Method for manufacturing a display device

Abstract

To provide a high-definition display device. To provide a display device with a high aperture ratio. [Solution] The display device has a first light-emitting element and a second light-emitting element. The first light-emitting element has a first pixel electrode, a first light-emitting layer, and a common electrode stacked in that order. The second light-emitting element has a second pixel electrode, a second light-emitting layer, and a common electrode stacked in that order. The region between the first light-emitting element and the second light-emitting element has a first layer and a second layer. The first layer is superimposed on the second light-emitting layer and contains the same material as the first light-emitting layer. The second layer is superimposed on the first light-emitting layer and contains the same material as the second light-emitting layer. In the region between the first light-emitting element and the second light-emitting element, the end of the first light-emitting layer and the end of the first layer are provided facing each other. In the region between the first light-emitting element and the second light-emitting element, the end of the second light-emitting layer and the end of the second layer are provided facing each other.

Description

[Technical Field]

[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. [Background technology]

[0003] In recent years, there has been a growing demand for higher resolution display panels. Examples of devices requiring high-resolution display panels include smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors are also demanding higher resolutions. Among the devices requiring the highest level of resolution are those used for virtual reality (VR) and augmented reality (AR).

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

[0005] For example, an example of a display device for VR using an organic EL element is described in Patent Document 1. [Prior art documents] [Patent Documents]

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] One aspect of the present invention aims to provide a high-definition display device. One aspect of the present invention aims to provide a display device with a high aperture ratio. One aspect of the present invention aims to provide a display device with high brightness. One aspect of the present invention aims to provide a display device with high contrast. One aspect of the present invention aims to provide a highly reliable display device.

[0008] One aspect of the present invention aims to provide a display device having a novel configuration. One aspect of the present invention aims to provide a method for manufacturing a novel display device. One aspect of the present invention aims to provide a method for manufacturing the above-described display device with high yield. One aspect of the present invention aims to at least alleviate at least one of the problems of the prior art.

[0009] Note that the description of these problems does not prevent the existence of other problems. Note that one aspect of the present invention does not need to solve all of these problems. Note that other problems can be extracted from the descriptions in the specification, drawings, claims, etc.

Means for Solving the Problems

[0010] One aspect of the present invention is a display device having a first light-emitting element and a second light-emitting element. The first light-emitting element has a first pixel electrode, a first light-emitting layer, and a common electrode laminated in this order. The second light-emitting element has a second pixel electrode, a second light-emitting layer, and a common electrode laminated in this order. In the region between the first light-emitting element and the second light-emitting element, there are a first layer and a second layer. The first layer overlaps with the second light-emitting layer and contains the same material as the first light-emitting layer. The second layer overlaps with the first light-emitting layer and contains the same material as the second light-emitting layer. In the region between the first light-emitting element and the second light-emitting element, the end of the first light-emitting layer and the end of the first layer are provided facing each other. In the region between the first light-emitting element and the second light-emitting element, the end of the second light-emitting layer and the end of the second layer are provided facing each other.

[0011] Another aspect of the present invention is a display device having a first light-emitting element and a second light-emitting element. The first light-emitting element has a first pixel electrode, a first light-emitting layer, a first intermediate layer, a third light-emitting layer, and a common electrode laminated in this order. The second light-emitting element has a second pixel electrode, a second light-emitting layer, a second intermediate layer, a fourth light-emitting layer, and a common electrode laminated in this order. Between the first light-emitting element and the second light-emitting element, there are a first layer, a second layer, a third layer, and a fourth layer. The first layer overlaps with the second light-emitting layer, the second intermediate layer, and the fourth light-emitting layer and contains the same material as the first light-emitting layer. The second layer overlaps with the first light-emitting layer, the first intermediate layer, and the third light-emitting layer and contains the same material as the second light-emitting layer. The third layer overlaps with the first layer and contains the same material as the third light-emitting layer. The fourth layer overlaps with the second layer and contains the same material as the fourth light-emitting layer. In the region between the first light-emitting element and the second light-emitting element, the end of the first light-emitting layer and the end of the first layer are provided facing each other. In the region between the first light-emitting element and the second light-emitting element, the end of the second light-emitting layer and the end of the second layer are provided facing each other. In the region between the first light-emitting element and the second light-emitting element, the end of the third light-emitting layer and the end of the third layer are provided facing each other. In the region between the first light-emitting element and the second light-emitting element, the end of the fourth light-emitting layer and the end of the fourth layer are provided facing each other.

[0012] Furthermore, it is preferable that the first light-emitting layer and the third light-emitting layer contain the same material, and the second light-emitting layer and the fourth light-emitting layer contain the same material.

[0013] Furthermore, it is preferable that the above configuration includes a resin layer. The resin layer is preferably located in the region between the first light-emitting element and the second light-emitting element. It is also preferable that the end of the first light-emitting layer and the end of the first layer face each other with the resin layer in between, and that the end of the second light-emitting layer and the end of the second layer face each other with the resin layer in between.

[0014] Furthermore, it is preferable that the above configuration includes a first insulating layer. The first insulating layer is located in the region between the first light-emitting element and the second light-emitting element, and it is preferable that the first insulating layer is in contact with the edges of the first light-emitting layer, the edges of the second light-emitting layer, the edges of the first layer, and the edges of the second layer.

[0015] Another aspect of the present invention is a method for manufacturing a display device, comprising: a first step of arranging a first pixel electrode and a second pixel electrode side by side; a second step of forming an island-shaped first light-emitting layer on the first pixel electrode using a first metal mask; a third step of forming an island-shaped second light-emitting layer on the second pixel electrode using a second metal mask so as to overlap with the edge of the first light-emitting layer; a fourth step of separating the first light-emitting layer and the second light-emitting layer by etching in the region between the first pixel electrode and the second pixel electrode; and a fifth step of covering the first light-emitting layer and the second light-emitting layer to form a common electrode.

[0016] Furthermore, it is preferable that the above process includes a sixth step, after the fourth step and before the fifth step, in which a resin layer is formed in the slit formed by etching.

[0017] Furthermore, in the above, it is preferable to use a photosensitive organic resin for the resin layer.

[0018] Furthermore, it is preferable that, in any of the above, there is a seventh step after the fourth step and before the sixth step, in which a first insulating layer is formed in contact with the side surfaces of the first light-emitting layer and the side surfaces of the second light-emitting layer that have been exposed by etching.

[0019] Furthermore, in the above, it is preferable to use an inorganic insulating film formed by atomic layer deposition for the first insulating layer. [Effects of the Invention]

[0020] According to one aspect of the present invention, a high-definition display device can be provided. Alternatively, a display device with a high aperture ratio can be provided. Alternatively, a display device with high brightness can be provided. Alternatively, a display device with high contrast can be provided. Alternatively, a highly reliable display device can be provided.

[0021] According to one aspect of the present invention, a display device having a novel configuration can be provided. Alternatively, a method for manufacturing a novel display device can be provided. Alternatively, a method for manufacturing the above-described 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.

[0022] 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. [Brief explanation of the drawing]

[0023] [Figure 1] Figures 1A to 1D show examples of the configuration of a display device. [Figure 2] Figures 2A to 2C show examples of display device configurations. [Figure 3] Figures 3A and 3B show examples of display device configurations. [Figure 4] Figures 4A and 4B show examples of the configuration of a display device. [Figure 5]Figures 5A and 5B show examples of display device configurations. [Figure 6] Figures 6A and 6B show examples of the configuration of a display device. [Figure 7] Figures 7A and 7B show examples of display device configurations. [Figure 8] Figures 8A to 8C show examples of methods for manufacturing a display device. [Figure 9] Figures 9A to 9C show examples of methods for manufacturing a display device. [Figure 10] Figures 10A to 10C show examples of methods for manufacturing a display device. [Figure 11] Figures 11A to 11C show examples of methods for manufacturing a display device. [Figure 12] Figures 12A to 12C show examples of methods for manufacturing a display device. [Figure 13] Figure 13 is a perspective view showing an example of a display device. [Figure 14] Figure 14A is a cross-sectional view showing an example of a display device. Figure 14B is a cross-sectional view showing an example of a transistor. [Figure 15] Figures 15A to 15E show examples of pixels in a display device. [Figure 16] Figures 16A to 16G show examples of pixels in a display device. [Figure 17] Figures 17A to 17F show examples of the configuration of a light-emitting device. [Figure 18] Figures 18A to 18D show examples of pixels in a display device. Figures 18E and 18F show examples of the pixel circuits in a display device. [Figure 19] Figures 19A to 19J show examples of display device configurations. [Figure 20] Figures 20A and 20B show examples of electronic devices. [Figure 21] Figures 21A to 21D show examples of electronic devices. [Figure 22] Figures 22A to 22F show examples of electronic devices. [Figure 23] Figures 23A to 23F show examples of electronic devices. [Figure 24] Figure 24 shows the relationship between the screen size and pixel density of the product. [Modes for carrying out the invention]

[0024] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope thereof. Accordingly, the present invention shall not be construed as being limited to the contents of the following embodiments.

[0025] In the configuration of the invention described below, the same reference numerals are used in common across different drawings for identical parts or parts having similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0026] In the figures described herein, the size of each component, the thickness of the layers, or the area may be exaggerated for clarity. Therefore, the scale is not necessarily limited to those figures.

[0027] Furthermore, ordinal numbers such as "the first," "the second," etc., used in this specification are added to avoid confusion of constituent elements and do not imply any numerical limitation.

[0028] Furthermore, in this specification, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" or "insulating layer" may be interchangeable with the terms "conductive film" or "insulating film."

[0029] In this specification, the term "EL layer" refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance, or a laminate including a light-emitting layer.

[0030] In this specification, a display panel, which is one form of a display device, has the function of displaying (outputting) images or the like on its display surface. Therefore, a display panel is one form of an output device.

[0031] Furthermore, in this specification, a display panel on which a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) is attached, or on which an IC is mounted on the board using a COG (Chip On Glass) method, may be referred to as a display panel module, display module, or simply a display panel.

[0032] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention, and an example of a method for manufacturing the display device.

[0033] 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. The light-emitting elements are preferably organic EL elements (organic electroluminescent elements). Two or more light-emitting elements that emit different 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.

[0034] 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 fine metal mask (FMM). 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 FMM, the misalignment between the FMM and the substrate, the bending of the FMM, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to increase the resolution and aperture ratio of the display device. For this reason, measures have been taken to artificially increase the resolution (also called pixel density) by applying special pixel arrangement methods such as pentile arrangements.

[0035] In fabrication methods using FMMs, to achieve higher resolution and aperture ratios, it is possible to form two adjacent island-shaped organic films so that parts of them overlap. This significantly reduces the distance between light-emitting regions compared to when the two island-shaped organic films are not overlapped. However, when two adjacent island-shaped organic films are formed by overlapping, current leakage may occur between the two adjacent light-emitting elements through the overlapping organic films, resulting in unintended light emission. This can lead to a decrease in brightness and contrast, thus degrading display quality. Furthermore, the leakage current can worsen power efficiency and power consumption.

[0036] Therefore, in one aspect of the present invention, the organic films between two adjacent light-emitting elements are fabricated separately using FMM such that a portion of each film overlaps. Specifically, layers containing at least a luminescent organic compound (also called a light-emitting layer) are fabricated separately using FMM. At this time, the other organic films constituting the light-emitting elements may be common films without being fabricated separately. In the region between the two adjacent light-emitting elements, an organic multilayer film is located, in which at least two types of light-emitting layers and other organic films are stacked. Subsequently, the organic multilayer film is divided by etching the portion of the organic multilayer film located between the two adjacent light-emitting elements using photolithography. This makes it possible to divide the current leakage path between the two adjacent light-emitting elements. As a result, it is possible to increase brightness, increase contrast, increase power efficiency, or reduce power consumption.

[0037] Furthermore, it is preferable to form an insulating layer to protect the sides of the organic multilayer film exposed by etching. This can improve the reliability of the display device.

[0038] Thus, one aspect of the present invention makes it possible to realize a display device that integrates fine light-emitting elements. For example, since there is no need to apply a special pixel arrangement method such as the pentile method to artificially increase the resolution, a display device can be realized with a resolution of 300 ppi or more, 500 ppi or more, 700 ppi or more, or 1000 ppi or more, using a so-called stripe arrangement in which R, G, and B are each arranged in one direction. Furthermore, a display device can be realized with an effective light-emitting area ratio (aperture ratio) of 15% or more, 20% or more, and even 30% or more, but less than 100%.

[0039] Furthermore, one aspect of the present invention makes it possible to accurately fabricate minute light-emitting elements, thereby enabling complex pixel arrangement methods. For example, various arrangement methods such as S-strip arrangements, Bayer arrangements, and delta arrangements can be applied in addition to stripe arrangements.

[0040] In this specification, the effective light-emitting area ratio refers to the ratio of the area of ​​the region that can be considered as a light-emitting region within a single pixel to the area of ​​a single pixel calculated from the repeating pitch of the pixels of the display device.

[0041] In the following section, a more specific configuration example and manufacturing method example of a display device according to one aspect of the present invention will be described with reference to the drawings.

[0042] [Configuration Example 1] Figure 1A shows a schematic top view of a display device 100 according to one embodiment of the present invention. The display device 100 has multiple red-emitting light-emitting elements 110R, green-emitting light-emitting elements 110G, and blue-emitting light-emitting elements 110B. In Figure 1A, the labels R, G, and B are added within the light-emitting area of ​​each light-emitting element to simplify the distinction between them.

[0043] 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 one direction. However, the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as S-stripe arrangement, delta arrangement, Bayer arrangement, zigzag arrangement may be applied, or a pentile arrangement may be used.

[0044] The light-emitting elements 110R, 110G, and 110B are arranged in the X direction. In addition, light-emitting elements of the same color are arranged in the Y direction, which intersects the X direction.

[0045] It is preferable to use EL elements such as OLED (Organic Light Emitting Diode) or QLED (Quantum-dot Light Emitting Diode) 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.

[0046] Figure 1B is a schematic cross-sectional view corresponding to the dashed line A1-A2 in Figure 1A, and Figure 1C is a schematic cross-sectional view corresponding to the dashed line B1-B2.

[0047] Figure 1B shows cross-sections of light-emitting elements 110R, 110G, and 110B. Light-emitting element 110R has a pixel electrode 111R, an organic layer 115, an organic layer 112R, an organic layer 116, an organic layer 114, and a common electrode 113. Light-emitting element 110G has a pixel electrode 111G, an organic layer 115, an organic layer 112G, an organic layer 116, an organic layer 114, and a common electrode 113. Light-emitting element 110B has a pixel electrode 111B, an organic layer 115, an organic layer 112B, an organic layer 116, an organic layer 114, and a common electrode 113. The organic layer 114 and the common electrode 113 are provided in common to light-emitting elements 110R, 110G, and 110B. The organic layer 114 can also be called a common layer.

[0048] The organic layer 112R of the light-emitting element 110R contains a luminescent organic compound that emits at least red light. The organic layer 112G of the light-emitting element 110G contains a luminescent organic compound that emits at least green light. The organic layer 112B of the light-emitting element 110B contains a luminescent organic compound that emits at least blue light. The organic layers 112R, 112G, and 112B can also be called light-emitting layers.

[0049] In the following, when describing matters common to the light-emitting element 110R, light-emitting element 110G, and light-emitting element 110B, they may be referred to simply as light-emitting element 110. Similarly, for components distinguished by letters, such as organic layer 112R, organic layer 112G, and organic layer 112B, when describing matters common to these components, the letters may be omitted and symbols used.

[0050] In each light-emitting element, the stacked film located between the pixel electrode and the common electrode 113 can be called the EL layer.

