Method for manufacturing a display device

Abstract

Provided is a display device having the function of detecting an object that comes into contact with or close to a display unit. This display device includes a light-emitting element, and a light-receiving element. The light-emitting element includes a first pixel electrode, a first function layer, a light-emitting layer, a common layer, and a common electrode. The light-receiving element includes a second pixel electrode, a second function layer, a light-receiving layer, a common layer, and a common electrode. The first function layer includes one of a hole-injection layer and an electron-injection layer, and the second function layer includes one of a hole transport layer and an electron transport layer. The common layer has the function as the other one of the hole-injection layer and the electron-injection layer in the light-emitting element, and has the function as the other one of the hole transport layer and the electron transport layer in the light-receiving element.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION One embodiment of the present invention relates to a display device and a manufacturing method of the display device.

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

[0003] In recent years, display devices have been used in a variety of devices, including information terminal devices such as smartphones, tablet devices, and laptop PCs, as well as television devices and monitor devices. In addition to displaying images, there is a demand for display devices that have various additional functions, such as a touch sensor function or a function for capturing fingerprint images for authentication.

[0004] As a display device, for example, a light-emitting device having a light-emitting element (also called a light-emitting device) has been developed. In particular, a light-emitting element (also called an EL element or an EL device) utilizing the electroluminescence (EL) phenomenon has features such as being easily thin and lightweight, being capable of high-speed response to input signals, and being able to be driven using a DC constant voltage power supply, and is therefore applied to a display device. For example, Patent Document 1 discloses a flexible light-emitting device using an organic EL element (also called an organic EL device). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-197522 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a display device having a function of detecting an object in contact with or close to a display portion, and a manufacturing method thereof.An object of one embodiment of the present invention is to provide a display device having a function of performing authentication, and a manufacturing method thereof.An object of one embodiment of the present invention is to provide a display device with a high aperture ratio, and a manufacturing method thereof.An object of one embodiment of the present invention is to provide a small-sized display device, and a manufacturing method thereof.An object of one embodiment of the present invention is to provide a highly reliable display device, and a manufacturing method thereof.An object of one embodiment of the present invention is to provide a novel display device, and a manufacturing method thereof.

[0007] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these can be extracted from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0008] One embodiment of the present invention is a display device that includes a light-emitting element and a light-receiving element. The light-emitting element has a first pixel electrode, a first functional layer, a light-emitting layer, a common layer, and a common electrode. The light-receiving element has a second pixel electrode, a second functional layer, a light-receiving layer, a common layer, and a common electrode. The first functional layer has one of a hole-injection layer and an electron-injection layer. The second functional layer has one of a hole-transport layer and an electron-transport layer. The common layer functions as the other of the hole-injection layer and the electron-injection layer in the light-emitting element.

[0009] Alternatively, in the above embodiment, the first functional layer and the second functional layer may be separated from each other.

[0010] Alternatively, in the above aspect, the semiconductor device may include a first transistor and a second transistor, one of a source or a drain of the first transistor being electrically connected to a first pixel electrode, one of a source or a drain of the second transistor being electrically connected to a second pixel electrode, and the first transistor and the second transistor may have silicon or a metal oxide in a channel formation region.

[0011] Alternatively, one embodiment of the present invention includes a first step of forming a first pixel electrode, a second pixel electrode, and a connecting electrode; a second step of forming a light-emitting film over the first pixel electrode and the second pixel electrode; a third step of forming a first sacrificial film over the light-emitting film and the connecting electrode; a fourth step of etching the first sacrificial film and the light-emitting film to expose the second pixel electrode and forming a light-emitting layer over the first pixel electrode and a first sacrificial layer over the light-emitting layer and the connecting electrode; and a fourth step of forming a light-receiving film over the light-emitting layer and the second pixel electrode. a fifth step of etching the light-receiving film and the light-receiving film to form a second sacrificial film on the light-receiving film and the connecting electrode; a seventh step 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 and the connecting electrode; an eighth step of removing the first sacrificial layer and the second sacrificial layer; a ninth step of forming a common layer on the light-emitting layer and the light-receiving layer; and a tenth step of forming the common electrode so as to have a region in contact with the common layer and the connecting electrode.

[0012] Alternatively, in the above embodiment, the common layer may function as either a hole injection layer or an electron injection layer in a light-emitting element having a first pixel electrode, a light-emitting layer, a common layer, and a common electrode.

[0013] Alternatively, in the above aspect, there may be an eleventh step between the first step and the second step of depositing a first functional film on the first pixel electrode and the second pixel electrode, a fourth step of etching the first functional film to form a first functional layer on the first pixel electrode, a twelfth step between the fourth step and the fifth step of depositing a second functional film on the first sacrificial layer and the second pixel electrode, and a seventh step of etching the second functional film to form a second functional layer on the second pixel electrode, wherein the first functional layer has the other of a hole injection layer or an electron injection layer, and the second functional layer has one of a hole transport layer or an electron transport layer.

[0014] Alternatively, in the above embodiment, the light-emitting film, the light-receiving film, and the common layer may be formed by a vapor deposition method using a shielding mask.

[0015] Alternatively, in the above aspect, the first sacrificial film and the second sacrificial film may comprise the same metal film, alloy film, metal oxide film, semiconductor film, or inorganic insulating film, and in the fourth step, the light-emitting film may be etched by dry etching using an etching gas that does not contain oxygen as a main component, and in the eighth step, the first sacrificial layer and the second sacrificial layer may 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.

[0016] Alternatively, in the above aspect, the first sacrificial film and the second sacrificial film may contain aluminum oxide.

[0017] Alternatively, in the above embodiment, a fourteenth step of forming a protective layer on the common electrode may be included after the tenth step. [Effects of the Invention]

[0018] According to one embodiment of the present invention, a display device having a function of detecting an object in contact with or close to a display portion and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a display device having a function of performing authentication and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a display device with a high aperture ratio and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a small-sized display device and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a highly reliable display device and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a novel display device and a manufacturing method thereof can be provided.

[0019] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these can be extracted from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0020] 1A to 1E are cross-sectional views showing examples of the configuration of a display device, and Fig. 1F is a diagram showing an example of a captured image. 2A and 2B are top views showing configuration examples of the display device. 3A and 3B are top views showing configuration examples of the display device. Fig. 4A is a top view showing an example of the configuration of a display device, and Fig. 4B is a diagram showing the light receiving range of a light receiving element. FIG. 5 is a top view showing an example of the configuration of the display device. 6A to 6E are cross-sectional views showing examples of the configuration of a display device. 7A to 7D are cross-sectional views showing an example of a method for manufacturing a display device. 8A to 8C are cross-sectional views showing an example of a method for manufacturing a display device. 9A to 9D are cross-sectional views showing an example of a method for manufacturing a display device. 10A to 10C are cross-sectional views showing an example of a method for manufacturing a display device. 11A to 11C are cross-sectional views showing an example of a method for manufacturing a display device. Fig. 12A is a top view showing an example of the configuration of a display device, and Figs. 12B and 12C are cross-sectional views showing the example of the configuration of a display device. 13A and 13B are a top view and a cross-sectional view, respectively, illustrating an example of the configuration of a display device. FIG. 14 is a perspective view showing a configuration example of a display device. FIG. 15 is a cross-sectional view showing an example of the configuration of a display device. FIG. 16 is a cross-sectional view showing an example of the configuration of a display device. FIG. 17 is a cross-sectional view showing an example of the configuration of a display device. FIG. 18 is a cross-sectional view showing an example of the configuration of a display device. FIG. 19 is a cross-sectional view showing an example of the configuration of a display device. 20A to 20D are cross-sectional views showing examples of the configuration of a light-emitting element. 21A and 21B are diagrams showing configuration examples of a display device. 22A to 22G are diagrams showing configuration examples of a display device. 23A to 23E are diagrams showing an example of an electronic device. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments will be described with reference to the drawings. However, it will be readily understood by those skilled in the art that the embodiments can be implemented in many different ways and that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the following description of the embodiments.

[0022] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0023] In the drawings described in this specification, the size of each component, the thickness of a layer, or an area may be exaggerated for clarity, and therefore, the drawings are not necessarily limited to the scale.

[0024] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components and do not limit the number.

[0025] Furthermore, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the terms "conductive layer" and "insulating layer" may be interchangeable with the terms "conductive film" and "insulating film."

[0026] In this specification and the like, the EL layer refers to a layer provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance (also referred to as a light-emitting layer), or a stack including a light-emitting layer.

[0027] In this specification and the like, a display panel, which is one aspect of a display device, has a function of displaying (outputting), for example, an image on a display surface, and therefore the display panel is one aspect of an output device.

[0028] In addition, in this specification, a display panel having a connector such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) attached to the substrate, or having an IC mounted on the substrate using a COG (Chip On Glass) method or the like, may be referred to as a display panel module, display module, or simply a display panel, etc.

[0029] (Embodiment 1) In this embodiment, a structural example 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.

[0030] A display device according to one embodiment of the present invention has a display portion in which pixels are arranged in a matrix. Each pixel includes a plurality of subpixels, each of which includes a light-emitting element (also referred to as a light-emitting device). The subpixels in the same pixel can emit light of different colors.

[0031] Each light-emitting element has a pair of electrodes and a light-emitting layer between them. The light-emitting element is preferably an organic EL element (organic electroluminescent element). Two or more light-emitting elements that emit different colors have light-emitting layers containing different materials. For example, a full-color display device can be realized by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light, respectively.

[0032] Here, when creating separate light-emitting layers for light-emitting elements of different colors, it is known to form them by vapor deposition using a shadow mask such as a metal mask. However, with this method, deviations from the design occur in the shape and position of the island-shaped organic film due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spread of the contours of the deposited film due to vapor scattering, making it difficult to achieve high definition and a high aperture ratio. For this reason, measures have been taken to artificially increase the definition (also known as pixel density) by applying special pixel arrangement methods such as a pentile arrangement.

[0033] In one embodiment of the present invention, a light-emitting layer is processed into a fine pattern without using a shadow mask such as a metal mask. This allows subpixels to be made finer than when light-emitting layers are separately formed using a shadow mask, thereby increasing the pixel aperture ratio. Furthermore, because light-emitting layers can be separately formed, a display device with extremely vivid, high-contrast, and high display quality can be realized.

[0034] By miniaturizing the subpixels, subpixels that do not contribute to display can be provided in the pixel. For example, in addition to subpixels having a light-emitting element, subpixels having a light-receiving element (also referred to as a light-receiving device) can be provided in the pixel. Even in this case, the display device of one embodiment of the present invention can prevent the pixel density from becoming low. 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.

[0035] The light-receiving element included in the display device of one embodiment of the present invention functions as an optical sensor. Therefore, the display device of one embodiment of the present invention can display an image using a light-emitting element and detect an object in contact with or near the display portion using the light-receiving element. Furthermore, when a user's finger touches the display portion, the display device of one embodiment of the present invention can perform authentication based on a fingerprint of the finger.

[0036] By providing the light receiving element in the display section, it is not necessary to attach a sensor externally to the display device, and therefore the number of components in the display device can be reduced, making it possible to make the display device smaller and lighter.

[0037] In addition, in the display device of one embodiment of the present invention, a light-receiving element can detect light that is emitted from a light-emitting element, irradiated onto an object, and reflected by the object. Therefore, for example, even in a dark place, an object that is in contact with or close to the display unit can be detected, and authentication such as fingerprint authentication can be performed.

[0038] In this specification, etc., a device fabricated using a metal mask or FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. In addition, in this specification, etc., a device fabricated without using a metal mask or FMM may be referred to as a device with an MML (metal maskless) structure.

[0039] In this specification etc., a structure in which different light-emitting layers are made for light-emitting elements of each color (here, blue (B), green (G), and red (R)), or in which the light-emitting layers are painted differently, may be referred to as an SBS (Side By Side) structure. In addition, in this specification etc., a light-emitting element that can emit white light may be referred to as a white light-emitting element. In addition, a white light-emitting element can be made into a light-emitting element that displays full color by combining it with a colored layer (for example, a color filter).

[0040] Furthermore, light-emitting elements can be broadly classified into single structures and tandem structures. A single-structure device has one light-emitting unit between a pair of electrodes, and the light-emitting unit preferably includes one or more light-emitting layers. To obtain white light emission, two or more light-emitting layers may be selected so that the light emitted from each of the two or more light-emitting layers has a complementary color relationship. For example, by making the emission color of the first light-emitting layer and the emission color of the second light-emitting layer complementary to each other, a configuration that emits white light as a whole can be obtained. The same applies to light-emitting elements having three or more light-emitting layers.

[0041] A tandem-structure device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers. To obtain white light, light from the light-emitting layers of multiple light-emitting units may be combined to obtain white light. The configuration for obtaining white light is the same as that of a single-structure device. In a tandem-structure device, it is preferable to provide an intermediate layer such as a charge-generating layer between multiple light-emitting units.

[0042] Furthermore, when comparing the above-mentioned white light-emitting element (single structure or tandem structure) with a light-emitting element having an SBS structure, the light-emitting element having an SBS structure can reduce power consumption compared to the white light-emitting element. Therefore, if you want to keep the power consumption of a display device low, it is preferable to use a light-emitting element having an SBS structure. On the other hand, the manufacturing process for a white light-emitting element is simpler than that for a light-emitting element having an SBS structure, so the manufacturing cost can be reduced or the manufacturing yield can be increased.

[0043] 1A to 1E are cross-sectional views illustrating structural examples of a display device according to one embodiment of the present invention.

[0044] A display device 10A shown in FIG. 1A has, between a substrate 51 and a substrate 59, a layer 53 having a light receiving element and a layer 57 having a light emitting element.

[0045] A display device 10B shown in FIG. 1B has, between a substrate 51 and a substrate 59, a layer 55 having transistors, a layer 53 having light receiving elements, and a layer 57 having light emitting elements.

[0046] The display device 10A and the display device 10B are configured such that red (R), green (G), and blue (B) light is emitted from a layer 57 having light-emitting elements.

[0047] In one embodiment of the present invention, a display portion includes a plurality of pixels arranged in a matrix. Each pixel includes one or more subpixels. Each subpixel includes one light-emitting element or one light-receiving element. For example, a pixel may include four subpixels. Specifically, each pixel may include light-emitting elements of three colors, R, G, and B, and a light-receiving element. Alternatively, each pixel may include light-emitting elements of three colors, yellow (Y), cyan (C), and magenta (M), and a light-receiving element. Alternatively, each pixel may include five subpixels. Specifically, each pixel may include light-emitting elements of four colors, R, G, B, and white (W), and a light-receiving element. Alternatively, each pixel may include light-emitting elements of four colors, R, G, B, and infrared (IR), and a light-receiving element. Note that a light-receiving element may be provided in all or some of the pixels. Furthermore, each pixel may include multiple light-receiving elements.

