Indication device

Abstract

Provided is a display device in which a voltage drop is sufficiently suppressed. The display device comprises: a first light emission device having a first lower electrode and a first organic compound layer that is positioned above the first lower electrode; a second light emission device having a second lower electrode and a second organic compound layer that is positioned above the second lower electrode; a common electrode of the first light emission device and the second light emission device; and auxiliary wiring electrically connected to the common electrode, wherein 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 via a contact hole in an insulating layer, and the second wiring layer has a lattice shape in a plan view.

Description

[Technical Field]

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

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. The technical fields of one aspect of the present invention disclosed herein include semiconductor devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, or input / output devices, and their manufacturing methods can be given as examples. [Background technology]

[0003] A configuration has been proposed for an active matrix display device that achieves high resolution, in which an upper auxiliary wiring is arranged adjacent only to red pixels, and a lower auxiliary wiring is connected to the upper auxiliary wiring to adjust the electrical resistance of the cathode electrode (upper electrode) (see Patent Document 1).

[0004] A method for manufacturing organic EL elements using standard UV photolithography has been disclosed (see Non-Patent Document 1). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-85866 [Non-patent literature]

[0006] [Non-Patent Document 1] B. Lamprecht et al., “Organic optoelectronic device fabrication using standard UV photolithography” phys.stat.sol. (RRL) 2, No. 1, p. 16-18 (2008) [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] In the active matrix display device disclosed in Patent Document 1 above, since the lower auxiliary wiring is formed on the same layer as the power line and the scanning line, the voltage drop of the upper electrode cannot be sufficiently suppressed. Voltage drop occurs mainly due to factors such as the thinning of the electrode or the large area of the electrode, etc. It refers to a state where energy is consumed due to heat generation of the above electrode, etc., and the voltage applied to the electrode drops by the amount of this energy.

[0008] Furthermore, it is difficult to provide a high-definition display device by the method of Non-Patent Document 1 above.

[0009] In view of the above, one aspect of the present invention aims to provide a display device in which voltage drop is sufficiently suppressed and a manufacturing method thereof. Another aspect of the present invention aims to provide a high-definition display device and a manufacturing method thereof.

[0010] Note that the description of these problems does not prevent the existence of other problems. Also, these problems are considered to be independent of each other, and one aspect of the present invention only needs to be able to solve any one of these problems and does not need to solve all of them. Furthermore, it is possible to extract other problems from the descriptions of the specification, drawings, and claims such as this specification.

Means for Solving the Problems

[0011] In view of the above problems, one aspect of the present invention includes a first light-emitting device having a first lower electrode and a first organic compound layer located on the first lower electrode, a second light-emitting device having a second lower electrode and a second organic compound layer located on the second lower electrode, a common electrode shared by the first light-emitting device and the second light-emitting device, and an auxiliary wiring electrically connected to the common 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, and the second wiring layer has a lattice shape in a top view, and it is a display device.

[0012] Another aspect of the present invention is a display device comprising: a first light-emitting device having a first lower electrode and a first organic compound layer located on the first lower electrode; a second light-emitting device having a second lower electrode and a second organic compound layer located on the second lower electrode; a common electrode between the first and second light-emitting devices; and auxiliary wiring electrically connected to the common electrode, wherein the auxiliary wiring comprises a first wiring layer and a second wiring layer, the second wiring layer being electrically connected to the first wiring layer via contact holes in an insulating layer, the first wiring layer having a grid pattern in a top view, and the first lower electrode, the second lower electrode, and the second wiring layer each having regions located on an insulating layer.

[0013] Another aspect of the present invention is a display device comprising: a first light-emitting device having a first lower electrode and a first organic compound layer located on the first lower electrode; a second light-emitting device having a second lower electrode and a second organic compound layer located on the second lower electrode; a common electrode between the first and second light-emitting devices; and auxiliary wiring electrically connected to the common electrode, wherein the auxiliary wiring comprises a first wiring layer and a second wiring layer, the second wiring layer being electrically connected to the first wiring layer via contact holes in an insulating layer, the first and second wiring layers each having a grid pattern in a top view, the first lower electrode, the second lower electrode and the second wiring layer each having regions located on the insulating layer, and the width of the second wiring layer being smaller than the width of the first wiring layer.

[0014] In the present invention, it is preferable that the ends of the first lower electrode and the second lower electrode each have a tapered shape.

[0015] In the present invention, it is preferable that the taper angle of the end face of the first organic compound layer is 45 degrees or more and less than 90 degrees.

[0016] In the present invention, it is preferable that the taper angle of the end face of the second organic compound layer is 45 degrees or more and less than 90 degrees. [Effects of the Invention]

[0017] According to one aspect of the present invention, a display device in which voltage drop is sufficiently suppressed and a method for manufacturing the same can be provided. Furthermore, according to one aspect of the present invention, a high-resolution display device and a method for manufacturing the same can be provided.

[0018] Furthermore, the description of these effects does not preclude the existence of other effects. These effects are considered independent of each other, and one aspect of the present invention only needs to achieve one of these effects; it does not need to achieve all of them. Moreover, it is possible to extract other effects from the description, drawings, and claims of this specification, etc. [Brief explanation of the drawing]

[0019] Figure 1A is a conceptual diagram of a pixel section with auxiliary wiring, and Figures 1B1 to 1C2 are top views of the pixel section. Figure 2A is a conceptual diagram of a pixel section with auxiliary wiring, and Figures 2B1 to 2C2 are top views of the pixel section. Figure 3A is a conceptual diagram of a pixel section with auxiliary wiring, and Figures 3B and 3C are top views of the pixel section. Figure 4A is a cross-sectional view of the pixel area, and Figure 4B is a top view of the pixel area. Figures 5A to 5D are top views of the pixel area. Figures 6A and 6B are top views of the pixel area. Figure 7A is a top view, Figure 7B is a cross-sectional view of the pixel area, and Figure 7C is a cross-sectional view of the connection area. Figures 8A to 8D are top views of the pixel area. Figures 9A to 9D are top views of the pixel area. Figure 10A is a conceptual diagram of a display device, and Figures 10B to 10E are pixel circuit diagrams. Figures 11A to 11D are cross-sectional views of transistors. Figures 12A to 12C are top views of the pixel section, and Figure 12D is a circuit diagram. Figures 13A to 13C are cross-sectional views of the manufacturing method. Figures 14A to 14C are cross-sectional views of the manufacturing method. Figures 15A to 15C are cross-sectional views of the manufacturing method. Figures 16A to 16C are cross-sectional views of the manufacturing method. Figures 17A and 17B are cross-sectional views of the manufacturing method. Figures 18A to 18C are cross-sectional views of the manufacturing method. Figures 19A to 19C are cross-sectional views of the manufacturing method. Figure 20A is a top view of the display device, and Figures 20B and 20C are perspective views of the display device. Figures 21A and 21B are perspective views of the display device. Figures 22A to 22D are diagrams of electronic devices. Figures 23A and 23B are diagrams of electronic devices. [Modes for carrying out the invention]

[0020] In this specification and other documents, configurations are sometimes classified by function and explained using independent block diagrams. However, in reality, it is difficult to separate configurations by function, and one configuration may be involved in multiple functions.

[0021] In this specification, the terms "source" and "drain" of a transistor are interchangeable depending on the transistor's polarity and the potential applied to each terminal. Generally, in an n-channel transistor, the terminal to which a low potential is applied is called the source, and the terminal to which a high potential is applied is called the drain. In a p-channel transistor, the terminal to which a low potential is applied is called the drain, and the terminal to which a high potential is applied is called the source. In practice, the terms "source" and "drain" may be interchangeable according to the above potential relationship, but in this specification, when explaining the connection relationship of a transistor, the terms "source" and "drain" are fixed for convenience.

[0022] In this specification, the source of a transistor refers to a source region which is part of the semiconductor layer that functions as the active layer, or a source electrode connected to the source region. Similarly, the drain of a transistor refers to a drain region which is part of the semiconductor film, or a drain electrode connected to the drain region. The gate of a transistor refers to the gate electrode.

[0023] In this specification, the state in which transistors are connected in series means, for example, a state in which only one of the sources or drains of the first transistor is connected to only one of the sources or drains of the second transistor. The state in which transistors are connected in parallel means a state in which one of the sources or drains of the first transistor is connected to one of the sources or drains of the second transistor, and the other of the sources or drains of the first transistor is connected to the other of the sources or drains of the second transistor.

[0024] In this specification, "connection" may refer to an electrical connection, and includes a state in which current, voltage, or potential can be supplied or transmitted. Therefore, it also includes states in which devices are connected to each other via elements such as wiring, resistors, diodes, and transistors. Furthermore, electrical connection also includes states in which devices are directly connected to each other without the use of elements such as wiring, resistors, diodes, and transistors.

[0025] In this specification and other documents, the source and drain of a transistor may be described using the terms "first electrode" and "second electrode." If one of the first electrode and the second electrode is the source, the other electrode refers to the drain.

[0026] In this specification, the conductive layer may have multiple functions, such as wiring or electrodes.

[0027] In this specification, a light-emitting device may be referred to as a light-emitting element. A light-emitting device has a structure in which an organic compound layer is sandwiched between a pair of electrodes. One of the pair of electrodes is the anode, the other is the cathode, and at least one of the organic compound layers is a light-emitting layer. The light-emitting layer has a light-emitting material, and fluorescent materials or phosphorescent materials can be used as the light-emitting material. The pair of electrodes may be referred to as the lower electrode and the upper electrode, respectively. One of the pair of electrodes can function as either the anode or the cathode, and the other of the pair of electrodes can function as either the anode or the cathode.

[0028] In this specification, a light-emitting device having an organic compound layer formed using a metal mask (MM) may be referred to as a light-emitting device having an MM structure. In this specification, a metal mask may be referred to as a fine metal mask (FMM, high-resolution metal mask) depending on the miniaturization of the apertures.

[0029] In this specification and other documents, a light-emitting device having an organic compound layer formed without using a metal mask or a fine metal mask may be referred to as a light-emitting device having a metal maskless (MML) structure.

[0030] In this specification, light-emitting devices that emit red, green, and blue light may be referred to as red light-emitting devices, green light-emitting devices, and blue light-emitting devices, respectively.

[0031] In this specification, a structure in which the light-emitting layers are fabricated separately for each color light-emitting device may be referred to as an SBS (Side By Side) structure. For example, by using an SBS structure to fabricate a red light-emitting device, a green light-emitting device, and a blue light-emitting device, a full-color display device can be provided.

[0032] In this specification, a light-emitting device that emits white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (e.g., a color filter or color conversion layer) to provide a full-color display device.

[0033] Furthermore, light-emitting devices can be broadly classified into single structures and tandem structures. A single structure has one light-emitting unit between a pair of electrodes. This light-emitting unit refers to a laminate containing one or more light-emitting layers.

[0034] To obtain a white light-emitting device using a single structure, it is sufficient to have two or more light-emitting layers within the light-emitting unit. The two or more light-emitting layers in the light-emitting unit may be in contact with each other. Alternatively, a white light-emitting device can be obtained using three or more light-emitting layers. The three or more light-emitting layers may be in contact with each other within the light-emitting unit.

[0035] A tandem structure has two or more light-emitting units between a pair of electrodes. In a tandem structure, it is preferable to provide an intermediate layer, such as a charge generation layer, between the two or more light-emitting units. The charge generation layer has the function of injecting holes into one of the light-emitting units that are in contact with the charge generation layer when a voltage is applied between the cathode and the anode, and injecting electrons into the other light-emitting unit. For example, in a tandem structure in which a first light-emitting unit, a charge generation layer, and a second light-emitting unit are stacked between a pair of electrodes, it is preferable that holes are injected into the first light-emitting unit and electrons are injected into the second light-emitting unit by the charge generation layer.

[0036] To obtain a white light-emitting device using a tandem structure, the structure should be designed so that white light emission is obtained by combining the light from the light-emitting layers of two or more light-emitting units.

[0037] Furthermore, when comparing the aforementioned white light-emitting devices with SBS structure light-emitting devices, the SBS structure light-emitting devices can consume less power than the white light-emitting devices. If you want to keep power consumption low, it is preferable to use an SBS structure light-emitting device. On the other hand, white light-emitting devices are preferable because their manufacturing process is simpler than that of SBS structure light-emitting devices, which can lead to lower manufacturing costs or higher manufacturing yields.

[0038] In this specification, a display module may refer to a display panel on which connectors such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package) are attached, or on which ICs are mounted on the board using a COG (Chip On Glass) method or the like. A display module is one form of a display device.

[0039] Next, embodiments will be described in detail with reference to the drawings. However, it will be readily apparent to those skilled in the art that the present invention is not limited to the following description, and that its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be interpreted as being limited to the contents of the embodiments shown below. In the configuration of the invention described below, the same reference numerals are used in common across different drawings for the same parts or parts having similar functions, and repeated explanations are omitted.

[0040] (Embodiment 1) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0041] <Auxiliary wiring function> The display device described in this embodiment is characterized by having auxiliary wiring. The auxiliary wiring is a layer that has an auxiliary function to the main electrode, and the auxiliary function described in this embodiment includes a function to suppress voltage drop caused by the main electrode. The main electrode can be a pair of electrodes of a light-emitting device, but since the pair of electrodes functions as the cathode or anode of the light-emitting device, it may be necessary to select a conductive material based on the work function. A conductive material that considers only the work function may have a high resistivity. Therefore, one characteristic of the display device described in this embodiment is that the auxiliary wiring is electrically connected to one of the pair of electrodes, which can have the effect of suppressing the above voltage drop.

[0042] The upper electrode is a pair of electrodes, but it can be formed from a continuous conductive layer without being interrupted between multiple light-emitting devices. This continuous electrode is sometimes referred to as a common electrode. As the size of the display device increases, the common electrode needs to be formed over a larger area, and voltage drops caused by such common electrodes tend to occur. Therefore, the display device described in this embodiment is typically a large-scale display device, and one of its features is that auxiliary wiring is electrically connected to the upper electrode, which can have the effect of suppressing the above-mentioned voltage drop.

[0043] Auxiliary wiring may also be referred to as auxiliary electrodes depending on its shape. This specification does not limit the shape of auxiliary wiring in any way, and auxiliary wiring is assumed to include auxiliary electrodes.

[0044] Figure 1A shows a conceptual diagram of a pixel section 103 in a display device according to one aspect of the present invention. The pixel section 103 has at least a light-emitting device and also has auxiliary wiring 151 according to one aspect of the present invention. In Figure 1A, light-emitting devices 11R, 11G, and 11B are shown, illustrating the three light-emitting devices that the pixel section 103 has. When light-emitting devices 11R, 11G, and 11B are not distinguished, they may be referred to as light-emitting device 11.

[0045] <Light-emitting devices> The light-emitting device 11 has a configuration in which at least a lower electrode, an organic compound layer, and an upper electrode are stacked in that order. In Figure 1A, the lower electrodes 111R, 111G, and 111B are shown, the organic compound layers 112R, 112G, and 112B are shown, and the upper electrodes 113R, 113G, and 113B are shown. When the lower electrodes 111R, 111G, and 111B are not distinguished, they may be referred to as lower electrode 111. When the organic compound layers 112R, 112G, and 112B are not distinguished, they may be referred to as organic compound layer 112. When the upper electrodes 113R, 113G, and 113B are not distinguished, they may be referred to as upper electrode 113E. The three light-emitting devices in the pixel section 103 can emit red (R), green (G), and blue (B), so the above symbols are followed by RGB to correspond to each color. The organic compound layers 112R, 112G, and 112B each have at least an emissive layer, and because the emissive materials of the emissive layers differ, they can emit red (R), green (G), and blue (B) light. The organic compound layer 112 also has components other than the emissive layer, but the components other than the emissive layer will be described later.

[0046] <Method for preparing an organic compound layer> The organic compound layer 112 is a laminate of an emissive layer and other layers, and each layer can be formed by a vapor deposition method using a metal mask. To reiterate, an emissive device having an organic compound layer fabricated using a metal mask is referred to as an emissive device having an MM structure. Furthermore, each layer of the organic compound layer 112 can also be formed using a photolithography process without using a metal mask. To reiterate, an emissive device having an organic compound layer formed without using a metal mask is referred to as an emissive device having an MML structure. The fabrication method using photolithography will be described later.

[0047] <Top electrode, common electrode> The upper electrode 113E of each light-emitting device may be separated. Figure 1A shows a separated upper electrode and a configuration in which auxiliary wiring 151 is electrically connected to the upper electrode 113E. In Figure 1A, this electrical connection is shown with a solid line following the circuit diagram. A display device using an upper electrode electrically connected to auxiliary wiring 151 is preferable because it suppresses voltage drop.

[0048] Furthermore, the upper electrode may be provided as a common electrode, which is a continuous electrode, rather than being separated at each light-emitting device. When a common wiring is used, voltage drop is more likely to occur, so a configuration with auxiliary wiring, which is one aspect of the present invention, is preferred. A person skilled in the art who has read this specification or the like can appropriately substitute the upper electrode and the common electrode to understand the effect of the auxiliary wiring 151.

[0049] Furthermore, as the display device becomes larger, voltage drops due to upper electrodes and the like are more likely to occur. Therefore, a person skilled in the art who has read this specification will understand that the auxiliary wiring 151 has a significant effect in large display devices.

[0050] <Configuration of auxiliary wiring> The auxiliary wiring 151 preferably has two or more wiring layers provided on different layers. For example, as shown in Figure 1A, the auxiliary wiring 151 has a first wiring layer 151a and a second wiring layer 151b. The first wiring layer 151a is formed on a different layer from the second wiring layer 151b, and the surface to which the first wiring layer 151a is formed is different from the surface to which the second wiring layer 151b is formed.

[0051] The wiring layer may also be referred to as the electrode layer depending on its shape. This specification does not limit the shape of the electrode layer, and the wiring layer is assumed to include the electrode layer.

[0052] In order for the first wiring layer 151a and the second wiring layer 151b to function as auxiliary wiring 151, the first wiring layer 151a is electrically connected to the second wiring layer 151b. Specifically, the first wiring layer 151a is electrically connected to the second wiring layer 151b through contact holes 15 in the insulating layer 14 located between the first wiring layer 151a and the second wiring layer 151b.

[0053] The number of wiring layers constituting the auxiliary wiring is not limited in any way, and it may have three or more wiring layers, such as a first to a third wiring layer. It can be said that increasing the number of wiring layers is preferable because it increases the degree of freedom in arranging the wiring layers that function as auxiliary wiring (hereinafter sometimes referred to as layout).

[0054] Thus, the auxiliary wiring 151 according to one aspect of the present invention is characterized by having two or more wiring layers provided in different layers, and the wiring layers located in different layers being electrically connected to each other via contact holes.

[0055] <Contact Hole> A contact hole refers to an opening formed in an insulating layer, which allows a wiring layer located below a certain insulating layer (referred to as a lower wiring layer) to be electrically connected to a wiring layer located above that insulating layer (referred to as an upper wiring layer). Specifically, for this electrical connection to be made, the lower wiring layer must have an area exposed through the opening, and the upper wiring layer must electrically connect to this exposed area; typically, contact is preferred.

