Indication device

Abstract

To provide a display device with high display quality. [Solution] The display device comprises a light-emitting device, a light-receiving device, a first plano-convex lens, and a second plano-convex lens, wherein the light-emitting device and the first plano-convex lens have overlapping regions, and the light-receiving device and the second plano-convex lens also have overlapping regions, each of the light-emitting device and the light-receiving device has a pair of electrodes and an organic compound provided between the pair of electrodes, one of the pair of electrodes is a conductive film that is transparent to visible light, the first plano-convex lens and the second plano-convex lens are provided with the surface opposite to the convex surface in contact with the conductive film, and the refractive index of the plano-convex lens is greater than the refractive index of the conductive film.

Description

[Technical Field]

[0001] One aspect of the present invention relates to 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 applied to a wide variety of uses. Examples of large-scale display devices include home television systems, digital signage, and PID (Public Information Display). Display devices are also used in 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, light-emitting devices (also called light-emitting elements) have 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 referred to as an organic EL element).

[0007] In addition, in the display device, in order to improve the light extraction efficiency, a structure in which light emitted by a light-emitting device is extracted through a microlens is also adopted. Patent Document 2 discloses a method for forming a microlens using a radiation-sensitive resin composition.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] One aspect of the present invention is to provide a display device with high display quality as one of the problems. One aspect of the present invention is to provide a high-definition display device as one of the problems. One aspect of the present invention is to provide a high-resolution display device as one of the problems. One aspect of the present invention is to provide a high-brightness display device as one of the problems. One aspect of the invention is to provide a display device having an imaging function as one of the problems. One aspect of the invention is to provide a display device having an authentication function as one of the problems. One aspect of the present invention is to provide a highly reliable display device as one of the problems.

[0010] Note that the description of these problems does not prevent the existence of other problems. One aspect of the present invention does not necessarily need to solve all of these problems. It is possible to extract other problems from the description of the specification, drawings, and claims.

Means for Solving the Problems

[0011] One aspect of the present invention has a light-emitting device and a lens. The light-emitting device and the lens have an overlapping region with each other. The light-emitting device has a pair of electrodes and an organic compound provided between the pair of electrodes. One of the pair of electrodes is a conductive film having light transmittance for visible light. The lens is provided in contact with the conductive film, and the refractive index of the lens is greater than the refractive index of the conductive film, which is a display device.

[0012] The lens is a plano-convex lens, and the surface opposite to the convex surface can be provided in contact with the conductive film.

[0013] Another aspect of the present invention has a first light-emitting device, a second light-emitting device, a first lens, and a second lens. The first light-emitting device and the second light-emitting device are provided at adjacent positions. An organic insulating layer is provided in a region including between the first light-emitting device and the second light-emitting device. The first light-emitting device and the first lens have an overlapping region with each other. The second light-emitting device and the second lens have an overlapping region with each other. Each of the first light-emitting device and the second light-emitting device has a pair of electrodes and an organic compound provided between the pair of electrodes. One of the pair of electrodes is a common electrode formed on the organic compound and on the organic insulating layer, which is a conductive film having light transmittance for visible light. The first lens and the second lens are provided in contact with the conductive film, and the refractive indices of the first lens and the second lens are greater than the refractive index of the conductive film, which is a display device.

[0014] Another aspect of the present invention is a display device comprising a light-emitting device, a light-receiving device, a first lens, and a second lens, wherein the light-emitting device and the light-receiving device are located adjacent to each other, an organic insulating layer is provided in the region including the space between the light-emitting device and the light-receiving device, the light-emitting device and the first lens have overlapping regions, the light-receiving device and the second lens have overlapping regions, each of the light-emitting device and the light-receiving device has a pair of electrodes and an organic compound provided between the pair of electrodes, one of the pair of electrodes is a common electrode formed on the organic compound and the organic insulating layer and is a conductive film that is transparent to visible light, the first lens and the second lens are provided in contact with the conductive film, and the refractive index of the first lens and the second lens is greater than the refractive index of the conductive film.

[0015] It is preferable that the organic insulating layer, the first lens, and the second lens be formed from the same material.

[0016] The first and second lenses are plano-convex lenses, and can be provided with the surface opposite to the convex surface in contact with the conductive film.

[0017] It is preferable to have an inorganic insulating layer between the organic compound and the organic insulating layer.

[0018] The organic insulating layer preferably has a convex curved shape on its upper surface.

[0019] Another aspect of the present invention is an electronic device comprising the above-mentioned display device and an optical member, wherein the display device can project a display onto the optical member, the optical member can transmit light, and by viewing the optical member, an image in which the image transmitted through the optical member and the display overlap can be viewed. [Effects of the Invention]

[0020] 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 high-brightness display device can be provided. According to one aspect of the present invention, a display device having an imaging function can be provided. According to one aspect of the present invention, a display device having an authentication function can be provided. According to one aspect of the present invention, a highly reliable display device can be provided.

[0021] 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]

[0022] [Figure 1] 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. [Figure 2] Figures 2A and 2B are cross-sectional views showing an example of a display device. [Figure 3] Figures 3A and 3B are cross-sectional views showing an example of a display device. [Figure 4] Figures 4A and 4B are cross-sectional views showing an example of a display device. [Figure 5] Figures 5A and 5B are cross-sectional views showing an example of a display device. [Figure 6] Figures 6A and 6B are cross-sectional views showing an example of a display device. [Figure 7] Figures 7A and 7B are cross-sectional views showing an example of a display device. [Figure 8] Figures 8A and 8B are cross-sectional views showing an example of a display device. [Figure 9] Figures 9A and 9B are cross-sectional views showing an example of a display device. [Figure 10] Figures 10A and 10B are cross-sectional views showing an example of a display device. [Figure 11]Figure 11 is a cross-sectional view showing an example of a display device. [Figure 12] Figure 12A is a top view showing an example of a display device. Figure 12B is a cross-sectional view showing an example of a display device. [Figure 13] Figures 13A to 13C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 14] Figures 14A to 14C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 15] Figures 15A to 15C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 16] Figures 16A to 16C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 17] Figures 17A to 17C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 18] Figures 18A to 18C are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 19] Figures 19A and 19B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 20] Figures 20A to 20D are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 21] Figures 21A to 21F show examples of pixels. [Figure 22] Figures 22A to 22K show examples of pixels. [Figure 23] Figures 23A and 23B are perspective views showing an example of a display device. [Figure 24] Figures 24A and 24B are cross-sectional views showing an example of a display device. [Figure 25] Figure 25 is a cross-sectional view showing an example of a display device. [Figure 26] Figure 26 is a cross-sectional view showing an example of a display device. [Figure 27] Figure 27 is a cross-sectional view showing an example of a display device. [Figure 28] Figure 28 is a cross-sectional view showing an example of a display device. [Figure 29] Figure 29 is a cross-sectional view showing an example of a display device. [Figure 30] Figure 30 is a perspective view showing an example of a display device. [Figure 31] Figure 31A is a cross-sectional view showing an example of a display device. Figures 31B and 31C are cross-sectional views showing an example of a transistor. [Figure 32] Figure 32 is a cross-sectional view showing an example of a display device. [Figure 33] Figures 33A to 33F show examples of the configuration of a light-emitting device. [Figure 34] Figures 34A and 34B show examples of the configuration of a light-receiving device. Figures 34C to 34E show examples of the configuration of a display device. [Figure 35] Figures 35A to 35D show examples of electronic devices. [Figure 36] Figures 36A to 36F show examples of electronic devices. [Figure 37] Figures 37A to 37G show examples of electronic devices. [Modes for carrying out the invention]

[0023] 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 invention. Accordingly, the present invention shall not be construed as being limited to the descriptions of the embodiments shown below.

[0024] In the invention described below, the same reference numerals are used in common across different drawings for parts that are identical or have similar functions, and repeated explanations are omitted. Furthermore, when referring to similar functions, the hatch patterns are the same, and reference numerals may not be assigned.

[0025] Furthermore, the position, size, and extent of each component shown in the drawings may not represent the actual position, size, and extent for the sake of ease of understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, and extent disclosed in the drawings.

[0026] 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."

[0027] 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.

[0028] 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.

[0029] In this specification, a light-emitting device (light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of layers (also called functional layers) that make up the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking 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.

[0030] In this specification, a tapered shape refers to a shape in which at least a portion of the side surface of the structure is inclined with respect to the substrate surface. For example, it is preferable to have a region in which the angle between the inclined side surface and the substrate surface (also called the taper angle) is less than 90°. The side surface of the structure and the substrate surface do not necessarily have to be perfectly flat; they may be substantially planar with a fine curvature, or substantially planar with fine irregularities.

[0031] (Embodiment 1) In this embodiment, a display device according to one aspect of the present invention will be described with reference to the drawings.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] In this specification, "island-like" refers to a state in which two or more layers formed using the same material 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.

[0036] Island-shaped light-emitting layers can be formed by vacuum deposition using a metal mask. However, this method makes it difficult to achieve high resolution and high aperture ratio in display devices because the shape and position of the island-shaped light-emitting layers deviate from the design 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. In addition, the contour of the layer may become blurred during deposition, and the thickness at the edges may become thinner.

[0037] In other words, the thickness of the island-shaped light-emitting layer can vary depending on the location. Furthermore, when manufacturing large, high-resolution, or high-definition display devices, there are concerns that the low dimensional accuracy of the metal mask and deformation due to heat, etc., may lead to low manufacturing yield.

[0038] 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 lithography and etching processes without using a metal mask or the like. 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 lithography and etching processes 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.

[0039] Furthermore, when the above-mentioned light-emitting layer is processed into an island shape, the light-emitting layer may be damaged during the lithography and etching processes, significantly impairing its reliability. Therefore, when manufacturing a display device according to one embodiment of the present invention, it is preferable to use a method in which a mask layer (also called a sacrificial layer, protective layer, etc.) is formed on a functional layer located above the light-emitting layer (for example, a carrier block layer, carrier transport layer, or carrier injection layer, more specifically a hole block layer, electron transport layer, or electron injection layer, etc.), and the light-emitting layer and the functional layer are processed into an island shape. By applying this method, 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.

[0040] In this specification, the mask film and 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.

[0041] Furthermore, when processing the above-mentioned light-emitting layer into an island shape, it is preferable to process the layers located below the light-emitting layer (for example, the carrier injection layer, carrier transport layer, or carrier block layer, more specifically the hole injection layer, hole transport layer, or electron block layer) into an island shape using the same pattern as the light-emitting layer. By processing the layers located below the light-emitting layer into an island shape using the same pattern as the light-emitting layer, it is possible to reduce the leakage current (sometimes called lateral leakage current or transverse leakage current) that may occur between adjacent subpixels.

[0042] When a hole injection layer is used as a common layer between adjacent subpixels, lateral leakage current can be generated due to the hole injection layer. On the other hand, in a display device according to one aspect of the present invention, since the hole injection layer can be processed in an island shape with the same pattern as the light-emitting layer, lateral leakage current between adjacent subpixels is substantially eliminated or can be made extremely small.

[0043] When processing an EL layer using photolithography, wet etching, and dry etching processes, the EL layer may be damaged during each process. Heating has a particularly significant impact; if the processes performed after the deposition of the EL layer are carried out at temperatures higher than the heat resistance temperature of the EL layer, the EL layer may degrade, potentially reducing the luminous efficiency and reliability of the light-emitting device.

[0044] Therefore, in one embodiment of the present invention, the heat resistance temperature of the compounds contained in the light-emitting device is set to 100°C or more and 180°C or less, preferably 120°C or more and 180°C or less, and more preferably 140°C or more and 180°C or less.

[0045] Indicators of heat resistance temperature include the glass transition temperature (Tg), softening point, melting point, thermal decomposition temperature, and 5% weight loss temperature. For example, the glass transition temperature of the material in each layer constituting the EL layer can be used as an indicator of the heat resistance temperature of that layer. If the layer is a mixed layer consisting of multiple materials, the glass transition temperature of the most abundant material can be used. Alternatively, the lowest glass transition temperature among the multiple materials may be used.

