Display apparatus

Abstract

Provided is a display apparatus in which a voltage drop is sufficiently inhibited. The display apparatus has: a shared electrode possessed by a first light-emitting device in which a plurality of light-emitting layers are layered, and by a second light-emitting device in which a plurality of light-emitting layers are layered; and an auxiliary wiring electrically connected to the shared electrode. The auxiliary wiring has a first wiring layer and a second wiring layer. The second wiring layer is electrically connected to the first wiring layer through a contact hole of an insulating layer. The first wiring layer has a lattice shape as viewed from above.

Description

display device

[0001] One aspect of the present invention relates to a display device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the present invention disclosed in this specification and the like includes semiconductor devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, and input / output devices, and manufacturing methods thereof can be given as examples.

[0003] In an active matrix display device using organic EL elements, a configuration in which auxiliary wiring is provided has been proposed (see Patent Document 1).

[0004] Since the auxiliary wiring is arranged around the organic EL element, there is a problem in that the aperture ratio of the pixel is limited by the arrangement space of the auxiliary wiring (see Patent Document 2).

[0005] As a method for manufacturing an organic EL element, a method for manufacturing an organic optoelectronic device using standard UV photolithography has been disclosed (see Non-Patent Document 1).

[0006] JP 2006-58815 A JP 2010-85866 A

[0007] B. Lamprecht et al. , “Organic optoelectronic device fabrication using standard UV photolithography” phys. stat. sol. (RRL) 2, No. 1, p. 16-18 (2008)

[0008] In order to solve the problem, Patent Document 2 above proposes a configuration having an upper electrode connection wiring provided in the same layer as the lower electrode of the light-emitting element, and a lower layer auxiliary wiring (also described as resistance adjustment wiring) provided in a layer below the lower electrode.

[0009] In the configuration disclosed in Patent Document 2, the lower-layer auxiliary wiring is formed in the same layer as the signal lines, power supply lines, or scanning lines. The lower-layer auxiliary wiring cannot contact the signal lines, power supply lines, or scanning lines, which imposes restrictions on the layout of the lower-layer auxiliary wiring. With such lower-layer auxiliary wiring, the suppression of voltage drop, which is an effect of auxiliary wiring, cannot be fully exerted.

[0010] Furthermore, it is difficult to provide a high-definition display device with the method of Non-Patent Document 1.

[0011] In view of the above, an object of one embodiment of the present invention is to provide an auxiliary wiring capable of sufficiently suppressing a voltage drop, specifically, an auxiliary wiring having a novel structure, and a display device including the auxiliary wiring.

[0012] Note that the description of these problems does not preclude the existence of other problems. Furthermore, these problems are considered to be independent of each other, and one embodiment of the present invention only needs to solve one of these problems, and does not need to solve all of them. Furthermore, problems other than these can be extracted from the description of the specification, drawings, and claims in this specification, etc.

[0013] In view of the above-described problems, one embodiment of the present invention provides a first light-emitting device including a first bottom electrode, a first light-emitting layer located over the first bottom electrode, a first layer located over the first light-emitting layer, and a second light-emitting layer located over the first layer; a second light-emitting device including a second bottom electrode, a third light-emitting layer located over the second bottom electrode, a second layer located over the third light-emitting layer, and a fourth light-emitting layer located over the second layer; and a common electrode included in the first light-emitting device and the second light-emitting device, and an auxiliary wiring electrically connected to the common electrode. a color emitted from the light-emitting material of the first light-emitting layer is the same as a color emitted from the light-emitting material of the second light-emitting layer, a color emitted from the light-emitting material of the third light-emitting layer is the same as a color emitted from the light-emitting material of the fourth light-emitting layer, the first layer and the second layer each contain lithium, the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, and the first wiring layer has a lattice shape when viewed from above.

[0014] Another aspect of the present invention is a light-emitting device including: a first light-emitting device having a first lower electrode, a first light-emitting layer located on the first lower electrode, a first layer located on the first light-emitting layer, and a second light-emitting layer located on the first layer; a second light-emitting device having a second lower electrode, a third light-emitting layer located on the second lower electrode, a second layer located on the third light-emitting layer, and a fourth light-emitting layer located on the second layer; a common electrode included in the first light-emitting device and the second light-emitting device; and an auxiliary wiring electrically connected to the common electrode, wherein the color emitted from the light-emitting material included in the first light-emitting layer is is the same as the color emitted from the light-emitting material of the second light-emitting layer, the color emitted from the light-emitting material of the third light-emitting layer is the same as the color emitted from the light-emitting material of the fourth light-emitting layer, the first layer and the second layer each contain lithium, the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, the first wiring layer has a lattice shape in a top view, and the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer.

[0015] Another aspect of the present invention is a light-emitting device including: a first light-emitting device having a first lower electrode, a first light-emitting layer located on the first lower electrode, a first layer located on the first light-emitting layer, and a second light-emitting layer located on the first layer; a second light-emitting device having a second lower electrode, a third light-emitting layer located on the second lower electrode, a second layer located on the third light-emitting layer, and a fourth light-emitting layer located on the second layer; a common electrode included in the first light-emitting device and the second light-emitting device; and auxiliary wiring electrically connected to the common electrode, wherein the color emitted from the light-emitting material included in the first light-emitting layer is different from the color emitted from the light-emitting material included in the second light-emitting layer. the color emitted from the light-emitting material of the third light-emitting layer is the same as the color emitted from the light-emitting material of the fourth light-emitting layer; the first layer and the second layer each contain lithium; the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, the first wiring layer and the second wiring layer each have a lattice shape in top view; the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer; and the width of the second wiring layer is smaller than the width of the first wiring layer.

[0016] Another aspect of the present invention is a first light-emitting device having a first lower electrode, a first light-emitting layer located on the first lower electrode, a first layer located on the first light-emitting layer, and a second light-emitting layer located on the first layer; a first color filter located so as to overlap the first light-emitting device; a second light-emitting device having a second lower electrode, a third light-emitting layer located on the second lower electrode, a second layer located on the third light-emitting layer, and a fourth light-emitting layer located on the second layer; a second color filter located so as to overlap the second light-emitting device; a common electrode having a first light-emitting layer and a second light-emitting layer, and an auxiliary wiring electrically connected to the common electrode, wherein a color emitted from a light-emitting material of the first light-emitting layer is the same as a color emitted from a light-emitting material of the second light-emitting layer, a color emitted from a light-emitting material of the third light-emitting layer is the same as a color emitted from a light-emitting material of the fourth light-emitting layer, the first layer and the second layer each contain lithium, the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, and the first wiring layer has a lattice shape in a top view.

[0017] Another aspect of the present invention is a first light-emitting device having a first lower electrode, a first light-emitting layer located on the first lower electrode, a first layer located on the first light-emitting layer, and a second light-emitting layer located on the first layer; a first color filter located so as to overlap the first light-emitting device; a second light-emitting device having a second lower electrode, a third light-emitting layer located on the second lower electrode, a second layer located on the third light-emitting layer, and a fourth light-emitting layer located on the second layer; a second color filter located so as to overlap the second light-emitting device; a common electrode included in the first light-emitting device and the second light-emitting device; and auxiliary wiring, wherein the color emitted from the light-emitting material of the first light-emitting layer is the same as the color emitted from the light-emitting material of the second light-emitting layer, the color emitted from the light-emitting material of the third light-emitting layer is the same as the color emitted from the light-emitting material of the fourth light-emitting layer, the first layer and the second layer each contain lithium, the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, the first wiring layer has a lattice shape in a top view, and the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer.

[0018] Another embodiment of the present invention provides a first light-emitting device including a first lower electrode, a first light-emitting layer located on the first lower electrode, a first layer located on the first light-emitting layer, and a second light-emitting layer located on the first layer; a first color filter located so as to overlap the first light-emitting device; a second light-emitting device including a second lower electrode, a third light-emitting layer located on the second lower electrode, a second layer located on the third light-emitting layer, and a fourth light-emitting layer located on the second layer; a second color filter located so as to overlap the second light-emitting device; a common electrode included in the first light-emitting device and the second light-emitting device; and an auxiliary wiring electrically connected to the common electrode, a color emitted from the light-emitting material of the third light-emitting layer is the same as a color emitted from the light-emitting material of the fourth light-emitting layer; the first layer and the second layer each contain lithium; the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer, the first wiring layer and the second wiring layer each have a lattice shape in a top view; the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer; and the width of the second wiring layer is smaller than the width of the first wiring layer.

[0019] In another aspect of the present invention, it is preferable that the distance between the first lower electrode and the common electrode is shorter than the distance between the second lower electrode and the common electrode.

[0020] In another aspect of the present invention, it is preferable that the ends of the first lower electrode and the second lower electrode each have a taper.

[0021] In another embodiment of the present invention, the taper angle of an end surface of the organic compound layer including the first light-emitting layer and the second light-emitting layer is preferably greater than or equal to 45 degrees and less than 90 degrees in a cross-sectional view.

[0022] In another embodiment of the present invention, the taper angle of an end surface of the organic compound layer including the third light-emitting layer and the fourth light-emitting layer is preferably greater than or equal to 45 degrees and less than 90 degrees in a cross-sectional view.

[0023] According to one embodiment of the present invention, an auxiliary wiring having a novel structure can be provided, and a display device in which a voltage drop is sufficiently suppressed by the auxiliary wiring can be provided.

[0024] Note that the description of these effects does not preclude the existence of other effects. Furthermore, these effects are considered to be independent of each other, and one embodiment of the present invention may achieve any one of these effects, but need not achieve all of them. Furthermore, effects other than these can be extracted from the description of the specification, drawings, and claims, including this specification.

[0025] FIGS. 1A and 1B are diagrams illustrating a pixel portion having an auxiliary wiring. FIGS. 2A and 2B are diagrams illustrating a pixel portion having an auxiliary wiring. FIG. 3A is a perspective view of the auxiliary wiring, and FIGS. 3B and 3C are top views of the pixel portion. FIGS. 4A to 4F are top views of a pixel portion having an auxiliary wiring. FIG. 5A is a perspective view of the auxiliary wiring, and FIGS. 5B and 5C are top views of the pixel portion. FIGS. 6A and 6B are perspective views of the auxiliary wiring. FIGS. 7A and 7B are diagrams illustrating a pixel portion having an auxiliary wiring. FIGS. 8A and 8B are diagrams illustrating a pixel portion having an auxiliary wiring. FIG. 9A is a cross-sectional view of the auxiliary wiring, and FIGS. 9B and 9C are top views of the pixel portion. FIGS. 10A to 10I are top views of the pixel portion and the auxiliary wiring. FIGS. 11A to 11F are top views of the pixel portion and the auxiliary wiring. FIGS. 12A to 12F are top views of the pixel portion and the auxiliary wiring. FIG. 13A is a top view of a pixel portion, FIG. 13B is a cross-sectional view of the pixel portion, and FIG. 13C is a cross-sectional view of a connection portion. FIGS. 14A and 14B are cross-sectional views of a light-emitting device. FIGS. 15A and 15B are cross-sectional views of a light-emitting device. FIG. 16A is a circuit diagram of a display device, and FIGS. 16B to 16E are pixel circuit diagrams. FIGS. 17A to 17D are cross-sectional views of a transistor. FIGS. 18A to 18C are top views of a pixel portion, and FIG. 18D is a circuit diagram. FIGS. 19A to 19C are cross-sectional views illustrating a manufacturing method. FIGS. 20A to 20C are cross-sectional views illustrating a manufacturing method. FIGS. 21A to 21C are cross-sectional views illustrating a manufacturing method. FIGS. 22A to 22C are cross-sectional views illustrating a manufacturing method. FIGS. 23A and 23B are cross-sectional views illustrating a manufacturing method. FIGS. 24A to 24C are cross-sectional views illustrating a manufacturing method. FIG. 25 is a cross-sectional view illustrating a manufacturing method. FIG. 26 is a cross-sectional view illustrating a manufacturing method. Fig. 27A is a top view of the display device, and Figs. 27B and 27C are perspective views of the display device. Figs. 28A and 28B are cross-sectional views of the display device. Figs. 29A and 29B are cross-sectional views of the display device. Figs. 30A and 30B are perspective views of the display device. Figs. 31A to 31D are views of electronic equipment. Figs. 32A and 32B are views of electronic equipment.

[0026] In this specification, the configuration may be classified by function and explained using block diagrams that are independent of each other, but in reality it is difficult to separate the configuration by function, and one configuration may be involved in multiple functions.

[0027] In this specification and the like, the names of the source and drain of a transistor are interchangeable depending on the polarity of the transistor and the level of the potential applied to each terminal. Generally, in an n-channel transistor, a terminal to which a low potential is applied is called a source, and a terminal to which a high potential is applied is called a drain. In addition, in a p-channel transistor, a terminal to which a low potential is applied is called a drain, and a terminal to which a high potential is applied is called a source. In practice, the names of the source and the drain may be interchangeable depending on the above-mentioned potential relationship. However, in this specification and the like, when describing the connection relationship of a transistor, the source and the drain are fixed for convenience.

[0028] In this specification, the source of a transistor refers to a source region that is part of a semiconductor layer that functions as an active layer, or a source electrode connected to the source region. Similarly, the drain of a transistor refers to a drain region that is part of the semiconductor layer, or a drain electrode connected to the drain region. Furthermore, the gate of a transistor refers to a gate electrode.

[0029] In this specification, a state in which transistors are connected in series means, for example, a state in which only one of the source or drain of a first transistor is connected to only one of the source or drain of a second transistor, and a state in which transistors are connected in parallel means a state in which one of the source or drain of a first transistor is connected to one of the source or drain of a second transistor, and the other of the source or drain of the first transistor is connected to the other of the source or drain of the second transistor.

[0030] In this specification, connection may be referred to as electrical connection, and includes a state in which a current, voltage, or potential can be supplied or transmitted. Therefore, it also includes a state in which things are connected to each other via elements such as wiring, resistors, diodes, and transistors. Electrical connection also includes a state in which things are directly connected to each other without using elements such as wiring, resistors, diodes, and transistors.

[0031] In this specification and the like, the source and drain of a transistor may be described using a first electrode and a second electrode; however, when one of the first electrode and the second electrode is the source, the other is the drain.

[0032] In this specification and the like, a conductive layer may have multiple functions such as wiring or an electrode.

[0033] In this specification, a tapered shape refers to a shape in which at least a portion of the side of a structure is inclined relative to the surface on which the structure is to be formed or the substrate surface. For example, the angle between the inclined side and the substrate surface is called the taper angle, and a tapered shape refers to a region in which the taper angle is less than 90°. The side of the structure may be substantially planar with a slight curvature or a slight unevenness. The taper angle can also be measured by drawing a line extending from the top to the bottom of the side of the structure. Similarly, the surface on which the structure is to be formed or the substrate surface may be substantially planar with a slight curvature or a slight unevenness.

[0034] In this specification and the like, a light-emitting device may be referred to as a light-emitting element. A light-emitting device has an organic compound layer, which is a laminate in which functional layers are stacked between a pair of electrodes. Each functional layer may include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), or a carrier block layer (hole block layer and electron block layer). A hole injection layer refers to a layer containing a substance with high hole injection properties. An electron injection layer refers to a layer containing a substance with high electron injection properties. A hole transport layer refers to a layer containing a substance with high hole transport properties. An electron transport layer refers to a layer containing a substance with high electron transport properties. A hole block layer refers to a layer containing a substance with high hole blocking properties. An electron block layer refers to a layer containing a substance with high electron blocking properties.

[0035] The functional layer described above can function as a light-emitting device even if it does not have any other layers than the light-emitting layer. The functional layer may contain an inorganic material or an inorganic compound material in addition to an organic compound material. Therefore, the organic compound layer located between a pair of electrodes is sometimes referred to as an EL layer or a light-emitting unit.

[0036] In this specification and the like, one of a pair of electrodes in a light-emitting device functions as an anode, and the other functions as a cathode. One of the pair of electrodes may be referred to as a lower electrode, and the other as an upper electrode. When one of the pair of electrodes is located on the side where light from the light-emitting layer is extracted, it may be referred to as an extraction electrode, and the other as a counter electrode. Note that the terms "one" and "the other" are merely examples and may be interpreted interchangeably.

[0037] In this specification, a light-emitting device formed using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device having an MM (metal mask) structure. Also, in this specification, a light-emitting device formed without using a metal mask or an FMM may be referred to as a device having an MML (metal maskless) structure.

[0038] In this specification and the like, light-emitting devices that emit red, green, blue, etc. may be referred to as a red-light-emitting device, a green-light-emitting device, and a blue-light-emitting device, respectively. A full-color display device can be provided by fabricating a red-light-emitting device, a green-light-emitting device, and a blue-light-emitting device.

[0039] In this specification and the like, a structure in which light-emitting layers are individually fabricated in light-emitting devices with different emission wavelengths may be referred to as an SBS (Side By Side) structure. For example, a red-light-emitting device, a green-light-emitting device, and a blue-light-emitting device can be fabricated using the SBS structure. The SBS structure allows the functional layer material or functional layer stacking configuration to be optimized for each light-emitting device, thereby increasing the freedom of selection of the material and stacking configuration, and improving brightness and reliability.

[0040] In this specification, a light-emitting device having multiple stacked light-emitting layers can have a tandem structure. A tandem structure is a structure having two or more light-emitting units between a pair of electrodes. Each of the two or more light-emitting units may include one or more light-emitting layers. In a tandem structure, it is preferable to provide a charge generation layer or the like between the two or more light-emitting units. The charge generation layer has the function of injecting holes into one light-emitting unit formed in contact with the charge generation layer and the function of injecting electrons into the other light-emitting unit when a voltage is applied between the cathode and the anode. In other words, the charge generation layer is located between the light-emitting units. For this reason, the charge generation layer is sometimes referred to as an intermediate layer. Note that the terms "one" and "the other" are merely examples and can be interpreted interchangeably.

[0041] In this specification, a light-receiving device may be referred to as a light-receiving element. A light-receiving device has an active layer that functions as at least a photoelectric conversion layer between a pair of electrodes.

[0042] In this specification and the like, the mask layer has the function of protecting the light-emitting layer of a light-emitting device or the active layer of a light-receiving device during the fabrication process. Specifically, when processing the light-emitting device or the light-receiving device, the mask layer is formed at a position where damage caused by processing will not enter the light-emitting layer or the active layer. During the fabrication process of the light-emitting device or the light-receiving device, the mask layer may be completely removed, or a portion may be left. The mask layer may also be called a sacrificial layer.

[0043] In this specification and the like, a display panel having a connector such as a flexible printed circuit (FPC) or a tape carrier package (TCP) attached to a substrate, or a display panel having an IC mounted on a substrate by a chip-on-glass (COG) method or the like, may be referred to as a display module. A display module is one aspect of a display device.

[0044] Next, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art 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 description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0045] Embodiment 1 In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described.

[0046] <Function of Auxiliary Wiring> A display device according to one embodiment of the present invention includes auxiliary wiring. The auxiliary wiring refers to a layer that has an auxiliary function for the main electrode, and the auxiliary function includes, for example, suppressing a voltage drop due to the main electrode. An example of the main electrode is an extraction electrode of a light-emitting device. The extraction electrode is formed using a so-called transparent conductive material that transmits visible light in order to extract light from the light-emitting layer. An example of a transparent conductive material is an oxide containing indium and tin (sometimes referred to as ITO), but ITO is known to have a higher resistivity than metals. Therefore, the auxiliary wiring is electrically connected to the extraction electrode to suppress a voltage drop due to the extraction electrode. In a structure in which the extraction electrode and the auxiliary wiring are electrically connected, the extraction electrode includes a conductive material with a high resistivity, and the auxiliary wiring includes a conductive material with a low resistivity.

[0047] The extraction electrode can be a continuous layer without being separated between multiple light-emitting devices. A continuous layer is sometimes referred to as a common layer, and a continuous electrode is sometimes referred to as a common electrode. As display devices become larger, the extraction electrode has a larger area, and when taking into account that it is made of ITO, voltage drops are likely to occur. Therefore, a configuration in which auxiliary wiring is electrically connected to the extraction electrode to suppress voltage drops caused by the extraction electrode is suitable for large display devices.

[0048] The auxiliary wiring may be referred to as an auxiliary electrode depending on its shape, but in this specification and the like, the auxiliary wiring will be used for explanation regardless of its shape.

[0049] FIG. 1A illustrates a conceptual diagram of a pixel portion 103 included in a display device of one embodiment of the present invention.

[0050] <Characteristics of Auxiliary Wiring> The auxiliary wiring 151 of one embodiment of the present invention has a novel structure in which two or more wiring layers are provided in different layers. For example, as shown in FIG. 1A , the auxiliary wiring 151 includes a first wiring layer 151a and a second wiring layer 151b. The first wiring layer 151a is formed in a layer different from the second wiring layer 151b, and the formation surface of the first wiring layer 151a is different from the formation surface of the second wiring layer 151b. Wiring layers that are formed on different surfaces are referred to as wiring layers provided in different layers.

[0051] The wiring layer may be referred to as an electrode layer depending on its shape, but in this specification and the like, any shape will be described as a wiring layer.

[0052] 1A, an insulating layer 14 is located between a first wiring layer 151a and a second wiring layer 151b. The first wiring layer 151a is electrically connected to the second wiring layer 151b through a contact hole 15 in the insulating layer 14.

[0053] Although two wiring layers formed on different layers have been described, three or more wiring layers may also be formed on different layers. Such a wiring layer is sometimes referred to as a multilayered wiring layer. The advantage of a multilayered wiring layer is that it provides flexibility in the layout of each wiring layer. For example, one of the multilayered wiring layers can be laid out on a different layer from the lower electrode. This eliminates the constraints imposed by the layout of the lower electrode. Furthermore, one of the wiring layers can have a large area that overlaps with the lower electrode. Such multilayered wiring layers are electrically connected to each other through contact holes in the insulating layer and can function as auxiliary wiring.

[0054] <Conductive Material of Auxiliary Wiring> A conductive material for the auxiliary wiring 151 of one embodiment of the present invention, that is, a conductive material for the first wiring layer 151a or the second wiring layer 151b, can be a metal such as aluminum, copper, silver, gold, platinum, chromium, or molybdenum. An alloy of the above metals can also be used as the conductive material. The above conductive material is a metal and has non-light-transmitting properties. An electrode using a non-light-transmitting conductive material may be referred to as a reflective electrode. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a stacked layer using the above conductive material. For example, the first wiring layer 151a may be formed as a stacked layer, and the second wiring layer 151b may be formed as a single layer. Alternatively, the first wiring layer 151a may be formed as a single layer, and the second wiring layer 151b may be formed as a stacked layer. When the first wiring layer 151a or the second wiring layer 151b has a stacked structure, it is preferable that at least one layer contain the above-described non-light-transmitting conductive material.

[0055] A light-transmitting conductive material may be used as the conductive material of the auxiliary wiring of one embodiment of the present invention, that is, the conductive material of the first wiring layer 151a or the second wiring layer 151b. Specifically, ITO, an oxide containing indium, silicon, and tin (In-Si-Sn oxide, also referred to as ITSO), an oxide containing indium and zinc (indium zinc oxide, also referred to as In-Zn oxide), an oxide containing indium, tungsten, and zinc (In-W-Zn oxide), or the like can be used. An electrode using a light-transmitting conductive material may be referred to as a transparent electrode. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a stacked layer using the above conductive material. For example, the first wiring layer 151a may be formed as a stacked layer, and the second wiring layer 151b may be formed as a single layer. Alternatively, the first wiring layer 151a may be formed as a single layer, and the second wiring layer 151b may be formed as a stacked layer. When the first wiring layer 151a or the second wiring layer 151b has a stacked structure, it is preferable that at least one layer contain the above-described light-transmitting conductive material.

[0056] In one embodiment of the present invention, the resistivity of the conductive material used for the auxiliary wiring, i.e., the resistivity of the conductive material used for the first wiring layer 151a or the second wiring layer 151b, is preferably lower than the resistivity of the conductive material used for the extraction electrode. Comparing the areas of the first wiring layer and the second wiring layer in a top view, it is more preferable that the resistivity of the conductive material used for the wiring layer having a larger area be lower than the resistivity of the conductive material used for the extraction electrode. However, if a voltage drop due to the extraction electrode can be sufficiently suppressed, the above resistivity relationship does not need to be satisfied.