[0051] In each light-emitting element, the organic layer 115 is located between the organic layer 112 and the pixel electrode 111. The organic layer 116 is located between the organic layer 112 and the organic layer 114. The organic layer 114 is located between the organic layer 116 and the common electrode 113.

[0052] Organic layers 115, 116, and 114 can each independently have one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. For example, organic layer 115 can have a stacked structure of a hole injection layer and a hole transport layer from the pixel electrode 111 side, organic layer 116 can have an electron transport layer, and organic layer 114 can have an electron injection layer. Alternatively, organic layer 115 can have a stacked structure of an electron injection layer and an electron transport layer from the pixel electrode 111 side, organic layer 116 can have a hole transport layer, and organic layer 114 can have a hole injection layer.

[0053] Furthermore, regarding layers located between the pair of electrodes of the light-emitting element, such as organic layer 112, organic layer 114, organic layer 115, and organic layer 116, the name "organic layer" implies that these are layers constituting an organic EL element, and they do not necessarily need to contain organic compounds. For example, organic layer 112, organic layer 114, organic layer 115, and organic layer 116 can each be films that do not contain organic compounds, but only inorganic compounds or inorganic materials.

[0054] Pixel electrodes 111R, 111G, and 111B are provided for each light-emitting element. The common electrode 113 and the organic layer 114 are provided as a continuous layer common to each light-emitting element. A conductive film that is transparent to visible light is used on either each pixel electrode or the common electrode 113, while a conductive film that is reflective is used on the other. By making each pixel electrode transparent and the common electrode 113 reflective, a bottom-emission type display device can be created. Conversely, by making each pixel electrode reflective and the common electrode 113 transparent, a top-emission type display device can be created. Furthermore, by making both each pixel electrode and the common electrode 113 transparent, a dual-emission type display device can be created.

[0055] A protective layer 121 is provided on the common electrode 113, covering the light-emitting elements 110R, 110G, and 110B. The protective layer 121 has the function of preventing impurities such as water from diffusing to each light-emitting element from above.

[0056] A slit 120 is provided between two adjacent light-emitting elements. The slit 120 corresponds to the etched portion of the organic layer 115, organic layer 112, and organic layer 116 located between the two adjacent light-emitting elements.

[0057] The slit 120 is provided with an insulating layer 125 and a resin layer 126. The insulating layer 125 is provided along the side walls and bottom surface of the slit 120. The resin layer 126 is provided on top of the insulating layer 125 and has the function of filling the recesses located in the slit 120 and flattening its upper surface. By flattening the recesses in the slit 120 with the resin layer 126, the coverage of the organic layer 114, the common electrode 113, and the protective layer 121 can be improved. Furthermore, since the slit 120 can be formed simultaneously with the formation of the openings for external connection terminals such as the connecting electrode 111C, these can be formed without increasing the number of steps. In addition, because the slit 120 has an insulating layer 125 and a resin layer 126, it has the effect of preventing short circuits between the pixel electrode 111 and the common electrode 113. Furthermore, the resin layer 126 has the effect of improving the adhesion of the organic layer 114. In other words, by providing the resin layer 126, the adhesion of the organic layer 114 is improved, thereby suppressing peeling of the organic layer 114. Furthermore, since the insulating layer 125 is provided in contact with the side surface of the organic layer (for example, the organic layer 115), a structure can be created in which the organic layer and the resin layer 126 do not come into contact. If the organic layer and the resin layer 126 come into contact, the organic layer may dissolve due to organic solvents contained in the resin layer 126. Therefore, as shown in this embodiment, by providing the insulating layer 125 between the organic layer and the resin layer 126, it is possible to protect the side surface of the organic layer. Note that the slit 120 only needs to be configured to separate at least one or more of the hole injection layer, hole transport layer, electron suppression layer, light emission layer, hole suppression layer, electron transport layer, and electron injection layer.

[0058] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride oxide film and aluminum nitride oxide film. In particular, by applying inorganic insulating films such as aluminum oxide film, hafnium oxide film, and silicon oxide film formed by the ALD method to the insulating layer 125, an insulating layer 125 can be formed that has fewer pinholes and excellent function in protecting the EL layer.

[0059] In this specification, the term "oxide-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. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0060] The insulating layer 125 can be formed using sputtering, CVD, PLD, ALD, or other methods. It is preferable to form the insulating layer 125 using the ALD method, which provides good coverage.

[0061] As the resin layer 126, an insulating layer having an organic material can be suitably used. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used as the resin layer 126. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used as the resin layer 126. Furthermore, a photosensitive resin can be used as the resin layer 126. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material. Additionally, by using a colored material (for example, a material containing black pigment) as the resin layer 126, a function to block stray light from adjacent pixels and suppress color mixing may be provided. Furthermore, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, and aluminum) may be provided between the insulating layer 125 and the resin layer 126 to reflect the light emitted from the light-emitting layer and provide a function to improve light extraction efficiency.

[0062] The upper surface of the resin layer 126 is preferably flat, but it may have a gently curved shape. Figure 1B and others show an example in which the upper surface of the resin layer 126 has a wave-like shape with concave and convex portions, but it is not limited to this. For example, the upper surface of the resin layer 126 may be convex, concave, or flat.

[0063] As the protective layer 121, a laminated film of an inorganic insulating film and an organic insulating film can also be used. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This makes the upper surface of the organic insulating film flat, thereby improving the coverage of the inorganic insulating film on top of it and enhancing its barrier properties. In addition, since the upper surface of the protective layer 121 is flat, it is preferable because it reduces the influence of uneven shapes caused by the structure below when a structure (e.g., a color filter, touch sensor electrodes, or lens array, etc.) is provided above the protective layer 121.

[0064] The protective layer 121 can be, for example, a single-layer structure or a multilayer 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 121.

[0065] As shown in Figure 1C, slits 120 may be provided even between light-emitting elements of the same color. By providing slits 120 even between light-emitting elements of the same color, it is possible to effectively prevent current from flowing through two adjacent EL layers and causing unintended light emission. As a result, contrast can be increased, and a display device with high display quality can be realized.

[0066] In the Y direction, the organic layers 112R, 112G, or 112B may be formed in a strip shape so that they form a continuous strip between light-emitting elements of the same color. By forming the organic layers 112R, 112G, or 112B in a strip shape, the space required to separate them is eliminated, and the area of ​​the non-emitting region between light-emitting elements can be reduced, thereby increasing the aperture ratio.

[0067] Figure 1A also shows a connecting electrode 111C that is electrically connected to the common electrode 113. The connecting electrode 111C is supplied with a potential (e.g., anode potential or cathode potential) to the common electrode 113. The connecting electrode 111C is located outside the display area where the light-emitting elements 110R and the like are arranged. The common electrode 113 is also shown with a dashed line in Figure 1A.

[0068] The connecting electrode 111C can be provided along the outer perimeter of the display area. For example, it may be provided along one side of the outer perimeter of the display area, or it may be provided across two or more sides of the outer perimeter of the display area. That is, if the top surface shape of the display area is rectangular, the top surface shape of the connecting electrode 111C can be a strip, L-shape, U-shape (angle bracket shape), or square, etc.

[0069] Figure 1D is a schematic cross-sectional view corresponding to the dashed line C1-C2 in Figure 1A. Figure 1D shows a connection portion 130 where the connecting electrode 111C and the common electrode 113 are electrically connected. In the connection portion 130, the common electrode 113 is provided on the connecting electrode 111C via an organic layer 114. In addition, an insulating layer 125 is provided in contact with the side surface of the connecting electrode 111C, and a resin layer 126 is provided on the insulating layer 125.

[0070] It is not necessary to provide the organic layer 114 at the connection portion 130. In that case, at the connection portion 130, the common electrode 113 is provided in contact with the connecting electrode 111C, and the protective layer 121 is provided covering the common electrode 113.

[0071] Figures 2A, 2B, and 2C show examples where the insulating layer 125 is not provided.

[0072] As shown in Figures 2A and 2B, the resin layer 126 is provided in contact with the sides of the organic layers 115, 112, and 116. Also, as shown in Figure 2C, the resin layer 126 is provided in contact with the side of the connecting electrode 111C.

[0073] Next, preferred configurations of the slit 120 and its vicinity will be described in detail. Figure 3A is a schematic cross-sectional view including a portion of the light-emitting element 110R, a portion of the light-emitting element 110G, and the region between them in Figure 1B.

[0074] As shown in Figure 3A, the ends of the pixel electrode 111 are preferably tapered. This improves the step coverage of the organic layer 115, etc. In this specification, a tapered end of an object means that the angle between the surface and the surface to be formed in the region of that end is greater than 0 degrees and less than 90 degrees, and that the cross-sectional shape has such that the thickness increases continuously from the end. Here, the case where the pixel electrode 111R etc. is a single-layer structure is shown, but multiple layers may be stacked.

[0075] An organic layer 115 is provided covering the pixel electrode 111R. Similarly, an organic layer 115 is provided covering the pixel electrode 111G. These organic layers 115 are formed by dividing a continuous film with a slit 120.

[0076] On the side of the light-emitting element 110R beyond the slit 120, an organic layer 112R is provided covering the organic layer 115. Furthermore, on the side of the light-emitting element 110G beyond the slit 120, a layer 135R is provided on the organic layer 115. Layer 135R can be described as a portion of the film that becomes the organic layer 112R, which is separated by the slit 120 and remains on the side of the light-emitting element 110G.

[0077] Furthermore, on the side of the light-emitting element 110G beyond the slit 120, an organic layer 112G is provided covering the organic layer 115. Also, on the side of the light-emitting element 110R beyond the slit 120, a layer 135G is provided on the organic layer 112R. Layer 135G can be described as a portion of the film that becomes the organic layer 112G that is separated by the slit 120 and remains on the side of the light-emitting element 110R.

[0078] In addition, depending on the position and width of the slit 120, the formation position of the organic layer 112R, and the formation position of the organic layer 112G, one or both of layers 135R and 135G may not be formed. Specifically, if the end of the organic layer 112R before the formation of the slit 120 coincides with the formation position of the slit 120, layer 135R may not be formed.

[0079] An organic layer 116 is provided covering organic layers 112R and 135G. Similarly, an organic layer 116 is provided covering organic layers 112G and 135R. These organic layers 116 are formed by dividing a continuous film at a slit 120, similar to the organic layer 115.

[0080] The insulating layer 125 is provided inside the slit 120 and is in contact with the sides of the pair of organic layers 115, the sides of organic layer 112R, the sides of organic layer 112G, the sides of layer 135R, the sides of layer 135G, and the sides of the pair of organic layers 116. The insulating layer 125 is also provided covering the upper surface of the substrate 101.

[0081] The resin layer 126 is provided in contact with the upper and side surfaces of the insulating layer 125. The resin layer 126 has the function of flattening the recesses on the surface of the organic layer 114.

[0082] The organic layer 114, common electrode 113, and protective layer 121 are formed in this order, covering the upper surfaces of the organic layer 116, insulating layer 125, and resin layer 126. Note that the organic layer 114 may be omitted if it is not needed.

[0083] Here, layers 135R and 135G are located at the edges of the film that will become organic layer 112R or organic layer 112G. In the film deposition method using FMM, the thickness of the organic film tends to gradually decrease towards the edges, so layers 135R and 135G have portions that are thinner than organic layer 112R or organic layer 112G. Layers 135R and 135G may be so thin that they cannot be confirmed by cross-sectional observation. Furthermore, even if layers 135R or 135G are present, it may be difficult to confirm the boundary between layer 135R and organic layer 112G, or between layer 135G and organic layer 112R, by cross-sectional observation.

[0084] On the other hand, layers 135R and 135G contain luminescent compounds (e.g., fluorescent materials, phosphorescent materials, or quantum dots), so when irradiated with ultraviolet or visible light in a planar view, photoluminescence can be obtained. The presence of layers 135R and 135G can be confirmed by observing this emission with an optical microscope. Specifically, since layer 135R and organic layer 112G overlap in the area where layer 135R is located, irradiating this area with ultraviolet light will allow both light from layer 135R and light from organic layer 112G to be observed. Furthermore, from the emission spectrum, wavelength, and emission color of the light emitted from layers 135R and 135G, it can be confirmed that layer 135R or layer 135G contains the same material as organic layer 112R or organic layer 112G. In some cases, it may also be possible to estimate the compounds contained in layers 135R and 135G.

[0085] In this example, organic layer 112R and organic layer 112G are fabricated separately using FMM, while the other organic layers (organic layer 115, organic layer 116) are formed as a continuous film. However, this is not the only example. For instance, either organic layer 115, organic layer 116, or both may be fabricated separately using FMM. In this case, fragments of organic layer 115 or organic layer 116 may remain near the slit 120, similar to layer 135R, etc.

[0086] Figure 3B is a schematic cross-sectional view of the case without the insulating layer 125. The resin layer 126 is provided in contact with the sides of the pair of organic layers 115, the sides of organic layer 112R, the sides of organic layer 112G, the sides of layer 135R, the sides of layer 135G, and the sides of the pair of organic layers 116.

[0087] In this case, the solvent used to form the film that becomes the resin layer 126 may cause a portion of the EL layer to dissolve. Therefore, if an insulating layer 125 is not provided, it is preferable to use water, or an alcohol such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin as the solvent for the resin layer 126. However, it is not limited to these, and any solvent that does not dissolve or does not easily dissolve the EL layer may be used.

[0088] In the enlarged views shown in Figures 3A and 3B, the light-emitting element 110R, light-emitting element 110G, and the region between them were explained, but the same configuration is also found between light-emitting element 110R and light-emitting element 110B, and between light-emitting element 110G and light-emitting element 110B.

[0089] [Configuration Example 2] By stacking multiple light-emitting layers, it is possible to obtain higher brightness when the same current is applied, compared to when a single light-emitting layer is used. Furthermore, since the current density required to obtain the same brightness can be reduced, reliability can be improved. The following describes an example of a case where multiple light-emitting layers are stacked.

[0090] Figure 4A shows a schematic cross-sectional view of the display device illustrated below. The display device has light-emitting elements 110R, 110G, and 110B. The light-emitting elements 110R, 110G, and 110B shown in Figure 4A are light-emitting elements that employ a so-called tandem structure, in which two light-emitting layers are stacked with a charge generation layer (also called an intermediate layer) in between.

[0091] The light-emitting element 110R has a structure in which organic layers 115, 112R1, 116, 117, 118, 112R2, 119, 114, and a common electrode 113 are stacked on the pixel electrode 111R. Similarly, the light-emitting element 110G has a pixel electrode 111G, organic layers 115, 112G1, 116, 117, 118, 112G2, 119, 114, and a common electrode 113. Furthermore, the light-emitting element 110B has a pixel electrode 111B, organic layers 115, 112B1, 116, 117, 118, 112B2, 119, 114, and a common electrode 113.

[0092] A slit 120 is provided between two adjacent light-emitting elements. The slit 120 is formed to divide the laminated structure from organic layer 115 to organic layer 119, which is provided in the region between the two pixel electrodes. Furthermore, an insulating layer 125 and a resin layer 126 are provided inside the slit 120. Note that a configuration without the insulating layer 125 is also possible.

[0093] Figure 4B is a schematic cross-sectional view including a portion of the light-emitting element 110R, a portion of the light-emitting element 110G, and the region between them in Figure 4A.

[0094] On the side of the light-emitting element 110R relative to the slit 120, layer 135G1 is provided between organic layer 115 and organic layer 116. Additionally, layer 135G2 is provided between organic layer 118 and organic layer 119.

[0095] On the side of the light-emitting element 110G relative to the slit 120, layer 135R1 is provided between organic layer 115 and organic layer 116. Additionally, layer 135R2 is provided between organic layer 118 and organic layer 119.

