Display device, electronic appliance, and head mount display

Abstract

To provide a display device that enables a user to see a bright image.SOLUTION: In a display device, a first substrate, a light-emitting element, an insulating layer, a colored layer, a flattened layer, a plane-convex lens, a resin layer, and a second substrate are provided by stacking in this order from the bottom. The plane-convex lens has a shape projecting upward in the display device. A projecting part of the plane-convex lens is in contact with the resin layer and a refractive index of the resin layer is lower than that of the plane-convex lens. The light emitted from the light-emitting element is condensed in a front direction by the plane-convex lens.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] 1. Field of the Invention

[0003] One embodiment of the present invention relates to a display device, an electronic device, and a head-mounted display.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the technical field of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, driving methods thereof, and manufacturing methods thereof. A semiconductor device refers to any device that can function by utilizing semiconductor characteristics. [Background technology]

[0003] Wearable display devices and stationary display devices are becoming popular as display devices for Augmented Reality (AR) or Virtual Reality (VR). Examples of wearable display devices include head-mounted displays (HMDs) and eyeglass-type display devices. Examples of stationary display devices include head-up displays (HUDs). For example, Patent Document 1 discloses a head-mounted display that can easily capture an image of a user's eyes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-80354 Summary of the Invention [Problem to be solved by the invention]

[0005] In display devices such as HMDs, where the display surface is close to the user, the user can easily see the pixels, which can cause a strong sense of graininess, which can diminish the immersive and realistic feel of AR or VR. For this reason, display devices with fine pixels that prevent the user from seeing the pixels are desired. In other words, high-resolution display devices are desired.

[0006] When pixels are miniaturized, the aperture ratio of the pixel may decrease. As a result, the proportion of the area occupied by the display element in the area occupied by the pixel decreases. Therefore, for example, when a light-emitting element is used as the display element, the image viewed by the user of the display device may become dark. Furthermore, when attempting to display a bright image on the display device, a large current must be passed through the light-emitting element, which increases the power consumption of the display device and shortens the lifespan of the display device, resulting in a decrease in the reliability of the display device.

[0007] An object of one embodiment of the present invention is to provide a display device which allows a user to view a bright image. Another object of one embodiment of the present invention is to provide a display device with low power consumption. Another object of one embodiment of the present invention is to provide a highly reliable display device. Another object of one embodiment of the present invention is to provide a display device having fine pixels. Another object of one embodiment of the present invention is to provide a display device which can display a high-quality image. Another object of one embodiment of the present invention is to provide a low-cost display device. Another object of one embodiment of the present invention is to provide a novel display device. Another object of one embodiment of the present invention is to provide a manufacturing method of the display device.

[0008] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0009] One embodiment of the present invention is a display device including a first light-emitting element, a first coloring layer, a first lens, a first substrate, a second substrate, an insulating layer, a planarization layer, and a resin layer. The first lens has a first flat portion and a first convex portion. The first light-emitting element is provided over the first substrate. The insulating layer is provided over the first light-emitting element. The first coloring layer is provided on the insulating layer to have a region overlapping with the first light-emitting element. The planarization layer is provided over the first coloring layer. The first flat portion is in contact with the planarization layer and the first lens is provided to have a region overlapping with the first light-emitting element. The resin layer is in contact with the first convex portion. The second substrate is in contact with the resin layer. The refractive index of the resin layer is lower than that of the first lens.

[0010] Alternatively, in the above aspect, the light-emitting element may have a second light-emitting element, a second colored layer, and a second lens, the second lens having a second flat portion and a second convex portion, the second light-emitting element being provided on a first substrate, an insulating layer being provided on the second light-emitting element, the second colored layer being provided on the insulating layer so as to have an area overlapping with the second light-emitting element, the second flat portion being in contact with the planarizing layer and the second lens being provided so as to have an area overlapping with the second light-emitting element, a resin layer being in contact with the second convex portion, the refractive index of the resin layer being lower than the refractive index of the second lens, the first colored layer and the second colored layer transmitting light of different colors, and the thickness of the first colored layer and the thickness of the second colored layer may be different.

[0011] Another embodiment of the present invention is a display device including a light-emitting element, a wavelength conversion layer, a lens, a first substrate, a second substrate, an insulating layer, a planarization layer, and a resin layer, the lens having a flat portion and a convex portion, the light-emitting element being provided over the first substrate, the insulating layer being provided over the light-emitting element, the wavelength conversion layer being provided over the insulating layer to have a region overlapping with the light-emitting element, the planarization layer being provided over the wavelength conversion layer, the lens being provided so that its flat portion is in contact with the planarization layer and has a region overlapping with the light-emitting element, the resin layer being in contact with the convex portion, and the second substrate being in contact with the resin layer, and the refractive index of the resin layer is lower than that of the lens.

[0012] Alternatively, one embodiment of the present invention is a display device including a first substrate, a first light-emitting element, a second light-emitting element, an insulating layer, a first coloring layer, a second coloring layer, a partition wall, a first lens, and a second lens, in which the first light-emitting element and the second light-emitting element are provided over the first substrate, an insulating layer is provided over the first light-emitting element and the second light-emitting element, a partition wall is provided over the insulating layer, the first coloring layer is provided on the insulating layer to be in contact with a side surface of the partition wall and to have a region overlapping with the first light-emitting element, the second coloring layer is provided on the insulating layer to be in contact with a side surface of the partition wall and to have a region overlapping with the second light-emitting element, the first lens is provided on the first coloring layer to have a region overlapping with the first light-emitting element, and the second lens is provided on the second coloring layer to have a region overlapping with the second light-emitting element, and the refractive index of the partition wall is lower than that of the first coloring layer and that of the second coloring layer.

[0013] Alternatively, in the above aspect, the display device may have a planarization layer, the first lens may have a first flat portion and a first convex portion, the second lens may have a second flat portion and a second convex portion, the planarization layer may be provided on the first colored layer and the second colored layer, and the first flat portion and the second flat portion may be in contact with the planarization layer.

[0014] Alternatively, in the above embodiment, the thickness of the first colored layer and the thickness of the second colored layer may be different.

[0015] Another embodiment of the present invention is a display device including a first substrate, a first light-emitting element, a second light-emitting element, an insulating layer, a wavelength conversion layer, a partition, a first lens, and a second lens, in which the first light-emitting element and the second light-emitting element are provided over the first substrate, an insulating layer is provided over the first light-emitting element and the second light-emitting element, a partition is provided over the insulating layer, the wavelength conversion layer is in contact with a side surface of the partition and is provided over the insulating layer to have a region overlapping with the first light-emitting element, the first lens is provided over the wavelength conversion layer to have a region overlapping with the first light-emitting element, and the second lens is provided to have a region overlapping with the second light-emitting element, and the refractive index of the partition is lower than that of the wavelength conversion layer.

[0016] Alternatively, in the above aspect, the display device may have a planarization layer, the first lens may have a first flat portion and a first convex portion, the second lens may have a second flat portion and a second convex portion, the planarization layer may be provided on the wavelength conversion layer, and the first flat portion and the second flat portion may be in contact with the planarization layer.

[0017] Alternatively, in the above aspect, the display device may have a second substrate and a resin layer, the resin layer being in contact with the first convex portion and the second convex portion, the second substrate being in contact with the resin layer, and the refractive index of the resin layer being lower than the refractive index of the first lens and the refractive index of the second lens.

[0018] Alternatively, in the above embodiment, the planarizing layer may be in contact with the upper and side surfaces of the first colored layer and the upper and side surfaces of the second colored layer, and the refractive index of the planarizing layer may be lower than the refractive index of the first colored layer and the refractive index of the second colored layer.

[0019] Alternatively, in the above embodiment, the first lens and the second lens may be adjacent to each other, and the first colored layer and the second colored layer may be spaced apart.

[0020] Alternatively, in the above embodiment, the insulating layer may be a planarized layer.

[0021] An electronic device including a display device according to one embodiment of the present invention and a battery is also one embodiment of the present invention.

[0022] A head-mounted display including the display device of one embodiment of the present invention and a mounting unit is also one embodiment of the present invention. [Effects of the Invention]

[0023] According to one embodiment of the present invention, a display device which allows a user to view a bright image can be provided. According to another embodiment of the present invention, a display device with low power consumption can be provided. According to another embodiment of the present invention, a display device with high reliability can be provided. According to another embodiment of the present invention, a display device having fine pixels can be provided. According to another embodiment of the present invention, a display device which can display a high-quality image can be provided. According to another embodiment of the present invention, a low-cost display device can be provided. According to another embodiment of the present invention, a novel display device can be provided. According to another embodiment of the present invention, a manufacturing method of the display device can be provided.

[0024] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0025] [Figure 1] Fig. 1A is a cross-sectional view showing an example of the configuration of a display device, and Fig. 1B is a diagram showing an example of the traveling direction of light. [Figure 2] 2A and 2B are cross-sectional views showing configuration examples of a display device. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the configuration of a display device. [Figure 4] Fig. 4A is a cross-sectional view showing an example of the configuration of a display device, and Fig. 4B is a diagram showing an example of the traveling direction of light. [Figure 5] Fig. 5A is a cross-sectional view showing an example of the configuration of a display device, and Fig. 5B is a diagram showing an example of the traveling direction of light. [Figure 6] 6A and 6B are cross-sectional views showing examples of the configuration of a display device. [Figure 7] 7A and 7B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 8] 8A and 8B are cross-sectional views showing an example of a method for manufacturing a display device. [Figure 9] FIG. 9 is a cross-sectional view showing an example of the configuration of a display device. [Figure 10] 10A is a top view illustrating an example of a transistor, and FIGS. 10B to 10D are cross-sectional views illustrating an example of a transistor. [Figure 11] Fig. 11A is a diagram illustrating the classification of IGZO crystal structures, Fig. 11B is a diagram illustrating the XRD spectrum of a CAAC-IGZO film, and Fig. 11C is a diagram illustrating the electron microbeam diffraction pattern of a CAAC-IGZO film. [Figure 12] 12A to 12D are diagrams showing an example of an electronic device. [Figure 13] 13A to 13F are diagrams showing an example of an electronic device. [Figure 14] FIG. 14 is a schematic diagram of a display device used in the simulation. [Figure 15] FIG. 15 is a graph showing the light distribution characteristics of the light emitting element used in the simulation. [Figure 16] FIG. 16 is a graph showing the simulation results. [Figure 17] 17A and 17B are electron microscope images of the display device. [Figure 18] FIG. 18 is a schematic diagram of a display device used in the simulation. [Figure 19] FIG. 19 is a graph showing the actual measurement results and the simulation results of the radiance in the display device according to this example. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0027] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0028] In the drawings described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0029] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0030] In the following, expressions indicating directions such as "up" and "down" will basically be used in accordance with the directions in the drawings. However, for purposes such as facilitating explanation, the directions indicated by "up" or "down" in the specification may not match those in the drawings. For example, when explaining the stacking order (or formation order) of a laminate, etc., even if the surface on which the laminate is provided in the drawing (the surface to be formed, the supporting surface, the adhesive surface, the flat surface, etc.) is located above the laminate, the direction toward that surface may be expressed as "down" and the opposite direction as "up."

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

[0032] (Embodiment 1) In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described.

[0033] [Configuration example 1] FIG. 1A is a cross-sectional view showing an example of the configuration of a display device 10, which is a display device according to one embodiment of the present invention. The display device 10 includes a pixel 15R, a pixel 15G, and a pixel 15B. The pixels 15R, 15G, and 15B are provided on a display surface of the display device 10. The display surface can be configured such that the pixels 15R, 15G, and 15B are arranged in a matrix. The pixels 15R, 15G, and 15B constitute one pixel, and the pixels can be said to be arranged in a matrix on the display surface of the display device 10. In this case, the pixels 15R, 15G, and 15B can be said to be subpixels.

[0034] The display device 10 includes a substrate 11, a transistor 52, an insulating layer 13, a light-emitting element 30, a partition wall 14, an insulating layer 63, an insulating layer 21, a colored layer 25R, a colored layer 25G, a colored layer 25B, a planarization layer 27, a lens 29, a resin layer 33, and a substrate 12. One light-emitting element 30 and one lens 29 are provided for each of the pixels 15R, 15G, and 15B. The colored layer 25R is provided for the pixel 15R, the colored layer 25G is provided for the pixel 15G, and the colored layer 25B is provided for the pixel 15B.

[0035] In this specification and the like, a light-emitting element can be referred to as a light-emitting device, and a display element can be referred to as a display device.

[0036] In the display device 10 shown in FIG. 1A, pixel 15G is adjacent to pixel 15R and pixel 15B. The light-emitting elements 30, colored layers, and lenses 29 of adjacent pixels are adjacent to each other. For example, the light-emitting element 30 of pixel 15R shown in FIG. 1A and the light-emitting element 30 of pixel 15G are adjacent to each other. The colored layers 25R and 25G shown in FIG. 1A are adjacent to each other. The lens 29 of pixel 15R shown in FIG. 1A and the lens 29 of pixel 15G are adjacent to each other. Although pixel 15R and pixel 15B are not adjacent to each other in FIG. 1A, pixel 15R and pixel 15B may be adjacent to each other.

[0037] The insulating layer 13 and the transistor 52 are provided on the substrate 11. The light-emitting element 30 is provided on the insulating layer 13. The insulating layer 63 is provided on the light-emitting element 30. The insulating layer 21 is provided on the insulating layer 63. The coloring layers 25R, 25G, and 25B are provided on the insulating layer 21. The planarization layer 27 is provided on the coloring layers 25R, 25G, and 25B. The lens 29 is provided on the planarization layer 27. The resin layer 33 is provided on the lens 29. The substrate 12 is provided on the resin layer 33. Here, although the upper surface of the insulating layer 13 is planarized in FIG. 1A, it does not have to be planarized.

[0038] In this specification, for example, when "B on A" is mentioned, as long as at least a part of A and at least a part of B overlap, A and B do not necessarily have to have an area where they contact each other.

[0039] The substrate 11 can be an insulating substrate such as a glass substrate, a quartz substrate, a sapphire substrate, or a ceramic substrate, or a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate. In addition, by using a flexible substrate as the substrate 11 and also making the substrate 12 a flexible substrate, the display device 10 can be made a flexible display device.

[0040] For example, an organic insulating film is preferably used for the insulating layer 13 and the insulating layer 21. Examples of organic insulating films include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimideamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins. For example, an inorganic insulating film is preferably used for the insulating layer 63. Examples of inorganic insulating films that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, a hafnium oxynitride film, a hafnium nitride oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may be used. Two or more of the above insulating films may be stacked. An inorganic insulating film may be used for the insulating layer 13 or the insulating layer 21, and an organic insulating film may be used for the insulating layer 63. The other insulating layers of the display device 10 can also be made of the same materials as those that can be used as the insulating layer 13, the insulating layer 63, or the insulating layer 21.

