Display 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

display device

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

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

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

[0004] As a method for manufacturing an organic EL element, a method for manufacturing an organic optoelectronic device using standard UV photolithography has been disclosed (see Non-Patent Document 1).

[0005] JP 2010-85866 A

[0006] B. Lamprecht et al. , “Organic optoelectronic device fabrication using standard UV photolithography” phys. stat. sol. (RRL) 2, No. 1, p. 16-18 (2008)

[0007] In the active matrix display device shown in Patent Document 1, the lower layer auxiliary wiring is formed in the same layer as the power supply line and the scanning line, and therefore it is not possible to sufficiently suppress the voltage drop in the upper electrode. The voltage drop occurs mainly due to the electrode being thin or having a large area, and refers to a state in which the electrode consumes energy due to heat generation or the like, and the voltage applied to the electrode drops by the amount of that energy.

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

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

[0010] Note that the description of these problems does not preclude the existence of other problems. Furthermore, these problems are considered to be independent of each other, and one embodiment of the present invention only needs to solve one of these problems, and does not need to solve all of them. Furthermore, problems other than these can be extracted from the description of the specification, drawings, and claims in this specification, etc.

[0011] In view of the above problems, one embodiment of the present invention is a display device including: a first light-emitting device having a first bottom electrode and a first organic compound layer located over the first bottom electrode; a second light-emitting device having a second bottom electrode and a second organic compound layer located over the second bottom electrode; a common electrode included in the first light-emitting device and the second light-emitting device; and an auxiliary wiring electrically connected to the common electrode, the auxiliary wiring having a first wiring layer and a second wiring layer, the second wiring layer being electrically connected to the first wiring layer through a contact hole in an insulating layer, and the second wiring layer having a lattice shape in a top view.

[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 possessed by the first light-emitting device and the second light-emitting 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, the first wiring layer has a lattice shape in a top view, and the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer.

[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 provided to the first light-emitting device and the second light-emitting device; and auxiliary wiring electrically connected to the common electrode, the auxiliary wiring having a first wiring layer and a second wiring layer, the second wiring layer being electrically connected to the first wiring layer through a contact hole in an insulating layer, the first wiring layer and the second wiring layer each having a lattice shape in a top view, the first lower electrode, the second lower electrode and the second wiring layer each having a region 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 equal to or greater than 45 degrees 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 equal to or greater than 45 degrees and less than 90 degrees.

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

[0018] Note that the description of these effects does not preclude the existence of other effects. Furthermore, these effects are considered to be independent of each other, and one embodiment of the present invention may achieve any one of these effects, but need not achieve all of them. Furthermore, effects other than these can be extracted from the description of the specification, drawings, and claims, including this specification.

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

[0020] In this specification, the configuration may be classified by function and explained using block diagrams that are independent of each other, but in reality it is difficult to separate the configuration by function, and one configuration may be involved in multiple functions.

[0021] In this specification and the like, the names of the source and drain of a transistor are interchangeable depending on the polarity of the transistor and the level of the potential applied to each terminal. Generally, in an n-channel transistor, a terminal to which a low potential is applied is called a source, and a terminal to which a high potential is applied is called a drain. In addition, in a p-channel transistor, a terminal to which a low potential is applied is called a drain, and a terminal to which a high potential is applied is called a source. In practice, the names of the source and the drain may be interchangeable depending on the above-mentioned potential relationship. However, in this specification and the like, when describing the connection relationship of a transistor, the source and the drain are fixed for convenience.

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

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

[0024] In this specification, connection may be referred to as electrical connection, and includes a state in which a current, voltage, or potential can be supplied or transmitted. Therefore, it also includes a state in which things are connected to each other via elements such as wiring, resistors, diodes, and transistors. Electrical connection also includes a state in which things are directly connected to each other without using elements such as wiring, resistors, diodes, and transistors.

[0025] In this specification and the like, the source and drain of a transistor are sometimes described using a first electrode and a second electrode; however, when one of the first electrode and the second electrode is the source, the other is the drain.

[0026] In this specification and the like, a conductive layer may have multiple functions such as wiring or an electrode.

[0027] In this specification and the like, 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 an anode, the other of the pair of electrodes is a cathode, and at least one of the organic compound layers is a light-emitting layer. The light-emitting layer contains a light-emitting material, and a fluorescent material, a phosphorescent material, or the like may be used as the light-emitting material. The pair of electrodes may be referred to as a lower electrode and an upper electrode, respectively. One of the pair of electrodes can function as either an anode or a cathode, and the other of the pair of electrodes can function as the other of the anode and 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-definition metal mask) due to the miniaturization of openings.

[0029] In this specification and the like, 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 and the like, light-emitting devices that emit red, green, blue, etc. may be referred to as a red light-emitting device, a green light-emitting device, and a blue light-emitting device, respectively.

[0031] In this specification, a structure in which 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, a full-color display device can be provided by fabricating a red light-emitting device, a green light-emitting device, and a blue light-emitting device using the SBS structure.

[0032] In this specification and the like, a light-emitting device that emits white light may be referred to as a white light-emitting device. Note that a white light-emitting device can provide a full-color display device by combining it with a colored layer (for example, a color filter or a color conversion layer).

[0033] Light-emitting devices can be broadly classified into a single structure and a tandem structure. A single structure has one light-emitting unit between a pair of electrodes. The light-emitting unit is a laminate including one or more light-emitting layers.

[0034] To obtain a white light-emitting device using a single structure, two or more light-emitting layers may be included in the light-emitting unit. In the light-emitting unit, the two or more light-emitting layers may be in contact with each other. Also, a white light-emitting device may be obtained by using three or more light-emitting layers. In the light-emitting unit, the three or more light-emitting layers may be in contact with each other.

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

[0036] To obtain a white light emitting device using a tandem structure, light from the light emitting layers of two or more light emitting units may be combined to produce white light.

[0037] Furthermore, when the above-described white light-emitting device is compared with a light-emitting device having an SBS structure, the light-emitting device having an SBS structure can reduce power consumption compared to the white light-emitting device. When it is desired to reduce power consumption, it is preferable to use a light-emitting device having an SBS structure. On the other hand, the manufacturing process of a white light-emitting device is simpler than that of a light-emitting device having an SBS structure, and therefore the manufacturing cost can be reduced or the manufacturing yield can be increased, making it preferable.

[0038] In this specification and the like, a display panel having a connector such as a flexible printed circuit (FPC) or a tape carrier package (TCP) attached to a substrate, or a display panel having an IC mounted on a substrate by a chip-on-glass (COG) method or the like, may be referred to as a display module. A display module is one aspect of a display device.

[0039] Next, embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same parts or parts having similar functions will be denoted by the same reference numerals in different drawings, and repeated explanations will be omitted.

[0040] Embodiment 1 In this embodiment, a structural example of a display device according to one embodiment of the present invention will be described.

[0041] <Function of Auxiliary Wiring> The display device described in this embodiment is characterized by having auxiliary wiring. The auxiliary wiring is a layer that has an auxiliary function for the main electrode, and the auxiliary function described in this embodiment includes a function to suppress a voltage drop caused by the main electrode. An example of the main electrode is a pair of electrodes of a light-emitting device. However, since the pair of electrodes functions as a cathode or anode of the light-emitting device, a conductive material may need to be selected based on the work function. A conductive material that takes only the work function into consideration may have a high resistivity. Therefore, one feature 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 suppress the voltage drop.

[0042] The pair of electrodes includes an upper electrode, which can be formed from a continuous conductive layer without being separated between multiple light-emitting devices. This continuous electrode is sometimes referred to as a common electrode. As the display device becomes larger, the common electrode needs to be formed over a larger area, and voltage drops due to such common electrodes are more likely to occur. Therefore, the display device described in this embodiment is typically a large-sized display device, and one of its features is that auxiliary wiring is electrically connected to the upper electrode, which can provide the effect of suppressing the voltage drop.

[0043] The auxiliary wiring may also be referred to as an auxiliary electrode according to its shape. In this specification and the like, the shape of the auxiliary wiring is not limited in any way, and the auxiliary wiring includes an auxiliary electrode.

[0044] 1A shows a conceptual diagram of a pixel portion 103 included in a display device according to one embodiment of the present invention. The pixel portion 103 includes at least a light-emitting device and also includes an auxiliary wiring 151 according to one embodiment of the present invention. FIG. 1A illustrates light-emitting devices 11R, 11G, and 11B, which are examples of three light-emitting devices included in the pixel portion 103. When the light-emitting devices 11R, 11G, and 11B are not distinguished from one another, they may be referred to as light-emitting device 11.

[0045] <Light-Emitting Device> 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 this order. In FIG. 1A , lower electrodes 111R, 111G, and 111B are shown, organic compound layers 112R, 112G, and 112B are shown, and 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 the lower electrode 111. When the organic compound layers 112R, 112G, and 112B are not distinguished, they may be referred to as the organic compound layer 112. When the upper electrodes 113R, 113G, and 113B are not distinguished, they may be referred to as the upper electrode 113E. The three light-emitting devices in the pixel section 103 can emit red (R), green (G), and blue (B), and therefore the above-mentioned reference symbols are appended with RGB to correspond to each color. The organic compound layers 112R, 112G, and 112B each have at least a light-emitting layer, and can emit red (R), green (G), and blue (B) because the light-emitting layers are made of different light-emitting materials, etc. Note that the organic compound layer 112 also has other layers in addition to the light-emitting layer, and the configuration other than the light-emitting layer will be described later.

[0046] <Method of Manufacturing Organic Compound Layer> The organic compound layer 112 is a laminate of a light-emitting layer and other layers, and each layer can be formed by a vapor deposition method using a metal mask. Again, a light-emitting device having an organic compound layer manufactured using a metal mask is referred to as a light-emitting 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. Again, a light-emitting device having an organic compound layer formed without using a metal mask is referred to as a light-emitting device having an MML structure. A manufacturing method using a photolithography process will be described later.

[0047] <Upper electrode, common electrode> The upper electrode 113E of the light-emitting device may be divided for each light-emitting device. Fig. 1A shows a divided upper electrode, and a configuration in which auxiliary wiring 151 is electrically connected to the upper electrode 113E. This electrical connection is shown by a solid line in Fig. 1A 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] The upper electrode may be provided as a common electrode, which is a continuous electrode, without being divided among the light-emitting devices. When a common wiring is used, a voltage drop is likely to occur. Therefore, a configuration in which an auxiliary wiring, which is one embodiment of the present invention, is provided is preferable. Those skilled in the art who have read this specification and the like can understand the effect of the auxiliary wiring 151 by appropriately interpreting the terms "upper electrode" and "common electrode."

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

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

[0051] The wiring layer may also be referred to as an electrode layer according to its shape. In this specification and the like, the shape of the electrode layer is not limited in any way, and the wiring layer includes the electrode layer.

[0052] The first wiring layer 151a is electrically connected to the second wiring layer 151b so that the first wiring layer 151a and the second wiring layer 151b function as auxiliary wiring 151. Specifically, the first wiring layer 151a is electrically connected to the second wiring layer 151b through a contact hole 15 in the insulating layer 14 located between the first wiring layer 151a and the second wiring layer 151b.

[0053] There is no limitation on the number of stacked wiring layers constituting the auxiliary wiring, and the auxiliary wiring may have three or more wiring layers, such as a first wiring layer to a third wiring layer, etc. As the number of wiring layers increases, the degree of freedom in arranging the wiring layers to function as the auxiliary wiring (hereinafter, sometimes referred to as layout) increases, which can be said to be preferable.

[0054] As described above, the auxiliary wiring 151 of one embodiment of the present invention has two or more wiring layers provided in different layers, and the wiring layers located in different layers are electrically connected to each other through contact holes.

[0055] <Contact Hole> A contact hole refers to an opening formed in an insulating layer, which enables 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). To achieve this electrical connection, specifically, the lower wiring layer has an area exposed through the opening, and the upper wiring layer is electrically connected to, or typically comes into contact with, the exposed area.

[0056] Furthermore, the insulating layer in which the contact hole is provided may be stacked. This is called a stacked insulating layer, or a laminated insulating layer. For example, a contact hole can be formed in a laminated insulating layer 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 a region overlapping 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 be larger than the width of the first contact hole. Of course, there is no limitation on the width of the contact holes in each insulating layer, as long as the lower wiring layer can be electrically connected to the upper wiring layer.

[0057] In a high-definition display device, the interval between the lower electrodes 111 becomes narrow, making it difficult to layout the auxiliary wiring 151 in accordance with the interval. Therefore, a layout of the auxiliary wiring 151 that is not affected or is affected only slightly by the interval between the lower electrodes 111 is desired.

[0058] As a layout of the auxiliary wiring 151 that is not affected by the lower electrode 111, typically, the first wiring layer 151a and the second wiring layer 151b may be formed in a layer different from the lower electrode 111. For example, the auxiliary wiring 151 may be formed such that the first wiring layer 151a and the second wiring layer 151b are positioned in a layer below the lower electrode 111.

[0059] Furthermore, the first wiring layer 151a and the second wiring layer 151b can be made to have different shapes in a top view, typically different areas. For example, the first wiring layer 151a may be formed with a smaller area than the second wiring layer 151b. In other words, the second wiring layer 151b may be laid out so as to have a larger area than the first wiring layer 151a. For example, the second wiring layer 151b may be laid out in a grid pattern. In this case, the second wiring layer 151b may be formed in a strip or island shape. A grid pattern refers to a pattern combining multiple parallel vertical lines and multiple parallel horizontal lines. A strip shape is sometimes called a rectangular shape or a stripe shape. An island shape refers to a shape shorter than a strip shape. Of course, the first wiring layer 151a may be formed in a grid pattern, and the second wiring layer 151b may be formed in a strip shape.

[0060] 1B1 and 1B2 show top views of the pixel portion 103, each showing a grid-shaped second wiring layer 151b. Although not shown, the first wiring layer 151a is electrically connected to the second wiring layer 151b through a contact hole 15. The first wiring layer 151a may have any shape, for example, a strip shape or an island shape. It is preferable that the first wiring layer 151a has a region overlapping with a part of the second wiring layer 151b, because this makes it easier to ensure electrical connection through the contact hole 15.

[0061] 1B1 and 1B2, an X direction and a Y direction intersecting the X direction are also shown, and the configuration of the pixel unit 103 and the like may be described using these directions.

[0062] 1B1 has a plurality of vertical lines extending in the Y direction. The vertical lines overlap with gaps between sub-pixels. The gaps between sub-pixels include the regions between the ends of the lower electrodes 111R and 111G, and the regions between the ends of the lower electrodes 111G and 111B.

[0063] The second wiring layer 151b shown in FIG. 1B2 has a different spacing between its vertical lines than that shown in FIG. 1B1, and the vertical lines overlap with the gaps between the pixels 150. The gaps between the pixels 150 include, for example, the region between the end of the lower electrode 111B corresponding to the subpixel B located at the edge of the pixel 150 and the end of the lower electrode 111R corresponding to the subpixel R located at the edge of the adjacent pixel. "Adjacent" may mean either an adjacent relationship along the X direction or an adjacent relationship along the Y direction. In other words, the second wiring layer 151b shown in FIG. 1B2 does not have vertical lines with regions that overlap with the gaps between the subpixels as shown in FIG. 1B1.