[0096] Layers 135R1 and 135R2 can be described as fragments remaining on the light-emitting element 110G side when a portion of the film that will become organic layer 112R1 or organic layer 112R2 is separated by the slit 120. Similarly, layers 135G1 and 135G2 can be described as fragments remaining on the light-emitting element 110R side when a portion of the film that will become organic layer 112G1 or organic layer 112G2 is separated by the slit 120.

[0097] The sides of layer 135R1 and the sides of organic layer 112R1 are arranged facing each other via resin layer 126 (and insulating layer 125). Similarly, the sides of layer 135R2 and organic layer 112R2, layer 135G1 and organic layer 112G1, and layer 135G2 and organic layer 112G2 are arranged facing each other via resin layer 126 (and insulating layer 125).

[0098] In addition, there may be cases where one or more of layers 135R1, 135R2, 135G1, and 135G2 are not provided.

[0099] The stacking order of organic layer 112R1 and layer 135G1, organic layer 112R2 and layer 135G2, organic layer 112G1 and layer 135R1, and organic layer 112G2 and layer 135R2 are based on the stacking order of organic layer 112R1 and organic layer 112G1 or organic layer 112R2 and organic layer 112G2, respectively, and the order is not important.

[0100] The charge generation layer 117 is provided between the two light-emitting layers (organic layer 112R1 and organic layer 112R2) of the light-emitting element. The organic layer 118 is provided between the charge generation layer 117 and the organic layer 112R2. The organic layer 119 is provided between the organic layer 112R2 and the organic layer 114. The organic layers 118 and 119 can each independently have one or more of the following: an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.

[0101] The stacked structure from organic layer 115 to organic layer 116 and the stacked structure from organic layer 118 to organic layer 114 can each be called a single light-emitting unit. The light-emitting element 110 shown in Figure 4A, etc., can be called a light-emitting element having a tandem structure in which two light-emitting units are stacked via a charge generation layer 117.

[0102] [Differentiation] Figure 5A is a modified version of Figure 3A. Figure 5A shows an example in which an insulating layer 131 is provided to cover the ends of the pixel electrodes.

[0103] The insulating layer 131 has the function of flattening the surface on which the organic layer 115 is formed. The edges of the insulating layer 131 are preferably tapered. Furthermore, by using an organic resin for the insulating layer 131, its surface can be made gently curved. Therefore, the coverage of the film formed on the insulating layer 131 can be improved.

[0104] Examples of materials that can be used for the insulating layer 131 include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0105] As shown in Figure 5A, the insulating layer 131 may have a recess in the region overlapping with the slit 120. This recess can be formed when a portion of the upper part of the insulating layer 131 is etched during the etching process to form the slit 120. A portion of the insulating layer 125 is formed to fit into the recess of the insulating layer 131, thereby improving their adhesion.

[0106] The slit 120 is provided in the region that overlaps with the insulating layer 131. Similarly, layers 135R and 135G are also provided in the regions that overlap with the insulating layer 131.

[0107] Figure 5B shows an example where the insulating layer 131 is applied to Figure 4B.

[0108] In Figure 5B, the slit 120, layer 135R1, layer 135R2, layer 135G1, and layer 135G2 are each provided in a region that overlaps with the insulating layer 131.

[0109] Figures 6A and 6B show examples where an insulating layer 132 is provided on an insulating layer 131.

[0110] The insulating layer 132 overlaps with the edge of the pixel electrode 111 via the insulating layer 131. Furthermore, the insulating layer 132 is provided covering the edge of the insulating layer 131. Additionally, the insulating layer 132 has a portion that contacts the upper surface of the pixel electrode 111.

[0111] The insulating layer 132 preferably has a tapered shape at its edges. This improves the stepped coverage of films formed on the insulating layer 132, such as the EL layer that covers the edges of the insulating layer 132.

[0112] Furthermore, it is preferable that the insulating layer 132 is thinner than the insulating layer 131. By making the insulating layer 132 thinner, the step coverage of the film formed on the insulating layer 132 can be improved.

[0113] As inorganic insulating materials that can be used for the insulating layer 132, for example, oxides or nitrides such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, aluminum oxide, aluminum oxide nitride, or hafnium oxide can be used. Alternatively, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used.

[0114] Furthermore, the insulating layer 132 may be laminated with a film containing the inorganic insulating material described above. For example, it can be a laminated structure in which a silicon oxide film or a silicon oxynitride film is laminated on a silicon nitride film, or a laminated structure in which a silicon oxide film or a silicon oxynitride film is laminated on an aluminum oxide film. Since the silicon oxide film and the silicon oxynitride film are particularly resistant to etching, it is preferable to place them on the upper side. Also, since the silicon nitride film and the aluminum oxide film are films that do not easily absorb water, hydrogen, oxygen, etc., placing them on the insulating layer 131 side functions as a barrier layer that prevents gases detached from the insulating layer 131 from diffusing into the light-emitting element.

[0115] The slit 120 is provided in the region that overlaps with the insulating layer 132. Similarly, layers 135R and 135G are also provided in the regions that overlap with the insulating layer 132.

[0116] By providing the insulating layer 132, it is possible to prevent the upper surface of the insulating layer 131 from being etched when the slit 120 is formed.

[0117] Figure 6B shows an example where the insulating layer 132 is applied to Figure 5B.

[0118] In Figure 6B, the slit 120, layer 135R1, layer 135R2, layer 135G1, and layer 135G2 are each provided in a region that overlaps with the insulating layer 132.

[0119] [Configuration Example 3] The following sections will explain more specific configuration examples.

[0120] Figure 7A is a schematic cross-sectional view of the display device illustrated below. Figure 7A shows a cross-section of the region including the light-emitting element 110R, light-emitting element 110G, light-emitting element 110B, and the connection part 130. Figure 7B is an enlarged schematic cross-sectional view of the slit 120 located between the light-emitting element 110R and the light-emitting element 110G and its vicinity.

[0121] In the configuration shown in Figure 7A, layer 135B, which is a part (fragment) of the organic layer 112B separated by the slit 120, is provided near the light-emitting element 110R and near the light-emitting element 110G.

[0122] Below the pixel electrode 111, a conductive layer 161, a conductive layer 162, and a resin layer 163 are provided.

[0123] The conductive layer 161 is provided on the insulating layer 105. The conductive layer 161 has a portion that penetrates the insulating layer 105 at an opening provided in the insulating layer 105. The conductive layer 161 functions as a wiring or electrode that electrically connects the pixel electrode 111 to wiring, transistors, or electrodes (not shown) located below the insulating layer 105.

[0124] The conductive layer 161 has a recess formed in the portion located at the opening of the insulating layer 105. The resin layer 163 is provided to fill this recess and functions as a planarizing film. The upper surface of the resin layer 163 is preferably flat, but may have a gently curved shape. Figure 7A and others show an example in which the upper surface of the resin layer 163 has a wave-like shape with recesses and convex portions, but is not limited to this. For example, the upper surface of the resin layer 163 may be convex, concave, or flat.

[0125] A conductive layer 162 is provided on the conductive layer 161 and the resin layer 163. The conductive layer 162 functions as an electrode that electrically connects the conductive layer 161 and the pixel electrode 111.

[0126] Here, if the light-emitting element 110 is an upward-extrusion type light-emitting element, the conductive layer 162 can be made to function as a reflective electrode by using a film that is reflective to visible light as the conductive layer 162 and a film that is transparent to visible light as the pixel electrode 111R. Furthermore, the conductive layer 162 and the pixel electrode 111 can also be provided above the opening (also called the contact portion) of the insulating layer 105 via the resin layer 163, so that the portion overlapping with the contact portion can be made into a light-emitting region. Therefore, the aperture ratio can be increased.

[0127] Figures 7A and 7B show examples where the shape of the resin layer 126 differs from that described above.

[0128] As shown in Figure 7B, the upper part of the resin layer 126 has a shape that is wider than the slit 120. As will be described later, the insulating layer 125 is processed using the resin layer 126 as an etching mask, so a portion of the insulating layer 125 remains covered by the upper part of the resin layer 126. Furthermore, a portion of the sacrificial layer 145 used in the manufacturing process of the display device also remains for the same reason. Specifically, the sacrificial layer 145 is provided on the organic layer 116 near the slit 120. Also, a portion of the insulating layer 125 is provided covering the upper surface of the sacrificial layer 145. In addition, the resin layer 126 is provided covering the sacrificial layer 145 and the insulating layer 125.

[0129] In this case, it is preferable that the ends of the insulating layer 125 and the ends of the sacrificial layer 145 each have a tapered shape. This makes it possible to improve the stepped coverage of the organic layer 114 and the like.

[0130] As shown in Figures 7A and 7B, layers 135R, 135G, and 135B are in contact with the insulating layer 125 and each has a region that overlaps with the insulating layer 125, the sacrificial layer 145, and the resin layer 126.

[0131] [Example of manufacturing method] In the following, an example of a method for manufacturing a display device according to one aspect of the present invention will be described with reference to the drawings. Here, the display device shown in Figure 7A will be used as an example. Figures 8A to 11C are schematic cross-sectional views of each step in the example of the method for manufacturing the display device described below. In addition, in Figure 8A and the following, schematic cross-sectional views of the connection portion 130 and its vicinity are also shown on the right side.

[0132] The thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device can be formed using sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), atomic layer deposition (ALD), and other methods. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0133] 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 method, slit coating, roll coating, curtain coating, and knife coating.

[0134] Furthermore, when processing the thin films that constitute the display device, photolithography or the like can be used. In addition, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. Alternatively, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0135] 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.

[0136] 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, X-rays, etc., 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 an electron beam.

[0137] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0138] [Preparation of circuit board 101] As the substrate 101, a substrate having at least sufficient heat resistance to withstand subsequent heat treatment can be used. When an insulating substrate is used as the substrate 101, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, organic resin substrates, etc., can be used. In addition, semiconductor substrates such as single-crystal semiconductor substrates made of silicon, silicon carbide, etc., polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon germanium, and SOI substrates can be used.

[0139] In particular, it is preferable to use a substrate 101 on which a semiconductor circuit including semiconductor elements such as transistors is formed on the semiconductor substrate or insulating substrate. It is preferable that the semiconductor circuit constitutes, for example, a pixel circuit, a gate line driving circuit (gate driver), a source line driving circuit (source driver), etc. In addition to the above, an arithmetic circuit, a memory circuit, etc. may also be configured.

[0140] An insulating layer 105 is provided at the top of the substrate 101. The insulating layer 105 has multiple openings that reach transistors, wiring, electrodes, etc., provided on the substrate 101. These openings can be formed by photolithography.

[0141] As the insulating layer 105, an inorganic insulating material or an organic insulating material can be used.

[0142] [Formation of conductive layer 161, resin layer 163, conductive layer 162, and pixel electrode 111] A conductive film, which will become the conductive layer 161, is formed on the insulating layer 105. At this time, a recess is formed in the conductive film due to the opening in the insulating layer 105.

[0143] Next, a resin layer 163 is formed in the recess of the conductive film.

[0144] It is preferable to use a photosensitive resin as the resin layer 163. In this case, the resin layer 163 can be formed by first depositing a resin film, exposing the resin film through a photomask, and then performing a development process. After that, the upper part of the resin layer 163 may be etched by ashing or the like to adjust the height of the upper surface of the resin layer 163.

[0145] Furthermore, when a non-photosensitive resin is used as the resin layer 163, the resin layer 163 can be formed by etching the upper part of the resin film by ashing or the like after the resin film has been formed, until the surface of the conductive film that will become the conductive layer 161 is exposed, so that the thickness is optimized.

[0146] Next, a conductive film to become the conductive layer 161 and a conductive film to become the conductive layer 162 are formed on the resin layer 163. Then, a resist mask is formed on the two conductive films by photolithography, and unnecessary parts of the conductive film are removed by etching. After that, the resist mask is removed, allowing the conductive layer 161 and the conductive layer 162 to be formed in the same process.

[0147] In this example, conductive layer 161 and conductive layer 162 were formed using the same photomask and in the same process, but conductive layer 161 and conductive layer 162 may be formed individually using different photomasks.

[0148] Next, a conductive film is formed by covering the conductive layer 161 and the conductive layer 162, and a portion of the conductive film is removed by etching to form the pixel electrode 111 and the connecting electrode 111C (Figure 8A). At this time, as shown in Figure 8A, it is preferable to form the pixel electrode 111 and the connecting electrode 111C so as to encompass the conductive layer 161 and the conductive layer 162, because the conductive layer 161 and the conductive layer 162 are not exposed to the etching atmosphere during the formation of the pixel electrode 111, etc.

[0149] [Formation of organic layer 115] Next, an organic layer 115 is formed on the pixel electrode 111 (Figure 8B). It is preferable to form the organic layer 115 without using an FMM.

[0150] Alternatively, the organic layer 115 may be fabricated using FMM. In that case, the description of the subsequent organic layer 112R, etc., can be applied.

[0151] The organic layer 115 can preferably be formed by vacuum deposition. However, it is not limited to this, and can also be formed by sputtering, inkjet, or the like. Furthermore, the above-described film formation methods can be used as appropriate.

[0152] [Formation of organic layer 112R, organic layer 112G, and organic layer 112B] Next, an island-shaped organic layer 112R is formed on the organic layer 115, encompassing the region that overlaps with the pixel electrode 111R.

[0153] The organic layer 112R is preferably formed by a vacuum deposition method via an FMM. Alternatively, island-like organic layers 112R may be formed using a sputtering method with an FMM or an inkjet method.

[0154] Figure 8C shows the deposition of the organic layer 112R via FMM151R. Figure 8C shows the deposition process using the so-called face-down method, where the substrate is inverted so that the surface to be deposited is facing downwards.

[0155] In deposition methods using FMMs, deposition often occurs over a wider area than the aperture pattern of the FMM. Therefore, as shown by the dashed line in Figure 8C, even when using an FMM 151R with the same pattern as the pixel electrode 111R and aperture pattern, the organic layer 112R can be deposited in the region between the pixel electrode 111R and the adjacent pixel electrode.

[0156] Next, an organic layer 112G is formed on the pixel electrode 111G using FMM151G (Figure 9A).

[0157] Similar to organic layer 112R, organic layer 112G can form a pattern that extends beyond the pixel electrode 111G. As a result, a region in which organic layer 112G is stacked on organic layer 112R can be formed, as shown in region RG in Figure 9A.

[0158] Next, an organic layer 112B is formed on the pixel electrode 111B using FMM151B (Figure 9B).

[0159] Similar to organic layers 112R and 112G, organic layer 112B can also form a pattern that extends outward beyond the pixel electrode 111B. As a result, as shown in Figure 9B, a region RB in which organic layer 112B is stacked on organic layer 112R, and a region GB in which organic layer 112B is stacked on organic layer 112G can be formed.

[0160] In this case, it is preferable not to form organic layers 112R, 112G, and 112B on the connecting electrode 111C.

[0161] In this example, organic layer 112R, organic layer 112G, and organic layer 112B were formed in that order, but the formation order is not limited to this.

[0162] [Formation of organic layer 116] Next, organic layer 116 is formed by covering organic layer 112R, organic layer 112G, and organic layer 112B (Figure 9C). Organic layer 116 can be formed in the same manner as organic layer 115.

[0163] [Formation of sacrificial film 144] Next, a sacrificial film 144 is formed by covering the organic layer 116.

[0164] The sacrificial film 144 can be a film with high resistance to etching of the organic layers 115, 112, and 116, i.e., a film with a high etching selectivity ratio. Alternatively, the sacrificial film 144 can be a film with a high etching selectivity ratio with other sacrificial films, such as the sacrificial film 146 described later. Furthermore, it is particularly preferable that the sacrificial film 144 be a film that can be removed by a wet etching method that causes minimal damage to the organic layers 115, 112, and 116.