[0041] In this specification and the like, silicon oxynitride refers to a composition in which the oxygen content is higher than the nitrogen content, and silicon nitride oxide refers to a composition in which the nitrogen content is higher than the oxygen content.

[0042] As shown in FIG. 1A , the colored layer 25R, the colored layer 25G, and the colored layer 25B are provided on different light-emitting elements 30. Different lenses 29 are provided on the colored layer 25R, the colored layer 25G, and the colored layer 25B, respectively. As described above, the light-emitting element 30, the colored layer 25R, and the lens 29 are provided so as to have overlapping regions with each other. The light-emitting element 30, the colored layer 25G, and the lens 29 are also provided so as to have overlapping regions with each other. The light-emitting element 30, the colored layer 25B, and the lens 29 are also provided so as to have overlapping regions with each other.

[0043] 1A, a configuration having an overlapping region between two types of colored layers is indicated by a dotted line. Also, FIG. 1A shows a configuration in which lenses 29 are spaced apart from each other. Note that the colored layers do not have to overlap, and lenses 29 provided in adjacent pixels may have an area where they contact each other.

[0044] The light-emitting element 30 has a laminated structure of a conductive layer 42, a light-emitting layer 31, and a conductive layer 60. Here, the conductive layer 42 can be used as a pixel electrode of the light-emitting element 30, and the conductive layer 60 can be used as a common electrode of the light-emitting element 30.

[0045] The light-emitting element 30 can emit, for example, white light. Specifically, white light can be emitted from the light-emitting layer 31. As the light-emitting element 30, an EL element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode) can be used. Alternatively, as the light-emitting element 30, a micro LED can be used.

[0046] When a white-emitting light-emitting element is used as the light-emitting element 30, it is preferable that the light-emitting layer 31 contains two or more types of light-emitting materials. For example, white light can be obtained by selecting light-emitting materials such that the light emitted from the two or more light-emitting materials has a complementary color relationship. For example, it is preferable to include two or more light-emitting materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), etc., or light-emitting materials that emit light containing spectral components of two or more colors of R, G, and B. It is also preferable to use a light-emitting element whose emission spectrum has two or more peaks within the wavelength range of the visible light region (e.g., 350 nm to 750 nm). It is also preferable that the emission spectrum of a material that has a peak in the yellow wavelength region also contains spectral components in the green and red wavelength regions.

[0047] The light-emitting layer 31 is preferably configured by stacking a light-emitting layer containing a light-emitting material that emits one color and a light-emitting layer containing a light-emitting material that emits another color. For example, the multiple light-emitting layers in the light-emitting layer 31 may be stacked in contact with each other, or may be stacked via a region that does not contain any light-emitting material. For example, a region that contains the same material (e.g., host material, assist material) as the fluorescent or phosphorescent light-emitting layer but does not contain any light-emitting material may be provided between the fluorescent or phosphorescent light-emitting layer. This facilitates fabrication of the light-emitting element 30 and reduces the driving voltage. When the light-emitting element 30 is configured by stacking multiple light-emitting layers 31, the multiple light-emitting layers 31 may be stacked via a charge-generating layer.

[0048] The conductive layer 42 can be electrically connected to the transistor 52 through an opening provided in the insulating layer 13 that reaches the transistor 52. For example, the conductive layer 42 can be electrically connected to the source or drain of the transistor 52.

[0049] The partition wall 14 has a function of electrically insulating (also referred to as electrically separating) the conductive layers 42 included in different light-emitting elements 30. Ends of the conductive layers 42 are covered with the partition wall 14.

[0050] It is preferable to use an inorganic insulating film as the partition wall 14. For example, the same material as that which can be used for the insulating layer 63 or the like can be used as the partition wall 14. Note that an organic insulating film may also be used as the partition wall 14. The partition wall 14 is a layer that transmits visible light. Instead of the partition wall 14, a partition wall that blocks visible light may be provided.

[0051] The insulating layer 63 can be provided so as to cover the light-emitting element 30. The insulating layer 63 is preferably made of a film that is difficult to permeate impurities such as water or hydrogen. By providing the insulating layer 63 made of a film that is difficult to permeate impurities such as water or hydrogen so as to cover the light-emitting element 30, it is possible to prevent impurities such as water or hydrogen from entering the light-emitting element 30. This improves the reliability of the light-emitting element 30. As described above, the insulating layer 63 functions as a protective layer for the light-emitting element 30. Note that the insulating layer 63 does not necessarily have to be provided. In this case, it is preferable that the insulating layer 21 function as the protective layer described above.

[0052] As described above, the insulating layer 21 can be provided on the light-emitting element 30, and the coloring layer 25R, the coloring layer 25G, and the coloring layer 25B can be provided on the insulating layer 21. For example, the coloring layer 25R, the coloring layer 25G, and the coloring layer 25B can be provided so as to be in contact with the upper surface of the insulating layer 21. Here, by flattening the upper surface of the insulating layer 21 as shown in FIG. 1A, the coloring layer 25R, the coloring layer 25G, and the coloring layer 25B can be provided on a flat surface.

[0053] The coloring layer 25R has a function of transmitting, for example, red light. The coloring layer 25G has a function of transmitting, for example, green light. The coloring layer 25B has a function of transmitting, for example, blue light. In this case, red light is emitted from the pixel 15R, green light is emitted from the pixel 15G, and blue light is emitted from the pixel 15B. Note that the coloring layer 25R, the coloring layer 25G, or the coloring layer 25B may also have a function of transmitting light of cyan, magenta, yellow, etc. Also, although FIG. 1A shows three types of coloring layers, the display device 10 may have four or more types of coloring layers.

[0054] The colored layers 25R, 25G, and 25B may be made of a metal material, a resin material, a resin material containing a pigment or a dye, or the like.

[0055] By providing the colored layer so as to have an area overlapping with the light emitting element 30, it is no longer necessary to form the light emitting layer 31 by applying different colors, and this allows the pixels in which the light emitting element 30 is provided to be minute.

[0056] Here, the colored layers provided in adjacent pixels can partially overlap each other. In the example shown in FIG. 1A, the colored layers 25R and 25G can have overlapping regions. Furthermore, the colored layers 25G and 25B can have overlapping regions. This allows the colored layers 25R, 25G, and 25B to be formed, for example, by photolithography and etching, even if the alignment accuracy of the mask used in photolithography is low. Therefore, the pixels in which the light-emitting elements 30 are provided can be made fine.

[0057] Here, the thicknesses of the colored layers 25R, 25G, and 25B can be different from one another. This allows, for example, a desired balance between the color purity of light transmitted through the colored layers and the light absorption rate of the colored layers to be achieved for each color. This allows the display device 10 to display high-quality images. Note that the thicknesses of the colored layers 25R, 25G, and 25B may be the same.

[0058] As described above, the planarizing layer 27 is provided on the colored layer 25R, the colored layer 25G, and the colored layer 25B. For example, the planarizing layer 27 can be provided so as to be in contact with the colored layer 25R, the colored layer 25G, and the colored layer 25B. Specifically, the planarizing layer 27 can be provided so as to be in contact with the upper surfaces and side surfaces of the colored layer 25R, the colored layer 25G, and the colored layer 25B.

[0059] The planarizing layer 27 may be made of the same material as that used for the insulating layer 21, for example.

[0060] As described above, the lens 29 is provided on the planarization layer 27. Here, the lens 29 may be a plano-convex lens having a flat portion 29a and a convex portion 29b. The lens 29 may be provided so that the flat portion 29a faces the substrate 11 side and the convex portion 29b faces the substrate 12 side. For example, the lens 29 may be provided so that the flat portion 29a contacts the upper surface of the planarization layer 27.

[0061] As described above, the thicknesses of the colored layers 25R, 25G, and 25B can be different from one another. Even in such a case, by providing a planarizing layer 27 on the colored layers 25R, 25G, and 25B and providing lenses 29 on the planarizing layer 27, the flat portions 29a of the lenses 29 can be arranged on the same plane. This allows the distance L from the light-emitting layer 31 of the light-emitting element 30 to the flat portions 29a of the lenses 29 to be equal to one another. Specifically, the distance from the light-emitting layer 31 overlapping with the colored layer 25R to the flat portions 29a, the distance from the light-emitting layer 31 overlapping with the colored layer 25G to the flat portions 29a, and the distance from the light-emitting layer 31 overlapping with the colored layer 25B to the flat portions 29a can be equal to one another.

[0062] A resin layer 33 is provided so as to be in contact with the convex portion 29b of the lens 29. Furthermore, the substrate 12 is provided so as to be in contact with the upper surface of the resin layer 33. The lens 29 and the substrate 12 can be bonded together by the resin layer 33.

[0063] The resin layer 33 may be made of an epoxy resin, an acrylic resin, a silicone resin, a phenolic resin, a polyimide resin, an imide resin, a PVC (polyvinyl chloride) resin, a PVB (polyvinyl butyral) resin, an EVA (ethylene vinyl acetate) resin, or the like. A two-component resin may also be used. Here, the refractive index of the resin layer 33 is preferably lower than that of the lens 29, as will be described in detail later.

[0064] 1A, the lens 29 and the substrate 12 are bonded together by the resin layer 33, but this is not a limitation of one embodiment of the present invention. For example, the lens 29 and the substrate 12 can be bonded together by creating a vacuum between them. In this case, the resin layer 33 may not be provided.

[0065] A light-transmitting substrate is used as the substrate 12. For example, a glass substrate, a quartz substrate, a sapphire substrate, etc. can be used as the substrate 12. Furthermore, by using a flexible substrate as the substrate 12, together with the substrate 11, the display device 10 can be made a flexible display device.

[0066] 1B is a cross-sectional view of the section from dashed dotted line A1 to dashed dotted line A2 in the cross-sectional view of FIG.

[0067] In this specification and the like, the term "light" may sometimes be replaced with "luminous flux."

[0068] The light-emitting element 30 emits light 43 not only in the front direction but also in oblique directions. If the light 43 emitted in the oblique direction were to exit the pixel at the same angle, for example, when a user of the display device 10 views the display surface of the display device 10 from directly in front of the display surface, the user may not be able to see the light 43 emitted in the oblique direction. Here, since the light emitted by the light-emitting element 30 is incident on the flat portion 29a of the lens 29, if the refractive index of the resin layer 33 is lower than that of the lens 29 as described above, Snell's law allows the light emitted in the oblique direction to be focused in the front direction as shown in FIG. 1B. As a result, for example, when a user of the display device 10 views the display surface of the display device 10 from directly in front of the display surface, the amount of light 43 visible to the user of the display device 10 can be increased. Therefore, the user of the display device 10 can view a bright image. Furthermore, since the luminous intensity of the light-emitting element 30 can be reduced, the display device 10 can be a low-power display device and a highly reliable display device.

[0069] Here, the refractive index of the lens 29 may be, for example, 1.5 or more and 1.8 or less, for example, 1.5 or more and 1.6 or less, such as 1.56. The refractive index of the resin layer 33 may be, for example, 1.2 or more and 1.5 or less, for example, 1.3 or more and less than 1.5, such as 1.40. Note that if the lens 29 and the substrate 12 are bonded together by creating a vacuum between them without providing the resin layer 33, the refractive index of the lens 29 may be greater than 1.

[0070] It is also preferable to set the distance L so that the relationship shown in formula (1) holds. Here, R1 is the radius of curvature of the convex portion 29b, N1 is the refractive index of the lens 29, N2 is the refractive index of the resin layer 33, and N3 is the refractive index of the planarization layer 27. The focal length of the lens 29 is "R1×N3 / (N1-N2)".

[0071] 0.1×R1×N3 / (N1-N2) ≦ L ≦ 5×R1×N3 / (N1-N2) (1)

[0072] As described above, the thicknesses of the colored layers 25R, 25G, and 25B can be different from one another. Therefore, if the planarization layer 27 is not provided and lenses 29 are provided on the colored layers 25R, 25G, and 25B, the distance L will be different for each pixel. If the distance L is different for each pixel, it may be necessary to change the radius of curvature R1 of the convex portion 29b or the refractive index N1 of the lens 29 for each pixel, as shown in Equation (1). In this case, the lens 29 must be fabricated for each pixel, complicating the manufacturing process of the display device. On the other hand, in the display device 10, the lens 29 is provided on the planarization layer 27, so the distance L can be made equal for each pixel. Therefore, the manufacturing process of the display device 10 can be simplified. This reduces the manufacturing cost of the display device 10, allowing the display device 10 to be manufactured at a low price.

[0073] [Configuration example 2] Fig. 2A is a modified example of the display device 10 shown in Fig. 1A. The display device 10 shown in Fig. 2A differs from the display device 10 shown in Fig. 1A in that a light-emitting layer 51 is provided instead of the light-emitting layer 31, and wavelength conversion layers 55R and 55G are provided instead of the coloring layers 25R, 25G, and 25B.

[0074] The light-emitting layer 51 has a function of emitting, for example, blue light. The wavelength conversion layer 55R provided in the pixel 15R has a function of converting the light emitted by the light-emitting layer 51 into red light. The wavelength conversion layer 55G provided in the pixel 15G has a function of converting the light emitted by the light-emitting layer 51 into green light. Here, if the light-emitting layer 51 emits blue light, the pixel 15B does not need to be provided with a wavelength conversion layer. The light-emitting layer 51 may also have a function of emitting ultraviolet light. In this case, by providing the pixel 15B with a wavelength conversion layer that converts the light emitted by the light-emitting layer 51 into blue light, the pixel 15B can emit blue light.

[0075] The wavelength conversion layers 55R and 55G preferably contain a fluorescent material or quantum dots (QDs). Quantum dots, in particular, have a narrow peak width in the emission spectrum, high conversion efficiency, and can emit light with high color purity. This improves the color reproducibility of the display device 10, enabling the display device 10 to display high-quality images.

[0076] The wavelength conversion layers 55R and 55G may be formed by dispersing phosphors or quantum dots in an organic resin. The organic resin may be a curable material that is translucent to the light emitted by the light-emitting layer 51 and the light emitted by the wavelength conversion layer 55R or 55G.

[0077] The wavelength conversion layers 55R and 55G can be formed by, for example, a droplet discharge method (e.g., an inkjet method), a coating method, an imprint method, various printing methods (e.g., screen printing, offset printing), etc. Alternatively, by using a photosensitive resin material as the organic resin, the organic resin may be applied by a method such as spin coating, and then processed into any desired shape through exposure and development.

[0078] The material constituting the quantum dots is not particularly limited, and examples thereof include a Group 14 element, a Group 15 element, a Group 16 element, a compound consisting of multiple Group 14 elements, a compound of an element belonging to Groups 4 to 14 and a Group 16 element, a compound of a Group 2 element and a Group 16 element, a compound of a Group 13 element and a Group 15 element, a compound of a Group 13 element and a Group 17 element, a compound of a Group 14 element and a Group 15 element, a compound of a Group 11 element and a Group 17 element, iron oxides, titanium oxides, chalcogenide spinels, and semiconductor clusters.

