Display device and method of manufacturing display device

Abstract

A display device is provided that has the function of detecting objects touching or approaching the display section. The present invention is a display device including a light-emitting element and a light-receiving element. The light-emitting element includes a first pixel electrode, a first light-emitting layer on the first pixel electrode, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, and a common electrode on the second light-emitting layer. The light-receiving element includes a second pixel electrode, a light-receiving layer on the second pixel electrode, and a common electrode on the light-receiving layer. The first light-emitting layer and the second light-emitting layer have the function of emitting light of the same color as each other.

Description

Technical Field

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

[0002] Note that one embodiment of the present invention is not limited to the above-described technical fields. Examples of technical fields within the scope of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting equipment, input devices, input / output devices, methods for driving these devices, and methods for manufacturing these devices. A semiconductor device refers to any device capable of operating by utilizing the characteristics of semiconductors. Prior Technology

[0003] In recent years, display devices have been used in various devices such as smartphones, tablets, laptop PCs (personal computers), televisions, and monitors. Furthermore, there is a demand for a display device that not only displays images but also possesses various functions, such as a touch panel or fingerprint recognition capabilities.

[0004] As display devices, light-emitting devices including light-emitting elements (also called light-emitting devices) have been developed. In particular, light-emitting devices utilizing the electroluminescence (EL) phenomenon (also called "EL elements") have the characteristics of being easy to achieve in a thin and lightweight form; being able to respond to input signals at high speed; and being able to be driven by a DC regulated power supply, etc., and have been applied to display devices. For example, Patent Document 1 discloses a flexible light-emitting device using an organic EL element (also called an organic EL device).

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2014-197522 Summary of the Invention

[0006] One embodiment of the present invention provides a display device and a method for manufacturing the same, which have the function of detecting objects touching or approaching the display portion. Another embodiment of the present invention provides a display device and a method for manufacturing the same, which have a recognition function. Another embodiment of the present invention provides a display device with a high aperture ratio and a method for manufacturing the same. Another embodiment of the present invention provides a small display device and a method for manufacturing the same. Another embodiment of the present invention provides a display device with high reliability and a method for manufacturing the same. A novel display device and a method for manufacturing the same are also provided.

[0007] Note that the description of these objectives does not preclude the existence of other objectives. Also note that one embodiment of the present invention does not need to achieve all of the above objectives. Furthermore, objectives other than those described above can be derived from the description in the specification, drawings, claims, etc.

[0008] One embodiment of the present invention is a display device, which includes a light-emitting element and a light-receiving element. The light-emitting element includes a first pixel electrode, a first light-emitting layer on the first pixel electrode, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, a common layer on the second light-emitting layer, and a common electrode on the common layer. The light-receiving element includes a second pixel electrode, a light-receiving layer on the second pixel electrode, a common layer on the light-receiving layer, and a common electrode on the common layer. The common layer is used as a hole injection layer or an electron injection layer in the light-emitting element, and the common layer is used as a hole transport layer or an electron transport layer in the light-receiving element.

[0009] In addition, in the above embodiments, the first light-emitting layer and the second light-emitting layer may also have the function of emitting light of the same color as each other.

[0010] In addition, the above embodiments may also include a first transistor and a second transistor. One of the source and drain of the first transistor may be electrically connected to the first pixel electrode, and one of the source and drain of the second transistor may be electrically connected to the second pixel electrode. The first transistor and the second transistor may also contain silicon or metal oxide in the channel forming region.

[0011] In addition, one embodiment of the present invention is a method for manufacturing a display device, comprising the following steps: a first process for forming a first pixel electrode, a second pixel electrode, and a connecting electrode; a second process for sequentially depositing a first light-emitting film, an intermediate film, and a second light-emitting film on the first pixel electrode and the second pixel electrode; a third process for forming a first sacrificial film on the second light-emitting film and the connecting electrode; a fourth process for etching the first sacrificial film, the second light-emitting film, the intermediate film, and the first light-emitting film to expose the second pixel electrode, and forming a first light-emitting layer, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, the second light-emitting layer, and a first sacrificial layer on the connecting electrode on the first pixel electrode; a fifth process for depositing a light-receiving film on the first sacrificial layer and the second pixel electrode; a sixth process for forming a second sacrificial film on the light-receiving film; a seventh process for etching the second sacrificial film and the light-receiving film to form a light-receiving layer on the second pixel electrode and a second sacrificial layer on the light-receiving layer; an eighth process for removing the first sacrificial layer and the second sacrificial layer; and a ninth process for forming a common electrode on the second light-emitting layer and the light-receiving layer in such a way as to have a region in contact with the connecting electrode.

[0012] In addition, in the above embodiments, the first light-emitting film, the second light-emitting film, and the light-receiving film can also be formed by vapor deposition using a shadow mask.

[0013] In addition, in the above embodiments, the first sacrificial film and the second sacrificial film may also include the same metal film, alloy film, metal oxide film, semiconductor film or inorganic insulating film. In the fourth process, the first light-emitting film and the second light-emitting film may also be etched by dry etching using an etching gas that does not contain oxygen as the main component. In the eighth process, the first sacrificial layer and the second sacrificial layer may also be removed by wet etching using a tetramethylammonium hydroxide aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid or a mixture thereof.

[0014] In addition, in the above embodiments, the first sacrificial film and the second sacrificial film may also contain aluminum oxide.

[0015] In addition, the above embodiments may also include a tenth process, which forms a protective layer on the common electrode, following the ninth process.

[0016] According to one embodiment of the present invention, a display device and a method thereof are provided that have the function of detecting objects touching or approaching the display portion. According to one embodiment of the present invention, a display device and a method thereof are provided that have the function of identification. According to one embodiment of the present invention, a display device and a method thereof are provided that have a high aperture ratio. According to one embodiment of the present invention, a small display device and a method thereof are provided that have a manufacturing method. According to one embodiment of the present invention, a display device and a method thereof with high reliability are provided that have a manufacturing method. According to one embodiment of the present invention, a novel display device and a method thereof are provided that have a manufacturing method.

[0017] Note that the description of these effects does not preclude the existence of other effects. Furthermore, one embodiment of the present invention does not necessarily require all of the aforementioned effects. Additionally, effects other than those described above can be derived from the description in the specification, drawings, claims, etc. Simple Explanation of the Diagram

[0018] Figures 1A to 1E are cross-sectional views showing examples of the structure of a display device. Figure 1F is a diagram showing an example of a captured image. [Figure 2A] and [Figure 2B] are cross-sectional views showing examples of the structure of a display device. [Figure 3A] and [Figure 3B] are cross-sectional views showing examples of the structure of a display device. [Figure 4] is a cross-sectional view showing an example of the structure of a display device. [Figure 5A] and [Figure 5B] are cross-sectional views showing examples of the structure of a display device. Figures 6A to 6C are cross-sectional views showing examples of the structure of a display device. [Figure 7A] and [Figure 7B] are top views showing an example of the structure of a display device. [Figure 8A] and [Figure 8B] show top views of an example of the structure of a display device. [Figure 9A] is a top view showing an example of the structure of a display device. [Figure 9B] is a diagram showing the light-receiving range of the light-receiving element. [Figure 10] is a top view showing an example of the structure of a display device. Figures 11A to 11E are cross-sectional views showing examples of the structure of a display device. Figures 12A to 12D are cross-sectional views illustrating examples of manufacturing methods for display devices. Figures 13A to 13C are cross-sectional views showing examples of manufacturing methods for display devices. Figures 14A to 14D are cross-sectional views showing examples of manufacturing methods for display devices. Figures 15A to 15C are cross-sectional views illustrating examples of manufacturing methods for display devices. [Figure 16] is a perspective view of an example of the structure of a display device. [Figure 17] is a cross-sectional view showing an example of the structure of a display device. [Figure 18] is a cross-sectional view showing an example of the structure of a display device. [Figure 19] is a cross-sectional view showing an example of the structure of a display device. [Figure 20] is a cross-sectional view showing an example of the structure of a display device. [Figure 21] is a cross-sectional view showing an example of the structure of a display device. [Figure 22A] and [Figure 22B] are figures illustrating an example of an electronic device. [Figure 23A] and [Figure 23B] are figures illustrating an example of an electronic device. Figures 24A through 24E are diagrams illustrating an example of an electronic device. Implementation

[0019] The embodiments will now be described with reference to the accompanying drawings. However, the embodiments can be implemented in many different ways, and those skilled in the art will readily understand that the methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the invention should not be construed as being limited to the contents described in the embodiments shown below.

[0020] Note that in the structure of the invention described below, the same element symbols are used in different figures to represent the same parts or parts with the same function, and repeated descriptions are omitted. Furthermore, when representing parts with the same function, the same shading lines are sometimes used without additional element symbols.

[0021] Note that in the various figures described in this specification, the size of components, the thickness of layers, or areas are sometimes exaggerated for clarity. Therefore, the invention is not limited to the dimensions shown in the figures.

[0022] The ordinal numbers such as "first" and "second" used in this specification are appended to avoid confusion of components, and are not intended to limit the number of components.

[0023] In this specification and other materials, the terms "film" and "layer" may be interchanged. For example, sometimes "conductive layer" may be changed to "conductive film," and "insulating layer" may be changed to "insulating film."

[0024] Note that in this specification, etc., the EL layer refers to a layer disposed between a pair of electrodes of a light-emitting element and including at least a light-emitting material (also called a light-emitting layer) or a stack including a light-emitting layer.

[0025] In this specification and the like, a display panel in one embodiment of a display device refers to a panel capable of displaying (outputting) images on a display surface. Therefore, a display panel is one embodiment of an output device.

[0026] In this specification and other documents, the structure in which connectors such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are mounted on the substrate of the display panel, or the structure in which ICs are directly mounted on the substrate in the form of COG (Chip On Glass), is sometimes referred to as a display panel module or display module, or simply as a display panel.

[0027] Implementation Method 1 In this embodiment, an example of the structure of a display device according to one embodiment of the present invention and an example of a method for manufacturing the display device will be described.

[0028] One embodiment of the display device of the present invention includes a display section in which pixels are arranged in a matrix. Each pixel includes a plurality of sub-pixels, and each sub-pixel is provided with a light-emitting element (also referred to as a light-emitting device). The plurality of sub-pixels disposed in the same pixel can have the function of emitting light of different colors.

[0029] Each light-emitting element includes a pair of electrodes and a light-emitting layer between the pair of electrodes. The light-emitting element is preferably an organic EL element (organic electroluminescent element). Two or more light-emitting elements emitting different colors of light each include a light-emitting layer containing different materials. For example, a full-color display device can be realized by including three light-emitting elements that emit red (R), green (G), or blue (B) light respectively.

[0030] Here, it is known that when forming light-emitting layers between light-emitting elements of different colors, a vapor deposition method using a shadow mask such as a metal mask is employed. However, this method suffers from various influences, such as the precision of the metal mask, misalignment between the metal mask and the substrate, metal mask deflection, and enlargement of the deposited film outline due to vapor scattering, resulting in deviations in the shape and position of the island-shaped organic film from the designed shape and position, making it difficult to achieve high resolution and high aperture ratio. Therefore, special pixel arrangements, such as pentile arrangements, have been employed to tentatively improve resolution (also known as pixel density).

[0031] In one embodiment of the present invention, the light-emitting layer is processed into a fine pattern without using a shadow mask such as a metal mask. Therefore, compared to forming the light-emitting layer separately using a shadow mask, the sub-pixels can be miniaturized further, and the pixel aperture ratio can be increased. Furthermore, because the light-emitting layers can be formed separately, a display device with extremely vivid colors, extremely high contrast, and extremely high display quality can be achieved.

[0032] By miniaturizing subpixels, subpixels that do not contribute to display can be placed within subpixels. For example, in addition to subpixels that include light-emitting elements, subpixels that include light-receiving elements (also called light-receiving devices) can be placed within pixels. Even in this case, the display device according to one embodiment of the present invention can suppress the pixel density value from decreasing. For example, the pixel density can be set to 400 ppi or more, 1000 ppi or more, 3000 ppi or more, or 5000 ppi or more.

[0033] In one embodiment of the display device of the present invention, the light-receiving element is used as a light sensor. Therefore, the display device of one embodiment of the present invention can display images using a light-emitting element and detect, for example, objects touching or approaching the display section using the light-receiving element. Furthermore, in one embodiment of the display device of the present invention, for example, when a user's finger touches the display section, identification can be performed based on the fingerprint of that finger.

[0034] By placing the light-receiving element within the display section, there is no need to externally connect the sensor to the display device. Therefore, the number of components in the display device can be reduced, enabling miniaturization and weight reduction of the display device.

[0035] Furthermore, in a display device according to one embodiment of the present invention, the light-receiving element can detect light emitted by the light-emitting element that illuminates an object and is reflected by the object. Therefore, for example, even in a dark place, an object touching or approaching the display section can be detected, and identification such as fingerprint recognition can be performed.

[0036] In this specification, etc., devices manufactured using a metal mask or FMM (Fine Metal Mask) are sometimes referred to as devices having an MM (Metal Mask) structure. Furthermore, in this specification, etc., devices manufactured without a metal mask or FMM are sometimes referred to as devices having an MML (Metal Mask Less) structure.

[0037] Furthermore, in this specification, the structure in which light-emitting elements of each color (here, blue (B), green (G), and red (R)) are separately formed or coated with light-emitting layers is sometimes referred to as an SBS (Side By Side) structure. Additionally, in this specification, a light-emitting element capable of emitting white light is sometimes referred to as a white light-emitting element. A white light-emitting element, combined with a color layer (e.g., a color filter), can realize a display device that displays in full color.

[0038] Furthermore, light-emitting elements can be broadly categorized into single-structure and series-structure elements. A preferred single-structure light-emitting element has the following structure: a light-emitting unit is included between a pair of electrodes, and this light-emitting unit includes one or more light-emitting layers. To obtain white light emission, the light-emitting layers are selected such that their light emission colors are complementary. For example, by making the light emission colors of the first and second light-emitting layers complementary, a structure in which the entire light-emitting element emits white light can be obtained. The same applies to light-emitting elements comprising three or more light-emitting layers.

[0039] A preferred structure for a series-connected light-emitting element is one in which two or more light-emitting units are located between a pair of electrodes, and each light-emitting unit includes one or more light-emitting layers. To obtain white light emission, a structure is created by combining the light emitted from the light-emitting layers of multiple light-emitting units. Note that the structure for obtaining white light emission is the same as that in a single-structure light-emitting element. Furthermore, in a series-connected light-emitting element, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0040] Furthermore, when comparing the aforementioned white light-emitting elements (single-structure or series-structure) and SBS structure light-emitting elements, the SBS structure light-emitting element has lower power consumption than the white light-emitting element. Therefore, when it is desirable to reduce the power consumption of a display device, it is preferable to use an SBS structure light-emitting element. On the other hand, the manufacturing process of white light-emitting elements is simpler than that of SBS structure light-emitting elements, thereby reducing manufacturing costs or improving manufacturing yield.

[0041] Figures 1A to 1E are cross-sectional views illustrating a structural example of a display device according to an embodiment of the present invention.

[0042] The display device 10A shown in FIG1A has a layer 53 including a light-receiving element and a layer 57 including a light-emitting element between a substrate 51 and a substrate 59.

[0043] The display device 10B shown in FIG1B has a layer 55 including a transistor, a layer 53 including a light-receiving element and a layer 57 including a light-emitting element between a substrate 51 and a substrate 59.

[0044] Display devices 10A and 10B have a structure that emits red (R), green (G) and blue (B) light from a layer 57 including a light-emitting element.

[0045] In a display device according to one embodiment of the present invention, a plurality of pixels arranged in a matrix are disposed in a display unit. A pixel includes one or more sub-pixels. A sub-pixel includes a light-emitting element or a light-receiving element. For example, a pixel may have a structure including four sub-pixels. Specifically, for example, a pixel may include light-emitting elements and light-receiving elements of three colors: R, G, and B. Furthermore, it may have a structure including light-emitting elements and light-receiving elements of three colors: yellow (Y), cyan (C), and magenta (M). Additionally, a pixel may have a structure including five sub-pixels. Specifically, for example, a pixel may have a structure including light-emitting elements and light-receiving elements of four colors: R, G, B, and white (W). Alternatively, it may have a structure including light-emitting elements and light-receiving elements of four colors: R, G, B, and infrared (IR). The light-receiving elements may be disposed in all pixels or in a subset of pixels. Furthermore, a pixel may also include multiple light-receiving elements.

[0046] A display device according to one embodiment of the present invention can also have the function of detecting objects such as fingers that touch the display device. For example, as shown in FIG1C, when light emitted by the light-emitting element in layer 57, which includes a light-emitting element, is reflected by a finger 52 touching the display device 10B, the light-receiving element in layer 53, which includes a light-receiving element, detects the reflected light. Thus, it can be detected that the finger 52 is touching the display device 10B. Furthermore, as shown in FIG1D, when light emitted by the light-emitting element in layer 57 is reflected by a finger 52 approaching the display device 10B, the light-receiving element in layer 53 detects the reflected light. Thus, it can be detected that the finger 52 is approaching the display device 10B. That is to say, a display device according to one embodiment of the present invention can function as a touch sensor (also called a direct touch sensor) and can function as a near touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or contactless sensor).

