CN118104420A

CN118104420A - Display device and method for manufacturing display device

Info

Publication number: CN118104420A
Application number: CN202280069743.7A
Authority: CN
Inventors: 方堂凉太; 笹村康纪; 笹川慎也
Original assignee: Semiconductor Energy Laboratory Co Ltd
Current assignee: Semiconductor Energy Laboratory Co Ltd
Priority date: 2021-10-27
Filing date: 2022-10-14
Publication date: 2024-05-28

Abstract

Provided is a display device with high display quality. The display device includes a first light emitting device including a first pixel electrode on the first insulating layer, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer, a second light emitting device including a second pixel electrode on the first insulating layer, a second EL layer on the second pixel electrode, and a common electrode on the second EL layer, the first coloring layer being disposed so as to overlap the first light emitting device, the second coloring layer being disposed so as to overlap the second light emitting device, wavelength regions of light transmitted by the second coloring layer and the first coloring layer being different from each other, the first insulating layer having a recess between the first pixel electrode and the second pixel electrode, the recess of the first insulating layer being provided with a third EL layer, the first EL layer, the second EL layer, and the third EL layer containing the same material, and a sum of thicknesses of the first pixel electrode and depths of the recess being a thickness of the third layer or more.

Description

Display device and method for manufacturing display device

Technical Field

One embodiment of the present invention relates to a display device. One aspect of the present invention relates to an electronic device.

Note that one embodiment of the present invention is not limited to the above-described technical field. As an example of the technical field of one embodiment of the present invention disclosed in the present specification and the like, a semiconductor device, a display device, a light-emitting device, a power storage device, a storage device, an electronic device, a lighting device, an input/output device, a driving method thereof, or a manufacturing method thereof can be given. The semiconductor device refers to all devices that can operate using semiconductor characteristics.

Background

In recent years, high definition display panels are demanded. As devices requiring a high-definition display panel, there are, for example, a smart phone, a tablet terminal, a notebook computer, and the like. In addition, a stationary display device such as a television device and a monitor device is also required to have higher definition with higher resolution. As the most demanded high definition device, there is, for example, a device applied to Virtual Reality (VR: virtual Reality) or augmented Reality (AR: augmented Reality).

In addition, as a display device which can be applied to a display panel, a liquid crystal display device, a light-emitting device including a light-emitting device such as an organic EL (Electro Luminescence: electroluminescence) element or a light-emitting Diode (LED: LIGHT EMITTING Diode), an electronic paper which displays by an electrophoresis method, or the like are typically given.

For example, the basic structure of an organic EL element is a structure in which a layer containing a light-emitting organic compound is sandwiched between a pair of electrodes. By applying a voltage to this element, light emission from the light-emitting organic compound can be obtained. Since a display device using the organic EL element does not require a backlight source required for a liquid crystal display device or the like, a thin, lightweight, high-contrast, and low-power display device can be realized. For example, patent document 1 discloses an example of a display device using an organic EL element.

[ Prior Art literature ]

[ Patent literature ]

[ Patent document 1] Japanese patent application laid-open No. 2002-324673

Disclosure of Invention

Technical problem to be solved by the invention

An object of one embodiment of the present invention is to provide a display device with high display quality. An object of one embodiment of the present invention is to provide a display device having a high aperture ratio. An object of one embodiment of the present invention is to provide a display device with high reliability. An object of one embodiment of the present invention is to provide a display device which can easily achieve high definition. An object of one embodiment of the present invention is to provide a display device with low power consumption.

It is an object of one embodiment of the present invention to at least ameliorate at least one of the problems of the prior art.

Note that the description of these objects does not prevent the existence of other objects. Note that one embodiment of the present invention is not required to achieve all of the above objects. Note that objects other than the above can be extracted from the description of the specification, drawings, claims, and the like.

Means for solving the technical problems

One embodiment of the present invention is a display device including a first light-emitting device, a second light-emitting device, a first coloring layer, a second coloring layer, and a first insulating layer, the first light-emitting device including a first pixel electrode over the first insulating layer, a first EL layer over the first pixel electrode, and a common electrode over the first EL layer, the second light-emitting device including a second pixel electrode over the first insulating layer, a second EL layer over the second pixel electrode, and a common electrode over the second EL layer, the first coloring layer being disposed so as to overlap the first light-emitting device, the second coloring layer being disposed so as to overlap the second light-emitting device, wavelength regions of transmitted light of the second coloring layer and the first coloring layer being different from each other, the first insulating layer having a recess between the first pixel electrode and the second pixel electrode, a third EL layer being disposed in the recess of the first insulating layer, the first EL layer, the second EL layer, and the third EL layer containing the same material, and the thickness of the first pixel and the depth of the recess being the depth of the third layer.

In the above-described structure, the third EL layer may be in contact with the bottom surface and the side surface of the recess of the first insulating layer, the side surface of the first pixel electrode, and the side surface of the second pixel electrode.

In the above structure, the thickness of the first pixel electrode is preferably equal to or greater than the thickness of the third EL layer.

In the above structure, it is preferable that the depth of the recess is equal to or greater than the thickness of the third EL layer, and the third EL layer is not in contact with the first pixel electrode and the second pixel electrode.

Further, in the above structure, the first pixel electrode and the second pixel electrode preferably each include a first conductive layer over the first insulating layer and a second conductive layer over the first conductive layer, and a side surface of the second conductive layer protrudes from a side surface of the first conductive layer. In the above structure, the sum of the thickness below the bottom surface of the second conductive layer in the first pixel electrode and the depth of the recess is preferably equal to or greater than the thickness of the third EL layer.

In addition, in the above structure, the first pixel electrode and the second pixel electrode preferably each include a third conductive layer under the first conductive layer, the first conductive layer is reflective, and the second conductive layer and the third conductive layer have a function of protecting the first conductive layer.

Further, in the above structure, the first conductive layer preferably contains aluminum. In addition, in the above structure, the second conductive layer preferably contains titanium oxide. In addition, in the above structure, the third conductive layer preferably contains titanium.

In addition, in the above structure, it is preferable that the first pixel electrode and the second pixel electrode each include a fourth conductive layer over the second conductive layer, the fourth conductive layer has a larger work function than the second conductive layer, the second conductive layer and the fourth conductive layer have light transmittance, and the fourth conductive layer include an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon.

In the above configuration, it is preferable that the organic EL device further includes a second insulating layer over the third EL layer and a third insulating layer over the second insulating layer, the second insulating layer includes an inorganic material, the third insulating layer includes an organic material, a part of the second insulating layer and a part of the third insulating layer are disposed at positions sandwiched between a side surface of the first EL layer and a side surface of the first pixel electrode and a side surface of the second EL layer and a part of a top surface of the second EL layer, and the other part of the third insulating layer overlaps with a part of the top surface of the first EL layer and a part of the top surface of the second EL layer with the second insulating layer interposed therebetween.

In the above structure, the second insulating layer is preferably in contact with a side surface of the first pixel electrode and a side surface of the second pixel electrode. Further, the common electrode is preferably disposed on the third insulating layer.

Further, in the above-described structure, it is preferable that the first light emitting device includes a common layer disposed between the first EL layer and the common electrode, and the second light emitting device includes a common layer disposed between the second EL layer and the common electrode.

In the above structure, the first coloring layer and the second coloring layer are preferably arranged on the common electrode.

Further, in the above-described structure, it is preferable that the first EL layer includes a first light-emitting unit on the first pixel electrode, a first charge generation layer on the first light-emitting unit, and a second light-emitting unit on the first charge generation layer, the second EL layer includes a third light-emitting unit on the second pixel electrode, a second charge generation layer on the third light-emitting unit, and a fourth light-emitting unit on the second charge generation layer, and the third EL layer includes a fifth light-emitting unit on the first insulating layer, a third charge generation layer on the fifth light-emitting unit, and a sixth light-emitting unit on the third charge generation layer.

In addition, in the above-described structure, it is preferable that the first light emitting unit, the third light emitting unit, and the fifth light emitting unit include the same material, the first charge generating layer, the second charge generating layer, and the third charge generating layer include the same material, and the second light emitting unit, the fourth light emitting unit, and the sixth light emitting unit include the same material.

Another embodiment of the present invention is a method for manufacturing a display device including a plurality of pixel electrodes including a first conductive layer, a second conductive layer, and a third conductive layer, in manufacturing the display device: sequentially depositing a first conductive film, a second conductive film and a third conductive film on the insulating layer; processing the third conductive film, the second conductive film, and the first conductive film into a third conductive layer, a second conductive layer, and a first conductive layer by first dry etching; anisotropically etching the side surface of the second conductive layer; forming a recess in a region of the insulating layer not overlapping the plurality of pixel electrodes by second dry etching; and forming an EL film by vapor deposition, wherein in anisotropic etching, an etching rate of the second conductive layer is larger than an etching rate of the third conductive layer, and the EL film is divided into a first EL layer formed on the plurality of pixel electrodes and a second EL layer formed between the plurality of pixel electrodes in a self-aligned manner.

In the above method for manufacturing a display device, a gas containing chlorine is preferably used for anisotropic etching.

Effects of the invention

According to one embodiment of the present invention, a display device with high display quality can be provided. Further, according to one embodiment of the present invention, a display device having a high aperture ratio can be provided. Further, according to one embodiment of the present invention, a display device with high reliability can be provided. Further, according to one embodiment of the present invention, a display device which can easily achieve high definition can be provided. Further, according to one embodiment of the present invention, a display device with low power consumption can be provided. Furthermore, at least one of the problems of the prior art may be ameliorated according to one embodiment of the present invention.

Note that the description of these effects does not prevent the existence of other effects. Note that one mode of the present invention is not required to have all of the above effects. Note that effects other than the above can be extracted from the description of the specification, drawings, claims, and the like.

Brief description of the drawings

Fig. 1A is a plan view showing an example of a display device. Fig. 1B is a sectional view showing an example of a display device.

Fig. 2A to 2D are enlarged sectional views showing one example of the display device.

Fig. 3A to 3C are enlarged sectional views showing one example of the display device.

Fig. 4A and 4B are enlarged cross-sectional views showing an example of a display device.

Fig. 5A and 5B are cross-sectional views showing an example of a display device.

Fig. 6A to 6C are sectional views showing one example of a display device.

Fig. 7A to 7C are sectional views showing an example of a manufacturing method of a display device.

Fig. 8A to 8C are sectional views showing an example of a manufacturing method of the display device.

Fig. 9A to 9E are plan views showing an example of a manufacturing method of a display device.

Fig. 10A is a cross-sectional view showing an example of a manufacturing method of a display device, and fig. 10B and 10C are cross-sectional views showing an example of a display device.

Fig. 11A to 11G are plan views showing one example of a pixel.

Fig. 12A to 12I are plan views showing one example of a pixel.

Fig. 13A to 13K are plan views showing one example of a pixel.

Fig. 14A and 14B are perspective views showing an example of a display device.

Fig. 15 is a cross-sectional view showing an example of a display device.

Fig. 16 is a cross-sectional view showing an example of a display device.

Fig. 17 is a cross-sectional view showing an example of a display device.

Fig. 18 is a cross-sectional view showing an example of a display device.

Fig. 19 is a cross-sectional view showing an example of a display device.

Fig. 20 is a cross-sectional view showing an example of a display device.

Fig. 21 is a perspective view showing an example of a display device.

Fig. 22A is a cross-sectional view showing an example of a display device. Fig. 22B and 22C are cross-sectional views showing an example of a transistor.

Fig. 23 is a cross-sectional view showing an example of a display device.

Fig. 24A to 24D are sectional views showing one example of a display device.

Fig. 25A is a block diagram showing an example of a display device. Fig. 25B to 25E are diagrams showing one example of a pixel circuit.

Fig. 26A to 26D are diagrams showing one example of a transistor.

Fig. 27A to 27F are diagrams showing structural examples of the light emitting device.

Fig. 28A to 28C are diagrams showing structural examples of the light emitting device.

Fig. 29A to 29D are diagrams showing one example of an electronic device.

Fig. 30A to 30F are diagrams showing one example of an electronic device.

Fig. 31A to 31G are diagrams showing one example of an electronic device.

Fig. 32A to 32D are sectional STEM images of the present embodiment.

Modes for carrying out the invention

The embodiments will be described below with reference to the drawings. It is noted that the embodiments may be implemented in a number of different ways, and one skilled in the art can easily understand the fact that the manner and details thereof can be changed into various forms without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the following embodiments.

Note that in the structure of the invention described below, the same reference numerals are used in common in different drawings to denote the same parts or parts having the same functions, and repetitive description thereof will be omitted. In addition, the same hatching is sometimes used when representing portions having the same function, and no reference numerals are particularly attached.

Note that in the drawings described in this specification, the size of each component, the thickness of a layer, and a region may be exaggerated for clarity. Accordingly, the present invention is not limited to the dimensions in the drawings.

The ordinal numbers such as "first", "second", etc., used in the present specification are attached to avoid confusion of the constituent elements, and are not limited in number.

In this specification and the like, the display device may be referred to as an electronic device.

In this specification and the like, a device manufactured using a metal mask or an FMM (FINE METAL MASK, high-definition metal mask) is sometimes referred to as a device having a MM (Metal Mask) structure. In this specification and the like, a device manufactured without using a metal mask or an FMM is sometimes referred to as a device having a MML (Metal Mask Less) structure.

In this specification and the like, holes or electrons are sometimes referred to as "carriers". Specifically, the hole injection layer or electron injection layer, the hole transport layer or electron transport layer, and the hole blocking layer or electron blocking layer are sometimes referred to as "carrier injection layer", "carrier transport layer", and "carrier blocking layer", respectively. Note that the carrier injection layer, the carrier transport layer, and the carrier blocking layer may not be clearly distinguished from each other depending on the cross-sectional shape, the characteristics, and the like. In addition, one layer sometimes has a function as two or three of a carrier injection layer, a carrier transport layer, and a carrier blocking layer.

In this specification and the like, a light-emitting device (also referred to as a light-emitting element) includes an EL layer between a pair of electrodes. The EL layer includes at least a light emitting layer. Here, examples of the layers included in the EL layer (also referred to as functional layers) include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier blocking layer (hole blocking layer and electron blocking layer).

(Embodiment 1)

In this embodiment mode, a display device according to an embodiment of the present invention will be described with reference to fig. 1 to 9.

One embodiment of the present invention is a display device including a display unit capable of full-color display. The display section includes a first subpixel and a second subpixel which exhibit different colors of light from each other. The first sub-pixel comprises a first light emitting device emitting white light and the second sub-pixel also comprises a second light emitting device emitting white light. A first coloring layer is provided in the first subpixel so as to overlap the first light emitting device, and a second coloring layer is provided in the second subpixel so as to overlap the second light emitting device. The wavelength regions of light transmitted by the first coloring layer and the second coloring layer are different from each other. In this way, full-color display can be performed by using colored layers that transmit visible light of different colors for each subpixel. Further, since the light emitting devices for the respective sub-pixels can be formed using the same material, the manufacturing process can be simplified and the manufacturing cost can be reduced.

Here, when each sub-pixel is formed using a light emitting device that emits white light, separate application of a light emitting layer is not required in each sub-pixel. Accordingly, the sub-pixels can be made to commonly use a layer (e.g., a light-emitting layer or the like) other than the pixel electrode included in the light-emitting device. However, since a layer having high conductivity is also included in the light-emitting device, when the layer having high conductivity is commonly provided in each sub-pixel, a leakage current may be generated between sub-pixels. In particular, when the display device is made higher in definition or higher in aperture ratio and the distance between the sub-pixels is made smaller, the leakage current is made larger to a size that cannot be ignored. This causes a decrease in brightness, contrast, and the like, and thus, the display quality is degraded. In addition, the power consumption efficiency, the power consumption, and the like are reduced due to the leakage current.

In the sub-pixels according to one embodiment of the present invention, the step formed by the pixel electrode and the recess portion of the insulating layer under the pixel electrode is sufficiently large so that the deposited EL film is divided into the EL layer formed on the pixel electrode and the EL layer formed between the pixel electrodes in a self-aligned manner. Here, it is preferable that a step formed by the pixel electrode and the concave portion of the insulating layer under the pixel electrode is larger than the thickness of the EL layer formed between the pixel electrodes.

By adopting such a structure, a leakage path (leakage path) of current can be divided between two adjacent light emitting devices to suppress leakage current. Thus, improvement in brightness, improvement in contrast, improvement in display quality, improvement in power efficiency, reduction in power consumption, and the like can be achieved.

As described above, the EL layer manufactured by the manufacturing method of the display device according to one embodiment of the present invention is not formed using a metal mask including a fine pattern, but is formed by being divided in a self-aligned manner when the EL film is deposited on the entire surface. Therefore, a high-definition display device or a high aperture ratio display device which has been difficult to realize hitherto can be realized.

In addition, for example, it is difficult to make the interval between adjacent light emitting devices smaller than 10 μm by using the method of forming a high-definition metal mask, but according to the above method, in a process on a glass substrate, for example, the interval between adjacent light emitting devices, the interval between adjacent EL layers, or the interval between adjacent pixel electrodes can be reduced to be smaller than 10 μm, 8 μm or smaller, 5 μm or smaller, 3 μm or smaller, 2 μm or smaller, 1.5 μm or smaller, 1 μm or 0.5 μm or smaller. Thus, the area of the non-light-emitting region which can exist between the two light-emitting devices can be greatly reduced, and the aperture ratio can be made close to 100%. For example, in the display device according to one embodiment of the present invention, an aperture ratio of 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more and less than 100% can be achieved.

Further, by increasing the aperture ratio of the display device, the reliability of the display device can be improved. More specifically, when the lifetime of a display device using an organic EL element and having an aperture ratio of 10% is taken as a reference, the lifetime of a display device having an aperture ratio of 20% (i.e., 2 times the aperture ratio as a reference) is about 3.25 times the lifetime thereof, and the lifetime of a display device having an aperture ratio of 40% (i.e., 4 times the aperture ratio as a reference) is about 10.6 times the lifetime thereof. In this way, as the aperture ratio increases, the current density flowing through the organic EL element can be reduced, and thus the lifetime of the display device can be increased. The display device according to one embodiment of the present invention can have a higher aperture ratio and thus can have a higher display quality. Further, with an increase in the aperture ratio of the display device, a very good effect such as a significant increase in reliability (particularly lifetime) of the display device can be obtained.

Structural example 1 of display device

Fig. 1 to 12 show a display device according to an embodiment of the present invention.

Fig. 1A shows a top view of the display device 100. The display device 100 includes a display portion in which a plurality of pixels 110 are arranged, and a connection portion 140 outside the display portion. In the display section, a plurality of subpixels are arranged in a matrix. Fig. 1A shows two rows and six columns of subpixels, from which two rows and two columns of pixels are formed. The connection portion 140 may also be referred to as a cathode contact portion.

The pixel 110 shown in fig. 1A adopts a stripe arrangement. The pixel 110 shown in fig. 1A is composed of three sub-pixels 110a, 110b, and 110 c. The sub-pixels 110a, 110b, 110c each comprise a light emitting device emitting white light. The sub-pixels 110a, 110b, and 110c are provided with a colored layer 132a, 132b, or 132c (hereinafter, may be collectively referred to as a colored layer 132) so as to overlap the light-emitting devices. Note that wavelengths of light transmitted through the colored layers 132a, 132b, and 132c are different from each other, and thus the sub-pixels 110a, 110b, and 110c emit light of different colors from each other. For example, the subpixels 110a, 110B, and 110C include three-color subpixels of red (R), green (G), and blue (B), and three-color subpixels of yellow (Y), cyan (C), and magenta (M). The types of the sub-pixels are not limited to three, and four or more sub-pixels may be used. Examples of the four sub-pixels include four-color sub-pixels of R, G, B and white (W), and four-color sub-pixels of R, G, B, Y.

