where substrate 452 does not overlap. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as the pixel electrode and a conductive film obtained by processing the same conductive film as the optical adjustment layer. The conductive layer 466 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0230] It is preferable to provide a light-shielding layer 417 on the surface of the substrate 452 that faces the substrate 451. Various optical components can also be arranged on the outside of the substrate 452. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting films. Furthermore, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may also be arranged on the outside of the substrate 452.

[0231] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the entry of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0232] In the region 228 near the edge of the display device 400A, it is preferable that the insulating layer 215 and the protective layer 416 are in contact with each other through an opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 416 are in contact with each other. This makes it possible to suppress impurities from entering the display unit 462 from the outside through the organic insulating film. Therefore, the reliability of the display device 400A can be improved.

[0233] The protective layer 416 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the edges of the inorganic insulating film extend outward more than the edges of the organic insulating film.

[0234] Substrates 451 and 452 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc., respectively. The substrate on the side that extracts light from the light-emitting element should be made of a material that transmits the light. Using flexible materials for substrates 451 and 452 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 451 or substrate 452.

[0235] As substrates 451 and 452, the following can be used: 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, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 451 and 452 may be made of glass of a thickness sufficient to provide flexibility.

[0236] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0237] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0238] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0239] Furthermore, when using a film as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0240] Various types of curing adhesives can be used as the adhesive layer, including UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. 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. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0241] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like can be used.

[0242] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used as single layers or in a multilayer structure.

[0243] Furthermore, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used as the light-transmitting conductive material. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers of various wirings and electrodes that constitute a display device, and for conductive layers of light-emitting elements (conductive layers that function as pixel electrodes or common electrodes).

[0244] 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 oxide nitride, silicon nitride, silicon oxide, and aluminum oxide.

[0245] [Display Device 400B] Figure 23A shows a cross-sectional view of the display device 400B. The perspective view of the display device 400B is the same as that of the display device 400A (Figure 21). Figure 23A shows an example of a cross-section of the display device 400B when a part of the area including the FPC 472, a part of the circuit 464, and a part of the display unit 462 are cut. In Figure 23A, an example of a cross-section is shown when a part of the display unit 462, in particular, including the light-emitting element 430b that emits green light and the light-emitting element 430c that emits blue light, is cut. Note that explanations of parts that are the same as those of the display device 400A may be omitted.

[0246] The display device 400B shown in Figure 23A has transistors 202, 210, light-emitting elements 430b, and 430c between substrates 453 and 454.

[0247] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlap with the light-emitting elements 430b and 430c, respectively, and a solid encapsulation structure is applied to the display device 400B.

[0248] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0249] The method for manufacturing the display device 400B involves first bonding a fabricated substrate, on which an insulating layer 212, transistors, and light-emitting elements are provided, to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer 442. Then, the fabricated substrate is peeled off and a substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabricated substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This increases the flexibility of the display device 400B.

[0250] The insulating layer 212 can be made of an inorganic insulating film that can be used for insulating layer 211, insulating layer 213, and insulating layer 215, respectively.

[0251] The pixel electrodes are connected to the conductive layer 222b of the transistor 210 through an opening in the insulating layer 214. The conductive layer 222b is connected to the low-resistance region 231n through openings in the insulating layer 215 and the insulating layer 225. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0252] The ends of the pixel electrodes are covered by an insulating layer 421.

[0253] The light emitted by the light-emitting elements 430b and 430c is emitted towards the substrate 454. It is preferable to use a material with high transparency to visible light for the substrate 454.

[0254] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0255] Transistors 202 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel forming region 231i.

[0256] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n via openings provided in the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0257] Figure 23A shows an example in which the insulating layer 225 covers the top and sides of the semiconductor layer. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively.

[0258] On the other hand, in the transistor 209 shown in Figure 23B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 23B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 23B, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0259] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0260] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0261] (Embodiment 3) In this embodiment, an example of a display device configuration different from that described above will be explained.

[0262] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used in the display section of wearable devices that can be worn on the head, such as information terminals (wearable devices) such as wristwatches and bracelets, as well as VR devices such as head-mounted displays and AR devices such as glasses.

[0263] [Display Module] Figure 24A shows a perspective view of the display module 280. The display module 280 includes a display device 400C and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 400C, but may be the display device 400D or the display device 400E, which will be described later.

[0264] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0265] Figure 24B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0266] 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 Figure 24B. The pixel 284a has light-emitting elements 430a, 430b, and 430c that emit light in different colors from each other. The plurality of light-emitting elements may be arranged in a stripe arrangement as shown in Figure 24B. A stripe arrangement allows for a high-density arrangement of pixel circuits, thus providing a high-definition display device. Furthermore, various arrangement methods such as delta arrangement and pentile arrangement can be applied.

[0267] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0268] A single pixel circuit 283a is a circuit that controls the light emission of the three light-emitting elements of a single pixel 284a. A single pixel circuit 283a may be configured to have three circuits that control the light emission of a single light-emitting element. For example, a single pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element for each light-emitting element. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active-matrix type display device.

[0269] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0270] The FPC 290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC 290.