[0064] In display devices with a high aperture ratio or display devices with advanced high definition, the gap between the lower electrodes becomes narrower, making it difficult to layout 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 second wiring layer 151b is located on the same layer as lower electrode 111, in display devices with advanced high definition, a layout of second wiring layer 151b with fewer vertical lines, as shown in FIG. 1B2, is preferable.

[0065] It is preferable that wirings that perform functions such as scanning lines, signal lines, and power lines are not provided in the same layer as the grid-shaped second wiring layer 151b. This is because wirings that perform the above functions need to extend in the X direction or the Y direction, and would come into contact with the second wiring layer 151b. If scanning lines, signal lines, and power lines are to be provided, the lengths of the scanning lines, signal lines, and power lines along the X direction or the Y direction can be adjusted to lay them out in an island shape so as not to contact the second wiring layer. Then, an electrically conductive layer in a layer different from the second wiring layer is used to ensure electrical connection between the island-shaped scanning lines, etc. Wiring for ensuring such electrical connection is sometimes referred to as bridge wiring.

[0066] The bridge wiring may also be referred to as a bridge electrode according to its shape. In this specification, the shape of the bridge wiring is not limited in any way, and the bridge wiring includes the bridge electrode.

[0067] 1C1 and 1C2 show a pixel unit 103 having signal lines and bridge wirings. Although the light-emitting devices 11R, 11G, and 11B are not shown in FIGS. 1C1 and 1C2, the layout of the light-emitting devices 11R, 11G, and 11B can be seen in FIGS. 1B1 and 1B2.

[0068] The signal line shown in FIGS. 1C1 and 1C2 includes a third wiring layer 153a and a fourth wiring layer 153b, and the third wiring layer 153a is separated from the fourth wiring layer 153b. The third wiring layer 153a and the fourth wiring layer 153b may be referred to as island-shaped wiring layers. The island-shaped wiring layers are electrically connected to each other using a bridge wiring 154. The third wiring layer 153a and the fourth wiring layer 153b may both be formed using a conductive layer located on a different formation surface from the second wiring layer 151b. For example, the third wiring layer 153a and the fourth wiring layer 153b may both be formed using a conductive layer located below the second wiring layer 151b. Furthermore, the third wiring layer 153a and the fourth wiring layer 153b may also be formed using a conductive layer located on the same formation surface as the second wiring layer 151b. In either case, the bridge wiring 154 is formed using a conductive layer located on a surface different from that on which the second wiring layer 151b is formed. For example, the bridge wiring 154 may be formed using a conductive layer located below the second wiring layer 151b.

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

[0070] The layout of the second wiring layer 151b with fewer vertical lines as shown in FIG. 1B2 is also suitable for the case where the second wiring layer 151b has signal lines and bridge lines as shown in FIG. 1C2.

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

[0072] 2B1 and 2B2 are top views of the pixel portion 103, showing the first wiring layer 151a having a lattice shape. For the layout of the lattice shape, the layout of the second wiring layer 151b having a lattice shape shown in FIGS. 1B1 and 1B2 can be referred to.

[0073] In the contact holes 15 shown in FIGS. 2B1 and 2B2, the second wiring layer 151b is positioned so as to overlap the intersections of the lattice-shaped first wiring layer 151a. The second wiring layer 151b only needs to overlap the intersections, and does not need to overlap the entire lattice-shaped first wiring layer 151a. Furthermore, the second wiring layer 151b does not need to overlap all of the intersections. Because 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 contact 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 be made large, and voltage drop can be suppressed even when the area of ​​the second wiring layer 151b is small. It may be preferable to refer to the second wiring layer 151b, which is laid out with a small area, as an electrode layer.

[0074] 2C1 and 2C2 show a pixel unit 103 having signal lines and bridge wirings. Although the light-emitting devices 11R, 11G, and 11B are not shown in FIGS. 2C1 and 2C2, the layout of the light-emitting devices 11R, 11G, and 11B can be seen in FIGS.

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

[0076] 3A shows another example of the pixel portion 103 of one embodiment of the present invention. Unlike FIG. 2A , FIG. 3A has a structure in which the width (denoted by dB) of the second wiring layer 151b in a cross-sectional view is smaller than the width (denoted by dA) of the first wiring layer 151a. Other configurations can be similar to those in FIG. 2A .

[0077] 3B is a top view of the pixel portion 103, showing the first wiring layer 151a and the second wiring layer 151b having a lattice pattern. For the lattice layout, refer to the layout of the lattice-shaped second wiring layer 151b shown in FIG. 1B2.

[0078] 3B may have a shape that matches the area where the first wiring layer 151 a and the second wiring layer 151 b overlap each other. For example, the contact hole 15 may have a shape that follows one side of the second wiring layer 151 b.

[0079] 3C shows a pixel unit 103 having a signal line and a bridge line. The signal line shown in FIG. 3C has a third wiring layer 153a and a fourth wiring layer 153b, and the third wiring layer 153a is separated from the fourth wiring layer 153b. Therefore, the third wiring layer 153a and the fourth wiring layer 153b are electrically connected using a bridge line 154. The third wiring layer 153a and the fourth wiring layer 153b have a conductive layer in the same layer as the first wiring layer 151a. The bridge line 154 has a conductive layer in a different layer from the first wiring layer 151a, preferably a conductive layer below 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 has a higher degree of freedom in the layout of the auxiliary wiring 151 than when the auxiliary wiring is formed from a single wiring layer. The auxiliary wiring 151 of one embodiment of the present invention is suitable for use in a high-resolution display device.

[0081] <Conductive Material of Auxiliary Wiring> A conductive material for the auxiliary wiring 151 of one embodiment of the present invention, that is, a conductive material for the first wiring layer 151a or the second wiring layer 151b, can be a metal such as aluminum, copper, silver, gold, platinum, chromium, or molybdenum. An alloy of the above metals can also be used as the conductive material. The above conductive material is a metal and is a non-light-transmitting conductive material. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a stacked layer using the above conductive material. For example, the first wiring layer 151a may be a stacked layer, and the second wiring layer 151b may be a single layer. Alternatively, the first wiring layer 151a may be a single layer, and the second wiring layer 151b may be a stacked layer. Alternatively, the first wiring layer 151a may be a stacked layer, and the second wiring layer 151b may also be a stacked layer.

[0082] A light-transmitting conductive material may be used as the conductive material of the auxiliary wiring of one embodiment of the present invention, that is, the conductive material of the first wiring layer 151a or the second wiring layer 151b. Specifically, an oxide containing indium and tin (also referred to as indium tin oxide, In—Sn oxide, or ITO), an oxide containing indium, silicon, and tin (also referred to as In—Si—Sn oxide or ITSO), an oxide containing indium and zinc (also referred to as indium zinc oxide or In—Zn oxide), an oxide containing indium, tungsten, and zinc (also referred to as In-W—Zn oxide), or the like can be used. The first wiring layer 151a or the second wiring layer 151b can be formed as a single layer or a stacked layer using any of the above conductive materials. When a stacked layer structure is used for the first wiring layer 151a or the second wiring layer 151b, it is preferable that at least one layer contain a conductive material using the above metal or the like.

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

[0084] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0085] Embodiment 2 In this embodiment, a specific example of a display device according to one embodiment of the present invention will be described.

[0086] <Top-Emission Structure> A display device according to one embodiment of the present invention preferably has a top-emission structure. In the top-emission structure, a light-transmitting upper electrode is required, and light is emitted toward the upper electrode. The light-transmitting property means that visible light (light with a wavelength of 400 nm or more and less than 750 nm) passes through the upper electrode, and the light-transmitting property preferably has a transmittance of 40% or more.

[0087] A light-transmitting conductive material may have high resistivity, which may increase the resistance of the common electrode. As a result, a voltage drop occurs due to the common electrode, which causes a non-uniform potential distribution in the display surface and thus causes variations in the luminance of the light-emitting device. Therefore, a display device having a top-emission structure according to one embodiment of the present invention may include an auxiliary wiring electrically connected to the common electrode. The auxiliary wiring can suppress the voltage drop. The upper electrode may be referred to as a common electrode.

[0088] <Bottom Emission Structure> Note that even when the display device of one embodiment of the present invention has a bottom emission structure, it may include an auxiliary wiring electrically connected to the common electrode. The auxiliary wiring can provide an effect of suppressing a voltage drop.

[0089] In the bottom emission structure, the lower electrode must be light-transmitting, and light is emitted in the direction of the lower electrode.

[0090] <Dual Emission Structure> Note that even when the display device of one embodiment of the present invention has a dual emission structure, it may have an auxiliary wiring electrically connected to the common electrode. The auxiliary wiring can provide an effect of suppressing a voltage drop.

[0091] The dual emission structure requires that the lower and upper electrodes are transparent, and light is emitted in both directions of the lower and upper electrodes. A dual emission type display device can be called a transparent display.

[0092] In this embodiment, a configuration in which auxiliary wiring is applied to a display device having a top emission structure will be described.

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

[0094] The pixel portion 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 the substrate 101.

[0095] 4A , 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 through a contact hole 19 in the insulating layer 104 and functions as the auxiliary wiring 151. The common electrode 113 is located on the insulating layer 126, and the common electrode 113 can be electrically connected to the auxiliary wiring 151 through 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 formation surface as the formation surface of the lower electrode 111, the auxiliary wiring 151 can be formed without being influenced by the layout of the lower electrode or by minimizing the influence of the layout of the lower electrode, which is preferable.

[0097] 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 in a larger area than the second wiring layer 151b. When the first wiring layer 151a is located below the lower electrode 111, the aperture ratio is not reduced and the degree of freedom in layout is increased. The first wiring layer 151a formed in a position that does not reduce the aperture ratio does not need to be light-transmitting, so a conductive material with low resistivity can be used.

[0098] In this way, the auxiliary wiring 151 of one embodiment of the present invention can have a wiring layer on a formation surface different from the formation surface of the lower electrode, and the wiring layer can be formed over a large area without being affected by the lower electrode layout, and the voltage drop suppression effect can be fully exerted.

[0099] Next, a structure of the pixel portion 103 other than the auxiliary wiring 151 will be described. Also refer to the top view of the pixel portion 103 shown in Fig. 4B. Note that Fig. 4B shows the second wiring layer 151b, and omits the first wiring layer 151a.

[0100] A1-A2 indicated by a dashed line in Fig. 4B corresponds to A1-A2 in Fig. 4A . Fig. 4B also shows an X direction and a Y direction intersecting the X direction, and these directions may be used to describe the layout of the configuration of the pixel portion 103.

[0101] As shown in Fig. 4B , the pixel unit 103 located in the display region has a plurality of pixels 150. The 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 Fig. 4B . To achieve full-color display, the sub-pixels 110R, 110G, and 110B may each have a colored layer, which may be, for example, a color filter or a color conversion layer.

[0102] When describing matters common to the subpixels 110R, 110G, and 110B, they may be referred to as subpixels 110.

[0103] The subpixels 110R, 110G, and 110B correspond to the light-emitting regions of the respective light-emitting devices, and FIG. 4B illustrates each light-emitting region as being rectangular. The subpixel 110R in FIG. 4B corresponds to the light-emitting region (denoted as R) of a red light-emitting device, the subpixel 110G corresponds to the light-emitting region (denoted as G) of a green light-emitting device, and the subpixel 110B corresponds to the light-emitting region (denoted as B) of a blue light-emitting device. The display device of one embodiment of the present invention is not limited to the above-described light-emitting colors, and may include, for example, a white light-emitting device in addition to red, green, and blue light-emitting devices.

[0104] As shown in FIG. 4B , a plurality of subpixels 110R and 110G are arranged along the Y direction and are positioned alternately. A plurality of subpixels 110B are arranged along the Y direction. The subpixel 110B can have a larger area than the subpixels 110R and 110G. For example, when a light-emitting layer containing a fluorescent material is used in the blue light-emitting device and light-emitting layers containing phosphorescent materials are used in the red light-emitting device and the green light-emitting device, respectively, it is preferable that the subpixel 110B have a larger area than the subpixels 110R and 110G, as shown in FIG. 4B .

[0105] 4A , in the subpixel 110R, an insulating layer 104 is provided 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 toward the common electrode 113, that is, in the direction indicated by the arrow in FIG. 4A .

[0106] 4A , in the subpixel 110G, an insulating layer 104 is provided 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 toward the common electrode 113, that is, in the direction indicated by the arrow in FIG. 4A .

[0107] 4A , in the subpixel 110B, an insulating layer 104 is provided on the substrate 101, a lower electrode 111B of the light-emitting device 11B is provided on the insulating layer 104, an organic compound layer 112B of the light-emitting device 11B is provided on the lower electrode 111B, and a common electrode 113 is provided on the organic compound layer 112B. The light-emitting device 11B emits light toward the common electrode 113, that is, in the direction indicated by the arrow in FIG. 4A .

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

[0109] 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] 4A , the second wiring layer 151b has a wiring layer on the same formation surface as the lower electrode 111, and is therefore provided in a region that does not contact the lower electrode 111, i.e., does not overlap with the subpixel. For example, the second wiring layer 151b has a lattice shape when viewed from above. The lattice-shaped second wiring layer 151b has regions that extend in the X direction as horizontal lines, and these regions are parallel to each other, and also has regions that extend in the Y direction as vertical lines, and these regions are parallel to each other.

[0111] 4B includes a region extending along the X direction that is located between the subpixels 110R and 110G, and these regions are arranged in parallel. The region between the subpixels 110R and 110G corresponds to the inter-pixel region. The second wiring layer 151b shown in FIG. 4B includes a region extending along the Y direction that is located between the subpixels 110G and 110B, and these regions are arranged in parallel.

[0112] The gap between the lower electrodes 111 becomes narrower as the display device becomes higher resolution. For example, in the pixel portion 103 of FIG. 4B , which is included in a high-resolution display device, the distance between the subpixels de and the distance between the pixels dc become narrower. As the distance becomes narrower, it becomes more difficult to form a wiring layer for the auxiliary wiring. Therefore, it is preferable to designate the wiring layer that overlaps the gap between the subpixels in a top view as the first wiring layer 151a, and to designate the first wiring layer 151a as a wiring layer in a layer different from the lower electrodes.

[0113] <Insulating Layer 126> In a display device according to one embodiment of the present invention, an insulating layer 126 is preferably located between light-emitting devices as shown in FIG. 4A . The insulating layer 126 can fill spaces between pixels and subpixels, 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 contacting the lower electrode 111. Furthermore, the insulating layer 126 can separate the organic compound layers of the light-emitting devices, thereby preventing crosstalk between the light-emitting devices. Crosstalk is a phenomenon in which light is unintentionally emitted from a light-emitting device.

[0114] 4A, the top surface of the insulating layer 126 is shown to be approximately aligned or aligned with the top surface of the organic compound layer 112. When such a positional relationship is satisfied, the surface on which the common electrode 113 is formed becomes flat, and cutting of the common electrode 113 is suppressed, which is preferable.

[0115] 4A , in order to prevent the common electrode 113 from being cut, the top surface of the insulating layer 126 may be located above the top surface of the organic compound layer 112. In this case, it is preferable that the end portions of the insulating layer 126 are gradually thinned toward the center of the organic compound layer 112. A gradually thinned shape may be referred to as a tapered shape.