[0046] In particular, it is preferable to increase the heat resistance temperature of the light-emitting layer and the functional layer provided on the light-emitting layer. By increasing the heat resistance of the light-emitting layer, it is possible to suppress damage to the light-emitting layer due to heating, which reduces the luminous efficiency and shortens its lifespan. In addition, by increasing the heat resistance of the functional layer, it is possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0047] By increasing the heat resistance temperature of light-emitting devices, their reliability can be improved. Furthermore, the temperature range in the manufacturing process of display devices can be broadened, leading to improved manufacturing yield and reliability.

[0048] In light-emitting devices that emit different colors, some of the layers constituting the EL layer can be formed in the same process. 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 light-emitting color, then a portion of the mask layer is removed, and the remaining layers constituting the EL layer (sometimes called a common layer) and a common electrode (also called an upper electrode) are formed in common for each color (as a single film). For example, the carrier injection layer and the common electrode can be formed in common for each color.

[0049] On the other hand, the carrier injection layer is often a relatively conductive layer within the EL layer. Therefore, if the carrier injection layer comes into contact with the side surface of some of the island-shaped EL layers, or with the side surface of the pixel electrode, there is a risk of a short circuit in the light-emitting device. Furthermore, even when the carrier injection layer is provided in an island shape and a common electrode is formed common to each color, there is a risk of a short circuit in the light-emitting device if the common electrode comes into contact with the side surface of the EL layer, or with the side surface of the pixel electrode.

[0050] 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.

[0051] This prevents at least a portion of the island-shaped EL layers 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.

[0052] 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 the common layer and common electrode provided on the insulating layer from being interrupted by a step. Therefore, connection failures due to step interruptions 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.

[0053] 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).

[0054] 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.

[0055] Furthermore, while it is difficult to reduce the spacing between adjacent light-emitting devices to less than 10 μm using a formation method with a fine metal mask, according to a lithography method in one aspect of the present invention, the spacing between adjacent light-emitting devices, the spacing between adjacent EL layers, or the spacing between adjacent pixel electrodes can be reduced 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 during the process on a glass substrate.

[0056] Furthermore, by using an exposure apparatus designed for LSIs, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes in the Si Wafer process can be reduced to 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​non-light-emitting regions that may exist between two light-emitting devices, making it possible to bring the aperture ratio closer to 100%. In one embodiment 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 still being less than 100%.

[0057] Furthermore, increasing the aperture ratio of a display device can improve its reliability. More specifically, using an organic EL device, if we use the lifespan of a display device with an aperture ratio of 10% as a baseline, the lifespan of a display device with an aperture ratio of 20% will be approximately 3.25 times longer, and the lifespan of a display device with an aperture ratio of 40% will be approximately 10.6 times longer. In this way, as the aperture ratio increases, the current density flowing through the organic EL device can be reduced, making it possible to improve the lifespan of the display device.

[0058] In one embodiment of the present invention, the aperture ratio can be improved, thereby improving the display quality of the display device. Furthermore, the improved aperture ratio of the display device has the excellent effect of significantly improving the reliability (especially the lifespan) of the display device.

[0059] Furthermore, the pattern of the light-emitting layer itself can be made extremely small compared to when a fine metal mask is used. Also, when a metal mask is used to create different light-emitting layers, variations in thickness occur between the center and edges of the pattern, so the effective area that can be used as a light-emitting region is small relative to the total area of ​​the pattern.

[0060] On the other hand, in 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 fine patterns, almost the entire area can be used as a light-emitting region. As a result, a display device that combines high resolution and a high aperture ratio can be manufactured. Furthermore, miniaturization and weight reduction of the display device can be achieved.

[0061] Specifically, a display device according to one aspect of the present invention has a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0062] Furthermore, a display device according to one aspect of the present invention has a convex lens-shaped structure on the light-emitting device. By providing the structure on the light-emitting device, the efficiency of extracting light emitted by the light-emitting device to the outside can be increased.

[0063] In one aspect of the present invention, the light-emitting device is of the top-emission type, and light is extracted to the outside through a translucent conductive film that transmits visible light, which is one electrode of the light-emitting device. In this case, some of the light emitted by the light-emitting device propagates laterally using the translucent conductive film as a waveguide, reducing the efficiency of light extraction. In one aspect of the present invention, by providing a convex lens-shaped structure on the translucent conductive film, the light propagating laterally can be suppressed and the efficiency of light extraction can be improved.

[0064] Furthermore, in one embodiment of the present invention, if the display device has a light-receiving device, a convex lens-shaped structure can also be provided on the light-receiving device. By making the diameter of the structure provided on the light-receiving device larger than the effective area of ​​the light-receiving portion, the light-collecting ability can be increased, and the light sensitivity of the light-receiving device can be improved.

[0065] The convex lens-shaped structure can be provided on both the light-emitting device and the light-receiving device, but it may also be provided on only one of them.

[0066] In this specification, the above-mentioned convex lens-shaped structure may be simply referred to as a lens or a microlens. Furthermore, a structure in which such lenses are arranged regularly may be referred to as a microlens array (MLA).

[0067] 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.

[0068] 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 outside the display unit. Multiple subpixels are arranged at equal intervals in the display unit. Figure 1A shows some of the subpixels, and multiple subpixels make up a pixel. The connection unit 140 can also be called the cathode contact unit.

[0069] In this specification and other documents, the row direction may be referred to as the X direction and the column direction as the Y direction. The X and Y directions intersect, or intersect perpendicularly or nearly perpendicularly (see Figure 1A).

[0070] The top surface shape of the sub-pixel shown in Figure 1A corresponds to the top surface shape of the light-emitting region. Examples of top surface shapes of sub-pixels include polygons such as triangles, quadrilaterals (including rectangles and squares), and pentagons, as well as polygons with rounded corners, ellipses, and circles. In this specification, the term "top surface shape" refers to the shape as seen from above.

[0071] 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. 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.

[0072] 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.

[0073] The pixel 110 shown in Figure 1A employs a delta array. Pixel 110 in Figure 1A is composed of three subpixels: subpixels 110a, 110b, and 110c. Each subpixel 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; 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; or subpixels of R, G, B, and infrared (IR).

[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 cross-sectional views 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 are provided on the insulating layer, and a lens 133 is provided on each light-emitting device. A protective layer 131 is also provided to cover the lens 133. A 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 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] One embodiment of the present invention is a top-emission type display device that emits light in the direction opposite to the substrate on which the light-emitting device is formed.

[0079] The layer 101 containing transistors can be a laminated structure having multiple transistors provided on a substrate and insulating layers covering these transistors. The insulating layers on the transistors may be single-layer or laminated. 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 a recess is provided in insulating layer 255c. Note that the insulating layers on the transistors (insulating layers 255a to insulating layers 255c) can also be considered as part of the layer 101 containing 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] It is preferable to use an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode) as the light-emitting device. 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. LEDs such as microLEDs (Light Emitting Diodes) can also be used as the light-emitting device.

[0085] The light emitted by the light-emitting device can be infrared light or visible light (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.

[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 cathode and the other as the anode. 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 layers 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 levels.

[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. 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 (also called dirt 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. 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 in the 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, the first layer 113a may have an emissive layer that emits red light, the second layer 113b may have an emissive layer that emits green light, and the third layer 113c may have 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] 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. An electron blocking layer may also be present between the hole transport layer and the emissive layer. Furthermore, a hole blocking layer may be present between the electron transport layer and the emissive layer. Additionally, an electron injection layer may be present on the electron transport layer.

[0101] Furthermore, 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. An electron blocking layer may also be present between the hole transport layer and the emissive layer. Furthermore, a hole injection layer may be present on the hole transport layer.

[0102] Thus, it is preferable that 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. Furthermore, it is preferable that the first layer 113a, the second layer 113b, and the third layer 113c each have an emissive layer and a carrier block layer (hole block layer or electron block layer) on the emissive layer. Furthermore, it is preferable that the first layer 113a, the second layer 113b, and the third layer 113c each have an emissive layer, a carrier block layer on the emissive layer, and a carrier transport layer on the carrier block 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, by providing one or both of the carrier transport layer and the carrier block layer on the emissive layer, it is possible to suppress the exposure of the emissive layer to the outermost surface and reduce the damage to the emissive layer. This can improve the reliability of light-emitting devices.

[0103] The heat resistance temperatures of the compounds contained in the first layer 113a, the second layer 113b, and the third layer 113c are, respectively, 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C. The glass transition temperatures (Tg) of these compounds are, respectively, 100°C to 180°C, preferably 120°C to 180°C, and more preferably 140°C to 180°C.

[0104] In particular, it is preferable that the heat resistance temperature of the functional layer provided on the light-emitting layer is high. Furthermore, it is even more preferable that the heat resistance temperature of the functional layer provided in contact with the light-emitting layer is high. The high heat resistance of the functional layer makes it possible to effectively protect the light-emitting layer and reduce the damage it receives.

[0105] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c may have a first light-emitting unit, a charge-generating layer, and a second light-emitting unit.

[0106] The second light-emitting unit preferably has a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer and a carrier block layer (hole block layer or electron block layer) on the light-emitting layer. Alternatively, the second light-emitting unit preferably has a light-emitting layer, a carrier block layer on the light-emitting layer, and a carrier transport layer on the carrier block layer.

[0107] Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, providing one or both of the carrier transport layer and the carrier block layer on the light-emitting layer suppresses exposure of the light-emitting layer to the outermost surface and reduces damage to the light-emitting layer. This improves the reliability of the light-emitting device. When there are three or more light-emitting units, it is preferable that the uppermost light-emitting unit has a light-emitting layer and one or both of the carrier transport layer and the carrier block layer on the light-emitting layer.

[0108] The common layer 114 may have 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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 on the connection portion 140 (see Figures 2A and 2B). 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.

[0113] In Figure 2A, 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 2B, 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.

[0114] 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.

[0115] The 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, the mask layer 118b is a portion of the mask layer that remained when the second layer 113b was formed, and the mask layer 118c is a portion of the mask layer that remained when the third layer 113c was formed.

[0116] Thus, in one embodiment of the present invention, the display device may have a portion of the mask layer used to protect the EL layer during its manufacture remaining. Two or all of the mask layers 118a to 118c may be made of the same material, or different materials may be used. In the following, the mask layers 118a, 118b, and 118c may be collectively referred to as the mask layer 118.

[0117] 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.

[0118] In this case, the other end of the mask layer 118a is more likely to be formed on the generally 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.

[0119] 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.

[0120] Each side of the first layer 113a, the second layer 113b, and the third layer 113c is covered by an insulating layer 125. The insulating layer 127 overlaps with each side of the first layer 113a, the second layer 113b, and the third layer 113c via the insulating layer 125.

[0121] Furthermore, portions of the upper surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are covered by the mask layer 118. The insulating layer 125 and the insulating layer 127 overlap portions 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 7A) located outside the upper surfaces of the pixel electrodes.

[0122] By covering a portion of the top surface and sides of the first layer 113a, the second layer 113b, and the third layer 113c with at least one of the insulating layer 125, the insulating layer 127, and the mask layer 118, it is possible to suppress contact between the common layer 114 (or common electrode 115) and the sides of 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.

[0123] 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. 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.

[0124] 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 3A). 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 films of the first layer 113a, the second layer 113b, and the third layer 113c can be prevented.

[0125] The insulating layer adheres closely to the first layer 113a, the second layer 113b, or the third layer 113c, resulting in the effect of fixing or bonding adjacent first layers 113a, etc., to each other. This improves the reliability of the light-emitting device and increases the manufacturing yield of the light-emitting device.

[0126] 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.

[0127] 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.

[0128] 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 surfaces of the second layer 113b and the third layer 113c.