[0057] <Contact Hole> A contact hole is an opening formed in an insulating layer, which enables a wiring layer located below the insulating layer (referred to as a lower wiring layer) to be electrically connected to a wiring layer located above the insulating layer (referred to as an upper wiring layer). To achieve the electrical connection, the lower wiring layer has a region exposed from the opening in a top view, and the upper wiring layer has a region located within the opening in a cross-sectional view.

[0058] In the display device according to one embodiment of the present invention, the insulating layer in which the contact hole is provided may be an insulating layer having a stacked structure (sometimes referred to as a stacked insulating layer). For example, when a contact hole is formed in a stacked insulating layer in which a first insulating layer and a second insulating layer are stacked, the first contact hole is formed in the first insulating layer, and the second contact hole is formed in the second insulating layer. In this case, as long as the first contact hole has at least a region overlapping with the second contact hole, a lower wiring layer can be electrically connected to an upper wiring layer. For example, when the second insulating layer is located above the first insulating layer, the width of the second contact hole in a cross-sectional view is preferably larger than the width of the first contact hole. However, the width of the contact hole in each insulating layer is not particularly limited as long as the lower wiring layer can be electrically connected to the upper wiring layer.

[0059] 1A , the pixel portion 103 includes a red light-emitting device 11R, a green light-emitting device 11G, and a blue light-emitting device 11B in addition to an auxiliary wiring 151. The red light-emitting device 11R includes a lower electrode 111R, an organic compound layer 112R, and an upper electrode 113. The green light-emitting device 11G includes a lower electrode 111G, an organic compound layer 112G, and an upper electrode 113. The blue light-emitting device 11B includes a lower electrode 111B, an organic compound layer 112B, and an upper electrode 113. It is preferable that the ends of the lower electrodes 111R, 111G, and 111B have a tapered shape. When the ends have a tapered shape, a film having the lower electrodes as a formation surface is less likely to be divided.

[0060] The organic compound layer 112R has a structure in which a first organic compound layer 112R1 and a second organic compound layer 112R2 are stacked with a charge generation layer 115 interposed therebetween. A so-called tandem structure is applied to the organic compound layer 112R. Note that the charge generation layer 115 is indicated by a dotted line in FIG. 1A. The function or material of the charge generation layer 115 will be described later. If one of the materials contained in the charge generation layer is lithium, the charge generation layer may be referred to as a layer containing lithium. The first organic compound layer 112R1 has at least one light-emitting layer, which may be referred to as a first light-emitting layer. The second organic compound layer 112R2 has at least one light-emitting layer, which may be referred to as a second light-emitting layer. In the tandem structure, the number of layers of the first organic compound layer 112R1 contained in the light-emitting unit located below the charge generation layer 115 may be different from the number of layers of the second organic compound layer 112R2 contained in the light-emitting unit located above the charge generation layer 115.

[0061] The color of light emitted from the light-emitting material of the first light-emitting layer is the same as the color of light emitted from the light-emitting material of the second light-emitting layer. Since light-emitting device 11R emits red light, the light-emitting material of both the first light-emitting layer and the second light-emitting layer emits red light. The first light-emitting layer and the second light-emitting layer can use the same material as the light-emitting material that emits red light, or they do not have to use the same material as long as they are within the range of light-emitting materials that emit red light.

[0062] The above description is about the organic compound layer 112R, but the same applies to the organic compound layer 112G and the organic compound layer 112B.

[0063] That is, the organic compound layer 112G has a structure in which a first organic compound layer 112G1 and a second organic compound layer 112G2 are stacked with a charge generation layer 115 interposed therebetween. The first organic compound layer 112G1 has at least one light-emitting layer, which may be referred to as a first light-emitting layer. The second organic compound layer 112G2 has at least one light-emitting layer, which may be referred to as a second light-emitting layer. In the tandem structure, the number of layers of the first organic compound layer 112G1 included in the light-emitting unit located below the charge generation layer 115 may be different from the number of layers of the second organic compound layer 112G2 included in the light-emitting unit located above the charge generation layer 115.

[0064] The color of light emitted from the light-emitting material of the first light-emitting layer is the same as the color of light emitted from the light-emitting material of the second light-emitting layer. Since light-emitting device 11G emits green light, both the light-emitting material of the first light-emitting layer and the light-emitting material of the second light-emitting layer emit green light. The first light-emitting layer and the second light-emitting layer can use the same material as the light-emitting material that emits green light, but they do not have to use the same material as long as they are within the range of light-emitting materials that emit green light.

[0065] The organic compound layer 112B has a structure in which a first organic compound layer 112B1 and a second organic compound layer 112B2 are stacked with a charge generation layer 115 interposed therebetween. The first organic compound layer 112B1 has at least one light-emitting layer, which may be referred to as a first light-emitting layer. The second organic compound layer 112B2 has at least one light-emitting layer, which may be referred to as a second light-emitting layer. In the tandem structure, the number of layers of the first organic compound layer 112B1 included in the light-emitting unit located below the charge generation layer 115 may be different from the number of layers of the second organic compound layer 112B2 included in the light-emitting unit located above the charge generation layer 115.

[0066] The color of light emitted from the light-emitting material of the first light-emitting layer is the same as the color of light emitted from the light-emitting material of the second light-emitting layer. Since light-emitting device 11B emits blue light, both the light-emitting material of the first light-emitting layer and the light-emitting material of the second light-emitting layer emit blue light. The first light-emitting layer and the second light-emitting layer can use the same material as the light-emitting material that emits blue light, or they do not have to use the same material as long as they are within the range of light-emitting materials that emit blue light.

[0067] As the light-emitting device, for example, an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used. Examples of the light-emitting material (also referred to as a light-emitting substance) included in the light-emitting device include a fluorescent material (fluorescent material), a phosphorescent material (phosphorescent material), a material exhibiting thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material), and an inorganic compound (quantum dot material, etc.). Furthermore, an LED such as a micro LED (light-emitting diode) can also be used as the light-emitting device.

[0068] The light emitting device may emit light in other colors such as cyan, magenta, yellow, or white. If the light emitting device emits infrared light, it can be used as a light source for a sensor. The sensor will be described in the sixth embodiment.

[0069] The structure and materials of the light-emitting device will be described in Embodiment 4 and the like.

[0070] 1A, the upper electrode 113 is shared by each of the light-emitting devices 11R, 11G, and 11B. Such a layer may be referred to as a common layer, and if the common layer functions as an electrode, it may be referred to as a common electrode. In other words, the upper electrode 113 can be read as a common electrode.

[0071] Of course, the upper electrode 113 may be divided into sections for each light-emitting device.

[0072] Light emitted from the light-emitting devices 11R, 11G, and 11B can be extracted via the upper electrode 113. That is, the upper electrode 113 serves as an extraction electrode. In FIG. 1A, an arrow indicates the direction in which light is emitted. A display device in which the upper electrode 113 serves as an extraction electrode is sometimes referred to as a top-emission display device.

[0073] As mentioned above, the extraction electrode is made of a conductive material with high resistivity, such as ITO. Therefore, the extraction electrode, i.e., the upper electrode, is used as the main electrode, and auxiliary wiring 151 is electrically connected to it. This is shown by solid lines in Figure 1A, following the circuit diagram. Voltage drop is sufficiently suppressed in the upper electrode 113 to which auxiliary wiring 151 is electrically connected.

[0074] Those skilled in the art who have read this specification and the like will be able to understand the effect of the auxiliary wiring 151 by interpreting the terms upper electrode, common electrode, and extraction electrode interchangeably.

[0075] It is preferable that each of the light-emitting devices 11R, 11G, and 11B has an SBS structure in which the light-emitting layers are individually fabricated. In the SBS structure, a lithography method or the like can be used to separate the organic compound layers including the light-emitting layers. Photolithography can be used as the lithography method. Photolithography is a method in which a photosensitive material is exposed to light in a desired pattern, and a pattern is formed from exposed and unexposed portions. Reduction exposure using a stepper can be used for exposure.

[0076] Dividing using a photolithography method or the like is sometimes referred to as pattern formation, or simply as processing. The end faces of the organic compound layers 112R, 112G, and 112B processed using a photolithography method often rise perpendicular or approximately perpendicular to the surface on which the layer is to be formed, such as a substrate. The taper angle of the end face of the organic compound layer 112 can be greater than or equal to 45 degrees and less than 90 degrees. The taper angle can be determined from the side face in a cross-sectional view, and the taper angle of the side face satisfies the requirement of greater than or equal to 45 degrees and less than 90 degrees. Because the organic compound layers 112R, 112G, and 112B are laminates, the taper angle of the side face can also be considered as the angle between a line passing through the top end of the top layer of the laminate and the bottom end of the bottom layer, and the surface on which the layer is to be formed, such as a substrate.

[0077] The spacing between the organic compound layers 112R and 112G or the spacing between the organic compound layers 112G and 112B processed by photolithography can be 5 μm or less, 1 μm or less, 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. Because the organic compound layers 112R, 112G, and 112B are laminated bodies, the spacing can also be considered as the spacing between the bottom ends of the bottommost layers of the laminated body.

[0078] On the other hand, in the method of forming a pattern of an organic compound layer using a fine metal mask during vacuum deposition, it is difficult to narrow the interval between organic compound layers. Typically, when a fine metal mask is used, it is difficult to form an interval of 10 μm or less between adjacent organic compound layers.

[0079] Note that a manufacturing method of a light-emitting device including a photolithography method or the like will be described in Embodiment Mode 8 or the like.

[0080] <Microcavity Structure> A microcavity structure may be applied to the light-emitting device according to one embodiment of the present invention. By providing a microcavity structure, the color purity of light emitted from the light-emitting device can be improved.

[0081] Figure 1B shows an example in which a microcavity structure is applied to the light-emitting device shown in Figure 1A. In the light-emitting device of Figure 1B in which a microcavity structure is applied, the distance between electrodes is different between each light-emitting device. That is, the light-emitting device of Figure 1B differs from the light-emitting device of Figure 1A in that the distance between electrodes is different. However, the other configurations are the same as those of Figure 1A, so a description thereof will be omitted.

[0082] The microcavity structure is a structure in which a specific wavelength λ is resonated between an extraction electrode and a counter electrode.

[0083] In order to resonate a specific wavelength λ, the extraction electrode may have a laminated structure of a transparent electrode and a reflective electrode. That is, the extraction electrode is made of a conductive material that is light-transmitting and light-reflective. Such an electrode may be referred to as a semi-transparent / semi-reflective electrode. Alternatively, the extraction electrode may have a reflective electrode with a thickness of 1 nm to 10 nm, which allows visible light to pass through.

[0084] In order to resonate a specific wavelength λ, a reflective electrode may be used as the counter electrode. Alternatively, the counter electrode may have a structure in which a reflective electrode and a transparent electrode are stacked. In a structure in which a reflective electrode and a transparent electrode are stacked, light transmitted through the transparent electrode is reflected by the reflective electrode, thereby resonating a specific wavelength λ.

[0085] The transparent electrode described above preferably has a light transmittance of 40% or more, and the transparent electrode used in the light-emitting device preferably has a visible light (light with a wavelength of 400 nm or more and less than 750 nm) transmittance of 40% or more. To reiterate, the transparent electrode may be made of ITO, an oxide containing indium, silicon, and tin (In-Si-Sn oxide, also referred to as ITSO), an oxide containing indium and zinc (indium zinc oxide, also referred to as In-Zn oxide), or an oxide containing indium, tungsten, and zinc (also referred to as In-W-Zn oxide).

[0086] The light reflectance of the above-mentioned semi-transmitting / semi-reflective electrode is preferably 10% or more and 95% or less, and more preferably 30% or more and 80% or less. For example, a semi-transmitting / semi-reflective electrode used in a light-emitting device may have a reflectance of visible light (light with a wavelength of 400 nm or more and less than 750 nm) of 10% or more and 95% or less, and more preferably 30% or more and 80% or less.

[0087] The light reflectance of the reflective electrode described above is preferably 40% to 100%, and more preferably 70% to 100%. For example, a reflective electrode used in a light-emitting device may have a reflectance of 40% to 100%, and more preferably 70% to 100%, for visible light (light with a wavelength of 400 nm to less than 750 nm). To reiterate, the reflective electrode may be made of a metal such as aluminum, copper, silver, gold, platinum, chromium, or molybdenum, or the conductive material may be an alloy of the above metals.

[0088] The specific wavelength λ corresponds to the wavelength λ of light extracted from the light-emitting device. Since the specific wavelength λ differs for each light-emitting device, the optical distance between electrodes of the light-emitting device differs in a display device having a microcavity structure. The different optical distances are equivalent to the different distances between the top surface of the lower electrode 111R and the bottom surface of the upper electrode 113, the distance between the top surface of the lower electrode 111G and the bottom surface of the upper electrode 113, and the distance between the top surface of the lower electrode 111B and the bottom surface of the upper electrode 113, as shown in FIG. 1B. While FIG. 1B shows a representative example, the distance between the top surface of the lower electrode 111B and the bottom surface of the upper electrode 113 is shorter than the distance between the top surface of the lower electrode 111G and the bottom surface of the upper electrode 113, and the distance between the top surface of the lower electrode 111G and the bottom surface of the upper electrode 113 is shorter than the distance between the top surface of the lower electrode 111R and the bottom surface of the upper electrode 113. Thus, a display device having a microcavity structure results in a light-emitting device with different inter-electrode distances. The inter-electrode distance corresponds to the distance between light-reflecting surfaces. For example, in the case of a semi-transparent / semi-reflective electrode, the light reflecting surface is the surface of the reflective electrode. Note that light-emitting devices with different inter-electrode distances can also be said to be light-emitting devices with different organic compound layer thicknesses.

[0089] 1B , the number of layers of the organic compound layer 112G may be smaller than the number of layers of the organic compound layer 112R, and the number of layers of the organic compound layer 112B may be smaller than the number of layers of the organic compound layer 112G.

[0090] In order to resonate a specific wavelength λ, the optical distance may be, for example, nλ / 2 (where n is an integer greater than or equal to 1, and λ is the wavelength of light to be resonated). In the above formula, the value of n may be different for each light-emitting device. For example, the optical distance between electrodes may be calculated as n=1 for a subpixel that emits red light or a subpixel that emits green light, and as n=2 for a subpixel that emits blue light. In this case, in each light-emitting device shown in FIG. 1B , the distance from the top surface of lower electrode 111G to the bottom surface of upper electrode 113 is shorter than the distance from the top surface of lower electrode 111R to the bottom surface of upper electrode 113, and the distance from the top surface of lower electrode 111R to the bottom surface of upper electrode 113 is shorter than the distance from the top surface of lower electrode 111B to the bottom surface of upper electrode 113.

[0091] In a microcavity structure, light with wavelengths that do not resonate are attenuated. This allows light with a narrow half-width to be extracted from the light-emitting device. Light with a narrow half-width is highly directional and desirable, allowing light with high color purity to be extracted from the light-emitting device.

[0092] In addition, when a light-emitting device combines a tandem structure with a microcavity structure, the optical distance between a pair of electrodes may increase, in other words, the distance between the pair of electrodes may become large. In this case, since the voltage applied between the pair of electrodes may become high, it is preferable to make the optical distance between the pair of electrodes as small as possible. For example, in the case of a light-emitting device with a tandem structure, it is sufficient to make the thickness of one light-emitting unit as thin as possible and to make the optical distance between the pair of electrodes satisfy nλ / 2. As described above, it is also possible to omit the functional layer in order to reduce the thickness of the light-emitting unit.

[0093] <Color Filter> A color filter may be applied to the light-emitting device of one embodiment of the present invention. By providing a color filter, the color purity of light emitted from the light-emitting device can be improved.

[0094] Figure 2A shows an example in which color filters 148R, 148G, and 148B are applied to the light-emitting device shown in Figure 1A. Other configurations are the same as those in Figure 1A, so descriptions thereof will be omitted. Figure 2B shows an example in which color filters 148R, 148G, and 148B are applied to the light-emitting device shown in Figure 1B. Other configurations are the same as those in Figure 1B, so descriptions thereof will be omitted.

[0095] The color filters used are a red color filter 148R that transmits light in the red wavelength range, a green color filter 148G that transmits light in the green wavelength range, and a blue color filter 148B that transmits light in the blue wavelength range. Each light-emitting device can emit red, green, and blue light in the direction of the arrow via the color filter 148.

[0096] A color filter can be called a colored layer that transmits light in a specific wavelength range. Transmitting light in a specific wavelength range means that the transmitted light through the color filter has at least a peak wavelength corresponding to a specific color.

[0097] The color filters can be formed at desired positions using various materials such as chromatic translucent resins by printing, inkjet printing, photolithography, and etching. As the chromatic translucent resins, photosensitive or non-photosensitive organic resins can be used, but if a photosensitive organic resin is used, the etching step can be omitted.

[0098] Chromatic colors are colors other than achromatic colors such as black, gray, and white, and specifically, red, green, blue, etc. Furthermore, cyan, magenta, yellow, etc. may also be used as the color of the color filter.

[0099] The thickness of the color filter can be set to 500 nm or more and 5 μm or less.

[0100] The use of a color filter can eliminate the need for optical elements such as a circular polarizer or a polarizing plate, which is preferable because the display device can be made lighter and thinner by eliminating the need for such optical elements.

[0101] <Overall Image 1 of Auxiliary Wiring, etc.> The display device 100 shown in FIG. 3A includes an upper electrode 113, auxiliary wiring 151 located below the upper electrode 113 and connected to the upper electrode, and a connection portion 140 having a function of supplying signals to the upper electrode 113. The connection portion 140 will be described in Embodiment 3, etc. The auxiliary wiring 151 is electrically connected to the upper electrode 113. Specifically, the auxiliary wiring 151 includes a first wiring layer 151a having a lattice shape in a top view and a second wiring layer 151b located above the first wiring layer 151a. A contact hole is provided in a region overlapping with the second wiring layer 151b to enable electrical connection between the upper electrode 113 and the auxiliary wiring 151. The contact hole is omitted in FIG. 3A. The contact hole is located at least near the connection portion 140, and preferably multiple contact holes are provided for the upper electrode 113. Note that the second wiring layer 151b has an island shape, but is not limited to this, and the second wiring layer 151b may have a band shape, a lattice shape, etc. Note that the island shape refers to a shape whose length in the X direction and whose length in the Y direction are equal or approximately equal in top view, the band shape refers to a shape whose length in one of the X direction and the Y direction is different from the length in the X direction and the Y direction in top view, specifically a long shape, and the lattice shape includes a shape having at least a region extending in the X direction and the Y direction.

[0102] A signal from the connection portion 140 is supplied to the upper electrode 113 and also to the auxiliary wiring 151 via a contact hole (omitted in FIG. 3A), thereby suppressing a voltage drop.

[0103] A power supply potential (e.g., a cathode potential) or a signal is supplied to the upper electrode 113 via the connection portion 140. Since the light-emitting device is an element driven by current, specifically, when the upper electrode 113 is a cathode, current is supplied from the light-emitting device to the connection portion 140, and when the upper electrode 113 is an anode, current is supplied from the connection portion 140 to the light-emitting device. This current is also supplied to the auxiliary wiring 151 via a contact hole (omitted in FIG. 3A ). With this configuration, even if a voltage drop may occur in the upper electrode 113, the current can be supplied via the auxiliary wiring 151, and therefore the voltage drop can be effectively suppressed.

[0104] 3A, the auxiliary wiring 151 is configured so that a power supply potential (e.g., a cathode potential) or a signal is not directly supplied thereto. In other words, the auxiliary wiring 151 can be configured so as not to be connected to any wiring or electrode other than the upper electrode 113.

[0105] 3B and 3C are top views of the pixel portion 103, and show the first wiring layer 151a having a lattice shape according to Fig. 3A and the contact hole 15. The contact hole 15 enables electrical connection between the first wiring layer 151a and the second wiring layer 151b, and therefore the second wiring layer 151b is provided at a position overlapping with the contact hole 15.

[0106] 3B and 3C, the X direction and the Y direction intersecting the X direction are also shown, and the layout of the first wiring layer 151a and the like may be described using these directions.

[0107] <Grid-shaped auxiliary wiring surrounding sub-pixels> The first wiring layer 151a shown in Fig. 3B has a grid shape that surrounds the sub-pixels 110R, 110G, and 110B. That is, the first wiring layer 151a has at least a region located between the sub-pixels. In Fig. 3B, the first wiring layer 151a does not have a region overlapping with the sub-pixels, but the first wiring layer 151a may have a region overlapping with the sub-pixels 110R, 110G, and 110B.

[0108] Note that the sub-pixels 110R, 110G, and 110B shown in the figures in this embodiment correspond to the top surface shape of the light-emitting region. For example, in the light-emitting device shown in Figures 1A and 1B, these correspond to the top surface shape of the light-emitting region obtained through the upper electrode 113. In addition, in the light-emitting device shown in Figures 2A and 2B, these correspond to the top surface shape of the light-emitting region obtained through the color filters 148R, 148G, and 148B.

[0109] The layout of the first wiring layer 151a shown in FIG. 3B will be described. The first wiring layer 151a has a lattice shape surrounding the subpixels 110R, 110G, and 110B. The lattice-shaped first wiring layer 151a has multiple vertical lines and multiple horizontal lines. The vertical lines correspond to lines along the Y direction, and the first wiring layer 151a has regions that overlap the lines between the subpixels 110R and 110G, or between the subpixels 110G and 110B. In this manner, the first wiring layer 151a can be disposed between the regularly laid out subpixels 110R, 110G, and 110B. Note that the space between the subpixels refers to the space between the end of the lower electrode 111R and the end of the lower electrode 111G, and the space between the end of the lower electrode 111G and the end of the lower electrode 111B, as shown in FIGS. 1A to 2B , etc.

[0110] Although the first wiring layer 151a shown in FIG. 3B does not have an area overlapping with the subpixels, the first wiring layer 151a may have an area overlapping with the subpixels 110R, 110G, and 110B.

[0111] 3B may have a plurality of vertical lines and a plurality of horizontal lines, and there is no limitation on the density of the vertical lines or the horizontal lines. Therefore, the first wiring layer 151a does not need to have an area disposed in all the spaces between the sub-pixels, and can be disposed at any interval.

[0112] <Grid-Shaped Auxiliary Wiring Surrounding Pixels> The first wiring layer 151a shown in FIG. 3C has a different density of vertical lines from that shown in FIG. 3B. Specifically, the first wiring layer 151a shown in FIG. 3C has a grid shape that surrounds the pixels 150. The vertical lines of the first wiring layer 151a extend along the Y direction and have regions that overlap with the spaces between the pixels 150. In this way, the first wiring layer 151a can be disposed between the regularly laid out pixels 150. Note that the spaces between the pixels 150 refer to, for example, the spaces between the ends of the lower electrode 111R and the lower electrode 111B of the pixel adjacent in the X direction, as shown in FIGS. 1A to 2B, etc.

[0113] Although the first wiring layer 151 a shown in FIG. 3C does not have an area overlapping with the pixel 150 , the first wiring layer 151 a may have an area overlapping with the pixel 150 .

[0114] 3B and 3C show the contact hole 15 located in the region overlapping with the second wiring layer 151b. The shape of the second wiring layer 151b is called an island shape (including a shape in which the long side is equal to or approximately equal to the short side). That is, the first wiring layer 151a is electrically connected to the second wiring layer 151b through the contact hole 15.

[0115] The first wiring layer 151a is not limited to a lattice shape, but may also be a band shape (which may also be called a stripe shape, including a shape in which the long side is twice or more the length of the short side). For example, a lattice-shaped auxiliary wiring can be obtained by combining a first wiring layer 151a having a band shape along vertical lines with a second wiring layer 151b having a band shape along horizontal lines. Even in such a case, the first wiring layer 151a can be electrically connected to the second wiring layer 151b via the contact holes 15.

[0116] <Contact Holes for Auxiliary Wiring> As described above, the first wiring layer 151a and the second wiring layer 151b are electrically connected via contact holes. The layout of the contact holes or the second wiring layer 151b will be described with reference to Figures 4A to 4F. Figures 4A to 4F show the lattice-shaped first wiring layer 151a shown in Figure 3B or 3C.