[0048] The display device of one embodiment of the present invention may have a function of detecting an object, such as a finger, in contact with the display device. For example, as shown in FIGS. 1C and 1D , light emitted from a light-emitting element in a layer 57 having a light-emitting element is reflected by a finger 52 in contact with the display device 10B, and the light-receiving element in a layer 53 having a light-receiving element detects the reflected light. As a result, in the case shown in FIG. 1C , it is possible to detect that the finger 52 has come into contact with the display device 10B. In addition, in the case shown in FIG. 1D , it is possible to detect that the finger 52 has come into proximity with the display device 10B. That is, the display device of one embodiment of the present invention can function as a touch sensor (also referred to as a direct touch sensor) and can also function as a near-touch sensor (also referred to as a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor).

[0049] As described above, for example, if the display device 10B functions as a near-touch sensor, the finger 52 can be detected when the finger 52 is close to the display device 10B, even if the finger 52 does not touch the display device 10B. For example, it is preferable that the display device 10B be configured to detect the finger 52 when the distance between the display device 10B and the finger 52 is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. This configuration allows the finger 52 to operate the display device 10B without directly touching it, in other words, allows the display device 10B to be operated in a contactless (touchless) manner. This configuration reduces the risk of the display device 10B becoming dirty or scratched. Furthermore, the display device 10B can be operated with the finger 52 while preventing the finger 52 from directly touching the display device 10B with dirt (e.g., dust, viruses, etc.).

[0050] Furthermore, the display device of one embodiment of the present invention can have a function of detecting, for example, a fingerprint of a finger 52. Fig. 1E is a schematic enlarged view of a contact portion when a finger 52 is in contact with a substrate 59. Fig. 1E also shows that a layer 57 having a light-emitting element and a layer 53 having a light-receiving element are alternately arranged.

[0051] A fingerprint is formed by concave and convex portions of finger 52. Therefore, the convex portions of the fingerprint are in contact with substrate 59 as shown in FIG.

[0052] Light reflected from a surface or interface can be classified into specular reflection and diffuse reflection. Specular reflection is highly directional light, with the angle of incidence and the angle of reflection matching, while diffuse reflection is low-directional light, with its intensity less dependent on the angle. The diffuse reflection component is dominant in the light reflected from the surface of the finger 52. On the other hand, the specular reflection component is dominant in the light reflected from the interface between the substrate 59 and the atmosphere.

[0053] The intensity of light reflected by the contact or non-contact surface between the finger 52 and the substrate 59 and incident on the layer 53 located directly below them is the sum of specularly reflected light and diffusely reflected light. As described above, at the concave portions of the finger 52, the substrate 59 and the finger 52 do not come into contact, so specularly reflected light (indicated by the solid arrows) is dominant, whereas at the convex portions, they come into contact, so diffusely reflected light (indicated by the dashed arrows) from the finger 52 is dominant. Therefore, the intensity of light received by the light receiving element in the layer 53 located directly below the concave portions is higher than the intensity of light received by the light receiving element in the layer 53 located directly below the convex portions. Therefore, the fingerprint of the finger 52 can be captured using the light receiving element.

[0054] The arrangement interval of the light receiving elements in layer 53 is set to be smaller than the distance between two convex portions of a fingerprint, preferably the distance between adjacent convex and concave portions, so that a clear fingerprint image can be obtained. Since the distance between convex and concave portions of a human fingerprint is generally between 150 μm and 250 μm, the arrangement interval of the light receiving elements is set to, for example, 400 μm or less, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 120 μm or less, even more preferably 100 μm or less, and even more preferably 50 μm or less. The smaller the arrangement interval, the better, but it can be set to, for example, 1 μm or more, 10 μm or more, or 20 μm or more.

[0055] 1F shows an example of a fingerprint image captured by a display device according to one embodiment of the present invention. In FIG. 1F, the outline of finger 52 is indicated by a dashed line in region 65, and the outline of contact portion 69 is indicated by a dashed line. In region 65, a fingerprint 67 with high contrast can be captured due to differences in the amount of light incident on the light receiving element.

[0056] As described above, in the display device of one embodiment of the present invention, the light-receiving element can detect light that is emitted from the light-emitting element, irradiated onto an object such as the finger 52, and reflected by the object. Therefore, for example, even in a dark place, an object in contact with or close to the display portion can be detected, and authentication such as fingerprint authentication can be performed.

[0057] Furthermore, by providing the light receiving element in the display section, it is not necessary to attach a sensor externally to the display device, which reduces the number of components in the display device, thereby enabling the display device to be made smaller and lighter.

[0058] [Configuration example 1] 2A is a schematic top view illustrating an example of the configuration of a display device 10 according to one embodiment of the present invention. The display device 10 includes a plurality of light-emitting elements 110R that emit red light, a plurality of light-emitting elements 110G that emit green light, a plurality of light-emitting elements 110B that emit blue light, and a plurality of light-receiving elements 150. In FIG. 2A, in order to easily distinguish between the light-emitting elements 110, the light-emitting regions of the light-emitting elements 110 are labeled with R, G, and B. Furthermore, the light-receiving regions of the light-receiving elements 150 are labeled with PD.

[0059] In this specification and the like, when describing matters common to the display device 10A and the display device 10B, or when there is no need to distinguish between them, they will simply be referred to as "display device 10." In other words, the configuration of the display device 10 can be applied to both the display device 10A shown in FIG. 1A and the display device 10B shown in FIG. 1B. The same applies to other elements.

[0060] The light-emitting elements 110R, 110G, 110B, and the light-receiving elements 150 are arranged in a matrix. FIG. 2A shows an example in which the light-emitting elements 110R, 110G, and 110B are arranged in the X direction, with the light-receiving elements 150 arranged below them. FIG. 2A also shows an example in which the light-emitting elements 110 emitting light of the same color are arranged in the Y direction intersecting the X direction. In the display device 10 shown in FIG. 2A, a pixel 20 can be configured by, for example, a sub-pixel having the light-emitting element 110R, a sub-pixel having the light-emitting element 110G, and a sub-pixel having the light-emitting element 110B arranged in the X direction, and a sub-pixel having the light-receiving element 150 provided below these sub-pixels.

[0061] As the light-emitting elements 110R, 110G, and 110B, it is preferable to use EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes). Examples of light-emitting materials that the EL elements have include fluorescent materials, phosphorescent materials, inorganic compounds (e.g., quantum dot materials), and materials that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF materials).

[0062] For example, a pn-type or pin-type photodiode can be used as the light receiving element 150. The light receiving element 150 functions as a photoelectric conversion device that detects light incident on the light receiving element 150 and generates electric charges. The amount of electric charges generated is determined based on the amount of incident light.

[0063] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light receiving element 150. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of display devices.

[0064] In one embodiment of the present invention, an organic EL device is used as the light-emitting element 110, and an organic photodiode is used as the light-receiving element 150. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL device.

[0065] 2A shows a common electrode 123 and a connection electrode 111C. Here, the connection electrode 111C is electrically connected to the common electrode 123. The connection electrode 111C is provided outside the display section where the light-emitting elements 110 and the light-receiving elements 150 are arranged. Also in FIG. 2A, the common electrode 123 having an area overlapping with the light-emitting elements 110, the light-receiving elements 150, and the connection electrode 111C is shown by a dashed line.

[0066] The connection electrode 111C can be provided along the periphery of the display unit. For example, it may be provided along one side of the periphery of the display unit, or it may be provided over two or more sides of the periphery of the display unit. That is, if the top surface of the display unit has a rectangular shape, the top surface of the connection electrode 111C can have a strip-like, L-shaped, U-shaped (square bracket-shaped), frame-like, or the like shape.

[0067] Fig. 2B is a schematic top view showing an example of the configuration of the display device 10, which is a modification of the display device 10 shown in Fig. 2A. The display device 10 shown in Fig. 2B differs from the display device 10 shown in Fig. 2A in that it includes a light-emitting element 110IR that emits infrared light. The light-emitting element 110IR can emit, for example, near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less).

[0068] 2B, in addition to the light emitting elements 110R, 110G, and 110B, a light emitting element 110IR is arranged in the X direction, and below that, a light receiving element 150 is arranged. The light receiving element 150 has a function of detecting infrared light.

[0069] Fig. 3A is a schematic top view showing an example of the configuration of the display device 10, which is a modified example of the display device 10 shown in Fig. 2B. The display device 10 shown in Fig. 3A differs from the display device 10 shown in Fig. 2B in that the light receiving elements 150 and the light emitting elements 110IR are arranged alternately in the X direction.

[0070] 3A, the light-emitting elements 110R, 110G, and 110B are arranged in different rows from the light-emitting element 110IR. This allows the widths (lengths in the X direction) of the light-emitting elements 110R, 110G, and 110B to be increased, thereby increasing the brightness of the light emitted by the pixel 20.

[0071] Fig. 3B is a schematic top view showing an example of the configuration of the display device 10, which is a modification of the display device 10 shown in Fig. 3A. The display device 10 shown in Fig. 3A differs from the display device 10 shown in Fig. 3A in that the light-emitting elements 110 are arranged in the order G, B, R rather than R, G, B in the X direction. Also, it differs from the display device 10 shown in Fig. 3A in that the light-receiving element 150 is provided below the light-emitting elements 110G and 110B, and the light-emitting element 110IR is provided below the light-emitting element 110R.

[0072] The area occupied by the light receiving element 150 in the display device 10 shown in FIG. 3B is larger than the area occupied by the light receiving element 150 in the display device 10 shown in FIG. 3A. This increases the sensitivity of light detection by the light receiving element 150. Therefore, for example, when the display device 10 functions as a touch sensor or a near-touch sensor, it is possible to detect an object in contact with or in proximity to the display device 10 with high accuracy. In particular, when the display device 10 functions as a near-touch sensor, the sensitivity of light detection by the light receiving element 150 has a significant effect on the accuracy of object detection, so it is preferable to increase the area occupied by the light receiving element 150.

[0073] Fig. 4A is a schematic top view showing an example of the configuration of the display device 10, which is a modified example of the display device 10 shown in Fig. 3B. The display device 10 shown in Fig. 4A differs from the display device 10 shown in Fig. 3B in that the light receiving element 150 is provided below the light emitting element 110G, and the light emitting element 110IR is provided below the light emitting elements 110B and 110R.

[0074] The area occupied by the light receiving elements 150 in the display device 10 shown in FIG. 4A is smaller than the area occupied by the light receiving elements 150 in the display device 10 shown in FIG. 3B. By narrowing the area occupied by the light receiving elements 150, the light receiving range of each light receiving element 150 can be narrowed. This reduces the overlap of the light receiving ranges between different light receiving elements 150, for example, between adjacent light receiving elements 150. This prevents the image captured using the light receiving elements 150 from becoming blurred, making it difficult to capture a clear image. For the above reasons, if the display device 10 has a function for performing authentication such as fingerprint authentication, reducing the area occupied by the light receiving elements 150 is preferable because it allows, for example, a fingerprint to be clearly captured, thereby improving the accuracy of authentication.

[0075] 4B is a cross-sectional view showing the change in the light-receiving range of the light-receiving element 150 when the occupation area of ​​the light-receiving element 150, specifically the length in the X direction, is changed. In FIG. 4B, the light-receiving element 150 is shown on the lower surface side of the layer 71, and the light-shielding layer 73 is shown on the upper surface side of the layer 71. Also, the substrate 59 is shown on the layer 71. Furthermore, a light-receiving element whose length in the X direction is approximately three times that of the light-receiving element 150 is designated as light-receiving element 150L.

[0076] 4B, light incident on light receiving element 150 is designated as light 75 and is indicated by a solid line. Light that is not incident on light receiving element 150 but is incident on light receiving element 150L is designated as light 77 and is indicated by a dashed line. The light receiving range of each light receiving element 150 is designated as light receiving range 80, and the light receiving range of each light receiving element 150L is designated as light receiving range 81.

[0077] As shown in Fig. 4B, the light-receiving range 80 of the light-receiving element 150 is narrower than the light-receiving range 81 of the light-receiving element 150L. In other words, as the area occupied by the light-receiving element becomes smaller, the light-receiving range per light-receiving element becomes narrower, and the overlap of the light-receiving ranges between different light-receiving elements becomes smaller. Fig. 4B shows an example in which the light-receiving ranges 80 of adjacent light-receiving elements 150 on the surface of the substrate 59 do not overlap, but the light-receiving ranges 81 of adjacent light-receiving elements 150L partially overlap.

[0078] Fig. 5 is a schematic top view showing an example of the configuration of the display device 10, which is a modified example of the display device 10 shown in Fig. 2A. The display device 10 shown in Fig. 5 differs from the display device 10 shown in Fig. 2A in that light receiving elements 150 are provided only in some of the pixels 20. In Fig. 5, the pixels 20 not provided with the light receiving elements 150 are referred to as pixels 20a.

[0079] 5, the drive frequency of the display device 10 can be increased. Therefore, for example, if the display device 10 functions as a touch sensor or a near-touch sensor, the position of an object in contact with or near the display device 10 can be quickly detected. Therefore, for example, the movement of an object in contact with or near the display device 10 can be detected quickly and accurately.

[0080] FIG. 6A is a cross-sectional view corresponding to dashed-dotted line A1-A2 in FIG. 2A, and FIG. 6B is a cross-sectional view corresponding to dashed-dotted line B1-B2 in FIG. 2A. FIG. 6C is a cross-sectional view corresponding to dashed-dotted line C1-C2 in FIG. 2A, and FIG. 6D is a cross-sectional view corresponding to dashed-dotted line D1-D2 in FIG. 2A. FIG. 6E is a cross-sectional view corresponding to dashed-dotted line B3-B4 in FIG. 3A. The light-emitting element 110R, the light-emitting element 110G, the light-emitting element 110B, and the light-receiving element 150 are provided on a substrate 101. When the display device 10 includes a light-emitting element 110IR, the light-emitting element 110IR is provided on the substrate 101.

[0081] In this specification and the like, for example, when it is said that "B is on A" or "B is below A," A and B do not necessarily have to have an area where they contact each other.

[0082] 6A shows an example of the cross-sectional configuration of the light-emitting element 110R, the light-emitting element 110G, and the light-emitting element 110B. Also, FIG.