[0116] 4A, it is more preferable that the center of the insulating layer 126 is located above the ends of the insulating layer 126 and that the center has a region that is raised higher than the ends. If the common electrode 113 is provided on such an insulating layer 126, it is preferable because cutting of the common electrode 113 is suppressed.

[0117] Figure 4A shows a configuration in which the second wiring layer 151b of the auxiliary wiring 151 has an area that contacts the bottom of the common electrode 113, but any configuration can be used as long as the auxiliary wiring 151 is electrically connected to the common electrode 113.

[0118] [Layout of Auxiliary Wiring] The auxiliary wiring 151 of one embodiment of the present invention is characterized by having at least two wiring layers, and a layout example of the first wiring layer 151a and the second wiring layer 151b will be described with reference to Figure 5 etc. In Figure 5 etc., subpixels (R, G, B) are shown according to Figure 4B, but the lower electrode 111 is omitted.

[0119] 5A, the auxiliary wiring 151 has a lattice shape in top view, and includes a first wiring layer 151a extending in the Y direction and a second wiring layer 151b extending in the X direction. Note that contact holes are located in regions where the first wiring layer 151a and the second wiring layer 151b intersect, but are not shown in FIG.

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

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

[0122] 5B shows auxiliary wiring 151 in which the length of second wiring layer 151b shown in FIG. 5A is shorter. Because the length of second wiring layer 151b is shorter, first wiring layer 151a has an area extending in the X direction. The second wiring layer 151b has a length such that one end overlaps with subpixel G and the other end overlaps with subpixel B. The other configuration is the same as that shown in FIG. 5A.

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

[0124] 5D shows auxiliary wiring 151 in which the length of first wiring layer 151a shown in FIG. 5C is shorter. Because the length of first wiring layer 151a is shorter, second wiring layer 151b has an area extending in the X direction. The first wiring layer 151a has a length such that one end overlaps with subpixel G and the other end overlaps with subpixel B. The other configuration is the same as that shown in FIG. 5C.

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

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

[0127] As described above, the auxiliary wiring 151 of one embodiment of the present invention includes the first wiring layer 151a and the second wiring layer 151b, and therefore can have various forms. Furthermore, the auxiliary wiring 151 is electrically connected to the common electrode, so that a voltage drop in the common electrode can be sufficiently suppressed. Furthermore, a high-resolution pixel portion can be used in the display device of one embodiment of the present invention.

[0128] The auxiliary wiring 151 may also be applied to a bottom emission structure and a dual emission structure. In this case, the cross-sectional structure of the auxiliary wiring 151 described in the above embodiment with reference to FIGS. 1 to 3 and the like can be applied. In the bottom emission structure and the dual emission structure, light is emitted below the lower electrode 111. Therefore, the first wiring layer 151a provided below the lower electrode 111 may have a lattice shape or an area smaller than the lattice shape so as to overlap with the gaps between subpixels or the gaps between pixels. Furthermore, the second wiring layer 151b provided below the lower electrode 111 may have a lattice shape or an area smaller than the lattice shape so as to overlap with the gaps between subpixels or the gaps between pixels.

[0129] 7A to 7C , a specific example of a display device having the top-emission structure shown in FIG. 4 and the like will be described. The display device 100 has a pixel unit 103 and a connection unit 140. The pixel unit 103 has a plurality of pixels 150. The pixel 150 has a plurality of sub-pixels 110, and for example, the sub-pixel 110R has a light-emitting device 11R that exhibits red light, the sub-pixel 110G has a light-emitting device 11G that exhibits green light, and the sub-pixel 110B has a light-emitting device 11B that exhibits blue light. The pixel unit 103 has a contact hole 141. The contact hole 141 is selectively provided, and can be provided, for example, in a region corresponding to the periphery of the pixel 150, or in regions corresponding to the four corners of the pixel 150 within the region.

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

[0131] An element such as an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used as the light-emitting device 11. Examples of light-emitting materials that the light-emitting device has include fluorescent materials, phosphorescent materials, inorganic compounds (quantum dot materials, etc.), and materials that exhibit thermally activated delayed fluorescence (thermally activated delayed fluorescence: TADF materials).

[0132] Furthermore, the connection portion 140 shown in FIG. 7A is a region having a connection electrode 111C 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 FIG. 7A, the common electrode 113 extending to the connection portion 140 is indicated by a dotted line. The connection electrode 111C is given a potential to be supplied to the common electrode 113. If a voltage drop occurs due to the common electrode 113, the value of the potential will vary. The display device of this embodiment preferably has an auxiliary wiring 151 at least in the pixel portion 103, which suppresses the variation in the potential. The auxiliary wiring 151 can also be provided in the connection portion 140 in addition to the pixel portion 103.

[0133] The connection electrode 111C can be provided along the outer periphery of the pixel unit 103. For example, the connection electrode 111C may be provided along one side of the outer periphery of the pixel unit 103, or the connection electrode 111C may be provided over two or more sides of the outer periphery of the pixel unit 103. That is, when the top surface shape of the pixel unit 103 is rectangular, the top surface shape of the connection electrode 111C can be a strip shape along one side of the outer periphery, an L-shape along two sides of the outer periphery, a U-shape along three sides of the outer periphery, a square shape along four sides of the outer periphery, or the like.

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

[0135] 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 via the contact hole 141.

[0136] 7A , the insulating layer 104 has a contact hole 142. The second wiring layer 151b and the first wiring layer 151a can be electrically connected to each other through the contact hole 142. The contact hole 142 may be formed in a region overlapping with the contact hole 141, or may be formed in a region not overlapping with the contact hole 141. When the thickness of the insulating layer 126 is larger than the thickness of the insulating layer 104, the size of the contact hole 141 (e.g., width in a cross-sectional view) is preferably larger than the size of the contact hole 142 (e.g., width in a cross-sectional view).

[0137] 7B , the end face of the organic compound layer 112B is preferably vertical or approximately vertical, which facilitates processing 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 inclination angle between the side surface and the bottom surface of a target layer when the layer is observed from a direction perpendicular to the cross section (for example, a surface perpendicular to the surface of the substrate). If the bottom surface is unclear, the inclination angle can be determined using the surface of the substrate.

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

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

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

[0142] In this embodiment mode, the organic compound layer 112 has a stacked structure of a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer in this order from the lower electrode 111 side, and the common layer 114 has an electron injection layer.

[0143] The functional layer does not necessarily have to contain an organic compound as long as it can perform its function. For example, an electron injection layer or the like can be made of an inorganic compound or a film containing only inorganic substances.

[0144] The lower electrode 111R, the lower electrode 111G, and the lower electrode 111B are provided for each light-emitting device. The common electrode 113 and the common layer 114 are provided as a continuous layer common to each light-emitting device. A reflective conductive film is used for the lower electrode 111, and a conductive film transparent to visible light is used for the common electrode 113, thereby making it possible to provide a display device with a top-emission structure.

[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 when the end of the lower electrode 111 has a tapered shape, the organic compound layer 112 has a shape that conforms to the tapered shape. By tapering the side surface of the lower electrode 111, coverage by the organic compound layer and the like can be improved.

[0146] The organic compound layer 112 is processed by photolithography. Therefore, the angle formed by the edge of the organic compound layer 112 and the surface on which it is formed may be close to 90 degrees. The edge of the organic compound layer 112 is located in a region 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 two adjacent light-emitting devices and is provided so as to fill the gap between at least two adjacent organic compound layers 112. More preferably, the insulating layer 126 has a region that overlaps with an end of the organic compound layer 112. That is, the end of the insulating layer 126 can be located on the organic compound layer 112, and the difference in height between the top and end of the insulating layer 126 is small. If the difference in height between the top and end of the insulating layer 126 becomes large, the insulating layer 126 may be easily peeled off, so it is preferable that this difference be small.

[0148] The insulating layer 126 preferably has a smooth convex upper shape. A convex upper shape can also be described as a shape in which the center of the insulating layer 126 is higher than the ends.

[0149] At least the common layer 114 and the common electrode 113 are provided to cover the insulating layer 126, and cutting of the common layer 114 and the common electrode 113 can be suppressed.

[0150] Furthermore, an insulating layer 125 may be provided in contact with a side surface of the organic compound layer 112. The insulating layer 125 is located between the insulating layer 126 and the organic compound layer 112 and functions as a protective film for preventing the insulating layer 126 from contacting the organic compound layer 112. If the organic compound layer 112 and the insulating layer 126 come into contact with each other, the organic compound layer 112 may be dissolved by an organic solvent or the like used in forming or processing the insulating layer 126. Therefore, by providing the insulating layer 125 between the organic compound layer 112 and the insulating layer 126 as shown in this embodiment, the organic compound layer 112 can be protected.

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

[0152] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0153] The insulating layer 125 can be formed by a sputtering method, a chemical vapor deposition (CVD) method, a pulsed laser deposition (PLD) method, an ALD method, or the like. The insulating layer 125 is preferably formed by an ALD method, which has good coverage.

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

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

[0156] When a photosensitive material is used for the insulating layer 126, a processed insulating layer 126 can be formed by exposure and development. The surface of the processed insulating layer 126 may have a rounded or uneven shape. Etching may be performed to adjust the surface height of the processed insulating layer 126. The surface height can be adjusted by processing the insulating layer 126 by ashing using oxygen plasma.

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

[0158] The upper surface of the insulating layer 126 preferably has a portion higher than the height of the upper surface of the organic compound layer 112. This makes it possible to absorb light emitted obliquely upward from the light-emitting device 11, and in combination with the auxiliary electrode, it is possible to achieve an even greater effect of suppressing stray light.

[0159] The insulating layer 126 can be formed using a wet film formation method such as spin coating, dipping, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating. In particular, it is preferable to form the organic insulating film that becomes the insulating layer 126 by spin coating.

[0160] After the insulating layer 126 is formed, heat treatment may be performed in the air at a temperature of 85° C. to 120° C. for 45 minutes to 100 minutes.

[0161] Furthermore, a reflective film (for example, a metal film containing one or more selected from silver, palladium, copper, titanium, aluminum, etc.) may be provided between the insulating layer 125 and the insulating layer 126. For example, the reflective film can be formed after the insulating layer 125 is formed. The reflective film can be configured to reflect light emitted from the light-emitting layer. This can improve the light extraction efficiency.

[0162] 7B , an insulating layer 128 may be provided between the insulating layer 125 and the top surface of the organic compound layer 112. The insulating layer 128 is formed by leaving a part of a protective layer (also referred to as a mask layer) for protecting the organic compound layer 112 when the organic compound layer 112 is etched. The insulating layer 128 may be formed using the same material as that used for the insulating layer 125. In particular, it is preferable to use the same material for the insulating layer 128 and the insulating layer 125 because this facilitates processing. For example, the insulating layer 128 and the insulating layer 125 may both include an aluminum oxide film, a hafnium oxide film, or a silicon oxide film.

[0163] The insulating layer 125, the insulating layer 126, and the insulating layer 128 are all insulating layers located between light-emitting devices and may be collectively referred to as an insulating laminate. Because the common layer 114 and the common electrode 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 disconnected. To have a tapered shape at the end of the insulating laminate, the end of the insulating layer 125 may have a tapered shape, the end of the insulating layer 126 may have a tapered shape, the end of the insulating layer 128 may have a tapered shape, or the ends of the insulating layer 125, the insulating layer 126, and the insulating layer 128 may all have a tapered shape. When a tapered shape is formed using multiple insulating layers, it is preferable that the tapered shapes of the ends of each insulating layer are formed continuously.

[0164] Furthermore, the insulating laminate preferably has a rounded top surface at its center. In other words, the insulating laminate has a shape that is higher than the edges. To achieve this shape, the insulating layer 126 located at the top of the insulating laminate is preferably formed using an organic material.

[0165] Furthermore, the edge of the insulating laminate may have various shapes. For example, the insulating layer 125 located below the insulating laminate may protrude from the insulating layer 126. In this case, a portion of the upper part of the insulating layer 125 may be removed when the insulating layer 126 is processed. Removing the portion of the upper part of the insulating layer 125 protruding from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 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 when the insulating layer 126 is processed. Removing the portion of the upper part of the insulating layer 128 protruding from the insulating layer 126 has the effect of preventing the common layer 114 and the common electrode 113 from being cut.

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

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

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

[0170] The protective layer 121 is bonded to the substrate 170 by an adhesive layer 171. Various curing adhesives can be used for the adhesive layer 171, such as a photo-curing adhesive such as an ultraviolet curing adhesive, a reaction-curing adhesive, a thermosetting adhesive, or an anaerobic adhesive. Alternatively, an adhesive sheet or the like may be used for the adhesive layer 171.

[0171] 7C , an opening is provided in the insulating layer 125 and the insulating layer 126 above the connection electrode 111C. The connection electrode 111C and the common electrode 113 are electrically connected through the opening. The opening for electrically connecting the connection electrode 111C and the common electrode 113 may be provided in any of the insulating layers.

[0172] 7C shows a configuration in which a common layer 114 is provided on the connection 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 that the connection electrode 111C can be electrically connected to the common electrode 113 via the common layer 114. This allows the common electrode 113 and the common layer 114 to be formed using the same mask (also called an area mask or a rough metal mask, to distinguish it from a fine metal mask), thereby reducing manufacturing costs. Of course, the connection electrode 111C may also be a connection portion 140 having an area where it contacts the common electrode 113.

[0173] Below, we will explain a configuration example of a display device that is partially different from the above. Note that below, parts that overlap with the above specific example will be given the same reference numerals, and repeated explanations may not be provided.

[0174] In the display device described in the specific example, at least the organic compound layer is separated. This structure suppresses crosstalk due to leakage current, and an image with extremely high display quality can be displayed. Furthermore, both a high aperture ratio and high definition can be achieved. The display device of one embodiment of the present invention can be applied to an ultra-large display of 40 to 100 inches, or even more than 100 inches.

[0175] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0176] Embodiment Mode 3 In this embodiment mode, the layout of sub-pixels will be described.

[0177] <Layout> There are no particular limitations on the arrangement of the sub-pixels, and a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, a pentile arrangement, or the like can be used.

[0178] Examples of the top surface shape of the sub-pixel include a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, a circle, etc. The top surface shape of the sub-pixel here corresponds to the light-emitting region of the light-emitting device.

[0179] The pixel portion 103 shown in FIG. 8A includes a second wiring layer 151b as part of the auxiliary wiring, and the pixel 150 includes a light-emitting device 11a having a generally trapezoidal top surface shape with rounded corners, a light-emitting device 11b having a generally triangular top surface shape with rounded corners, and a light-emitting device 11c having a generally rectangular or 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 manner, the shape and size of each light-emitting device can be determined independently. For example, the more reliable the light-emitting device, the smaller the size can be.

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

[0181] 8B has a second wiring layer 151b as part of the auxiliary wiring, and the sub-pixels are arranged in a Pentile arrangement, in which a pair of sub-pixels 124a including light-emitting devices 11a and 11b and a pair of sub-pixels 124b including light-emitting devices 11b and 11c are alternately laid out.