In the present specification, the row direction is sometimes referred to as the X direction and the column direction is sometimes referred to as the Y direction. The X direction intersects the Y direction, for example, perpendicularly (see fig. 1A).

In the example shown in fig. 1A, the subpixels of different colors are arranged in the X direction, and the subpixels of the same color are arranged in the Y direction.

Fig. 1A shows an example in which the connection portion 140 is located on the lower side of the display portion in a plan view, but is not particularly limited. The connection portion 140 may be provided at least one of the upper side, the right side, the left side, and the lower side of the display portion in a plan view, or may be provided so as to surround four sides of the display portion. The top surface of the connection portion 140 may be in the shape of a band, an L, a U, a frame, or the like. In addition, the connection part 140 may be one or more.

Fig. 1B is a sectional view taken along the line X1-X2 in fig. 1A. In the display device 100, a layer including a transistor is provided over the substrate 101, insulating layers 255a, 255b, and 255c are provided over the layer including a transistor, light-emitting devices 130a, 130b, and 130c are provided over the insulating layers 255a, 255b, and 255c, and a protective layer 131 is provided so as to cover the light-emitting devices. Further, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in a region between adjacent light emitting devices. Note that, hereinafter, the light emitting devices 130a, 130b, 130c may be collectively referred to as the light emitting device 130.

Fig. 1B and the like show a cross section of the plurality of insulating layers 125 and a cross section of the plurality of insulating layers 127, but the insulating layers 125 and 127 are one layer connected in a plan view of the display device 100. In other words, the display device 100 may include, for example, one insulating layer 125 and one insulating layer 127. The display device 100 may include a plurality of insulating layers 125 separated from each other, or may include a plurality of insulating layers 127 separated from each other.

In fig. 1B and the like, a resin layer 147 is provided on the protective layer 131, and a coloring layer 132 is provided on the resin layer 147. Here, the coloring layer 132a is provided so as to overlap the light emitting device 130a, the coloring layer 132b is provided so as to overlap the light emitting device 130b, and the coloring layer 132c is provided so as to overlap the light emitting device 130 c.

As shown in fig. 1B, in the display device 100, the adhesive layer 107 and the substrate 102 are provided on the coloring layer 132. The substrate 102 is bonded to the substrate 101 by an adhesive layer 107. Here, the adhesive layer 107 is in contact with the coloring layer 132 and the substrate 102.

Further, as shown in fig. 1B, a display device according to an embodiment of the present invention has a top emission structure (top emission) that emits light in a direction opposite to a substrate in which a light emitting device is formed. Note that the present invention is not limited thereto, and may have a bottom emission structure (bottom emission) that emits light to a side of a substrate where a light emitting device is formed or a double emission structure (dual emission) that emits light to double sides.

As the light emitting devices 130a, 130b, and 130c, light emitting devices such as an OLED (Organic LIGHT EMITTING Diode) and a QLED (Quantum-dot LIGHT EMITTING Diode) are preferably used. Examples of the light-emitting substance included in the light-emitting device include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescent material), an inorganic compound (quantum dot material, or the like), a substance that exhibits thermally activated delayed fluorescence (THERMALLY ACTIVATED DELAYED fluorescence (TADF) material), and the like. Note that as the TADF material, a material in which a singlet excited state and a triplet excited state are in a thermal equilibrium state may be used. Such TADF material can suppress a decrease in luminous efficiency in a high-luminance region of the light-emitting device because of a short luminous lifetime (excitation lifetime).

The light emitting device includes an EL layer between a pair of electrodes. The EL layer includes at least a light emitting layer. In this specification or the like, one of a pair of electrodes is sometimes referred to as a pixel electrode and the other is sometimes referred to as a common electrode.

Of the pair of electrodes included in the light-emitting device, one electrode is used as an anode and the other electrode is used as a cathode. Hereinafter, a case where a pixel electrode is used as an anode and a common electrode is used as a cathode will be described as an example.

The light emitting device 130a includes a pixel electrode 111a over an insulating layer 255c, an island-shaped first layer 113a over the pixel electrode 111a, a common layer 114 over the island-shaped first layer 113a, and a common electrode 115 over the common layer 114. Here, the first layer 113a is used as an EL layer including a light-emitting layer. In the light-emitting device 130a, the first layer 113a and the common layer 114 may be collectively referred to as an EL layer.

The light emitting device 130b includes the pixel electrode 111b on the insulating layer 255c, the island-shaped second layer 113b on the pixel electrode 111b, the common layer 114 on the island-shaped second layer 113b, and the common electrode 115 on the common layer 114. Here, the second layer 113b is used as an EL layer including a light-emitting layer. In the light-emitting device 130b, the second layer 113b and the common layer 114 may be collectively referred to as an EL layer.

The light emitting device 130c includes the pixel electrode 111c over the insulating layer 255c, the island-shaped third layer 113c over the pixel electrode 111c, the common layer 114 over the island-shaped third layer 113c, and the common electrode 115 over the common layer 114. Here, the third layer 113c is used as an EL layer including a light-emitting layer. In the light-emitting device 130c, the third layer 113c and the common layer 114 may be collectively referred to as an EL layer. Hereinafter, the first layer 113a, the second layer 113b, and the third layer 113c may be collectively referred to as an EL layer 113.

Note that in this specification and the like, an island shape refers to a state in which two or more layers formed in the same process and using the same material are physically separated. For example, the island-shaped light emitting layer refers to a state in which the light emitting layer is physically separated from an adjacent light emitting layer. For example, the island-shaped light emitting layer refers to a state in which the light emitting layer is physically separated from an adjacent light emitting layer.

The pixel electrodes 111a, 111b, and 111c are sometimes collectively referred to as a pixel electrode 111.

As a material for forming the pixel electrode 111, a metal, an alloy, a conductive compound, a mixture thereof, or the like can be suitably used. Specifically, an alloy (ag—pd—cu, also referred to as APC) containing aluminum alloy (aluminum alloy) and silver, palladium, and copper, such as indium tin oxide (in—sn oxide, also referred to as ITO), in—si—sn oxide (also referred to as ITSO), indium zinc oxide (in—zn oxide), in—w-Zn oxide, aluminum, nickel, and lanthanum alloy (al—ni—la), and the like, can be cited. In addition to the above, metals such as aluminum (Al), magnesium (Mg) titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and the like, and alloys thereof may be used as appropriate. In addition to the above, rare earth metals such as lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), europium (Eu), ytterbium (Yb) and the like, which are not shown above, and alloys, graphene and the like, which are appropriately combined, can be used.

The layer having transistors as the upper portion of the substrate 101 may, for example, have a stacked structure in which a plurality of transistors are provided over the substrate and an insulating layer is provided so as to cover the transistors. The insulating layer over the transistor may have either a single-layer structure or a stacked-layer structure. Fig. 1B and the like show an insulating layer 255a among insulating layers over a transistor, an insulating layer 255B over the insulating layer 255a, and an insulating layer 255c over the insulating layer 255B. These insulating layers may also have recesses between adjacent light emitting devices. Fig. 1B and the like show an example in which a concave portion is provided in a region of the insulating layer 255c that does not overlap with the pixel electrode 111 (for example, between the pixel electrode 111a and the pixel electrode 111B).

As each of the insulating layers 255a, 255b, and 255c, various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and an oxynitride insulating film can be used as appropriate. As the insulating layer 255a and the insulating layer 255c, an oxide insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film, or an oxynitride insulating film is preferably used. As the insulating layer 255b, a nitride insulating film or an oxynitride insulating film such as a silicon nitride film or a silicon oxynitride film is preferably used. More specifically, a silicon oxide film is preferably used for the insulating layers 255a and 255c, and a silicon nitride film is preferably used for the insulating layer 255 b. The insulating layer 255b is preferably used as an etching protective film. By adopting this structure, when a recess is formed in the insulating layer 255c, formation of the recess can be stopped by the insulating layer 255 b.

In this specification and the like, "oxynitride" refers to a material having a greater oxygen content than nitrogen content in its composition, and "nitride oxide" refers to a material having a greater nitrogen content than oxygen content in its composition. For example, when referred to as "silicon oxynitride" it refers to a material having a greater oxygen content than nitrogen in its composition, and when referred to as "silicon oxynitride" it refers to a material having a greater nitrogen content than oxygen in its composition.

A structural example of a layer having a transistor over the substrate 101 will be described in embodiment modes 3 and 4 below.

The first layer 113a, the second layer 113b, and the third layer 113c preferably emit white (W) light. The first layer 113a, the second layer 113b, and the third layer 113c are layers including at least a light-emitting layer. A coloring layer 132a is provided so as to overlap the first layer 113a, a coloring layer 132b is provided so as to overlap the second layer 113b, and a coloring layer 132c is provided so as to overlap the third layer 113 c. Since the wavelength regions of light transmitted through the colored layers 132 are different, the sub-pixels 110a, 110b, and 110c that emit light of different colors can be formed. Note that the structure of the light emitting device of the present embodiment is not particularly limited, and a single structure or a series structure may be employed. Reference may be made to the following embodiments with respect to structural examples of the light emitting device.

In this embodiment mode, among the EL layers included in the light-emitting devices, island-shaped layers provided for each light-emitting device are a first layer 113a, a second layer 113b, and a third layer 113c, and a layer including a plurality of light-emitting devices in common is a common layer 114.

The first layer 113a, the second layer 113b, and the third layer 113c are provided so as to be separated from each other in an island shape by being divided in a self-aligned manner from the same EL film at the end portion of the pixel electrode 111. Therefore, a leakage path (leakage path) of current can be divided between adjacent EL layers to suppress leakage current. Thus, the light emitting device can be improved in brightness, contrast, display quality, power efficiency, power consumption, or the like.

In addition, when the first layer 113a, the second layer 113b, and the third layer 113c are formed in a self-aligned manner, the fourth layer 113d is formed in a recess of the insulating layer 255 c. The fourth layer 113d contacts the bottom surface and the side surface of the recess of the insulating layer 255c and the side surface of the pixel electrode 111. Further, an insulating layer 125 is formed over the fourth layer 113d. The fourth layer 113d is preferably separated from the first layer 113a, the second layer 113b, and the third layer 113 c. Since the fourth layer 113d is formed of the same EL film as the first layer 113a, the second layer 113b, and the third layer 113c, it has the same material and structure as the first layer 113a, the second layer 113b, and the third layer 113 c.

The first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d may each include one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer.

For example, the first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d may include a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer. In addition, an electron blocking layer may be included between the hole transport layer and the light emitting layer. In addition, an electron injection layer may be included on the electron transport layer.

For example, the first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d may include an electron injection layer, an electron transport layer, a light emitting layer, and a hole transport layer in this order. In addition, a hole blocking layer may be included between the electron transport layer and the light emitting layer. In addition, a hole injection layer may be included on the hole transport layer.

The first layer 113a, the second layer 113b, and the third layer 113c preferably include a light-emitting layer and a carrier-transporting layer (an electron-transporting layer or a hole-transporting layer) over the light-emitting layer. Since the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are exposed in the manufacturing process of the display device, the carrier transport layer is provided over the light-emitting layer, so that the light-emitting layer can be prevented from being exposed to the outermost surface, and damage to the light-emitting layer can be reduced. Thereby, the reliability of the light emitting device can be improved.

The first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d may include, for example, a first light-emitting unit, a charge generation layer, and a second light-emitting unit. The second light emitting unit preferably includes a light emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light emitting layer. Since the surface of the second light emitting element is exposed in the manufacturing process of the display device, the carrier transport layer is provided over the light emitting layer, so that the light emitting layer is prevented from being exposed to the outermost surface, and damage to the light emitting layer can be reduced. Thereby, the reliability of the light emitting device can be improved.

The first layer 113a, the second layer 113b, and the third layer 113c may emit white light. Therefore, the first layer 113a, the second layer 113b, and the third layer 113c may have the same structure. Therefore, a stacked film may be deposited using the same material as the first layer 113a, the second layer 113b, and the third layer 113c, and the stacked film may be formed by dividing the stacked film at the end portion of the pixel electrode 111 in a self-aligned manner. Since the fourth layer 113d is formed simultaneously, the first layer 113a, the second layer 113b, and the third layer 113c and the fourth layer 113d have the same structure. Thus, the manufacturing process of the display device can be simplified, and the manufacturing cost can be reduced.

The common layer 114 includes, for example, an electron injection layer or a hole injection layer. Or the common layer 114 may have a stack of an electron transport layer and an electron injection layer, or may have a stack of a hole transport layer and a hole injection layer. The light emitting devices 130a, 130b, 130c collectively include a common layer 114.

Further, the light emitting devices 130a, 130b, 130c commonly include a common electrode 115. As shown in fig. 6A and 6B, the common electrode 115 included in common in the plurality of light emitting devices is electrically connected to the conductive layer 123 provided at the connection portion 140. Here, fig. 6A and 6B are sectional views taken along the line Y1-Y2 in fig. 1A. Note that the constituent elements on the protective layer 131 are not shown in fig. 6A and 6B, but at least one or more of the resin layer 147, the adhesive layer 107, and the substrate 102 may be provided appropriately. In addition, a conductive layer formed using the same material and process as those of the pixel electrode 111 is preferably used as the conductive layer 123.

Fig. 6A shows an example in which the common layer 114 is provided over the conductive layer 123 and the conductive layer 123 is electrically connected to the common electrode 115 through the common layer 114. In addition, the common layer 114 may not be provided in the connection portion 140. In fig. 6B, the conductive layer 123 is directly connected to the common electrode 115. For example, by using a mask (also referred to as a region mask, a coarse metal mask, or the like for distinction from a high-definition metal mask), the deposition regions of the common layer 114 and the common electrode 115 can be made different.

It is preferable to include a protective layer 131 on the light emitting devices 130a, 130b, 130 c. By providing the protective layer 131, the reliability of the light emitting device can be improved. The protective layer 131 may have a single-layer structure or a stacked structure of two or more layers.

The conductivity of the protective layer 131 is not limited. As the protective layer 131, at least one of an insulating film, a semiconductor film, and a conductive film can be used.

When the protective layer 131 includes an inorganic film, deterioration of the light emitting device, such as prevention of oxidation of the common electrode 115, inhibition of entry of impurities (moisture, oxygen, and the like) into the light emitting device, and the like, can be suppressed, whereby reliability of the display device can be improved.

As the protective layer 131, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a oxynitride insulating film can be used. Examples of the oxide insulating film include a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, a yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. The nitride insulating film may be a silicon nitride film, an aluminum nitride film, or the like. The oxynitride insulating film may be a silicon oxynitride film, an aluminum oxynitride film, or the like. The oxynitride insulating film may be a silicon oxynitride film, an aluminum oxynitride film, or the like. In particular, the protective layer 131 preferably includes a nitride insulating film or an oxynitride insulating film, more preferably includes a nitride insulating film.

In addition, an inorganic film containing an in—sn oxide (also referred to as ITO), an in—zn oxide, a ga—zn oxide, an al—zn oxide, an indium gallium zinc oxide (also referred to as in—ga—zn oxide, IGZO), or the like may be used for the protective layer 131. The inorganic film preferably has a high resistance, and in particular, the inorganic film preferably has a higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

In the case where light emission of the light-emitting device is extracted through the protective layer 131, the protective layer 131 preferably has high transmittance to visible light. For example, ITO, IGZO, and alumina are all inorganic materials having high transparency to visible light, and are therefore preferable.

As the protective layer 131, for example, a stacked structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, a stacked structure of an aluminum oxide film and an IGZO film on the aluminum oxide film, or the like can be used. By using this stacked structure, entry of impurities (water, oxygen, and the like) into the EL layer side can be suppressed.

Also, the protective layer 131 may include an organic film. For example, the protective layer 131 may include both an organic film and an inorganic film. As an organic material that can be used for the protective layer 131, for example, an organic insulating material that can be used for the resin layer 147, which will be described later, can be given.

The protective layer 131 may also have a two-layer structure formed using different deposition methods. Specifically, the first layer of the protective layer 131 may be formed by an atomic layer deposition (ALD: atomic Layer Deposition) method, and the second layer of the protective layer 131 may be formed by a sputtering method.

In fig. 1B and the like, an insulating layer covering the top end of the pixel electrode 111a is not provided between the pixel electrode 111a and the first layer 113 a. Further, an insulating layer covering the top end of the pixel electrode 111b is not provided between the pixel electrode 111b and the second layer 113 b. Further, an insulating layer covering the top end of the pixel electrode 111c is not provided between the pixel electrode 111c and the third layer 113 c. Therefore, the interval between adjacent light emitting devices can be made extremely narrow. Accordingly, a high-definition or high-resolution display device can be realized.

As shown in fig. 1B, the side surfaces of the first layer 113a, the second layer 113B, and the third layer 113c are covered with an insulating layer 127 and an insulating layer 125, respectively. In other words, a part of the insulating layer 125 and a part of the insulating layer 127 are sandwiched between the side surfaces of the EL layers adjacent to each other (for example, the side surface of the first layer 113a and the side surface of the second layer 113 b) and the side surfaces of the pixel electrodes adjacent to each other (for example, the side surfaces of the pixel electrodes 111a and the side surfaces of the pixel electrodes 111 b). Further, a part of the top surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are covered with the insulating layer 127 and the insulating layer 125.

The insulating layer 125 preferably covers at least one of the side surfaces of the island-shaped EL layer, and more preferably covers both of the side surfaces of the island-shaped EL layer. The insulating layer 125 may be in contact with each side of the island-shaped EL layer. Further, the insulating layer 125 contacts the side surfaces of the island-shaped pixel electrodes.

In fig. 1B and the like, the insulating layer 125 covers a portion of the top surface and the side surface of the first layer 113a and contacts the side surface of the pixel electrode 111 a. Similarly, the insulating layer 125 covers a portion of the top surface and the side surface of the second layer 113b and contacts the side surface of the pixel electrode 111 b. In addition, similarly, the insulating layer 125 covers a portion of the top surface and the side surface of the third layer 113c and contacts the side surface of the pixel electrode 111 c.

By adopting the above structure, the common layer 114 (or the common electrode 115) can be suppressed from contacting the side surfaces of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c, and short circuits of the light emitting device can be suppressed. Thereby, the reliability of the light emitting device can be improved.

The insulating layer 127 is provided on the insulating layer 125 in such a manner as to fill the recess in the insulating layer 125. The insulating layer 127 may be formed so as to overlap with a part of the top surface and the side surface of each of the first layer 113a, the second layer 113b, and the third layer 113c through the insulating layer 125 (also referred to as a structure covering the side surface).

Since the insulating layers 125 and 127 can fill the space between the adjacent island-shaped EL layers and the pixel electrode, irregularities having large level differences on the surface to be formed of layers (for example, a carrier injection layer, a common electrode, and the like) provided on the island-shaped EL layers can be reduced, and planarization can be further realized. Therefore, the coverage of the carrier injection layer, the common electrode, and the like can be improved, and disconnection of the carrier injection layer and the common electrode can be prevented.

The common layer 114 and the common electrode 115 are provided over the first layer 113a, the second layer 113b, the third layer 113c, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, steps are generated due to the region where the pixel electrode and the EL layer are provided and the region where the pixel electrode and the EL layer are not provided (the region between light emitting devices). The display device according to one embodiment of the present invention includes the insulating layer 125 and the insulating layer 127, whereby the step can be planarized, and thus the coverage of the common layer 114 and the common electrode 115 can be improved. Therefore, the connection failure caused by disconnection can be suppressed. In addition, the common electrode 115 can be prevented from being locally thinned by the step, and the resistance can be prevented from rising.