[0083] The light-emitting element 110R has a pixel electrode 111R, a hole injection layer 113R, a hole transport layer 115R, a light-emitting layer 117R, an electron transport layer 119R, a common layer 121, and a common electrode 123. The light-emitting element 110G has a pixel electrode 111G, a hole injection layer 113G, a hole transport layer 115G, a light-emitting layer 117G, an electron transport layer 119G, a common layer 121, and a common electrode 123. The light-emitting element 110B has a pixel electrode 111B, a hole injection layer 113B, a hole transport layer 115B, a light-emitting layer 117B, an electron transport layer 119B, a common layer 121, and a common electrode 123. The light-receiving element 150 has a pixel electrode 111PD, a hole transport layer 115PD, a light-receiving layer 157, an electron transport layer 119PD, a common layer 121, and a common electrode 123.

[0084] The common layer 121 functions as an electron injection layer in the light-emitting element 110. On the other hand, the common layer 121 functions as an electron transport layer in the light-receiving element 150. Therefore, the light-receiving element 150 does not need to have the electron transport layer 119PD.

[0085] The hole injection layer 113, the hole transport layer 115, the electron transport layer 119, and the common layer 121 can also be referred to as functional layers.

[0086] The pixel electrode 111, the hole injection layer 113, the hole transport layer 115, the light-emitting layer 117, and the electron transport layer 119 can be provided separately for each element. The common layer 121 and the common electrode 123 are provided in common to the light-emitting element 110R, the light-emitting element 110G, the light-emitting element 110B, and the light-receiving element 150.

[0087] 6A and 6B, the light-emitting element 110 and the light-receiving element 150 may have a hole-blocking layer and an electron-blocking layer. The light-emitting element 110 and the light-receiving element 150 may also have a layer containing a bipolar substance (a substance with high electron-transporting and hole-transporting properties) or the like.

[0088] A gap is provided between the common layer 121 and the insulating layer 131. This prevents the common layer 121 from coming into contact with the side surfaces of the light-emitting layer 117, the light-receiving layer 157, the hole-transporting layer 115, and the hole-injecting layer 113. This prevents short circuits in the light-emitting element 110 and the light-receiving element 150.

[0089] The voids are more easily formed, for example, as the distance between the light-emitting layers 117 becomes shorter. For example, the voids can be suitably formed when the distance is 1 μm or less, preferably 500 nm or less, and 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.

[0090] 6A illustrates a configuration in which, from bottom to top, the light-emitting element 110 is provided with a pixel electrode 111, a hole injection layer 113, a hole transport layer 115, a light-emitting layer 117, an electron transport layer 119, a common layer 121 (electron injection layer), and a common electrode 123, and the light-receiving element 150 is provided with a pixel electrode 111PD, a hole transport layer 115PD, a light-receiving layer 157, an electron transport layer 119PD, a common layer 121, and a common electrode 123, but this is not a limitation of one embodiment of the present invention. For example, the light-emitting element 110 may be provided with, from bottom to top, a pixel electrode, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, a hole injection layer, and a common electrode, and the light-receiving element 150 may be provided with, from bottom to top, a pixel electrode, an electron transport layer, a light-receiving layer, a hole transport layer, and a common electrode. In this case, the hole injection layer of the light-emitting element 110 can be a common layer, and the common layer can be provided between the hole transport layer and the common electrode of the light-receiving element 150. Also, in the light-emitting element 110, the electron injection layer can be separated for each element.

[0091] In the following description, the electron transport layer is assumed to be provided above the hole transport layer. However, the following description can also be applied to the case where the electron transport layer is provided below the hole transport layer, for example, by replacing "electrons" with "holes" and "holes" with "electrons."

[0092] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[0093] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer that contains a hole transport material. The hole transport material is a material having a concentration of 1×10 -6 cm 2 A material having a hole mobility of 1 / Vs or more is preferred. Note that other materials can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, or a furan derivative), or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[0094] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light emitting layer. The electron transport layer is a layer that contains an electron transporting material. The electron transporting material is a material having a molecular weight of 1×10 -6 cm 2A substance having an electron mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher electron transporting property than holes. Examples of electron-transporting materials that can be used include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds including nitrogen-containing heteroaromatic compounds.

[0095] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

[0096] Examples of the electron injection layer include lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), and lithium oxide (LiO x ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used.

[0097] Alternatively, the electron injection layer may be formed using a material having electron transport properties. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring may be used as the material having electron transport properties. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring may be used.

[0098] The lowest unoccupied molecular orbital (LUMO) of an organic compound having an unshared electron pair is preferably -3.6 eV or more and -2.3 eV or less. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by CV (cyclic voltammetry), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, etc.

[0099] Examples of organic compounds with lone electron pairs include 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz). NBPhen has a higher glass transition temperature (Tg) and better heat resistance than BPhen.

[0100] The light-emitting layer is a layer containing a light-emitting substance. The light-emitting layer can contain one or more light-emitting substances. As the light-emitting substance, a substance that emits light of a color such as blue, purple, blue-purple, green, yellow-green, yellow, orange, or red is appropriately used. Furthermore, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0101] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0102] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0103] Examples of phosphorescent materials include organometallic complexes (particularly 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 (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0104] The light-emitting layer may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). One or more organic compounds may be a hole-transporting material or an electron-transporting material, or both. Alternatively, a bipolar material or a TADF material may be used as the one or more organic compounds.

[0105] The light-emitting layer preferably contains, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This configuration allows for efficient light emission using Exciplex-Triplet Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, the energy transfer becomes smooth, allowing for efficient light emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting element.

[0106] The light-emitting layer 117R of the light-emitting element 110R contains a light-emitting organic compound that emits light having an intensity in at least the red wavelength range. The light-emitting layer 117G of the light-emitting element 110G contains a light-emitting organic compound that emits light having an intensity in at least the green wavelength range. The light-emitting layer 117B of the light-emitting element 110B contains a light-emitting organic compound that emits light having an intensity in at least the blue wavelength range. The light-receiving layer 157 of the light-receiving element 150 contains an organic compound that has detection sensitivity in the wavelength range of visible light, for example.

[0107] A conductive film that is translucent to visible light is used for either the pixel electrode 111 or the common electrode 123, and a conductive film that is reflective is used for the other. By making the pixel electrode 111 translucent and the common electrode 123 reflective, the display device 10 can be a bottom-emission display device. On the other hand, by making the pixel electrode 111 reflective and the common electrode 123 translucent, the display device 10 can be a top-emission display device. Note that by making both the pixel electrode 111 and the common electrode 123 translucent, the display device 10 can also be a dual-emission display device.

[0108] Furthermore, the light emitting element 110 preferably has a micro-optical resonator (microcavity) structure, which allows the light emitted from the light emitting layer 117 to resonate between the pixel electrode 111 and the common electrode 123, thereby intensifying the light emitted from the light emitting element 110.

[0109] When the light-emitting element 110 has a microcavity structure, it is preferable that one of the common electrode 123 or the pixel electrode 111 is an electrode having both light-transmitting and reflective properties (semi-transmissive / semi-reflective electrode), and the other of the common electrode 123 or the pixel electrode 111 is an electrode having reflective properties (reflective electrode). Here, the semi-transmissive / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode having transparency to visible light (also called a transparent electrode). The transparent electrode can be called an optical adjustment layer.

[0110] The light transmittance of the transparent electrode is 40% or more. For example, it is preferable to use an electrode for the light emitting element 110 that has a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more. The visible light reflectance of the semi-transmissive / semi-reflective electrode is 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is 1×10 -2 When a light-emitting element that emits near-infrared light is used in the display device, the transmittance and reflectance of these electrodes for near-infrared light (light with a wavelength of 750 nm or more and 1300 nm or less) are preferably within the above-mentioned ranges.

[0111] An insulating layer 131 is provided to cover the end portions of the pixel electrodes 111R, 111G, 111B, and 111PD. The end portions of the insulating layer 131 are preferably tapered. Note that the insulating layer 131 need not be provided if it is not necessary.

[0112] For example, the hole injection layer 113R, the hole injection layer 113G, the hole injection layer 113B, and the hole transport layer 115PD each have a region in contact with the upper surface of the pixel electrode 111 and a region in contact with the surface of the insulating layer 131. In addition, the end of the hole injection layer 113R, the end of the hole injection layer 113G, the end of the hole injection layer 113B, and the end of the hole transport layer 115PD are located on the insulating layer 131.

[0113] 6A, between light-emitting elements 110 emitting light of different colors, a gap is provided, for example, between two light-emitting layers 117. In this manner, for example, light-emitting layer 117R, light-emitting layer 117G, and light-emitting layer 117B are preferably provided so as not to be in contact with one another. This makes it possible to preferably prevent current from flowing through two adjacent light-emitting layers 117, thereby preventing unintended light emission. This makes it possible to increase the contrast of display device 10, thereby improving the display quality of display device 10.

[0114] A protective layer 125 is provided on the common electrode 123. The protective layer 125 has a function of preventing impurities such as water from diffusing from above into each light-emitting element.

[0115] The protective layer 125 may have, for example, a single-layer structure or a stacked-layer structure including at least an inorganic insulating film. Examples of the inorganic insulating film include oxide films or nitride films such as a silicon oxide film, a silicon oxynitride film, a silicon nitride oxide film, a silicon nitride film, an aluminum oxide film, an aluminum oxynitride film, and a hafnium oxide film. Alternatively, the protective layer 125 may be made of a semiconductor material such as indium gallium oxide or indium gallium zinc oxide.

[0116] In this specification and the like, a silicon oxynitride film refers to a film whose composition contains more oxygen than nitrogen, and a silicon nitride oxide film refers to a film whose composition contains more nitrogen than oxygen.

[0117] Alternatively, the protective layer 125 may be a laminated film of an inorganic insulating film and an organic insulating film. For example, a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable. Furthermore, it is preferable that the organic insulating film functions as a planarizing film. This allows the upper surface of the organic insulating film to be flat, improving the coverage of the inorganic insulating film thereon and enhancing the barrier properties. Furthermore, since the upper surface of the protective layer 125 is flat, when a structure (e.g., a color filter, a touch sensor electrode, a lens array, or the like) is provided above the protective layer 125, the influence of uneven shapes caused by the structure below can be reduced, which is preferable.

[0118] 6C shows an example of a cross-sectional configuration of the display device 10 in the Y direction, specifically showing an example of a cross-sectional configuration of the light-emitting element 110R and the light-receiving element 150. Note that the light-emitting element 110G and the light-emitting element 110B can also be arranged in the Y direction in the same manner as the light-emitting element 110R.

[0119] 6D shows a connection portion 130 that electrically connects the connection electrode 111C and the common electrode 123. In the connection portion 130, the common electrode 123 is provided in contact with the connection electrode 111C, and a protective layer 125 is provided to cover the common electrode 123. Furthermore, an insulating layer 131 is provided to cover the end of the connection electrode 111C.

[0120] 6E shows an example of the cross-sectional configuration of the light receiving element 150, as well as an example of the cross-sectional configuration of the light emitting element 110IR. The light emitting element 110IR has a pixel electrode 111IR, a hole injection layer 113IR, a hole transport layer 115IR, a light emitting layer 117IR, an electron transport layer 119IR, a common layer 121, and a common electrode 123.

[0121] The light-emitting layer 117IR of the light-emitting element 110IR contains a light-emitting organic compound that emits light having an intensity in at least the wavelength range of infrared light. For example, the light-emitting layer 117IR contains a light-emitting organic compound that emits light having an intensity in the wavelength range of near-infrared light. When the display device 10 includes the light-emitting element 110IR, the light-receiving layer 157 of the light-receiving element 150 contains an organic compound that has detection sensitivity in the wavelength range of infrared light, for example, near-infrared light.

[0122] [Example of manufacturing method] An example of a manufacturing method of a display device according to one embodiment of the present invention will be described below with reference to the drawings. Here, the manufacturing method of the display device 10 shown in FIG. 2A and FIGS. 6A to 6D will be described as an example. FIGS. 7A to 10C are schematic cross-sectional views illustrating steps in the manufacturing method of the display device exemplified below. FIGS. 7A to 10C show cross sections corresponding to dashed dotted lines A1-A2, B1-B2, and D1-D2 in FIG. 2A.

[0123] The thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an atomic layer deposition (ALD) method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0124] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0125] Furthermore, when processing the thin film that constitutes the display device, for example, a photolithography method can be used, but the thin film may also be processed by a nanoimprint method, a sandblasting method, or a lift-off method.

[0126] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0127] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other light sources that can be used include ultraviolet light, KrF laser light, and ArF laser light. Exposure can also be performed by immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0128] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0129] To fabricate the display device 10, first, a substrate 101 is prepared. The substrate 101 may be a substrate having heat resistance sufficient to withstand at least a subsequent heat treatment. When an insulating substrate is used as the substrate 101, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like may be used. Alternatively, a semiconductor substrate such as a single crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate may be used.

[0130] Next, pixel electrodes 111R, 111G, 111B, 111PD, and connection electrode 111C are formed on the substrate 101. First, a conductive film that will become the pixel electrodes is formed, a resist mask is formed by photolithography, and unnecessary portions of the conductive film are removed by etching. After that, the resist mask is removed, thereby forming the pixel electrodes 111R, 111G, and 111B.

[0131] When a conductive film reflective to visible light is used as each pixel electrode, it is preferable to use a material (such as silver or aluminum) with as high a reflectance as possible over the entire wavelength range of visible light, which not only increases the light extraction efficiency of the light-emitting element but also improves color reproducibility.

[0132] Next, an insulating layer 131 is formed to cover the edges of the pixel electrodes 111R, 111G, 111B, and 111PD (FIG. 7A). An organic insulating film or an inorganic insulating film can be used as the insulating layer 131. The insulating layer 131 preferably has tapered edges to improve step coverage of subsequent films. In particular, when an organic insulating film is used, it is preferable to use a photosensitive material, as this makes it easier to control the edge shape by adjusting the exposure and development conditions. Note that an inorganic insulating film may also be used as the insulating layer 131. Using an inorganic insulating film as the insulating layer 131 allows the display device 10 to be a high-definition display device.

[0133] Next, a functional film 113Rf, which will later become the hole injection layer 113R, is formed on the pixel electrodes 111R, 111G, 111B, 111PD, and the insulating layer 131. Then, a functional film 115Rf, which will later become the hole transport layer 115R, a light-emitting film 117Rf, which will become the light-emitting layer 117R, and a functional film 119Rf, which will become the electron transport layer 119R, are formed in this order on the functional film 113Rf. The functional film 113Rf, the functional film 115Rf, the light-emitting film 117Rf, and the functional film 119Rf can be formed by, for example, a vapor deposition method, a sputtering method, an inkjet method, or the like. However, the methods are not limited to these, and any of the above-mentioned film formation methods can be used as appropriate.