[0271] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby making the aperture ratio (effective display area ratio) of the display section 281 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%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, making the resolution of the display section 281 extremely high. For example, it is preferable that the pixels 284a in the display section 281 are arranged at a density of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0272] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, enabling a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0273] [Display device 400C] The display device 400C shown in Figure 25 has a substrate 301, light-emitting elements 430a, 430b, 430c, a capacitor 240, and a transistor 310.

[0274] Substrate 301 corresponds to substrate 291 in Figures 24A and 24B.

[0275] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion 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 of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0276] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0277] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0278] The capacitor 240 has 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 the dielectric of the capacitor 240.

[0279] 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 either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0280] An insulating layer 255 is provided covering the capacitance 240, and light-emitting elements 430a, 430b, 430c, etc. are provided on the insulating layer 255. A protective layer 416 is provided on the light-emitting elements 430a, 430b, 430c, and a substrate 401 is bonded to the upper surface of the protective layer 416 by a resin layer 419. The substrate 401 corresponds to the substrate 292 in Figure 24A.

[0281] The pixel electrodes of the light-emitting element are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261.

[0282] An insulating layer 421 is provided to cover the ends of the pixel electrodes. It is preferable to use an inorganic insulating material for the insulating layer 421. For example, inorganic insulating materials such as silicon oxide, silicon nitride, and aluminum oxide can be used.

[0283] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the description of the partition wall 120 shown in Embodiment 1. On the partition wall 420, a layer is provided which includes a part of the upper electrodes of two adjacent light-emitting elements on either side of the partition wall 420, and the same material as the EL layer.

[0284] [Display Device 400D] The display device 400D shown in Figure 26 differs from the display device 400C mainly in its transistor configuration. Note that explanations of parts similar to those of the display device 400C may be omitted.

[0285] Transistor 320 is a transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0286] The transistor 320 has 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.

[0287] The substrate 331 corresponds to the substrate 291 in Figures 24A and 24B. An insulating substrate or a semiconductor substrate can be used as the substrate 331.

[0288] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0289] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a part of the 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 the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0290] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. Details of materials that can be suitably used for the semiconductor layer 321 will be described later.

[0291] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0292] Furthermore, an insulating layer 328 is provided covering the top and side surfaces of the pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0293] The insulating layer 328 and the insulating layer 264 are provided with openings that reach the semiconductor layer 321. Inside these openings, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the insulating layer 264, the insulating layer 328, the side surfaces of the conductive layer 325, and the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0294] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are roughly the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0295] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from the insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0296] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layer 265, insulating layer 329, and insulating layer 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layer 265, insulating layer 329, insulating layer 264, and insulating layer 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0297] The configuration from the insulating layer 254 to the substrate 401 in the display device 400D is the same as that of the display device 400C.

[0298] [Display Device 400E] The display device 400E shown in Figure 27 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide on a semiconductor layer in which the channel is formed are stacked. Note that the same parts as those of display devices 400C and 400D may be omitted from the explanation.

[0299] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering 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.

[0300] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0301] This configuration allows for the formation of not only pixel circuits but also drive circuits and other components directly beneath the light-emitting element, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0302] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0303] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0304] (Embodiment 4) In this embodiment, a light-emitting element (also called a light-emitting device) that can be used in a display device according to one aspect of the present invention will be described.

[0305] In this specification, a light-emitting device (also called a light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of the layers (also called functional layers) of the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier block layer (hole block layer and electron block layer).

[0306] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. In addition, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0307] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. The SBS structure allows for optimization of materials and configuration for each light-emitting device, thus increasing the freedom of material and configuration selection and making it easier to improve brightness and reliability. In this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to create a full-color display device.

[0308] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole blocking layer or electron blocking layer may be called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not always be clearly distinguishable. Furthermore, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0309] [Light-emitting devices] Light-emitting devices can be broadly classified into single-structure and tandem-structure. A single-structure device has one light-emitting unit between a pair of electrodes. This light-emitting unit has a configuration that includes one or more light-emitting layers. To obtain white light emission in a single-structure device, one should select light-emitting layers such that the light emitted by each of the two or more layers can produce white light. For example, in the case of two colors, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors, a configuration that produces white light emission as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light-emitting device can be configured so that the light-emitting colors of the three or more layers combine to produce white light emission as a whole.

[0310] A tandem device has multiple light-emitting units between a pair of electrodes. Each light-emitting unit includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the brightness per unit current can be increased, and a more reliable light-emitting device can be achieved compared to a single-unit structure. To obtain white light emission in a tandem structure, the light from the light-emitting layers of multiple light-emitting units can be combined to produce white light emission. The combination of light-emitting colors that produces white light emission is the same as that for a single-unit structure. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0311] When comparing white light-emitting devices with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. On the other hand, white light-emitting devices have a simpler manufacturing process than SBS structure light-emitting devices, resulting in lower manufacturing costs and higher manufacturing yields.

[0312] As shown in Figure 28A, the light-emitting device has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0313] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0314] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0315] A configuration having a layer 780, a light-emitting layer 771, and a layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and in this specification, the configuration shown in Figure 28A is referred to as a single structure.

[0316] Furthermore, Figure 28B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 28A. Specifically, the light-emitting device shown in Figure 28B has a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0317] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0318] As shown in Figures 28C and 28D, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 28C and 28D show an example with three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two or four or more.

[0319] Furthermore, a single-layer light-emitting device may have a buffer layer between the two light-emitting layers.