[0165] As the sacrificial film 144, suitable examples include metal films, alloy films, metal oxide films, semiconductor films, and inorganic films such as inorganic insulating films. The sacrificial film 144 can be formed by various film deposition methods such as sputtering, vapor deposition, CVD, and ALD.

[0166] In particular, since the ALD method causes little damage to the layer to be formed, it is preferable to form the sacrificial film 144 directly on the organic layer 116 using the ALD method.

[0167] As the sacrificial film 144, 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. In particular, it is preferable to use low-melting-point materials such as aluminum or silver.

[0168] Furthermore, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) can be used as the sacrificial film 144. In addition, indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Alternatively, indium tin oxide containing silicon can also be used.

[0169] Furthermore, the above-mentioned method can also be applied when element M (where M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) is used instead of gallium. In particular, it is preferable that M be one or more selected from gallium, aluminum, or yttrium.

[0170] Furthermore, the sacrificial film 144 can be an oxide such as aluminum oxide, hafnium oxide, or silicon oxide, a nitride such as silicon nitride or aluminum nitride, or an oxynitride such as silicon oxynitride. Such inorganic insulating materials can be formed using film deposition methods such as sputtering, CVD, or ALD.

[0171] Furthermore, as the sacrificial film 144, a material that is soluble in a chemically stable solvent may be used, at least for the organic layer 116 located at the top of the EL layer. In particular, a material soluble in water or alcohol can be suitably used for the sacrificial film 144. When forming the sacrificial film 144, it is preferable to apply it using a wet deposition method while dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL layer.

[0172] Wet film deposition methods that can be used to form the sacrificial film 144 include spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating.

[0173] As the sacrificial film 144, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.

[0174] [Formation of sacrificial film 146] Next, a sacrificial film 146 is formed on the sacrificial film 144.

[0175] Sacrificial film 146 is a film used as a hard mask when etching sacrificial film 144 later. Also, sacrificial film 144 is exposed when processing sacrificial film 146 later. Therefore, a combination of sacrificial film 144 and sacrificial film 146 is selected, each having a high etching selectivity ratio. Thus, depending on the etching conditions of sacrificial film 144 and sacrificial film 146, the film that can be used for sacrificial film 146 can be selected.

[0176] The sacrificial film 146 can be selected from a variety of materials, depending on the etching conditions of the sacrificial film 144 and the sacrificial film 146. For example, it can be selected from films that can be used for the sacrificial film 144.

[0177] For example, an oxide film can be used as the sacrificial film 146. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride can be used.

[0178] Furthermore, a nitride film can be used as the sacrificial film 146, for example. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride can be used.

[0179] For example, it is preferable to use an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide formed by the ALD method as the sacrificial film 144, and to use an indium-containing metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) formed by the sputtering method as the sacrificial film 146. Alternatively, it is preferable to use a metal such as tungsten, molybdenum, copper, aluminum, titanium, or tantalum, or an alloy containing such a metal, as the sacrificial film 146.

[0180] Furthermore, an organic film that can be used for organic layers 115, 112, and 116 may be used as the sacrificial film 146. For example, the same organic film used for organic layers 115, 112, or 116 can be used for the sacrificial film 146. Using such an organic film is preferable because it allows the same deposition apparatus to be used for organic layers 115, 112, and 116. Moreover, the process can be simplified because the sacrificial film 147 can be used as a mask to simultaneously remove organic layers 115, 112, and 116 when etching them.

[0181] [Formation of resist mask 143] Next, a resist mask 143 is formed on the sacrificial film 146 at positions that overlap with the pixel electrodes 111R, 111G, and 111B, respectively (Figure 10A).

[0182] The resist mask 143 can use a resist material containing a photosensitive resin, such as a positive-type resist material or a negative-type resist material.

[0183] In this case, if the resist mask 143 is formed on the sacrificial film 144 without the sacrificial film 146, there is a risk that if defects such as pinholes exist in the sacrificial film 144, the organic layers 115, 112, and 116 may dissolve due to the solvent of the resist material. Using the sacrificial film 146 can prevent such problems from occurring.

[0184] Furthermore, in cases where a solvent for the resist material is used that does not dissolve the organic layers 115, 112, and 116, the resist mask 143 may be formed directly on the sacrificial layer 144 without using the sacrificial layer 146.

[0185] [Etching of sacrificial film 146] Next, the portion of the sacrificial film 146 that is not covered by the resist mask 143 is removed by etching to form a sacrificial layer 147.

[0186] When etching the sacrificial film 146, it is preferable to use etching conditions with a high selectivity ratio so that the sacrificial film 144 is not removed by the etching. The sacrificial film 146 can be etched by wet etching or dry etching, but by using dry etching, it is possible to suppress the reduction of the pattern of the sacrificial layer 147.

[0187] [Removal of Resist Mask 143] Next, remove the resist mask 143.

[0188] The resist mask 143 can be removed by wet etching or dry etching. In particular, it is preferable to remove the resist mask 143 by dry etching (also called plasma ashing) using oxygen gas as the etching gas.

[0189] In this case, the removal of the resist mask 143 is performed with the organic layer 116 covered by the sacrificial film 144, thus suppressing the impact on the organic layers 115, 112, and 116. In particular, since contact with oxygen can adversely affect the electrical properties of the organic layers 115, 112, and 116, this method is suitable when etching is performed using oxygen gas, such as plasma ashing. Furthermore, even when the resist mask 143 is removed by wet etching, the organic layers 116 and the like do not come into contact with the chemical solution, thus preventing them from dissolving.

[0190] [Etching of sacrificial film 144] Next, using the sacrificial layer 147 as a hard mask, a portion of the sacrificial film 144 is removed by etching to form the sacrificial layer 145 (Figure 10B).

[0191] The sacrificial film 144 can be etched by wet etching or dry etching, but dry etching is preferred because it can suppress pattern reduction.

[0192] [Etching of organic layer 116, organic layer 112, and organic layer 115] Next, the organic layers 116, 112, and a portion of the organic layer 115 that are not covered by the sacrificial layer 145 are removed by etching to form the slit 120. At the same time, the upper surface of the connecting electrode 111C is also exposed.

[0193] At this time, parts of organic layer 112R, organic layer 112G, and organic layer 112B are separated by etching, forming layer 135R, which is the fragment of organic layer 112R, layer 135G, which is the fragment of organic layer 112G, and layer 135B, which is the fragment of organic layer 112B.

[0194] In particular, for etching organic layers 116, 112, and 115, it is preferable to use dry etching with an etching gas that does not contain oxygen as its main component. This suppresses deterioration of organic layers 116, 112, and 115, enabling the realization of a highly reliable display device. Examples of etching gases that do not contain oxygen as their main component include CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or noble gases (such as He). Alternatively, a mixed gas of the above gases and an oxygen-free diluent gas can be used as the etching gas.

[0195] Furthermore, the etching of organic layers 116, 112, and 115 is not limited to the above, and may be carried out by dry etching using other gases or by wet etching.

[0196] Furthermore, using an etching gas containing oxygen gas, or dry etching using oxygen gas, for etching organic layers 116, 112, and 115 can increase the etching rate. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate, thereby reducing etching damage. In addition, defects such as the adhesion of reaction products generated during etching can be suppressed. For example, an etching gas to which oxygen gas is added to the above-mentioned etching gas that does not primarily contain oxygen can be used.

[0197] During etching of organic layers 116, 112, and 115, the insulating layer 105 is exposed. Therefore, it is preferable to use a film with high resistance to etching of organic layers 115 for the insulating layer 105. Note that during etching of organic layers 115, the upper part of the insulating layer 105 may be etched, and the portion not covered by organic layers 115 may become a thin film.

[0198] Furthermore, the sacrificial layer 147 may be etched simultaneously with the etching of organic layers 116, 112, and 115. Etching organic layers 116, 112, 115, and the sacrificial layer 147 using the same process simplifies the process and reduces the manufacturing cost of the display device, which is therefore preferable.

[0199] [Removal of the sacrificial layer] Next, the sacrificial layer 147 is removed, exposing the upper surface of the sacrificial layer 145 (Figure 10C). At this point, it is preferable to leave the sacrificial layer 145 in place. It is also not necessary to remove the sacrificial layer 147 at this stage.

[0200] [Formation of insulating film 125f] Next, an insulating film 125f is formed, covering the sacrificial layer 145 and the slit 120.

[0201] The insulating film 125f functions as a barrier layer that prevents impurities such as water from diffusing into the EL layer. Forming the insulating film 125f by the ALD method, which has excellent step coverage, is preferable because it can suitably cover the sides of the EL layer.

[0202] It is preferable to use a film of the same material as the sacrificial layer 145 for the insulating film 125f, as this allows for simultaneous etching in a later process. For example, it is preferable to use inorganic insulating materials such as aluminum oxide, hafnium oxide, or silicon oxide formed by the ALD method for both the insulating film 125f and the sacrificial layer 145.

[0203] Furthermore, the materials that can be used for the insulating film 125f are not limited to those mentioned above, and any materials that can be used for the sacrificial film 144 can be used as appropriate.

[0204] [Formation of resin layer 126] Next, a resin layer 126 is formed in the region overlapping with the slit 120 (Figure 11A). The resin layer 126 can be formed in the same manner as the resin layer 163.

[0205] Here, we show an example where the resin layer 126 is formed to have a width greater than the width of the slit 120.

[0206] [Etching of insulating film 125f and sacrificial layer 145] Next, the portions of the insulating film 125f and the sacrificial layer 145 that are not covered by the resin layer 126 are removed by etching, exposing the upper surface of the organic layer 116. At the same time, the insulating layer 125 and the sacrificial layer 145 are formed in the region covered by the resin layer 126 (Figure 11B).

[0207] It is preferable to perform the etching of the insulating film 125f and the sacrificial layer 145 in the same process. In particular, it is preferable to perform the etching of the sacrificial layer 145 by wet etching, which causes less etching damage to the organic layer 116. For example, it is preferable to use wet etching with an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0208] Alternatively, it is preferable to remove either or both of the insulating film 125f and the sacrificial layer 145 by dissolving them in a solvent such as water or alcohol. Here, various alcohols can be used as the alcohol that can dissolve the insulating film 125f and the sacrificial layer 145, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0209] After removing the insulating film 125f and the sacrificial layer 145, it is preferable to perform a drying treatment to remove water contained inside the organic layer 115, organic layer 112, and organic layer 116, as well as water adsorbed on the surface. For example, it is preferable to perform a heat treatment under an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0210] [Formation of organic layer 114] Next, the organic layer 114 is formed by covering the organic layer 116, the insulating layer 125, the sacrificial layer 145, and the resin layer 126, etc.

[0211] The organic layer 114 can be formed using the same method as the organic layer 115. When forming the organic layer 114 by vapor deposition, a shielding mask may be used to prevent the organic layer 114 from being formed on the connecting electrode 111C.

[0212] [Formation of common electrode 113] Next, the common electrode 113 is formed by covering the organic layer 114.

[0213] The common electrode 113 can be formed by a film deposition method such as vapor deposition or sputtering. Alternatively, a film formed by vapor deposition and a film formed by sputtering may be laminated together.

[0214] It is preferable that the common electrode 113 be formed to encompass the region where the organic layer 114 is deposited. That is, the edges of the organic layer 114 can overlap with the common electrode 113. The common electrode 113 may also be formed using a shielding mask.

[0215] The connection portion 130 has a configuration in which an organic layer 114 is sandwiched between the connecting electrode 111C and the common electrode 113. In this case, it is preferable to use a material with the lowest possible electrical resistance for the organic layer 114. Alternatively, it is preferable to reduce the electrical resistance in the thickness direction of the organic layer 114 by forming it as thin as possible. For example, by using an electron-injection or hole-injection material with a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the organic layer 114, the electrical resistance between the connecting electrode 111C and the common electrode 113 can be reduced to a negligible degree.

[0216] [Formation of a protective layer] Next, a protective layer 121 is formed on the common electrode 113 (Figure 11C). For depositing the inorganic insulating film used in the protective layer 121, sputtering, PECVD, or ALD methods are preferred. The ALD method is particularly preferred because it offers excellent step coverage and is less prone to defects such as pinholes. Furthermore, for depositing the organic insulating film, the inkjet method is preferred because it allows for the formation of a uniform film in the desired area.

[0217] Based on the above, the display device shown in Figure 7A can be manufactured.

[0218] In the above example, the resin layer 126 is formed to be wider than the slit 120, but the resin layer 126 may be formed to be the same width as the slit 120.

[0219] Figure 12A is a schematic cross-sectional view of the point in time when the resin layer 126 is formed after the insulating film 125f has been formed.

[0220] For example, as shown in Figure 12A, by forming a resin layer 126 wider than the slit 120 and then etching the upper part of the resin layer 126 by ashing or the like, the resin layer 126 can be formed only inside the slit 120. In this case, it is preferable to bring the upper surface of the resin layer 126 as close as possible to the height of the upper surface of the adjacent organic layer 116. This reduces the step caused by the slit 120 and improves the step coverage of the organic layer 114, etc.

[0221] Next, the insulating film 125f and the sacrificial layer 145 are etched in the same manner as described above (Figure 12B). At this time, since there is no portion of the sacrificial layer 145 that is covered by the resin layer 126, the sacrificial layer 145 is removed without leaving any fragments.

[0222] Next, by forming the organic layer 114, the common electrode 113, and the protective layer 121 in the same manner as described above, a display device can be manufactured as shown in Figure 12C.

[0223] Furthermore, Figure 12C shows an example where the organic layer 114 is not provided between the connecting electrode 111C and the common electrode 113. Because the connecting electrode 111C and the common electrode 113 are in contact, the contact resistance between them can be made extremely small, thereby reducing power consumption.

[0224] The above is an explanation of an example of a method for manufacturing a display device.

[0225] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0226] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0227] 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.

[0228] [Display device 400] Figure 13 shows a perspective view of the display device 400, and Figure 14A shows a cross-sectional view of the display device 400.

[0229] The display device 400 has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 13, substrate 452 is clearly indicated by a dashed line.

[0230] The display device 400 includes a display unit 462, a circuit 464, wiring 465, etc. Figure 13 shows an example in which IC 473 and FPC 472 are mounted on the display device 400. Therefore, the configuration shown in Figure 13 can also be described as a display module having the display device 400, an IC (integrated circuit), and an FPC.

[0231] For example, a scan line drive circuit can be used as circuit 464.

[0232] 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 wiring 465 from an external source via FPC 472 or from IC 473.

[0233] Figure 13 shows an example in which IC 473 is provided on the substrate 451 using a COG (Chip On Glass) method or 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 400 and the display module may be configured without an IC. Alternatively, the IC may be mounted on an FPC using a COF method or the like.

[0234] Figure 14A shows an example of a cross-section of the display device 400 when 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 connection portion are cut. In Figure 14A, an example of a cross-section is shown when a portion of the display unit 462, in particular, including the green light-emitting element 430b and the blue light-emitting element 430c, is cut.

[0235] The display device 400 shown in Figure 14A has transistors 202, 210, light-emitting elements 430b, and 430c between substrates 453 and 454.

[0236] The light-emitting elements 430b and 430c can be the light-emitting elements exemplified in Embodiment 1.

[0237] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting element that emits a different color from the others, examples of these three subpixels include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of these four subpixels include subpixels of four colors: R, G, B, and white (W); and subpixels of four colors: R, G, B, and Y.

[0238] 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 400.

[0239] The light-emitting element 430b and 430c have conductive layers 411a, 411b, and 411c as pixel electrodes. Conductive layer 411b is reflective to visible light and functions as a reflective electrode. Conductive layer 411c is transparent to visible light and functions as an optical adjustment layer.