[0056] Furthermore, insulating layers with contact holes may be laminated. This is called a laminated insulating layer and is denoted as a laminated insulating layer. For example, contact holes can be formed in a laminated insulating layer consisting of a first insulating layer and a second insulating layer. In this case, a first contact hole is formed in the first insulating layer, and a second contact hole is formed in the second insulating layer. If the first contact hole has at least an area that overlaps with the second contact hole, the lower wiring layer can be electrically connected to the upper wiring layer. For example, if the second insulating layer is located above the first insulating layer, it is preferable that the width of the second contact hole in a cross-sectional view is greater than the width of the first contact hole. Of course, as long as the lower wiring layer can be electrically connected to the upper wiring layer, there are no limitations on the width of the contact holes in each insulating layer.

[0057] In high-resolution display devices, the spacing between the lower electrodes 111 becomes narrower, making it difficult to lay out the auxiliary wiring 151 to accommodate this spacing. Therefore, a layout for the auxiliary wiring 151 that is not affected or is only slightly affected by the spacing between the lower electrodes 111 is desirable.

[0058] As a layout for auxiliary wiring 151 that is not affected by the lower electrode 111, typically both the first wiring layer 151a and the second wiring layer 151b can be formed on layers different from the lower electrode 111. For example, auxiliary wiring 151 can be formed with the first wiring layer 151a and the second wiring layer 151b located below the lower electrode 111.

[0059] Furthermore, the first wiring layer 151a and the second wiring layer 151b can have different shapes when viewed from above, and typically, different areas. For example, the first wiring layer 151a can be formed with a smaller area than the second wiring layer 151b. In other words, the second wiring layer 151b may be laid out to have a larger area than the first wiring layer 151a. For example, the second wiring layer 151b can be laid out in a grid pattern. In this case, the second wiring layer 151b may be in the shape of strips or islands. A grid pattern refers to a pattern that combines multiple parallel vertical lines and multiple parallel horizontal lines. A strip pattern is sometimes called a rectangular or striped pattern. An island pattern refers to something shorter in length than a strip pattern. Of course, the first wiring layer 151a may be in a grid pattern, and in this case, the second wiring layer 151b may be in the shape of strips.

[0060] Figures 1B1 and 1B2 show top views of the pixel section 103, both of which show a grid-like second wiring layer 151b. The first wiring layer 151a is not shown, but is electrically connected to the second wiring layer 151b via contact holes 15. The first wiring layer 151a may have any shape, for example, it can be strip-shaped or island-shaped. It is preferable for the first wiring layer 151a to have an overlapping region with a part of the second wiring layer 151b, as this facilitates electrical connection via the contact holes 15.

[0061] Figures 1B1 and 1B2 include the X direction and the Y direction intersecting the X direction, and these directions are sometimes used to explain the configuration of the pixel section 103.

[0062] The grid-like second wiring layer 151b shown in Figure 1B1 has multiple vertical lines that are aligned in the Y direction. These vertical lines overlap with the gaps between subpixels. The gaps between subpixels consist of the region between the end of the lower electrode 111R and the end of the lower electrode 111G, and the region between the end of the lower electrode 111G and the end of the lower electrode 111B.

[0063] The second wiring layer 151b shown in Figure 1B2 has a different spacing between vertical lines than that in Figure 1B1, and the vertical lines overlap with the gaps between pixels 150. The gap between pixels 150 has a region between, for example, the end of the lower electrode 111B corresponding to sub-pixel B located at the end of pixel 150 and the end of the lower electrode 111R corresponding to sub-pixel R located at the end of an adjacent pixel. Adjacent means adjacent along the X direction or adjacent along the Y direction. In other words, the second wiring layer 151b shown in Figure 1B2 does not have vertical lines that overlap with the gaps between sub-pixels as in Figure 1B1.

[0064] In display devices with a high aperture ratio or high resolution, the gap between the lower electrodes narrows, making it difficult to lay out auxiliary wiring in the gap between the lower electrodes. The gap between the lower electrodes is, for example, the distance between the end of lower electrode 111R and the end of lower electrode 111G, or the distance between the end of lower electrode 111G and the end of lower electrode 111B. Therefore, when the second wiring layer 151b is located on the same layer as the lower electrode 111, in the case of a high-resolution display device, a layout of the second wiring layer 151b with fewer vertical lines, as shown in Figure 1B2, is preferable.

[0065] Preferably, the same layer as the grid-like second wiring layer 151b does not contain wiring that performs functions such as scanning lines, signal lines, and power lines. This is because wiring that performs the above functions needs to extend in either the X direction or the Y direction, and therefore would come into contact with the second wiring layer 151b. If scanning lines, signal lines, and power lines are to be provided, the length of the scanning lines, signal lines, and power lines along the X direction or the Y direction should be adjusted to arrange them in an island-like configuration so that they do not come into contact with the second wiring layer. Then, an electrical connection between the island-like scanning lines, etc., is secured using a conductive layer on a different layer from the second wiring layer. Wiring used to secure such electrical connections is sometimes referred to as bridge wiring.

[0066] Bridge wiring may also be referred to as bridge electrodes depending on its shape. This specification does not limit the shape of bridge wiring in any way, and bridge wiring is assumed to include bridge electrodes.

[0067] Figures 1C1 and 1C2 show the pixel section 103 having signal lines and bridge wiring. The light-emitting devices 11R, 11G, and 11B are not shown in Figures 1C1 and 1C2, but their layout and other details can be found in Figures 1B1 and 1B2.

[0068] The signal lines shown in Figures 1C1 and 1C2 have a third wiring layer 153a and a fourth wiring layer 153b, with the third wiring layer 153a being separated from the fourth wiring layer 153b. The third wiring layer 153a and the fourth wiring layer 153b may also be called island-shaped wiring layers. The island-shaped wiring layers are electrically connected to each other using bridge wiring 154. Both the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located on different surfaces than the second wiring layer 151b. For example, both the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located below the second wiring layer 151b. Furthermore, the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located on the same surface as the second wiring layer 151b. In either case, the bridge wiring 154 is formed using a conductive layer located on a different surface from the second wiring layer 151b. For example, the bridge wiring 154 may use a conductive layer located below the second wiring layer 151b.

[0069] Even when scanning lines or power lines are formed using island-shaped wiring layers in addition to signal lines, electrical connections can be ensured using bridge wiring 154 or the like.

[0070] The layout of the second wiring layer 151b with fewer vertical lines, as shown in Figure 1B2, is also suitable when there are signal lines and bridge wiring as shown in Figure 1C2.

[0071] Figure 2A shows another configuration of the pixel section 103. Figure 2A has a configuration in which the second wiring layer 151b is located on the same formation surface as the lower electrode 111. This same formation surface corresponds to the upper surface of the insulating layer 14. The other configurations are the same as in Figure 1A.

[0072] Figures 2B1 and 2B2 show top views of the pixel section 103, which show a first wiring layer 151a having a grid pattern. For the grid layout, refer to the grid-like layout of the second wiring layer 151b shown in Figures 1B1 and 1B2.

[0073] In the contact hole 15 shown in Figures 2B1 and 2B2, the second wiring layer 151b is positioned so as to overlap with the intersections of the grid-like first wiring layer 151a. The second wiring layer 151b only needs to overlap with the intersections, and does not need to overlap with the entire grid-like first wiring layer 151a. Furthermore, the second wiring layer 151b does not need to overlap with all the intersections. Since the second wiring layer 151b has the same conductive layer as the lower electrode 111, the second wiring layer 151b must be laid out so as not to be in contact with the lower electrode 111, but the layout of the first wiring layer 151a is not affected by the lower electrode 111. Therefore, the first wiring layer 151a can have a large area, and even if the area of ​​the second wiring layer 151b is small, voltage drop can be suppressed. When the second wiring layer 151b is laid out in a small area, it may be preferable to refer to it as an electrode layer.

[0074] Figures 2C1 and 2C2 show the pixel section 103 having signal lines and bridge wiring. The light-emitting devices 11R, 11G, and 11B are not shown in Figures 2C1 and 2C2, but their layout and other details can be found in Figures 2B1 and 2B2.

[0075] The signal lines shown in Figures 2C1 and 2C2 have a third wiring layer 153a and a fourth wiring layer 153b, with the third wiring layer 153a being separated from the fourth wiring layer 153b. As described above, the third wiring layer 153a and the fourth wiring layer 153b may also be called island-shaped wiring layers, and these island-shaped wiring layers are electrically connected to each other using bridge wiring 154. Both the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located on a different surface than the second wiring layer 151b. For example, both the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located below the second wiring layer 151b. Furthermore, both the third wiring layer 153a and the fourth wiring layer 153b may be formed using conductive layers located on the same surface as the first wiring layer 151a. In either case, the bridge wiring 154 is formed using a conductive layer located on a different surface than the first wiring layer 151a. For example, the bridge wiring 154 may be formed using a conductive layer located below the first wiring layer 151a. Alternatively, the bridge wiring 154 may be formed using a conductive layer located on the same surface as the second wiring layer 151b. In this case, the lower electrode 111 and the bridge wiring 154 are laid out so as not to come into contact.

[0076] Next, Figure 3A shows another embodiment of the pixel section 103 according to one aspect of the present invention. Unlike Figure 2A, Figure 3A has a configuration in which the width (width with dB) of the second wiring layer 151b in a cross-sectional view is smaller than the width (width with dA) of the first wiring layer 151a. Other configurations can be the same as in Figure 2A.

[0077] Figure 3B shows a top view of the pixel section 103, illustrating how the first wiring layer 151a and the second wiring layer 151b have a grid-like structure. For the grid-like layout, refer to the grid-like layout of the second wiring layer 151b shown in Figure 1B2.

[0078] The contact hole 15 shown in Figure 3B can have a shape that matches the region where the first wiring layer 151a and the second wiring layer 151b overlap. For example, the contact hole 15 can have a shape that follows one side of the second wiring layer 151b.

[0079] Figure 3C shows a pixel section 103 having a signal line and a bridge wiring. The signal line shown in Figure 3C has a third wiring layer 153a and a fourth wiring layer 153b, with the third wiring layer 153a being separated from the fourth wiring layer 153b. Therefore, a bridge wiring 154 is used to electrically connect the third wiring layer 153a and the fourth wiring layer 153b. The third wiring layer 153a and the fourth wiring layer 153b have the same conductive layer as the first wiring layer 151a. The bridge wiring 154 has a conductive layer of a different layer than the first wiring layer 151a, preferably a conductive layer lower than the first wiring layer 151a.

[0080] As described above, the auxiliary wiring 151 of one embodiment of the present invention has two or more wiring layers provided in different layers, which is preferable because it offers greater freedom in the layout of the auxiliary wiring 151 compared to the case where the auxiliary wiring is formed from a single wiring layer. The auxiliary wiring 151 of one embodiment of the present invention is suitable for application to high-definition display devices.

[0081] <Conductive materials used in auxiliary wiring> In one aspect of the present invention, the conductive material of the auxiliary wiring 151, that is, the conductive material of 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. Alternatively, an alloy of the above metals can be used as the conductive material. The conductive material is a metal and is a non-transparent conductive material. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a laminate using the above conductive material. For example, the first wiring layer 151a may be formed as a laminate and the second wiring layer 151b as a single layer. Alternatively, the first wiring layer 151a may be formed as a single layer and the second wiring layer 151b as a laminate. Or, the first wiring layer 151a may be formed as a laminate and the second wiring layer 151b as a laminate.

[0082] In one aspect of the present invention, the conductive material of the auxiliary wiring, that is, the conductive material of the first wiring layer 151a or the second wiring layer 151b, may be a light-transmitting conductive material. Specifically, oxides having indium and tin (also called indium tin oxide, In-Sn oxide, or ITO), oxides having indium, silicon, and tin (also called In-Si-Sn oxide, or ITSO), oxides having indium and zinc (also called indium zinc oxide, or In-Zn oxide), or oxides having indium, tungsten, and zinc (also called In-W-Zn oxide) can be used. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a laminate using the above conductive material. When a laminated structure is used for the first wiring layer 151a or the second wiring layer 151b, it is preferable to have at least one layer of conductive material using the above metals, etc.

[0083] The resistivity of the conductive material used in the auxiliary wiring according to one aspect of the present invention, that is, the resistivity of the conductive material used in the first wiring layer 151a or the second wiring layer 151b, is preferably lower than the resistivity of the conductive material used in the common electrode. However, if the voltage drop caused by the common electrode can be sufficiently suppressed, the above resistivity relationship does not need to be satisfied.

[0084] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0085] (Embodiment 2) This embodiment describes a specific example of a display device according to one aspect of the present invention.

[0086] <Top Emission Structure> In one aspect of the present invention, a display device preferably uses a top-emission structure. In a top-emission structure, the upper electrode needs to be light-transmitting, and light is emitted in the direction of the upper electrode. Light-transmitting means that visible light (light with a wavelength of 400 nm or more and less than 750 nm) can pass through, and it is preferable that it has a transmittance of 40% or more.

[0087] Transparent conductive materials may have high resistivity, which can increase the resistance of the common electrode. This can lead to a voltage drop caused by the common electrode, resulting in an uneven potential distribution within the display surface and variations in the brightness of the light-emitting device. Therefore, one embodiment of the present invention, a display device having a top emission structure, may have auxiliary wiring electrically connected to the common electrode. This auxiliary wiring can suppress the voltage drop. The term "upper electrode" may be replaced with "common electrode."

[0088] <Bottom Emission Structure> Furthermore, even if the display device according to one aspect of the present invention has a bottom emission structure, it may also have auxiliary wiring electrically connected to a common electrode. This auxiliary wiring can provide the effect of suppressing voltage drop.

[0089] In a bottom emission structure, the lower electrode needs to be translucent, and light is emitted in the direction of the lower electrode.

[0090] <Dual Emission Structure> Furthermore, even if the display device according to one aspect of the present invention has a dual emission structure, it may also have auxiliary wiring electrically connected to a common electrode. This auxiliary wiring can provide the effect of suppressing voltage drop.

[0091] A dual-emission structure requires light transmission for both the lower and upper electrodes, and light is emitted in both directions from the lower and upper electrodes. A dual-emission type display device can be described as a transparent display.

[0092] This embodiment describes a configuration in which auxiliary wiring is applied to a display device with a top emission structure.

[0093] [Specific examples of auxiliary wiring] Figure 4A shows the pixel section 103 of a top-emission display device and a cross-sectional view of the auxiliary wiring 151, etc. In Figure 4A, the cross-sectional structure of the auxiliary wiring 151 described in Figure 3, etc. in the above embodiment is applied, but the top-emission display device may have the cross-sectional structure of the auxiliary wiring 151 described in Figures 1 and 2, etc. in the above embodiment.

[0094] Each pixel 103 has a light-emitting device 11, and the light-emitting device 11 has a common electrode 113. Since the common electrode 113 is light-transmitting, light is emitted from each light-emitting device in the direction of the arrow shown in Figure 4A. The light-emitting device 11 is formed on an insulating layer 104, and the insulating layer 104 is formed on a substrate 101.

[0095] As shown in Figure 4(A), the auxiliary wiring 151 has a first wiring layer 151a and a second wiring layer 151b. The first wiring layer 151a is a wiring layer formed on the substrate 101, and the second wiring layer 151b is a wiring layer formed on the insulating layer 104. The second wiring layer 151b is electrically connected to the first wiring layer 151a via a contact hole 19 in the insulating layer 104 and functions as the auxiliary wiring 151. A common electrode 113 is located on the insulating layer 126, and the common electrode 113 can be electrically connected to the auxiliary wiring 151 via a contact hole 18 in the insulating layer 126.

[0096] Since the auxiliary wiring 151 has two or more wiring layers provided in different layers, even if any one of the wiring layers is provided on the same surface to be formed as the surface to be formed of the lower electrode 111, it is preferable that the auxiliary wiring 151 can be formed without being affected by the layout of the lower electrode, or with the influence of the layout of the lower electrode minimized.

[0097] In Figure 4A, the second wiring layer 151b is provided in the same layer as the lower electrode 111, but the first wiring layer 151a is provided in a different layer from the lower electrode 111, so the first wiring layer 151a can be laid out over a larger area than the second wiring layer 151b. When the first wiring layer 151a is located below the lower electrode 111, the degree of freedom in layout is increased without reducing the aperture ratio. Since the first wiring layer 151a formed in a position that does not reduce the aperture ratio does not need to be light-transmitting, a conductive material with low resistivity can be applied.

[0098] Thus, in one embodiment of the present invention, the auxiliary wiring 151 can have a wiring layer on a surface to be formed that is different from the surface to be formed on the lower electrode, and the wiring layer can be formed over a wide area without being affected by the lower electrode layout, thereby fully exhibiting a voltage drop suppression effect.

[0099] Next, the configuration of the pixel section 103 other than the auxiliary wiring 151 will be described. Refer to the top view of the pixel section 103 shown in Figure 4B. Note that in Figure 4B, the second wiring layer 151b is shown, and the first wiring layer 151a is omitted.

[0100] The dashed line A1-A2 in Figure 4B corresponds to A1-A2 in Figure 4A. Figure 4B also includes the X direction and the Y direction intersecting the X direction, and these directions are sometimes used to explain the layout of the pixel section 103.

[0101] As shown in Figure 4B, the pixel section 103 located in the display area has multiple pixels 150. Each pixel 150 is used as the smallest unit capable of full-color display and has at least sub-pixels 110R, 110G, and 110B, as shown in Figure 4B. In order to achieve full-color display, each of the sub-pixels 110R, 110G, and 110B may have a coloring layer, which may be a color filter or a color conversion layer, for example.

[0102] When explaining matters common to sub-pixels 110R, 110G, and 110B, they may be referred to simply as sub-pixel 110.

[0103] Sub-pixels 110R, 110G, and 110B correspond to the light-emitting regions of each light-emitting device, and in Figure 4B, each light-emitting region is exemplified as being rectangular. In Figure 4B, sub-pixel 110R corresponds to the light-emitting region of a red light-emitting device (indicated as R), sub-pixel 110G corresponds to the light-emitting region of a green light-emitting device (indicated as G), and sub-pixel 110B corresponds to the light-emitting region of a blue light-emitting device (indicated as B). Note that the display device according to one embodiment of the present invention is not limited to the above-mentioned light-emitting colors, and for example, in addition to red, green, and blue light-emitting devices, it may also have a white light-emitting device.

[0104] As shown in Figure 4B, multiple sub-pixels 110R and 110G are arranged along the Y direction and are positioned alternately. Multiple sub-pixels 110B are also arranged along the Y direction. Sub-pixels 110B can have a larger area than sub-pixels 110R and 110G. For example, if a light-emitting layer having a fluorescent material is used in a blue light-emitting device, and light-emitting layers having a phosphorescent material are used in a red light-emitting device and a green light-emitting device, respectively, it is preferable that sub-pixels 110B have a larger area than sub-pixels 110R and 110G, as shown in Figure 4B.

[0105] To reiterate, as shown in Figure 4A, the sub-pixel 110R has an insulating layer 104 on the substrate 101, a lower electrode 111R of the light-emitting device 11R is provided on the insulating layer 104, an organic compound layer 112R of the light-emitting device 11R is provided on the lower electrode 111R, and a common electrode 113 is provided on the organic compound layer 112R. The light-emitting device 11R emits light towards the common electrode 113, that is, in the direction indicated by the arrow in Figure 4A.