[0129] The insulating layer 127 is provided on the insulating layer 125 so as to fill any recesses formed in the insulating layer 125. The insulating layer 127 can be configured to overlap with a portion of the upper surface and sides 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 sides of the insulating layer 125.

[0130] By providing insulating layers 125 and 127, the gaps between adjacent island-shaped layers can be filled, thereby reducing extreme 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.

[0131] 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 layers 125 and 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).

[0132] A display device according to one aspect of the present invention has insulating layers 125 and 127, which flatten the step 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 and the resulting increase in electrical resistance.

[0133] The upper surface of the insulating layer 127 preferably has a shape that is more flat, but it may have convex portions, convex curved surfaces, concave curved surfaces, or recesses. For example, the upper surface of the insulating layer 127 preferably has a smooth convex curved shape.

[0134] In one embodiment of the present invention, an insulating layer 127 is provided on the insulating layer 125 so as to fill the recess where the insulating layer 125 is formed. The insulating layer 127 is provided between island-shaped EL layers. In other words, in one embodiment of the present invention, a process (hereinafter referred to as process 1) is applied in which island-shaped EL layers are formed, and then an insulating layer 127 is provided so as to overlap with the edges of the island-shaped EL layers.

[0135] On the other hand, a process different from Process 1 is a process (hereinafter referred to as Process 2) in which, after forming the pixel electrodes in an island shape, an insulating film (also called a dam or structure) is formed to cover the ends of the pixel electrodes, and then an island-shaped EL layer is formed on the pixel electrodes and the insulating film.

[0136] Process 1 is preferable to Process 2 because it allows for a wider margin. More specifically, Process 1 provides a display device with a wider margin for alignment accuracy between different patterns and less variation than Process 2. Therefore, in a method for manufacturing a display device according to one aspect of the present invention, since the process is similar to Process 1, a display device with less variation and high display quality can be provided.

[0137] Next, we will describe examples of materials for insulating layer 125 and insulating layer 127.

[0138] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 may be a single layer or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride oxide film and aluminum nitride oxide film. In particular, 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.

[0139] 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.

[0140] 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.

[0141] 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 (getters) the corresponding substance.

[0142] 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.

[0143] 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. It is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration and / or carbon concentration, preferably both.

[0144] 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 perceived 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 that single layer.

[0145] The insulating layer 127, provided on the insulating layer 125, has the function of flattening the extreme irregularities in the insulating layer 125 formed between adjacent light-emitting devices. In other words, the presence of the insulating layer 127 has the effect of improving the flatness of the surface forming the common electrode 115.

[0146] 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 resin composition containing an acrylic resin can be used. 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] Next, the structure of the insulating layer 127 and its vicinity will be described using Figures 3A and 3B. Figure 3A is an enlarged cross-sectional view of the insulating layer 127 between light-emitting devices 130a and 130b and some of the surrounding elements. In the following explanation, 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.

[0152] Figure 3B is an enlarged view of the edge of the insulating layer 127 on the second layer 113b and its vicinity, as shown in Figure 3A. In the following explanation, the edge of the insulating layer 127 on the second layer 113b may be used as an example, but the same applies to the edges of the insulating layer 127 on the first layer 113a, the edges of the insulating layer 127 on the third layer 113c, and so on.

[0153] As shown in Figure 3A, 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 of the first layer 113a, and a portion of the upper surface and side of the second layer 113b, via the insulating layer 125, and is in contact with at least a portion of the side 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.

[0154] Furthermore, the insulating layer 127 is formed in the region between the two island-shaped EL layers (in Figure 3A, the region between the first layer 113a and the second layer 113b). At this time, at least a portion of the insulating layer 127 is positioned between the side edge of one EL layer (in Figure 3A, the first layer 113a) and the side edge of the other EL layer (in Figure 3A, the second layer 113b). By providing such an insulating layer 127, it is possible to prevent the formation of divided areas and locally thin areas in the common layer 114 and common electrode 115 formed on the island-shaped EL layers and the insulating layer 127.

[0155] 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, as shown in Figure 3B. 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.

[0156] 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.

[0157] Furthermore, as shown in Figure 3A, 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.

[0158] As shown in Figure 3B, it is preferable that the edge of the insulating layer 127 is located outside the edge of the insulating layer 125. This reduces 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.

[0159] As shown in Figure 3B, 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.

[0160] 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.

[0161] 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 3B. 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.

[0162] 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 giving the mask layer 118b such a forward taper shape, the common layer 114 and common electrode 115 provided on the mask layer 118b can be formed with good coverage.

[0163] Preferably, the edges of mask layer 118a and mask layer 118b are located outside the edges of the insulating layer 125. This reduces surface irregularities on the common layer 114 and common electrode 115, thereby improving the coverage of the common layer 114 and common electrode 115.

[0164] 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. 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.

[0165] Furthermore, since the second etching process involves etching a thin film, the amount of side etching is reduced, making it less likely for voids to form, and even if voids do form, they can be made extremely small. As a result, it is possible to suppress the occurrence of irregularities on the surface forming the common layer 114 and the common electrode 115, and also to suppress the step-breaking of the common layer 114 and the common electrode 115.

[0166] 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.

[0167] 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. Figure 3B 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.

[0168] Furthermore, Figures 4A and 4B 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 4B, 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 4B 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 3B, and may be aligned with or approximately aligned with the edge of the mask layer 118b. Also, as shown in Figure 4B, the insulating layer 127 may be in contact with the second layer 113b.

[0169] Furthermore, Figures 5A, 5B, 6A, and 6B 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.

[0170] Figures 5A and 5B 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 6A and 6B 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.

[0171] In Figures 4 to 6, it is preferable that the taper angles θ1 to θ3 are within the above ranges.

[0172] Furthermore, as shown in Figures 3 to 6, 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 generally flat region of the first layer 113a and the second layer 113b.

[0173] 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.

[0174] Furthermore, the insulating layer 127 does not necessarily have to overlap with the upper surface of the pixel electrode. As shown in Figure 7A, 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 7B, the insulating layer 127 may not overlap with the pixel electrode, but be provided in the region sandwiched between the pixel electrode 111a and the pixel electrode 111b.

[0175] In Figures 7A and 7B, part or all of the upper surfaces of the inclined and flat portions (region 103) located outside the upper surface of the pixel electrode, of 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, the insulating layer 125, and the insulating layer 127, the surface irregularities forming the common layer 114 and the common electrode 115 can be reduced, and the coverage of the common layer 114 and the common electrode 115 can be improved.

[0176] Furthermore, as shown in Figure 8A, the upper surface of the insulating layer 127 may have a flat shape in a cross-sectional view of the display device. Alternatively, as shown in Figure 8B, the upper surface of the insulating layer 127 may have a concave curved shape. In Figure 8B, the upper surface of the insulating layer 127 has a shape that bulges gently towards the center, i.e., a convex curved surface, and a shape that is concave in the center and its vicinity. Also in Figure 8B, the convex curved portion of the upper surface of the insulating layer 127 is smoothly connected to the tapered portion at the end. Even if the insulating layer 127 has such a shape, the common layer 114 and the common electrode 115 can be formed on the entire insulating layer 127 with good coverage.

[0177] Furthermore, as shown in Figure 8B, by providing a concave curved surface in the center of the insulating layer 127, the stress on the insulating layer 127 can be relieved. More specifically, by providing a concave curved surface in the center of the insulating layer 127, local stress occurring at the edges of the insulating layer 127 can be relieved, thereby suppressing one or more of the following: delamination between the first layer 113a and the mask layer 118a, delamination between the mask layer 118a and the insulating layer 125, and delamination between the insulating layer 125 and the insulating layer 127.

[0178] As described above, in each configuration shown in Figures 3 to 8, 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 generally flat region of the first layer 113a to the generally flat region of the second layer 113b. Furthermore, it is possible to prevent the formation of areas separated by the common layer 114 and common electrode 115, as well as areas with locally thin film thickness.

[0179] Therefore, it is possible to suppress connection failures caused by the divided portions and increases in electrical resistance caused by locally thin film thicknesses 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 the display quality.

[0180] Next, the lenses 133 provided on each of the light-emitting devices 130a to 130c will be described using the cross-sectional views in Figures 9A to 10B. Figures 9A, 9B, 10A, and 11 show typical elements of the light-emitting device 130a. Figure 10B shows typical elements of the light-emitting devices 130a and 130b.

[0181] Figure 9A is a comparative example without the lens 133, and is a simplified diagram showing the optical path of the light emitted by the light-emitting device. Note that minute reflections at the boundaries of each layer are not shown. Most of the light emitted by the light-emitting device is extracted to the outside via a straight or nearly straight optical path. However, as shown in Figure 9A, some of the light emitted by the light-emitting device travels laterally using the common electrode 115, which is formed of a translucent conductive film provided on the insulating layer 127, as a waveguide, and becomes light that is not extracted to the outside. In other words, this phenomenon is one of the factors that reduces the efficiency of light extraction.

[0182] One factor contributing to the common electrode 115 acting as a waveguide is the difference in refractive index between the common electrode 115 and the layers above and below it. Another factor is that because the common electrode 115 is positioned to cross over the insulating layer 127, the angle of incidence of light entering the common electrode 115 on the insulating layer 127 becomes larger.

[0183] As shown in Figure 9A, a protective layer 131 is provided in contact with the common electrode 115, and a common layer 114 is provided in contact with the common electrode 115. Here, the refractive index of the common electrode 115 is n 115 The refractive index of the protective layer 131 is n 131 The refractive index of the common layer 114 is n 114 When n 115 >n 131 , and n 115 >n 114 In this case, light with a large angle of incidence to each interface is more likely to undergo total internal reflection. Therefore, light does not pass through the protective layer 131 and the common layer 114, but instead propagates laterally using the common electrode 115 as a waveguide. Note that the refractive index here refers to the refractive index in the wavelength range of the light emitted by the light-emitting device (blue to red wavelength range) or in visible light.

[0184] In addition, when a micro optical resonator (micro cavity) structure is applied to the light-emitting device, it is preferable to use an electrode (semi-transmissive and semi-reflective electrode) having light transmissivity and reflectivity as the common electrode 115. Therefore, there may be a case where an electrode having reflectivity is formed on the common layer 114 side of the common electrode 115. Accordingly, the reflection of light by the electrode also becomes one of the factors causing the common electrode 115 to function as a waveguide.

[0185] Therefore, in one aspect of the present invention, as shown in FIG. 9B, a lens 133 is provided between the common electrode 115 and the protective layer 131 in a region overlapping with the light-emitting portion of the light-emitting device. In FIG. 9B, the light-emitting portion is defined as the region where the first layer 113a and the common layer 114 are in contact. When the common layer 114 is not provided, it is defined as the region where the first layer 113a and the common electrode 115 are in contact.

[0186] A lens having a convex surface and a flat surface on the side opposite to the convex surface as shown in FIG. 9B is called a plano-convex lens. The lens 133 can be manufactured using the same material and process as the insulating layer 127 described above.

[0187] In one aspect of the present invention, the lens 133 is formed such that the surface opposite to the convex surface of the plano-convex lens contacts the common electrode 115. Also, when the refractive index of the lens 133 is n 133 then n 133 is equivalent to n 115 preferably n 133 is larger than n 115 to form a configuration.

[0188] With such a configuration, even when light with a large incident angle is incident on the interface between the common electrode 115 and the lens 133, total reflection does not occur, and the light passes from the common electrode 115 to the lens 133. Also, the light that enters the lens 133 reaches the protective layer 131 and the resin layer 122 provided on the lens 133. Since the incident angles at each interface are not large, the light can be extracted to the outside regardless of the refractive indices of the protective layer 131 and the resin layer 122. Therefore, by providing the lens 133 with the above-described refractive index, the light extraction efficiency can be increased.