[0047] As described above, for example, when the display device 10B functions as a near-touch sensor, it can detect a finger 52 as long as it approaches the display device 10B without actually touching it. Preferably, the display device 10B can detect a finger 52 within a distance of 0.1 mm to 300 mm, and more preferably 3 mm to 50 mm, between the display device 10B and the finger 52. By employing this structure, operation can be performed without the finger 52 directly contacting the display device 10B; in other words, the display device 10B can be operated in a non-contact (contactless) manner. By employing the above structure, the risk of the display device 10B becoming dirty or injured can be reduced. Furthermore, the display device 10B can be operated by the finger 52 without directly contacting dirt (e.g., dust or bacteria) that may adhere to it.

[0048] Furthermore, a display device according to one embodiment of the present invention may, for example, have the function of detecting the fingerprint of finger 52. FIG1E schematically shows an enlarged view of the contact portion when finger 52 contacts substrate 59. In addition, FIG1E shows a case where layer 57 including light-emitting elements and layer 53 including light-receiving light-emitting elements are arranged alternately.

[0049] The fingerprint of finger 52 is formed by concave and convex portions. Therefore, the convex portion of the fingerprint contacts the substrate 59 as shown in FIG1E.

[0050] Light reflected from a surface or interface can be either regular or diffuse. Regularly reflected light is highly directional light where the angle of incidence and the angle of reflection are the same, while diffusely reflected light is less directional light with low intensity dependence on angle. In the light reflected from the surface of finger 52, diffuse reflection is predominant compared to regular reflection. On the other hand, in the light reflected from the interface between substrate 59 and the atmosphere, regular reflection is predominant.

[0051] The light intensity reflected from or incident on the contact or non-contact surfaces of the finger 52 and the substrate 59 onto the layer 53 directly beneath them is the combined intensity of regular reflected light and diffuse reflected light. As described above, in the recess of the finger 52, the finger 52 does not touch the substrate 59, thus regular reflected light (indicated by solid arrows) is dominant; in its protrusion, the finger 52 touches the substrate 59, thus diffuse reflected light (indicated by dashed arrows) reflected from the finger 52 is dominant. Therefore, the light intensity received by the light-receiving element in the layer 53 directly beneath the recess is higher than the light intensity received by the light-receiving element in the layer 53 directly beneath the protrusion. Thus, the fingerprint of the finger 52 can be captured using the light-receiving element.

[0052] When the spacing between the light-receiving elements in layer 53 is smaller than the distance between two convex parts of a fingerprint, and more preferably smaller than the distance between adjacent concave and convex parts, a clear fingerprint image can be obtained. Since the distance between the concave and convex parts of a human fingerprint is approximately 150 μm to 200 μm, the spacing between the light-receiving elements can be, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, further preferably 120 μm or less, even more preferably 100 μm or less, and still more preferably 50 μm or less. The smaller the spacing, the better; for example, it can be 1 μm or more, 10 μm or more, or 20 μm or more.

[0053] Figure 1F is an example of a fingerprint image captured by a display device according to one embodiment of the present invention. In Figure 1F, the outline of the finger 52 is shown in dashed lines within region 65, and the outline of the contact portion 69 is shown in dotted lines. Within region 65, a high-contrast fingerprint 67 can be captured by utilizing the different amounts of light incident on the light-receiving element.

[0054] As described above, in a display device according to one embodiment of the present invention, the light-receiving element can detect light emitted by the light-emitting element that illuminates an object such as a finger 52 and is reflected by that object. Therefore, for example, even in a dark place, an object touching or approaching the display section can be detected, and identification such as fingerprint recognition can be performed.

[0055] Furthermore, by placing the light-receiving element within the display section, there is no need to externally connect the sensor to the display device. Therefore, the number of components in the display device can be reduced, enabling miniaturization and weight reduction of the display device.

[0056] <Example of a display device structure> Figure 2A shows a cross-sectional schematic diagram of the display device 10. The display device 10 includes a light-emitting element 550R that emits red light, a light-emitting element 550G that emits green light, a light-emitting element 550B that emits blue light, and a light-receiving element 560.

[0057] Light-emitting element 550R has a structure in which two light-emitting units 512R (light-emitting unit 512R_1 and light-emitting unit 512R_2) are stacked between a pair of electrodes (electrodes 501R and 502) and an intermediate layer 531R. Similarly, light-emitting element 550G has a structure in which two light-emitting units 512G (light-emitting unit 512G_1 and light-emitting unit 512G_2) are stacked between a pair of electrodes (electrodes 501G and 502) and an intermediate layer 531G. Furthermore, light-emitting element 550B has a structure in which two light-emitting units 512B (light-emitting unit 512B_1 and light-emitting unit 512B_2) are stacked between a pair of electrodes (electrodes 501B and 502) and an intermediate layer 531B.

[0058] In the light-receiving element 560, a light-receiving unit 542 is disposed between a pair of electrodes (electrode 501PD, electrode 502).

[0059] In this specification, etc., for example, when describing common content between display device 10A and display device 10B, or when there is no need to distinguish them, they are simply referred to as "display device 10". That is to say, the components of display device 10 can be used for both display device 10A shown in FIG. 1A and display device 10B shown in FIG. 1B. The same applies to other components.

[0060] Electrode 501 is used as a pixel electrode, and each light-emitting element 550 and each light-receiving element 560 is provided with electrode 501. Electrode 502 is used as a common electrode, and is shared by multiple light-emitting elements 550 and light-receiving elements 560.

[0061] The light-emitting unit 512R_1 includes layers 521, 522, 523R, and 524. The light-emitting unit 512R_2 includes layers 522, 523R, and 524. Additionally, the light-emitting element 550R includes, for example, a layer 525R between the light-emitting unit 512R_2 and the electrode 502. Furthermore, layer 525R can be considered as part of the light-emitting unit 512R_2.

[0062] Layer 521 includes, for example, a layer containing a material with high hole injection capacity (hole injection layer). Layer 522 includes, for example, a layer containing a material with high hole transport capacity (hole transport layer). Layer 524 includes, for example, a layer containing a material with high electron transport capacity (electron transport layer). Layer 525 includes, for example, a layer containing a material with high electron injection capacity (electron injection layer).

[0063] Alternatively, the following structure may be adopted: layer 521 includes an electron injection layer, layer 522 includes an electron transport layer, layer 524 includes a hole transport layer, and layer 525 includes a hole injection layer.

[0064] Between light-emitting unit 512R_1 and light-emitting unit 512R_2, the composition (material, thickness, etc.) of layer 522, light-emitting layer 523R and layer 524 can be the same or different.

[0065] Note that in Figure 2A, layers 521 and 522 are separate, but this is not a limitation. For example, when layer 521 functions as both a hole injection layer and a hole transport layer, or when layer 521 functions as both an electron injection layer and an electron transport layer, layer 522 may be omitted.

[0066] In addition, the intermediate layer 531R has the following functions: when a voltage is applied between electrodes 501 and 502, it injects electrons into one of the light-emitting units 512R_1 and 512R_2, and injects holes into the other of the light-emitting units 512R_1 and 512R_2. The intermediate layer 531R can be referred to as the charge generation layer.

[0067] The above description refers to light-emitting unit 512R, and the same structure can be used for light-emitting units 512G and 512B.

[0068] The light-emitting element 550R includes a light-emitting layer 523R containing a light-emitting material that emits red light; the light-emitting element 550G includes a light-emitting layer 523G containing a light-emitting material that emits green light; and the light-emitting element 550B includes a light-emitting layer 523B containing a light-emitting material that emits blue light. Note that light-emitting elements 550G and 550B have a structure in which the light-emitting layer 523R in light-emitting element 550R is replaced with light-emitting layers 523G and 523B, respectively; other structures are the same as those of light-emitting element 550R.

[0069] The composition (material, thickness, etc.) of layers 521, 522, 524, and 525 can be the same or different among the light-emitting elements of different colors.

[0070] In this specification, a structure in which multiple light-emitting units, such as light-emitting elements 550R, 550G, and 550B, are connected in series with an intermediate layer 531 is referred to as a series structure. Conversely, a structure in which one light-emitting unit is included between a pair of electrodes is referred to as a single structure. While the term "series structure" is used in this specification, it is not limited to this; for example, a series structure may also be referred to as a stacked structure. By employing a series structure, light-emitting elements capable of emitting light with high brightness can be realized. Furthermore, when using a series structure, the current required to obtain the same brightness can be reduced compared to a single structure, thus improving the reliability of the display device.

[0071] In addition, the structure in which light-emitting elements such as 550R, 550G, and 550B each form their own light-emitting layer is sometimes referred to as an SBS structure. In an SBS structure, the materials and structures of each light-emitting element can be optimized separately, increasing the flexibility in material and structure selection and making it easier to improve brightness and reliability.

[0072] The display device 10 of one embodiment of the present invention can be said to have both a series structure and an SBS structure. Therefore, it can simultaneously possess the advantages of both the series structure and the SBS structure. Note that the display device 10 of one embodiment of the present invention has a structure formed by two layers of light-emitting units connected in series as shown in FIG. 2A, so it can be referred to as a two-layer series structure. In addition, in the two-layer series structure shown in FIG. 2A, a second light-emitting unit including a red light-emitting layer is stacked on top of a first light-emitting unit including a red light-emitting layer. Similarly, in the two-layer series structure shown in FIG. 2A, a second light-emitting unit including a green light-emitting layer is stacked on top of a first light-emitting unit including a green light-emitting layer, and a second light-emitting unit including a blue light-emitting layer is stacked on top of a first light-emitting unit including a blue light-emitting layer.

[0073] The light-receiving element 560 includes a light-receiving unit 542 comprising layer 522, a light-receiving layer 543, and a layer 524. The light-receiving unit 542 may also exclude the hole injection layer and the electron injection layer. The composition (material, thickness, etc.) of layers 522 and 524 included in the light-receiving unit 542 may be the same as or different from that of layers 522 and 524 included in the light-emitting unit 512.

[0074] Figure 2B is a modified example of the display device 10 shown in Figure 2A. The display device 10 shown in Figure 2B is an example where, similar to the electrode 502, a common layer 525 is provided between each light-emitting element 550 and between each light-receiving element 560. In this case, layer 525 can be referred to as a common layer. Thus, by providing more than one common layer in each light-emitting element 550 and each light-receiving element 560, the manufacturing process can be simplified, and manufacturing costs can be reduced.

[0075] Here, layer 525 functions as an electron injection layer in the light-emitting element 550. On the other hand, it functions as an electron transport layer in the light-receiving element 560. Therefore, when the display device 10 has the structure shown in FIG. 2B, it is not necessary to provide layer 524, which serves as an electron transport layer, in the light-receiving unit 542.

[0076] The display device 10 shown in Figure 3A is an example of a case where three light-emitting units are stacked. In the light-emitting element 550R of Figure 3A, a light-emitting unit 512R_3 is stacked on top of the light-emitting unit 512R_2, with an intermediate layer 531R in between. The light-emitting unit 512R_3 has the same structure as the light-emitting unit 512R_2. The light-emitting unit 512G_3 included in the light-emitting element 550G and the light-emitting unit 512B_3 included in the light-emitting element 550B are also the same.

[0077] Figure 3B shows an example of a case where n light-emitting units are stacked (n is an integer greater than 2).

[0078] Thus, by increasing the number of light-emitting units stacked together, the brightness obtainable from the light-emitting element with the same current can be increased according to the number of stacked units. In addition, by increasing the number of light-emitting units stacked together, the current required to obtain the same brightness can be reduced, thereby reducing the power consumption of the light-emitting element according to the number of stacked units.

[0079] Figure 4 is a modified example of the display device 10 shown in Figure 2A. The display device 10 shown in Figure 4 is an example where the light-receiving element 560 includes two light-receiving units 542 (light-receiving unit 542_1 and light-receiving unit 542_2). The light-receiving unit 542_1 and the light-receiving unit 542_2 are stacked with an intermediate layer 531PD in between. Note that Figure 4 illustrates a structure with two stacked light-receiving units, but it is not limited to this. For example, a structure with three or more stacked light-receiving units can also be used.

[0080] The display device 10 shown in Figure 5A illustrates an example where two adjacent light-emitting elements are separated, and the electrode 502 is disposed along the side of the light-emitting unit 512, the side of the intermediate layer 531, and the side of the light-receiving unit 542.

[0081] Here, when the intermediate layer 531 and the electrode 502 come into contact, a short circuit may occur. Therefore, it is preferable to insulate the intermediate layer 531 and the electrode 502.

[0082] Figure 5A shows an example in which an insulating layer 541 is provided in such a way that it covers the side surfaces of the electrode 501, each light-emitting unit 512, the side surfaces of the intermediate layer 531, and the side surfaces of the light-receiving unit 542. The insulating layer 541 can be referred to as a sidewall protective layer or a sidewall insulating film, etc. By providing the insulating layer 541, the intermediate layer 531 and the electrode 502 can be electrically insulated.

[0083] Furthermore, the side surfaces of each light-emitting unit 512, the side surfaces of the intermediate layer 531, and the side surfaces of the light-receiving unit 542 are preferably perpendicular or substantially perpendicular to the surface to be formed. For example, the angle formed between the surface to be formed and these side surfaces is preferably 60 degrees or more and 90 degrees or less.

[0084] Figure 5B shows an example where layer 525 and electrode 502 are disposed along the side of light-emitting unit 512, the side of intermediate layer 531, and the side of light-receiving unit 542. Furthermore, a two-layer structure of insulating layer 541 and insulating layer 544 is adopted as the sidewall protective layer.

[0085] Furthermore, Figure 6A is a modified example of Figure 5B. Figure 6B is an enlarged view of region 503 shown in Figure 6A. The end shapes of the insulating layer 544 differ between Figures 6A and 5B. Because the end shapes of the insulating layer 544 are different, the layers 525 and 502 are formed along the shape of the insulating layer 544, and therefore the shapes of the layers 525 and 502 are also different. Additionally, the thicknesses of the insulating layers 541 and 544 differ between Figures 6A and 5B. In Figure 6A, the thickness of the insulating layer 544 is greater than the thickness of the insulating layer 541. The end shape of the insulating layer 544 is circular as shown in Figure 6B. For example, when forming the insulating layer 544, if the top surface of the insulating layer 544 is etched using anisotropic etching via dry etching, the end shape of the insulating layer 544 becomes circular as shown in Figure 6B. By making the end shape of the insulating layer 544 circular, the coverage of the layers 525 and 502 is improved, which is preferable. In addition, as shown in Figures 6A and 6B, when the thickness of the insulating layer 544 is greater than the thickness of the insulating layer 541, the end shape is sometimes easily rounded.

[0086] Since insulating layers 541 and 544, which serve as sidewall protective layers, can prevent short circuits between electrode 502 and intermediate layer 531, and since insulating layers 541 and 544 cover the sides of electrode 501, they can prevent short circuits between electrode 501 and electrode 502, short circuits at the four corners of the light-emitting element can be prevented.

[0087] Insulating layers 541 and 544 are preferably made of inorganic insulating films. For example, films of oxides or nitrides such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, aluminum oxide, aluminum oxynitride, or hafnium oxide can be used. Alternatively, films of yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, or neodymium oxide can also be used.

[0088] The insulating layers 541 and 544 can be formed using various deposition methods, such as sputtering, evaporation, chemical vapor deposition (CVD), and atomic layer deposition (ALD). In particular, ALD causes less deposition damage to the formed layer, so it is preferable to form the insulating layer 541 directly on the light-emitting unit and the intermediate layer 531 using ALD. Furthermore, using sputtering to form the insulating layer 544 improves productivity, making it a preferred method.

[0089] For example, an aluminum oxide film formed by the ALD method can be used as the insulating layer 541, and a silicon nitride film formed by sputtering can be used as the insulating layer 544.

[0090] Furthermore, either or both of insulating layers 541 and 544 are preferably used as a barrier insulating film against at least one of water and oxygen. Alternatively, either or both of insulating layers 541 and 544 are preferably used to inhibit the diffusion of at least one of water and oxygen. Alternatively, either or both of insulating layers 541 and 544 are preferably used to trap or fix (also known as gettering) at least one of water and oxygen.

[0091] In this specification, the term "barrier insulating film" refers to an insulating film that possesses barrier properties. Furthermore, in this specification, "barrier property" refers to the function of inhibiting the diffusion of the corresponding substance (or, in other words, low permeability). Alternatively, it refers to the function of capturing or fixing (also known as gettering) the corresponding substance.

[0092] When either or both of insulating layers 541 and 544 have the function of acting as a barrier insulating film or a gettering function, the entry of impurities (typically water or oxygen) that may diffuse from the outside into each light-emitting element can be suppressed. By adopting this structure, a highly reliable display device can be provided.

[0093] Furthermore, as shown in FIG6C, the display device 10 may also exclude the insulating layer 541 and insulating layer 544 used as sidewall protective layers. In FIG6C, layer 525 is provided in contact with the side surfaces of each light-emitting unit 512, the side surface of the intermediate layer 531, and the side surface of the light-receiving unit 542.

[0094] <Example of a light-emitting element's structure> Depending on the materials constituting the light-emitting layer 523, the light-emitting color of each light-emitting element can be red, green, blue, cyan, magenta, yellow, or white. Furthermore, by giving the light-emitting element a microcavity structure, color purity can be further improved.