[0182] In the pixel section 103 shown in FIG. 8B, the light-emitting device 11a can be a red light-emitting device R, the light-emitting device 11b can be a green light-emitting device G, and the light-emitting device 11c can be a blue light-emitting device B, as shown in FIG. 9B.

[0183] 8C includes a second wiring layer 151b as part of the auxiliary wiring, and pixels 150a and 150b are arranged in a delta arrangement. In the delta arrangement, pixel 150a includes two light-emitting devices (light-emitting device 11a and light-emitting device 11b) in the top row (first row) and one light-emitting device (light-emitting device 11c) in the bottom row (second row). Pixel 150b includes one light-emitting device (light-emitting device 11c) in the top row (first row) and two light-emitting devices (light-emitting device 11a and light-emitting device 11b) in the bottom row (second row).

[0184] The pixel section 103 shown in FIG. 8C may have the light emitting device 11a as a red light emitting device R, the light emitting device 11b as a green light emitting device G, and the light emitting device 11c as a blue light emitting device B, as shown in FIG. 9C.

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

[0186] The pixel section 103 shown in FIG. 8D may have the light emitting device 11a as a red light emitting device R, the light emitting device 11b as a green light emitting device G, and the light emitting device 11c as a blue light emitting device B, as shown in FIG. 9D.

[0187] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This reduces the fidelity of the resist mask pattern when transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the resist mask pattern is rectangular, it is likely to have rounded corners. As a result, the top surface shape of the light-emitting device may become polygonal with rounded corners, elliptical, circular, or the like.

[0188] Furthermore, in a manufacturing method of a display device according to one embodiment of the present invention, an organic compound layer is processed using a resist mask. 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 material for the organic compound layer and the curing temperature of the resist material, curing for forming the resist mask may be insufficient. A resist mask that is insufficiently cured may have a shape different from the desired shape during processing. As a result, the top surface shape of the organic compound layer may be a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the organic compound layer.

[0189] In order to make the top surface of the organic compound layer have a desired shape, a technique for correcting a mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, the OPC technique adds a correction pattern to the corners of figures on the mask pattern.

[0190] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0191] Embodiment Mode 4 In this embodiment mode, materials and the like that can be used for a light-emitting device will be described.

[0192] [Light-emitting device] In a light-emitting device, it is preferable to use a light-transmitting conductive film for the electrode on the side from which light is extracted, and a conductive film that reflects visible light for the electrode on the side from which light is not extracted. A conductive film that transmits visible light may also be used for the electrode on the side from which light is not extracted. 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, it is sufficient if light emitted from the light-emitting device can be reflected by the conductive film that reflects visible light and extracted from the display device.

[0193] Materials for forming electrodes of light-emitting devices can include metals, alloys, electrically conductive compounds, and mixtures thereof. Specific examples include indium tin oxide, In-Si-Sn oxide, indium zinc oxide, In-W-Zn oxide, aluminum-containing alloys (also referred to as aluminum alloys) such as alloys of aluminum, nickel, and lanthanum (also referred to as Al-Ni-La alloys), and alloys of silver, palladium, and copper (also referred to as Ag-Pd-Cu, APC). Other metals that can be used include 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 metals in combination. Other examples that can be used include elements belonging to Group 1 or 2 of the periodic table (e.g., lithium, cesium, calcium, and strontium) that are not listed above, rare earth metals such as europium and ytterbium, alloys containing appropriate combinations of these, and graphene.

[0194] Of the above materials, those capable of emitting holes can be used as the anode, and those capable of emitting electrons can be used as the cathode.

[0195] It is preferable that a micro-optical resonator (microcavity) structure is applied to the light-emitting device. Therefore, it is preferable that one of a pair of electrodes of the light-emitting device has an electrode that is transparent and reflective to visible light (semi-transmissive / semi-reflective electrode), and the other has an electrode that is reflective to visible light (reflective electrode). By having the light-emitting device have a microcavity structure, light emission can be resonated between the pair of electrodes, narrowing the line of light emitted from the light-emitting device and further strengthening it.

[0196] When a micro-optical resonator (microcavity) structure is applied, the distance between a pair of electrodes is different from each other in the red, green, and blue light-emitting devices.

[0197] The semi-transmitting / semi-reflective electrode can have a laminated structure of a reflective electrode and an electrode that is transparent to visible light (also called a transparent electrode).

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

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

[0200] Examples of the light-emitting material 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 (particularly iridium complexes) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton, or a pyridine skeleton; organometallic complexes (particularly iridium complexes) having a phenylpyridine derivative having an electron-withdrawing group as a ligand; platinum complexes; and rare earth metal complexes.

[0203] The light-emitting layer may contain one or more organic compounds (host materials, assist materials, etc.) in addition to a light-emitting substance (guest material). As the one or more organic compounds, one or both of a hole-transporting material and an electron-transporting material can be used. Furthermore, as the one or more organic compounds, a bipolar material or a TADF material can be used.

[0204] The light-emitting layer preferably includes, for example, a phosphorescent material and a hole-transporting material and an electron-transporting material that are a combination that easily forms an exciplex. This configuration allows for efficient emission using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from the exciplex to the light-emitting material (phosphorescent material). By selecting a combination that forms an exciplex that emits light that overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material, energy transfer becomes smooth, allowing for efficient emission. This configuration simultaneously enables high efficiency, low-voltage operation, and long life of the light-emitting device.

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

[0206] The light-emitting device can be made of either a low-molecular-weight compound or a high-molecular-weight compound, and may contain an inorganic compound. The layers constituting the light-emitting device can be formed by a method such as vapor deposition (including vacuum vapor deposition), transfer, printing, inkjet printing, or coating.

[0207] For example, each of the organic compound layers 112 may have one or more of 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 may be one or more of 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 may not have the common layer 114.

[0209] The hole injection layer is a layer that injects holes from the anode into the hole transport layer and contains a material with high hole injection properties, such as an aromatic amine compound and a composite material containing a hole transport material and an acceptor material (electron acceptor material).

[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 that contains a hole transporting material. Examples of the hole transporting material include 10 −６ cm ２ A substance having a hole mobility of 1 / Vs or more is preferred. Note that other substances can also be used as long as they have a higher hole transporting property than electron transporting property. As the hole transporting material, a material having a high hole transporting property, such as a π-electron-rich heteroaromatic compound (e.g., a carbazole derivative, a thiophene derivative, a furan derivative, etc.) or an aromatic amine (a compound having an aromatic amine skeleton), is preferred.

[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 transport properties and can block electrons. The electron blocking layer can be made of a material that has electron blocking properties among the hole transport materials described above.

[0212] The electron blocking layer has hole transport properties and can therefore also be called a hole transport layer. Furthermore, a layer of the hole transport layer that has electron blocking properties can also be called an electron blocking layer.

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

[0214] Other examples of electron transporting materials that can be used include compounds having an electron-deficient heteroaromatic ring with an unshared electron pair, such as a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, or pyridazine ring), or a triazine ring.

[0215] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) level of −3.6 eV to −2.3 eV. Generally, the highest occupied molecular orbital (HOMO) level and the LUMO level of an organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0216] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition point (Tg) and is superior in heat resistance compared to BPhen.

[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 transport properties and can block holes. The hole-blocking layer can be made of a material that has hole-blocking properties and is selected from the above electron-transporting materials.

[0218] The hole blocking layer has electron transport properties and can therefore also be called an electron transport layer. Furthermore, a layer of the electron transport layer that has hole blocking properties can also be called a hole blocking layer.

[0219] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer and contains a material with high electron injection properties. Examples of the material with high electron injection properties include alkali metals, alkaline earth metals, and compounds thereof. Examples of the material with high electron injection properties include a composite material containing an electron transport material and a donor material (electron donor material).

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

[0221] The electron injection layer may also be made of an organic compound, such as 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatolithium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatolithium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatolithium (abbreviation: LiPPP), 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), or 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen).

[0222] The organic compound may contain a dopant, which may be a metal, such as silver (Ag) or ytterbium (Yb).

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

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

[0225] The electron-transporting material described above may be used for the electron-injecting layer.

[0226] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0227] Embodiment Mode 5 In this embodiment mode, a display device will be described.

[0228] 10A shows a block diagram of a display device 10. The display device 10 includes a pixel portion 103, a driver circuit portion 12, a driver circuit portion 13, and the like.

[0229] The pixel unit 103 has a plurality of pixels 150 laid out 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] The pixel 150 is electrically connected to a wiring GL, a wiring SLR, a wiring SLG, and a wiring SLB. The wirings SLR, SLG, and SLB are each electrically connected to a driver circuit unit 12. The wiring GL is electrically connected to a driver circuit unit 13. The driver circuit unit 12 functions as a source line driver circuit (also referred to as a source driver), and the driver circuit unit 13 functions as a gate line driver circuit (also referred to as a gate driver). The wiring GL functions as a gate line, and the wirings SLR, SLG, and SLB function as source lines.

[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 full color. Note that pixel 150 may also have sub-pixels that have light-emitting devices that emit light of other colors. For example, in addition to the above three sub-pixels, pixel 150 may also have a sub-pixel that has a light-emitting device that emits white light, or a sub-pixel that has a light-emitting device that emits yellow light, etc.

[0232] The line GL is electrically connected to the sub-pixels 110R, 110G, and 110B arranged in the row direction (extension direction of the line GL). The line SLR, line SLG, and line SLB are electrically connected to the sub-pixels 110R, 110G, and 110B (not shown) arranged in the column direction (extension direction of the line SLR, etc.), respectively.

[0233] 10B shows an example of a circuit diagram of a pixel 150 that can be applied to the subpixels 110R, 110G, and 110B. The pixel 150 includes a transistor M1, a transistor M2, a transistor M3, a capacitor C1, and a light-emitting device EL. A wiring GL and a wiring SL are electrically connected to the pixel 150. The wiring SL corresponds to any one of the wirings SLR, SLG, and SLB shown in FIG. 10A.

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

[0235] The wiring SL is supplied with a data potential D. The wiring GL is supplied with a selection signal. The selection signal includes a potential that turns on a transistor and a potential that turns off a transistor.

[0236] A reset potential is applied to the wiring RL. An anode potential is applied to the wiring AL. A cathode potential is applied to the wiring CL. In the pixel 150, the anode potential is higher than the cathode potential. The reset potential applied to the wiring RL can be a potential such that the potential difference between the reset potential and the cathode potential is smaller than the threshold voltage of the light-emitting device EL. The reset potential can be a potential higher than the cathode potential, the same as the cathode potential, or a potential lower than the cathode potential.

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

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

[0239] Alternatively, OS transistors may be used for all of the transistors M1 to M3. In this case, an LTPS transistor may be used for one or more of the transistors included in the driver circuit portion 12 and the transistors included in the driver circuit portion 13, and OS transistors may be used for the remaining transistors. For example, an OS transistor may be used for the transistor provided in the pixel portion 103, and an LTPS transistor may be used for the transistors provided in the driver circuit portion 12 and the driver circuit portion 13.

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

[0241] A transistor using an oxide semiconductor, which has a wider band gap and a lower carrier density than silicon, can achieve an extremely small off-state current. Therefore, the small off-state current allows charge stored in a capacitor connected in series with the transistor to be held for a long period of time. Therefore, it is preferable to use transistors including oxide semiconductors for the transistors M1 and M3 connected in series with the capacitor C1. Using transistors including oxide semiconductors as the transistors M1 and M3 can prevent charge stored in the capacitor C1 from leaking through the transistor M1 or M3. Furthermore, because charge stored in the capacitor C1 can be held for a long period of time, a still image can be displayed for a long period of time without rewriting data in the pixel 150.

[0242] Although the transistors are shown as n-channel transistors in FIG. 10B, p-channel transistors can also be used.

[0243] In addition, the transistors included in the pixel 150 are preferably formed side by side on the same substrate.

[0244] As the transistor included in the pixel 150, a transistor having a pair of gates overlapping with each other with a semiconductor layer interposed therebetween can be used.

[0245] In a transistor having a pair of gates, when the pair of gates are electrically connected to each other and supplied with the same potential, the on-state current of the transistor is increased and the saturation characteristics are improved. A potential for controlling the threshold voltage of the transistor may be supplied to one of the pair of gates. Supplying a constant potential to one of the pair of gates can improve the stability of the electrical characteristics of the transistor. For example, one gate of the transistor may be electrically connected to a wiring to which a constant potential is supplied, or to its own source or drain.

[0246] 10C is an example of a pixel 150 in which a transistor having a pair of gates is used as the transistor M3. The pair of gates of the transistor M3 are electrically connected. With this configuration, the period for writing data to the pixel 150 can be shortened.

[0247] 10D is an example in which transistors having a pair of gates are used for transistors M1 and M2 in addition to transistor M3. In each of the transistors, the pair of gates is electrically connected to each other. By using such a transistor at least for transistor M2, the saturation characteristics are improved, making it easier to control the emission luminance of light-emitting device EL, and thus improving display quality.

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

[0249] [Example of Transistor Structure] Hereinafter, an example of a cross-sectional structure of a transistor that can be applied to the display device will be described.

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

[0251] The transistor 410 is provided on the substrate 401 and has a semiconductor layer made of polycrystalline silicon. For example, the transistor 410 corresponds to the transistor M2 of the pixel 150. That is, Fig. 11A illustrates an example in which one of the source and the drain of the transistor 410 is electrically connected to the lower electrode 111 of the light-emitting device.

[0252] The transistor 410 includes a semiconductor layer 411, an insulating layer 412, a conductive layer 413, and the like. The semiconductor layer 411 includes a channel formation region 411i and a low-resistance region 411n. The semiconductor layer 411 includes silicon. The semiconductor layer 411 preferably includes polycrystalline silicon. A part of the insulating layer 412 functions as a gate insulating layer. A part of the conductive layer 413 functions as a gate electrode.

[0253] Note that the semiconductor layer 411 can also include a metal oxide (also referred to as an oxide semiconductor) that exhibits semiconductor characteristics. In this case, the transistor 410 can be called an OS transistor.

[0254] The low-resistance region 411n is a region containing an impurity element. For example, when the transistor 410 is an n-channel transistor, phosphorus, arsenic, or the like may be added to the low-resistance region 411n. On the other hand, when the transistor 410 is a p-channel transistor, boron, aluminum, or the like may be added to the low-resistance region 411n. Furthermore, in order to control the threshold voltage of the transistor 410, the above-mentioned impurities may be added to the channel formation region 411i.

[0255] An insulating layer 421 is provided over a substrate 401. A semiconductor layer 411 is provided over the insulating layer 421. An insulating layer 412 is provided to cover the semiconductor layer 411 and the insulating layer 421. A conductive layer 413 is provided over the insulating layer 412 so as to overlap with the semiconductor layer 411.

[0256] An insulating layer 422 is provided to cover the conductive layer 413 and the insulating layer 412. A conductive layer 414a and a conductive layer 414b are provided over the insulating layer 422. The conductive layer 414a and the conductive layer 414b are electrically connected to the low-resistance region 411n through openings provided in the insulating layer 422 and the insulating layer 412. A part of the conductive layer 414a functions as one of the source electrode and the drain electrode, and a part of the conductive layer 414b functions as the other of the source electrode and the drain electrode. An insulating layer 104 is provided to cover the conductive layer 414a, the conductive layer 414b, and the insulating layer 422.