Further, although the top surface of the insulating layer 127 preferably has a shape with high flatness, it may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion. For example, the top surface of the insulating layer 127 preferably has a gently convex curved surface shape with high flatness.

The insulating layer 125 may be provided in contact with the island-like EL layer. This prevents the island-shaped EL layer from peeling off. By the close contact of the insulating layer 125 with the EL layer, an effect can be produced in which adjacent island-like EL layers are fixed or bonded together by the insulating layer 125. Thereby, the reliability of the light emitting device can be improved. In addition, the manufacturing yield of the light emitting device can be improved.

Here, the insulating layer 125 has a region in contact with the side surface of the island-shaped EL layer, and is used as a protective insulating layer of the EL layer. By providing the insulating layer 125, entry of impurities (oxygen, moisture, and the like) from the side surfaces of the island-shaped EL layers into the inside can be suppressed, and thus a highly reliable display device can be realized.

Next, examples of materials and a forming method of the insulating layer 125 and the insulating layer 127 are described.

The insulating layer 125 may be an insulating layer including an inorganic material. As the insulating layer 125, for example, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or an oxynitride insulating film can be used. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of the oxide insulating film 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, a yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. The nitride insulating film may be a silicon nitride film, an aluminum nitride film, or the like. The oxynitride insulating film may be a silicon oxynitride film, an aluminum oxynitride film, or the like. The oxynitride insulating film may be a silicon oxynitride film, an aluminum oxynitride film, or the like. In particular, the etching is preferable because the selectivity ratio of alumina to the EL layer is high, and the insulating layer 127 to be described later is formed to have a function of protecting the EL layer. In particular, by applying an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by an ALD method to the insulating layer 125, the insulating layer 125 having few pinholes and excellent function of protecting the EL layer can be formed. The insulating layer 125 may have a stacked-layer structure of a film formed by an ALD method and a film formed by a sputtering method. The insulating layer 125 may be formed by, for example, a stacked structure of an aluminum oxide film formed by an ALD method and a silicon nitride film formed by a sputtering method.

The insulating layer 125 preferably has a function of blocking the insulating layer with respect to at least one of water and oxygen. The insulating layer 125 preferably has a function of suppressing diffusion of at least one of water and oxygen. In addition, the insulating layer 125 preferably has a function of trapping or fixing (also referred to as gettering) at least one of water and oxygen.

In this specification and the like, the barrier insulating layer means an insulating layer having barrier properties. In the present specification, the barrier property means a function of suppressing diffusion of a corresponding substance (also referred to as low permeability). Or refers to the function of capturing or immobilizing the corresponding substance (also known as gettering).

When the insulating layer 125 is used as a barrier insulating layer or has a gettering function, it may have a structure in which entry of impurities (typically, at least one of water and oxygen) which may be diffused to each light-emitting device from the outside is suppressed. By adopting this structure, a light emitting device with high reliability can be provided, and a display device with high reliability can be provided.

In addition, the impurity concentration of the insulating layer 125 is preferably low. This can suppress deterioration of the EL layer due to the contamination of impurities from the insulating layer 125 into the EL layer. In addition, by reducing the impurity concentration in the insulating layer 125, barrier properties against at least one of water and oxygen can be improved. For example, one of the hydrogen concentration and the carbon concentration in the insulating layer 125 is preferably sufficiently low, and both of the hydrogen concentration and the carbon concentration are preferably sufficiently low.

Examples of the method for forming the insulating layer 125 include a sputtering method, a chemical vapor deposition (CVD: chemical Vapor Deposition) method, a pulsed laser deposition (PLD: pulsed Laser Deposition) method, and an ALD method. The insulating layer 125 is preferably formed by an ALD method having good coverage.

By increasing the substrate temperature at the time of depositing the insulating layer 125, the insulating layer 125 can be formed to have a thin film thickness, a low impurity concentration, and a high barrier property against at least one of water and oxygen. Therefore, the substrate temperature is preferably 60℃or higher, more preferably 80℃or higher, still more preferably 100℃or higher, and still more preferably 120℃or higher. On the other hand, the insulating layer 125 is deposited after the island-shaped EL layer is formed, so it is preferably formed at a temperature lower than the heat-resistant temperature of the EL layer. Therefore, the substrate temperature is preferably 200 ℃ or less, more preferably 180 ℃ or less, further preferably 160 ℃ or less, further preferably 150 ℃ or less, and further preferably 140 ℃ or less.

Examples of the index of the heat-resistant temperature include a glass transition point, a softening point, a melting point, a thermal decomposition temperature, and a 5% weight loss temperature. As the heat-resistant temperature of the EL layer, any of the above-mentioned temperatures can be used, and the lowest temperature among the above-mentioned temperatures is preferably used.

The insulating layer 125 is preferably formed of an insulating film having a thickness of 3nm or more, 5nm or more, or 10nm or more and 200nm or less, 150nm or less, 100nm or less, or 50nm or less, for example.

The insulating layer 127 provided on the insulating layer 125 has a function of planarizing irregularities of the insulating layer 125 formed between adjacent light emitting devices with a large level difference. In other words, by including the insulating layer 127, an effect of improving the flatness of the surface where the common electrode 115 is formed is produced.

As the insulating layer 127, an insulating layer containing an organic material can be suitably used. As the organic material, a photosensitive organic resin is preferably used, and for example, a photosensitive resin composition containing an acrylic resin can be used. The viscosity of the material of the insulating layer 127 may be 1cP to 1500cP, and preferably 1cP to 12 cP. By setting the viscosity of the material of the insulating layer 127 to be in the above range, the insulating layer 127 having a tapered shape described later can be formed relatively easily. Note that in this specification and the like, acrylic resin refers not only to polymethacrylate or methacrylic resin, but also to a broad sense of acrylic polymer in some cases.

Note that as described later, the insulating layer 127 may have a tapered shape on the side, and the organic material that can be used for the insulating layer 127 is not limited to the above-described material. For example, an acrylic resin, a polyimide resin, an epoxy resin, an imide resin, a polyamide resin, a polyimide amide resin, a silicone resin, a siloxane resin, a benzocyclobutene resin, a phenol resin, a precursor of the above-described resin, or the like may be used as the insulating layer 127. For example, an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used as the insulating layer 127. A photoresist may be used as the photosensitive resin. Positive type materials or negative type materials may also be used as the photosensitive resin in some cases.

As the insulating layer 127, a material that absorbs visible light can be used. By absorbing light emission from the light emitting device through the insulating layer 127, light leakage from the light emitting device to an adjacent light emitting device (stray light) through the insulating layer 127 can be suppressed. Thus, the display quality of the display device can be improved. In addition, since the display quality can be improved without using a polarizing plate in the display device, the display device can be reduced in weight and thickness.

As the material absorbing visible light, a material including a pigment of black or the like, a material including a dye, a resin material including light absorbability (for example, polyimide or the like), and a resin material (color filter material) usable for a color filter can be given. In particular, a resin material obtained by laminating or mixing color filter materials of two colors or three or more colors is preferable because the effect of shielding visible light can be improved. In particular, by mixing color filter materials of three or more colors, a black or near-black resin layer can be realized.

The insulating layer 127 can be formed by a wet deposition method such as a spin coating method, a dipping method, a spray coating method, an inkjet method, a dispenser method, a screen printing method, an offset printing method, a doctor blade (doctor knife) method, a slit coating method, a roll coating method, a curtain coating method, or a doctor blade coating method. In particular, the organic insulating film to be the insulating layer 127 is preferably formed by spin coating.

The insulating layer 127 is formed at a temperature lower than the heat resistant temperature of the EL layer. The substrate temperature at the time of forming the insulating layer 127 is typically 200 ℃ or less, preferably 180 ℃ or less, more preferably 160 ℃ or less, further preferably 150 ℃ or less, and still further preferably 140 ℃ or less.

Hereinafter, the structure of the insulating layer 127 and the like between the light emitting devices 130a and 130b will be described as an example. Note that the insulating layer 127 between the light emitting device 130b and the light emitting device 130c, the insulating layer 127 between the light emitting device 130c and the light emitting device 130a, and the like are also the same. Hereinafter, an end portion of the insulating layer 127 on the second layer 113b is described as an example, and an end portion of the insulating layer 127 on the first layer 113a, an end portion of the insulating layer 127 on the third layer 113c, and the like are also the same.

The side surface of the insulating layer 127 above the second layer 113b is preferably tapered in a taper shape of a taper angle θ when the display device is viewed in cross section. Hereinafter, in this specification or the like, the side surface of the insulating layer 127 may be the side surface of a convex curved surface-shaped portion above the flat portion of the first layer 113a, the second layer 113b, or the third layer 113 c. The taper angle θ is the angle formed between the side surface of the insulating layer 127 and the substrate surface. Note that the taper angle θ is not limited to the substrate surface, and may be an angle formed with the side surface of the insulating layer 127, such as the top surface of the flat portion of the insulating layer 125, the top surface of the flat portion of the second layer 113b, or the top surface of the flat portion of the pixel electrode 111 b. In addition, by making the side surface of the insulating layer 127 have a tapered shape, the side surface of the insulating layer 125 may have a tapered shape.

In the present specification, the tapered shape refers to a shape in which at least a part of a side surface of a constituent element is provided obliquely to a substrate surface. For example, it is preferable to have inclined sides and areas of the substrate surface (also referred to as cone angles) less than 90 °.

The taper angle θ of the insulating layer 127 is less than 90 °, preferably 60 ° or less, and more preferably 45 ° or less. By providing such a forward taper to the side edge portion of the insulating layer 127, deposition can be performed with high coverage in a state where disconnection, partial thinning, or the like does not occur in the common layer 114 and the common electrode 115 provided on the side edge portion of the insulating layer 127. This can improve the in-plane uniformity of the common layer 114 and the common electrode 115, and can improve the display quality of the display device.

In addition, the top surface of the insulating layer 127 preferably has a convex curved surface shape when viewed in a cross section of the display device. The convex curved surface shape of the top surface of the insulating layer 127 is preferably a shape that gently expands toward the center. Further, the convex curved surface portion of the center portion of the top surface of the insulating layer 127 is preferably in the shape of a tapered portion smoothly connected to the side end portions. By adopting such a shape as the insulating layer 127, the common layer 114 and the common electrode 115 can be deposited with high coverage over the insulating layer 127 as a whole.

In addition, an insulating layer 127 is formed in a region between two EL layers (for example, a region between the first layer 113a and the second layer 113 b). At this time, at least a part of the insulating layer 127 is arranged at a position sandwiched between the side end portion of one EL layer (for example, the first layer 113 a) and the side end portion of the other EL layer (for example, the second layer 113 b).

Preferably, one end portion of the insulating layer 127 overlaps the pixel electrode 111a and the other end portion of the insulating layer 127 overlaps the pixel electrode 111 b. By adopting the above structure, an end portion of the insulating layer 127 can be formed over a substantially flat region of the first layer 113a (the second layer 113 b). Therefore, the tapered shape of the insulating layer 127 is easily formed by the above-described processing.

As described above, by providing the insulating layer 127 or the like, a disconnected portion and a portion where the thickness is locally reduced can be prevented from being formed in the common layer 114 and the common electrode 115 from the substantially flat region of the first layer 113a to the substantially flat region of the second layer 113 b. Therefore, it is possible to suppress an occurrence of a connection failure due to a disconnected portion and an increase in resistance due to a portion locally thinned in the common layer 114 and the common electrode 115 between the light emitting devices. Thus, the display device according to one embodiment of the present invention can improve display quality.

In the display device of the present embodiment, the distance between the light emitting devices can be reduced. Specifically, the distance between light emitting devices, the distance between EL layers, or the distance between pixel electrodes can be reduced to less than 10 μm, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, 1 μm or less, 500nm or less, 200nm or less, or 100nm or less. In other words, the display device of the present embodiment has a region in which the interval between two adjacent island-like EL layers is 1 μm or less, preferably a region in which the interval is 0.5 μm (500 nm) or less, and more preferably a region in which the interval is 100nm or less. By reducing the distance between the light emitting devices as described above, a display device with high definition and high aperture ratio can be provided.

Note that the structure in which the insulating layer 127 is provided is shown above, but the present invention is not limited thereto. For example, as shown in fig. 6C, the insulating layer 127 may not be provided. When the insulating layer 127 is not provided, as shown in fig. 6C, the common layer 114 may not be provided. Here, the first layer 113a to the third layer 113c are preferably stacked to a functional layer (for example, a carrier injection layer) included in the common layer 114 in the structure shown in fig. 1B.

When the insulating layer 127 is not provided, the common electrode 115 has a shape that enters into a region sandwiched between the pixel electrodes. Here, as shown in fig. 6C, a part of the common electrode 115 may be in contact with the fourth layer 113 d. Thus, the common electrode 115 is preferably prevented from being disconnected. Here, as shown in fig. 6C, a void may be formed in a region sandwiched between the pixel electrode 111 and the common electrode 115 and between the first layer 113a (the second layer 113b or the third layer 113C) and the fourth layer 113 d.

A coloring layer 132a, a coloring layer 132b, and a coloring layer 132c are provided between the common electrode 115 and the substrate 102. For example, as shown in fig. 1B, the colored layer 132a, the colored layer 132B, and the colored layer 132c may be provided on the resin layer 147. By adopting such a structure, the distance between the light emitting device 130 and the colored layer 132 can be shortened. Therefore, light emitted from the light emitting device 130 can be suppressed from leaking to adjacent sub-pixels. For example, light emitted from the light-emitting device 130a overlapping with the colored layer 132a can be suppressed from being incident on the colored layer 132b. Therefore, the contrast of an image displayed on the display device can be improved, and thus a display device with high display quality can be realized.

The coloring layer 132a includes a region overlapping the light emitting device 130a, the coloring layer 132b includes a region overlapping the light emitting device 130b, and the coloring layer 132c includes a region overlapping the light emitting device 130 c. The colored layer 132a, the colored layer 132b, and the colored layer 132c include at least a region overlapping with the light-emitting layer included in each light-emitting device 130.

The colored layers 132a, 132b, and 132c have a function of transmitting light having different wavelength regions from each other. For example, the following structure may be adopted: the colored layer 132a has a function of transmitting light having intensity in a red wavelength region; the colored layer 132b has a function of transmitting light having intensity in a green wavelength region; and the colored layer 132c has a function of transmitting light having intensity in a wavelength region of blue. Thus, the display device 100 can perform full-color display. Note that, not limited to this, the coloring layer 132 may have a function of transmitting any of cyan, magenta, and yellow light.

Here, adjacent colored layers 132 preferably have overlapping regions. Specifically, in the region not overlapping the light emitting device 130, it is preferable to have a region overlapping the adjacent colored layer 132. For example, as shown in fig. 1B, a coloring layer 132a is provided so as to overlap a part of the coloring layer 132B in a region sandwiched between the light emitting device 130a and the light emitting device 130B. At this time, the overlapping portion of the coloring layer 132a and the coloring layer 132b preferably overlaps with the insulating layer 127. The same applies to the colored layers 132a and 132c and the colored layers 132b and 132 c.

In this way, by overlapping the colored layers 132 that transmit light of different colors, the colored layers 132 can be used as a light shielding layer in the region where the colored layers 132 overlap. Therefore, light emitted from the light emitting device 130 can be suppressed from leaking to adjacent sub-pixels. This can improve the contrast of an image displayed on the display device, and thus can realize a display device with high display quality.

Further, as shown in fig. 1B and the like, the coloring layer 132 is preferably provided in contact with the top surface of the resin layer 147 serving as a planarizing film. Accordingly, the colored layer 132 can be formed on a surface having high flatness, and thus irregularities due to the formed surface in the colored layer 132 can be reduced. This suppresses diffuse reflection of a part of the light emitted from the light emitting device 130 by the irregularities of the colored layer 132, thereby improving the display quality of the display device. Further, by providing the resin layer 147 on the protective layer 131, even if the protective layer 131 has a defect such as a pinhole, for example, the defect can be filled with the resin layer 147 having high step coverage.

As the coloring layer 132, a colored light-transmitting resin may be used. Examples thereof include a metal material, a resin material, and a resin material containing a pigment or a dye.

The resin layer 147 preferably contains an organic insulating material. Examples thereof include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimide amide resins, silicone resins, benzocyclobutene resins, phenolic resins, and precursors of the above resins.

Next, a structure of a broken portion of the first layer 113a and the fourth layer 113d will be described with reference to fig. 2A to 3B. Note that in fig. 2A to 3B, only the first layer 113a, the fourth layer 113d, the pixel electrode 111a, and the insulating layer 255c are illustrated in order to avoid complexity. Hereinafter, the first layer 113a and the pixel electrode 111a will be described as an example, and the second layer 113b and the pixel electrode 111b, and the third layer 113c and the pixel electrode 111c are also similar to each other.

As shown in fig. 2A, the pixel electrode 111a is provided over the insulating layer 255c, the first layer 113a is provided over the pixel electrode 111a, and the fourth layer 113d is provided in a recess of the insulating layer 255 c. Here, in depositing the EL film, in order to divide the first layer 113a and the fourth layer 113d in a self-aligned manner, a step formed in the concave portion of the pixel electrode 111a and the insulating layer 255c needs to be sufficiently large.

Specifically, the step formed by the recess of the pixel electrode 111a and the insulating layer 255c is preferably equal to or greater than the thickness of the fourth layer 113 d. That is, as shown in fig. 2A, when the thickness of the pixel electrode 111a is represented by T1, the depth of the recess of the insulating layer 255c is represented by T2, and the thickness of the fourth layer 113d is represented by T3, it is preferable that the relationship of t1+t2+.t3 be satisfied.

Further, the step formed in the concave portion of the pixel electrode 111a and the insulating layer 255c preferably has a steep shape. As shown in fig. 2A, an angle formed by the bottom surface and the side surface of the pixel electrode 111a is set to a taper angle θ1, and an angle formed by the extended surface and the side surface of the bottom surface of the recess of the insulating layer 255c is set to a taper angle θ2. Here, the taper angles θ1 and θ2 are 60 degrees to 140 degrees, preferably 70 degrees to 140 degrees, more preferably 80 degrees to 140 degrees.

By adopting the above-described structure for the insulating layer 255c and the pixel electrode 111a, a sufficiently large step is formed, and the first layer 113a and the fourth layer 113d can be divided in a self-aligned manner when an EL film is deposited. By forming the EL layer in this manner, a leakage path (leakage path) of current can be divided between two adjacent light emitting devices to suppress leakage current. Thus, it is possible to achieve an improvement in brightness, an improvement in contrast, an improvement in display quality, an improvement in power efficiency, or a reduction in power consumption.

Here, as shown in fig. 2A, the first layer 113a may be formed so as to contact the upper end portion of the side surface of the pixel electrode 111 a. In this case, the side of the first layer 113a is located outside the side of the pixel electrode 111 a. In addition, although the side surface of the fourth layer 113d may be in contact with a part of the side surface of the pixel electrode 111a, the area of the fourth layer 113d in contact with the pixel electrode 111a may be sufficiently small, so that leakage current may be suppressed or sufficiently reduced.

In addition, the height of a side portion of the fourth layer 113d in contact with the pixel electrode 111a is sometimes lower than the thickness T3. At this time, even if the sum of the thickness T1 and the depth T2 of the recess is equal to or greater than eight times the thickness T3 or equal to or greater than nine times the thickness T3, the first layer 113a and the fourth layer 113d may be divided in a self-aligned manner.