[0240] The conductive layer 411a is connected to the conductive layer 222b of the transistor 210 through an opening provided in the insulating layer 214. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0241] An EL layer 412G or EL layer 412B is provided covering the pixel electrodes. An insulating layer 421 is provided in contact with the side surfaces of the EL layer 412G and the EL layer 412B, and a resin layer 422 is provided to fill the recesses of the insulating layer 421. An organic layer 414, a common electrode 413, and a protective layer 416 are provided covering the EL layer 412G and EL layer 412B. Layers 415B and 415G are also provided in contact with the insulating layer 421. Layer 415B contains the same material as EL layer 412B, and layer 415G contains the same material as EL layer 412G.

[0242] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transmittance to visible light for the substrate 452.

[0243] Both transistors 202 and 210 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0244] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0245] The method for manufacturing the display device 400 involves first bonding a fabrication substrate, on which an insulating layer 212, transistors, light-emitting elements, etc., are provided, to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer 442. Then, the fabrication substrate is peeled off and a substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabrication 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 400.

[0246] The insulating layer 212 can be made of an inorganic insulating film that can be used for the insulating layer 211 and the insulating layer 215, respectively.

[0247] 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 conductive layer 466 and connection 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 connection layer 242.

[0248] Transistors 202 and 210 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel formation 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 positioned between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is positioned between the conductive layer 223 and the channel formation region 231i.

[0249] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n through an opening 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.

[0250] In FIG. 14A, an example in which the insulating layer 225 covers the upper surface and the side surface of the semiconductor layer is shown. The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n through an opening provided in the insulating layer 225 and the insulating layer 215.

[0251] On the other hand, in the transistor 209 shown in FIG. 14B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 and does not overlap with the low-resistance region 231n. For example, the structure shown in FIG. 14B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In FIG. 14B, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n through an opening in the insulating layer 215. Further, an insulating layer 218 covering the transistor may be provided.

[0252] The structure of the transistor included in the display device of the present embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverse staggered transistor, or the like can be used. Also, either a top gate type or a bottom gate type transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0253] For transistors 202 and 210, a configuration in which the semiconductor layer in which the channel is formed is sandwiched between two gates is applied. The transistors may be driven by connecting the two gates and supplying the same signal thereto. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0254] The crystallinity of the semiconductor material used for the semiconductor layer of the transistor is also not particularly limited, and any of an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity other than a single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystal region in part) may be used. It is preferable to use a single crystal semiconductor or a semiconductor having crystallinity because deterioration of transistor characteristics can be suppressed.

[0255] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). That is, the display device of the present embodiment preferably uses a transistor (hereinafter, an OS transistor) using a metal oxide for the channel formation region.

[0256] The band gap of the metal oxide used for the semiconductor layer of the transistor is preferably 2 eV or more, and more preferably 2.5 eV or more. By using a metal oxide having a large band gap, the off-current of the OS transistor can be reduced.

[0257] The metal oxide preferably contains at least indium or zinc, and more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (where M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and gallium is more preferred. A metal oxide containing indium, M, and zinc may hereafter be referred to as In-M-Zn oxide.

[0258] When the metal oxide 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 close to it, In:M:Zn=1:1:1.2 or close to it, In:M:Zn=2:1:3 or close to it, In:M:Zn=3:1:2 or close to it, In:M:Zn=4:2:3 or close to it, In:M:Zn=4:2:4.1 or close to it, In:M:Zn=5:1:3 or close to it, In:M:Zn=5:1:6 or close to it, In:M:Zn=5:1:7 or close to it, In:M:Zn=5:1:8 or close to it, In:M:Zn=6:1:6 or close to it, In:M:Zn=5:2:5 or close to it, and so on. Note that "close to it" compositions include a range of ±30% of the desired atomic ratio. By increasing the atomic ratio of indium in a metal oxide, the on-current or field-effect mobility of a transistor can be increased.

[0259] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when the atomic ratio of In is 4, the atomic ratio of Ga is between 1 and 3, and the atomic ratio of Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0260] Furthermore, the atomic ratio of In in an In-M-Zn oxide may be less than the atomic ratio of M. Examples of such atomic ratios of metal elements in an In-M-Zn oxide include compositions where In:M:Zn = 1:3:2 or close to it, In:M:Zn = 1:3:3 or close to it, In:M:Zn = 1:3:4 or close to it, etc. By increasing the atomic ratio of M in the metal oxide, it is possible to increase the band gap of the In-M-Zn oxide and improve its resistance to photo-negative bias stress testing. Specifically, it is possible to reduce the change in threshold voltage or the change in shift voltage (Vsh) measured in the NBTIS (Negative Bias Temperature Illumination Stress) test of a transistor. Note that the shift voltage (Vsh) is defined as the Vg at which the tangent line at the point where the slope of the drain current (Id)-gate voltage (Vg) curve is maximum intersects the straight line where Id = 1 pA.

[0261] Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polysilicon and single-crystal silicon).

[0262] Alternatively, the semiconductor layer of a transistor may have a layered material that functions as a semiconductor. A layered material is a general term for a group of materials having a layered crystalline structure. A layered crystalline structure is a structure in which layers formed by covalent or ionic bonds are stacked via weaker bonds than covalent or ionic bonds, such as van der Waals forces. Layered materials have high electrical conductivity within a unit layer, that is, high two-dimensional electrical conductivity. By using a material that functions as a semiconductor and has high two-dimensional electrical conductivity in the channel formation region, a transistor with a large on-current can be provided.

[0263] Examples of the above-mentioned layered materials include graphene, silicene, and chalcogenides. Chalcogenides are compounds containing chalcogens (elements belonging to Group 16). Examples of chalcogenides include transition metal chalcogenides and Group 13 chalcogenides. Specific examples of transition metal chalcogenides applicable as semiconductor layers in transistors include molybdenum sulfide (typically MoS2), molybdenum selenide (typically MoSe2), molybdenum tellurium (typically MoTe2), tungsten sulfide (typically WS2), tungsten selenide (typically WSe2), tungsten tellurium (typically WTe2), hafnium sulfide (typically HfS2), hafnium selenide (typically HfSe2), zirconium sulfide (typically ZrS2), and zirconium selenide (typically ZrSe2).

[0264] 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.

[0265] 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.

[0266] It is preferable to use an inorganic insulating film for insulating layer 211, insulating layer 212, insulating layer 215, insulating layer 218, and insulating layer 225. Examples of inorganic insulating films that can be used include silicon nitride film, silicon oxynitride film, silicon oxide film, silicon nitride film, aluminum oxide film, and aluminum nitride film. Alternatively, hafnium oxide film, yttrium oxide film, zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, lanthanum oxide film, cerium oxide film, and neodymium oxide film may also be used. Furthermore, two or more of the above-mentioned inorganic insulating films may be laminated together.

[0267] 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 400. This prevents impurities from entering through the organic insulating film from the edge of the display device 400. Alternatively, the organic insulating film may be formed so that its edge is inside the edge of the display device 400, so that the organic insulating film is not exposed at the edge of the display device 400.

[0268] 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.

[0269] It is preferable to provide a light-shielding layer 417 on the surface of the substrate 454 that faces the substrate 453. Various optical components can also be placed on the outside of the substrate 454. 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 placed on the outside of the substrate 454.

[0270] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the ingress of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0271] Figure 14A shows the connection section 228. At the connection section 228, the common electrode 413 and the wiring are electrically connected. Figure 14A shows an example where the same stacked structure as the pixel electrode is applied as the wiring.

[0272] Substrates 453 and 454 can be made of glass, quartz, ceramic, 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 453 and 454 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 453 or substrate 454.

[0273] As the substrates 453 and 454, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. can be used respectively. Glass with a thickness that provides flexibility may be used for one or both of the substrates 453 and 454.

[0274] When a circular polarizing plate is overlaid on the 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 small birefringence (it can also be said that the amount of birefringence is small).

[0275] The absolute value of the retardation (phase difference) value of a substrate with high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0276] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also called cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0277] Also, when using a film as the substrate, there is a risk that shape changes such as wrinkles may occur on the display panel due to the film absorbing water. Therefore, it is preferable to use a film with a low water absorption rate for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferably 0.1% or less, and even more preferably 0.01% or less.

[0278] 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.

[0279] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0280] 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.

[0281] 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).

[0282] 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.

[0283] 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.

[0284] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0285] (Embodiment 3) The following describes an example of the pixel configuration in the display section of a display device.

[0286] The display device 100 shown in Figure 1A is an example in which a stripe array is applied. In Figure 1A, it is composed of three subpixels, R, G, and B. Each of the subpixels R, G, and B has a light-emitting device with a different emitted color. For example, subpixels R, G, and B can be red, green, and blue subpixels, respectively.

[0287] The pixel 103 shown in Figure 15A has an S-stripe array applied to it. The pixel 103 shown in Figure 15A is composed of three subpixels: subpixels R, G, and B.

[0288] The pixel 103 shown in Figure 15B has a sub-pixel G with a roughly trapezoidal top surface shape with rounded corners, a sub-pixel R with a roughly triangular top surface shape with rounded corners, and a sub-pixel B with a roughly quadrilateral or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel G has a larger light-emitting area than sub-pixel R. In this way, the shape and size of each sub-pixel can be determined independently. For example, the size of a sub-pixel can be reduced to a level that provides a more reliable light-emitting device. For example, sub-pixel R may be a red sub-pixel, sub-pixel G a green sub-pixel, and sub-pixel B a blue sub-pixel.

[0289] A Pentile array is applied to pixels 125a and 125b shown in Figure 15C. Figure 15C shows an example in which pixels 125a having subpixels R and G, and pixels 125b having subpixels G and B, are arranged alternately. For example, subpixel R may be a red subpixel, subpixel G a green subpixel, and subpixel B a blue subpixel.

[0290] Pixels 125a and 125b, shown in Figures 15D and 15E, have a delta array applied. Pixel 125a has two subpixels (subpixels R and G) in the top row (row 1) and one subpixel (subpixel B) in the bottom row (row 2). Pixel 125b has one subpixel (subpixel B) in the top row (row 1) and two subpixels (subpixels R and G) in the bottom row (row 2).

[0291] Figure 15D shows an example where each subpixel has a roughly square top shape with rounded corners, and Figure 15E shows an example where each subpixel has a circular top shape.

[0292] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of the transfer of the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0293] Furthermore, in a method for manufacturing a display device according to one aspect of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the EL layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the EL layer.

[0294] Furthermore, in order to achieve the desired shape of the upper surface of the EL layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0295] The pixel 103 shown in Figures 16A to 16C has a stripe arrangement applied to it. The pixel 103 shown in Figures 16A to 16C consists of four subpixels: subpixels R, G, B, and W. Each subpixel R, G, B, and W has a light-emitting device with a different emitted color. For example, subpixels R, G, B, and W can be red, green, blue, and white subpixels, respectively.

[0296] Figure 16A shows an example where each subpixel has a rectangular top surface shape, Figure 16B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 16C shows an example where each subpixel has an elliptical top surface shape.

[0297] Pixel 103, shown in Figures 16D to 16F, has a matrix array applied to it. Pixel 103, shown in Figures 16D to 16F, is composed of four subpixels: subpixels R, G, B, and W.

[0298] Figure 16D shows an example where each subpixel has a square top shape, Figure 16E shows an example where each subpixel has a roughly square top shape with rounded corners, and Figure 16F shows an example where each subpixel has a circular top shape. Figure 16G shows an example with subpixels R, G, and B to which a stripe arrangement is applied, and three subpixels W.

[0299] (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.

[0300] In this specification, devices fabricated using a metal mask or an FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. Furthermore, in this specification, devices fabricated without using a metal mask or an FMM may be referred to as MML (Metal Maskless) structured devices.

[0301] 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. Also, 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.

[0302] Furthermore, light-emitting devices can be broadly classified into single-structure and tandem-structure devices. A single-structure device has one light-emitting unit between a pair of electrodes, and it is preferable that this light-emitting unit 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 from each of the two or more layers 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, a configuration that emits white light as a whole can be obtained. The same applies to light-emitting devices having three or more light-emitting layers.

[0303] A tandem device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably 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 given current can be increased, and a more reliable light-emitting device can be achieved compared to a single 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 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.

[0304] Furthermore, when comparing the aforementioned white light-emitting devices (single or tandem structure) with light-emitting devices with an SBS structure, the SBS structure light-emitting device can consume less power than the white light-emitting device. Therefore, when minimizing power consumption is desired, the SBS structure light-emitting device is preferable. On the other hand, the white light-emitting device is preferable because its manufacturing process is simpler than that of the SBS structure light-emitting device, allowing for lower manufacturing costs or higher manufacturing yields.

[0305] <Example of light-emitting device configuration> As shown in Figure 17A, the light-emitting device has an EL layer 786 between a pair of electrodes (lower electrode 772, upper electrode 788). The EL layer 786 can be composed of multiple layers, such as layer 4420, light-emitting layer 4411, and layer 4430. Layer 4420 may include, for example, a layer containing a material with high electron injection properties (electron injection layer) and a layer containing a material with high electron transport properties (electron transport layer). Light-emitting layer 4411 may include, for example, a light-emitting compound. Layer 4430 may include, for example, a layer containing a material with high hole injection properties (hole injection layer) and a layer containing a material with high hole transport properties (hole transport layer).

[0306] A configuration having a layer 4420, an emissive layer 4411, and a layer 4430 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 17A is referred to as a single structure.

[0307] Furthermore, Figure 17B shows a modified example of the EL layer 786 of the light-emitting device shown in Figure 17A. Specifically, the light-emitting device shown in Figure 17B has a layer 4430-1 on the lower electrode 772, a layer 4430-2 on layer 4430-1, a light-emitting layer 4411 on layer 4430-2, a layer 4420-1 on the light-emitting layer 4411, a layer 4420-2 on layer 4420-1, and an upper electrode 788 on layer 4420-2. For example, when the lower electrode 772 is the anode and the upper electrode 788 is the cathode, layer 4430-1 functions as a hole injection layer, layer 4430-2 functions as a hole transport layer, layer 4420-1 functions as an electron transport layer, and layer 4420-2 functions as an electron injection layer. Alternatively, when the lower electrode 772 is used as the cathode and the upper electrode 788 is used as the anode, layer 4430-1 functions as an electron injection layer, layer 4430-2 functions as an electron transport layer, layer 4420-1 functions as a hole transport layer, and layer 4420-2 functions as a hole injection layer. By using such a layer structure, it is possible to efficiently inject carriers into the light-emitting layer 4411 and increase the efficiency of carrier recombination within the light-emitting layer 4411.

[0308] Furthermore, as shown in Figures 17C and 17D, a configuration in which multiple light-emitting layers (light-emitting layers 4411, 4412, and 4413) are provided between layer 4420 and layer 4430 is also a variation of the single structure.

[0309] Furthermore, as shown in Figures 17E and 17F, a configuration in which multiple light-emitting units (EL layer 786a, EL layer 786b) are connected in series via an intermediate layer (charge generation layer) 4440 is referred to as a tandem structure in this specification. In this specification, the configuration shown in Figures 17E and 17F is referred to as a tandem structure, but it is not limited to this, and for example, a tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness light emission can be made.

[0310] In Figure 17C, the light-emitting layers 4411, 4412, and 4413 may be made of light-emitting materials that emit light of the same color.

[0311] Furthermore, different light-emitting materials may be used for the light-emitting layers 4411, 4412, and 4413. When the light emitted by the light-emitting layers 4411, 4412, and 4413 are complementary in color, white light emission is obtained. Figure 17D shows an example in which a colored layer 785, which functions as a color filter, is provided. By passing white light through the color filter, light of the desired color can be obtained.

