Method for manufacturing a display device

Abstract

Provided is a display device having good display quality. The display device of the present invention comprises a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer. The first light-emitting device comprises a first pixel electrode, a first light-emitting layer on the first pixel electrode, and a common electrode on the first light-emitting layer. The second light-emitting device comprises a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer. The first insulating layer covers a portion of the top surface and the side surface of the first light-emitting layer, and a portion of the top surface and the side surface of the second light-emitting layer. The second insulating layer overlaps a portion of the top surface and the side surface of the first light-emitting layer and a portion of the top surface and the side surface of the second light-emitting layer with the first insulating layer interposed. The common electrode covers the second insulating layer. In cross-sectional view, the end part of the second insulating layer has a tapered shape with a taper angle of less than 90°, and the second insulating layer covers at least a portion of the side surface of the first insulating layer.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device, a display module, and electronic equipment. 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 include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), methods for driving them, or methods for manufacturing them. [Background technology]

[0003] In recent years, display devices have been expected to have applications in a variety of uses. For example, large-scale display devices are used in home television systems (also called televisions or television receivers), digital signage, and PID (Public Information Display). Furthermore, development is progressing on mobile information terminals such as smartphones and tablet devices equipped with touch panels.

[0004] Furthermore, there is a demand for higher resolution display devices. Devices requiring high-resolution displays, such as those for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), are being actively developed.

[0005] As a display device, for example, a light-emitting device (also called a light-emitting element) has been developed. Light-emitting devices that utilize the electroluminescence (EL) phenomenon (also called EL devices or EL elements) have features such as being easy to make thin and light, being able to respond quickly to input signals, and being able to be driven using a DC constant voltage power supply, and are being applied to display devices.

[0006] Patent Document 1 discloses a display device for VR using an organic EL device (also called an organic EL element). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2018 / 087625 [Overview of the project] [Problems that the invention aims to solve]

[0008] One aspect of the present invention aims to provide a display device with high display quality. One aspect of the present invention aims to provide a high-definition display device. One aspect of the present invention aims to provide a high-resolution display device. One aspect of the present invention aims to provide a highly reliable display device.

[0009] One aspect of the present invention aims to provide a method for manufacturing a high-definition display device. Another aspect of the present invention aims to provide a method for manufacturing a high-resolution display device. Another aspect of the present invention aims to provide a method for manufacturing a highly reliable display device. Another aspect of the present invention aims to provide a method for manufacturing a display device with a high yield.

[0010] Furthermore, the description of these problems does not preclude the existence of other problems. One aspect of the present invention does not necessarily have to solve all of these problems. It is possible to extract other problems from the description in the specification, drawings, and claims. [Means for solving the problem]

[0011] One aspect of the present invention is a display device comprising a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer, wherein the first light-emitting device comprises a first pixel electrode, a first light-emitting layer on the first pixel electrode, and a common electrode on the first light-emitting layer; the second light-emitting device comprises a second pixel electrode, a second light-emitting layer on the second pixel electrode, and a common electrode on the second light-emitting layer; the first insulating layer covers a portion of the upper surface and sides of the first light-emitting layer, and a portion of the upper surface and sides of the second light-emitting layer; the second insulating layer overlaps with a portion of the upper surface and sides of the first light-emitting layer, and a portion of the upper surface and sides of the second light-emitting layer via the first insulating layer; the common electrode covers the second insulating layer; in cross-sectional view, the end of the second insulating layer has a tapered shape with a taper angle of less than 90°; and the second insulating layer covers at least a portion of the side surface of the first insulating layer.

[0012] The end of the second insulating layer is preferably located outside the end of the first insulating layer.

[0013] The second insulating layer preferably has a convex curved shape on its upper surface.

[0014] In a cross-sectional view, it is preferable that the end of the first insulating layer has a tapered shape with a taper angle of less than 90°.

[0015] The second insulating layer preferably has a concave curved shape on its side surface.

[0016] The above display device has a third insulating layer and a fourth insulating layer. The third insulating layer is located between the upper surface of the first light-emitting layer and the first insulating layer, and the fourth insulating layer is located between the upper surface of the second light-emitting layer and the first insulating layer. It is preferable that the ends of the third insulating layer and the ends of the fourth insulating layer are each located outside the ends of the first insulating layer.

[0017] The second insulating layer preferably covers at least a part of the side surface of the third insulating layer and at least a part of the side surface of the fourth insulating layer.

[0018] In a cross-sectional view, it is preferable that the ends of the third insulating layer and the ends of the fourth insulating layer each have a tapered shape with a taper angle of less than 90°.

[0019] The first light-emitting device has a first functional layer between the first light-emitting layer and the common electrode, and the second light-emitting device has a second functional layer between the second light-emitting layer and the common electrode. The first insulating layer covers a part of the upper surface and the side surface of the first functional layer, and a part of the upper surface and the side surface of the second functional layer. The second insulating layer preferably overlaps a part of the upper surface and the side surface of the first functional layer, and a part of the upper surface and the side surface of the second functional layer via the first insulating layer.

[0020] The first functional layer and the second functional layer preferably each have at least one of a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, a hole blocking layer, and an electron blocking layer.

[0021] The first insulating layer and the second insulating layer preferably each have a portion overlapping the upper surface of the first pixel electrode and a portion overlapping the upper surface of the second pixel electrode.

[0022] The first light-emitting layer preferably covers the side surface of the first pixel electrode, and the second light-emitting layer preferably covers the side surface of the second pixel electrode.

[0023] In a cross-sectional view, it is preferable that the ends of the first pixel electrode and the ends of the second pixel electrode each have a tapered shape with a taper angle of less than 90°.

[0024] The first insulating layer is preferably an inorganic insulating layer, and the second insulating layer is preferably an organic insulating layer. The first insulating layer is preferably aluminum oxide. The second insulating layer is preferably acrylic resin.

[0025] The first light-emitting device has a common layer between the first light-emitting layer and the common electrode, and the second light-emitting device has a common layer between the second light-emitting layer and the common electrode, and it is preferable that the common layer is located between the second insulating layer and the common electrode.

[0026] One aspect of the present invention is a display module having a display device with any of the above configurations, to which a connector such as a Flexible Printed Circuit (FPC) or TCP (Tape Carrier Package) is attached, or a display module on which an integrated circuit (IC) is mounted by a COG (Chip On Glass) method or a COF (Chip On Film) method, etc.

[0027] One aspect of the present invention is an electronic device having the above-mentioned display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0028] One aspect of the present invention involves forming a first pixel electrode and a second pixel electrode, forming a first film on the first pixel electrode and the second pixel electrode, forming a first mask film on the first film, processing the first film and the first mask film to form a first layer and a first mask layer on the first pixel electrode, and exposing the second pixel electrode, forming a second film on the first mask layer and the second pixel electrode, forming a second mask film on the second film, processing the second film and the second mask film to form a second layer and a second mask layer on the second pixel electrode, and exposing the first mask layer, forming a first insulating film on the first mask layer and the second mask layer, forming a second insulating film on the first insulating film, and a second This is a method for manufacturing a display device, comprising: processing an insulating film to form a second insulating layer that overlaps with the region sandwiched between the first and second pixel electrodes; using the second insulating layer as a mask to perform a first etching process to remove a portion of the first insulating film and thin the film thickness of a portion of the first mask layer and a portion of the second mask layer; performing a heat treatment; then using the second insulating layer as a mask to perform a second etching process to remove a portion of the first mask layer and a portion of the second mask layer, exposing the upper surfaces of the first and second layers, covering the first layer, the second layer and the second insulating layer to form a common electrode, the first layer having at least a first light-emitting layer, and the second layer having at least a second light-emitting layer.

[0029] Preferably, the first layer has a first functional layer on a first light-emitting layer, and the second layer has a second functional layer on a second light-emitting layer, with the first and second functional layers each having at least one of the following: a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, a hole blocking layer, and an electron blocking layer.

[0030] It is preferable to deposit an aluminum oxide film as the first insulating film using the ALD method, and to deposit aluminum oxide films as the first mask film and the second mask film using the ALD method.

[0031] It is preferable to irradiate the second insulating layer with light before the heat treatment.

[0032] The second insulating film is preferably formed using a photosensitive acrylic resin.

[0033] The first etching process and the second etching process are preferably carried out by wet etching. [Effects of the Invention]

[0034] According to one aspect of the present invention, a display device with high display quality can be provided. According to one aspect of the present invention, a high-definition display device can be provided. According to one aspect of the present invention, a high-resolution display device can be provided. According to one aspect of the present invention, a highly reliable display device can be provided.

[0035] According to one aspect of the present invention, a method for manufacturing a high-definition display device can be provided. According to one aspect of the present invention, a method for manufacturing a high-resolution display device can be provided. According to one aspect of the present invention, a method for manufacturing a highly reliable display device can be provided. According to one aspect of the present invention, a method for manufacturing a display device with a high yield can be provided.

[0036] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description, drawings, and claims. [Brief explanation of the drawing]

[0037] Figure 1A is a top view showing an example of a display device. Figure 1B is a cross-sectional view showing an example of a display device. Figures 2A and 2B are cross-sectional views showing an example of a display device. Figures 3A and 3B are cross-sectional views showing an example of a display device. Figures 4A and 4B are cross-sectional views showing an example of a display device. Figures 5A and 5B are cross-sectional views showing an example of a display device. Figures 6A and 6B are cross-sectional views showing an example of a display device. Figures 7A and 7B are cross-sectional views showing an example of a display device. Figure 8A is a top view showing an example of a display device. Figure 8B is a cross-sectional view showing an example of a display device. Figures 9A to 9C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 10A to 10C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 11A to 11C are cross-sectional views showing an example of a method for manufacturing a display device. Figures 12A and 12B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 13A and 13B are cross-sectional views showing an example of a method for manufacturing a display device. Figures 14A to 14D are cross-sectional views showing an example of a method for manufacturing a display device. Figures 15A to 15F show examples of pixels. Figures 16A to 16K show examples of pixels. Figures 17A and 17B are perspective views showing an example of a display device. Figures 18A and 18B are cross-sectional views showing an example of a display device. Figure 19 is a cross-sectional view showing an example of a display device. Figure 20 is a cross-sectional view showing an example of a display device. Figure 21 is a cross-sectional view showing an example of a display device. Figure 22 is a cross-sectional view showing an example of a display device. Figure 23 is a cross-sectional view showing an example of a display device. Figure 24 is a perspective view showing an example of a display device. Figure 25A is a cross-sectional view showing an example of a display device. Figures 25B and 25C are cross-sectional views showing an example of a transistor. Figures 26A to 26D are cross-sectional views showing an example of a display device. Figure 27 is a cross-sectional view showing an example of a display device. Figures 28A to 28F show examples of the configuration of a light-emitting device. Figures 29A and 29B show examples of the configuration of a light receiving device. Figures 29C to 29E show examples of the configuration of a display device. Figures 30A to 30D show examples of electronic devices. Figures 31A to 31F show examples of electronic devices. Figures 32A to 32G show examples of electronic devices. Figure 33 is a photograph showing the display result of the display device of Example 1. Figure 34 shows the results of measuring the volume shrinkage rate of the sample from Example 2. [Modes for carrying out the invention]

[0038] Embodiments will be described in detail with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be construed as being limited to the descriptions of the embodiments shown below.

[0039] In 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 same hatching pattern may be used, and reference numerals may not be assigned.

[0040] Furthermore, for the sake of ease of understanding, the position, size, and scope of each component shown in the drawings may not represent their actual position, size, and scope. Therefore, the disclosed invention is not necessarily limited to the position, size, and scope disclosed in the drawings.

[0041] It should be noted that the terms "film" and "layer" can be interchanged depending on the context or situation. For example, the term "conductive layer" can be changed to "conductive film." Or, for example, the term "insulating film" can be changed to "insulating layer."

[0042] 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.

[0043] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole block layer or electron block layer may be called a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable by their cross-sectional shape or characteristics. Furthermore, a single layer may combine the functions of two or three of these carrier injection, carrier transport, and carrier block layers.

[0044] In this specification, a light-emitting device (also called a light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. In this specification, a light-receiving device (also called a 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 a pixel electrode and the other as a common electrode.

[0045] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of a structure is inclined with respect to the substrate surface or the surface to be formed. For example, it is preferable to have a region in which the angle (also called the taper angle) between the inclined side surface and the substrate surface or the surface to be formed is less than 90°. The side surface of the structure, the substrate surface, and the surface to be formed do not necessarily have to be perfectly flat, and may be substantially planar with fine curvature, or substantially planar with fine irregularities.

[0046] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 1 to 8.

[0047] A display device according to one aspect of the present invention has light-emitting devices that are manufactured separately for each light-emitting color, and is capable of full-color display.

[0048] A structure in which different light-emitting layers are created or painted for each color of light-emitting device (for example, blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure. Because the SBS structure allows for the optimization of materials and configuration for each light-emitting device, it increases the freedom of material and configuration selection, making it easier to improve brightness and reliability.

[0049] When manufacturing a display device that has multiple light-emitting devices, each with a different light-emitting color, it is necessary to form each light-emitting layer with a different light-emitting color in an island-like structure.

[0050] In this specification, "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer and an adjacent light-emitting layer are physically separated.

[0051] For example, island-shaped light-emitting layers can be formed using a vacuum deposition method with a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-shaped light-emitting layers due to various factors such as the precision of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to achieve high resolution and high aperture ratio in display devices. In addition, the contour of the layer may become blurred during deposition, and the thickness at the edges may become thinner. In other words, the thickness of the island-shaped light-emitting layer may vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there is a concern that the low dimensional accuracy of the metal mask and deformation due to heat, etc., may lead to low manufacturing yield.

[0052] Therefore, when manufacturing a display device according to one aspect of the present invention, the light-emitting layer is processed into a fine pattern by photolithography without using a shadow mask such as a metal mask. Specifically, after forming a pixel electrode for each sub-pixel, a light-emitting layer is deposited across multiple pixel electrodes. Subsequently, the light-emitting layer is processed using photolithography to form one island-shaped light-emitting layer for each pixel electrode. This divides the light-emitting layer for each sub-pixel, allowing for the formation of an island-shaped light-emitting layer for each sub-pixel.

[0053] When processing the above-mentioned light-emitting layer into an island shape, a structure in which the processing is performed using photolithography directly above the light-emitting layer is conceivable. In this structure, the light-emitting layer may be damaged (e.g., damage from processing), and its reliability may be significantly impaired. Therefore, when manufacturing a display device according to one aspect of the present invention, it is preferable to use a method in which a mask layer (also called a sacrificial layer or protective layer) is formed on a layer located above the light-emitting layer (for example, a carrier transport layer or carrier injection layer, more specifically an electron transport layer or electron injection layer), and the light-emitting layer is processed into an island shape. By applying this method, a highly reliable display device can be provided. By having another layer between the light-emitting layer and the mask layer, it is possible to suppress the exposure of the light-emitting layer to the outermost surface during the manufacturing process of the display device and reduce the damage the light-emitting layer receives.

[0054] In this specification, the mask film and the mask layer are each located above at least the light-emitting layer (more specifically, the layer that is processed into an island shape among the layers constituting the EL layer) and have the function of protecting the light-emitting layer during the manufacturing process.

[0055] In light-emitting devices that emit light of different colors, it is not necessary to fabricate all the layers constituting the EL layer separately; some layers can be formed in the same process. Examples of the layers (also called functional layers) that make up the EL layer include the light-emitting layer, carrier injection layer (hole injection layer and electron injection layer), carrier transport layer (hole transport layer and electron transport layer), and carrier block layer (hole block layer and electron block layer). In a method for manufacturing a display device according to one aspect of the present invention, some of the layers constituting the EL layer are formed in island-like structures for each color, then at least a portion of the mask layer is removed, and the remaining layers constituting the EL layer (sometimes called common layers) and a common electrode (also called an upper electrode) are formed in common (as a single film) for each color of light-emitting device. For example, the carrier injection layer and the common electrode can be formed in common for each color of light-emitting device.

[0056] On the other hand, the carrier injection layer is often a relatively conductive layer within the EL layer. Therefore, there is a risk of short-circuiting the light-emitting device if the carrier injection layer comes into contact with the side surface of some of the island-shaped EL layers or the side surface of the pixel electrode. Furthermore, even when the carrier injection layer is provided in an island shape and a common electrode is formed in common for each color light-emitting device, there is a risk of short-circuiting the light-emitting device if the common electrode comes into contact with the side surface of the EL layer or the side surface of the pixel electrode.

[0057] Therefore, a display device according to one aspect of the present invention has an insulating layer that covers at least the sides of the island-shaped light-emitting layer. Furthermore, it is preferable that the insulating layer covers a portion of the upper surface of the island-shaped light-emitting layer.

[0058] This prevents at least a portion of the island-shaped EL layer and the pixel electrodes from coming into contact with the carrier injection layer or common electrode. Therefore, it is possible to suppress short circuits in the light-emitting device and improve the reliability of the light-emitting device.

[0059] In a cross-sectional view, it is preferable that the edges of the insulating layer have a tapered shape with a taper angle of less than 90°. This prevents step breaks in the common layer and common electrode provided on the insulating layer. Therefore, connection failures due to step breaks can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode due to the step, which would increase electrical resistance.

[0060] In this specification, "step breakage" refers to the phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (e.g., a step).

[0061] Thus, the island-shaped light-emitting layer produced by the method for manufacturing a display device according to one aspect of the present invention is not formed using a fine metal mask, but rather by processing after the light-emitting layer has been deposited on one surface. Therefore, it is possible to realize a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the light-emitting layer can be made separately for each color, it is possible to realize a display device that is extremely vivid, has high contrast, and has high display quality. In addition, by providing a mask layer on the light-emitting layer, the damage that the light-emitting layer receives during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0062] Furthermore, while it is difficult to reduce the spacing between adjacent light-emitting devices to less than 10 μm using, for example, a formation method employing a fine metal mask, according to one embodiment of the present invention, in a process on a glass substrate, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be narrowed to less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less. Moreover, by using, for example, an exposure apparatus for LSIs, in a process on a Si Wafer, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes can be narrowed to, for example, 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting devices, making it possible to bring the aperture ratio closer to 100%. For example, in a display device according to one aspect of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, while achieving less than 100%.

[0063] Furthermore, increasing the aperture ratio of a display device can improve its reliability. More specifically, using an organic EL device, if the lifespan of a display device with an aperture ratio of 10% is used as a baseline, the lifespan of a display device with an aperture ratio of 20% (i.e., twice the aperture ratio of the baseline) is approximately 3.25 times longer, and the lifespan of a display device with an aperture ratio of 40% (i.e., four times the aperture ratio of the baseline) is approximately 10.6 times longer. Thus, as the aperture ratio is increased, the current density flowing through the organic EL device can be reduced, making it possible to improve the lifespan of the display device. In one embodiment of the present invention, since the aperture ratio can be increased, the display quality of the display device can be improved. Moreover, as the aperture ratio of the display device is increased, the reliability (especially the lifespan) of the display device is significantly improved, which is a great effect.

[0064] Furthermore, the pattern of the light-emitting layer itself (which can also be called the processing size) can be made extremely small compared to when using a fine metal mask. Also, for example, when a metal mask is used to create different types of light-emitting layers, variations in thickness occur between the center and edges of the light-emitting layer, so the effective area that can be used as a light-emitting region is small relative to the area of ​​the light-emitting layer. On the other hand, with the above manufacturing method, since a film deposited to a uniform thickness is processed, island-shaped light-emitting layers can be formed with a uniform thickness. Therefore, even with a fine pattern, almost the entire area can be used as a light-emitting region. As a result, it is possible to manufacture a display device that combines high resolution and a high aperture ratio. In addition, it is possible to achieve miniaturization and weight reduction of the display device.

[0065] Specifically, a display device according to one aspect of the present invention may have a resolution of, for example, 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and may be 20000 ppi or less, or 30000 ppi or less.

[0066] In this embodiment, the cross-sectional structure of the display device according to one aspect of the present invention will be mainly described, and the method for manufacturing the display device according to one aspect of the present invention will be described in detail in Embodiment 2.