[0257] A lower electrode 111 functioning as a pixel electrode is provided over the insulating layer 104. The lower electrode 111 is provided over the insulating layer 104 and is electrically connected to the conductive layer 414b in an opening provided in the insulating layer 104. Although not shown here, an EL layer and a common electrode can be stacked over the lower electrode 111.

[0258] 11B shows a transistor 410a having a pair of gate electrodes, which is different from the transistor 410a shown in FIG. 11A in that a conductive layer 415 and an insulating layer 416 are included.

[0259] The conductive layer 415 is provided over the insulating layer 421. An insulating layer 416 is provided to cover the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided so that at least a channel formation region 411i overlaps with the conductive layer 415 with the insulating layer 416 interposed therebetween.

[0260] 11B, part of the conductive layer 413 functions as a first gate electrode, part of the conductive layer 415 functions as a second gate electrode, part of the insulating layer 412 functions as a first gate insulating layer, and part of the insulating layer 416 functions as a second gate insulating layer.

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

[0262] 11A or the transistor 410a illustrated in FIG. 11B can be used for all the transistors constituting the pixel 150. In this case, the transistor 410a may be used for all the transistors constituting the pixel 150, the transistor 410 may be used for all the transistors, or the transistor 410a and the transistor 410 may be used in combination.

[0263] [Structure Example 3] Hereinafter, a structure example including both a transistor in which silicon is used for a semiconductor layer and a transistor in which a metal oxide is used for a semiconductor layer will be described.

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

[0265] The transistor 410a can be configured as in the above-described Structure Example 1. Note that although the example using the transistor 410a is shown here, a structure including the transistor 410 and the transistor 450 may be used, or a structure including all of the transistor 410, the transistor 410a, and the transistor 450 may be used.

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

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

[0268] The transistor 450 includes a conductive layer 455, an insulating layer 422, a semiconductor layer 451, an insulating layer 452, a conductive layer 453, and the like. Part of the conductive layer 453 functions as a first gate of the transistor 450, and part of the conductive layer 455 functions as a second gate of the transistor 450. In this case, part of the insulating layer 452 functions as a first gate insulating layer of the transistor 450, and part of the insulating layer 422 functions as a second gate insulating layer of the transistor 450.

[0269] The conductive layer 455 is provided over the insulating layer 412. The insulating layer 422 is provided to cover the conductive layer 455. The semiconductor layer 451 is provided over the insulating layer 422. The insulating layer 452 is provided to cover the semiconductor layer 451 and the insulating layer 422. The conductive layer 453 is provided over the insulating layer 452 and has a region overlapping with the semiconductor layer 451 and the conductive layer 455.

[0270] An insulating layer 426 is provided to cover the insulating layer 452 and the conductive layer 453. A conductive layer 454a and a conductive layer 454b are provided over the insulating layer 426. The conductive layer 454a and the conductive layer 454b are electrically connected to the semiconductor layer 451 through openings provided in the insulating layer 426 and the insulating layer 452. A part of the conductive layer 454a functions as one of the source electrode and the drain electrode, and a part of the conductive layer 454b functions as the other of the source electrode and the drain electrode. An insulating layer 104 is provided to cover the conductive layer 454a, the conductive layer 454b, and the insulating layer 426.

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

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

[0273] In FIG. 11C , the insulating layer 452 functioning as the first gate insulating layer of the transistor 450 covers the end portion of the semiconductor layer 451. However, as in the transistor 450a shown in FIG. 11D , the insulating layer 452 may be processed so that the top surface shape thereof matches or substantially matches the top surface shape of the conductive layer 453.

[0274] In this specification, the phrase "top surface shapes generally match" refers to the overlap of at least a portion of the contours between stacked layers. For example, this includes cases where the upper and lower layers are processed using the same mask pattern, or where a portion of the mask pattern is the same. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, the phrase "top surface shapes generally match" also applies.

[0275] Although the example in which the transistor 410a corresponds to the transistor M2 and is electrically connected to the pixel electrode has been described, this is not limiting. For example, the transistor 450 or the transistor 450a may correspond to the transistor M2. In this case, the transistor 410a corresponds to the transistor M1, the transistor M3, or another transistor.

[0276] By having the pixel circuit and the light-emitting device structure of the above embodiment, the display device can have one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. The leakage current that can flow through the transistors of the pixel circuit is extremely low, and the lateral leakage current between the light-emitting devices of the above embodiment is extremely low, which is preferable because the display device minimizes light leakage and the like that can occur when displaying black.

[0277] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0278] Embodiment Mode 6 In this embodiment mode, a display device having a light receiving device (also referred to as a light receiving element) will be described.

[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 has 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, instead of displaying an image using all of the sub-pixels of the display device, some of the sub-pixels may emit light as a light source, and the remaining sub-pixels may display an image.

[0281] 12A, 12B, and 12C includes subpixels 110G, 110B, and 110R, and a light receiving portion S (labeled R, G, B, and S in the drawings), and also includes 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, the symbols R, G, B, and S are assigned within each region to simplify the distinction between the subpixels, etc.

[0282] The pixel 150 shown in FIG. 12A is configured in a stripe arrangement, and a second wiring layer 151b is provided to surround the subpixels 110G, 110B, 110R, and the light receiving portion S (labeled R, G, B, and S in the figure).

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

[0284] The pixel 150 shown in FIG. 12C has an arrangement in which three subpixels (subpixel 110R, subpixel 110G, and light receiving portion S) are vertically arranged next to one subpixel (subpixel 110B), and a second wiring layer 151b is provided to surround the subpixels 110G, 110B, 110R, and the light receiving portion S.

[0285] The layout of the subpixels is not limited to the configurations shown in Figures 12A to 12C. The layout of the second wiring layer 151b is not limited to the configurations shown in Figures 12A to 12C.

[0286] When the light-receiving area of ​​the light-receiving portion S is smaller than the light-emitting area of ​​the other subpixels, the imaging range is narrowed, which makes it possible to suppress blurring of the imaging result and improve the resolution. Therefore, the display device of one embodiment of the present invention can capture high-definition or high-resolution images. For example, the light-receiving portion S can be used to capture images of a fingerprint, palm print, iris, pulse shape (including vein shape and artery shape), face, or the like for personal authentication.

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

[0288] A touch sensor or near-touch sensor can detect the proximity or contact of an object (such as a finger, hand, or pen). A touch sensor can detect an object when the display device and the object are in direct contact with each other. A near-touch sensor can detect an object even if the object does not come into contact with the display device. For example, a configuration in which the display device can detect an object when the distance between the display device and the object is in the range of 0.1 mm to 300 mm, preferably 3 mm to 50 mm, is preferable. This configuration enables the display device to be operated without the object directly touching the display device, in other words, it enables the display device to be operated in a non-contact (touchless) manner. This configuration reduces the risk of the display device becoming dirty or scratched, or enables the display device to be operated without the object directly touching dirt (e.g., dust, viruses, etc.) attached to the display device.

[0289] When high-resolution imaging is performed, it is preferable that the light receiving unit S is provided in all pixels of the display device. On the other hand, when used in a touch sensor or near-touch sensor, the light receiving unit S does not require high accuracy compared to when imaging a fingerprint, etc., so it is sufficient that it is provided in some of the pixels of the display device. By making the number of light receiving units S in the display device smaller than the number of sub-pixels 110R, etc., the detection speed can be increased.

[0290] FIG. 12D shows an example of a pixel circuit of a sub-pixel (PIX1) having a light-receiving device.

[0291] 12D includes a light receiving device PD, a transistor M11, a transistor M12, a transistor M13, a transistor M14, and a capacitance element C2. Here, an example is shown in which a photodiode is used as the light receiving device PD.

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

[0293] A constant potential is supplied to the wiring V1, the wiring V2, and the wiring V3. When the light-receiving device PD is driven, a potential higher than the potential of the wiring V1 is supplied to the wiring V2. The transistor M12 is controlled by a signal supplied to the wiring RES and has a function of resetting the potential of a node connected to the gate of the transistor M13 to the potential supplied to the wiring V2. The transistor M11 is controlled by a signal supplied to the wiring TX and has a function of controlling the timing at which the potential of the node changes depending on the current flowing through the light-receiving device PD. The transistor M13 functions as an amplifying transistor that outputs according to the potential of the node. The transistor M14 is controlled by a signal supplied to the wiring SE and functions as a selection transistor that reads out an output according to the potential of the node to an external circuit electrically connected to the wiring OUT1.

[0294] The transistors M11, M12, M13, and M14 are preferably transistors (OS transistors) that use a metal oxide (oxide semiconductor) in a semiconductor layer in which a channel is formed.

[0295] An OS transistor has a wider band gap and a lower carrier density than silicon transistors, and can achieve extremely low off-state current.

[0296] Alternatively, the transistors M11 to M14 may be transistors using silicon as a semiconductor in which a channel is formed. In particular, using silicon with high crystallinity, such as single crystal silicon or polycrystalline silicon, is preferable because high field-effect mobility can be achieved and higher-speed operation is possible.

[0297] Alternatively, a structure may be used in which at least one of the transistors M11 to M14 includes an oxide semiconductor and the remaining transistors include silicon.

[0298] Although the transistors are shown as n-channel transistors in FIG. 12D, p-channel transistors can also be used.

[0299] Furthermore, the display device of one embodiment of the present invention can have a variable refresh rate. For example, the refresh rate can be adjusted (for example, within a range of 0.01 Hz to 240 Hz) depending on the content displayed on the display device, thereby reducing power consumption. Furthermore, driving that reduces the power consumption of the display device by driving it at a reduced refresh rate may be called idling stop (IDS) driving.

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

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

[0302] Embodiment 7 In this embodiment, a metal oxide (also referred to as an oxide semiconductor) that can be used for the OS transistor described in the above embodiment will be described.

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

[0304] The metal oxide can be formed by a sputtering method, a CVD method such as an MOCVD method, an ALD method, or the like.

[0305] <Classification of Crystal Structure> Examples of the crystal structure of an oxide semiconductor include amorphous (including completely amorphous), c-axis-aligned crystalline line (CAAC), nanocrystalline line (nc), cloud-aligned composite (CAC), single crystal, and polycrystalline.

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

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

[0308] In addition, the crystalline structure of the film or substrate can be evaluated by a diffraction pattern (also referred to as a nanobeam electron diffraction pattern) observed by nanobeam electron diffraction (NBED). For example, a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state. In addition, a spot-like pattern is observed in the diffraction pattern of an IGZO film formed at room temperature, rather than a halo. For this reason, it is estimated that the IGZO film formed at room temperature is neither in a crystalline state nor in an amorphous state, but in an intermediate state, and it cannot be concluded that it is in an amorphous state.

[0309] <<Structure of Oxide Semiconductor>> Note that oxide semiconductors may be classified differently from the above when focusing on their structures. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above-mentioned CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, pseudo-amorphous-like oxide semiconductors (a-like OSs), amorphous oxide semiconductors, and the like.

[0310] Here, the above-mentioned CAAC-OS, nc-OS, and a-like OS will be described in detail.

[0311] [CAAC-OS] A CAAC-OS is an oxide semiconductor having multiple crystalline regions, each with its c-axis aligned in a specific direction. The specific direction refers to the thickness direction of the CAAC-OS film, the normal direction to the surface where the CAAC-OS film is formed, or the normal direction to the surface of the CAAC-OS film. A crystalline region is a region having periodic atomic arrangement. If the atomic arrangement is considered as a lattice arrangement, a crystalline region is also a region with a uniform lattice arrangement. Furthermore, a CAAC-OS has a region where multiple crystalline regions are connected in the a-b plane direction, and the region may have distortion. Note that distortion refers to a portion where the lattice arrangement changes between a region with a uniform lattice arrangement and a region with another uniform lattice arrangement in a region where multiple crystalline regions are connected. In other words, a CAAC-OS is an oxide semiconductor whose c-axes are aligned and whose orientation is not clearly aligned in the a-b plane direction.

[0312] Each of the multiple crystalline regions is composed of one or more minute crystals (crystals with a maximum diameter of less than 10 nm). When a crystalline region is composed of one minute crystal, the maximum diameter of the crystalline region is less than 10 nm. When a crystalline region is composed of multiple minute crystals, the size of the crystalline region may be several tens of nanometers.

[0313] In an In-M-Zn oxide (wherein the element M is one or more elements selected from aluminum, gallium, yttrium, tin, titanium, and the like), the CAAC-OS tends to have a layered crystal structure (also referred to as a layered structure) in which a layer containing indium (In) and oxygen (hereinafter referred to as an In layer) and a layer containing the element M, zinc (Zn), and oxygen (hereinafter referred to as an (M, Zn) layer) are stacked. Note that indium and the element M are mutually substituted. Therefore, the (M, Zn) layer may contain indium. The In layer may contain the element M. The In layer may contain Zn. The layered structure is observed as a lattice image in a high-resolution transmission electron microscope (TEM) image, for example.

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

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

[0316] When a crystalline region is observed from the specific direction, the lattice arrangement in the crystalline region is basically a hexagonal lattice, but the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. The distortion may have a pentagonal, heptagonal, or other lattice arrangement. In the CAAC-OS, no clear grain boundary can be identified even near the distortion. This indicates that the distortion in the lattice arrangement suppresses the formation of grain boundaries. This is thought to be because the CAAC-OS can tolerate distortion due to the lack of close-packed arrangement of oxygen atoms in the a-b plane and the change in interatomic bond distance caused by metal atom substitution.

[0317] Note that a crystal structure in which clear grain boundaries are observed is called polycrystalline. The grain boundaries act as recombination centers, and are likely to trap carriers, resulting in a decrease in the on-state current of a transistor and a decrease in field-effect mobility. Therefore, CAAC-OS, in which clear grain boundaries are not observed, is one of the crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor. Note that a structure containing Zn is preferable for forming a CAAC-OS. For example, In—Zn oxide and In—Ga—Zn oxide are suitable because they can suppress the generation of grain boundaries more effectively than In oxide.

[0318] CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the CAAC-OS is less susceptible to a decrease in electron mobility due to crystal grain boundaries. Furthermore, since the crystallinity of an oxide semiconductor can be reduced by the inclusion of impurities, the formation of defects, or the like, the CAAC-OS can also be said to be an oxide semiconductor with few impurities and defects (oxygen vacancies, etc.). Therefore, an oxide semiconductor having CAAC-OS has stable physical properties. Therefore, an oxide semiconductor having CAAC-OS is heat-resistant and highly reliable. Furthermore, the CAAC-OS is stable even against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, using a CAAC-OS for an OS transistor can increase the flexibility of the manufacturing process.