[0134] It is preferable that the functional film 113Rf, the functional film 115Rf, the light-emitting film 117Rf, and the functional film 119Rf are formed so as not to be provided on the connection electrode 111C. For example, when the functional film 113Rf, the functional film 115Rf, the light-emitting film 117Rf, and the functional film 119Rf are formed by a vapor deposition method or a sputtering method, it is preferable that they are formed using a shielding mask so that the functional film 113Rf, the functional film 115Rf, the light-emitting film 117Rf, and the functional film 119Rf are not formed on the connection electrode 111C.

[0135] Subsequently, a sacrificial film 141a is formed on the functional film 119Rf. The sacrificial film 141a can be provided in contact with the upper surface of the connection electrode 111C.

[0136] The sacrificial film 141a can be a film that is highly resistant to the etching process of the functional films 119Rf, luminescent films 117Rf, 115Rf, and 113Rf, i.e., a film with a large etching selectivity. The sacrificial film 141a can also be a film that has a large etching selectivity with respect to a protective film such as the protective film 143a described below. Furthermore, the sacrificial film 141a can also be a film that can be removed by wet etching, which causes little damage to the functional films 119Rf, luminescent films 117Rf, 115Rf, and 113Rf.

[0137] The sacrificial film 141a may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic film such as an inorganic insulating film. The sacrificial film 141a may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, or an ALD method.

[0138] The sacrificial film 141a may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0139] The sacrificial film 141a may be made of a metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO). Other examples include 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), and indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide). Alternatively, silicon-containing indium tin oxide may be used.

[0140] Instead of the gallium, an element M (wherein M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can also be used. In particular, it is preferable that M is one or more elements selected from gallium, aluminum, and yttrium.

[0141] The sacrificial film 141a may be made of an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide.

[0142] Furthermore, it is preferable to use a material for the sacrificial film 141a that can be dissolved in a solvent that is chemically stable with respect to at least the functional film 119Rf. In particular, a material that dissolves in water or alcohol is suitable for use as the sacrificial film 141a. When forming the sacrificial film 141a, it is preferable to apply the sacrificial film 141a by a wet film formation method while the sacrificial film 141a is dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf.

[0143] Wet film formation methods that can be used to form the sacrificial film 141a include spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating.

[0144] The sacrificial film 141a may be made of an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin.

[0145] Subsequently, a protective film 143a is formed on the sacrificial film 141a (FIG. 7B).

[0146] The protective film 143a is a film used as a hard mask when etching the sacrificial film 141a later. Furthermore, when processing the protective film 143a later, the sacrificial film 141a is exposed. Therefore, a combination of films with a high etching selectivity between the sacrificial film 141a and the protective film 143a is selected. Therefore, a film that can be used for the protective film 143a can be selected depending on the etching conditions for the sacrificial film 141a and the etching conditions for the protective film 143a.

[0147] For example, when dry etching using a gas containing fluorine (also called a fluorine-based gas) is used to etch the protective film 143a, silicon, silicon nitride, silicon oxide, tungsten, titanium, molybdenum, tantalum, tantalum nitride, an alloy containing molybdenum and niobium, an alloy containing molybdenum and tungsten, etc. can be used for the protective film 143a. Here, examples of films that can achieve a large etching selectivity (i.e., a slow etching rate) compared to dry etching using the fluorine-based gas include metal oxide films such as IGZO and ITO, which can be used for the sacrificial film 141a.

[0148] However, the protective film 143a is not limited to this, and can be selected from various materials depending on the etching conditions of the sacrificial film 141a and the etching conditions of the protective film 143a. For example, it can be selected from the films that can be used for the sacrificial film 141a.

[0149] The protective film 143a may be, for example, a nitride film, such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0150] Alternatively, an oxide film can be used as the protective film 143a. Typically, an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.

[0151] Furthermore, the protective film 143a may be an organic film that can be used for the light-emitting film 117Rf, for example. By using such an organic film, it is possible to use a film-forming device in common with the light-emitting film 117Rf, which is preferable.

[0152] Subsequently, resist masks 145a are formed on the protective film 143a at positions overlapping the pixel electrode 111R and the connection electrode 111C (FIG. 7C).

[0153] The resist mask 145a can be made of a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.

[0154] If the resist mask 145a is formed on the sacrificial film 141a without forming the protective film 143a, defects such as pinholes in the sacrificial film 141a may cause the functional film 119Rf, for example, to dissolve in the solvent of the resist material. By using the protective film 143a, such defects can be prevented.

[0155] When the sacrificial film 141a is made of a film that is less likely to have defects such as pinholes, the resist mask 145a may be formed directly on the sacrificial film 141a without using the protective film 143a.

[0156] Subsequently, a part of the protective film 143a that is not covered by the resist mask 145a is removed by etching to form a protective layer 149a. At the same time, the protective layer 149a is also formed on the connection electrode 111C.

[0157] When etching the protective film 143a, it is preferable to use etching conditions with a high selectivity so that the sacrificial film 141a is not removed by the etching. The protective film 143a can be etched by wet etching or dry etching, but by using dry etching, it is possible to prevent the pattern of the protective film 143a from shrinking.

[0158] Subsequently, the resist mask 145a is removed (FIG. 7D).

[0159] The resist mask 145a can be removed by wet etching or dry etching. In particular, the resist mask 145a is preferably removed by dry etching (also called plasma ashing) using oxygen gas as an etching gas.

[0160] At this time, the resist mask 145a is removed in a state in which the sacrificial film 141a remains on the functional film 119Rf, and therefore, the effect on the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf is suppressed. In particular, if the light-emitting film 117Rf comes into contact with oxygen, for example, this may adversely affect the electrical characteristics, and therefore this is suitable for etching using oxygen gas, such as plasma ashing.

[0161] Next, using the protective layer 149a as a mask, a portion of the sacrificial film 141a that is not covered by the protective layer 149a is removed by etching to form a sacrificial layer 147a (FIG. 8A). At the same time, the sacrificial layer 147a is also formed on the connection electrode 111C.

[0162] The sacrificial film 141a can be etched by wet etching or dry etching, but dry etching is preferable because it can prevent the pattern from shrinking.

[0163] Next, the protective layer 149a is removed by etching, and portions of the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf that are not covered by the sacrificial layer 147a are removed by etching to form the electron transport layer 119R, the light-emitting layer 117R, the hole transport layer 115R, and the hole injection layer 113R (Figure 8B).

[0164] In particular, dry etching using an etching gas that does not contain oxygen as a main component is preferably used to etch the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf. This suppresses deterioration of the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, and the functional film 113Rf, resulting in a highly reliable display device. Examples of etching gases that do not contain oxygen as a main component include noble gases such as CF4, C4F8, SF6, CHF3, Cl2, HO, BCl3, H2, and He. Alternatively, a mixture of any of the above gases with a dilution gas that does not contain oxygen can be used as the etching gas.

[0165] Next, a functional film 113Gf that will later become the hole injection layer 113G, a functional film 115Gf that will later become the hole transport layer 115G, a light-emitting film 117Gf that will later become the light-emitting layer 117G, and a functional film 119Gf that will later become the electron transport layer 119G are formed in this order on the sacrificial layer 147a, the insulating layer 131, the pixel electrode 111G, the pixel electrode 111B, and the pixel electrode 111PD. At this time, it is preferable that the functional film 113Gf, the functional film 115Gf, the light-emitting film 117Gf, and the functional film 119Gf are not provided on the connection electrode 111C.

[0166] For the methods of forming the functional films 113Gf, 115Gf, 117Gf, and 119Gf, the descriptions of the methods of forming the functional films 113Rf, 115Rf, 117Rf, and 119Rf can be cited.

[0167] Next, a sacrificial film 141b is formed on the functional film 119Gf. The sacrificial film 141b can be formed by the same method as the sacrificial film 141a. In particular, it is preferable that the sacrificial film 141b is made of the same material as the sacrificial film 141a.

[0168] At the same time, a sacrificial film 141b is formed on the connection electrode 111C to cover the sacrificial layer 147a.

[0169] Next, a protective film 143b is formed on the sacrificial film 141b. The protective film 143b can be formed by the same method as the protective film 143a. In particular, it is preferable that the protective film 143b is made of the same material as the protective film 143a.

[0170] Subsequently, a resist mask 145b is formed on the protective film 143b in an area overlapping with the pixel electrode 111G and an area overlapping with the connection electrode 111C (FIG. 8C).

[0171] The resist mask 145b can be formed in a manner similar to that for the resist mask 145a.

[0172] Subsequently, a part of the protective film 143b that is not covered by the resist mask 145b is removed by etching to form a protective layer 149b. At the same time, the protective layer 149b is also formed on the connection electrode 111C.

[0173] The above description of the protective film 143a can be applied to the etching of the protective film 143b.

[0174] Next, the resist mask 145a is removed (FIG. 9A). Regarding the removal of the resist mask 145b, the same description as for the resist mask 145a can be applied.

[0175] Next, using the protective layer 149b as a mask, a portion of the sacrificial film 141b that is not covered by the protective layer 149b is removed by etching to form a sacrificial layer 147b. At the same time, a sacrificial layer 147b is also formed on the connection electrode 111C. The sacrificial layer 147a and the sacrificial layer 147b are stacked on the connection electrode 111C.

[0176] The above description of the sacrificial film 141a can be applied to the etching of the sacrificial film 141b.

[0177] Next, the protective layer 149b is removed by etching, and portions of the functional film 119Gf, the light-emitting film 117Gf, the functional film 115Gf, and the functional film 113Gf that are not covered by the sacrificial layer 147b are removed by etching to form the electron transport layer 119G, the light-emitting layer 117G, the hole transport layer 115G, and the hole injection layer 113G (Figure 9B).

[0178] For etching of the functional film 119Gf, the light-emitting film 117Gf, the functional film 115Gf, the functional film 113Gf, and the protective layer 149b, the same descriptions as for the functional film 119Rf, the light-emitting film 117Rf, the functional film 115Rf, the functional film 113Rf, and the protective layer 149a can be cited.

[0179] At this time, the electron transport layer 119R, the light-emitting layer 117R, the hole transport layer 115R, and the hole injection layer 113R are protected by the sacrificial layer 147a, and therefore can be prevented from being damaged during the etching process of the functional film 119Gf, the light-emitting film 117Gf, the functional film 115Gf, and the functional film 113Gf.

[0180] In this way, the hole injection layer 113R, the hole transport layer 115R, the light-emitting layer 117R, and the electron transport layer 119R, and the hole injection layer 113G, the hole transport layer 115G, the light-emitting layer 117G, and the electron transport layer 119G can be separately formed with high positional accuracy.

[0181] By the same processes as those described above, the hole injection layer 113B, the hole transport layer 115B, the light emitting layer 117B, the electron transport layer 119B, and the sacrificial layer 147c can be formed (FIG. 9C). The sacrificial layers 147a, 147b, and 147c are stacked on the connection electrode 111C.

[0182] After forming the hole injection layer 113B, the hole transport layer 115B, the light-emitting layer 117B, the electron transport layer 119B, and the sacrificial layer 147c, the hole transport layer 115PD, the light-receiving layer 157, the electron transport layer 119PD, and the sacrificial layer 147d are formed by the same process as above (FIG. 9D). The sacrificial layers 147a, 147b, 147c, and 147d are stacked on the connection electrode 111C. Note that the electron transport layer 119PD does not necessarily have to be formed.

[0183] Furthermore, when manufacturing a display device having light-emitting element 110IR, for example, after forming hole injection layer 113B, hole transport layer 115B, light-emitting layer 117B, electron transport layer 119B, and sacrificial layer 147c, and before forming hole transport layer 115PD, light-receiving layer 157, electron transport layer 119PD, and sacrificial layer 147d, hole injection layer 113IR, hole transport layer 115IR, light-emitting layer 117IR, electron transport layer 119IR, and sacrificial layer 147d are formed by the same processes as those described above. In this case, five sacrificial layers are stacked on connection electrode 111C.

[0184] Next, the sacrificial layers 147a, 147b, 147c, and 147d are removed to expose the upper surfaces of the electron transport layers 119R, 119G, 119B, and 119PD (FIG. 10A). At the same time, the upper surface of the connection electrode 111C is also exposed.

[0185] The sacrificial layers 147a, 147b, 147c, and 147d can be removed by wet etching or dry etching. At this time, it is preferable to use a method that causes as little damage as possible to the hole injection layer 113, the hole transport layer 115, the light-emitting layer 117, the light-receiving layer 157, and the electron transport layer 119. In particular, it is preferable to use a wet etching method. For example, it is preferable to use wet etching using a tetramethylammonium hydroxide aqueous solution (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0186] Alternatively, it is preferable to remove the sacrificial layers 147a, 147b, 147c, and 147d by dissolving them in a solvent such as water or alcohol. Here, various alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin can be used as the alcohol capable of dissolving the sacrificial layers 147a, 147b, 147c, and 147d.

[0187] After removing the sacrificial layers 147a, 147b, 147c, and 147d, it is preferable to perform a drying treatment to remove water contained inside the light-emitting layers 117R, 117G, 117B, and the light-receiving layer 157, etc., and water adsorbed on the surfaces. For example, it is preferable to perform a heat treatment in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment 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. A reduced-pressure atmosphere is preferable because it allows drying at a lower temperature.

[0188] In this manner, the light-emitting layer 117R, the light-emitting layer 117G, the light-emitting layer 117B, the light-receiving layer 157, etc. can be separately produced.

[0189] Subsequently, the common layer 121 is formed on the electron transport layer 119R, the electron transport layer 119G, the electron transport layer 119B, and the electron transport layer 119PD. As described above, a gap can be formed between the common layer 121 and the insulating layer 131.

[0190] The common layer 121 can be formed by, for example, a vapor deposition method, a sputtering method, an inkjet method, etc. When the common layer 121 is formed by a vapor deposition method, it is preferable to form the common layer 121 using a shielding mask so that the common layer 121 is not formed on the connection electrode 111C.

[0191] Subsequently, a common electrode 123 is formed to cover the common layer 121 and the connection electrode 111C (FIG. 10B).

[0192] The common electrode 123 can be formed by a film formation method such as evaporation or sputtering. Alternatively, a film formed by evaporation and a film formed by sputtering may be stacked. In this case, the common electrode 123 is preferably formed so as to encompass the region where the common layer 121 is formed. That is, the edge of the common layer 121 can be configured to overlap with the common electrode 123. The common electrode 123 is preferably formed using a shielding mask.

[0193] The common electrode 123 is electrically connected to the connection electrode 111C outside the display section.

[0194] Next, a protective layer 125 is formed on the common electrode 123 (FIG. 10C). The inorganic insulating film used for the protective layer 125 is preferably formed by sputtering, PECVD, or ALD. The ALD method is particularly preferred because it has excellent step coverage and is less likely to cause defects such as pinholes. The organic insulating film is preferably formed by inkjet printing, which allows for the formation of a uniform film in a desired area.