[0067] Figure 1A shows a top view of the display device 100. The display device 100 has a display unit on which a plurality of pixels 110 are arranged, and a connection unit 140 on the outside of the display unit. Multiple subpixels are arranged in a matrix on the display unit. In Figure 1A, subpixels in 2 rows and 6 columns are shown, and these constitute a 2 row and 2 column pixel. The connection unit 140 can also be called the cathode contact unit.

[0068] The top surface shape of the subpixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region. In this specification, the term "top surface shape" refers to the shape in a plan view, that is, the shape viewed from above.

[0069] The top surface shape of the subpixel may include, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0070] Furthermore, the circuit layout constituting the subpixel is not limited to the subpixel range shown in Figure 1A, but may be located outside of it. For example, the transistors in subpixel 110a may be located within the range of subpixel 110b shown in Figure 1A, or some or all of them may be located outside the range of subpixel 110a.

[0071] In Figure 1A, the aperture ratios (size, also known as the size of the light-emitting area) of the sub-pixels 110a, 110b, and 110c are shown to be equal or approximately equal, but one aspect of the present invention is not limited thereto. The aperture ratios of the sub-pixels 110a, 110b, and 110c can be determined as appropriate. The aperture ratios of the sub-pixels 110a, 110b, and 110c may be different, or two or more may be equal or approximately equal.

[0072] The pixel 110 shown in Figure 1A has a stripe arrangement applied to it. The pixel 110 shown in Figure 1A is composed of three subpixels: subpixels 110a, 110b, and 110c. Each of the subpixels 110a, 110b, and 110c has a light-emitting device that emits light of a different color. Examples of subpixels 110a, 110b, and 110c include subpixels of three colors: red (R), green (G), and blue (B); and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). Furthermore, the number of subpixel types is not limited to three, and there may be four or more. Examples of four subpixels include subpixels of four colors: R, G, B, and white (W); subpixels of four colors: R, G, B, and Y; and subpixels of four colors: R, G, B, and infrared (IR).

[0073] In this specification, the row direction is sometimes referred to as the X direction, and the column direction as the Y direction. The X and Y directions intersect, for example, perpendicularly (see Figure 1A). Figure 1A shows an example where subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction.

[0074] Figure 1A shows an example where the connecting portion 140 is located below the display portion in a top view, but the position of the connecting portion 140 is not particularly limited. The connecting portion 140 only needs to be provided at least one location on the top, right, left, or bottom of the display portion in a top view, and may be provided so as to surround all four sides of the display portion. The top shape of the connecting portion 140 can be a strip, L-shape, U-shape, or frame shape, etc. Also, there may be one or more connecting portions 140.

[0075] Figure 1B shows a cross-sectional view between the dashed lines X1 and X2 in Figure 1A. Figures 2A and 2B show enlarged views of a portion of the cross-sectional view shown in Figure 1B. Figures 3 to 6 show modified examples of Figure 2. Figures 7A and 7B show a cross-sectional view between the dashed lines Y1 and Y2 in Figure 1A.

[0076] As shown in Figure 1B, the display device 100 has an insulating layer on a layer 101 containing transistors, light-emitting devices 130a, 130b, and 130c on the insulating layer, and a protective layer 131 covering these light-emitting devices. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices.

[0077] In Figure 1B, multiple cross-sections of the insulating layer 125 and insulating layer 127 are shown, but when the display device 100 is viewed from above, the insulating layer 125 and insulating layer 127 are connected as one unit each. In other words, the display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. The display device 100 may also have multiple insulating layers 125 that are separated from each other, or multiple insulating layers 127 that are separated from each other.

[0078] A display device according to one aspect of the present invention may be a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting device is formed, a bottom-emission type that emits light toward the substrate on which the light-emitting device is formed, or a dual-emission type that emits light on both sides.

[0079] The layer 101 containing the transistors can, for example, be a laminated structure in which multiple transistors are provided on a substrate and insulating layers are provided to cover these transistors. The insulating layers on the transistors may be a single layer or a laminated structure. Figure 1B shows insulating layer 255a, insulating layer 255b on insulating layer 255a, and insulating layer 255c on insulating layer 255b, which are insulating layers on the transistors. These insulating layers may have recesses between adjacent light-emitting devices. Figure 1B and others show an example in which insulating layer 255c has a recess. Note that the insulating layers on the transistors (insulating layers 255a to insulating layers 255c) may also be considered as part of the layer 101 containing the transistors.

[0080] Various inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride-oxide insulating films can be suitably used as insulating layers 255a, 255b, and 255c, respectively. For insulating layers 255a and 255c, it is preferable to use oxide insulating films or oxidative nitride insulating films such as silicon oxide films, silicon oxidative nitride films, and aluminum oxide films, respectively. For insulating layer 255b, it is preferable to use nitride insulating films or nitride-oxide insulating films such as silicon nitride films and silicon nitride-oxide films. More specifically, it is preferable to use silicon oxide films as insulating layers 255a and 255c, and silicon nitride films as insulating layer 255b. It is preferable that insulating layer 255b has the function of an etching protective film.

[0081] In this specification, "oxide nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "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.

[0082] An example of the configuration of layer 101 including the transistor will be described later in Embodiment 4.

[0083] Each of the light-emitting devices 130a, 130b, and 130c emits light of a different color. Preferably, the light-emitting devices 130a, 130b, and 130c are a combination that emits, for example, red (R), green (G), and blue (B) light.

[0084] As the light-emitting device, it is preferable to use, for example, an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and thermally activated delayed fluorescence (TADF) materials. In addition, LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device.

[0085] The light-emitting device can emit light in the following colors: infrared, red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting device.

[0086] For details regarding the configuration and materials of the light-emitting device, refer to Embodiment 5.

[0087] In a light-emitting device, one electrode functions as the anode and the other as the cathode. In the following explanation, we may use the example where the pixel electrode functions as the anode and the common electrode functions as the cathode.

[0088] The light-emitting device 130a includes a pixel electrode 111a on an insulating layer 255c, an island-shaped first layer 113a on the pixel electrode 111a, a common layer 114 on the island-shaped first layer 113a, and a common electrode 115 on the common layer 114. In the light-emitting device 130a, the first layer 113a and the common layer 114 can be collectively referred to as the EL layer.

[0089] The light-emitting device 130b includes a pixel electrode 111b on an insulating layer 255c, an island-shaped second layer 113b on the pixel electrode 111b, a common layer 114 on the island-shaped second layer 113b, and a common electrode 115 on the common layer 114. In the light-emitting device 130b, the second layer 113b and the common layer 114 can be collectively referred to as the EL layer.

[0090] The light-emitting device 130c includes a pixel electrode 111c on an insulating layer 255c, an island-shaped third layer 113c on the pixel electrode 111c, a common layer 114 on the island-shaped third layer 113c, and a common electrode 115 on the common layer 114. In the light-emitting device 130c, the third layer 113c and the common layer 114 can be collectively referred to as the EL layer.

[0091] In this specification, among the EL layers of a light-emitting device, layers provided in an island-like manner for each light-emitting device are referred to as the first layer 113a, the second layer 113b, or the third layer 113c, and a layer shared by multiple light-emitting devices is referred to as the common layer 114. In this specification, the common layer 114 may also be omitted, and the first layer 113a, the second layer 113b, and the third layer 113c may be referred to as island-like EL layers, island-shaped EL layers, etc.

[0092] The first layer 113a, the second layer 113b, and the third layer 113c are separated from each other. By providing the EL layer in an island-like configuration for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness.

[0093] It is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape. Specifically, it is preferable that the ends of each of the pixel electrodes 111a, 111b, and 111c have a tapered shape with a taper angle of less than 90°. When the ends of these pixel electrodes have a tapered shape, the first layer 113a, the second layer 113b, and the third layer 113c provided along the side surface of the pixel electrode also have a tapered shape (corresponding to the inclined portion described later). By making the side surface of the pixel electrode tapered, the coverage of the EL layer provided along the side surface of the pixel electrode can be improved. Furthermore, by making the side surface of the pixel electrode tapered, it becomes easier to remove foreign matter (for example, dust or particles) during the manufacturing process by washing or other processes, which is preferable.

[0094] In Figure 1B, there is no insulating layer covering the upper edge of the pixel electrode 111a between the pixel electrode 111a and the first layer 113a. Similarly, there is no insulating layer covering the upper edge of the pixel electrode 111b between the pixel electrode 111b and the second layer 113b. As a result, the spacing between adjacent light-emitting devices can be made extremely narrow. Consequently, a high-definition or high-resolution display device can be produced. Furthermore, a mask for forming the insulating layer becomes unnecessary, reducing the manufacturing cost of the display device.

[0095] Furthermore, by not providing an insulating layer covering the edges of the pixel electrodes between the pixel electrodes and the EL layer, in other words, by not providing an insulating layer between the pixel electrodes and the EL layer, the light emitted from the EL layer can be efficiently extracted. Therefore, a display device according to one aspect of the present invention can have extremely low viewing angle dependence. By reducing viewing angle dependence, the visibility of images in the display device can be improved. For example, in a display device according to one aspect of the present invention, the viewing angle (the maximum angle at which a constant contrast ratio is maintained when viewing the screen from an oblique direction) can be set to a range of 100° or more and less than 180°, preferably 150° or more and 170° or less. The above viewing angle can be applied to both vertical and horizontal directions.

[0096] The light-emitting device of this embodiment may be a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0097] The first layer 113a, the second layer 113b, and the third layer 113c each have at least an emissive layer. For example, it is preferable that the first layer 113a has an emissive layer that emits red light, the second layer 113b has an emissive layer that emits green light, and the third layer 113c has an emissive layer that emits blue light.

[0098] Furthermore, when using a tandem light-emitting device, it is preferable that the first layer 113a has a structure having multiple light-emitting units that emit red light, the second layer 113b has a structure having multiple light-emitting units that emit green light, and the third layer 113c has a structure having multiple light-emitting units that emit blue light. It is preferable to provide a charge generation layer between each light-emitting unit.

[0099] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0100] For example, the first layer 113a, the second layer 113b, and the third layer 113c may have a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer in that order. Alternatively, an electron blocking layer may be present between the hole transport layer and the emissive layer. Furthermore, an electron injection layer may be present on the electron transport layer.

[0101] Furthermore, for example, the first layer 113a, the second layer 113b, and the third layer 113c may have an electron injection layer, an electron transport layer, an emissive layer, and a hole transport layer in that order. A hole blocking layer may also be present between the electron transport layer and the emissive layer. Additionally, a hole injection layer may be present on the hole transport layer.

[0102] Preferably, the first layer 113a, the second layer 113b, and the third layer 113c each have an emissive layer and a carrier transport layer (electron transport layer or hole transport layer) on the emissive layer. Since the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are exposed during the manufacturing process of the display device, providing the carrier transport layer on the emissive layer suppresses exposure of the emissive layer to the outermost surface, thereby reducing damage to the emissive layer. This improves the reliability of the light-emitting device.

[0103] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c are, for example, stacked on a pixel electrode in the order of a first light-emitting unit, a charge-generating layer, and a second light-emitting unit.

[0104] The second light-emitting unit preferably includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, providing the carrier transport layer on the light-emitting layer suppresses the exposure of the light-emitting layer to the outermost surface, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device. If there are three or more light-emitting units, it is preferable that the uppermost light-emitting unit includes a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer.

[0105] The common layer 114 may have, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may have an electron transport layer and an electron injection layer stacked together, or a hole transport layer and a hole injection layer stacked together. The common layer 114 is shared by the light-emitting devices 130a, 130b, and 130c.

[0106] Figure 1B shows an example where the edge of the first layer 113a is located outside the edge of the pixel electrode 111a. Although the pixel electrode 111a and the first layer 113a are used as examples, the same applies to the pixel electrode 111b and the second layer 113b, and the pixel electrode 111c and the third layer 113c.

[0107] In Figure 1B, the first layer 113a is formed to cover the edge of the pixel electrode 111a. With this configuration, it becomes possible to make the entire upper surface of the pixel electrode an emitting region, and it becomes easier to increase the aperture ratio compared to a configuration in which the edge of the island-shaped EL layer is located inside the edge of the pixel electrode.

[0108] Furthermore, by covering the sides of the pixel electrodes with the EL layer, contact between the pixel electrodes and the common electrode 115 can be suppressed, thereby preventing short circuits in the light-emitting device. In addition, the distance between the light-emitting region of the EL layer (i.e., the region overlapping with the pixel electrodes) and the edge of the EL layer can be increased. Since the edge of the EL layer may be damaged during processing, using a region away from the edge of the EL layer as the light-emitting region can sometimes improve the reliability of the light-emitting device.

[0109] Furthermore, the common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115, which is shared by multiple light-emitting devices, is electrically connected to the conductive layer 123 provided in the connection portion 140 (see Figures 7A and 7B). It is preferable to use a conductive layer for the conductive layer 123 that is made of the same material and formed using the same process as the pixel electrodes 111a, 111b, and 111c.

[0110] In Figure 7A, a common layer 114 is provided on the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. The common layer 114 does not need to be provided at the connection part 140. In Figure 7B, the conductive layer 123 and the common electrode 115 are directly connected. For example, by using a mask to define the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the areas to be film-deposited by the common layer 114 and the common electrode 115 can be changed.

[0111] Furthermore, in Figure 1B, a mask layer 118a is located on the first layer 113a of the light-emitting device 130a, a mask layer 118b is located on the second layer 113b of the light-emitting device 130b, and a mask layer 118c is located on the third layer 113c of the light-emitting device 130c. Mask layer 118a is a portion of the mask layer that remained when the first layer 113a was processed and was in contact with the upper surface of the first layer 113a. Similarly, mask layer 118b is a portion of the mask layer that remained when the second layer 113b was formed, and mask layer 118c is a portion of the mask layer that remained when the third layer 113c was formed. Thus, in one embodiment of the present invention, a portion of the mask layer used to protect the EL layer may remain during its manufacture. Any two or all of the mask layers 118a to 118c may be made of the same material, or they may be made of different materials. In the following, mask layers 118a, 118b, and 118c may be collectively referred to as mask layer 118.

[0112] In Figure 1B, one end of the mask layer 118a is aligned with or approximately aligned with the end of the first layer 113a, and the other end of the mask layer 118a is located on the first layer 113a. Here, it is preferable that the other end of the mask layer 118a overlaps with the first layer 113a and the pixel electrode 111a. In this case, the other end of the mask layer 118a is more likely to be formed on a flat or approximately flat surface of the first layer 113a. The same applies to the mask layers 118b and 118c. The mask layer 118 remains between the upper surface of the island-shaped EL layer (first layer 113a, second layer 113b, or third layer 113c) and the insulating layer 125. The mask layer will be described in detail in Embodiment 2.

[0113] Furthermore, if the edges are aligned or roughly aligned, and the top surface shapes match or roughly match, then in a top view, at least a portion of the contours overlaps between the stacked layers. This includes, for example, cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case as well, the edges are said to be roughly aligned, or the top surface shapes roughly match.

[0114] Each side of the first layer 113a, the second layer 113b, and the third layer 113c is covered by the insulating layer 125. The insulating layer 127 overlaps with (or covers) each side of the first layer 113a, the second layer 113b, and the third layer 113c via the insulating layer 125.

[0115] Furthermore, a portion of the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c is covered by the mask layer 118. The insulating layer 125 and the insulating layer 127 overlap with a portion of the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c via the mask layer 118. Note that the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are not limited to the upper surfaces of the flat portions that overlap with the upper surfaces of the pixel electrodes, but may also include the upper surfaces of the inclined portions and flat portions (see region 103 in Figure 6A) located outside the upper surfaces of the pixel electrodes.

[0116] Since a portion of the upper surface and sides of the first layer 113a, the second layer 113b, and the third layer 113c are covered by at least one of the insulating layer 125, the insulating layer 127, and the mask layer 118, it is possible to suppress the common layer 114 (or common electrode 115) from coming into contact with the pixel electrodes 111a, 111b, 111c, the first layer 113a, the second layer 113b, and the third layer 113c, thereby suppressing short circuits in the light-emitting device. This improves the reliability of the light-emitting device.

[0117] In Figure 1B, the film thicknesses of the first layer 113a to the third layer 113c are all shown to be the same, but the present invention is not limited to this. The film thicknesses of the first layer 113a to the third layer 113c may be different. For example, it is preferable to set the film thickness to correspond to the optical path length that intensifies the light emitted by each of the first layer 113a to the third layer 113c. This makes it possible to realize a microcavity structure and improve the color purity in each light-emitting device.

[0118] The insulating layer 125 is preferably in contact with the respective sides of the first layer 113a, the second layer 113b, and the third layer 113c (see the dashed lines at the edges of the first layer 113a and the second layer 113b and the surrounding areas shown in Figure 2A). By configuring the insulating layer 125 to be in contact with the first layer 113a, the second layer 113b, and the third layer 113c, peeling of the first layer 113a, the second layer 113b, and the third layer 113c can be prevented. The close contact between the insulating layer 125 and the first layer 113a, the second layer 113b, or the third layer 113c provides the effect of fixing or bonding adjacent first layers 113a, etc., to the insulating layer 125. This can improve the reliability of the light-emitting device. It can also improve the manufacturing yield of the light-emitting device.

[0119] Furthermore, as shown in Figure 1B, the insulating layers 125 and 127 cover both a portion of the top surface and the sides of the first layer 113a, the second layer 113b, and the third layer 113c, thereby further preventing delamination of the EL layer and improving the reliability of the light-emitting device. In addition, the manufacturing yield of the light-emitting device can be further improved.

[0120] Figure 1B shows an example where a stacked structure of the first layer 113a, mask layer 118a, insulating layer 125, and insulating layer 127 is located on the end of the pixel electrode 111a. Similarly, a stacked structure of the second layer 113b, mask layer 118b, insulating layer 125, and insulating layer 127 is located on the end of the pixel electrode 111b, and a stacked structure of the third layer 113c, mask layer 118c, insulating layer 125, and insulating layer 127 is located on the end of the pixel electrode 111c.

[0121] Figure 1B shows a configuration in which the end of the pixel electrode 111a is covered by the first layer 113a, and the insulating layer 125 is in contact with the side surface of the first layer 113a. Similarly, the end of the pixel electrode 111b is covered by the second layer 113b, and the end of the pixel electrode 111c is covered by the third layer 113c, with the insulating layer 125 in contact with the side surface of the second layer 113b and the side surface of the third layer 113c.

[0122] The insulating layer 127 is provided on the insulating layer 125 so as to fill the recesses of the insulating layer 125. The insulating layer 127 can be configured to overlap with a portion of the upper surface and side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, respectively, via the insulating layer 125. Preferably, the insulating layer 127 covers at least a portion of the side surfaces of the insulating layer 125.

[0123] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing the large height differences and irregularities on the surface of layers formed on the island-shaped layers (e.g., carrier injection layers and common electrodes), making them flatter. Consequently, the coverage of the carrier injection layers and common electrodes can be improved.

[0124] The common layer 114 and common electrode 115 are provided on the first layer 113a, the second layer 113b, the third layer 113c, the mask layer 118, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step difference occurs due to the region where the pixel electrode and island-shaped EL layer are provided and the region where the pixel electrode and island-shaped EL layer are not provided (the region between light-emitting devices). In one embodiment of the present invention, the presence of the insulating layer 125 and the insulating layer 127 can flatten this step difference and improve the coverage of the common layer 114 and the common electrode 115. Therefore, connection failures due to step breaks can be suppressed. In addition, it is possible to suppress the local thinning of the common electrode 115 due to the step difference, which would increase its electrical resistance.

[0125] The upper surface of the insulating layer 127 preferably has a shape that is highly flat, but it may also have convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, the upper surface of the insulating layer 127 preferably has a highly flat, smooth convex curved surface shape.

[0126] Next, we will describe examples of materials for the insulating layer 125 and the insulating layer 127.

[0127] 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 film and aluminum nitride film. In particular, aluminum oxide is preferred because it has a high selectivity ratio with the EL layer during etching and has the function of protecting the EL layer during the formation of the insulating layer 127, which will be described later. In particular, by applying an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by atomic layer deposition (ALD) to the insulating layer 125, an insulating layer 125 with fewer pinholes and excellent protection for the EL layer can be formed. Alternatively, the insulating layer 125 may have a laminated structure of a film formed by ALD and a film formed by sputtering. For example, the insulating layer 125 may have a laminated structure of an aluminum oxide film formed by ALD and a silicon nitride film formed by sputtering.