As shown in fig. 2B, the thickness T1 of the pixel electrode 111a may be equal to or greater than the thickness T3 of the fourth layer 113 d. In this case, a structure in which t2=0 nm, that is, the insulating layer 255c has no concave portion may be used.

As shown in fig. 2C, the depth T2 of the recess of the insulating layer 255C may be equal to or greater than the thickness T3 of the fourth layer 113 d. In this case, as shown in fig. 2C, the fourth layer 113d may not contact the side surface of the pixel electrode 111 a. Further, by exposing a part of the side surface of the insulating layer 255c from the fourth layer 113d, the insulating layer 125 may be in contact with a part of the side surface of the insulating layer 255 c.

Further, as shown in fig. 2A and the like, the first layer 113a is preferably separated from the fourth layer 113d, but the present invention is not limited thereto. For example, as shown in fig. 2D, the first layer 113a and the fourth layer 113D are sometimes connected to each other by forming an EL layer thinner on the side surface of the pixel electrode 111 a. Here, the thickness T4 of the EL layer formed to be thin on the side surface of the pixel electrode 111a is preferably sufficiently thin. The thickness T4 is half (50%) or less, preferably 30% or less, more preferably 10% or less and more than 0% of the thickness T3. By making the thickness of T4 thin, leakage current between adjacent light emitting devices can be suppressed or sufficiently reduced.

Note that the fourth layer 113d may be separated from one of the adjacent EL layers and connected to the other of the adjacent EL layers by an EL layer formed thinner. For example, in the fourth layer 113d formed between the first layer 113a and the second layer 113b, the first layer 113a and the fourth layer 113d may be separated, and the second layer 113b and the fourth layer 113d may be connected by an EL layer formed thinner on the side surface of the pixel electrode 111 b.

As shown in fig. 3A, a part of the side surface of the pixel electrode 111a may be retracted. The side surface of the lower portion of the pixel electrode 111a is set back from the side surface of the recess of the insulating layer 255 c. A protrusion 109a is formed on the upper side surface of the pixel electrode 111a, and the protrusion 109a protrudes a distance T5 (T5 is greater than 0 nm) from the lower side surface. In this manner, by forming the projection 109a on the upper portion of the pixel electrode 111a, the EL film can be more easily broken at the projection 109a when the EL film is deposited. Thus, the first layer 113a is preferably formed so as to cover the protruding portion 109 a. Note that, as shown in fig. 3A, the protruding portion 109a may also have a tapered shape.

As described above, in the structure shown in fig. 3A, the deposited EL film is preferably broken at the protruding portion 109 a. Thus, the step below the protruding portion of the pixel electrode 111a is preferably equal to or greater than the thickness of the fourth layer 113 d. That is, as shown in fig. 3A, when the thickness below the protruding portion 109a of the pixel electrode 111a is denoted by T1a, the depth of the recess of the insulating layer 255c is denoted by T2, and the thickness of the fourth layer 113d is denoted by T3, it is preferable that the relationship of t1a+t2+.t3 be satisfied.

The pixel electrode 111a shown in fig. 3A may be formed using, for example, conductive layers of two layers (a first conductive layer and a second conductive layer on the first conductive layer) having different materials. The first conductive layer may be made of a material having a higher etching rate than the second conductive layer.

Further, as shown in fig. 3B, the center portion of the side surface of the pixel electrode 111a may be set back and the upper and lower portions of the side surface of the pixel electrode 111a may be protruded. In the structure shown in fig. 3B, it can be said that the structure shown in fig. 3A is also provided with the protruding portion 109B at the lower portion of the pixel electrode 111 a. At this time, the taper angle θ1 may be measured on the upper side surface of the protruding portion 109 b. Note that, as shown in fig. 3B, the protruding portion 109B may also have a tapered shape.

The pixel electrode 111a shown in fig. 3B may be formed using, for example, conductive layers of three layers (a first conductive layer, a second conductive layer on the first conductive layer, and a third conductive layer on the second conductive layer) having different materials. The second conductive layer is preferably formed of a material having a higher etching rate than the first conductive layer and the third conductive layer.

Fig. 3C shows a specific example in which the center portion of the side surface of the pixel electrode 111a shown in fig. 3B is set back and the upper and lower portions of the side surface of the pixel electrode 111a are protruded. Fig. 3C is an enlarged cross-sectional view of the vicinity of the fourth layer 113d, the insulating layer 125, and the insulating layer 127 provided between the pixel electrode 111a and the pixel electrode 111 b.

The pixel electrode 111 of the structure shown in fig. 1B in the structure shown in fig. 3C has a four-layer structure of the conductive layer 11a, the conductive layer 11B on the conductive layer 11a, the conductive layer 11C on the conductive layer 11B, and the conductive layer 11d on the conductive layer 11C.

The conductive layer 11a includes a protruding portion 109B corresponding to the lower portion of the pixel electrode 111a shown in fig. 3B. The conductive layer 11B is provided so that its side surface is set back from the conductive layer 11a and the conductive layer 11c, and corresponds to the central portion of the pixel electrode 111a shown in fig. 3B. Thus, the sum of the thickness of the conductive layer 11a and the thickness of the conductive layer 11B corresponds to the thickness T1a shown in fig. 3B. The conductive layer 11c and the conductive layer 11d include a protruding portion 109a at the conductive layer 11c, corresponding to an upper portion of the pixel electrode 111a shown in fig. 3B.

As shown in fig. 3C, in the case where the pixel electrode 111 has a four-layer structure of the conductive layers 11a to 11d, a conductive film having reflectivity for visible light is preferably used for the conductive layer 11b. As the conductive film having light reflectivity to visible light, for example, a metal material such as aluminum, gold, platinum, silver, nickel, magnesium, tungsten, chromium, titanium, tantalum, molybdenum, iron, cobalt, copper, or palladium, or an alloy containing these metal materials can be used. Copper is preferred because of its high reflectivity to visible light. In addition, aluminum is preferable because it is easy to etch an electrode, and it is easy to process, and it has high reflectivity to visible light and near infrared light. Further, as described above, by using a material having high reflectance in the entire wavelength region of visible light such as silver or aluminum as the conductive layer 11b, not only the light extraction efficiency of the light-emitting device but also the color reproducibility can be improved. Lanthanum, neodymium, germanium, or the like may be added to the metal material or alloy. For example, an aluminum-containing alloy (aluminum alloy) such as an alloy of aluminum, nickel, and lanthanum (al—ni—la) may be used. In addition, an alloy containing silver, palladium, and copper (ag—pd—cu, also referred to as APC) may also be used. In addition, alloys containing silver, palladium, magnesium, and copper may also be used. An alloy containing silver and copper has high heat resistance, and is therefore preferable. In addition, an alloy containing silver and magnesium may also be used. In addition, two or more of the above materials may be stacked and used. Examples of such a laminate include aluminum and APC on the aluminum.

For example, aluminum may be used for the conductive layer 11 b. When aluminum is used as the conductive layer 11b, the reflectance of visible light or the like can be sufficiently improved by setting the thickness to preferably 40nm or more, more preferably 70nm or more.

Further, a conductive film having a function of protecting a conductive film that reflects visible light may be provided so as to be in contact with the top surface, the bottom surface, or both of the conductive film that reflects visible light (conductive layer 11 b). By adopting such a structure, oxidation and corrosion of the conductive film reflecting visible light can be suppressed. For example, by stacking a metal film or a metal oxide film in contact with an aluminum film or an aluminum alloy film, oxidation can be suppressed. Also, hillocks can be suppressed from being formed in the aluminum film or the aluminum alloy film. Examples of the material of the metal film or the metal oxide film include titanium and titanium oxide. For example, in the case of the structure shown in fig. 3C, titanium may be used for the conductive layer 11a and titanium oxide may be used for the conductive layer 11C. By using titanium oxide having light transmittance as the conductive layer 11c, attenuation of visible light reflected on the conductive layer 11b in the conductive layer 11c can be suppressed.

In the case of using a conductive metal oxide having transparency to visible light, the metal oxide may be formed by oxidizing the surface of a conductive material. For example, when titanium oxide is used, titanium may be deposited by sputtering or the like, and the surface of the titanium may be oxidized to form titanium oxide.

In addition, in the pixel electrode 111, a conductive film having transparency to visible light may be used over a conductive film having reflectivity to visible light. In the pixel electrode 111, a conductive film having transparency to visible light is stacked over a conductive film having reflectivity to visible light, and thus the conductive film having transparency to visible light can be used as an optical adjustment layer. For example, the conductive layer 11d may be used as an optical adjustment layer. As the conductive material having transparency to visible light, an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, a conductive oxide including any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, indium zinc oxide containing silicon, and the like is preferably used. By providing an oxide on the surface of the pixel electrode 111, oxidation reaction with the pixel electrode 111 or the like can be suppressed when the EL layer 113 is formed.

In the case where the pixel electrode 111 is used as an anode, a conductive film having a large work function (for example, a work function of 4.0eV or more) is preferably used. For example, in the case of using the structure shown in fig. 3C, indium tin oxide or indium tin oxide containing silicon may be used for the conductive layer 11 d. Here, the thicknesses of the conductive layers 11d and 11c having transparency to visible light are preferably smaller than those of the conductive layer 11 b. Further, it is more preferable that the sum of the thicknesses of the conductive layer 11d and the conductive layer 11c is thinner than the thickness of the conductive layer 11 b.

Here, the optical path length can be adjusted by including an optical adjustment layer in the pixel electrode 111. The optical path length of each light-emitting device corresponds to, for example, the sum of the thickness of the optical adjustment layer and the thickness of a layer of the EL layer 113 provided under the film containing the light-emitting compound.

In the light emitting device, light of a specific wavelength can be enhanced by making the optical path lengths different by using a microcavity structure (a micro resonator structure). Thus, a display device with improved color purity can be realized.

For example, in each light emitting device, a microcavity structure can be realized by making the thickness of the EL layer 113 different. For example, the thickness of the EL layer 113 of the light emitting device that emits light having the longest wavelength (e.g., red light) is maximized and the thickness of the EL layer 113 of the light emitting device that emits light having the shortest wavelength (e.g., blue light) is minimized. Note that, the thickness of each EL layer may be adjusted in consideration of the wavelength of light emitted by each light-emitting device, the optical characteristics of layers constituting the light-emitting device, the electrical characteristics of the light-emitting device, and the like.

Note that in fig. 3C, an example in which the pixel electrode 111 is a four-layer stack of the conductive layers 11a to 11d is shown, but a structure of three or less layers or a structure of five or more layers may be adopted. For example, when the pixel electrode 111 has a three-layer stacked structure of the conductive layers 11a to 11c, indium tin oxide or indium tin oxide containing silicon may be used for the conductive layers 11a and 11c, and an alloy containing silver (for example, APC or the like) may be used for the conductive layer 11b.

As shown in fig. 4A, the side surface of the center portion of the pixel electrode 111 can be largely retreated by performing isotropic etching. At this time, the side surface of the center portion of the pixel electrode 111a is significantly retreated compared to fig. 3B and the like. Thus, the protruding portion 109a can be relatively enlarged. Therefore, the first layer 113a and the fourth layer 113d can be separated relatively easily. At this time, the protruding portion 109b may be relatively large.

Note that details of the above-described isotropic etching will be described later.

Further, fig. 4B shows a four-layer structure in which the pixel electrode 111 in the structure of fig. 4A has conductive layers 11a to 11 d. As shown in fig. 4B, the side surface of the conductive layer 11B may be largely retracted by performing isotropic etching. Accordingly, the protruding portion 109a of the conductive layer 11c can be relatively enlarged, and the first layer 113a (including the second layer 113b or the third layer 113 c) and the fourth layer 113d can be easily divided in a self-aligned manner. At this time, the protruding portion 109b of the conductive layer 11a may be relatively enlarged.

The substrate 101 and the substrate 102 may be made of glass, quartz, ceramic, sapphire, resin, metal, alloy, semiconductor, or the like. The substrate on the side from which light from the light-emitting device is extracted uses a material that transmits the light. By using a material having flexibility for the substrate 101 and the substrate 102, flexibility of the display device can be improved. As the substrate 101 and the substrate 102, a polarizing plate can be used.

As the substrate 101 and the substrate 102, the following materials can be used, respectively: polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resins, acrylic resins, polyimide resins, polymethyl methacrylate resins, polycarbonate (PC) resins, polyethersulfone (PES) resins, polyamide resins (nylon, aramid, etc.), polysiloxane resins, cycloolefin resins, polystyrene resins, polyamide-imide resins, polyurethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, polypropylene resins, polytetrafluoroethylene (PTFE) resins, ABS resins, cellulose nanofibers, and the like. Further, glass having a thickness of a degree of flexibility may be used as the substrate 101 and the substrate 102.

In the case of overlapping the circularly polarizing plate on the display device, a substrate having high optical isotropy is preferably used as the substrate included in the display device. Substrates with high optical isotropy have lower birefringence (also referred to as lower birefringence).

The absolute value of the phase difference value (retardation value) of the substrate having high optical isotropy is preferably 30nm or less, more preferably 20nm or less, and further preferably 10nm or less.

Examples of the film having high optical isotropy include a cellulose triacetate (also referred to as TAC or Cellulose triacetate) film, a cycloolefin polymer (COP) film, a cycloolefin copolymer (COC) film, and an acrylic film.

When a film is used as a substrate, there is a possibility that shape changes such as wrinkles of the display device occur due to water absorption of the film. Therefore, a film having low water absorption is preferably used as the substrate. For example, a film having a water absorption of 1% or less is preferably used, a film having a water absorption of 0.1% or less is more preferably used, and a film having a water absorption of 0.01% or less is more preferably used.

As the adhesive layer 107 for bonding the substrate 101 and the substrate 102, various types of cured adhesives such as a photo-cured adhesive such as an ultraviolet-cured adhesive, a reaction-cured adhesive, a heat-cured adhesive, and an anaerobic adhesive can be used. Examples of such binders include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene-vinyl acetate) resins. In particular, a material having low moisture permeability such as epoxy resin is preferably used. In addition, a two-liquid mixed type resin may be used. In addition, an adhesive sheet or the like may be used.

A light shielding layer may be provided on the surface of the substrate 102 on the side of the adhesive layer 107. In addition, the outside of the substrate 102 may be provided with various optical members. As the optical member, a polarizing plate, a retardation plate, a light diffusion layer (diffusion film or the like), an antireflection layer, a condensing film (condensing film) and the like can be used. Further, a surface protective layer such as an antistatic film that suppresses adhesion of dust, a film having water repellency that is less likely to be stained, a hard coat film that suppresses damage during use, or a buffer layer may be disposed on the outer side of the substrate 102. For example, a glass layer or a silicon oxide layer (SiO _x layer) is provided as a surface protective layer, so that the surface can be prevented from being stained or damaged, and is preferable. Further, DLC (diamond-like carbon), alumina (AlO _x), a polyester material, a polycarbonate material, or the like may be used as the surface protective layer. In addition, a material having high transmittance to visible light is preferably used as the surface protective layer. In addition, a material having high hardness is preferably used for the surface protective layer.

[ Deformation example of display device ]

Next, a modified example of the display device 100 in which the structure of the coloring layer is changed will be described with reference to fig. 5A and 5B. Here, fig. 5A and 5B correspond to cross-sectional views along the dash-dot line X1-X2 in fig. 1A. Note that, among the components shown in fig. 5A and 5B, the same reference numerals as those of the components shown in fig. 1B are used, and the description of fig. 1B and the like is referred to.

Fig. 1B shows a structure in which the coloring layer 132 is provided in contact with the top surface of the resin layer 147, but the present invention is not limited thereto. For example, as shown in fig. 5A, the colored layers 132a, 132b, 132c may be provided in contact with the substrate 102. Here, the coloring layer 132 may be provided so as to be in contact with the substrate 102 and the adhesive layer 107. Note that in the display device shown in fig. 5A, since the resin layer 147 may not be provided over the protective layer 131, simplification of the manufacturing process of the display device can be achieved.

Fig. 5B shows a structure in which light shielding layers 108 are provided over the substrate 102, and a coloring layer 132 is provided between the light shielding layers 108. In the display device shown in fig. 5B, the substrate 102 and the substrate 101 are bonded by an adhesive layer 107. Therefore, the adhesive layer 107 contacts the protective layer 131, the light shielding layer 108, and the coloring layer 132. Further, the coloring layer 132 is preferably provided so as to overlap a part of the light shielding layer 108.

A light shielding layer 108 is provided on a surface of the substrate 102 on the substrate 101 side. By providing the light shielding layer 108, leakage of light emitted from the light emitting device 130 to adjacent sub-pixels can be suppressed. The light shielding layer 108 includes an opening at least at a position overlapping the light emitting device 130. Further, the light shielding layer 108 preferably has a region overlapping with the insulating layer 127. In other words, at least a part of the light shielding layer 108 overlaps with a region sandwiched between two adjacent light emitting devices or a region sandwiched between two adjacent EL layers. By providing the light shielding layer 108 in this manner, the light shielding layer 108 can be provided without lowering the aperture ratio.

As the light shielding layer 108, a material that shields light emission from the light emitting device can be used. The light shielding layer 108 preferably absorbs visible light. As the light shielding layer 108, for example, a metal material, a resin material containing a pigment (carbon black or the like) or a dye, or the like can be used to form a black matrix. The light shielding layer 108 may have a stacked structure in which two or more of a red color filter, a green color filter, and a blue color filter are stacked. As shown in fig. 5A, the light shielding layer 108 may not be provided.

[ Example of a method for manufacturing a display device ]

Next, an example of a method for manufacturing the display device 100 shown in fig. 1B and the like will be described with reference to fig. 7 to 9. In fig. 7A to 8C, a sectional view along the dash-dot line X1-X2 and a sectional view of Y1-Y2 in fig. 1A are shown side by side.

The thin films (insulating film, semiconductor film, conductive film, and the like) constituting the display device can be formed by a sputtering method, a CVD method, a vacuum deposition method, a PLD method, an ALD method, or the like. The CVD method includes a plasma enhanced chemical vapor deposition (PECVD: PLASMA ENHANCED CVD) method, a thermal CVD method, and the like. In addition, as one of the thermal CVD methods, there is a metal organic chemical vapor deposition (MOCVD: metal Organic CVD) method.

The thin film (insulating film, semiconductor film, conductive film, and the like) constituting the display device can be formed by spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, doctor blade (doctor knife), slit coating, roll coating, curtain coating, doctor blade coating, or the like.

In particular, when a light emitting device is manufactured, a vacuum process such as a vapor deposition method, a solution process such as a spin coating method, an inkjet method, or the like may be used. Examples of the vapor deposition method include a physical vapor deposition method (PVD method) such as a sputtering method, an ion plating method, an ion beam vapor deposition method, a molecular beam vapor deposition method, and a vacuum vapor deposition method, and a chemical vapor deposition method (CVD method). In particular, the functional layers (hole injection layer, hole transport layer, light emitting layer, electron transport layer, electron injection layer, and the like) included in the EL layer can be formed by a method such as a vapor deposition method (vacuum vapor deposition method), a coating method (dip coating method, dye coating method, bar coating method, spin coating method, spray coating method), a printing method (inkjet method, screen printing (stencil printing) method, offset printing (lithographic printing) method, flexography (relief printing) method, gravure printing method, microcontact printing method, or the like).