[0189] Also, n 133 ga n 115 Even if it is smaller than this, if the difference is small, total internal reflection will be less likely to occur even when light with a relatively large angle of incidence is incident, and the light will more easily pass from the common electrode 115 to the lens 133. In this case, for example, n 133 to n 115 A value 1% to 30% smaller than, preferably n 133 to n 115 A value 1% to 20% smaller than, more preferably n 133 to n 115 The value should be 1% to 10% smaller than that.

[0190] Note that n 133 and n 131 ga n 115 Equivalent to, or n 133 and n 131 They are equivalent, and they are n 115 If the configuration is larger than that, a protective layer 131 may be provided between the common electrode 115 and the lens 133, as shown in Figure 10A.

[0191] Furthermore, as shown in Figure 10B, the ends of the lens 133 may be connected at adjacent pixels. This configuration eliminates the region where the common electrode 115 and the protective layer 131 are in contact. Therefore, the interface between the common electrode 115 and the protective layer 131 that causes total internal reflection can be eliminated, and the light extraction efficiency can be improved.

[0192] Furthermore, as shown in Figure 11, an insulating layer 134 may be provided between the common electrode 115 and the lens 133. The insulating layer 134 is a layer for adjusting the distance between the lens 133 and the light-emitting part. It is preferable that the insulating layer 134 be made of the same material as the lens 133. Note that the configurations shown in Figures 10A, 10B, and 11 can be combined as appropriate.

[0193] The protective layer 131 provided on the light-emitting devices 130a, 130b, and 130c may be a single-layer structure or a laminated structure of two or more layers. Providing the protective layer 131 can improve the reliability of the light-emitting devices.

[0194] 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.

[0195] The presence of an inorganic film in the protective layer 131 prevents oxidation of the common electrode 115 and 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.

[0196] For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidoxide-nitride insulating films, and nitride-oxide insulating films can be used for the protective layer 131. 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 a nitride insulating film.

[0197] 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.

[0198] When the light emitted from a light-emitting device is extracted through a protective layer 131, it is preferable that the protective layer 131 has high transmittance to visible light. ITO, IGZO, and aluminum oxide are preferred because they are inorganic materials that each have high transmittance to visible light.

[0199] 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 impurities (water, oxygen, etc.) from entering the EL layer.

[0200] Furthermore, the protective layer 131 may have an organic film. 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.

[0201] 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.

[0202] 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-collecting films. Furthermore, surface protection layers such as an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may be placed on the outside of the substrate 120.

[0203] As a surface protective layer, a glass layer or silica layer (SiO x By providing a protective layer, surface contamination and scratching can be suppressed, which is preferable. Also, 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.

[0204] The substrate 120 can be made of glass, quartz, ceramics, 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. Using a flexible material for the substrate 120 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as the substrate 120.

[0205] As the substrate 120, various materials can be used, including 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. Glass with a thickness sufficient to provide flexibility may also be used for the substrate 120.

[0206] 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).

[0207] 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.

[0208] 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 resin film.

[0209] 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.

[0210] 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.

[0211] Figure 12A shows a top view of a display device 100 different from that shown in Figure 1A. The pixel 110 shown in Figure 12A is composed of four types of subpixels: subpixels 110a, 110b, 110c, and 110d.

[0212] 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.

[0213] Furthermore, a display device according to one aspect of the present invention may have a light-receiving device in each pixel. For example, of the four subpixels of the pixel 110 shown in Figure 12A, three may be configured to have light-emitting devices and the remaining one to have a light-receiving device.

[0214] 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.

[0215] The light-receiving device can detect either visible light or infrared light, or both. When detecting visible light, it can detect one or more colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it allows for the detection of objects even in dark places.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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.

[0220] For details regarding the configuration and materials of the light-receiving device, refer to Embodiment 6.

[0221] Figure 12B shows a cross-sectional view between the dashed-dotted line X3 and X4 in Figure 12A. Note that the cross-sectional views of subpixels 110a and 110b in Figure 12A can be found in Figure 1B, and the cross-sectional view between the dashed-dotted line Y1 and Y2 can be found in Figure 2A or Figure 2B.

[0222] As shown in Figure 12B, the display device 100 has an insulating layer on a layer 101 containing transistors, an light-emitting device 130c and a light-receiving device 150 are provided on the insulating layer, and lenses 133 are provided on the light-emitting device 130c and the light-receiving device 150. A protective layer 131 is also provided to cover the lenses 133. A 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 and light-receiving devices 150.

[0223] Figure 12B shows an example where light emitted from the light-emitting device 130c is emitted towards the substrate 120 via the lens 133, and light entering from the substrate 120 side is incident on the light-receiving device 150 via the lens 133 (see optical Lem and optical Lin).

[0224] The configuration of the light-emitting device 130c is as described above.

[0225] 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.

[0226] Here, the fourth layer 113d includes at least an active layer and preferably has multiple functional layers. For example, the functional layers include carrier transport layers (hole transport layers and electron transport layers) and carrier block layers (hole block layers and electron block layers). It is also preferable to have one or more layers on the active layer. By having other layers between the active layer and the mask layer, it is possible to suppress the exposure of the active layer to the outermost surface during the manufacturing process of the display device and reduce the damage the active layer receives. This can improve the reliability of the photodetector 150. Therefore, it is preferable that the fourth layer 113d includes an active layer and a carrier block layer (hole block layer or electron block layer) or a carrier transport layer (electron transport layer or hole transport layer) on the active layer.

[0227] The fourth layer 113d is provided on the light-receiving device 150 but not on the light-emitting device. However, the functional layers other than the active layer included in the fourth layer 113d may have the same material as the functional layers other than the light-emitting layer included in the first layers 113a to the third layers 113c. On the other hand, the common layer 114 is a continuous layer shared by the light-emitting device and the light-receiving device.

[0228] 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.

[0229] 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.

[0230] Figure 12A shows an example in which the aperture ratios (size, also known as the size of the light-emitting or light-receiving area) of sub-pixels 110a, 110b, 110c, and 110d are the same, 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.

[0231] 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 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 sub-pixel 110d may be higher than that of the other sub-pixels.

[0232] 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.

[0233] Thus, the sub-pixel 110d can be configured with a detection wavelength, resolution, and aperture ratio suitable for the application.

[0234] Furthermore, it is preferable that the diameter (L2) of the lens 133 provided on the light-receiving device 150 is larger than the diameter (L1) of the light-receiving portion of the light-receiving device 150. With this configuration, light incident on a wider area than the light-receiving portion can be collected and incident on the light-receiving portion, thereby increasing the light sensitivity. The light-receiving portion is defined as the area where the fourth layer 113d and the common layer 114 are in contact. If the common layer 114 is not provided, the light-receiving portion is defined as the area where the fourth layer 113d and the common electrode 115 are in contact.

[0235] 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 its edges between adjacent island-shaped EL layers, it is possible to suppress the occurrence of step breaks during the formation of the common electrode and to prevent the formation of locally thin areas in the common electrode. This suppresses connection failures caused by the separated areas and increases in electrical resistance caused by locally thin areas in the common layer and common electrode.

[0236] Therefore, a display device according to one aspect of the present invention makes it possible to achieve both high resolution and high display quality. Furthermore, in a display device according to one aspect of the present invention, a lens is provided on a common electrode that overlaps with the light-emitting area. By providing this lens, light propagating laterally with the common electrode as a waveguide can be suppressed, and the efficiency of light extraction can be improved. In other words, a high-brightness display device can be formed.

[0237] Furthermore, in one embodiment of the present invention, a display device having a light-receiving device may also have a lens on the light-receiving device. By making the diameter of the lens provided on the light-receiving device larger than the effective area of ​​the light-receiving part, the light-collecting ability can be increased, and the light sensitivity of the light-receiving device can be improved.

[0238] 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.

[0239] (Embodiment 2) In this embodiment, a method for manufacturing a display device according to one aspect of the present invention will be described with reference to Figures 13 to 18. Note that descriptions of the materials and formation methods of each element may be omitted if they are the same as those described in Embodiment 1. Furthermore, the details of the configuration of the light-emitting device will be described in Embodiment 5.

[0240] Figures 13 to 18 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 19 shows an enlarged view of the end of the insulating layer 127 and its vicinity.

[0241] Thin films (insulating films, semiconductor films, and conductive films, etc.) that constitute display devices can be formed using deposition methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD). CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0242] 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.

[0243] For the fabrication of light-emitting and light-receiving devices, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used. Examples of film deposition methods in vacuum processes 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).

[0244] In particular, the functional layers included in the EL layer (such as hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, and charge generation layer) are preferably formed by methods such as vapor deposition (vacuum deposition, etc.), coating (dip coating, die coating, bar coating, spin coating, spray coating, etc.), and printing (inkjet, screen printing, offset printing, flexographic printing, gravure, or microcontact printing, etc.).

[0245] Furthermore, when processing the thin film constituting the display device, it can be processed using photolithography and etching methods, etc. Alternatively, the thin film may be processed by sandblasting, lift-off, etc. In addition, island-shaped thin films may be directly formed by a film deposition method using a shielding mask such as a metal mask. Furthermore, nanoimprint lithography may be substituted for photolithography.

[0246] There are two main methods for using photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching, and finally removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0247] In photolithography, the light used for exposure can be i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light may also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. Visible light may also be used in some cases.

[0248] Alternatively, instead of the light used for exposure, an electron beam can also be used. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because extremely fine processing becomes possible. When performing exposure by scanning a beam such as an electron beam, a photomask is unnecessary.

[0249] For the etching of the thin film, a dry etching method, a wet etching method, a sandblasting method, or the like can be used.

[0250] First, an insulating layer 255a, an insulating layer 255b, and an insulating layer 255c are formed in this order on the layer 101 including the transistor. Subsequently, pixel electrodes 111a, 111b, 111c and a conductive layer 123 are formed on the insulating layer 255c (FIG. 13A). For the formation of the pixel electrodes, for example, a sputtering method or a vacuum evaporation method can be used.

[0251] Subsequently, it is preferable to perform a hydrophobic treatment on the pixel electrodes. In the hydrophobic treatment, the surface to be treated can be changed from hydrophilic to hydrophobic, or the hydrophobicity of the surface to be treated can be enhanced. By performing a hydrophobic treatment on the pixel electrodes, the adhesion between the pixel electrodes and the film (here, film 113A) formed in a later step can be enhanced, and film peeling can be suppressed. Note that the hydrophobic treatment may not be performed.

[0252] The hydrophobic treatment can be performed by fluorine modification on the pixel electrodes. The fluorine modification can be performed, for example, by treatment with a gas containing fluorine or heat treatment, plasma treatment in an atmosphere of a gas containing fluorine, or the like.

[0253] As the gas containing fluorine, for example, fluorocarbon gases such as carbon tetrafluoride (CF4) gas, C4F6 gas, C2F6 gas, C4F8 gas, C5F8, etc. can be used. Alternatively, as the gas containing fluorine, SF6 gas, NF3 gas, CHF3 gas, etc. may be used. Further, helium gas, argon gas, hydrogen gas, or the like can be appropriately added to these gases.

[0254] Further, after performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, by performing a treatment using a silylating agent, the surface of the pixel electrode can be hydrophobized. As the silylating agent, hexamethyldisilazane (HMDS), trimethylsilylimidazole (TMSI), or the like can be used. Furthermore, after performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, by performing a treatment using a silane coupling agent, the surface of the pixel electrode can also be hydrophobized.

[0255] 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 imparted to the surface of the pixel electrode. Thereby, the methyl group contained in a silylating agent such as HMDS becomes likely to bind to the surface of the pixel electrode. Also, silane coupling by the silane coupling agent becomes likely to occur. As described above, after performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, by performing a treatment using a silylating agent or a silane coupling agent, the surface of the pixel electrode can be hydrophobized.

[0256] The treatment using a silylating agent or a silane coupling agent or the like can be performed, for example, by applying a silylating agent or a silane coupling agent or the like using a spin coating method or a dip method or the like. Also, the treatment using a silylating agent or a silane coupling agent or the like can be performed by forming a film having a silylating agent or a film having a silane coupling agent or the like on the pixel electrode or the like using a vapor phase method.