[0079] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, terephthalic acid, Indium sulfide, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, selenide Calcium, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tungsten oxide Examples of the quantum dots include tantalum, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, a compound of selenium, zinc, and cadmium, a compound of indium, arsenic, and phosphorus, a compound of cadmium, selenium, and sulfur, a compound of cadmium, selenium, and tellurium, a compound of indium, gallium, and arsenic, a compound of indium, gallium, and selenium, a compound of indium, selenium, and sulfur, a compound of copper, indium, and sulfur, and combinations thereof. Also, so-called alloy-type quantum dots, whose composition is expressed in any ratio, may be used.

[0080] Quantum dot structures include core, core-shell, and core-multishell types. Quantum dots have a high proportion of surface atoms, making them highly reactive and prone to aggregation. Therefore, it is preferable that a protective agent or protective group is attached to the surface of the quantum dots. By attaching the protective agent or providing the protective group, aggregation can be prevented and solubility in a solvent can be increased. It is also possible to reduce reactivity and improve electrical stability.

[0081] Since the band gap of quantum dots increases as their size decreases, their size can be adjusted appropriately to obtain light of the desired wavelength. As the crystal size decreases, the emission of quantum dots shifts toward the blue side, i.e., toward higher energy, so by changing the size of the quantum dots, the emission wavelength can be adjusted across the wavelength ranges of the ultraviolet, visible, and infrared spectrum. The size (diameter) of the quantum dots is, for example, 0.5 nm or more and 20 nm or less, preferably 1 nm or more and 10 nm or less. The narrower the size distribution of quantum dots, the narrower the emission spectrum, and the more excellent the color purity of the light emitted. Furthermore, the shape of the quantum dots is not limited to spherical, but may also be rod-shaped, disk-shaped, or other shapes.

[0082] Here, when quantum dots are dispersed in the wavelength conversion layers 55R and 55G, the light emitted by the wavelength conversion layers 55R and 55G has low directivity. However, in the display device 10, the flat portion 29a of the lens 29 faces the wavelength conversion layers 55R and 55G, and the convex portion 29b faces the substrate 12. Furthermore, in the display device 10, the refractive index of the resin layer 33 is lower than that of the lens 29. As a result, even if the light emitted by the wavelength conversion layers 55R and 55G has low directivity, the lens 29 can focus the light in a forward direction. This allows, for example, a user of the display device 10 to view the display surface of the display device 10 from directly in front of the display surface, increasing the amount of light 43 perceived by the user. Therefore, the user of the display device 10 can view a bright image. Furthermore, since the luminous intensity of the light emitting element 30 can be reduced, the display device 10 can be a display device with low power consumption and high reliability.

[0083] 2A, pixel 15R and pixel 15G are provided with wavelength conversion layers, but pixel 15B is not provided with a wavelength conversion layer. However, by providing a planarization layer 27 and providing a lens 29 thereon, the flat portion 29a of the lens 29 provided in pixel 15R or pixel 15G and the flat portion 29a of the lens 29 provided in pixel 15B can be provided on the same plane. This makes it possible to make the distance L from the light-emitting layer of the light-emitting element 30 to the flat portion 29a of the lens 29 equal to each other, thereby simplifying the manufacturing process of the display device 10.

[0084] [Configuration example 3] Fig. 2B is a modified example of the display device 10 shown in Fig. 2A. The display device 10 shown in Fig. 2B differs from the display device 10 shown in Fig. 2A in that a colored layer 25R and a colored layer 25G are provided.

[0085] The coloring layer 25R is provided on the wavelength conversion layer 55R. The coloring layer 25G is provided on the wavelength conversion layer 55G.

[0086] In some cases, some of the light incident on the wavelength conversion layer 55R or 55G from the light-emitting layer 51 is not wavelength-converted. As a result, for example, if the light-emitting layer 51 emits blue light, the red light emitted by the wavelength conversion layer 55R or the green light emitted by the wavelength conversion layer 55G may mix with the blue light emitted by the light-emitting layer 51, resulting in a decrease in color purity. Therefore, by arranging the colored layer 25R or the colored layer 25G closer to the substrate 12 than the wavelength conversion layer 55R or the wavelength conversion layer 55G, respectively, it is possible to prevent the blue light transmitted through the wavelength conversion layer 55R or the wavelength conversion layer 55G from being emitted to the outside of the display device 10. This prevents a decrease in color purity of the light emitted from the pixel 15R and the light emitted from the pixel 15G, enabling the display device 10 to display high-quality images.

[0087] [Configuration example 4] Fig. 3 is a cross-sectional view showing another example of the configuration of the display device 10. The display device 10 shown in Fig. 3 differs from the display device 10 shown in Fig. 1A in the configuration of layers above the insulating layer 21.

[0088] 3, a lens 29 is provided on an insulating layer 21. For example, a flat portion 29a of the lens 29 can be provided so as to contact the upper surface of the insulating layer 21. A resin layer 33 is also provided so as to contact a convex portion 29b of the lens 29. As described above, the refractive index of the resin layer 33 is preferably lower than that of the lens 29.

[0089] Colored layers 25R, 25G, and 25B are provided on the resin layer 33. In addition, adhesive layers 37 are provided on the colored layers 25R, 25G, and 25B. As the adhesive layer 37, various curable adhesives can be used, such as a photocurable adhesive such as an ultraviolet curable adhesive, a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive, and for example, the same materials as those that can be used for the resin layer 33 can be used.

[0090] The substrate 12 is provided on the adhesive layer 37. The adhesive layer 37 allows the colored layer 25R, the colored layer 25G, and the colored layer 25B to be bonded to the substrate 12.

[0091] In the display device 10 shown in FIG. 3, the lens 29 is provided between the light-emitting element 30 and the colored layer 25R, the colored layer 25G, and the colored layer 25B. This allows the distance L from the light-emitting layer 31 of the light-emitting element 30 to the flat portion 29a of the lens 29 to be shorter than in the display device 10 shown in FIG. 1A, etc. Therefore, as can be seen from equation (1), the radius of curvature R1 of the convex portion 29b can be reduced. Furthermore, the refractive index N1 of the lens 29 can be increased. Furthermore, the refractive index N2 of the resin layer 33 can be reduced. Furthermore, the refractive index N3 of the planarization layer 27 can be reduced.

[0092] [Configuration example 5] Fig. 4A is a cross-sectional view showing another example of the configuration of the display device 10. The display device 10 shown in Fig. 4A differs from the display device 10 shown in Fig. 1A in that it has a partition wall 35.

[0093] The partition wall 35 can be provided at the boundary between pixels. For example, as shown in Fig. 4A, the partition wall 35 can be provided across the pixel 15R and the pixel 15G. Alternatively, the partition wall 35 can be provided across the pixel 15G and the pixel 15B.

[0094] The partition wall 35 is provided on the insulating layer 21. For example, the partition wall 35 can be provided so as to be in contact with the upper surface of the insulating layer 21. The shape of the partition wall 35 can be, for example, a hexahedron.

[0095] The colored layer 25R, the colored layer 25G, and the colored layer 25B can be provided so as to be in contact with the side surface of the partition wall 35. Here, for example, in the partition wall 35 provided at the boundary between the pixel 15R and the pixel 15G, the colored layer 25G can be configured to be in contact with the surface of the side surface of the partition wall 35 that faces the side surface with which the colored layer 25R faces. Furthermore, for example, in the partition wall 35 provided at the boundary between the pixel 15G and the pixel 15B, the colored layer 25B can be configured to be in contact with the surface of the side surface of the partition wall 35 that faces the side surface with which the colored layer 25G faces.

[0096] As will be described in detail later, it is preferable that the refractive index of the partition wall 35 be lower than the refractive index of the colored layer 25R, the colored layer 25G, and the colored layer 25B. For example, a fluorine-containing polymer is preferably used as the partition wall 35. Alternatively, an organic insulating film such as an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin, a polyimideamide resin, a siloxane resin, a benzocyclobutene-based resin, a phenolic resin, or a precursor of these resins may be used as the partition wall 35. Alternatively, an inorganic insulating film may be used as the partition wall 35.

[0097] Fig. 4B is a cross-sectional view of the section from dashed dotted line A3 to dashed dotted line A4 in Fig. 4A. In Fig. 4B, light emitted from light-emitting element 30 and irradiated onto partition wall 35 is shown as light 47.

[0098] When the refractive index of the partition wall 35 is set lower than the refractive index of the colored layer 25R, the refractive index of the colored layer 25G, and the refractive index of the colored layer 25B, light 47 is totally reflected at the interface between the partition wall 35 and the colored layer (colored layer 25G in FIG. 4B). This prevents light 47 from being incident on and absorbed in areas where two or more types of colored layers overlap. Therefore, the display device 10 shown in FIG. 4A can be a display device with high light extraction efficiency. Therefore, the display device 10 shown in FIG. 4A allows a user of the display device 10 to view a bright image. Furthermore, the display device 10 shown in FIG. 4A can be a display device with low power consumption and high reliability.

[0099] 4A, the light 47 can be prevented from entering a colored layer provided in an adjacent pixel, for example, thereby improving color purity, and the display device 10 can display high-quality images.

[0100] Furthermore, since the light 47 is reflected by the partitions 35 in a total reflection manner, absorption of the light 47 by the partitions 35 can be suppressed compared to when, for example, a reflective material such as a metal is used for the partitions 35. Therefore, the display device 10 shown in Fig. 4A can be a display device with high light extraction efficiency. Note that, if the absorption of the light 47 by the partitions 35 is within an acceptable range, a reflective material such as a metal may be used for the partitions 35.

[0101] Here, it is preferable to adjust the taper angle of the partition 35 so that the light 47 is totally reflected while preventing the totally reflected light 47 from entering an adjacent pixel. For example, if the taper angle is small, that is, if the side surface of the partition 35 is nearly vertical, the light 47 totally reflected by the side surface of the partition 35 may enter an adjacent pixel. For example, the light 47 totally reflected by the partition 35 may enter a lens 29 provided in an adjacent pixel. On the other hand, if the taper angle is large, that is, if the side surface of the partition 35 is nearly horizontal, the angle of incidence of the light 47 at the interface between the partition 35 and the colored layer becomes small, and the light 47 may not be totally reflected. Taking the above into consideration, it is preferable to adjust the taper angle of the partition 35.

[0102] 4A, the thickness of the partition wall 35 is equal to that of the colored layer 25B, but this is not a limitation of the present invention. The thickness of the partition wall 35 may be thinner or thicker than that of the colored layer 25B. The thickness of the partition wall 35 may be thinner or thicker than that of the colored layer 25G. The thickness of the partition wall 35 may be thinner or thicker than that of the colored layer 25R. Increasing the thickness of the partition wall 35 can reduce the amount of light emitted by the light-emitting element 30 that leaks to adjacent pixels without entering the partition wall 35. On the other hand, reducing the thickness of the partition wall 35 can reduce the aspect ratio of the partition wall 35, thereby preventing the partition wall 35 from collapsing during the manufacturing process of the display device 10.

[0103] [Configuration example 6] Fig. 5A is a modified example of the display device 10 shown in Fig. 4A. The display device 10 shown in Fig. 5A differs from the display device 10 shown in Fig. 4A in that a light-shielding layer 45 is provided.

[0104] The light-shielding layer 45 can be provided between the layer on which the light-emitting element 30 is provided and the layer on which the partition wall 35 is provided. 5A shows an example in which the light-shielding layer 45 is provided so as to be in contact with the upper surface of the insulating layer 21, and the partition wall 35 is provided so as to be in contact with the upper surface of the light-shielding layer 45.

[0105] Fig. 5B is a cross-sectional view of the section from dashed dotted line A5 to dashed dotted line A6 in Fig. 5A. In Fig. 5B, light emitted by light-emitting element 30 and irradiated onto the bottom surface of light-shielding layer 45 is shown as light 49.

[0106] If the light-shielding layer 45 is not provided in the display device 10, the light 49 is irradiated onto the bottom surface of the partition wall 35. If the refractive index of the partition wall 35 is lower than that of the insulating layer 21, the light 49 may be totally reflected at the interface between the bottom surface of the partition wall 35 and the upper surface of the insulating layer 21. This may cause stray light of the light 49, which may leak to adjacent pixels. On the other hand, if the light-shielding layer 45 is provided, the light-shielding layer 45 can absorb the light 49. This can prevent the light 49 from leaking to adjacent pixels. This can prevent the light 49 from entering, for example, a colored layer provided in an adjacent pixel, thereby improving color purity. As a result, the display device 10 can display high-quality images.

[0107] 5A, the partition walls 35 are configured to cover the side surfaces of the light-shielding layer 45. This prevents light that would be incident on the side surfaces of the partition walls 35 and totally reflected at the interface with the colored layer in the absence of the light-shielding layer 45 from being irradiated onto and absorbed by the side surfaces of the light-shielding layer 45. Note that the partition walls 35 may not cover the side surfaces of the light-shielding layer 45, and the side surfaces of the light-shielding layer 45 may be in contact with the colored layer.

[0108] The light-shielding layer 45 may be made of carbon black, metal oxide, composite oxide including a solid solution of a plurality of metal oxides, or the like.

[0109] [Configuration Example 7] Fig. 6A is a cross-sectional view showing another example of the configuration of the display device 10. The display device 10 shown in Fig. 6A differs from the display device 10 shown in Fig. 1A in that the colored layer 25R, the colored layer 25G, and the colored layer 25B are provided spaced apart from one another. Also, it differs from the display device 10 shown in Fig. 1A in that a planarization layer 57 is provided instead of the planarization layer 27.

[0110] In the display device 10 shown in FIG. 6A, the refractive index of the planarization layer 57 is preferably lower than the refractive indexes of the colored layer 25R, the colored layer 25G, and the colored layer 25B. This allows light emitted from the light-emitting element 30 to be totally reflected at the interface between the side surface of the colored layer 25R, the colored layer 25G, or the colored layer 25B and the planarization layer 57. This allows the display device 10 shown in FIG. 6A to be a display device that allows a user of the display device 10 to view a bright image, similar to the display device 10 shown in FIG. 4A. Furthermore, the display device 10 shown in FIG. 6A can be a display device that consumes low power and is highly reliable.

[0111] The planarizing layer 57 can be made of the same material as that which can be used for the resin layer 33. The planarizing layer 57 can be made of the same material as that which can be used for the partition walls .

[0112] As described above, the display device 10 shown in Fig. 6A can achieve the same effect as when the partition wall 35 is provided, even though the partition wall 35 is not provided. Therefore, the manufacturing process of the display device 10 shown in Fig. 6A can be simplified by the absence of the partition wall 35. This reduces the manufacturing cost of the display device 10, allowing the display device 10 to be made inexpensive.