[0106] As shown again in Figure 4A, the sub-pixel 110G has an insulating layer 104 on the substrate 101, a lower electrode 111G of the light-emitting device 11G is provided on the insulating layer 104, an organic compound layer 112G of the light-emitting device 11G is provided on the lower electrode 111G, and a common electrode 113 is provided on the organic compound layer 112G. The light-emitting device 11G emits light towards the common electrode 113, that is, in the direction indicated by the arrow in Figure 4A.

[0107] As shown again in Figure 4A, the sub-pixel 110B has an insulating layer 104 on the substrate 101, a lower electrode 111B of the light-emitting device 11B on the insulating layer 104, an organic compound layer 112B of the light-emitting device 11B on the lower electrode 111B, and a common electrode 113 on the organic compound layer 112B. The light-emitting device 11B emits light towards the common electrode 113, that is, in the direction indicated by the arrow in Figure 4A.

[0108] The sub-pixel 110 has a switching element that controls the light-emitting device in addition to the light-emitting device, but the switching element is not shown in Figures 4A and 4B. In one embodiment of the present invention, a display device can display in full color by emitting light from a light-emitting device controlled by a switching element.

[0109] As shown in Figure 4A, the second wiring layer 151b is formed using a conductive layer provided in the same layer as the lower electrode 111. In addition, the first wiring layer 151a is a wiring layer provided in a different layer from the lower electrode 111.

[0110] As shown in Figure 4A, the second wiring layer 151b has a wiring layer formed on the same surface as the lower electrode, and is therefore provided in a region that does not come into contact with the lower electrode 111, that is, a region that does not overlap with the subpixel. For example, the second wiring layer 151b has a grid pattern when viewed from above. The grid-like second wiring layer 151b has regions that extend along the X direction as horizontal lines, and these regions are parallel, as well as regions that extend along the Y direction as vertical lines, and these regions are parallel.

[0111] Furthermore, the second wiring layer 151b shown in Figure 4B has a region that extends along the X direction, located between sub-pixels 110R and 110G, and these regions are arranged in parallel. The region located between sub-pixels 110R and 110G corresponds to the region between pixels. The second wiring layer 151b shown in Figure 4B has a region that extends along the Y direction, located between sub-pixels 110G and 110B, and these regions are arranged in parallel.

[0112] The gap between the lower electrodes 111 becomes narrower as the resolution of the display device increases. For example, in the pixel section 103 of Figure 4B, which is present in a high-resolution display device, the distances between sub-pixels de and between pixels dc become narrower. As the spacing narrows, it becomes more difficult to form wiring layers for auxiliary wiring. Therefore, it is preferable to designate the wiring layer that overlaps the gap between sub-pixels in a top view as the first wiring layer 151a, and to make the first wiring layer 151a a wiring layer of a different layer from the lower electrodes.

[0113] <Insulating layer 126> In one embodiment of the present invention, it is preferable that an insulating layer 126 is positioned between light-emitting devices, as shown in Figure 4A. The insulating layer 126 can fill the spaces between pixels and sub-pixels, and the second wiring layer 151b is preferably provided so as to overlap with the insulating layer 126. The insulating layer 126 can prevent the second wiring layer 151b from coming into contact with the lower electrode 111. Furthermore, the insulating layer 126 can separate the organic compound layers of each light-emitting device, thereby suppressing crosstalk between light-emitting devices. Crosstalk is a phenomenon in which light is emitted from an unintended light-emitting device.

[0114] In Figure 4A, the upper surface of the insulating layer 126 is shown to be roughly in agreement with or in agreement with the upper surface of the organic compound layer 112. This positional relationship is preferable because it makes the surface of the common electrode 113 flat, thereby suppressing the breakage of the common electrode 113.

[0115] Although not shown in Figure 4A, in order for the common electrode 113 not to be cut, the upper surface of the insulating layer 126 may be positioned above the upper surface of the organic compound layer 112. In this case, the edges of the insulating layer 126 should gradually become thinner towards the center of the organic compound layer 112. This gradually thinning shape is sometimes described as a tapered shape.

[0116] Although not shown in Figure 4A, it is preferable that the central part of the insulating layer 126 is located above the edges of the insulating layer 126, and that the central part has a raised region above the edges. Providing the common electrode 113 on such an insulating layer 126 is preferable because it suppresses the cutting of the common electrode 113.

[0117] Figure 4A shows a configuration in which the second wiring layer 151b of the auxiliary wiring 151 has a region in contact with the area below the common electrode 113, but any configuration is possible as long as the auxiliary wiring 151 is electrically connected to the common electrode 113.

[0118] [Layout of auxiliary wiring] An auxiliary wiring 151 according to one aspect of the present invention is characterized by having at least two or more wiring layers. An example of the layout of the first wiring layer 151a and the second wiring layer 151b will be explained using Figure 5, etc. In Figure 5, etc., the sub-pixels (R, G, B) are shown according to Figure 4B, but the lower electrode 111 is omitted.

[0119] In the pixel section 103 shown in Figure 5A, the auxiliary wiring 151 forms a grid pattern when viewed from above and has a first wiring layer 151a extending in the Y direction and a second wiring layer 151b extending in the X direction. Contact holes are located in the region where the first wiring layer 151a and the second wiring layer 151b intersect, but these are not shown in Figure 5A.

[0120] Either the first wiring layer 151a or the second wiring layer 151b may be formed in the same layer as the lower electrode 111, or both may be formed in layers different from the lower electrode 111.

[0121] In the pixel section 103 shown in Figure 5A, both the first wiring layer 151a and the second wiring layer 151b are located between pixels. The pixel section 103 is used in a high-definition display device.

[0122] Figure 5B shows an auxiliary wiring 151 with a shorter length than the second wiring layer 151b shown in Figure 5A. Due to the shorter length of the second wiring layer 151b, the first wiring layer 151a has a region that extends in the X direction. The shorter second wiring layer 151b has a length such that one end overlaps with sub-pixel G and the other end overlaps with sub-pixel B. The other configurations are the same as in Figure 5A.

[0123] Figure 5C shows an auxiliary wiring 151 in which the first wiring layer 151a shown in Figure 5A is replaced with the second wiring layer 151b, and the second wiring layer 151b shown in the same figure is replaced with the first wiring layer 151a. The other configurations are the same as in Figure 5A.

[0124] Figure 5D shows an auxiliary wiring 151 with a shorter length than the first wiring layer 151a shown in Figure 5C. Due to the shorter length of the first wiring layer 151a, the second wiring layer 151b has a region that extends in the X direction. The shorter first wiring layer 151a has a length such that one end overlaps with sub-pixel G and the other end overlaps with sub-pixel B. The other configurations are the same as in Figure 5C.

[0125] Figure 5A shows auxiliary wiring 151 in which the first wiring layer 151a and the second wiring layer 151b have the same shape. In Figure 6A, the first wiring layer 151a is shown as a dotted line. The other configurations are the same as in Figure 5A.

[0126] Figure 6B shows an auxiliary wiring 151 having a first wiring layer 151a with a larger area than the second wiring layer 151b. Because it is formed on a different layer from the lower electrode 111, the first wiring layer 151a can be formed with a large area. The other configurations are the same as in Figure 5A.

[0127] As described above, the auxiliary wiring 151 of one embodiment of the present invention has a first wiring layer 151a and a second wiring layer 151b, and can therefore take on a variety of forms. Furthermore, by electrically connecting the auxiliary wiring 151 to the common electrode, the voltage drop of the common electrode can be sufficiently suppressed. In addition, the display device of one embodiment of the present invention can use high-resolution pixels.

[0128] Furthermore, auxiliary wiring 151 may be applied to the bottom emission structure and the dual emission structure. In this case, the cross-sectional structure of the auxiliary wiring 151 described in Figures 1 to 3, etc. in the above embodiment can be applied. Since light is emitted below the lower electrode 111 in the bottom emission structure and the dual emission structure, the first wiring layer 151a provided below the lower electrode 111 may have a grid-like or smaller area that overlaps with the gaps between subpixels or the gaps between pixels. Similarly, the second wiring layer 151b provided below the lower electrode 111 may have a grid-like or smaller area that overlaps with the gaps between subpixels or the gaps between pixels.

[0129] <Specific examples of display devices> Using Figures 7A to 7C, a specific example of a display device with a top emission structure as shown in Figure 4, etc., will be explained. The display device 100 has a pixel section 103 and a connection section 140. The pixel section 103 has a plurality of pixels 150. Each pixel 150 has a plurality of sub-pixels 110, for example, sub-pixel 110R has a red light-emitting device 11R, sub-pixel 110G has a green light-emitting device 11G, and sub-pixel 110B has a blue light-emitting device 11B. The pixel section 103 has contact holes 141. The contact holes 141 are selectively provided and can be provided, for example, in an area corresponding to the outer periphery of the pixel 150, or in an area corresponding to the four corners of the pixel 150.

[0130] In Figure 7A, the regions corresponding to light-emitting devices 11R, 11G, and 11B are labeled with the symbols R, G, and B. The arrangement in Figure 7A is the same as the arrangement shown in Figure 4B, etc., and is a regular arrangement.

[0131] As the light-emitting device 11, it is preferable to use an element such as an OLED (Organic Light Emitting Diode) or a QLED (Quantum-dot Light Emitting Diode). Examples of light-emitting materials for the light-emitting device include fluorescent materials, phosphorescent materials, inorganic compounds (such as quantum dot materials), and thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) materials).

[0132] Furthermore, the connection portion 140 shown in Figure 7A is a region having a connecting electrode 111C that is electrically connected to the common electrode 113. The common electrode 113 may extend beyond the edge of the pixel portion 103 to the connection portion 140. In Figure 7A, the common electrode 113 extending to the connection portion 140 is shown by a dotted line. The connecting electrode 111C is supplied with a potential for supplying to the common electrode 113. If a voltage drop occurs due to the common electrode 113, the value of the above potential will vary. The display device of this embodiment is preferable because it has auxiliary wiring 151 at least in the pixel portion 103, thereby suppressing the above potential variation. The auxiliary wiring 151 can also be provided in the connection portion 140 in addition to the pixel portion 103.

[0133] The connecting electrode 111C can be provided along the outer circumference of the pixel portion 103. For example, the connecting electrode 111C may be provided along one side of the outer circumference of the pixel portion 103, or it may be provided along two or more sides of the outer circumference of the pixel portion 103. That is, if the upper surface shape of the pixel portion 103 is rectangular, the upper surface shape of the connecting electrode 111C can be a strip along one side of the outer circumference, an L-shape along two sides of the outer circumference, a U-shape along three sides of the outer circumference, or a rectangle along all four sides of the outer circumference.

[0134] Figures 7B and 7C are cross-sectional views corresponding to the dashed lines B1-B2 and B3-B4 in Figure 7A, respectively. Figure 7B shows cross-sectional views of the light-emitting device 11G, light-emitting device 11B, and auxiliary wiring 151, while Figure 7C shows a cross-sectional view of the connecting electrode 111C.

[0135] Figure 7B shows a cross-sectional view of the contact hole 141. The contact hole 141 is formed in the insulating layer 126. The second wiring layer 151b and the common electrode 113 can be electrically connected through the contact hole 141.

[0136] Although not shown in Figure 7A, the insulating layer 104 has contact holes 142. The second wiring layer 151b and the first wiring layer 151a can be electrically connected through the contact holes 142. The contact holes 142 may be formed in a region that overlaps with the contact holes 141, or in a region that does not overlap with the contact holes 141. If the thickness of the insulating layer 126 is greater than the thickness of the insulating layer 104, the size of the contact holes 141 (e.g., the width in a cross-sectional view) should be larger than the size of the contact holes 142 (e.g., the width in a cross-sectional view).

[0137] As shown in Figure 7B, the end face of the organic compound layer 112B is perpendicular or approximately perpendicular, which is preferable as it facilitates the machining of the contact hole 141. The taper angle of the end face of the organic compound layer 112B is preferably 45 degrees or more and less than 90 degrees. The taper angles of the end faces of the other organic compound layers are also preferably 45 degrees or more and less than 90 degrees.

[0138] In this specification, the taper angle refers to the angle of inclination between the side surface and the bottom surface of a target layer when the layer is observed from a direction perpendicular to its cross-section (for example, a plane perpendicular to the surface of the substrate). If the bottom surface is unclear, the angle of inclination can be determined using the surface of the substrate.

[0139] Although not shown in Figure 7B, the light-emitting device 11R has a lower electrode 111R, an organic compound layer 112R, a common layer 114, and a common electrode 113. The light-emitting device 11G shown in Figure 7B has a lower electrode 111G, an organic compound layer 112G, a common layer 114, and a common electrode 113. The light-emitting device 11B shown in Figure 7B has a lower electrode 111B, an organic compound layer 112B, a common layer 114, and a common electrode 113. A functional layer that can be used for the common layer 114 is, for example, an electron injection layer. The lower electrode 111 is an electrode electrically connected to the transistor and is sometimes referred to as a pixel electrode. The lower electrode 111 also functions as either the anode or cathode of the light-emitting device and is sometimes referred to as the anode or cathode.

[0140] The organic compound layer 112R contains a luminescent organic compound that emits light with intensity in at least the red wavelength range. The organic compound layer 112G contains a luminescent organic compound that emits light with intensity in at least the green wavelength range. The organic compound layer 112B contains a luminescent organic compound that emits light with intensity in at least the blue wavelength range. A layer containing a luminescent organic compound can be described as a light-emitting layer.

[0141] The organic compound layer 112 and the common layer 114 may each independently have one or more layers selected from electron injection layers, electron transport layers, light-emitting layers, hole injection layers, and hole transport layers. These electron injection layers, electron transport layers, light-emitting layers, hole injection layers, and hole transport layers may be referred to as functional layers. Having two or more layers includes cases where two or more layers are combined from different functional layers, and cases where two or more layers are combined from layers of the same functional layer but made of different materials. Specific materials that can be used for the functional layers will be described later.

[0142] In this embodiment, the organic compound layer 112 has a laminated structure consisting of a hole injection layer, a hole transport layer, an emissive layer, and an electron transport layer, in that order from the lower electrode 111 side, and the common layer 114 has an electron injection layer.

[0143] Furthermore, the functional layer only needs to perform its respective function and does not necessarily need to contain organic compounds. For example, an electron injection layer can be made from a film containing only inorganic compounds or inorganic materials.

[0144] Lower electrodes 111R, 111G, and 111B are provided for each light-emitting device. Furthermore, the common electrode 113 and common layer 114 are provided as a continuous layer common to each light-emitting device. By using a reflective conductive film for the lower electrode 111 and a conductive film that is transparent to visible light for the common electrode 113, a top-emission type display device can be constructed.

[0145] The end of the lower electrode 111 preferably has a tapered shape. The end of the organic compound layer 112 is preferably located in a region beyond the lower electrode 111, and if the end of the lower electrode 111 has a tapered shape, the organic compound layer 112 has a shape that follows the tapered shape. By making the side surface of the lower electrode 111 tapered, the coverage of the organic compound layer and the like can be improved.

[0146] The organic compound layer 112 is processed by photolithography. Therefore, the angle between the edge of the organic compound layer 112 and the surface to be formed may be close to 90 degrees. The edge of the organic compound layer 112 is located in a region that extends beyond the edge of the lower electrode 111.

[0147] It is preferable to have an insulating layer 126 between two adjacent light-emitting devices. The insulating layer 126 is located between the two adjacent light-emitting devices and is provided to fill the space between at least two adjacent organic compound layers 112. More preferably, the insulating layer 126 has a region that overlaps with the edges of the organic compound layers 112. That is, the edges of the insulating layer 126 can be located on the organic compound layers 112, and the height difference between the top and edges of the insulating layer 126 becomes small. If the height difference between the top and edges of the insulating layer 126 becomes large, the insulating layer 126 may become prone to peeling, so it is preferable that this difference be small.

[0148] The upper shape of the insulating layer 126 is preferably a smooth convex shape. A convex upper shape can also be described as a shape in which the central part of the insulating layer 126 is raised higher than the edges.

[0149] At least a common layer 114 and a common electrode 113 are provided covering the insulating layer 126, thereby suppressing the cutting of the common layer 114 and the common electrode 113.

[0150] Furthermore, it is preferable that an insulating layer 125 be provided in contact with the 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 to prevent the insulating layer 126 from coming into contact with the organic compound layer 112. If the organic compound layer 112 and the insulating layer 126 come into contact, the organic compound layer 112 may dissolve due to organic solvents used during the formation or processing of the insulating layer 126. Therefore, as shown in this embodiment, by providing an insulating layer 125 between the organic compound layer 112 and the insulating layer 126, it is possible to protect the organic compound layer 112.

[0151] The insulating layer 125 can be an insulating layer having an inorganic material. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxidative nitride insulating films, and nitride oxide insulating films can be used for the insulating layer 125. The insulating layer 125 may be a single layer structure or a laminated structure. Examples of oxide insulating films include silicon oxide film, aluminum oxide film, magnesium oxide film, indium gallium zinc oxide film, gallium oxide film, germanium oxide film, yttrium oxide film, zirconium oxide film, lanthanum oxide film, neodymium oxide film, hafnium oxide film, and tantalum oxide film. Examples of nitride insulating films include silicon nitride film and aluminum nitride film. Examples of oxidative nitride insulating films include silicon oxidative nitride film and aluminum oxidative nitride film. Examples of nitride oxide insulating films include silicon nitride film and aluminum nitride film. In particular, by applying an aluminum oxide film, a metal oxide film such as a hafnium oxide film, or an inorganic insulating film such as a silicon oxide film, formed by atomic layer deposition (ALD), to the insulating layer 125, it is possible to form an insulating layer 125 with fewer pinholes and excellent function in protecting the organic compound layer.

[0152] In this specification, "oxide nitride" refers to a material in which the oxygen content is greater than the nitrogen content, and "nitride oxide" refers to a material in which the nitrogen content is greater than the oxygen content. For example, when "silicon oxynitride" is written, it refers to a material in which the oxygen content is greater than the nitrogen content, and when "silicon nitride oxide" is written, it refers to a material in which the nitrogen content is greater than the oxygen content.

[0153] The insulating layer 125 can be formed using sputtering, chemical vapor deposition (CVD), pulsed laser deposition (PLD), ALD, or the like. It is preferable to form the insulating layer 125 using the ALD method, which provides good coverage.

[0154] As the insulating layer 126, an insulating layer having an organic material can be suitably used. For example, as the insulating layer 126, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be applied. Alternatively, as the insulating layer 126, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

[0155] Furthermore, a photosensitive resin can be used as the insulating layer 126. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0156] When a photosensitive material is used as the insulating layer 126, the 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 of the insulating layer 126 can be adjusted by processing it with oxygen plasma ashing.

[0157] 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. As the insulating layer 126, for example, 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 can be used.

[0158] Preferably, the upper surface of the insulating layer 126 has a portion that is higher than the height of the upper surface of the organic compound layer 112. This allows light emitted diagonally upward from the light-emitting device 11 to be absorbed, and in combination with the auxiliary electrode, an even greater stray light suppression effect can be achieved.

[0159] The insulating layer 126 can be formed using wet film deposition methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating. In particular, it is preferable to form the organic insulating film that will become the insulating layer 126 by spin coating.

[0160] After forming the insulating layer 126, it is preferable to perform a heat treatment in air at a temperature of 85°C to 120°C for 45 minutes to 100 minutes. This allows for dehydration or degassing from the insulating layer 126.