In addition, when a thin film constituting the display device is processed, photolithography or the like can be used. Alternatively, the thin film may be processed by nanoimprint, sandblasting, peeling, or the like. Further, the island-like thin film can be directly formed by a deposition method using a shadow mask such as a metal mask.

Photolithography typically involves two methods. One is a method of forming a resist mask on a thin film to be processed, processing the thin film by etching or the like, and removing the resist mask. Another is a method of processing a photosensitive film into a desired shape by exposing and developing the film after depositing the film.

In the photolithography, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light in which these light are mixed can be used as light for exposure. Ultraviolet rays, krF laser, arF laser, or the like may also be used. In addition, exposure may also be performed using a liquid immersion exposure technique. Furthermore, as the light for exposure, extreme Ultraviolet (EUV) light or X-ray may also be used. In addition, an electron beam may be used instead of the light for exposure. When extreme ultraviolet light, X-rays, or electron beams are used, extremely fine processing can be performed, so that it is preferable. In addition, when exposure is performed by scanning with a light beam such as an electron beam, a photomask may not be used.

In etching of the thin film, a dry etching method, a wet etching method, a sand blasting method, or the like can be used.

First, as shown in fig. 7A, an insulating layer 255b, and an insulating layer 255c are sequentially formed over the substrate 101. The insulating layers 255a, 255b, 255c can have a structure which can be used for the insulating layers 255a, 255b, 255c.

Next, as shown in fig. 7A, the pixel electrodes 111a, 111b, and 111c and the conductive layer 123 are formed over the insulating layer 255c, and a recess is formed in a region of the insulating layer 255c which does not overlap with the pixel electrodes 111a, 111b, and 111c and the conductive layer 123. The processing of the recesses of the pixel electrodes 111a, 111b, and 111c and the insulating layer 255c is preferably performed by anisotropic etching. For example, the recesses of the pixel electrodes 111a, 111b, and 111c and the insulating layer 255c may be formed by dry etching.

The pixel electrodes 111a, 111b, 111c may employ the above-described structure applicable to the pixel electrodes. The pixel electrodes 111a, 111b, and 111c can be formed by, for example, sputtering or vacuum deposition.

The step formed by the recesses of the pixel electrodes 111a, 111b, 111c and the insulating layer 255c is preferably large enough to break the EL film deposited later.

Here, an example of a method for manufacturing the pixel electrode 111 having the four-layer structure shown in fig. 3B will be described with reference to fig. 9A to 9E. Note that fig. 9A to 9E show enlarged views of the vicinity of the pixel electrode 111a, and the pixel electrodes 111b, 111c are also the same as this.

First, a conductive film 11aA, a conductive film 11bA, a conductive film 11cA, and a conductive film 11dA are sequentially deposited over the insulating layer 255c over the substrate 101 over which a semiconductor circuit is formed. Here, the conductive film 11aA is a conductive layer 11a in the subsequent step, the conductive film 11bA is a conductive layer 11b in the subsequent step, the conductive film 11cA is a conductive layer 11c in the subsequent step, and the conductive film 11dA is a conductive layer 11d in the subsequent step.

The conductive films 11aA, 11bA, 11cA, and 11dA may be deposited using the conductive materials described above that can be used for the conductive layers 11a, 11b, 11c, and 11 d. For example, titanium deposited by a sputtering method can be used for the conductive film 11aA and the conductive film 11 cA. In addition, for example, aluminum deposited by a sputtering method can be used as the conductive film 11 bA. For example, indium tin oxide containing silicon deposited by a sputtering method can be used as the conductive film 11 dA.

In addition, the conductive film 11aA, the conductive film 11bA, and the conductive film 11cA are preferably deposited continuously without being exposed to the atmosphere. Thereby, deposition is performed in a state where the conductive film 11bA is not oxidized. In addition, it is preferable to oxidize the conductive film 11cA by performing a heat treatment after depositing the conductive film 11cA. Thus, the conductive film 11cA may contain titanium oxide having high light transmittance.

Next, a resist mask 12 is formed over the conductive film 11dA (fig. 9A). As the resist mask 12, a resist material containing a photosensitive resin such as a positive resist material or a negative resist material can be used.

Next, an etching treatment is performed, and the conductive film 11dA is processed to form a conductive layer 11d (fig. 9B). When indium tin oxide containing silicon is used for the conductive film 11dA, the etching treatment is preferably performed by wet etching. For example, an organic acid containing citric acid, oxalic acid, or the like can be used. At this time, the side surface of the conductive layer 11d may be formed to be more retarded than the side surface of the resist mask 12.

Next, etching treatment is performed, and the conductive film 11cA, the conductive film 11bA, and the conductive film 11aA are processed to form a conductive layer 11C, a conductive layer 11b, and a conductive layer 11a (fig. 9C). Thereby, the pixel electrode 111a in which the conductive layers 11a to 11d are stacked can be formed. Here, the sum of the thickness of the conductive layer 11a and the thickness of the conductive layer 11B corresponds to the thickness T1a shown in fig. 3B.

Here, when etching the conductive film 11cA, the conductive film 11bA, and the conductive film 11aA, deformation of the resist mask 12 is preferably small. By doing so, the side surface of the pixel electrode 111 can be reduced from having a tapered shape. That is, the taper angle θ1 shown in fig. 3B and the like may be 60 degrees or more and 140 degrees or less, preferably 70 degrees or more and 140 degrees or less, and more preferably 80 degrees or more and 140 degrees or less.

In addition, in the etching treatment described above, it is preferable that the etching rate of the conductive film 11bA is higher than that of the conductive film 11 cA. By doing so, the side surface of the conductive layer 11c may have a shape protruding from the side surface of the conductive layer 11 b. That is, the protruding portion 109a may be formed at the conductive layer 11 c. At this time, the etching rate of the conductive film 11bA is sometimes higher than that of the conductive film 11 aA. By doing so, the side surface of the conductive layer 11a may have a shape protruding from the side surface of the conductive layer 11 b. That is, the protruding portion 109b may be formed at the conductive layer 11 a.

When titanium nitride is used for the conductive film 11cA, titanium is used for the conductive film 11aA, and aluminum is used for the conductive film 11bA, the etching treatment is preferably performed by a dry etching method. In this case, chlorine-based gas is preferably used as the etching gas. The chlorine-based gas may be a gas containing at least chlorine. For example, cl ₂、BCl₃、SiCl₄, CCl ₄, or the like may be used as the chlorine-based gas, alone or in combination of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, or the like may be added to the chlorine-based gas as appropriate, singly or in combination of two or more kinds of gases.

As the dry etching apparatus, a dry etching apparatus having a high-density plasma source may be used. For example, as a dry etching apparatus having a high-density plasma source, an inductively coupled plasma (ICP: inductively Coupled Plasma) etching apparatus or the like can be used. Alternatively, a capacitively coupled plasma (CCP: CAPACITIVELY COUPLED PLASMA) etching apparatus including parallel plate electrodes may be used. The capacitive coupling type plasma etching apparatus including parallel plate electrodes may be configured to apply a high-frequency voltage to one of the parallel plate electrodes. Alternatively, a plurality of different high-frequency voltages may be applied to one of the parallel plate electrodes. Alternatively, the parallel plate electrodes may be applied with a high-frequency voltage having the same frequency. Alternatively, a configuration may be adopted in which high-frequency voltages having different frequencies are applied to the parallel plate electrodes.

Next, etching is performed to remove the vicinity of the surface of the insulating layer 255c in the region not overlapping with the pixel electrode 111a, and a recess having a depth T2 is formed in the insulating layer 255c (fig. 9D). Here, in the etching treatment, considering the thickness T1a and the thickness T3 of the fourth layer 113d to be formed later, it is preferable to form the concave portion having the depth T2 so as to satisfy t1a+t2+.t3.

In the above etching process, the etching rate of the insulating layer 255c is preferably higher than the etching rate of at least a portion of the pixel electrode 111 a. For example, when silicon oxide or silicon oxynitride is used for the insulating layer 255c, the etching treatment is preferably performed by a dry etching method using a fluorine-based gas. Here, CF₄、SF₆、NF₃、CHF₃、C₄F₆、C₅F₆、C₄F₈, C ₅F₈, and the like may be used as the fluorine-based gas, either alone or as a mixture of two or more gases. In addition, oxygen gas, hydrogen gas, helium gas, argon gas, or the like may be added to the chlorine-based gas and fluorine-based gas as appropriate, singly or in combination of two or more kinds of gases.

Further, by performing the etching treatment in this manner, the case where the side surface of the recess portion of the insulating layer 255c has a tapered shape can be reduced. That is, the taper angle θ2 shown in fig. 3B may be 60 degrees or more and 140 degrees or less, preferably 70 degrees or more and 140 degrees or less, and more preferably 80 degrees or more and 140 degrees or less.

In the case where the insulating layer 255b is used as a protective film for the etching treatment, the etching treatment may be performed until the insulating layer 255b is exposed through the insulating layer 255 c.

Thus, the pixel electrode 111a and the insulating layer 255c having sufficiently large steps can be formed.

Note that in the above, before forming the concave portion of the insulating layer 255c shown in fig. 9D, isotropic etching may be performed to further recede the side surface of the conductive layer 11b (fig. 10A). By making the side surface of the conductive layer 11B more recede, the pixel electrode 111 having the shape shown in fig. 4B can be formed.

Further, the isotropic etching may be performed by introducing an etching gas into the chamber without applying a bias by using the above-described dry etching apparatus. When titanium nitride is used for the conductive film 11cA, titanium is used for the conductive film 11aA, and aluminum is used for the conductive film 11bA, a chlorine-based gas is preferably used as the etching gas. The chlorine-based gas may be a gas containing at least chlorine. For example, cl ₂、BCl₃、SiCl₄, CCl ₄, or the like may be used as the chlorine-based gas, alone or in combination of two or more gases.

The etching is performed under the above conditions, whereby the conductive layer 11b can be isotropically etched in the case where the etching rate of the conductive layer 11b is higher than the etching rate of the conductive layer 11 c. Thus, the distance between the side surface of the conductive layer 11b and the side surface of the conductive layer 11c can be increased, and the protruding portion 109a can be relatively increased. Therefore, in the deposition of an EL film to be described later, the EL film can be easily divided in a self-aligned manner.

At this time, the etching rate of the conductive layer 11b is sometimes greater than that of the conductive layer 11 a. As a result, the distance between the side surface of the conductive layer 11b and the side surface of the conductive layer 11a may be increased, and the protruding portion 109b may be relatively increased.

Next, the resist mask 12 is removed (fig. 9E). For example, the resist mask 12 may be removed by ashing or the like using oxygen plasma. Alternatively, an oxygen gas and a noble gas (also referred to as a rare gas) such as CF ₄、C₄F₈、SF₆、CHF₃、Cl₂、H₂O、BCl₃ or He may be used. Alternatively, the resist mask 12 may be removed by wet etching. Alternatively, the resist mask 12 may be removed by a combination of ashing and wet etching as described above.

Further, the pixel electrodes 111a, 111b, and 111c are preferably subjected to a hydrophobization treatment. In the hydrophobizing treatment, the surface state of the treatment object may be changed from hydrophilic to hydrophobic or the hydrophobicity of the surface of the treatment object may be increased. By performing the hydrophobization treatment of the pixel electrode, adhesion between the pixel electrode and the first layer 113a, the second layer 113b, and the third layer 113c formed in a later process can be improved, and thus film peeling can be suppressed. Note that the hydrophobizing treatment may not be performed.

The hydrophobization treatment can be performed by, for example, fluorine modification of the pixel electrode. The fluorine modification can be performed by, for example, a treatment with a fluorine-containing gas, a heat treatment, a plasma treatment in a fluorine-containing gas atmosphere, or the like. As the fluorine-containing gas, for example, a fluorine gas, for example, a fluorocarbon gas can be used. As the fluorocarbon gas, for example, a lower fluorocarbon gas such as carbon tetrafluoride (CF ₄) gas, C ₄F₆ gas, C ₂F₆ gas, C ₄F₈ gas, C ₅F₈ gas, or the like can be used. Examples of the fluorine-containing gas include SF ₆ gas, NF ₃ gas, and CHF ₃ gas. Helium gas, argon gas, hydrogen gas, or the like may be added to these gases as appropriate.

The surface of the pixel electrode may be hydrophobized by performing plasma treatment under a gas atmosphere containing an element of group 18 such as argon, and then performing treatment with a silylation agent. As the silylating agent, hexamethyldisilazane (HMDS), trimethylsilazole (TMSI), and the like can be used. The surface of the pixel electrode may be subjected to plasma treatment under a gas atmosphere containing an element of group 18 such as argon, and then treated with a silane coupling agent to hydrophobize the surface of the pixel electrode.

The surface of the pixel electrode is subjected to plasma treatment in a gas atmosphere containing an element of group 18 such as argon, whereby the surface of the pixel electrode can be damaged. Thus, methyl groups in the silylation agent such as HMDS are easily bonded to the surface of the pixel electrode. In addition, silane coupling by a silane coupling agent is liable to occur. In this way, the surface of the pixel electrode may be hydrophobized by performing plasma treatment under a gas atmosphere containing an 18 th group element such as argon, and then performing treatment with a silylation agent or a silane coupling agent.

The treatment with the silylation agent, the silane coupling agent, or the like may be performed by, for example, coating the silylation agent, the silane coupling agent, or the like by spin coating, dipping, or the like. The treatment with the silylation agent, the silane coupling agent, or the like may be performed by, for example, forming a film containing the silylation agent, a film containing the silane coupling agent, or the like on the pixel electrode, or the like, using a gas phase method. In the gas phase method, first, a material containing a silylation agent, a material containing a silane coupling agent, or the like is volatilized to contain the silylation agent, the silane coupling agent, or the like in an atmosphere. Next, the substrate over which the pixel electrode or the like is formed is placed in the atmosphere. Thus, a film having a silylation agent, a silane coupling agent, or the like can be formed on the pixel electrode, whereby the surface of the pixel electrode can be hydrophobized.

Next, an EL film is deposited on the pixel electrodes 111a, 111b, 111 c. Here, the steps formed by the pixel electrodes 111a, 111b, and 111c and the insulating layer 255c are sufficiently large as described above, and thus the EL film is divided in a self-aligned manner at the end portions of the pixel electrodes. That is, as shown in fig. 7B, a first layer 113a is formed over the pixel electrode 111a, a second layer 113B is formed over the pixel electrode 111B, a third layer 113c is formed over the pixel electrode 111c, and a fourth layer 113d is formed in a recess between adjacent pixel electrodes 111.

The EL film is to be formed into a first layer 113a, a second layer 113b, a third layer 113c, and a fourth layer 113 d. Accordingly, the above-described structure that can be used for the first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d can be employed. The EL film can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method. The EL film is preferably formed by vapor deposition. Premix materials may also be used in deposition by vapor deposition. Note that in this specification and the like, a premix refers to a composite material in which a plurality of materials are formulated or mixed in advance.

Further, as shown in fig. 7B, in a sectional view along Y1-Y2, an end portion of the fourth layer 113d is located on the display portion side of the connection portion 140. In other words, the conductive layer 123 in the connection portion 140 is not formed with the EL film including the fourth layer 113 d. For example, by using a mask for defining a deposition region (also referred to as a region mask or a coarse metal mask or the like for distinction from a high-definition metal mask), a region where the fourth layer 113d is deposited can be changed. By combining with the area mask as described above, a light emitting device can be manufactured in a simpler process.

Next, as shown in fig. 7C, an insulating film 125A is formed so as to cover the first layer 113a, the second layer 113b, the third layer 113C, and the fourth layer 113 d.

The insulating film 125A is a film to be the insulating layer 125 later. Accordingly, a material that can be used for the insulating layer 125 can be used for the insulating film 125. The insulating film 125A can be formed by an ALD method, a vapor deposition method, a sputtering method, a CVD method, or a PLD method, for example. The thickness of the insulating film 125A is preferably 3nm or more, 5nm or more, or 10nm or more and 200nm or less, 150nm or less, 100nm or less, or 50nm or less.

As the insulating film 125A, for example, an aluminum oxide film is preferably formed by an ALD method. The ALD method is preferable because deposition damage can be reduced and a film having high coverage can be deposited.

As described later, the insulating layer 127A including a photosensitive organic resin is formed so as to be in contact with the top surface of the insulating film 125A. Therefore, the top surface of the insulating film 125A preferably has high affinity with a photosensitive organic resin (for example, a photosensitive resin composition including an acrylic resin) used for the insulating layer 127A. In order to improve the affinity, it is preferable to perform a surface treatment to hydrophobize (or improve the hydrophobicity of) the top surface of the insulating film 125A. For example, it is preferable to use a silylating agent such as Hexamethyldisilazane (HMDS). By hydrophobizing the top surface of the insulating film 125A in this manner, the insulating layer 127A can be formed with good adhesion. The surface treatment may be performed by the above-mentioned hydrophobization treatment.

Next, as shown in fig. 7C, an insulating layer 127A is coated on the insulating film 125A.

The insulating layer 127A is a film to be the insulating layer 127 in a later process, and the insulating layer 127A can be made of the above-described organic material. As the organic material, a photosensitive organic resin is preferably used, and for example, a photosensitive resin composition containing an acrylic resin can be used. The viscosity of the insulating layer 127A may be 1cP to 1500cP, and preferably 1cP to 12 cP. By setting the viscosity of the insulating layer 127A to be within the above range, the insulating layer 127 having a tapered shape as shown in fig. 1B can be formed relatively easily.

For example, the insulating layer 127A is preferably formed using a resin composition containing a polymer, an acid generator, and a solvent. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also referred to as constituent units) are repeated regularly or irregularly. As the acid generator, one or both of a compound that generates an acid by irradiation with light and a compound that generates an acid by heating may be used. The resin composition may further comprise one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion promoter, a surfactant, and an antioxidant.

The method for forming the insulating layer 127A is not particularly limited, and may be formed by a wet deposition method such as a spin coating method, a dipping method, a spraying method, an inkjet method, a dispenser method, a screen printing method, an offset printing method, a doctor blade (doctor knife) method, a slit coating method, a roll coating method, a curtain coating method, or a doctor blade coating method. In particular, the organic insulating film to be the insulating layer 127A is preferably formed by spin coating.

Further, it is preferable to perform a heat treatment after the insulating layer 127A is applied. The heating treatment is formed at a temperature lower than the heat-resistant temperature of the EL layer. The substrate temperature during the heat treatment may be 50 ℃ or more and 200 ℃ or less, preferably 60 ℃ or more and 150 ℃ or less, and more preferably 70 ℃ or more and 120 ℃ or less. Thereby, the solvent in the insulating layer 127A can be removed.

Next, exposure is performed to expose a portion of the insulating layer 127A to visible light or ultraviolet light. Then, as shown in fig. 8A, the exposed region of the insulating layer 127A is removed by development, so that the insulating layer 127 is formed.

Here, by providing an insulating layer (for example, an aluminum oxide film) having a barrier property against oxygen as the insulating film 125A, diffusion of oxygen into the EL layer can be reduced. In particular, when the EL layer is irradiated with light (visible light or ultraviolet light), the organic compound contained in the EL layer may be in an excited state, and thus, the reaction with oxygen in the atmosphere may be promoted. More specifically, when light (visible light or ultraviolet light) is irradiated to the EL layer under an atmosphere containing oxygen, oxygen is likely to bond to an organic compound contained in the EL layer. By providing the insulating film 125A over the EL layer, oxygen in the atmosphere can be reduced from bonding to an organic compound contained in the EL layer.