[0312] Furthermore, in Figure 17E, the same light-emitting material may be used for both the light-emitting layer 4411 and the light-emitting layer 4412. Alternatively, light-emitting materials emitting different colors of light may be used for both the light-emitting layer 4411 and the light-emitting layer 4412. When the light emitted by the light-emitting layer 4411 and the light emitted by the light-emitting layer 4412 are complementary colors, white light emission is obtained. Figure 17F shows an example in which a colored layer 785 is further provided.

[0313] Furthermore, in Figures 17C, 17D, 17E, and 17F, as shown in Figure 17B, layer 4420 and layer 4430 may be a laminated structure consisting of two or more layers.

[0314] A structure in which different light-emitting layers (in this case, blue (B), green (G), and red (R)) are created for each light-emitting device is sometimes called an SBS (Side By Side) structure.

[0315] The light-emitting color of the light-emitting device can be red, green, blue, cyan, magenta, yellow, or white, depending on the material that makes up the EL layer 786. Furthermore, the color purity can be further enhanced by adding a microcavity structure to the light-emitting device.

[0316] A light-emitting device that emits white light preferably has a configuration that includes two or more types of light-emitting materials in its light-emitting layer. To obtain white light emission, it is sufficient to select light-emitting materials 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, 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.

[0317] The light-emitting layer preferably contains two or more light-emitting materials that emit light such as R (red), G (green), B (blue), Y (yellow), and O (orange). Alternatively, it is preferable to have two or more light-emitting materials, and for each light-emitting material to emit light that contains spectral components of two or more colors from R, G, and B.

[0318] Here, we will describe a specific example of the configuration of a light-emitting device.

[0319] The light-emitting device has at least a light-emitting layer. The light-emitting device may also have layers other than the light-emitting layer that include a material with high hole injection properties, a material with high hole transport properties, a hole-blocking material, a material with high electron transport properties, an electron-blocking material, a material with high electron injection properties, or a bipolar material (a material with high electron transport and hole transport properties).

[0320] 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.

[0321] 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, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0322] 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).

[0323] 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 × 10⁻¹⁶ -6 cm 2Materials having a hole mobility of / Vs or higher are preferred. However, 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.

[0324] 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 / 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.

[0325] 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 capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0326] Examples of electron injection layers include lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolate (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolate (abbreviated as LiPPP), and lithium oxide (LiO2). x ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used.

[0327] Alternatively, an electron-transporting material may be used as the electron injection layer described above. 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.

[0328] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) of an organic compound containing a lone pair of electrons is between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and LUMO level of an organic compound can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0329] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds containing lone pairs of electrons. NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0330] The luminescent layer is a layer containing a luminescent material. The luminescent layer may contain one or more types of luminescent materials. Suitable luminescent materials include those exhibiting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. Furthermore, materials emitting near-infrared light may also be used as luminescent materials.

[0331] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0332] 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.

[0333] 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.

[0334] 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 of these organic compounds may be hole-transporting materials and / or electron-transporting materials. Alternatively, one or more of these organic compounds may be bipolar materials or TADF materials.

[0335] 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.

[0336] 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.

[0337] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0338] (Embodiment 5) In this embodiment, an example of a display device according to one aspect of the present invention having a light-receiving device, etc., will be described.

[0339] In the display device of this embodiment, each pixel can be configured to have multiple subpixels, each having a light-emitting device that emits a different color from the others. For example, a pixel can be configured to have three types of subpixels. Examples of these three subpixels include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Alternatively, a pixel can be configured to have four types of subpixels. Examples of these four subpixels include subpixels of four colors: red, green, blue, and white (W); and subpixels of four colors: red, green, blue, and yellow.

[0340] There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0341] Furthermore, the top surface shape of a sub-pixel can be, for example, a polygon such as a triangle, quadrilateral (including rectangles and squares), or pentagon, or a polygon with rounded corners, or an ellipse or a circle. Here, the top surface shape of a sub-pixel corresponds to the top surface shape of the light-emitting region of the light-emitting device.

[0342] A display device according to one aspect of the present invention may have a light-receiving device in each pixel.

[0343] In a display device having light-emitting and light-receiving devices in its pixels, the pixels have a light-receiving function, allowing for the detection of contact or proximity of an object while displaying an image. For example, not only can the display device display an image using all of its subpixels, but some subpixels can also emit light as a light source, while the remaining subpixels display an image.

[0344] A display device according to one aspect of the present invention has a display unit in which light-emitting devices are arranged in a matrix, and an image can be displayed on the display unit. Furthermore, light-receiving devices are arranged in a matrix on the display unit, and the display unit has an image display function, as well as one or both of an imaging function and a sensing function. The display unit can be used as an image sensor or a touch sensor. That is, by detecting light on the display unit, an image can be captured, or the proximity or contact of an object (such as a finger, hand, or pen) can be detected. Moreover, in a display device according to one aspect of the present invention, the light-emitting devices can be used as a light source for a sensor. Therefore, it is not necessary to provide a separate light-receiving unit and light source from the display device, and the number of components in the electronic device can be reduced.

[0345] In one embodiment of the present invention, when an object reflects (or scatters) light emitted by a light-emitting device of the display unit, a light-receiving device can detect the reflected light (or scattered light), thus enabling image capture or touch detection even in dark places.

[0346] When a light-receiving device is used as an image sensor, the display device can capture an image using the light-receiving device. For example, the display device of this embodiment can be used as a scanner.

[0347] For example, an image sensor can be used to acquire biometric data such as fingerprints and palm prints. In other words, a biometric authentication sensor can be built into the display device. By having the display device incorporate the biometric authentication sensor, the number of components in the electronic device can be reduced compared to when a separate biometric authentication sensor is provided, enabling miniaturization and weight reduction of the electronic device.

[0348] Furthermore, when a light-receiving device is used as a touch sensor, the display device can use the light-receiving device to detect the proximity or contact of an object.

[0349] For example, a pn-type or pin-type photodiode can be used as the light-receiving device. The light-receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on it and generates an electric charge. The amount of charge generated from the light-receiving device is determined by the amount of light incident on it.

[0350] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. Organic photodiodes can be easily made thinner, lighter, and larger in area, and because they offer a high degree of freedom in shape and design, they can be applied to various display devices.

[0351] In one aspect of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, an organic photodiode can be incorporated into a display device using an organic EL device.

[0352] The pixels shown in Figures 18A and 18B have sub-pixels G, B, R, and PS.

[0353] The pixels shown in Figure 18A have a stripe array applied. The pixels shown in Figure 18B have a matrix array applied.

[0354] The pixels shown in Figures 18C and 18D have sub-pixels G, B, R, PS, and IRS.

[0355] Figures 18C and 18D show examples where a single pixel is arranged across two rows and three columns. The top row (row 1) has three subpixels (subpixel G, subpixel B, and subpixel R). In Figure 18C, the bottom row (row 2) has three subpixels (one subpixel PS and two subpixels IRS). On the other hand, in Figure 18D, the bottom row (row 2) has two subpixels (one subpixel PS and one subpixel IRS). Note that the layout of the subpixels is not limited to the configuration shown in Figures 18A to 18D.

[0356] Sub-pixel R has a light-emitting device that emits red light. Sub-pixel G has a light-emitting device that emits green light. Sub-pixel B has a light-emitting device that emits blue light.

[0357] Sub-pixels PS and IRS each have a light-receiving device. The wavelength of light detected by sub-pixels PS and IRS is not particularly limited.

[0358] The light-receiving area of ​​the sub-pixel PS is smaller than that of the sub-pixel IRS. A smaller light-receiving area results in a narrower imaging range, which helps suppress blurring in the image and improves resolution. Therefore, using sub-pixel PS allows for higher-definition or higher-resolution imaging compared to using sub-pixel IRS. For example, sub-pixel PS can be used to capture images for personal authentication, such as fingerprints, palm prints, irises, pulse patterns (including vein and artery patterns), or faces.

[0359] The light-receiving device in the sub-pixel PS preferably detects visible light, and more preferably detects one or more colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. Alternatively, the light-receiving device in the sub-pixel PS may also detect infrared light.

[0360] Furthermore, sub-pixel IRS can be used in touch sensors (also called direct touch sensors) or near-touch sensors (also called hover sensors, hover-touch sensors, non-contact sensors, or touchless sensors). Depending on the application, the wavelength of light detected by the sub-pixel IRS can be appropriately determined. For example, it is preferable for the sub-pixel IRS to detect infrared light. This enables touch detection even in dark places.

[0361] Here, a touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object when it comes into direct contact with the display device. A near-touch sensor can detect an object even if it does not come into contact with the display device. For example, it is preferable that the display device can detect an object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. With this configuration, it becomes possible to operate the display device without the object directly touching it; in other words, it becomes possible to operate the display device without contact (touchless). With the above configuration, the risk of the display device becoming dirty or scratched can be reduced, or it becomes possible to operate the display device without the object directly touching any dirt (e.g., dust or viruses) attached to the display device.

[0362] By equipping a single pixel with two types of light-receiving devices, it becomes possible to add two additional functions to the display function, thus enabling the multi-functionality of the display device.

[0363] Furthermore, in order to perform high-resolution imaging, it is preferable that sub-pixels PS be provided on all pixels of the display device. On the other hand, sub-pixels IRS used in touch sensors or near-touch sensors do not require the same high detection accuracy as sub-pixels PS, so it is sufficient to provide them on only some of the pixels of the display device. By reducing the number of sub-pixels IRS in the display device to fewer than the number of sub-pixels PS, the detection speed can be increased.

[0364] Here, we will describe the configuration of a photodetector that can be used for sub-pixel PS and sub-pixel IRS.

[0365] The photodetector has at least an active layer that functions as a photoelectric conversion layer between a pair of electrodes. In this specification, one of the pair of electrodes may be referred to as the pixel electrode and the other as the common electrode.

[0366] In a photodetector, one electrode functions as the anode and the other as the cathode. The following explanation uses the example where the pixel electrode functions as the anode and the common electrode functions as the cathode. In other words, by applying a reverse bias between the pixel electrode and the common electrode, the photodetector can detect incoming light, generate an electric charge, and extract it as an electric current.

[0367] The same manufacturing methods as for light-emitting devices can be applied to light-receiving devices. The island-shaped active layer (also called the photoelectric conversion layer) of the light-receiving device is not formed by the pattern of the metal mask, but rather by processing after depositing the film that will become the active layer onto the entire surface, so that the island-shaped active layer can be formed with a uniform thickness. In addition, by providing a sacrificial layer on the active layer, the damage that the active layer receives during the manufacturing process of the display device can be reduced, and the reliability of the light-receiving device can be improved.

[0368] Here, the layers shared by the light-receiving device and the light-emitting device may have different functions in the light-emitting device and the light-receiving device. In this specification, components may be named based on their functions in the light-emitting device. For example, the hole injection layer functions as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, the electron injection layer functions as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. Also, the layers shared by the light-receiving device and the light-emitting device may have the same functions in the light-emitting device and the light-receiving device. For example, the hole transport layer functions as a hole transport layer in both the light-emitting device and the light-receiving device, and the electron transport layer functions as an electron transport layer in both the light-emitting device and the light-receiving device.

[0369] The active layer of the light-receiving device contains a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example using an organic semiconductor as the semiconductor in the active layer is shown. Using an organic semiconductor is preferable because the light-emitting layer and the active layer can be formed by the same method (e.g., vacuum evaporation method), and the manufacturing equipment can be shared.

[0370] Examples of the material of the n-type semiconductor in the active layer include electron-accepting organic semiconductor materials such as fullerenes (e.g., C 60 , C 70 etc.) and fullerene derivatives. Fullerenes have a shape like a soccer ball, and this shape is energetically stable. Fullerenes have deep (low) HOMO levels and LUMO levels. Due to the deep LUMO level of fullerenes, they have extremely high electron-accepting (acceptor) properties. Usually, when π-electron conjugation (resonance) spreads in a plane like benzene, the electron-donating (donor) property increases. However, fullerenes have a spherical shape, so despite the large spread of π-electrons, they have high electron-accepting properties. High electron-accepting properties are beneficial for a light-receiving device because they cause charge separation to occur efficiently at high speed. C 60 , C 70Both have a broad absorption band in the visible light region, and especially C 70 is C 60 Compared to [6,6]-Phenyl-C, it is preferable because it has a larger π-electron conjugation system and a broad absorption band in the long-wavelength region. In addition, [6,6]-Phenyl-C is a suitable fullerene derivative. 71 -butyric acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C 61 -butyric acid methyl ester (abbreviation: PC60BM), 1',1'',4',4''-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fulrerene-C 60 Examples include (abbreviated as ICBA).

[0371] Furthermore, examples of n-type semiconductor 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, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

[0372] Examples of p-type semiconductor materials for the active layer include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0373] Furthermore, examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. In addition, examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indrocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0374] The HOMO level of electron-donating organic semiconductor materials is preferably shallower (higher) than the HOMO level of electron-accepting organic semiconductor materials. The LUMO level of electron-donating organic semiconductor materials is preferably shallower (higher) than the LUMO level of electron-accepting organic semiconductor materials.

[0375] It is preferable to use spherical fullerenes as electron-accepting organic semiconductor materials and organic semiconductor materials with a near-planar shape as electron-donating organic semiconductor materials. Molecules with similar shapes tend to aggregate, and when molecules of the same type aggregate, their molecular orbital energy levels are close, which can improve carrier transport.

[0376] For example, the active layer is preferably formed by co-depositing an n-type semiconductor and a p-type semiconductor. Alternatively, the active layer may be formed by stacking an n-type semiconductor and a p-type semiconductor.

[0377] The photodetector may further include layers other than the active layer, such as a material with high hole transport properties, a material with high electron transport properties, or a bipolar material (a material with high electron and hole transport properties). Furthermore, it may also further include layers containing a material with high hole injection properties, a hole blocking material, a material with high electron injection properties, an electron blocking material, etc.

[0378] The light-receiving device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-receiving device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0379] For example, polymer compounds such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS), and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used as hole transport materials. In addition, inorganic compounds such as zinc oxide (ZnO) can be used as electron transport materials.

[0380] Furthermore, the active layer can use polymer compounds such as Poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]]polymer (abbreviated as PBDB-T) or PBDB-T derivatives, which function as donors. For example, a method of dispersing the acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0381] Furthermore, the active layer may contain a mixture of three or more materials. For example, to broaden the wavelength range, a third material may be mixed with an n-type semiconductor material and a p-type semiconductor material. In this case, the third material may be a low-molecular-weight compound or a high-molecular-weight compound.

[0382] The above is a description of the light-receiving device.

[0383] Figure 18E shows an example of a pixel circuit for a subpixel having a light-receiving device, and Figure 18F shows an example of a pixel circuit for a subpixel having a light-emitting device.

[0384] The pixel circuit PIX1 shown in Figure 18E includes a light-receiving device PD, transistors M11, M12, M13, M14, and a capacitive element C2. Here, an example is shown in which a photodiode is used as the light-receiving device PD.

[0385] The photodetector PD has its cathode electrically connected to wiring V1 and its anode electrically connected to either the source or drain of transistor M11. Transistor M11 has its gate electrically connected to wiring TX and its other source or drain electrically connected to one electrode of capacitive element C2, one source or drain of transistor M12, and the gate of transistor M13. Transistor M12 has its gate electrically connected to wiring RES and its other source or drain electrically connected to wiring V2. Transistor M13 has its source or drain electrically connected to wiring V3 and its other source or drain electrically connected to either the source or drain of transistor M14. Transistor M14 has its gate electrically connected to wiring SE and its other source or drain electrically connected to wiring OUT1.