[0257] In the vapor phase method, first, by volatilizing a material having a silylating agent or a material having a silane coupling agent or the like, a silylating agent or a silane coupling agent or the like is included in the atmosphere. Subsequently, a substrate on which pixel electrodes or the like are formed is placed in the atmosphere. Thereby, a film having a silylating agent or a silane coupling agent or the like can be formed on the pixel electrode, and the surface of the pixel electrode can be hydrophobized.

[0258] Next, a film 113A, which will later become the first layer 113a, is formed on the pixel electrode (Figure 13A).

[0259] As shown in Figure 13A, 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 region. 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.

[0260] As described in Embodiment 1, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device in the display device. Specifically, the heat resistance temperature of the compound contained in the film 113A is set to 100°C or higher and 180°C or lower, preferably 120°C or higher and 180°C or lower, and more preferably 140°C or higher and 180°C or lower. This improves the reliability of the light-emitting device. It also allows for an increase in the upper limit of the temperature that can be applied during the manufacturing process of the display device. Therefore, the range of materials and forming methods used in the display device can be broadened, leading to improved manufacturing yield and reliability.

[0261] 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.

[0262] 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 13A).

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] Indicators of heat resistance temperature include 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.

[0268] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the mask film can be set to 100°C or higher, 120°C or higher, or 140°C or higher. The higher the deposition temperature of the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by forming the mask film at such a temperature, the damage to the film 113A can be further reduced, and the reliability of the light-emitting device can be improved.

[0269] 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.

[0270] For the formation of mask films 118A and 119A, for example, sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum deposition can be used. Alternatively, they may be formed using the wet film formation method described above.

[0271] 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.

[0272] The mask films 118A and 119A can be one or more of the following: metal films, alloy films, metal oxide films, semiconductor films, organic insulating films, and inorganic insulating films, respectively.

[0273] 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 rays in one or both of mask films 118A and 119A, as this can suppress the irradiation of film 113A with ultraviolet rays and thus suppress the degradation of film 113A.

[0274] In addition, for the mask film 118A and the mask film 119A, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanate (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), indium tin oxide containing silicon, etc. can be used respectively.

[0275] In addition, instead of the above gallium, an element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) can be used. Particularly, it is preferable that M is one or more selected from gallium, aluminum, or yttrium.

[0276] Also, as the mask film, a film containing a material having light-shielding properties against light, particularly ultraviolet light, can be used. For example, a film having reflectivity against ultraviolet light or a film that absorbs ultraviolet light can be used. As the material having light-shielding properties, various materials such as a metal, insulator, semiconductor, and semimetal having light-shielding properties against ultraviolet light can be used, but since a part or all of the mask film is removed in a later process, it is preferably a film that can be processed by etching, and particularly preferably has good processability.

[0277] As materials highly compatible with semiconductor manufacturing processes, semiconductor materials such as silicon or germanium can be used for the mask film. 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.

[0278] By using a mask film containing a material that blocks 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.

[0279] Furthermore, a film containing a material that has light-shielding properties against ultraviolet rays can be used as the material for the insulating film 125A, as described later, to achieve the same effect.

[0280] 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).

[0281] As the mask film 118A, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used, and as the mask film 119A, 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.

[0282] 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 them.

[0283] 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. For this reason, 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.

[0284] Organic materials may be used in one or both of the mask films 118A and 119A. As the organic material, a material that is soluble in a chemically stable solvent may be used, at least for the film located at the top of film 113A. 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 is possible to remove the solvent at a low temperature and in a short time, thereby reducing thermal damage to film 113A.

[0285] 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.

[0286] As the mask film 118A, an organic film (e.g., a PVA film) formed by either the vapor deposition method or the wet film formation method described above can be used, and as the mask film 119A, an inorganic film (e.g., a silicon nitride film) formed by the sputtering method can be used.

[0287] 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.

[0288] Next, a resist mask 190a is formed on the mask film 119A (Figure 13A). The resist mask 190a can be formed by applying a photosensitive resin (photoresist), exposing it to light, and developing it.

[0289] The resist mask 190a may be made using either a positive-type resist material or a negative-type resist material.

[0290] 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.

[0291] 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 13A. 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 13C).

[0292] This prevents the insulating layers 255a to 255c and a portion of the insulating layer in the transistor-containing layer 101 from being removed by etching or the like, thus preventing the conductive layer in the transistor-containing layer 101 from being exposed. Therefore, it is possible to suppress the conductive layer from being unintentionally electrically connected to other conductive layers. For example, it is possible to suppress a short circuit between the conductive layer and the common electrode 115.

[0293] Next, a resist mask 190a is used to remove a portion of the mask film 119A, forming a mask layer 119a (Figure 13B). 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, forming a mask layer 118a (Figure 13C).

[0294] 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.

[0295] 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, aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0296] 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.

[0297] 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 such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He as the etching gas.

[0298] When using an aluminum oxide film formed by the ALD method as the mask film 118A, CHF3 and He, or CHF 3、 The mask film 118A can be processed by dry etching using He and CH4. Alternatively, when an In-Ga-Zn oxide film formed by sputtering is used 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 a tungsten film formed by sputtering is used 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.

[0299] The resist mask 190a can be removed by ashing using oxygen plasma, or by using oxygen gas and a noble gas such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He. 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 removal process of the resist mask 190a. Furthermore, the range of selectable methods for removing the resist mask 190a can be broadened.

[0300] Next, mask layers 119a and 118a are used as a hard mask to remove a portion of film 113A and form the first layer 113a (Figure 13C).

[0301] As a result, as shown in Figure 13C, 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.

[0302] Figure 13C 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 pixel. Although not shown in Figure 13C, 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.

[0303] 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 processes such as etching. Products generated by the corrosion of the pixel electrode 111a may be unstable, and in the case of wet etching, there is a concern that they will dissolve in the solution, and in the case of dry etching, they may scatter into the atmosphere.

[0304] Dissolution of the product into the solution or scattering into the atmosphere can cause the product to adhere to the treated surface and the sides of the first layer 113a, potentially adversely affecting the characteristics of the light-emitting device or forming leak paths between multiple light-emitting devices. In addition, in areas where the edges of the pixel electrodes 111a are exposed, the adhesion between the layers in contact with each other may decrease, making the first layer 113a or the pixel electrodes 111a more susceptible to delamination.

[0305] Therefore, by configuring the first layer 113a to cover the top and side surfaces of the pixel electrode 111a, the yield and characteristics of the light-emitting device can be improved.

[0306] 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.

[0307] As mentioned above, in the cross-sectional view between Y1 and Y2 in Figure 13C, 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.

[0308] The film 113A is preferably processed by anisotropic etching. In particular, anisotropic dry etching is preferred. Alternatively, wet etching may be used.

[0309] When using the dry etching method, the degradation of film 113A can be suppressed by not using an oxygen-containing gas as the etching gas.

[0310] 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.

[0311] 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, a gas containing H2 and Ar, or a gas containing CF4 and He, can be used as the etching gas. Furthermore, a gas containing CF4, He, and oxygen can be used as the etching gas. Also, a gas containing H2 and Ar, and a gas containing oxygen can be used as the etching gas.

[0312] 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.

[0313] 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.

[0314] 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 14A).

[0315] The film 113B can be formed in the same manner as the method used to form film 113A.

[0316] Next, a mask film 118B, which will later become the mask layer 118b, and a mask film 119B, which will later become the mask layer 119b, are formed sequentially on film 113B, and then the resist mask 190b is formed (Figure 14A). The materials and formation methods for mask films 118B and 119B are the same as those applicable to mask films 118A and 119A. The materials and formation methods for resist mask 190b are the same as those applicable to resist mask 190a.

[0317] The resist mask 190b is positioned to overlap with the pixel electrode 111b.

[0318] Next, a portion of the mask film 119B is removed using the resist mask 190b to form a mask layer 119b. The mask layer 119b remains on the pixel electrode 111b. After that, the resist mask 190b is removed. Subsequently, a portion of the mask film 118B is removed using the mask layer 119b as a mask to form a mask layer 118b.

[0319] Next, mask layers 119b and 118b are used as a hard mask to remove a portion of film 113B and form a second layer 113b (Figure 14B).

[0320] As a result, as shown in Figure 14B, the stacked structure of the second layer 113b, the mask layer 118b, and the mask layer 119b remains on the pixel electrode 111b. The mask layer 119a and the pixel electrode 111c are exposed.

[0321] Next, it is preferable to perform a hydrophobic treatment on the pixel electrodes. During the processing of film 113B, 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 113C) formed in a later process can be improved, and film peeling can be suppressed. However, the hydrophobic treatment is not required.

[0322] Next, a film 113C, which will later become the third layer 113c, is formed on the pixel electrode 111c and the mask layers 119a and 119b (Figure 14B).

[0323] The film 113C can be formed in a manner similar to that used for forming the film 113A.

[0324] Next, a mask film 118C, which will later become the mask layer 118c, and a mask film 119C, which will later become the mask layer 119c, are formed sequentially on film 113C, and then the resist mask 190c is formed (Figure 14B). The materials and formation methods for mask films 118C and 119C are the same as those applicable to mask films 118A and 119A. The materials and formation methods for resist mask 190c are the same as those applicable to resist mask 190a.

[0325] The resist mask 190c is positioned to overlap with the pixel electrode 111c.

[0326] Next, a portion of the mask film 119C is removed using the resist mask 190c to form a mask layer 119c. The mask layer 119c remains on the pixel electrode 111c. After that, the resist mask 190c is removed.

[0327] Next, using mask layer 119c as a mask, a portion of mask film 118C is removed to form mask layer 118c. Subsequently, using mask layer 119c and mask layer 118c as a hard mask, a portion of film 113C is removed to form a third layer 113c (Figure 14C).

[0328] As a result, as shown in Figure 14C, the stacked structure of the third layer 113c, the mask layer 118c, and the mask layer 119c remains on the pixel electrode 111c. In addition, the mask layers 119a and 119b are exposed.

[0329] Furthermore, it is preferable that the sides of the first layer 113a, the second layer 113b, and the third layer 113c are perpendicular or approximately perpendicular to the surface to be formed. For example, it is preferable that the angle between the surface to be formed and these sides be 60° or more and 90° or less.

[0330] 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 by 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.

[0331] Furthermore, as shown in Figures 12A and 12B, 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 layers 113a to the third layers 113c. The formation order of the first layers 113a to the fourth layers 113d is not particularly limited.

[0332] By forming a layer with high adhesion to the pixel electrode first, film peeling during the process can be suppressed. For example, if the first layer 113a to the third layer 113c has higher adhesion to the pixel electrode than the fourth layer 113d, it is preferable to form the first layer 113a to the third layer 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 deposition 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.

[0333] 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.

[0334] Next, it is preferable to remove the mask layers 119a, 119b, and 119c (Figure 15A). Depending on subsequent processes, the mask layers 118a, 118b, 118c, 119a, 119b, and 119c may remain on 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 on the display device.

[0335] When conductive materials are 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.

[0336] 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 rays, it is preferable to proceed to the next step without removing them, as this protects the EL layer from ultraviolet rays.

[0337] 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.

[0338] 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.

[0339] After removing the mask layer, heat treatment may be performed to remove water contained in the first layer 113a, the second layer 113b, and the third layer 113c, and water adsorbed on the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. The heat treatment is preferably 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.

[0340] 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 15A).

[0341] Next, an insulating film 127a is formed on the insulating film 125A (Figure 15B). Here, it is preferable that the upper surface of the insulating film 125A has high affinity for the resin composition used for the insulating film 127a (for example, a photosensitive resin composition containing acrylic resin). To improve this affinity, it is preferable to hydrophobize (or increase the hydrophobicity of) the upper surface of the insulating film 125A by performing a surface treatment. For example, it is preferable to perform the treatment using a silylation agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the insulating film 125A in this way, the insulating film 127a can be formed with good adhesion. Note that the aforementioned hydrophobic treatment may be performed as the surface treatment.