[0320] Furthermore, as shown in Figures 28E and 28F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0321] Figures 28D and 28F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 28D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 28C, and Figure 28F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 28E. In Figures 28D and 28F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0322] As layer 764, one or both of the following can be used: a color conversion layer and / or a color filter (coloring layer).

[0323] In Figures 28C and 28D, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 771, 772, and 773. In subpixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In subpixels that emit red light and subpixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 28D, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. It is also preferable to use both a color conversion layer and a coloring layer as layer 764. Some of the light emitted by the light-emitting device may be transmitted directly without being converted by the color conversion layer. By extracting the light that has passed through the color conversion layer via the coloring layer, the color of light other than the desired color can be absorbed by the coloring layer, and the color purity of the light emitted by the subpixel can be increased.

[0324] Furthermore, in Figures 28C and 28D, different light-emitting materials with different emission colors may be used for the light-emitting layers 771, 772, and 773, respectively. When the light emitted by the light-emitting layers 771, 772, and 773 are complementary in color, white light emission is obtained. For example, a single-structure light-emitting device preferably has a light-emitting layer having a light-emitting material that emits blue light, and a light-emitting layer having a light-emitting material that emits visible light with a longer wavelength than blue.

[0325] A color filter may be provided as layer 764, as shown in Figure 28D. By passing white light through the color filter, light of the desired color can be obtained.

[0326] For example, if a single-structure light-emitting device has three light-emitting layers, it is preferable that it has a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0327] Furthermore, for example, when a single-structure light-emitting device has two light-emitting layers, a configuration is preferred in which one light-emitting layer has a light-emitting material that emits blue (B) light, and the other light-emitting layer has a light-emitting material that emits yellow (Y) light. This configuration may be referred to as a BY single structure.

[0328] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, the light-emitting materials should be selected such that the light emitted by each of the two or more materials is complementary in color. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary in color, a light-emitting device that emits white light as a whole can be obtained. The same applies to light-emitting devices that have three or more light-emitting layers.

[0329] In addition, in Figures 28C and 28D, as shown in Figure 28B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0330] Furthermore, in Figures 28E and 28F, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, in a light-emitting device having sub-pixels that emit light of each color, the light-emitting layer 771 and the light-emitting layer 772 may each be made of light-emitting materials that emit blue light. In the sub-pixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In addition, in the sub-pixels that emit red light and the sub-pixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 28F, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. Furthermore, it is preferable to use both a color conversion layer and a coloring layer as layer 764.

[0331] Furthermore, in Figures 28E and 28F, different light-emitting materials with different emission colors may be used for the light-emitting layer 771 and the light-emitting layer 772. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are complementary colors, white light emission is obtained. A color filter may be provided as layer 764 as shown in Figure 28F. By passing white light through the color filter, light of a desired color can be obtained.

[0332] In Figures 28E and 28F, examples are shown in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but the design is not limited to this. The light-emitting unit 763a and the light-emitting unit 763b may each have two or more light-emitting layers.

[0333] Furthermore, while Figures 28E and 28F illustrate a light-emitting device having two light-emitting units, the device is not limited to this. A light-emitting device may have three or more light-emitting units. A configuration with two light-emitting units may be referred to as a two-stage tandem structure, and a configuration with three light-emitting units may be referred to as a three-stage tandem structure.

[0334] Furthermore, in Figures 28E and 28F, the light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a, and the light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b.

[0335] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layers 780a and 780b each have one or more of the following: a hole injection layer, a hole transport layer, and an electron blocking layer. Similarly, layers 790a and 790b each have one or more of the following: an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780a and 790a have the opposite configurations to those described above, and layers 780b and 790b also have the opposite configurations to those described above.

[0336] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 780a may have a hole injection layer and a hole transport layer on the hole injection layer, and may further have an electron blocking layer on the hole transport layer. Layer 790a may have an electron transport layer and may further have a hole blocking layer between the light-emitting layer 771 and the electron transport layer. Layer 780b may have a hole transport layer and may further have an electron blocking layer on the hole transport layer. Layer 790b may have an electron transport layer and an electron injection layer on the electron transport layer, and may further have a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, for example, layer 780a may have an electron injection layer and an electron transport layer on the electron injection layer, and may further have a hole blocking layer on the electron transport layer. Furthermore, layer 790a may have a hole transport layer and an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Also, layer 780b may have an electron transport layer and an electron blocking layer on the electron transport layer. Also, layer 790b may have a hole transport layer and a hole injection layer on the hole transport layer and an electron blocking layer between the light-emitting layer 772 and the hole transport layer.

[0337] Furthermore, when fabricating a tandem light-emitting device, the two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between the pair of electrodes.

[0338] Furthermore, an example of a tandem-structured light-emitting device is the configuration shown in Figures 29A to 29C.

[0339] Figure 29A shows a configuration having three light-emitting units. In Figure 29A, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0340] In Figure 29A, the light-emitting layers 771, 772, and 773 can each have a light-emitting material that emits light of the same color. Specifically, the light-emitting layers 771, 772, and 773 can all be configured to have a blue (B) light-emitting material (a so-called B / B / B three-stage tandem structure). Note that "b / a" means that a light-emitting unit having a light-emitting material that emits light of color a is provided on a light-emitting unit having a light-emitting material, via a charge generation layer, and a and b represent colors.