[0161] Furthermore, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, and aluminum) 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 the light emitted from the light-emitting layer. This can improve the light extraction efficiency.

[0162] Furthermore, as shown in Figure 7B, an insulating layer 128 may be provided between the insulating layer 125 and the upper surface of the organic compound layer 112. The insulating layer 128 is a portion of the protective layer (also called a mask layer) that remains after etching the organic compound layer 112. It is preferable to use the same material for the insulating layer 128 as for the insulating layer 125. In particular, it is preferable to use the same material for both the insulating layer 128 and the insulating layer 125 because it facilitates processing. For example, both the insulating layer 128 and the insulating layer 125 may have an aluminum oxide film, a hafnium oxide film, or a silicon oxide film.

[0163] Insulating layer 125, insulating layer 126, and insulating layer 128 are all insulating layers located between light-emitting devices, and are sometimes collectively referred to as an insulating laminate. Since a common layer 114 and a common electrode 113 are provided on the insulating laminate, it is preferable that the ends of the insulating laminate have a tapered shape so that the common layer 114 and the common electrode 113 are not interrupted. For the ends of the insulating laminate to have a tapered shape, the ends of insulating layer 125 may have a tapered shape, the ends of insulating layer 126 may have a tapered shape, the ends of insulating layer 128 may have a tapered shape, or the ends of insulating layer 125, insulating layer 126, and insulating layer 128 may all have a tapered shape. When a tapered shape is formed with multiple insulating layers, it is preferable that the tapered shape of the ends of each insulating layer is formed continuously.

[0164] Furthermore, the central part of the insulating laminate may have a rounded upper surface. In other words, the central part of the insulating laminate has a shape that is raised above the edges. To achieve the above shape, the insulating layer 126 located at the top of the insulating laminate may be formed using an organic material.

[0165] Furthermore, the edges of the insulating laminate can take on a variety of 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 during processing of the insulating layer 126. Removing a portion of the upper part of the insulating layer 125 that protrudes from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 113 from being cut.

[0166] 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 during processing of the insulating layer 126. Removing a portion of the upper part of the insulating layer 128 that protrudes from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 113 from being cut.

[0167] If the insulating layer 128 protrudes from the insulating layer 126, the end of the insulating layer 125 located below the insulating layer 128 should coincide with or approximately coincide with the end of the insulating layer 128.

[0168] As shown in Figure 7B, a protective layer 121 is provided on the common electrode 113. The protective layer 121 has the function of preventing impurities from diffusing to each light-emitting element from above.

[0169] The protective layer 121 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 121.

[0170] The protective layer 121 is bonded to the substrate 170 by an adhesive layer 171. Various types of curing adhesives can be used for the adhesive layer 171, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Adhesive sheets or the like may also be used for the adhesive layer 171.

[0171] In the connection portion 140 shown in Figure 7C, openings are provided in the insulating layer 125 and the insulating layer 126 on the connecting electrode 111C. The connecting electrode 111C and the common electrode 113 are electrically connected through these openings. The openings for electrically connecting the connecting electrode 111C and the common electrode 113 may be provided in either insulating layer.

[0172] Figure 7C shows a configuration in which a common layer 114 is provided on the connecting electrode 111C, and a common electrode 113 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, so the connecting electrode 111C can be electrically connected to the common electrode 113 via the common layer 114. As a result, the common electrode 113 and the common layer 114 can be formed using the same mask (also called an area mask or rough metal mask, to distinguish it from a fine metal mask), thus reducing manufacturing costs. Of course, the connecting portion 140 may also have a region where the connecting electrode 111C is in contact with the common electrode 113.

[0173] The following describes an example of a display device configuration that differs in some aspects from the one described above. Note that in the following, parts that overlap with the above example are denoted by the same reference numerals, and repeated explanations may not be provided.

[0174] The display device described in the specific example has at least an organic compound layer separated. This configuration suppresses crosstalk due to leakage current, enabling the display of images with extremely high display quality. Furthermore, it is possible to achieve both a high aperture ratio and high resolution. One embodiment of the display device of the present invention can be applied to ultra-large displays of 40 inches or more, 100 inches or more, and even beyond 100 inches.

[0175] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0176] (Embodiment 3) This embodiment describes the layout of the sub-pixels.

[0177] <Layout> There are no particular limitations on the arrangement of subpixels; stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, or pentile arrangements can be used.

[0178] Furthermore, the top surface shape of a sub-pixel can be, for example, a triangle, a quadrilateral (including rectangles and squares), a pentagon, or other polygons, or a polygon with rounded corners, an ellipse, or a circle. The top surface shape of a sub-pixel, as referred to here, corresponds to the light-emitting area of ​​the light-emitting device.

[0179] The pixel section 103 shown in Figure 8A has a second wiring layer 151b as part of the auxiliary wiring, and the pixel 150 has a light-emitting device 11a with a roughly trapezoidal top surface shape with rounded corners, a light-emitting device 11b with a roughly triangular top surface shape with rounded corners, and a light-emitting device 11c with a roughly square or roughly hexagonal top surface shape with rounded corners. Furthermore, the light-emitting device 11a has a larger light-emitting area than the light-emitting device 11b. In this way, the shape and size of each light-emitting device can be determined independently. For example, the more reliable the light-emitting device, the smaller its size can be.

[0180] As shown in Figure 8A, the pixel section 103 can be configured such that light-emitting device 11a is a green light-emitting device G, light-emitting device 11b is a red light-emitting device R, and light-emitting device 11c is a blue light-emitting device B, as shown in Figure 9A.

[0181] The pixel section 103 shown in Figure 8B has a second wiring layer 151b as part of the auxiliary wiring, and a Pentile arrangement is applied to the arrangement of subpixels. In the Pentile arrangement, pairs of subpixels 124a having light-emitting devices 11a and 11b, and pairs of subpixels 124b having light-emitting devices 11b and 11c are laid out alternately.

[0182] As shown in Figure 8B, the pixel section 103 can be configured such that light-emitting device 11a is a red light-emitting device R, light-emitting device 11b is a green light-emitting device G, and light-emitting device 11c is a blue light-emitting device B, as shown in Figure 9B.

[0183] The pixel section 103 shown in Figure 8C has a second wiring layer 151b as part of the auxiliary wiring, and pixels 150a and 150b are configured in a delta array. In the delta array, pixel 150a has two light-emitting devices (light-emitting devices 11a and 11b) in the top row (1st row) and one light-emitting device (light-emitting device 11c) in the bottom row (2nd row). Pixel 150b has one light-emitting device (light-emitting device 11c) in the top row (1st row) and two light-emitting devices (light-emitting devices 11a and 11b) in the bottom row (2nd row).

[0184] As shown in Figure 8C, the pixel section 103 may be configured such that light-emitting device 11a is a red light-emitting device R, light-emitting device 11b is a green light-emitting device G, and light-emitting device 11c is a blue light-emitting device B, as shown in Figure 9C.

[0185] The pixel section 103 shown in Figure 8D has a second wiring layer 151b as part of the auxiliary wiring, and is an example in which the light-emitting devices of each color are laid out in a zigzag pattern. When laid out in a zigzag pattern, the upper edges of two light-emitting devices arranged in the column direction (for example, light-emitting device 11a and light-emitting device 11b, or light-emitting device 11b and light-emitting device 11c) are offset when viewed from above.

[0186] As shown in Figure 8D, the pixel section 103 may be configured such that light-emitting device 11a is a red light-emitting device R, light-emitting device 11b is a green light-emitting device G, and light-emitting device 11c is a blue light-emitting device B, as shown in Figure 9D.

[0187] In photolithography, the finer the pattern to be processed, the more significant the effects of light diffraction become. This compromises the fidelity of transferring the pattern to the resist mask through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the resist mask pattern is rectangular, patterns with rounded corners are likely to be formed. Consequently, the top surface shape of the light-emitting device may be a polygon with rounded corners, an ellipse, or a circle.

[0188] Furthermore, in a method for manufacturing a display device according to one aspect of the present invention, a resist mask is used to process the organic compound layer. The resist mask formed on the organic compound layer needs to be cured at a temperature lower than the heat resistance temperature of the organic compound layer. Therefore, depending on the heat resistance temperature of the organic compound layer material and the curing temperature of the resist material, curing for resist mask formation may be insufficient. A resist mask that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the organic compound layer may become a polygon with rounded corners, an ellipse, or a circle. For example, when attempting to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the organic compound layer.

[0189] Furthermore, in order to achieve the desired shape of the upper surface of the organic compound layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, a correction pattern is added to the corners of the shape on the mask pattern.

[0190] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0191] (Embodiment 4) This embodiment describes materials and other elements that can be used in light-emitting devices.

[0192] [Light-emitting devices] In a light-emitting device, it is preferable to use a light-transmitting conductive film on the electrode that extracts light, and a conductive film that reflects visible light on the electrode that does not extract light. Alternatively, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to lay out the electrode between the conductive film that reflects visible light and the organic compound layer. In other words, the light emitted from the light-emitting device should be reflected by the conductive film that reflects visible light and extracted from the display device.

[0193] As materials for forming electrodes in light-emitting devices, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, examples include aluminum-containing alloys such as indium tin oxide, In-Si-Sn oxide, indium zinc oxide, In-W-Zn oxide, aluminum, nickel, and lanthanum alloys (also written as Al-Ni-La alloys), and silver-palladium-copper alloys (also written as Ag-Pd-Cu or APC). In addition, metals such as aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, neodymium, and alloys containing these in appropriate combinations can also be used. In addition, elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (for example, lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, etc., can be used.

[0194] Of the above materials, those that can emit holes can be used as the anode, and those that can emit electrons can be used as the cathode.

[0195] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device has an electrode that is transparent to and reflective to visible light (a semi-transmissive / semi-reflective electrode), and the other has an electrode that is reflective to visible light (a reflective electrode). By having a microcavity structure in the light-emitting device, the light emission can be made to resonate between the pair of electrodes, narrowing and further intensifying the light emission emitted from the light-emitting device.

[0196] When a microcavity structure is applied, the distance between pairs of electrodes differs from one another in red, green, and blue light-emitting devices.

[0197] Furthermore, semi-transmissive / semi-reflective electrodes can have a laminated structure consisting of a reflective electrode and an electrode that transmits visible light (also called a transparent electrode).

[0198] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode in the light-emitting device that has a transmittance of 40% or more for visible light (light with a wavelength of 400 nm or more and less than 750 nm). The visible light reflectance of the semi-transparent / semi-reflective electrode shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less.

[0199] The organic compound layer of the light-emitting device has at least a light-emitting layer. The light-emitting layer is a layer containing a light-emitting material (also called a light-emitting substance). The light-emitting layer may contain one or more types of light-emitting substances. As the light-emitting substance, substances that exhibit light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, and red can be used as appropriate. In addition, substances that emit near-infrared light can also be used as light-emitting substances.

[0200] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0201] 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.

[0202] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0203] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more of these organic compounds may be hole-transporting materials and / or electron-transporting materials. Alternatively, one or more of these organic compounds may be bipolar materials or TADF materials.

[0204] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0205] Each organic compound layer 112 may further include layers other than the light-emitting layer, such as a material with high hole injection properties, a material with high hole transport properties, a hole blocking material, a material with high electron transport properties, a material with high electron injection properties, an electron blocking material, or a bipolar material (a material with high electron transport and hole transport properties).

[0206] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0207] For example, each organic compound layer 112 may have one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

[0208] The common layer 114 can be one or more of the following: a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer. For example, a carrier injection layer (hole injection layer or electron injection layer) may be formed as the common layer 114. Note that the light-emitting device does not necessarily have a common layer 114.

[0209] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0210] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. As for the hole-transporting material, 10 -6 cm 2Materials having a hole mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0211] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material that has electron-blocking properties can be used for the electron blocking layer.

[0212] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0213] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ -6 cm 2 Materials having an electron mobility of / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0214] Other electron-transporting materials include, for example, compounds having lone pairs of electrons and electron-deficient heteroaromatic rings. Specifically, compounds having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0215] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of organic compounds containing lone pairs of electrons is between -3.6 eV and -2.3 eV. In addition, the highest occupied molecular orbital (HOMO) level and LUMO level of organic compounds can generally be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0216] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-bidi(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), and 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz) can be used in organic compounds containing lone pairs of electrons. NBPhen has a higher glass transition temperature (Tg) and superior heat resistance compared to BPhen.

[0217] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0218] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0219] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection capabilities. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection capabilities. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection capabilities.

[0220] For example, alkali metals or alkaline earth metals include lithium, cesium, magnesium, etc., and compounds include lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). x (where X is any number), lithium oxide (LiO x (where X is any number), or cesium carbonate, etc.

[0221] Organic compounds can also be used as materials for the electron injection layer. Examples of organic compounds include 8-(quinolinolato)lithium (abbreviated as Liq), 2-(2-pyridyl)phenolatrium (abbreviated as LiPP), 2-(2-pyridyl)-3-pyridinolatrium (abbreviated as LiPPy), 4-phenyl-2-(2-pyridyl)phenolatrium (abbreviated as LiPPP), 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), and 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen).

[0222] The above organic compounds may contain dopants. Any metal can be used as the dopant; for example, silver (Ag) or ytterbium (Yb) can be used.

[0223] Furthermore, a composite material containing the above-mentioned alkali metal or alkaline earth metal and the above-mentioned organic compound can also be used as a material for the electron injection layer.

[0224] Furthermore, the electron injection layer may be a stacked structure of two or more layers. The materials described above can be appropriately combined to form this stacked structure. For example, a configuration can be used in which lithium fluoride is used as the first layer and ytterbium as the second layer.

[0225] The electron transport material described above may be used as the electron injection layer.

[0226] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0227] (Embodiment 5) This embodiment will describe a display device.

[0228] [Example of a display device configuration] Figure 10A shows a block diagram of the display device 10. The display device 10 includes a pixel unit 103, a drive circuit unit 12, a drive circuit unit 13, and the like.

[0229] The pixel section 103 has a plurality of pixels 150 arranged in a matrix. Each pixel 150 has sub-pixels 110R, 110G, and 110B. Each of the sub-pixels 110R, 110G, and 110B has a light-emitting device that functions as a display device.

[0230] Pixel 150 is electrically connected to wiring GL, wiring SLR, wiring SLG, and wiring SLB. Wiring SLR, wiring SLG, and wiring SLB are each electrically connected to the drive circuit unit 12. Wiring GL is electrically connected to the drive circuit unit 13. Drive circuit unit 12 functions as a source line drive circuit (also called a source driver), and drive circuit unit 13 functions as a gate line drive circuit (also called a gate driver). Wiring GL functions as a gate line, and wiring SLR, wiring SLG, and wiring SLB each function as source lines.

[0231] Sub-pixel 110R has a light-emitting device that emits red light. Sub-pixel 110G has a light-emitting device that emits green light. Sub-pixel 110B has a light-emitting device that emits blue light. This allows the display device 10 to display in full color. Pixel 150 may also have sub-pixels that emit light of other colors. For example, in addition to the three sub-pixels described above, pixel 150 may have a sub-pixel that emits white light, or a sub-pixel that emits yellow light, etc.

[0232] Wiring GL is electrically connected to sub-pixels 110R, 110G, and 110B, which are arranged in the row direction (the direction in which wiring GL extends). Wiring SLR, SLG, and SLB are electrically connected to sub-pixels 110R, 110G, or 110B (not shown), which are arranged in the column direction (the direction in which wiring SLR, etc. extends).

[0233] [Example of pixel circuit configuration] Figure 10B shows an example of a circuit diagram for a pixel 150 that can be applied to the sub-pixels 110R, 110G, and 110B. Pixel 150 has transistors M1, M2, M3, capacitor C1, and light-emitting device EL. Wiring GL and wiring SL are electrically connected to pixel 150. Wiring SL corresponds to one of the wirings SLR, SLG, and SLB shown in Figure 10A.

[0234] Transistor M1 has its gate electrically connected to wiring GL, one of its source and drain electrically connected to wiring SL, and the other of its source and drain electrically connected to one electrode of capacitor C1 and the gate of transistor M2. Transistor M2 has one of its source and drain electrically connected to wiring AL, and the other of its source and drain electrically connected to one electrode of light-emitting device EL, the other electrode of capacitor C1, and one of its source and drain. Transistor M3 has its gate electrically connected to wiring GL, and the other of its source and drain electrically connected to wiring RL. Light-emitting device EL has its other electrode electrically connected to wiring CL.

[0235] A data potential D is applied to wiring SL. A selection signal is applied to wiring GL. This selection signal includes a potential that makes the transistor conduct and a potential that makes it non-conductive.

[0236] A reset potential is applied to wiring RL. An anode potential is applied to wiring AL. A cathode potential is applied to wiring CL. At pixel 150, the anode potential is set to a higher potential than the cathode potential. The reset potential applied to wiring RL can be set 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 set to a potential higher than the cathode potential, the same as the cathode potential, or lower than the cathode potential.

[0237] Transistors M1 and M3 function as switches. Transistor M2 functions as a transistor for controlling the current flowing to the light-emitting device EL. For example, it can be said that transistor M1 functions as a selector transistor and transistor M2 functions as a drive transistor.

[0238] Here, it is preferable to apply LTPS transistors to all of transistors M1 through M3. Alternatively, it is preferable to apply OS transistors to transistors M1 and M3, and an LTPS transistor to transistor M2.

[0239] Alternatively, OS transistors may be applied to all of transistors M1 to M3. In this case, one or more of the transistors in the drive circuit section 12 and the drive circuit section 13 may be LTPS transistors, and the other transistors may be OS transistors. For example, OS transistors may be applied to the transistors provided in the pixel section 103, and LTPS transistors may be applied to the transistors provided in the drive circuit section 12 and the drive circuit section 13.

[0240] As an OS transistor, a transistor using an oxide semiconductor in the semiconductor layer where the channel is formed can be used. The semiconductor layer preferably contains, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, it is preferable that M is one or more selected from aluminum, gallium, yttrium, and tin. In particular, it is preferable to use an oxide containing indium, gallium, and zinc (also written as IGZO) as the semiconductor layer of the OS transistor. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc.

[0241] Transistors using oxide semiconductors, which have a wider bandgap and lower carrier density than silicon, can achieve extremely low off-currents. Therefore, this low off-current allows the charge stored in a capacitor connected in series with the transistor to be retained for extended periods. For this reason, it is preferable to use transistors made of oxide semiconductors for transistors M1 and M3, which are connected in series with capacitor C1. By using transistors with oxide semiconductors as transistors M1 and M3, it is possible to prevent the charge held in capacitor C1 from leaking through transistor M1 or M3. Furthermore, because the charge held in capacitor C1 can be retained for extended periods, it becomes possible to display still images for extended periods without rewriting the data of pixel 150.

[0242] Note that in Figure 10B, the transistor is shown as an n-channel type transistor, but a p-channel type transistor can also be used.

[0243] Furthermore, it is preferable that each transistor in the pixel 150 is formed in a row on the same substrate.

[0244] As the transistor in pixel 150, a transistor having a pair of gates that overlap across a semiconductor layer can be applied.