[0342] It is preferable that the insulating film 125A and insulating film 127a are formed using a method that causes minimal 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 is 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.

[0343] 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.

[0344] The substrate temperature when forming insulating film 125A and insulating film 127a 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.

[0345] As described above, in one embodiment of the present invention, a heat-resistant material is used for the light-emitting device. Therefore, the substrate temperature when forming the insulating film 125A and insulating film 127a can be set to 100°C or higher, 120°C or higher, or 140°C or higher, respectively. The higher the deposition temperature of the inorganic insulating film, the denser and more barrier-oriented the film can be. Therefore, by depositing the insulating film 125A at such a temperature, the damage to the first layer 113a, the second layer 113b, and the third layer 113c can be further reduced, and the reliability of the light-emitting device can be improved.

[0346] 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 a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less, within the above substrate temperature range.

[0347] The insulating film 125A is preferably formed using the ALD method. The ALD method is preferable because it can reduce film formation damage and allow for the formation of a highly covering film. For example, it is preferable to form an aluminum oxide film as the insulating film 125A using the ALD method.

[0348] In addition, the insulating film 125A may be formed using a sputtering method, CVD method, or PECVD method, which have a faster deposition rate than the ALD method. This allows for the production of highly reliable display devices with high productivity.

[0349] The insulating film 127a is preferably formed using the wet film formation method described above. The insulating film 127a is preferably formed using a photosensitive resin, for example, by spin coating, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0350] The insulating film 127a is preferably formed using a resin composition having a polymer, an acid generator, and a solvent. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also called constituent units) are repeated regularly or irregularly. As the acid generator, one or both of the following can be used: a compound that generates acid upon irradiation with light, and a compound that generates acid upon heating.

[0351] The resin composition may further contain one or more of the following: a photosensitive agent, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant. For example, the resin composition described in Patent Document 2 (Japanese Patent Application Publication No. 2020-101659) can be suitably used as such a resin composition. For instance, the resin composition may have a quinone diazide compound as an acid generator.

[0352] Furthermore, it is preferable to perform a heat treatment (also called pre-baking) after the formation of the insulating film 127a. This 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. The substrate temperature during the heat treatment is preferably 50°C to 200°C, more preferably 60°C to 150°C, and even more preferably 70°C to 120°C. This makes it possible to remove the solvent contained in the insulating film 127a.

[0353] Next, as shown in Figure 15C, exposure is performed to expose a portion of the insulating film 127a to visible light or ultraviolet light. Here, if a positive-type photosensitive resin composition containing acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated using a mask 132 in the area where the insulating layer 127 will not be formed in a later step.

[0354] The insulating layer 127 is formed in the region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and around the conductive layer 123. Therefore, as shown in Figure 13C, visible light or ultraviolet light is irradiated onto the pixel electrode 111a, the pixel electrode 111b, the pixel electrode 111c, and the conductive layer 123 using the mask 132.

[0355] 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 3A and 3B). As shown in Figure 7A or Figure 7B, the insulating layer 127 does not have to have a portion that overlaps with the upper surface of the pixel electrode.

[0356] 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).

[0357] Here, by providing an oxygen barrier insulating layer (e.g., an aluminum oxide film) as one or both of the mask layer 118 (mask layers 118a, 118b, 118c) and the insulating film 125A, the diffusion of oxygen into the first layer 113a, the second layer 113b, and the third layer 113c can be reduced.

[0358] When an EL layer is irradiated with light (visible light or ultraviolet light), the organic compounds contained in the EL layer may become excited, and their reaction with oxygen in the atmosphere may be promoted. More specifically, when an EL layer is irradiated with light (visible light or ultraviolet light) in an oxygen-containing atmosphere, oxygen may bond to the organic compounds in the EL layer. By providing the mask layer 118 and the insulating film 125A on the island-shaped EL layer, the bonding of oxygen in the atmosphere to the organic compounds contained in the EL layer can be reduced.

[0359] In Figure 15C, 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.

[0360] Next, as shown in Figures 16A and 20A, a developing process is performed to remove the exposed area of ​​the insulating film 127a and form the insulating layer 127b. Figure 20A is an enlarged view of the second layer 113b shown in Figure 16A 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.

[0361] 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.

[0362] 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.

[0363] Next, as shown in Figures 16B and 20B, 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 20B is a magnified view of the second layer 113b shown in Figure 16B, 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.

[0364] 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.

[0365] As shown in Figure 20B, by etching using the insulating layer 127b, which has a tapered side surface, as a mask, the side surface of the insulating layer 125 and the upper edges of the side surfaces of the mask layers 118a, 118b, and 118c can be made tapered relatively easily.

[0366] 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, oxygen gas, hydrogen gas, helium gas, and argon gas can be added individually or in mixtures of two or more gases as appropriate to 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.

[0367] As the 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.

[0368] A capacitively coupled plasma etching apparatus having parallel plate electrodes may be configured to apply a high-frequency voltage to one of the parallel plate electrodes. Alternatively, it may be configured to apply multiple different high-frequency voltages to one 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.

[0369] 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.

[0370] 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. Wet etching can be performed using an alkaline solution or the like. 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. Note that if the insulating film 125A is formed using the same material as the mask layers 118a, 118b, and 118c, it is preferable because the above etching process can be performed all at once.

[0371] As shown in Figures 16B and 20B, 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 damage to the first layer 113a, the second layer 113b, and the third layer 113c in subsequent processing steps.

[0372] In Figures 16B and 20B, the mask layers 118a, 118b, and 118c are configured to have thin films, but the present invention is not limited to this. 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.

[0373] Furthermore, if the insulating film 125A is deposited 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.

[0374] Furthermore, Figures 16B and 20B show examples where the shape of the insulating layer 127b has not changed from that in Figures 16A and 20A, but the present invention is not limited to these examples. For example, the edge of the insulating layer 127b may droop and cover the edge of the insulating layer 125. Also, the edge of the insulating layer 127b may be in contact with the upper surface of the mask layers 118a, 118b, and 118c.

[0375] Next, exposure is performed from above, and it is preferable to irradiate the insulating layer 127b with visible light or ultraviolet light (Figure 16C). 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 reduce the post-bake temperature required for reflow of the insulating layer 127b in a later step.

[0376] Here, by providing oxygen barrier insulating layers (for example, an aluminum oxide film) as mask layers 118a, 118b, and 118c, the diffusion of oxygen into the first layer 113a, the second layer 113b, and the third layer 113c can be reduced.

[0377] When an EL layer is irradiated with light (visible light or ultraviolet light), the organic compounds contained in the EL layer may become excited, and their reaction with oxygen in the atmosphere may be promoted. More specifically, when an EL layer is irradiated with light (visible light or ultraviolet light) in an oxygen-containing atmosphere, oxygen may bind to the organic compounds in the EL layer. By providing mask layers 118a, 118b, and 118c on an island-shaped EL layer, the binding of oxygen in the atmosphere to the organic compounds contained in the EL layer can be reduced.

[0378] 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 (reflow) 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.

[0379] For example, when a photocurable resin is used as the material for the insulating layer 127b, polymerization is initiated by exposure to the insulating layer 127b, and the insulating layer 127b can be cured. Alternatively, at this stage, the insulating layer 127b may not be exposed to light, and at least one of the post-bake and the second etching process described later may be performed while the insulating layer 127b remains in a state where it is relatively easy to change shape. This suppresses the occurrence of irregularities on the surface forming the common layer 114 and the common electrode 115, and also suppresses the step breakage of the common layer 114 and the common electrode 115.

[0380] Furthermore, exposure may be performed on the insulating layer 127b (or insulating layer 127) after the post-bake or second etching process described later. Alternatively, exposure may be performed after development but before the first etching process. On the other hand, depending on the material of the insulating layer 127b (e.g., positive-type material) and the conditions of the first etching process, exposure may cause the insulating layer 127b to dissolve in the chemical solution during the first etching process. Therefore, it is preferable to perform exposure after the first etching process but before post-bake. This makes it possible to reliably and stably produce an insulating layer 127 of the desired shape.

[0381] Here, the irradiation with visible light or ultraviolet light shown in Figure 16C is preferably carried out in an oxygen-free atmosphere or an atmosphere with a low oxygen content. For example, the irradiation with visible light or ultraviolet light is preferably carried out in an inert gas atmosphere such as a nitrogen atmosphere or a reduced pressure atmosphere. If the irradiation with visible light or ultraviolet light is carried out in an atmosphere with a high oxygen content, the compounds contained in the EL layer may oxidize and deteriorate. However, by carrying out the irradiation with visible light or ultraviolet light in an oxygen-free atmosphere or an atmosphere with a low oxygen content, deterioration of the EL layer can be prevented, and a more reliable display device can be provided.

[0382] Next, as shown in Figures 17A and 20C, a heat treatment (also called post-bake) is performed. By performing the heat treatment, the insulating layer 127b reflows, and an insulating layer 127 having a tapered shape on its side surface can be formed. 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. This 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.

[0383] The heating atmosphere may be an atmospheric atmosphere or an inert gas atmosphere. Furthermore, the heating atmosphere may be an atmospheric pressure atmosphere or a reduced pressure atmosphere. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature. In this step, it is preferable to raise the substrate temperature higher than in the heat treatment (pre-bake) after the formation of the insulating film 127a. 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 20C is an enlarged view of the second layer 113b shown in Figure 17A, the edge of the insulating layer 127, and its vicinity.

[0384] As described above, in one embodiment of the present invention, a highly heat-resistant material is used for the light-emitting device. Therefore, the pre-bake temperature and post-bake temperature can be set to 100°C or higher, 120°C or higher, or 140°C or higher, respectively. This further improves the adhesion between the insulating layer 127 and the insulating layer 125, and also improves the corrosion resistance of the insulating layer 127. Furthermore, it broadens the range of materials that can be used as the insulating layer 127. In addition, by sufficiently removing solvents and other substances contained in the insulating layer 127, it is possible to suppress the penetration of impurities such as water and oxygen into the EL layer.

[0385] In the first etching process, the mask layers 118a, 118b, and 118c are not completely removed, but rather thinned mask layers 118a, 118b, and 118c remain. This prevents 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.

[0386] 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 5A and 5B. 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.

[0387] Next, as shown in Figures 17B and 20D, 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 20D is a magnified view of the second layer 113b shown in Figure 17B, 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.

[0388] The edges of the insulating layer 125 are covered with the insulating layer 127. Figures 17B and 20D 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. This corresponds to the structure shown in Figures 3A and 3B.

[0389] If the first etching process is omitted and the etching of the insulating layer 125 and the mask layer is performed all at once after post-baking, 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. This cavity causes irregularities on the surface forming the common layer 114 and the common electrode 115, which can lead to stepped breaks in the common layer 114 and the common electrode 115.

[0390] However, even if the insulating layer 125 and the mask layer are side-etched and voids are created during the first etching process, the insulating layer 127 can be reflowed by post-bake, filling these voids. Subsequently, in the second etching process, the mask layer, which has become thinner, is etched, resulting in less side etching and making void formation less likely. Furthermore, even if voids are formed, they can be made extremely small. As a result, the surfaces forming the common layer 114 and the common electrode 115 can be made flatter.

[0391] As shown in Figures 5A, 5B, 7A, and 7B, 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, 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.

[0392] 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.

[0393] 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.

[0394] 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 5A and 5B.

[0395] The heat treatment is preferably carried out under an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows for dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the above heat treatment, taking into consideration 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 preferred within the above temperature range.

[0396] Next, a common layer 114 and a common electrode 115 are formed on the insulating layer 127, the first layer 113a, the second layer 113b, and the third layer 113c in that order (Figure 17C).

[0397] The common layer 114 can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0398] 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.