[0113] [Configuration example 8] Fig. 6B is a modified example of the display device 10 shown in Fig. 6A. The display device 10 shown in Fig. 6B differs from the display device 10 shown in Fig. 6A in that a light-shielding layer 45 is provided.

[0114] If the display device 10 is configured so that the colored layers do not overlap, some of the light emitted by the light-emitting element 30 may leak into an adjacent pixel, and the leaked light may be incident on the colored layer provided in the adjacent pixel. For example, some of the light emitted by the light-emitting element 30 provided in pixel 15G may be incident on colored layer 25R or colored layer 25B. Here, by providing a light-shielding layer 45 as shown in FIG. 6B, the above-mentioned light leakage can be suppressed, thereby improving color purity. Therefore, the display device 10 can display high-quality images.

[0115] 6B, the light-shielding layer 45 is provided at a distance from the colored layer 25R, the colored layer 25G, and the colored layer 25B. This reduces the proportion of light incident on the light-shielding layer 45 out of the light incident on the colored layer 25R, the colored layer 25G, or the colored layer 25B, compared to when the light-shielding layer 45 overlaps with a portion of the colored layer 25R, the colored layer 25G, or the colored layer 25B. The light-shielding layer 45 may overlap with a portion of the colored layer 25R, the colored layer 25G, or the colored layer 25B.

[0116] The configurations described herein can be implemented in appropriate combination. For example, the configuration shown in Figure 2A or 2B can be implemented in combination with the configuration shown in Figure 3, 4A, 5A, 6A, or 6B. Specifically, for example, the configuration shown in Figure 3, 4A, 5A, 6A, or 6B can be configured to include wavelength conversion layer 55R and wavelength conversion layer 55G.

[0117] [Example of manufacturing method] An example of a method for manufacturing the display device 10 will be described below with reference to the drawings. Here, the display device 10 shown in FIG. 1A will be described as an example.

[0118] The thin films (insulating films, semiconductor films, conductive films, colored films, etc.) that make up the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), and atomic layer deposition (ALD). The CVD method may be plasma enhanced chemical vapor deposition (PECVD) or thermal CVD. An example of a thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0119] The thin films constituting the display device can be formed by methods such as spin coating, dipping, spray coating, ink jetting, dispensing, screen printing, offset printing, doctor knife, slit coating, roll coating, curtain coating, and knife coating.

[0120] When processing a thin film that constitutes a display device, it can be processed using a lithography method or the like. Alternatively, an island-shaped thin film may be formed by a film formation method using a masking mask. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method or the like. There are, for example, the following two photolithography methods. One is a method in which a photosensitive resist material is applied to the thin film to be processed, exposed to light through a photomask, and developed to form a resist mask, and the thin film is processed by etching or the like, and the resist mask is then removed. The other is a method in which a photosensitive thin film is formed, and then exposed and developed to process the thin film into a desired shape.

[0121] When light is used in lithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other examples include ultraviolet light, KrF laser light, and ArF laser light. Exposure may also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays may also be used as light for exposure. Electron beams may also be used instead of light for exposure. Extreme ultraviolet light, X-rays, or electron beams are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, no photomask is required.

[0122] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0123] 7A, first, a transistor 52 is formed on a substrate 11. Next, an insulating layer 13 is formed on the substrate 11 and the transistor 52. After that, an opening reaching the transistor 52 is formed in the insulating layer 13. Next, a conductive film that will become the conductive layer 42 is formed on the insulating layer 13, and part of the conductive film is etched to form the conductive layer 42.

[0124] Thereafter, the partition wall 14 is formed so as to cover the end portion of the conductive layer 42. Next, the light emitting layer 31 and the conductive layer 60 are formed.

[0125] The light-emitting layer 31 can be formed by a method such as a vapor deposition method, a coating method, a printing method, or a discharging method. For example, a vapor deposition method that does not use a metal mask can be used for the light-emitting layer 31. The conductive layer 60 can be formed by a method such as a vapor deposition method or a sputtering method.

[0126] Thereafter, an insulating layer 63 is formed on the conductive layer 60. The light-emitting element 30 is sealed by the insulating layer 63. After the conductive layer 60 is formed, the insulating layer 63 is preferably formed without exposing the light-emitting element 30 to the air.

[0127] Next, the insulating layer 21 is formed on the insulating layer 63. For example, an organic insulating film is formed by a spin coating method or the like. When the organic insulating film is formed by a spin coating method or the like, the insulating layer 21 can be used as a planarizing layer. Note that the upper surface of the insulating layer 21 does not have to be planarized.

[0128] Thereafter, the colored layers 25R, 25G, and 25B are formed on the insulating layer 21 (FIG. 7B). Here, it is preferable to form the colored layers in order from thinnest to thinnest. Therefore, in the example shown in FIG. 7B, it is preferable to form the colored layer 25G after forming the colored layer 25B, and then form the colored layer 25R.

[0129] For example, first, a colored film that will become colored layer 25B is formed, and the colored film is processed by, for example, lithography, such as photolithography, to form colored layer 25B. Next, a colored film that will become colored layer 25G is formed, and the colored film is processed by, for example, lithography, such as photolithography, to form colored layer 25G. Thereafter, a colored film that will become colored layer 25R is formed, and the colored film is processed by, for example, lithography, such as photolithography, to form colored layer 25R.

[0130] 4A, after forming the insulating layer 21, a film that will become the partition walls 35 is formed, and a portion of the film is etched to form the partition walls 35. Thereafter, the colored layers 25B, 25G, and 25R are formed. Furthermore, when forming the display device 10 shown in FIG. 5A, a film that will become the light-shielding layer 45 is formed, and a portion of the film is etched to form the light-shielding layer 45. Thereafter, a film that will become the partition walls 35 is formed, and a portion of the film is etched to form the partition walls 35.

[0131] Thereafter, a film that will become the planarizing layer 27 is formed on the colored layers 25R, 25G, and 25B. For example, an organic insulating film is formed by spin coating or the like (FIG. 8A).

[0132] Next, lenses 29 are formed on the planarization layer 27 (FIG. 8B). The lenses 29 can be formed by forming a resist pattern by, for example, lithography, and then heating the substrate 11 to reflow the resist.

[0133] Thereafter, the substrate 12 is prepared, and a resin layer 33 is formed on the substrate 12. The resin layer 33 can be formed by a screen printing method, a dispensing method, or the like. Next, the lens 29 and the substrate 12 are bonded together by the resin layer 33. In this manner, the display device 10 shown in FIG. 1B can be produced.

[0134] [Configuration Example 9] 9 is a cross-sectional view showing an example of the configuration of the display device 10. FIG. 9 shows a more specific example of the configuration of the display device 10 shown in FIG.

[0135] 9 , an insulating layer 152, a transistor 52, an insulating layer 162, an insulating layer 181, an insulating layer 182, an insulating layer 183, an insulating layer 185, a conductive layer 189a, a conductive layer 189b, a conductive layer 189c, a conductive layer 189d, an insulating layer 186, and an insulating layer 187 are provided on a substrate 11. Further, a conductive layer 190, a conductive layer 195, a light-emitting element 30, a partition wall 14, an insulating layer 63, an insulating layer 21, a colored layer 25, a planarizing layer 27, a lens 29, a resin layer 33, and a substrate 12 are provided on the insulating layer 187. As described above, the light-emitting element 30 has a conductive layer 42, a light-emitting layer 31, and a conductive layer 60.

[0136] The transistor 52 includes a conductive layer 161, an insulating layer 163, an insulating layer 164, a metal oxide layer 165, a pair of conductive layers 166, an insulating layer 167, a conductive layer 168, and the like. Note that specific examples of transistors that can be used in the display device of one embodiment of the present invention, such as the transistor 52, are described in detail in Embodiment 2.

[0137] The metal oxide layer 165 has a channel formation region. The metal oxide layer 165 has a first region overlapping with one of the pair of conductive layers 166, a second region overlapping with the other of the pair of conductive layers 166, and a third region between the first region and the second region.

[0138] A conductive layer 161 and an insulating layer 162 are provided over the insulating layer 152, and an insulating layer 163 and an insulating layer 164 are provided to cover the conductive layer 161 and the insulating layer 162. A metal oxide layer 165 is provided over the insulating layer 164. The conductive layer 161 functions as a gate electrode, and the insulating layers 163 and 164 function as gate insulating layers. The conductive layer 161 overlaps with the metal oxide layer 165 with the insulating layers 163 and 164 interposed therebetween. The insulating layer 163 preferably functions as a barrier layer, similar to the insulating layer 152. The insulating layer 164 in contact with the metal oxide layer 165 is preferably an oxide insulating film such as a silicon oxide film.

[0139] Here, the height of the upper surface of the conductive layer 161 is approximately the same as the height of the upper surface of the insulating layer 162. This allows the size of the transistor 52 to be reduced.

[0140] The pair of conductive layers 166 are spaced apart over the metal oxide layer 165. The pair of conductive layers 166 function as a source and a drain. An insulating layer 181 is provided to cover the metal oxide layer 165 and the pair of conductive layers 166, and an insulating layer 182 is provided over the insulating layer 181. Openings reaching the metal oxide layer 165 are provided in the insulating layer 181 and the insulating layer 182, and the insulating layer 167 and the conductive layer 168 are embedded in the openings. The openings overlap the third region. The insulating layer 167 overlaps with side surfaces of the insulating layer 181 and the insulating layer 182. The conductive layer 168 overlaps with side surfaces of the insulating layer 181 and the insulating layer 182 with the insulating layer 167 interposed therebetween. The conductive layer 168 functions as a gate electrode, and the insulating layer 167 functions as a gate insulating layer. The conductive layer 168 overlaps with the metal oxide layer 165 with the insulating layer 167 interposed therebetween.

[0141] Here, the height of the upper surface of the conductive layer 168 is approximately the same as the height of the upper surface of the insulating layer 182. This allows the size of the transistor 52 to be reduced.

[0142] An insulating layer 183 and an insulating layer 185 are provided to cover the top surfaces of the insulating layer 182 , the insulating layer 167 , and the conductive layer 168 .

[0143] The insulating layer 152, the insulating layer 181, and the insulating layer 183 function as barrier layers that prevent impurities such as water or hydrogen from entering the metal oxide layer 165 and prevent oxygen from being released from the metal oxide layer 165. Furthermore, the insulating layer 181 covers the pair of conductive layers 166, which can prevent the pair of conductive layers 166 from being oxidized by oxygen contained in the insulating layer 182.

[0144] The insulating layer 152, the insulating layer 181, and the insulating layer 183 can be formed using a film through which hydrogen and oxygen diffuse less than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0145] A plug electrically connected to one of the pair of conductive layers 166 and the conductive layer 189a is embedded in an opening provided in the insulating layers 181, 182, 183, and 185. The plug preferably includes a conductive layer 184b in contact with the side surface of the opening and an upper surface of one of the pair of conductive layers 166, and a conductive layer 184a embedded inwardly of the conductive layer 184b. In this case, the conductive layer 184b is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0146] Conductive layers 189a and 186 are provided on insulating layer 185, conductive layer 189b is provided on conductive layer 189a, and insulating layer 187 is provided on insulating layer 186. Insulating layer 186 preferably has a planarization function. Here, the height of the top surface of conductive layer 189b is approximately the same as the height of the top surface of insulating layer 187. Openings reaching conductive layer 189a are provided in insulating layers 187 and 186, and conductive layer 189b is embedded in the openings. Conductive layer 189b functions as a plug that electrically connects conductive layer 189a and conductive layer 42.

[0147] One of the pair of conductive layers 166 of the transistor 52 is electrically connected to the conductive layer 42 included in the light-emitting element 30 through the conductive layer 184a, the conductive layer 184b, the conductive layer 189a, and the conductive layer 189b.

[0148] The insulating layer 186 is preferably formed using an inorganic insulating material such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, hafnium oxide, or titanium nitride.

[0149] For example, a film through which hydrogen and oxygen diffuse less easily than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, can be used for the insulating layer 187. The insulating layer 187 preferably functions as a barrier layer that prevents impurities such as water or hydrogen from entering the transistor 52.

[0150] The conductive layer 189c is electrically connected to the FPC via the conductive layer 189d, the conductive layer 190, and the conductive layer 195. Signals and power are supplied to the display device 10 via the FPC.

[0151] The conductive layer 189c can be formed using the same material and process as the conductive layer 189a. The conductive layer 189d can be formed using the same material and process as the conductive layer 189b. The conductive layer 190 can be formed using the same material and process as the conductive layer 42.

[0152] The conductive layer 195 may be, for example, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP).

[0153] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes or examples described in this specification.

[0154] (Embodiment 2) In this embodiment, a transistor that can be used in a display device of one embodiment of the present invention will be described.

[0155] The structure of the transistor included in the display device is not particularly limited. For example, a planar transistor, a staggered transistor, or an inverted staggered transistor may be used. Furthermore, the transistor may have either a top-gate structure or a bottom-gate structure. Alternatively, gate electrodes may be provided above and below a channel.

[0156] For example, a transistor including a metal oxide in a channel formation region can be used as a transistor included in a display device, which can have an extremely small off-state current.

[0157] A transistor having silicon in a channel formation region may be used as a transistor included in a display device. Examples of such a transistor include a transistor having amorphous silicon, a transistor having crystalline silicon (typically, low-temperature polysilicon), a transistor having single crystal silicon, etc. For example, a transistor using a metal oxide in a channel formation region and a transistor having silicon in a channel formation region may be used in combination.

[0158] In this specification and the like, a transistor is an element having at least three terminals including a gate, a drain, and a source. A transistor has a region (hereinafter also referred to as a channel formation region) where a channel is formed between the drain (drain terminal, drain region, or drain electrode) and the source (source terminal, source region, or source electrode), and a current can flow between the source and the drain through the channel formation region. In this specification and the like, the channel formation region refers to a region through which a current mainly flows.

[0159] Furthermore, the functions of the source and drain may be interchanged when transistors of different polarities are used, or when the direction of current flow changes during circuit operation, etc. For this reason, in this specification and the like, the terms source and drain may be used interchangeably.

[0160] Note that the channel length refers to, for example, a region where a semiconductor (or a portion in the semiconductor through which current flows when the transistor is on) and a gate electrode overlap each other in a top view of a transistor, or the distance between a source (a source region or a source electrode) and a drain (a drain region or a drain electrode) in a channel formation region. Note that the channel length of one transistor does not necessarily have the same value in all regions. That is, the channel length of one transistor may not be fixed to one value. Therefore, in this specification, the channel length is defined as any one value, a maximum value, a minimum value, or an average value in the channel formation region.

[0161] The channel width refers to, for example, a region where a semiconductor (or a portion of the semiconductor through which current flows when the transistor is on) and a gate electrode overlap in a top view of a transistor, or the length of a channel formation region in a direction perpendicular to the channel length direction in the channel formation region. Note that the channel width of a single transistor does not necessarily have the same value in all regions. That is, the channel width of a single transistor may not be determined to a single value. Therefore, in this specification, the channel width is defined as any one value, maximum value, minimum value, or average value in the channel formation region.