[0095] When using a light-emitting element that emits white light, it is preferable to have a structure in which the light-emitting layer contains two or more light-emitting materials. To obtain white light emission, two or more light-emitting materials whose light emission is complementary in color can be selected. For example, by making the light emission color of the first light-emitting layer complementary to the light emission color of the second light-emitting layer, a light-emitting element that emits white light throughout can be obtained. Furthermore, the same applies to light-emitting elements that include three or more light-emitting layers.

[0096] The luminescent layer preferably contains two or more luminescent materials, each exhibiting an luminescence of R (red), G (green), B (blue), Y (yellow), or O (orange).

[0097] Here, specific examples of the layers of a light-emitting element are given.

[0098] A light-emitting element includes at least a light-emitting layer. As a layer other than the light-emitting layer, the light-emitting element may also include a layer containing a material with high hole injection capacity, a material with high hole transport capacity, a hole blocking material, a material with high electron transport capacity, an electron blocking material, a material with high electron injection capacity, or a bipolar material (a material with both high electron transport capacity and high hole transport capacity).

[0099] Light-emitting elements can use low-molecular-weight compounds or high-molecular-weight compounds, and may also include inorganic compounds. The layers constituting the light-emitting element can be formed by methods such as vapor deposition (including vacuum vapor deposition), transfer printing, printing, inkjet printing, or coating.

[0100] For example, a light-emitting element may include one or more of a hole injection layer, a hole transport layer, a hole barrier layer, an electron barrier layer, an electron transport layer, and an electron injection layer.

[0101] A hole injection layer is a layer containing a material with high hole injection capability that allows holes to be injected from the anode into the hole transport layer. Examples of materials with high hole injection capability include aromatic amine compounds and composite materials containing both hole transport and acceptor materials (electron acceptor materials).

[0102] The hole transport layer is the layer through which holes injected from the anode via the hole injection layer are transported to the light-emitting layer. The hole transport layer contains a hole-transporting material. Preferably, the hole-transporting material is a substance with a hole mobility of 1 × 10⁻⁶ cm² / Vs or higher. Note that any other material can be used as long as its hole transportability is higher than its electron transportability. Preferably, the hole transporting material is a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, or a furan derivative) or an aromatic amine (a compound containing an aromatic amine skeleton), which are materials with high hole transportability.

[0103] The electron transport layer is the layer that transports electrons injected from the cathode through the electron injection layer to the light-emitting layer. The electron transport layer contains an electron transport material. Preferably, the electron transport material is a substance with an electron mobility of 1 × 10⁻⁶ cm² / Vs or higher. Note that any other material can be used as long as its electron transport capability is higher than its hole transport capability. Materials with high electron transport capabilities include metal complexes containing a quinoline skeleton, metal complexes containing a benzoquinoline skeleton, metal complexes containing a chloroazole skeleton, metal complexes containing a thiazole skeleton, chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole derivatives, thiazole derivatives, phenocyanate derivatives, quinoline derivatives containing quinoline ligands, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, or nitrogen-containing heteroaromatic compounds and other π-electron-deficient heteroaromatic compounds.

[0104] The electron injection layer is a layer containing a material with high electron injection capability, through which electrons are injected from the cathode into the electron transport layer. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capability. Composite materials containing both electron transport materials and donor materials (electron donor materials) can also be used as materials with high electron injection capability.

[0105] As the electron injection layer, alkali metals, alkaline earth metals, or compounds thereof, such as lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaFx, where X is any number), lithium 8-(hydroxyoxoline) (Liq), lithium 2-(2-pyridyl)phenol (LiPP), lithium 2-(2-pyridyl)-3-hydroxypyridinolato (LiPPy), lithium 4-phenyl-2-(2-pyridyl)phenol (LiPPP), lithium oxide (LiOx), or cesium carbonate, can be used. Furthermore, the electron injection layer can also have a stacked structure of two or more layers. For example, a structure using lithium fluoride as the first layer and ytterbium as the second layer can be used.

[0106] Alternatively, materials with electron transport properties can be used as the aforementioned electron injection layer. For example, compounds having non-shared electron pairs and electron-deficient heteroaromatic rings can be used as electron transport materials. Specifically, compounds having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyrazine ring), and a triazine ring can be used.

[0107] Furthermore, the lowest unoccupied molecular orbital (LUMO) of organic compounds with non-shared electron pairs is preferably above -3.6 eV and below -2.3 eV. Generally, cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy can be used to estimate the highest occupied molecular orbital (HOMO) and LUMO levels of organic compounds.

[0108] For example, as organic compounds with non-shared electron pairs, 4,7-diphenyl-1,10-phenanthroline (BPhen), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBPhen), diquinoline[2,3-a:2',3'-c]phenazine (HATNA), or 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (TmPPPyTz) can be used. Furthermore, compared to BPhen, NBPhen has a higher glass transition temperature (Tg), thus exhibiting higher heat resistance.

[0109] The luminescent layer is a layer containing a luminescent substance. The luminescent layer may include one or more luminescent substances. Suitable luminescent substances are those emitting blue, purple, blue-violet, green, yellow-green, yellow, orange, or red light. Alternatively, substances emitting near-infrared radiation may also be used as luminescent substances.

[0110] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0111] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fumonisin derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoline derivatives, quinoline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, or naphthalene derivatives.

[0112] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (especially iridium complexes) with phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; or rare earth metal complexes.

[0113] In addition to the luminescent material (guest material), the luminescent layer may also contain one or more organic compounds (host material, auxiliary material, etc.). As one or more organic compounds, one or both of hole-transporting materials and electron-transporting materials can be used. Furthermore, bipolar materials or TADF materials can also be used as one or more organic compounds.

[0114] For example, the luminescent layer is preferably a combination of a phosphorescent material, a hole-transporting material that readily forms excited-state complexes, and an electron-transporting material. By employing such a structure, ExTET (Exciplex-Triplet Energy Transfer) luminescence, utilizing energy transfer from the excited-state complex to the luminescent material (phosphorescent material), can be efficiently obtained. Furthermore, by selecting and combining excited-state complexes that emit light with wavelengths overlapping the absorption band of the lowest energy side of the luminescent material, energy transfer can be facilitated, thereby achieving efficient luminescence. By employing the above structure, high efficiency, low-voltage operation, and long lifetime of the luminescent element can be simultaneously achieved.

[0115] As an intermediate layer, materials suitable for use in electron injection layers, such as lithium, can be appropriately used. Alternatively, materials suitable for use in hole injection layers can be appropriately used. Furthermore, a layer comprising both a hole-transporting material and an acceptor material (electron-receiving material) can be used as an intermediate layer. Additionally, a layer comprising both an electron-transporting material and a donor material can be used as an intermediate layer. By forming an intermediate layer including such a layer, the rise in driving voltage in the case of stacked light-emitting units can be suppressed.

[0116] In the display device 10 shown in FIG2A, there are no particular restrictions on the light-emitting material of the light-emitting layer. For example, the display device 10 shown in FIG2A can adopt the following structure: the light-emitting layer 523R included in the light-emitting unit 512R_1 contains phosphorescent material, the light-emitting layer 523R included in the light-emitting unit 512R_2 contains phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_1 contains fluorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_2 contains fluorescent material, the light-emitting layer 523B included in the light-emitting unit 512B_1 contains fluorescent material, and the light-emitting layer 523B included in the light-emitting unit 512B_2 contains fluorescent material.

[0117] Alternatively, the display device 10 shown in FIG2A may adopt the following structure: the light-emitting layer 523R included in the light-emitting unit 512R_1 contains phosphorescent material, the light-emitting layer 523R included in the light-emitting unit 512R_2 contains phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_1 contains phosphorescent material, the light-emitting layer 523G included in the light-emitting unit 512G_2 contains phosphorescent material, the light-emitting layer 523B included in the light-emitting unit 512B_1 contains fluorescent material, and the light-emitting layer 523B included in the light-emitting unit 512B_2 contains fluorescent material.

[0118] Furthermore, the display device of one embodiment of the present invention may also have the following structure: all light-emitting layers in the display device 10 shown in FIG. 2A are fluorescent materials; or all light-emitting layers in the display device 10 shown in FIG. 2A are phosphorescent materials.

[0119] Alternatively, the display device according to one embodiment of the present invention may also have the following structure: In the display device 10 shown in FIG. 2A, the light-emitting layer 523R included in the light-emitting unit 512R_1 is a phosphorescent material and the light-emitting layer 523R included in the light-emitting unit 512R_2 is a fluorescent material; or the light-emitting layer 523R included in the light-emitting unit 512R_1 is a fluorescent material and the light-emitting layer 523R included in the light-emitting unit 512R_2 is a phosphorescent material. That is, the light-emitting material used for the first light-emitting layer and the light-emitting material used for the second light-emitting layer have different structures. Note that the description here refers to the light-emitting units 512R_1 and 512R_2, but the same structure can be used for the light-emitting units 512G_1 and 512G_2, and the light-emitting units 512B_1 and 512B_2.

[0120] <Example of a light-receiving element structure> The light-receiving element 560 includes a light-receiving layer 543 comprising a semiconductor. Examples of such semiconductors include inorganic semiconductors such as silicon and organic semiconductors containing organic compounds. In this embodiment, an example is shown where an organic semiconductor is used as the semiconductor contained in the light-receiving layer 543. Because an organic semiconductor is used, the light-emitting layer 523 and the light-receiving layer 543 can be formed using the same method (e.g., vacuum evaporation) and can share the same manufacturing equipment, which is preferable.

[0121] Materials that can be used as n-type semiconductors in the light-receiving layer 543 include fullerenes (e.g., C60 or C70) or fullerene derivatives, which are organic semiconductors with electron-accepting properties. Fullerenes have a soccer ball shape, which is energy stable. Fullerenes have deep (low) HOMO and LUMO energy levels. Because of the deep LUMO energy level of fullerenes, their electron-accepting properties are extremely high. Generally, when π-electron conjugation (resonance) extends in a plane, as in benzene, electron donor properties become high. On the other hand, fullerenes have a spherical shape, and although π-electrons extend widely, their electron-accepting properties are high. With high electron-accepting properties, charge separation is induced quickly and efficiently, which is beneficial for light-receiving elements. Both C60 and C70 have broad absorption bands in the visible light region, especially C70, which has a larger π-electron conjugation class than C60 and also has a broad absorption band in the long wavelength region, making it superior. In addition, examples of fullerene derivatives include methyl [6,6]-phenyl-C71-butyrate (abbreviated as PC70BM), methyl [6,6]-phenyl-C61-butyrate (abbreviated as PC60BM), or 1',1'',4',4''-tetrahydro-bis[1,4]methanenaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C60 (abbreviated as ICBA).

[0122] Materials that can be used as n-type semiconductors include metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, metal complexes with a chloroazole skeleton, metal complexes with a thiazole skeleton, chlorodiazole derivatives, triazole derivatives, imidazole derivatives, chloroazole derivatives, thiazole derivatives, phenoline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoline derivatives, dibenzoquinoline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, or quinone derivatives, etc.

[0123] Examples of p-type semiconductor materials contained in the light-receiving layer 543 include copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), or quinacridone, which are organic semiconductor materials with electronic donor properties.

[0124] Furthermore, examples of materials that can be used as p-type semiconductors include carbazole derivatives, thiophene derivatives, furan derivatives, or compounds with an aromatic amine skeleton. Additionally, examples of materials that can be used as p-type semiconductors include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, benzo[a]furan derivatives, benzo[a]thiophene derivatives, indole derivatives, dibenzo[a]furan derivatives, dibenzo[a]thiophene derivatives, indole-carbazole derivatives, violet derivatives, phthalocyanine derivatives, naphthylphthalocyanine derivatives, quinacridone derivatives, polyphenylene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, poly[a]benzene oxide derivatives, polyvinylcarbazole derivatives, or polythiophene derivatives.

[0125] The HOMO energy level of organic semiconductor materials with electron donor properties is preferably shallower (higher) than that of organic semiconductor materials with electron acceptor properties. Similarly, the LUMO energy level of organic semiconductor materials with electron donor properties is preferably shallower (higher) than that of organic semiconductor materials with electron acceptor properties.

[0126] Preferably, spherical fullerenes are used as organic semiconductor materials with electron-accepting properties, and even more preferably, organic semiconductor materials with shapes similar to planar structures are used as organic semiconductor materials with electron-donating properties. Molecules with similar shapes tend to aggregate easily, and when the same type of molecules aggregate, the carrier transport can be improved because the energy levels of the molecular orbitals are similar.

[0127] For example, the light-receiving layer 543 is preferably formed by co-depositing an n-type semiconductor and a p-type semiconductor. Alternatively, the light-receiving layer 543 may also be formed by stacking an n-type semiconductor and a p-type semiconductor.

[0128] <Example of the top surface structure of a display device> Figure 7A is a top view showing a structural example of the display device 10. The display device 10 includes multiple light-emitting elements 550R that emit red light, multiple light-emitting elements 550G that emit green light, multiple light-emitting elements 550B that emit blue light, and multiple light-receiving elements 560. In Figure 7A, to facilitate the distinction between each light-emitting element 550, the symbols "R", "G", and "B" are affixed to the light-emitting area of ​​each light-emitting element 550. Additionally, the symbol "PD" is affixed to the light-receiving area of ​​each light-receiving element 560.

[0129] The light-emitting elements 550R, 550G, 550B, and light-receiving elements 560 are arranged in a matrix. Figure 7A shows an example of light-emitting elements 550R, 550G, and 550B arranged in the X direction, with light-receiving elements 560 arranged below them. As an example, Figure 7A shows a structure in which light-emitting elements 550 emit light of the same color in the Y direction, which intersects the X direction. In the display device 10 shown in Figure 7A, for example, a pixel 20 can be formed by sub-pixels including light-emitting elements 550R, sub-pixels including light-emitting elements 550G, and sub-pixels including light-emitting elements 550B arranged in the X direction, and sub-pixels including light-receiving elements 560 disposed below these sub-pixels.

[0130] Figure 7A shows the connecting electrode 501C. The connecting electrode 501C is disposed on the outside of the display section where the light-emitting element 550 and the light-receiving element 560 are arranged.

[0131] The connecting electrode 501C can also be provided along the outer periphery of the display unit. For example, the connecting electrode 501C can be provided along one side of the outer periphery of the display unit, or along two or more sides of the outer periphery of the display unit. In other words, when the top surface of the display unit is rectangular, the top surface shape of the connecting electrode 501C can be strip-shaped, L-shaped, C-shaped (square bracket-shaped), or frame-shaped, etc.

[0132] Figure 7B is a top view showing a structural example of the display device 10, and is also a modified example of the display device 10 shown in Figure 7A. The difference between the display device 10 shown in Figure 7B and the display device 10 shown in Figure 7A is that it includes a light-emitting element 550IR that emits infrared light. The light-emitting element 550IR can, for example, emit near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less).

[0133] In the example shown in Figure 7B, light-emitting elements 550IR are arranged in the X direction, except for light-emitting elements 550R, 550G, and 550B, and light-receiving elements 560 are arranged below them. In addition, the light-receiving elements 560 have the function of detecting infrared light.

[0134] Figure 8A is a top view showing a structural example of the display device 10, and is also a modified example of the display device 10 shown in Figure 7B. The difference between the display device 10 shown in Figure 8A and the display device 10 shown in Figure 7B is that the light-receiving element 560 and the light-emitting element 550IR are arranged alternately in the X direction.

[0135] In the display device 10 shown in FIG8A, light-emitting elements 550R, 550G, and 550B are arranged in different rows from light-emitting element 550IR. Therefore, the width (length in the X direction) of light-emitting elements 550R, 550G, and 550B can be increased, thereby improving the brightness of the light emitted by pixel 20.

[0136] Figure 8B is a top view showing a structural example of the display device 10, and is also a variation of the display device 10 shown in Figure 8A. The display device 10 shown in Figure 8B differs from the display device 10 shown in Figure 8A in that the light-emitting elements 550 are arranged in the X direction in the order G, B, R, instead of in the order R, G, B. Furthermore, unlike the display device 10 shown in Figure 8A, the light-receiving element 560 is disposed below the light-emitting elements 550G and 550B, and the light-emitting element 550IR is disposed below the light-emitting element 550R.

[0137] The area occupied by the light-receiving element 560 in the display device 10 shown in Figure 8B is larger than that of the light-receiving element 560 in the display device 10 shown in Figure 8A. Therefore, the sensitivity of light detection using the light-receiving element 560 can be improved. Thus, for example, when the display device 10 is used as a touch sensor or a near-touch sensor, the display device 10 can detect objects in contact or near with high accuracy. In particular, when the display device 10 is used as a near-touch sensor, the sensitivity of light detection using the light-receiving element 560 has a significant impact on the accuracy of object detection; therefore, the larger the area occupied by the light-receiving element 560, the better.

[0138] Figure 9A is a top view showing a structural example of the display device 10, and is also a modified example of the display device 10 shown in Figure 8B. The difference between the display device 10 shown in Figure 9A and the display device 10 shown in Figure 8B is that the light-receiving element 560 is disposed below the light-emitting element 550G, and the light-emitting element 550IR is disposed below the light-emitting elements 550B and 550R.