[0245] In a transistor having a pair of gates, configuring the pair of gates to be electrically connected to each other and given the same potential offers advantages such as increased on-current and improved saturation characteristics. Alternatively, one of the pair of gates may be given a potential that controls the transistor's threshold voltage. Furthermore, providing a constant potential to one of the pair of gates can improve the stability of the transistor's electrical characteristics. For example, one of the transistor's gates may be electrically connected to a wiring to which a constant potential is provided, or it may be electrically connected to its own source or drain.

[0246] The pixel 150 shown in Figure 10C is an example where a transistor with a pair of gates is applied to transistor M3. The pair of gates of transistor M3 are electrically connected. This configuration allows for a reduction in the data writing time to the pixel 150.

[0247] The pixel 150 shown in Figure 10D is an example in which transistors with a pair of gates are applied not only to transistor M3, but also to transistors M1 and M2. In each of these transistors, the pair of gates are electrically connected to each other. By applying such a transistor to at least transistor M2, the saturation characteristics are improved, making it easier to control the luminescence brightness of the light-emitting device EL and improving the display quality.

[0248] Pixel 150 shown in Figure 10E is an example where one of the pair of gates of transistor M2 in pixel 150 shown in Figure 10D is electrically connected to the source of transistor M2.

[0249] [Example of transistor configuration] The following describes examples of transistor cross-sectional configurations that can be applied to the above-mentioned display device.

[0250] [Configuration Example 1] Figure 11A is a cross-sectional view including transistor 410.

[0251] Transistor 410 is a transistor provided on substrate 401, with polycrystalline silicon applied to its semiconductor layer. For example, transistor 410 corresponds to transistor M2 of pixel 150. That is, Figure 11A shows an example where one of the source and drain of transistor 410 is electrically connected to the lower electrode 111 of the light-emitting device.

[0252] The transistor 410 has a semiconductor layer 411, an insulating layer 412, a conductive layer 413, etc. The semiconductor layer 411 has a channel-forming region 411i and a low-resistance region 411n. The semiconductor layer 411 is made of silicon. Preferably, the semiconductor layer 411 is made of polycrystalline silicon. A portion of the insulating layer 412 functions as a gate insulating layer. A portion of the conductive layer 413 functions as a gate electrode.

[0253] Furthermore, the semiconductor layer 411 may also be configured to include a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties. In this case, the transistor 410 can be called an OS transistor.

[0254] The low-resistance region 411n is a region containing impurity elements. For example, if transistor 410 is an n-channel type transistor, phosphorus, arsenic, etc., can be added to the low-resistance region 411n. On the other hand, if it is a p-channel type transistor, boron, aluminum, etc., can be added to the low-resistance region 411n. Furthermore, in order to control the threshold voltage of transistor 410, the aforementioned impurities may also be added to the channel formation region 411i.

[0255] An insulating layer 421 is provided on the substrate 401. The semiconductor layer 411 is provided on the insulating layer 421. The insulating layer 412 is provided covering the semiconductor layer 411 and the insulating layer 421. The conductive layer 413 is provided on the insulating layer 412 in a position overlapping with the semiconductor layer 411.

[0256] Furthermore, an insulating layer 422 is provided covering the conductive layer 413 and the insulating layer 412. Conductive layers 414a and 414b are provided on the insulating layer 422. Conductive layers 414a and 414b are electrically connected to the low-resistance region 411n at openings provided in the insulating layers 422 and 412. A portion of the conductive layer 414a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 414b functions as the other of the source electrode and drain electrode. In addition, an insulating layer 104 is provided covering the conductive layer 414a, conductive layer 414b, and insulating layer 422.

[0257] On the insulating layer 104, a lower electrode 111 that functions as a pixel electrode is provided. The lower electrode 111 is provided on the insulating layer 104 and is electrically connected to the conductive layer 414b at an opening provided in the insulating layer 104. Although not shown here, an EL layer and a common electrode can be laminated on the lower electrode 111.

[0258] 〔Configuration Example 2〕 FIG. 11B shows a transistor 410a having a pair of gate electrodes. The transistor 410a shown in FIG. 11B is mainly different from FIG. 11A in that it has a conductive layer 415 and an insulating layer 416.

[0259] The conductive layer 415 is provided on the insulating layer 421. Also, an insulating layer 416 is provided to cover the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided such that at least the channel formation region 411i overlaps the conductive layer 415 via the insulating layer 416.

[0260] In the transistor 410a shown in FIG. 11B, a part of the conductive layer 413 functions as a first gate electrode, and a part of the conductive layer 415 functions as a second gate electrode. Also at this time, a part of the insulating layer 412 functions as a first gate insulating layer, and a part of the insulating layer 416 functions as a second gate insulating layer.

[0261] Here, when electrically connecting the first gate electrode and the second gate electrode, in a region not shown, the conductive layer 413 and the conductive layer 415 may be electrically connected through openings provided in the insulating layer 412 and the insulating layer 416. Also, when electrically connecting the second gate electrode and the source or drain, in a region not shown, the conductive layer 414a or the conductive layer 414b and the conductive layer 415 may be electrically connected through openings provided in the insulating layer 422, the insulating layer 412, and the insulating layer 416.

[0262] When applying LTPS transistors to all the transistors constituting pixel 150, transistor 410 illustrated in FIG. 11A or transistor 410a illustrated in FIG. 11B can be applied. At this time, transistor 410a may be used for all the transistors constituting pixel 150, or transistor 410 may be applied to all the transistors, or transistor 410a and transistor 410 may be used in combination.

[0263] 〔Configuration Example 3〕 Hereinafter, an example of a configuration having both a transistor in which silicon is applied to a semiconductor layer and a transistor in which a metal oxide is applied to the semiconductor layer will be described.

[0264] FIG. 11C shows a cross-sectional view including transistor 410a and transistor 450.

[0265] Regarding transistor 410a, Configuration Example 1 described above can be applied. Although an example using transistor 410a is shown here, a configuration having transistor 410 and transistor 450 may be used, or a configuration having all of transistor 410, transistor 410a, and transistor 450 may be used.

[0266] Transistor 450 is a transistor in which a metal oxide is applied to a semiconductor layer. The configuration shown in FIG. 11C is an example in which, for example, transistor 450 corresponds to transistor M1 of pixel 150 and transistor 410a corresponds to transistor M2. That is, FIG. 11C is an example in which one of the source and drain of transistor 410a is electrically connected to lower electrode 111.

[0267] Also, FIG. 11C shows an example in which transistor 450 has a pair of gates.

[0268] The transistor 450 has a conductive layer 455, an insulating layer 422, a semiconductor layer 451, an insulating layer 452, a conductive layer 453, etc. A portion of the conductive layer 453 functions as the first gate of the transistor 450, and a portion of the conductive layer 455 functions as the second gate of the transistor 450. At this time, a portion of the insulating layer 452 functions as the first gate insulating layer of the transistor 450, and a portion of the insulating layer 422 functions as the second gate insulating layer of the transistor 450.

[0269] The conductive layer 455 is provided on the insulating layer 412. The insulating layer 422 covers the conductive layer 455. The semiconductor layer 451 is provided on the insulating layer 422. The insulating layer 452 covers the semiconductor layer 451 and the insulating layer 422. The conductive layer 453 is provided on the insulating layer 452 and has a region that overlaps with the semiconductor layer 451 and the conductive layer 455.

[0270] Furthermore, an insulating layer 426 is provided covering the insulating layer 452 and the conductive layer 453. Conductive layers 454a and 454b are provided on the insulating layer 426. Conductive layers 454a and 454b are electrically connected to the semiconductor layer 451 at openings provided in the insulating layer 426 and the insulating layer 452. A portion of the conductive layer 454a functions as one of the source electrode and drain electrode, and a portion of the conductive layer 454b functions as the other of the source electrode and drain electrode. In addition, an insulating layer 104 is provided covering the conductive layer 454a, the conductive layer 454b, and the insulating layer 426.

[0271] Here, it is preferable that the conductive layers 414a and 414b, which are electrically connected to the transistor 410a, are formed by processing the same conductive film as conductive layers 454a and 454b. Figure 11C shows a configuration in which conductive layers 414a, 414b, 454a, and 454b are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 426) and contain the same metal element. In this case, conductive layers 414a and 414b are electrically connected to the low-resistance region 411n through openings provided in the insulating layer 426, insulating layer 452, insulating layer 422, and insulating layer 412. This is preferable because it simplifies the manufacturing process.

[0272] Furthermore, it is preferable that the conductive layer 413, which functions as the first gate electrode of transistor 410a, and the conductive layer 455, which functions as the second gate electrode of transistor 450, are formed by processing the same conductive film. Figure 11C shows a configuration in which the conductive layer 413 and the conductive layer 455 are formed on the same plane (i.e., in contact with the upper surface of the insulating layer 412) and contain the same metal element. This is preferable because it simplifies the manufacturing process.

[0273] In Figure 11C, the insulating layer 452, which functions as the first gate insulating layer of the transistor 450, is configured to cover the edge of the semiconductor layer 451. However, as shown in Figure 11D, the insulating layer 452 may be processed so that its upper surface shape matches or is approximately the same as that of the conductive layer 453.

[0274] In this specification, "approximately matching top surface shapes" means that at least a portion of the contours overlap between stacked layers. For example, this includes cases where the upper and lower layers are processed with the same mask pattern, or partially with the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or the upper layer may be located outside the lower layer; in this case, too, it is said that the "top surface shapes are approximately matching."

[0275] In this example, transistor 410a corresponds to transistor M2 and is electrically connected to the pixel electrode, but this is not the only configuration. For example, transistor 450 or transistor 450a may correspond to transistor M2. In this case, transistor 410a corresponds to transistor M1, transistor M3, or another transistor.

[0276] By having the above-described pixel circuit and the light-emitting device structure of the above embodiment, the display device can have one or more of the following: image sharpness, image clarity, high saturation, and high contrast ratio. The leakage current that can flow through the transistors of the above-described 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 as it minimizes light leakage that may occur when displaying black.

[0277] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0278] (Embodiment 6) This embodiment describes a display device having a light-receiving device (also referred to as a light-receiving element).

[0279] 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 includes a switching element that controls the light-receiving device. The light-receiving device controlled by the switching element has the function of receiving light from a light source and can convert the received light into an electrical signal.

[0280] Furthermore, in addition to displaying an image using all of the subpixels of the display device, some subpixels may emit light as a light source, while the remaining subpixels display the image.

[0281] The pixel 150 shown in FIGS. 12A, 12B, and 12C has sub-pixels 110G, 110B, 110R, and a light-receiving portion S (labeled R, G, B, S in the figure), and further has auxiliary wiring. FIGS. 12A, 12B, and 12C show a second wiring layer 151b that is part of the auxiliary wiring 151. In FIGS. 12A, 12B, and 12C, for simplicity of distinguishing each sub-pixel and the like, the regions are labeled with the symbols R, G, B, and S.

[0282] In the pixel 150 shown in FIG. 12A, a stripe arrangement is applied, and the second wiring layer 151b is provided so as to surround the sub-pixels 110G, 110B, 110R, and the light-receiving portion S (labeled R, G, B, S in the figure).

[0283] In the pixel shown in FIG. 12B, a matrix arrangement is applied, and the second wiring layer 151b is provided so as to surround the sub-pixels 110G, 110B, 110R, and the light-receiving portion S.

[0284] In the pixel 150 shown in FIG. 12C, an arrangement in which three sub-pixels (sub-pixels 110R, 110G, and the light-receiving portion S) are arranged vertically side by side next to one sub-pixel (sub-pixel 110B) is applied, and the second wiring layer 151b is provided so as to surround the sub-pixels 110G, 110B, 110R, and the light-receiving portion S.

[0285] Note that the layout of the sub-pixels is not limited to the configurations of FIGS. 12A to 12C. The layout of the second wiring layer 151b is not limited to the configurations of FIGS. 12A to 12C.

[0286] When the light-receiving area of the light-receiving portion S is smaller than the light-emitting areas of the other sub-pixels, the imaging range becomes narrower, and it becomes possible to suppress blurring of the imaging result and improve the resolution. Therefore, the display device according to one aspect of the present invention can perform high-definition or high-resolution imaging. For example, using the light-receiving portion S, imaging for personal authentication using a fingerprint, palm print, iris, vein shape (including vein and artery shapes), or face can be performed.

[0287] Furthermore, the light-receiving unit S can be used as a touch sensor (also called a direct touch sensor) or a near-touch sensor (also called a hover sensor, hover-touch sensor, non-contact sensor, or touchless sensor), etc.

[0288] Touch sensors or near-touch sensors can detect the proximity or contact of an object (such as a finger, hand, or pen). Touch sensors can detect an object when the display device and the object are in direct contact. Near-touch sensors can detect an object even if the object does not touch the display device. For example, it is preferable that the display device can detect an object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm. This configuration makes it possible to operate the display device without the object directly touching it, in other words, it becomes possible to operate the display device without contact (touchless). This configuration reduces the risk of the display device becoming dirty or scratched, or makes it possible to operate the display device without the object directly touching any dirt (e.g., dust or viruses) attached to the display device.

[0289] Furthermore, when performing high-resolution imaging, it is preferable that the light-receiving unit S be provided on all pixels of the display device. On the other hand, when used as a touch sensor or near-touch sensor, the light-receiving unit S does not require the same high precision as when imaging fingerprints, etc., so it is sufficient to provide it on some of the pixels of the display device. The detection speed can be increased by reducing the number of light-receiving units S in the display device to less than the number of sub-pixels 110R, etc.

[0290] Figure 12D shows an example of a pixel circuit for a sub-pixel (PIX1) that has a light-receiving device.

[0291] The pixel circuit shown in Figure 12D includes a light-receiving device PD, transistors M11, M12, M13, M14, and a capacitive element C2. Here, an example is shown in which a photodiode is used as the light-receiving device PD.

[0292] The light-receiving device PD has its anode electrically connected to wiring V1 and its cathode electrically connected to either the source or drain of transistor M11. Transistor M11 has its gate electrically connected to wiring TX and its other source or drain electrically connected to one electrode of capacitive element C2, one source or drain of transistor M12, and the gate of transistor M13. Transistor M12 has its gate electrically connected to wiring RES and its other source or drain electrically connected to wiring V2. Transistor M13 has its source or drain electrically connected to wiring V3 and its other source or drain electrically connected to either the source or drain of transistor M14. Transistor M14 has its gate electrically connected to wiring SE and its other source or drain electrically connected to wiring OUT1.

[0293] A constant potential is supplied to wirings V1, V2, and V3, respectively. When driving the photodetector PD, a potential higher than that of wiring V1 is supplied to wiring V2. Transistor M12 is controlled by a signal supplied to wiring RES and has the function of resetting the potential of the node connected to the gate of transistor M13 to the potential supplied to wiring V2. Transistor M11 is controlled by a signal supplied to wiring TX and has the function of controlling the timing at which the potential of the above node changes according to the current flowing through the photodetector PD. Transistor M13 functions as an amplifying transistor that provides an output according to the potential of the above node. Transistor M14 is controlled by a signal supplied to wiring SE and functions as a selection transistor for reading out the output according to the potential of the above node with an external circuit electrically connected to wiring OUT1.

[0294] It is preferable to apply transistors (OS transistors) in which a metal oxide (oxide semiconductor) is used in the semiconductor layer where the channel is formed, for transistors M11, M12, M13, and M14, respectively.

[0295] OS transistors, which have a wider bandgap and lower carrier density than silicon transistors, can achieve extremely low off-currents.

[0296] Furthermore, transistors M11 to M14 can also be transistors in which silicon is applied as the semiconductor in which the channel is formed. In particular, using highly crystalline silicon such as single-crystal silicon or polycrystalline silicon is preferable because it can achieve a high field-effect mobility, enabling faster operation.

[0297] Alternatively, a configuration may be used in which one or more of transistors M11 to M14 have an oxide semiconductor applied, and the others have silicon applied.

[0298] Note that in Figure 12D, the transistor is shown as an n-channel type transistor, but a p-channel type transistor can also be used.

[0299] Furthermore, a display device according to one aspect of the present invention can have a variable refresh rate. For example, power consumption can be reduced by adjusting the refresh rate according to the content displayed on the display device (for example, within a range of 0.01 Hz to 240 Hz). In addition, a drive that reduces the power consumption of the display device by driving with a reduced refresh rate may be called an idling stop (IDS) drive.

[0300] Furthermore, the drive frequency of the touch sensor or near-touch sensor may be changed according to the refresh rate mentioned above. For example, if the refresh rate of the display device is 120Hz, the drive frequency of the touch sensor or near-touch sensor can be set to a frequency higher than 120Hz (typically 240Hz). This configuration enables low power consumption and increases the response speed of the touch sensor or near-touch sensor.

[0301] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0302] (Embodiment 7) This embodiment describes metal oxides (also called oxide semiconductors) that can be used in the OS transistor described in the above embodiment.

[0303] The metal oxide preferably contains at least indium or zinc. It is particularly preferable that it contains indium and zinc. In addition, it is preferable that it contains aluminum, gallium, yttrium, tin, etc. It may also contain one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc.

[0304] Furthermore, metal oxides can be formed by sputtering, CVD methods such as MOCVD, or ALD methods.

[0305] <Classification of crystal structures> Examples of crystalline structures for oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal.

[0306] The crystal structure of a film or substrate can be evaluated using X-ray diffraction (XRD) spectroscopy. For example, it can be evaluated using the XRD spectrum obtained by GIXD (Grazing-Incidence XRD) measurement. The GIXD method is also known as the thin-film method or the Seemann-Bohlin method.

[0307] For example, in a quartz glass substrate, the peak shape of the XRD spectrum is nearly symmetrical. On the other hand, in an IGZO film with a crystalline structure, the peak shape of the XRD spectrum is asymmetrical. The asymmetrical shape of the XRD spectrum peak clearly indicates the presence of crystals in the film or substrate. In other words, if the peak shape of the XRD spectrum is not symmetrical, the film or substrate cannot be said to be in an amorphous state.

[0308] Furthermore, the crystalline structure of a film or substrate can be evaluated by the diffraction pattern (also called the nano-beam electron diffraction pattern) observed using nano-beam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, confirming that the quartz glass is in an amorphous state. In contrast, a spot-like pattern is observed in the diffraction pattern of an IGZO film deposited at room temperature, rather than a halo. Therefore, it is presumed that an IGZO film deposited at room temperature is in an intermediate state, neither crystalline nor amorphous, and cannot be concluded to be in an amorphous state.

[0309] <<Oxide semiconductor structure>> It should be noted that oxide semiconductors may be classified differently from those described above when considering their structure. For example, oxide semiconductors can be divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors also include polycrystalline oxide semiconductors, pseudo-amorphous oxide semiconductors (a-like OS), amorphous oxide semiconductors, etc.

[0310] Here, we will explain the details of the CAAC-OS, nc-OS, and a-like OS mentioned above.

[0311] [CAAC-OS] CAAC-OS is an oxide semiconductor having multiple crystalline regions, the c-axis of which is oriented in a specific direction. This specific direction is the thickness direction of the CAAC-OS film, the normal direction to the surface on which the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region with periodic atomic arrangement. If we consider the atomic arrangement as a lattice arrangement, then a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC-OS has regions where multiple crystalline regions are connected in the ab-plane direction, and these regions may exhibit distortion. Distortion refers to a point in the connected region where the orientation of the lattice arrangement changes between a region with a aligned lattice arrangement and another region with a aligned lattice arrangement. In short, CAAC-OS is an oxide semiconductor that is c-axis oriented and does not exhibit clear orientation in the ab-plane direction.