[0128] Preferably, the insulating layer 125 functions as a barrier insulating layer against at least one of water and oxygen. Furthermore, preferably, the insulating layer 125 has the function of suppressing the diffusion of at least one of water and oxygen. Also, preferably, the insulating layer 125 has the function of capturing or fixing (also known as gettering) at least one of water and oxygen.

[0129] In this specification, the term "barrier insulating layer" refers to an insulating layer that has barrier properties. Furthermore, in this specification, "barrier properties" refers to a function that suppresses the diffusion of the corresponding substance (also known as low permeability), or a function that captures or fixes the corresponding substance (also known as gettering).

[0130] The insulating layer 125 has the function of a barrier insulating layer or a gettering function, thereby suppressing the intrusion of impurities (typically at least one of water and oxygen) that could diffuse from the outside into each light-emitting device. This configuration makes it possible to provide a highly reliable light-emitting device, and furthermore, a highly reliable display device.

[0131] Furthermore, it is preferable that the insulating layer 125 has a low impurity concentration. This prevents impurities from mixing from the insulating layer 125 into the EL layer and degrading the EL layer. Also, by lowering the impurity concentration in the insulating layer 125, the barrier properties against at least one of water and oxygen can be improved. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration and a sufficiently low carbon concentration, preferably both.

[0132] Furthermore, the same material can be used for the insulating layer 125 and the mask layers 118a, 118b, and 118c. In this case, the boundary between any of the mask layers 118a, 118b, and 118c and the insulating layer 125 may become unclear and indistinguishable. Therefore, the mask layer 118a, 118b, and 118c and the insulating layer 125 may be identified as a single layer. In other words, one layer may be provided in contact with a portion of the upper surface and side surface of the first layer 113a, the second layer 113b, and the third layer 113c, and the insulating layer 127 may be observed to cover at least a portion of the side surface of the said single layer.

[0133] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the large height differences and irregularities in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the presence of the insulating layer 127 improves the flatness of the surface forming the common electrode 115.

[0134] As the insulating layer 127, an insulating layer having an organic material can be suitably used. Preferably, a photosensitive organic resin is used as the organic material; for example, a photosensitive acrylic resin is preferred. In this specification, the term "acrylic resin" does not refer only to polymethacrylate esters or methacrylic resins, but may refer to acrylic polymers in a broad sense.

[0135] Furthermore, as the insulating layer 127, 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 may be used. Alternatively, as the insulating layer 127, 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. Additionally, a photoresist may be used as the photosensitive resin. Either a positive-type or negative-type material may be used as the photosensitive organic resin.

[0136] The insulating layer 127 may be made of a material that absorbs visible light. By absorbing the light emitted from the light-emitting device, the insulating layer 127 can suppress light leakage (stray light) from the light-emitting device to adjacent light-emitting devices through the insulating layer 127. This improves the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner.

[0137] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used as color filters (color filter materials). In particular, it is preferable to use a resin material which is made by laminating or mixing two or more color filter materials, as this can enhance the visible light shielding effect. In particular, by mixing three or more color filter materials, it is possible to create a black or near-black resin layer.

[0138] Furthermore, it is preferable that the material used for the insulating layer 127 has a low volume shrinkage rate. This makes it easier to form the insulating layer 127 in a desired shape. It is also preferable that the insulating layer 127 has a low volume shrinkage rate after curing. This makes it easier to maintain the shape of the insulating layer 127 in various processes after its formation. Specifically, the volume shrinkage rate of the insulating layer 127 after heat curing, after photocuring, or after both photocuring and heat curing is preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less. Here, the volume shrinkage rate can be the value of either the volume shrinkage rate due to light irradiation or the volume shrinkage rate due to heating, or the sum of both.

[0139] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 2A and 2B. Figure 2A is an enlarged cross-sectional view of the region including the insulating layer 127 and its surroundings between light-emitting devices 130a and 130b. In the following description, the insulating layer 127 between light-emitting devices 130a and 130b will be used as an example, but the same applies to the insulating layer 127 between light-emitting devices 130b and 130c, and the insulating layer 127 between light-emitting devices 130c and 130a, etc. Figure 2B is an enlarged view of the edge of the insulating layer 127 on the second layer 113b and its vicinity, as shown in Figure 2A. In the following description, the edge of the insulating layer 127 on the second layer 113b will be used as an example, but the same applies to the edge of the insulating layer 127 on the first layer 113a, and the edge of the insulating layer 127 on the third layer 113c, etc.

[0140] As shown in Figure 2A, a first layer 113a is provided covering the pixel electrode 111a, and a second layer 113b is provided covering the pixel electrode 111b. A mask layer 118a is provided in contact with a part of the upper surface of the first layer 113a, and a mask layer 118b is provided in contact with a part of the upper surface of the second layer 113b. An insulating layer 125 is provided in contact with the upper and side surfaces of the mask layer 118a, the side surfaces of the first layer 113a, the upper surface of the insulating layer 255c, the upper and side surfaces of the mask layer 118b, and the side surfaces of the second layer 113b. The insulating layer 125 also covers a part of the upper surface of the first layer 113a and a part of the upper surface of the second layer 113b. An insulating layer 127 is provided in contact with the upper surface of the insulating layer 125. Furthermore, the insulating layer 127 overlaps with a portion of the upper surface and side surface of the first layer 113a, and a portion of the upper surface and side surface of the second layer 113b, via the insulating layer 125, and is in contact with at least a portion of the side surface of the insulating layer 125. A common layer 114 is provided covering the first layer 113a, the mask layer 118a, the second layer 113b, the mask layer 118b, the insulating layer 125, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0141] As shown in Figure 2B, the insulating layer 127 preferably has a tapered shape with a taper angle θ1 at its end in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface of the insulating layer 127 and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of the second layer 113b, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface of the insulating layer 127.

[0142] The taper angle θ1 of the insulating layer 127 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By making the edges of the insulating layer 127 have such a forward taper shape, the common layer 114 and common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of step breaks or localized thinning can be suppressed. As a result, the in-plane uniformity of the common layer 114 and common electrode 115 can be improved, and the display quality of the display device can be improved.

[0143] Furthermore, as shown in Figure 2A, in a cross-sectional view of the display device, it is preferable that the upper surface of the insulating layer 127 has a convex curved shape. It is preferable that the convex curved shape of the upper surface of the insulating layer 127 is a shape that bulges gently towards the center. It is also preferable that the convex curved portion at the center of the upper surface of the insulating layer 127 is smoothly connected to the tapered portion at the end. By making the insulating layer 127 such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0144] As shown in Figure 2B, it is preferable that the edge of the insulating layer 127 is located outside the edge of the insulating layer 125. This reduces the surface irregularities forming the common layer 114 and the common electrode 115, thereby improving the coverage of the common layer 114 and the common electrode 115.

[0145] As shown in Figure 2B, the insulating layer 125 preferably has a tapered shape with a taper angle θ2 at its end in a cross-sectional view of the display device. The taper angle θ2 is the angle between the side surface of the insulating layer 125 and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of the second layer 113b, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface of the insulating layer 125.

[0146] The taper angle θ2 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less.

[0147] The mask layer 118b preferably has a tapered shape with a taper angle θ3 at its end in a cross-sectional view of the display device, as shown in Figure 2B. The taper angle θ3 is the angle between the side surface of the mask layer 118b and the substrate surface. However, it is not limited to the substrate surface; it may also be the angle between the upper surface of the flat portion of the second layer 113b, or the upper surface of the flat portion of the pixel electrode 111b, and the side surface of the insulating layer 127.

[0148] The taper angle θ3 of the mask layer 118b is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By making the mask layer 118b such a forward taper shape, the common layer 114 and the common electrode 115 provided on the mask layer 118b can be formed with good coverage.

[0149] It is preferable that the edges of the mask layer 118a and the edges of the mask layer 118b are located outside the edges of the insulating layer 125. This reduces the surface irregularities forming the common layer 114 and the common electrode 115, thereby improving the coverage of the common layer 114 and the common electrode 115.

[0150] As will be detailed in Embodiment 2, if the etching process of the insulating layer 125 and the mask layer 118 is performed at the same time, side etching may cause the insulating layer 125 and the mask layer below the edge of the insulating layer 127 to disappear, forming a cavity (which can also be called a hole). This cavity can cause unevenness on the surface forming the common layer 114 and the common electrode 115, making it easier for the common layer 114 and the common electrode 115 to break down. Therefore, by performing the etching process in two stages and performing a heat treatment between the two etching stages, even if a cavity is formed in the first etching stage, the insulating layer 127 can be deformed by the heat treatment and the cavity can be filled. In addition, since the second etching stage involves etching a thin film, the amount of side etching is reduced, making it less likely for a cavity to form, and even if a cavity is formed, it can be made extremely small. Therefore, it is possible to suppress the occurrence of unevenness on the surface forming the common layer 114 and the common electrode 115, and to suppress the breaking down of the common layer 114 and the common electrode 115. Because the etching process is performed twice, the taper angles θ2 and θ3 may be different angles. Alternatively, taper angles θ2 and θ3 may be the same angle. Furthermore, taper angles θ2 and θ3 may each be smaller than taper angle θ1.

[0151] The insulating layer 127 may cover at least a portion of the side surface of the mask layer 118a and at least a portion of the side surface of the mask layer 118b. For example, Figure 2B shows an example where the insulating layer 127 in contact with and covers the inclined surface located at the edge of the mask layer 118b formed by the first etching process, while the inclined surface located at the edge of the mask layer 118b formed by the second etching process is exposed. These two inclined surfaces can sometimes be distinguished by their different taper angles. Alternatively, there may be little difference in the taper angles of the side surfaces formed by the two etching processes, making them indistinguishable.

[0152] Furthermore, Figures 3A and 3B show examples in which the insulating layer 127 covers the entire side surface of the mask layer 118a and the entire side surface of the mask layer 118b. Specifically, in Figure 3B, the insulating layer 127 covers both of the two inclined surfaces in contact with each other. This is preferable because it can further reduce the unevenness of the surfaces forming the common layer 114 and the common electrode 115. Figure 3B shows an example in which the edge of the insulating layer 127 is located outside the edge of the mask layer 118b. The edge of the insulating layer 127 may be located inside the edge of the mask layer 118b, as shown in Figure 2B, and may be aligned with or approximately aligned with the edge of the mask layer 118b. Also, as shown in Figure 3B, the insulating layer 127 may be in contact with the second layer 113b.

[0153] Furthermore, if the edges are aligned or roughly aligned, and the top surface shapes match or roughly match, then in a top view, at least a portion of the contours overlaps between the stacked layers. This includes, for example, cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case as well, the edges are said to be roughly aligned, or the top surface shapes roughly match.

[0154] Furthermore, Figures 4A, 4B, 5A, and 5B show examples in which the insulating layer 127 has a concave curved shape (also called a constricted portion, recess, indentation, or depression) on its side surface. Depending on the material of the insulating layer 127 and the formation conditions (heating temperature, heating time, and heating atmosphere, etc.), a concave curved shape may be formed on the side surface of the insulating layer 127.

[0155] Figures 4A and 4B show examples where the insulating layer 127 covers a portion of the side surface of the mask layer 118b, leaving the rest of the side surface of the mask layer 118b exposed. Figures 5A and 5B show examples where the insulating layer 127 is in contact with and covers the entire side surface of the mask layer 118a and the entire side surface of the mask layer 118b.

[0156] In Figures 3 to 5, it is preferable that the taper angles θ1 to θ3 are within the above ranges.

[0157] Furthermore, as shown in Figures 2 to 5, it is preferable that one end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111a, and the other end of the insulating layer 127 overlaps with the upper surface of the pixel electrode 111b. With this structure, the end of the insulating layer 127 can be formed on the flat or substantially flat regions of the first layer 113a and the second layer 113b. Therefore, it becomes relatively easy to form the tapered shapes of the insulating layer 127, the insulating layer 125, and the mask layer 118. In addition, peeling of the pixel electrodes 111a, 111b, the first layer 113a, and the second layer 113b can be suppressed. On the other hand, the smaller the overlap between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device becomes, and the higher the aperture ratio can be, which is preferable.

[0158] Note that the insulating layer 127 does not have to overlap with the upper surface of the pixel electrode. As shown in Figure 6A, the insulating layer 127 may not overlap with the upper surface of the pixel electrode, with one end of the insulating layer 127 overlapping with the side surface of the pixel electrode 111a and the other end of the insulating layer 127 overlapping with the side surface of the pixel electrode 111b. Also, as shown in Figure 6B, the insulating layer 127 may not overlap with the pixel electrode and may be provided in the region sandwiched between the pixel electrode 111a and the pixel electrode 111b. In Figures 6A and 6B, part or all of the upper surfaces of the inclined portion and flat portion (region 103) located outside the upper surface of the pixel electrode, among the upper surfaces of the first layer 113a and the second layer 113b, are covered by the mask layer 118, the insulating layer 125, and the insulating layer 127. Even with this configuration, compared to a configuration without the mask layer 118, insulating layer 125, and insulating layer 127, the surface irregularities forming the common layer 114 and common electrode 115 can be reduced, and the coverage of the common layer 114 and common electrode 115 can be improved.

[0159] As described above, in each configuration shown in Figures 2 to 6, by providing insulating layer 127, insulating layer 125, mask layer 118a, and mask layer 118b, the common layer 114 and common electrode 115 can be formed with high coverage from the flat or approximately flat region of the first layer 113a to the flat or approximately flat region of the second layer 113b. This prevents the formation of divided areas in the common layer 114 and common electrode 115, as well as areas with locally thin film thickness. Therefore, it is possible to suppress connection failures caused by divided areas and increases in electrical resistance caused by locally thin film thickness in the common layer 114 and common electrode 115 between each light-emitting device. As a result, the display device according to one aspect of the present invention can improve display quality.

[0160] It is preferable to have a protective layer 131 on the light-emitting devices 130a, 130b, and 130c. Providing the protective layer 131 can improve the reliability of the light-emitting devices. The protective layer 131 may be a single layer or a laminated structure of two or more layers.

[0161] The conductivity of the protective layer 131 is not required. The protective layer 131 can be at least one of an insulating film, a semiconductor film, and a conductive film.

[0162] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115, suppresses the intrusion of impurities (such as moisture and oxygen) into the light-emitting device, thereby suppressing degradation of the light-emitting device and improving the reliability of the display device.

[0163] For the protective layer 131, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidoxide-nitriding insulating films, and nitride-oxide insulating films can be used. Specific examples of these inorganic insulating films are given in the description of the insulating layer 125. In particular, the protective layer 131 preferably has a nitride insulating film or a nitride-oxide insulating film, and more preferably has a nitride insulating film.

[0164] Furthermore, the protective layer 131 may also be an inorganic film containing In-Sn oxide (also known as ITO), In-Zn oxide, Ga-Zn oxide, Al-Zn oxide, or indium gallium zinc oxide (In-Ga-Zn oxide, also known as IGZO). The inorganic film is preferably highly resistive, and more specifically, it is preferably more resistive than the common electrode 115. The inorganic film may further contain nitrogen.

[0165] When the light emitted from a light-emitting device is extracted via a protective layer 131, it is preferable that the protective layer 131 has high transmittance to visible light. For example, ITO, IGZO, and aluminum oxide are preferred because they are inorganic materials with high transmittance to visible light.

[0166] As the protective layer 131, for example, a laminated structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a laminated structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used. By using such a laminated structure, it is possible to suppress the penetration of impurities (water, oxygen, etc.) into the EL layer.

[0167] Furthermore, the protective layer 131 may have an organic film. For example, the protective layer 131 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 131 include organic insulating materials that can be used for the insulating layer 127.

[0168] The protective layer 131 may have a two-layer structure formed using different film deposition methods. Specifically, the first layer of the protective layer 131 may be formed using the ALD method, and the second layer of the protective layer 131 may be formed using the sputtering method.

[0169] A light-shielding layer may be provided on the side of the substrate 120 facing the resin layer 122. Various optical components can also be placed on the outside of the substrate 120. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-gathering films. Furthermore, surface protection layers such as an antistatic film to suppress dust adhesion, a water-repellent film to prevent dirt from adhering, a hard coat film to suppress scratches during use, and an impact-absorbing layer may be placed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO₂) may be used as the surface protection layer. x By providing a protective layer, surface contamination and scratching can be suppressed, which is preferable. Furthermore, as a surface protective layer, DLC (diamond-like carbon), aluminum oxide (AlO2) x ), polyester-based materials, or polycarbonate-based materials may be used. It is preferable to use a material with high transmittance to visible light for the surface protective layer. Furthermore, it is preferable to use a material with high hardness for the surface protective layer.

[0170] The substrate 120 can be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, etc. The substrate on the side that extracts light from the light-emitting device should be made of a material that transmits the light. If a flexible material is used for the substrate 120, the flexibility of the display device can be increased, and a flexible display can be realized. Alternatively, a polarizing plate may be used as the substrate 120.

[0171] As the substrate 120, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. may be used. Glass with a thickness sufficient to provide flexibility may also be used as the substrate 120.

[0172] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0173] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0174] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0175] Furthermore, when a film is used as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display device. Therefore, it is preferable to use a film with a low water absorption rate as the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0176] As the resin layer 122, various types of curing adhesives can be used, such as 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.

[0177] 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, for example, 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.

[0178] 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 as conductive layers for various wirings and electrodes that constitute a display device, and as conductive layers (conductive layers that function as pixel electrodes or counter electrodes) in light-emitting devices.

[0179] 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.

[0180] Figure 8A shows a top view of a display device 100 different from that shown in Figure 1A. The pixel 110 shown in Figure 8A is composed of four types of subpixels: subpixels 110a, 110b, 110c, and 110d.

[0181] The sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device that emits light of a different color. For example, sub-pixels 110a, 110b, 110c, and 110d can be a set of four sub-pixels with R, G, B, and W colors, a set of four sub-pixels with R, G, B, and Y colors, and a set of four sub-pixels with R, G, B, and IR colors.

[0182] Furthermore, a display device according to one aspect of the present invention may have a light-receiving device in each pixel.

[0183] Of the four subpixels of pixel 110 shown in Figure 8A, three may be configured to have light-emitting devices, and the remaining one may be configured to have a light-receiving device.

[0184] 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.

[0185] The light-receiving device can detect either visible light or infrared light, or both. When detecting visible light, it can detect one or more of the following colors, for example, blue, violet, blue-violet, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it enables the detection of objects even in dark places.

[0186] 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.

[0187] 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.

[0188] A light-receiving device can detect light incident on it, generate an electric charge, and extract it as an electric current by driving it with a reverse bias applied between the pixel electrode and the common electrode.

[0189] 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 using a fine metal mask, but rather by processing after depositing a film that will become the active layer onto one surface, thus enabling the formation of an island-shaped active layer with a uniform thickness. Furthermore, by providing a mask layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0190] For details regarding the configuration and materials of the light-receiving device, refer to Embodiment 6.

[0191] Figure 8B shows a cross-sectional view between the dashed lines X3 and X4 in Figure 8A. Note that the cross-sectional view between the dashed lines X1 and X2 in Figure 8A can be found in Figure 1B, and the cross-sectional view between the dashed lines Y1 and Y2 can be found in Figure 7A or Figure 7B.

[0192] As shown in Figure 8B, the display device 100 has an insulating layer on a layer 101 containing transistors, an insulating layer on the insulating layer on a light-emitting device 130a and a light-receiving device 150, a protective layer 131 covering the light-emitting device and the light-receiving device, and a substrate 120 bonded to it by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between adjacent light-emitting devices and light-receiving devices.

[0193] Figure 8B shows an example where the light-emitting device 130a emits light towards the substrate 120, and light is incident on the light-receiving device 150 from the substrate 120 side (see optical Lem and optical Lin).

[0194] The configuration of the light-emitting device 130a is as described above.