[0341] Furthermore, in Figure 29A, some or all of the light-emitting layers 771, 772, and 773 may be made of light-emitting materials with different light-emitting colors. Examples of combinations of light-emitting colors for the light-emitting layers 771, 772, and 773 include a configuration where two are blue (B) and the remaining one is yellow (Y), and a configuration where one is red (R), another is green (G), and the remaining one is blue (B).

[0342] The light-emitting materials that each emit light of the same color are not limited to the above configuration. For example, as shown in Figure 29B, a tandem-type light-emitting device may be used in which multiple light-emitting units having multiple light-emitting layers are stacked. Figure 29B shows a configuration in which two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge-generating layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b has layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0343] In Figure 29B, luminescent materials with complementary colors are selected for luminescent layers 771a, 771b, and 771c, and the luminescent unit 763a is configured to emit white light (W). Similarly, luminescent materials with complementary colors are selected for luminescent layers 772a, 772b, and 772c, and the luminescent unit 763b is configured to emit white light (W). In other words, the configuration shown in Figure 29B is a two-stage tandem structure of W / W. There are no particular limitations on the stacking order of the complementary luminescent materials. The implementer can select the optimal stacking order as appropriate. In addition, although not shown, a three-stage tandem structure of W / W / W or a tandem structure of four or more stages may also be used.

[0344] Furthermore, when using a tandem light-emitting device, there are two-stage tandem structures: B / Y or Y / B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light; R・G / B or B / R・G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light; and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light, and a light-emitting unit that emits blue (B) light. Examples include a B / Y / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light in that order, and a B / YG / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light in that order. Note that "a and b" means that one light-emitting unit has a light-emitting material that emits light a and a light-emitting material that emits light b.

[0345] Furthermore, as shown in Figure 29C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0346] Specifically, in the configuration shown in Figure 29C, a plurality of light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a has a layer 780a, a light-emitting layer 771, and a layer 790a; light-emitting unit 763b has a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b; and light-emitting unit 763c has a layer 780c, a light-emitting layer 773, and a layer 790c.

[0347] For example, in the configuration shown in Figure 29C, a three-stage tandem structure of B / R, G, YG / B can be applied, where light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0348] For example, the number of layers and color order of the light-emitting unit can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, B, or a three-layer structure of B, X, B. The number of layers and color order of the light-emitting layers in light-emitting unit X can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, G, or a three-layer structure of R, G, R. In addition, other layers may be provided between the two light-emitting layers.

[0349] Next, we will describe materials that can be used in light-emitting devices.

[0350] Of the lower electrode 761 and the upper electrode 762, the electrode that extracts light preferably uses a conductive film that transmits visible light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light. In addition, if the display device has a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits both visible light and infrared light on the electrode that extracts light, and a conductive film that reflects both visible light and infrared light on the electrode that does not extract light.

[0351] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0352] As the material for forming the pair of electrodes of the light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, such materials include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys containing these in appropriate combinations. Other examples of such materials include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Furthermore, examples of such materials include aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver, palladium, and copper alloys (Ag-Pd-Cu, also written as APC). Other materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, and the like.

[0353] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device is a semitransmitting / semi-reflective electrode that transmits and reflects visible light, and the other is a reflective electrode that reflects 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, thereby strengthening the light emitted from the light-emitting device.

[0354] Furthermore, the semi-transparent / semi-reflective electrode can have a laminated structure consisting of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that transmits visible light (also called a transparent electrode).

[0355] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode with a visible light transmittance (light with a wavelength of 400 nm or more and less than 750 nm) of 40% or more for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transparent and semi-reflective electrodes shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ −２ A value of Ωcm or less is preferable.

[0356] A light-emitting device has at least a light-emitting layer. Furthermore, a light-emitting device may have layers other than the light-emitting layer, including materials with high hole injection properties, materials with high hole transport properties, hole-blocking materials, materials with high electron transport properties, electron-blocking materials, materials with high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device can have a configuration that includes, in addition to the light-emitting layer, one or more layers from among a hole injection layer, a hole transport layer, a hole-blocking layer, a charge generation layer, an electron-blocking layer, an electron transport layer, and an electron injection layer.

[0357] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0358] The light-emitting layer has one or more types of light-emitting materials. The light-emitting materials may include substances that exhibit light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red, as appropriate. Furthermore, materials that emit near-infrared light may also be used as light-emitting materials.

[0359] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0360] Examples of fluorescent materials 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.

[0361] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0362] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more types of organic compounds may include materials with high hole transport properties (hole transport materials) and / or materials with high electron transport properties (electron transport materials). As the hole transport material, one of the materials with high hole transport properties that can be used in the hole transport layer, as described later, may be used. As the electron transport material, one of the materials with high electron transport properties that can be used in the electron transport layer, as described later, may be used. Furthermore, one or more types of organic compounds may include bipolar materials or TADF materials.

[0363] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0364] 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 capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0365] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0366] As acceptor materials, for example, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0367] For example, as a material with high hole injection properties, a material containing a hole transport material and an oxide of a metal belonging to Group 4 to Group 8 of the periodic table (typically molybdenum oxide) may be used.