[0312] Each of the above-mentioned 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 that crystalline region will be less than 10 nm. When a crystalline region is composed of multiple minute crystals, the size of that crystalline region may be around several tens of nanometers.

[0313] Furthermore, in In-M-Zn oxides (where element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, etc.), CAAC-OS tends to have a layered crystalline structure (also called a layered structure) consisting of layers containing indium (In) and oxygen (hereinafter referred to as the In layer) and layers containing element M, zinc (Zn), and oxygen (hereinafter referred to as the (M,Zn) layer). Note that indium and element M are mutually substitutable. Therefore, the (M,Zn) layer may contain indium. Also, the In layer may contain element M. Also, the In layer may contain Zn. This layered structure can be observed, for example, as a lattice image in high-resolution TEM (Transmission Electron Microscope) images.

[0314] When structural analysis of a CAAC-OS film is performed using, for example, an XRD instrument, out-of-plane XRD measurements using θ / 2θ scanning show a peak indicating c-axis orientation at 2θ = 31° or nearby. Note that the position of the peak indicating c-axis orientation (value of 2θ) may vary depending on the type and composition of the metal elements constituting the CAAC-OS.

[0315] Furthermore, for example, multiple bright spots are observed in the electron diffraction pattern of a CAAC-OS film. These spots are observed at point-symmetric positions with respect to the incident electron beam spot (also called the direct spot) that passed through the sample.

[0316] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is based on a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be non-regular hexagonal. Furthermore, the strain may have lattice arrangements such as pentagons or heptagons. Moreover, in CAAC-OS, clear grain boundaries cannot be observed even near the strain. In other words, it can be seen that the formation of grain boundaries is suppressed by the strain in the lattice arrangement. This is thought to be because CAAC-OS can tolerate strain due to the fact that the arrangement of oxygen atoms is not dense in the ab-plane direction, and the bond distance between atoms changes due to the substitution of metal atoms.

[0317] A crystal structure in which clear grain boundaries are observed is called a polycrystal. Grain boundaries act as recombination centers, trapping carriers and potentially causing a decrease in transistor on-current and field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides with a suitable crystal structure for the semiconductor layer of a transistor. In addition, a structure containing Zn is preferred for the composition of CAAC-OS. For example, In-Zn oxide and In-Ga-Zn oxide are preferred because they suppress the generation of grain boundaries more effectively than In oxide.

[0318] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less susceptible to the decrease in electron mobility caused by grain boundaries. Furthermore, since the crystallinity of oxide semiconductors can decrease due to the inclusion of impurities and the generation of defects, CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Consequently, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. In addition, CAAC-OS is stable even at high temperatures (so-called thermal budget) during the manufacturing process. Therefore, using CAAC-OS in OS transistors allows for greater flexibility in the manufacturing process.

[0319] [nc-OS] nc-OS exhibits periodicity in atomic arrangement in minute regions (e.g., regions between 1 nm and 10 nm, particularly between 1 nm and 3 nm). In other words, nc-OS contains minute crystals. These minute crystals are also called nanocrystals because their size is, for example, between 1 nm and 10 nm, particularly between 1 nm and 3 nm. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Consequently, depending on the analytical method, nc-OS may be indistinguishable from a-like OS or amorphous oxide semiconductors. For example, when structural analysis of an nc-OS film is performed using an XRD instrument, no peaks indicating crystallinity are detected in out-of-plane XRD measurements using θ / 2θ scanning. Also, when electron diffraction (also called limited-field electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter larger than that of the nanocrystals (e.g., 50 nm or larger), a diffraction pattern resembling a halo pattern is observed. On the other hand, when electron diffraction (also called nanobeam electron diffraction) is performed on an nc-OS film using an electron beam with a probe diameter close to or smaller than the size of the nanocrystal (for example, 1 nm to 30 nm), an electron diffraction pattern may be obtained in which multiple spots are observed within a ring-shaped region centered on the direct spot.

[0320] [a-like OS] a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, a-like OS has a higher hydrogen concentration in the film compared to nc-OS and CAAC-OS.

[0321] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS refers to the material composition.

[0322] [CAC-OS] CAC-OS is a material composition in which, for example, the elements constituting the metal oxide are unevenly distributed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size. In the following, a state in which one or more metal elements are unevenly distributed in a metal oxide, and the regions containing the metal elements are mixed in sizes of 0.5 nm to 10 nm, preferably 1 nm to 3 nm, or close to that size, is also referred to as a mosaic or patchy state.

[0323] Furthermore, CAC-OS is a composite metal oxide having a mosaic-like structure formed by the separation of the material into a first region and a second region, with the first region distributed within the film (hereinafter also referred to as a cloud-like structure). In other words, CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

[0324] Here, the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in In-Ga-Zn oxide are denoted as [In], [Ga], and [Zn], respectively. For example, in the CAC-OS of In-Ga-Zn oxide, the first region is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. Alternatively, for example, the first region is the region where [In] is greater than the [In] in the second region, and [Ga] is smaller than the [Ga] in the second region. The second region is the region where [Ga] is greater than the [Ga] in the first region, and [In] is smaller than the [In] in the first region.

[0325] Specifically, the first region described above is a region whose main components are indium oxide, indium zinc oxide, etc. The second region described above is a region whose main components are gallium oxide, gallium zinc oxide, etc. In other words, the first region can be rephrased as a region whose main component is In. Similarly, the second region can be rephrased as a region whose main component is Ga.

[0326] Furthermore, a clear boundary may not be observed between the first region and the second region described above.

[0327] Furthermore, CAC-OS in In-Ga-Zn oxide refers to a material composition containing In, Ga, Zn, and O, in which regions with Ga as the main component and regions with In as the main component are arranged in a mosaic-like manner, with these regions existing randomly. Therefore, it is presumed that CAC-OS has a structure in which metal elements are unevenly distributed.

[0328] CAC-OS can be formed, for example, by sputtering under conditions where the substrate is not heated. When forming CAC-OS by sputtering, one or more gases selected from inert gases (typically argon), oxygen gas, and nitrogen gas may be used as the film-forming gas. Furthermore, it is preferable that the ratio of the oxygen gas flow rate to the total flow rate of the film-forming gas during film formation be as low as possible. For example, it is preferable that the ratio of the oxygen gas flow rate to the total flow rate of the film-forming gas during film formation be 0% or more and less than 30%, preferably 0% or more and 10% or less.

[0329] Furthermore, for example, in the case of CAC-OS in In-Ga-Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) confirms that it has a structure in which regions mainly composed of In (first region) and regions mainly composed of Ga (second region) are unevenly distributed and mixed.

[0330] Here, the first region is a region with higher conductivity compared to the second region. In other words, the conductivity of the metal oxide is exhibited when carriers flow through the first region. Therefore, a high field-effect mobility (μ) can be achieved when the first region is distributed in a cloud-like manner within the metal oxide.

[0331] On the other hand, the second region is a region with higher insulating properties compared to the first region. In other words, the distribution of the second region within the metal oxide can suppress leakage current.

[0332] Therefore, when using CAC-OS in a transistor, the conductivity caused by the first region and the insulating property caused by the second region act complementarily, enabling the function of switching (on / off function) to be imparted to the CAC-OS. That is, CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and has a semiconductor function as a whole. By separating the conductive function and the insulating function, both functions can be enhanced to the maximum extent. Therefore, by using CAC-OS in a transistor, a high on-current (I on ), a high field-effect mobility (μ), and a good switching operation can be realized.

[0333] Also, a transistor using CAC-OS has high reliability. Therefore, CAC-OS is optimal for various semiconductor devices including display devices.

[0334] Oxide semiconductors have various structures and each has different characteristics. The oxide semiconductor of one aspect of the present invention may have two or more of amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, CAC-OS, nc-OS, and CAAC-OS.

[0335] <Transistor having an oxide semiconductor> Subsequently, the case of using the above oxide semiconductor in a transistor will be described.

[0336] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility can be realized. Also, a highly reliable transistor can be realized.

[0337] It is preferable to use an oxide semiconductor with a low carrier concentration in the transistor. For example, the carrier concentration of the oxide semiconductor is 1×10 17 cm -3 or less, preferably 1×10 15 cm -3 or less, and more preferably 1×10 13 cm -3More preferably 1 × 10 11 cm -3 More preferably 1 × 10 10 cm -3 It is less than 1 × 10 -9 cm -3 This concludes the explanation. Furthermore, when lowering the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film should be lowered to reduce the defect level density. In this specification, a low impurity concentration and low defect level density are referred to as high-purity intrinsic or substantially high-purity intrinsic. Note that oxide semiconductors with low carrier concentrations are sometimes referred to as high-purity intrinsic or substantially high-purity intrinsic oxide semiconductors.

[0338] Furthermore, oxide semiconductor films that are highly pure or substantially highly pure have a low defect level density, which may result in a low trap level density.

[0339] Furthermore, charges trapped in the trap levels of oxide semiconductors can take a long time to disappear, sometimes behaving like fixed charges. Therefore, transistors in which channel formation regions are formed in oxide semiconductors with a high trap level density may exhibit unstable electrical properties.

[0340] Therefore, reducing the impurity concentration in the oxide semiconductor is effective in stabilizing the electrical characteristics of the transistor. Furthermore, in order to reduce the impurity concentration in the oxide semiconductor, it is preferable to also reduce the impurity concentration in adjacent films. Examples of impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, and silicon.

[0341] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0342] In oxide semiconductors, the presence of silicon or carbon, which are Group 14 elements, leads to the formation of defect levels 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 compared by 2 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 17 atoms / cm 3 The following applies:

[0343] Furthermore, if an oxide semiconductor contains alkali metals or alkaline earth metals, it may form defect levels and generate carriers. Therefore, transistors using oxide semiconductors containing alkali metals or alkaline earth metals tend to exhibit normally-on characteristics. For this reason, the concentration of alkali metals or alkaline earth metals in the oxide semiconductor obtained by SIMS should be set to 1 × 10⁻⁶. 18 atoms / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0344] Furthermore, in oxide semiconductors, the presence of nitrogen generates electrons, which act as carriers, increasing the carrier concentration and making it easier for the semiconductor to become n-type. As a result, transistors using oxide semiconductors containing nitrogen tend to exhibit normally-on characteristics. Alternatively, the presence of nitrogen in oxide semiconductors can lead to the formation of trap levels. As a result, the electrical properties of the transistor may become unstable. For this reason, the nitrogen concentration in oxide semiconductors obtained by SIMS should be set to 5 × 10⁻⁶. 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm 3 More preferably 5 × 10 17 atoms / cm 3 Do the following:

[0345] Furthermore, hydrogen contained in oxide semiconductors can react with oxygen bonded to metal atoms to form water, potentially creating oxygen vacancies. Hydrogen can then fill these vacancies, generating electrons, which act as carriers. Additionally, some of the hydrogen can combine with oxygen bonded to metal atoms to generate electrons. Therefore, transistors using oxide semiconductors containing hydrogen tend to exhibit normally-on characteristics. For this reason, it is preferable to reduce the hydrogen content in oxide semiconductors as much as possible. Specifically, in oxide semiconductors, the hydrogen concentration obtained by SIMS should be 1 × 10⁻⁶. 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x10 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 Make it less than.

[0346] By using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor, stable electrical characteristics can be imparted.

[0347] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate.

[0348] (Embodiment 8) An example of the method for manufacturing the above-described display device will be explained with reference to Figures 13 to 17, etc. In the figures, the area related to the pixel 150 is shown on the left, and the area related to the auxiliary wiring 151 is shown on the right.

[0349] [Example of manufacturing method 1] Thin films (insulating films, semiconductor films, conductive films, etc.) that constitute display devices can be formed using sputtering, CVD, vacuum deposition, PLD, or ALD methods. CVD methods include plasma-enhanced CVD (PECVD) and thermal CVD. One type of thermal CVD is metal-organic CVD (MOCVD).

[0350] Thin films (insulating films, semiconductor films, conductive films, resin films, etc.) that constitute a display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating. These are wet film formation methods.

[0351] When processing the thin film that constitutes the display device, photolithography or the like can be used. In addition, the thin film may be processed by nanoimprint lithography, sandblasting, lift-off lithography, or the like. Furthermore, the thin film may be directly formed by a film deposition method using a metal mask or the like.

[0352] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0353] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other options include ultraviolet light, KrF laser light, or ArF laser light. Extreme ultraviolet (EUV) light, X-rays, etc., may also be used for exposure. Alternatively, an electron beam can be used instead of light. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it allows for extremely fine processing. Note that a resist mask is not required when exposure is performed by scanning a beam such as an electron beam.

[0354] For etching thin films, dry etching, wet etching, or sandblasting methods can be used.

[0355] [Preparing the circuit board] Although not shown in the diagram, a substrate is prepared. The substrate should have at least sufficient heat resistance to withstand subsequent heat treatment. If an insulating substrate is used, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, or organic resin substrates can be used. In addition, semiconductor substrates such as single-crystal semiconductor substrates made of silicon, silicon carbide, etc., polycrystalline semiconductor substrates, compound semiconductor substrates such as silicon germanium, and SOI substrates can be used.

[0356] Preferably, the substrate is a semiconductor substrate or an insulating substrate on which a pixel circuit including semiconductor elements such as transistors is formed. In addition to the pixel circuit, a substrate on which a gate line drive circuit (gate driver) or a source line drive circuit (source driver) is formed may also be used. Furthermore, a substrate on which an arithmetic circuit or a memory circuit is formed in addition to the above may also be used.

[0357] [Formation of insulating layer 102] As shown in Figure 13A, an insulating layer 102 is formed on the substrate described above. The insulating layer 102 can be made of an inorganic or organic material. Organic materials are preferred because they ensure the flatness of the upper surface of the insulating layer 104. As the organic material, one or more selected from acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used. If two or more are used, the selected organic materials can be laminated.

[0358] As shown in Figure 13A, the insulating layer 102 has contact holes 158. These contact holes 158 can be formed by photolithography or the like.

[0359] [Formation of conductive layer 160 and first wiring layer 151a] As shown in Figure 13A, the conductive layer 160 and the first wiring layer 151a are formed on the insulating layer 102 and the contact holes 158. That is, the conductive layer 160 and the first wiring layer 151a are formed on the same surface and through the same process. Specifically, the conductive layer 160 and the first wiring layer 151a can be obtained by processing the conductive film formed on the insulating layer 102 and the contact holes 158.

[0360] The conductive layer 160 is electrically connected to the transistor of the pixel circuit and also to the lower electrode 111. The conductive layer 160 can also be processed into an extended shape on the insulating layer 102 and can function as a signal line, power line, or scanning line. Alternatively, the conductive layer 160 may be used as a conductive layer to electrically connect the transistor and the lower electrode 111 without functioning as wiring. The first wiring layer 151a can function as a lower wiring layer for the auxiliary wiring 151 and can be processed into an extended shape or a grid shape on the insulating layer 102. Since the first wiring layer 151a does not affect the aperture ratio, it may have a shape that provides a large area. However, the first wiring layer 151a should not come into contact with the conductive layer 160.

[0361] The conductive layer 160 and the first wiring layer 151a can be made of one or more metallic materials selected from aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, as well as alloys of these materials in appropriate combinations. Since the first wiring layer 151a functions as a lower wiring layer for auxiliary wiring, it is preferable to use a metallic material with low resistivity.

[0362] The conductive layer 160 and the first wiring layer 151a may have a single-layer structure having the above-mentioned metal material, or they may have a laminated structure having the above-mentioned metal material.

[0363] [Formation of insulating layer 104] As shown in Figure 13A, an insulating layer 104 is formed on the insulating layer 102. The insulating layer 104 can be made of an inorganic or organic material. Organic materials are preferred because they ensure the flatness of the upper surface of the insulating layer 104. As the organic material, one or more selected from acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used. If two or more are used, the selected organic materials can be laminated.

[0364] The insulating layer 104 has a contact hole 159. This contact hole 159 can be formed by photolithography or the like, and a portion of the conductive layer 160 is exposed through the contact hole 159. The contact hole 159 should not overlap with the contact hole 158, but should be positioned to overlap with the conductive layer 160 provided on the flat upper surface of the insulating layer 102. If the contact hole 159 overlaps with the contact hole 158, it is preferable that the contact hole 159 is larger than the contact hole 158.

[0365] [Formation of conductive layer 161, resin layer 163, and conductive layer 162] As shown in Figure 13A, a conductive layer 161 is formed in the contact hole 159, followed by a resin layer 163, and then a conductive layer 162. Alternatively, the lower electrode 111 and the second wiring layer 151b may be formed without forming the conductive layer 161, the resin layer 163, and the conductive layer 162.

[0366] A conductive film, which will become the conductive layer 161, is formed on the insulating layer 104 and the contact holes 159. The upper surface of the insulating layer 104 is the surface on which the conductive film is formed, and it is preferable that the upper surface is flat so that the conductive film is less likely to be cut. The conductive layer 161 can be made of one or more metallic materials selected from aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, as well as alloys of these materials in appropriate combinations.

[0367] If the surface of the conductive film has depressions after the conductive film has been formed, it is preferable to form a layer (referred to as a resin layer) 163 having a resin as an organic material in the depressions. The resin layer 163 can reduce the irregularities caused by the insulating layer 104, contact holes 159, and conductive layer 161.

[0368] It is preferable to use a photosensitive resin as the resin layer 163. In this case, the resin layer 163 can be formed by first depositing a resin film, exposing the resin film through a resist mask, and then performing a development process. More preferably, the upper part of the resin layer 163 may be etched by ashing or the like to adjust the height of the upper surface of the resin layer 163.

[0369] Furthermore, when a non-photosensitive resin is used as the resin layer 163, the resin layer 163 can be formed by etching the upper part of the resin film after the resin film has been deposited, using methods such as ashing. The ashing is carried out until 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 other methods.

[0370] Next, a conductive film that will become the conductive layer 162 is formed on the resin layer 163. The conductive layer 162 may have one or more selected from the metals shown as the conductive layer 161.

[0371] [Formation of the lower electrode 111 and the second wiring layer 151b] As shown in Figure 13A, conductive films that will form the lower electrode 111 and the second wiring layer 151b are formed by covering the conductive film that will form the conductive layer 161 and the conductive film that will form the conductive layer 162. The lower electrode 111 has the function of either an anode or a cathode, and metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. For specific materials that can be used for the lower electrode 111, please refer to the description related to the lower electrode. The second wiring layer 151b may be formed using the same material as the lower electrode 111.

[0372] Subsequently, a resist mask is formed on the three conductive films by photolithography, and unnecessary portions of each conductive film are removed by etching. After removing the resist mask, the conductive layer 161, conductive layer 162, lower electrode 111, and second wiring layer 151b can be formed using the same resist mask and the same etching process. The lower electrode 111 and the second wiring layer 151b can have a flat upper surface due to the resin layer 163, etc.

[0373] Although conductive layer 161 and conductive layer 162 were formed using the same resist mask and the same etching process, conductive layer 161 and conductive layer 162 may be processed individually using different resist masks. In this case, it is preferable to process conductive layer 161 and conductive layer 162 such that, in a top view, conductive layer 162 is contained inside the contour of conductive layer 161.