[0117] FIG. 4A shows a first wiring layer 151a having a lattice shape similar to that shown in FIG. 3B. That is, in FIG. 4A, the first wiring layer 151a has a lattice shape surrounding the subpixels 110R, 110G, and 110B. Furthermore, the auxiliary wiring includes a second wiring layer 151b at a position overlapping the contact hole 15. The second wiring layer 151b has an island shape similar to that shown in FIG. 3A. The contact hole 15 and the second wiring layer 151b are provided at positions overlapping the first wiring layer 151a adjacent to the upper and lower parts of the subpixel 110R and the upper and lower parts of the subpixel 110B. The arrangement of the contact hole 15 and the second wiring layer 151b shown in FIG. 4A is the same as the arrangement of the contact hole 15 and the second wiring layer 151b shown in FIG. 4B, which will be described later. That is, the contact hole 15 and the second wiring layer 151b do not need to be provided for each subpixel.

[0118] 4B also shows the first wiring layer 151a having a lattice shape similar to that of FIG. 3C. That is, in FIG. 4B, the first wiring layer 151a has a lattice shape that surrounds the pixel 150. Furthermore, the auxiliary wiring has a second wiring layer 151b at a position overlapping with the contact hole 15. The second wiring layer 151b has an island shape similar to that of FIG. 3A. The contact hole 15 and the second wiring layer 151b are provided at a position overlapping with the first wiring layer 151a that is close to the upper and lower parts of the pixel 150.

[0119] Although the shape of the second wiring layer 151b is shown as an island shape in FIGS. 4A and 4B, it is not limited to the island shape and may be a strip shape, a lattice shape, or the like.

[0120] 4C and 4D show a strip-shaped second wiring layer 151b, the first wiring layer 151a in FIG. 4C has a lattice shape surrounding subpixels, and the first wiring layer 151a in FIG. 4D has a lattice shape surrounding pixels. The shape of the contact hole may be determined to match the strip-shaped second wiring layer 151b. In FIGS. 4C and 4D, a contact hole 17 extending in the x-direction is formed to match the second wiring layer 151b. The first wiring layer 151a and the second wiring layer 151b are electrically connected via the contact hole 17.

[0121] 4E and 4F show a strip-shaped second wiring layer 151b and an island-shaped second wiring layer 151b, where the first wiring layer 151a in FIG. 4E has a lattice shape surrounding subpixels, and the first wiring layer 151a in FIG. 4F has a lattice shape surrounding pixels. The shape of the contact holes may be determined to match the strip-shaped second wiring layer 151b. In FIGS. 4E and 4F, contact holes 15 and 17 are formed to match the second wiring layer 151b. The first wiring layer 151a and the second wiring layer 151b are electrically connected via the contact holes 15 and 17.

[0122] When the first wiring layer 151a is formed in a lattice shape, the second wiring layer 151b can have a variety of shapes. The various shapes include a combination of multiple shapes, as shown in FIGS. 4E and 4F. It is preferable that the contact hole 15 or the contact hole 17 has a shape or area that conforms to the shape of the second wiring layer 151b. That is, the contact hole can have a variety of shapes, just like the second wiring layer. The various shapes include a combination of multiple shapes, as shown in FIGS. 4E and 4F.

[0123] <Auxiliary Wiring and Other Wiring> When forming the lattice-shaped first wiring layer 151a, it is preferable not to provide wiring that performs functions such as scanning lines, signal lines, and power supply lines in the same layer as the first wiring layer 151a. This is because wiring that performs these functions needs to extend in the X direction or the Y direction, and would short-circuit with the lattice-shaped first wiring layer 151a.

[0124] When wirings that perform functions such as scanning lines, signal lines, and power lines are provided in the same layer as the grid-shaped first wiring layer 151a described above, it is possible to adjust the lengths of the scanning lines, signal lines, and power lines in the X-axis direction or the Y-axis direction, and lay them out so as not to short-circuit with the first wiring layer 151a. When adjusting the length in the X-axis direction or the Y-axis direction, it is recommended to prepare bridge wiring. Bridge wiring is used to connect wirings whose lengths have been adjusted, and is a conductive layer or the like that is arranged in a different layer from the wirings whose lengths have been adjusted. Depending on the shape, bridge wiring may be referred to as a bridge electrode, but in this specification and the like, bridge wiring will be used for explanation.

[0125] <Overall Image 2 of Auxiliary Wiring, etc.> Similar to Fig. 3A, Fig. 5A shows display device 100 having upper electrode 113, auxiliary wiring 151 located below upper electrode 113 and connected to the upper electrode, and connection portion 140 having the function of supplying a signal to upper electrode 113. Unlike Fig. 3A, Fig. 5A also shows signal line 153 and bridge wiring 154 running along auxiliary wiring 151. In Fig. 5A, bridge wiring 154 is located in the same layer as second wiring layer 151b.

[0126] 5B and 5C are top views of the pixel portion 103, and respectively show a lattice-shaped first wiring layer 151a and an island-shaped second wiring layer 151b similar to those in FIGS. 3B and 3C, as well as a bridge wiring 154 and a signal line 153. The signal line 153 has a configuration in which the first conductive layer 153a and the second conductive layer 153b are electrically connected via the bridge wiring 154. A contact hole 16 between the bridge wiring 154 and the first conductive layer 153a is also shown. The contact hole between the bridge wiring 154 and the second conductive layer 153b is similar to the contact hole 16.

[0127] By using bridge wiring or the like, the lattice-shaped first wiring layer 151a and the signal lines 153 can be formed in the same layer.

[0128] In addition to the signal line 153, when a scanning line or a power supply line is formed using the same conductive layer as the first wiring layer 151a, the bridge wiring 154 or the like can be used.

[0129] <Overall Picture 3 of Auxiliary Wiring, etc.> In the display device of one embodiment of the present invention, a power supply potential (e.g., a cathode potential) or a signal may be directly applied to the auxiliary wiring 151. When a power supply potential (e.g., a cathode potential) or a signal is directly applied to the auxiliary wiring 151, the power supply potential or the signal is supplied from the auxiliary wiring 151 to the upper electrode 113 without providing the connection portion 140 or the like. A structure without providing the connection portion 140 or the like can realize miniaturization of the display device.

[0130] FIG. 6A shows a display device 100 capable of directly applying a power supply potential (e.g., a cathode potential) or a signal to the auxiliary wiring 151. In FIG. 6A, similar to FIG. 3A, the auxiliary wiring 151 includes a lattice-shaped first wiring layer 151a and an island-shaped second wiring layer 151b. Unlike FIG. 3A, FIG. 6A includes a terminal portion 139 to which a signal is supplied from an FPC (Flexible Printed Circuit) or the like, rather than a connection portion 140. The power supply potential (e.g., a cathode potential) or a signal is supplied to the auxiliary wiring 151 from the terminal portion. Furthermore, the power supply potential (e.g., a cathode potential) or a signal supplied to the lattice-shaped first wiring layer 151a can be supplied to the upper electrode 113 via multiple contact holes. Because the first wiring layer 151a is made of a conductive material with low resistivity, voltage drop is suppressed. The display device shown in FIG. 6A can be miniaturized because the connection portion 140 can be omitted.

[0131] FIG. 6B illustrates a display device 100 that can directly apply a power supply potential (e.g., a cathode potential) or a signal to the auxiliary wiring 151 and includes a bridge wiring 154. In FIG. 6B, similar to FIG. 5A, the auxiliary wiring 151 includes a lattice-shaped first wiring layer 151a, an island-shaped second wiring layer 151b, a signal line 153, and a bridge wiring 154. Unlike FIG. 5A, FIG. 6B includes a terminal portion 139 to which a signal is supplied from an FPC or the like, rather than a connection portion 140. The power supply potential (e.g., a cathode potential) or a signal is supplied to the auxiliary wiring 151 from the terminal portion. Furthermore, the power supply potential (e.g., a cathode potential) or a signal supplied to the lattice-shaped first wiring layer 151a can be supplied to the upper electrode 113 through multiple contact holes. Because the first wiring layer 151a is made of a conductive material with low resistivity, voltage drop is suppressed. The display device shown in FIG. 6B can be miniaturized because the connection portion 140 can be omitted.

[0132] <Cross-sectional shape 1 of auxiliary wiring> As shown in Figure 7A, the second wiring layer 151b can be formed in the same layer as the lower electrodes 111R, 111G, and 111B. Specifically, the second wiring layer 151b and the lower electrodes 111R, 111G, and 111B can be formed on the insulating layer 14. As described above, the second wiring layer 151b does not require a large area compared to the first wiring layer 151a, so even if the second wiring layer is formed in the same layer as the lower electrodes, the aperture ratio of the pixel is not limited. Note that the other configurations in Figure 7A are the same as those in Figure 1A, and therefore will not be described here.

[0133] 7B shows an example in which a microcavity structure is applied to FIG. 7A. In FIG. 7B, the second wiring layer 151b and the lower electrodes 111R, 111G, and 111B can be formed on the insulating layer 14, as in FIG. 7A. As described above, the second wiring layer 151b does not require a large area compared to the first wiring layer 151a. Therefore, even if the second wiring layer is formed in the same layer as the lower electrodes, the aperture ratio of the pixel is not limited. Note that the other configurations in FIG. 7B are the same as those in FIG. 1B, and therefore will not be described here.

[0134] 8A shows an example in which a color filter is applied to FIG. 7A. In FIG. 8A, the second wiring layer 151b and the lower electrodes 111R, 111G, and 111B can be formed on the insulating layer 14, similarly to FIG. 7A. As described above, the second wiring layer 151b does not require a large area compared to the first wiring layer 151a. Therefore, even if the second wiring layer is formed in the same layer as the lower electrodes, the aperture ratio of the pixel is not limited. Note that the other configurations in FIG. 8A are the same as those in FIG. 7A, and therefore description thereof will be omitted.

[0135] Figure 8B shows an example in which a color filter is applied to Figure 7B. In Figure 8B, the second wiring layer 151b and the lower electrodes 111R, 111G, and 111B can be formed on the insulating layer 14, as in Figure 7A. As described above, the second wiring layer 151b does not require a large area compared to the first wiring layer 151a, so even if the second wiring layer is formed in the same layer as the lower electrodes, the aperture ratio of the pixel is not limited. Note that the other configurations in Figure 8B are the same as those in Figure 7B, and therefore their description will be omitted.

[0136] The configurations of the top surface shapes shown in FIGS. 3A to 6B can be applied as appropriate to the auxiliary wirings shown in FIGS. 7A to 8B.

[0137] <Cross-sectional shape 2 of auxiliary wiring> Fig. 9A shows another form of auxiliary wiring 151. The auxiliary wiring 151 in Fig. 9A has a configuration in which the width of the second wiring layer 151b (width marked with disB) is smaller than the width of the first wiring layer 151a (width marked with disA) in cross-sectional views in the X and Y directions.

[0138] The configurations of the top surface shapes shown in FIGS. 3A to 6B can be applied appropriately to the auxiliary wiring shown in FIG. 9A.

[0139] <Top Surface Shape 2 of Auxiliary Wiring> Next, top surface shapes other than those shown in FIGS. 3A to 6B will be described. FIGS. 9B and 9C are top views of the pixel portion 103, showing the first wiring layer 151a and the second wiring layer 151b each having a lattice shape. Specifically, the first wiring layer 151a in FIG. 9B has a lattice shape surrounding the subpixels 110R, 110G, and 110B, and the second wiring layer 151b also has a lattice shape surrounding the subpixels 110R, 110G, and 110B. For an explanation of the lattice shape surrounding the subpixels 110R, 110G, and 110B, refer to FIG. 3B and the paragraphs describing it. Also, the first wiring layer 151a in FIG. 9C has a lattice shape surrounding the pixel 150, and the second wiring layer 151b also has a lattice shape surrounding the pixel 150. For an explanation of the lattice shape surrounding the pixel 150, refer to FIG. 3C and the paragraphs describing it.

[0140] As described above, the contact hole 15 can be formed in a region overlapping with the second wiring layer 151b. In Figures 9B and 9C, the second wiring layer 151b overlaps with the first wiring layer 151a, so the contact hole 15 can be formed in any region of the auxiliary wiring 151. Figures 9B and 9C show an example in which the contact hole 15 is provided in the same position as in Figures 3B and 3C. The shape of the contact hole can be determined according to the second wiring layer 151b, and the contact hole 17 extending in the x-direction shown in Figures 4C and 4D etc. may be formed.

[0141] As described above, the auxiliary wiring 151 of one embodiment of the present invention has multilayered wiring layers, which increases the degree of freedom in the layout of the auxiliary wiring 151. Furthermore, the auxiliary wiring 151 of one embodiment of the present invention can also be applied to a high-resolution display device.

[0142] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0143] Embodiment 2 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0144] [Layout Examples of Pixels and Auxiliary Wiring] In this embodiment, pixel layouts and auxiliary wiring layouts different from those in Figures 3A to 6B, 9B, 9C, etc. will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of arrangements of sub-pixels include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a Pentile arrangement. Each arrangement will be described later. The top surface shape of the sub-pixels shown in the figures in this embodiment corresponds to the top surface shape of the light-emitting region.

[0145] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0146] An S-stripe arrangement is applied to the pixel 150 shown in FIG. 10A . The pixel 150 shown in FIG. 10A is composed of three subpixels: subpixels 110a, 110b, and 110c. The subpixels 110a and 110b are adjacent to each other in the Y direction, and the subpixel 110c is adjacent to the subpixels 110a and 110b in the X direction. Other layouts of the subpixels 110a, 110b, and 110c can be seen from FIG. 10A . Furthermore, the light-emitting area of ​​the subpixel 110c can be made different from that of the subpixels 110a and 110b, and for example, the light-emitting area can be made larger.

[0147] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0148] 10B and 10C show examples of layouts of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 10A.

[0149] 10B shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 10B.

[0150] 10C shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. Furthermore, the first wiring layer 151a may overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 10C.

[0151] The pixel 150 shown in Figure 10D includes a subpixel 110a having a generally trapezoidal top surface shape with rounded corners, a subpixel 110b having a generally triangular top surface shape with rounded corners, and a subpixel 110c having a generally rectangular or hexagonal top surface shape with rounded corners. The subpixel 110a is positioned along one side of the subpixel 110c, and the subpixel 110b is positioned along the other side of the subpixel 110c that is continuous with the aforementioned side. Other layouts of the subpixels 110a, 110b, and 110c can be seen in Figure 10D. The light-emitting area of ​​the subpixel 110c can be made different from that of the subpixels 110a and 110b, for example, making the light-emitting area larger.

[0152] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0153] Layout examples of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 10D are shown in FIGS. 10E and 10F.

[0154] 10E shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 10E.

[0155] 10F shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. Furthermore, the first wiring layer 151a may overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 10F.

[0156] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0157] The pixels 150a and 150b shown in Figure 10G are arranged in a Pentile arrangement. The pixels 150a and 150b each have subpixels 110a, 110b, and 110c, with the subpixels 110a and 110c being arranged differently in the pixels 150a and 150b. The subpixels 110a, 110b, and 110c are arranged alternately. Other layouts of the subpixels 110a, 110b, and 110c can be seen in Figure 10G. The light-emitting areas of the subpixels 110a and 110c can be made different from those of the subpixel 110b, for example, to increase the light-emitting area.

[0158] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0159] Layout examples of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 10G are shown in FIGS. 10H and 10I.

[0160] 10H shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 10H.

[0161] 10I shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. The first wiring layer 151a may also overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG.

[0162] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0163] The pixels 150a and 150b shown in FIG. 11A are arranged in a delta configuration. FIG. 11A shows an example in which each subpixel has a substantially rectangular top view shape with rounded corners. The pixel 150a has two subpixels (subpixels 110a and 110b) in the upper row (first row) and one subpixel (subpixel 110c) in the lower row (second row). The pixel 150b has one subpixel (subpixel 110c) in the upper row (first row) and two subpixels (subpixels 110a and 110b) in the lower row (second row). The rest of the layout of the subpixels 110a, 110b, and 110c can be seen from FIG. 11A.

[0164] 11B and 11C show examples of layouts of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 11A.

[0165] 11B shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 11B.

[0166] 11C shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. Furthermore, the first wiring layer 151a may overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 11C.

[0167] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0168] The pixels 150a and 150b shown in Figure 11D are arranged in a delta configuration. Unlike Figure 11A, Figure 11D shows an example in which each subpixel has a circular top surface shape. Pixel 150a has two subpixels (subpixels 110a and 110b) in the upper row (first row) and one subpixel (subpixel 110c) in the lower row (second row). Pixel 150b has one subpixel (subpixel 110c) in the upper row (first row) and two subpixels (subpixels 110a and 110b) in the lower row (second row). Other layouts of the subpixels 110a, 110b, and 110c can be seen from Figure 11D.

[0169] Layout examples of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 11D are shown in FIGS. 11E and 11F.

[0170] 11E shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 11E.

[0171] 11F shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. Furthermore, the first wiring layer 151a may overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 11F.

[0172] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0173] The pixels 150a and 150b shown in Figure 12A are arranged in a delta configuration. Unlike Figures 11A and 11D, Figure 12A shows an example in which each subpixel has a substantially hexagonal top surface shape. The pixel 150a has two subpixels (subpixels 110a and 110b) in the upper row (first row) and one subpixel (subpixel 110c) in the lower row (second row). The pixel 150b has one subpixel (subpixel 110c) in the upper row (first row) and two subpixels (subpixels 110a and 110b) in the lower row (second row).

[0174] In Fig. 12A, each subpixel is arranged inside a closely packed hexagonal region. When focusing on one subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, when focusing on subpixel 110a, three subpixels 110b and three subpixels 110c are arranged so that they surround it and are alternately arranged. The rest of the layout of the subpixels 110a, 110b, and 110c can be seen from Fig. 12A.

[0175] 12B and 12C show examples of layouts of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 12A.

[0176] 12B shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 12B.

[0177] 12C shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region surrounding the pixel 150. The first wiring layer 151a may also overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 12C.

[0178] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0179] 12D shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper edges of two subpixels aligned in the column direction (e.g., subpixels 110a and 110b, or subpixels 110b and 110c) are misaligned. The rest of the layout of the subpixels 110a, 110b, and 110c can be seen from FIG. 12D.

[0180] Layout examples of auxiliary wiring that can be applied to the pixel 150 shown in FIG. 12D are shown in FIGS. 12E and 12F.

[0181] 12E shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a has a region between the subpixels 110a and 110b, a region between the subpixels 110b and 110c, and a region between the subpixels 110c and 110a. Furthermore, the first wiring layer 151a may overlap the subpixels 110a, 110b, and 110c. Of course, the first wiring layer 151a can also be laid out so as not to overlap the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 12E.

[0182] 12F shows the first wiring layer 151a of the auxiliary wiring 151. The first wiring layer 151a does not surround the pixel, but has a major axis region and a minor axis region. Furthermore, the first wiring layer 151a may overlap with the subpixels 110a, 110b, and 110c. Other layouts of the first wiring layer 151a can be seen from FIG. 12F.

[0183] In this way, the shape and size of each sub-pixel can be determined for each light-emitting device. For example, the size of a sub-pixel having a light-emitting device with higher reliability can be made smaller.

[0184] In this embodiment, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their arrangement order can be determined appropriately. For example, the subpixel 110b may be the subpixel R that emits red light, and the subpixel 110a may be the subpixel G that emits green light.

[0185] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This reduces the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, it is likely to have rounded corners. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0186] As described above, in the display device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0187] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0188] Embodiment 3 In this embodiment, a specific example of a display device according to one embodiment of the present invention will be described.

[0189] As shown in FIG. 13A , the display device 100 has a pixel section 103 and a connection section 140 located outside the pixel section 103. The pixel section 103 is an area in which pixels 150 are regularly arranged and may be referred to as a display area. The pixel 150 has subpixels 110R, 110G, and 110B, and the layout of the subpixels 110R, 110G, and 110B shown in FIG. 13A is the same as that shown in FIG. 10A . Specifically, the subpixel 110R, which is a red light-emitting region, is applied to the subpixel 110a in FIG. 10A , the subpixel 110G, which is a green light-emitting region, is applied to the subpixel 110b, and the subpixel 110B, which is a blue light-emitting region, is applied to the subpixel 110c. The subpixel 110B has a larger area than the subpixels 110R and 110G.

[0190] Note that the display device of one embodiment of the present invention is not limited to emitting the above-mentioned light colors, and may be provided with a white light-emitting region.

[0191] 13A, the upper electrode of the light-emitting device is shown as a common electrode 113b, and the common electrode 113b is provided from the connection portion 140 to the pixel portion 103. The common electrode 113b has an area extending from the connection portion 140, and this area is indicated by a dotted line. In addition, at the connection portion 140, a connection wiring 111C is located below the common electrode 113b.

[0192] 13A, contact holes 141 are located. The common electrode 113b can be electrically connected to the auxiliary wiring 151 via the contact holes 141. In this embodiment, the contact holes 141 are located at the four corners surrounding the pixel 150, but the arrangement of the contact holes 141 is just an example.

[0193] Figure 13B shows a cross-sectional view of B1-B2 indicated by the dashed line in Figure 13A. As shown in Figure 13B, subpixel 110G has a light-emitting device 11G and a color filter 148G, and corresponds to a light-emitting region where light is emitted in the direction of the arrow via color filter 148G. Subpixel 110B has a light-emitting device 11B and a color filter 148B, and corresponds to a light-emitting region where light is emitted in the direction of the arrow via color filter 148B. Although illustration of subpixel 110R is omitted, like subpixels 110G and 110B, it has a light-emitting device and a color filter, and corresponds to a light-emitting region where light is emitted via the color filter.

[0194] The light-emitting devices 11R, 11G, and 11B have lower electrodes 111R, 111G, and 111B, respectively. The lower electrodes 111R, 111G, and 111B preferably have tapered ends. Tapered ends make it difficult for an organic compound layer to be separated when the organic compound layer is formed on the lower electrode.

[0195] The light-emitting devices 11R, 11G, and 11B have organic compound layers 112R, 112G, and 112B, respectively. To apply a tandem structure to the organic compound layers 112R, 112G, and 112B, each of the organic compound layers 112R, 112G, and 112B has a charge generation layer 115 and light-emitting units above and below it. However, the organic compound layer 112R is not shown in FIG. 13B .

[0196] The organic compound layers 112R, 112G, and 112B are processed using photolithography and are separated from one another. Therefore, the ends of the organic compound layers 112R, 112G, and 112B have a taper angle of 45 degrees or more and less than 90 degrees. The taper angle can be determined from the side surface in a cross-sectional view, and the taper angle of the side surface satisfies the condition of 45 degrees or more and less than 90 degrees. Because the organic compound layers 112R, 112G, and 112B are laminated bodies, the taper angle of the side surface can also be considered as the angle between a line passing through the top end of the uppermost layer of the laminate and the bottom end of the lowermost layer, and the surface on which the substrate or the like is to be formed.

[0197] The structure in which the organic compound layers are separated suppresses crosstalk caused by leakage current, enabling extremely high-quality images to be displayed. Furthermore, it is possible to achieve both a high aperture ratio and high definition.

[0198] The subpixels 110R, 110G, and 110B may each include, in addition to the light-emitting devices 11R, 11G, and 11B, switching elements that control the light-emitting devices. However, the switching elements are not illustrated in FIG. 13B . A display device according to one embodiment of the present invention can display a picture by emitting light from the light-emitting devices controlled by the switching elements. A transistor can be used as the switching element, and a silicon semiconductor layer or an oxide semiconductor layer can be used as an active layer of the transistor.

[0199] The color filters 148G and 148B are provided on a substrate 170, and a light-shielding layer 149 is also provided on the substrate 170 so as to overlap the boundary between the color filters 148G and 148B. The substrate 170 may be referred to as an opposing substrate. The substrate 170 is bonded to the substrate 101 and the like using an adhesive layer 171.

[0200] Since the contact hole 141 is located in a non-light-emitting region, the light-shielding layer 149 is also formed in the region overlapping the contact hole 141, as shown in FIG. 13B.

[0201] As shown in FIG. 13B , the auxiliary wiring 151 includes a first wiring layer 151a and a second wiring layer 151b, which are electrically connected to each other through a contact hole 142. The second wiring layer 151b is formed using a conductive layer provided in the same layer as the lower electrodes 111G and 111B, but the first wiring layer 151a is provided in a different layer from the lower electrodes 111G and 111B. Therefore, as shown in FIG. 13B , the first wiring layer 151a may have a region overlapping with the lower electrodes 111G and 111B. The top surface of the first wiring layer 151a can have a grid shape or the like as described above. The auxiliary wiring 151 includes multiple wiring layers, which increases the degree of freedom in the layout of at least the first wiring layer 151a. Furthermore, the auxiliary wiring 151 of one embodiment of the present invention can be applied to a high-resolution display device.