[0139] The area occupied by the light-receiving element 560 in the display device 10 shown in Figure 9A is smaller than that occupied by the light-receiving element 560 in the display device 10 shown in Figure 8B. By reducing the area occupied by the light-receiving element 560, the light-receiving range of each light-receiving element 560 can be reduced. This reduces the overlap of light-receiving ranges between different light-receiving elements 560, such as between adjacent light-receiving elements 560. Therefore, blurring that prevents clear images from being captured using the light-receiving element 560 can be suppressed. Thus, when the display device 10 has a recognition function such as fingerprint recognition, reducing the area occupied by the light-receiving element 560 allows for clearer fingerprint capture, improving recognition accuracy, which is preferable.

[0140] Figure 9B is a cross-sectional view showing the change in the light-receiving range of the light-receiving element 560 when its occupied area is changed, specifically its length in the X direction. In Figure 9B, the light-receiving element 560 on the bottom side of layer 71 and the light-shielding layer 73 on the top side of layer 71 are shown. The substrate 59 on layer 71 is also shown. Furthermore, a light-receiving element whose length in the X direction is approximately three times that of the light-receiving element 560 is designated as light-receiving element 560L.

[0141] In Figure 9B, the light incident on the light-receiving element 560 is denoted as light 75 and represented by a solid line. Light that does not incident on the light-receiving element 560 but does incident on the light-receiving element 560L is denoted as light 77 and represented by a dashed line. Furthermore, the light-receiving range of each light-receiving element 560 is denoted as light-receiving range 80, and the light-receiving range of each light-receiving element 560L is denoted as light-receiving range 81.

[0142] As shown in Figure 9B, the light-receiving range 80 of the light-receiving element 560 is smaller than the light-receiving range 81 of the light-receiving element 560L. That is, the smaller the area occupied by the light-receiving element, the smaller the light-receiving range of each light-receiving element, and the less overlap there is between the light-receiving ranges of different light-receiving elements. Figure 9B shows an example where, on the surface of the substrate 59, the light-receiving ranges 80 of adjacent light-receiving elements 560 do not overlap, while a portion of the light-receiving ranges 81 of adjacent light-receiving elements 560L overlap.

[0143] Figure 10 is a top view showing a structural example of the display device 10, and is also a modified example of the display device 10 shown in Figure 7A. The difference between the display device 10 shown in Figure 10 and the display device 10 shown in Figure 7A is that the light-receiving element 560 is provided only in a portion of the pixels 20.

[0144] When the display device 10 has the structure shown in FIG. 10, the driving frequency of the display device 10 can be increased. Therefore, for example, when the display device 10 is used as a touch sensor or a near touch sensor, the position of an object touching or approaching the display device 10 can be detected quickly. Therefore, for example, the movement of an object touching or approaching the display device 10 can be detected with high speed and high accuracy.

[0145] <Example of a cross-sectional structure of a display device> Figure 11A is a cross-sectional view corresponding to the dashed lines A1-A2 in Figure 7A, and Figure 11B is a cross-sectional view corresponding to the dashed lines B1-B2 in Figure 7A. Furthermore, Figure 11C is a cross-sectional view corresponding to the dashed lines C1-C2 in Figure 7A, and Figure 11D is a cross-sectional view corresponding to the dashed lines D1-D2 in Figure 7A. Finally, Figure 11E is a cross-sectional view corresponding to the dashed lines B3-B4 in Figure 8A. Figures 11A to 11E illustrate a structural example corresponding to Figure 2A.

[0146] Light-emitting elements 550R, 550G, 550B, and light-receiving element 560 are disposed on substrate 101. Additionally, when the display device 10 includes light-emitting element 550IR, light-emitting element 550IR is disposed on substrate 101.

[0147] In this specification, etc., when it is described, for example, as "B on A" or "B under A", it is not necessarily required to have an area where A and B are in contact.

[0148] Figure 11A shows an example of the cross-sectional structure of light-emitting elements 550R, 550G, and 550B. Figure 11B shows an example of the cross-sectional structure of light-receiving element 560.

[0149] As described above, the light-emitting element 550R includes an electrode 501R, a light-emitting unit 512R_1, an intermediate layer 531R, a light-emitting unit 512R_2, a layer 525R, and an electrode 502. The light-emitting element 550G includes an electrode 501G, a light-emitting unit 512G_1, an intermediate layer 531G, a light-emitting unit 512G_2, a layer 525G, and an electrode 502. The light-emitting element 550B includes an electrode 501B, a light-emitting unit 512B_1, an intermediate layer 531B, a light-emitting unit 512B_2, a layer 525B, and an electrode 502. The light-receiving element 560 includes an electrode 501PD, a light-receiving unit 542, and an electrode 502.

[0150] A gap is provided between the electrode 502 and the insulating layer 131. This prevents the electrode 502 from contacting the side of the light-emitting unit 512 and the side of the light-receiving unit 542. This also prevents short circuits in the light-emitting element 550 and the light-receiving element 560.

[0151] For example, the shorter the distance between the light-emitting units 512, the easier it is to form the aforementioned gap. For example, by setting the distance to 1 μm or less, preferably 500 nm or less, more preferably 200 nm or less, 100 nm or less, 90 nm or less, 70 nm or less, 50 nm or less, 30 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less, the aforementioned gap can be appropriately formed.

[0152] An insulating layer 131 is provided to cover the ends of electrodes 501R, 501G, 501B, and 501PD. The ends of the insulating layer 131 are preferably tapered. If not required, the insulating layer 131 can be omitted.

[0153] For example, the light-emitting unit 512R_1, the light-emitting unit 512G_1, the light-emitting unit 512B_1, and the light-receiving unit 542 all have a region that contacts the top surface of the electrode 501 and a region that contacts the surface of the insulating layer 131. In addition, the ends of the light-emitting unit 512R_1, the light-emitting unit 512G_1, the light-emitting unit 512B_1, and the light-receiving unit 542 are located on the insulating layer 131.

[0154] As shown in Figure 11A, gaps are provided between light-emitting elements 550 that emit different colors of light, for example, between two light-emitting units 512. Thus, it is preferable, for example, that light-emitting units 512R_1, 512G_1, and 512B_1 are arranged so that they do not contact each other. Similarly, it is preferable, for example, that light-emitting units 512R_2, 512G_2, and 512B_2 are arranged so that they do not contact each other. This appropriately prevents unintentional light emission caused by current flowing through adjacent light-emitting units 512. Therefore, the contrast ratio of the display device 10 can be improved, thereby improving the display quality of the display device 10.

[0155] A protective layer 125 is provided on the electrode 502. The protective layer 125 has the function of allowing impurities such as water to diffuse from above to the light-emitting element 550 and the light-receiving element 560.

[0156] The protective layer 125 can, for example, be a single-layer structure or a multilayer structure comprising at least an inorganic insulating film. Examples of inorganic insulating films include oxide films and nitride films such as silicon oxide films, silicon oxynitride films, silicon oxynitride films, silicon nitride films, aluminum oxide films, aluminum oxynitride films, and hafnium oxide films. Alternatively, semiconductor materials such as indium gallium oxide or indium gallium zinc oxide can also be used as the protective layer 125.

[0157] In this specification, "silicon oxynitride membrane" refers to a membrane in which the oxygen content is greater than the nitrogen content. "Silicon oxynitride membrane" refers to a membrane in which the nitrogen content is greater than the oxygen content.

[0158] Alternatively, the protective layer 125 can be a laminated film of inorganic and organic insulating films. For example, it is preferable to have a structure in which an organic insulating film is sandwiched between a pair of inorganic insulating films. Furthermore, the organic insulating film is preferably used as a planarization film. This allows for a flat top surface of the organic insulating film, improving the coverage of the inorganic insulating film thereon and enhancing its barrier properties. In addition, because the top surface of the protective layer 125 is flat, it is preferable to mitigate the influence of the uneven shape of the underlying structure when structures (e.g., color filters, electrodes of touch sensors, or lens arrays) are placed above the protective layer 125.

[0159] Figure 11C shows an example of a cross-sectional structure of the display device 10 in the Y direction, specifically showing an example of a cross-sectional structure of the light-emitting element 550R and the light-receiving element 560. Furthermore, the light-emitting elements 550G and 550B may also be arranged in the Y direction in the same manner as the light-emitting element 550R.

[0160] Figure 11D shows a connection portion 130 that electrically connects electrode 501C and electrode 502. In the connection portion 130, electrode 502 is disposed in contact with electrode 501C, and a protective layer 125 is provided to cover electrode 502. Additionally, an insulating layer 131 is provided to cover the end of electrode 501C.

[0161] In Figure 11E, in addition to the example of the cross-sectional structure of the light-receiving element 560, an example of the cross-sectional structure of the light-emitting element 550IR is also shown. The light-emitting element 550IR includes an electrode 501IR, a light-emitting unit 512IR_1, an intermediate layer 531IR, a light-emitting unit 512IR_2, a layer 525IR, and an electrode 502.

[0162] The light-emitting element 550IR includes light-emitting units 512IR_1 and 512IR_2, which contain luminescent organic compounds that emit light with intensity in at least the wavelength range of infrared light. For example, light-emitting units 512IR_1 and 512IR_2 contain luminescent organic compounds that emit light with intensity in the wavelength range of near-infrared light. When the display device 10 includes the light-emitting element 550IR, the light-receiving unit 542 included in the light-receiving element 560 contains, for example, an organic compound that has detection sensitivity in the wavelength range of infrared light, such as near-infrared light.

[0163] <Example of a manufacturing method for a display device> Hereinafter, an example of a method for manufacturing a display device according to an embodiment of the present invention will be described with reference to the drawings. The manufacturing method of the display device 10 shown in FIG7A and FIG11A to FIG11D will be described as an example. FIG12A to FIG15C are schematic cross-sectional views of each process of the manufacturing method of the display device illustrated below. FIG12A to FIG15C show cross-sections corresponding to dashed lines A1-A2, B1-B2, and D1-D2 in FIG7A.

[0164] Thin films (insulating films, semiconductor films, and conductive films, etc.) constituting display devices can be formed using methods such as sputtering, CVD, vacuum evaporation, pulsed laser deposition (PLD), or ALD. CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Furthermore, metal-organic chemical vapor deposition (MOCVD) is one type of thermal CVD method.

[0165] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet coating, distributor coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, or doctor knife coating.

[0166] Furthermore, when processing the thin film constituting the display device, methods such as photolithography can be used. In addition, methods such as nanoimprinting, sandblasting, or peeling can also be used to process the thin film.

[0167] Photolithography typically involves two methods. One method involves forming a photoresist mask on the thin film to be processed, for example, by etching the film and then removing the photoresist mask. The other method involves depositing a photosensitive thin film and then exposing and developing it to process the film into the desired shape.

[0168] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm), or a mixture of these. Additionally, ultraviolet light, KrF lasers, or ArF lasers can also be used. Furthermore, immersion exposure techniques can be employed. Extreme ultraviolet (EUV) light or X-rays can also be used as the light for exposure. Electron beams can also be used instead of the light used for exposure. When using EUV light, X-rays, or electron beams, extremely fine processing can be achieved, making them preferable. Furthermore, when exposure is performed by scanning with a beam such as an electron beam, a photomask is not required.

[0169] In thin film etching, dry etching, wet etching, or sandblasting methods can be used.

[0170] To manufacture the display device 10, a substrate 101 is first prepared. The substrate 101 can be a substrate with heat resistance sufficient to withstand subsequent heat treatment. When using an insulating substrate as the substrate 101, a glass substrate, quartz substrate, sapphire substrate, ceramic substrate, or organic resin substrate can be used. Furthermore, semiconductor substrates such as single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of silicon or silicon carbide, compound semiconductor substrates made of silicon or germanium, or SOI substrates can also be used.

[0171] Next, electrodes 501R, 501G, 501B, 501PD, and a connecting electrode 501C are formed on the substrate 101. First, a conductive film is deposited, and a photoresist mask is formed by photolithography. Unwanted portions of the conductive film are removed by etching. Then, the photoresist mask is removed, thereby forming electrodes 501R, 501G, and 501B.

[0172] When a conductive film that is reflective to visible light is used as the aforementioned conductive film, it is preferable to use a material with the highest possible reflectivity across the entire wavelength range of visible light (e.g., silver or aluminum). This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0173] Next, an insulating layer 131 (FIG. 12A) is formed to cover the ends of electrodes 501R, 501G, 501B, and 501PD. An organic or inorganic insulating film can be used as the insulating layer 131. The ends of the insulating layer 131 are preferably tapered to improve the step coverage of the subsequent film. In particular, when using an organic insulating film, a photosensitive material is preferred, thereby making it easier to control the end shape according to the exposure and development conditions. An inorganic insulating film can also be used as the insulating layer 131. By using an inorganic insulating film as the insulating layer 131, the display device 10 can be a high-definition display device.

[0174] Next, layer 512Rf_1, which will later become light-emitting unit 512R_1, is formed on electrodes 501R, 501G, 501B, 501PD, and insulating layer 131. Specifically, a film that will later become layer 521, a film that will later become layer 522, a light-emitting film that will later become light-emitting layer 523R, and a film that will later become layer 524 are deposited sequentially. Then, an intermediate film 531Rf, which will later become intermediate layer 531R, is deposited on layer 512Rf_1.

[0175] Next, layer 512Rf_2, which will later become light-emitting unit 512R_2, is formed on the intermediate film 531Rf. Specifically, a film that will later become layer 522, a light-emitting film that will later become light-emitting layer 523R, and a film that will later become layer 524 are deposited sequentially. Then, film 525Rf, which will later become layer 525R, is deposited on layer 512Rf_2.

[0176] The film included in layer 512Rf_1, the intermediate film 531Rf, the film included in layer 512Rf_2, and the film 525Rf can be formed, for example, by vapor deposition, sputtering, or inkjet printing. Note that this is not a limitation, and the above-mentioned deposition methods can be appropriately utilized.

[0177] Layer 512Rf_1, intermediate film 531Rf, layer 512Rf_2, and film 525Rf are preferably formed without being disposed on the connecting electrode 501C. For example, when the film included in layer 512Rf_1, intermediate film 531Rf, film included in layer 512Rf_2, and film 525Rf are formed by vapor deposition or sputtering, it is preferable to form them using a shadow mask to prevent the film included in layer 512Rf_1, intermediate film 531Rf, film included in layer 512Rf_2, and film 525Rf from depositing on the connecting electrode 501C.

[0178] Next, a sacrificial film 141a is deposited on the film 525Rf. Furthermore, the sacrificial film 141a can be positioned in contact with the top surface of the connecting electrode 501C.

[0179] The sacrificial film 141a can be a film with high resistance to etching of the films included in film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1, i.e., a film with a large etching selectivity. Furthermore, the sacrificial film 141a can be a film with a large etching selectivity compared to protective films such as protective film 143a described later. Moreover, the sacrificial film 141a can be a film that can be removed by wet etching with minimal damage to the films included in film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1.

[0180] The sacrificial film 141a can be an inorganic film, such as a metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film. Alternatively, the sacrificial film 141a can be formed using various deposition methods such as sputtering, evaporation, CVD, or ALD.

[0181] As the sacrificial film 141a, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing such metallic materials, can be used. Low-melting-point materials such as aluminum or silver are particularly preferred.

[0182] Alternatively, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also denoted as IGZO) can be used as the sacrificial film 141a. Furthermore, indium oxide, indium zinc oxide (In-Zn oxide), indium tin oxide (In-Sn oxide), indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), or indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide) can be used. Alternatively, silicon-containing indium tin oxide can also be used.

[0183] Note that this can also be used in cases where element M (selected from one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used to replace gallium.

[0184] In addition, inorganic insulating materials such as alumina, hafnium oxide, or silicon oxide can be used as the sacrificial membrane 141a.

[0185] As the sacrificial membrane 141a, it is preferable to use a material that is soluble in a solvent that is chemically stable at least relative to membrane 525Rf. In particular, materials soluble in water or alcohol can be suitably used for the sacrificial membrane 141a. When depositing the sacrificial membrane 141a, it is preferable to coat the sacrificial membrane 141a by a wet deposition method in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, it is preferable to perform the heat treatment under a reduced pressure atmosphere, thereby removing the solvent at a low temperature and for a short time, and reducing the thermal damage to membrane 525Rf, layer 512Rf_2, intermediate membrane 531Rf, and layer 512Rf_1.

[0186] Wet deposition methods that can be used to form sacrificial films 141a include spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, flatbed printing, doctor knife coating, slot coating, roller coating, curtain coating, or doctor knife coating.

[0187] As the sacrificial membrane 141a, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.

[0188] Next, a protective film 143a is formed on the sacrificial film 141a (Fig. 12B).

[0189] The protective film 143a is used as a hard mask during subsequent etching of the sacrificial film 141a. Furthermore, during the processing of the protective film 143a, the sacrificial film 141a is exposed. Therefore, a combination of films with a high etching selectivity is selected as both the sacrificial film 141a and the protective film 143a. Thus, the film suitable for use as the protective film 143a can be selected based on the etching conditions of both the sacrificial film 141a and the protective film 143a.

[0190] For example, when dry etching using a fluorine-containing gas (also known as a fluorine-based gas) is used for etching as the protective film 143a, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, alloys containing molybdenum and niobium, or alloys containing molybdenum and tungsten can be used as the protective film 143a. Here, as a film with a large etching selectivity relative to the aforementioned dry etching using fluorine-based gases (in other words, a slower etching rate), such as metal oxide films like IGZO or ITO, the aforementioned films can be used as the sacrificial film 141a.