[0368] The hole transport layer is a layer that transports 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-transporting material. The hole-transporting material is 1 × 10 −６ cm ２ Materials having a hole mobility of 1 / Vs or higher are preferred. Other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0369] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material with electron-blocking properties can be used for the electron blocking layer.

[0370] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0371] The electron transport layer is a layer that transports 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-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ −６ cm ２ Materials having an electron mobility of 1 / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, 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.

[0372] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0373] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0374] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection potential. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection potential. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection potential.

[0375] Furthermore, it is preferable that the LUMO level of a material with high electron injection capacity has a small difference (specifically, 0.5 eV or less) from the work function value of the material used as the cathode.

[0376] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). ｘ (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatritium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatritium (abbreviation: LiPPP), lithium oxide (LiO ｘ Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0377] The electron injection layer may contain an electron-transporting material. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0378] Furthermore, the Lowest Unoccupied Molecular Orbital (LUMO) level of organic compounds containing lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the Highest Occupied Molecular Orbital (HOMO) level and the LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0379] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz), etc., can be used in organic compounds containing lone pairs of electrons. Compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and superior heat resistance.

[0380] The charge generation layer preferably has a P-type layer. The P-type layer preferably contains an acceptor material, and preferably contains, for example, a hole transport material and an acceptor material applicable to the hole injection layer described above.

[0381] Furthermore, the charge generation layer preferably includes a layer containing a material with high electron injection properties. This layer can also be called an electron injection buffer layer or an N-type layer. The electron injection buffer layer is preferably provided between the P-type layer and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the P-type layer and the electron transport layer can be relaxed, allowing electrons generated in the P-type layer to be easily injected into the electron transport layer.

[0382] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, for example, a compound of an alkali metal or an alkaline earth metal. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ It is more preferable to have (O), etc. In addition, the electron injection buffer layer can suitably use materials applicable to the electron injection layer described above.

[0383] The charge generation layer preferably has a layer containing a material with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the P-type layer and the electron injection buffer layer. If the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the P-type layer and the electron transport layer. The electron relay layer has the function of preventing interaction between the P-type layer and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0384] As the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper(II) phthalocyanine (abbreviated as CuPc), or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0385] Furthermore, the P-type layer, electron injection buffer layer, and electron relay layer described above may not be clearly distinguishable depending on their cross-sectional shape or characteristics.

[0386] When stacking light-emitting units, the rise in driving voltage can be suppressed by providing a charge generation layer between the two light-emitting units.

[0387] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0388] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 30 to 33.

[0389] The electronic device of this embodiment has a display panel (display device) according to one aspect of the present invention in its display unit. The display panel according to one aspect of the present invention is easily made high-definition and high-resolution, and can achieve high display quality. Therefore, it can be used in the display units of various electronic devices.

[0390] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as other electronic devices with relatively large screens, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0391] In particular, a display panel according to one embodiment of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0392] A display panel according to one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display panel according to one embodiment 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 panel having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth. Furthermore, there are no particular limitations on the aspect ratio of the display panel in one embodiment of the present invention. For example, the display panel can support various aspect ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0393] The electronic device of this embodiment may have sensors (including those with the function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0394] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0395] Figures 30A to 30D illustrate an example of a wearable device that can be worn on the head. These wearable devices have one or both functions: the ability to display AR content and / or VR content. In addition to AR and VR, these wearable devices may also have functions to display SR or MR content. By having an electronic device that can display at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0396] The electronic device 700A shown in Figure 30A and the electronic device 700B shown in Figure 30B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 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.

[0397] A display panel according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created.

[0398] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0399] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0400] The communications unit has a wireless communication device, which can supply video signals and the like. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable supplying video signals and power potential can be connected.

[0401] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0402] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0403] Various types of touch sensors can be applied to the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be used. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0404] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric element) can be used as the light-receiving device (also called a photoelectric element). The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0405] The electronic device 800A shown in Figure 30C and the electronic device 800B shown in Figure 30D each include 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.

[0406] A display panel according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of displaying extremely high resolution can be created. This allows the user to experience a high level of immersion.

[0407] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can be achieved.

[0408] Electronic devices 800A and 800B can each be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0409] It is preferable that electronic devices 800A and 800B each have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 so that they are in the optimal position according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0410] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. While the attachment portion 823 is exemplified in Figure 30C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0411] The imaging unit 825 has the 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 in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0412] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as 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, enabling more accurate gesture control.

[0413] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This allows users to enjoy video and audio simply by wearing the electronic device 800A, without needing separate audio equipment such as headphones, earphones, or speakers.

[0414] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided in the electronic devices.

[0415] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 30A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 30C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0416] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 30B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0417] Similarly, the electronic device 800B shown in Figure 30D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0418] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a sound-collecting device such as a microphone can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0419] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0420] The electronic device 6500 shown in Figure 31A is a portable information terminal that can be used as a smartphone.

[0421] 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, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0422] A display panel according to one embodiment of the present invention can be applied to the display unit 6502.

[0423] Figure 31B is a schematic cross-sectional view of the housing 6501 including the end on the microphone 6506 side.

[0424] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, battery 6518, etc. are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0425] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0426] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded portion. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0427] A display device according to one embodiment of the present invention can be applied to the display panel 6511. As a result, an extremely lightweight electronic device can be realized. Furthermore, because the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel section, an electronic device with a narrow bezel can be realized.