[0202] It is preferable to have an insulating layer 126 between two adjacent light-emitting devices. In FIG. 13B , the insulating layer 126 is located between the light-emitting device 11G and the light-emitting device 11B, for example. Furthermore, the insulating layer 126 is located between the light-emitting device 11B and the contact hole 141. Such an insulating layer 126 is provided so as to fill the gap. Furthermore, the insulating layer 126 preferably has a region that overlaps with an end of the organic compound layer 112, and specifically, the end of the insulating layer 126 is preferably located on the organic compound layer 112. This configuration is preferable because the difference in height between the top and end of the insulating layer 126 is small, making it difficult for the insulating layer 126 to peel off.

[0203] The upper portion of the insulating layer 126 preferably has a smooth convex shape. A convex upper portion can also be described as a shape in which the center of the insulating layer 126 is higher than the edges. The common layer 114 and the common electrode 113b provided to cover the insulating layer 126 are less likely to be cut, thereby suppressing display defects.

[0204] Furthermore, an insulating layer 125 may be provided in contact with a side surface of the organic compound layer 112. The insulating layer 125 is located between the insulating layer 126 and the organic compound layer 112 and functions as a protective film for preventing the insulating layer 126 from contacting the organic compound layer 112. If the organic compound layer 112 and the insulating layer 126 come into contact with each other, the organic compound layer 112 may be dissolved by an organic solvent or the like used in forming or processing the insulating layer 126. Therefore, by providing the insulating layer 125 between the organic compound layer 112 and the insulating layer 126 as shown in this embodiment, the organic compound layer 112 can be protected.

[0205] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, by using an inorganic insulating film such as a metal oxide film, an aluminum oxide film, or a silicon oxide film formed by an ALD method as the insulating layer 125, an insulating layer 125 with few pinholes and excellent protection of the organic compound layer can be formed.

[0206] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0207] The insulating layer 125 can be formed by a sputtering method, a CVD method, a PLD method, an ALD method, or the like. The insulating layer 125 is preferably formed by an ALD method because it has good coverage.

[0208] An insulating layer containing an organic material can be suitably used as the insulating layer 126. For example, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, precursors of these resins, or the like can be used as the insulating layer 126. Alternatively, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used as the insulating layer 126.

[0209] Furthermore, a photosensitive resin can be used for the insulating layer 126. A photoresist can be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0210] When a photosensitive material is used for the insulating layer 126, a processed insulating layer 126 can be formed by exposure and development. The surface of the processed insulating layer 126 may have a rounded or uneven shape. Etching may be performed to adjust the surface height of the processed insulating layer 126. The surface height can be adjusted by processing the insulating layer 126 by ashing using oxygen plasma.

[0211] The insulating layer 126 preferably contains a material that absorbs visible light. For example, the insulating layer 126 itself may be made of a material that absorbs visible light, or the insulating layer 126 may contain a pigment that absorbs visible light. For example, the insulating layer 126 may be made of a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix.

[0212] The upper surface of the insulating layer 126 preferably has a portion higher than the upper surface of the organic compound layer 112 .

[0213] The insulating layer 126 can be formed using a wet film formation method such as spin coating, dipping, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating. In particular, it is preferable to form the organic insulating film that becomes the insulating layer 126 by spin coating.

[0214] After the insulating layer 126 is formed, heat treatment may be performed in the air at a temperature of 85° C. to 120° C. for 45 minutes to 100 minutes.

[0215] Furthermore, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, aluminum, etc.) may be provided between the insulating layer 125 and the insulating layer 126. For example, the reflective film can be formed after the insulating layer 125 is formed. The reflective film can be configured to reflect light emitted from the light-emitting layer. This can improve the light extraction efficiency.

[0216] 13B , an insulating layer 128 may be provided between the insulating layer 125 and the top surface of the organic compound layer 112. The insulating layer 128 is a portion of a protective layer (also referred to as a mask layer) for protecting the organic compound layer 112 when the organic compound layer 112 is etched. The insulating layer 128 may be made of the same material as that used for the insulating layer 125. In particular, it is preferable to use the same material for the insulating layer 128 and the insulating layer 125 because this facilitates processing. For example, the insulating layer 128 and the insulating layer 125 may both include an aluminum oxide film, a hafnium oxide film, or a silicon oxide film.

[0217] The insulating layers 125, 126, and 128 are all insulating layers located between light-emitting devices and may be collectively referred to as an insulating laminate. Because the common layer 114 and the common electrode 113b are provided on the insulating laminate, it is preferable that the edges of the insulating laminate be tapered to prevent the common layer 114 and the common electrode 113b from being cut. To have a tapered edge of the insulating laminate, the edge of the insulating layer 125 may be tapered, the edge of the insulating layer 126 may be tapered, the edge of the insulating layer 128 may be tapered, or the edges of the insulating layer 125, 126, and 128 may all be tapered. When a tapered edge is formed using multiple insulating layers, it is preferable that the tapered edges of each insulating layer be continuously formed.

[0218] Furthermore, the insulating laminate preferably has a rounded top surface at its center. In other words, the insulating laminate has a shape that is higher than the edges. To achieve this shape, the insulating layer 126 located at the top of the insulating laminate is preferably formed using an organic material.

[0219] Furthermore, the edge of the insulating laminate may have various shapes. For example, the insulating layer 125 located below the insulating laminate may protrude from the insulating layer 126. In this case, a portion of the upper part of the insulating layer 125 may be removed when the insulating layer 126 is processed. Removing the portion of the upper part of the insulating layer 125 protruding from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 113b from being cut.

[0220] The insulating layer 128 may protrude from the insulating layer 126. In this case, a portion of the upper part of the insulating layer 128 may be removed when the insulating layer 126 is processed. Removing the portion of the upper part of the insulating layer 128 protruding from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 113b from being cut.

[0221] When the insulating layer 128 protrudes from the insulating layer 126 , the end of the insulating layer 125 located below the insulating layer 128 may coincide or approximately coincide with the end of the insulating layer 128 .

[0222] 13B, a protective layer 121 is provided on the common electrode 113b. The protective layer 121 has a function of preventing impurities from diffusing into each light-emitting element from above.

[0223] The protective layer 121 may have, for example, a single-layer structure or a multilayer 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 121 may be made of a semiconductor material such as indium gallium oxide or indium gallium zinc oxide.

[0224] The protective layer 121 is bonded to the substrate 170 by an adhesive layer 171. Various curing adhesives can be used for the adhesive layer 171, such as a photo-curing adhesive such as an ultraviolet curing adhesive, a reaction-curing adhesive, a thermosetting adhesive, or an anaerobic adhesive. Alternatively, an adhesive sheet or the like may be used for the adhesive layer 171.

[0225] 13C, an opening is provided above the connection wiring 111C in the insulating layer 125 and the insulating layer 126. The connection wiring 111C and the common electrode 113b are electrically connected to each other through the opening.

[0226] FIG. 13C shows a configuration in which a common layer 114 is provided on the connection wiring 111C, and a common electrode 113b is provided on the common layer 114. When a carrier injection layer such as an electron injection layer is used for the common layer 114, the resistivity of the material used for the common layer 114 is sufficiently low, allowing the connection wiring 111C to be electrically connected to the common electrode 113b via the common layer 114. This allows the common electrode 113b and the common layer 114 to be formed using the same area mask or rough metal mask, thereby reducing manufacturing costs. An area mask or rough metal mask is different from a fine metal mask. Of course, the connection wiring 111C may have a connection portion 140 having an area in direct contact with the common electrode 113b.

[0227] The display device of one embodiment of the present invention can be applied to an extra-large display of 40 to 100 inches, or even more than 100 inches.

[0228] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0229] Embodiment 4 In this embodiment, examples of a structure and a material of a light-emitting device that can be used for a display device of one embodiment of the present invention will be described.

[0230] 14A is a schematic cross-sectional view of a pixel portion 103 of a display device. The pixel portion 103 of the display device includes a light-emitting device 550R that emits red light, a light-emitting device 550G that emits green light, and a light-emitting device 550B that emits blue light.

[0231] The light-emitting device 550R has a tandem structure, in which two light-emitting units (light-emitting unit 512R_1 and light-emitting unit 512R_2) are stacked between a pair of electrodes (electrode 501 and electrode 502) with a charge generation layer 531 interposed therebetween. The light-emitting device 550G has a tandem structure, in which two light-emitting units (light-emitting unit 512G_1 and light-emitting unit 512G_2) are stacked between a pair of electrodes with a charge generation layer 531 interposed therebetween. The light-emitting device 550B has a tandem structure, in which two light-emitting units (light-emitting unit 512B_1 and light-emitting unit 512R_B) are stacked between a pair of electrodes with a charge generation layer 531 interposed therebetween.

[0232] In this embodiment, the electrode 501 of each light-emitting unit can correspond to the lower electrodes 111R, 111G, and 111B of the above-mentioned embodiment 1, etc., the charge generation layer 531 can correspond to the charge generation layer 115 of the above-mentioned embodiment 1, etc., and the electrode 502 can correspond to the upper electrode 113 of the above-mentioned embodiment 1, etc.

[0233] 14A, the light-emitting unit 512R_1 includes a layer 521, a layer 522, a light-emitting layer 523R, and a layer 524. The light-emitting unit 512R_2 includes a layer 522, a light-emitting layer 523R, and a layer 524, and also includes a layer 525.

[0234] When the electrode 501 functions as an anode and the electrode 502 functions as a cathode in the light-emitting device, the layer 521 includes, for example, a hole injection layer. The layer 522 includes, for example, a hole transport layer or an electron blocking layer. The layer 522 may be formed by stacking functional layers. When stacked, the layer 522 may include, for example, a hole transport layer and an electron blocking layer. In the layer 522 formed by stacking the above layers, the hole transport layer may be located on the light-emitting layer 523R side, but it is preferable that the electron blocking layer be located on the light-emitting layer 523R side. The layer 524 includes, for example, an electron transport layer or a hole blocking layer. The layer 524 may be formed by stacking functional layers. When stacked, the layer 524 may include, for example, an electron transport layer and a hole blocking layer. In the layer 524 formed by stacking the above layers, the electron transport layer may be located on the light-emitting layer 523R side, but it is preferable that the hole blocking layer be located on the light-emitting layer 523R side. Layer 525 may also include, for example, an electron injection layer.

[0235] When the electrode 501 functions as a cathode and the electrode 502 functions as an anode in the light-emitting device, the layer 521 includes, for example, an electron injection layer. The layer 522 includes, for example, an electron transport layer or a hole blocking layer. The layer 522 may be formed by stacking functional layers. When stacked, the layer 522 may include, for example, an electron transport layer and a hole blocking layer. In the layer 522 formed by stacking the above layers, the electron transport layer may be located on the light-emitting layer 523R side, but it is preferable that the hole blocking layer be located on the light-emitting layer 523R side. The layer 524 includes, for example, a hole transport layer or an electron blocking layer. The layer 524 may be formed by stacking functional layers. When stacked, the layer 524 may include, for example, a hole transport layer and an electron blocking layer. In the layer 524 formed by stacking the above layers, the hole transport layer may be located on the light-emitting layer 523R side, but it is preferable that the electron blocking layer be located on the light-emitting layer 523R side. Layer 525 may also comprise, for example, a hole injection layer.

[0236] The layer 522, the light-emitting layer 523R, and the layer 524 may have the same configuration (material, film thickness, etc.) between the light-emitting unit 512R_1 and the light-emitting unit 512R_2, or may have different configurations.

[0237] The different configurations of the layer 522 include, for example, a configuration in which the layer 522 in the light-emitting unit 512R_1 has a hole-transporting layer, and a configuration in which the layer 522 in the light-emitting unit 512R_2 has a hole-transporting layer and an electron-blocking layer. The light-emitting unit 512R_1 and the light-emitting unit 512R_2 are merely examples, and the light-emitting unit 512R_1 and the light-emitting unit 512R_2 may be interpreted interchangeably.

[0238] The different configuration of the light-emitting layer 523R may be, for example, a configuration in which the light-emitting material contained in the light-emitting layer 523R is different within a range that satisfies the red light emission wavelength.

[0239] The different configurations of the layer 524 include, for example, a configuration in which the layer 524 in the light-emitting unit 512R_1 has an electron transport layer, and a configuration in which the layer 524 in the light-emitting unit 512R_2 has an electron transport layer and a hole blocking layer. The light-emitting unit 512R_1 and the light-emitting unit 512R_2 are merely examples, and the light-emitting unit 512R_1 and the light-emitting unit 512R_2 may be interpreted interchangeably.

[0240] 14A , the layer 521 and the layer 522 are shown separately, but this is an example and is not limiting. For example, when the layer 521 has a function of both a hole injection layer and a hole transport layer, the hole transport layer may be omitted from the layer 522. Alternatively, when the layer 521 has a function of both an electron injection layer and an electron transport layer, the electron transport layer may be omitted from the layer 522.

[0241] In the case of a light-emitting device having a tandem structure, two light-emitting units are stacked via a charge generation layer 531. A region of the charge generation layer 531 exhibits the function of injecting electrons into one of the light-emitting unit 512R_1 and the light-emitting unit 512R_2 and injecting holes into the other when a voltage is applied between the electrode 501 and the electrode 502. This region is referred to as a charge generation region. That is, the charge generation layer 531 has at least a charge generation region.

[0242] The light-emitting layer 523R of the light-emitting device 550R contains a light-emitting substance (also referred to as a light-emitting material) that emits red light, the light-emitting layer 523G of the light-emitting device 550G contains a light-emitting substance that emits green light, and the light-emitting layer 523B of the light-emitting device 550B contains a light-emitting substance that emits blue light.

[0243] Note that the light-emitting device 550G has a configuration in which the light-emitting layer 523R of the light-emitting device 550R is replaced with the light-emitting layer 523G, and the other functional layers are the same as those of the light-emitting device 550R. Similarly, the light-emitting device 550B has a configuration in which the light-emitting layer 523R of the light-emitting device 550R is replaced with the light-emitting layer 523B, and the other functional layers are the same as those of the light-emitting device 550R. Based on the above, in Figure 14A, the same reference numerals are used for the functional layers, etc., of the light-emitting device 550R, the light-emitting device 550G, and the light-emitting device 550B.

[0244] Note that layers 521, 522, 524, and 525 may each have the same configuration (material, film thickness, etc.) in light-emitting devices of two or more colors or all colors, or may have different configurations in light-emitting devices of all colors.

[0245] Again, a configuration in which multiple light-emitting units are connected in series via the charge generation layer 531, such as light-emitting device 550R, light-emitting device 550G, and light-emitting device 550B, is referred to as a tandem structure. The tandem structure may also be referred to as a stack structure. A tandem structure can provide a light-emitting device capable of emitting high-brightness light. On the other hand, a configuration having one light-emitting unit between a pair of electrodes is referred to as a single structure. Furthermore, compared to a single structure, a tandem structure can reduce the current required to obtain the same brightness, thereby improving the reliability of the light-emitting device.

[0246] Again, a configuration in which at least a light-emitting layer is separately fabricated for each light-emitting device, such as light-emitting device 550R, light-emitting device 550G, and light-emitting device 550B, is referred to as an SBS structure. Furthermore, a tandem structure is applied to light-emitting device 550R, light-emitting device 550G, and light-emitting device 550B. Therefore, the display device of the present invention can combine the advantages of both the tandem structure and the SBS structure.

[0247] The light-emitting device shown in FIG. 14A is sometimes referred to as a two-tier tandem structure because it has two tiers of light-emitting units formed in series. The two-tier tandem structure shown in FIG. 14A has light-emitting units having light-emitting layers that emit the same color stacked on top of one another. Specifically, in light-emitting device 550R, a second light-emitting unit having a red light-emitting layer is stacked on top of a first light-emitting unit having a red light-emitting layer. Similarly, in light-emitting device 550G, a second light-emitting unit having a green light-emitting layer is stacked on top of a first light-emitting unit having a green light-emitting layer. Similarly, in light-emitting device 550B, a second light-emitting unit having a blue light-emitting layer is stacked on top of a first light-emitting unit having a blue light-emitting layer.

[0248] 14B is a modification of the light-emitting device shown in FIG. 14A. The light-emitting device shown in FIG. 14B is an example in which the layer 525 is shared by a plurality of light-emitting devices, similar to the electrode 502. In this case, the layer 525 can be called a common layer. By providing one or more common layers among a plurality of light-emitting devices in this way, the manufacturing process can be simplified, and therefore, manufacturing costs can be reduced.

[0249] 15A illustrates a three-tier tandem structure, i.e., a case where three light-emitting units are stacked. In FIG. 15A, the light-emitting device 550R includes a light-emitting unit 512R_3 on the light-emitting unit 512R_2 via a charge generation layer 531. The light-emitting unit 512R_3 can have the same structure as the light-emitting unit 512R_1 or the light-emitting unit 512R_2. Specifically, the light-emitting unit 512R_3 can include the same light-emitting material as the light-emitting unit 512R_1 or the light-emitting unit 512R_2.

[0250] The light-emitting device 550G further includes a light-emitting unit 512G_3 above the light-emitting unit 512G_2 with a charge generation layer 531 interposed therebetween. The light-emitting unit 512G_3 can have the same structure as the light-emitting unit 512G_1 or the light-emitting unit 512G_2. Specifically, the light-emitting unit 512G_3 can include the same light-emitting material as the light-emitting unit 512G_1 or the light-emitting unit 512G_2.

[0251] The light-emitting device 550B further includes a light-emitting unit 512B_3 above the light-emitting unit 512B_2 with a charge generation layer 531 interposed therebetween. The light-emitting unit 512B_3 can have the same structure as the light-emitting unit 512B_1 or the light-emitting unit 512B_2. Specifically, the light-emitting unit 512B_3 can include the same light-emitting material as the light-emitting unit 512B_1 or the light-emitting unit 512B_2.

[0252] In a tandem structure, as the number of stacked light-emitting units increases, the number of charge generation layers 531 also increases. When multiple charge generation layers 531 are provided in this manner, the multiple charge generation layers 531 may all have the same configuration (material, film thickness, etc.) in the light-emitting device, or may have different configurations. Furthermore, the multiple charge generation layers 531 may all have the same configuration in each light-emitting device, or may have different configurations.

[0253] 15B illustrates an n-stage tandem structure, that is, a case where n light-emitting units (n is an integer of 2 or more) are stacked. The n-stage tandem structure has (n-1) charge generation layers 531.

[0254] In this way, by increasing the number of stacked light-emitting units, the luminance obtained from the light-emitting device with the same amount of current can be increased in proportion to the number of stacked light-emitting units.Furthermore, by increasing the number of stacked light-emitting units, the current required to obtain the same luminance can be reduced, and therefore the power consumption of the light-emitting device can be reduced in proportion to the number of stacked light-emitting units.

[0255] Next, materials that can be used in light-emitting devices will be described.

[0256] A conductive film that transmits visible light is used for the electrode that serves as the extraction electrode, out of the electrodes 501 and 502. It is preferable to use a conductive film that reflects visible light for the counter electrode that faces the extraction electrode.

[0257] Furthermore, when a light-emitting device that emits infrared light is added to a display device, it is preferable to use a conductive film that transmits visible light and infrared light for the extraction electrode and a conductive film that reflects visible light and infrared light for the counter electrode.

[0258] A conductive film that transmits visible light may also be used for the counter electrode. In this case, the conductive film that transmits visible light is laminated with a conductive film that reflects visible light, and the conductive film that transmits visible light is located on the light-emitting layer side.

[0259] Materials for forming the pair of electrodes of a light-emitting device include metals, alloys, electrically conductive compounds, and mixtures thereof. Specific examples of such materials include alloys containing one or more elements selected from aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium. Examples of such materials include oxides containing indium and tin (also referred to as indium tin oxide, In—Sn oxide, or ITO), oxides containing indium, silicon, and tin (also referred to as In—Si—Sn oxide or ITSO), oxides containing indium and zinc (also referred to as indium zinc oxide or In—Zn oxide), and oxides containing indium, tungsten, and zinc (also referred to as In-W—Zn oxide). Examples of the material include an aluminum alloy (aluminum alloy), such as an alloy of aluminum, nickel, and lanthanum (Al-Ni-La), and an alloy of silver, palladium, and copper (Ag-Pd-Cu, also referred to as APC). Other examples of the material include alloys of one or more elements selected from elements belonging to Group 1 or Group 2 of the periodic table (e.g., lithium, cesium, calcium, strontium), and rare earth metals such as europium and ytterbium. Other examples of the material include graphene.

[0260] To reiterate, the light-emitting device has at least a light-emitting layer, and may have one or more functional layers other than the light-emitting layer, such as a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0261] Each of the functional layers may be formed using either a low molecular weight compound or a high molecular weight compound, and may contain an inorganic compound. The layers constituting the light-emitting device may be formed by a method such as vapor deposition (including vacuum deposition), transfer, printing, inkjet printing, or coating.

[0262] <Light-emitting layer> The light-emitting layer contains one or more light-emitting substances. As the light-emitting substance, a substance that emits light of blue, purple, blue-purple, green, yellow-green, yellow, orange, red, or the like is appropriately used. Furthermore, a substance that emits near-infrared light can also be used as the light-emitting substance.

[0263] Examples of the light-emitting material include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0264] 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.

[0265] Examples of phosphorescent materials include organometallic complexes (particularly iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton. Other phosphorescent materials include organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, platinum complexes, and rare earth metal complexes.

[0266] The light-emitting layer may contain one or more organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). As the one or more organic compounds, one or both of a substance with high hole transport properties (hole transport material) and a substance with high electron transport properties (electron transport material) can be used. As the hole-transporting material, a material with high hole transport properties that can be used for the hole-transporting layer, which will be described later, can be used. As the electron-transporting material, a material with high electron transport properties that can be used for the electron-transporting layer, which will be described later, can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material may be used.

[0267] The light-emitting layer preferably includes, 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 emission using Exciplex-Triple 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, energy transfer becomes smooth, allowing for efficient emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting device.

[0268] 15A , for example, two light-emitting layers 523R of light-emitting device 550R may each contain a phosphorescent material, two light-emitting layers 523G of light-emitting device 550G may each contain a fluorescent material, and two light-emitting layers 523B of light-emitting device 550B may each contain a fluorescent material.

[0269] Alternatively, the two light-emitting layers 523R of the light-emitting device 550R each contain a phosphorescent material, the two light-emitting layers 523G of the light-emitting device 550G each contain a phosphorescent material, and the two light-emitting layers 523B of the light-emitting device 550B each contain a fluorescent material.

[0270] Furthermore, in the display device of one embodiment of the present invention, a structure in which a fluorescent material is used for all light-emitting layers of the light-emitting devices 550R, 550G, and 550B, or a structure in which a phosphorescent material is used for all light-emitting layers of the light-emitting devices 550R, 550G, and 550B, may be applied.

[0271] Alternatively, a configuration in which a phosphorescent material is used for the light-emitting layer 523R of the light-emitting unit 512R_1 and a fluorescent material is used for the light-emitting layer 523R of the light-emitting unit 512R_2, or a configuration in which a fluorescent material is used for the light-emitting layer 523R of the light-emitting unit 512R_1 and a phosphorescent material is used for the light-emitting layer 523R of the light-emitting unit 512R_2, that is, a configuration in which different light-emitting materials are used for the light-emitting layer in the first stage and the light-emitting layer in the second stage, may be applied. Note that although the description here has been made with respect to the light-emitting unit 512R_1 and the light-emitting unit 512R_2, a similar configuration can also be applied to the light-emitting unit 512G_1 and the light-emitting unit 512G_2, and the light-emitting unit 512B_1 and the light-emitting unit 512B_2.

[0272] <Hole Injection Layer> The hole injection layer is a layer that injects holes from the anode to the hole transport layer and contains a material with high hole injection properties. Examples of the material with high hole injection properties include aromatic amine compounds. Other examples of the material with high hole injection properties include acceptor materials (electron-accepting materials) and composite materials containing an acceptor material and a hole transport material.

[0273] As the acceptor material, for example, an oxide of a metal belonging to Groups 4 to 8 of the periodic table can be used. Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the air, has low hygroscopicity, and is easy to handle. Alternatively, an organic acceptor material containing fluorine can be used. Alternatively, an organic acceptor material such as a quinodimethane derivative, a chloranil derivative, or a hexaazatriphenylene derivative can be used.