When an acrylic resin is used for the insulating layer 127A, an alkali solution is preferably used as the developer, and for example, an aqueous solution of tetramethylammonium hydroxide (TMAH) may be used. Further, after development, visible rays or ultraviolet rays may be irradiated. By performing such exposure, transparency of the insulating layer 127 can sometimes be improved.

Further, the heat treatment may be performed after the development. As shown in fig. 8A, by performing this heat treatment, the insulating layer 127 can have a tapered shape on its side surface. Further, by performing this heat treatment, polymerization can be started in the insulating layer 127, and the insulating layer 127 can be cured. The heating treatment is formed at a temperature lower than the heat-resistant temperature of the EL layer. The substrate temperature during the heat treatment may be 50 ℃ or more and 200 ℃ or less, preferably 60 ℃ or more and 150 ℃ or less, and more preferably 70 ℃ or more and 130 ℃ or less. In the heating treatment in this step, the substrate temperature is preferably higher than that in the heating treatment after the insulating layer 127 is applied. Thereby, the adhesion of the insulating layer 127 to the insulating film 125A can be improved, and the corrosion resistance of the insulating layer 127 can be improved.

Further, the insulating layer 127 may be processed into a tapered shape and then subjected to a heat treatment. In addition, etching may be performed so as to adjust the surface height of the insulating layer 127. The insulating layer 127 can be processed by ashing using oxygen plasma, for example.

Note that the process of depositing the insulating layer 127A to provide the insulating layer 127 is shown above, but the present invention is not limited thereto. The insulating layer 127A may not be deposited and the insulating layer 127 may not be provided.

Next, as shown in fig. 8A, at least a portion of the insulating film 125A is removed, so that the first layer 113a, the second layer 113b, the third layer 113c, and the conductive layer 123 are exposed.

As shown in fig. 8A, a region overlapping with the insulating layer 127 in the insulating film 125A remains as the insulating layer 125.

The insulating layer 125 (and the insulating layer 127) is provided so as to cover part of the side surfaces and the top surface of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113 c. Thus, the film to be formed later can be suppressed from contacting the side surface of the above layer, and the short circuit of the light emitting device can be suppressed. In addition, damage to the first layer 113a, the second layer 113b, and the third layer 113c in a later process can be suppressed.

The insulating film 125A can be formed by wet etching or dry etching.

By using the wet etching method, damage to the EL layer when the insulating film 125A is processed can be reduced as compared with the case of using the dry etching method. In the case of wet etching, for example, a developer, an aqueous solution of tetramethylammonium hydroxide (TMAH), a chemical solution of dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof is preferably used.

In addition, in the case of using the dry etching method, deterioration of the EL layer can be suppressed by not using a gas containing oxygen as an etching gas. In the case of using the dry etching method, for example, a gas containing a noble gas (also referred to as a rare gas) such as CF ₄、C₄F₈、SF₆、CHF₃、Cl₂、H₂O、BCl₃ or He is preferably used as the etching gas.

For example, when an aluminum oxide film formed by an ALD method is used as the insulating film 125A, the insulating film 125A can be processed by a dry etching method using CHF ₃ and He.

Next, as shown in fig. 8B, the common layer 114 is formed so as to cover the insulating layer 125, the insulating layer 127, the first layer 113a, the second layer 113B, and the third layer 113 c.

The cross-sectional view between Y1 and Y2 shown in fig. 8B shows an example in which the common layer 114 is not provided in the connection portion 140. As shown in fig. 8B, an end portion of the common layer 114 on the connection portion 140 side is preferably located inside the connection portion 140. For example, in depositing the common layer 114, a mask (also referred to as a region mask or a rough metal mask or the like) for defining a deposition region is preferably used.

In addition, the common layer 114 may be provided in the connection portion 140 according to the height of the conductivity of the common layer 114. By adopting such a structure, the connection portion 140 of the structure in which the conductive layer 123 and the common electrode 115 are electrically connected through the common layer 114 shown in fig. 6A can be formed.

The materials that can be used for the common layer 114 are as described above. The common layer 114 may be formed by a method such as an evaporation method (including a vacuum evaporation method), a transfer method, a printing method, an inkjet method, or a coating method. In addition, the common layer 114 may also be formed using a premix material.

The common layer 114 is provided so as to cover the top surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, and the top surface and the side surface of the insulating layer 127. Here, when the conductivity of the common layer 114 is high, the side surface of any one of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c may contact the common layer 114, and thus the light emitting device may be short-circuited. However, in the display device according to one embodiment of the present invention, the insulating layers 125 and 127 cover the side surfaces of the first layer 113a, the second layer 113b, the third layer 113c, the pixel electrode 111a, the pixel electrode 111b, and the pixel electrode 111c, respectively. Thus, the common layer 114 having a high conductivity type can be suppressed from being in contact with the side surfaces of these layers, and thus a short circuit of the light emitting device can be suppressed. Thereby, the reliability of the light emitting device can be improved.

Further, since the insulating layers 125 and 127 are filled between the first layer 113a and the second layer 113b and between the second layer 113b and the third layer 113c, the step of the formed surface of the common layer 114 is smaller and flattened than in the case where the insulating layers 125 and 127 are not provided. Thereby, the coverage of the common layer 114 can be improved.

As shown in fig. 8C, the common electrode 115 is formed on the common layer 114 and on the conductive layer 123. Thereby, the conductive layer 123 is in direct contact with the common electrode 115 to be electrically connected. By adopting such a structure, the connection portion 140 of the structure in which the top surface of the conductive layer 123 is in contact with the common electrode 115 shown in fig. 6B can be formed.

In depositing the common electrode 115, a mask (also referred to as a region mask, a coarse metal mask, or the like) for defining a deposition region may also be used. Alternatively, the common electrode 115 may be processed using a resist mask or the like after the common electrode 115 is deposited without using the mask when the common electrode 115 is deposited.

The material that can be used as the common electrode 115 is as described above. The common electrode 115 may be formed by, for example, a sputtering method or a vacuum evaporation method. Alternatively, a film formed by vapor deposition and a film formed by sputtering may be stacked.

Next, as shown in fig. 8C, a protective layer 131 is formed on the common electrode 115. Materials and deposition methods that can be used for the protective layer 131 are as described above. Examples of the deposition method of the protective layer 131 include a vacuum deposition method, a sputtering method, a CVD method, and an ALD method. The protective layer 131 may have a single-layer structure or a stacked-layer structure.

Then, a resin layer 147 is formed on the protective layer 131, and a coloring layer 132 is formed on the resin layer 147. Further, by bonding the substrate 102 to the coloring layer 132 using the adhesive layer 107, the display device 100 shown in fig. 1B can be manufactured. In addition, in the process shown in fig. 10A, the display device 100 shown in fig. 10B having a shape in which the side surface of the pixel electrode 111 is retreated can be manufactured.

Further, when the insulating layer 127 is not formed, the display device 100 shown in fig. 6C can be manufactured. Further, in the process shown in fig. 10A, the display device 100 shown in fig. 10C having a shape in which the side surface of the pixel electrode 111 is retreated can be manufactured.

Thereby, the display device 100 described above can be manufactured.

This embodiment mode can be combined with other embodiment modes as appropriate.

(Embodiment 2)

In this embodiment mode, a display device according to an embodiment of the present invention will be described with reference to fig. 11 to 13.

[ Layout of pixels ]

In this embodiment, a pixel layout different from that of fig. 1A will be mainly described. The arrangement of the sub-pixels is not particularly limited, and various methods may be employed. Examples of the arrangement of the subpixels include stripe arrangement, S-stripe arrangement, matrix arrangement, delta arrangement, bayer arrangement, penTile arrangement, and the like.

Examples of the top surface shape of the sub-pixel include a polygon such as a triangle, a quadrangle (including a rectangle and a square), a pentagon, and the like, and a shape in which corners of the polygon are rounded, an ellipse, a circle, and the like. Here, the top surface shape of the sub-pixel corresponds to the top surface shape of the light emitting region of the light emitting device.

The circuit layout of the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and may be disposed outside the sub-pixels.

The pixel 110 shown in fig. 11A adopts an S stripe arrangement. The pixel 110 shown in fig. 11A is composed of three sub-pixels of sub-pixels 110a, 110b, 110 c. For example, as shown in fig. 13A, the sub-pixel 110a may be a blue sub-pixel B, the sub-pixel 110B may be a red sub-pixel R, and the sub-pixel 110c may be a green sub-pixel G.

The pixel 110 shown in fig. 11B includes a sub-pixel 110a having a top surface shape of an approximately trapezoid with rounded corners, a sub-pixel 110B having a top surface shape of an approximately triangle with rounded corners, and a sub-pixel 110c having a top surface shape of an approximately quadrangle or an approximately hexagon with rounded corners. Further, the light emitting area of the sub-pixel 110a is larger than that of the sub-pixel 110 b. Thus, the shape and size of each sub-pixel can be independently determined. For example, a sub-pixel including a light emitting device with higher reliability may be made smaller in size. For example, as shown in fig. 13B, the sub-pixel 110a may be a green sub-pixel G, the sub-pixel 110B may be a red sub-pixel R, and the sub-pixel 110c may be a blue sub-pixel B.

The pixels 124a, 124b shown in fig. 11C are arranged in PenTile. Fig. 11C shows an example in which the pixel 124a including the sub-pixel 110a and the sub-pixel 110b and the pixel 124b including the sub-pixel 110b and the sub-pixel 110C are alternately arranged. For example, as shown in fig. 13C, the sub-pixel 110a may be a red sub-pixel R, the sub-pixel 110B may be a green sub-pixel G, and the sub-pixel 110C may be a blue sub-pixel B.

The pixels 124a, 124b shown in fig. 11D to 11F adopt a delta arrangement. Pixel 124a includes two sub-pixels (sub-pixels 110a, 110 b) in the upstream (first row) and one sub-pixel (sub-pixel 110 c) in the downstream (second row). Pixel 124b includes one subpixel (subpixel 110 c) in the upstream line (first line) and two subpixels (subpixels 110a, 110 b) in the downstream line (second line). For example, as shown in fig. 13D, the sub-pixel 110a may be a red sub-pixel R, the sub-pixel 110B may be a green sub-pixel G, and the sub-pixel 110c may be a blue sub-pixel B.

Fig. 11D shows an example in which each sub-pixel has an approximately quadrangular top surface shape with rounded corners, fig. 11E shows an example in which each sub-pixel has a circular top surface shape, and fig. 11F shows an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

In fig. 11F, the subpixels are arranged inside the hexagonal areas that are most closely arranged. Each of the sub-pixels is arranged so as to be surrounded by six sub-pixels when focusing on one of the sub-pixels. Further, the subpixels that present the same color light are disposed in such a manner as not to be adjacent. For example, each of the sub-pixels is provided so that three sub-pixels 110b and three sub-pixels 110c alternately arranged when focusing on the sub-pixel 110a surround the sub-pixel 110 a.

Fig. 11G shows an example in which subpixels of respective colors are arranged in a zigzag shape. Specifically, in a plan view, the positions of the upper sides of two sub-pixels (for example, sub-pixel 110a and sub-pixel 110b or sub-pixel 110b and sub-pixel 110 c) arranged in the column direction are not uniform. For example, as shown in fig. 13E, the sub-pixel 110a may be a red sub-pixel R, the sub-pixel 110B may be a green sub-pixel G, and the sub-pixel 110c may be a blue sub-pixel B.

Since the effect of diffraction of light cannot be ignored as the processed pattern becomes finer, it is difficult to process the resist mask into a desired shape by losing reproducibility when transferring the pattern of the photomask by exposure. Therefore, even if the pattern of the photomask is rectangular, a pattern having a circular corner is easily formed. Therefore, the top surface of the pixel electrode may have a rounded shape, an elliptical shape, or a circular shape at the corners of the polygon. In the display device according to one embodiment of the present invention, the top surface shape of the EL layer, even the top surface shape of the light-emitting device, may be affected by the top surface shape of the pixel electrode to have a polygonal shape with rounded corners, an elliptical shape, a circular shape, or the like.

Note that, in order to make the top surface shape of the pixel electrode a desired shape, a technique of correcting the mask pattern in advance (OPC (Optical Proximity Correction: optical proximity correction) technique) may be used so that the design pattern coincides with the transfer pattern. Specifically, in the OPC technique, a pattern for correction is added to a pattern corner or the like on a mask pattern.

Note that, in the pixel 110 in stripe arrangement shown in fig. 1A, for example, as shown in fig. 13F, the sub-pixel 110a may be a red sub-pixel R, the sub-pixel 110B may be a green sub-pixel G, and the sub-pixel 110c may be a blue sub-pixel B.

As shown in fig. 12A to 12I, the pixel may include four sub-pixels.

The pixels 110 shown in fig. 12A to 12C adopt a stripe arrangement.

Fig. 12A shows an example in which each sub-pixel has a rectangular top surface shape, fig. 12B shows an example in which each sub-pixel has a top surface shape in which two semicircles are connected to a rectangle, and fig. 12C shows an example in which each sub-pixel has an elliptical top surface shape.

The pixels 110 shown in fig. 12D to 12F are arranged in a matrix.

Fig. 12D shows an example in which each sub-pixel has a square top surface shape, fig. 12E shows an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and fig. 12F shows an example in which each sub-pixel has a circular top surface shape.

Fig. 12G and 12H show an example in which one pixel 110 is formed in two rows and three columns.

The pixel 110 shown in fig. 12G includes three sub-pixels (sub-pixels 110a, 110b, 110 c) in an upper line (first line) and one sub-pixel (sub-pixel 110 d) in a lower line (second line). In other words, the pixel 110 includes the sub-pixel 110a in the left column (first column), the sub-pixel 110b in the center column (second column), the sub-pixel 110c in the right column (third column), and the sub-pixel 110d across the three columns.

The pixel 110 shown in fig. 12H includes three sub-pixels (sub-pixels 110a, 110b, 110 c) in an upper line (first line) and three sub-pixels 110d in a lower line (second line). In other words, the pixel 110 includes the sub-pixel 110a and the sub-pixel 110d in the left column (first column), the sub-pixel 110b and the sub-pixel 110d in the center column (second column), and the sub-pixel 110c and the sub-pixel 110d in the right column (third column). As shown in fig. 12H, by matching the arrangement of the upper and lower sub-pixels, dust and the like generated in the manufacturing process can be efficiently removed. Thus, a display device with high display quality can be provided.

Fig. 12I shows an example in which one pixel 110 is configured in three rows and two columns.

The pixel 110 shown in fig. 12I includes a sub-pixel 110a in the upper row (first row), a sub-pixel 110b in the middle row (second row), a sub-pixel 110c crossing the first row to the second row, and a sub-pixel (sub-pixel 110 d) in the lower row (third row). In other words, the pixel 110 includes the sub-pixels 110a, 110b in the left column (first column), the sub-pixel 110c in the right column (second column), and the sub-pixel 110d crossing both columns.

The pixel 110 shown in fig. 12A to 12I is composed of four sub-pixels of sub-pixels 110a, 110b, 110c, 110 d. The sub-pixels 110a, 110b, 110c, 110d are sub-pixels that respectively emit light of different colors. The sub-pixels 110a, 110b, 110c, and 110d include: r, G, B, four color subpixels of white (W); r, G, B, Y sub-pixels of four colors; or R, G, B, infrared (IR) subpixels; etc.

For example, as shown in fig. 13G to 13K, the subpixel 110a may be a subpixel R that emits red light, the subpixel 110B may be a subpixel G that emits green light, the subpixel 110c may be a subpixel B that emits blue light, and the subpixel 110d may be a subpixel W that emits white light. In this case, the light emitting device 130 and the coloring layer 132 may be provided in the sub-pixels 110a, 110B, and 110c in the same manner as in the configuration shown in fig. 1B and the like. In contrast, in the sub-pixel 110d, the light emitting device 130 is similarly provided, but the coloring layer 132 is not provided. Thereby, white light of the light emitting device 130 is directly emitted from the sub-pixel 110 d. The subpixel 110d may be a subpixel Y that emits yellow light or a subpixel IR that emits near-infrared light. In the case of adopting the above configuration, the layout of R, G, B is arranged in stripes in the pixel 110 shown in fig. 13I and 13J, so that the display quality can be improved. In addition, in the pixel 110 shown in fig. 13K, the layout of R, G, B is so-called S-stripe arrangement, so that the display quality can be improved. Note that the sub-pixels are not limited to four, but may be five or more.

As described above, in the display device according to one embodiment of the present invention, various layouts can be adopted for pixels composed of sub-pixels including light emitting devices.

Embodiment 3

In this embodiment mode, a display device according to an embodiment of the present invention will be described with reference to fig. 14 to 29. The display device of this embodiment uses a part or all of the structure of the display device shown in the above embodiment, and the same reference numerals are used for the same structure as the structure of the display device shown in the above embodiment. In the configuration using the same reference numerals, the description of the above embodiments can be referred to.

The display device of the present embodiment may be a high-definition display device. Therefore, the display device according to the present embodiment can be used as, for example, a display portion of an information terminal device (wearable device) such as a wristwatch type or a bracelet type, and a display portion of a wearable device such as a VR device such as a head mount display or an AR device such as a glasses type.

The display device according to the present embodiment may be a high-resolution display device or a large-sized display device. Therefore, for example, the display device of the present embodiment can be used as a display portion of: electronic devices having a large screen such as a television set, a desktop or notebook type personal computer, a display for a computer or the like, a digital signage, a large-sized game machine such as a pachinko machine, and the like; a digital camera; a digital video camera; a digital photo frame; a mobile telephone; a portable game machine; a portable information terminal; and a sound reproducing device.

In the display device of the present embodiment, since the EL layers in the light emitting devices are separated, the occurrence of crosstalk between adjacent sub-pixels can be suppressed even in a high-definition display device. Therefore, a display device with high definition and high display quality can be realized.

[ Display Module ]

Fig. 14A shows a perspective view of the display module 280. The display module 280 includes the display device 100A and the FPC290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any one of the display devices 100B to 100F which will be described later.

The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display portion 281. The display portion 281 is an image display area in the display module 280, and can see light from each pixel provided in a pixel portion 284 described below.

Fig. 14B shows a schematic perspective view of the structure on the side of the substrate 291. The circuit portion 282, the pixel circuit portion 283 on the circuit portion 282, and the pixel portion 284 on the pixel circuit portion 283 are stacked over the substrate 291. Further, a terminal portion 285 for connection to the FPC290 is provided over a portion of the substrate 291 which does not overlap with the pixel portion 284. The terminal portion 285 is electrically connected to the circuit portion 282 through a wiring portion 286 composed of a plurality of wirings.

The pixel portion 284 includes a plurality of pixels 284a arranged periodically. The right side of fig. 14B shows an enlarged view of one pixel 284a. The pixel 284a includes a red-emitting subpixel 110R, a green-emitting subpixel 110G, and a blue-emitting subpixel 110B. Here, the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B correspond to any one of the sub-pixel 110a, the sub-pixel 110B, and the sub-pixel 110c shown in fig. 1B, and the like, respectively.

The pixel circuit portion 283 includes a plurality of pixel circuits 283a arranged periodically.

One pixel circuit 283a controls light emission of three light emitting devices included in one pixel 284 a. One pixel circuit 283a may be constituted by three circuits that control light emission of one light emitting device. For example, the pixel circuit 283a may have a structure including at least one selection transistor, one transistor for current control (driving transistor), and a capacitor for one light emitting device. At this time, the gate of the selection transistor is inputted with a gate signal, and the source is inputted with a source signal. Thus, an active matrix display device is realized.

The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, one or both of the gate line driver circuit and the source line driver circuit are preferably included. Further, at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like may be provided.