[0386] Constant potentials are supplied to wirings V1, V2, and V3, respectively. When the photodetector PD is driven with reverse bias, a potential lower than that of wiring V1 is supplied to wiring V2. Transistor M12 is controlled by a signal supplied to wiring RES and has the function of resetting the potential of the node connected to the gate of transistor M13 to the potential supplied to wiring V2. Transistor M11 is controlled by a signal supplied to wiring TX and has the function of controlling the timing at which the potential of the above node changes according to the current flowing through the photodetector PD. Transistor M13 functions as an amplifying transistor that provides an output according to the potential of the above node. Transistor M14 is controlled by a signal supplied to wiring SE and functions as a selection transistor for reading the output according to the potential of the above node with an external circuit connected to wiring OUT1.

[0387] The pixel circuit PIX2 shown in Figure 18F includes a light-emitting device EL, transistors M15, M16, M17, and a capacitive element C3. Here, an example using a light-emitting diode as the light-emitting device EL is shown. In particular, it is preferable to use an organic EL element as the light-emitting device EL.

[0388] Transistor M15 has its gate electrically connected to wiring VG, one of its source or drain electrically connected to wiring VS, and the other of its source or drain electrically connected to one electrode of capacitive element C3 and the gate of transistor M16. One of the source or drain of transistor M16 is electrically connected to wiring V4, and the other is electrically connected to the anode of light-emitting device EL and one of the source or drain of transistor M17. Transistor M17 has its gate electrically connected to wiring MS, and the other of its source or drain electrically connected to wiring OUT2. The cathode of light-emitting device EL is electrically connected to wiring V5.

[0389] Constant potentials are supplied to wirings V4 and V5, respectively. This allows the anode side of the light-emitting device EL to be at a high potential and the cathode side to be at a lower potential than the anode side. Transistor M15 is controlled by a signal supplied to wiring VG and functions as a selection transistor to control the selected state of the pixel circuit PIX2. Transistor M16 functions as a drive transistor that controls the current flowing to the light-emitting device EL according to the potential supplied to its gate. When transistor M15 is conducting, the potential supplied to wiring VS is supplied to the gate of transistor M16, and the luminescence brightness of the light-emitting device EL can be controlled according to that potential. Transistor M17 is controlled by a signal supplied to wiring MS and has the function of outputting the potential between transistor M16 and the light-emitting device EL to the outside via wiring OUT2.

[0390] In this embodiment, the display panel may display an image by emitting light from the light-emitting elements in a pulsed manner. By shortening the driving time of the light-emitting elements, the power consumption of the display panel and the generation of heat can be reduced. Organic EL elements are particularly suitable because they have excellent frequency characteristics. The frequency can be, for example, 1 kHz or more and 100 MHz or less.

[0391] Here, it is preferable to apply transistors to which the semiconductor layer in which the channel is formed is made of a metal oxide (oxide semiconductor) for transistors M11, M12, M13, and M14 in the pixel circuit PIX1, and transistors M15, M16, and M17 in the pixel circuit PIX2.

[0392] Transistors using metal oxides, which have a wider bandgap and lower carrier density than silicon, can achieve extremely low off-currents. Therefore, this low off-current allows the charge accumulated in the capacitive element connected in series with the transistor to be retained for extended periods. For this reason, it is preferable to use transistors made of oxide semiconductors, particularly for transistors M11, M12, and M15 connected in series with capacitive element C2 or C3. Similarly, using oxide semiconductor transistors for other transistors can reduce manufacturing costs.

[0393] Furthermore, transistors M11 to M17 can also be transistors in which silicon is applied as the semiconductor in which the channel is formed. In particular, using highly crystalline silicon such as single-crystal silicon or polycrystalline silicon is preferable because it can achieve high field-effect mobility, enabling faster operation.

[0394] Alternatively, a configuration may be used in which one or more transistors among transistors M11 to M17 have oxide semiconductors applied, and the others have silicon applied.

[0395] Note that in Figures 18E and 18F, transistors are shown as n-channel transistors, but p-channel transistors can also be used.

[0396] It is preferable that the transistors in pixel circuit PIX1 and pixel circuit PIX2 be formed side by side on the same substrate. In particular, it is preferable to configure the transistors in pixel circuit PIX1 and pixel circuit PIX2 to be mixed within a single region and arranged periodically.

[0397] Furthermore, it is preferable to provide one or more layers having either or both transistors and / or capacitive elements in a position that overlaps with the light-receiving device PD or light-emitting device EL. This reduces the effective area occupied by each pixel circuit, enabling the realization of a high-definition light-receiving or display unit.

[0398] As described above, the display device of this embodiment can add two additional functions to the display function by equipping a single pixel with two types of light-receiving devices, thereby enabling the display device to be multifunctional. For example, it can realize a high-definition imaging function and a sensing function such as a touch sensor or near-touch sensor. Furthermore, the functionality of the display device can be further increased by combining a pixel equipped with two types of light-receiving devices with a pixel with a different configuration. For example, a pixel having a light-emitting device that emits infrared light, or various sensor devices, can be used.

[0399] (Embodiment 6) This embodiment describes a high-resolution display device.

[0400] [Example of display panel configuration] Wearable electronic devices for VR and AR can provide 3D images by using parallax. In this case, the image for the right eye must be displayed within the right eye's field of view, and the image for the left eye must be displayed within the left eye's field of view. Here, the display area of ​​the display device may be a horizontally elongated rectangle, but pixels located outside the fields of view of the right and left eyes do not contribute to the display, and therefore these pixels will always display black.

[0401] Therefore, it is preferable to divide the display panel into two areas, one for the right eye and one for the left eye, and to configure it so that pixels are not placed in the outer area that does not contribute to the display. This reduces the power consumption required for writing pixels. In addition, the load on source lines, gate lines, etc. is reduced, making it possible to display at a higher frame rate. As a result, smoother video can be displayed, which enhances the sense of realism.

[0402] Figure 19A shows an example of the display panel configuration. In Figure 19A, the left eye display unit 702L and the right eye display unit 702R are arranged inside the circuit board 701. In addition to the display units 702L and 702R, the circuit board 701 may also contain drive circuits, wiring, ICs, FPCs, etc.

[0403] The display units 702L and 702R shown in Figure 19A have a square top surface shape.

[0404] Furthermore, the top surface shapes of the display units 702L and 702R may be other regular polygons. Figure 19B shows an example of a regular hexagon, Figure 19C shows an example of a regular octagon, Figure 19D shows an example of a regular decagon, and Figure 19E shows an example of a regular dodecagon. In this way, by using a polygon with an even number of corners, the shape of the display unit can be made symmetrical. Note that polygons that are not regular polygons may also be used. In addition, regular polygons or polygons with rounded corners may be used.

[0405] Furthermore, because the display area is composed of pixels arranged in a matrix, the straight sections of the outline of each display area are not strictly straight lines, and there may be stepped sections. In particular, the straight sections that are not parallel to the direction of pixel arrangement will have a stepped top surface shape. However, since the user does not perceive the shape of the pixels when viewing the display, even if the diagonal outline of the display area is strictly stepped, it can be considered a straight line. Similarly, even if the curved sections of the outline of the display area are strictly stepped, they can be considered curves.

[0406] Figure 19F also shows an example where the top surface shape of the display unit 702L and the display unit 702R is a circle.

[0407] Furthermore, the top shapes of the display units 702L and 702R may be asymmetrical. Also, they do not have to be regular polygons.

[0408] Figure 19G shows an example where the top surfaces of the display units 702L and 702R are asymmetrical octagons. Figure 19H shows an example where they are regular heptagons. Even when the top surfaces of the display units 702L and 702R are asymmetrical, it is preferable to arrange the display units 702L and 702R symmetrically. This allows for the provision of images that do not appear unnatural.

[0409] The above describes a configuration where the display unit is divided into two parts, but it may also be a single, continuous shape.

[0410] Figure 19I shows an example of connecting the two circular display units in Figure 19F. Figure 19J shows an example of connecting the two regular octagonal display units in Figure 19C.

[0411] The above is an explanation of an example of a display panel configuration.

[0412] 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.

[0413] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0414] (Embodiment 7) This embodiment describes metal oxides (also called oxide semiconductors) that can be used in the OS transistor described in the above embodiment.

[0415] The metal oxide used in the OS transistor preferably contains at least indium or zinc, and more preferably indium and zinc. For example, the metal oxide preferably contains indium, M (where M is one or more selected from gallium, aluminum, yttrium, tin, silicon, boron, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt), and zinc. In particular, M is preferably one or more selected from gallium, aluminum, yttrium, and tin, and more preferably gallium.

[0416] Furthermore, metal oxides can be formed by methods such as sputtering, chemical vapor deposition (CVD) methods including metal-organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD).

[0417] In the following sections, we will describe oxides containing indium (In), gallium (Ga), and zinc (Zn) as examples of metal oxides. Note that oxides containing indium (In), gallium (Ga), and zinc (Zn) are sometimes called In-Ga-Zn oxides.

[0418] <Classification of crystal structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0419] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, it can be evaluated using the XRD spectrum obtained from a GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also known as the thin-film method or the Seemann-Bohlin method. In the following text, the XRD spectrum obtained from a GIXD measurement may simply be referred to as the XRD spectrum.

[0420] For example, in a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, in an In-Ga-Zn oxide film with a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical shape of the XRD spectrum peaks clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0421] Furthermore, the crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nano-beam electron diffraction pattern) observed using nano-beam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. On the other hand, a spot-like pattern is observed in the diffraction pattern of an In-Ga-Zn oxide film deposited at room temperature, rather than a halo. Therefore, it is presumed that an In-Ga-Zn oxide film deposited at room temperature is in an intermediate state, neither single-crystal nor polycrystalline, nor amorphous, and cannot be concluded to be in an amorphous state.

[0422] <<Oxide semiconductor structure>> It should be noted that oxide semiconductors may be classified differently from those described above when considering their structure. For example, oxide semiconductors can be divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors also include polycrystalline oxide semiconductors, pseudo-amorphous oxide semiconductors (a-like OS), and amorphous oxide semiconductors.

[0423] Here, we will explain the details of the CAAC-OS, nc-OS, and a-like OS mentioned above.

[0424] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, the c-axis of which is oriented in a specific direction. This specific direction is the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If we consider the atomic arrangement as a lattice arrangement, then a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-OS has regions where multiple crystalline regions are connected in the ab-plane direction, and these regions may exhibit distortion. Distortion refers to a point in the connected region where the orientation of the lattice arrangement changes between a region with a aligned lattice arrangement and another region with a aligned lattice arrangement. In short, CAAC-OS is an oxide semiconductor that is c-axis oriented and does not exhibit clear orientation in the ab-plane direction.

[0425] Each of the multiple crystalline regions described above is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single minute crystal, the maximum diameter of that crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of that crystalline region may be around several tens of nanometers.

[0426] Furthermore, in In-Ga-Zn oxides, CAAC-OS tends to have a layered crystalline structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter referred to as the In layer) and layers containing gallium (Ga), zinc (Zn), and oxygen (hereinafter referred to as the (Ga,Zn) layer). Note that indium and gallium are mutually substitutable. Therefore, the (Ga,Zn) layer may contain indium. Also, the In layer may contain gallium. Also, the In layer may contain zinc. This layered structure can be observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0427] When structural analysis of a CAAC-OS film is performed using an XRD instrument, for example, out-of-plane XRD measurements using θ / 2θ scanning show a peak indicating c-axis orientation at 2θ = 31° or nearby. Note that the position of the c-axis orientation peak (value of 2θ) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0428] Furthermore, for example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film. These spots are observed at point-symmetric positions with respect to the incident electron beam spot (also called the direct spot) that passed through the sample.

[0429] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the strain may have lattice arrangements such as pentagons or heptagons. Moreover, in CAAC-OS, clear grain boundaries cannot be observed even near the strain. In other words, it can be seen that the formation of grain boundaries is suppressed by the strain in the lattice arrangement. This is thought to be because CAAC-OS can tolerate strain due to factors such as the non-dense arrangement of oxygen atoms in the ab-plane direction and the change in interatomic bond distances due to the substitution of metal atoms.

[0430] A crystal structure in which clear grain boundaries are observed is called a polycrystal. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in transistor on-current and field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides with a suitable crystal structure for the semiconductor layer of a transistor. In addition, a structure containing Zn is preferred for the composition of CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are preferred because they suppress the generation of grain boundaries more than In oxide.

[0431] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. Furthermore, since the crystallinity of oxide semiconductors can decrease due to the inclusion of impurities and the generation of defects, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Consequently, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat resistant and highly reliable. In addition, CAAC-OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors allows for greater flexibility in the manufacturing process.

[0432] [nc-OS] nc-OS exhibits periodicity in atomic arrangement in minute regions (e.g., regions between 1 nm and 10 nm, particularly between 1 nm and 3 nm). In other words, nc-OS contains minute crystals. These minute crystals are also called nanocrystals because their size is, for example, between 1 nm and 10 nm, particularly between 1 nm and 3 nm. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Consequently, depending on the analytical method, nc-OS may be indistinguishable from a-like OS or amorphous oxide semiconductors. For example, when structural analysis of an nc-OS film is performed using an XRD instrument, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Also, when electron diffraction (also called limited-field electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter larger than that of the nanocrystals (e.g., 50 nm or larger), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystal (for example, 1 nm to 30 nm), an electron diffraction pattern may be obtained in which multiple spots are observed within a ring-shaped region centered on a direct spot.

[0433] [a-like OS] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, a-like OS has a higher hydrogen concentration in the film compared to nc-OS and CAAC-OS.

[0434] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS refers to the material composition.

[0435] [CAC-OS] CAC-OS is a material composition in which, for example, the elements constituting the metal oxide are unevenly distributed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide, and the regions containing these metal elements are mixed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size, is also referred to as a mosaic or patchy state.

[0436] Furthermore, CAC-OS is a composite metal oxide having a mosaic-like structure formed by the separation of the material into a first region and a second region, with the first region distributed within the film (hereinafter also referred to as a cloud-like structure). In other words, CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0437] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS of In-Ga-Zn oxide, the first region is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is the region where [In] is greater than the [In] in the second region, and [Ga] is smaller than the [Ga] in the second region. The second region is the region where [Ga] is greater than the [Ga] in the first region, and [In] is smaller than the [In] in the first region.

[0438] Specifically, the first region described above is a region whose main components are indium oxide, indium zinc oxide, etc. The second region described above is a region whose main components are gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region whose main component is In. Similarly, the second region can be rephrased as a region whose main component is Ga.

[0439] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0440] Furthermore, CAC-OS in In-Ga-Zn oxide refers to a material composition containing In, Ga, Zn, and O, in which regions with Ga as the main component and regions with In as the main component are arranged in a mosaic-like manner, with these regions existing randomly. Therefore, it is presumed that CAC-OS has a structure in which metal elements are unevenly distributed.

[0441] CAC-OS can be formed by sputtering, for example, under conditions where the substrate is not intentionally heated. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. Furthermore, a lower ratio of the oxygen gas flow rate to the total deposition gas flow rate during film formation is preferable. For example, the ratio of the oxygen gas flow rate to the total deposition gas flow rate during film formation should be 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0442] Furthermore, for example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) confirms that it has a structure in which regions mainly composed of In (first region) and regions mainly composed of Ga (second region) are unevenly distributed and mixed.

[0443] Here, the first region is a region with higher conductivity compared to the second region. In other words, the conductivity of the metal oxide is exhibited when carriers flow through the first region. Therefore, a high field-effect mobility (μ) can be achieved when the first region is distributed in a cloud-like manner within the metal oxide.

[0444] On the other hand, the second region is a region with higher insulating properties compared to the first region. In other words, the distribution of the second region within the metal oxide can suppress leakage current.

[0445] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulation due to the second region work complementaryly to give CAC-OS a switching function (on / off function). In other words, CAC-OS has conductive function in part of the material, insulating function in part of the material, and semiconductor function as a whole. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching operation can be achieved.