[0374] Furthermore, although the conductive layer 162 and the lower electrode 111 etc. were formed using the same resist mask and the same etching process, the conductive layer 162 and the lower electrode 111 etc. may be processed individually using different resist masks. In this case, it is preferable to process the conductive layer 162 and the lower electrode 111 etc. such that, in a top view, the lower electrode 111 is contained inside the contour of the conductive layer 162 etc.

[0375] [Deposition of organic compound film 112fR] As shown in Figure 13B, a red-emitting organic compound film 112fR is formed covering the lower electrode 111 and the second wiring layer 151b. The organic compound film 112fR is a laminate of each functional layer of the light-emitting device. Although the film is formed from a red-emitting organic compound, in one aspect of the present invention, it may be formed from a green-emitting organic compound. In another aspect of the present invention, it may be formed from a blue-emitting organic compound.

[0376] The organic compound film 112fR may be a single structure or a tandem structure. When the organic compound film 112fR is in a tandem structure, it is preferable to have a charge generation layer between the first light-emitting unit and the second light-emitting unit.

[0377] The charge generation layer can include a layer containing a hole-transporting material and an acceptor material (electron-accepting material). Alternatively, the charge generation layer can include a layer containing an electron-transporting material and a donor material.

[0378] The materials used in the electron injection layer described above may be used as electron transport materials. Since the charge generation layer is later processed by etching or the like, materials that do not contain alkali metals or alkaline earth metals are preferred among the materials used in the electron injection layer, and for example, organic compounds containing dopants are suitable. NBPhen can be used as the organic compound, and Ag can be used as the dopant.

[0379] The functional layer of the organic compound film 112fR can be formed by vacuum deposition. However, it is not limited to this method; the functional layer of the organic compound film 112fR can also be formed by sputtering, inkjet, or other methods.

[0380] In Figure 13B, the organic compound film 112fR is formed to cover the second wiring layer 151b, but it is not necessary to cover the second wiring layer 151b. This prevents the second wiring layer 151b from coming into contact with the organic compound film 112fR, and is preferable because the removal agent used to remove the organic compound film 112fR does not come into contact with the lower electrode 111 or the surface of the second wiring layer 151b.

[0381] Alternatively, the organic compound film 112fR may be fabricated and deposited using a fine metal mask. In this case, it is preferable to form the organic compound film 112fR so as to cover only the lower electrode 111R. This prevents the second wiring layer 151b from coming into contact with the organic compound film 112fR, and is also preferable because the removal agent used to remove the organic compound film 112fR does not come into contact with the surface of the lower electrode 111 and the second wiring layer 151b.

[0382] The organic compound film 112fR has various functional layers, and preferably forms a laminate having, in order from the bottom electrode 111, at least a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer.

[0383] Furthermore, one of the functional layers is the electron injection layer located on the electron transport layer. In this embodiment, the electron injection layer is a common layer and is formed later. The common layer can be any functional layer located between the light-emitting layer and the common electrode. Of course, it is also possible to omit the common layer and separate all functional layers for each sub-pixel.

[0384] The electron transport layer, located at the top of the organic compound film 112fR, is exposed to a processing method using photolithography. Therefore, it is preferable to use a material with high heat resistance for the electron transport layer. As a material with high heat resistance, for example, a material with a glass transition temperature of 110°C to 165°C, preferably 120°C to 135°C, is preferable.

[0385] Furthermore, the electron transport layer exposed to processing may be a laminated structure. One example of a laminated structure is one in which a second electron transport layer is laminated on a first electron transport layer. During processing, the first electron transport layer is covered by the second electron transport layer for a period of time, so 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 with a glass transition temperature of 110°C to 165°C, preferably 120°C to 135°C, and the glass transition temperature of the first electron transport layer may be lower than that of the second electron transport layer, for example, a material with a glass transition temperature of 100°C to 155°C, preferably 110°C to 125°C.

[0386] While it is conceivable to use the top layer of the organic compound film 112fR as the light-emitting layer, damage from such processing may penetrate the light-emitting layer, significantly impairing its reliability. Therefore, when manufacturing a display device according to one embodiment of the present invention, it is preferable to form a functional layer (e.g., an electron transport layer) above the light-emitting layer before performing the above processing.

[0387] [Deposition of mask film 144R] Furthermore, it is preferable to form a mask layer or the like on the organic compound film. The mask layer can also suppress damage caused by processing from entering the light-emitting layer. By applying this method, a highly reliable display panel can be provided. In this specification, 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 Figure 13C, a mask film 144R is formed by covering the organic compound film 112fR.

[0388] When etching the organic compound film 112fR, it is preferable to use a mask film 144R that has a high etching selectivity ratio with the organic compound film 112fR. Furthermore, if mask films 144R are stacked, it is preferable to use a mask film 144R that has a high etching selectivity ratio with the upper mask film (specifically, mask film 146R) described later. Additionally, when removing the mask film 144R, it is preferable to use a film that can be removed by a wet etching method that minimizes damage to the organic compound film 112fR.

[0389] As the mask film 144R, suitable examples include metal films, alloy films, metal oxide films, semiconductor films, inorganic films such as inorganic insulating films, etc. The mask film 144R can be formed by various film deposition methods such as sputtering, vapor deposition, CVD, and ALD.

[0390] In particular, since the ALD method causes less damage to the layer to be formed, it is preferable to form the mask film 144R directly on the organic compound film 112fR using the ALD method.

[0391] As the mask film 144R, for example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used. In particular, it is preferable to use low-melting-point materials such as aluminum or silver.

[0392] Furthermore, metal oxides such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) can be used as the mask film 144R. In addition, 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), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), etc. can be used. Alternatively, indium tin oxide containing silicon can also be used.

[0393] Furthermore, this method can also be applied when element M (where M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) is used instead of gallium. In particular, it is preferable that M be one or more elements selected from gallium, aluminum, or yttrium.

[0394] Furthermore, the mask film 144R may contain an inorganic material. As the inorganic material, oxides such as aluminum oxide, hafnium oxide, and silicon oxide, nitrides such as silicon nitride and aluminum nitride, or oxynitrides such as silicon oxynitride can be used. Such inorganic materials can be formed using film deposition methods such as sputtering, CVD, or ALD.

[0395] Furthermore, the mask film 144R may contain an organic material. For example, as the organic material, a material that is soluble in a chemically stable solvent relative to the organic compound film 112fR may be used. In particular, a material soluble in water or alcohol can be suitably used for the mask film 144R. When forming the mask film 144R, it is preferable to apply it using a wet deposition method while dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the EL layer.

[0396] A wet deposition method can be used to form the mask film 144R.

[0397] The mask film 144R can be an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. Alternatively, a fluororesin such as perfluoropolymer may be used for the mask film 144R.

[0398] [Deposition of mask film 146R] As shown in Figure 13C, a mask film 146R is deposited 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 using only the mask film 144R or only the mask film 146R as a single layer mask film.

[0399] Mask film 146R is best used as a hard mask when etching mask film 144R later. After processing mask film 146R, mask film 144R is exposed. Therefore, when using mask film 146R as a half-degree mask, it is best to select a combination of mask films 144R and 146R that have a high selectivity ratio for etching each other.

[0400] The mask film 146R can be selected from a variety of materials, depending on the etching conditions of the mask film 144R and the mask film 146R. For example, it can be selected from films that can be used for the mask film 144R, and a different material from the mask film 144R can be chosen.

[0401] 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, or hafnium oxynitride.

[0402] Furthermore, a nitride film can be used as the mask film 146R, for example. Typical nitride films include silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, or germanium nitride.

[0403] As a combination of mask film 144R and 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 mask film 144R, and an indium-containing metal oxide such as indium gallium zinc oxide (In-Ga-Zn oxide, also written as IGZO) formed by the sputtering method can be used as mask film 146R.

[0404] Furthermore, the mask film 146R, which is combined with the mask film 144R, may also be made of one or more metals selected from tungsten, molybdenum, copper, aluminum, titanium, and tantalum, as well as alloys containing such metals. When forming the mask film 146R as a hard mask, it is preferable to use the above metals or alloys. When forming the mask film 146R as a hard mask, it is preferable to make the film thickness of the mask film 146R greater than the film thickness of the mask film 144R.

[0405] [Formation of resist mask 143] As shown in Figure 14A, a resist mask 143 is formed on the mask film 146R at a position overlapping with the lower electrode 111R. At this time, a resist mask is not formed at positions overlapping with the lower electrode 111G, the lower electrode 111B, and the auxiliary wiring 151.

[0406] The resist mask 143 can use a resist material containing a photosensitive resin, such as a positive-type resist material or a negative-type resist material.

[0407] When a solvent for the resist material is used that dissolves the organic compound film 112fR, and a mask film 146R is not provided, and defects such as pinholes exist in the mask film 144R, there is a risk that the organic compound film 112fR may dissolve. In this case, when forming the resist mask 143, positioning the mask film 146R on top of the mask film 144R can prevent such a problem from occurring.

[0408] When a solvent for the resist material is used that does not dissolve the organic compound film 112fR, the resist mask 143 may be formed directly on the mask film 144R without providing a mask film 146R.

[0409] [Etching of mask film 146R] As shown in Figure 14B, a portion of the mask film 146R that is not covered by the resist mask 143 is removed by etching to form a mask layer 147R.

[0410] When etching the mask film 146R, it is preferable to use etching conditions with a high selectivity ratio so that the mask film 144R is not removed by the etching. The mask film 146R can be etched by wet etching or dry etching.

[0411] [Removal of Resist Mask 143] As shown in Figure 14B, the resist mask 143 is removed. The removal of the resist mask 143 is performed while the organic compound film 112fR is covered by the mask film 144R.

[0412] The resist mask 143 can be removed by wet etching or dry etching. In particular, it is preferable to remove the resist mask 143 by dry etching (also called plasma ashing) using oxygen gas as the etching gas.

[0413] To reiterate, the removal of the resist mask 143 is performed with the organic compound film 112fR covered by the mask film 144R, thus suppressing processing damage to the organic compound film 112fR. In particular, since oxygen can adversely affect the properties of the organic compound film 112fR when it comes into contact with it, it is preferable to perform the etching using the above-mentioned oxygen gas while the organic compound film 112fR is covered by the mask film 144R. Furthermore, even when the resist mask 143 is removed by wet etching, the organic compound film 112fR does not come into contact with the chemical solution, thus preventing the organic compound film 112fR from dissolving.

[0414] [Etching of mask film 144R] As shown in Figure 14C, the mask layer 147R is used as a hard mask, and a portion of the mask film 144R is removed by etching to form the mask layer 145R.

[0415] The mask film 144R can be etched by wet etching or dry etching.

[0416] [Etching of organic compound film 112fR] As shown in Figure 15A, a portion of the organic compound film 112fR not covered by the mask layer 145R is removed by etching to form an organic compound layer 112R. The organic compound layer 112R becomes the organic compound layer of the light-emitting device from which red light is emitted.

[0417] For etching the organic compound film 112fR, it is preferable to use dry etching with an etching gas that does not contain oxygen as its main component. This is because, as mentioned above, contact with oxygen can adversely affect the properties of the organic compound film 112fR. Specifically, the organic compound film 112fR may be altered, but by using an etching gas that does not contain oxygen as its main component, this alteration can be suppressed, and a highly reliable display device can be realized. Examples of etching gases that do not contain oxygen as its main component include noble gases such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, H2, or He. Alternatively, a mixed gas of the above gases and an oxygen-free diluent gas may be used as the etching gas.

[0418] Furthermore, etching of the organic compound film 112fR is not limited to the above; it may also be performed by dry etching using other gases or by wet etching.

[0419] After etching, it is preferable that the taper angle of the end face of the organic compound layer 112R is between 45 degrees and less than 90 degrees.

[0420] During etching of the organic compound film 112fR, the insulating layer 104 is exposed. As a result, recesses may be formed in the insulating layer 104 in the region overlapping with the slit 118. If it is not possible to form recesses, it is preferable to use a film with high resistance to etching of the organic compound film 112fR for the insulating layer 104. For example, an insulating film having an inorganic material may be used as the insulating layer 104.

[0421] [Deposition and etching of a green organic compound film 112fG] As shown in Figure 15B, the organic compound layer 112G is formed using mask layers 145G and 147G, following etching after deposition of the organic compound film 112fR. Preferably, the taper angle of the end face of the organic compound layer 112G is 45 degrees or more and less than 90 degrees. The organic compound layer 112G becomes the organic compound layer of a light-emitting device that emits green light.

[0422] [Deposition and etching of blue organic compound film 112fB] As shown in Figure 15B, the organic compound layer 112B is formed using mask layers 145B and 147B, following etching after deposition of the organic compound film 112fR. Preferably, the taper angle of the end face of the organic compound layer 112B is 45 degrees or more and less than 90 degrees. The organic compound layer 112B becomes the organic compound layer of a light-emitting device that emits green light.

[0423] When describing matters common to organic compound layer 112R, organic compound layer 112G, and organic compound layer 112B, they shall be referred to as organic compound layer 112. At least a highly heat-resistant functional layer, such as an electron transport layer, should be located on the outermost surface of organic compound layer 112.

[0424] No organic compound film is placed on the second wiring layer 151b, and the second wiring layer 151b is exposed.

[0425] Furthermore, slits 118 are formed between the organic compound layers 112. That is, the organic compound layers 112 obtained through the process of processing using photolithography can have slits 118 with widths of 8 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less, as indicated by the arrows in Figure 15B. The width of the slits 118 corresponds to the distance between each subpixel. By narrowing the distance between each subpixel, a display device with high resolution and a high aperture ratio can be provided.

[0426] As shown by the slit 118, the adjacent organic compound layers 112 are spaced apart, interrupting the current leakage path and suppressing leakage current (also called side leakage or side leakage current). This makes it possible to increase brightness, enhance contrast, improve display quality, increase power efficiency, or reduce power consumption in the light-emitting device.

[0427] The end faces of adjacent organic compound layers 112 should preferably face each other with a slit 118 in between. In organic compound layers formed using a metal mask, the end faces cannot face each other. Therefore, an organic compound layer having the above-mentioned shape where the end faces face each other is different from an organic compound layer formed using a metal mask.

[0428] During etching of the organic compound film, the insulating layer 104 is exposed. As a result, recesses may be formed in the insulating layer 104 in the region overlapping with the slit 118. If it is not possible to form recesses, it is preferable to use a film with high resistance to etching of the organic compound film for the insulating layer 104. For example, an insulating film having an inorganic material may be used as the insulating layer 104.

[0429] [Removal of the mask layer] As shown in Figure 15C, the mask layer 147 is removed, exposing the upper surface of the mask layer 145.

[0430] [Formation of insulating film 125f] As shown in Figure 16A, an insulating film 125f is formed covering the mask layer 145 and the second wiring layer 151b.

[0431] The insulating film 125f functions as a barrier layer that prevents impurities such as water from diffusing into the organic compound layer 112. It is preferable to form the insulating film 125f by the ALD method, which has excellent step coverage, because it can suitably cover the sides of the organic compound layer 112.

[0432] It is preferable to use the same film for the insulating film 125f as for the mask layer 145 and the mask layer 147, as this allows for easy and simultaneous removal during the subsequent etching process. For example, it is preferable to use one or more inorganic materials selected from aluminum oxide, hafnium oxide, and silicon oxide formed by the ALD method as the insulating film 125f, the mask layer 145, and the mask layer 147.

[0433] The materials that can be used for the insulating film 125f are not limited to those mentioned above. For example, any material that can be used for the mask layer 145 can be used as appropriate.

[0434] [Formation of insulating layer 126] As shown in Figure 16A, an insulating layer 126 is formed in the area overlapping with the slit 118. The insulating layer 126 can be formed in the same manner as the resin layer 163. For example, the insulating layer 126 can be formed by exposing and developing a photosensitive resin after it has been formed. Alternatively, the insulating layer 126 may be formed by etching a portion of the resin after the resin has been formed over the entire surface, such as by ashing.

[0435] Here, the insulating layer 126 is shown to have a width greater than the width of the slit 118. The insulating layer 126 is provided such that a portion of the upper surface of the second wiring layer 151b is exposed.

[0436] [Etching of insulating film 125f and mask layer 145] As shown in Figure 16B, the portions of the insulating film 125f and the mask layer 145 not covered by the insulating layer 126 are removed by etching, exposing a portion of the upper surface of the organic compound layer 112. As a result, the insulating layer 125 and the mask layer 145 remain in the region overlapping with the insulating layer 126. The central part of the insulating layer 126 is located above the edges of the insulating layer 126, and it is preferable that the central part has a raised region above the edges. It is preferable that the upper surface of the insulating layer 126 is located above the upper surface of the organic compound layer 112. Furthermore, it is preferable that the edges of the insulating layer 126 have a tapered shape.

[0437] It is preferable to perform the etching of the insulating film 125f and the mask layer 145 in the same process. In particular, it is preferable to perform the etching of the mask layer 145 by wet etching, which causes less etching damage to the organic compound layer 112. For example, it is preferable to use wet etching with an aqueous solution of tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0438] It is preferable to remove at least one of the insulating film 125f and the mask layer 145 by dissolving it in a solvent such as water or alcohol. Here, various alcohols can be used as the alcohol that can dissolve the insulating film 125f and the mask layer 145, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0439] After removing the insulating film 125f and a portion of the mask layer 145, it is preferable to perform a drying treatment to remove water contained inside the organic compound layer 112 and other components, as well as water adsorbed on the surface. For example, it is preferable to perform a heat treatment under an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C to 200°C, preferably 60°C to 150°C, and more preferably 70°C to 120°C. A reduced pressure atmosphere is preferable because it allows drying at a lower temperature.

[0440] By removing a portion of the insulating film 125f, a portion of the upper surface of the second wiring layer 151b is exposed.

[0441] [Formation of common layer 114] As shown in Figure 16C, a common layer 114 is formed by covering the organic compound layer 112, the insulating layer 125, the mask layer 145, and the insulating layer 126, etc.

[0442] The common layer 114 can be made of a material that can be used in the electron injection layer described above, such as alkali metals, alkaline earth metals, or compounds thereof. Alternatively, composite materials of organic compounds and alkali metals or alkaline earth metals can be used. Specifically, lithium fluoride (LiF), or composite materials containing NBPhen and Ag are suitable.

[0443] The common layer 114 can be formed using the same method as for the organic compound film 112fR, etc. To obtain the above composite material, it is preferable to form the film using co-evaporation.

[0444] [Formation of common electrode 113] As shown in Figure 16C, a common electrode 113 is formed by covering the common layer 114.

[0445] The common electrode 113 can be formed by a film deposition method such as vapor deposition or sputtering. Alternatively, a film formed by vapor deposition and a film formed by sputtering may be laminated together.

[0446] It is preferable to form the common electrode 113 so as to encompass the region where the common layer 114 is formed.

[0447] A common layer 114 may be positioned between the second wiring layer 151b and the common electrode 113. In this case, it is preferable to use a material with the lowest possible 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 it as thin as possible. For example, by using an electron-injection or hole-injection material with a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the common layer 114, the electrical resistance between the second wiring layer 151b and the common electrode 113 can be reduced to a negligible degree.

[0448] The common layer 114 does not necessarily have to be located between the second wiring layer 151b and the common electrode 113.