[0195] The light-receiving device 150 includes a pixel electrode 111d on an insulating layer 255c, a fourth layer 113d on the pixel electrode 111d, a common layer 114 on the fourth layer 113d, and a common electrode 115 on the common layer 114. The fourth layer 113d includes at least an active layer.

[0196] The fourth layer 113d is provided on the light-receiving device 150 but not on the light-emitting device. On the other hand, the common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0197] Here, layers common to both the light-receiving and light-emitting devices may have different functions in the light-emitting device and the light-receiving device. In this specification, components may be referred to based on their function in the light-emitting device. For example, a 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, an 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. Furthermore, layers common to both the light-receiving and light-emitting devices may have the same function in the light-emitting device and the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting and light-receiving devices, and an electron transport layer functions as an electron transport layer in both the light-emitting and light-receiving devices.

[0198] A mask layer 118a is located between the first layer 113a and the insulating layer 125, and a mask layer 118d is located between the fourth layer 113d and the insulating layer 125. Mask layer 118a is a portion of the mask layer that remained after processing the first layer 113a. Mask layer 118d is a portion of the mask layer that remained after processing the fourth layer 113d, which is a layer containing an active layer, by being in contact with the upper surface of the mask layer. Mask layers 118a and 118d may be made of the same material or different materials.

[0199] Figure 8A shows an example where the aperture ratio (size, also known as the size of the light-emitting or light-receiving area) of sub-pixel 110d is larger than that of sub-pixels 110a, 110b, and 110c, but the present invention is not limited to this. The aperture ratios of sub-pixels 110a, 110b, 110c, and 110d can be determined as appropriate. The aperture ratios of sub-pixels 110a, 110b, 110c, and 110d may be different, or two or more may be equal or approximately equal.

[0200] The sub-pixel 110d may have a higher aperture ratio than at least one of the sub-pixels 110a, 110b, and 110c. A larger light-receiving area for the sub-pixel 110d may make object detection easier. For example, depending on the resolution of the display device and the circuit configuration of the sub-pixels, the aperture ratio of the sub-pixel 110d may be higher than that of the other sub-pixels.

[0201] Furthermore, the aperture ratio of sub-pixel 110d may be lower than that of at least one of sub-pixels 110a, 110b, and 110c. A smaller light-receiving area for sub-pixel 110d results in a narrower imaging range, which suppresses blurring in the imaging result and improves resolution. Therefore, it is preferable to be able to perform high-definition or high-resolution imaging.

[0202] Thus, the sub-pixel 110d can be configured with a detection wavelength, resolution, and aperture ratio suitable for the application.

[0203] In one embodiment of the present invention, the display device has an EL layer arranged in an island shape for each light-emitting device, thereby suppressing the generation of leakage current between subpixels. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast. Furthermore, by providing an insulating layer with a tapered shape at the end between adjacent island-shaped EL layers, it is possible to suppress the occurrence of step breaks when forming a common electrode, and to prevent the formation of locally thin areas in the common electrode. This suppresses connection failures caused by separated areas and increases in electrical resistance caused by locally thin areas in the common layer and common electrode. As a result, the display device in one embodiment of the present invention can achieve both high resolution and high display quality.

[0204] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0205] (Embodiment 2) In this embodiment, a method for manufacturing a display device according to one aspect of the present invention will be explained with reference to Figures 9 to 14. Note that the explanation of the materials and formation methods of each element may be omitted if it is the same as that described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be explained in Embodiment 5.

[0206] Figures 9 to 13 show side-by-side cross-sectional views of the area between the dashed-dotted lines X1 and X2 shown in Figure 1A, and the area between the dashed-dotted lines Y1 and Y2. Figure 14 shows an enlarged view of the end of the insulating layer 127 and its vicinity.

[0207] Thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute display devices 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).

[0208] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by wet film deposition 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, or knife coating.

[0209] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet can be used to fabricate light-emitting devices. Examples of vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, as well as chemical vapor deposition (CVD). Functional layers included in the EL layer (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing methods (inkjet, screen printing, offset printing, flexographic printing, gravure, or microcontact printing, etc.).

[0210] Furthermore, when processing the thin film that constitutes the display device, photolithography or the like can be used. Alternatively, the thin film may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. In addition, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask.

[0211] 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 finally removing the resist mask. The other method involves depositing a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0212] 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 options include ultraviolet light, KrF laser light, or ArF laser light. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as an electron beam.

[0213] For etching thin films, methods such as dry etching, wet etching, and sandblasting can be used.

[0214] First, insulating layers 255a, 255b, and 255c are formed in this order on the layer 101 containing the transistor. Subsequently, pixel electrodes 111a, 111b, 111c and a conductive layer 123 are formed on the insulating layer 255c (Figure 9A). For the formation of the pixel electrodes, for example, sputtering or vacuum deposition can be used.

[0215] Next, it is preferable to perform a hydrophobic treatment on the pixel electrodes. By performing a hydrophobic treatment on the pixel electrodes, the adhesion between the pixel electrodes and the film (in this case, film 113A) formed in a later step can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0216] Hydrophobic treatment can be performed, for example, by fluorine modification of the pixel electrodes. Fluorine modification can be performed, for example, by treatment with a fluorine-containing gas or heat treatment, or by plasma treatment in a fluorine-containing gas atmosphere. As the fluorine-containing gas, for example, fluorine gas can be used, or for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, lower fluorinated carbon gases such as carbon tetrafluoride (CF4) gas, C4F6 gas, C2F6 gas, C4F8 gas, and C5F8 can be used. In addition, as the fluorine-containing gas, for example, SF6 gas, NF3 gas, CHF3 gas, etc. can be used. Furthermore, helium gas, argon gas, or hydrogen gas can be added to these gases as appropriate.

[0217] Furthermore, the surface of the pixel electrode can be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent. Hexamethyldisilazane (HMDS), trimethylsilylimidazole (TMSI), etc., can be used as silylation agents. In addition, the surface of the pixel electrode can also be made hydrophobic by performing plasma treatment in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silane coupling agent.

[0218] By performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a group 18 element such as argon, damage can be inflicted on the surface of the pixel electrode. This makes it easier for methyl groups contained in silylation agents such as HMDS to bond to the surface of the pixel electrode. Furthermore, silane coupling by silane coupling agents becomes more likely to occur. Thus, by performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a group 18 element such as argon, followed by treatment with a silylation agent or a silane coupling agent, the surface of the pixel electrode can be made hydrophobic.

[0219] Treatment using silylation agents or silane coupling agents can be carried out by applying the silylation agent or silane coupling agent using methods such as spin coating or dip coating. Alternatively, treatment using silylation agents or silane coupling agents can be carried out by forming a film containing a silylation agent or silane coupling agent on the pixel electrode, for example, using a gas-phase method. In the gas-phase method, first, the silylation agent or silane coupling agent is introduced into the atmosphere by volatilizing the material containing the silylation agent or silane coupling agent. Subsequently, the substrate on which the pixel electrode is formed is placed in this atmosphere. This allows a film containing a silylation agent or silane coupling agent to be formed on the pixel electrode, thereby hydrophobicizing the surface of the pixel electrode.

[0220] Next, a film 113A, which will later become the first layer 113a, is formed on the pixel electrode (Figure 9A).

[0221] As shown in Figure 9A, in the cross-sectional view between the dashed-dotted line Y1-Y2, no film 113A is formed on the conductive layer 123. For example, by using a mask to define the film deposition area (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), the film 113A can be deposited only in the desired area. By employing a film deposition process using an area mask and a processing process using a resist mask, a light-emitting device can be manufactured using a relatively simple process.

[0222] The film 113A can be formed, for example, by a vapor deposition method, specifically by a vacuum vapor deposition method. Alternatively, the film 113A may be formed by methods such as a transfer method, a printing method, an inkjet method, or a coating method.

[0223] Next, a mask film 118A, which will later become the mask layer 118a, and a mask film 119A, which will later become the mask layer 119a, are formed in order on film 113A and conductive layer 123, respectively (Figure 9A).

[0224] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure consisting of mask film 118A and mask film 119A. However, the mask film may also have a single-layer structure or a laminated structure of three or more layers.

[0225] By providing a mask layer on the film 113A, damage to the film 113A during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0226] For mask film 118A, a film with high resistance to the processing conditions of film 113A is used; specifically, a film with a high etching selectivity ratio with film 113A. For mask film 119A, a film with a high etching selectivity ratio with mask film 118A is used.

[0227] Furthermore, mask films 118A and 119A are formed at a temperature lower than the heat resistance temperature of film 113A. The substrate temperature when forming mask films 118A and 119A is typically 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0228] Indicators of heat resistance temperature include, for example, the glass transition temperature, softening temperature, melting point, thermal decomposition temperature, and 5% weight loss temperature. The heat resistance temperature of films 113A to 113C (i.e., the first layer 113a to the third layer 113c) can be any of these temperatures, preferably the lowest of these temperatures.

[0229] It is preferable to use mask films 118A and 119A that can be removed by a wet etching method. By using a wet etching method, the damage to film 113A during processing of mask films 118A and 119A can be reduced compared to when a dry etching method is used.

[0230] For the formation of mask films 118A and 119A, for example, sputtering, ALD (including thermal ALD and PEALD), CVD, and vacuum deposition can be used. Alternatively, they may be formed using the wet film formation method described above.

[0231] Furthermore, it is preferable that the mask film 118A, which is formed in contact with film 113A, is formed using a method that causes less damage to film 113A than the mask film 119A. For example, it is preferable to form the mask film 118A using the ALD method or vacuum deposition method rather than the sputtering method.

[0232] For the mask film 118A and the mask film 119A, one or more types can be used, for example, from among metal films, alloy films, metal oxide films, semiconductor films, organic insulating films, and inorganic insulating films.

[0233] Mask films 118A and 119A can be made from 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. In particular, it is preferable to use low-melting-point materials such as aluminum or silver. It is preferable to use a metallic material capable of shielding ultraviolet light in one or both of the mask films 118A and 119A, as this can suppress irradiation of film 113A with ultraviolet light and suppress the degradation of film 113A.

[0234] Furthermore, the mask films 118A and 119A can be made from metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and silicon-containing indium tin oxide, respectively.

[0235] In addition, element M (where M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used instead of gallium.

[0236] Furthermore, a film containing a material that has light-shielding properties against light, particularly ultraviolet light, can be used as the mask film. For example, a film that reflects ultraviolet light or a film that absorbs ultraviolet light can be used. Various materials can be used as the light-shielding material, such as metals, insulators, semiconductors, and metalloids that have light-shielding properties against ultraviolet light. However, since part or all of the mask film will be removed in a later process, it is preferable that the film be processable by etching, and in particular, that it has good processability.

[0237] For example, semiconductor materials such as silicon or germanium can be used as materials with high affinity to semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, nonmetallic (metalloid) materials such as carbon, or compounds thereof, can be used. Alternatively, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these, can be used. Alternatively, oxides containing the above metals such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0238] By using a mask film containing a material that has light-shielding properties against ultraviolet light, it is possible to suppress the irradiation of the EL layer with ultraviolet light during the exposure process. By suppressing damage to the EL layer from ultraviolet light, the reliability of the light-emitting device can be improved.

[0239] Furthermore, a film containing a material that has light-shielding properties against ultraviolet light can be used as the material for the insulating film 125A described later to achieve the same effect.

[0240] Furthermore, various inorganic insulating films that can be used in the protective layer 131 can be used as mask films 118A and 119A, respectively. In particular, oxide insulating films are preferred because they have higher adhesion to film 113A compared to nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as mask films 118A and 119A, respectively. For example, aluminum oxide films can be formed as mask films 118A and 119A using the ALD method. Using the ALD method is preferred because it reduces damage to the substrate (especially the EL layer).

[0241] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used as the mask film 118A, and an inorganic film (e.g., an In-Ga-Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method can be used as the mask film 119A.

[0242] Furthermore, the same inorganic insulating film can be used for both the mask film 118A and the insulating layer 125 that is formed later. For example, an aluminum oxide film formed using the ALD method can be used for both the mask film 118A and the insulating layer 125. Here, the same film formation conditions may be applied to the mask film 118A and the insulating layer 125, or different film formation conditions may be applied to each. For example, by forming the mask film 118A under the same conditions as the insulating layer 125, the mask film 118A can be made into an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, since the mask film 118A is a layer that will be mostly or completely removed in a later process, it is preferable that it be easy to process. Therefore, it is preferable to form the mask film 118A under conditions where the substrate temperature during film formation is lower than that of the insulating layer 125.

[0243] Organic materials may be used in one or both of the mask films 118A and 119A. For example, as the organic material, a material that is soluble in a chemically stable solvent for at least the uppermost film of film 113A may be used. Materials that are soluble in water or alcohol are particularly suitable. When forming such a film, it is preferable to apply the material by a wet film formation method while it is 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 film 113A.

[0244] Mask films 118A and 119A may each be made of organic resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or fluoropolymers.

[0245] For example, an organic film (e.g., a PVA film) formed using either a vapor deposition method or the wet film formation method described above can be used as the mask film 118A, and an inorganic film (e.g., a silicon nitride film) formed using a sputtering method can be used as the mask film 119A.

[0246] As described in Embodiment 1, in one embodiment of the present invention, a portion of the mask film may remain as a mask layer in the display device.

[0247] Next, a resist mask 190a is formed on the mask film 119A (Figure 9A). The resist mask 190a can be formed by applying a photosensitive resin (photoresist), followed by exposure and development.

[0248] The resist mask 190a may be made using either a positive-type resist material or a negative-type resist material.

[0249] The resist mask 190a is provided in a position that overlaps with the pixel electrode 111a. Preferably, the resist mask 190a is also provided in a position that overlaps with the conductive layer 123. This helps to suppress damage to the conductive layer 123 during the manufacturing process of the display device. Note that it is not necessary to provide the resist mask 190a on the conductive layer 123.

[0250] Furthermore, it is preferable that the resist mask 190a be provided so as to cover from the edge of the first layer 113a to the edge of the conductive layer 123 (the edge on the first layer 113a side), as shown in the cross-sectional view between Y1 and Y2 in Figure 9A. This ensures that even after processing the mask films 118A and 119A, the edges of the mask layers 118a and 119a overlap with the edge of the first layer 113a. Also, since the mask layers 118a and 119a are provided so as to cover from the edge of the first layer 113a to the edge of the conductive layer 123 (the edge on the first layer 113a side), exposure of the insulating layer 255c can be suppressed (see the cross-sectional view between Y1 and Y2 in Figure 9C). This prevents the insulating layers 255a to 255c and a portion of the insulating layer included in the layer 101 containing the transistor from being removed by etching or the like, and prevents the conductive layer included in the layer 101 containing the transistor from being exposed. Therefore, it is possible to suppress the unintentional electrical connection of the conductive layer with other conductive layers. For example, it is possible to suppress a short circuit between the conductive layer and the common electrode 115.

[0251] Next, a portion of the mask film 119A is removed using the resist mask 190a to form a mask layer 119a (Figure 9B). The mask layer 119a remains on the pixel electrode 111a and on the conductive layer 123. After that, the resist mask 190a is removed. Subsequently, the mask layer 119a is used as a mask (also called a hard mask) to remove a portion of the mask film 118A to form a mask layer 118a (Figure 9C).

[0252] Mask films 118A and 119A can be processed by wet etching or dry etching, respectively. It is preferable to process mask films 118A and 119A by anisotropic etching.

[0253] By using the wet etching method, the damage to film 113A during the processing of mask films 118A and 119A can be reduced compared to using the dry etching method. When using the wet etching method, it is preferable to use chemical solutions such as a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0254] In the processing of the mask film 119A, the film 113A is not exposed, so there is a wider range of processing methods to choose from compared to the processing of the mask film 118A. Specifically, when processing the mask film 119A, even if an oxygen-containing gas is used as the etching gas, the degradation of the film 113A can be further suppressed.

[0255] Furthermore, when using a dry etching method for processing the mask film 118A, the degradation of film 113A can be suppressed by not using an oxygen-containing gas as the etching gas. When using a dry etching method, it is preferable to use a gas containing noble gases (also called rare gases) such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He as the etching gas.

[0256] For example, when using an aluminum oxide film formed by the ALD method as the mask film 118A, the mask film 118A can be processed by dry etching using CHF3 and He, or CHF3, He, and CH4. Also, when using an In-Ga-Zn oxide film formed by the sputtering method as the mask film 119A, the mask film 119A can be processed by wet etching using diluted phosphoric acid. Alternatively, it may be processed by dry etching using CH4 and Ar. Alternatively, the mask film 119A can be processed by wet etching using diluted phosphoric acid. Furthermore, when using a tungsten film formed by the sputtering method as the mask film 119A, the mask film 119A can be processed by dry etching using SF6, CF4, and O2, or CF4, Cl2, and O2.

[0257] The resist mask 190a can be removed, for example, by ashing using oxygen plasma. Alternatively, oxygen gas and a noble gas such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He may be used. Alternatively, the resist mask 190a may be removed by wet etching. In this case, since the mask film 118A is located on the outermost surface and film 113A is not exposed, damage to film 113A can be suppressed during the resist mask 190a removal process. Furthermore, the range of selectable methods for removing the resist mask 190a can be broadened.

[0258] Next, the film 113A is processed to form the first layer 113a. For example, mask layers 119a and 118a are used as a hard mask to remove a portion of the film 113A and form the first layer 113a (Figure 9C).

[0259] As a result, as shown in Figure 9C, the stacked structure of the first layer 113a, the mask layer 118a, and the mask layer 119a remains on the pixel electrode 111a. The pixel electrodes 111b and 111c are exposed.

[0260] Figure 9C shows an example where the edge of the first layer 113a is located outside the edge of the pixel electrode 111a. This configuration allows for a higher aperture ratio of the pixels. Although not shown in Figure 9C, the etching process may result in the formation of recesses in the region of the insulating layer 255c that does not overlap with the first layer 113a.

[0261] Furthermore, since the first layer 113a covers the top and sides of the pixel electrode 111a, subsequent processes can be carried out without exposing the pixel electrode 111a. If the edges of the pixel electrode 111a are exposed, corrosion may occur during etching processes. Products generated by the corrosion of the pixel electrode 111a may be unstable; for example, in the case of wet etching, they may dissolve in the solution, and in the case of dry etching, there is a concern that they may scatter into the atmosphere. Dissolution of the products into the solution or scattering into the atmosphere may cause the products to adhere to the processed surface and the sides of the first layer 113a, for example, adversely affecting the characteristics of the light-emitting device or potentially forming a leak path between multiple light-emitting devices. In addition, in areas where the edges of the pixel electrode 111a are exposed, the adhesion between layers in contact with each other decreases, which may make the first layer 113a or the pixel electrode 111a more prone to peeling.

[0262] Therefore, by configuring the first layer 113a to cover the top and side surfaces of the pixel electrode 111a, for example, the yield and characteristics of the light-emitting device can be improved.

[0263] Furthermore, in the region corresponding to the connection portion 140, the laminated structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0264] As mentioned above, in the cross-sectional view between Y1 and Y2 in Figure 9C, the mask layers 118a and 119a are provided so as to cover the edges of the first layer 113a and the conductive layer 123, and the insulating layer 255c is not exposed. Therefore, it is possible to prevent the insulating layers 255a to 255c and a portion of the insulating layer included in the layer 101 containing the transistor from being removed by etching or the like, and to prevent the conductive layer included in the layer 101 containing the transistor from being exposed. As a result, it is possible to suppress the conductive layer from being unintentionally electrically connected to other conductive layers.

[0265] The film 113A is preferably processed by anisotropic etching. In particular, anisotropic dry etching is preferred. Alternatively, wet etching may be used.

[0266] When using the dry etching method, the degradation of film 113A can be suppressed by not using an etching gas that contains oxygen.

[0267] Furthermore, an etching gas containing oxygen may be used. Including oxygen in the etching gas can increase the etching rate. Therefore, etching can be performed under low power conditions while maintaining a sufficiently fast etching rate. This suppresses damage to the film 113A. Additionally, it suppresses problems such as the adhesion of reaction products generated during etching.