[0195] In this manner, the display device 10 can be manufactured.

[0196] In the above description, the common electrode 123 and the common layer 121 are formed to have different top surface shapes, but they may be formed in the same region.

[0197] 11A shows a schematic cross-sectional view after the sacrificial layer is removed. Next, as shown in FIG. 11B, the common layer 121 and the common electrode 123 are formed using the same masking mask or without a masking mask. This reduces manufacturing costs compared to when different masking masks are used.

[0198] 11B, the connection portion 130 has a configuration in which the common layer 121 is sandwiched between the connection electrode 111C and the common electrode 123. In this case, it is preferable to use a material with as low an electrical resistance as possible for the common layer 121. Alternatively, it is preferable to form the common layer 121 as thin as possible to reduce the electrical resistance in the thickness direction of the common layer 121. For example, by using an electron-injecting or hole-injecting material with a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the common layer 121, it may be possible to reduce the electrical resistance between the connection electrode 111C and the common electrode 123 to a negligible level.

[0199] 11C, protective layer 125 is formed. At this time, as shown in Fig. 11C, protective layer 125 is preferably provided so as to cover the end of common electrode 123 and the end of common layer 121. This makes it possible to effectively prevent impurities such as water or oxygen from diffusing from the outside into common layer 121 and the interface between common layer 121 and common electrode 123.

[0200] This completes the description of an example of a method for manufacturing a display device.

[0201] As described above, in the method for manufacturing a display device according to one embodiment of the present invention, the light-emitting elements 110 can be individually formed without using a shadow mask such as a metal mask. This allows the subpixels to be miniaturized and the pixel aperture ratio to be increased compared to the case where the light-emitting elements 110 are individually formed using a shadow mask. Furthermore, because the light-emitting layers 117 can be individually formed, a display device with extremely vivid, high contrast, and high display quality can be realized.

[0202] By miniaturizing the subpixels, subpixels that do not contribute to display can be provided in the pixel. For example, a subpixel having a light-receiving element 150 can be provided in the pixel, and a subpixel having a light-emitting element 110IR that emits infrared light can be provided in the pixel. In the display device of one embodiment of the present invention, even when such subpixels that do not contribute to display are provided in the pixel, the pixel density can be prevented from becoming low. For example, the pixel density can be 400 ppi or more, 1000 ppi or more, 3000 ppi or more, or 5000 ppi or more.

[0203] [Configuration example 2] The following describes a configuration example of a display device that is partially different from the above-described configuration example 1. In the following, descriptions of parts that overlap with the above-described configuration example may be omitted.

[0204] Fig. 12A is a schematic top view showing an example of the configuration of the display device 10, which is a modified example of the display device 10 shown in Fig. 2A. The display device 10 shown in Fig. 12A differs from the display device 10 shown in Fig. 2A in the shape of the common layer 121 and the shape of the common electrode 123. In Fig. 12A, the outlines of the common electrode 123 and the common layer 121 are indicated by dashed lines.

[0205] 12B is a cross-sectional view corresponding to the dashed-dotted line C3-C4 in FIG. 12A, showing a cross section in the Y direction. As shown in FIG. 12A and FIG. 12B, the common layer 121 and the common electrode 123 are separated between adjacent pixels. In other words, the common layer 121 and the common electrode 123 have ends in the regions where they overlap with the insulating layer 131.

[0206] 12C is an enlarged cross-sectional view of a portion of the light receiving element 150 and the light emitting element 110R provided in adjacent pixels extracted from FIG. 12B. As shown in FIG. 12C, a recess may be formed in a portion of the upper surface of the insulating layer 131. In this case, it is preferable that the protective layer 125 be provided in contact with the surface of the recess in the insulating layer 131. This increases the contact area between the insulating layer 131 and the protective layer 125, which is preferable because it improves adhesion between them.

[0207] 12C, a void (also referred to as a gap or space) 127 may be provided above the insulating layer 131. The void 127 is formed during deposition of the protective layer 125 due to the high aspect ratio of the opening separating adjacent pixels. The void 127 may be under reduced pressure or atmospheric pressure. The void 127 may also contain a gas such as air, nitrogen, or a noble gas, or a deposition gas used to deposit the protective layer 125.

[0208] Although not shown here, the light emitting element 110G and the light emitting element 110B can also have a similar configuration.

[0209] Fig. 13A is a schematic top view showing an example of the configuration of display device 10, which is a modification of display device 10 shown in Fig. 12A. Fig. 13B is a cross-sectional view corresponding to dashed dotted line C5-C6 in Fig. 13A, showing a cross section in the Y direction. Display device 10 shown in Figs. 13A and 13B differs from display device 10 shown in Figs. 12A and 12B in that common layer 121 and common electrode 123 are separated not only between adjacent pixels but also between the same pixels.

[0210] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0211] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0212] (Embodiment 2) In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described.

[0213] [Configuration example 1] Fig. 14 is a perspective view showing an example of the configuration of the display device 100. The display device 100 has a configuration in which a substrate 151 and a substrate 152 are bonded together. In Fig. 14, the substrate 152 is indicated by a dashed line.

[0214] The display device 100 has a display unit 162, a circuit 164, wiring 165, etc. Fig. 14 also shows an example in which an IC (integrated circuit) 173 and an FPC 172 are mounted on the display device 100. Therefore, the configuration shown in Fig. 14 can also be said to be a display module having a display device, an IC, and an FPC.

[0215] The circuit 164 may be, for example, a gate driver. Signals and power may be supplied to the circuit 164 and the like via wiring 165. The signals and power may be input to the wiring 165 via an FPC 172 from outside the display device 10, for example. Alternatively, the signals and power may be generated by an IC 173 and output to the wiring 165.

[0216] FIG. 14 shows an example in which the IC 173 is provided on the substrate 151 by a COG (Chip On Glass) method, but a TCP (Tape Carrier Package) method, a COF (Chip On Film) method, or the like may also be used.

[0217] Fig. 15 is a diagram showing an example of a cross section of a part of an area including FPC 172, a part of an area including circuit 164, a part of an area including display unit 162, and a part of an area including an end portion in display device 100 shown in Fig. 14. Note that display device 100 shown in Fig. 15 is referred to as display device 100A.

[0218] The display device 100A includes a transistor 201, a transistor 141, a transistor 142, a light-emitting element 110, a light-receiving element 150, and the like between a substrate 151 and a substrate 152.

[0219] The substrate 152 and the insulating layer 214 are bonded via an adhesive layer 242. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light emitting element 110 and the light receiving element 150. A space 143 surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 is filled with an inert gas (nitrogen, argon, or the like), and a hollow sealing structure is applied. The adhesive layer 242 may be provided so as to overlap the light emitting element 110. Furthermore, the region surrounded by the substrate 152, the adhesive layer 242, and the insulating layer 214 may be filled with a resin different from the adhesive layer 242.

[0220] The pixel electrode 111 of the light-emitting element 110 is electrically connected to the conductive layer 222b of the transistor 142 through an opening provided in the insulating layer 214. The transistor 142 has a function of controlling driving of the light-emitting element 110. The pixel electrode 111PD of the light-receiving element 150 is electrically connected to the conductive layer 222b of the transistor 141 through an opening provided in the insulating layer 214.

[0221] Light emitted by the light emitting element 110 is emitted toward the substrate 152. Furthermore, light is incident on the light receiving element 150 via the substrate 152 and the space 143. It is preferable that the substrate 152 be made of a material that is highly transparent to visible light and infrared light.

[0222] A light-shielding layer 148 is provided on the surface of the substrate 152 facing the substrate 151. The light-shielding layer 148 has openings at positions overlapping the light receiving element 150 and the light emitting element 110. A filter 146 that cuts ultraviolet light is provided at the position overlapping the light receiving element 150. Note that a configuration in which the filter 146 is not provided is also possible.

[0223] The transistor 201, the transistor 141, and the transistor 142 are all formed over a substrate 151. These transistors can be manufactured using the same material and through the same process.

[0224] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 151 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0225] At least one insulating layer covering the transistor is preferably made of a material that is resistant to the diffusion of impurities such as water or hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the display device.

[0226] The insulating layer 211, the insulating layer 213, and the insulating layer 215 are preferably formed using an inorganic insulating film. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may be used. Two or more of the above insulating films may be stacked.

[0227] An organic insulating film is preferably used for the insulating layer 214, which functions as a planarizing layer. Materials that can be used for the organic insulating film include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0228] Here, organic insulating films often have a lower barrier property against impurities than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 100A. This makes it possible to prevent impurities from diffusing from the edge of the display device 100A through the organic insulating film. Alternatively, the organic insulating film may be formed so that the edge of the organic insulating film is located inside the edge of the display device 100A, so that the organic insulating film is not exposed at the edge of the display device 100A.

[0229] 15, an opening is formed in the insulating layer 214. This makes it possible to prevent impurities from diffusing from the outside into the display unit 162 through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. This makes it possible to improve the reliability of the display device 100A.

[0230] The transistor 201, the transistor 141, and the transistor 142 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0231] The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0232] The transistor 201, the transistor 141, and the transistor 142 each have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and supplied with the same signal to drive the transistor. Alternatively, a potential for controlling the threshold voltage of the transistor may be applied to one of the two gates, and a potential for driving the transistor may be applied to the other gate.

[0233] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor, a single-crystal semiconductor, and a semiconductor having crystallinity other than single crystal (a microcrystalline semiconductor, a polycrystalline semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a single-crystal semiconductor or a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0234] The semiconductor layer of the transistor preferably contains a metal oxide (also referred to as an oxide semiconductor). Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon, crystalline silicon (low-temperature polysilicon, single-crystal silicon, or the like), and the like.

[0235] When the semiconductor layer contains a metal oxide, the metal oxide preferably contains at least indium or zinc, as described above. It is particularly preferable that the metal oxide contains indium and zinc. Furthermore, it is preferable that the metal oxide further contains aluminum, gallium, yttrium, tin, or the like. Furthermore, the metal oxide may contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, and the like.

[0236] The transistors included in the circuit 164 and the transistors included in the display portion 162 may have the same structure or different structures. The transistors included in the circuit 164 may all have the same structure or may have two or more types. Similarly, the transistors included in the display portion 162 may all have the same structure or may have two or more types.

[0237] A connection section 204 is provided in an area on the substrate 151 where the substrate 152 does not overlap. In the connection section 204, the wiring 165 is electrically connected to the FPC 172 via a conductive layer 166 and a connection layer 244. The conductive layer 166, which is obtained by processing the same conductive film as the pixel electrode 111, is exposed on the upper surface of the connection section 204. This allows the connection section 204 and the FPC 172 to be electrically connected via the connection layer 244.

[0238] Various optical members can be disposed on the outside of the substrate 152. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light collecting film. In addition, an antistatic film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches during use, or an impact absorbing layer may be disposed on the outside of the substrate 152.

[0239] The substrates 151 and 152 may be made of glass, quartz, ceramic, sapphire, resin, or the like.

[0240] The adhesive layer can be made of various curable adhesives, such as photo-curable adhesives (e.g., ultraviolet curable), reactive curable adhesives, thermosetting adhesives, or anaerobic adhesives. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Alternatively, an adhesive sheet may be used.

[0241] The connection layer 244 may be an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP).

[0242] Materials that can be used for the gate, source, and drain of a transistor as well as conductive layers such as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as main components, etc. Films containing these materials can be used as a single-layer structure or a stacked-layer structure.

[0243] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium. Alternatively, graphene can be used. Metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, as well as alloy materials containing these metal materials, can be used. Alternatively, nitrides of these metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers such as various wirings and electrodes constituting a display device, and conductive layers (conductive layers functioning as pixel electrodes or common electrodes) in display elements.

[0244] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0245] [Configuration example 2] 16 is a cross-sectional view showing an example of the configuration of display device 100B, which is a modification of display device 100A. Display device 100B differs from display device 100A in that display device 100B has substrate 153, adhesive layer 155, and insulating layer 212 instead of substrate 151, and has substrate 154, adhesive layer 156, and insulating layer 158 instead of substrate 152.

[0246] In the display device 100B, the substrate 153 and the insulating layer 212 are bonded together by an adhesive layer 155. Furthermore, the substrate 154 and the insulating layer 158 are bonded together by an adhesive layer 156.

[0247] When manufacturing the display device 100B shown in FIG. 16, first, a first manufacturing substrate provided with the insulating layer 212, the transistors, the light-emitting element 110, the light-receiving element 150, and the like is bonded to a second manufacturing substrate provided with the insulating layer 158, the light-shielding layer 148, the filter 146, and the like using an adhesive layer 242. Then, the first manufacturing substrate is peeled off, and a substrate 153 is attached to the exposed surface using an adhesive layer 155. In this way, the components formed on the first manufacturing substrate are transferred to the substrate 153. In addition, the second manufacturing substrate is peeled off, and a substrate 154 is attached to the exposed surface using an adhesive layer 156. In this way, the components formed on the second manufacturing substrate are transferred to the substrate 154. The substrate 153 and the substrate 154 are preferably flexible. This allows the display device 100B to have flexibility. That is, the display device 100B can be a flexible display.

[0248] The insulating layer 212 and the insulating layer 158 can be formed using the inorganic insulating film that can be used for the insulating layer 211, the insulating layer 213, and the insulating layer 215, respectively.

[0249] [Configuration example 3] 17 is a cross-sectional view showing an example of the configuration of a display device 100C. The display device 100C has a substrate 301, a light emitting element 110, a light receiving element 150, a capacitor 240, and a transistor 310. The substrate 301 corresponds to, for example, the substrate 151 in FIG.

[0250] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0251] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0252] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0253] Capacitor 240 has conductive layer 241, conductive layer 245, and insulating layer 243 positioned therebetween. Conductive layer 241 functions as one electrode of capacitor 240, conductive layer 245 functions as the other electrode of capacitor 240, and insulating layer 243 functions as a dielectric of capacitor 240.

[0254] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0255] An insulating layer 255 is provided to cover the capacitor 240, and the light emitting element 110, the light receiving element 150, etc. are provided on the insulating layer 255. A protective layer 125 is provided on the light emitting element 110 and the light receiving element 150, and a substrate 420 is bonded to the upper surface of the protective layer 125 by a resin layer 419. The substrate 420 corresponds to, for example, the substrate 152 in FIG. 14 .

[0256] The pixel electrode 111 of the light-emitting element 110 and the pixel electrode 111PD of the light-receiving element 150 are electrically connected to either the source or drain of the transistor 310 by an insulating layer 255, a plug 256 embedded in the insulating layer 243, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261.