[0274] As the hole transporting material, a material having high hole transporting properties that can be used for the hole transport layer described later can be used.

[0275] For example, as a material with high hole injection properties, a material containing a hole transporting material and an oxide of a metal belonging to Groups 4 to 8 of the periodic table (typically, molybdenum oxide) may be used.

[0276] <Hole transport layer> The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light emitting layer. The hole transport layer is a layer containing a hole transport material. The hole transport material is a material containing 1×10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property.

[0277] Examples of hole-transporting materials include materials with high hole-transporting properties, such as π-electron-rich heteroaromatic compounds (for example, carbazole derivatives, thiophene derivatives, and furan derivatives) and aromatic amines (compounds having an aromatic amine skeleton).

[0278] <Electron Blocking Layer> The electron blocking layer is a layer containing a material that has hole transport properties and can block electrons. The electron blocking layer can be made of a material that has electron blocking properties among the hole transport materials described above. Such an electron blocking layer may also be called a hole transport layer.

[0279] <Electron Transport Layer> 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 containing 1×10 −６ cm ２ A 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 a hole transporting property.

[0280] Examples of the electron-transporting material 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. Other examples of the electron-transporting material include 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, and pyrimidine derivatives. Other electron-transporting materials that can be used include materials with high electron-transporting properties, such as π-electron-deficient heteroaromatic compounds including other nitrogen-containing heteroaromatic compounds.

[0281] <Hole Blocking Layer> The hole blocking layer is a layer containing a material that has electron transport properties and is capable of blocking holes. Among the electron transport materials described above, a material that has hole blocking properties can be used for the hole blocking layer. Such a hole blocking layer may also be called an electron transport layer.

[0282] <Electron Injection Layer> 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, alkali metal compounds, and alkaline earth metal compounds. As the material with high electron injection properties, a composite material containing an electron transport material and a donor material (electron donor material) can also be used.

[0283] Furthermore, it is preferable that the LUMO level of a material with high electron injection properties has a small difference (specifically, 0.5 eV or less) from the work function value of the material used for the cathode.

[0284] The electron injection layer may contain, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ｘ, where X is an arbitrary number), 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), lithium oxide (LiO ｘ ), alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may have a stacked structure of two or more layers. For example, the stacked structure may have a structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer.

[0285] The electron injection layer may contain an electron transporting material. For example, a compound having an unshared electron pair and an electron-deficient heteroaromatic ring can be used as the electron transporting material. Specifically, a compound having one or more rings selected from a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used.

[0286] The lowest unoccupied molecular orbital (LUMO) level 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, or the like.

[0287] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2-(1,3-phenylene)bis[9-phenyl-1,10-phenanthroline] (abbreviation: mPPhen2P), diquinoxalino[2,3-a:2′,3′-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3′-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition point (Tg) and is superior in heat resistance compared to BPhen.

[0288] <Charge Generation Region> As described above, the charge generation layer has at least a charge generation region. The charge generation region preferably contains an acceptor material. For example, the acceptor material may be the same as the material described above in <Hole Injection Layer>. For example, the charge generation layer may contain the same acceptor material as the hole injection layer.

[0289] Furthermore, the charge generation region preferably contains a composite material containing an acceptor material and a hole transport material. For example, the materials described above in <Hole Transport Layer> can be used as the hole transport material. For example, the charge generation layer may contain the same hole transport material as the hole injection layer or the hole transport layer. Note that the composite material containing an acceptor material and a hole transport material may be a laminated structure of a layer containing an acceptor material and a layer containing a hole transport material, or may be a layer in which the acceptor material and the hole transport material are mixed. The mixed layer can be obtained, for example, by co-evaporating the acceptor material and the hole transport material.

[0290] The charge generation layer may contain a donor material instead of the acceptor material. When the charge generation layer contains a donor material, the charge generation layer may be a layer containing the donor material and the electron transport material and donor material described in the above <Electron Injection Layer>.

[0291] <Electron Injection Buffer Layer> The charge generation layer may also have a layer containing a material with high electron injection properties in addition to the charge generation region. This layer may be very thin and may be referred to as a region. This layer may also be called an electron injection buffer layer, and this region may also be called an electron injection buffer region. By providing the electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be alleviated, making it possible to easily inject electrons generated in the charge generation region into the electron transport layer. Therefore, it is preferable to provide the electron injection buffer layer between the charge generation region and the electron transport layer.

[0292] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal. For example, it may contain a compound of the alkali metal or a compound of the alkaline earth metal. Specifically, the electron injection buffer layer preferably uses an alkali metal (lithium, sodium, calcium, or the like), and preferably uses an inorganic compound containing the alkali metal and oxygen or an inorganic compound containing the alkali metal and fluorine. The inorganic compound containing the alkali metal and oxygen is an inorganic compound containing lithium and oxygen, specifically lithium oxide (Li ２ The inorganic compound containing an alkali metal and fluorine may be an inorganic compound containing lithium and fluorine, specifically lithium fluoride (LiF). The electron injection buffer layer preferably contains an inorganic compound containing an alkaline earth metal and oxygen.

[0293] In addition, the materials described above in the section on <Electron Injection Layer> can be suitably used for the electron injection buffer layer. For example, the electron injection buffer layer may contain the same material with high electron injection properties as the electron injection layer.

[0294] Furthermore, the electron injection buffer layer preferably includes a composite material containing an alkali metal or alkaline earth metal and an electron transport material. The inorganic compound containing an alkali metal and oxygen may be the inorganic compound containing the alkali metal and oxygen. For example, the electron transport material may be the same as the electron transport material contained in the electron injection layer or the electron transport layer. The composite material containing an alkali metal, an alkaline earth metal, an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an electron transport material may be a stacked structure of a layer containing an alkali metal, an alkaline earth metal, an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and a layer containing an electron transport material, or may be a layer in which an alkali metal, an alkaline earth metal, an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an electron transport material are mixed. The mixed layer can be obtained, for example, by co-evaporating an alkali metal, an alkaline earth metal, an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen with an electron transporting material.

[0295] The boundary between the charge generation region and the electron injection buffer layer may be unclear. For example, when a very thin charge generation layer is analyzed by time-of-flight secondary ion mass spectrometry (TOF-SIMS), elements contained in both the charge generation region and the electron injection buffer layer may be detected. When lithium oxide is used as the electron injection buffer layer, lithium may be detected not only in the electron injection buffer layer but also throughout the charge generation layer due to the high diffusivity of alkali metals such as lithium. Therefore, the region where lithium is detected by TOF-SIMS can be considered the charge generation layer.

[0296] <Electron Relay Layer> The charge generation layer may further include a layer containing a material with high electron transport properties in addition to the charge generation region. This layer may be very thin and may be referred to as a region. This layer may also be called an electron relay layer, and this region may also be called an electron relay region. The electron relay layer has the function of preventing interaction between the charge generation region and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons. Therefore, the electron relay layer is preferably provided between the charge generation region and the electron injection buffer layer. Furthermore, when the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the charge generation region and the electron transport layer.

[0297] The electron relay layer can be suitably made of the electron transporting materials described above in the "Electron Transport Layer" section. Also, phthalocyanine-based materials such as copper (II) phthalocyanine (abbreviated as CuPc) can be suitably used for the electron relay layer. Furthermore, metal complexes having a metal-oxygen bond and an aromatic ligand can be suitably used for the electron relay layer.

[0298] In a charge generation layer in which an electron relay layer is provided between the charge generation region and the electron injection buffer layer, the boundary between the charge generation region and the electron relay layer, or the boundary between the electron relay layer and the electron injection buffer layer, may be unclear. For example, when a very thin charge generation layer is analyzed by TOF-SIMS, elements contained in the charge generation region, elements contained in the electron relay layer, and elements contained in the electron injection buffer layer may all be detected. When lithium oxide is used as the electron injection buffer layer, alkali metals such as lithium have high diffusivity, so lithium may be detected not only in the electron injection buffer layer but also throughout the charge generation layer. Therefore, the region in which lithium is detected by TOF-SIMS can be considered as the charge generation layer.

[0299] In a charge generation layer in which an electron relay layer is provided between the charge generation region and the electron transport layer, the boundary between the charge generation region and the electron relay layer may be unclear. For example, when a very thin charge generation layer is analyzed by TOF-SIMS, elements contained in both the charge generation region and the electron relay layer may be detected.

[0300] When light-emitting units are stacked, an increase in driving voltage can be suppressed by providing a charge generating layer between two light-emitting units.

[0301] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0302] Embodiment Mode 5 In this embodiment mode, a display device will be described.

[0303] 16A shows a block diagram of a display device 10. The display device 10 includes a pixel portion 103, a driver circuit portion 201, a driver circuit portion 202, and the like.

[0304] The pixel section 103 has a plurality of pixels 150 laid out in a matrix. Each pixel 150 has a sub-pixel 21R, a sub-pixel 21G, and a sub-pixel 21B.

[0305] The pixel 150 is electrically connected to a wiring GL, a wiring SLR, a wiring SLG, and a wiring SLB. The wirings SLR, SLG, and SLB are each electrically connected to a driver circuit unit 201. The wiring GL is electrically connected to a driver circuit unit 202. The driver circuit unit 201 functions as a source line driver circuit (also referred to as a source driver), and the driver circuit unit 202 functions as a gate line driver circuit (also referred to as a gate driver). The wiring GL functions as a gate line, and the wirings SLR, SLG, and SLB function as source lines.

[0306] The sub-pixel 21R emits red light. The sub-pixel 21G emits green light. The sub-pixel 21B emits blue light. This allows the display device 10 to display full color. Note that the pixel 150 may also have sub-pixels that emit light of other colors. For example, in addition to the above three sub-pixels, the pixel 150 may also have a sub-pixel that emits white light or a sub-pixel that emits yellow light.

[0307] The wiring GL is electrically connected to the sub-pixels 21R, 21G, and 21B arranged in the row direction (extension direction of the wiring GL). The wiring SLR, wiring SLG, and wiring SLB are electrically connected to the sub-pixels 21R, 21G, and 21B (not shown) arranged in the column direction (extension direction of the wiring SLR, etc.), respectively.

[0308] 16B shows an example of a circuit diagram of a pixel 150 that can be applied to the subpixels 21R, 21G, and 21B. The pixel 150 includes a transistor M1, a transistor M2, a transistor M3, a capacitor C1, and a light-emitting device EL. A wiring GL and a wiring SL are electrically connected to the pixel 150. The wiring SL corresponds to any one of the wirings SLR, SLG, and SLB shown in FIG. 12A.

[0309] The transistor M1 has a gate electrically connected to a wiring GL, one of a source and a drain electrically connected to a wiring SL, and the other electrically connected to one electrode of a capacitor C1 and the gate of the transistor M2. The transistor M2 has one of a source and a drain electrically connected to a wiring AL, and the other of a source and a drain electrically connected to one electrode of a light-emitting device EL, the other electrode of the capacitor C1, and one of a source and a drain of the transistor M3. The transistor M3 has a gate electrically connected to a wiring GL, and the other of a source and a drain electrically connected to a wiring RL. The light-emitting device EL has the other electrode electrically connected to a wiring CL.

[0310] The wiring SL is supplied with a data potential D. The wiring GL is supplied with a selection signal. The selection signal includes a potential that turns on a transistor and a potential that turns off a transistor.

[0311] A reset potential is applied to the wiring RL. An anode potential is applied to the wiring AL. A cathode potential is applied to the wiring CL. In the pixel 150, the anode potential is higher than the cathode potential. The reset potential applied to the wiring RL can be a potential such that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting device EL. The reset potential can be a potential higher than the cathode potential, the same as the cathode potential, or a potential lower than the cathode potential.

[0312] The transistors M1 and M3 function as switches. The transistor M2 functions as a transistor for controlling the current flowing through the light-emitting device EL. For example, it can be said that the transistor M1 functions as a selection transistor and the transistor M2 functions as a drive transistor.

[0313] Here, it is preferable that all of the transistors M1 to M3 be LTPS transistors. Alternatively, it is preferable that the transistors M1 and M3 be OS transistors and the transistor M2 be an LTPS transistor.

[0314] Alternatively, OS transistors may be used for all of the transistors M1 to M3. In this case, an LTPS transistor may be used for one or more of the transistors included in the driver circuit portion 201 and the driver circuit portion 202, and OS transistors may be used for the remaining transistors. For example, an OS transistor may be used for the transistor provided in the pixel portion 103, and an LTPS transistor may be used for the transistors provided in the driver circuit portion 201 and the driver circuit portion 202.

[0315] As the OS transistor, a transistor including an oxide semiconductor for a semiconductor layer in which a channel is formed can be used. The semiconductor layer preferably contains, for example, indium, M (M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin. In particular, an oxide containing indium, gallium, and zinc (also referred to as IGZO) is preferably used for the semiconductor layer of the OS transistor. Alternatively, an oxide containing indium, tin, and zinc is preferably used. Alternatively, an oxide containing indium, gallium, tin, and zinc is preferably used.

[0316] A transistor using an oxide semiconductor, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use transistors including oxide semiconductors for the transistors M1 and M3 connected in series with the capacitor C1. Using transistors including oxide semiconductors as the transistors M1 and M3 can prevent charge stored in the capacitor C1 from leaking through the transistor M1 or M3. Furthermore, because charge stored in the capacitor C1 can be held for a long period of time, a still image can be displayed for a long period of time without rewriting data in the pixel 150.

[0317] Note that although the transistors are shown as n-channel transistors in FIG. 16B, p-channel transistors can also be used.

[0318] In addition, the transistors included in the pixel 150 are preferably formed side by side on the same substrate.

[0319] As the transistor included in the pixel 150, a transistor having a pair of gates overlapping with each other with a semiconductor layer interposed therebetween can be used.

[0320] In a transistor having a pair of gates, when the pair of gates are electrically connected to each other and supplied with the same potential, the on-state current of the transistor is increased and the saturation characteristics are improved. A potential for controlling the threshold voltage of the transistor may be supplied to one of the pair of gates. Supplying a constant potential to one of the pair of gates can improve the stability of the electrical characteristics of the transistor. For example, one gate of the transistor may be electrically connected to a wiring to which a constant potential is supplied, or to its own source or drain.

[0321] 16C is an example of a pixel 150 in which a transistor having a pair of gates is used as the transistor M3. The pair of gates of the transistor M3 are electrically connected. With this configuration, the period for writing data to the pixel 150 can be shortened.

[0322] 16D is an example in which transistors having a pair of gates are used for the transistors M1 and M2 in addition to the transistor M3. In each of the transistors, the pair of gates is electrically connected to each other. By using such a transistor at least for the transistor M2, the saturation characteristics are improved, which makes it easier to control the emission luminance of the light-emitting device EL and improves the display quality.

[0323] The pixel 150 shown in FIG. 16E is an example in which one of the pair of gates of the transistor M2 of the pixel 150 shown in FIG. 16D is electrically connected to the source of the transistor M2.

[0324] [Example of Transistor Structure] An example of the cross-sectional structure of the transistor will be described below.

[0325] Configuration Example 1 FIG. 17A is a cross-sectional view including a transistor 410. FIG.

[0326] The transistor 410 is provided on the substrate 401 and has polycrystalline silicon applied to a semiconductor layer. For example, the transistor 410 corresponds to the transistor M2 of the pixel 150. That is, Fig. 17A illustrates an example in which one of the source and the drain of the transistor 410 is electrically connected to the lower electrode 111 of the light-emitting device.

[0327] The transistor 410 includes a semiconductor layer 411, an insulating layer 412, a conductive layer 413, and the like. The semiconductor layer 411 includes a channel formation region 411i and a low-resistance region 411n. The semiconductor layer 411 includes silicon. The semiconductor layer 411 preferably includes polycrystalline silicon. A part of the insulating layer 412 functions as a gate insulating layer. A part of the conductive layer 413 functions as a gate electrode.

[0328] Note that the semiconductor layer 411 can also include a metal oxide (also referred to as an oxide semiconductor) that exhibits semiconductor characteristics. In this case, the transistor 410 can be called an OS transistor.

[0329] The low-resistance region 411n is a region containing an impurity element. For example, when the transistor 410 is an n-channel transistor, phosphorus, arsenic, or the like may be added to the low-resistance region 411n. On the other hand, when the transistor 410 is a p-channel transistor, boron, aluminum, or the like may be added to the low-resistance region 411n. Furthermore, in order to control the threshold voltage of the transistor 410, the above-mentioned impurities may be added to the channel formation region 411i.

[0330] An insulating layer 421 is provided over a substrate 401. A semiconductor layer 411 is provided over the insulating layer 421. An insulating layer 412 is provided to cover the semiconductor layer 411 and the insulating layer 421. A conductive layer 413 is provided over the insulating layer 412 so as to overlap with the semiconductor layer 411.

[0331] An insulating layer 422 is provided to cover the conductive layer 413 and the insulating layer 412. A conductive layer 414a and a conductive layer 414b are provided over the insulating layer 422. The conductive layer 414a and the conductive layer 414b are electrically connected to the low-resistance region 411n through openings provided in the insulating layer 422 and the insulating layer 412. A part of the conductive layer 414a functions as one of the source electrode and the drain electrode, and a part of the conductive layer 414b functions as the other of the source electrode and the drain electrode. An insulating layer 104 is provided to cover the conductive layer 414a, the conductive layer 414b, and the insulating layer 422.

[0332] A lower electrode 111 functioning as a pixel electrode is provided over the insulating layer 104. The lower electrode 111 is provided over the insulating layer 104 and is electrically connected to the conductive layer 414b in an opening provided in the insulating layer 104. Although not shown here, an EL layer and a common electrode can be stacked over the lower electrode 111.

[0333] 17B shows a transistor 410a having a pair of gate electrodes, which is different from the transistor 410a shown in FIG. 17A mainly in that a conductive layer 415 and an insulating layer 416 are included.

[0334] The conductive layer 415 is provided over the insulating layer 421. An insulating layer 416 is provided to cover the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided so that at least a channel formation region 411i overlaps with the conductive layer 415 with the insulating layer 416 interposed therebetween.

[0335] 17B, ​​part of the conductive layer 413 functions as a first gate electrode, part of the conductive layer 415 functions as a second gate electrode, part of the insulating layer 412 functions as a first gate insulating layer, and part of the insulating layer 416 functions as a second gate insulating layer.

[0336] Here, when the first gate electrode and the second gate electrode are electrically connected, the conductive layer 413 and the conductive layer 415 may be electrically connected through openings provided in the insulating layers 412 and 416 in a region not shown. When the second gate electrode and the source or drain are electrically connected, the conductive layer 414a or the conductive layer 414b may be electrically connected to the conductive layer 415 through openings provided in the insulating layers 422, 412, and 416 in a region not shown.

[0337] 17A or 17B can be used as an example of the transistors constituting the pixel 150. In this case, the transistor 410a may be used as all the transistors constituting the pixel 150, the transistor 410 may be used as all the transistors constituting the pixel 150, or the transistor 410 may be used as all the transistors constituting the pixel 150, or the transistor 410a and the transistor 410 may be used in combination.

[0338] [Structure Example 3] Hereinafter, a structure example including both a transistor in which silicon is used for a semiconductor layer and a transistor in which a metal oxide is used for a semiconductor layer will be described.

[0339] FIG. 17C shows a cross-sectional view including transistor 410a and transistor 450.

[0340] For the transistor 410a, refer to the above-described Structure Example 1. Note that although the example using the transistor 410a is shown here, a structure including the transistor 410 and the transistor 450 may be used, or a structure including all of the transistor 410, the transistor 410a, and the transistor 450 may be used.

[0341] The transistor 450 is a transistor in which a metal oxide is used for a semiconductor layer. The configuration shown in Fig. 17C is an example in which the transistor 450 corresponds to the transistor M1 of the pixel 150 and the transistor 410a corresponds to the transistor M2. That is, Fig. 17C is an example in which one of the source and the drain of the transistor 410a is electrically connected to the lower electrode 111.

[0342] FIG. 17C shows an example in which the transistor 450 has a pair of gates.

[0343] The transistor 450 includes a conductive layer 455, an insulating layer 422, a semiconductor layer 451, an insulating layer 452, a conductive layer 453, and the like. Part of the conductive layer 453 functions as a first gate of the transistor 450, and part of the conductive layer 455 functions as a second gate of the transistor 450. In this case, part of the insulating layer 452 functions as a first gate insulating layer of the transistor 450, and part of the insulating layer 422 functions as a second gate insulating layer of the transistor 450.

[0344] The conductive layer 455 is provided over the insulating layer 412. The insulating layer 422 is provided to cover the conductive layer 455. The semiconductor layer 451 is provided over the insulating layer 422. The insulating layer 452 is provided to cover the semiconductor layer 451 and the insulating layer 422. The conductive layer 453 is provided over the insulating layer 452 and has a region overlapping with the semiconductor layer 451 and the conductive layer 455.

[0345] An insulating layer 426 is provided to cover the insulating layer 452 and the conductive layer 453. A conductive layer 454a and a conductive layer 454b are provided over the insulating layer 426. The conductive layer 454a and the conductive layer 454b are electrically connected to the semiconductor layer 451 through openings provided in the insulating layer 426 and the insulating layer 452. A part of the conductive layer 454a functions as one of the source electrode and the drain electrode, and a part of the conductive layer 454b functions as the other of the source electrode and the drain electrode. An insulating layer 104 is provided to cover the conductive layer 454a, the conductive layer 454b, and the insulating layer 426.

[0346] Here, the conductive layers 414a and 414b electrically connected to the transistor 410a are preferably formed by processing the same conductive film as the conductive layers 454a and 454b. Figure 17C shows a configuration in which the conductive layers 414a, 414b, 454a, and 454b are formed on the same surface (i.e., in contact with the top surface of the insulating layer 426) and contain the same metal element. In this case, the conductive layers 414a and 414b are electrically connected to the low-resistance region 411n through openings provided in the insulating layer 426, the insulating layer 452, the insulating layer 422, and the insulating layer 412. This is preferable because it simplifies the manufacturing process.

[0347] The conductive layer 413 functioning as the first gate electrode of the transistor 410a and the conductive layer 455 functioning as the second gate electrode of the transistor 450 are preferably formed by processing the same conductive film. In Figure 17C, the conductive layer 413 and the conductive layer 455 are formed on the same surface (i.e., in contact with the top surface of the insulating layer 412) and contain the same metal element. This is preferable because it simplifies the manufacturing process.

[0348] In FIG. 17C , the insulating layer 452 functioning as the first gate insulating layer of the transistor 450 covers the end portion of the semiconductor layer 451; however, as in the transistor 450a shown in FIG. 17D , the insulating layer 452 may be processed so that the top surface shape thereof matches or substantially matches the top surface shape of the conductive layer 453.

[0349] In this specification, the phrase "top surface shapes generally match" refers to the overlap of at least a portion of the contours between stacked layers. For example, this includes cases where the upper and lower layers are processed using the same mask pattern, or where a portion of the mask pattern is the same. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, the phrase "top surface shapes generally match" also applies.

[0350] Although the example in which the transistor 410a corresponds to the transistor M2 and is electrically connected to the pixel electrode has been described, this is not limiting. For example, the transistor 450 or the transistor 450a may correspond to the transistor M2. In this case, the transistor 410a corresponds to the transistor M1, the transistor M3, or another transistor.

[0351] By having the pixel circuit and the light-emitting device structure of the above embodiment, the display device can have one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. The leakage current that can flow through the transistors of the pixel circuit is extremely low, and the lateral leakage current between the light-emitting devices of the above embodiment is extremely low, which is preferable because the display device minimizes light leakage and the like that can occur when displaying black.

[0352] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0353] Embodiment Mode 6 In this embodiment mode, a display device having a light receiving device (also referred to as a light receiving element) will be described.

[0354] The pixel section may have a light-receiving device in addition to the light-emitting device, thereby providing a display device with a light-receiving function. A display device with a light-receiving function can detect contact or proximity of an object while displaying an image. The area where the light-receiving device is located is referred to as the light-receiving section, and the light-receiving section also has a switching element that controls the light-receiving device. The light-receiving device controlled by the switching element can detect one or both of visible light and infrared light. Specifically, the light-receiving device has the function of receiving light from a light source and can convert the received light into an electrical signal.

[0355] The light source for visible light can be light from a light-emitting device. When using a light-emitting device, it is preferable to use green wavelengths through a green color filter, as this increases light sensitivity. When some light-emitting devices emit light as a light source, the remaining sub-pixels may display an image. In addition, an infrared light source located outside the pixel area can be used as the light source for infrared light.