The FPC290 serves as a wiring for supplying video signals, power supply potentials, or the like from the outside to the circuit portion 282. Further, an IC may be mounted on the FPC 290.

The display module 280 may have a structure in which one or both of the pixel circuit portion 283 and the circuit portion 282 are laminated under the pixel portion 284, and thus the display portion 281 can have a very high aperture ratio (effective display area ratio). For example, the aperture ratio of the display portion 281 may 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. Further, the pixels 284a can be arranged at an extremely high density, whereby the display portion 281 can have extremely high definition. For example, the display portion 281 preferably configures the pixel 284a with a definition of 2000ppi or more, more preferably 3000ppi or more, still more preferably 5000ppi or more, still more preferably 6000ppi or more and 20000ppi or less or 30000ppi or less.

The display module 280 is very clear and therefore is suitable for VR devices such as head-mounted displays and glasses-type AR devices. For example, since the display module 280 has the display portion 281 having extremely high definition, in a structure in which the display portion of the display module 280 is viewed through a lens, the user cannot see the pixels even if the display portion is enlarged by the lens, whereby display having high immersion can be achieved. In addition, the display module 280 may be applied to an electronic device having a relatively small display part. For example, the display unit is suitable for a wearable electronic device such as a wristwatch type device.

[ Display device 100A ]

The display device 100A shown in fig. 15 includes a substrate 301, light-emitting devices 130R, 130G, 130B, coloring layers 132a, 132B, 132c, a capacitor 240, and a transistor 310. The sub-pixel 110R shown in fig. 14B includes a light emitting device 130R and a coloring layer 132a transmitting red light. In addition, the sub-pixel 110G shown in fig. 14B includes a light emitting device 130G and a coloring layer 132B transmitting green light. In addition, the sub-pixel 110B shown in fig. 14B includes a light emitting device 130B and a coloring layer 132c transmitting blue light.

The substrate 301 corresponds to the substrate 291 in fig. 14A and 14B. The stacked structure of the substrate 301 to the insulating layer 255a corresponds to the substrate 101 having a transistor in embodiment mode 1.

The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, a semiconductor substrate such as a single crystal silicon substrate can be used, for example. Transistor 310 includes a portion of substrate 301, conductive layer 311, low resistance region 312, insulating layer 313, and insulating layer 314. The conductive layer 311 is used as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311, and is used as a gate insulating layer. The low-resistance region 312 is a region doped with impurities in the substrate 301, and is used as one of a source and a drain. The insulating layer 314 is provided so as to cover the side surface of the conductive layer 311, and is used as an insulating layer.

Further, between the adjacent two transistors 310, an element separation layer 315 is provided so as to be embedded in the substrate 301.

Further, an insulating layer 261 is provided so as to cover the transistor 310, and the capacitor 240 is provided over the insulating layer 261.

The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 therebetween. The conductive layer 241 serves as one electrode of the capacitor 240, the conductive layer 245 serves as the other electrode of the capacitor 240, and the insulating layer 243 serves as a dielectric of the capacitor 240.

The conductive layer 241 is disposed on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of a source and a drain of the transistor 310 through a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided so as to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

The cover capacitor 240 is provided with an insulating layer 255a, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255 b.

As the insulating layer 255a, the insulating layer 255b, and the insulating layer 255c, various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and an oxynitride insulating film can be used as appropriate. As the insulating layer 255a and the insulating layer 255c, an oxide insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film, or an oxynitride insulating film is preferably used. As the insulating layer 255b, a nitride insulating film such as a silicon nitride film or a silicon oxynitride film or an oxynitride insulating film is preferably used. More specifically, a silicon oxide film is preferably used for the insulating layers 255a and 255c, and a silicon nitride film is preferably used for the insulating layer 255 b. The insulating layer 255b is preferably used as an etching protective film. In this embodiment, an example in which a concave portion is provided in the insulating layer 255c is shown, but the concave portion may not be provided in the insulating layer 255 c.

The light emitting device 130R, the light emitting device 130G, and the light emitting device 130B are provided over the insulating layer 255 c. Fig. 15 shows an example in which light emitting device 130R, light emitting device 130G, and light emitting device 130B have a stacked structure shown in fig. 1B.

Since the first layer 113a, the second layer 113b, and the third layer 113c are separated and spaced apart from each other in the display device 100A, generation of crosstalk between adjacent sub-pixels can be suppressed even in a high-definition display device. Therefore, a display device with high definition and high display quality can be realized.

The region between adjacent light emitting devices is provided with a fourth layer 113d and an insulator. In fig. 15 and the like, the fourth layer 113d, the insulating layer 125 over the fourth layer 113d, and the insulating layer 127 over the insulating layer 125 are provided in this region.

The pixel electrode 111a, the pixel electrode 111b, and the pixel electrode 111c of the light emitting device are electrically connected to one of the source and the drain of the transistor 310 through the plug 256 embedded in the insulating layer 255a, the insulating layer 255b, and the insulating layer 255c, the conductive layer 241 embedded in the insulating layer 254, and the plug 271 embedded in the insulating layer 261. The top surface of insulating layer 255c has a height that is identical or substantially identical to the height of the top surface of plug 256. Various conductive materials may be used for the plug.

Here, as in the pixel electrode 111 shown in fig. 1B and the like, it is preferable that the recesses provided in the pixel electrode 111a, the pixel electrode 111B, and the pixel electrode 111c by the pixel electrode and the insulating layer 255c have sufficiently large steps. By adopting the above structure, the first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d can be divided in a self-aligned manner when the EL film is deposited.

Further, a protective layer 131 is provided over the light emitting devices 130R, 130G, and 130B. The protective layer 131 is provided with a resin layer 147, a coloring layer 132a, a coloring layer 132b, and a coloring layer 132c. Here, the light R emitted from the light emitting device 130R is emitted to the substrate 102 side through the coloring layer 132 a. Further, the light G emitted from the light emitting device 130G is emitted to the substrate 102 side through the coloring layer 132 b. Further, the light B emitted from the light emitting device 130B is emitted to the substrate 102 side through the coloring layer 132c. The substrate 102 is bonded to the colored layer 132 with the adhesive layer 107. For details of the constituent elements of the light-emitting device to the substrate 102, reference may be made to embodiment mode 1. Substrate 102 corresponds to substrate 292 in fig. 14A.

An insulating layer covering the top end of the pixel electrode 111a is not provided between the pixel electrode 111a and the first layer 113 a. Further, an insulating layer covering the top end of the pixel electrode 111b is not provided between the pixel electrode 111b and the second layer 113 b. Therefore, the interval between adjacent light emitting devices can be made extremely narrow. Accordingly, a high-definition or high-resolution display device can be realized.

Display device 100B

The display panel 100B shown in fig. 16 has a structure in which a transistor 310A and a transistor 310B each forming a channel in a semiconductor substrate are stacked. Note that in the description of the display panel described later, the same portions as those of the display panel described earlier may be omitted.

The display panel 100B has the following structure: a substrate 301B provided with a transistor 310B, a capacitor 240, and a light-emitting device is bonded to a substrate 301A provided with a transistor 310A.

Here, an insulating layer 345 is preferably provided on the bottom surface of the substrate 301B. Further, an insulating layer 346 is preferably provided over the insulating layer 261 provided over the substrate 301A. The insulating layers 345 and 346 are insulating layers which function as protective layers, and can suppress diffusion of impurities into the substrate 301B and the substrate 301A. As the insulating layers 345 and 346, an inorganic insulating film which can be used for the protective layer 131 or the insulating layer 332 can be used.

A plug 343 penetrating the substrate 301B and the insulating layer 345 is provided in the substrate 301B. Here, an insulating layer 344 is preferably provided to cover the side surface of the plug 343. The insulating layer 344 is an insulating layer which serves as a protective layer, and can suppress diffusion of impurities to the substrate 301B. As the insulating layer 344, an inorganic insulating film that can be used for the protective layer 131 can be used.

A conductive layer 342 is provided under the insulating layer 345 on the back surface (surface on the opposite side to the substrate 102) side of the substrate 301B. The conductive layer 342 is preferably buried in the insulating layer 335. Further, the bottom surfaces of the conductive layer 342 and the insulating layer 335 are preferably planarized. Here, the conductive layer 342 is electrically connected to the plug 343.

On the other hand, the substrate 301A is provided with a conductive layer 341 over the insulating layer 346. The conductive layer 341 is preferably buried in the insulating layer 336. Further, top surfaces of the conductive layer 341 and the insulating layer 336 are preferably planarized.

By bonding the conductive layer 341 and the conductive layer 342, the substrate 301A is electrically connected to the substrate 301B. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be bonded well.

The same conductive material is preferably used for the conductive layer 341 and the conductive layer 342. For example, a metal film containing an element selected from Al, cr, cu, ta, ti, mo, W, a metal nitride film (titanium nitride film, molybdenum nitride film, tungsten nitride film) containing the above element as a component, or the like can be used. Particularly, copper is preferably used for the conductive layer 341 and the conductive layer 342. Thus, a cu—cu (copper-copper) direct bonding technique (a technique of conducting electricity by connecting pads of Cu (copper) to each other) can be employed.

[ Display device 100C ]

The display device 100C shown in fig. 17 has a structure in which a conductive layer 341 and a conductive layer 342 are bonded by a bump 347.

As shown in fig. 17, the conductive layer 341 and the conductive layer 342 can be electrically connected by providing a bump 347 between the conductive layer 341 and the conductive layer 342. The bump 347 may be formed using a conductive material including gold (Au), nickel (Ni), indium (In), tin (Sn), or the like, for example. For example, solder may be used as the bump 347. In addition, an adhesive layer 348 may be provided between the insulating layer 345 and the insulating layer 346. In addition, when the bump 347 is provided, the insulating layer 345 and the insulating layer 346 may not be provided.

[ Display device 100D ]

The display device 100D shown in fig. 18 is mainly different from the display device 100A in the structure of a transistor.

The transistor 320 is a transistor (OS transistor) using a metal oxide (also referred to as an oxide semiconductor) in a semiconductor layer forming a channel.

The transistor 320 includes a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

The substrate 331 corresponds to the substrate 291 in fig. 14A and 14B. The stacked structure from the substrate 331 to the insulating layer 255b corresponds to the substrate 101 having a transistor in embodiment mode 1. As the substrate 331, an insulating substrate or a semiconductor substrate can be used.

An insulating layer 332 is provided over the substrate 331. The insulating layer 332 functions as a barrier layer which prevents diffusion of impurities such as water or hydrogen from the substrate 331 to the transistor 320 and prevents oxygen from being released from the semiconductor layer 321 to the insulating layer 332 side. As the insulating layer 332, for example, a film which is less likely to be diffused by hydrogen or oxygen than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, a silicon nitride film, or the like can be used.

A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided so as to cover the conductive layer 327. The conductive layer 327 serves as a first gate electrode of the transistor 320, and a portion of the insulating layer 326 serves as a first gate insulating layer. At least a portion of the insulating layer 326 which contacts the semiconductor layer 321 is preferably an oxide insulating film such as a silicon oxide film. The top surface of insulating layer 326 is preferably planarized.

The semiconductor layer 321 is disposed on the insulating layer 326. The semiconductor layer 321 preferably contains a metal oxide (also referred to as an oxide semiconductor) film having semiconductor characteristics. A pair of conductive layers 325 are in contact with the semiconductor layer 321 and serve as source and drain electrodes.

An insulating layer 328 is provided so as to cover the top surface and the side surfaces of the pair of conductive layers 325, the side surfaces of the semiconductor layer 321, and the like, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 serves as a barrier layer that prevents diffusion of impurities such as water and hydrogen from the insulating layer 264 or the like to the semiconductor layer 321 and separation of oxygen from the semiconductor layer 321. As the insulating layer 328, the same insulating film as the insulating layer 332 described above can be used.

Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. The opening is internally embedded with an insulating layer 323 and a conductive layer 324 which are in contact with the side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325, and the top surface of the semiconductor layer 321. The conductive layer 324 is used as a second gate electrode, and the insulating layer 323 is used as a second gate insulating layer.

The top surface of the conductive layer 324, the top surface of the insulating layer 323, and the top surface of the insulating layer 264 are planarized so that the heights thereof are uniform or substantially uniform, and an insulating layer 329 and an insulating layer 265 are provided so as to cover them.

The insulating layers 264 and 265 are used as interlayer insulating layers. The insulating layer 329 serves as a barrier layer which prevents diffusion of impurities such as water or hydrogen from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using the same insulating film as the insulating layer 328 and the insulating layer 332.

A plug 274 electrically connected to one of the pair of conductive layers 325 is embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably has a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and a part of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274 a. In this case, a conductive material which does not easily diffuse hydrogen and oxygen is preferably used for the conductive layer 274 a.

Display device 100E

The display device 100E shown in fig. 19 has a structure in which a transistor 320A and a transistor 320B each including an oxide semiconductor in a semiconductor forming a channel are stacked.

The structure of the transistor 320A, the transistor 320B, and the periphery thereof can be referred to the display device 100D.

Note that here, a structure in which two transistors including an oxide semiconductor are stacked is employed, but is not limited to this structure. For example, three or more transistors may be stacked.

[ Display device 100F ]

In the display device 100F shown in fig. 20, a transistor 310 having a channel formed over a substrate 301 and a transistor 320 having a semiconductor layer containing a metal oxide, which forms a channel, are stacked.

An insulating layer 261 is provided so as to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. Further, an insulating layer 262 is provided so as to cover the conductive layer 251, and the conductive layer 252 is provided over the insulating layer 262. Both the conductive layer 251 and the conductive layer 252 are used as wirings. Further, an insulating layer 263 and an insulating layer 332 are provided so as to cover the conductive layer 252, and the transistor 320 is provided over the insulating layer 332. Further, an insulating layer 265 is provided so as to cover the transistor 320, and the capacitor 240 is provided over the insulating layer 265. Capacitor 240 is electrically connected to transistor 320 through plug 274.

The transistor 320 can be used as a transistor constituting a pixel circuit. Further, the transistor 310 may be used as a transistor constituting a pixel circuit or a transistor constituting a driving circuit (a gate line driving circuit, a source line driving circuit) for driving the pixel circuit. The transistors 310 and 320 can be used as transistors constituting various circuits such as an arithmetic circuit and a memory circuit.

With this structure, not only the pixel circuit but also the driving circuit and the like can be formed immediately below the light emitting device, and thus the display device can be miniaturized as compared with the case where the driving circuit is provided around the display region.

Display device 100G

Fig. 21 shows a perspective view of the display device 100G, and fig. 22A shows a cross-sectional view of the display device 100G.

The display device 100G has a structure in which a substrate 152 and a substrate 151 are bonded. In fig. 21, the substrate 152 is shown in broken lines.

The display device 100G includes a display portion 162, a connection portion 140, a circuit 164, a wiring 165, and the like. Fig. 21 shows an example in which the IC173 and the FPC172 are mounted in the display device 100G. Accordingly, the structure shown in fig. 21 may also be referred to as a display module including the display device 100G, IC (integrated circuit) and an FPC.

The connection portion 140 is disposed outside the display portion 162. The connection part 140 may be disposed along one or more sides of the display part 162. The number of the connection parts 140 may be one or more. Fig. 21 shows an example in which the connection portions 140 are provided so as to surround four sides of the display portion. In the connection part 140, the common electrode of the light emitting device is electrically connected to the conductive layer, and power can be supplied to the common electrode.

As the circuit 164, for example, a scanning line driver circuit can be used.

The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signal and power are input to the wiring 165 from the outside through the FPC172 or input to the wiring 165 from the IC 173.

Fig. 21 shows an example in which an IC173 is provided over a substrate 151 by COG (Chip On Glass) method, COF (Chip On Film) method, or the like. As the IC173, for example, an IC including a scanning line driver circuit, a signal line driver circuit, or the like can be used. Note that the display device 100G and the display module are not necessarily provided with ICs. Further, the IC may be mounted on the FPC by COF method or the like.

Fig. 22A shows an example of a cross section of a portion of the region including the FPC172, a portion of the circuit 164, a portion of the display portion 162, a portion of the connection portion 140, and a portion of the region including the end portion of the display device 100G.

The display device 100G shown in fig. 22A includes, between the substrate 151 and the substrate 152, a transistor 201, a transistor 205, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a color layer 132A that transmits red light, a color layer 132B that transmits green light, a color layer 132c that transmits blue light, and the like.

The light emitting devices 130R, 130G, 130B all have a stacked structure shown in fig. 1B except for the structure of the pixel electrode. For details of the light emitting device, reference may be made to embodiment mode 1 and the like. For example, the light emitting device 130R corresponds to the light emitting device 130a shown in fig. 1B, the light emitting device 130G corresponds to the light emitting device 130B shown in fig. 1B, and the light emitting device 130B corresponds to the light emitting device 130c shown in fig. 1B.

Since the first layer 113a, the second layer 113b, and the third layer 113c are separated and spaced apart from each other in the display device 100G, generation of crosstalk between adjacent sub-pixels can be suppressed even in a high-definition display device. Therefore, a display device with high definition and high display quality can be realized.

The light emitting device 130R includes a conductive layer 112a provided over at least a portion of the insulating layer 214, a conductive layer 126a over the conductive layer 112a, and a conductive layer 129a over the conductive layer 126 a. Here, the insulating layer 214 corresponds to the insulating layer 255c shown in fig. 1B and the like. The conductive layers 112a, 126a, and 129a may be referred to as pixel electrodes, or some of the conductive layers 112a, 126a, and 129a may be referred to as pixel electrodes. It is preferable that the recess provided above the pixel electrode 111 and the insulating layer 214 have a sufficiently large step, as in the pixel electrode 111 shown in fig. 1B and the like.

The light emitting device 130G includes a conductive layer 112b provided over at least a portion of the insulating layer 214, a conductive layer 126b over the conductive layer 112b, and a conductive layer 129b over the conductive layer 126 b.

The light emitting device 130B includes a conductive layer 112c provided over at least a portion of the insulating layer 214, a conductive layer 126c over the conductive layer 112c, and a conductive layer 129c over the conductive layer 126 c.

Conductive layer 112a is connected to conductive layer 222b included in transistor 205 through an opening provided in insulating layer 214. The end of the conductive layer 126a is located outside the end of the conductive layer 112 a. The end of conductive layer 126a is aligned or substantially aligned with the end of conductive layer 129 a. For example, a conductive layer used as a reflective electrode is used as the conductive layer 112a and the conductive layer 126a, and a conductive layer used as a transparent electrode is used as the conductive layer 129 a.

The conductive layers 112B, 126B, 129B in the light emitting device 130G and the conductive layers 112c, 126c, 129c in the light emitting device 130B are the same as the conductive layers 112a, 126a, 129a in the light emitting device 130R, and thus detailed description thereof is omitted.

The conductive layers 112a, 112b, and 112c have recesses formed therein so as to cover openings provided in the insulating layer 214. The recess is filled with a layer 128.

The layer 128 has a function of planarizing the concave portions of the conductive layers 112a, 112b, 112 c. Conductive layers 112a, 112b, 112c and conductive layers 126a, 126b, 126c electrically connected to conductive layers 112a, 112b, 112c are provided over layer 128. Therefore, a region overlapping with the concave portions of the conductive layers 112a, 112b, 112c can also be used as a light-emitting region, whereby the aperture ratio of the pixel can be improved.

Layer 128 may also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be suitably used for the layer 128. In particular, the layer 128 is preferably formed using an insulating material.