[0162] In this specification and the like, depending on the structure of a transistor, the channel width in a region where a channel is actually formed (hereinafter also referred to as an "effective channel width") may differ from the channel width shown in a top view of the transistor (hereinafter also referred to as an "apparent channel width"). For example, when a gate electrode covers the side surface of a semiconductor, the effective channel width may be larger than the apparent channel width, and the influence thereof may not be negligible. For example, in a fine transistor in which a gate electrode covers the side surface of a semiconductor, the proportion of the channel formation region formed on the side surface of the semiconductor may be large. In such a case, the effective channel width is larger than the apparent channel width.

[0163] In such cases, it may be difficult to estimate the effective channel width by actual measurement. For example, in order to estimate the effective channel width from the design value, it is necessary to assume that the shape of the semiconductor is known. Therefore, if the shape of the semiconductor is not accurately known, it is difficult to accurately measure the effective channel width.

[0164] In this specification, when simply referred to as a channel width, it may refer to an apparent channel width. Alternatively, when simply referred to as a channel width, it may refer to an effective channel width. Note that values ​​of the channel length, channel width, effective channel width, apparent channel width, etc. can be determined by analyzing a cross-sectional TEM image, etc.

[0165] In this specification and the like, the term "insulator" can be replaced with an insulating film or an insulating layer. The term "conductor" can be replaced with a conductive film or a conductive layer. The term "oxide" can be replaced with an oxide film or an oxide layer. The term "semiconductor" can be replaced with a semiconductor film or a semiconductor layer.

[0166] FIG. 10A shows a top view of transistor 200. Note that some elements are omitted in FIG. 10A for clarity. FIG. 10B shows a cross-sectional view taken along dashed line X1-X2 in FIG. 10A. FIG. 10B can be considered a cross-sectional view of transistor 200 in the channel length direction. FIG. 10C shows a cross-sectional view taken along dashed line Y1-Y2 in FIG. 10A. FIG. 10C can be considered a cross-sectional view of transistor 200 in the channel width direction. FIG. 10D shows a cross-sectional view taken along dashed line Y3-Y4 in FIG. 10A.

[0167] 10A to 10D includes an insulator 212 on a substrate (not shown), an insulator 214 on the insulator 212, a transistor 200 on the insulator 214, an insulator 280 on the transistor 200, an insulator 282 on the insulator 280, an insulator 283 on the insulator 282, and an insulator 285 on the insulator 283. The insulators 212, 214, 280, 282, 283, and 285 function as interlayer insulating films. The semiconductor device also includes a conductor 240 (conductor 240a and conductor 240b) electrically connected to the transistor 200 and functioning as a plug. Note that an insulator 241 (insulator 241a and insulator 241b) is provided in contact with a side surface of the conductor 240 functioning as a plug. In addition, over the insulator 285 and the conductor 240, a conductor 246 (conductor 246a and conductor 246b) that is electrically connected to the conductor 240 and functions as wiring is provided.

[0168] Insulator 241a is provided in contact with the inner walls of the openings of insulators 280, 282, 283, and 285. A first conductor of conductor 240a is provided in contact with the side surface of insulator 241a, and a second conductor of conductor 240a is provided further inward. Insulator 241b is provided in contact with the inner walls of the openings of insulators 280, 282, 283, and 285. A first conductor of conductor 240b is provided in contact with the side surface of insulator 241b, and a second conductor of conductor 240b is provided further inward. Here, the height of the top surface of conductor 240 and the height of the top surface of insulator 285 in the region overlapping with conductor 246 can be made approximately the same. Note that, although the transistor 200 illustrates a structure in which a first conductor and a second conductor are stacked as conductor 240, the present invention is not limited to this. For example, the conductor 240 may be configured to have a single layer or a laminated structure of three or more layers. When the structure has a laminated structure, it may be distinguished by assigning an ordinal number to the order of formation.

[0169] [Transistor 200] As shown in FIGS. 10A to 10D , the transistor 200 includes an insulator 216 on an insulator 214, conductors 205 (conductors 205a, 205b, and 205c) disposed so as to be embedded in the insulator 216, an insulator 222 on the insulator 216 and on the conductor 205, an insulator 224 on the insulator 222, an oxide 230a on the insulator 224, an oxide 230b on the oxide 230a, an oxide 243 (oxide 243a and oxide 243b) on the oxide 230b, a conductor 242a on the oxide 243a, and a conductor 242b on the oxide 243a. a, conductor 242b on oxide 243b, insulator 271b on conductor 242b, insulator 250 (insulator 250a and insulator 250b) on oxide 230b, conductor 260 (conductor 260a and conductor 260b) located on insulator 250 and overlapping with part of oxide 230b, and insulator 275 arranged to cover insulator 222, insulator 224, oxide 230a, oxide 230b, oxide 243a, oxide 243b, conductor 242a, conductor 242b, insulator 271a, and insulator 271b.

[0170] In the following, the oxide 230a and the oxide 230b may be collectively referred to as the oxide 230. The conductor 242a and the conductor 242b may be collectively referred to as the conductor 242. The insulator 271a and the insulator 271b may be collectively referred to as the insulator 271.

[0171] Openings reaching the oxide 230b are provided in the insulator 280 and the insulator 275. The insulator 250 and the conductor 260 are disposed in the openings. In addition, in the channel length direction of the transistor 200, the conductor 260 and the insulator 250 are provided between the insulator 271a, the conductor 242a, and the oxide 243a and the insulator 271b, the conductor 242b, and the oxide 243b. The insulator 250 has a region in contact with the side surface of the conductor 260 and a region in contact with the bottom surface of the conductor 260.

[0172] The oxide 230 preferably has an oxide 230a disposed on the insulator 224 and an oxide 230b disposed on the oxide 230a. By having the oxide 230a below the oxide 230b, it is possible to suppress the diffusion of impurities from structures formed below the oxide 230a to the oxide 230b.

[0173] Note that in the transistor 200, the oxide 230 has a stacked structure of two layers, the oxide 230a and the oxide 230b, but the present invention is not limited to this. For example, the oxide 230b may have a single layer or a stacked structure of three or more layers, or each of the oxide 230a and the oxide 230b may have a stacked structure.

[0174] The conductor 260 functions as a first gate (also referred to as a top gate) electrode, and the conductor 205 functions as a second gate (also referred to as a back gate) electrode. The insulator 250 functions as a first gate insulating film, and the insulators 224 and 222 function as a second gate insulating film. The conductor 242a functions as one of a source electrode and a drain electrode, and the conductor 242b functions as the other of the source electrode and the drain electrode. At least a part of a region of the oxide 230 that overlaps with the conductor 260 functions as a channel formation region.

[0175] The oxide 230b has one of a source region and a drain region in a region overlapping with the conductor 242a, and the other of the source region and the drain region in a region overlapping with the conductor 242b. The oxide 230b also has a channel formation region (the region indicated by the hatched area in FIG. 10B) between the source region and the drain region.

[0176] The channel formation region has fewer oxygen vacancies or a lower impurity concentration than the source and drain regions, and is therefore a high-resistance region with a low carrier concentration. 18 cm -3 Preferably, it is 1×10 or less. 17 cm-3 More preferably, it is less than 1×10 16 cm -3 More preferably, it is less than 1×10 13 cm -3 More preferably, it is less than 1×10 12 cm -3 The lower limit of the carrier concentration in the channel formation region is not particularly limited, but is preferably, for example, 1×10 -9 cm -3 It can be said that:

[0177] Although the above example shows a case where a channel formation region, a source region, and a drain region are formed in the oxide 230b, the present invention is not limited to this. For example, a channel formation region, a source region, and a drain region may also be formed in the oxide 230a.

[0178] In the transistor 200, a metal oxide that functions as a semiconductor (also referred to as an oxide semiconductor) is preferably used for the oxide 230 (the oxide 230a and the oxide 230b) including the channel formation region.

[0179] The metal oxide functioning as a semiconductor preferably has a band gap of 2 eV or more, more preferably 2.5 eV or more. By using such a metal oxide with a wide band gap, the off-state current of the transistor can be reduced.

[0180] For example, a metal oxide such as In-M-Zn oxide containing indium, element M, and zinc (element M is one or more elements selected from aluminum, gallium, yttrium, tin, copper, vanadium, beryllium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc.) may be used as the oxide 230. Alternatively, In-Ga oxide, In-Zn oxide, or indium oxide may be used as the oxide 230.

[0181] Here, it is preferable that the atomic ratio of In to element M in the metal oxide used for oxide 230b is greater than the atomic ratio of In to element M in the metal oxide used for oxide 230a.

[0182] Specifically, the oxide 230a may be a metal oxide having an atomic ratio of In:M:Zn=1:3:4 or a similar composition, or an atomic ratio of In:M:Zn=1:1:0.5 or a similar composition. The oxide 230b may be a metal oxide having an atomic ratio of In:M:Zn=1:1:1 or a similar composition, or an atomic ratio of In:M:Zn=4:2:3 or a similar composition. Note that a similar composition includes a range of ±30% of the desired atomic ratio. Gallium is preferably used as the element M.

[0183] When a metal oxide film is formed by sputtering, the atomic ratio is not limited to the atomic ratio of the formed metal oxide film, but may be the atomic ratio of a sputtering target used to form the metal oxide film.

[0184] In this way, by disposing the oxide 230a below the oxide 230b, it is possible to suppress the diffusion of impurities and oxygen from structures formed below the oxide 230a into the oxide 230b.

[0185] Furthermore, since the oxide 230a and the oxide 230b have a common element other than oxygen (as a main component), the defect state density at the interface between the oxide 230a and the oxide 230b can be reduced. Because the defect state density at the interface between the oxide 230a and the oxide 230b can be reduced, the effect of interface scattering on carrier conduction is reduced, and a high on-current can be obtained.

[0186] The oxide 230a and the oxide 230b preferably have crystallinity, and it is particularly preferable to use c-axis aligned crystalline oxide semiconductor (CAAC-OS) as the oxide 230b.

[0187] CAAC-OS has a highly crystalline and dense structure, and is free of impurities and defects (e.g., oxygen vacancies (V O The CAAC-OS is a metal oxide having a low oxygen vacancy. In particular, by subjecting the formed metal oxide to heat treatment at a temperature (for example, 400°C or higher and 600°C or lower) at which the metal oxide does not polycrystallize, the CAAC-OS can be made to have a dense structure with higher crystallinity. In this way, the density of the CAAC-OS can be increased, thereby further reducing the diffusion of impurities or oxygen in the CAAC-OS.

[0188] On the other hand, since it is difficult to identify clear grain boundaries in CAAC-OS, it is said that the decrease in electron mobility due to grain boundaries is unlikely to occur. Therefore, metal oxides with CAAC-OS have stable physical properties. As a result, metal oxides with CAAC-OS are heat-resistant and highly reliable.

[0189] At least one of the insulators 212, 214, 271, 275, 282, and 283 preferably functions as a barrier insulating film that suppresses diffusion of impurities such as water and hydrogen from the substrate side or from above the transistor 200 into the transistor 200. Therefore, at least one of the insulators 212, 214, 271, 275, 282, and 283 is preferably made of an insulating material that suppresses diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (NO, NO, NO, etc.), and copper atoms (i.e., through which the above impurities are less likely to permeate). Alternatively, it is preferably made of an insulating material that suppresses diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.) (i.e., through which the above oxygen is less likely to permeate).

[0190] Note that in this specification, a barrier insulating film refers to an insulating film having a barrier property. In this specification, the barrier property refers to a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing and fixing a corresponding substance (also referred to as gettering).

[0191] For example, aluminum oxide, magnesium oxide, hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon nitride, or silicon nitride oxide can be used for the insulators 212, 214, 271, 275, 282, and 283. For example, silicon nitride, which has a higher hydrogen barrier property, is preferably used for the insulators 212, 275, and 283. Furthermore, for example, aluminum oxide or magnesium oxide, which has a high hydrogen capture and fixation function, is preferably used for the insulators 214, 271, and 282. This can prevent impurities such as water and hydrogen from diffusing from the substrate to the transistor 200 through the insulators 212 and 214. Alternatively, it can prevent impurities such as water and hydrogen from diffusing from an interlayer insulating film or the like disposed outside the insulator 283 to the transistor 200. Alternatively, oxygen contained in the insulator 224 and the like can be prevented from diffusing toward the substrate through the insulators 212 and 214. Alternatively, oxygen contained in the insulator 280 and the like can be prevented from diffusing upward from the transistor 200 through the insulator 282 and the like. In this way, it is preferable to have a structure in which the transistor 200 is surrounded by the insulators 212, 214, 271, 275, 282, and 283, which have the function of preventing the diffusion of impurities such as water and hydrogen, and oxygen.

[0192] Here, it is preferable to use an oxide having an amorphous structure as the insulators 212, 214, 271, 275, 282, and 283. For example, AlO x (x is any number greater than 0), or MgO yIt is preferable to use a metal oxide such as y (where y is any number greater than 0). In such metal oxides having an amorphous structure, oxygen atoms have dangling bonds, and the dangling bonds may have the property of capturing or fixing hydrogen. By using such a metal oxide having an amorphous structure as a component of the transistor 200 or providing it around the transistor 200, hydrogen contained in the transistor 200 or hydrogen present around the transistor 200 can be captured or fixed. In particular, it is preferable to capture or fix hydrogen contained in the channel formation region of the transistor 200. By using a metal oxide having an amorphous structure as a component of the transistor 200 or providing it around the transistor 200, a highly reliable transistor 200 and a semiconductor device can be manufactured that have excellent characteristics.

[0193] Note that the insulators 212, 214, 271, 275, 282, and 283 preferably have an amorphous structure, but may have a polycrystalline structure region formed in a portion thereof. The insulators 212, 214, 271, 275, 282, and 283 may also have a multilayer structure in which an amorphous layer and a polycrystalline layer are stacked. For example, they may have a stacked structure in which a polycrystalline layer is formed on an amorphous layer.

[0194] The insulators 212, 214, 271, 275, 282, and 283 can be formed by, for example, a sputtering method. Sputtering does not require the use of hydrogen as a film formation gas, and therefore can reduce the hydrogen concentration of the insulators 212, 214, 271, 275, 282, and 283. Note that the film formation method is not limited to sputtering, and a CVD method, an MBE method, a PLD method, an ALD method, or the like may also be used as appropriate.

[0195] The insulators 216, 280, and 285 preferably have a lower dielectric constant than the insulator 214. Using a material with a low dielectric constant as an interlayer insulating film can reduce parasitic capacitance between wirings. For example, the insulators 216, 280, and 285 may be formed using silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide to which fluorine has been added, silicon oxide to which carbon has been added, silicon oxide to which carbon and nitrogen have been added, silicon oxide having vacancies, or the like as appropriate.