[0428] Figure 31C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown to be supported by a stand 7103.

[0429] The operation of the television device 7100 shown in FIG. 31C can be performed by operation switches provided on the housing 7101 and a separate remote control operation device 7111. Alternatively, the display portion 7000 may be provided with a touch sensor, and the television device 7100 may be operated by touching the display portion 7000 with a finger or the like. The remote control operation device 7111 may include a display portion that displays information output from the remote control operation device 7111. Channel and volume operations can be performed by operation keys or a touch panel provided in the remote control operation device 7111, and an image displayed on the display portion 7000 can be operated.

[0430] Note that the television device 7100 is configured to include a receiver, a modem, and the like. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via a modem, it is also possible to perform one-way (from a sender to a receiver) or two-way information communication (between a sender and a receiver, between receivers, etc.).

[0431] FIG. 31D shows an example of a laptop personal computer. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. The display portion 7000 is incorporated in the housing 7211.

[0432] FIGS. 31E and 31F show an example of digital signage.

[0433] The digital signage 7300 shown in FIG. 31E includes a housing 7301, the display portion 7000, a speaker 7303, and the like. Furthermore, it can include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0434] FIG. 31F is digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 includes the display portion 7000 provided along the curved surface of the pillar 7401.

[0435] The wider the display unit 7000 is, the more the amount of information that can be provided at one time can be increased. In addition, the wider the display unit 7000 is, the more easily it attracts people's attention, and for example, the advertising effect of an advertisement can be enhanced.

[0436] Applying a touch panel to the display unit 7000 is preferable because it not only allows images or videos to be displayed on the display unit 7000, but also allows a user to perform intuitive operations. In addition, when the device is used for the purpose of providing information such as route information or traffic information, usability can be improved by intuitive operations.

[0437] In addition, as shown in FIGS. 31E and 31F, the digital signage 7300 or the digital signage 7400 is preferably capable of cooperating via wireless communication with an information terminal 7311 or an information terminal 7411 such as a smartphone owned by a user. For example, advertisement information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. In addition, the display on the display unit 7000 can be switched by operating the information terminal 7311 or the information terminal 7411.

[0438] In addition, it is also possible to cause the digital signage 7300 or the digital signage 7400 to execute a game that uses the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller). This allows an unspecified number of users to participate in and enjoy the game at the same time.

[0439] In FIGS. 31C to 31F, the display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0440] The electronic device shown in FIGS. 32A to 32G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function of detecting, sensing, or measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, electric power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), a microphone 9008, and the like.

[0441] The electronic devices shown in Figures 32A to 32G have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0442] Details of the electronic equipment shown in Figures 32A to 32G will be explained below.

[0443] Figure 32A is a perspective view showing a personal digital information terminal (PDI) 9101. The PDI 9101 can be used, for example, as a smartphone. The PDI 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. The PDI 9101 can also display text and image information on multiple surfaces. Figure 32A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, and phone calls, the subject of an email or SNS message, the sender's name, date and time, battery level, and signal strength. Alternatively, icons 9050 or the like may be displayed in the location where the information 9051 is displayed.

[0444] Figure 32B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0445] Figure 32C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000. The left side of the housing 9000 has operation keys 9005 as buttons for operation, and the bottom has connection terminals 9006.

[0446] Figure 32D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. The charging operation may be performed by wireless power supply.

[0447] Figures 32E to 32G are perspective views showing a foldable portable information terminal 9201. Figure 32E shows the portable information terminal 9201 in an unfolded state, Figure 32G shows it in a folded state, and Figure 32F shows a perspective view of the state in between, transitioning from one of Figures 32E or 32G to the other. The portable information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0448] Figures 33A and 33B show the external appearance of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a band-shaped fixing device 8304, and a pair of lenses 8305.

[0449] The user can view the display on the display unit 8302 through the lens 8305. It is preferable to arrange the display unit 8302 in a curved shape, as this allows the user to experience a greater sense of presence. Furthermore, by viewing different images displayed in different areas of the display unit 8302 through the lens 8305, three-dimensional display using parallax can be performed. Note that the configuration is not limited to having one display unit 8302; two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0450] A display device according to one embodiment of the present invention can be applied to the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. Therefore, even when the display is magnified and viewed using the lens 8305, the pixels are difficult for the user to see. In other words, the display unit 8302 can be used to allow the user to view a highly realistic image.

[0451] Furthermore, it is preferable that the head-mounted display 8300 has head tracking and eye tracking functions. This allows the displayed image to move in accordance with the user's movements and the direction of the user's gaze. This makes it possible to present the user with highly immersive images. For example, as shown in Figure 33C, a passenger in the back seat of a car can wear the head-mounted display 8300. In this case, because the image moves in sync with the shaking of the car body and the gaze is not fixed, motion sickness can be reduced compared to viewing images on a smartphone or tablet device, for example.

[0452] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0453] In this example, an insulating layer and a reverse-tapered partition wall were fabricated above it, and cross-sectional observation was performed.