[0399] Next, an insulating film 133a is formed on the common electrode 115 (Figure 18A). The insulating film 133a can be formed using the same material and process as the insulating film 127a shown in Figure 15B. By forming the insulating film 133a and the insulating film 127a from the same material, in other words, by having the insulating film 133a and the insulating film 127a made from the same material, manufacturing costs can be reduced. Furthermore, by having the insulating film 133a and the insulating film 127a made from the same material, the shrinkage of the materials due to heat treatment during the manufacturing process (for example, the shrinkage of organic resin materials) can be made the same. Having the same shrinkage or shrinkage rate of the materials used for the insulating film 133a and the insulating film 127a is preferable because it makes it easier to control the stress on the entire display device.

[0400] Next, as shown in Figure 18B, exposure is performed to expose a portion of the insulating film 133a to visible light or ultraviolet light. Here, if a positive-type photosensitive resin composition is used for the insulating film 133a, visible light or ultraviolet light is irradiated using a mask 132 in the area where the lens 133 will not be formed in a later step. The lens 133 is formed in the area that overlaps with the first layer 113a, the second layer 113b, and the third layer 113c, respectively.

[0401] Furthermore, the width (diameter) of the lens 133 to be formed later can be controlled by the area exposed to light at this stage. In this embodiment, the lens 133 is processed to form an island shape (Figure 9B). Alternatively, as shown in Figure 10B, the edges of the lens 133 may be connected at adjacent pixels. In this case, the width of the area exposed to light in the insulating film 133a is narrowed, and the edges of the lens 133 are connected by reflow in a later process.

[0402] Exposure to the insulating film 133a can be performed using the same method as the exposure of the insulating film 127a shown in Figure 15C.

[0403] Next, as shown in Figure 18C, development is performed to remove the exposed area of ​​the insulating film 133a and form the insulating layer 133b. The insulating layer 133b is formed in the area that overlaps with the first layer 113a, the second layer 113b, and the third layer 113c. Here, when acrylic resin is used for the insulating film 133a, it is preferable to use an alkaline solution as the developer, for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

[0404] Next, the residue (scum) from the development process may be removed. For example, the residue can be removed by ashing using oxygen plasma.

[0405] Furthermore, etching may be performed to adjust the surface height of the insulating layer 133b. The insulating layer 133b may be processed, for example, by ashing using oxygen plasma. Also, even when a non-photosensitive material is used as the insulating film 133a, the surface height of the insulating film 133a can be adjusted by ashing or the like.

[0406] Next, it is preferable to expose the insulating layer 133b from above, irradiating it with visible light or ultraviolet light (Figure 19A). Exposure after development may improve the transparency of the insulating layer 127b. Improving the transparency of the insulating layer 127b can increase the transmittance of the lens 133 that is formed later. The same method as the exposure of the insulating layer 127b shown in Figure 16C can be used for exposure of the insulating layer 133b.

[0407] Next, as shown in Figure 19B, a heat treatment (post-bake) is performed. By performing the heat treatment, the insulating layer 133b is reflowed and deformed into a convex lens 133 with a tapered shape on its side. The same process as the heat treatment of the insulating layer 127 shown in Figure 17A can be used for this heat treatment.

[0408] Next, a protective layer 131 is formed on the common electrode 115 and the lens 133. Furthermore, by using a resin layer 122 to bond the substrate 120 onto the protective layer 131, a display device can be manufactured (Figure 1B).

[0409] Methods for forming the protective layer 131 include vacuum deposition, sputtering, CVD, and ALD.

[0410] 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 has been deposited on one surface. Therefore, 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.

[0411] Furthermore, even with high resolution or aperture ratio and extremely short distances between subpixels, it is possible to suppress contact between the first layer 113a, the second layer 113b, and the third layer 113c in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk caused by unintended light emission, enabling the realization of a display device with extremely high contrast.

[0412] 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.

[0413] Furthermore, by providing a lens on the common electrode that overlaps with the light-emitting region, it is possible to suppress light propagating laterally using the common electrode 115 as a waveguide, thereby improving the efficiency of light extraction.

[0414] Furthermore, if the display device has a light-receiving device, a lens can also be provided on the light-receiving device. By making the diameter of the lens larger than the effective area of ​​the light-receiving part, the light-collecting ability can be increased, and the light sensitivity of the light-receiving device can be improved.

[0415] This embodiment can be combined with other embodiments as appropriate.

[0416] (Embodiment 3) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 21 and 22.

[0417] [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.

[0418] 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).

[0419] 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.

[0420] Furthermore, the circuit layout constituting the sub-pixel is not limited to the sub-pixel range shown in the figure, but may be arranged outside of it.

[0421] A stripe array is applied to pixel 110 shown in Figure 21A. Pixel 110 shown in Figure 21A is composed of three subpixels: subpixels 110a, 110b, and 110c.

[0422] The pixel 110 shown in Figure 21B has an S-stripe array applied to it. The pixel 110 shown in Figure 21B is composed of three subpixels: subpixels 110a, 110b, and 110c.

[0423] The pixel 110 shown in Figure 21C 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.

[0424] Pixels 124a and 124b shown in Figure 21D 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).

[0425] Figure 21D shows an example where each subpixel has a circular top surface shape, while Figure 1A shows an example where each subpixel has a roughly square top surface shape with rounded corners.

[0426] A Pentile array is applied to pixels 124a and 124b shown in Figure 21E. Figure 21E shows an example in which pixels 124a having subpixels 110a and 110b, and pixels 124b having subpixels 110b and 110c are arranged alternately.

[0427] Figure 21F 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.

[0428] In each pixel shown in Figures 21A to 21F, 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.

[0429] 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.

[0430] 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.

[0431] 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.

[0432] As shown in Figures 22A to 22I, a pixel can be configured to have four types of subpixels.

[0433] The pixels 110 shown in Figures 22A to 22C have a stripe arrangement applied to them.

[0434] Figure 22A shows an example where each subpixel has a rectangular top surface shape, Figure 22B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 22C shows an example where each subpixel has an elliptical top surface shape.

[0435] The pixels 110 shown in Figures 22D to 22F have a matrix array applied to them.

[0436] Figure 22D shows an example where each subpixel has a square top surface shape, Figure 22E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 22F shows an example where each subpixel has a circular top surface shape.

[0437] Figures 22G and 22H show an example where one pixel 110 is composed of 2 rows and 3 columns.

[0438] Pixel 110, shown in Figure 22G, 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.

[0439] The pixel 110 shown in Figure 22H 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 22H, 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.

[0440] Figure 22I shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0441] Pixel 110, shown in Figure 22I, 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.

[0442] The pixel 110 shown in Figures 22A to 22I is composed of four subpixels: subpixels 110a, 110b, 110c, and 110d.

[0443] 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).

[0444] In each pixel 110 shown in Figures 22A to 22I, 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 22G and 22H, 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 22I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0445] Furthermore, the pixel 110 may have subpixels that have a light-receiving device.

[0446] In each pixel 110 shown in Figures 22A to 22I, one of the sub-pixels 110a to 110d may be a sub-pixel having a light-receiving device.

[0447] In each pixel 110 shown in Figures 22A to 22I, 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 22G and 22H, 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 22I, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0448] 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.

[0449] As shown in Figures 22J and 22K, a pixel can be configured to have five types of subpixels.

[0450] Figure 22J shows an example where one pixel 110 is composed of 2 rows and 3 columns.

[0451] Pixel 110, shown in Figure 22J, has three subpixels (subpixels 110a, 110b, and 110c) in the top row (1st row) and two subpixels (subpixels 110d and 110e) in the bottom row (2nd row). In other words, pixel 110 has subpixels 110a and 110d in the left column (1st column), subpixel 110b in the middle column (2nd column), subpixel 110c in the right column (3rd column), and subpixel 110e extending from the 2nd to the 3rd column.

[0452] Figure 22K shows an example where one pixel 110 is composed of 3 rows and 2 columns.

[0453] Pixel 110, shown in Figure 22K, 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).

[0454] In each pixel 110 shown in Figures 22J and 22K, 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 22J, 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 22K, the layout of R, G, and B becomes a so-called S-stripe arrangement, which can improve the display quality.

[0455] Furthermore, in each pixel 110 shown in Figures 22J and 22K, 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 they detect may differ. Specifically, one of the sub-pixels 110d and 110e may have a photodetector that mainly detects visible light, while the other has a photodetector that mainly detects infrared light.

[0456] Furthermore, in each pixel 110 shown in Figures 22J and 22K, 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.

[0457] 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.

[0458] 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.

[0459] This embodiment can be combined with other embodiments as appropriate.

[0460] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figures 23 to 32.

[0461] 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.

[0462] 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.

[0463] [Display Module] Figure 23A 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.

[0464] 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.

[0465] Figure 23B 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.

[0466] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 23B. Various configurations described in the previous embodiment can be applied to the pixel 284a. Figure 23B shows an example where the pixel has a configuration similar to that of the pixel 110 shown in Figure 1A.

[0467] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0468] 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.

[0469] 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.

[0470] 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.

[0471] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked 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.

[0472] 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.

[0473] [Display device 100A] The display device 100A shown in Figure 24A includes a substrate 301, light-emitting devices 130R, 130G, 130B, capacitor 240, and transistor 310.

[0474] Substrate 301 corresponds to substrate 291 in Figures 23A and 23B. The laminated structure from substrate 301 to insulating layer 255c corresponds to layer 101 containing the transistor in Embodiment 1.

[0475] The transistor 310 is a transistor having a channel-forming region in the substrate 301. For example, a semiconductor substrate such as a single-crystal silicon substrate can be used as the substrate 301. 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 covers the side surface of the conductive layer 311 and functions as an insulating layer.

[0476] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0477] Furthermore, an insulating layer 261 is provided covering the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0478] 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.

[0479] 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.

[0480] 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 24A shows an example in which light-emitting devices 130R, 130G, and 130B have the laminated structure shown in Figure 1B. An insulator is provided in the region between adjacent light-emitting devices. In Figure 24A and other figures, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in this region.

[0481] 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.

[0482] 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 top surface of insulating layer 255c and the height of the top surface of plug 256 are equal or approximately equal. Various conductive materials can be used for the plugs. Figure 24A, 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.

[0483] Furthermore, a lens 133 and a protective layer 131 are 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 23A.

[0484] The display device shown in Figure 24B 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.

[0485] [Display device 100B] The display device 100B shown in Figure 25 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.

[0486] 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.

[0487] 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.

[0488] 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.

[0489] 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.

[0490] 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.

[0491] 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.

[0492] 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).

[0493] [Display device 100C] The display device 100C shown in Figure 26 has a configuration in which conductive layer 341 and conductive layer 342 are joined via bumps 347.

[0494] As shown in Figure 26, 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 containing, 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.

[0495] [Display device 100D] The display device 100D shown in Figure 27 differs from the display device 100A mainly in its transistor configuration.

[0496] 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.

[0497] 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.

[0498] Substrate 331 corresponds to substrate 291 in Figures 23A and 23B. 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.

[0499] 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.

[0500] 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.

[0501] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0502] 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 top of 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 of the insulating layer 332 can be used as the insulating layer 328.

[0503] The insulating layer 328 and the insulating layer 264 are provided with openings that reach the semiconductor layer 321. Inside these openings, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the insulating layer 264, the insulating layer 328, the sides of the conductive layer 325, and the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0504] 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.

[0505] 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.

[0506] 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 portion 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.

[0507] [Display device 100E] The display device 100E shown in Figure 28 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.

[0508] The configuration of transistors 320A, 320B, and their surrounding components can be based on the display device 100D described above.

[0509] 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.

[0510] [Display device 100F] The display device 100F shown in Figure 29 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.

[0511] 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.

[0512] 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.

[0513] 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.

[0514] [Display device 100G] Figure 30 shows a perspective view of the display device 100G, and Figure 31A shows a cross-sectional view of the display device 100G.

[0515] The display device 100G has a configuration in which substrate 152 and substrate 151 are bonded together. In Figure 30, substrate 152 is clearly indicated by a dashed line.