[0196] The conductor 205 is disposed so as to overlap the oxide 230 and the conductor 260. Here, the conductor 205 is preferably provided by being embedded in an opening formed in the insulator 216.

[0197] The conductor 205 includes conductor 205a, conductor 205b, and conductor 205c. The conductor 205a is provided in contact with the bottom surface and sidewall of the opening. The conductor 205b is provided so as to be embedded in a recess formed in the conductor 205a. Here, the upper surface of the conductor 205b is lower than the upper surface of the conductor 205a and the upper surface of the insulator 216. The conductor 205c is provided in contact with the upper surface of the conductor 205b and the side surface of the conductor 205a. Here, the height of the upper surface of the conductor 205c is approximately the same as the height of the upper surface of the conductor 205a and the height of the upper surface of the insulator 216. In other words, the conductor 205b is configured to be enclosed by the conductors 205a and 205c.

[0198] The conductor 205a and the conductor 205c may be formed using a conductive material that can be used for the conductor 260a (described later). The conductor 205b may be formed using a conductive material that can be used for the conductor 260b (described later). Although the transistor 200 illustrates a structure in which the conductor 205 is formed by stacking the conductors 205a, 205b, and 205c, the present invention is not limited to this. For example, the conductor 205 may be formed as a single layer, a two-layer, or a four-layer or more layer structure.

[0199] The insulators 222 and 224 function as gate insulating films.

[0200] The insulator 222 preferably has a function of suppressing the diffusion of hydrogen (e.g., at least one of hydrogen atoms, hydrogen molecules, etc.). The insulator 222 preferably has a function of suppressing the diffusion of oxygen (e.g., at least one of oxygen atoms, oxygen molecules, etc.). For example, the insulator 222 preferably has a function of suppressing the diffusion of one or both of hydrogen and oxygen more than the insulator 224.

[0201] The insulator 222 may be an insulator containing an oxide of one or both of aluminum and hafnium, which are insulating materials. Aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), or the like is preferably used as the insulator. Alternatively, the insulator 222 may be a barrier insulating film that can be used for the insulator 214 or the like.

[0202] The insulator 224 may be made of silicon oxide, silicon oxynitride, or the like as appropriate. By providing the insulator 224 containing oxygen in contact with the oxide 230, oxygen vacancies in the oxide 230 can be reduced and the reliability of the transistor 200 can be improved. The insulator 224 is preferably processed into an island shape so as to overlap with the oxide 230a. In this case, the insulator 275 is in contact with the side surface of the insulator 224 and the top surface of the insulator 222. This separates the insulator 224 and the insulator 280 from each other by the insulator 275, thereby preventing the oxygen contained in the insulator 280 from diffusing into the insulator 224 and preventing excessive oxygen in the insulator 224.

[0203] The insulators 222 and 224 may have a stacked structure of two or more layers. In this case, the stacked structure is not limited to being made of the same material, and may be made of different materials. While FIG. 10B and other figures show a configuration in which the insulator 224 is formed in an island shape by overlapping with the oxide 230a, the present invention is not limited to this. As long as the amount of oxygen contained in the insulator 224 can be appropriately adjusted, the insulator 224 may be configured without being patterned, similar to the insulator 222.

[0204] The oxide 243a and the oxide 243b are provided on the oxide 230b. The oxide 243a and the oxide 243b are provided to be separated from each other with the conductor 260 interposed therebetween. The oxide 243 (the oxide 243a and the oxide 243b) preferably has a function of suppressing oxygen permeation. By disposing the oxide 243, which has a function of suppressing oxygen permeation, between the conductor 242 functioning as a source or drain electrode and the oxide 230b, the electrical resistance between the conductor 242 and the oxide 230b is reduced, which is preferable. Note that if the electrical resistance between the conductor 242 and the oxide 230b can be sufficiently reduced, the oxide 243 may not be provided.

[0205] A metal oxide containing the element M may be used as the oxide 243. In particular, the element M may be aluminum, gallium, yttrium, or tin. The oxide 243 preferably has a higher concentration of the element M than the oxide 230b. Gallium oxide may be used as the oxide 243. A metal oxide such as an In-M-Zn oxide may be used as the oxide 243. Specifically, the atomic ratio of the element M to In in the metal oxide used for the oxide 243 is preferably greater than the atomic ratio of the element M to In in the metal oxide used for the oxide 230b. The film thickness of the oxide 243 is preferably 0.5 nm to 5 nm, more preferably 1 nm to 3 nm, and even more preferably 1 nm to 2 nm.

[0206] The conductor 242a is preferably provided in contact with the top surface of the oxide 243a, and the conductor 242b is preferably provided in contact with the top surface of the oxide 243b. The conductor 242a and the conductor 242b function as a source electrode and a drain electrode of the transistor 200, respectively.

[0207] As the conductor 242 (conductor 242a and conductor 242b), it is preferable to use, for example, a nitride containing tantalum, a nitride containing titanium, a nitride containing molybdenum, a nitride containing tungsten, a nitride containing tantalum and aluminum, or a nitride containing titanium and aluminum. In one embodiment of the present invention, a nitride containing tantalum is particularly preferable. Also, for example, ruthenium oxide, ruthenium nitride, an oxide containing strontium and ruthenium, an oxide containing lanthanum and nickel, or the like may be used. These materials are preferable because they are conductive materials that are resistant to oxidation or materials that maintain conductivity even when they absorb oxygen.

[0208] Preferably, no curved surface is formed between the side surface of the conductor 242 and the top surface of the conductor 242. By forming the conductor 242 without such a curved surface, the cross-sectional area of ​​the conductor 242 in the cross section in the channel width direction can be increased, as shown in Fig. 10D. This increases the conductivity of the conductor 242 and the on-state current of the transistor 200.

[0209] The insulator 271a is provided in contact with the upper surface of the conductor 242a, and the insulator 271b is provided in contact with the upper surface of the conductor 242b.

[0210] The insulator 275 is provided in contact with the top surface of the insulator 222, the side surface of the insulator 224, the side surface of the oxide 230a, the side surface of the oxide 230b, the side surface of the oxide 243, the side surface of the conductor 242, and the side surface and top surface of the insulator 271. The insulator 275 has openings formed in the regions where the insulator 250 and the conductor 260 are provided.

[0211] By providing insulators 214, 271, and 275, which have the function of capturing impurities such as hydrogen, in the region sandwiched between insulators 212 and 280, it is possible to capture impurities such as hydrogen contained in insulator 224 or insulator 216, etc., and keep the amount of hydrogen in the region constant. In this case, it is preferable that insulators 214, 271, and 275 contain aluminum oxide with an amorphous structure.

[0212] The insulator 250 has an insulator 250a and an insulator 250b on the insulator 250a, and functions as a gate insulating film. The insulator 250a is preferably disposed in contact with the top surface of the oxide 230b, the side surface of the oxide 243, the side surface of the conductor 242, the side surface of the insulator 271, the side surface of the insulator 275, and the side surface of the insulator 280. The thickness of the insulator 250 is preferably 1 nm or more and 20 nm or less.

[0213] The insulator 250a can be made of silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, silicon oxide doped with fluorine, silicon oxide doped with carbon, silicon oxide doped with carbon and nitrogen, silicon oxide having vacancies, or the like. Silicon oxide and silicon oxynitride are particularly preferred because they are stable against heat. As with the insulator 224, the insulator 250a preferably has a reduced concentration of impurities such as water and hydrogen.

[0214] Preferably, the insulator 250a is formed using an insulator that releases oxygen when heated, and the insulator 250b is formed using an insulator that has a function of suppressing oxygen diffusion. With this configuration, it is possible to suppress the oxygen contained in the insulator 250a from diffusing into the conductor 260. In other words, it is possible to suppress a decrease in the amount of oxygen supplied to the oxide 230. It is also possible to suppress oxidation of the conductor 260 due to the oxygen contained in the insulator 250a. For example, the insulator 250b can be formed using the same material as the insulator 222.

[0215] Specifically, the insulator 250b may be a metal oxide containing one or more elements selected from hafnium, aluminum, gallium, yttrium, zirconium, tungsten, titanium, tantalum, nickel, germanium, magnesium, etc., or a metal oxide that can be used as the oxide 230. In particular, it is preferable to use an insulator containing an oxide of one or both of aluminum and hafnium. As the insulator, it is preferable to use aluminum oxide, hafnium oxide, an oxide containing aluminum and hafnium (hafnium aluminate), etc. Furthermore, the thickness of the insulator 250b is preferably 0.5 nm or more and 3.0 nm or less, and more preferably 1.0 nm or more and 1.5 nm or less.

[0216] 10B and 10C, the insulator 250 is illustrated as having a two-layer laminated structure, but the present invention is not limited to this. The insulator 250 may have a single layer or a laminated structure of three or more layers.

[0217] The conductor 260 is provided on the insulator 250b and functions as a first gate electrode of the transistor 200. The conductor 260 preferably includes a conductor 260a and a conductor 260b disposed on the conductor 260a. For example, the conductor 260a is preferably disposed so as to surround the bottom and side surfaces of the conductor 260b. As shown in FIGS. 10B and 10C, the top surface of the conductor 260 is substantially flush with the top surface of the insulator 250. Note that although the conductor 260 is shown as having a two-layer structure of the conductor 260a and the conductor 260b in FIGS. 10B and 10C, it may have a single-layer structure or a stacked structure of three or more layers.

[0218] The conductor 260a is preferably made of a conductive material that has a function of suppressing the diffusion of impurities such as hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules, copper atoms, etc. Alternatively, it is preferably made of a conductive material that has a function of suppressing the diffusion of oxygen (for example, at least one of oxygen atoms, oxygen molecules, etc.).

[0219] Furthermore, since the conductor 260a has the function of suppressing oxygen diffusion, it is possible to suppress a decrease in conductivity due to oxidation of the conductor 260b caused by oxygen contained in the insulator 250. As a conductive material having the function of suppressing oxygen diffusion, it is preferable to use, for example, titanium, titanium nitride, tantalum, tantalum nitride, ruthenium, ruthenium oxide, or the like.

[0220] Furthermore, since the conductor 260 also functions as wiring, it is preferable to use a conductor with high conductivity. For example, the conductor 260b can be made of a conductive material containing tungsten, copper, or aluminum as a main component. The conductor 260b may also have a layered structure, for example, a layered structure of titanium or titanium nitride and the above-mentioned conductive material.

[0221] Furthermore, in the transistor 200, the conductor 260 is formed in a self-aligned manner so as to fill the opening formed in the insulator 280, etc. By forming the conductor 260 in this manner, the conductor 260 can be reliably placed in the region between the conductor 242a and the conductor 242b without alignment.

[0222] 10C , in the channel width direction of the transistor 200, the height of the bottom surface of the conductor 260 in a region where the conductor 260 and the oxide 230b do not overlap is preferably lower than the height of the bottom surface of the oxide 230b, relative to the bottom surface of the insulator 222. When the conductor 260, which functions as a gate electrode, covers the side and top surfaces of the channel formation region of the oxide 230b via the insulator 250 or the like, the electric field of the conductor 260 can be easily applied to the entire channel formation region of the oxide 230b. This increases the on-state current of the transistor 200 and improves its frequency characteristics. The difference between the height of the bottom surface of the conductor 260 and the height of the bottom surface of the oxide 230b in a region where the oxides 230a and 230b do not overlap with the conductor 260, relative to the bottom surface of the insulator 222, is 0 nm or more and 100 nm or less, preferably 3 nm or more and 50 nm or less, and more preferably 5 nm or more and 20 nm or less.

[0223] The insulator 280 is provided on the insulator 275, and openings are formed in the regions where the insulator 250 and the conductor 260 are provided. The upper surface of the insulator 280 may be flattened. In this case, it is preferable that the upper surface of the insulator 280 be roughly flush with the upper surfaces of the insulator 250 and the conductor 260.

[0224] The insulator 282 is provided in contact with the top surface of the insulator 280, the top surface of the insulator 250, and the top surface of the conductor 260. The insulator 282 preferably functions as a barrier insulating film that suppresses diffusion of impurities such as water and hydrogen from above into the insulator 280 and preferably has a function of capturing impurities such as hydrogen. The insulator 282 also preferably functions as a barrier insulating film that suppresses oxygen permeation. For example, an insulator such as aluminum oxide may be used as the insulator 282. By providing the insulator 282, which is in contact with the insulator 280 and has a function of capturing impurities such as hydrogen, in the region sandwiched between the insulator 212 and the insulator 283, the insulator 282 can capture impurities such as hydrogen contained in the insulator 280 and maintain the amount of hydrogen in the region at a constant value. In particular, using aluminum oxide having an amorphous structure as the insulator 282 is preferable because it may be able to more effectively capture or fix hydrogen. This enables the manufacture of a highly reliable transistor 200 and semiconductor device with excellent characteristics.

[0225] The conductor 240a and the conductor 240b are preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. The conductor 240a and the conductor 240b may have a layered structure. When the conductor 240 has a layered structure, the conductor in contact with the insulator 241 is preferably made of a conductive material that has a function of suppressing the permeation of impurities such as water and hydrogen. For example, the conductive material that can be used for the conductor 260a described above may be used.

[0226] The insulators 241a and 241b may be, for example, insulators such as silicon nitride, aluminum oxide, and silicon nitride oxide. The insulators 241a and 241b are provided in contact with the insulators 283, 282, and 271, and therefore can prevent impurities such as water and hydrogen contained in the insulator 280 and the like from being mixed into the oxide 230 through the conductors 240a and 240b.

[0227] Furthermore, conductors 246 (conductors 246a and 246b) functioning as wiring may be disposed in contact with the upper surfaces of the conductors 240a and 240b. The conductors 246 are preferably made of a conductive material containing tungsten, copper, or aluminum as a main component. The conductors may also have a layered structure, for example, a layered structure of titanium or titanium nitride and the above-mentioned conductive material. The conductors may also be formed so as to be embedded in openings provided in an insulator.

[0228] As a result, a semiconductor device having good electrical characteristics, a highly reliable semiconductor device, a semiconductor device that can be miniaturized or highly integrated, and a semiconductor device with low power consumption can be provided.

[0229] [Metal oxides] Next, a metal oxide (also referred to as an oxide semiconductor) that can be used in a transistor will be described.

[0230] <Classification of crystal structures> First, classification of crystal structures in oxide semiconductors will be described with reference to Fig. 11A. Fig. 11A is a diagram illustrating classification of crystal structures of oxide semiconductors, typically IGZO (a metal oxide containing In, Ga, and Zn).

[0231] As shown in FIG. 11A, oxide semiconductors are broadly classified into "amorphous," "crystalline," and "crystal." "Amorphous" includes completely amorphous. "Crystalline" includes CAAC, nc (nanocrystalline), and CAC (cloud-aligned composite). The "Crystalline" classification excludes single crystal, polycrystal, and completely amorphous. "Crystalline" includes single crystal and polycrystal.