[0257] [Configuration example 4] 18 is a cross-sectional view showing an example of the configuration of a display device 100D. The display device 100D differs from the display device 100C mainly in the configuration of the transistors. Note that descriptions of parts that are the same as those of the display device 100C may be omitted.

[0258] The transistor 320 is a transistor in which a metal oxide is used for a semiconductor layer in which a channel is formed (hereinafter also referred to as an OS transistor).

[0259] The 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 .

[0260] The substrate 331 corresponds to, for example, the substrate 151 in Fig. 14. The substrate 331 may be an insulating substrate or a semiconductor substrate.

[0261] An insulating layer 332 is provided over a substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0262] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0263] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide film having semiconductor properties.

[0264] A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0265] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like to the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be formed using an insulating film similar to the insulating layer 332.

[0266] An opening is provided in the insulating layer 328 and the insulating layer 264, reaching the semiconductor layer 321. An insulating layer 323 and a conductive layer 324 are buried inside the opening and are in contact with the side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325, as well as the top surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0267] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0268] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0269] The plug 274 electrically connected to one of the pair of conductive layers 325 is provided to be embedded in the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328. Here, the plug 274 preferably includes a conductive layer 274a covering side surfaces of the openings in the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and part 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. In this case, the conductive layer 274a is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0270] The configuration of the display device 100D from the insulating layer 254 to the substrate 420 is the same as that of the display device 100C.

[0271] [Configuration example 5] 19 is a cross-sectional view showing a configuration example of a display device 100E. The display device 100E has a configuration in which a transistor 310 having a channel formed in a substrate 301 and a transistor 320 having a channel formed in a semiconductor layer containing a metal oxide are stacked. Note that descriptions of parts similar to those of the display device 100C or the display device 100D may be omitted.

[0272] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided over the insulating layer 262. The conductive layers 251 and 252 each function as wirings. An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and a transistor 320 is provided over the insulating layer 332. An insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided over the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0273] The transistor 320 can be used as a transistor included in a pixel circuit. The transistor 310 can be used as a transistor included in a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) for driving the pixel circuit. The transistors 310 and 320 can be used as transistors included in various circuits such as an arithmetic circuit or a memory circuit.

[0274] With this configuration, not only pixel circuits but also driver circuits and the like can be formed directly under the light-emitting elements, making it possible to miniaturize the display device compared to when driver circuits are provided around the display unit.

[0275] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0276] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0277] (Embodiment 3) In this embodiment, a light-emitting element that can be used for a display device of one embodiment of the present invention will be described.

[0278] <Configuration example of light-emitting element> As shown in FIG. 20A , the light-emitting element has an EL layer 686 between a pair of electrodes (electrode 672 and electrode 688). The EL layer 686 can be composed of multiple layers such as a layer 4420, a light-emitting layer 4411, and a layer 4430. The layer 4420 can have, for example, a layer containing a substance with high electron-injecting properties (electron-injecting layer) and a layer containing a substance with high electron-transporting properties (electron-transporting layer). The light-emitting layer 4411 contains, for example, a light-emitting compound. The layer 4430 can have, for example, a layer containing a substance with high hole-injecting properties (hole-injecting layer) and a layer containing a substance with high hole-transporting properties (hole-transporting layer).

[0279] A structure including the layer 4420, the light-emitting layer 4411, and the layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 20A is referred to as a single structure in this specification.

[0280] 20B shows a modification of the EL layer 686 included in the light-emitting element shown in Fig. 20A. Specifically, the light-emitting element shown in Fig. 20B includes a layer 4430-1 on an electrode 672, a layer 4430-2 on the layer 4430-1, a light-emitting layer 4411 on the layer 4430-2, a layer 4420-1 on the light-emitting layer 4411, a layer 4420-2 on the layer 4420-1, and an electrode 688 on the layer 4420-2. For example, when the electrode 672 is an anode and the electrode 688 is a cathode, the layer 4430-1 functions as a hole injection layer, the layer 4430-2 functions as a hole transport layer, the layer 4420-1 functions as an electron transport layer, and the layer 4420-2 functions as an electron injection layer. Alternatively, when the electrode 672 is a cathode and the electrode 688 is an anode, the layer 4430-1 functions as an electron injection layer, the layer 4430-2 functions as an electron transport layer, the layer 4420-1 functions as a hole transport layer, and the layer 4420-2 functions as a hole injection layer. Such a layer structure allows carriers to be efficiently injected into the light-emitting layer 4411, and makes it possible to increase the efficiency of carrier recombination in the light-emitting layer 4411.

[0281] As shown in FIG. 20C, a configuration in which a plurality of light-emitting layers (light-emitting layer 4411, light-emitting layer 4412, light-emitting layer 4413) are provided between layer 4420 and layer 4430 is also a variation of the single structure.

[0282] 20D, a configuration in which a plurality of light-emitting units (EL layer 686a, EL layer 686b) are connected in series via an intermediate layer (charge generating layer) 4440 is referred to as a tandem structure in this specification. Note that, although the configuration shown in FIG. 20D is referred to as a tandem structure in this specification, the present invention is not limited to this, and for example, the tandem structure may also be referred to as a stack structure. Note that a tandem structure can be used to obtain a light-emitting element that can emit light with high brightness.

[0283] 20C and 20D, the layer 4420 and the layer 4430 may have a laminated structure made up of two or more layers, as shown in FIG. 20B.

[0284] Furthermore, when comparing the above-mentioned single and tandem structures with the SBS structure, the order of decreasing power consumption is SBS, tandem, and single. If you want to keep power consumption low, the SBS structure is preferable. On the other hand, the single and tandem structures are preferable because their manufacturing processes are simpler than those of the SBS structure, allowing for lower manufacturing costs or higher manufacturing yields.

[0285] The light-emitting element can emit light of red, green, blue, cyan, magenta, yellow, white, or the like, depending on the material of the EL layer 686. Furthermore, by providing the light-emitting element with a microcavity structure, the color purity can be further improved.

[0286] A light-emitting element that emits white light preferably has a structure in which two or more light-emitting materials are contained in the light-emitting layer. To obtain white light emission, light-emitting materials can be selected so that the light emitted from each of the two or more light-emitting materials has a complementary color relationship. For example, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary to each other, a light-emitting element that emits white light as a whole can be obtained. The same applies to a light-emitting element having three or more light-emitting layers.

[0287] The light-emitting layer preferably contains two or more light-emitting materials that emit light of R (red), G (green), B (blue), Y (yellow), O (orange), or the like.

[0288] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0289] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0290] (Fourth embodiment) In this embodiment, detailed structures of a light-emitting element, a light-receiving element, and a light-emitting and light-emitting element that can be used in a display device of one embodiment of the present invention will be described.

[0291] The display device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting element is formed, a bottom emission type that emits light toward a substrate on which a light-emitting element is formed, and a dual emission type that emits light to both sides.

[0292] In this embodiment, a top-emission display device will be described as an example.

[0293] In this specification, unless otherwise specified, even when describing a configuration having a plurality of elements (e.g., light-emitting elements or light-emitting layers), when describing matters common to each element, the alphabet will be omitted. For example, when describing matters common to light-emitting layer 383R and light-emitting layer 383G, the light-emitting layer may be referred to as light-emitting layer 383.

[0294] A display device 380A shown in FIG. 21A has a light receiving element 370PD, a light emitting element 370R that emits red (R) light, a light emitting element 370G that emits green (G) light, and a light emitting element 370B that emits blue (B) light.

[0295] Each light-emitting element has a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​a light-emitting layer, an electron transport layer 384, an electron injection layer 385, and a common electrode 375 stacked in this order. Light-emitting element 370R has a light-emitting layer 383R, light-emitting element 370G has a light-emitting layer 383G, and light-emitting element 370B has a light-emitting layer 383B. Light-emitting layer 383R contains a light-emitting material that emits red light, light-emitting layer 383G contains a light-emitting material that emits green light, and light-emitting layer 383B contains a light-emitting material that emits blue light.

[0296] The light emitting element is an electroluminescent element that emits light toward the common electrode 375 when a voltage is applied between the pixel electrode 371 and the common electrode 375 .

[0297] The light receiving element 370PD has a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, an electron transport layer 384, an electron injection layer 385, and a common electrode 375 stacked in this order.

[0298] The light receiving element 370PD is a photoelectric conversion element that receives light incident from outside the display device 380A and converts it into an electrical signal.

[0299] In this embodiment, in both the light-emitting element and the light-receiving element, the pixel electrode 371 functions as an anode and the common electrode 375 functions as a cathode. In other words, by applying a reverse bias between the pixel electrode 371 and the common electrode 375 and driving the light-receiving element, the light-receiving element can detect light incident on the light-receiving element, generate electric charges, and extract the electric charges as a current.

[0300] In the display device of this embodiment, an organic compound is used for the active layer 373 of the light-receiving element 370PD. The layers of the light-receiving element 370PD other than the active layer 373 can be configured in common with the light-emitting element. Therefore, by simply adding a step of forming the active layer 373 to the manufacturing process of the light-emitting element, the light-receiving element 370PD can be formed in parallel with the formation of the light-emitting element. Furthermore, the light-emitting element and the light-receiving element 370PD can be formed on the same substrate. Therefore, the light-receiving element 370PD can be built into the display device without significantly increasing the number of manufacturing steps.

[0301] In the display device 380A, the light receiving element 370PD and the light emitting element have a common configuration, except that the active layer 373 of the light receiving element 370PD and the light emitting layer 383 of the light emitting element are fabricated separately. However, the configuration of the light receiving element 370PD and the light emitting element is not limited to this. The light receiving element 370PD and the light emitting element may have layers fabricated separately from each other, in addition to the active layer 373 and the light emitting layer 383. It is preferable that the light receiving element 370PD and the light emitting element have one or more layers used in common (common layers). This allows the light receiving element 370PD to be incorporated into the display device without significantly increasing the number of manufacturing steps.

[0302] A conductive film that transmits visible light is used for the electrode from which light is extracted, between the pixel electrode 371 and the common electrode 375. It is preferable to use a conductive film that reflects visible light for the electrode from which light is not extracted.

[0303] The light-emitting element has at least a light-emitting layer 383. The light-emitting element may further have, in addition to the light-emitting layer 383, a layer containing a substance having a high hole-injecting property, a substance having a high hole-transporting property, a hole-blocking material, a substance having a high electron-transporting property, a substance having a high electron-injecting property, an electron-blocking material, a bipolar substance (a substance having a high electron-transporting property and a high hole-transporting property), or the like.

[0304] For example, the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer in common, or the light-emitting element and the light-receiving element may have one or more layers of the hole injection layer, hole transport layer, electron transport layer, and electron injection layer formed differently from each other.

[0305] The active layer 373 includes a semiconductor. Examples of the semiconductor include an inorganic semiconductor such as silicon and an organic semiconductor including an organic compound. In this embodiment, an example in which an organic semiconductor is used as the semiconductor included in the active layer 373 is shown. By using an organic semiconductor, the light-emitting layer 383 and the active layer 373 can be formed by the same method (for example, vacuum evaporation), which is preferable because a common manufacturing device can be used.

[0306] The active layer 373 has an n-type semiconductor material, such as fullerene (e.g., C 60 , or C 70 Examples of suitable materials include electron-accepting organic semiconductor materials such as fullerene derivatives, or fullerene derivatives. Fullerenes have a soccer ball-like shape, which is energetically stable. Fullerenes have deep (low) HOMO and LUMO levels. Because fullerenes have a deep LUMO level, they have extremely high electron-accepting (acceptor) properties. Normally, when the π-electron conjugation (resonance) spreads on a plane, as in benzene, the electron-donating (donor) properties increase, but fullerenes have a spherical shape, so they have high electron-accepting properties despite the large spread of π-electrons. High electron-accepting properties allow charge separation to occur quickly and efficiently, making them useful as light-receiving elements. C 60 , C 70 Both have a wide absorption band in the visible light region, especially C 70 is C 60 It is preferable because it has a larger π-electron conjugated system and a broad absorption band in the long wavelength region compared to [6,6]-Phenyl-C71-butyric acid methyl ester (abbreviation: PC70BM), [6,6]-Phenyl-C61-butyric acid methyl ester (abbreviation: PC60BM), and 1',1'',4',4''-Tetrahydro-di[1,4]methanonaphthaleno[1,2:2',3',56,60:2'',3''][5,6]fullerene-C60 (abbreviation: ICBA).

[0307] Examples of n-type semiconductor materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, naphthalene derivatives, anthracene derivatives, coumarin derivatives, rhodamine derivatives, triazine derivatives, and quinone derivatives.

[0308] Examples of the p-type semiconductor material of the active layer 373 include electron-donating organic semiconductor materials such as copper(II) phthalocyanine (CuPc), tetraphenyldibenzoperiflanthene (DBP), zinc phthalocyanine (ZnPc), tin phthalocyanine (SnPc), and quinacridone.

[0309] Examples of p-type semiconductor materials include carbazole derivatives, thiophene derivatives, furan derivatives, and compounds having an aromatic amine skeleton. Examples of p-type semiconductor materials include naphthalene derivatives, anthracene derivatives, pyrene derivatives, triphenylene derivatives, fluorene derivatives, pyrrole derivatives, benzofuran derivatives, benzothiophene derivatives, indole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, indolocarbazole derivatives, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, quinacridone derivatives, polyphenylenevinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polythiophene derivatives.

[0310] The HOMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the HOMO level of the electron-accepting organic semiconductor material, and the LUMO level of the electron-donating organic semiconductor material is preferably shallower (higher) than the LUMO level of the electron-accepting organic semiconductor material.

[0311] It is preferable to use a spherical fullerene as the electron-accepting organic semiconductor material and a planar organic semiconductor material as the electron-donating organic semiconductor material. Molecules with similar shapes tend to aggregate together, and when molecules of the same type aggregate, the energy levels of their molecular orbitals become close, which can improve carrier transport properties.

[0312] For example, the active layer 373 is preferably formed by co-evaporating an n-type semiconductor and a p-type semiconductor, or alternatively, the active layer 373 may be formed by laminating an n-type semiconductor and a p-type semiconductor.

[0313] The light-emitting element and the light-receiving element can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting element and the light-receiving element can be formed by a method such as vapor deposition (including vacuum vapor deposition), a transfer method, a printing method, an inkjet method, or a coating method.

[0314] For example, polymer compounds such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) and inorganic compounds such as molybdenum oxide and copper iodide (CuI) can be used as hole transport materials, and inorganic compounds such as zinc oxide (ZnO) can be used as electron transport materials.