[0356] The pixel 150 shown in Figures 18A, 18B, and 18C includes subpixels 110G, 110B, and 110R, and a light receiving portion 110S, and further includes auxiliary wiring. Figures 18A, 18B, and 18C show a second wiring layer 151b that is part of the auxiliary wiring 151. In Figures 18A, 18B, and 18C, the symbols R, G, B, and S are assigned within each region to simplify the distinction between the subpixels, etc.

[0357] The pixel 150 shown in FIG. 18A is configured in a stripe arrangement, and a second wiring layer 151b is provided so as to surround the subpixels 110G, 110B, 110R, and the light receiving section 110S.

[0358] The pixel shown in FIG. 18B is arranged in a matrix, and a second wiring layer 151b is provided to surround the sub-pixels 110G, 110B, 110R, and the light receiving portion 110S.

[0359] The pixel 150 shown in FIG. 18C has an arrangement in which three subpixels (subpixel 110R, subpixel 110G, and light receiving portion 110S) are vertically arranged next to one subpixel (subpixel 110B), and a second wiring layer 151b is provided to surround the subpixels 110G, 110B, 110R, and 110S.

[0360] The layout of the subpixels is not limited to the configurations shown in Figures 18A to 18C. The layout of the second wiring layer 151b is not limited to the configurations shown in Figures 18A to 18C.

[0361] When the light-receiving area of ​​the light-receiving portion 110S is smaller than the light-emitting area of ​​the other subpixels, the imaging range is narrowed, which can suppress blurring of the imaging result and improve the resolution. Therefore, the display device of one embodiment of the present invention can capture high-definition or high-resolution images. For example, the light-receiving portion 110S can be used to capture images for personal authentication using a fingerprint, palm print, iris, pulse shape (including vein shape and artery shape), face, or the like.

[0362] The light receiving unit 110S can also be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover touch sensor, non-contact sensor, or touchless sensor).

[0363] A touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object when the display device and the object are in direct contact with each other. A near-touch sensor can detect an object even if the object does not come into contact with the display device. For example, a configuration in which the display device can detect an object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm, is preferable. This configuration enables the display device to be operated without the object directly touching the display device, in other words, it enables the display device to be operated in a non-contact (touchless) manner. This configuration reduces the risk of the display device becoming dirty or scratched, or enables the display device to be operated without the object directly touching dirt (e.g., dust, viruses, etc.) attached to the display device.

[0364] When high-resolution imaging is performed, it is preferable that the light receiving unit 110S is provided in all pixels of the display device. On the other hand, when used in a touch sensor or near-touch sensor, the light receiving unit 110S does not require high accuracy compared to when imaging a fingerprint, etc., so it is sufficient that it is provided in some of the pixels of the display device. By making the number of light receiving units 110S in the display device smaller than the number of sub-pixels 110R, etc., the detection speed can be increased.

[0365] FIG. 18D shows an example of a pixel circuit of a sub-pixel (PIX1) having a light-receiving device.

[0366] 18D includes a light receiving device PD, a transistor M11, a transistor M12, a transistor M13, a transistor M14, and a capacitance element C2. Here, an example is shown in which a photodiode is used as the light receiving device PD.

[0367] The light-receiving device PD has an anode electrically connected to the wiring V1 and a cathode electrically connected to one of the source and drain of the transistor M11. The transistor M11 has a gate electrically connected to the wiring TX and the other of the source and drain electrically connected to one electrode of the capacitor C2, one of the source and drain of the transistor M12, and the gate of the transistor M13. The transistor M12 has a gate electrically connected to the wiring RES and the other of the source and drain electrically connected to the wiring V2. The transistor M13 has one of the source and drain electrically connected to the wiring V3 and the other of the source and drain electrically connected to one of the source and drain of the transistor M14. The transistor M14 has a gate electrically connected to the wiring SE and the other of the source and drain electrically connected to the wiring OUT1.

[0368] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light-receiving device PD is driven, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving device PD. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE and functions as a selection transistor that reads out an output according to the potential of the node to an external circuit electrically connected to the wiring OUT1.

[0369] The transistors M11, M12, M13, and M14 are preferably OS transistors each including a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed.

[0370] An OS transistor has a wider band gap and a lower carrier density than silicon transistors, and can achieve extremely low off-state current.

[0371] Alternatively, the transistors M11 to M14 may be transistors using silicon as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0372] Alternatively, a structure may be used in which at least one of the transistors M11 to M14 includes an oxide semiconductor and the remaining transistors include silicon.

[0373] Note that although the transistors are shown as n-channel transistors in FIG. 18D, p-channel transistors can also be used.

[0374] Furthermore, the display device of one embodiment of the present invention can have a variable refresh rate. For example, the refresh rate can be adjusted (for example, within a range of 0.01 Hz to 240 Hz) depending on the content displayed on the display device, thereby reducing power consumption. Furthermore, driving that reduces the power consumption of the display device by driving it at a reduced refresh rate may be called idling stop (IDS) driving.

[0375] The drive frequency of the touch sensor or near-touch sensor may be changed depending on the refresh rate. For example, if the refresh rate of the display device is 120 Hz, the drive frequency of the touch sensor or near-touch sensor may be set to a frequency higher than 120 Hz (typically 240 Hz). This configuration enables low power consumption and an increased response speed of the touch sensor or near-touch sensor.

[0376] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0377] Embodiment 7 In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the OS transistor described in the above embodiment will be described.

[0378] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. In addition to these, it is preferable that it contains aluminum, gallium, yttrium, tin, etc. 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, etc.

[0379] The metal oxide can be formed by a sputtering method, a CVD method such as an MOCVD method, an ALD method, or the like.

[0380] <Classification of Crystal Structure> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline (CAAC), nanocrystalline (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

[0381] The crystalline structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum. For example, it can be evaluated using an XRD spectrum obtained by a GIXD (Grazing-Incident XRD) measurement. The GIXD method is also called the thin film method or the Seemann-Bohlin method.

[0382] For example, in the case of a quartz glass substrate, the shape of the peak in the XRD spectrum is almost symmetrical. On the other hand, in the case of an IGZO film having a crystalline structure, the shape of the peak in the XRD spectrum is asymmetrical. The asymmetrical shape of the peak in the XRD spectrum clearly indicates the presence of crystals in the film or substrate. In other words, if the shape of the peak in the XRD spectrum is not symmetrical, it cannot be said that the film or substrate is in an amorphous state.

[0383] In addition, the crystalline structure of the film or substrate can be evaluated by a diffraction pattern (also referred to as a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is estimated that the IGZO film formed at room temperature is neither in a crystalline state nor in an amorphous state, but in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0384] <<Structure of Oxide Semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified 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, pseudo-amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0385] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0386] [CAAC-OS] A CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction refers to the thickness direction of the CAAC-OS film, the normal direction to the surface where the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region is also a region with a uniform lattice arrangement. Furthermore, a CAAC-OS has a region where multiple crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that distortion refers to a portion where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with another uniform lattice arrangement in a region where multiple crystalline regions are connected. In other words, a CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

[0387] 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 multiple minute crystals, the size of the crystalline region may be several tens of nanometers.

[0388] In an In-M-Zn oxide (wherein the element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, and the like), 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 the element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and the element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. The In layer may contain the element M. The In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

[0389] When a CAAC-OS film is subjected to structural analysis using an XRD apparatus, for example, a peak indicating c-axis orientation is detected at or near 2θ = 31° in out-of-plane XRD measurement using θ / 2θ scanning. Note that the position of the peak indicating c-axis orientation (the value of 2θ) may vary depending on the type, composition, and the like of the metal elements constituting the CAAC-OS.

[0390] For example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film, and the spots are observed at positions that are point-symmetric with respect to a spot of an incident electron beam that has passed through the sample (also referred to as a direct spot).

[0391] When a 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 a non-regular hexagon. The distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundary can be identified even near the distortion. This indicates that the distortion in the lattice arrangement suppresses the formation of grain boundaries. 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 a-b plane and the change in interatomic bond distance caused by metal atom substitution.

[0392] Note that a crystal structure in which clear grain boundaries are observed is called polycrystalline. The grain boundaries act as recombination centers, and are likely to trap carriers, resulting in a decrease in the on-state current of a transistor and a decrease in field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming a 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.

[0393] 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, the formation of defects, or the like, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (oxygen vacancies, etc.). Therefore, an oxide semiconductor having CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having CAAC-OS is heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0394] [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 does not exhibit regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis 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 peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0395] [a-Like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has pores or low-density regions. 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.

[0396] <<Structure of Oxide Semiconductor>> Next, the above-described CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

[0397] [CAC-OS] CAC-OS is, for example, a material in which elements constituting a metal oxide are unevenly distributed in a size of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or in the vicinity thereof. Note that hereinafter, a state in which one or more metal elements are unevenly distributed in a metal oxide and regions containing the metal elements are mixed in a size 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.

[0398] Furthermore, the CAC-OS has a mosaic structure in which a material is separated into a first region and a second region, and the first region is distributed throughout the film (hereinafter also referred to as a cloud structure). That is, the CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0399] 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.

[0400] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0401] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

[0402] Furthermore, CAC-OS in In—Ga—Zn oxide refers to a structure in which a mosaic of regions containing Ga as the main component and regions containing In as the main component are randomly arranged in a material composition containing In, Ga, Zn, and O. Therefore, it is presumed that CAC-OS has a structure in which metal elements are distributed nonuniformly.

[0403] The CAC-OS can be formed by sputtering without heating the substrate. When the CAC-OS is formed by sputtering, 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 of oxygen gas relative to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate of oxygen gas relative 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.

[0404] Furthermore, for example, in the case of CAC-OS in an In—Ga—Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) can confirm 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.

[0405] 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).

[0406] 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.

[0407] Therefore, when a 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 (a function of turning on / off). In other words, a CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the entire material functions as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using a CAC-OS in a transistor, a high on-current (I ｏｎ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0408] Furthermore, a transistor using the CAC-OS has high reliability, and therefore, the CAC-OS is ideal for various semiconductor devices such as display devices.

[0409] Oxide semiconductors have a variety of structures, each of which has different characteristics. The oxide semiconductor of one embodiment of the present invention may include two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS.

[0410] <Transistor Having Oxide Semiconductor> Next, a case where the oxide semiconductor is used for a transistor will be described.

[0411] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0412] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 １７ cm −３ Below 1 × 10, preferably １５ cm −３ More preferably, 1×10 １３ cm −３ Less than 1×10, more preferably 1×10 １１ cm −３ More preferably, 1×10 １０ cm −３ is less than 1×10 −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.

[0413] 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.

[0414] 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.

[0415] Therefore, in order to stabilize the electrical characteristics of a transistor, it is effective to reduce the impurity concentration in the oxide semiconductor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in the adjacent film. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0416] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0417] When an oxide semiconductor contains silicon or carbon, which is one of 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 Below 2 × 10, preferably １７ atoms / cm ３ The following applies.

[0418] Furthermore, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 １８ atoms / cm ３ Below 2 × 10, preferably １６atoms / cm ３ Do the following:

[0419] 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 5×10 １８ atoms / cm ３ Less than 1×10, more preferably 1×10 １８ atoms / cm ３ or less, more preferably 5 × 10 １７ atoms / cm ３ Do the following:

[0420] Furthermore, hydrogen contained in an oxide semiconductor may react with oxygen bonded to a metal atom to form water, forming an oxygen vacancy. Hydrogen entering the oxygen vacancy may generate electrons as carriers. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. Therefore, it is preferable to reduce 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 1×10 １９ atoms / cm ３ less than 5×10 １８ atoms / cm ３ less than 1×10 １８ atoms / cm ３ Make it less than.

[0421] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0422] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0423] 19 to 26. In the drawings, a region related to a pixel 150 is shown on the left side, and a region related to an auxiliary wiring 151 is shown on the right side.

[0424] [Fabrication Method Example 1] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting a 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, a thermal CVD method, etc. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0425] Thin films (insulating films, semiconductor films, conductive films, resin films, etc.) constituting display devices can be formed by methods such as spin coating, dipping, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, knife coating, etc. These are wet film formation methods.

[0426] When processing the thin film that constitutes the display device, a photolithography method or the like can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method or the like. Furthermore, the thin film may be directly formed by a film formation method using a metal mask or the like.

[0427] There are two typical processing methods using photolithography. One is a method in which a resist mask is formed on the thin film to be processed, the thin film is processed by etching or the like, and then the resist mask is removed. The other is a method in which a photosensitive thin film is formed, and then the thin film is exposed to light and developed to be processed into the desired shape.

[0428] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other examples include ultraviolet light, KrF laser light, and ArF laser light. Extreme ultraviolet (EUV) light, X-rays, and the like may also be used as light for exposure. An electron beam may 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 resist mask is not required.

[0429] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0430] [Preparation of Substrate] Although not shown, a substrate is prepared. A substrate having heat resistance sufficient to withstand at least the subsequent heat treatment can be used as the substrate. When an insulating substrate is used as the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. Furthermore, a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0431] As the substrate, it is preferable to prepare a substrate on which a pixel circuit including a semiconductor element such as a transistor is formed on the semiconductor substrate or insulating substrate. A substrate on which a gate line driver circuit (gate driver), a source line driver circuit (source driver), or the like is formed in addition to the pixel circuit may also be used. Furthermore, a substrate on which an arithmetic circuit, a memory circuit, or the like is formed in addition to the above may also be used.

[0432] [Formation of Insulating Layer 102] As shown in Figure 19A, an insulating layer 102 is formed on the above-described substrate. The insulating layer 102 can be made of an inorganic material or an organic material. An organic material is preferable because it can ensure the flatness of the upper surface of the insulating layer 104. As the organic material, one or more materials selected from acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used. When two or more materials are used, the selected organic materials can be laminated.

[0433] 19A, the insulating layer 102 has a contact hole 158. The contact hole 158 can be formed by photolithography or the like.

[0434] 19A , the conductive layer 160 is formed on the insulating layer 102 and in the contact hole 158. The first wiring layer 151a is also formed on the insulating layer 102. That is, the conductive layer 160 and the first wiring layer 151a are formed on the same formation surface through the same process. Specifically, the conductive film formed on the insulating layer 102 and in the contact hole 158 is processed to obtain the conductive layer 160 and the first wiring layer 151a.

[0435] The conductive layer 160 is electrically connected to a transistor in a pixel circuit. The conductive layer 160 can be processed into an extended shape over the insulating layer 102 and can function as a signal line, a power supply line, a scan line, or the like. The conductive layer 160 may be a conductive layer for electrically connecting a transistor to a lower electrode 111 without functioning as a wiring. The first wiring layer 151a can function as a lower wiring layer of the auxiliary wiring 151 and is processed into an extended shape, a lattice shape, or the like over the insulating layer 102. However, the first wiring layer 151a is not in contact with the conductive layer 160. The first wiring layer 151a can be formed over a wide area over the insulating layer 102 and is preferable as an auxiliary wiring.

[0436] The conductive layer 160 and the first wiring layer 151a can be made of a metal such as aluminum, copper, silver, gold, platinum, chromium, or molybdenum. Furthermore, an alloy of the above metals can be used as the conductive material. The above metals and metal alloys have a relatively low resistivity, and it is preferable that the resistivity be lower than that of the conductive material of the shared electrode to be formed later.

[0437] The conductive layer 160 and the first wiring layer 151a may have a single layer structure containing the above metal or the above alloy, or may have a stacked layer structure containing the above metal material.

[0438] Alternatively, the conductive layer 160 and the first wiring layer 151a may be made of one or more metals selected from titanium, manganese, iron, cobalt, nickel, gallium, zinc, indium, tin, tantalum, tungsten, palladium, yttrium, neodymium, and the like, or an alloy containing these metals. The above-mentioned metals and metal alloys do not have low resistivity compared to the metals in the upper row, so it is preferable to adjust the film thickness or apply a stacked structure.

[0439] [Formation of insulating layer 104] As shown in Figure 19A, an insulating layer 104 is formed on the insulating layer 102. The insulating layer 104 can be made of an inorganic material or an organic material. An organic material is preferable because it can ensure the flatness of the upper surface of the insulating layer 104. As the organic material, one or more materials selected from acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenolic resin, and precursors of these resins can be used. When two or more materials are used, the selected organic materials can be laminated.

[0440] The insulating layer 104 has a contact hole 159. The contact hole 159 can be formed by photolithography or the like, and the conductive layer 160 and part of the first wiring layer 151a are exposed through the contact hole 159. The contact hole 159 is preferably provided at a position that does not overlap with the contact hole 158 but overlaps with the conductive layer 160 provided on the flat top surface of the insulating layer 102. When the contact hole 159 overlaps with the contact hole 158, the diameter of the contact hole 159 in a cross-sectional view is preferably larger than the diameter of the contact hole 158.

[0441] 19A , the conductive layer 161 is formed in the contact hole 159, then the resin layer 163 is formed, and then the conductive layer 162 is formed. The conductive layer 164 described below may be formed without forming the conductive layer 161, the resin layer 163, and the conductive layer 162.

[0442] A conductive film to be a conductive layer 161 is formed over the insulating layer 104 and the contact hole 159. The upper surface of the insulating layer 104 is a surface where the conductive film is formed, and if the upper surface is flat, the conductive film is less likely to be cut.

[0443] The conductive layer 160 and the first wiring layer 151a can be made of a metal such as aluminum, copper, silver, gold, platinum, chromium, or molybdenum. Furthermore, an alloy of the above metals can be used as the conductive material. The above metals and metal alloys have a relatively low resistivity, and it is preferable that the resistivity be lower than that of the conductive material of the shared electrode to be formed later.

[0444] The conductive layer 160 and the first wiring layer 151a may have a single layer structure containing the above metal or a stacked layer structure containing the above metal material.

[0445] The conductive layer 160 and the first wiring layer 151a can be made of one or more metals selected from titanium, manganese, iron, cobalt, nickel, gallium, zinc, indium, tin, tantalum, tungsten, palladium, yttrium, neodymium, and the like, or alloys containing these metals. The above-mentioned metals and metal alloys have lower resistivity than the metals in the upper layer, so it is preferable to adjust the film thickness or apply a stacked structure. The conductive layer 161 can be made of one or more metals selected from aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, neodymium, and the like, or alloys containing these metals.

[0446] If the conductive film has a recess on its surface after being formed, a layer containing a resin as an organic material (hereinafter referred to as a resin layer) 163 may be formed in the recess. The resin layer 163 can reduce unevenness caused by the insulating layer 104, the contact hole 159, and the conductive layer 161.

[0447] It is preferable to use a photosensitive resin as the resin layer 163. In this case, a resin film is first formed, and then the resin film is exposed to light through a photomask, and then a development process is performed to form the resin layer 163. More preferably, in order to adjust the height of the upper surface of the resin layer 163, the upper part of the resin layer 163 may be etched by ashing or the like.

[0448] Furthermore, when a non-photosensitive resin is used as the resin layer 163, the resin layer 163 can be formed by forming a resin film and then etching the upper part of the resin film by ashing or the like. Ashing is carried out until a part of the surface of the conductive film that will become the conductive layer 161 is exposed. The thickness of the resin layer 163 can be optimized by ashing or the like.

[0449] Subsequently, a conductive film to be the conductive layer 162 is formed on the resin layer 163. The conductive layer 162 may include one or more materials selected from the metals and the like shown for the conductive layer 161.

[0450] 19A , a conductive film to be the conductive layer 164 is formed to cover the conductive film to be the conductive layer 161 and the conductive film to be the conductive layer 162. The conductive layer 164 may include one or more metals selected from the metals shown as the conductive layer 161.

[0451] The stack of the conductive layer 161, the conductive layer 162, and the conductive layer 164 can correspond to the lower electrodes 111R, 111G, and 111B. In this embodiment, the lower electrode 111 is used to describe a structure common to the lower electrodes 111R, 111G, and 111B.

[0452] The lower electrode 111 is an electrode that functions as an anode or a cathode. Since the conductive layer 164 is located on the top layer of the lower electrode 111, a specific material that can be used for the conductive layer 164 is preferable in consideration of the work function.

[0453] In addition, a stack of the conductive layers 161, 162, and 164 can correspond to the second wiring layer 151b.

[0454] Then, a resist mask is formed on the three conductive films by photolithography, and unnecessary portions of each conductive film are removed by etching. The resist mask is then removed, so that the conductive layers 161, 162, and 164 can be formed in the same etching process using the same resist mask. The resin layer 163 and the like enable the conductive layer 164 to have a flat top surface.

[0455] Although the conductive layers 161 and 162 are formed in the same etching step using the same resist mask, the conductive layers 161 and 162 may be individually processed using different resist masks. In this case, the conductive layers 161 and 162 are preferably processed so that the conductive layer 162 is included inside the contour of the conductive layer 161 when viewed from above.

[0456] Although the conductive layer 162 and the conductive layer 164, etc. are formed in the same etching step using the same resist mask, the conductive layer 162 and the conductive layer 164, etc. may be individually processed using different resist masks. In this case, it is preferable to process the conductive layer 162 and the conductive layer 164, etc. so that the conductive layer 164 is included inside the contour of the conductive layer 162, etc. when viewed from above.

[0457] 19B , an organic compound film capable of emitting red, green, or blue light is formed to cover the conductive layer 164. In this embodiment, for example, an organic compound film 112fR capable of emitting red light is formed.

[0458] The organic compound film 112fR is a laminate of the functional layers of the light-emitting device, and is formed in order for each functional layer, for example, according to the light-emitting device 550R shown in FIG. 14B described in the fourth embodiment. However, the layer 525 is not formed, but is formed later. The organic compound film 112fR also has a charge generation layer. Note that, since the charge generation layer will be processed later by etching or the like, a material that does not contain alkali metals or alkaline earth metals may be used.

[0459] The functional layer of the organic compound film 112fR can be formed by evaporation (including vacuum evaporation), but is not limited to this, and the functional layer of the organic compound film 112fR can also be formed by sputtering, inkjet, or the like.

[0460] Again, in this embodiment, the electron injection layer is a common layer, so it is not included in the organic compound film 112fR and is formed later. The common layer can be any functional layer located between the light-emitting layer and the common electrode. Of course, without providing a common layer, all functional layers may be separated for each subpixel, as shown in FIG. 14A described in the fourth embodiment.

[0461] Since the organic compound film 112fR does not include an electron injection layer, an electron transport layer is located at the top layer. The electron transport layer is exposed to a subsequent processing process using photolithography. Therefore, it is preferable to use a material having high heat resistance for the electron transport layer. As a material having high heat resistance, for example, a material having a glass transition point of 110° C. or higher and 165° C. or lower, preferably 120° C. or higher and 135° C. or lower, is preferably used.

[0462] The electron transport layer exposed to processing may have a laminated structure. An example of such a laminated structure is a structure in which a second electron transport layer is laminated on a first electron transport layer. Because the first electron transport layer is covered with the second electron transport layer for a period during processing, the first electron transport layer may have lower heat resistance than the second electron transport layer. For example, the second electron transport layer may be made of a material having a glass transition temperature of 110°C or higher and 165°C or lower, preferably 120°C or higher and 135°C or lower, and the first electron transport layer may have a glass transition temperature lower than that of the second electron transport layer, for example, 100°C or higher and 155°C or lower, preferably 110°C or higher and 125°C or lower.

[0463] Since the electron-transporting layer can also be a common layer, it is possible to use the light-emitting layer as the top layer of the organic compound film 112fR. However, damage caused by the processing may enter the light-emitting layer, which may significantly impair reliability. Therefore, when manufacturing a display device of one embodiment of the present invention, it is preferable to perform the above processing after forming a functional layer (for example, an electron-transporting layer) above the light-emitting layer.

[0464] [Deposition of Mask Film 144R] It is preferable to further form a mask layer or the like on the organic compound film 112fR. The mask layer can also prevent damage caused by processing from reaching the light-emitting layer. By applying this method, a highly reliable display panel can be provided. Note that in this specification and the like, the mask layer is located above the organic compound film and has the function of protecting the organic compound film during the manufacturing process. Therefore, as shown in FIG. 19C, a mask film 144R is formed to cover the organic compound film 112fR.

[0465] The mask film 144R is preferably a film having a high etching selectivity with respect to the organic compound film 112fR when etching the organic compound film 112fR. In some cases, the mask film 144R is stacked, and the mask film 144R is preferably a film having a high etching selectivity with respect to an upper mask film (specifically, the mask film 146R) described later. Furthermore, when removing the mask film 144R, it is preferably a film that can be removed by wet etching, which does not damage the organic compound film 112fR.