[0268] When using the dry etching method, it is preferable to use an etching gas containing one or more of the following noble gases: H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He, Ar. Alternatively, it is preferable to use an etching gas containing one or more of these and oxygen. Or, oxygen gas may be used as the etching gas. Specifically, for example, a gas containing H2 and Ar, or a gas containing CF4 and He, can be used as the etching gas. Also, for example, a gas containing CF4, He, and oxygen can be used as the etching gas. Furthermore, for example, a gas containing H2 and Ar, and a gas containing oxygen can be used as the etching gas.

[0269] As described above, in one aspect of the present invention, a resist mask 190a is formed on the mask film 119A, and a mask layer 119a is formed by removing a portion of the mask film 119A using the resist mask 190a. Subsequently, the first layer 113a is formed by removing a portion of the film 113A using the mask layer 119a as a hard mask. Thus, the first layer 113a can be formed by processing the film 113A using photolithography. Note that a portion of the film 113A may be removed using the resist mask 190a. Subsequently, the resist mask 190a may be removed.

[0270] Next, it is preferable to perform a hydrophobic treatment on the pixel electrodes. During the processing of film 113A, the surface state of the pixel electrodes may change to hydrophilic. By performing a hydrophobic treatment on the pixel electrodes, the adhesion between the pixel electrodes and the film (in this case, film 113B) formed in a later process can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0271] Next, a film 113B, which will later become the second layer 113b, is formed on the pixel electrodes 111b and 111c and on the mask layer 119a (Figure 10A).

[0272] The film 113B can be formed in the same manner as the method used to form film 113A.

[0273] Subsequently, a mask film 118B that will later become a mask layer 118b and a mask film 119B that will later become a mask layer 119b are successively formed on the film 113B, and then a resist mask 190b is formed (FIG. 10A). The materials and formation methods of the mask film 118B and the mask film 119B are the same as the conditions applicable to the mask film 118A and the mask film 119A. The materials and formation methods of the resist mask 190b are the same as the conditions applicable to the resist mask 190a.

[0274] The resist mask 190b is provided at a position overlapping with the pixel electrode 111b.

[0275] Subsequently, using the resist mask 190b, a part of the mask film 119B is removed to form a mask layer 119b. The mask layer 119b remains on the pixel electrode 111b. Then, the resist mask 190b is removed. Subsequently, using the mask layer 119b as a mask, a part of the mask film 118B is removed to form a mask layer 118b. Subsequently, the film 113B is processed to form a second layer 113b. For example, using the mask layer 119b and the mask layer 118b as hard masks, a part of the film 113B is removed to form the second layer 113b (FIG. 10B).

[0276] As a result, as shown in FIG. 10B, a laminated structure of the second layer 113b, the mask layer 118b, and the mask layer 119b remains on the pixel electrode 111b. Also, the mask layer 119a and the pixel electrode 111c are exposed.

[0277] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode. When processing the film 113B, the surface state of the pixel electrode may change to hydrophilic. By performing a hydrophobic treatment on the pixel electrode, the adhesion between the pixel electrode and a film (here, the film 113C) formed in a later process can be enhanced, and film peeling can be suppressed. Note that the hydrophobic treatment may not be performed. <00,00905>[[ID=2,1]] Subsequently, a film 113C that will later become a third layer 113c is formed on the pixel electrode 111c, on the mask layers 119a and 119b (FIG. 10B).

[0279] The film 113C can be formed by a method similar to the method used for forming the film 113A.

[0280] Subsequently, a mask film 118C that will later become the mask layer 118c and a mask film 119C that will later become the mask layer 119c are sequentially formed on the film 113C, and then a resist mask 190c is formed (FIG. 10B). The materials and formation methods of the mask film 118C and the mask film 119C are the same as the conditions applicable to the mask film 118A and the mask film 119A. The materials and formation methods of the resist mask 190c are the same as the conditions applicable to the resist mask 190a.

[0281] The resist mask 190c is provided at a position overlapping the pixel electrode 111c.

[0282] Subsequently, using the resist mask 190c, a part of the mask film 119C is removed to form the mask layer 119c. The mask layer 119c remains on the pixel electrode 111c. Then, the resist mask 190c is removed. Subsequently, using the mask layer 119c as a mask, a part of the mask film 118C is removed to form the mask layer 118c. Subsequently, the film 113C is processed to form the third layer 113c. For example, using the mask layer 119c and the mask layer 118c as hard masks, a part of the film 113C is removed to form the third layer 113c (FIG. 10C).

[0283] As a result, as shown in FIG. 10C, a stacked structure of the third layer 113c, the mask layer 118c, and the mask layer 119c remains on the pixel electrode 111c. Also, the mask layers 119a and 119b are exposed.

[0284] Note that the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are preferably perpendicular or substantially perpendicular to the formation surface, respectively. For example, it is preferable that the angle formed by the formation surface and these side surfaces is 60° or more and 90° or less.

[0285] As described above, the distance between two adjacent layers of the first layer 113a, second layer 113b, and third layer 113c formed using photolithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, this distance can be defined, for example, as the distance between two adjacent opposing ends of the first layer 113a, second layer 113b, and third layer 113c. By narrowing the distance between the island-shaped EL layers in this way, a display device with high resolution and a large aperture ratio can be provided.

[0286] Furthermore, as shown in Figures 8A and 8B, when manufacturing a display device having both a light-emitting device and a light-receiving device, the fourth layer 113d of the light-receiving device is formed in the same manner as the first to third layers 113a and 113c. The formation order of the first to fourth layers 113a and 113d is not particularly limited. For example, forming the layer with high adhesion to the pixel electrode first can suppress film peeling during the process. For example, if the first to third layers 113a and 113c have higher adhesion to the pixel electrode than the fourth layer 113d, it is preferable to form the first to third layers 113a and 113c first. Also, the thickness of the layer formed first may affect the spacing between the substrate and the mask used to define the film formation area in the subsequent layer formation process. By forming the thinner layer first, shadowing (formation of a layer in the shadowed area) can be suppressed. For example, when forming a tandem light-emitting device, the first to third layers 113a to 113c are often thicker than the fourth layer 113d, so it is preferable to form the fourth layer 113d first. Also, when forming a film using a polymer material by a wet process, it is preferable to form the film first. For example, when using a polymer material for the active layer, it is preferable to form the fourth layer 113d first. As described above, by determining the formation order according to the material and film formation method, the yield in the manufacture of the display device can be increased.

[0287] Next, it is preferable to remove the mask layers 119a, 119b, and 119c (Figure 11A). Depending on subsequent processes, the mask layers 118a, 118b, 118c, 119a, 119b, and 119c may remain in the display device. By removing the mask layers 119a, 119b, and 119c at this stage, it is possible to suppress the remaining mask layers 119a, 119b, and 119c in the display device. For example, if conductive material is used for the mask layers 119a, 119b, and 119c, removing the mask layers 119a, 119b, and 119c in advance can suppress the generation of leakage current and the formation of capacitance due to the remaining mask layers 119a, 119b, and 119c.

[0288] In this embodiment, the case where mask layers 119a, 119b, and 119c are removed is described as an example, but the mask layers 119a, 119b, and 119c do not need to be removed. For example, if the mask layers 119a, 119b, and 119c contain the aforementioned material that has light-shielding properties against ultraviolet light, it is preferable to proceed to the next step without removing them, as this protects the EL layer from ultraviolet light.

[0289] The same method as the mask layer processing method can be used for the mask layer removal process. In particular, by using a wet etching method, the damage inflicted on the first layer 113a, the second layer 113b, and the third layer 113c when removing the mask layer can be reduced compared to when using a dry etching method.

[0290] Alternatively, the mask layer may be removed by dissolving it in a solvent such as water or alcohol. Examples of alcohols include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0291] After removing the mask layer, a drying treatment may be performed to remove water contained in the first layer 113a, the second layer 113b, and the third layer 113c, as well as water adsorbed on the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. For example, a heat treatment can be performed in 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.

[0292] Next, an insulating film 125A, which will later become the insulating layer 125, is formed to cover the pixel electrode, the first layer 113a, the second layer 113b, the third layer 113c, the mask layer 118a, the mask layer 118b, and the mask layer 118c (Figure 11A). Subsequently, an insulating film 127a is formed on the insulating film 125A (Figure 11B).

[0293] It is preferable that the insulating film 125A and insulating film 127a are formed using a method that causes less damage to the first layer 113a, the second layer 113b, and the third layer 113c. In particular, since insulating film 125A is formed in contact with the sides of the first layer 113a, the second layer 113b, and the third layer 113c, it is preferable that it be formed using a method that causes less damage to the first layer 113a, the second layer 113b, and the third layer 113c than insulating film 127a.

[0294] Furthermore, insulating film 125A and insulating film 127a are formed at a temperature lower than the heat resistance temperature of the first layer 113a, the second layer 113b, and the third layer 113c, respectively. In addition, by increasing the substrate temperature during film formation of insulating film 125A, it is possible to create a film with a low impurity concentration and high barrier properties against at least one of water and oxygen, even with a thin film thickness.

[0295] When forming the insulating film 125A and the insulating film 127a, the substrate temperature is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0296] As the insulating film 125A, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above range of the substrate temperature.

[0297] The insulating film 125A is preferably formed, for example, by using the ALD method. By using the ALD method, film formation damage can be reduced, and a film with high coverage can be formed, which is preferable. As the insulating film 125A, it is preferable to form an aluminum oxide film, for example, by using the ALD method.

[0298] In addition, the insulating film 125A may be formed by using a sputtering method, a CVD method, or a PECVD method, which has a higher film formation rate than the ALD method. Thereby, a highly reliable display device can be manufactured with high productivity.

[0299] The insulating film 127a is preferably formed by using the above-described wet film formation method. The insulating film 127a is preferably formed, for example, by spin coating using a photosensitive resin, and more specifically, by using a photosensitive acrylic resin.

[0300] In addition, it is preferable to perform a heat treatment (also referred to as pre-baking) after forming the insulating film 127a. The heat treatment is performed at a temperature lower than the heat resistance temperature of the first layer 113a, the second layer 113b, and the third layer 113c. As the substrate temperature during the heat treatment, 50°C or higher and 200°C or lower is preferable, 60°C or higher and 150°C or lower is more preferable, and 70°C or higher and 120°C or lower is even more preferable. Thereby, the solvent contained in the insulating film 127a can be removed.

[0301] Next, as shown in Figure 11C, exposure is performed to expose a portion of the insulating film 127a to visible light or ultraviolet light. Here, if a positive-type acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated using a mask in the area where the insulating layer 127 will not be formed in a later step. The insulating layer 127 is formed in the area sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and around the conductive layer 123. Therefore, as shown in Figure 11C, visible light or ultraviolet light is irradiated using a mask onto the pixel electrode 111a, the pixel electrode 111b, the pixel electrode 111c, and the conductive layer 123.

[0302] Furthermore, the width of the insulating layer 127 to be formed later can be controlled by the area exposed to light at this stage. In this embodiment, the insulating layer 127 is processed so that it has a portion that overlaps with the upper surface of the pixel electrode (Figures 2A and 2B). As shown in Figure 6A or Figure 6B, the insulating layer 127 does not have to have a portion that overlaps with the upper surface of the pixel electrode.

[0303] The light used for exposure preferably includes the i-line (wavelength 365 nm). Furthermore, the light used for exposure may also include at least one of the g-line (wavelength 436 nm) and the h-line (wavelength 405 nm).

[0304] In Figure 11C, an example is shown in which a positive-type photosensitive resin is used for the insulating film 127a and visible light or ultraviolet light is irradiated into the area where the insulating layer 127 is not formed. However, the present invention is not limited to this. For example, a negative-type photosensitive resin may be used for the insulating film 127a. In this case, visible light or ultraviolet light is irradiated into the area where the insulating layer 127 is formed.

[0305] Next, as shown in Figures 12A and 14A, development is performed to remove the exposed area of ​​the insulating film 127a and form the insulating layer 127b. Figure 14A is an enlarged view of the second layer 113b shown in Figure 12A and the edge and vicinity of the insulating layer 127b. The insulating layer 127b is formed in the region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and in the region surrounding the conductive layer 123. When acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0306] Next, the residue (so-called scum) from the development process may be removed. For example, the residue can be removed by ashing using oxygen plasma.

[0307] Furthermore, etching may be performed to adjust the surface height of the insulating layer 127b. The insulating layer 127b may be processed, for example, by ashing using oxygen plasma. Also, even when a non-photosensitive material is used as the insulating film 127a, the surface height of the insulating film 127a can be adjusted by ashing or the like.

[0308] Next, the entire substrate may be exposed to visible light or ultraviolet light, irradiating the insulating layer 127b. The energy density of this exposure is 0 mJ / cm². 2 Even larger, 800 mJ / cm 2 The following is preferable: 0 mJ / cm 2 Larger, 500 mJ / cm 2 The following is more preferable: Performing such exposure after development may improve the transparency of the insulating layer 127b. In addition, it may be possible to lower the substrate temperature required for the heat treatment in a later process to deform the insulating layer 127b into a tapered shape.

[0309] On the other hand, as will be described later, by not exposing the insulating layer 127b, it may be easier to change the shape of the insulating layer 127b or to deform the insulating layer 127 into a tapered shape in a later process. Therefore, it may be preferable not to expose the insulating layer 127b or 127 after development.

[0310] For example, when a photocurable resin is used as the material for the insulating layer 127b, polymerization can be initiated and the insulating layer 127b can be cured by exposing the insulating layer 127b to light. Alternatively, at least one of the first etching process, post-bake, and second etching process described later may be performed without exposing the insulating layer 127b to light at this stage, while maintaining a state in which the insulating layer 127b is relatively easy to change shape. This can suppress the occurrence of irregularities on the surface forming the common layer 114 and the common electrode 115, and can also suppress the common layer 114 and the common electrode 115 from being broken into steps. Alternatively, exposure of the insulating layer 127b (or insulating layer 127) may be performed after any of the first etching process, post-bake, and second etching process described later.

[0311] Next, as shown in Figures 12B and 14B, etching is performed using the insulating layer 127b as a mask to remove a portion of the insulating film 125A and thin the film thickness of parts of the mask layers 118a, 118b, and 118c. As a result, the insulating layer 125 is formed beneath the insulating layer 127b. In addition, the surfaces of the thinned portions of the mask layers 118a, 118b, and 118c are exposed. Figure 14B is a magnified view of the second layer 113b shown in Figure 12B, the edge of the insulating layer 127b, and its vicinity. In the following, the etching process using the insulating layer 127b as a mask may be referred to as the first etching process.

[0312] The first etching process can be carried out by dry etching or wet etching. It is preferable that the insulating film 125A is deposited using the same material as the mask layers 118a, 118b, and 118c, as this allows the first etching process to be performed in a single step.

[0313] As shown in Figure 14B, by etching using the insulating layer 127b, which has a tapered side surface, as a mask, the sides of the insulating layer 125 and the upper edges of the sides of the mask layers 118a, 118b, and 118c can be made tapered relatively easily.

[0314] When performing dry etching, it is preferable to use a chlorine-based gas. As chlorine-based gases, Cl2, BCl3, SiCl4, and CCl4 can be used individually or in mixtures of two or more gases. In addition, one or more gases such as oxygen gas, hydrogen gas, helium gas, and argon gas can be appropriately mixed with the above chlorine-based gas. By using dry etching, thin areas of the mask layers 118a, 118b, and 118c can be formed with good in-plane uniformity.

[0315] As a dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. A dry etching apparatus having a high-density plasma source can be, for example, an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used. A capacitively coupled plasma etching apparatus having parallel plate electrodes may be configured to apply a high-frequency voltage to one electrode of the parallel plate electrodes. Alternatively, it may be configured to apply multiple different high-frequency voltages to one electrode of the parallel plate electrodes. Alternatively, it may be configured to apply a high-frequency voltage of the same frequency to each of the parallel plate electrodes. Alternatively, it may be configured to apply high-frequency voltages of different frequencies to each of the parallel plate electrodes.

[0316] Furthermore, when dry etching is performed, by-products generated during dry etching may accumulate on the upper and side surfaces of the insulating layer 127b. As a result, components contained in the etching gas, components contained in the insulating film 125A, and components contained in the mask layers 118a, 118b, and 118c may be present in the insulating layer 127 after the display device is completed.

[0317] Furthermore, it is preferable to perform the first etching process by wet etching. By using the wet etching method, damage to the first layer 113a, the second layer 113b, and the third layer 113c can be reduced compared to when the dry etching method is used. For example, wet etching can be performed using an alkaline solution. For example, for wet etching of an aluminum oxide film, it is preferable to use an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution. In this case, wet etching can be performed using a paddle method. It is also preferable if the insulating film 125A is formed using the same material as the mask layers 118a, 118b, and 118c, as this allows the above etching process to be performed all at once.

[0318] As shown in Figures 12B and 14B, in the first etching process, the mask layers 118a, 118b, and 118c are not completely removed, and the etching process is stopped when the film thickness is reduced. By leaving the corresponding mask layers 118a, 118b, and 118c on the first layer 113a, the second layer 113b, and the third layer 113c in this way, it is possible to prevent the first layer 113a, the second layer 113b, and the third layer 113c from being damaged in subsequent processing steps.

[0319] In Figures 12B and 14B, the mask layers 118a, 118b, and 118c are configured to have thinner films, but the present invention is not limited to this. For example, depending on the film thickness of the insulating film 125A and the film thicknesses of the mask layers 118a, 118b, and 118c, the first etching process may be stopped before the insulating film 125A is processed into the insulating layer 125. Specifically, the first etching process may be stopped after only thinning a portion of the insulating film 125A. Furthermore, if the insulating film 125A is formed using the same material as the mask layers 118a, 118b, and 118c, the boundary between the insulating film 125A and the mask layers 118a, 118b, and 118c may become unclear, making it impossible to determine whether the insulating layer 125 has been formed, or whether the film thicknesses of the mask layers 118a, 118b, and 118c have been thinned.

[0320] Furthermore, Figures 12B and 14B show examples where the shape of the insulating layer 127b is unchanged from that in Figures 12A and 14A, but the present invention is not limited to these examples. For example, the edges of the insulating layer 127b may droop and cover the edges of the insulating layer 125. Also, for example, the edges of the insulating layer 127b may come into contact with the upper surfaces of the mask layers 118a, 118b, and 118c. As mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127b may change.

[0321] Next, a heat treatment (also called post-bake) is performed. As shown in Figures 13A and 14C, the heat treatment can deform the insulating layer 127b into an insulating layer 127 having a tapered shape on its side surface. As mentioned above, the shape of the insulating layer 127b may have already changed and have a tapered shape on its side surface by the time the first etching treatment is completed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. 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 130°C. The heating atmosphere may be an atmospheric atmosphere or an inert gas atmosphere. The heating atmosphere may also be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature. It is preferable to use a higher substrate temperature for the heat treatment in this step than for the heat treatment after the formation of the insulating film 127a (pre-bake). This improves the adhesion between the insulating layer 127 and the insulating layer 125, and also improves the corrosion resistance of the insulating layer 127. Figure 14C is an enlarged view of the second layer 113b shown in Figure 13A, and the edge and vicinity of the insulating layer 127.

[0322] In the first etching process, by not completely removing the mask layers 118a, 118b, and 118c, and leaving them in a thinned state, it is possible to prevent the first layer 113a, the second layer 113b, and the third layer 113c from being damaged and degraded during the heat treatment. Therefore, the reliability of the light-emitting device can be improved.

[0323] Furthermore, depending on the material of the insulating layer 127, as well as the post-bake temperature, time, and atmosphere, a concave curved shape may be formed on the side surface of the insulating layer 127, as shown in Figures 4A and 4B. For example, the higher the temperature or the longer the post-bake conditions, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed. Also, as mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127 may change during post-bake.

[0324] Next, as shown in Figures 13B and 14D, etching is performed using the insulating layer 127 as a mask to remove portions of the mask layers 118a, 118b, and 118c. Note that a portion of the insulating layer 125 may also be removed. This creates openings in the mask layers 118a, 118b, and 118c, exposing the upper surfaces of the first layer 113a, the second layer 113b, the third layer 113c, and the conductive layer 123. Figure 14D is a magnified view of the second layer 113b shown in Figure 13B, the edge of the insulating layer 127, and its vicinity. Hereafter, the etching process using the insulating layer 127 as a mask will be referred to as the second etching process.