[0319] [nc-OS] The nc-OS has periodic atomic arrangement in a microscopic region (e.g., a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In other words, the nc-OS has microcrystals. Note that the size of the microcrystals is, for example, 1 nm to 10 nm, particularly 1 nm to 3 nm, and therefore the microcrystals are also called nanocrystals. Furthermore, the nc-OS does not exhibit regularity in the crystal orientation between different nanocrystals. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, the nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor. For example, when a structural analysis of an nc-OS film is performed using an XRD apparatus, no peak indicating crystallinity is detected in out-of-plane XRD measurement using θ / 2θ scanning. When an nc-OS film is subjected to electron diffraction (also referred to as selected-area electron diffraction) using an electron beam with a probe diameter larger than that of a nanocrystal (e.g., 50 nm or more), a diffraction pattern resembling a halo pattern is observed. On the other hand, when an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than that of a nanocrystal (e.g., 1 nm to 30 nm), an electron diffraction pattern in which multiple spots are observed within a ring-shaped region centered on a direct spot may be obtained.

[0320] [a-Like OS] The a-like OS is an oxide semiconductor having a structure between the nc-OS and an amorphous oxide semiconductor. The a-like OS has pores or low-density regions. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. Furthermore, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and CAAC-OS.

[0321] <<Structure of Oxide Semiconductor>> Next, the above-described CAC-OS will be described in detail. Note that the CAC-OS relates to a material structure.

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

[0323] Furthermore, the CAC-OS has a mosaic structure in which a material is separated into a first region and a second region, and the first region is distributed throughout the film (hereinafter also referred to as a cloud structure). That is, the CAC-OS is a composite metal oxide having a structure in which the first region and the second region are mixed.

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

[0325] Specifically, the first region is a region whose main component is indium oxide, indium zinc oxide, or the like. The second region is a region whose main component is gallium oxide, gallium zinc oxide, or the like. In other words, the first region can be rephrased as a region whose main component is In. The second region can be rephrased as a region whose main component is Ga.

[0326] It should be noted that there are cases where a clear boundary between the first region and the second region cannot be observed.

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

[0328] The CAC-OS can be formed by sputtering without heating the substrate. When the CAC-OS is formed by sputtering, one or more of an inert gas (typically argon), oxygen gas, and nitrogen gas may be used as the deposition gas. The lower the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition, the more preferable it is. For example, the flow rate of oxygen gas relative to the total flow rate of deposition gas during deposition is preferably 0% or more and less than 30%, and more preferably 0% or more and 10% or less.

[0329] Furthermore, for example, in the case of CAC-OS in an In—Ga—Zn oxide, EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX) can confirm that the CAC-OS has a structure in which a region containing In as a main component (first region) and a region containing Ga as a main component (second region) are unevenly distributed and mixed.

[0330] Here, the first region has higher conductivity than the second region. That is, the flow of carriers through the first region causes the metal oxide to exhibit conductivity. Therefore, the first region is distributed in a cloud-like manner in the metal oxide, thereby achieving a high field-effect mobility (μ).

[0331] On the other hand, the second region has higher insulating properties than the first region. That is, the second region is distributed in the metal oxide, thereby suppressing leakage current.

[0332] Therefore, when a CAC-OS is used in a transistor, the conductivity due to the first region and the insulating property due to the second region act complementarily, thereby providing the CAC-OS with a switching function (a function of turning on / off). In other words, a CAC-OS has a conductive function in a part of the material and an insulating function in a part of the material, and the entire material functions as a semiconductor. By separating the conductive function and the insulating function, both functions can be maximized. Therefore, by using a CAC-OS in a transistor, a high on-current (I ｏｎ), high field-effect mobility (μ), and good switching behavior can be achieved.

[0333] Furthermore, a transistor using the CAC-OS has high reliability, and therefore, the CAC-OS is ideal for various semiconductor devices such as display devices.

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

[0335] <Transistor Having Oxide Semiconductor> Next, a case where the oxide semiconductor is used for a transistor will be described.

[0336] By using the oxide semiconductor for a transistor, a transistor with high field-effect mobility and high reliability can be realized.

[0337] For the transistor, an oxide semiconductor having a low carrier concentration is preferably used. For example, the carrier concentration of the oxide semiconductor is 1×10 １７ cm −３ Below 1 × 10, preferably １５ cm −３ More preferably, 1×10 １３ cm −３ or less, more preferably 1 × 10 １１ cm −３ More preferably, 1×10 １０ cm −３ is less than 1×10 −９ cm −３ The above is the case. Note that in order to reduce the carrier concentration of an oxide semiconductor film, the impurity concentration in the oxide semiconductor film may be reduced to reduce the density of defect states. In this specification and the like, a semiconductor having a low impurity concentration and a low density of defect states is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Note that an oxide semiconductor having a low carrier concentration may also be referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.

[0338] Furthermore, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor film has a low density of defect states, and therefore the density of trap states may also be low.

[0339] Furthermore, charges trapped in the trap states of an oxide semiconductor take a long time to dissipate and may behave like fixed charges. Therefore, a transistor in which a channel formation region is formed in an oxide semiconductor with a high density of trap states may have unstable electrical characteristics.

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

[0341] <Impurities> Here, the influence of each impurity in an oxide semiconductor will be described.

[0342] When an oxide semiconductor contains silicon or carbon, which is one of Group 14 elements, defect levels are formed in the oxide semiconductor. Therefore, the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon near the interface with the oxide semiconductor (concentration obtained by secondary ion mass spectrometry (SIMS)) are calculated to be 2×10 １８ atoms / cm ３ Below 2 × 10, preferably １７ atoms / cm ３ The following applies.

[0343] Furthermore, when an oxide semiconductor contains an alkali metal or an alkaline earth metal, defect levels are formed and carriers are generated in some cases. Therefore, a transistor using an oxide semiconductor containing an alkali metal or an alkaline earth metal is likely to have normally-on characteristics. For this reason, when the concentration of the alkali metal or the alkaline earth metal in the oxide semiconductor obtained by SIMS is 1×10 １８ atoms / cm ３ Below 2 × 10, preferably １６atoms / cm ３ Do the following:

[0344] Furthermore, when nitrogen is contained in an oxide semiconductor, electrons serving as carriers are generated, the carrier concentration increases, and the semiconductor is likely to become n-type. As a result, a transistor using an oxide semiconductor containing nitrogen as a semiconductor tends to have normally-on characteristics. Alternatively, when nitrogen is contained in an oxide semiconductor, trap states may be formed. As a result, the electrical characteristics of the transistor may become unstable. For this reason, the nitrogen concentration in the oxide semiconductor obtained by SIMS is set to 5×10 １９ atoms / cm ３ Less than 5×10 １８ atoms / cm ３ or less, more preferably 1 × 10 １８ atoms / cm ３ or less, more preferably 5 × 10 １７ atoms / cm ３ Do the following:

[0345] Furthermore, hydrogen contained in an oxide semiconductor may react with oxygen bonded to a metal atom to form water, which may form an oxygen vacancy. Hydrogen entering the oxygen vacancy may generate electrons as carriers. Furthermore, some of the hydrogen may bond with oxygen bonded to a metal atom to generate electrons as carriers. Therefore, a transistor using an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. Therefore, it is preferable to reduce hydrogen in the oxide semiconductor as much as possible. Specifically, the hydrogen concentration in the oxide semiconductor measured by SIMS is 1×10 ２０ atoms / cm ３ less than 1×10 １９ atoms / cm ３ less than 5×10 １８ atoms / cm ３ less than 1×10 １８ atoms / cm ３ Make it less than.

[0346] When an oxide semiconductor with sufficiently reduced impurities is used for a channel formation region of a transistor, stable electrical characteristics can be obtained.

[0347] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0348] 13 to 17. In the drawings, a region related to a pixel 150 is shown on the left side, and a region related to an auxiliary wiring 151 is shown on the right side.

[0349] [Fabrication Method Example 1] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting a display device can be formed by a sputtering method, a CVD method, a vacuum deposition method, a PLD method, an ALD method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

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

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

[0352] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0353] In photolithography, the light used for exposure may be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these. Other examples include ultraviolet light, KrF laser light, and ArF laser light. Extreme ultraviolet (EUV) light, X-rays, and the like may also be used as light for exposure. An electron beam may also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a resist mask is not required.

[0354] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0355] [Preparation of Substrate] Although not shown, a substrate is prepared. A substrate having heat resistance sufficient to withstand at least the subsequent heat treatment can be used as the substrate. When an insulating substrate is used as the substrate, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used. Furthermore, a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.

[0356] As the substrate, it is preferable to prepare a substrate on which a pixel circuit including a semiconductor element such as a transistor is formed on the semiconductor substrate or insulating substrate. A substrate on which a gate line driver circuit (gate driver), a source line driver circuit (source driver), or the like is formed in addition to the pixel circuit may also be used. Furthermore, a substrate on which an arithmetic circuit, a memory circuit, or the like is formed in addition to the above may also be used.

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

[0358] 13A, the insulating layer 102 has a contact hole 158. The contact hole 158 can be formed by photolithography or the like.

[0359] 13A, the conductive layer 160 and the first wiring layer 151a are formed on the insulating layer 102 and in the contact hole 158. That is, the conductive layer 160 and the first wiring layer 151a are formed on the same formation surface through the same process. Specifically, the conductive film formed on the insulating layer 102 and in the contact hole 158 is processed to obtain the conductive layer 160 and the first wiring layer 151a.

[0360] The conductive layer 160 is electrically connected to the transistor of the pixel circuit and also electrically connected to the lower electrode 111. The conductive layer 160 can be processed into an extended shape on the insulating layer 102 and can function as a signal line, a power supply line, a scan line, or the like. The conductive layer 160 may also be a conductive layer for electrically connecting the transistor and the lower electrode 111 without functioning as a wiring. The first wiring layer 151a can function as a lower wiring layer of the auxiliary wiring 151 and is processed into an extended shape, a lattice shape, or the like on the insulating layer 102. The first wiring layer 151a does not affect the aperture ratio and may therefore have a shape with a large area. However, the first wiring layer 151a is not in contact with the conductive layer 160.

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

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

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

[0364] The insulating layer 104 has a contact hole 159. The contact hole 159 can be formed by photolithography or the like, and a part of the conductive layer 160 is exposed through the contact hole 159. The contact hole 159 is preferably provided at a position that does not overlap with the contact hole 158 but overlaps with the conductive layer 160 provided on the flat top surface of the insulating layer 102. When the contact hole 159 overlaps with the contact hole 158, the contact hole 159 is preferably larger than the contact hole 158.

[0365] 13A , the conductive layer 161 is formed in the contact hole 159, then the resin layer 163 is formed, and then the conductive layer 162 is formed. The 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 to be the conductive layer 161 is formed over the insulating layer 104 and the contact hole 159. The top surface of the insulating layer 104 is a surface where the conductive film is formed, and it is preferable that the top surface is flat because the conductive film is less likely to be cut. The conductive layer 161 can be formed using one or more metal materials selected from aluminum, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, neodymium, and the like, or an alloy in which these metal materials are appropriately combined.

[0367] If the conductive film has a recess on its surface after being formed, a layer containing a resin as an organic material (hereinafter referred to as a resin layer) 163 may be formed in the recess. The resin layer 163 can reduce unevenness caused by the insulating layer 104, the contact hole 159, and the conductive layer 161.

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

[0369] Furthermore, when a non-photosensitive resin is used as the resin layer 163, the resin layer 163 can be formed by forming a resin film and then etching the upper part of the resin film by ashing or the like. Ashing is performed 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 the like.

[0370] Subsequently, a conductive film to be the conductive layer 162 is formed on the resin layer 163. The conductive layer 162 may include one or more materials selected from the metals shown as the conductive layer 161.

[0371] [Formation of the Lower Electrode 111 and the Second Wiring Layer 151b] As shown in FIG. 13A , a conductive film that will become the lower electrode 111 and the second wiring layer 151b is formed to cover the conductive film that will become the conductive layer 161 and the conductive film that will become the conductive layer 162. The lower electrode 111 functions as 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 of the lower electrode. The second wiring layer 151b is preferably formed using the same material as the lower electrode 111.

[0372] Then, a resist mask is formed on the three conductive films by photolithography, and unnecessary portions of each conductive film are removed by etching. The resist mask is then removed, so that the conductive layer 161, the conductive layer 162, the bottom electrode 111, and the second wiring layer 151b can be formed in the same etching process using the same resist mask. The resin layer 163 and the like enable the bottom electrode 111 and the second wiring layer 151b to have flat upper surfaces.

[0373] Although the conductive layers 161 and 162 are formed in the same etching step using the same resist mask, the conductive layers 161 and 162 may be individually processed using different resist masks. In this case, the conductive layers 161 and 162 are preferably processed so that the conductive layer 162 is included inside the contour of the conductive layer 161 when viewed from above.

[0374] Although the conductive layer 162 and the lower electrode 111, etc. are formed in the same etching process using the same resist mask, the conductive layer 162 and the lower electrode 111, etc. may be processed separately using different resist masks. In this case, it is preferable to process the conductive layer 162 and the lower electrode 111, etc. so that the lower electrode 111 is included inside the contour of the conductive layer 162, etc. when viewed from above.

[0375] [Deposition of Organic Compound Film 112fR] As shown in FIG. 13B, an organic compound film 112fR capable of emitting red light is deposited to cover the lower electrode 111 and the second wiring layer 151b. The organic compound film 112fR is formed by stacking the functional layers of the light-emitting device. Although the organic compound film 112fR is deposited from an organic compound capable of emitting red light, in one embodiment of the present invention, it may be deposited from an organic compound capable of emitting green light. In another embodiment of the present invention, it may be deposited from an organic compound capable of emitting blue light.

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

[0377] The charge generation layer can be a layer containing a hole transport material and an acceptor material (electron acceptor material), or a layer containing an electron transport material and a donor material.

[0378] The electron transport material may be the same as the material used for the electron injection layer. Because the charge generation layer is subsequently processed by etching or the like, materials that do not contain alkali metals or alkaline earth metals are preferred for the electron injection layer. For example, an organic compound containing a dopant may be used. NBPhen may be used as the organic compound, and Ag may be used as the dopant.

[0379] The functional layers of the organic compound film 112fR can be formed by vacuum evaporation. However, the present invention is not limited to this, and the functional layers of the organic compound film 112fR can also be formed by sputtering, ink-jet printing, or the like.

[0380] 13B, the organic compound film 112fR is formed so as to cover the second wiring layer 151b, but it is not necessary to cover the second wiring layer 151b. This is preferable because the second wiring layer 151b can be prevented from contacting the organic compound film 112fR and the remover used to remove the organic compound film 112fR does not come into contact with the surfaces of the lower electrode 111 and the second wiring layer 151b.

[0381] The organic compound film 112fR may be separately formed using a fine metal mask. In this case, the organic compound film 112fR is preferably formed so as to cover only the lower electrode 111R. This prevents the second wiring layer 151b from contacting the organic compound film 112fR, and is also preferable because the remover used to remove the organic compound film 112fR does not come into contact with the surfaces of the lower electrode 111 and the second wiring layer 151b.

[0382] The organic compound film 112fR has various functional layers, and may be a laminate having, in this order from the lower electrode 111, at least a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, for example.

[0383] One of the functional layers is an electron injection layer located on the electron transport layer. In this embodiment, the electron injection layer is formed later to serve as a common layer. The common layer may be any functional layer located between the light-emitting layer and the common electrode. Of course, all functional layers may be separated into subpixels without providing a common layer.