[0315] Furthermore, a polymer compound such as Poly[[4,8-bis[5-(2-ethylhexyl)-2-thienyl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl]-2,5-thiophenediyl[5,7-bis(2-ethylhexyl)-4,8-dioxo-4H,8H-benzo[1,2-c:4,5-c']dithiophene-1,3-diyl]]polymer (abbreviated as PBDB-T) or a PBDB-T derivative, which functions as a donor, can be used for the active layer 373. For example, a method of dispersing an acceptor material in PBDB-T or a PBDB-T derivative can be used.

[0316] Furthermore, three or more types of materials may be mixed in the active layer 373. For example, in order to expand the wavelength range, a third material may be mixed in addition to an n-type semiconductor material and a p-type semiconductor material. In this case, the third material may be a low-molecular-weight compound or a high-molecular-weight compound.

[0317] Display device 380B shown in FIG. 21B differs from display device 380A in that light receiving element 370PD and light emitting element 370R have the same configuration.

[0318] The light receiving element 370PD and the light emitting element 370R have the active layer 373 and the light emitting layer 383R in common.

[0319] Here, it is preferable that the light receiving element 370PD has a common configuration with a light emitting element that emits light of a longer wavelength than the light to be detected. For example, the light receiving element 370PD configured to detect blue light can have the same configuration as one or both of the light emitting element 370R and the light emitting element 370G. For example, the light receiving element 370PD configured to detect green light can have the same configuration as the light emitting element 370R.

[0320] By using a common structure for the light-receiving element 370PD and the light-emitting element 370R, the number of film-forming steps and the number of masks can be reduced compared to a structure in which the light-receiving element 370PD and the light-emitting element 370R have separate layers, thereby reducing the manufacturing steps and manufacturing costs of the display device.

[0321] Furthermore, by using a common configuration for the light receiving element 370PD and the light emitting element 370R, the margin for misalignment can be narrowed compared to a configuration in which the light receiving element 370PD and the light emitting element 370R have separate layers. This allows for an increased pixel aperture ratio and improved light extraction efficiency of the display device. This also extends the life of the light emitting element. Furthermore, the display device can display high brightness. Furthermore, it also allows for higher resolution of the display device.

[0322] Light-emitting layer 383R includes a light-emitting material that emits red light. Active layer 373 includes an organic compound that absorbs light with a wavelength shorter than red (for example, one or both of green light and blue light). Active layer 373 preferably includes an organic compound that does not easily absorb red light and absorbs light with a wavelength shorter than red. This allows red light to be extracted efficiently from light-emitting element 370R, and light-receiving element 370PD to detect light with a wavelength shorter than red with high accuracy.

[0323] Furthermore, in the display device 380B, an example is shown in which the light emitting element 370R and the light receiving element 370PD have the same configuration, but the light emitting element 370R and the light receiving element 370PD may have optical adjustment layers of different thicknesses.

[0324] 22A and 22B includes a light receiving / emitting element 370SR that emits red (R) light and has a light receiving function, a light emitting element 370G, and a light emitting element 370B. The configuration of the light emitting element 370G and the light emitting element 370B can be, for example, that of the display device 380A.

[0325] The light emitting / receiving element 370SR has, stacked in this order, a pixel electrode 371, a hole injection layer 381, a hole transport layer 382, ​​an active layer 373, a light emitting layer 383R, an electron transport layer 384, an electron injection layer 385, and a common electrode 375. The light emitting / receiving element 370SR has the same configuration as the light emitting element 370R and the light receiving element 370PD exemplified in the display device 380B.

[0326] 22A shows a case where the light emitting / receiving element 370SR functions as a light emitting element. In FIG. 22A, an example is shown in which the light emitting element 370B emits blue light, the light emitting element 370G emits green light, and the light emitting / receiving element 370SR emits red light.

[0327] Fig. 22B shows a case where the light receiving / emitting element 370SR functions as a light receiving element. Fig. 22B shows an example where the light receiving / emitting element 370SR receives blue light emitted by the light emitting element 370B and green light emitted by the light emitting element 370G.

[0328] The light emitting element 370B, the light emitting element 370G, and the light emitting / receiving element 370SR each have a pixel electrode 371 and a common electrode 375. In this embodiment, a case will be described in which the pixel electrode 371 functions as an anode and the common electrode 375 functions as a cathode. The light emitting / receiving element 370SR is driven by applying a reverse bias between the pixel electrode 371 and the common electrode 375, so that the light emitting / receiving element 370SR can detect light incident on the light emitting / receiving element 370SR, generate electric charges, and extract the charges as a current.

[0329] The light emitting / receiving element 370SR can be said to have a configuration in which an active layer 373 is added to a light emitting element. In other words, the light emitting / receiving element 370SR can be formed in parallel with the formation of the light emitting element by simply adding a step of forming the active layer 373 to the manufacturing process of the light emitting element. Furthermore, the light emitting element and the light emitting / receiving element can be formed on the same substrate. Therefore, it is possible to provide the display unit with either or both of an imaging function and a sensing function without significantly increasing the manufacturing process.

[0330] There are no limitations on the stacking order of the light-emitting layer 383R and the active layer 373. Figures 22A and 22B show an example in which the active layer 373 is provided on the hole-transport layer 382, ​​and the light-emitting layer 383R is provided on the active layer 373. The stacking order of the light-emitting layer 383R and the active layer 373 may be reversed.

[0331] Furthermore, the light emitting / receiving element may not have at least one layer selected from the hole injection layer 381, the hole transport layer 382, ​​the electron transport layer 384, and the electron injection layer 385. The light emitting / receiving element may also have other functional layers such as a hole blocking layer and an electron blocking layer.

[0332] In the light emitting / receiving element, a conductive film that transmits visible light is used for the electrode on the light extraction side, and a conductive film that reflects visible light is preferably used for the electrode on the non-light extraction side.

[0333] The functions and materials of the layers constituting the light emitting / receiving element are similar to those of the layers constituting the light emitting element and the light receiving element, and therefore detailed description thereof will be omitted.

[0334] 22C to 22G show examples of the stacked structure of the light emitting and receiving element.

[0335] The light emitting / receiving element shown in FIG. 22C has a first electrode 377, a hole injection layer 381, a hole transport layer 382, ​​a light emitting layer 383R, an active layer 373, an electron transport layer 384, an electron injection layer 385, and a second electrode 378.

[0336] FIG. 22C shows an example in which a light-emitting layer 383R is provided on a hole-transporting layer 382, ​​and an active layer 373 is laminated on the light-emitting layer 383R.

[0337] As shown in FIGS. 22A to 22C, the active layer 373 and the light emitting layer 383R may be in contact with each other.

[0338] A buffer layer is preferably provided between the active layer 373 and the light-emitting layer 383R. In this case, the buffer layer preferably has hole-transporting and electron-transporting properties. For example, a bipolar substance is preferably used for the buffer layer. Alternatively, the buffer layer may be at least one layer selected from a hole-injection layer, a hole-transporting layer, an electron-transporting layer, an electron-injection layer, a hole-blocking layer, and an electron-blocking layer. FIG. 22D shows an example in which a hole-transporting layer 382 is used as the buffer layer.

[0339] By providing a buffer layer between the active layer 373 and the light-emitting layer 383R, it is possible to suppress the transfer of excitation energy from the light-emitting layer 383R to the active layer 373. In addition, the buffer layer can be used to adjust the optical path length (cavity length) of the microcavity structure. Therefore, a light-emitting / receiving element having a buffer layer between the active layer 373 and the light-emitting layer 383R can obtain high light-emitting efficiency.

[0340] FIG. 22E shows an example of a laminated structure in which a hole transport layer 382-1, an active layer 373, a hole transport layer 382-2, and an emitting layer 383R are laminated in this order on a hole injection layer 381. The hole transport layer 382-2 functions as a buffer layer. The hole transport layer 382-1 and the hole transport layer 281-2 may contain the same material or different materials. Alternatively, a layer that can be used as the buffer layer described above may be used instead of the hole transport layer 281-2. Alternatively, the positions of the active layer 373 and the emitting layer 383R may be interchanged.

[0341] 22F differs from the light emitting / receiving device shown in Fig. 22A in that it does not have the hole transport layer 382. In this way, the light emitting / receiving device may not have at least one layer among the hole injection layer 381, the hole transport layer 382, ​​the electron transport layer 384, and the electron injection layer 385. The light emitting / receiving device may also have other functional layers such as a hole blocking layer and an electron blocking layer.

[0342] The light emitting / receiving device shown in FIG. 22G differs from the light emitting / receiving device shown in FIG. 22A in that it does not have an active layer 373 and a light emitting layer 383R, but has a layer 389 that serves as both a light emitting layer and an active layer.

[0343] The layer that serves as both the light-emitting layer and the active layer can be, for example, a layer containing three materials: an n-type semiconductor that can be used for the active layer 373, a p-type semiconductor that can be used for the active layer 373, and a light-emitting substance that can be used for the light-emitting layer 383R.

[0344] It is preferable that the lowest energy absorption band in the absorption spectrum of the mixed material of n-type and p-type semiconductors does not overlap with the maximum peak in the emission spectrum (PL spectrum) of the luminescent substance, and it is more preferable that they are sufficiently separated from each other.

[0345] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0346] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0347] (Embodiment 5) In this embodiment, a metal oxide that can be used for the OS transistor described in the above embodiment will be described.

[0348] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. Furthermore, it is preferable that it contains aluminum, gallium, yttrium, tin, or the like in addition to these. It may also contain one or more elements selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, and the like.

[0349] The metal oxide can be formed by a sputtering method, a CVD method such as an MOCVD method, or an ALD method.

[0350] <Classification of crystal structures> Examples of the crystalline structure of oxide semiconductors include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystal.

[0351] The crystalline structure of the film or substrate can be evaluated using X-ray diffraction (XRD) spectra. For example, it can be evaluated using XRD spectra obtained by GIXD (Grazing-Incidence XRD) measurements. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0352] For example, in the case of a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, in the case of an IGZO film having a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical peak shape of the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0353] The crystalline structure of a film or substrate can be evaluated by a diffraction pattern (also called a nanobeam electron diffraction pattern) observed using nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. Furthermore, a spot-like pattern is observed in the diffraction pattern of an IGZO film deposited at room temperature, rather than a halo. For this reason, it is estimated that an IGZO film deposited at room temperature is neither crystalline nor amorphous, but is in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0354] <<Oxide semiconductor structure>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0355] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0356] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction can be the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region can also be a region with a uniform lattice arrangement. Furthermore, CAAC-OS has a region where multiple crystalline regions are connected in the ab-plane direction, and the region may have distortion. Note that distortion refers to a location where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with a different uniform lattice arrangement in the region where multiple crystalline regions are connected. In other words, CAAC-OS is an oxide semiconductor with a c-axis aligned but no clear orientation in the ab-plane direction.

[0357] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of many minute crystals, the size of the crystalline region may be several tens of nm.

[0358] In an In-M-Zn oxide (wherein element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. Furthermore, the In layer may contain element M. Furthermore, the In layer may contain Zn. The layered structure is observed as a lattice image in, for example, a high-resolution transmission electron microscope (TEM) image.

[0359] When the CAAC-OS film is subjected to structural analysis using, for example, an XRD apparatus, a peak indicating c-axis orientation is detected at or near 2θ=31° in out-of-plane XRD measurement using θ / 2θ scan. Note that the position of the peak indicating c-axis orientation (2θ value) may vary depending on the type or composition of the metal elements constituting the CAAC-OS.

[0360] For example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots are observed, and the spots are observed at positions that are point-symmetric with respect to the spot of the incident electron beam that has passed through the sample (also called the direct spot).

[0361] When the crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. The distortion may also have a pentagonal or heptagonal lattice arrangement. In the CAAC-OS, no clear grain boundaries can be identified even near the distortion. This indicates that the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of close-packed arrangement of oxygen atoms in the ab-plane direction or the change in interatomic bond distance caused by metal atom substitution.

[0362] A crystal structure with clear grain boundaries is called polycrystalline. Grain boundaries act as recombination centers, trapping carriers and potentially reducing the on-state current or field-effect mobility of a transistor. Therefore, CAAC-OS, which lacks clear grain boundaries, is one of the crystalline oxides with a crystal structure suitable for use in a transistor semiconductor layer. Zn is preferred for use in CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0363] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities or the formation of defects, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, oxide semiconductors with CAAC-OS have stable physical properties. Therefore, oxide semiconductors with CAAC-OS are heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even under high temperatures (so-called thermal budgets) during the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0364] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. Furthermore, the nc-OS exhibits no regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analytical method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Furthermore, when an nc-OS film is subjected to electron diffraction (also known as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of nanocrystals (e.g., 50 nm or larger), a halo-like diffraction pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystals (for example, 1 nm to 30 nm), an electron diffraction pattern can be obtained in which multiple spots are observed within a ring-shaped region centered on the direct spot.

[0365] [a-like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and the amorphous oxide semiconductor. The a-like OS has a pore or low-density region. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0366] <<Oxide semiconductor structure>> Next, the above-mentioned CAC-OS will be described in detail, which relates to the material composition.

[0367] [CAC-OS] CAC-OS is a material structure in which elements constituting a metal oxide are unevenly distributed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that, hereinafter, a metal oxide in which one or more metal elements are unevenly distributed and the regions containing the metal elements are mixed in a size range of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof, is also referred to as a mosaic or patch state.

[0368] Furthermore, CAC-OS has a mosaic structure in which the material is separated into first and second regions, and the first regions are distributed throughout the film (hereinafter also referred to as a cloud structure). That is, CAC-OS is a composite metal oxide having a structure in which the first and second regions are mixed.

[0369] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS in the In-Ga-Zn oxide, the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film. The second region is a region where [Ga] is larger than [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is a region where [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region. The second region is a region where [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.

[0370] Specifically, the first region is a region whose main components are indium oxide, indium zinc oxide, etc. The second region is a region whose main components are gallium oxide, gallium zinc oxide, etc. That is, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0371] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0372] In addition, CAC-OS in In-Ga-Zn oxide refers to a material structure containing In, Ga, Zn, and O, in which some regions primarily composed of Ga and other regions primarily composed of In are randomly arranged in a mosaic pattern. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0373] The CAC-OS can be formed, for example, by a sputtering method under conditions where the substrate is not intentionally heated. When the CAC-OS is formed by a sputtering method, one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition, the better. For example, the flow rate ratio of oxygen gas to the total flow rate of deposition gas during deposition is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0374] Furthermore, for example, in the case of CAC-OS in an In-Ga-Zn oxide, EDX mapping obtained using EDX (Energy Dispersive X-ray spectroscopy) confirms that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0375] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0376] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0377] Therefore, when CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, thereby providing the CAC-OS with a switching function (the ability to turn on / off). In other words, CAC-OS has a conductive function in part of the material and an insulating function in part of the material, and the material as a whole functions as a semiconductor. By separating the conductive function from the insulating function, both functions can be maximized. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0378] Furthermore, a transistor using CAC-OS has high reliability, making it ideal for various semiconductor devices such as display devices.