[0454] [Sample Preparation] First, a silicon oxide nitride (SiON) film with a thickness of approximately 300 nm was deposited on a glass substrate as an insulating layer using plasma CVD. The silicon oxide nitride film was deposited using SiH as the deposition gas. ４ Gas, N ２ A mixed gas of O was used. Subsequently, N was used under conditions of 200°C. ２ Plasma treatment was performed under a gas atmosphere.

[0455] Next, a molybdenum film (Mo film) with a thickness of approximately 300 nm was deposited on the insulating layer as a conductive film to act as a barrier, using the DC sputtering method. The molybdenum film was first deposited as a first layer of approximately 100 nm under conditions of a pressure of 0.85 Pa and a power supply of 10 kW, and then, without exposure to the atmosphere, a second layer with a thickness of approximately 200 nm was formed continuously under conditions of a pressure of 0.75 Pa and a power supply of 35 kW.

[0456] Next, a resist mask was formed on the conductive film. Following this, etching of the conductive film and half-etching of the insulating layer were performed. Dry etching was used for the etching, with SF6 as the deposition gas. ６The experiment was conducted using gas under the following conditions: lower electrode temperature 80°C, ICP power 2000W, bias power 1000W, and pressure 3.5Pa.

[0457] [Cross-sectional observation] Next, the prepared sample was thinned using a focused ion beam (FIB), and the cross-section was observed using a scanning transmission electron microscope (STEM). For STEM observation, a Hitachi High-Tech HD-2300 scanning transmission electron microscope was used, with an acceleration voltage of 200 kV.

[0458] Figure 34A shows a transmission electron (TE) image of the sample cross-section observed at 50,000x magnification. It was confirmed that a partition wall of Mo film with an inverse tapered shape was formed between the SiON film and the resist mask. Although not shown here, the lateral shape of the partition wall was symmetrical.

[0459] Figure 34B shows an enlarged view of the side of the partition wall and its vicinity. The angle θ between the straight line along the side of the partition wall and the upper surface of the insulating layer was approximately 115 degrees (i.e., θ' was approximately 65 degrees).

[0460] Furthermore, focusing on the insulating layer, it was confirmed that it consists of a thicker portion R1 that overlaps with the partition wall, a thinner portion R2 that does not overlap with the partition wall, and a portion R3 located between these two portions, where the height of the upper surface changes. The difference in the height of the upper surfaces of portions R1 and R2 (i.e., the difference in thickness between portion R1 and portion R2) was approximately 167 nm. It was also confirmed that the corner R located at the boundary between portion R1 and portion R3 has a gently curved surface. Moreover, it was confirmed that the corner R is located inside the most protruding part at the top of the partition wall, that is, the corner R is covered by the side surface of the partition wall.

[0461] 100: Display device, 101: Substrate, 110: Light-emitting element, 110B: Light-emitting element, 110G: Light-emitting element, 110R: Light-emitting element, 110S: Photodetector, 110W: Light-emitting element, 111: Pixel electrode, 111B: Pixel electrode, 111G: Pixel electrode, 111R: Pixel electrode, 111S: Pixel electrode, 111W: Pixel electrode, 112: EL layer, 112B: EL layer, 112Ba: EL layer, 112G: EL layer, 112Ga: EL layer, 112R: EL layer, 112Ra: EL layer, 112S: Sensor layer, 112W: EL layer, 113: Upper electrode, 113B: Upper electrode, 113G: Upper electrode, 113R: Upper electrode, 114: Common layer, 115B: Color filter, 115G: Color filter, 115R: Color filter, 120: Partition wall, 120B: Lower part, 120f: Conductive film, 120T: Upper part, 121: Film deposition material, 122: Film deposition material, 123: Film deposition material, 125: Rotating shaft, 127a: Unit, 127b: Unit, 127c: Unit, 128: Nozzle, 131: Insulating layer, 132: Insulating layer, 133: Insulating layer, 133a: Insulating layer, 133b: Insulating layer, 134: Sacrificial layer, 134B: Sacrificial layer, 134G: Sacrificial layer, 134R: Sacrificial layer, 135: Protective layer, 1 35B: Protective layer, 135G: Protective layer, 135R: Protective layer, 141: Resist mask, 142a: Resist mask, 142b: Resist mask, 142c: Resist mask, 150: Transistor, 151: Semiconductor layer, 152: Insulating layer, 153: Conductive layer, 154: Conductive layer, 201: Transistor, 202: Transistor, 204: Connector, 205: Transistor, 209: Transistor, 210: Transistor, 211: Insulating layer, 212: Insulating layer, 213: Insulating layer, 214: Insulating layer, 215: Insulating layer, 218: Insulating layer, 221: Conductive layer, 222a: Conductive layer , 222b: conductive layer, 223: conductive layer, 225: insulating layer, 228: region, 231: semiconductor layer, 231i: channel formation region, 231n: low resistance region, 240: capacitance, 241: conductive layer, 242: connection 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, 274: plug, 274a: conductive layer, 274b: conductive layer, 280: display module, 281: display section, 282: circuit section,283: Pixel circuit section, 283a: Pixel circuit, 284: Pixel section, 284a: Pixel, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low-resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element 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, 400A: Display device, 400B: Display device, 40 0C: Display device, 400D: Display device, 400E: Display device, 401: Substrate, 411a: Pixel electrode, 411b: Pixel electrode, 411c: Pixel electrode, 416: Protective layer, 417: Light-shielding layer, 419: Resin layer, 420: Partition, 421: Insulating layer, 426: Optical adjustment layer, 426a: Optical adjustment layer, 426b: Optical adjustment layer, 426c: Optical adjustment layer, 430: Light-emitting element, 430a: Light-emitting element, 430b: Light-emitting element, 430c: Light-emitting element, 442: Adhesive layer, 443: Space, 451: Substrate, 452: Substrate, 453: Substrate, 454: Substrate, 455: Adhesive layer, 462: Display section, 464: Circuit, 465: Wiring, 466: Conductive layer, 472: FPC, 473: IC, 700A: Electronic equipment, 700B: Electronic equipment, 721: Housing, 723: Mounting part, 727: Earphone part, 750: Earphone, 751: Display panel, 753: Optical component, 756: Display area, 757: Frame, 758: Nose pad, 761: Lower electrode, 762: Upper electrode, 763: EL layer, 763a: Light-emitting unit, 763b: Light-emitting unit, 763c: Light-emitting unit, 764: Layer, 771: Light-emitting layer, 771a: Light-emitting layer, 771b: Light-emitting layer, 771c: Light-emitting layer, 772: Light-emitting layer, 772a: 772b: Light-emitting layer, 772c: Light-emitting layer, 773: Light-emitting layer, 780: Layer, 780a: Layer, 780b: Layer, 780c: Layer, 781: Layer, 782: Layer, 785: Charge generation layer, 790: Layer, 790a: Layer, 790b: Layer, 790c: Layer, 791: Layer, 792: Layer, 800A: Electronic equipment, 800B: Electronic equipment, 820: Display unit, 821: Housing, 822: Communication unit, 823: Mounting unit, 824: Control unit, 825: Imaging unit, 827: Earphone unit, 832: Lens, 6500: Electronic equipment, 6501: Housing, 6502: Display unit, 6503: Power button, 6504: Button,6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protective component, 6511: Display panel, 6512: Optical component, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television equipment, 7101: Enclosure, 7103: Stand, 7111: Remote control operator, 7200: Notebook personal computer, 7211: Enclosure, 7212: Keyboard, 7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Enclosure, 7303: Speaker, 7311: Information terminal, 7400: Digital signage, 7401: Pillar, 7411: Information terminal, 8300: Head-mounted display, 8301: Housing, 8302: Display unit, 8304: Fixture, 8305: Lens, 9000: Housing, 9001: Display unit, 9002: Camera, 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, 9103: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