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

[0385] The electron transport layer exposed to processing may have a laminated structure. An example of such a laminated structure is a structure in which a second electron transport layer is laminated on a first electron transport layer. Because the first electron transport layer is covered with the second electron transport layer for a period during processing, the first electron transport layer may have lower heat resistance than the second electron transport layer. For example, the second electron transport layer may be made of a material having a glass transition temperature of 110°C or higher and 165°C or lower, preferably 120°C or higher and 135°C or lower, and the first electron transport layer may have a glass transition temperature lower than that of the second electron transport layer, for example, 100°C or higher and 155°C or lower, preferably 110°C or higher and 125°C or lower.

[0386] Although it is possible to form the uppermost layer of the organic compound film 112fR as the light-emitting layer, damage caused by the processing may enter the light-emitting layer, which may significantly impair reliability. Therefore, when manufacturing a display device of one embodiment of the present invention, it is preferable to perform the above processing after forming a functional layer (for example, an electron-transport layer) above the light-emitting layer.

[0387] [Deposition of Mask Film 144R] It is preferable to further form a mask layer or the like on the organic compound film. The mask layer can also prevent damage caused by processing from reaching the light-emitting layer. By applying this method, a highly reliable display panel can be provided. Note that in this specification and the like, the mask layer is located above the organic compound film and has the function of protecting the organic compound film during the manufacturing process. Therefore, as shown in FIG. 13C, a mask film 144R is formed to cover the organic compound film 112fR.

[0388] The mask film 144R is preferably a film having a high etching selectivity with respect to the organic compound film 112fR when etching the organic compound film 112fR. In some cases, the mask film 144R is stacked, and the mask film 144R is preferably a film having a high etching selectivity with respect to an upper mask film (specifically, the mask film 146R) described later. Furthermore, when removing the mask film 144R, it is preferably a film that can be removed by wet etching, which does not damage the organic compound film 112fR.

[0389] The mask film 144R may be, for example, a metal film, an alloy film, a metal oxide film, a semiconductor film, an inorganic insulating film, etc. The mask film 144R may be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, an ALD method, etc.

[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 by using the ALD method.

[0391] The mask film 144R may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0392] The mask film 144R can be made of a metal oxide such as indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO). Other examples include indium oxide, indium zinc oxide (In—Zn oxide), indium tin oxide (In—Sn oxide), indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn—Zn oxide), indium titanium zinc oxide (In—Ti—Zn oxide), and indium gallium tin zinc oxide (In—Ga—Sn—Zn oxide). Alternatively, indium tin oxide containing silicon can be used.

[0393] The present invention can also be applied to a case where an element M (wherein M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) is used instead of the gallium. In particular, it is preferable that M is one or more selected from gallium, aluminum, and yttrium.

[0394] The mask film 144R may also include an inorganic material. Examples of inorganic materials that can be used include oxides such as aluminum oxide, hafnium oxide, and silicon oxide, nitrides such as silicon nitride and aluminum nitride, and oxynitrides such as silicon oxynitride. Such inorganic materials can be formed using a film formation method such as a sputtering method, a CVD method, or an ALD method.

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

[0396] The mask film 144R can be formed by a wet film forming method.

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

[0398] 13C, a mask film 146R is formed on the mask film 144R. In this embodiment, the mask films are stacked, but it is also possible to protect the organic compound film 112fR by using only the mask film 144R or only the mask film 146R as a single-layer mask film.

[0399] The mask film 146R may be used as a hard mask when etching the mask film 144R later. After processing the mask film 146R, the mask film 144R is exposed. Therefore, when using the mask film 146R as a half-etch mask, it is preferable to select a combination of the mask films 144R and 146R that have a large etching selectivity relative to each other.

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

[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, and hafnium oxynitride.

[0402] The mask film 146R may be, for example, a nitride film. Typical nitride films include silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride.

[0403] As a combination of the mask film 144R and the mask film 146R, for example, an inorganic material such as aluminum oxide, hafnium oxide, or silicon oxide formed by the ALD method can be used as the mask film 144R, and a metal oxide containing indium such as indium gallium zinc oxide (In-Ga-Zn oxide, also referred to as IGZO) formed by the sputtering method can be used as the mask film 146R.

[0404] Furthermore, the mask film 146R to be combined with the mask film 144R may be made of one or more metals selected from tungsten, molybdenum, copper, aluminum, titanium, tantalum, etc., or an alloy containing such metals. When the mask film 146R is formed as a hard mask, it is preferable to use the above metals or alloys. When the mask film 146R is formed as a hard mask, it is preferable to make the film thickness of the mask film 146R larger than that of the mask film 144R.

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

[0406] The resist mask 143 can be made of a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.

[0407] When a material that dissolves the organic compound film 112fR is used in a solvent for the resist material, if the mask film 146R is not provided and there are defects such as pinholes in the mask film 144R, there is a risk that the organic compound film 112fR etc. will dissolve. In this case, by positioning the mask film 146R on the mask film 144R when forming the resist mask 143, it is possible to prevent such a problem from occurring.

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

[0409] [Etching of Mask Film 146R] As shown in FIG. 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 so that the mask film 144R is not removed by the etching. The etching of the mask film 146R can be performed by wet etching or dry etching.

[0411] 14B, the resist mask 143 is removed. The resist mask 143 is removed in a state where the organic compound film 112fR is covered with 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 an etching gas.

[0413] Again, the removal of the resist mask 143 is performed while the organic compound film 112fR is covered with the mask film 144R, thereby suppressing processing damage to the organic compound film 112fR. In particular, contact of oxygen with the organic compound film 112fR can adversely affect its characteristics. Therefore, when etching is performed using the oxygen gas, it is advisable to perform the etching while the organic compound film 112fR is covered with the mask film 144R. Furthermore, even when the resist mask 143 is removed by wet etching, the organic compound film 112fR does not come into contact with the chemical solution, thereby preventing the organic compound film 112fR from being dissolved.

[0414] [Etching of Mask Film 144R] As shown in FIG. 14C, the mask layer 147R is used as a hard mask to remove a portion of the mask film 144R by etching, thereby forming a mask layer 145R.

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

[0416] 15A , a portion of the organic compound film 112fR that is not covered with the mask layer 145R is removed by etching to form an organic compound layer 112R. The organic compound layer 112R will be an organic compound layer of a light-emitting device that emits red light.

[0417] For etching the organic compound film 112fR, it is preferable to use dry etching using an etching gas that does not contain oxygen as a main component. This is because, as mentioned above, contact of oxygen with the organic compound film 112fR may adversely affect the characteristics. Specifically, the organic compound film 112fR may be altered in quality, but using an etching gas that does not contain oxygen as a main component can suppress the alteration and realize a highly reliable display device. An example of an etching gas that does not contain oxygen as a main component is CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ , H ２ Alternatively, a rare gas such as He may be used. A mixed gas of the above gas and a dilution gas not containing oxygen may be used as the etching gas.

[0418] The etching of the organic compound film 112fR is not limited to the above, and may be dry etching using other gases or wet etching.

[0419] After etching, the taper angle of the end face of the organic compound layer 112R preferably satisfies the range of 45 degrees or more and less than 90 degrees.

[0420] Note that the insulating layer 104 is exposed when the organic compound film 112fR is etched. Therefore, a recess may be formed in the insulating layer 104 in a region overlapping with the slit 118. Note that if the formation of a recess is not desired, it is preferable to use a film that is highly resistant to the etching process of the organic compound film 112fR for the insulating layer 104. For example, it is preferable to use an insulating film containing an inorganic material as the insulating layer 104.

[0421] 15B , referring to the process from the formation to the etching of the organic compound film 112fR, an organic compound layer 112G is formed using a mask layer 145G and a mask layer 147G. The taper angle of the end face of the organic compound layer 112G is preferably 45 degrees or more and less than 90 degrees. The organic compound layer 112G will be the organic compound layer of the light-emitting device that emits green light.

[0422] 15B , referring to the process from the formation to the etching of the organic compound film 112fR, the organic compound layer 112B is formed using a mask layer 145B and a mask layer 147B. 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 organic compound layer 112B will be the organic compound layer of the light-emitting device that emits green light.

[0423] When describing matters common to the organic compound layer 112R, the organic compound layer 112G, and the organic compound layer 112B, they will be referred to as the organic compound layer 112. It is preferable that at least a functional layer having high heat resistance, such as an electron transport layer, be located on the outermost surface of the organic compound layer 112.

[0424] No organic compound film is disposed 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 a processing step using photolithography can have the width of the slits 118, indicated by the arrows in FIG. 15B, set to 8 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. 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 definition and a high aperture ratio can be provided.

[0426] As shown by the slits 118, adjacent organic compound layers 112 are spaced apart, which divides the leakage path of current and suppresses leakage current (also called side leakage current). This makes it possible to increase the luminance, contrast, display quality, power efficiency, or power consumption of the light-emitting device.

[0427] The end faces of adjacent organic compound layers 112 preferably face each other with the slit 118 therebetween. However, in organic compound layers formed using a metal mask, the end faces cannot face each other. Therefore, an organic compound layer having the end faces facing each other is different from an organic compound layer formed using a metal mask.

[0428] Note that the insulating layer 104 is exposed when the organic compound film is etched. Therefore, a recess may be formed in the insulating layer 104 in a region overlapping with the slit 118. Note that if the formation of a recess is not desired, it is preferable to use a film that is highly resistant to etching of the organic compound film as the insulating layer 104. For example, it is preferable to use an insulating film containing an inorganic material as the insulating layer 104.

[0429] [Removal of Mask Layer] As shown in FIG. 15C, the mask layer 147 is removed to expose the upper surface of the mask layer 145.

[0430] [Formation of Insulating Film 125f] As shown in FIG. 16A, an insulating film 125f is formed to cover 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. The insulating film 125f is preferably formed by an ALD method, which has excellent step coverage, because it can suitably cover the side surfaces of the organic compound layer 112.

[0432] The insulating film 125f is preferably the same film as the mask layers 145 and 147, because they can be easily removed simultaneously during etching in a later step. For example, the insulating film 125f, the mask layers 145, and the mask layers 147 are preferably made of one or more inorganic materials selected from aluminum oxide, hafnium oxide, silicon oxide, and the like, which are formed by the ALD method.

[0433] The material that can be used for the insulating film 125f is not limited to this, and for example, the material that can be used for the mask layer 145 can be used appropriately.

[0434] 16A , the insulating layer 126 is formed in areas overlapping with the slits 118, etc. The insulating layer 126 can be formed by the same method as the resin layer 163. For example, the insulating layer 126 can be formed by forming a photosensitive resin, followed by exposure and development. The insulating layer 126 may also be formed by forming the resin over the entire surface, and then etching part of the resin by ashing or the like.

[0435] Here, the insulating layer 126 has a width larger than that of the slit 118. Note that the insulating layer 126 is provided so that a part of the top surface of the second wiring layer 151b is exposed.

[0436] [Etching of insulating film 125f and mask layer 145] As shown in FIG. 16B , portions of the insulating film 125f and the mask layer 145 that are not covered by the insulating layer 126 are removed by etching, exposing a portion of the top surface of the organic compound layer 112. As a result, the insulating layer 125 and the mask layer 145 remain in the region that overlaps with the insulating layer 126. The central portion of the insulating layer 126 is preferably located above the ends of the insulating layer 126, and the central portion preferably has a region that is raised higher than the ends. The top surface of the insulating layer 126 is preferably located above the top surface of the organic compound layer 112. Furthermore, the ends of the insulating layer 126 preferably have a tapered shape.

[0437] The insulating film 125f and the mask layer 145 are preferably etched in the same process. In particular, the mask layer 145 is preferably etched by wet etching, which causes less etching damage to the organic compound layer 112. For example, wet etching using a tetramethylammonium hydroxide solution (TMAH), diluted hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof is preferably used.

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

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

[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 FIG. 16C, the common layer 114 is formed to cover the organic compound layer 112, the insulating layer 125, the mask layer 145, the insulating layer 126, and the like.

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

[0443] The common layer 114 can be formed by the same method as the organic compound film 112fR, etc. The composite material may be formed by co-evaporation.

[0444] [Formation of Common Electrode 113] As shown in FIG. 16C, the common electrode 113 is formed to cover the common layer 114.

[0445] The common electrode 113 can be formed by a film formation method such as evaporation or sputtering. Alternatively, a film formed by evaporation and a film formed by sputtering may be stacked.

[0446] The common electrode 113 is preferably formed so as to encompass the area where the common layer 114 is to be deposited.

[0447] The common layer 114 may be located between the second wiring layer 151b and the common electrode 113. In this case, it is preferable to use a material with as low an electrical resistance as possible for the common layer 114. Alternatively, it is preferable to form the common layer 114 as thin as possible to reduce the electrical resistance in the thickness direction of the common layer 114. For example, by using an electron-injecting or hole-injecting material with a thickness of 1 nm to 5 nm, preferably 1 nm to 3 nm, for the common layer 114, the electrical resistance between the second wiring layer 151b and the common electrode 113 can be reduced to a negligible level.

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

[0449] [Formation of Protective Layer] As shown in Figure 16C, a protective layer 121 is formed on the common electrode 113. The inorganic insulating film used for the protective layer 121 is preferably formed by sputtering, PECVD, or ALD. The ALD method is particularly preferred because it has excellent step coverage and is less likely to cause defects such as pinholes. Furthermore, the inkjet method is preferably used to form the organic insulating film because it can form a uniform film in the desired area.

[0450] 17A, a substrate 170 is bonded using an adhesive layer 171. The bonded substrate 170 may be referred to as a counter substrate. When the display device has a hollow sealing structure, the substrate 170 may be bonded using a sealant or the like. When the substrates are bonded using a sealant, a space is generated, and the space may be filled with an inert gas (a gas containing nitrogen or argon).

[0451] The adhesive layer 171 may be made of an organic material such as a reaction-curing adhesive, a photo-curing adhesive, a thermosetting adhesive, and / or an anaerobic adhesive.

[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 for the adhesive layer 171, etc.

[0453] 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 a region overlapping with the insulating layer 126. The substrate 170 may be bonded so that the colored layer 173R, the colored layer 173G, and the colored layer 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 using an inkjet method, photolithography, etc. Specifically, a different colored layer 173 (colored layer 173R, colored layer 173G, or colored layer 173B) can be formed for each pixel.

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

[0456] In this manner, a display device can be manufactured.

[0457] [Fabrication Method Example 2] A fabrication method using a metal mask will be described with reference to Figures 18 and 19. In the figure, the region related to the pixel 150 is shown on the left side, and the region related to the auxiliary wiring 151 is shown on the right side.

[0458] The lower electrode 111 and the second wiring layer 151b are formed in the same manner as in Fabrication Method Example 1. As shown in Fig. 18A, an organic compound film 112jR is formed using a metal mask 135R. By using the metal mask 135R, the organic compound film 112jR can be formed only in the region that will become the red light-emitting device.

[0459] 18B, an organic compound film 112jG is formed using a metal mask 135G. Because the 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 an area that overlaps with part of the organic compound film 112jR. In other words, at the boundary of the light-emitting device, the organic compound film has an area that overlaps with part of the organic compound film that was previously formed.