[0379] Oxide semiconductors have a variety of structures, each with different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0380] <Transistors containing oxide semiconductors> Next, a case where the oxide semiconductor is used in a transistor will be described.

[0381] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0382] For the transistor, an oxide semiconductor with a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 Less than 1 × 10 15 cm -3 or less, more preferably 1 × 10 13 cm -3Less than 1×10, more preferably 11 cm -3 or less, more preferably 1 × 10 10 cm -3 Less than 1 x 10 -9 cm -3 The above is the case. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0383] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0384] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to disappear and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

[0385] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in a nearby film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0386] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0387] When an oxide semiconductor contains silicon or carbon, which is one of the Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are calculated to be 2×10 18 atoms / cm 3 Less than or equal to 2 x 10 17 atoms / cm 3 The following applies.

[0388] Furthermore, when an oxide semiconductor contains an alkali metal or alkaline earth metal, defect levels may be formed and carriers may be generated. Therefore, a transistor using an oxide semiconductor containing an alkali metal or alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of the alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 18 atoms / cm 3 Less than or equal to 2 x 10 16 atoms / cm 3 Do the following:

[0389] Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to 5×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than 1×10, more preferably 18 atoms / cm 3 Less than 5 × 10, more preferably 17 atoms / cm 3 Do the following:

[0390] Furthermore, hydrogen contained in an oxide semiconductor may react with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. When hydrogen enters the oxygen vacancy, electrons serving as carriers may be generated. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons serving as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. For this reason, it is preferable to reduce the amount of hydrogen in the oxide semiconductor as much as possible. Specifically, the hydrogen concentration in an oxide semiconductor measured by SIMS is 1×10 20 atoms / cm 3 Less than 1 x 10 19 atoms / cm 3 less than 5 × 10 18 atoms / cm 3 less than 1×10 18 atoms / cm 3 Make it less than.

[0391] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0392] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0393] (Embodiment 6) In this embodiment, an electronic device including a display device according to one embodiment of the present invention will be described.

[0394] The display device of one embodiment of the present invention can be provided in various electronic devices. For example, the display device of one embodiment of the present invention can be provided in electronic devices with relatively large screens, such as television devices, desktop or notebook computers, tablet computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, portable game machines, personal digital assistants, and sound players. Configuration examples of electronic devices that can include the display device of one embodiment of the present invention are described with reference to FIGS. 23A to 23E.

[0395] 23A is a diagram showing an example of an oximeter 900. The oximeter 900 has a housing 911 and a light emitting and receiving device 912. A hollow portion is provided in the housing 911, and the light emitting and receiving device 912 is provided so as to be in contact with the wall surface of the hollow portion.

[0396] The light emitting and receiving device 912 functions as a light source that emits light and as a sensor that detects light. For example, when an object is placed in the hollow portion of the housing 911, the light emitting and receiving device 912 can detect the light that is emitted by the light emitting and receiving device 912, irradiated onto the object, and reflected from the object.

[0397] For example, when a finger is inserted into the hollow portion of the housing 911, the color of the blood changes depending on the oxygen saturation of the hemoglobin contained in the blood (the proportion of hemoglobin bound to oxygen). This causes a change in the intensity of light reflected by the finger, which is detected by the light receiving and emitting device 912. For example, the intensity of red light detected by the light receiving and emitting device 912 changes. As described above, the oximeter 900 can measure the oxygen saturation by detecting the intensity of the reflected light with the light receiving and emitting device 912. The oximeter 900 can be, for example, a pulse oximeter.

[0398] The display device of one embodiment of the present invention can be applied to the light-emitting and receiving device 912. In this case, the light-emitting and receiving device 912 includes at least a light-emitting element that emits red light (R). The light-emitting and receiving device 912 preferably includes a light-emitting element that emits infrared light (IR). The red light (R) reflectance of hemoglobin bound to oxygen is significantly different from the red light (R) reflectance of hemoglobin not bound to oxygen. On the other hand, the difference between the infrared light (IR) reflectance of hemoglobin bound to oxygen and the infrared light (IR) reflectance of hemoglobin not bound to oxygen is small. Therefore, when the light-emitting and 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 oximeter 900 can measure oxygen saturation with high accuracy.

[0399] When the display device of one embodiment of the present invention is used as the light-emitting and receiving device 912, the light-emitting and receiving device 912 preferably has flexibility. The flexibility of the light-emitting and receiving device 912 allows the light-emitting and receiving device 912 to have a curved shape. This allows light to be uniformly irradiated onto a finger, for example, and enables oxygen saturation to be measured with high accuracy, for example.

[0400] 23B is a diagram showing an example of a portable data terminal 9100. The portable data terminal 9100 includes a display unit 9110, a housing 9101, keys 9102, and a speaker 9103. The portable data terminal 9100 may be, for example, a tablet. Here, a key such as the key 9102 may be, for example, a key for turning the power on and off. That is, the key such as the key 9102 may be, for example, a power switch. Furthermore, the key such as the key 9102 may be, for example, an operation key used to cause an electronic device to perform a desired operation.

[0401] The display unit 9110 can display information 9104, operation buttons (also referred to as operation icons or simply icons) 9105, and the like.

[0402] When the display device of one embodiment of the present invention is provided in the portable data terminal 9100, the display portion 9110 can function as a touch sensor or a near-touch sensor.

[0403] 23C is a diagram showing an example of a digital signage 9200. The digital signage 9200 can have a configuration in which a display unit 9210 is attached to a pillar 9201.

[0404] When the display device of one embodiment of the present invention is provided in the digital signage 9200, the display portion 9210 can function as a touch sensor or a near-touch sensor.

[0405] 23D is a diagram showing an example of a mobile information terminal 9300. The mobile information terminal 9300 includes a display portion 9310, a housing 9301, a speaker 9302, a camera 9303, keys 9304, a connection terminal 9305, and a connection terminal 9306. The mobile information terminal 9300 may be, for example, a smartphone. The connection terminal 9305 may be, for example, a microUSB, a lightning connector, or a Type-C connector. The connection terminal 9306 may be, for example, an earphone jack.

[0406] The display unit 9310 can display, for example, operation buttons 9307. The display unit 9310 can also display information 9308. Examples of the information 9308 include a display notifying an incoming email, SNS (social networking service), or phone call, the title of the email or SNS, the name of the sender of the email or SNS, the date and time, the remaining battery level, and signal strength.

[0407] When the display device of one embodiment of the present invention is provided in the portable information terminal 9300, the display portion 9310 can function as a touch sensor or a near-touch sensor.

[0408] 23E is a diagram showing an example of a wristwatch-type portable information terminal 9400. The portable information terminal 9400 includes a display portion 9410, a housing 9401, a wristband 9402, keys 9403, and a connection terminal 9404. Note that the connection terminal 9404 can be, for example, a microUSB, a lightning, or a Type-C, similar to the connection terminal 9305.

[0409] 23E shows an example in which the time is displayed on the display unit 9410 as the information 9406. In the example shown in FIG.

[0410] When the display device of one embodiment of the present invention is provided in the portable information terminal 9400, the display portion 9410 can function as a touch sensor or a near-touch sensor.

[0411] At least a part of the configuration examples exemplified in this embodiment and the corresponding drawings can be combined as appropriate with other configuration examples or drawings.

[0412] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification. [Explanation of symbols]

[0413] 10: display device, 10A: display device, 10B: display device, 20: pixel, 51: substrate, 52: finger, 53: layer, 55: layer, 57: layer, 59: substrate, 65: area, 67: fingerprint, 69: contact portion, 71: layer, 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, 110: light-emitting element, 110B: light-emitting element, 110G: light-emitting element, 110IR: light-emitting element, 110R: light-emitting element, 111: pixel electrode, 111 B: pixel electrode, 111C: connection electrode, 111G: pixel electrode, 111IR: pixel electrode, 111PD: pixel electrode, 111R: pixel electrode, 113: hole injection layer, 113B: hole injection layer, 113G: hole injection layer, 113Gf: functional film, 113IR: hole injection layer, 113R: hole injection layer, 113Rf: functional film, 115: hole transport layer, 115B: hole transport layer, 115G: hole transport layer, 115Gf: functional film, 115IR: hole transport layer, 115PD: hole transport layer, 115R: hole transport layer, 115Rf: functional film, 117: light emitting layer, 117B: light emitting layer, 117G: light emitting layer, 117 Gf: luminescent film, 117IR: luminescent layer, 117R: luminescent layer, 117Rf: luminescent film, 119: electron transport layer, 119B: electron transport layer, 119G: electron transport layer, 119Gf: functional film, 119IR: electron transport layer, 119PD: electron transport layer, 119R: electron transport layer, 119Rf: functional film, 121: common layer, 123: common electrode, 125: protective layer, 127: gap, 130: connection portion, 131: insulating layer, 141: transistor, 141a: sacrificial film, 141b: sacrificial film, 142: transistor, 143: space, 143a: protective film, 143b: protective film, 145a: resist mask, 1 45b: resist mask, 146: filter, 147a: sacrificial layer, 147b: sacrificial layer, 147c: sacrificial layer, 147d: sacrificial layer, 148: light-shielding layer, 149a: protective layer, 149b: protective layer, 150: light-receiving element, 150L: light-receiving element, 151: substrate, 152: substrate, 153: substrate, 154: substrate, 155: adhesive layer, 156: adhesive layer, 157: light-receiving layer, 158: insulating layer, 162: display unit, 164: circuit, 165: wiring, 166: conductive layer, 172: FPC, 173: IC, 201: transistor, 204: connection unit, 211: insulating layer, 212: insulating layer, 213: insulating layer,214: insulating layer, 215: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 228: region, 231: semiconductor layer, 240: capacitor, 241: conductive layer, 242: adhesive layer, 243: insulating layer, 244: connection layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255: insulating layer, 256: plug, 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274: plug, 274a: conductive layer, 274b: conductive layer, 281-2: hole transport layer, 301: substrate, 310: Transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element isolation layer, 320: transistor, 321: semiconductor layer, 323: insulating layer, 324: conductive layer, 325: conductive layer, 326: insulating layer, 327: conductive layer, 328: insulating layer, 329: insulating layer, 331: substrate, 332: insulating layer, 370B: light emitting element, 370G: light emitting element, 370PD: light receiving element, 370R: light emitting element, 370SR: light receiving / emitting element, 371: pixel electrode, 373: active layer, 375: common electrode, 377: electrode, 378: electrode, 380A: display device, 380B: Display device, 380C: display device, 381: hole injection layer, 382: hole transport layer, 382-1: hole transport layer, 382-2: hole transport layer, 383: light emitting layer, 383B: light emitting layer, 383G: light emitting layer, 383R: light emitting layer, 384: electron transport layer, 385: electron injection layer, 389: layer, 419: resin layer, 420: substrate, 672: electrode, 686: EL layer, 686a: EL layer, 686b: EL layer, 688: electrode, 900: oxygen concentration meter, 911: housing, 912: light emitting / receiving device, 4411: light emitting layer, 4412: light emitting layer, 4413: light emitting layer, 4420: layer, 4420-1: layer, 4420- 2: layer, 4430: layer, 4430-1: layer, 4430-2: layer, 9100: portable data terminal, 9101: housing, 9102: key, 9103: speaker, 9104: information, 9110: display unit, 9200: digital signage, 9201: pillar, 9210: display unit, 9300: portable information terminal, 9301: housing, 9302: speaker, 9303: camera, 9304: key, 9305: connection terminal, 9306: connection terminal, 9307: operation button, 9308: information, 9310: display unit, 9400: portable information terminal, 9401: housing, 9402: wristband, 9403: key,9404: Connection terminal, 9406: Information, 9407: Operation button, 9410: Display unit,

Claims

1. a first step of forming a first pixel electrode, a second pixel electrode, and a connection electrode; a second step of forming a light-emitting film on the first pixel electrode and the second pixel electrode; a third step of forming a first sacrificial film on the light-emitting film and on the connection electrode; forming a first resist mask on the first sacrificial film at a position overlapping the first pixel electrode; a fourth step of etching the first sacrificial film and the light-emitting film that are not covered by the first resist mask to expose the second pixel electrode, and forming a light-emitting layer on the first pixel electrode and a first sacrificial layer on the light-emitting layer and on the connection electrode; a fifth step of forming a light receiving film on the light emitting layer and the second pixel electrode; a sixth step of forming a second sacrificial film on the light receiving film and the connection electrode; forming a second resist mask on the second sacrificial film at a position overlapping the second pixel electrode; a seventh step of etching the second sacrificial film and the light-receiving film that are not covered by the second resist mask to form a light-receiving layer on the second pixel electrode and second sacrificial layers on the light-receiving layer and on the connection electrode; an eighth step of removing the first sacrificial layer and the second sacrificial layer; a ninth step of forming a common layer on the light-emitting layer and the light-receiving layer; a tenth step of forming a common electrode so as to have an area in contact with the common layer and the connection electrode; A method for manufacturing a display device, wherein the first sacrificial film and the second sacrificial film include the same metal film, the same alloy film, the same metal oxide film, the same semiconductor film, or the same inorganic insulating film.

2. In claim 1, A method for manufacturing a display device, wherein the common layer functions as either a hole injection layer or an electron injection layer in a light-emitting element having the first pixel electrode, the light-emitting layer, the common layer, and the common electrode.

3. In claim 2, an eleventh step of forming a first functional film on the first pixel electrode and the second pixel electrode between the first step and the second step; In the fourth step, the first functional film is etched to form a first functional layer on the first pixel electrode; a twelfth step of forming a second functional film on the first sacrificial layer and on the second pixel electrode between the fourth step and the fifth step; In the seventh step, the second functional film is etched to form a second functional layer on the second pixel electrode; the first functional layer has the other of the hole injection layer or the electron injection layer, The method for manufacturing a display device includes the second functional layer having one of a hole transport layer and an electron transport layer.

4. In any one of claims 1 to 3, The method for manufacturing a display device includes forming the light-emitting film, the light-receiving film, and the common layer by a vapor deposition method using a shielding mask.

5. In any one of claims 1 to 4, In the fourth step, the light-emitting film is etched by dry etching using an etching gas that does not contain oxygen as a main component, In the eighth step, the first sacrificial layer and the second sacrificial layer are 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.

6. In claim 5, The method for manufacturing a display device, wherein the first sacrificial film and the second sacrificial film contain aluminum oxide.

7. In any one of claims 1 to 6, A method for manufacturing a display device, comprising a fourteenth step of forming a protective layer on the common electrode after the tenth step.

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