[0449] [Formation of a protective layer] As shown in Figure 16C, a protective layer 121 is formed on the common electrode 113. For depositing the inorganic insulating film used in the protective layer 121, sputtering, PECVD, or ALD methods are preferred. The ALD method is particularly preferred because it offers excellent step coverage and is less prone to defects such as pinholes. Furthermore, for depositing the organic insulating film, the inkjet method is preferred because it allows for the formation of a uniform film in the desired area.

[0450] [Formation of opposing substrate] As shown in Figure 17A, the substrate 170 is bonded using the adhesive layer 171. The substrate 170 to be bonded is sometimes referred to as the opposing substrate. When the display device has a hollow sealing structure, it is preferable to bond the substrate 170 using a sealing material. When the substrate is bonded using a sealing material, a space is created, and it is preferable to fill this space with an inert gas (a gas containing nitrogen or argon).

[0451] For example, organic materials such as reaction-curing adhesives, photocuring adhesives, thermosetting adhesives, and / or anaerobic adhesives can be used for the adhesive layer 171.

[0452] 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 in the adhesive layer 171, etc.

[0453] As shown in Figure 17B, the substrate 170 is provided with a light-shielding layer 152, a colored layer 173R, a colored layer 173G, and a colored layer 173B. The light-shielding layer 152 is provided in the region that overlaps with the insulating layer 126. The substrate 170 should be bonded together so that the colored layers 173R, 173G, and 173B overlap with the lower electrodes 111R, 111G, and 111B, respectively.

[0454] The colored layers 173R, 173G, and 173B can be formed at desired positions by etching processes using inkjet or photolithography. Specifically, different colored layers 173 (colored layer 173R, colored layer 173G, or colored layer 173B) can be formed for each pixel.

[0455] Light emitted toward the common electrode 113 is colored by the absorption of light in a predetermined wavelength range by the colored layer 173R, colored layer 173G, or colored layer 173B (not shown), and is emitted to the outside via the substrate 170, enabling full-color display.

[0456] Based on the above, a display device can be manufactured.

[0457] [Example of manufacturing method 2] A method for fabrication using a metal mask will be explained with reference to Figures 18 and 19. In the figures, the area related to pixel 150 is shown on the left, and the area related to auxiliary wiring 151 is shown on the right.

[0458] Similar to the above example of fabrication method 1, the lower electrode 111 and the second wiring layer 151b are formed. As shown in Figure 18A, the organic compound film 112jR is formed using a metal mask 135R. Because a metal mask 135R is used, the organic compound film 112jR can be formed only in the region that will become the red light-emitting device.

[0459] As shown in Figure 18B, the organic compound film 112jG is formed using a metal mask 135G. Because a metal mask 135G is used, the organic compound film 112jG can be formed only in the region that will become the green light-emitting device, but the organic compound film 112jG has a region that overlaps with a part of the organic compound film 112jR. That is, at the boundary of the light-emitting device, the organic compound film has a region that overlaps with a part of the previously formed organic compound film.

[0460] As shown in Figure 18C, the organic compound film 112jB is formed using the metal mask 135B. Because the metal mask 135B is used, the organic compound film 112jB can be formed only in the region that will become the blue light-emitting device, but the organic compound film 112jB has a region that overlaps with a part of the organic compound film 112jG. Although not shown, the organic compound film 112jB also has a region that overlaps with a part of the organic compound film 112jR. In other words, at the boundary of the light-emitting device, the organic compound film has a region that overlaps with a part of the previously formed organic compound film.

[0461] As shown in Figure 19A, mask films 144 and 146 are formed. Mask films 144 and 146 can be formed in the same manner as in manufacturing method example 1.

[0462] As shown in Figure 19B, resist masks 143R, 143G, and 143B are formed. Resist masks 143R, 143G, and 143B can be formed in the same manner as in example 1 of the manufacturing method.

[0463] As shown in Figure 19C, the organic compound films 112jR, 112jG, and 112jB are etched using resist masks 143R, 143G, and 143B. The etching conditions can be the same as in Fabrication Method Example 1. Then, just like in Fabrication Method Example 1, the organic compound layers 112R, 112G, and 112B are formed with gaps between the slits 118.

[0464] Subsequently, the insulating layer 126, common layer 114, common electrode 113, and protective layer 121 are formed in the same manner as in manufacturing method example 1. Finally, the substrate 170 and the like are bonded together to manufacture the display device.

[0465] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0466] (Embodiment 9) In this embodiment, a display device according to one aspect of the present invention will be described with reference to the drawings.

[0467] [Specific examples of display devices] A large-scale display device using multiple display modules DP having the display device shown in the above embodiment and an FPC74 will be described with reference to Figure 20.

[0468] Figure 20A shows a top view of the display module DP. The display module DP has a region 72 adjacent to the pixel section 103 that transmits visible light and a region 73 that blocks visible light.

[0469] Figures 20B and 20C show perspective views of a display device having four display modules DP. By arranging multiple display modules DP in one or more directions (for example, in a row or matrix), a large display device with a wide display area can be manufactured.

[0470] When manufacturing a large display device using multiple display modules (DPs), the size of each individual DP does not need to be large. Therefore, the manufacturing equipment for producing the DPs does not need to be enlarged, allowing for space savings. Furthermore, manufacturing equipment for small to medium-sized display panels can be used, eliminating the need for new manufacturing equipment to enlarge the display device, thus reducing manufacturing costs. In addition, the decrease in yield associated with increasing the size of the DPs can be suppressed.

[0471] The outer periphery of the pixel section 103 contains a non-display area where wiring and other components are routed. This non-display area corresponds to the visible light-blocking area 73. When multiple display modules DP are stacked, the non-display area and other components may cause the image to appear separated.

[0472] Therefore, in one aspect of the present invention, a visible light-transmitting region 72 is provided in the display module DP, and in two overlapping display modules, the pixel portion 103 of the lower display module DP and the visible light-transmitting region 72 of the upper display module DP are superimposed.

[0473] By providing a region 72 that transmits visible light in this way, there is no need to actively reduce the non-display area in the display module DP. However, in the case of two overlapping display modules DP, the non-display area is reduced, which is preferable. This makes it possible to realize a large display device in which the seam between the display modules DP is less noticeable to the user.

[0474] In the upper display module DP, a visible light-transmitting area 72 may be provided in at least a portion of the non-display area. This visible light-transmitting area 72 can be superimposed with the pixel portion 103 of the lower display module DP.

[0475] Furthermore, at least a portion of the non-display area of ​​the lower display module DP overlaps with the pixel area 103 or the visible light-blocking area 73 of the upper display module DP.

[0476] A larger non-display area in the display module DP is preferable because it increases the distance between the edges of the display module DP and the elements within the display module DP, thereby suppressing degradation of the elements due to impurities entering from outside the display module DP.

[0477] Thus, when a display device is equipped with multiple display modules DP, the pixel sections 103 are continuous between adjacent display modules DP, thus providing a wide display area.

[0478] The pixel section 103 contains multiple pixels.

[0479] The visible light-transmitting region 72 may be provided with a resin material or the like for sealing a pair of substrates constituting the display module DP and the display elements sandwiched between the pair of substrates. In this case, the material provided in the visible light-transmitting region 72 is a material that is transparent to visible light.

[0480] The visible light-blocking region 73 may be provided with wiring or the like that is electrically connected to the pixels included in the pixel section 103. Furthermore, the visible light-blocking region 73 may be provided with either or both of a scan line drive circuit and a signal line drive circuit. Additionally, the visible light-blocking region 73 may be provided with terminals connected to the FPC 74, wiring or the like that is connected to those terminals.

[0481] Figures 20B and 20C show an example in which the display module DP shown in Figure 20A is arranged in a 2x2 matrix (two in the vertical direction and two in the horizontal direction). Figure 20B is a perspective view of the display side of the display module DP, and Figure 20C is a perspective view of the display module DP on the opposite side from the display side.

[0482] The four display modules DP (display modules DPa, DPb, DPc, and DPd) are arranged so that they have overlapping regions. Specifically, the display modules DPa, DPb, DPc, and DPd are arranged such that the visible light-transmitting region 72 of one display module DP overlaps with the pixel portion 103 of another display module DP (on the display surface side). In addition, the display modules DPa, DPb, DPc, and DPd are arranged so that the visible light-blocking region 73 of one display module DP does not overlap with the pixel portion 103 of another display module DP. In the overlapping portions of the four display modules DP, display module DPb overlaps display module DPa, display module DPc overlaps display module DPb, and display module DPd overlaps display module DPc.

[0483] The shorter sides of display modules DPa and DPb overlap with each other, and a portion of the pixel area 103a overlaps with a portion of the visible light-transmitting area 72b. Also, the longer sides of display modules DPa and DPc overlap with each other, and a portion of the pixel area 103a overlaps with a portion of the visible light-transmitting area 72c.

[0484] A portion of the pixel portion 103b overlaps with a portion of the visible light-transmitting region 72c and a portion of the visible light-transmitting region 72d. Furthermore, a portion of the pixel portion 103c overlaps with a portion of the visible light-transmitting region 72d.

[0485] Therefore, the area in which the pixel portions 103a to 103d are arranged almost seamlessly can be designated as the display area 79.

[0486] Here, it is preferable that the display module DP is flexible. For example, it is preferable that the pair of substrates constituting the display module DP are flexible.

[0487] As a result, for example, as shown in Figures 20B and 20C, the area near 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 positioned below the pixel portion 103b of the display module DPb adjacent to the FPC 74a. As a result, the FPC 74a can be positioned without physically interfering with the back surface of the display module DPb. Furthermore, when the display modules DPa and DPb are stacked and fixed together, the thickness of the FPC 74a does not need to be considered, thus reducing the height difference between the upper surface of the visible light-transmitting region 72b and the upper surface of the display module DPa. As a result, the edges of the display module DPb located on the pixel portion 103a can be made less conspicuous.

[0488] Furthermore, by giving each display module DP flexibility, 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. Therefore, except for the vicinity of the overlapping area of ​​the display modules DPa and DPb, the height of each display area can be made equal, thereby improving the display quality of the image displayed in the display area 79.

[0489] The above explanation used the relationship between display modules DPa and DPb as an example, but the same applies to any other pair of adjacent display modules DP.

[0490] Furthermore, in order to reduce the height difference between two adjacent display modules DP, it is preferable that the thickness of the display modules DP be thin. For example, the thickness of the display modules DP is preferably 1 mm or less, more preferably 300 μm or less, and even more preferably 100 μm or less.

[0491] It is preferable that the display module DP incorporates both a scan line drive circuit and a signal line drive circuit. When the drive circuit is located separately from the display panel, the printed circuit board containing the drive circuit, numerous wires, and terminals are located on the back side of the display panel (opposite the display side). As a result, the total number of components in the display device becomes enormous, which can increase the weight of the display device. By having both a scan line drive circuit and a signal line drive circuit in the display module DP, the number of components in the display device can be reduced, and the display device can be made lighter. This improves the portability of the display device.

[0492] Here, the scan line drive circuit and the signal line drive circuit are required to operate at a high drive frequency depending on the frame frequency of the image to be displayed. In particular, the signal line drive circuit is required to operate at an even higher drive frequency than the scan line drive circuit. Therefore, some of the transistors used in the signal line drive circuit may be required to have the ability to supply large currents. On the other hand, some of the transistors provided in the pixel section may be required to have sufficient voltage resistance to drive the display elements.

[0493] Therefore, it is preferable to design the transistors in the drive circuit and the transistors in the pixel section to be distinct. For example, one or more transistors in the pixel section may be high-voltage transistors, and one or more transistors in the drive circuit may be high-frequency transistors.

[0494] More specifically, one or more transistors applied to the signal line driving circuit are transistors with thinner gate insulation layers than those applied to the pixel section. By creating these two types of transistors, the signal line driving circuit can be fabricated on the substrate where the pixel section is located.

[0495] Furthermore, it is preferable to apply a metal oxide to the semiconductor in which the channel is formed for the scanning line driving circuit, the signal line driving circuit, and each transistor applied to the pixel section.

[0496] Furthermore, it is preferable to use silicon as the semiconductor in which the channel is formed for the scan line drive circuit, the signal line drive circuit, and each transistor applied to the pixel section.

[0497] Furthermore, it is preferable that the scanning line driving circuit, signal line driving circuit, and each transistor applied to the pixel section combine a semiconductor in which a metal oxide is applied to the semiconductor in which the channel is formed, and a semiconductor in which silicon is applied to the semiconductor in which the channel is formed.

[0498] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0499] (Embodiment 10) In this embodiment, a display device according to one aspect of the present invention will be described with reference to Figure 21.

[0500] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used in the display section of wearable devices that can be worn on the head, such as information terminals (wearable devices) such as wristwatches and bracelets, as well as VR devices such as head-mounted displays and AR devices such as glasses.

[0501] [Display Module] Figure 21A shows a perspective view of the display module 280. The display module 280 includes a display device 100 and an FPC 290.

[0502] The display module 280 has substrates 291 and 292. The display module 280 has a pixel section 103. The pixel section 103 is the area in the display module 280 that displays an image, and is the area in which light from each pixel provided in the pixel section 103, which will be described later, can be seen.

[0503] Figure 21B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 103 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 (sometimes referred to as the FPC terminal section) for connecting to the FPC 290 is provided in a part of the substrate 291 that does not overlap with the pixel section 103. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0504] The pixel section 103 has a plurality of pixels 150 arranged periodically. A magnified view of a single pixel 150 is shown on the right side of Figure 21B. Each pixel 150 has light-emitting devices 11R, 11G, and 11B, each with a different emission color. The plurality of light-emitting devices can be laid out in a stripe arrangement as shown in Figure 21B. Furthermore, various arrangement methods for light-emitting devices, such as a delta arrangement or a pentile arrangement, can be applied.

[0505] The pixel circuit section 283 includes a pixel circuit 283a having a plurality of transistors arranged periodically.

[0506] Each pixel circuit 283a is a circuit that controls the light emission of a light-emitting device in a single pixel 150. A single pixel circuit 283a may be configured to have three circuits for controlling the light emission of a single light-emitting device. For example, each pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element. In this configuration, 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.

[0507] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0508] The FPC290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC290.

[0509] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 103, thereby making the aperture ratio (effective display area ratio) of the pixel section 103 extremely high. For example, the aperture ratio of the pixel section 103 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to lay out the pixels 150 at an extremely high density, making the resolution of the pixel section 103 extremely high. For example, it is preferable that the pixels 150 in the pixel section 103 are laid out with a resolution of 20000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0510] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has extremely high-resolution pixel parts 103, so even when the display part is magnified with lenses, the pixels are not visible, enabling 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 parts. For example, it can be suitably used in the display part of wearable electronic devices such as watches.

[0511] (Embodiment 11) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 22 and 23.

[0512] The electronic device of this embodiment has a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention is easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0513] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, and other electronic devices with relatively large screens, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0514] In particular, a display device according to one aspect of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0515] A display device according to one aspect of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display device having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth in personal electronic devices such as portable or home-use devices. Furthermore, there are no particular limitations on the screen ratio (aspect ratio) of the display device according to one embodiment of the present invention. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0516] The electronic device of this embodiment may have sensors (including those with functions to measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0517] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0518] Figure 22A shows an example of a television system. The television system 7100 has a pixel unit 7000 incorporated into a housing 7101. Here, the housing 7101 is shown to be supported by a stand 7103.

[0519] A pixel unit 103 according to one aspect of the present invention can be applied to the pixel unit 7000.

[0520] The television device 7100 shown in Figure 22A can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the pixel unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the pixel unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the pixel unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0521] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0522] Figure 22B shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. The pixel unit 7000 is incorporated into the casing 7211.

[0523] A pixel unit 103 according to one aspect of the present invention can be applied to the pixel unit 7000.

[0524] Figures 22C and 22D show examples of digital signage.

[0525] The digital signage 7300 shown in Figure 22C includes a housing 7301, a pixel unit 7000, and a speaker 7303, etc. Furthermore, it may have LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0526] Figure 22D shows a digital signage display 7400 mounted on a cylindrical column 7401. The digital signage display 7400 has pixel sections 7000 arranged along the curved surface of the column 7401.

[0527] In Figures 22C and 22D, a pixel unit 103 according to one embodiment of the present invention can be applied to the pixel unit 7000.

[0528] The larger the pixel area (7000 pixels), the more information can be provided at once. Furthermore, a larger pixel area (7000 pixels) makes the image more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0529] Applying a touch panel to the pixel unit 7000 is preferable because it not only allows for the display of images or videos on the pixel unit 7000, but also enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0530] Furthermore, as shown in Figures 22C and 22D, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the pixel unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the pixel unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0531] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0532] The electronic device 6500 shown in Figure 23A is a portable information terminal that can be used as a smartphone.

[0533] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0534] A pixel unit 103 according to one aspect of the present invention can be applied to the display unit 6502.

[0535] Figure 23B is a cross-sectional view of the housing 6501 including the end on the microphone 6506 side.

[0536] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, battery 6518, etc. are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0537] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0538] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded portion. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0539] A flexible display according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel area, it is possible to realize an electronic device with a narrow bezel.

[0540] This embodiment can be combined with other embodiments as appropriate. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be combined as appropriate. [Explanation of Symbols]

[0541] 103: Pixel section, 151: Auxiliary wiring, 151a: First wiring layer, 151b: Second wiring layer, 14: Insulation layer, 15: Contact hole, 11R: Light-emitting device, 11G: Light-emitting device, 11B: Light-emitting device, 111R: Lower electrode, 111G: Lower electrode, 111B: Lower electrode, 112R: Organic compound layer, 112G: Organic compound layer, 112B: Organic compound layer, 113: Common electrode, 153a: Third wiring layer, 153b: Fourth wiring layer, 154: Bridge wiring

Claims

1. A first light-emitting device comprising a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A second light-emitting device comprising a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A common electrode between the first light-emitting device and the second light-emitting device, The common electrode and the auxiliary wiring electrically connected thereto The auxiliary wiring comprises a first wiring layer and a second wiring layer. The second wiring layer is electrically connected to the first wiring layer via contact holes in the insulating layer. The second wiring layer has a grid pattern when viewed from above. Display device.

2. A first light-emitting device comprising a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A second light-emitting device comprising a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A common electrode between the first light-emitting device and the second light-emitting device, The common electrode and the auxiliary wiring electrically connected thereto The auxiliary wiring comprises a first wiring layer and a second wiring layer. The second wiring layer is electrically connected to the first wiring layer via contact holes in the insulating layer. The first wiring layer has a grid pattern when viewed from above. The first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer. Display device.

3. A first light-emitting device comprising a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A second light-emitting device comprising a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with the side surface of the end of the first lower electrode, A common electrode between the first light-emitting device and the second light-emitting device, The common electrode and the auxiliary wiring electrically connected thereto The auxiliary wiring comprises a first wiring layer and a second wiring layer. The second wiring layer is electrically connected to the first wiring layer via contact holes in the insulating layer. The first wiring layer and the second wiring layer each have a grid pattern when viewed from above. 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.

4. In any one of claims 1 to 3, The 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 3, The taper angle of the end face of the first organic compound layer satisfies the condition of being 45 degrees or more and less than 90 degrees. Display device.

6. In any one of claims 1 to 3, The taper angle of the end face of the second organic compound layer satisfies the condition of being 45 degrees or more and less than 90 degrees. Display device.

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