[0466] The mask film 144R can be formed by various film formation methods such as sputtering, evaporation, CVD, ALD, etc. In particular, the ALD method causes less film formation damage to the layer on which the mask film 144R is formed, so it is preferable to form the mask film 144R directly on the organic compound film 112fR by using the ALD method.

[0467] The mask film 144R may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic film, such as an insulating film containing an inorganic or organic material.

[0468] The mask film 144R 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.

[0469] The mask film 144R can 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, indium tin oxide containing silicon can be used.

[0470] The present invention can also be applied to a case where an element M (wherein M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used instead of the gallium. In particular, it is preferable that M is one or more selected from gallium, aluminum, and yttrium.

[0471] The mask film 144R may also include an inorganic material. Examples of inorganic materials that can be used include oxides such as aluminum oxide, hafnium oxide, and silicon oxide, nitrides such as silicon nitride and aluminum nitride, and oxynitrides such as silicon oxynitride. Such inorganic materials can be formed using a film formation method such as a sputtering method, a CVD method, or an ALD method.

[0472] The mask film 144R may also contain an organic material. For example, a material that can be dissolved in a chemically stable solvent for the organic compound film 112fR may be used as the organic material. In particular, a material that dissolves in water or alcohol is preferably used for the mask film 144R. When forming the mask film 144R, it is preferable to apply the mask film 144R by dissolving it in a solvent such as water or alcohol using a wet film formation method, 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 functional layers such as the light-emitting layer.

[0473] The mask film 144R can be formed by a wet film forming method.

[0474] The mask film 144R may be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. Alternatively, the mask film 144R may be made of a fluororesin such as perfluoropolymer.

[0475] 19C, a mask film 146R is formed on the mask film 144R. In this embodiment, the mask films are stacked, but it is also possible to protect the organic compound film 112fR by using only the mask film 144R or only the mask film 146R as a single-layer mask film.

[0476] The mask film 146R may be used as a hard mask when etching the mask film 144R later. After processing the mask film 146R, the mask film 144R is exposed. Therefore, when using the mask film 146R as a hard mask, it is preferable to select a combination of the mask films 144R and 146R that has a high etching selectivity relative to each other.

[0477] The mask film 146R can be selected from various materials depending on the etching conditions of the mask film 144R and the etching conditions of the mask film 146R. For example, the mask film 146R can be selected from among the films that can be used for the mask film 144R, and a material different from that of the mask film 144R can be selected.

[0478] For example, an oxide film or an oxynitride film can be used as the mask film 146R. Typical oxide films or oxynitride films include silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, and hafnium oxynitride.

[0479] The mask film 146R may be, for example, a nitride film. Typical nitride films include silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride.

[0480] As a combination of the mask film 144R and the mask film 146R, for example, an inorganic material such as aluminum oxide, hafnium oxide, or silicon oxide formed by the ALD method can be used as the mask film 144R, and a metal oxide containing indium such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO) formed by the sputtering method can be used as the mask film 146R.

[0481] Furthermore, the mask film 146R to be combined with the mask film 144R may be made of one or more metals selected from tungsten, molybdenum, copper, aluminum, titanium, tantalum, etc., or an alloy containing such metals. When the mask film 146R is formed as a hard mask, it is preferable to use the above metals or alloys. When the mask film 146R is formed as a hard mask, it is preferable to make the film thickness of the mask film 146R larger than the film thickness of the mask film 144R.

[0482] 20A, a resist mask 143R is formed on the mask film 146R at a position overlapping the conductive layer 164. At this time, no resist mask is formed at a position overlapping the auxiliary wiring 151.

[0483] The resist mask 143R can be made of a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.

[0484] When a material that dissolves the organic compound film 112fR is used in a solvent for the resist material, if the mask film 146R is not provided and there are defects such as pinholes in the mask film 144R, there is a risk that the organic compound film 112fR etc. will dissolve. In this case, by positioning the mask film 146R on the mask film 144R when forming the resist mask 143R, it is possible to prevent such a problem from occurring.

[0485] When a material that does not dissolve the organic compound film 112fR is used as a solvent for the resist material, there are cases where the resist mask 143R may be formed directly on the mask film 144R without providing the mask film 146R.

[0486] [Etching of Mask Film 146R] As shown in FIG. 20B, a portion of the mask film 146R that is not covered by the resist mask 143R is removed by etching to form a mask layer 147R.

[0487] When etching the mask film 146R, it is preferable to use etching conditions with a high selectivity so that the mask film 144R is not removed by the etching. The etching of the mask film 146R can be performed by wet etching or dry etching.

[0488] 20B, the resist mask 143R is removed. The resist mask 143R can be removed by wet etching or dry etching. In particular, it is preferable to remove the resist mask 143R by dry etching (also called plasma ashing) using oxygen gas as an etching gas.

[0489] The resist mask 143R is removed while the organic compound film 112fR is covered with the mask film 144R, thereby preventing processing damage to the organic compound film 112fR. In particular, contact of oxygen with the organic compound film 112fR can adversely affect its characteristics. Therefore, when etching is performed using the oxygen gas, it is advisable to perform the etching while the organic compound film 112fR is covered with the mask film 144R. Furthermore, even when the resist mask 143R is removed by wet etching, the organic compound film 112fR does not come into contact with the chemical solution, thereby preventing the organic compound film 112fR from being dissolved.

[0490] [Etching of Mask Film 144R] As shown in FIG. 20C, the mask layer 147R is used as a hard mask to remove a portion of the mask film 144R by etching, thereby forming a mask layer 145R.

[0491] The mask film 144R can be etched by wet etching or dry etching.

[0492] [Etching of Organic Compound Film 112fR] As shown in FIG. 21A, a part of the organic compound film 112fR that is not covered by the mask layer 145 is removed by etching to form an organic compound layer 112R.

[0493] For etching the organic compound film 112fR, it is preferable to use dry etching using an etching gas that does not contain oxygen as a main component. This is because, as mentioned above, contact of oxygen with the organic compound film 112fR may adversely affect the characteristics. Specifically, the organic compound film 112fR may be altered in quality, but using an etching gas that does not contain oxygen as a main component can suppress the alteration and realize a highly reliable display device. An example of an etching gas that does not contain oxygen as a main component is CF ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H ２ Alternatively, a rare gas such as He may be used. A mixed gas of the above gas and a dilution gas not containing oxygen may be used as the etching gas.

[0494] The etching of the organic compound film 112fR is not limited to the above, and may be dry etching using other gases or wet etching.

[0495] Furthermore, when dry etching is performed on the organic compound film 112fR using oxygen gas or a mixed gas containing oxygen gas as an etching gas, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate, thereby reducing damage caused by etching. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed. For example, a mixed gas obtained by adding oxygen gas to the above-mentioned etching gas that does not contain oxygen as a main component can be used as the etching gas.

[0496] After etching, the taper angle of the end face of the organic compound layer 112R preferably satisfies the range of 45 degrees or more and less than 90 degrees.

[0497] 21B , the organic compound layer 112G is formed using a mask layer 145G and a mask layer 147G, following the steps from the deposition to the etching of the organic compound film 112fR. The organic compound layer 112G is an organic compound layer corresponding to a green light-emitting device.

[0498] 21B , referring to the process from the formation to the etching of the organic compound film 112fR, the organic compound layer 112B is formed using the mask layer 145B and the mask layer 147B. The organic compound layer 112B is an organic compound layer corresponding to a blue light-emitting device.

[0499] No organic compound film is disposed on the second wiring layer 151b, and the second wiring layer 151b is exposed. Specifically, the conductive layer 164, which is the top layer of the second wiring layer 151b, is exposed.

[0500] When there is no need to distinguish between the organic compound layers 112R, 112G, and 112B, the organic compound layer 112 is used. Slits 118 are formed between the organic compound layers 112R, 112G, and 112B. That is, the organic compound layer 112 obtained through a processing step using photolithography can have the width of the slits 118, indicated by the arrows in FIG. 21B, of 8 μm or less, 3 μm or less, 2 μm or less, or 1 μm or more. The width of the slits 118 corresponds to the distance between each subpixel and can be determined by measuring the distance between the bottom ends of the organic compound layers 112. By narrowing the distance between each subpixel, a display device with high definition and a large aperture ratio can be provided.

[0501] As shown by the slits 118, adjacent organic compound layers 112 are separated or spaced apart from each other, which divides the leakage path of current and suppresses leakage current (also referred to as side leakage current). This makes it possible to increase the luminance, contrast, display quality, power efficiency, or power consumption of the light-emitting device.

[0502] The end faces of adjacent organic compound layers 112 preferably face each other across the slit 118. However, in organic compound layers formed using a metal mask, the end faces cannot face each other. The shape in which the end faces face each other clearly distinguishes the organic compound layers formed using a metal mask.

[0503] When the organic compound film is etched, the insulating layer 104 is exposed. Therefore, a recess may be formed in the insulating layer 104 in a region overlapping with the slit 118. If the formation of a recess is not desired, it is preferable to use a film that is highly resistant to etching of the organic compound film as the insulating layer 104. For example, it is preferable to use an insulating film containing an inorganic material as the insulating layer 104.

[0504] [Removal of Mask Layers] As shown in FIG. 21C, the mask layers 147R, 147G, and 147B are removed to expose the upper surfaces of the mask layers 145R, 145G, and 145B.

[0505] [Formation of Insulating Layer 125f] As shown in FIG. 22A, an insulating layer 125f is formed to cover the mask layers 145R, 145G, and 145B and the second wiring layer 151b.

[0506] The insulating layer 125f functions as a barrier layer that prevents impurities such as water from diffusing into the organic compound layer 112. The insulating layer 125f is preferably formed by an ALD method, which has excellent step coverage, because it can suitably cover the side surfaces of the organic compound layer 112.

[0507] It is preferable to use the same film for the insulating layer 125f as the mask layers 145R, 145G, and 145B and the mask layers 147R, 145G, and 145B, since these can be easily removed simultaneously during etching in a later step. For example, it is preferable to use one or more inorganic materials selected from aluminum oxide, hafnium oxide, silicon oxide, and the like, formed by the ALD method, for the insulating layer 125f, the mask layers 145R, 145G, and 145B, and the mask layers 147R, 145G, and 145B.

[0508] The material that can be used for the insulating layer 125f is not limited to this, and for example, any material that can be used for the mask layers 145R, 145G, and 145B can be used as appropriate.

[0509] 22A , the insulating layer 126 is formed in areas overlapping with the slits 118, etc. The insulating layer 126 can be formed by the same method as the resin layer 163. For example, the insulating layer 126 can be formed by forming a photosensitive resin, followed by exposure and development. The insulating layer 126 may also be formed by forming the resin over the entire surface, and then etching part of the resin by ashing or the like.

[0510] Here, the insulating layer 126 has a width larger than that of the slit 118. The insulating layer 126 has an opening in a region overlapping with part of the top surface of the second wiring layer 151b.

[0511] [Etching of Insulating Layer 125f and Mask Layer 145] As shown in FIG. 22B , portions of the insulating layer 125f and the mask layers 145R, 145G, and 145B that are not covered by the insulating layer 126 are removed by etching, exposing a portion of the top surface of the organic compound layer 112. In the region overlapping the insulating layer 126, portions of the insulating layer 125f and the mask layers 145R, 145G, and 145B (indicated by 145 in the figure) remain. The center of the insulating layer 126 is preferably located above the edges of the insulating layer 126, and the center should be raised higher than the edges. The center of the insulating layer 126 is preferably located above the top surface of the organic compound layer 112. Furthermore, the edges of the insulating layer 126 should be tapered.

[0512] The insulating layer 125f and the mask layers 145R, 145G, and 145B are preferably etched in the same process. In particular, the mask layers 145R, 145G, and 145B are preferably etched by wet etching, which causes less etching damage to the organic compound layer 112. For example, wet etching using a tetramethylammonium hydroxide (TMAH) aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof is preferably used. Furthermore, when using the wet etching method, a mixed acid solution containing water, phosphoric acid, dilute hydrofluoric acid, and nitric acid may be used. The chemical solution used in the wet etching process may be alkaline or acidic.

[0513] It is preferable to remove at least one of the insulating layer 125f and the mask layers 145R, 145G, and 145B by dissolving them in a solvent such as water or alcohol. Here, various alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), and glycerin can be used as the alcohol capable of dissolving the insulating layer 125f and the mask layers 145R, 145G, and 145B.

[0514] After removing the insulating layer 125f and the mask layers 145R, 145G, and 145B, it is preferable to perform drying treatment to remove water contained inside the organic compound layer 112 and the like and water adsorbed to the surface. For example, it is preferable to perform 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 drying can be performed at a lower temperature.

[0515] By removing a portion of the insulating layer 125f, a portion of the upper surface of the second wiring layer 151b is exposed.

[0516] [Formation of Common Layer 114] As shown in FIG. 22C, the common layer 114 is formed to cover the organic compound layer 112, the insulating layer 125, the mask layer 145, the insulating layer 126, and the like.

[0517] The common layer 114 can be made of the materials that can be used for the electron injection layer described above, such as alkali metals, alkaline earth metals, or compounds thereof.

[0518] The common layer 114 can be formed by a method similar to that for the organic compound film 112fR and the like, and is preferably formed by evaporation.

[0519] [Formation of Common Electrode 113b] As shown in FIG. 22C, the common electrode 113b is formed to cover the common layer 114.

[0520] The common electrode 113b can be formed by a film formation method such as evaporation or sputtering, or by stacking a film formed by evaporation and a film formed by sputtering.

[0521] The common electrode 113b is preferably formed so as to encompass the region where the common layer 114 is formed.

[0522] In this embodiment, the common layer 114 is located between the conductive layer 164 of the second wiring layer 151b and the common electrode 113b. When the common layer 114 is located, it is preferable to use a material with low electrical resistance for the common layer 114. Alternatively, it is preferable to reduce the electrical resistance in the thickness direction of the common layer 114 by forming the common layer 114 thin. For example, by using a material with electron injecting or hole injecting properties and a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the common layer 114, the electrical resistance between the conductive layer 164 and the common electrode 113b can be reduced to a negligible level.

[0523] In the present invention, the common layer 114 does not have to be located between the second wiring layer 151b and the common electrode 113b. In this case, the common layer 114 is formed to cover the area other than the light-emitting device. Alternatively, the common layer 114 is formed in the areas of the light-emitting device and auxiliary wiring, and the common layer 114 in the area of ​​the auxiliary wiring is removed.

[0524] [Formation of Protective Layer] As shown in Figure 22C, a protective layer 121 is formed on the common electrode 113b. The inorganic insulating film used for the protective layer 121 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. Furthermore, the inkjet method is preferably used to form the organic insulating film, because it can form a uniform film in the desired area.

[0525] 23A , a substrate 170 is bonded using an adhesive layer 171. When the display device has a hollow sealing structure, the substrate 170 may be bonded using a sealant or the like. When the substrates are bonded using a sealant, a space is generated, and the space may be filled with an inert gas (a gas containing nitrogen or argon).

[0526] The adhesive layer 171 may be made of an organic material such as a reaction-curing adhesive, a photo-curing adhesive, a thermosetting adhesive, and / or an anaerobic adhesive.

[0527] Specifically, adhesives containing epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, EVA (ethylene vinyl acetate) resin, etc. can be used for the adhesive layer 171, etc.

[0528] 23B , a light-shielding layer 149 and color filters 148R, 148G, and 148B may be provided on the substrate 170. The light-shielding layer 149 is provided in a region overlapping with the insulating layer 126. The substrate 170 may be attached so that the color filters 148R, 148G, and 148B overlap the lower electrodes 111R, 111G, and 111B, respectively.

[0529] The color filters 148 R, 148 G, and 148 B may be provided on the protective layer 121 instead of on the substrate 170 .

[0530] The color filters 148R, 148G, and 148B can be formed at desired positions by an ink jet method, an etching process using photolithography, or the like.

[0531] The light emitted to the common electrode 113b side is colored by the color filters 148R, 148G, and 148B, which absorb light in a predetermined wavelength range, and is then emitted to the outside through the substrate 170, enabling full-color display.

[0532] 24A to 24C, etc. In the drawings, a region related to the pixel 150 is shown on the left side, and a region related to the auxiliary wiring 151 is shown on the right side.

[0533] As in the above-described Manufacturing Method Example 1, a substrate is prepared, and an insulating layer 102a is formed as shown in FIG. 24A . The insulating layer 102a can be formed of the same material as the insulating layer 102 in the above-described Manufacturing Method Example 1. Next, a contact hole 158 is formed in the insulating layer 102a in the same manner as in the above-described Manufacturing Method Example 1, and a conductive layer 160a is formed in the contact hole 158. The conductive layer 160a can be formed of the same material as the conductive layer 160 in the above-described Manufacturing Method Example 1. The conductive layer 160a can correspond to the first wiring layer 151a1 of the auxiliary wiring.

[0534] The conductive layer 160 a has a shape that conforms to the shape of the contact hole 158 , and therefore has a recess in the region that overlaps with the contact hole 158 .

[0535] Next, the insulating layer 102b is formed. The insulating layer 102b is preferably formed using a material that can fill the recessed portion. Therefore, the insulating layer 102b is preferably formed using an organic material among the materials described for the insulating layer 102 in the above-described Manufacturing Method Example 1.

[0536] Next, a conductive layer 160b is formed over the insulating layer 102b. The conductive layer 160a can be formed using a material similar to that of the conductive layer 160 in Manufacturing Method Example 1. The conductive layer 160b is formed to have a region overlapping with the conductive layer 160a. The conductive layer 160b can correspond to the first wiring layer 151a2 of the auxiliary wiring.

[0537] 24B, an insulating layer 104 is formed. The insulating layer 104 can be formed using the same material as the insulating layer 104 in the above-described Manufacturing Method Example 1.

[0538] Next, a contact hole 159a is formed in the insulating layer 104, the conductive layer 160b, and the insulating layer 102b. The contact hole 159a formed in a plurality of materials at once may be referred to as a through contact or a through contact hole. The contact hole 159a can be formed in the same manner as the contact hole 159 in the above-described manufacturing method example 1. It is preferable to form the contact hole 159a by dry etching, which allows the sidewall surface of the contact hole 159a to be processed cleanly. The etching gas may be, for example, CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H ２ Alternatively, rare gases such as He may be used.

[0539] 24C , a conductive layer 161 is formed in the contact hole 159a. The conductive layer 161 can be formed of a material similar to that of the conductive layer 161 in the above-described Manufacturing Method Example 1. The conductive layer 161 has a region in contact with a side surface of the conductive layer 160b, ensuring electrical connection. This structure is sometimes referred to as a side contact.

[0540] The conductive layer 161 has a shape that conforms to the shape of the contact hole 159a, and therefore has a recess in the region that overlaps with the contact hole 159a.

[0541] Next, a resin layer 163 is formed. The resin layer 163 is preferably formed using a material that can fill the recesses. The resin layer 163 may be formed using the material described for the resin layer 163 in the above-described Manufacturing Method Example 1.

[0542] Next, a conductive layer 162 is formed. The conductive layer 162 can be formed using a material similar to that of the conductive layer 162 in Manufacturing Method Example 1.

[0543] Thereafter, a conductive layer 164 is formed. The conductive layer 164 can be formed using a material similar to that of the conductive layer 164 in Manufacturing Method Example 1. Through these steps, the lower electrodes 111R, 111G, and 111B and the auxiliary wiring 151 each having a stacked structure of the conductive layer 164, the conductive layer 162, and the conductive layer 161 can be formed. The auxiliary wiring 151 in this embodiment is preferably multilayered.

[0544] After such a configuration, the steps from forming an organic compound film and the like to attaching an opposing substrate are carried out in the same manner as in the above-described Example 1 of Manufacturing Method, whereby a display device can be manufactured.

[0545] Forming a through contact as in manufacturing method 2 is preferable because when a plurality of contact holes are formed, the contact holes overlap each other without being misaligned, and therefore a high aperture ratio can be maintained.

[0546] [Manufacturing Method Example 3] An example of a manufacturing method for a display device that is different from the above-described methods will be described with reference to Fig. 25 etc. In the drawing, a region related to a pixel 150 is shown on the left side, and a region related to an auxiliary wiring 151 is shown on the right side.

[0547] 25, a substrate is prepared in the same manner as in the above-described manufacturing method examples 1 and 2, and as shown in FIG. 25, the steps up to the insulating layer 104 are formed in the same manner as in the above-described manufacturing method 2. A contact hole 159b is formed in the insulating layer 104. The contact hole 159b may also be referred to as a through contact or a through contact hole.

[0548] When the contact hole 159b is divided into upper and lower parts with the conductive layer 160b as the boundary, the diameter of the contact hole formed above the conductive layer 160b is larger than the diameter of the contact hole formed below the conductive layer 160b. The contact hole 159b is preferably formed by dry etching in the same manner as the contact hole 159a. The etching gas may be, for example, CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H２ Alternatively, rare gases such as He may be used.

[0549] 25, a conductive layer 161 is formed in the contact hole 159b. The conductive layer 161 can be formed of a material similar to that of the conductive layer 161 in Manufacturing Method Example 1. The conductive layer 161 has regions in contact with the side and top surfaces of the conductive layer 160b, ensuring electrical connection. Such a structure in contact with the side surfaces is sometimes referred to as a side contact.

[0550] Thereafter, a resin layer 163, a conductive layer 161, a conductive layer 162, and a conductive layer 164 are formed in the same manner as in the above-described manufacturing method 2. Through these steps, the lower electrodes 111R, 111G, and 111B and the auxiliary wiring 151 each having a stacked structure of the conductive layer 164, the conductive layer 162, and the conductive layer 161 can be formed. The auxiliary wiring 151 of this embodiment is preferably multilayered.

[0551] After such a configuration, the steps from forming an organic compound film and the like to attaching an opposing substrate are carried out in the same manner as in the above-described Example 1 of Manufacturing Method, whereby a display device can be manufactured.

[0552] Forming a through contact having contact holes of different diameters as in manufacturing method 3 is preferable because it not only allows the aperture ratio to be maintained high, but also increases the contact surface, i.e., the contact area, between the conductive layers at the through contact.

[0553] [Manufacturing Method Example 4] An example of a manufacturing method for a display device that is different from the above-described methods will be described with reference to Fig. 26 etc. In the drawing, a region related to a pixel 150 is shown on the left side, and a region related to an auxiliary wiring 151 is shown on the right side.

[0554] A substrate is prepared in the same manner as in Manufacturing Method Examples 1 to 3. As shown in FIG. 26 , an insulating layer 102 is formed and a contact hole 158 is formed in the same manner as in Manufacturing Method Example 1. Then, a conductive layer 160 is formed in the contact hole 158 in the same manner as in Manufacturing Method Example 1.

[0555] Next, similarly to the above-described Manufacturing Method Example 1, the insulating layer 104 is formed over the conductive layer 160. When the contact hole 159a is formed in the insulating layer 104, it serves as the through contact or the through contact hole of the above-described Manufacturing Method Examples 2 and 3.

[0556] Next, a conductive layer 161 is formed in the contact hole 159a in the same manner as in Manufacturing Method Example 1. The conductive layer 161 can be in contact with the side surface and top surface of the conductive layer 160. Thereafter, a resin layer 163, a conductive layer 162, and a conductive layer 164 are formed in the same manner as in Manufacturing Method Example 1. Through these steps, the lower electrodes 111R, 111G, and 111B and the auxiliary wiring 151 each having a stacked structure of the conductive layer 164, the conductive layer 162, and the conductive layer 161 can be formed. The auxiliary wiring 151 in this embodiment is preferably multilayered.

[0557] After such a configuration, the steps from forming an organic compound film and the like to attaching an opposing substrate are carried out in the same manner as in the above-described Example 1 of Manufacturing Method, whereby a display device can be manufactured.

[0558] Forming a through contact as in manufacturing method 4 is preferable because it allows maintaining a high aperture ratio.

[0559] In this manner, a display device can be manufactured.

[0560] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0561] Embodiment 9 In this embodiment, a display device according to one embodiment of the present invention will be described with reference to drawings.

[0562] [Specific Example of Display Device] One mode of the display device described in the above embodiment is a display module DP attached with an FPC 74. A large display device using a plurality of display modules DP will be described with reference to FIG.