[0232] The structure within the bold frame in Figure 11A is an intermediate state between "amorphous" and "crystal" and belongs to a new boundary region (new crystalline phase). In other words, this structure can be said to be completely different from the energetically unstable "amorphous" and "crystal."

[0233] The crystalline structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. Figure 11B shows the XRD spectrum obtained by GIXD (Grazing-Incidence XRD) measurement of a CAAC-IGZO film classified as "Crystalline." The GIXD method is also known as the thin-film method or the Seemann-Bohlin method. Hereinafter, the XRD spectrum obtained by GIXD measurement shown in Figure 11B will be simply referred to as the XRD spectrum. The composition of the CAAC-IGZO film shown in Figure 11B is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. The thickness of the CAAC-IGZO film shown in Figure 11B is 500 nm.

[0234] As shown in Figure 11B, a clear peak indicating crystallinity is detected in the XRD spectrum of the CAAC-IGZO film. Specifically, a peak indicating c-axis orientation is detected near 2θ = 31° in the XRD spectrum of the CAAC-IGZO film. As shown in Figure 11B, the peak near 2θ = 31° is asymmetrical with respect to the angle at which the peak intensity is detected.

[0235] The crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). The diffraction pattern of the CAAC-IGZO film is shown in Figure 11C. Figure 11C shows a diffraction pattern observed by NBED, in which an electron beam is incident parallel to the substrate. The composition of the CAAC-IGZO film shown in Figure 11C is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. In the nanobeam electron diffraction method, electron diffraction is performed using a probe diameter of 1 nm.

[0236] As shown in Figure 11C, multiple spots indicating c-axis orientation are observed in the diffraction pattern of the CAAC-IGZO film.

[0237] [Structure of oxide semiconductor] Note that oxide semiconductors may be classified differently from those shown in FIG. 11A when focusing on their crystal structures. For example, oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0238] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0239] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction can be the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. Considering an atomic arrangement as a lattice arrangement, a crystalline region can also be a region with a uniform lattice arrangement. Furthermore, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and the region may have distortion. The distortion refers to a location where the lattice orientation changes between a region with a uniform lattice arrangement and a region with a different uniform lattice arrangement in the region where multiple crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor with a c-axis aligned but no clear orientation in the ab-plane direction.

[0240] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nm.

[0241] In an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. Furthermore, the In layer may contain element M. Furthermore, the In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution TEM image, for example.

[0242] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD apparatus, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type and composition of the metallic elements constituting the CAAC-OS.

[0243] For example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots are observed, and the spots are observed at positions that are point-symmetric with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0244] When the crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. The distortion may also have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundaries can be identified even near the distortion. This indicates that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of close-packed oxygen atom arrangement in the ab-plane direction and the change in interatomic bond distance caused by metal atom substitution.

[0245] A crystal structure with clear grain boundaries is called polycrystalline. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in the on-state current and field-effect mobility of a transistor. Therefore, CAAC-OS, which lacks clear grain boundaries, is one of the crystalline oxides with a crystal structure suitable for use in the semiconductor layer of a transistor. Zn is preferred for use in CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0246] The CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities or the generation of defects, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors with CAAC-OS have stable physical properties. Therefore, oxide semiconductors with CAAC-OS are heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even under high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0247] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystalline structures. The size of the microcrystalline structures is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore these microcrystalline structures are also called nanocrystalline structures. Furthermore, the nc-OS exhibits no regularity in the crystal orientation between different nanocrystalline structures. Therefore, the entire film lacks orientation. Therefore, depending on the analytical method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when an nc-OS film is subjected to electron diffraction (also known as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystalline structures (e.g., 50 nm or larger), a halo-like diffraction pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystals (for example, 1 nm to 30 nm), an electron diffraction pattern can be obtained in which multiple spots are observed within a ring-shaped region centered on the direct spot.

[0248] [a-like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and the amorphous oxide semiconductor. The a-like OS has a pore or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0249] [Oxide semiconductor composition] Next, the above-mentioned CAC-OS will be described in detail, which relates to the material composition.

[0250] [CAC-OS] CAC-OS is a material structure in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that, hereinafter, a metal oxide in which one or more metal elements are unevenly distributed and the regions containing the metal elements are mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0251] Furthermore, CAC-OS is a composite metal oxide in which the material is separated into first and second regions, forming a mosaic structure in which the first regions are distributed throughout the film (hereinafter also referred to as a cloud structure).

[0252] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0253] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0254] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0255] For example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) confirms that the CAC-OS has a structure in which a region mainly composed of In (first region) and a region mainly composed of Ga (second region) are unevenly distributed and mixed.

[0256] When CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, giving the CAC-OS a switching function (the ability to turn on and off). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0257] Oxide semiconductors have a variety of structures and each has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0258] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0259] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0260] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 cm -3 or less, more preferably 1 × 10 13 cm -3 Less than or equal to 1×10 11 cm -3 or less, more preferably 1 × 10 10 cm -3 Less than 1 x 10 -9 cm -3The above is the case. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0261] A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore, the density of trap states may also be low.

[0262] Charges trapped in the trap states of an oxide semiconductor take a long time to dissipate and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0263] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.

[0264] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0265] When an oxide semiconductor contains silicon or carbon, which is one of the Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by SIMS) are calculated to be 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0266] When an oxide semiconductor contains an alkali metal or alkaline earth metal, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0267] When nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to 5×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than 5 × 10, more preferably 17 atoms / cm 3 Do the following:

[0268] Hydrogen contained in an oxide semiconductor reacts with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. When hydrogen enters the oxygen vacancy, electrons serving as carriers may be generated. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable to reduce the amount of hydrogen in the oxide semiconductor as much as possible. Specifically, when the hydrogen concentration in an oxide semiconductor obtained by SIMS is 1×10 20 atoms / cm3 Less than 1 x 10 19 atoms / cm 3 less than 5 × 10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 Make it less than.

[0269] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0270] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes or examples described in this specification.

[0271] (Embodiment 3) In this embodiment, an electronic device including a display device according to one embodiment of the present invention will be described.

[0272] FIG. 12A is a diagram showing the appearance of the head mounted display 8200.

[0273] The head mounted display 8200 has a mounting part 8201, a lens 8202, a main body 8203, a display screen 8204, and a cable 8205. The mounting part 8201 has a built-in battery 8206.

[0274] A cable 8205 supplies power from a battery 8206 to the main body 8203. The main body 8203 is equipped with a wireless receiver or the like, and can display an image corresponding to received image data or the like on a display surface 8204. In addition, a camera provided in the main body 8203 captures the movement of the user's eyeballs or eyelids, and calculates the coordinates of the user's line of sight based on that information, thereby allowing the user's line of sight to be used as an input means.

[0275] The wearing unit 8201 may be provided with a plurality of electrodes at positions that come into contact with the user. The main body 8203 may have a function of recognizing the user's line of sight by detecting a current flowing through the electrodes in accordance with the movement of the user's eyeballs. The main body 8203 may also have a function of monitoring the user's pulse by detecting the current flowing through the electrodes. The wearing unit 8201 may also have various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, etc., and may have a function of displaying the user's biological information on the display surface 8204. The wearing unit 8201 may also detect the movement of the user's head, etc., and change the image displayed on the display surface 8204 in accordance with the movement.

[0276] The display device of one embodiment of the present invention can be applied to the display surface 8204. This allows a user of the head-mounted display 8200 to view a bright image. Furthermore, fine pixels can be provided on the display surface 8204.

[0277] 12B, 12C, and 12D are diagrams showing the external appearance of a head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display surface 8302, a band-shaped attachment part 8304, and a pair of lenses 8305. A battery 8306 is built into the housing 8301, and power can be supplied from the battery 8306 to the display surface 8302 and the like.

[0278] The user can view the display on the display surface 8302 through the lens 8305. It is preferable to arrange the display surface 8302 in a curved manner. Arranging the display surface 8302 in a curved manner allows the user to feel a high sense of presence. It is to be noted that, although the present embodiment has been described with reference to a configuration in which one display surface 8302 is provided, the present invention is not limited thereto, and for example, two display surfaces 8302 may be provided. In this case, if one display surface is arranged at one eye of the user, it becomes possible to perform three-dimensional display using parallax.

[0279] Note that the display device of one embodiment of the present invention can be applied to the display surface 8302. This allows a user of the head-mounted display 8300 to view a bright image. Furthermore, fine pixels can be provided on the display surface 8302.

[0280] Next, an example of an electronic device different from the electronic device shown in FIGS. 12A to 12D is shown in FIGS. 13A to 13F.

[0281] The electronic device shown in Figures 13A to 13F has a housing 9000, a display surface 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (including a function to measure force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), and a battery 9009.

[0282] The electronic devices shown in FIGS. 13A to 13F have various functions. For example, they may have a function to display various information (still images, videos, text images, etc.) on a display surface, a touch panel function, a function to display a calendar, date, or time, a function to control processing using various software (programs), a wireless communication function, a function to connect to various computer networks using the wireless communication function, a function to send or receive various data using the wireless communication function, a function to read programs or data recorded on a recording medium and display them on the display surface, etc. Note that the functions that the electronic devices shown in FIGS. 13A to 13F can have are not limited to these, and various other functions may be included. Also, although not shown in FIGS. 13A to 13F, the electronic devices may be configured to have multiple display surfaces. Furthermore, the electronic devices may be equipped with a camera or the like to capture still images, capture videos, store captured images on a recording medium (external or built-in to the camera), and display captured images on the display surface, etc.

[0283] The electronic device shown in FIGS. 13A to 13F will be described in detail below.

[0284] FIG. 13A is a perspective view showing a mobile information terminal 9101. The mobile information terminal 9101 has one or more functions selected from, for example, a telephone, a notebook, an information viewing device, and the like. Specifically, it can be used as a smartphone. The mobile information terminal 9101 can display text or images on multiple surfaces thereof. For example, three operation buttons 9050 (also referred to as operation icons or simply icons) can be displayed on one surface of the display surface 9001. Information 9051, indicated by a dashed rectangle, can be displayed on the other surface of the display surface 9001. Examples of the information 9051 include a display notifying an incoming email, SNS (social networking service), or phone call, the title of the email or SNS, the name of the sender of the email or SNS, the date and time, the remaining battery level, and the strength of the antenna reception. Alternatively, the operation buttons 9050, etc., may be displayed in place of the information 9051.

[0285] The display device of one embodiment of the present invention can be applied to the portable information terminal 9101. This allows the portable information terminal 9101 to display high-quality images.

[0286] FIG. 13B is a perspective view showing a wristwatch-type mobile information terminal 9200. The mobile information terminal 9200 can execute various applications such as mobile phone calls, e-mail, text browsing and creation, music playback, internet communication, and computer games. The display surface 9001 is curved, and display can be performed along the curved display surface. FIG. 13B shows an example in which time 9251, operation buttons 9252 (also referred to as operation icons or simply icons), and content 9253 are displayed on the display surface 9001. The content 9253 can be, for example, a video.

[0287] The mobile information terminal 9200 can also perform short-distance wireless communication according to a communication standard. For example, hands-free conversation is also possible by mutual communication with a wireless headset. The mobile information terminal 9200 also has a connection terminal 9006, and can directly exchange data with other information terminals via a connector. Charging can also be performed via the connection terminal 9006. Note that charging may also be performed by wireless power supply without using the connection terminal 9006.

[0288] The display device of one embodiment of the present invention can be applied to the portable information terminal 9200. Thus, the portable information terminal 9200 can display high-quality images.

[0289] 13C, 13D, and 13E are perspective views showing a foldable mobile information terminal 9201. Also, FIG. 13C is a perspective view of the mobile information terminal 9201 in an unfolded state, FIG. 13D is a perspective view of the mobile information terminal 9201 in the process of changing from the unfolded state to the folded state, and FIG. 13E is a perspective view of the mobile information terminal 9201 in a folded state. The mobile information terminal 9201 is highly portable in the folded state, and has a seamless, wide display area in the unfolded state, providing excellent viewability of the display. The display surface 9001 of the mobile information terminal 9201 is supported by three housings 9000 connected by hinges 9055. By bending the two housings 9000 via the hinges 9055, the mobile information terminal 9201 can be reversibly transformed from an unfolded state to a folded state. For example, the portable information terminal 9201 can be bent with a curvature radius of 1 mm or more and 150 mm or less.

[0290] The display device of one embodiment of the present invention can be applied to the portable information terminal 9201. This allows the portable information terminal 9201 to display high-quality images.

[0291] FIG. 13F is a perspective view showing a television device 9100. The television device 9100 can incorporate a large screen, for example, a display surface 9001 of 50 inches or more, or 100 inches or more. The television device 9100 can be operated using operation keys 9005 as well as a separate remote control device 9110. Alternatively, the display surface 9001 may be equipped with a touch sensor, and the television device 9100 may be operated by touching the display surface 9001 with a finger or the like. The remote control device 9110 may have a display surface that displays information output from the remote control device 9110. The channel and volume can be controlled using the operation keys or touch panel of the remote control device 9110, and the video displayed on the display surface 9001 can be controlled.

[0292] The display device of one embodiment of the present invention can be applied to the television set 9100. Thus, the television set 9100 can display high-quality images.

[0293] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes or examples described in this specification. [Example]

[0294] In this example, the results of optical simulation (ray tracing) performed on a display device of one embodiment of the present invention will be described.

[0295] Fig. 14 is a schematic diagram of a display device used in the simulation in this example. As shown in Fig. 14, a layer 71 is provided on a light-emitting element 30, a colored layer 25 is provided on the layer 71, and a layer 77 is provided on the colored layer 25. A lens 29 is provided on the layer 77, a resin layer 33 is provided to cover the lens 29, a substrate 12 is provided on the resin layer 33, and a layer 79 is provided on the substrate 12.

[0296] The light emitting element 30 has an elliptical shape with a long side of 1.9 μm and a short side of 1.6 μm when viewed from above.

[0297] Furthermore, the light-emitting layer 31 of the light-emitting element 30 was configured by laminating a light-emitting layer that emits blue light and a light-emitting layer that emits yellow light. The light distribution characteristics of the light-emitting element 30 were as shown in Fig. 15. In Fig. 15, the normalized luminous intensity indicates the luminous intensity when the luminous intensity at a light distribution angle of 0° is set to 1. In other words, Fig. 15 shows the light distribution characteristics of the light-emitting element 30 normalized at an angle of 0°.

[0298] The colored layer 25 had a hexagonal shape with long sides of 2.9 μm and short sides of 2.8 μm when viewed from above. The distance from the bottom surface of the colored layer 25 to the flat portion 29a of the lens 29 was 2 μm.