[0191] Note that, not limited to this, the protective film 143a can be selected from various materials depending on the etching conditions of both the sacrificial film 141a and the protective film 143a. For example, it can also be selected from films that can be used for the sacrificial film 141a described above.

[0192] Alternatively, a nitride film can be used as the protective film 143a, for example. Specifically, nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride can also be used.

[0193] Alternatively, an oxide film can be used as the protective film 143a. Typically, oxide films or oxynitride films such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0194] Next, photoresist shields 145a are formed on the protective film 143a at the position overlapping with the electrode 501R and at the position overlapping with the connecting electrode 501C, respectively (Fig. 12C).

[0195] The photoresist mask 145a can be a photoresist material containing a photosensitive resin, such as a positive photoresist material or a negative photoresist material.

[0196] Here, when a photoresist mask 145a is formed on the sacrificial film 141a without forming a protective film 143a, if there are defects such as pinholes in the sacrificial film 141a, the film 525Rf may dissolve due to the solvent of the photoresist material. By using the protective film 143a, this defect can be prevented.

[0197] When a film that is not prone to defects such as pinholes is used as the sacrificial film 141a, a photoresist mask 145a can be formed directly on the sacrificial film 141a without using a protective film 143a.

[0198] Next, the portion of the protective film 143a not covered by the photoresist mask 145a is removed by etching to form a protective layer 149a. At the same time, a protective layer 149a is also formed on the connecting electrode 501C.

[0199] When etching the protective film 143a, it is preferable to use etching conditions with a high selectivity to prevent the sacrificial film 141a from being removed by the etching. The etching of the protective film 143a can be performed using wet etching or dry etching, but by using dry etching, the pattern shrinkage of the protective film 143a can be suppressed.

[0200] Next, the photoresist mask 145a is removed (Fig. 12D).

[0201] The removal of the photoresist mask 145a can be performed using wet etching or dry etching. It is particularly preferred to remove the photoresist mask 145a using dry etching (also known as plasma ashing) that uses oxygen gas as the etching gas.

[0202] At this point, with the sacrificial film 141a on the film 525Rf, the photoresist mask 145a is removed, thus suppressing the effects on the film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1. This is particularly suitable for etching processes using oxygen gases, such as plasma ashing, because the electrical properties of layers 512Rf_1 and 512Rf_2 may be negatively affected when they come into contact with oxygen.

[0203] Next, the protective layer 149a is used as a mask, and the portion of the sacrificial film 141a not covered by the protective layer 149a is removed by etching to form the sacrificial layer 147a (Fig. 13A). At the same time, the sacrificial layer 147a is also formed on the connecting electrode 501C.

[0204] The etching of the sacrificial film 141a can be performed using wet etching or dry etching, but dry etching is preferred, thereby suppressing pattern shrinkage.

[0205] Next, while removing the protective layer 149a by etching, a portion of the film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1 that are not covered by the sacrificial layer 147a are also removed by etching, thereby forming layer 525R, light-emitting unit 512R_2, intermediate layer 531R, and light-emitting unit 512R_1 (Fig. 13B).

[0206] In particular, dry etching using an etching gas that does not contain oxygen as its main component is preferred in the etching of film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1. This suppresses the deterioration of film 525Rf, layer 512Rf_2, intermediate film 531Rf, and layer 512Rf_1, resulting in a highly reliable display device. Examples of etching gases that do not contain oxygen as their main component include CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or noble gases. Helium can be used as an example of a noble gas. Alternatively, a mixture of the above gases and an oxygen-free diluent gas can be used as the etching gas.

[0207] Next, layer 512Gf_1, which will later become light-emitting unit 512G_1, intermediate film 531Gf, which will later become intermediate layer 531G, layer 512Gf_2, and film 525Gf, which will later become layer 525G, are sequentially deposited on sacrificial layer 147a, insulating layer 131, electrode 501G, electrode 501B, and electrode 501PD. Preferably, layers 512Gf_1, intermediate film 531Gf, layer 512Gf_2, and film 525Gf are not disposed on connecting electrode 501C.

[0208] The deposition methods for the membrane included in layer 512Gf_1, the intermediate membrane 531Gf, the membrane included in layer 512Gf_2, and the membrane 525Gf can be referenced from the above-described deposition methods for the membrane included in layer 512Rf_1, the intermediate membrane 531Rf, the membrane included in layer 512Rf_2, and the membrane 525Rf.

[0209] Next, a sacrificial membrane 141b is formed on membrane 525Gf. The sacrificial membrane 141b can be formed in the same manner as the sacrificial membrane 141a described above. In particular, the sacrificial membrane 141b is preferably made of the same material as the sacrificial membrane 141a.

[0210] Meanwhile, a sacrificial film 141b is deposited on the connecting electrode 501C in such a manner as to cover the sacrificial layer 147a.

[0211] Next, a protective film 143b is formed on the sacrificial film 141b. The protective film 143b can be formed using the same method as the protective film 143a described above. In particular, the protective film 143b is preferably made of the same material as the protective film 143a described above.

[0212] Next, a photoresist shield 145b is formed on the protective film 143b in the region overlapping with the electrode 501G and in the region overlapping with the connecting electrode 501C (Fig. 13C).

[0213] The photoresist mask 145b can be formed using the same method as the photoresist mask 145a described above.

[0214] Next, the portion of the protective film 143b not covered by the photoresist mask 145b is removed by etching to form a protective layer 149b. At the same time, a protective layer 149b is also formed on the connecting electrode 501C.

[0215] The etching of protective film 143b can be referenced from the description of protective film 143a above.

[0216] Next, the photoresist mask 145b is removed (Fig. 14A). Regarding the removal of the photoresist mask 145b, the description of the photoresist mask 145a above can be referenced.

[0217] Next, using the protective layer 149b as a mask, the portion of the sacrificial film 141b not covered by the protective layer 149b is removed by etching to form the sacrificial layer 147b. Simultaneously, the sacrificial layer 147b is also formed on the connection electrode 501C. The sacrificial layers 147a and 147b are stacked on the connection electrode 501C.

[0218] The etching of sacrificial film 141b can be referenced from the description of sacrificial film 141a above.

[0219] Next, while removing the protective layer 149b by etching, a portion of the film 525Gf, layer 512Gf_2, intermediate film 531Gf, and layer 512Gf_1 that are not covered by the sacrificial layer 147b are also removed by etching, thereby forming layer 525G, light-emitting unit 512G_2, intermediate layer 531G, and light-emitting unit 512G_1 (Fig. 14B).

[0220] The etching of film 525Gf, layer 512Gf_2, intermediate film 531Gf, layer 512Gf_1 and protective layer 149b can be referenced from the above description of film 525Rf, layer 512Rf_2, intermediate film 531Rf, layer 512Rf_1 and protective layer 149a.

[0221] At this time, layer 525R, light-emitting unit 512R_2, intermediate layer 531R and light-emitting unit 512R_1 are protected by sacrificial layer 147a, so they can be prevented from being damaged during the etching process of film 525Gf, layer 512Gf_2, intermediate film 531Gf and layer 512Gf_1.

[0222] Through the above steps, light-emitting unit 512R_1, intermediate layer 531R, light-emitting unit 512R_2, layer 525R, and light-emitting unit 512G_1, intermediate layer 531G, light-emitting unit 512G_2, and layer 525G can be formed with high positional accuracy.

[0223] The same process as described above can be used to form light-emitting unit 512B_1, intermediate layer 531B, light-emitting unit 512B_2, layer 525B, and sacrificial layer 147c (Figure 14C). Sacrificial layers 147a, 147b, and 147c are stacked on the connecting electrode 501C.

[0224] After forming the light-emitting unit 512B_1, intermediate layer 531B, light-emitting unit 512B_2, layer 525B, and sacrificial layer 147c, the light-receiving unit 542 and sacrificial layer 147d (FIG. 14D) are formed by the same process as described above. Sacrificial layers 147a, 147b, 147c, and 147d are stacked on the connecting electrode 501C.

[0225] Furthermore, when manufacturing a display device including a light-emitting element 550IR, for example, after forming the light-emitting unit 512B_1, intermediate layer 531B, light-emitting unit 512B_2, layer 525B, and sacrificial layer 147c, and before forming the light-receiving unit 542 and sacrificial layer 147d, the light-emitting unit 512IR_1, intermediate layer 531IR, light-emitting unit 512IR_2, layer 525IR, and sacrificial layer are formed by the same process as described above. At this time, five sacrificial layers are stacked on the connecting electrode 501C.

[0226] Next, sacrificial layers 147a, 147b, 147c, and 147d are removed, exposing the top surfaces of layer 525R, layer 525G, layer 525B, and the light-receiving unit 542 (Fig. 15A). At the same time, the top surface of the connecting electrode 501C is also exposed.

[0227] Sacrificial layers 147a, 147b, 147c, and 147d can be removed by wet etching or dry etching. In this case, it is preferable to use a method that minimizes damage to the light-emitting unit 512, intermediate layer 531, layer 525, and light-receiving unit 542. Wet etching is particularly preferred. For example, wet etching using a tetramethylammonium hydroxide aqueous solution (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or mixtures thereof is preferred.

[0228] Alternatively, it is preferable to dissolve and remove sacrificial layers 147a, 147b, 147c, and 147d using solvents such as water or alcohol. Here, various alcohols such as ethanol, methanol, isopropanol (IPA), or glycerol can be used as alcohols that can potentially dissolve sacrificial layers 147a, 147b, 147c, and 147d.

[0229] To remove water contained within the light-emitting unit 512 and the light-receiving unit 542, as well as water adsorbed on the surface, after removing sacrificial layers 147a, 147b, 147c, and 147d, a drying process is preferably performed. For example, a heating process is preferably performed under an inert gas atmosphere or a reduced pressure atmosphere. The heating process can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. Using a reduced pressure atmosphere allows drying to be performed at a lower temperature, which is therefore preferable.

[0230] In this way, light-emitting unit 512R, light-emitting unit 512G, light-emitting unit 512B and light-receiving unit 542 can be formed respectively.

[0231] Next, electrode 502 is formed on layer 525R, layer 525G, layer 525B, light-receiving unit 542, and connecting electrode 501C (FIG. 15B). As described above, a gap can be formed between electrode 502 and insulating layer 131.

[0232] Electrode 502 can be formed using deposition methods such as vapor deposition or sputtering. Alternatively, films formed by vapor deposition and films formed by sputtering can be stacked. Electrode 502 is preferably formed using a shadow mask.

[0233] Electrode 502 is electrically connected to connecting electrode 501C outside the display unit.

[0234] Next, a protective layer 125 (FIG. 15C) is formed on electrode 502. The inorganic insulating film used for the protective layer 125 is preferably deposited using sputtering, PECVD, or ALD methods. ALD is particularly preferred because it offers excellent step coverage and is less prone to defects such as pinholes. Alternatively, the organic insulating film is preferably deposited using inkjet printing, thereby forming a uniform film over the desired area.

[0235] Therefore, a display device 10 can be manufactured.

[0236] As described above, in the method for manufacturing a display device according to one embodiment of the present invention, the light-emitting elements 550 can be manufactured separately without using a shadow mask such as a metal mask. Therefore, compared to the case where the light-emitting elements 550 are manufactured separately using a shadow mask, the sub-pixels can be miniaturized, and the pixel aperture ratio can be increased. Furthermore, since the light-emitting units 512 can be formed separately, a display device with extremely vivid colors, extremely high contrast, and extremely high display quality can be realized.

[0237] By miniaturizing subpixels, subpixels that do not contribute to display quality can be placed within a pixel. For example, a subpixel including a light-receiving element 560 can be placed within a pixel, and a subpixel including a light-emitting element 550IR that emits infrared light can also be placed within a pixel. In a display device according to one embodiment of the present invention, even when such subpixels that do not contribute to display quality are placed within a pixel, the decrease in pixel density can be suppressed. For example, the pixel density can be set to 400 ppi or more, 1000 ppi or more, 3000 ppi or more, or 5000 ppi or more.

[0238] The structural examples shown in this embodiment and at least a portion of the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0239] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0240] Implementation Method 2 In this embodiment, an example of the structure of a display device according to one embodiment of the present invention will be described.

[0241] [Structure Example 1] Figure 16 is a perspective view showing an example of the structure of the display device 100. The display device 100 has a structure for bonding substrate 151 and substrate 152. In Figure 16, substrate 152 is indicated by dashed lines.

[0242] The display device 100 includes a display section 162, circuitry 164, and wiring 165, etc. Figure 16 shows an example in which an IC (integrated circuit) 173 and an FPC 172 are installed in the display device 100. Therefore, the structure shown in Figure 16 can also be referred to as a display module including a display device, an IC, and an FPC.

[0243] Circuit 164 may be, for example, a gate driver. Signals and power may be supplied to circuit 164 via wiring 165. For example, the signals and power may be input from outside the display device 10 to wiring 165 via FPC 172. Alternatively, the signals and power may be generated by IC 173 and output to wiring 165.

[0244] Although Figure 16 shows an example of IC173 being mounted on substrate 151 using COG (Chip On Glass) bonding, TCP (Tape Carrier Package) or COF (Chip On Film) bonding can also be used.

[0245] Figure 17 is a diagram showing an example of a cross-section of the display device 100 shown in Figure 16, including a portion of the region including the FPC 172, a portion of the region including the circuit 164, a portion of the region including the display section 162, and a portion of the region including the end. The display device 100 shown in Figure 17 is referred to as display device 100A.

[0246] The display device 100A includes transistors 201, 141, 142, light-emitting element 550, and light-receiving element 560 between substrates 151 and 152.

[0247] The substrate 152 and the insulating layer 214 are bonded together by the adhesive layer 242. A solid sealing structure or a hollow sealing structure can be used to seal the light-emitting element 550 and the light-receiving element 560. The space 143 surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 is filled with an inert gas (nitrogen or argon, etc.), employing a hollow sealing structure. The adhesive layer 242 may also overlap with the light-emitting element 550. Furthermore, the area surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 may also be filled with a resin different from the adhesive layer 242.

[0248] The electrode 501 of the light-emitting element 550 is electrically connected to the conductive layer 222b of the transistor 141 through an opening formed in the insulating layer 214. The transistor 142 has the function of controlling the driving of the light-emitting element 550. The electrode 501PD of the light-receiving element 560 is electrically connected to the conductive layer 222b of the transistor 142 through an opening formed in the insulating layer 214.

[0249] The light emitted by the light-emitting element 550 is projected onto one side of the substrate 152. Furthermore, light passes through the substrate 152 and the space 143 and is incident on the light-receiving element 560. The substrate 152 is preferably made of a material with high transmittance to visible and infrared light.

[0250] A light-shielding layer 148 is provided on one side of the substrate 151 of the substrate 152. The light-shielding layer 148 has openings at the positions where it overlaps with the light-receiving element 560 and the light-emitting element 550. In addition, a filter 146 for blocking ultraviolet light is provided at the position where it overlaps with the light-receiving element 560. Note that the filter 146 may also be omitted.

[0251] Transistors 201, 141, and 142 are all formed on substrate 151. These transistors can be formed using the same material and the same process.

[0252] Insulating layers 211, 213, 215, and 214 are sequentially disposed on substrate 151. A portion of insulating layer 211 serves as the gate insulating layer for each transistor. A portion of insulating layer 213 serves as the gate insulating layer for each transistor. Insulating layer 215 is disposed to cover the transistor. Insulating layer 214 is disposed to cover the transistor and serves as a planarization layer. Furthermore, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor; there can be one or more.

[0253] Preferably, at least one layer of the insulating layer covering the transistor is made of a material that impurities such as water or hydrogen do not easily diffuse. This allows the insulating layer to function as a barrier layer. By employing this structure, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0254] Inorganic insulating films are preferably used as insulating layers 211, 213, and 215. Examples of inorganic insulating films include silicon nitride films, silicon oxynitride films, silicon oxide films, silicon oxynitride films, aluminum oxide films, or aluminum nitride films. Additionally, hafnium oxide films, yttrium oxide films, zirconium oxide films, gallium oxide films, tantalum oxide films, magnesium oxide films, lanthanum oxide films, cerium oxide films, or neodymium oxide films can also be used. Furthermore, two or more of the above-mentioned insulating films can be laminated.

[0255] The insulating layer 214 used as the planarization layer is preferably an organic insulating film. Materials suitable for use as organic insulating films include, for example, acrylic resins, polyimide resins, epoxy resins, polyimide resins, polyimide-polyimide resins, silicone resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0256] Here, the impurity blocking properties of organic insulating films are often lower than those of inorganic insulating films. Therefore, it is preferable that the organic insulating film includes an opening near the end of the display device 100A. This can suppress the diffusion of impurities from the end of the display device 100A through the organic insulating film. Alternatively, the organic insulating film can be formed with its end located inside the end of the display device 100A, so that the organic insulating film is not exposed at the end of the display device 100A.

[0257] In region 228 shown in Figure 17, an opening is formed in the insulating layer 214. Therefore, even when an organic insulating film is used as the insulating layer 214, the diffusion of impurities from the outside to the display section 162 via the insulating layer 214 can be suppressed. This improves the reliability of the display device 100A.