[0325] The edges of the insulating layer 125 are covered with the insulating layer 127. Figures 13B and 14D show an example where the insulating layer 127 covers a portion of the edge of the mask layer 118b (specifically, the tapered portion formed by the first etching process), while the tapered portion formed by the second etching process is exposed. In other words, this corresponds to the structure shown in Figures 2A and 2B.

[0326] If the first etching process is omitted and the insulating layer 125 and mask layer are etched together after post-bake, side etching may cause the insulating layer 125 and mask layer beneath the edges of the insulating layer 127 to disappear, forming a cavity. This cavity can cause unevenness on the surface forming the common layer 114 and common electrode 115, making it easier for the common layer 114 and common electrode 115 to break down. Even if the insulating layer 125 and mask layer are side-etched and a cavity is formed in the first etching process, the insulating layer 127 can fill the cavity by performing post-bake afterward. Subsequently, in the second etching process, the mask layer, which is now thinner, is etched, resulting in less side etching and making it less likely for a cavity to form. If a cavity does form, it can be made extremely small. Therefore, the surface forming the common layer 114 and common electrode 115 can be made flatter.

[0327] Furthermore, as shown in Figures 3A, 3B and 5A, 5B, the insulating layer 127 may cover the entire edge of the mask layer 118b. For example, the edge of the insulating layer 127 may droop and cover the edge of the mask layer 118b. Also, for example, the edge of the insulating layer 127 may be in contact with at least one upper surface of the first layer 113a, the second layer 113b, and the third layer 113c. As mentioned above, if the insulating layer 127b is not exposed after development, the shape of the insulating layer 127 may change easily.

[0328] The second etching process is preferably performed by wet etching. By using the wet etching method, damage to the first layer 113a, the second layer 113b, and the third layer 113c can be reduced compared to when using the dry etching method. Wet etching can be performed using an alkaline solution or the like.

[0329] As described above, by providing insulating layer 127, insulating layer 125, mask layer 118a, mask layer 118b, and mask layer 118c, connection failures caused by the separation of the common layer 114 and common electrode 115 between each light-emitting device, and increases in electrical resistance caused by locally thin film thicknesses, can be suppressed. As a result, a display device according to one embodiment of the present invention can improve display quality.

[0330] Furthermore, after exposing a portion of the first layer 113a, the second layer 113b, and the third layer 113c, further heat treatment may be performed. This heat treatment can remove water contained in the EL layer and water adsorbed on the surface of the EL layer. In addition, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may spread to cover at least one of the following: the edge of the insulating layer 125, the edges of the mask layers 118a, 118b, and 118c, and the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. For example, the insulating layer 127 may take on the shape shown in Figures 3A and 3B. For example, the heat treatment can be performed in 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. Using a reduced pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into account the heat resistance temperature of the EL layer. When considering the heat resistance temperature of the EL layer, a temperature of 70°C to 120°C is particularly preferable within the above temperature range.

[0331] Next, a common layer 114, a common electrode 115, and a protective layer 131 are formed in this order on the insulating layer 127, the first layer 113a, the second layer 113b, and the third layer 113c. Furthermore, a display device can be manufactured by laminating the substrate 120 onto the protective layer 131 using the resin layer 122 (Figure 1B).

[0332] The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0333] For the formation of the common electrode 115, for example, sputtering or vacuum deposition can be used. Alternatively, a film formed by deposition and a film formed by sputtering may be laminated together.

[0334] Methods for forming the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD.

[0335] As described above, in the method for manufacturing the display device of this embodiment, the island-shaped first layer 113a, the island-shaped second layer 113b, and the third layer 113c are formed not using a fine metal mask, but by processing after a film is deposited on one surface, so that the island-shaped layers can be formed with a uniform thickness. This makes it possible to realize a high-definition display device or a display device with a high aperture ratio. Furthermore, even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, it is possible to suppress contact between the first layer 113a, the second layer 113b, and the third layer 113c in adjacent subpixels. Therefore, it is possible to suppress the generation of leakage current between subpixels. This makes it possible to prevent crosstalk caused by unintended light emission and realize a display device with extremely high contrast.

[0336] Furthermore, by providing an insulating layer 127 having a tapered shape at its end between adjacent island-shaped EL layers, it is possible to suppress the occurrence of step breaks when forming the common electrode 115, and to prevent the formation of locally thin areas in the common electrode 115. As a result, connection failures caused by the divided areas and increases in electrical resistance caused by locally thin areas can be suppressed in the common layer 114 and the common electrode 115. Therefore, a display device according to one aspect of the present invention can achieve both high resolution and high display quality.

[0337] This embodiment can be combined with other embodiments as appropriate.

[0338] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 15 and 16.

[0339] [Pixel layout] This embodiment primarily describes a pixel layout different from that shown in Figure 1A. 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.

[0340] In this embodiment, the top surface shape of the subpixel shown in the figure corresponds to the top surface shape of the light-emitting region (or light-receiving region).

[0341] The top surface shape of the subpixel may include, for example, polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0342] Furthermore, the circuit layout constituting the subpixels is not limited to the subpixel range shown in the figure, and may be arranged outside of it. The circuit arrangement and the light-emitting device arrangement do not necessarily have to be the same, and different arrangement methods are possible. For example, the circuit arrangement can be a stripe arrangement, and the light-emitting device arrangement can be an S-stripe arrangement.

[0343] The pixel 110 shown in Figure 15A has an S-stripe array applied to it. The pixel 110 shown in Figure 15A is composed of three subpixels: subpixels 110a, 110b, and 110c.

[0344] The pixel 110 shown in Figure 15B includes sub-pixels 110a with a roughly triangular or trapezoidal top surface shape with rounded corners, sub-pixels 110b with a roughly triangular or trapezoidal top surface shape with rounded corners, and sub-pixels 110c with a roughly square or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel 110b has a larger light-emitting area than sub-pixel 110a. In this way, the shape and size of each sub-pixel can be determined independently. For example, sub-pixels with more reliable light-emitting devices can be made smaller in size.

[0345] A Pentile array is applied to pixels 124a and 124b shown in Figure 15C. Figure 15C shows an example in which pixels 124a having sub-pixels 110a and 110b, and pixels 124b having sub-pixels 110b and 110c are arranged alternately.

[0346] Pixels 124a and 124b, shown in Figures 15D and 15E, have a delta array applied. Pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (1st row) and one subpixel (subpixel 110c) in the bottom row (2nd row). Pixel 124b has one subpixel (subpixel 110c) in the top row (1st row) and two subpixels (subpixels 110a and 110b) in the bottom row (2nd row).

[0347] 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.

[0348] Figure 15F shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are offset.

[0349] In each pixel shown in Figures 15A to 15F, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 110b may be sub-pixel R that emits red light, and sub-pixel 110a may be sub-pixel G that emits green light.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] As shown in Figures 16A to 16I, a pixel can be configured to have four types of subpixels.

[0354] The pixels 110 shown in Figures 16A to 16C have a stripe arrangement applied to them.

[0355] 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.

[0356] The pixels 110 shown in Figures 16D to 16F have a matrix array applied to them.

[0357] Figure 16D shows an example where each subpixel has a square top surface shape, Figure 16E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 16F shows an example where each subpixel has a circular top surface shape.

[0358] Figures 16G and 16H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0359] Pixel 110, shown in Figure 16G, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (row 1) and one subpixel (subpixel 110d) in the bottom row (row 2). In other words, pixel 110 has subpixel 110a in the left column (column 1), subpixel 110b in the middle column (column 2), subpixel 110c in the right column (column 3), and subpixel 110d across these three columns.

[0360] The pixel 110 shown in Figure 16H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and three subpixels 110d in the bottom row (2nd row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixels 110b and 110d in the middle column (2nd column), and subpixels 110c and 110d in the right column (3rd column). As shown in Figure 16H, by aligning the arrangement of subpixels in the top row and the bottom row, it becomes possible to efficiently remove dust and other debris that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0361] Figure 16I shows an example where one pixel 110 is composed of a 3x2 grid.

[0362] Pixel 110, shown in Figure 16I, has a sub-pixel 110a in the top row (1st row), a sub-pixel 110b in the middle row (2nd row), a sub-pixel 110c spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 110d) in the bottom row (3rd row). In other words, pixel 110 has sub-pixels 110a and 110b in the left column (1st column), a sub-pixel 110c in the right column (2nd column), and a sub-pixel 110d spanning these two columns.

[0363] The pixel 110 shown in Figures 16A to 16I is composed of four subpixels: subpixels 110a, 110b, 110c, and 110d.

[0364] The sub-pixels 110a, 110b, 110c, and 110d can each be configured to have a light-emitting device that emits light of a different color. Examples of sub-pixels 110a, 110b, 110c, and 110d include sub-pixels of four colors: R, G, B, and white (W); sub-pixels of four colors: R, G, B, and Y; or sub-pixels of R, G, B, and infrared (IR).

[0365] In each pixel 110 shown in Figures 16A to 16I, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, sub-pixel 110c be sub-pixel B that emits blue light, and sub-pixel 110d be sub-pixel W that emits white light, sub-pixel Y that emits yellow light, or sub-pixel IR that emits near-infrared light. With such a configuration, in the pixels 110 shown in Figures 16G and 16H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 16I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0366] Furthermore, the pixel 110 may have subpixels that have a light-receiving device.

[0367] In each pixel 110 shown in Figures 16A to 16I, one of the sub-pixels 110a to 110d may be a sub-pixel having a light-receiving device.

[0368] In each pixel 110 shown in Figures 16A to 16I, it is preferable, for example, that sub-pixel 110a be a sub-pixel R that emits red light, sub-pixel 110b be a sub-pixel G that emits green light, sub-pixel 110c be a sub-pixel B that emits blue light, and sub-pixel 110d be a sub-pixel S having a light-receiving device. With such a configuration, in the pixels 110 shown in Figures 16G and 16H, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixels 110 shown in Figure 16I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0369] The wavelength of light detected by the sub-pixel S, which has a light-receiving device, is not particularly limited. The sub-pixel S can be configured to detect either visible light or infrared light, or both.

[0370] As shown in Figures 16J and 16K, a pixel can be configured to have five types of subpixels.

[0371] Figure 16J shows an example where one pixel 110 is composed of 2 rows and 3 columns.

[0372] Pixel 110, shown in Figure 16J, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (row 1) and two subpixels (subpixels 110d and 110e) in the bottom row (row 2). In other words, pixel 110 has subpixels 110a and 110d in the left column (column 1), subpixel 110b in the middle column (column 2), subpixel 110c in the right column (column 3), and subpixel 110e extending from column 2 to column 3.

[0373] Figure 16K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0374] Pixel 110, shown in Figure 16K, has subpixel 110a in the top row (1st row), subpixel 110b in the middle row (2nd row), subpixel 110c spanning from the 1st to the 2nd row, and two subpixels (subpixels 110d and 110e) in the bottom row (3rd row). In other words, pixel 110 has subpixels 110a, 110b, and 110d in the left column (1st column), and subpixels 110c and 110e in the right column (2nd column).

[0375] In each pixel 110 shown in Figures 16J and 16K, it is preferable, for example, that sub-pixel 110a be sub-pixel R that emits red light, sub-pixel 110b be sub-pixel G that emits green light, and sub-pixel 110c be sub-pixel B that emits blue light. With such a configuration, in the pixel 110 shown in Figure 16J, the layout of R, G, and B becomes a stripe arrangement, which can improve the display quality. Also, in the pixel 110 shown in Figure 16K, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0376] Furthermore, in each pixel 110 shown in Figures 16J and 16K, it is preferable to apply a sub-pixel S having a photodetector to at least one of the sub-pixels 110d and 110e. When photodetectors are used for both sub-pixels 110d and 110e, the configurations of the photodetectors may differ from each other. For example, at least a portion of the wavelength ranges of light detected by each may differ. Specifically, one of the sub-pixels 110d and 110e may have a photodetector that mainly detects visible light, and the other may have a photodetector that mainly detects infrared light.

[0377] Furthermore, in each pixel 110 shown in Figures 16J and 16K, it is preferable to apply a sub-pixel S having a light-receiving device to one of the sub-pixels 110d and 110e, and a sub-pixel having a light-emitting device that can be used as a light source to the other. For example, it is preferable that one of the sub-pixels 110d and 110e is a sub-pixel IR that emits infrared light, and the other is a sub-pixel S having a light-receiving device that detects infrared light.

[0378] In pixels having sub-pixels R, G, B, IR, and S, an image can be displayed using sub-pixels R, G, and B, while sub-pixel IR is used as a light source to detect the reflected infrared light emitted by sub-pixel S.

[0379] As described above, in one aspect of the present invention, a display device can be configured to have pixels having subpixels with light-emitting devices, and various layouts can be applied to these pixels. Furthermore, in one aspect of the present invention, a display device can be configured to have pixels having both light-emitting devices and light-receiving devices. In this case as well, various layouts can be applied.

[0380] This embodiment can be combined with other embodiments as appropriate.

[0381] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 17 to 27.

[0382] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, and as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0383] Furthermore, 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 equipment, 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, personal information terminals, and audio playback devices.

[0384] [Display Module] Figure 17A shows a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to display device 100A, but may be any of the display devices 100B to 100F described later.

[0385] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0386] Figure 17B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286, which is composed of multiple wires.

[0387] The pixel section 284 has a plurality of pixels 284a arranged periodically. The right side of Figure 17B shows an enlarged view of one pixel 284a. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 17B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0388] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0389] A single pixel circuit 283a is a circuit that controls the driving of multiple elements in a single pixel 284a. A single pixel circuit 283a can be configured to have three circuits that control the light emission of a single light-emitting device. For example, a single pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active-matrix type display device.

[0390] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0391] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0392] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby enabling an extremely high aperture ratio (effective display area ratio) of the display section 281. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, enabling an extremely high resolution of the display section 281. For example, it is preferable that the pixels 284a in the display section 281 are arranged with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0393] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as HMDs or AR devices such as glasses. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, and a highly immersive display can be achieved. Furthermore, the display module 280 is not limited to this and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as watches.

[0394] [Display device 100A] The display device 100A shown in Figure 18A includes a substrate 301, light-emitting devices 130R, 130G, 130B, a capacitor 240, and a transistor 310.

[0395] Substrate 301 corresponds to substrate 291 in Figures 17A and 17B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 containing the transistor in Embodiment 1.

[0396] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0397] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0398] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0399] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 acts as one electrode of the capacitor 240, the conductive layer 245 acts as the other electrode of the capacitor 240, and the insulating layer 243 acts as the dielectric of the capacitor 240.

[0400] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0401] An insulating layer 255a is provided covering the capacitance 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 255c. Figure 18A shows an example in which light-emitting devices 130R, 130G, and 130B have a structure similar to the laminated structure shown in Figure 1B. An insulator is provided in the region between adjacent light-emitting devices. In Figure 18A and other figures, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in this region.

[0402] A mask layer 118a is located on the first layer 113a of the light-emitting device 130R, a mask layer 118b is located on the second layer 113b of the light-emitting device 130G, and a mask layer 118c is located on the third layer 113c of the light-emitting device 130B.

[0403] Pixel electrodes 111a, 111b, and 111c are electrically connected to either the source or drain of transistor 310 by plugs 256 embedded in insulating layers 243, 255a, 255b, and 255c, a conductive layer 241 embedded in insulating layer 254, and a plug 271 embedded in insulating layer 261. The height of the upper surface of insulating layer 255c and the height of the upper surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs. Figure 18A, etc., shows an example in which the pixel electrode has a two-layer structure consisting of a reflective electrode and a transparent electrode on the reflective electrode.

[0404] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices to the substrate 120 can be found in Embodiment 1. The substrate 120 corresponds to the substrate 292 in Figure 17A.

[0405] The display device shown in Figure 18B is an example having light-emitting devices 130R, 130G, and a light-receiving device 150. The light-receiving device 150 has a pixel electrode 111d, a fourth layer 113d, a common layer 114, and a common electrode 115 stacked together. For details of the display device having a light-receiving device, refer to Embodiments 1 and 6.

[0406] [Display device 100B] The display device 100B shown in Figure 19 has a configuration in which transistors 310A and 310B, each with a channel formed on a semiconductor substrate, are stacked. In the following description of the display device, parts that are the same as those described earlier may be omitted.

[0407] The display device 100B has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting device are provided, and a substrate 301A on which a transistor 310A is provided are bonded together.

[0408] Here, it is preferable to provide an insulating layer 345 on the lower surface of substrate 301B. It is also preferable to provide an insulating layer 346 on top of the insulating layer 261 provided on substrate 301A. Insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into substrates 301B and 301A. As insulating layers 345 and 346, inorganic insulating films that can be used for protective layer 131 or insulating layer 332 described later can be used.

[0409] A plug 343 is provided on the substrate 301B, penetrating both the substrate 301B and the insulating layer 345. It is preferable to provide an insulating layer 344 covering the sides of the plug 343. The insulating layer 344 functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. An inorganic insulating film, usable for the protective layer 131, can be used as the insulating layer 344.

[0410] Furthermore, a conductive layer 342 is provided on the back side of the substrate 301B (the side opposite to the substrate 120 side), beneath the insulating layer 345. Preferably, the conductive layer 342 is provided so as to be embedded in the insulating layer 335. Also, preferably, the undersides of the conductive layer 342 and the insulating layer 335 are flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0411] On the other hand, the substrate 301A has a conductive layer 341 provided on an insulating layer 346. Preferably, the conductive layer 341 is provided so as to be embedded in the insulating layer 336. Furthermore, it is preferable that the upper surfaces of the conductive layer 341 and the insulating layer 336 are flattened.

[0412] The conductive layer 341 and the conductive layer 342 are bonded together, thereby electrically connecting the substrate 301A and the substrate 301B. By improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335, and the surface formed by the conductive layer 341 and the insulating layer 336, the bonding of the conductive layer 341 and the conductive layer 342 can be improved.

[0413] It is preferable to use the same conductive material for conductive layer 341 and conductive layer 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) composed of the above elements can be used. In particular, it is preferable to use copper for conductive layer 341 and conductive layer 342. This makes it possible to apply Cu-Cu (copper-copper) direct bonding technology (a technology that achieves electrical conductivity by connecting Cu (copper) pads to each other).

[0414] [Display device 100C] The display device 100C shown in Figure 20 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0415] As shown in Figure 20, the conductive layer 341 and the conductive layer 342 can be electrically connected by providing a bump 347 between them. The bump 347 can be formed using a conductive material including, for example, gold (Au), nickel (Ni), indium (In), or tin (Sn). Solder may also be used as the bump 347. An adhesive layer 348 may also be provided between the insulating layer 345 and the insulating layer 346. Furthermore, when the bump 347 is provided, the insulating layer 335 and the insulating layer 336 may be omitted.

[0416] [Display device 100D] The display device 100D shown in Figure 21 differs from the display device 100A mainly in its transistor configuration.

[0417] Transistor 320 is an OS transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0418] The transistor 320 has a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0419] Substrate 331 corresponds to substrate 291 in Figures 17A and 17B. The laminated structure from substrate 331 to insulating layer 255c corresponds to layer 101 containing the transistor in Embodiment 1. An insulating substrate or a semiconductor substrate can be used as substrate 331.

[0420] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0421] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film, such as a silicon oxide film, for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0422] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.

[0423] An insulating layer 328 is provided covering the top and side surfaces of a pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0424] An opening is provided in the insulating layer 328 and the insulating layer 264 that reaches the semiconductor layer 321. Inside this opening, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the sides of the insulating layer 264, the insulating layer 328, and the conductive layer 325, as well as the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0425] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are the same or approximately the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0426] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0427] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layers 265, 329, and 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layers 265, 329, 264, and 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0428] [Display device 100E] The display device 100E shown in Figure 22 has a configuration in which transistors 320A and 320B, each having an oxide semiconductor in the semiconductor on which the channel is formed, are stacked.

[0429] For details regarding transistors 320A and 320B, and their peripheral configurations, please refer to the display device 100D described above.

[0430] In this example, we have used a configuration in which two transistors having oxide semiconductors are stacked, but this is not the only option. For example, a configuration in which three or more transistors are stacked may also be used.