[0563] 27A shows a top view of the display module DP. The display module DP has a region 72 adjacent to the pixel portion 103 that transmits visible light and a region 73 that blocks visible light.

[0564] 27B and 27C are perspective views of a display device having four display modules DP. By arranging the multiple display modules DP in one or more directions (for example, in a line or in a matrix), a large display device having a wide display area can be manufactured.

[0565] When a large display device is manufactured using multiple display modules DP, the size of each display module DP does not need to be large. Therefore, the manufacturing equipment for manufacturing the display module DP does not need to be large, and space can be saved. Furthermore, manufacturing equipment for small and medium-sized display panels can be used, and new manufacturing equipment does not need to be used to enlarge the display device, thereby reducing manufacturing costs. Furthermore, the decrease in yield due to the enlargement of the display module DP can be suppressed.

[0566] A non-display area where wiring and the like are routed is located on the periphery of the pixel unit 103. The non-display area corresponds to the area 73 that blocks visible light. When multiple display modules DP are stacked, the non-display area and the like may cause a single image to be viewed as if it were separated.

[0567] Therefore, in one embodiment of the present invention, a region 72 that transmits visible light is provided in the display module DP, and in two overlapping display modules, the pixel portion 103 of the display module DP located on the lower side is overlapped with the region 72 that transmits visible light of the display module DP located on the upper side.

[0568] By providing the visible light transmitting region 72 in this manner, it is not necessary to actively reduce the non-display region of the display module DP. However, when two display modules DP are stacked, the non-display region is reduced, which is preferable. This allows for the realization of a large display device in which the seams between the display modules DP are difficult for users to notice.

[0569] The display module DP located on the upper side may have a region 72 that transmits visible light in at least a part of the non-display region. The region 72 that transmits visible light can be overlapped with the pixel unit 103 of the display module DP located on the lower side.

[0570] Furthermore, at least a part of the non-display region of the display module DP located on the lower side overlaps with the pixel section 103 or the region 73 that blocks visible light of the display module DP located on the upper side.

[0571] If the non-display area of ​​the display module DP is wide, the distance between the edge of the display module DP and the elements within the display module DP becomes long, which is preferable because it can prevent the elements from being deteriorated by impurities entering from outside the display module DP.

[0572] In this way, when a plurality of display modules DP are provided in a display device, the pixel portions 103 are continuous between adjacent display modules DP, so that a display region with a large area can be provided.

[0573] The pixel section 103 includes a plurality of pixels.

[0574] The region 72 that transmits visible light may be provided with a resin material or the like for sealing the pair of substrates that constitute the display module DP and the display elements sandwiched between the pair of substrates. In this case, a material that is translucent to visible light is used for the member provided in the region 72 that transmits visible light.

[0575] The region 73 that blocks visible light may be provided with wirings or the like electrically connected to pixels included in the pixel portion 103. The region 73 that blocks visible light may also be provided with one or both of a scanning line driver circuit and a signal line driver circuit. The region 73 that blocks visible light may also be provided with terminals connected to the FPC 74, wirings or the like connected to the terminals.

[0576] 27B and 27C show examples in which the display modules DP shown in Fig. 27A are arranged in a 2 × 2 matrix (two in the vertical direction and two in the horizontal direction). Fig. 27B is a perspective view of the display surface side of the display module DP, and Fig. 27C is a perspective view of the side opposite to the display surface of the display module DP.

[0577] The four display modules DP (display modules DPa, DPb, DPc, and DPd) are arranged so as to have overlapping regions. Specifically, the display modules DPa, DPb, DPc, and DPd are arranged so that a visible light-transmitting region 72 (72a of display module DPa, 72b of display module DPb, 72c of display module DPc, and 72d of display module DPd) of one display module DP has a region that overlaps on top (on the display surface side) of the pixel unit 103 of the other display modules DP. Furthermore, the display modules DPa, DPb, DPc, and DPd are arranged so that a visible light-blocking region 73 of each display module DP does not overlap on the pixel unit 103 of the other display modules DP. In the overlapping portion of the four display modules DP, the display module DPb overlaps the display module DPa, the display module DPc overlaps the display module DPb, and the display module DPd overlaps the display module DPc.

[0578] The short sides of the display modules DPa and DPb overlap each other, so that part of the pixel unit 103a overlaps with part of the region 72b that transmits visible light, and the long sides of the display modules DPa and DPc overlap each other, so that part of the pixel unit 103a overlaps with part of the region 72c that transmits visible light.

[0579] A part of the pixel portion 103b overlaps with a part of the region 72c that transmits visible light and a part of the region 72d that transmits visible light. Also, a part of the pixel portion 103c overlaps with a part of the region 72d that transmits visible light.

[0580] Therefore, a region where the pixel portions 103 a to 103 d are arranged almost seamlessly can be used as a display region 79 .

[0581] Here, the display module DP is preferably flexible, for example, the pair of substrates constituting the display module DP are preferably flexible.

[0582] As a result, for example, as shown in Figures 27B and 27C, the vicinity of the FPC 74a of the display module DPa can be curved, and a portion of the display module DPa and a portion of the FPC 74a can be arranged below the pixel portion 103b of the display module DPb adjacent to the FPC 74a. As a result, the FPC 74a can be arranged without physically interfering with the rear surface of the display module DPb. Furthermore, when stacking and fixing the display modules DPa and DPb, the thickness of the FPC 74a does not need to be considered, so the difference in height between the top surface of the visible light-transmitting region 72b and the top surface of the display module DPa can be reduced. As a result, the edge of the display module DPb located above the pixel portion 103a can be made less noticeable. As shown in Figure 27C, the FPC 74c of the display module DPc can also be curved in the same way as the FPC 74a.

[0583] Furthermore, by providing flexibility to each display module DP, the display module DPb can be gently curved so that the height of the upper surface of the pixel portion 103b of the display module DPb matches the height of the upper surface of the pixel portion 103a of the display module DPa. This makes it possible to align the heights of the display areas except for the area near where the display modules DPa and DPb overlap, thereby improving the display quality of the image displayed in the display area 79.

[0584] Although the relationship between the display module DPa and the display module DPb has been described above as an example, the same applies to any other two adjacent display modules DP.

[0585] In order to reduce the step between two adjacent display modules DP, it is preferable that the thickness of the display module DP is thin. For example, the thickness of the display module DP is preferably 1 mm or less, more preferably 300 μm or less, and even more preferably 100 μm or less.

[0586] The display module DP preferably incorporates both a scanning line driver circuit and a signal line driver circuit. When the driver circuit is arranged separately from the display panel, a printed circuit board including the driver circuit, numerous wirings, terminals, etc., are arranged on the back side of the display panel (the side opposite the display surface). This can result in a huge number of components in the entire display device, which can increase the weight of the display device. By incorporating both a scanning line driver circuit and a signal line driver circuit in the display module DP, the number of components in the display device can be reduced, making the display device lighter. This can increase the portability of the display device.

[0587] Here, the scanning line driver circuit and the signal line driver circuit are required to operate at a high driving frequency according to the frame frequency of the image to be displayed. In particular, the signal line driver circuit is required to operate at a driving frequency even higher than that of the scanning line driver circuit. Therefore, some of the transistors used in the signal line driver circuit may be required to have the ability to pass a large current. On the other hand, some of the transistors provided in the pixel portion may be required to have sufficient voltage resistance to drive the display element.

[0588] Therefore, it is preferable to differentiate the structures of the transistors in the driver circuit from those in the pixel portion, for example, by using a high-voltage transistor as one or more of the transistors in the pixel portion and using a transistor with a high driving frequency as one or more of the transistors in the driver circuit.

[0589] In a more specific configuration, one or more transistors used in the signal line driver circuit have a thinner gate insulating layer than a transistor used in a pixel portion. By fabricating two types of transistors in this way, the signal line driver circuit can be fabricated over a substrate on which a pixel portion is provided.

[0590] In addition, it is preferable that a metal oxide be used as a semiconductor in which a channel is formed in each of the transistors applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion.

[0591] In addition, it is preferable that silicon be used as a semiconductor in which a channel is formed in each of the transistors applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion.

[0592] In addition, it is preferable that each transistor applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion be a combination of a semiconductor in which a channel is formed using a metal oxide and a semiconductor in which a channel is formed using silicon.

[0593] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0594] In this embodiment, a large display device using a plurality of flexible display modules DP will be described with reference to Figs. 28 and 29. The large display device using a plurality of display modules DP has a curved display surface. When viewing such a large display device, a sense of immersion can be obtained.

[0595] Fig. 28A shows a cross-sectional view of a display device in which a pixel portion is provided on a support 22 having a curved surface. Although the FPC is omitted in Fig. 28A, an FPC can be provided in the same manner as in the above embodiment. Fig. 29A shows an enlarged view of the area 20 surrounded by the dotted line in Fig. 28A.

[0596] The support 22 can also be called a housing or a support member, and is formed using a material that can have a curved surface in part. For example, when a display device is provided inside a vehicle, the support 22 can be made of plastic, metal, glass, rubber, or the like. Note that although the support 22 is shown in a plate shape in FIG. 28A , the shape of the support 22 is not limited to a plate shape, and the support 22 may have any shape as long as it has a curved surface in part.

[0597] In Figure 28A, four display modules, a first display module 16a, a second display module 16b, a third display module 16c, and a fourth display module 16d, are arranged side by side. The pixel sections of each display module can be arranged side by side to form a single display surface. In the display device of Figure 28A, an example in which four display modules form a single display surface is shown, but this is not particularly limited, and two or more display modules can form a single display surface. The arrow in Figure 28A indicates the light-emitting direction 19a of the third display module 16c.

[0598] The wiring layer 12 is provided on the support 22. The wiring layer 12 has a plurality of wires. At least one of the plurality of wires is electrically connected to an electrode of the second display module 16b. In addition to the wires, the wiring layer 12 also has an insulating film covering the wires. Contact holes are provided in the insulating film, and the plurality of wires of the wiring layer 12 can be electrically connected to the electrodes of each display module through the contact holes. The wires of the wiring layer 12 can also function as connection wires, power lines, signal lines, fixed potential lines, or the like.

[0599] The wiring of the wiring layer 12 can be formed on the support 22 by a method of selectively forming a silver paste, a transposition method, or a transfer method.

[0600] In the display device shown in FIG. 28A , the wiring of the wiring layer 12 can also function as a common wiring. A common wiring is a wiring that can be shared by at least the first display module 16 a and the second display module 16 b. For example, the wiring of the wiring layer 12 can be electrically connected to the electrode of the first display module 16 a and also electrically connected to the electrode of the second display module 16 b. The common wiring may also be shared with the third display module 16 c, etc. Such common wiring may preferably function as a power supply line.

[0601] The viewing surfaces of the first display module 16a, the second display module 16b, and the third display module 16c may be covered with a cover material 13. The cover material 13 may be bonded to each display module using a resin 24 or the like, as shown in FIG. 29A . For example, by adjusting the refractive index of the resin 24, it is possible to make less noticeable lines (vertical or horizontal stripes) that may appear near the boundaries between the first display module 16a, the second display module 16b, and the third display module 16c. Furthermore, a configuration in which the cover material 13 is bonded with the resin 24 can firmly fix the first display module 16a, the second display module 16b, the third display module 16c, and the fourth display module 16d.

[0602] Examples of materials that can be used as the cover material 13 include polyimide (PI), aramid, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), nylon, polyetheretherketone (PEEK), polysulfone (PSF), polyetherimide (PEI), polyarylate (PAR), polybutylene terephthalate (PBT), and silicone resin. A substrate made of any of the above materials can be referred to as a plastic substrate. Plastic substrates are light-transmitting and have a film shape.

[0603] The cover material 13 may be formed using an optical film (a polarizing film, a circularly polarizing film, or a light-scattering film). Alternatively, the cover material 13 may be a laminated film in which a plurality of optical films are laminated.

[0604] 29A , an edge of the second display module 16b overlaps an edge of the third display module 16c. An electrode 18b of the third display module 16c is provided in the overlapping region, and the electrode 18b is electrically connected to the wiring of the wiring layer 12. By overlapping the periphery of the electrode 18b with the edge of the pixel portion of the second display module 16b, lines (vertical or horizontal stripes) that may appear near the boundary between the third display module 16c and the second display module 16b can be made less noticeable.

[0605] In addition, by arranging a light-shielding layer such as a black matrix so that it overlaps the boundary, lines (vertical or horizontal stripes) that may appear near the boundary between the third display module 16c and the second display module 16b can be made less noticeable.

[0606] Furthermore, by overlapping the periphery of the electrode 18a of the second display module 16b with the edge of the pixel portion of the first display module 16a, lines (vertical or horizontal stripes) that may appear near the boundary between the first display module 16a and the second display module 16b can be made less noticeable.

[0607] In addition, by arranging a light-shielding layer such as a black matrix so that it overlaps near the boundary, lines (vertical or horizontal stripes) that may appear near the boundary between the first display module 16a and the second display module 16b can be made less noticeable.

[0608] The wiring layer 12 may also have a multi-layer structure, an example of which is shown in FIG. 29B.

[0609] In Figure 29B, a wiring layer 12a is provided on a curved support 22, an insulating film 21b is provided on the wiring layer 12a, and a wiring layer 12b is provided on the insulating film 21b. The wiring layers 12a and 12b may be arranged so that they intersect. Similar to the wiring layer 12 in Figure 29A, the wiring layer 12b can be electrically connected to the electrodes of each display module. Furthermore, the wiring layer 12a can be electrically connected to the electrodes of each display module via contact holes provided in the insulating film 21b.

[0610] The wiring of the wiring layer 12 can function as part of the wiring routing of the first display module 16 a, the second display module 16 b, the third display module 16 c, and the fourth display module 16 d. This can also reduce the wiring density in each display module, thereby reducing parasitic capacitance, etc.

[0611] Fig. 28B shows a modified example of the configuration of Fig. 28A. The light emission direction 19b in Fig. 28B is different from the light emission direction 19a in Fig. 28A. That is, Fig. 28A shows a configuration in which the display surface has a convex shape, while Fig. 28B shows a configuration in which the display surface has a concave shape.

[0612] 28B, a wiring layer 12c is provided, and a fifth display module 17a, a sixth display module 17b, a seventh display module 17c, and an eighth display module 17d are arranged and fixed to a light-transmitting support body 23. The fifth display module 17a, etc. may have a configuration similar to that of the first display module 16a, etc.

[0613] 28B, the material of the cover material 13 does not need to be light-transmitting, and the roof of a vehicle can be used as the cover material 13. A glass roof can also be used as the cover material 13. A light-transmitting support 23 is disposed on the viewing surface, and the support 23 has a curved surface.

[0614] In the display device of FIG. 28B, an example in which four display modules form one display surface is shown, but this is not particularly limited, and two or more display modules can form one display surface.

[0615] 28A to 29B may have a flat surface in part rather than being entirely curved. For example, the flat surface may be provided to match the internal component configuration of the vehicle (such as the dashboard, ceiling, pillars, window glass, steering wheel, seat, and inner parts of the doors).

[0616] Furthermore, the display surface, i.e., the viewing surface, of the display device can be provided with a touch sensor. The touch sensor can provide a display surface that can be touched and operated by the fingers of the vehicle driver.

[0617] The flexible substrate constituting the support is more susceptible to scratches than a glass substrate. Therefore, when a touch sensor is mounted, it is preferable to provide a surface protective film to prevent scratches caused by touching with fingers. The surface protective film may be a silicon oxide film having good optical properties (high visible light transmittance or high infrared light transmittance). Alternatively, the surface protective film may be made of DLC (diamond-like carbon), aluminum oxide (alumina, AlOx), polyester-based materials, polycarbonate-based materials, or the like. A material with high hardness is preferable for the surface protective film. Providing a surface protective film can also prevent contamination of the support.

[0618] When the surface protection film is formed by a coating method, it can be formed before or after the display device is fixed to the support having a curved surface.

[0619] As described above, it is possible to provide a large display device having a curved surface, and when viewing the large display device having a curved surface, a sense of immersion can be obtained.

[0620] This embodiment mode can be implemented in appropriate combination with other embodiment modes described in this specification etc. For example, part of the structure shown in this embodiment mode may be implemented in appropriate combination with other embodiment modes described in this specification etc.

[0621] Embodiment 11 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0622] The display device of the present embodiment can be a high-definition display device, and can therefore be used as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays and AR glasses-type devices.

[0623] 30A shows a perspective view of a display module 280. The display module 280 includes the display device 100 and an FPC 290.

[0624] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a pixel portion 103. The pixel portion 103 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in the pixel portion 103, which will be described later, can be viewed.

[0625] 30B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 103 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 (sometimes referred to as an FPC terminal portion) for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 103. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0626] The pixel section 103 has a plurality of pixels 150 arranged periodically. An enlarged view of one pixel 150 is shown on the right side of Fig. 30B. The pixel 150 has sub-pixels 110 that emit light of different colors. The plurality of light-emitting devices can be laid out in a stripe arrangement as shown in Fig. 30B. Various arrangement methods for the light-emitting devices, such as a delta arrangement or a pentile arrangement, can also be applied.

[0627] The pixel circuit section 283 includes pixel circuits 283a each having a plurality of periodically arranged transistors and the like.

[0628] One pixel circuit 283a is a circuit that controls the light emission of a light-emitting device included in one pixel 150. One pixel circuit 283a may be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a may be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active matrix display device.

[0629] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0630] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0631] The display module 280 can have a configuration in which one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked below the pixel portion 103, thereby enabling the aperture ratio (effective display area ratio) of the pixel portion 103 to be extremely high. For example, the aperture ratio of the pixel portion 103 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 150 can be laid out at an extremely high density, enabling the resolution of the pixel portion 103 to be extremely high. For example, it is preferable that the pixels 150 are laid out in the pixel portion 103 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and further preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0632] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as head-mounted displays, or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-density pixel unit 103, so even if the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0633] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0634] Embodiment 12 In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS.

[0635] The electronic devices of this embodiment include the display device of one embodiment of the present invention in their display portions. The display device of one embodiment of the present invention can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portions of various electronic devices.

[0636] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0637] In particular, the display device of one embodiment of the present invention can have high resolution and can therefore be suitably used in electronic devices having a relatively small display area. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices (e.g., head-mounted displays), AR glasses-type devices, and MR devices.

[0638] The display device of one embodiment of the present invention preferably has an extremely high resolution, such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the display device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a display device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth. Furthermore, the screen ratio (aspect ratio) of the display device of one embodiment of the present invention is not particularly limited. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0639] The electronic device of this embodiment may have a sensor (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays).

[0640] The electronic device of the present embodiment can have various functions, such as a function to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date, time, etc., a function to execute various software (programs), a wireless communication function, and a function to read out programs or data recorded on a recording medium.

[0641] 31A shows an example of a television set. In a television set 7100, a pixel portion 7000 is incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0642] The pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000 .

[0643] 31A can be operated using an operation switch provided on the housing 7101 and a separate remote control 7111. Alternatively, a touch sensor may be provided in the pixel portion 7000, and the television set 7100 may be operated by touching the pixel portion 7000 with a finger or the like. The remote control 7111 may have a display portion that displays information output from the remote control 7111. Channels and volume can be controlled by operation keys or a touch panel provided on the remote control 7111, and an image displayed on the pixel portion 7000 can be controlled.

[0644] The television device 7100 is configured to include a receiver, a modem, and the like. Ordinary television broadcasts can be received using the receiver. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from a sender to a receiver) or two-way (between a sender and a receiver, or between receivers, etc.) information communication.

[0645] 31B shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. The pixel portion 7000 is incorporated in the housing 7211.

[0646] The pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000 .

[0647] 31C and 31D show an example of digital signage.

[0648] 31C includes a housing 7301, a pixel portion 7000, and a speaker 7303. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0649] 31D shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a pixel portion 7000 provided along the curved surface of the pillar 7401.

[0650] 31C and 31D, the pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000.

[0651] The larger the pixel section 7000, the more information can be provided at one time. Also, the larger the pixel section 7000, the more easily it is noticed by people, which can increase the advertising effect, for example.

[0652] Applying a touch panel to the pixel portion 7000 is preferable because it not only displays an image or a video on the pixel portion 7000 but also allows a user to intuitively operate it. Furthermore, when used for providing information such as route information or traffic information, the intuitive operation can improve usability.

[0653] 31C and 31D , the digital signage 7300 or the digital signage 7400 is preferably capable of wirelessly linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user. For example, advertising information displayed in the pixel portion 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. By operating the information terminal 7311 or the information terminal 7411, the display of the pixel portion 7000 can be switched.

[0654] Furthermore, the digital signage 7300 or the digital signage 7400 can be made to run a game using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

[0655] The electronic device 6500 shown in FIG. 32A is a portable information terminal that can be used as a smartphone.

[0656] The electronic device 6500 includes a housing 6501, a display portion 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display portion 6502 has a touch panel function.

[0657] The pixel portion 103 of one embodiment of the present invention can be applied to the display portion 6502 .

[0658] FIG. 32B is a cross-sectional view including the end of the housing 6501 on the microphone 6506 side.

[0659] A light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, optical members 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in the space surrounded by the housing 6501 and the protective member 6510.

[0660] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0661] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0662] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0663] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0664] 103: pixel portion, 111: lower electrode, 111R: lower electrode, 111G: lower electrode, 111B: lower electrode, 112: organic compound layer, 112R: organic compound layer, 112G: organic compound layer, 112B: organic compound layer, 113: upper electrode, 115: charge generation layer, 151: auxiliary wiring, 151a: first wiring layer, 151b: second wiring layer

Claims

1. a first light-emitting device having a first bottom electrode, a first light-emitting layer overlying the first bottom electrode, a first layer overlying the first light-emitting layer, and a second light-emitting layer overlying the first layer; a second light-emitting device having a second bottom electrode, a third light-emitting layer overlying the second bottom electrode, a second layer overlying the third light-emitting layer, and a fourth light-emitting layer overlying the second layer; a common electrode included in the first light-emitting device and the second light-emitting device; an auxiliary wiring electrically connected to the common electrode, the color emitted from the light-emitting material contained in the first light-emitting layer is the same as the color emitted from the light-emitting material contained in the second light-emitting layer; the color emitted from the light-emitting material of the third light-emitting layer is the same as the color emitted from the light-emitting material of the fourth light-emitting layer; the first layer and the second layer each contain lithium; the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer; the first wiring layer and the second wiring layer each have a lattice shape in a top view, the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer; the width of the second wiring layer is smaller than the width of the first wiring layer; Display device.

2. a first light-emitting device having a first bottom electrode, a first light-emitting layer overlying the first bottom electrode, a first layer overlying the first light-emitting layer, and a second light-emitting layer overlying the first layer; a first color filter positioned to overlap the first light-emitting device; a second light-emitting device having a second bottom electrode, a third light-emitting layer overlying the second bottom electrode, a second layer overlying the third light-emitting layer, and a fourth light-emitting layer overlying the second layer; a second color filter positioned to overlap the second light-emitting device; a common electrode included in the first light-emitting device and the second light-emitting device; an auxiliary wiring electrically connected to the common electrode, the color emitted from the light-emitting material contained in the first light-emitting layer is the same as the color emitted from the light-emitting material contained in the second light-emitting layer; the color emitted from the light-emitting material of the third light-emitting layer is the same as the color emitted from the light-emitting material of the fourth light-emitting layer; the first layer and the second layer each contain lithium; the auxiliary wiring has a first wiring layer and a second wiring layer, the second wiring layer is electrically connected to the first wiring layer through a contact hole in the insulating layer; the first wiring layer and the second wiring layer each have a lattice shape in a top view, the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer; the width of the second wiring layer is smaller than the width of the first wiring layer; Display device.

3. In claim 1 or claim 2, a distance between the first lower electrode and the common electrode is shorter than a distance between the second lower electrode and the common electrode; Display device.

4. In any one of claims 1 to 3, Ends of the first lower electrode and the second lower electrode each have a tapered shape. Display device.

5. In any one of claims 1 to 4, a taper angle of an end surface of the organic compound layer including the first light-emitting layer and the second light-emitting layer is equal to or greater than 45 degrees and less than 90 degrees in a cross-sectional view; Display device.

6. In any one of claims 1 to 5, a taper angle of an end surface of the organic compound layer including the third light-emitting layer and the fourth light-emitting layer is equal to or greater than 45 degrees and less than 90 degrees in a cross-sectional view; Display device.