[0258] Transistors 201, 141, and 142 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as a source and drain, respectively; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate. Here, the multiple layers obtained by processing the same conductive film are given the same shaded lines. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0259] There are no particular limitations on the transistor structure included in the display device of this embodiment. For example, a planar transistor, an interleaved transistor, or an anti-interleaved transistor can be used. Furthermore, the transistor can have a top-gate structure or a bottom-gate structure. Alternatively, gates can be provided above and below the semiconductor layer forming the channel.

[0260] Transistors 201, 141, and 142 employ a structure in which a semiconductor layer forming a channel is sandwiched between two gates. Alternatively, the two gates can be connected, and the transistors can be driven by supplying the same signal to both gates. Or, a potential for controlling the threshold voltage of the transistor can be applied to one of the two gates, and a potential for driving can be applied to the other.

[0261] There are no particular restrictions on the crystallinity of the semiconductor material used for transistors; amorphous semiconductors, single-crystal semiconductors, or crystalline semiconductors other than single-crystal semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in some of them) can be used. When using single-crystal semiconductors or crystalline semiconductors, the degradation of transistor characteristics can be suppressed, so they are preferred.

[0262] The semiconductor layer of the transistor is preferably composed of a metal oxide (also known as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may also contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (such as low-temperature polycrystalline silicon or single-crystal silicon).

[0263] As described above, when the semiconductor layer comprises a metal oxide, the metal oxide preferably comprises at least indium or zinc. More preferably, it comprises both indium and zinc. Additionally, it preferably also comprises aluminum, gallium, yttrium, or tin. Furthermore, it may also comprise one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt.

[0264] The transistors included in circuit 164 and the transistors included in display unit 162 can have the same structure or different structures. The multiple transistors included in circuit 164 can have the same structure or two or more different structures. Similarly, the multiple transistors included in display unit 162 can have the same structure or two or more different structures.

[0265] A connection portion 204 is provided in the area where substrates 151 and 152 do not overlap. In the connection portion 204, wiring 165 is electrically connected to FPC 172 via a conductive layer 166 and a connection layer 244. The conductive layer 166, obtained by processing the same conductive film as electrode 501, is exposed on the top surface of the connection portion 204. Therefore, the connection portion 204 can be electrically connected to FPC 172 via the connection layer 244.

[0266] Various optical components can be disposed on the outer side of the substrate 152. Examples of optical components include polarizing plates, retardation plates, light diffusion layers (diffusion films, etc.), antireflective layers, and condensing films. In addition, antistatic films that suppress dust adhesion, water-repellent films that are not easily soiled, hard coatings that suppress damage caused by use, or impact-absorbing layers can also be disposed on the outer side of the substrate 152.

[0267] The substrates 151 and 152 can be made of glass, quartz, ceramic, sapphire, resin, etc.

[0268] As the adhesive layer, various curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, or anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, or EVA (ethylene vinyl acetate) resins. In particular, materials with low moisture permeability, such as epoxy resins, are preferred. Furthermore, two-component mixed resins can also be used. Additionally, adhesive sheets can also be used, for example.

[0269] As the connecting layer 244, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0270] Materials that can be used as gates, sources, and drains of transistors, as well as conductive layers such as wiring and electrodes in display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys with the above metals as the main components. Single layers or stacks of films containing these materials can be used.

[0271] Furthermore, as a transparent conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and gallium-containing zinc oxide, or graphene, can be used. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, as well as alloys containing these metallic materials, can be used. Alternatively, nitrides of these metallic materials (e.g., titanium nitride) can also be used. Furthermore, when using metallic materials or alloys (or their nitrides), it is preferable to form them thin enough to be transparent. Furthermore, a multilayer film of the above materials can be used as a conductive layer. For example, using a multilayer film of an alloy of silver and magnesium with indium tin oxide can improve conductivity, and is therefore preferred. The above materials can also be used to construct various conductive layers such as wiring and electrodes in a display device, as well as conductive layers included in display elements (conductive layers used as pixel electrodes or common electrodes).

[0272] Examples of insulating materials that can be used in various insulating layers include resins such as acrylic resin or epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon oxynitride, silicon nitride, or aluminum oxide.

[0273] [Structure Example 2] Figure 18 is a cross-sectional view showing a structural example of display device 100B, and is also a modified example of display device 100A. The difference between display device 100B and display device 100A is that: substrate 151 is replaced by substrate 153, adhesive layer 155 and insulating layer 212; and substrate 152 is replaced by substrate 154, adhesive layer 156 and insulating layer 158.

[0274] In the display device 100B, the substrate 153 and the insulating layer 212 are bonded together by the adhesive layer 155. The substrate 154 and the insulating layer 158 are bonded together by the adhesive layer 156.

[0275] When manufacturing the display device 100B shown in FIG. 18, firstly, a first manufacturing substrate, on which an insulating layer 212, transistors, light-emitting elements 550, and light-receiving elements 560 are disposed, and a second manufacturing substrate, on which an insulating layer 158, a light-shielding layer 148, and a light filter 146 are disposed, are bonded together by an adhesive layer 242. Then, a substrate 153 is bonded to the surface exposed after peeling off the first manufacturing substrate using an adhesive layer 155. This transfers the components formed on the first manufacturing substrate onto the substrate 153. Furthermore, a substrate 154 is bonded to the surface exposed after peeling off the second manufacturing substrate using an adhesive layer 156. This transfers the components formed on the second manufacturing substrate onto the substrate 154. The substrates 153 and 154 are preferably flexible. Therefore, the display device 100B can be flexible. That is, a display device 100B as a flexible display can be realized.

[0276] Inorganic insulating films that can be used for insulating layers 211, 213 and 215 can be used as insulating layers 212 and 158.

[0277] [Structure Example 3] Figure 19 is a cross-sectional view showing a structural example of the display device 100C. The display device 100C includes a substrate 301, a light-emitting element 550, a light-receiving element 560, a capacitor 240, and a transistor 310. The substrate 301 is, for example, equivalent to the substrate 151 in Figure 16.

[0278] Transistor 310 is a transistor having a channel formation region in substrate 301. Substrate 301 can be, for example, a semiconductor substrate such as a single-crystal silicon substrate. Transistor 310 includes a portion of substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. Conductive layer 311 serves as a gate electrode. Insulating layer 313 is located between substrate 301 and conductive layer 311 and serves as a gate insulating layer. Low-resistance region 312 is a region in substrate 301 doped with impurities and serves as a source or drain electrode. Insulating layer 314 is provided to cover the sides of conductive layer 311.

[0279] In addition, a component separation layer 315 is provided between two adjacent transistors 310 in a manner that is embedded in the substrate 301.

[0280] In addition, an insulating layer 261 is provided in such a way as to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0281] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 is used as one electrode of the capacitor 240, the conductive layer 245 is used as the other electrode of the capacitor 240, and the insulating layer 243 is used as the dielectric of the capacitor 240.

[0282] A conductive layer 241 is disposed on an insulating layer 261 and embedded in an insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain terminals of a transistor 310 via a plug 271 embedded in the insulating layer 261. An insulating layer 243 is disposed to cover the conductive layer 241. A conductive layer 245 is disposed in the region where it overlaps with the conductive layer 241, separated by the insulating layer 243.

[0283] An insulating layer 255 is provided to cover the capacitor 240, and a light-emitting element 550 and a light-receiving element 560 are provided on the insulating layer 255. A protective layer 125 is provided on the light-emitting element 550 and the light-receiving element 560, and a substrate 420 is attached to the top surface of the protective layer 125 by a resin layer 419. The substrate 420 is, for example, equivalent to the substrate 152 in FIG. 16.

[0284] The electrode 501 of the light-emitting element 550 and the electrode 501PD of the light-receiving element 560 are electrically connected to one of the source and drain electrodes of the transistor 310 via plugs 256 embedded in insulating layer 255 and insulating layer 243, conductive layer 241 embedded in insulating layer 254, and plugs 271 embedded in insulating layer 261.

[0285] [Structure Example 4] Figure 20 is a cross-sectional view showing a structural example of display device 100D. The main difference between display device 100D and display device 100C is the transistor structure. Note that descriptions of parts identical to those in display device 100C are sometimes omitted.

[0286] Transistor 320 is a transistor that uses metal oxide in the semiconductor layer forming the channel (hereinafter also referred to as OS transistor).

[0287] Transistor 320 includes a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0288] Substrate 331 is, for example, equivalent to substrate 151 in FIG16. As substrate 331, an insulating substrate or a semiconductor substrate can be used.

[0289] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 serves as a barrier layer to prevent impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and to prevent oxygen from detaching from the semiconductor layer 321 towards the insulating layer 332. For example, an aluminum oxide film, a hafnium oxide film, or a silicon nitride film can be used as the insulating layer 332, which are less prone to hydrogen or oxygen diffusion than a silicon oxide film.

[0290] A conductive layer 327 is disposed on the insulating layer 332, and an insulating layer 326 is disposed to cover the conductive layer 327. The conductive layer 327 serves as the first gate electrode of the transistor 320, and a portion of the insulating layer 326 serves as the first gate insulating layer. Preferably, the portion of the insulating layer 326 that is in contact with the semiconductor layer 321 is an oxide insulating film such as silicon oxide. Preferably, the top surface of the insulating layer 326 is planarized.

[0291] A semiconductor layer 321 is disposed on an insulating layer 326. Preferably, the semiconductor layer 321 comprises a metal oxide film having semiconductor properties.

[0292] A pair of conductive layers 325 are disposed in contact with the top surface of the semiconductor layer 321 and are used as source electrodes and drain electrodes.

[0293] In addition, an insulating layer 328 is provided to cover the top and side surfaces of a pair of conductive layers 325 and the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 can be used as a barrier layer to prevent impurities such as water or hydrogen from diffusing from the insulating layer 264 to the semiconductor layer 321 and to allow oxygen to escape from the semiconductor layer 321. As the insulating layer 328, the same insulating film as the insulating layer 332 described above can be used.

[0294] Openings leading to the semiconductor layer 321 are provided in insulating layers 328 and 264. An insulating layer 323 and a conductive layer 324, which are in contact with the sides of insulating layers 264, 328, and 325, and the top surface of the semiconductor layer 321, are embedded within these openings. The conductive layer 324 serves as a second gate electrode, and the insulating layer 323 serves as a second gate insulating layer.

[0295] The top surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened to make their heights approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0296] Insulating layers 264 and 265 are used as interlayer insulating layers. Insulating layer 329 is used as a barrier layer to prevent impurities such as water or hydrogen from diffusing from insulating layer 265 to transistor 320. As insulating layer 329, the same insulating film as insulating layers 328 and 332 described above can be used.

[0297] A plug 274, electrically connected to one of a pair of conductive layers 325, is embedded in insulating layers 265, 329, 264, and 328. Preferably, the plug 274 comprises a conductive layer 274a covering the sides of openings in insulating layers 265, 329, 264, and 328 and a portion of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274a. Preferably, the conductive layer 274a is made of a conductive material that does not readily diffuse hydrogen and oxygen.

[0298] The structure of the insulating layer 254 to the substrate 420 in the display device 100D is the same as that in the display device 100C.

[0299] [Structure Example 5] Figure 21 is a cross-sectional view showing a structural example of display device 100E. In display device 100E, transistors 310 with channels formed on substrate 301 and transistors 320 containing metal oxide semiconductor layers forming the channels are stacked. Note that descriptions of parts identical to those in display device 100C or display device 100D are sometimes omitted.

[0300] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. Furthermore, an insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. Both conductive layers 251 and 252 are used for wiring. Additionally, insulating layers 263 and 332 are provided to cover the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. Furthermore, an insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected via a connector 274.

[0301] Transistor 320 can be used as a transistor constituting a pixel circuit. Furthermore, transistor 310 can be used as a transistor constituting a pixel circuit or as a transistor constituting a driving circuit (gate line driving circuit, source line driving circuit) used to drive the pixel circuit. Moreover, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0302] With this structure, not only pixel circuits but also driving circuits can be formed directly under the light-emitting element. Therefore, compared with the case where driving circuits are arranged around the display section, the display device can be miniaturized.

[0303] The structural examples shown in this embodiment and at least a portion of the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0304] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0305] Implementation Method 3 In this embodiment, a metal oxide that can be used with the OS transistor described in the above embodiments is explained.

[0306] The metal oxide preferably contains at least indium or zinc. It is particularly preferred to contain both indium and zinc. Furthermore, it is also preferred to contain aluminum, gallium, yttrium, or tin. Additionally, it may contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, and cobalt.

[0307] In addition, metal oxides can be formed by sputtering, MOCVD and other CVD methods or ALD methods.

[0308] <Classification of Crystal Structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0309] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, the XRD spectrum obtained can be measured using GIXD (Grazing-Incidence XRD). Furthermore, the GIXD method is also known as the thin film method or the Seemann-Bohlin method.

[0310] For example, the peak shapes of the XRD patterns on a quartz glass substrate are generally symmetrical. On the other hand, the peak shapes of the XRD patterns on an IGZO film with a crystalline structure are not symmetrical. Asymmetrical peak shapes in the XRD patterns indicate the presence of crystals in the film or substrate. In other words, unless the peak shapes in the XRD patterns are symmetrical, it cannot be said that the film or substrate is in an amorphous state.

[0311] Furthermore, the crystal structure of the film or substrate can be evaluated using diffraction patterns observed by nano-beam electron diffraction (NBED). For example, the observation of a halo pattern in the diffraction pattern of a quartz glass substrate confirms that the quartz glass is in an amorphous state. Conversely, a spot-like pattern without a halo is observed in the diffraction pattern of an IGZO film deposited at room temperature. Therefore, it can be inferred that the IGZO film deposited at room temperature is in an intermediate state, neither crystalline nor amorphous, and the conclusion that the IGZO film is amorphous cannot be drawn.

[0312] <<Structure of Oxide Semiconductors>> Furthermore, when focusing on the structure of oxide semiconductors, the classification of oxide semiconductors sometimes differs from the classifications described above. For example, oxide semiconductors can be classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include, for instance, CAAC-OS and nc-OS, as mentioned above. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, a-like OS (amorphous-like oxide semiconductor), and amorphous oxide semiconductors, etc.

[0313] Here, we will explain the details of CAAC-OS, nc-OS, and a-like OS.

[0314] [CAAC-OS] CAAC-OS is an oxide semiconductor comprising multiple crystalline regions, whose c-axis is aligned in a specific direction. This specific direction refers to the thickness direction of the CAAC-OS film, the normal direction of the formed surface of the CAAC-OS film, or the normal direction of the surface of the CAAC-OS film. Furthermore, a crystalline region is a region exhibiting a periodic atomic arrangement. Note that when atomic arrangement is considered as lattice arrangement, a crystalline region is also a region with a consistent lattice arrangement. Moreover, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and sometimes this region exhibits distortion. Distortion refers to the portion of the lattice arrangement direction that changes between lattice-aligned regions and other lattice-aligned regions within the region where multiple crystalline regions are connected. In other words, CAAC-OS refers to an oxide semiconductor with c-axis alignment but no obvious alignment in the ab-plane direction.

[0315] Furthermore, each of the aforementioned crystalline regions is composed of one or more microcrystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of a single microcrystal, the maximum diameter of that region is less than 10 nm. Conversely, when a crystalline region is composed of multiple microcrystals, the size of that region can sometimes be around tens of nm.

[0316] Furthermore, in In-M-Zn oxides (where element M is selected from one or more of aluminum, gallium, yttrium, tin, and titanium), CAAC-OS tends to have a layered crystal structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter, In layer) and layers containing element M, zinc (Zn), and oxygen (hereinafter, (M,Zn) layer). In addition, indium and element M can substitute for each other. Therefore, sometimes the (M,Zn) layer contains indium. Furthermore, sometimes the In layer contains element M. Note that sometimes the In layer contains Zn. This layered structure is observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0317] For example, when performing structural analysis on CAAC-OS films using an XRD apparatus, peaks representing c-axis alignment are detected at or near 2θ = 31° in out-of-plane XRD measurements using θ / 2θ scanning. Note that the position (2θ value) of the peaks representing c-axis alignment can vary depending on the type or composition of the metallic elements constituting CAAC-OS.

[0318] Furthermore, for example, multiple bright spots (spots) were observed in the electron diffraction pattern of the CAAC-OS film. Additionally, when the spot of the incident electron beam passing through the sample (also known as the direct spot) is taken as the center of symmetry, one spot and other spots were observed at point-symmetrical positions.

[0319] When observing the crystalline region from the aforementioned specific directions, although the lattice arrangement in this region is primarily hexagonal, the unit lattice is not limited to a regular hexagon; there are also cases where it is non-regular hexagonal. Furthermore, in the aforementioned distortions, pentagonal, heptagonal, and other lattice arrangements are sometimes observed. Moreover, no clear grain boundary is observed near the distortion in CAAC-OS. That is, the lattice arrangement distortion inhibits grain boundary formation. This may be because CAAC-OS can accommodate distortion due to the low density of oxygen atoms along the ab-plane direction or changes in the bonding distance between atoms caused by the substitution of metal atoms.

[0320] Furthermore, a crystalline structure with clearly defined grain boundaries is called a polycrystalline structure. Grain boundaries act as recombination centers, trapping carriers and potentially leading to a decrease in the transistor's on-state current or field-effect mobility. Therefore, CAAC-OS, which lacks clearly defined grain boundaries, is one of the crystalline oxides that provides an excellent crystalline structure for the semiconductor layer of the transistor. Note that a Zn-containing structure is preferred for constructing CAAC-OS. For example, In-Zn oxides and In-Ga-Zn oxides are preferred because they can further suppress grain boundary formation compared to In oxides.