[0431] [Display device 100F] The display device 100F shown in Figure 23 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked.

[0432] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0433] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0434] This configuration allows for the formation of not only pixel circuits but also drive circuits directly beneath the light-emitting device, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0435] [Display device 100G] Figure 24 shows a perspective view of the display device 100G, and Figure 25A shows a cross-sectional view of the display device 100G.

[0436] The display device 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 24, substrate 152 is shown with a dashed line.

[0437] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 24 shows an example in which IC 173 and FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Figure 24 can also be described as a display module having the display device 100G, an IC (integrated circuit), and an FPC.

[0438] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one or more sides of the display portion 162. There may be one or more connection portions 140. Figure 24 shows an example in which the connection portion 140 is provided so as to surround all four sides of the display portion. At the connection portion 140, the common electrode of the light-emitting device and the conductive layer are electrically connected, and a potential can be supplied to the common electrode.

[0439] For example, a scan line drive circuit can be used as circuit 164.

[0440] Wiring 165 has the function of supplying signals and power to the display unit 162 and the circuit 164. These signals and power are input to wiring 165 from an external source via FPC 172 or from IC 173.

[0441] Figure 24 shows an example in which IC 173 is provided on the substrate 151 using a COG (Chip On Glass) method or COF (Chip On Film) method. IC 173 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 100G 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.

[0442] Figure 25A shows an example of a cross-section of the display device 100G when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection unit 140, and a portion of the area including the end are cut.

[0443] The display device 100G shown in Figure 25A has a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B, etc., between substrates 151 and 152.

[0444] The light-emitting devices 130R, 130G, and 130B each have a structure similar to the stacked structure shown in Figure 1B, except that the pixel electrode configuration differs. For details of the light-emitting devices, please refer to Embodiment 1.

[0445] The light-emitting device 130R has a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. All of the conductive layers 112a, 126a, and 129a can be called pixel electrodes, or only a part of them can be called pixel electrodes.

[0446] The light-emitting device 130G has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0447] The light-emitting device 130B includes a conductive layer 112c, a conductive layer 126c on the conductive layer 112c, and a conductive layer 129c on the conductive layer 126c.

[0448] The conductive layer 112a is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The edge of the conductive layer 126a is located outside the edge of the conductive layer 112a. The edges of the conductive layer 126a and the conductive layer 129a are aligned or approximately aligned. For example, conductive layers that function as reflective electrodes can be used for conductive layers 112a and 126a, and a conductive layer that functions as a transparent electrode can be used for conductive layer 129a.

[0449] The conductive layers 112b, 126b, and 129b in the light-emitting device 130G, and the conductive layers 112c, 126c, and 129c in the light-emitting device 130B, are the same as the conductive layers 112a, 126a, and 129a in the light-emitting device 130R, so a detailed explanation is omitted.

[0450] The conductive layers 112a, 112b, and 112c are formed to cover the openings provided in the insulating layer 214. Layer 128 is embedded in the recesses of the conductive layers 112a, 112b, and 112c.

[0451] Layer 128 has the function of flattening the recesses of the conductive layers 112a, 112b, and 112c. Conductive layers 126a, 126b, and 126c, which are electrically connected to conductive layers 112a, 112b, and 112c, are provided on conductive layers 112a, 112b, and 112c and on layer 128. Therefore, regions overlapping with the recesses of conductive layers 112a, 112b, and 112c can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0452] Layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for layer 128 as appropriate. In particular, it is preferable that layer 128 be formed using an insulating material, and especially preferable that it be formed using an organic insulating material. For example, an organic insulating material that can be used for the insulating layer 127 described above can be applied to layer 128.

[0453] The top and side surfaces of conductive layers 126a and 129a are covered by the first layer 113a. Similarly, the top and side surfaces of conductive layers 126b and 129b are covered by the second layer 113b, and the top and side surfaces of conductive layers 126c and 129c are covered by the third layer 113c. Therefore, the entire region where conductive layers 126a, 126b, and 126c are provided can be used as the light-emitting region of the light-emitting devices 130R, 130G, and 130B, thereby increasing the aperture ratio of the pixels.

[0454] The upper surfaces and sides of the first layer 113a, the second layer 113b, and the third layer 113c are covered by insulating layers 125 and 127. A mask layer 118a is located between the first layer 113a and the insulating layer 125. A mask layer 118b is located between the second layer 113b and the insulating layer 125, and a mask layer 118c is located between the third layer 113c and the insulating layer 125. A common layer 114 is provided on the first layer 113a, the second layer 113b, the third layer 113c, and the insulating layers 125 and 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 and the common electrode 115 are each a continuous film provided in common to multiple light-emitting devices.

[0455] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 152 are bonded via an adhesive layer 142. A light-shielding layer 117 is provided on the substrate 152. For sealing the light-emitting devices, a solid sealing structure or a hollow sealing structure can be applied. In Figure 25A, the space between the substrate 152 and the substrate 151 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. Also, the space may be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0456] In the connection portion 140, a conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. The ends of the conductive layer 123 are covered by a mask layer 118a, an insulating layer 125, and an insulating layer 127. A common layer 114 is provided on the conductive layer 123, and a common electrode 115 is provided on the common layer 114. The conductive layer 123 and the common electrode 115 are electrically connected via the common layer 114. Note that the common layer 114 does not necessarily have to be formed in the connection portion 140. In this case, the conductive layer 123 and the common electrode 115 are in direct contact and electrically connected.

[0457] The display device 100G is a top-emission type. The light emitted by the light-emitting device is emitted towards the substrate 152. It is preferable to use a material with high transmittance to visible light for the substrate 152. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 115) contain a material that transmits visible light.

[0458] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 containing the transistor in Embodiment 1.

[0459] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0460] On the substrate 151, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0461] 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.

[0462] It is preferable to use inorganic insulating films for insulating layer 211, insulating layer 213, and insulating layer 215. Examples of inorganic insulating films that can be used include silicon nitride film, silicon oxide nitride film, silicon oxide film, silicon nitride oxide 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 insulating films may be laminated together.

[0463] An organic insulating layer is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This makes it possible to suppress the formation of depressions in the insulating layer 214 during processing of conductive layers 112a, 126a, or 129a. Alternatively, depressions may be provided in the insulating layer 214 during processing of conductive layers 112a, 126a, or 129a.

[0464] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0465] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0466] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0467] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0468] The semiconductor layer of the transistor preferably has a metal oxide (also called an oxide semiconductor). In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) that uses a metal oxide in the channel formation region.

[0469] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0470] Alternatively, a transistor using silicon as the channel-forming region (Si transistor) may be used. Examples of silicon include single-crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in the semiconductor layer (hereinafter also referred to as an LTPS transistor) can be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0471] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (e.g., source driver circuits) can be fabricated on the same board as the display unit. This simplifies the external circuits implemented in the display device, reducing component and mounting costs.

[0472] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (also called off-current) in the off state, allowing them to retain charge stored in a capacitor connected in series with the transistor for extended periods. Additionally, the application of OS transistors can reduce the power consumption of display devices.

[0473] Furthermore, to increase the luminescence brightness of the light-emitting device included in the pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of the drive transistor included in the pixel circuit. Compared to Si transistors, OS transistors have a higher breakdown voltage between the source and drain, so a higher voltage can be applied between the source and drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in the pixel circuit, the amount of current flowing through the light-emitting device can be increased, thereby increasing the luminescence brightness of the light-emitting device.

[0474] Furthermore, when the transistor operates in the saturation region, OS transistors exhibit smaller changes in source-drain current in response to changes in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as driving transistors in the pixel circuit, the current flowing between the source and drain can be precisely controlled by changes in gate-source voltage, thereby allowing control of the current flowing to the light-emitting device. This allows for an increase in the number of grayscale levels in the pixel circuit.

[0475] Furthermore, in terms of the saturation characteristics of the current flowing when a transistor operates in the saturation region, OS transistors can supply a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using OS transistors as driving transistors, a stable current can be supplied to the light-emitting device even if there are variations in the current-voltage characteristics of the EL device. In other words, when operating in the saturation region, the source-drain current remains almost unchanged even when the source-drain voltage is increased, thus stabilizing the luminescence brightness of the light-emitting device.

[0476] As described above, by using OS transistors in the drive transistors included in the pixel circuit, it is possible to achieve "suppression of black level floating," "increase in luminescence brightness," "multi-gradation," and "suppression of variations in light-emitting devices."

[0477] The oxide semiconductor used in the semiconductor layer preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0478] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also written as IGZO) as the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also written as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also written as IAGZO).

[0479] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is greater than or equal to the atomic ratio of M. Possible atomic ratios of metal elements in such an In-M-Zn oxide include: In:M:Zn=1:1:1 or near that composition, In:M:Zn=1:1:1.2 or near that composition, In:M:Zn=1:3:2 or near that composition, In:M:Zn=1:3:4 or near that composition, In:M:Zn=2:1:3 or near that composition, In:M:Zn=3:1:2 or near that composition, and In:M:Zn=4:2:3 Examples include compositions near the desired atomic ratio, such as In:M:Zn=4:2:4.1 or near that ratio, In:M:Zn=5:1:3 or near that ratio, In:M:Zn=5:1:6 or near that ratio, In:M:Zn=5:1:7 or near that ratio, In:M:Zn=5:1:8 or near that ratio, In:M:Zn=6:1:6 or near that ratio, In:M:Zn=5:2:5 or near that ratio, etc. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0480] 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 In is set to 4, Ga is between 1 and 3, and 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 In is set to 5, Ga is greater than 0.1 and 2 or less, and 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 In is set to 1, Ga is greater than 0.1 and 2 or less, and Zn is greater than 0.1 and 2 or less.

[0481] The transistors in circuit 164 and the transistors in display unit 162 may have the same structure or different structures. The structures of the multiple transistors in circuit 164 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 162 may all be the same or there may be two or more different structures.

[0482] All of the transistors in the display unit 162 may be OS transistors, all of the transistors in the display unit 162 may be Si transistors, or some of the transistors in the display unit 162 may be OS transistors and the rest may be Si transistors.

[0483] For example, by using both LTPS transistors and OS transistors in the display unit 162, a display device with low power consumption and high driving capability can be realized. Furthermore, a configuration combining LTPS transistors and OS transistors is sometimes referred to as LTPO. A more suitable example is a configuration in which OS transistors are used for transistors that function as switches to control conduction and non-conduction between wires, and LTPS transistors are used for transistors that control current.

[0484] For example, one of the transistors in the display unit 162 functions as a transistor for controlling the current flowing to the light-emitting device, and can also be called a drive transistor. One of the source and drain of the drive transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor for this drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0485] On the other hand, the other transistor in the display unit 162 functions as a switch for controlling the selection and deselection of pixels, and can also be called a selection transistor. The gate of the selection transistor is electrically connected to the gate line, and one of the source and drain is electrically connected to the source line (signal line). It is preferable to use an OS transistor for the selection transistor. This makes it possible to maintain the gradation of pixels even when the frame frequency is significantly reduced (e.g., 1 fps or less), and thus power consumption can be reduced by stopping the driver when displaying still images.

[0486] Thus, a display device according to one aspect of the present invention can combine a high aperture ratio, high resolution, high display quality, and low power consumption.

[0487] Furthermore, one embodiment of the present invention is a display device having an OS transistor and a light-emitting device with an MML (metal maskless) structure. This configuration makes it possible to extremely reduce the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light-emitting devices (also called lateral leakage current or side leakage current). With this configuration, when an image is displayed on the display device, the observer can observe one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. Moreover, by having an extremely low leakage current that can flow through the transistor and lateral leakage current between light-emitting devices, it is possible to achieve a display with as little light leakage (so-called black floating) that may occur when displaying black as possible.

[0488] In particular, even among MML-structured light-emitting devices, applying the aforementioned SBS structure results in a configuration where the layers between light-emitting devices (for example, an organic layer used in common between light-emitting devices, also called a common layer) are separated, thus eliminating or significantly reducing side leakage.

[0489] Figures 25B and 25C show other examples of transistor configurations.

[0490] Transistors 209 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel forming region 231i. Furthermore, an insulating layer 218 covering the transistor may be provided.

[0491] In the transistor 209 shown in Figure 25B, an example is shown where the insulating layer 225 covers the top and sides of the semiconductor layer 231. The conductive layers 222a and 222b are connected to the low-resistance region 231n through openings provided in the insulating layers 225 and 215, respectively. Of the conductive layers 222a and 222b, one functions as the source and the other as the drain.

[0492] On the other hand, in the transistor 210 shown in Figure 25C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 25C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 25C, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215.

[0493] A connection portion 204 is provided in the region of substrate 151 where substrate 152 does not overlap. At the connection portion 204, wiring 165 is electrically connected to FPC 172 via conductive layer 166 and connection layer 242. The conductive layer 166 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as conductive layers 129a, 129b, and 129c. The conductive layer 166 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242.

[0494] It is preferable to provide a light-shielding layer 117 on the surface of the substrate 152 that faces the substrate 151. The light-shielding layer 117 can be provided between adjacent light-emitting devices, at connection points 140, and in circuits 164, etc. In addition, various optical components can be arranged on the outside of the substrate 152.

[0495] Materials that can be used for substrate 120 can be applied to substrate 151 and substrate 152, respectively.

[0496] As the adhesive layer 142, a material that can be used for the resin layer 122 can be applied.

[0497] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0498] [Display device 100H] The display device 100H shown in Figure 26A differs from the display device 100G mainly in that it is a bottom-emission type display device.

[0499] The light emitted by the light-emitting device is projected onto the substrate 151. It is preferable to use a material with high transparency to visible light for the substrate 151. On the other hand, the light transmittance of the material used for the substrate 152 is not a requirement.

[0500] It is preferable to form a light-shielding layer 117 between the substrate 151 and the transistor 201, and between the substrate 151 and the transistor 205. Figure 26A shows an example in which a light-shielding layer 117 is provided on the substrate 151, an insulating layer 153 is provided on the light-shielding layer 117, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0501] The light-emitting device 130R includes a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a.

[0502] The light-emitting device 130G has a conductive layer 112b, a conductive layer 126b on the conductive layer 112b, and a conductive layer 129b on the conductive layer 126b.

[0503] The conductive layers 112a, 112b, 126a, 126b, 129a, and 129b are made of materials with high transmittance to visible light. It is preferable to use a material that reflects visible light for the common electrode 115.

[0504] Furthermore, while Figures 25A and 26A show examples where the upper surface of layer 128 has a flat portion, the shape of layer 128 is not particularly limited. Figures 26B to 26D show modified examples of layer 128.

[0505] As shown in Figures 26B and 26D, the upper surface of layer 128 can be configured to have a shape in which the center and its vicinity are recessed in a cross-sectional view, that is, a shape having a concave curved surface.

[0506] Furthermore, as shown in Figure 26C, the upper surface of layer 128 can be configured to have a shape that bulges in the center and its vicinity when viewed in cross-section, that is, a shape with a convex curved surface.

[0507] Furthermore, the upper surface of layer 128 may have one or both of a convex and a concave surface. Also, the number of convex and concave surfaces on the upper surface of layer 128 is not limited and can be one or more.

[0508] Furthermore, the height of the top surface of layer 128 and the height of the top surface of the conductive layer 112a may be the same or approximately the same, or they may be different from each other. For example, the height of the top surface of layer 128 may be lower or higher than the height of the top surface of the conductive layer 112a.

[0509] Furthermore, Figure 26B can be seen as an example in which layer 128 is housed inside a recess in the conductive layer 112a. On the other hand, as shown in Figure 26D, layer 128 may exist outside the recess in the conductive layer 112a, that is, the width of the upper surface of layer 128 may be wider than that of the recess.

[0510] [Display device 100J] The display device 100J shown in Figure 27 differs from the display device 100G mainly in that it has a light receiving device 150.

[0511] The light-receiving device 150 has a conductive layer 112d, a conductive layer 126d on the conductive layer 112d, and a conductive layer 129d on the conductive layer 126d.

[0512] The conductive layer 112d is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0513] The top and side surfaces of conductive layer 126d and conductive layer 129d are covered by a fourth layer 113d. The fourth layer 113d has at least an active layer.

[0514] A portion of the upper surface and sides of the fourth layer 113d are covered by insulating layers 125 and 127. A mask layer 118d is located between the fourth layer 113d and the insulating layer 125. A common layer 114 is provided on the fourth layer 113d and the insulating layers 125 and 127, and a common electrode 115 is provided on the common layer 114. The common layer 114 is a continuous film provided in common to both the light-receiving device and the light-emitting device.

[0515] The display device 100J can, for example, apply the pixel layout shown in Figures 16A to 16K, as described in Embodiment 3. For details of the display device having a light-receiving device, refer to Embodiments 1 and 6.

[0516] This embodiment can be combined with other embodiments as appropriate.

[0517] (Embodiment 5) This embodiment describes a light-emitting device that can be used in a display device according to one aspect of the present invention.

[0518] In this specification, a structure that produces different light-emitting colors (e.g., blue (B), green (G), and red (R)) for each light-emitting device may be referred to as an SBS (Side By Side) structure.

[0519] The light-emitting device can emit colors such as red, green, blue, cyan, magenta, yellow, or white. Furthermore, the color purity can be improved by adding a microcavity structure to the light-emitting device.

[0520] [Light-emitting devices] As shown in Figure 28A, the light-emitting device has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0521] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0522] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0523] A configuration having a layer 780, an emissive layer 771, and a layer 790 provided between a pair of electrodes can function as a single emissive unit, and in this specification, the configuration shown in Figure 28A is referred to as a single structure.

[0524] Furthermore, Figure 28B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 28A. Specifically, the light-emitting device shown in Figure 28B has a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0525] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0526] Furthermore, as shown in Figures 28C and 28D, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a variation of the single structure.

[0527] Furthermore, as shown in Figures 28E and 28F, a configuration in which multiple light-emitting units (EL layers 763a and EL layers 763b) are connected in series via a charge generation layer 785 is referred to as a tandem structure in this specification. The tandem structure may also be called a stacked structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be achieved.

[0528] In Figures 28C and 28D, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material may be used. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 771, 772, and 773. A color conversion layer may be provided as layer 764 as shown in Figure 28D.

[0529] Furthermore, light-emitting materials that emit light of different colors may be used for the light-emitting layers 771, 772, and 773, respectively. If the light emitted by the light-emitting layers 771, 772, and 773 are complementary colors, white light emission can be obtained. A color filter (also called a colored layer) may be provided as layer 764 as shown in Figure 28D. By passing white light through the color filter, light of a desired color can be obtained.

[0530] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, one should 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.

[0531] Furthermore, in Figures 28E and 28F, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. Alternatively, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of different colors. When the light emitted by the light-emitting layer 771 and the light emitted by the light-emitting layer 772 are complementary colors, white light emission is obtained. Figure 28F shows an example in which an additional layer 764 is provided. As layer 764, one or both of a color conversion layer and a color filter (coloring layer) can be used. In Figures 28D and 28F, in order to extract light to the upper electrode 762 side, a conductive film that transmits visible light is used for the upper electrode 762.

[0532] Furthermore, in Figures 28C, 28D, 28E, and 28F, as shown in Figure 28B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0533] Next, we will describe materials that can be used in light-emitting devices.

[0534] Of the lower electrode 761 and upper electrode 762, the electrode that extracts light preferably uses a conductive film that transmits visible light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light. In addition, if the display device has a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits both visible light and infrared light on the electrode that extracts light, and a conductive film that reflects both visible light and infrared light on the electrode that does not extract light.

[0535] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0536] As materials for forming the pair of electrodes of a light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, examples include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), In-W-Zn oxide, aluminum-containing alloys such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), as well as silver-containing alloys such as silver-magnesium alloys and silver-palladium-copper alloys (Ag-Pd-Cu, also written as APC). In addition, metals such as aluminum (Al), magnesium (Mg), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these in appropriate combinations can also be used. Furthermore, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing these in appropriate combinations, graphene, and the like can also be used.

[0537] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device has an electrode that is transparent to and reflective to visible light (a semi-transmissive / semi-reflective electrode), and the other has an electrode that is reflective to visible light (a reflective electrode). By having a microcavity structure in the light-emitting device, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby strengthening the light emitted from the light-emitting device.