[0516] The display device 100G includes a display unit 162, a connection unit 140, a circuit 164, wiring 165, etc. Figure 30 shows an example in which IC 173 and FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Figure 30 can also be described as a display module having the display device 100G, an IC (integrated circuit), and an FPC.

[0517] 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 30 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.

[0518] For example, a scan line drive circuit can be used as circuit 164.

[0519] 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.

[0520] Figure 30 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.

[0521] Figure 31A 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.

[0522] The display device 100G shown in Figure 31A includes 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 that emits blue light, etc., between substrates 151 and 152.

[0523] The light-emitting devices 130R, 130G, and 130B each have the stacked structure shown in Figure 1B, except that they differ in the configuration of their pixel electrodes. For details of the light-emitting devices, please refer to Embodiment 1.

[0524] 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.

[0525] 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.

[0526] 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.

[0527] 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.

[0528] 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.

[0529] The conductive layers 112a, 112b, and 112c have recesses formed to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0530] 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.

[0531] 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.

[0532] 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.

[0533] 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.

[0534] Furthermore, a lens 133 and a protective layer 131 are 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 31A, 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.

[0535] 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.

[0536] 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.

[0537] The laminated structure from the substrate 151 to the insulating layer 214 corresponds to the layer 101 containing the transistor in Embodiment 1.

[0538] Both transistors 201 and 205 are formed on the substrate 151. These transistors can be manufactured using the same materials and the same process.

[0539] 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.

[0540] 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.

[0541] 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 oxynitride 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.

[0542] 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.

[0543] 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.

[0544] 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.

[0545] 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.

[0546] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with crystalline regions in part) may be used. Using a crystalline semiconductor is preferable because it can suppress the degradation of transistor characteristics.

[0547] The semiconductor layer of the transistor preferably has a metal oxide (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.

[0548] Examples of crystalline oxide semiconductors include CAAC (c-axis-aligned crystalline)-OS and nc (nanocrystalline)-OS.

[0549] 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.

[0550] 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.

[0551] OS transistors have extremely high field-effect mobility compared to transistors using amorphous silicon. Furthermore, OS transistors exhibit remarkably low source-drain leakage current (hereinafter also referred to as 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.

[0552] 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.

[0553] 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 controlling the amount of current flowing to the light-emitting device. This allows for a wider range of tonal gradations in the pixel circuit.

[0554] 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.

[0555] 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."

[0556] 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.

[0557] 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).

[0558] 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.

[0559] For example, when describing a composition with an atomic ratio of In:Ga:Zn = 4:2:3 or a similar ratio, it includes cases where, when the atomic ratio of In is 4, the atomic ratio of Ga is between 1 and 3, and the atomic ratio of Zn is between 2 and 4. Also, when describing a composition with an atomic ratio of In:Ga:Zn = 5:1:6 or a similar ratio, it includes cases where, when the atomic ratio of In is 5, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is between 5 and 7. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn = 1:1:1 or a similar ratio, it includes cases where, when the atomic ratio of In is 1, the atomic ratio of Ga is greater than 0.1 and 2 or less, and the atomic ratio of Zn is greater than 0.1 and 2 or less.

[0560] 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.

[0561] 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.

[0562] 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. In a more preferable example, it is preferable to apply OS transistors to transistors that function as switches for controlling conduction and non-conduction between wiring, and LTPS transistors to transistors that control current.

[0563] 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 the drive transistor. This makes it possible to increase the current flowing to the light-emitting device in the pixel circuit.

[0564] 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.

[0565] 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.

[0566] 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.

[0567] 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.

[0568] Figures 31B and 31C show other examples of transistor configurations.

[0569] Transistors 209 and 210 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer 231 having a channel 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.

[0570] In the transistor 209 shown in Figure 31B, 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.

[0571] On the other hand, in the transistor 210 shown in Figure 31C, 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 31C can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 31C, 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.

[0572] 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. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. This allows the connection portion 204 and FPC 172 to be electrically connected via the connection layer 242.

[0573] 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.

[0574] Materials that can be used for substrate 120 can be applied to substrate 151 and substrate 152, respectively.

[0575] As the adhesive layer 142, a material that can be used for the resin layer 122 can be applied.

[0576] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), etc., can be used.

[0577] [Display device 100J] The display device 100J shown in Figure 32 differs from the display device 100G mainly in that it has a light receiving device 150.

[0578] 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.

[0579] The conductive layer 112d is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214.

[0580] 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.

[0581] 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. A lens 133 is also provided on the common electrode 115.

[0582] The display device 100J can, for example, apply the pixel layout shown in Figures 22A to 22K, as described in Embodiment 3. For details of the display device having a light-receiving device, refer to Embodiments 1 and 6.

[0583] This embodiment can be combined with other embodiments as appropriate.

[0584] (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.

[0585] 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.

[0586] The light emitted by the light-emitting device can be infrared light or visible light (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.

[0587] [Light-emitting devices] As shown in Figure 33A, 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.

[0588] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0589] 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.

[0590] 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 33A is referred to as a single structure.

[0591] Furthermore, Figure 33B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 33A. Specifically, the light-emitting device shown in Figure 33B 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.

[0592] 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.

[0593] Furthermore, as shown in Figures 33C and 33D, 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.

[0594] Furthermore, as shown in Figures 33E and 33F, 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.

[0595] In Figures 33C and 33D, 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 33D.

[0596] Furthermore, light-emitting materials that emit light of different colors may be used for each of the light-emitting layers 771, 772, and 773. For example, a light-emitting material that emits red light, a light-emitting material that emits blue light, or a light-emitting material that emits green light may be used in each layer so that white light emission is obtained when the respective light emission colors of the light-emitting layers 771, 772, and 773 are combined. A color filter (also called a colored layer) may be provided as layer 764 as shown in Figure 33D. By passing white light through the color filter, light of the desired color can be obtained.

[0597] A light-emitting device that emits white light preferably contains two or more light-emitting materials. To obtain white light emission, two light-emitting materials should be selected such that the light emitted by each material 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.

[0598] Furthermore, in Figures 33E and 33F, 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 33F 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.

[0599] Furthermore, in Figures 33C, 33D, 33E, and 33F, as shown in Figure 33B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0600] Next, we will describe materials that can be used in light-emitting devices.

[0601] 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.

[0602] 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.

[0603] As materials for forming the pair of electrodes in a light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, these 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), and silver, palladium, and copper alloys (Ag-Pd-Cu, also written as APC). In addition, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys containing these in appropriate combinations can also be used. 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.

[0604] 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.

[0605] 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).

[0606] 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.

[0607] 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.

[0608] 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.

[0609] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0610] 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.

[0611] 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.

[0612] 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.

[0613] 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.

[0614] The EL layer 763 may further include layers other than the light-emitting layer, such as a material with high hole injection properties, a material with high hole transport properties, a hole blocking material, a material with high electron transport properties, a material with high electron injection properties, an electron blocking material, or a bipolar material (a material with high electron transport and hole transport properties).

[0615] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0616] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0617] As acceptor materials, for example, oxides of metals belonging to groups 4 to 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used. Furthermore, as a material with high hole injection properties, a mixed material may be used, which is a mixture of the above-mentioned oxides of metals belonging to groups 4 to 8 of the periodic table (typically molybdenum oxide) and an organic material.

[0618] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. As for the hole-transporting material, 10 -6 cm 2 Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0619] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material with electron-blocking properties can be used for the electron blocking layer.

[0620] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0621] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having an electron mobility of 1 / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds, which are materials with high electron transport capabilities.

[0622] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0623] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0624] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0625] 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.

[0626] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), 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 x Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0627] 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.

[0628] Furthermore, the lowest unoccupied molecular orbital (LUMO) level of organic compounds with 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.

[0629] 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.

[0630] 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.

[0631] 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.

[0632] This embodiment can be combined with other embodiments as appropriate.

[0633] (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.

[0634] As the light-receiving device, for example, a pn-type or pin-type photodiode can be used. In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device.

[0635] [Light receiving device] As shown in Figure 34A, 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.

[0636] Furthermore, Figure 34B shows a modified example of the layer 765 of the photodetector shown in Figure 34A. Specifically, the photodetector shown in Figure 34B 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.

[0637] The active layer 767 functions as a photoelectric conversion layer.

[0638] 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.

[0639] In one embodiment of the present invention, there may be layers that are common to 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). Such layers 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 device and the light-emitting device may have the same function in both the light-receiving device and the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-receiving device and the light-receiving device, and an electron transport layer functions as an electron transport layer in both the light-receiving device and the light-receiving device.

[0640] Next, we will describe the materials that can be used in light-receiving devices.

[0641] 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.

[0642] 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.

[0643] As for the n-type semiconductor material of the active layer, fullerene (for example, C 60 , C 70Examples 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).

[0644] 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).

[0645] 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.

[0646] 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.

[0647] 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.

[0648] 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.

[0649] 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.

[0650] 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.

[0651] 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.

[0652] Furthermore, the active layer may be a mixture of three or more materials. To broaden the wavelength range, a third material may be mixed in addition to the n-type semiconductor material and the p-type semiconductor material. In this case, the third material may be a low-molecular-weight compound or a high-molecular-weight compound.

[0653] 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.

[0654] As hole-transporting materials or electron-blocking materials, polymer compounds such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS), and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used. Furthermore, as electron-transporting materials or hole-blocking materials, inorganic compounds such as zinc oxide (ZnO) and organic compounds such as polyethyleneimine ethoxylate (PEIE) can be used. The light-receiving device may, for example, have a mixed film of PEIE and ZnO.

[0655] [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.

[0656] 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.

[0657] 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.

[0658] 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.

[0659] In a display device having light-emitting and light-receiving devices in its pixels, the pixels have a light-receiving function, allowing for the detection of contact or proximity of an object while displaying an image. For example, not only can the display device display an image using all of its subpixels, but some subpixels can also emit light as a light source while the remaining subpixels display an image.

[0660] 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.

[0661] 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.

[0662] 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.

[0663] 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).

[0664] Here, the touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen).

[0665] 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.

[0666] 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.

[0667] Furthermore, in a display device according to one aspect of the present invention, a lens can be provided on the light-receiving device. By making the diameter of the lens larger than the effective area of ​​the light-receiving part, the light-collecting ability can be increased, and the light sensitivity of the light-receiving device can be improved.

[0668] The display device 100 shown in Figures 34C to 34E 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.

[0669] The functional layer 355 includes circuits for driving a light-receiving device and circuits 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.

[0670] For example, as shown in Figure 34C, 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.

[0671] Furthermore, as shown in Figures 34D and 34E, the device may also have a function to detect or image objects that are close to (but not in contact with) the display device. Figure 34D shows an example of detecting a person's finger, and Figure 34E 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).

[0672] This embodiment can be combined with other embodiments as appropriate.

[0673] (Embodiment 7) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 35 to 37.

[0674] 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.

[0675] 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.

[0676] 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.

[0677] 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 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.

[0678] 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).

[0679] 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.

[0680] Figures 35A to 35D 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.

[0681] The electronic device 700A shown in Figure 35A and the electronic device 700B shown in Figure 35B 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.

[0682] A display device according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created. Furthermore, in the display device according to one embodiment of the present invention, since the light emitted from the light-emitting part is extracted through a lens, the light extraction efficiency is high, and an extremely bright image can be displayed. Therefore, when used as an electronic device capable of AR display, an image with good visibility can be displ...

Claims

[Claim 1] It comprises a light-emitting device and a lens, The light-emitting device and the lens have overlapping regions. The light-emitting device comprises a pair of electrodes and an organic compound provided between the pair of electrodes. One of the pair of electrodes is a conductive film that is transparent to visible light. The lens is provided in contact with the conductive film, The refractive index of the lens is greater than the refractive index of the conductive film. The aforementioned lens is a plano-convex lens, and the display device is provided with the surface opposite to the convex surface in contact with the conductive film.

Images