It has a pixel electrode, an EL layer, an upper electrode, a first insulating layer, and a partition wall. The first insulating layer has a first portion, a second portion, and a third portion between them. The second portion is lower in height from the surface to be formed than the first portion. The third portion has a change in the height of its upper surface from the first portion to the second portion. The partition wall is conductive, located on the first portion of the first insulating layer, and has an inverse tapered shape in cross-sectional view. The EL layer contains a light-emitting compound and is in contact with the upper surface of the pixel electrode and the second portion of the first insulating layer. The upper electrode covers the upper surface and edges of the EL layer and is in contact with the side surface of the partition wall. Display device. 　 In claim 1, The first insulating layer has a corner at the boundary between the first portion and the third portion in a cross-sectional view. The aforementioned corner overlaps with the side surface of the partition wall when viewed from above. Display device. 　 In claim 1, The first insulating layer has a corner at the boundary between the first portion and the third portion in a cross-sectional view. The aforementioned corner portion is located on the pixel electrode side of the most protruding end of the partition wall in a cross-sectional view. Display device. 　 In claim 1, The angle between the contact surface between the partition wall and the first insulating layer and the side surface of the partition wall is 105 degrees or more and 175 degrees or less. Display device. 　 In claim 1, The partition wall contains one or more of the following materials: molybdenum, silver, copper, aluminum, tungsten, and titanium. Display device. 　 A first insulating layer is formed to cover the pixel electrodes. A first conductive film is formed on the first insulating layer. A resist mask is formed on the first conductive film. The portion of the first conductive film not covered by the resist mask is etched to form a reverse tapered partition wall. A portion of the first insulating layer not covered by the resist mask is etched to form a first portion, a second portion whose upper surface height from the surface to be formed is lower than that of the first portion, and a third portion located between the first portion and the second portion, the upper surface height changing from the first portion to the second portion. Remove the aforementioned resist mask, By removing a portion of the second part of the first insulating layer, a portion of the pixel electrode is exposed. A first EL layer is formed in contact with the upper surface of the pixel electrode and the upper surface of the second portion, and a second EL layer is formed on the partition wall, which is physically separated from the first EL layer. The first EL layer is covered and an upper electrode is formed that is in contact with the side surface of the partition wall. Method for manufacturing a display device. 　 In claim 6, As the first conductive film, a first layer and a second layer on the first layer are formed by sputtering. The deposition of the second layer is carried out under deposition conditions that satisfy lower pressure, higher power supply voltage, or both, compared to the deposition conditions for the first layer. Method for manufacturing a display device. 　 In claim 6, The first conductive film and the first insulating layer are each processed by dry etching. Method for manufacturing a display device. 　 In claim 6, The first conductive film is formed to contain one or more of the following: molybdenum, silver, copper, aluminum, tungsten, and titanium. Method for manufacturing a display device.

Images