[0538] Furthermore, semi-transmissive / semi-reflective electrodes can have a laminated structure consisting of a reflective electrode and an electrode that transmits visible light (also called a transparent electrode).

[0539] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode in the light-emitting device that has a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The visible light reflectance of the semi-transparent / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ -2 A value of Ωcm or less is preferable.

[0540] 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.

[0541] The light-emitting layer may contain one or more types of light-emitting materials. The light-emitting materials may include those exhibiting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red, as appropriate. Furthermore, materials emitting near-infrared light may also be used as light-emitting materials.

[0542] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0543] 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.

[0544] 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.

[0545] 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). The one or more types of organic compounds may include one or both of materials with high hole transport properties (hole transport materials) and materials with high electron transport properties (electron transport materials). Furthermore, bipolar materials or TADF materials may be used as the one or more types of organic compounds.

[0546] 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.

[0547] The EL layer 763, as a layer other than the light-emitting layer, may further have a layer containing a substance with high hole injection property, a substance with high hole transport property, a hole blocking material, a substance with high electron transport property, a substance with high electron injection property, an electron blocking material, or a bipolar substance (a substance with high electron transport property and high hole transport property), etc.

[0548] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a substance with high hole injection property. Examples of substances with high hole injection property include aromatic amine compounds and composite materials containing a hole transport material and an acceptor material (electron-accepting material).

[0549] The hole transport layer is a layer that transports the holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more is preferable. As long as it is a substance with higher hole transport property than electrons, other substances can also be used. As the hole transport material, substances with high hole transport property such as π-electron-excessive heteroaromatic compounds (such as carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton) are preferable.

[0550] The electron transport layer is a layer that transports the electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron transport material. As the electron transport material, 1×10 -6 cm 2Materials 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, which are all highly electron-transporting materials.

[0551] The electron injection layer is a layer that injects electrons from the cathode into the electron transport layer, and is a layer containing a material with high electron-injection properties. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron-injection properties. Composite materials containing both electron-transporting materials and donor materials (electron-donating materials) can also be used as materials with high electron-injection properties.

[0552] Furthermore, it is preferable that the LUMO level of a material with high electron injection capacity has a small difference (specifically, 0.5 eV or less) from the work function value of the material used as the cathode.

[0553] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). x (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatrium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatrium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatrium (abbreviation: LiPPP), lithium oxide (LiO xAlkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0554] The electron injection layer may contain an electron-transporting material. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0555] Furthermore, the lowest unoccupied molecular orbital (LUMO) level of organic compounds containing lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0556] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 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.

[0557] Furthermore, when fabricating a tandem light-emitting device, a charge generation layer (also called an intermediate layer) is provided between the two light-emitting units. The intermediate layer has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between the pair of electrodes.

[0558] As the charge generation layer, for example, a material applicable to the electron injection layer, such as lithium, can be suitably used. Alternatively, as the charge generation layer, a material applicable to the hole injection layer can be suitably used. Furthermore, the charge generation layer can include a layer containing a hole transport material and an acceptor material (electron-accepting material). Alternatively, the charge generation layer can include a layer containing an electron transport material and a donor material. By forming such a charge generation layer, the increase in driving voltage when light-emitting units are stacked can be suppressed.

[0559] This embodiment can be combined with other embodiments as appropriate.

[0560] (Embodiment 6) This embodiment describes a light-receiving device and a display device having light-receiving and light-receiving functions that can be used in a display device according to one aspect of the present invention.

[0561] 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.

[0562] 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.

[0563] [Light receiving device] As shown in Figure 29A, the photodetector has a layer 765 between a pair of electrodes (lower electrode 761 and upper electrode 762). The layer 765 has at least one active layer and may have other layers.

[0564] Furthermore, Figure 29B shows a modified example of the layer 765 of the photodetector shown in Figure 29A. Specifically, the photodetector shown in Figure 29B has a layer 766 on the lower electrode 761, an active layer 767 on the layer 766, a layer 768 on the active layer 767, and an upper electrode 762 on the layer 768.

[0565] The active layer 767 functions as a photoelectric conversion layer.

[0566] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 766 has one or both of a hole transport layer and an electron blocking layer. Similarly, layer 768 has one or both of an electron transport layer and a hole blocking layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 766 and 768 have the opposite configurations to those described above.

[0567] In one embodiment of the present invention, there may be a layer shared by both the light-receiving device and the light-emitting device (which can also be described as a continuous layer shared by both the light-receiving device and the light-emitting device). The function of such a layer may differ between the light-emitting device and the light-receiving device. In this specification, components may be referred to based on their function in the light-emitting device. For example, a 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, an 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. Furthermore, a layer shared by both the light-receiving device and the light-emitting device may have the same function in both the light-emitting device and the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting device and the light-receiving device, and an electron transport layer functions as an electron transport layer in both the light-emitting device and the light-receiving device.

[0568] Next, we will describe the materials that can be used in light-receiving devices.

[0569] 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.

[0570] The active layer of a light-receiving device includes a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon, and organic semiconductors containing organic compounds. In this embodiment, an example is shown in which an organic semiconductor is used as the semiconductor of the active layer. Using an organic semiconductor is preferable because the light-emitting layer and the active layer can be formed using the same method (for example, vacuum deposition), and the manufacturing equipment can be shared.

[0571] As for the n-type semiconductor material of the active layer, fullerene (for example, C 60 , C 70 Examples of electron-accepting organic semiconductor materials include fullerene derivatives. Examples of fullerene derivatives include [6,6]-Phenyl-C71-butyric acid methyl ester (abbreviated as PC70BM), [6,6]-Phenyl-C61-butyric acid methyl ester (abbreviated as PC60BM), and 1',1'',4',4''-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C60 (abbreviated as ICBA).

[0572] Furthermore, examples of n-type semiconductor materials include perylenetetracarboxylic acid derivatives such as N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic acid diimide (abbreviated as Me-PTCDI), and 2,2'-(5,5'-(thieno[3,2-b]thiophene-2,5-diyl)bis(thiophene-5,2-diyl))bis(methane-1-yl-1-ylidene)dimalonitrile (abbreviated as FT2TDMN).

[0573] 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.

[0574] 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), quinacridone, and rubrene.

[0575] 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, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, rubrene derivatives, tetracene derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0576] 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.

[0577] 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.

[0578] 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.

[0579] 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.

[0580] Furthermore, the active layer may use three or more types of materials. For example, to broaden the absorption 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.

[0581] 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, or an electron blocking material. For example, the layers other than the active layer of the photodetector can be made of materials that can be used in the light-emitting devices described above.

[0582] 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 transporting materials or electron blocking materials. In addition, inorganic compounds such as zinc oxide (ZnO) and organic compounds such as polyethyleneimine ethoxylate (PEIE) can be used as electron transporting materials or hole blocking materials. The light-receiving device may have, for example, a mixed film of PEIE and ZnO.

[0583] [Display device with light detection function] 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. In addition, 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.

[0584] Furthermore, in one embodiment of the present invention, the light-emitting device can be used as the light source for the sensor. In one embodiment of the present invention, when an object reflects (or scatters) the light emitted by the light-emitting device of the display unit, the light-receiving device can detect the reflected light (or scattered light), thus enabling imaging or touch detection even in dark places.

[0585] Therefore, it is not necessary to provide a light receiving unit and a light source separately from the display device, and the number of components in the electronic device can be reduced. For example, there is no need to separately provide a biometric authentication device or a capacitive touch panel for scrolling, etc., which are provided in the electronic device. Therefore, by using a display device according to one aspect of the present invention, it is possible to provide an electronic device with reduced manufacturing costs.

[0586] Specifically, a display device according to one aspect of the present invention has a light-emitting device and a light-receiving device in each pixel. In a display device according to 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.

[0587] 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, in addition to displaying an image with all of the subpixels of the display device, some subpixels can emit light as a light source, some other subpixels can perform light detection, and the remaining subpixels can display an image.

[0588] 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.

[0589] For example, an image sensor can be used to capture images for personal authentication, such as fingerprints, palm prints, irises, pulse patterns (including vein and artery patterns), or faces.

[0590] For example, an image sensor can be used to image the area around the eyes, the surface of the eyes, or the inside of the eyes (such as the fundus) of the wearable device user. Therefore, the wearable device can be equipped with the ability to detect one or more of the user's blinking, pupil movement, and eyelid movement.

[0591] Furthermore, the light-receiving device can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover-touch sensor, non-contact sensor, or touchless sensor).

[0592] Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen).

[0593] A touch sensor can detect an object by making direct contact with the display device. A near-touch sensor can detect an object even if the object does not touch 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.

[0594] Furthermore, a display device according to one aspect of the present invention can have a variable refresh rate. For example, power consumption can be reduced by adjusting the refresh rate according to the content displayed on the display device (for example, within a range of 1 Hz to 240 Hz). In addition, the drive frequency of the touch sensor or near touch sensor may be changed according to the refresh rate. For example, if the refresh rate of the display device is 120 Hz, the drive frequency of the touch sensor or near touch sensor can be set to a frequency higher than 120 Hz (typically 240 Hz). This configuration makes it possible to achieve low power consumption and to increase the response speed of the touch sensor or near touch sensor.

[0595] The display device 100 shown in Figures 29C to 29E has a layer 353 having a light-receiving device, a functional layer 355, and a layer 357 having a light-emitting device between substrate 351 and substrate 359.

[0596] The functional layer 355 includes a circuit for driving a light-receiving device and a circuit for driving a light-emitting device. The functional layer 355 may include one or more of the following: switches, transistors, capacitors, resistors, wiring, and terminals. However, when the light-emitting device and light-receiving device are driven in a passive matrix manner, the configuration may be made without switches and transistors.

[0597] For example, as shown in Figure 29C, in layer 357 which has a light-emitting device, the light emitted by the light-emitting device is reflected by the finger 352 that is in contact with the display device 100, and the light-receiving device in layer 353 which has a light-receiving device detects the reflected light. This makes it possible to detect that the finger 352 has come into contact with the display device 100.

[0598] Furthermore, as shown in Figures 29D and 29E, the device may also have the function of detecting or imaging objects that are close to (i.e., not in contact with) the display device. Figure 29D shows an example of detecting a person's finger, and Figure 29E shows an example of detecting information around, on the surface of, or inside a person's eye (such as the number of blinks, eyeball movements, and eyelid movements).

[0599] This embodiment can be combined with other embodiments as appropriate.

[0600] (Embodiment 7) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 30 to 32.

[0601] The electronic device of this embodiment has a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention is easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0602] 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.

[0603] 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 wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0604] 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), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display device that has either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices. Furthermore, there are no particular limitations on the screen ratio (aspect ratio) of the display device according to one embodiment of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0605] The electronic device of this embodiment may have sensors (including those with the function of 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).

[0606] 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.

[0607] Figures 30A to 30D illustrate an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR content, and a function to display MR content. By having an electronic device that has the function to display at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0608] The electronic device 700A shown in Figure 30A and the electronic device 700B shown in Figure 30B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0609] A display device according to one aspect of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created.

[0610] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0611] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0612] The communications unit has a wireless communication device, which can supply video signals and the like. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable supplying video signals and power potential can be connected.

[0613] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0614] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0615] Various types of touch sensors can be applied to the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be used. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0616] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light-receiving device. The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0617] The electronic device 800A shown in Figure 30C and the electronic device 800B shown in Figure 30D each include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0618] A display device according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of displaying extremely high resolution can be created. This allows the user to experience a high level of immersion.

[0619] The display unit 820 is located inside the housing 821, in a position where it can be seen through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can also be performed.

[0620] Electronic devices 800A and 800B can be described as electronic devices for VR. A user wearing either electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0621] It is preferable that electronic devices 800A and 800B each have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 so that they are in the optimal position according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0622] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. While the attachment portion 823 is exemplified in Figure 30C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this shape. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0623] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0624] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of a detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0625] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This allows users to enjoy video and audio simply by wearing the electronic device 800A, without needing separate audio equipment such as headphones, earphones, or speakers.

[0626] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided within the electronic devices.

[0627] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 30A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 30C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0628] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 30B has an earphone section 727. For example, the earphone section 727 and the control section can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control section may be located inside the housing 721 or the mounting section 723.

[0629] Similarly, the electronic device 800B shown in Figure 30D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0630] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a sound-collecting device such as a microphone can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0631] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0632] Furthermore, an electronic device according to one aspect of the present invention can transmit information to earphones via wired or wireless means.

[0633] The electronic device 6500 shown in Figure 31A is a portable information terminal that can be used as a smartphone.

[0634] 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.

[0635] A display device according to one aspect of the present invention can be applied to the display unit 6502.

[0636] Figure 31B is a schematic cross-sectional view of the housing 6501, including the end on the microphone 6506 side.

[0637] 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.

[0638] 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).

[0639] 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.

[0640] A flexible display according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 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, it is possible to realize an electronic device with a narrow bezel.

[0641] Figure 31C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown supported by a stand 7103.

[0642] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0643] The television device 7100 shown in Figure 31C 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.

[0644] 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.

[0645] Figure 31D 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.

[0646] A display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0647] Figures 31E and 31F show examples of digital signage.

[0648] The digital signage 7300 shown in Figure 31E 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.

[0649] Figure 31F 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.

[0650] In Figures 31E and 31F, a display device according to one embodiment of the present invention can be applied to the display unit 7000.

[0651] 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.

[0652] 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.

[0653] Furthermore, as shown in Figures 31E and 31F, 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.

[0654] 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 an unspecified number of users to participate in and enjoy the game simultaneously.

[0655] The electronic equipment shown in Figures 32A to 32G 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 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.

[0656] In Figures 32A to 32G, a display device according to one embodiment of the present invention can be applied to the display unit 9001.

[0657] The electronic devices shown in Figures 32A to 32G have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0658] Details of the electronic equipment shown in Figures 32A to 32G will be explained below.

[0659] Figure 32A 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 32A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the subject of an email or SNS message, the sender's name, date and time, time, battery level, signal strength, etc. Alternatively, icons 9050 or the like may be displayed in the position where the information 9051 is displayed.

[0660] Figure 32B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0661] Figure 32C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000. The left side of the housing 9000 has operation keys 9005 as buttons for operation, and the bottom has connection terminals 9006.

[0662] Figure 32D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. Charging may be performed by wireless power supply.

[0663] Figures 32E to 32G are perspective views showing a foldable personal information terminal 9201. Figure 32E shows the personal information terminal 9201 in an unfolded state, Figure 32G shows it in a folded state, and Figure 32F shows a perspective view of the state in between, transitioning from one of Figures 32E or 32G to the other. The 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.

[0664] This embodiment can be combined with other embodiments as appropriate. [Examples]

[0665] In this embodiment, a display device according to one aspect of the present invention is fabricated, and the results of displaying an image are described.

[0666] The display device fabricated in this embodiment is a top-emission type OLED display with the cross-sectional structure shown in Figure 1B. The display area has a diagonal size of approximately 1.50 inches and a resolution of 3207 ppi.

[0667] The display device fabricated in this embodiment was manufactured by applying the method for fabricating the display device shown in Embodiment 2. In other words, the display device shown in Figure 33 has an MML (metal maskless) structured light-emitting device.

[0668] OS transistors were used in layer 101, which contains the transistors. Aluminum oxide films were used for mask layers 118a, 118b, and 118c. Tungsten films were used for mask layers 119a, 119b, and 119c, and were removed before the formation of the insulating film 125A to ensure that they did not remain in the finished display device.

[0669] As the insulating film 125A, an aluminum oxide film was formed using the ALD method at a substrate temperature of 80°C to a thickness of approximately 15 nm (Figure 11A).

[0670] As the insulating film 127a, a positive-type photosensitive resin containing acrylic resin was applied to a thickness of approximately 400 nm (Figure 11B). The pre-bake temperature was 90°C, and the post-bake temperature after development (Figure 13A) was 100°C. Both the first etching process (Figure 12A) and the second etching process (Figure 13B) were performed using the wet etching method.

[0671] Figure 33 shows a photograph illustrating the display results of the device fabricated in this embodiment. As shown in Figure 33, good display was obtained. Furthermore, the display resolution was 1350 cd / m² in full white. 2 This allowed for display with extremely high brightness. The fabricated display device achieved an extremely high aperture ratio of 65%. [Examples]

[0672] In this example, the results of measuring the volume shrinkage rate of the material that can be used for the insulating layer 127 will be explained with reference to Figure 34.

[0673] As sample A, a positive-type photosensitive resin containing acrylic resin, as used in Example 1, was deposited and heat-cured by heating at 100°C for 10 minutes. The film thickness after heating was then measured. In Figure 34, this film thickness is shown as the film thickness before vacuum baking.

[0674] Furthermore, as comparative sample B, a positive-type resist material was deposited and heated at 90°C for 90 seconds to allow it to heat-cur. The film thickness after heating was then measured. In Figure 34, this film thickness is shown as the film thickness before vacuum baking.

[0675] Next, sample A and comparative sample B were heated under reduced pressure at 100°C for 1 hour. The film thickness was then measured. In Figure 34, this film thickness is shown as the film thickness after reduced pressure baking.

[0676] As shown in Figure 34, in comparative sample B, the film thickness decreased by approximately 4.7% before and after vacuum baking. On the other hand, in sample A, the film thickness hardly decreased before and after vacuum baking, and no significant difference was observed (the decrease in film thickness was approximately 0.08%).

[0677] As described above, the positive-type photosensitive resin containing acrylic resin used in Example 1 was found to be a material with low volume shrinkage. Therefore, it was found to be suitable as a material for the insulating layer 127 of the display device according to one embodiment of the present invention. [Explanation of Symbols]

[0678] 100A: Display device, 100B: Display device, 100C: Display device, 100D: Display device, 100E: Display device, 100F: Display device, 100G: Display device, 100H: Display device, 100J: Display device, 100: Display device, 101: Layer containing transistors, 103: Region, 11...

Claims

1. A first pixel electrode and a second pixel electrode are formed. A first film is formed on the first pixel electrode and the second pixel electrode. A first mask film is formed on the first film. The first film and the first mask film are processed to form a first layer and a first mask layer on the first pixel electrode, and the second pixel electrode is exposed. A second film is formed on the first mask layer and the second pixel electrode. A second mask film is formed on the second film. The second film and the second mask film are processed to form a second layer and a second mask layer on the second pixel electrode, and the first mask layer is exposed. A first insulating film is formed on the first mask layer and the second mask layer. A second insulating film is formed on the first insulating film. The second insulating film is processed to form a second insulating layer that overlaps with the region sandwiched between the first pixel electrode and the second pixel electrode. Using the second insulating layer as a mask, the first etching process is performed to remove a portion of the first insulating film and to thin the film thickness of a portion of the first mask layer and a portion of the second mask layer. Heat treatment is performed, and then, using the second insulating layer as a mask, a second etching treatment is performed to remove a portion of the first mask layer and a portion of the second mask layer, exposing the upper surface of the first layer and the upper surface of the second layer. A common electrode is formed by covering the first layer, the second layer, and the second insulating layer. The first layer has at least a first light-emitting layer, A method for manufacturing a display device, wherein the second layer has at least a second light-emitting layer.

2. In claim 1, The first layer has a first functional layer on the first light-emitting layer, The second layer has a second functional layer on the second light-emitting layer, A method for manufacturing a display device, wherein the first functional layer and the second functional layer each have at least one of the following: a hole injection layer, an electron injection layer, a hole transport layer, an electron transport layer, a hole blocking layer, and an electron blocking layer.

3. In claim 1 or claim 2, As the first insulating film, an aluminum oxide film is formed using the ALD method. A method for manufacturing a display device, comprising forming aluminum oxide films as the first and second mask films using the ALD method.

4. In claim 1 or claim 2, A method for manufacturing a display device, comprising irradiating the second insulating layer with light before the aforementioned heat treatment.

5. In claim 1 or claim 2, A method for manufacturing a display device, wherein the second insulating film is formed using a photosensitive acrylic resin.

6. In claim 1 or claim 2, A method for manufacturing a display device, wherein the first etching process and the second etching process are performed by wet etching.

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