[0299] The flat portion 29a of the lens 29 had an elliptical shape with a long side of 3.1 μm and a short side of 2.8 μm when viewed from above. The lens 29 was a semi-ellipsoid with the flat portion 29a as the bottom surface. Here, when viewed from above, the centers of the light-emitting element 30, the colored layer 25, and the lens 29 were all overlapping with each other.

[0300] The refractive index of layer 71, colored layer 25, layer 77, and lens 29 was 1.56. The refractive index of resin layer 33 was 1.40. The substrate 12 was a glass substrate with a refractive index of 1.50. The layer 79 was air with a refractive index of 1.00. The thickness of resin layer 33 was 3 μm, the thickness of substrate 12 was 0.5 μm, and the thickness of layer 79 was 400.5 μm. Here, the upper surface of layer 79 was designated as evaluation surface 80.

[0301] 16 is a graph showing the results of a simulation of the relationship between the normalized radiance of light emitted by the light-emitting element 30 at the evaluation surface 80 and the distance L. Here, the thickness t of the lens 29 was set to 0.6 μm, 0.8 μm, 1.0 μm, 1.2 μm, or 1.4 μm. The radius of curvature R1 of the cross section along the short side of the flat portion 29a at each thickness t was set to 1.93 μm, 1.63 μm, 1.48 μm, 1.42 μm, or 1.40 μm.

[0302] The aperture radius at the evaluation surface 80 was set to 10 μm. Furthermore, the radiance at the front of the light-emitting element 30 was calculated by simulation. In Fig. 16, the normalized radiance indicates the radiance when the radiance at the evaluation surface 80 without the lens 29 is set to 1. Specifically, when the number of light rays reaching the evaluation surface 80 without the lens 29 is set to 1, the normalized radiance indicates the number of light rays reaching the evaluation surface 80 under each condition.

[0303] FIG. 16 shows that the normalized radiance is 1.0 or greater regardless of the distance L and the thickness t of the lens 29. In other words, FIG. 16 shows that the light emitted by the light-emitting element 30 is condensed by the lens 29 toward the front of the light-emitting element 30. FIG. 16 also shows that when the distance L is short, for example, 6 μm or less, the radiance increases as the thickness t increases (as the radius of curvature R1 decreases). However, when the distance L is long, for example, greater than 6 μm, the radiance increases as the thickness t decreases (as the radius of curvature R1 increases). For example, when the distance L is 4 μm, the radiance is highest when the thickness t is 1.0 μm. On the other hand, when the distance L is 7 μm, the radiance is highest when the thickness t is 0.8 μm.

[0304] At least a part of this embodiment can be implemented in appropriate combination with other embodiment modes or embodiments described in this specification. [Example]

[0305] In this example, a display device according to one embodiment of the present invention was manufactured and the results of measuring radiance will be described.

[0306] In this example, a display device having the configuration shown in FIG. 1A was fabricated. Here, when fabricating the lenses 29, first, a photosensitive film that would become the lenses 29 was applied. Next, exposure and development were performed to process the film that would become the lenses 29 into a desired shape. After that, bleaching exposure was performed to bleach the film that would become the lenses 29. After bleaching, thermal reflow was performed at 105°C for 10 minutes to sphericalize the film that would become the lenses 29. Lenses 29 were fabricated by the above method.

[0307] 17A and 17B are electron microscope images showing a cross section of the fabricated display device. Fig. 17A shows images 91 and 92. Image 92 is an electron microscope image showing a cross section in a direction perpendicular to image 91. Image 92 includes lenses 29. Fig. 17B shows image 91.

[0308] As shown in Figures 17A and 17B, it was confirmed that the light-emitting element 30, insulating layer 21, colored layer 25, planarizing layer 27, lens 29, etc. could be fabricated in the desired shapes, and pixels could be fabricated. Furthermore, the distance L from the light-emitting element 30 to the flat portion of the lens 29 was approximately 7 µm. Furthermore, the thickness t of the lens 29 was approximately 0.59 µm. The insulating layer 21 was composed of a resin layer 21a and a protective layer 21b.

[0309] Next, the radiance of light emitted from the pixels 15 of the manufactured display device was measured and compared with the results of optical simulation.

[0310] FIG. 18 is a schematic diagram of the display device used in the optical simulation of this example. As shown in FIG. 18, a layer 71 is provided on a light-emitting element 30, and colored layers 25R, 25B, and 25G are provided on the layer 71. A planarization layer 27 is provided on the colored layers 25R, 25B, and 25G, and a lens 29 is provided on the planarization layer 27. A resin layer 33 is provided to cover the lens 29, a substrate 12 is provided on the resin layer 33, and a layer 79 is provided on the substrate 12. The colored layers 25R, 25B, and 25G each have an area overlapping with a different light-emitting element 30 and the lens 29. In FIG. 18, the light-emitting element 30 overlapping with the colored layer 25R is referred to as light-emitting element 30R, the light-emitting element 30 overlapping with the colored layer 25B is referred to as light-emitting element 30B, and the light-emitting element 30 overlapping with the colored layer 25G is referred to as light-emitting element 30G.

[0311] Here, the distance L from the light emitting layer 31 of the light emitting element 30 to the flat portion 29a of the lens 29 was set to 7 μm based on the actual measurement value shown in FIG.

[0312] The light-emitting element 30R had a rectangular shape with long sides of 7.15 μm and short sides of 1.95 μm when viewed from above. The light-emitting elements 30B and 30G had rectangular shapes with long sides of 7.10 μm and short sides of 1.48 μm when viewed from above. The light-emitting layer 31 of the light-emitting element 30R, the light-emitting layer 31 of the light-emitting element 30B, and the light-emitting layer 31 of the light-emitting element 30G all had a configuration in which a light-emitting layer that emits blue light and a light-emitting layer that emits yellow light were stacked.

[0313] The colored layer 25R had a thickness of 1.8 μm and a width of 3.2 μm. The colored layer 25B had a thickness of 0.72 μm and a width of 2.9 μm. The colored layer 25G had a thickness of 1.0 μm and a width of 2.9 μm. The refractive index of the colored layer 25R was 1.768, the refractive index of the colored layer 25B was 1.635, and the refractive index of the colored layer 25G was 1.623.

[0314] The flat portion 29a of the lens 29 was assumed to have a rectangular shape with long sides of 7.85 μm and short sides of 2.2 μm when viewed from above. The thickness t of the lens 29 was assumed to be 0.59 μm based on the measured value shown in Fig. 17. Here, when viewed from above, the center of the lens 29 was shifted by 0.4 μm in the long side direction and by 0.2 μm in the short side direction from the center of the light-emitting element 30R, the light-emitting element 30B, or the light-emitting element 30G.

[0315] The refractive index of layer 71, the refractive index of planarizing layer 27, and the refractive index of lens 29 were set to 1.56. The refractive index of resin layer 33 was set to 1.40. The substrate 12 was a glass substrate with a refractive index of 1.50. The layer 79 was air with a refractive index of 1.00. The upper surface of layer 79 was designated as evaluation surface 80.

[0316] In the optical simulation of this example, the radiance of light emitted by light-emitting element 30R, light emitted by light-emitting element 30B, and light-emitting element 30G was calculated on evaluation surface 80, which is in front of each light-emitting element. Here, the thickness of layer 79 was 400.5 μm, and the upper surface of layer 79 was the evaluation surface 80. The aperture radius on evaluation surface 80 was 10 μm.

[0317] 19 is a graph showing actual measurement results and simulation results of the normalized radiance of light emitted by light-emitting element 30R, light emitted by light-emitting element 30G, and light emitted by light-emitting element 30B. Here, the normalized radiance indicates the radiance at evaluation surface 80 when the radiance at evaluation surface 80 without lens 29 is set to 1. Specifically, it indicates the number of light rays reaching evaluation surface 80 when the number of light rays reaching evaluation surface 80 without lens 29 is set to 1.

[0318] 19, the measured normalized radiance for light-emitting element 30R was 1.26, and the calculated value (simulated value) by optical simulation was 1.29. The measured normalized radiance for light-emitting element 30G was 1.54, and the simulated value was 1.55. The measured normalized radiance for light-emitting element 30B was 1.45, and the simulated value was 1.50.

[0319] Therefore, it was confirmed that the normalized radiance was 1.0 or more for all of the light-emitting element 30R, the light-emitting element 30G, and the light-emitting element 30B. In other words, it was confirmed that the light emitted from the light-emitting element 30 was condensed by the lens 29. Furthermore, the difference between the actual measured value and the simulated value of the normalized radiance was 0.05 or less, and it was confirmed that the optical simulation reproduced the actual measured value.

[0320] At least a part of this embodiment can be implemented in appropriate combination with other embodiment modes or embodiments described in this specification. [Explanation of symbols]

[0321] 10: display device, 11: substrate, 12: substrate, 13: insulating layer, 14: partition wall, 15: pixel, 15B: pixel, 15G: pixel, 15R: pixel, 21: insulating layer, 21a: resin layer, 21b: protective layer, 25: colored layer, 25B: colored layer, 25G: colored layer, 25R: colored layer, 27: planarizing layer, 29: lens, 29a: flat portion, 29b: convex portion, 30: light-emitting element, 30B: light-emitting element, 30G: light-emitting element, 30R: light-emitting element, 31: light-emitting layer, 33: resin layer, 35: partition wall, 37: adhesive layer, 42: conductive layer, 43: light, 45: light-shielding layer, 47: light, 49: light, 51: light-emitting layer, 52: transistor , 55G: wavelength conversion layer, 55R: wavelength conversion layer, 57: planarization layer, 60: conductive layer, 63: insulating layer, 71: layer, 77: layer, 79: layer, 80: evaluation surface, 91: image, 92: image, 152: insulating layer, 161: conductive layer, 162: insulating layer, 163: insulating layer, 164: insulating layer, 165: metal oxide layer, 166: conductive layer, 167: insulating layer, 168: conductive layer, 181: insulating layer, 182: insulating layer, 183: insulating layer, 184a: conductive layer, 184b: conductive layer, 185: insulating layer, 186: insulating layer, 187: insulating layer, 189a: conductive layer, 189b: conductive layer, 189c: conductive layer, 189d : Conductive layer, 190: Conductive layer, 195: Conductive layer, 200: Transistor, 205: Conductor, 205a: Conductor, 205b: Conductor, 205c: Conductor, 212: Insulator, 214: Insulator, 216: Insulator, 222: Insulator, 224: Insulator, 230: Oxide, 230a: Oxide, 230b: Oxide, 240: Conductor, 240a: Conductor, 240b: Conductor, 241: Insulator, 241a: Insulator, 241b: Insulator, 242: Conductor, 242a: Conductor, 242b: Conductor, 243: Oxide, 243a: Oxide, 243b: Oxide, 246: Conductor, 246a: Conductor, 246b: Conductor, 250: Insulator, 250a: Insulator, 250b: Insulator, 260: Conductor, 260a: Conductor, 260b: Conductor, 271: Insulator, 271a: Insulator, 271b: Insulator, 275: Insulator, 280: Insulator, 282: Insulator, 283: Insulator, 285: Insulator, 8200: Head mounted display, 8201: Mounting part, 8202: Lens, 8203: Main body, 8204: Display surface, 8205: Cable, 8206: Battery, 8300: Head mounted display, 8301: Housing, 8302: Display surface, 8304: Mounting part,8305: Lens, 8306: Battery, 9000: Housing, 9001: Display surface, 9003: Speaker, 9005: Operation keys, 9006: Connection terminal, 9007: Sensor, 9009: Battery, 9050: Operation buttons, 9051: Information, 9055: Hinge, 9100: Television device, 9101: Portable information terminal, 9110: Remote control device, 9200: Portable information terminal, 9201: Portable information terminal, 9251: Time, 9252: Operation buttons, 9253: Contents,

Claims

1. an insulating layer located on the first light-emitting element and the second light-emitting element; a first colored layer having an area overlapping the first light-emitting element and positioned on the insulating layer; a second colored layer having an area overlapping the second light-emitting element and positioned on the insulating layer; a planarization layer located on the first color layer and the second color layer; a first lens having a first flat portion and a first convex portion and positioned on the planarization layer; a second lens having a second flat portion and a second convex portion and located on the planarization layer; A resin layer; and the first lens has an area overlapping with the first light-emitting element, and is provided so that the first flat portion faces the planarization layer; the second lens has an area overlapping with the second light-emitting element, and is provided so that the second flat portion faces the planarization layer; the resin layer is in contact with the first convex portion and the second convex portion, the refractive index of the resin layer is lower than the refractive index of the first lens; the refractive index of the resin layer is lower than the refractive index of the second lens; the first colored layer and the second colored layer transmit light of different colors; A display device, wherein the first colored layer and the second colored layer have different thicknesses.

2. In claim 1, A display device, wherein the center of the first lens and the center of the first light-emitting element are different from each other when viewed from above.

3. In claim 1 or claim 2, A display device, wherein the center of the second lens and the center of the second light-emitting element are different from each other when viewed from above.

4. In any one of claims 1 to 3, A display device, wherein the first flat portion has a shape in which a long side and a short side have different lengths when viewed from above.

5. In any one of claims 1 to 4, A display device, wherein the second flat portion has a shape in which a long side and a short side have different lengths when viewed from above.

6. In any one of claims 1 to 5, A display device, wherein the thickness of the planarizing layer in a portion overlapping with the first colored layer is different from the thickness of the planarizing layer in a portion overlapping with the second colored layer.

7. In any one of claims 1 to 6, a partition wall is provided between the first colored layer and the second colored layer, The refractive index of the partition wall is lower than that of the first colored layer.

8. In any one of claims 1 to 7, a partition wall is provided between the first colored layer and the second colored layer, The refractive index of the partition wall is lower than that of the second colored layer.

9. In any one of claims 1 to 8, A display device, wherein the refractive index of the planarization layer is lower than that of the first colored layer.

10. In any one of claims 1 to 9, A display device, wherein the refractive index of the planarization layer is lower than that of the second colored layer.

11. In any one of claims 1 to 10, The display device, wherein the planarization layer contacts the upper surface and side surfaces of the first colored layer and the upper surface and side surfaces of the second colored layer.

12. In any one of claims 1 to 11, the first lens and the second lens are adjacent to each other, The display device, wherein the first colored layer and the second colored layer are spaced apart from each other.

13. In any one of claims 1 to 12, The display device, wherein the insulating layer is a planarized layer.

14. In any one of claims 1 to 13, the first light-emitting element is electrically connected to a transistor; The display device includes a transistor including an oxide semiconductor.

15. In any one of claims 1 to 13, the first light-emitting element is electrically connected to a transistor; The display device, wherein the transistor includes any one of In--Ga oxide, In--Zn oxide, and indium oxide.

16. A display device according to any one of claims 1 to 15; An electronic device having a battery.

17. A display device according to any one of claims 1 to 15; A head-mounted display having a mounting portion.

Images