[0321] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, it can be said that in CAAC-OS, the reduction in electron mobility due to grain boundaries is less likely to occur. Furthermore, the crystallinity of oxide semiconductors can sometimes decrease due to the incorporation of impurities and the formation of defects; therefore, CAAC-OS can be considered an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Thus, oxide semiconductors containing CAAC-OS exhibit stable physical properties. Consequently, oxide semiconductors containing CAAC-OS possess high heat resistance and high reliability. Moreover, CAAC-OS is also stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, by using CAAC-OS in OS transistors, process flexibility can be increased.

[0322] [nc-OS] In nc-OS, the atomic arrangement in tiny regions (e.g., regions larger than 1 nm and smaller than 10 nm, particularly regions larger than 1 nm and smaller than 3 nm) exhibits periodicity. In other words, nc-OS possesses tiny crystallinity. Furthermore, for example, these tiny crystallinity sizes are between 1 nm and 10 nm, particularly between 1 nm and 3 nm, and are referred to as nanocrystals. Moreover, no regularity in crystal orientation is observed between different nanocrystals in nc-OS. Therefore, no alignment is observed in the overall film. Thus, sometimes nc-OS is indistinguishable from a-like OS or amorphous oxide semiconductors in certain analytical methods. For example, when performing structural analysis on nc-OS films using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when performing electron diffraction (also known as selected area electron diffraction) on nc-OS films using an electron beam with a beam diameter larger than that of nanocrystals (e.g., larger than 50 nm), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also known as nano-beam electron diffraction) is performed on nc-OS films using an electron beam whose beam diameter is close to or smaller than the size of nanocrystals (e.g., more than 1 nm and less than 30 nm), sometimes an electron diffraction pattern of multiple spots is observed in an annular region centered on a direct spot.

[0323] [a-like OS] a-like OS is an oxide semiconductor with a structure intermediate between nc-OS and amorphous oxide semiconductors. a-like OS contains voids or low-density regions. That is, a-like OS has lower crystallinity than nc-OS and CAAC-OS. Furthermore, the hydrogen concentration in a-like OS films is higher than that in nc-OS and CAAC-OS films.

[0324] <<The Structure of Oxide Semiconductors>> Next, the details of the aforementioned CAC-OS will be explained. Furthermore, CAC-OS is related to material composition.

[0325] [CAC-OS] CAC-OS, for example, refers to a composition in which elements are non-uniformly distributed within a metal oxide, wherein the size of the material containing the non-uniformly distributed elements is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately. Note that, below, the state in which one or more metal elements are non-uniformly distributed within a metal oxide and the regions containing those metal elements are mixed is also referred to as mosaic or patch-like, wherein the size of the region is 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or approximately.

[0326] Furthermore, CAC-OS refers to a structure in which the material is divided into a first region and a second region, forming a mosaic-like structure, with the first region distributed throughout the film (hereinafter also referred to as cloud-like). In other words, CAC-OS refers to a composite metal oxide having a structure that combines the first and second regions.

[0327] Here, each of the atomic ratios of In, Ga, and Zn relative to the metal elements constituting the CAC-OS of In-Ga-Zn oxide is denoted as [In], [Ga], and [Zn]. For example, in the CAC-OS of In-Ga-Zn oxide, a first region is a region where [In] is greater than [In] in the composition of CAC-OS. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the composition of CAC-OS. Alternatively, for example, a first region is a region where [In] is greater than [In] in the second region and [Ga] is less than [Ga] in the second region. Furthermore, a second region is a region where [Ga] is greater than [Ga] in the first region and [In] is less than [In] in the first region.

[0328] Specifically, the first region mentioned above is a region whose main components are indium oxide and indium zinc oxide. Furthermore, the second region mentioned above is a region whose main components are gallium oxide and gallium zinc oxide. In other words, the first region can be referred to as a region whose main component is In. Furthermore, the second region can be referred to as a region whose main component is Ga.

[0329] Note that sometimes the clear boundaries between the first region and the second region mentioned above are not observable.

[0330] Furthermore, CAC-OS in In-Ga-Zn oxides refers to a structure in which regions dominated by Ga and regions dominated by In are irregularly arranged in a mosaic pattern within a material containing In, Ga, Zn, and O. Therefore, it can be inferred that CAC-OS has a structure with uneven distribution of metallic elements.

[0331] CAC-OS can be formed, for example, by sputtering without intentionally heating the substrate. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gases, and nitrogen gases can be used as the deposition gas. Furthermore, the lower the oxygen gas flow rate in the total flow rate of the deposition gas during deposition, the better; for example, it is preferable that the oxygen gas flow rate in the total flow rate of the deposition gas during deposition is 0% or more and less than 30%, more preferably 0% or more and less than 10%.

[0332] For example, in CAC-OS of In-Ga-Zn oxide, based on EDX-mapping images obtained by Energy Dispersive X-ray spectroscopy (EDX), a structure with an unevenly distributed mixture of regions with In as the main component (first region) and regions with Ga as the main component (second region) can be identified.

[0333] Here, the first region has higher conductivity than the second region. That is, when carriers flow through the first region, it exhibits the conductivity of a metal oxide. Therefore, when the first region is distributed in a cloud-like manner within the metal oxide, a high field mobility (μ) can be achieved.

[0334] On the other hand, the second region is a region with higher insulation than the first region. That is to say, when the second region is distributed in a metal oxide, leakage current can be suppressed.

[0335] When CAC-OS is used in transistors, the complementary effect of conductivity arising from the first region and insulation arising from the second region enables CAC-OS to possess switching functionality (the function of controlling on / off). In other words, a portion of the CAC-OS material exhibits conductivity while another portion exhibits insulation, resulting in a semiconductor function within the overall material. By separating the conductivity and insulation functions, each function can be maximized. Therefore, by using CAC-OS in transistors, large on-state current (Ion), high field-efficiency mobility (μ), and excellent switching performance can be achieved.

[0336] Furthermore, transistors using CAC-OS exhibit high reliability. Therefore, CAC-OS is best suited for various semiconductor devices, such as display devices.

[0337] Oxide semiconductors possess various structures and properties. In one embodiment of the present invention, the oxide semiconductor may also include two or more of the following: amorphous oxide semiconductor, polycrystalline oxide semiconductor, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0338] <Transistors with oxide semiconductor properties> Next, the use of the aforementioned oxide semiconductor in transistors will be explained.

[0339] By using the aforementioned oxide semiconductors in transistors, transistors with high field-effect mobility can be realized. Furthermore, transistors with high reliability can be achieved.

[0340] It is preferable to use oxide semiconductors with low carrier concentrations in transistors. For example, the carrier concentration in the oxide semiconductor is 1×10¹⁷ cm⁻³ or less, preferably 1×10¹⁵ cm⁻³ or less, more preferably 1×10¹³ cm⁻³ or less, further preferably 1×10¹¹ cm⁻³ or less, and even more preferably less than 1×10¹⁰ cm⁻³ and greater than 1×10⁻⁹ cm⁻³. When the purpose is to reduce the carrier concentration of the oxide semiconductor film, the impurity concentration in the oxide semiconductor film can be reduced to reduce the defect state density. In this specification, the state of low impurity concentration and low defect state density is referred to as high purity nature or substantially high purity nature. Furthermore, oxide semiconductors with low carrier concentrations are sometimes referred to as high purity nature or substantially high purity nature oxide semiconductors.

[0341] Because high-purity or essentially high-purity oxide semiconductor films have a low defect state density, they may also have a low trap state density.

[0342] Furthermore, the charge trapped in the trap state of an oxide semiconductor takes a relatively long time to dissipate, sometimes acting like a fixed charge. Therefore, the electrical properties of transistors forming channel formation regions in oxide semiconductors with high trap state density are sometimes unstable.

[0343] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical properties of the transistor. To further reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0344] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0345] When an oxide semiconductor contains silicon or carbon, one of the elements in Group 14, defect states are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor or near the interface with the oxide semiconductor (the concentration measured by secondary ion mass spectrometry) is set to 2 × 10¹⁸ atoms / cm³ or less, preferably 2 × 10¹⁷ atoms / cm³ or less.

[0346] Furthermore, when oxide semiconductors contain alkali metals or alkaline earth metals, defect states can sometimes be formed, thus creating carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to have always-on characteristics. Therefore, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor, as measured by SIMS, should be 1 × 10¹⁸ atoms / cm³ or less, preferably 2 × 10¹⁶ atoms / cm³ or less.

[0347] When oxide semiconductors contain nitrogen, electrons are readily generated as carriers, increasing the carrier concentration and resulting in n-type polarization. Consequently, transistors using nitrogen-containing oxide semiconductors tend to exhibit always-on characteristics. Alternatively, when nitrogen is included in the oxide semiconductor, trapped states can sometimes form. As a result, the electrical properties of the transistor can sometimes be unstable. Therefore, the nitrogen concentration in the oxide semiconductor, measured using SIMS, is set to be below 5 × 10¹⁹ atoms / cm³, preferably below 5 × 10¹⁸ atoms / cm³, more preferably below 1 × 10¹⁸ atoms / cm³, and even more preferably below 5 × 10¹⁷ atoms / cm³.

[0348] Hydrogen contained in oxide semiconductors reacts with oxygen bonded to metal atoms to form water, thus sometimes creating oxygen vacancies. When hydrogen enters these oxygen vacancies, electrons are sometimes generated as carriers. Furthermore, sometimes a portion of the hydrogen bonds with oxygen bonded to metal atoms, generating electrons as carriers. Therefore, transistors using oxide semiconductors containing hydrogen tend to have always-on characteristics. Thus, it is preferable to minimize the amount of hydrogen in the oxide semiconductor. Specifically, in the oxide semiconductor, the hydrogen concentration measured using SIMS is set to be less than 1 × 10²⁰ atoms / cm³, preferably less than 1 × 10¹⁹ atoms / cm³, more preferably less than 5 × 10¹⁸ atoms / cm³, and even more preferably less than 1 × 10¹⁸ atoms / cm³.

[0349] By using oxide semiconductors with sufficiently reduced impurities in the channel formation region of a transistor, the transistor can be made to have stable electrical characteristics.

[0350] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0351] Implementation Method 4 In this embodiment, an electronic device including a display device according to one embodiment of the present invention will be described.

[0352] The display device according to one embodiment of the present invention can be used in various electronic devices. For example, in addition to electronic devices with large screens such as televisions, desktop or laptop computers, tablet computers, monitors for computers, digital signage, and large game machines such as pinball machines, the display device according to one embodiment of the present invention can also be installed in digital cameras, digital camcorders, digital photo frames, portable game consoles, portable information terminals, audio playback devices, etc.

[0353] Figures 22A, 22B, 23A, and 23B illustrate an example of a wearable device that can be worn on the head. These wearable devices have the capability to display either AR (Augmented Reality) content or VR (Virtual Reality) content. Furthermore, these wearable devices may also have the capability to display SR (Alternative Reality) or MR (Mixed Reality) content in addition to AR and VR. When an electronic device has the capability to display AR, VR, SR, or MR content, the user's immersion experience can be enhanced.

[0354] The electronic device 700A shown in Figure 22A and the electronic device 700B shown in Figure 22B both include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), a sensor unit 725, a pair of optical components 753, a frame 757, and a pair of nose pads 758. For example, the sensor unit 725 may also be disposed in the housing 721.

[0355] The display panel 751 can be used with a display device according to one embodiment of the present invention. Therefore, an electronic device capable of displaying with extremely high clarity can be realized.

[0356] Both electronic devices 700A and 700B can project images displayed on the display panel 751 onto the display area 756 in the optical component 753. Because the optical component 753 is light-transmitting, the user can see the image displayed on the display area by superimposing it with the image seen through the optical component 753. Therefore, both electronic devices 700A and 700B are capable of AR display.

[0357] The electronic devices 700A and 700B can also be equipped with cameras capable of capturing images of the front as imaging units. In addition, by installing accelerometers such as gyroscopes in the electronic devices 700A and 700B, the orientation of the user's head can be detected and the image corresponding to that orientation can be displayed on the display area 756.

[0358] The communications unit includes a wireless communication device, through which video signals can be supplied, for example. Additionally, in addition to the wireless communication device, a connector capable of connecting cables that supply video signals and power may also be included.

[0359] In addition, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly or via wired means or both.

[0360] The sensor unit 725, for example, has the function of detecting whether the outer surface of the housing 721 is touched. The sensor unit 725 can detect user tapping or swiping operations and perform various processes. For example, tapping can perform processes such as temporarily pausing or replaying moving images, and swiping can perform processes such as fast forward and rewind. Furthermore, by providing the sensor unit 725 in each of the two housings 721, the operating range can be expanded.

[0361] The display device according to one embodiment of the present invention can be used in the sensor section 725. Specifically, a light-receiving element that can be included in the display device according to one embodiment of the present invention can be provided in the sensor section 725. In addition, the light-receiving element can be manufactured in the sensor section 725 using the manufacturing method of the display device according to one embodiment of the present invention. Therefore, the sensor section 725 can be made into a touch sensor including a light-receiving element with a high aperture ratio. Thus, the sensor section 725 can be made into a touch sensor with high detection sensitivity.

[0362] The electronic device 800A shown in Figure 23A and the electronic device 800B shown in Figure 23B both include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0363] The display unit 820 can be equipped with a display device according to one embodiment of the present invention. Therefore, an electronic device capable of displaying extremely high clarity can be realized. As a result, the user can experience a high degree of immersion.

[0364] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images between a pair of display units 820, three-dimensional display utilizing parallax can be achieved.

[0365] Both electronic devices 800A and 800B can be referred to as VR-oriented electronic devices. Users who install electronic devices 800A or 800B can see the image displayed on the display unit 820 through the lens 832.

[0366] Electronic devices 800A and 800B preferably have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 to position them in the most suitable way according to the user's eye position. Furthermore, it is preferable to have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0367] The user can use the mounting part 823 to attach the electronic device 800A or electronic device 800B to their head. For example, in Figure 23A, the mounting part 823 is shown to have a shape similar to the temple of an eyeglass (also called a hinge or temple thread, etc.), but it is not limited to this. As long as the user can attach it, the mounting part 823 can have a helmet-shaped or strap-shaped design, for example.

[0368] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. A light-receiving element, which can be included in the display device according to one embodiment of the present invention, can be provided in the imaging unit 825. Furthermore, the light-receiving element can be manufactured in the imaging unit 825 using the manufacturing method of the display device according to one embodiment of the present invention. Therefore, a light-receiving element with a high aperture ratio can be provided in the imaging unit 825, and thus the imaging unit 825 can perform imaging with high sensitivity. Therefore, the imaging unit 825 can perform imaging with a high signal-to-noise ratio, for example, even under low illumination.

[0369] Note that the example shown here includes an imaging unit 825, which can be a range sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object. In other words, the imaging unit 825 is one implementation of the detection unit. For example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used as the detection unit. By using images acquired by the camera and images acquired by the distance image sensor, more information can be obtained, and more precise attitude control can be achieved.

[0370] The electronic device 800A may also include a vibration mechanism used as a bone conduction headphone. For example, the structure including this vibration mechanism may be adopted as one or more of the display unit 820, housing 821, and mounting unit 823. Thus, there is no need to separately install audio equipment such as headphones, earphones, or speakers; one can enjoy images and sound simply by installing the electronic device 800A.

[0371] Electronic devices 800A and 800B may also include input terminals. For example, cables supplying image signals from image output devices and power for charging batteries installed in the electronic devices can be connected to the input terminals.

[0372] An electronic device according to one embodiment of the present invention may also have the function of wirelessly communicating with an earphone 750. The earphone 750 includes a communication unit (not shown) and has wireless communication functionality. The earphone 750 can receive information (e.g., audio data) from the electronic device via the wireless communication function. For example, the electronic device 700A shown in FIG. 22A has the function of transmitting information to the earphone 750 via wireless communication. Additionally, for example, the electronic device 800A shown in FIG. 23A has the function of transmitting information to the earphone 750 via wireless communication.

[0373] Alternatively, the electronic device may also include an earphone unit. The electronic device 700B shown in Figure 22B includes an earphone unit 727. For example, a structure can be adopted in which the earphone unit 727 and the control unit are connected by a wire. A portion of the wiring connecting the earphone unit 727 and the control unit can also be disposed inside the housing 721 or the mounting portion 723.

[0374] Similarly, the electronic device 800B shown in Figure 23B includes an earphone unit 827. For example, a structure can be adopted in which the earphone unit 827 and the control unit 824 are connected by a wire. A portion of the wiring connecting the earphone unit 827 and the control unit 824 can also be disposed inside the housing 821 or the mounting portion 823. Furthermore, the earphone unit 827 and the mounting portion 823 can also include magnets. Thus, the earphone unit 827 can be magnetically fixed to the mounting portion 823, making storage easier, which is preferable.

[0375] Electronic devices may also include an audio output terminal capable of connecting to headphones or headsets. Additionally, electronic devices may include one or both of an audio input terminal and an audio input mechanism. For example, a microphone or other sound-receiving device can be used as an audio input mechanism. By incorporating an audio input mechanism into the electronic device, it can be made to function as a so-called headset.