[0460] As shown in Fig. 18C, an organic compound film 112jB is formed using a 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 an area that overlaps with part of the organic compound film 112jG. Although not shown, the organic compound film 112jB also has an area that overlaps with part of the organic compound film 112jR. That is, at the boundary of the light-emitting device, the organic compound film has an area that overlaps with part of the organic compound film that was previously formed.

[0461] 19A, mask films 144 and 146 are formed. The mask films 144 and 146 can be formed in the same manner as in Example 1 of the manufacturing method.

[0462] 19B, resist masks 143R, 143G, and 143B are formed. The resist masks 143R, 143G, and 143B can be formed in the same manner as in Manufacturing Method Example 1.

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

[0464] Thereafter, the insulating layer 126, the common layer 114, the common electrode 113, and the protective layer 121 are formed in the same manner as in Manufacturing Method Example 1. Finally, a substrate 170 and the like are attached to complete the display device.

[0465] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

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

[0467] [Specific Example of Display Device] A large-scale display device using a plurality of display modules DP each having the display device described in the above embodiment and an FPC 74 will be described with reference to FIG.

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

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

[0470] When a large display device is manufactured using multiple display modules DP, the size of each display module DP does not need to be large. Therefore, the manufacturing equipment for manufacturing the display module DP does not need to be large, and space can be saved. Furthermore, manufacturing equipment for small and medium-sized display panels can be used, and new manufacturing equipment does not need to be used to enlarge the display device, thereby reducing manufacturing costs. Furthermore, the decrease in yield due to the enlargement of the display module DP can be suppressed.

[0471] A non-display area where wiring and the like are routed is located on the periphery of the pixel unit 103. The non-display area corresponds to the area 73 that blocks visible light. When multiple display modules DP are stacked, the non-display area and the like may cause a single image to be viewed as if it were separated.

[0472] Therefore, in one embodiment of the present invention, a region 72 that transmits visible light is provided in the display module DP, and in two overlapping display modules, the pixel portion 103 of the display module DP located on the lower side is overlapped with the region 72 that transmits visible light of the display module DP located on the upper side.

[0473] By providing the visible light transmitting region 72 in this manner, it is not necessary to actively reduce the non-display region of the display module DP. However, when two display modules DP are stacked, the non-display region is reduced, which is preferable. This allows for the realization of a large display device in which the seams between the display modules DP are difficult for users to notice.

[0474] The display module DP located on the upper side may have a region 72 that transmits visible light in at least a part of the non-display region. The region 72 that transmits visible light can be overlapped with the pixel unit 103 of the display module DP located on the lower side.

[0475] Furthermore, at least a part of the non-display region of the display module DP located on the lower side overlaps with the pixel section 103 or the region 73 that blocks visible light of the display module DP located on the upper side.

[0476] If the non-display area of ​​the display module DP is wide, the distance between the edge of the display module DP and the elements within the display module DP becomes long, which is preferable because it can prevent the elements from being deteriorated by impurities entering from outside the display module DP.

[0477] In this way, when a plurality of display modules DP are provided in a display device, the pixel portions 103 are continuous between adjacent display modules DP, so that a display region with a large area can be provided.

[0478] The pixel section 103 includes a plurality of pixels.

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

[0480] The region 73 that blocks visible light may be provided with wirings or the like electrically connected to pixels included in the pixel portion 103. The region 73 that blocks visible light may also be provided with one or both of a scanning line driver circuit and a signal line driver circuit. The region 73 that blocks visible light may also be provided with terminals connected to the FPC 74, wirings or the like connected to the terminals.

[0481] 20B and 20C show examples in which the display modules DP shown in Fig. 20A are arranged in a 2 × 2 matrix (two in the vertical direction and two in the horizontal direction). Fig. 20B is a perspective view of the display surface side of the display module DP, and Fig. 20C is a perspective view of the side opposite to the display surface of the display module DP.

[0482] The four display modules DP (display modules DPa, DPb, DPc, and DPd) are arranged so as to have overlapping regions. Specifically, the display modules DPa, DPb, DPc, and DPd are arranged so that the region 72 that transmits visible light of one display module DP has a region that overlaps with the pixel unit 103 (display surface side) of the other display modules DP. Furthermore, the display modules DPa, DPb, DPc, and DPd are arranged so that the region 73 that blocks visible light of one display module DP does not overlap with the pixel unit 103 of the other display modules DP. In the overlapping portions of the four display modules DP, the display module DPb overlaps with the display module DPa, the display module DPc overlaps with the display module DPb, and the display module DPd overlaps with the display module DPc.

[0483] The short sides of the display modules DPa and DPb overlap each other, so that part of the pixel unit 103a overlaps with part of the region 72b that transmits visible light, and the long sides of the display modules DPa and DPc overlap each other, so that part of the pixel unit 103a overlaps with part of the region 72c that transmits visible light.

[0484] A part of the pixel portion 103b overlaps with a part of the region 72c that transmits visible light and a part of the region 72d that transmits visible light. Also, a part of the pixel portion 103c overlaps with a part of the region 72d that transmits visible light.

[0485] Therefore, a region where the pixel portions 103 a to 103 d are arranged almost seamlessly can be used as a display region 79 .

[0486] Here, the display module DP is preferably flexible, for example, the pair of substrates constituting the display module DP are preferably flexible.

[0487] As a result, for example, as shown in Figures 20B and 20C, the vicinity of the FPC 74a of the display module DPa can be curved, and a portion of the display module DPa and a portion of the FPC 74a can be arranged below the pixel portion 103b of the display module DPb adjacent to the FPC 74a. As a result, the FPC 74a can be arranged without physically interfering with the rear surface of the display module DPb. Furthermore, when the display modules DPa and DPb are stacked and fixed, the thickness of the FPC 74a does not need to be taken into consideration, so the difference in height between the top surface of the visible light-transmitting region 72b and the top surface of the display module DPa can be reduced. As a result, the edge of the display module DPb located above the pixel portion 103a can be made less noticeable.

[0488] Furthermore, by providing flexibility to each display module DP, the display module DPb can be gently curved so that the height of the upper surface of the pixel portion 103b of the display module DPb matches the height of the upper surface of the pixel portion 103a of the display module DPa. This makes it possible to align the heights of the display areas except for the area near where the display modules DPa and DPb overlap, thereby improving the display quality of the image displayed in the display area 79.

[0489] Although the relationship between the display module DPa and the display module DPb has been described above as an example, the same applies to any other two adjacent display modules DP.

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

[0491] The display module DP preferably incorporates both a scanning line driver circuit and a signal line driver circuit. When the driver circuit is arranged separately from the display panel, a printed circuit board including the driver circuit, numerous wirings, terminals, etc., are arranged on the back side of the display panel (the side opposite the display surface). This can result in a huge number of components in the entire display device, which can increase the weight of the display device. By incorporating both a scanning line driver circuit and a signal line driver circuit in the display module DP, the number of components in the display device can be reduced, making the display device lighter. This can increase the portability of the display device.

[0492] Here, the scanning line driver circuit and the signal line driver circuit are required to operate at a high driving frequency according to the frame frequency of the image to be displayed. In particular, the signal line driver circuit is required to operate at a driving frequency even higher than that of the scanning line driver circuit. Therefore, some of the transistors used in the signal line driver circuit may be required to have the ability to pass a large current. On the other hand, some of the transistors provided in the pixel portion may be required to have sufficient voltage resistance to drive the display element.

[0493] Therefore, it is preferable to differentiate the structures of the transistors in the driver circuit from those in the pixel portion, for example, by using a high-voltage transistor as one or more of the transistors in the pixel portion and using a transistor with a high driving frequency as one or more of the transistors in the driver circuit.

[0494] In a more specific configuration, one or more transistors used in the signal line driver circuit have a thinner gate insulating layer than a transistor used in a pixel portion. By fabricating two types of transistors in this way, the signal line driver circuit can be fabricated over a substrate on which a pixel portion is provided.

[0495] In addition, it is preferable that a metal oxide be used as a semiconductor in which a channel is formed in each of the transistors applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion.

[0496] In addition, it is preferable that silicon be used as a semiconductor in which a channel is formed in each of the transistors applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion.

[0497] In addition, it is preferable that each transistor applied to the scan line driver circuit, the signal line driver circuit, and the pixel portion be a combination of a semiconductor in which a channel is formed using a metal oxide and a semiconductor in which a channel is formed using silicon.

[0498] This embodiment mode can be implemented by appropriately combining at least a part thereof with other embodiment modes described in this specification.

[0499] Embodiment 10 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

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

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

[0502] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a pixel portion 103. The pixel portion 103 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in the pixel portion 103, which will be described later, can be viewed.

[0503] 21B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 103 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 (sometimes referred to as an FPC terminal portion) for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 103. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0504] The pixel section 103 has a plurality of pixels 150 arranged periodically. An enlarged view of one pixel 150 is shown on the right side of Fig. 21B. The pixel 150 has a light-emitting device 11R, a light-emitting device 11G, and a light-emitting device 11B that emit light of different colors. The plurality of light-emitting devices can be laid out in a stripe arrangement as shown in Fig. 21B. Various arrangement methods for the light-emitting devices, such as a delta arrangement or a pentile arrangement, can also be applied.

[0505] The pixel circuit section 283 includes pixel circuits 283a each having a plurality of periodically arranged transistors and the like.

[0506] One pixel circuit 283a is a circuit that controls the light emission of a light-emitting device included in one pixel 150. One pixel circuit 283a may be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a may be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active matrix display device.

[0507] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0508] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0509] The display module 280 can have a configuration in which one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked below the pixel portion 103, thereby enabling the aperture ratio (effective display area ratio) of the pixel portion 103 to be extremely high. For example, the aperture ratio of the pixel portion 103 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 150 can be laid out at an extremely high density, enabling the resolution of the pixel portion 103 to be extremely high. For example, it is preferable that the pixels 150 are laid out in the pixel portion 103 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and further preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0510] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as head-mounted displays, or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution pixel unit 103, so even if the display unit is enlarged with the lens, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0511] Embodiment 11 In this embodiment, electronic devices of one embodiment of the present invention will be described with reference to FIGS. 22 and 23. FIG.

[0512] The electronic devices of this embodiment include the display device of one embodiment of the present invention in their display portions. The display device of one embodiment of the present invention can easily achieve high definition and high resolution. Therefore, the display device of one embodiment of the present invention can be used in the display portions of various electronic devices.

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

[0514] In particular, the display device of one embodiment of the present invention can have high resolution and can therefore be suitably used in electronic devices having a relatively small display area. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), and head-mounted wearable devices such as VR devices (e.g., head-mounted displays), AR glasses-type devices, and MR devices.

[0515] The display device of one embodiment of the present invention preferably has an extremely high resolution, such as HD (1280 × 720 pixels), FHD (1920 × 1080 pixels), WQHD (2560 × 1440 pixels), WQXGA (2560 × 1600 pixels), 4K (3840 × 2160 pixels), or 8K (7680 × 4320 pixels). A resolution of 4K, 8K, or higher is particularly preferable. Furthermore, the pixel density (resolution) of the display device of one embodiment of the present invention is preferably 100 ppi or higher, more preferably 300 ppi or higher, more preferably 500 ppi or higher, more preferably 1000 ppi or higher, more preferably 2000 ppi or higher, more preferably 3000 ppi or higher, more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using a display device having either or both of high resolution and high definition, it is possible to further enhance the sense of realism and depth in electronic devices for personal use, such as portable or home use. Furthermore, the screen ratio (aspect ratio) of the display device of one embodiment of the present invention is not particularly limited. For example, the display device can support various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

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

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

[0518] 22A shows an example of a television set. In a television set 7100, a pixel portion 7000 is incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7103.

[0519] The pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000 .

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

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

[0522] 22B shows an example of a laptop personal computer 7200. The laptop personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. The pixel portion 7000 is incorporated in the housing 7211.

[0523] The pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000 .

[0524] 22C and 22D show an example of digital signage.

[0525] 22C includes a housing 7301, a pixel portion 7000, a speaker 7303, and the like. The digital signage 7300 may further include an LED lamp, operation keys (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like.

[0526] 22D shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a pixel portion 7000 provided along the curved surface of the pillar 7401.

[0527] 22C and 22D, the pixel portion 103 of one embodiment of the present invention can be applied to the pixel portion 7000.

[0528] The larger the pixel section 7000, the more information can be provided at one time. Also, the larger the pixel section 7000, the more easily it is noticed by people, which can increase the advertising effect, for example.

[0529] Applying a touch panel to the pixel portion 7000 is preferable because it not only displays an image or a video on the pixel portion 7000 but also allows a user to intuitively operate it. Furthermore, when used for providing information such as route information or traffic information, the intuitive operation can improve usability.

[0530] 22C and 22D , the digital signage 7300 or the digital signage 7400 is preferably capable of wirelessly linking with an information terminal 7311 or an information terminal 7411 such as a smartphone carried by a user. For example, advertising information displayed in the pixel portion 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411. By operating the information terminal 7311 or the information terminal 7411, the display of the pixel portion 7000 can be switched.

[0531] Furthermore, the digital signage 7300 or the digital signage 7400 can be made to run a game using the screen of the information terminal 7311 or the information terminal 7411 as an operation means (controller), thereby allowing an unspecified number of users to simultaneously participate in and enjoy the game.

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

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

[0534] The pixel portion 103 of one embodiment of the present invention can be applied to the display portion 6502 .

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

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

[0537] A display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 by adhesive layers (not shown).

[0538] In a region outside the display portion 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0539] The flexible display of one embodiment of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted thereon while keeping the thickness of the electronic device small. Furthermore, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.

[0540] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0541] 103: pixel portion, 151: auxiliary wiring, 151a: first wiring layer, 151b: second wiring layer, 14: insulating 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 including a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A second light-emitting device including a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A common electrode shared by the first light-emitting device and the second light-emitting device; An auxiliary wiring electrically connected to the common electrode; wherein the auxiliary wiring includes a first wiring layer and a second wiring layer; the second wiring layer is electrically connected to the first wiring layer through a contact hole in an insulating layer; the second wiring layer has a lattice shape in a top view; A display device.

2. A first light-emitting device including a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A second light-emitting device including a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A common electrode shared by the first light-emitting device and the second light-emitting device; An auxiliary wiring electrically connected to the common electrode; wherein the auxiliary wiring includes a first wiring layer and a second wiring layer; the second wiring layer is electrically connected to the first wiring layer through a contact hole in an insulating layer; the first wiring layer has a lattice shape in a top view; the first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer; A display device.

3. A first light-emitting device including a first lower electrode and a first organic compound layer located on the first lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A second light-emitting device including a second lower electrode and a second organic compound layer located on the second lower electrode and having a region in contact with a side surface of an end portion of the first lower electrode; A common electrode shared by the first light-emitting device and the second light-emitting device; An auxiliary wiring electrically connected to the common electrode; wherein the auxiliary wiring includes a first wiring layer and a second wiring layer; the second wiring layer is electrically connected to the first wiring layer through a contact hole in an insulating layer; The first wiring layer and the second wiring layer each have a lattice shape in a top view. The first lower electrode, the second lower electrode, and the second wiring layer each have a region located on the insulating layer. The width of the second wiring layer is smaller than the width of the first wiring layer. Display device.

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 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 45 degrees or more and less than 90 degrees. Display device.