[0446] Furthermore, transistors using CAC-OS offer high reliability. Therefore, CAC-OS is ideal for various semiconductor devices, including display devices.

[0447] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention may include two or more of the following: amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0448] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0449] By using the above-mentioned oxide semiconductor in transistors, it is possible to realize transistors with high field-effect mobility. Furthermore, it is possible to realize highly reliable transistors.

[0450] It is preferable to use an oxide semiconductor with a low carrier concentration for the transistor. For example, the carrier concentration of an oxide semiconductor is 1 × 10⁻⁶. 17 cm -3 The following is preferably 1 × 10 15 cm -3 More preferably 1 × 10 13 cm -3 More preferably 1 × 10 11 cm -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm -3 This concludes the explanation. Furthermore, when lowering the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film should be lowered to reduce the defect level density. In this specification, a low impurity concentration and low defect level density are referred to as high-purity intrinsic or substantially high-purity intrinsic. Note that oxide semiconductors with low carrier concentrations are sometimes referred to as high-purity intrinsic or substantially high-purity intrinsic oxide semiconductors.

[0451] Furthermore, oxide semiconductor films that are highly intrinsic or substantially highly intrinsic may have a low trap level density due to their low defect level density.

[0452] Furthermore, charges trapped in the trap levels of oxide semiconductors can take a long time to disappear, sometimes behaving like fixed charges. Therefore, transistors in which channel formation regions are formed in oxide semiconductors with a high trap level density may exhibit unstable electrical properties.

[0453] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical characteristics of a transistor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon. Note that impurities in an oxide semiconductor refer to elements other than the main components that make up the oxide semiconductor. For example, elements with a concentration of less than 0.1 atomic percent can be considered impurities.

[0454] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0455] In oxide semiconductors, the presence of silicon or carbon, which are Group 14 elements, leads to the formation of defect levels in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are compared by 2 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0456] Furthermore, if an oxide semiconductor contains alkali metals or alkaline earth metals, it may form defect levels and generate carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to exhibit normally-on characteristics. For this reason, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor obtained by SIMS should be set to 1 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0457] Furthermore, in oxide semiconductors, the presence of nitrogen generates electrons, which act as carriers, increasing the carrier concentration and making it easier for the semiconductor to become n-type. As a result, transistors using oxide semiconductors containing nitrogen tend to exhibit normally-on characteristics. Alternatively, the presence of nitrogen in oxide semiconductors can lead to the formation of trap levels. As a result, the electrical properties of the transistor may become unstable. For this reason, the nitrogen concentration in oxide semiconductors obtained by SIMS should be set to 5 × 10⁻⁶. 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5 × 10 17 atoms / cm 3 Do the following:

[0458] Furthermore, hydrogen contained in oxide semiconductors can react with oxygen bonded to metal atoms to form water, potentially creating oxygen vacancies. Hydrogen can then fill these vacancies, generating electrons as carriers. Additionally, some of the hydrogen can combine with oxygen bonded to metal atoms to generate electrons. Therefore, transistors using oxide semiconductors containing hydrogen tend to exhibit normally-on characteristics. For this reason, it is preferable to reduce the hydrogen content in oxide semiconductors as much as possible. Specifically, the hydrogen concentration in the oxide semiconductor obtained by SIMS should be 1 × 10⁻⁶. 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 Make it less than.

[0459] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0460] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0461] (Embodiment 8) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 18 to 23.

[0462] The electronic device of this embodiment has a display device according to one aspect of the present invention. The display device according to one aspect of the present invention is easily made high-definition, high-resolution, and large-scale. Therefore, the display device according to one aspect of the present invention can be used in the display units of various electronic devices.

[0463] Furthermore, since the display device according to one aspect of the present invention can be manufactured at a low cost, the manufacturing cost of electronic devices can be reduced.

[0464] 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.

[0465] In particular, a display device according to one aspect 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 information terminals (wearable devices) such as wristwatches and bracelets, as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR devices such as glasses. Wearable devices also include devices for SR (Substitutional Reality) and devices for MR (Mixed Reality).

[0466] A display device according to one aspect 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), 4K2K (3840 x 2160 pixels), or 8K4K (7680 x 4320 pixels). In particular, a resolution of 4K2K, 8K4K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is 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 display devices with such high resolution or high detail, it becomes possible to enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices.

[0467] The electronic device of this embodiment can be incorporated along the curved surfaces of the interior or exterior walls of a house or building, or the interior or exterior of an automobile.

[0468] The electronic device in this embodiment may have an antenna. By receiving signals with the antenna, the display unit can display images and information. Furthermore, if the electronic device has an antenna and a secondary battery, the antenna may be used for contactless power transmission.

[0469] 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).

[0470] 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.

[0471] The electronic device 6500 shown in Figure 20A is a portable information terminal that can be used as a smartphone.

[0472] 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.

[0473] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0474] Figure 20B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0475] 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.

[0476] 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).

[0477] 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.

[0478] A flexible display (a display device with flexibility) 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 area, an electronic device with a narrow bezel can be realized.

[0479] Figure 21A 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 supported by a stand 7103.

[0480] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0481] The television device 7100 shown in Figure 21A can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0482] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0483] Figure 21B shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0484] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0485] Figures 21C and 21D show examples of digital signage.

[0486] The digital signage 7300 shown in Figure 21C includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switches), connection terminals, various sensors, a microphone, etc.

[0487] Figure 21D shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0488] In Figures 21C and 21D, a display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0489] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0490] 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 enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0491] Furthermore, as shown in Figures 21C and 21D, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0492] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows a large number of users to participate in and enjoy the game simultaneously.

[0493] Figure 22A shows the external appearance of the camera 8000 with the viewfinder 8100 attached.

[0494] The camera 8000 includes a housing 8001, a display unit 8002, operation buttons 8003, a shutter button 8004, etc. A detachable lens 8006 is also attached to the camera 8000. The lens 8006 and the housing 8001 may be integrated into a single unit.

[0495] Camera 8000 can take an image by pressing the shutter button 8004 or by touching the display unit 8002, which functions as a touch panel.

[0496] The housing 8001 has a mount with electrodes, and in addition to the viewfinder 8100, a strobe device and the like can be connected to it.

[0497] The viewfinder 8100 includes a housing 8101, a display unit 8102, buttons 8103, etc.

[0498] The housing 8101 is attached to the camera 8000 by a mount that engages with the camera 8000's mount. The viewfinder 8100 can display images and other data received from the camera 8000 on the display unit 8102.

[0499] Button 8103 functions as a power button, etc.

[0500] A display device according to one embodiment of the present invention can be applied to the display unit 8002 of the camera 8000 and the display unit 8102 of the viewfinder 8100. The camera 8000 may also have a built-in viewfinder.

[0501] Figure 22B shows the external appearance of the head-mounted display 8200.

[0502] The head-mounted display 8200 includes a mounting section 8201, lenses 8202, a main unit 8203, a display unit 8204, a cable 8205, etc. The mounting section 8201 also has a built-in battery 8206.

[0503] Cable 8205 supplies power from battery 8206 to main unit 8203. Main unit 8203 is equipped with a wireless receiver and can display received video information on display unit 8204. In addition, main unit 8203 is equipped with a camera and can use information about the user's eyeball or eyelid movements as an input means.

[0504] Furthermore, the attachment unit 8201 may be provided with multiple electrodes at a position that touches the user, capable of detecting the current flowing in accordance with the user's eye movements, and may have a function to recognize the user's gaze. It may also have a function to monitor the user's pulse rate based on the current flowing through the electrodes. In addition, the attachment unit 8201 may have various sensors such as a temperature sensor, a pressure sensor, and an acceleration sensor, and may have a function to display the user's biometric information on the display unit 8204, or a function to change the image displayed on the display unit 8204 in accordance with the user's head movements.

[0505] A display device according to one aspect of the present invention can be applied to the display unit 8204.

[0506] Figures 22C to 22E 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.

[0507] The user can view the display on the display unit 8302 through the lens 8305. It is preferable to position 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 a single display unit 8302; two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0508] A display device according to one embodiment of the present invention can be applied to the display unit 8302. This display device according to one embodiment of the present invention can achieve extremely high resolution. For example, even when the display is magnified and viewed using the lens 8305 as shown in Figure 22E, 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 highly realistic images.

[0509] Figure 22F shows the external appearance of a goggle-type head-mounted display 8400. The head-mounted display 8400 has a pair of housings 8401, a mounting part 8402, and a cushioning member 8403. A display unit 8404 and a lens 8405 are provided inside each of the pair of housings 8401. By displaying different images on the pair of display units 8404, a three-dimensional display using parallax can be achieved.

[0510] The user can view the display unit 8404 through the lens 8405. The lens 8405 has a focusing mechanism, which allows the position of the lens 8405 to be adjusted according to the user's eyesight. The display unit 8404 is preferably a square or a horizontally elongated rectangle. This can enhance the sense of realism.

[0511] The mounting portion 8402 is preferably adjustable to the size of the user's face and has plasticity and elasticity to prevent it from slipping off. Furthermore, it is preferable that a part of the mounting portion 8402 has a vibration mechanism that functions as a bone conduction earphone. This eliminates the need for separate audio equipment such as earphones or speakers, allowing users to enjoy video and audio simply by wearing the device. The housing 8401 may also have a function to output audio data via wireless communication.

[0512] The mounting portion 8402 and the cushioning member 8403 are parts that come into contact with the user's face (forehead, cheeks, etc.). By ensuring that the cushioning member 8403 is in close contact with the user's face, light leakage can be prevented, thereby enhancing the sense of immersion. It is preferable to use a soft material for the cushioning member 8403 so that it adheres closely to the user's face when the user wears the head-mounted display 8400. For example, materials such as rubber, silicone rubber, urethane, and sponge can be used. Furthermore, if the surface of a sponge or similar material is covered with cloth, leather (genuine leather or synthetic leather), gaps are less likely to form between the user's face and the cushioning member 8403, effectively preventing light leakage. In addition, using such materials is preferable because it feels good against the skin and does not make the user feel cold when worn in cold seasons. It is preferable that the components that come into contact with the user's skin, such as the cushioning member 8403 or the mounting portion 8402, are removable, as this makes cleaning or replacement easier.

[0513] The electronic equipment shown in Figures 23A to 23F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, sensors 9007 (including functions for 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), a microphone 9008, etc.

[0514] The electronic devices shown in Figures 23A to 23F 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.

[0515] A display device according to one embodiment of the present invention can be applied to the display unit 9001.

[0516] The details of the electronic equipment shown in Figures 23A to 23F will be explained below.

[0517] Figure 23A is a perspective view showing a personal digital assistant (PDA) 9101. The PDA 9101 can be used, for example, as a smartphone. The PDA 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. The PDA 9101 can also display text and image information on multiple surfaces. Figure 23A 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 emails and SNS messages, the sender's name, date and time, battery level, and antenna signal strength. Alternatively, icons 9050 or the like may be displayed in the location where the information 9051 is displayed.

[0518] Figure 23B 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.

[0519] Figure 23C 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 be used for 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. Charging may be performed by wireless power supply.

[0520] Figures 23D to 23F are perspective views showing a foldable personal information terminal 9201. Figure 23D shows the personal information terminal 9201 in an unfolded state, Figure 23F shows it in a folded state, and Figure 23E shows a perspective view of the state in between, transitioning from one of Figures 23D or 23F to the other. The personal 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 personal information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0521] 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.

[0522] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0523] (Embodiment 9) This embodiment describes the relationship between screen size and pixel density of an electronic device equipped with an OLED display device, and technologies applicable to said display device.

[0524] Figure 24 shows the relationship between product screen size and pixel density. The horizontal axis represents screen size (inches), and the vertical axis represents pixel density (ppi). Figure 24 shows typical screen sizes and pixel density ranges for products such as μOLEDs used in AR or VR products, smartphones, smartwatches, laptops, tablet devices, automotive displays, monitors, and televisions (TVs). Generally, it can be seen that the smaller the screen size, the higher the resolution.

[0525] Figure 24 also shows a list of technologies that can be applied to each product. Here, BP represents the backplane and FP represents the frontplane.

[0526] Regarding the front plane, there are several main technologies for achieving full color in OLEDs, including: a color separation technique using a fine metal mask (FMM+SBS); a color separation technique using printing methods such as inkjet (printing+SBS); a technique combining white OLED and a color filter (W+CF); and a technique combining blue OLED and quantum dots (B+Qd).

[0527] Furthermore, OLEDs come in two main types: tandem structures, which stack multiple light-emitting units, and single structures, which do not stack light-emitting units.

[0528] Backplane fabrication technologies include LSI technology using Si substrates, LTPS (Low Temperature Poly Silicon) technology, LTPO (Low Temperature Polysilicon and Oxide) technology, and OS (Oxide Semiconductor) technology.

[0529] Here, the technique of producing different OLEDs using photolithography without using a fine metal mask is called MML (Metal Mask Less) technology. Compared to the full-color technology described above, MML technology is capable of achieving high aperture ratio, high efficiency, high brightness, high display quality, high contrast, and high reliability. MML technology can be applied to display devices of all screen sizes and resolutions shown in Figure 24. In particular, it can be suitably used in microdisplays with a screen size of around 1 inch and a resolution exceeding 1000 ppi.

[0530] Furthermore, the technique of combining fine metal masks and photolithography is called HMML (Hybrid MML). HMML technology can replace conventional full-color technology using FMM+SBS, and it is a technology that can achieve higher aperture ratio, higher reliability, higher display quality, and higher contrast than conventional technology.

[0531] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part. [Explanation of symbols]

[0532] 100: Display device, 101: Substrate, 103: Pixel, 105: Insulating layer, 110B: Light-emitting element, 110G: Light-emitting element, 110R: Light-emitting element, 110: Light-emitting element, 111B: Pixel electrode, 111C: Connecting electrode, 111G: Pixel electrode, 111R: Pixel electrode, 111: Pixel electrode, 112B: Organic layer, 112G: Organic layer, 112R: Organic layer, 112: Organic layer, 113: Common electrode, 114: Organic layer, 115: Organic layer, 116: Organic layer, 117: Charge generation layer, 118: Organic layer, 119: Organic layer, 120: Slit, 121: Protective layer, 125a: Pixel, 125b: Pixel, 125f: Insulating film, 125: Insulating layer, 126: Resin layer, 130: Connection part, 131: Insulating layer, 132: Insulating layer, 135B: Layer, 135G: Layer, 135R: Layer, 143: Resist mask, 144: Sacrificial film, 145: Sacrificial layer, 146: Sacrificial film, 147: Sacrificial layer, 151B: FMM, 151G: FMM, 151R: FMM, 161: Conductive layer, 162: Conductive layer, 163: Resin layer

Claims

[Claim 1] A first step of arranging and forming a first pixel electrode and a second pixel electrode, A second step involves forming an island-shaped first light-emitting layer on the first pixel electrode using a first metal mask, A third step involves forming an island-shaped second light-emitting layer on the second pixel electrode using a second metal mask, so as to overlap with the edge of the first light-emitting layer. A fourth step involves separating the first light-emitting layer and the second light-emitting layer by etching in the region between the first pixel electrode and the second pixel electrode, The process includes a fifth step of covering the first light-emitting layer and the second light-emitting layer to form a common electrode, After the fourth step and before the fifth step, The sixth step involves forming a resin layer within the slit formed by the etching, The aforementioned resin layer uses a photosensitive organic resin, After the fourth step and before the sixth step, The process includes a seventh step of forming a first insulating layer in contact with the side surfaces of the first light-emitting layer and the side surfaces of the second light-emitting layer that are exposed by the etching, The first insulating layer uses an inorganic insulating film formed by atomic layer deposition. Method for manufacturing a display device.

Images