[0376] Thus, as an embodiment of the present invention, both eyeglass type (electronic device 700A and electronic device 700B, etc.) and goggle type (electronic device 800A and electronic device 800B, etc.) are preferred electronic devices.

[0377] In addition, the electronic device of one embodiment of the present invention can transmit information to the earphone in a wired or wireless manner.

[0378] Figure 24A is a diagram showing an example of a pulse oximeter 900. The pulse oximeter 900 includes a housing 911 and a light-receiving device 912. The housing 911 is provided with a cavity, and the light-receiving device 912 is disposed in contact with the wall of the cavity.

[0379] The light-emitting device 912 is used as a light source for emitting light and also as a light-sensor for detecting light. For example, when an object is placed in the cavity of the housing 911, the light-emitting device 912 can detect the light it emits that illuminates the object and is then reflected by the object.

[0380] Here, the color of the blood changes based on the oxygen saturation of hemoglobin (the proportion of hemoglobin bound to oxygen). Therefore, when a finger is placed in the hollow portion of the casing 911, the intensity of the light reflected from the finger, detected by the light-emitting device 912, changes. For example, the intensity of red light detected by the light-emitting device 912 changes. Thus, the pulse oximeter 900 can measure oxygen saturation by detecting the intensity of the reflected light using the light-emitting device 912. The pulse oximeter 900 can be, for example, a pulse oximeter.

[0381] The display device according to one embodiment of the present invention can be used as the light-receiving device 912. In this case, the light-receiving device 912 includes a light-emitting element that emits at least red light (R). Alternatively, the light-receiving device 912 preferably includes a light-emitting element that emits infrared light (IR). The difference between the red light (R) reflectance of oxygen-bound hemoglobin and that of non-oxygen-bound hemoglobin is significant. On the other hand, the difference between the infrared light (IR) reflectance of oxygen-bound hemoglobin and that of non-oxygen-bound hemoglobin is small. Therefore, when the light-receiving device 912 includes not only a light-emitting element that emits red light (R) but also a light-emitting element that emits infrared light (IR), the pulse oximeter 900 can measure oxygen saturation with high accuracy.

[0382] When the display device of one embodiment of the present invention is used as the light-receiving device 912, the light-receiving device 912 is preferably flexible. When the light-receiving device 912 is flexible, it can have a curved shape. This allows, for example, light to be uniformly irradiated onto the finger, and oxygen saturation to be measured with high precision.

[0383] Figure 24B is a diagram showing an example of a portable information terminal 9100. The portable information terminal 9100 includes a display unit 9110, a housing 9101, keys 9102, and a speaker 9103, etc. The portable information terminal 9100 can be, for example, a tablet. Here, keys such as key 9102 can be, for example, keys used to switch the power on or off. That is, keys such as key 9102 can be, for example, a power switch. Alternatively, keys such as key 9102 can be, for example, operation keys used to enable the electronic device to perform desired operations.

[0384] The display unit 9110 can display information 9104 and operation buttons (operation diagrams or simply diagrams) 9105, etc.

[0385] By providing a display device according to one embodiment of the present invention in a portable information terminal 9100, the display unit 9110 can be used as a touch sensor or a near-touch sensor.

[0386] Figure 24C is a diagram showing an example of a digital signboard 9200. The digital signboard 9200 may have a structure in which a display unit 9210 is attached to a column 9201.

[0387] By providing a display device according to one embodiment of the present invention in a digital signboard 9200, the display unit 9210 can be used as a touch sensor or a near-touch sensor.

[0388] Figure 24D is a diagram showing an example of a portable information terminal 9300. The portable information terminal 9300 includes a display unit 9310, a housing 9301, a speaker 9302, a camera 9303, keys 9304, a connection terminal 9305, and a connection terminal 9306. The portable information terminal 9300 can be, for example, a smartphone. Note that the connection terminal 9305 can be, for example, a microUSB, Lightning, or Type-C connector. Additionally, the connection terminal 9306 can be, for example, a headphone jack.

[0389] For example, operation buttons 9307 can be displayed on the display unit 9310. Additionally, information 9308 can be displayed on the display unit 9310. Examples of information 9308 include: notifications of incoming emails, SNS (Social Networking Services), or phone calls; the subject line of the email or SNS message; the sender's name; the date; the time; the remaining battery level; or the radio wave intensity.

[0390] By providing a display device according to one embodiment of the present invention in a portable information terminal 9300, the display unit 9310 can be used as a touch sensor or a near-touch sensor.

[0391] Figure 24E is a diagram showing an example of a watch-type portable information terminal 9400. The portable information terminal 9400 includes a display unit 9410, a housing 9401, a wristband 9402, buttons 9403, and a connection terminal 9404, etc. Note that the connection terminal 9404, like the connection terminal 9305, can be, for example, microUSB, Lightning, or Type-C.

[0392] The display unit 9410 can display information 9406 and operation buttons 9407, etc. Figure 24E shows an example of the time being displayed as information 9406 on the display unit 9410.

[0393] By providing a display device according to one embodiment of the present invention in a portable information terminal 9400, the display unit 9410 can be used as a touch sensor or a near-touch sensor.

[0394] The structural examples shown in this embodiment and at least a portion of the corresponding diagrams can be appropriately combined with other structural examples or diagrams.

[0395] At least a portion of this embodiment can be implemented in combination with other embodiments described in this specification.

[0396] 10: Display device 10A: Display device 10B: Display device 20: pixels 51:Substrate 52: fingers 53: Floor 55: Floor 57: Floor 59:Substrate 65: Area 67: Fingerprint 69:Contact Department 71: Floor 73: Light-shielding layer 75: Light 77: Light 80: Light-receiving range 81: Light-receiving range 100: Display device 100A: Display device 100B: Display device 100C: Display device 100D: Display device 100E: Display device 101:Substrate 125: Protective layer 130: Connecting part 131: Insulation layer 141: Transistor 141a: Sacrificial membrane 141b: Sacrificial membrane 142: Transistor 143: Space 143a: Protective film 143b: Protective film 145a: Light-blocking mask 145b: Light-blocking mask 146: Filter 147a: Sacrificial Layer 147b: Sacrificial Layer 147c: Sacrifice Layer 147d: Sacrificial Layer 148: Light-shielding layer 149a: Protective layer 149b: Protective layer 151:Substrate 152:Substrate 153:Substrate 154:Substrate 155: Adhesive layer 156: Adhesive layer 158: Insulation layer 162: Display Section 164: Circuit 165: Wiring 166: Conductive layer 172:FPC 173:IC 201: Transistor 204: Connecting part 211: Insulation layer 212: Insulation layer 213: Insulation layer 214: Insulation layer 215: Insulation layer 221: Conductive layer 222a: Conductive layer 222b: Conductive layer 223: Conductive layer 228: Area 231: Semiconductor layer 240: Capacitor 241: Conductive layer 242: Adhesive layer 243: Insulation layer 244: Connection Layer 245: Conductive layer 251: Conductive layer 252: Conductive layer 254: Insulation layer 255: Insulation layer 256: Plug 261: Insulation layer 262: Insulation layer 263: Insulation layer 264: Insulation layer 265: Insulation layer 271: Plug 274: Plug 274a: Conductive layer 274b: Conductive layer 301:Substrate 310: Transistor 311: Conductive layer 312: Low resistance region 313: Insulation layer 314: Insulation layer 315: Component Separation Layer 320: Transistor 321: Semiconductor layer 323: Insulation layer 324: Conductive layer 325: Conductive layer 326: Insulation layer 327: Conductive layer 328: Insulation layer 329: Insulation layer 331:Substrate 332: Insulation layer 419: Resin layer 420:Substrate 501: Electrode 501B: Electrode 501C: Connecting Electrode 501G: Electrode 501IR: Electrode 501PD: Electrode 501R: Electrode 502: Electrode 503: Area 512: Light-emitting unit 512B: Light-emitting unit 512B_1: Light-emitting unit 512B_2: Light-emitting unit 512B_3: Light-emitting unit 512G: Light Emitting Unit 512G_1: Light-emitting unit 512G_2: Light-emitting unit 512G_3: Light-emitting unit 512Gf_1: layer 512Gf_2: layer 512IR_1: Light-emitting unit 512IR_2: Light-emitting unit 512R: Light-emitting unit 512R_1: Light-emitting unit 512R_2: Light-emitting unit 512R_3: Light-emitting unit 512Rf_1: Layer 512Rf_2: layer 521: Floor 522: Floor 523: Emissive Layer 523B: Emissive layer 523G: Emissive Layer 523R: Emissive Layer 524: Floor 525: Floor 525B: Layer 525G: Layer 525Gf: membrane 525IR: layer 525R: Layer 525Rf: membrane 531: Intermediate Layer 531B: Intermediate Layer 531G: Intermediate Layer 531Gf: Intermediate membrane 531IR: Intermediate Layer 531PD: Intermediate Layer 531R: Intermediate Layer 531Rf: Intermediate membrane 541: Insulation layer 542: Light receiving unit 542_1: Light receiving unit 542_2: Light receiving unit 543: Light-receiving layer 544: Insulation layer 550: Light-emitting element 550B: Light-emitting element 550G: Light-emitting element 550IR: Light-emitting element 550R: Light-emitting element 560: Light receiving element 560L: Light receiving element 700A: Electronic Device 700B: Electronic Devices 721: Outer shell 723: Installation Department 725: Sensor Section 727: Headphone Department 750: Headphones 751: Display Panel 753: Optical components 756: Display area 757: Border 758: Nose pad 800A: Electronic device 800B: Electronic Device 820: Display Unit 821: Outer shell 822: Communications Department 823: Installation Department 824: Control Department 825: Imaging Unit 827: Headphone Department 832: Lens 900: Pulse Oxygen Meter 911: Outer shell 912: Light-emitting device 9100: Portable Information Terminal 9101: Outer casing 9102: key 9103: Speaker 9104: News 9110: Display Unit 9200: Digital Kanban 9201: Pillar 9210: Display Unit 9300: Portable Information Terminal 9301: Outer casing 9302: Speaker 9303: Camera 9304: key 9305: Connecting terminal 9306: Connecting terminal 9307: Operation Button 9308: News 9310: Display Unit 9400: Portable Information Terminal 9401: Outer casing 9402: Wristband 9403: key 9404: Connecting terminal 9406: News 9407: Operation Button 9410: Display Unit

Claims

1. A display device, comprising: Light-emitting elements; The light-emitting element includes: a first pixel electrode; a first light-emitting layer on the first pixel electrode; an intermediate layer on the first light-emitting layer; a second light-emitting layer on the intermediate layer; a common layer on the second light-emitting layer; a common electrode on the common layer; and a first insulating layer in contact with the side surface of the first light-emitting layer, the side surface of the intermediate layer, the side surface of the second light-emitting layer, and the side surface of the common electrode. The light-receiving element includes: a second pixel electrode; a light-receiving layer on the second pixel electrode; the common layer on the light-receiving layer; the common electrode on the common layer; and a second insulating layer in contact with the side surface of the light-receiving layer and the side surface of the common electrode. The common layer in the light-emitting element is used as a hole injection layer or an electron injection layer. If the common layer in the light-emitting element is used as a hole injection layer, it is used as a hole transport layer in the light-receiving element. If the common layer in the light-emitting element is used as an electron injection layer, it is used as an electron transport layer in the light-receiving element.

2. A display device, comprising: First light-emitting element; Second light-emitting element; The first light-emitting element includes: a first pixel electrode; a first light-emitting layer on the first pixel electrode; an intermediate layer on the first light-emitting layer; a second light-emitting layer on the intermediate layer; a common layer on the second light-emitting layer; and a common electrode on the common layer. The light-receiving element includes: a second pixel electrode; a light-receiving layer on the second pixel electrode; the common layer on the light-receiving layer; and the common electrode on the common layer. The common layer in the first light-emitting element is used as a hole injection layer or an electron injection layer. The second light-emitting element emits infrared or near-infrared light. A first insulating layer that contacts the side of the first light-emitting layer faces a second insulating layer that contacts the side of the light-receiving layer, and the common electrode is located between the first insulating layer and the second insulating layer.

3. The display device of claim 1 or 2, wherein the first light-emitting layer and the second light-emitting layer emit light of the same color as each other.

4. A display device, comprising: Light-emitting elements; Light-receiving element; First transistor; The light-emitting element includes: a first pixel electrode; a first light-emitting layer on the first pixel electrode; an intermediate layer on the first light-emitting layer; a second light-emitting layer on the intermediate layer; a common layer on the second light-emitting layer; and a common electrode on the common layer. The light-receiving element includes: a second pixel electrode; a light-receiving layer on the second pixel electrode; the common layer on the light-receiving layer; and the common electrode on the common layer. The common layer in the light-emitting element is used as a hole injection layer or an electron injection layer. If the common layer in the light-emitting element is used as a hole injection layer, it is also used as a hole transport layer in the light-receiving element. If the common layer in the light-emitting element is used as an electron injection layer, it is also used as an electron transport layer in the light-receiving element. One of the source and drain electrodes of the first transistor is electrically connected to the first pixel electrode, and one of the source and drain electrodes of the second transistor is electrically connected to the second pixel electrode. The first transistor and the second transistor include silicon or metal oxide in the channel formation region. Furthermore, the gap is in contact with the side surface of the first light-emitting layer, the side surface of the light-receiving layer, and the bottom surface of the common electrode.

5. A method for manufacturing a display device, comprising the following steps: a first process of forming a first pixel electrode, a second pixel electrode, and a connecting electrode; a second process of sequentially depositing a first light-emitting film, an intermediate film, and a second light-emitting film on the first pixel electrode and the second pixel electrode; a third process of forming a first sacrificial film on the second light-emitting film and the connecting electrode; a fourth process of etching the first sacrificial film, the second light-emitting film, the intermediate film, and the first light-emitting film to expose the second pixel electrode, and forming a first light-emitting layer, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, and a first sacrificial layer on the second light-emitting layer and the connecting electrode on the first pixel electrode; a fifth process of depositing a light-receiving film on the first sacrificial layer and the second pixel electrode; a sixth process of forming a second sacrificial film on the light-receiving film; and a seventh process of etching the second sacrificial film and the light-receiving film to form a light-receiving layer on the second pixel electrode and a second sacrificial layer on the light-receiving layer. The eighth process involves removing the first sacrificial layer and the second sacrificial layer; and the ninth process involves forming a common electrode on the second light-emitting layer and the light-receiving layer in such a way that it has a region in contact with the connecting electrode.

6. A method for manufacturing a display device, comprising the following steps: a first process for forming a first pixel electrode and a second pixel electrode; a second process for sequentially depositing a first light-emitting film, an intermediate film, and a second light-emitting film on the first pixel electrode and the second pixel electrode; a third process for forming a first sacrificial film on the second light-emitting film; a fourth process for etching the first sacrificial film, the second light-emitting film, the intermediate film, and the first light-emitting film to expose the second pixel electrode, and forming a first light-emitting layer, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, and a first sacrificial layer on the second light-emitting layer on the first pixel electrode; a fifth process for depositing a light-receiving film on the first sacrificial layer and the second pixel electrode; a sixth process for forming a second sacrificial film on the light-receiving film; a seventh process for etching the second sacrificial film and the light-receiving film to form a light-receiving layer on the second pixel electrode and a second sacrificial layer on the light-receiving layer; an eighth process for removing the first sacrificial layer and the second sacrificial layer; and a ninth process for forming a common electrode on the second light-emitting layer and the light-receiving layer.

7. The method of manufacturing a display device as claimed in claim 5 or 6, wherein the first light-emitting film, the second light-emitting film and the light-receiving film are formed by vapor deposition using a shadow mask.

8. A method for manufacturing a display device as claimed in claim 5 or 6, wherein the first sacrificial film and the second sacrificial film comprise the same metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film; in the fourth process, the first light-emitting film and the second light-emitting film are etched by a dry etching method using an etching gas that does not contain oxygen as the main component; and in the eighth process, the first sacrificial layer and the second sacrificial layer are removed by a wet etching method using at least one of tetramethylammonium hydroxide aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, and nitric acid.

9. A method for manufacturing a display device, comprising the following steps: a first process for forming a first pixel electrode and a second pixel electrode; a second process for sequentially depositing a first light-emitting film, an intermediate film, and a second light-emitting film on the first pixel electrode and the second pixel electrode; a third process for forming a first sacrificial film on the second light-emitting film; a fourth process for etching the first sacrificial film, the second light-emitting film, the intermediate film, and the first light-emitting film to expose the second pixel electrode, and forming a first light-emitting layer, an intermediate layer on the first light-emitting layer, a second light-emitting layer on the intermediate layer, and a first sacrificial layer on the second light-emitting layer on the first pixel electrode; a fifth process for depositing a light-receiving film on the first sacrificial layer and the second pixel electrode; a sixth process for forming a second sacrificial film on the light-receiving film; a seventh process for etching the second sacrificial film and the light-receiving film to form a light-receiving layer on the second pixel electrode and a second sacrificial layer on the light-receiving layer; an eighth process for removing the first sacrificial layer and the second sacrificial layer; and a ninth process for forming a common electrode on the second light-emitting layer and the light-receiving layer. The first sacrificial membrane and the second sacrificial membrane contain aluminum oxide.

10. The method of manufacturing the display device as described in claim 5 or 6 further includes: The tenth process, which follows the ninth process, forms a protective layer on the common electrode.

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