As the layer 128, an insulating layer containing an organic material can be suitably used. For example, an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin, a polyimide amide resin, a silicone resin, a benzocyclobutene resin, a phenol resin, a precursor of the above-mentioned resins, or the like can be used as the layer 128. Further, as the layer 128, a photosensitive resin can be used. The photosensitive resin may be a positive type material or a negative type material.

By using the photosensitive resin, the layer 128 can be manufactured only by the exposure and development steps, and the influence of the surfaces of the conductive layers 112a, 112b, and 112c due to dry etching, wet etching, or the like can be reduced. Further, by using the negative photosensitive resin formation layer 128, the same photomask (exposure mask) as that used when forming the opening of the insulating layer 214 may be used in some cases to form the layer 128.

The top surface of conductive layer 126a and the top surface of conductive layer 129a are covered by first layer 113 a. Similarly, the top surface of the conductive layer 126b and the top surface of the conductive layer 129b are covered with the second layer 113 b. Further, the top surface of the conductive layer 126c and the top surface of the conductive layer 129c are covered with the third layer 113 c. Accordingly, since the entire region where the conductive layers 126a, 126B, 126c are provided can be used as the light emitting region of the light emitting devices 130R, 130G, 130B, the aperture ratio of the pixel can be improved.

In addition, as in the display device 100 shown in fig. 1B, a fourth layer 113d is formed between adjacent light emitting devices, and an insulating layer 125 and an insulating layer 127 are provided over the fourth layer 113 d. By providing the recess provided above the pixel electrode and the insulating layer 214 with a sufficiently large step, the first layer 113a, the second layer 113b, the third layer 113c, and the fourth layer 113d can be divided in a self-aligned manner when the EL film is deposited.

The side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are covered with insulating layers 125 and 127. The first layer 113a, the second layer 113b, the third layer 113c, and the insulating layers 125 and 127 have a common layer 114 provided thereon, and the common layer 114 has a common electrode 115 provided thereon. The common layer 114 and the common electrode 115 are continuous films commonly provided in a plurality of light emitting devices.

The light emitting devices 130R, 130G, 130B are each provided with a protective layer 131. By forming the protective layer 131 covering the light emitting device, entry of impurities such as water into the light emitting device can be suppressed, whereby the reliability of the light emitting device can be improved.

In addition, in the display device 100G, as in the display device 100 shown in fig. 1B, the resin layer 147, the coloring layer 132a, the coloring layer 132B, and the coloring layer 132c are provided on the protective layer 131. Here, the light R emitted from the light emitting device 130R is emitted to the substrate 152 side through the coloring layer 132 a. Further, the light G emitted from the light emitting device 130G is emitted to the substrate 152 side through the coloring layer 132 b. Further, the light B emitted from the light emitting device 130B is emitted to the substrate 152 side through the coloring layer 132c.

The protective layer 131 and the substrate 152 are bonded by the adhesive layer 107. The sealing of the light emitting device may be a solid sealing structure, a hollow sealing structure, or the like. In fig. 22A, a space between the substrate 152 and the substrate 151 is filled with the adhesive layer 107, that is, a solid sealing structure is adopted. Alternatively, the space may be filled with an inert gas (nitrogen or argon, etc.), i.e., a hollow sealing structure may be employed. At this time, the adhesive layer 107 may be provided so as not to overlap with the light emitting device. In addition, the space may be filled with a resin different from the adhesive layer 107 provided around in a frame shape.

In the connection portion 140, the conductive layer 123 is provided on the insulating layer 214. The conductive layer 123 shows an example having the following stacked structure: a stack of a conductive film obtained by processing the same conductive film as the conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as the conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as the conductive layers 129a, 129b, and 129 c. The end of the conductive layer 123 is covered with an insulating layer 125 and an insulating layer 127. In addition, the common layer 114 is provided on the conductive layer 123, and the common electrode 115 is provided on the common layer 114. The conductive layer 123 is electrically connected to the common electrode 115 through the common layer 114. In addition, the connection portion 140 may not be formed with the common layer 114. In this case, the conductive layer 123 is in direct contact with and electrically connected to the common electrode 115.

The display device 100G adopts a top emission structure. The light emitting device emits light to one side of the substrate 152. The substrate 152 is preferably made of a material having high transmittance to visible light. The pixel electrode includes a material that reflects visible light, and the counter electrode (common electrode 115) includes a material that transmits visible light.

The stacked structure of the substrate 151 to the insulating layer 214 corresponds to the substrate 101 having a transistor in embodiment mode 1.

The transistor 201 and the transistor 205 are both provided over the substrate 151. These transistors may be formed using the same material and the same process.

An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided in this order over the substrate 151. A part of the insulating layer 211 is used as a gate insulating layer of each transistor. A part of the insulating layer 213 is used as a gate insulating layer of each transistor. The insulating layer 215 is provided so as to cover the transistor. The insulating layer 214 is provided so as to cover the transistor, and is used as a planarizing layer. The number of gate insulating layers and the number of insulating layers covering the transistor are not particularly limited, and may be one or two or more.

Preferably, a material which is not easily diffused by impurities such as water and hydrogen is used for at least one of insulating layers covering the transistor. Thereby, the insulating layer can be used as a barrier layer. By adopting such a structure, diffusion of impurities into the transistor from the outside can be effectively suppressed, so that the reliability of the display device can be improved.

An inorganic insulating film is preferably used for the insulating layer 211, the insulating layer 213, and the insulating layer 215. As the inorganic insulating film, for example, a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum nitride film, or the like can be used. Further, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, or the like can be used. Further, two or more of the insulating films may be stacked.

The insulating layer 214 used as the planarizing layer is preferably an organic insulating layer. As a material that can be used for the organic insulating layer, for example, an acrylic resin, a polyimide resin, an epoxy resin, a polyamide resin, a polyimide amide resin, a siloxane resin, a benzocyclobutene resin, a phenol resin, a precursor of the above-described resin, or the like can be used. The insulating layer 214 may have a stacked-layer structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 is preferably used as an etching protection layer. Thus, formation of a recess in the insulating layer 214 can be suppressed when the conductive layer 112a, the conductive layer 126a, the conductive layer 129a, or the like is processed. Alternatively, a concave portion may be provided in the insulating layer 214 when the conductive layer 112a, the conductive layer 126a, or the conductive layer 129a is formed.

Transistor 201 and transistor 205 include: a conductive layer 221 serving as a gate electrode; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as a source and a drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate electrode. Here, the same hatching lines are attached to a plurality of layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

The structure of the transistor included in the display device of this embodiment is not particularly limited. For example, a planar transistor, an interleaved transistor, an inverted interleaved transistor, or the like may be used. In addition, a top gate type or bottom gate type transistor structure may be employed. Alternatively, a gate electrode may be provided above and below the semiconductor layer forming the channel.

As the transistor 201 and the transistor 205, a structure in which a semiconductor layer forming a channel is sandwiched between two gates is adopted. Further, two gates may be connected to each other, and the same signal may be supplied to the two gates to drive the transistor. Alternatively, the threshold voltage of the transistor can be controlled by applying a potential for controlling the threshold voltage to one of the two gates and applying a potential for driving the other gate.

The crystallinity of the semiconductor material used for the transistor is not particularly limited, and an amorphous semiconductor, a single crystal semiconductor, or a semiconductor having crystallinity other than a single crystal semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor in which a part thereof has a crystal region) may be used. When a single crystal semiconductor or a semiconductor having crystallinity is used, deterioration in characteristics of a transistor can be suppressed, so that it is preferable.

The semiconductor layer of the transistor preferably uses a metal oxide (also referred to as an oxide semiconductor). That is, the display device of this embodiment mode preferably uses a transistor including a metal oxide in a channel formation region (hereinafter, an OS transistor).

Examples of the oxide semiconductor having crystallinity include CAAC (c-axis-ALIGNED CRYSTALLINE) -OS and nc (nanocrystalline) -OS.

Alternatively, a transistor using silicon for a channel formation region (Si transistor) may be used. The silicon may be monocrystalline silicon, polycrystalline silicon, amorphous silicon, or the like. In particular, a transistor (hereinafter, also referred to as LTPS transistor) including low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in a semiconductor layer can be used. LTPS transistors have high field effect mobility and good frequency characteristics.

By using Si transistors such as LTPS transistors, a circuit (e.g., a source driver circuit) which needs to be driven at a high frequency and a display portion can be formed over the same substrate. Therefore, an external circuit mounted to the display device can be simplified, and the component cost and the mounting cost can be reduced.

The field effect mobility of the OS transistor is very high compared to a transistor using amorphous silicon. In addition, the leakage current between the source and the drain (hereinafter, also referred to as off-state current) in the off state of the OS transistor is extremely low, and the charge stored in the capacitor connected in series with the transistor can be held for a long period of time. In addition, by using an OS transistor, power consumption of the display device can be reduced.

The off-state current value of the OS transistor per channel width of 1 μm at room temperature may be 1aA (1×10 ^-18 a) or less, 1zA (1×10 ^-21 a) or less, or 1yA (1×10 ^-24 a) or less. Note that the off-state current value of the Si transistor per channel width of 1 μm at room temperature is 1fA (1×10 ^-15 a) or more and 1pA (1×10 ^-12 a) or less. Therefore, it can be said that the off-state current of the OS transistor is about 10 bits lower than the off-state current of the Si transistor.

In addition, when the light-emitting luminance of the light-emitting device included in the pixel circuit is increased, the amount of current flowing through the light-emitting device needs to be increased. For this reason, it is necessary to increase the source-drain voltage of the driving transistor included in the pixel circuit. Since the withstand voltage between the source and drain of the OS transistor is higher than that of the Si transistor, a high voltage can be applied between the source and drain of the OS transistor. Thus, by using an OS transistor as a driving transistor included in the pixel circuit, the amount of current flowing through the light emitting device can be increased, and the light emitting luminance of the light emitting device can be improved.

In addition, when the transistor operates in the saturation region, the OS transistor can make a change in source-drain current for a change in gate-source voltage small as compared with the Si transistor. Therefore, by using an OS transistor as a driving transistor included in the pixel circuit, the current flowing between the source and the drain can be determined in detail according to the change in the gate-source voltage, and thus the amount of current flowing through the light emitting device can be controlled. Thus, the number of gradations of the pixel circuit can be increased.

In addition, regarding the saturation characteristics of the current flowing when the transistor operates in the saturation region, the OS transistor can flow a stable current (saturation current) even if the source-drain voltage is gradually increased as compared with the Si transistor. Therefore, by using the OS transistor as the driving transistor, even if, for example, the current-voltage characteristics of the EL device are uneven, a stable current can flow through the light emitting device. That is, the OS transistor hardly changes the source-drain current even if the source-drain voltage is increased when operating in the saturation region, and thus the light emission luminance of the light emitting device can be stabilized.

As described above, by using an OS transistor as a driving transistor included in a pixel circuit, it is possible to realize "suppression of black blur", "increase in emission luminance", "multi-gradation", "suppression of non-uniformity of a light emitting device", and the like.

For example, the semiconductor layer preferably contains 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, as the semiconductor layer, an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) is preferably used. Or preferably oxides comprising indium, tin and zinc are used. Or preferably oxides containing indium, gallium, tin and zinc are used. Alternatively, an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO) is preferably used. Alternatively, an oxide (also referred to as IAGZO) containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) is preferably used.

When an In-M-Zn oxide is used for the semiconductor layer, the atomic ratio of In the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. The atomic number ratio of the metal elements of the In-M-Zn oxide may be: in: m: zn=1: 1:1 or the vicinity thereof, in: m: zn=1: 1:1.2 composition at or near, in: m: zn=1: 3:2 or the vicinity thereof, in: m: zn=1: 3:4 or the vicinity thereof, in: m: zn=2: 1:3 or the vicinity thereof, in: m: zn=3: 1:2 or the vicinity thereof, in: m: zn=4: 2:3 or the vicinity thereof, in: m: zn=4: 2:4.1 or the vicinity thereof, in: m: zn=5: 1:3 or the vicinity thereof, in: m: zn=5: 1:6 or the vicinity thereof, in: m: zn=5: 1:7 or the vicinity thereof, in: m: zn=5: 1:8 or the vicinity thereof, in: m: zn=6: 1:6 or the vicinity thereof, in: m: zn=5: 2:5 or the vicinity thereof, and the like. Note that the nearby composition includes a range of ±30% of the desired atomic number ratio.

For example, when the atomic ratio is described as In: ga: zn=4: 2:3 or its vicinity, including the following: in is 4, ga is 1 to 3, zn is 2 to 4. Note that, when the atomic ratio is expressed as In: ga: zn=5: 1:6 or its vicinity, including the following: in is 5, ga is more than 0.1 and not more than 2, and Zn is not less than 5 and not more than 7. Note that, when the atomic ratio is expressed as In: ga: zn=1: 1:1 or its vicinity, including the following: in is 1, ga is more than 0.1 and not more than 2, and Zn is more than 0.1 and not more than 2.

The transistor included in the circuit 164 and the transistor included in the display portion 162 may have the same structure or may have different structures. The plurality of transistors included in the circuit 164 may have the same structure or may have two or more structures. In the same manner, the plurality of transistors included in the display portion 162 may have the same structure or may have two or more structures.

All the transistors included in the display portion 162 may be OS transistors, all the transistors included in the display portion 162 may be Si transistors, some of the transistors included in the display portion 162 may be OS transistors, and the remaining transistors may be Si transistors.

For example, by using both LTPS transistors and OS transistors in the display portion 162, a display device having low power consumption and high driving capability can be realized. In addition, the structure of the combination LTPS transistor and OS transistor is sometimes referred to as LTPO. As more preferable examples, the following structures are given: an OS transistor is used for a transistor or the like used as a switch for controlling conduction/non-conduction between wirings, and an LTPS transistor is used for a transistor or the like for controlling current.

For example, one of the transistors included in the display portion 162 is used as a transistor for controlling a current flowing through the light emitting device and may also be referred to as a driving transistor. One of a source and a drain of the driving transistor is electrically connected to a pixel electrode of the light emitting device. LTPS transistors are preferably used as the driving transistors. Accordingly, a current flowing through the light emitting device in the pixel circuit can be increased.

On the other hand, one of the other transistors included in the display portion 162 is used as a switching function for controlling selection and non-selection of a pixel, and may be referred to as a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and the drain is electrically connected to a source line (signal line). The selection transistor is preferably an OS transistor. Therefore, the gradation of the pixel can be maintained even if the frame rate is made significantly small (for example, 1fps or less), whereby by stopping the driver when displaying a still image, the power consumption can be reduced.

Thus, the display device according to one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

A display device according to one embodiment of the present invention has a structure including an OS transistor and a light emitting device having an MML structure. By adopting this structure, the leakage current that can flow through the transistor and the leakage current that can flow between adjacent light emitting devices (also referred to as lateral leakage current, side leakage current, or the like) can be made extremely low. In addition, by adopting the above-described structure, the viewer can observe any one or more of the sharpness of the image, the high color saturation, and the high contrast when the image is displayed on the display device. Further, by adopting a structure in which the leakage current that can flow through the transistor and the lateral leakage current between the light-emitting devices are extremely low, display with extremely little light leakage or the like that can occur when black is displayed can be performed.

In addition, the structure of the OS transistor is not limited to that shown in fig. 22A. For example, the structure shown in fig. 22B and 22C may be adopted.

Transistor 209 and transistor 210 include: a conductive layer 221 serving as a gate electrode; an insulating layer 211 serving as a gate insulating layer; a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231 n; a conductive layer 222a connected to one of the pair of low-resistance regions 231 n; a conductive layer 222b connected to the other of the pair of low-resistance regions 231 n; an insulating layer 225 serving as a gate insulating layer; a conductive layer 223 serving as a gate electrode; and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231 i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231 i. Furthermore, an insulating layer 218 covering the transistor may be provided.

The transistor 209 shown in fig. 22B shows an example in which the insulating layer 225 covers the top surface and the side surface of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

On the other hand, in the transistor 210 illustrated in fig. 22C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 and does not overlap with the low-resistance region 231 n. For example, the structure shown in fig. 22C can be formed by processing the insulating layer 225 using the conductive layer 223 as a mask. In fig. 22C, the insulating layer 215 covers the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings of the insulating layer 215, respectively.

A connection portion 204 is provided in a region where the substrate 151 and the substrate 152 do not overlap. In the connection portion 204, the wiring 165 is electrically connected to the FPC172 through the conductive layer 166 and the connection layer 242. The conductive layer 166 shows an example having the following stacked structure: a stack of a conductive film obtained by processing the same conductive film as the conductive layers 112a, 112b, and 112c, a conductive film obtained by processing the same conductive film as the conductive layers 126a, 126b, and 126c, and a conductive film obtained by processing the same conductive film as the conductive layers 129a, 129b, and 129 c. Conductive layer 166 is exposed on the top surface of connection portion 204. Accordingly, the connection portion 204 can be electrically connected to the FPC172 through the connection layer 242.

The light shielding layer 108 may be provided on the surface of the substrate 152 on the substrate 151 side. The light shielding layer 108 may be provided between adjacent light emitting elements, in the connection portion 140, in the circuit 164, and the like. Further, various optical members may be arranged outside the substrate 152.

The substrate 151 and the substrate 152 can be each made of a material which can be used for the substrate 101 and the substrate 102.

As the connection layer 242, an anisotropic conductive film (ACF: anisotropic Conductive Film), an anisotropic conductive paste (ACP: anisotropic Conductive Paste), or the like can be used.

Although fig. 22 shows the coloring layer 132 arranged in the same manner as the structure shown in fig. 1B, the present invention is not limited to this, and the arrangement of the coloring layer 132 shown in the above embodiment may be suitably adopted. For example, as shown in fig. 23, the configuration of the coloring layer 132 may be the same as that shown in fig. 5B. In the display device 100G shown in fig. 23, the light shielding layer 108, the coloring layer 132a, the coloring layer 132B, and the coloring layer 132c may be provided on the surface of the substrate 152 on the substrate 151 side, as in the structure shown in fig. 5B. Here, the colored layer 132a, the colored layer 132b, and the end portion of the colored layer 132c are preferably provided so as to overlap with the light shielding layer 108. At this time, the adhesive layer 107 is in contact with the light shielding layer 108, the colored layer 132a, the colored layer 132b, the colored layer 132c, and the protective layer 131.

Display device 100H

The display device 100H shown in fig. 24A is mainly different from the display device 100G in that the display device 100H is a display device of a bottom emission structure. Note that the same portions as those of the display device 100G of fig. 24A are not described.

Light emitted from the light emitting device is emitted to the substrate 151 side. The substrate 151 is preferably made of a material having high transmittance to visible light. On the other hand, there is no limitation on the light transmittance of the material used for the substrate 152.

The light shielding layer 108 is preferably formed between the substrate 151 and the transistor 201 and between the substrate 151 and the transistor 205. Fig. 24A shows an example of the following case: the light shielding layer 108 is provided over the substrate 151, the insulating layer 153 is provided over the light shielding layer 108, and the transistors 201 and 205 are provided over the insulating layer 153.

Further, a coloring layer 132 is provided between the insulating layer 215 and the insulating layer 214. The end portion of the coloring layer 132 is preferably overlapped with the light shielding layer 108. The colored layer 132a is provided so as to overlap the light emitting device 130R, and the colored layer 132b is provided so as to overlap the light emitting device 130G. Note that in fig. 24A, the light-emitting device 130B and the coloring layer 132c are omitted, but these may be provided in the same manner as the light-emitting device 130R and the coloring layer 132 a.

The light emitting device 130R includes a conductive layer 112a, a conductive layer 126a over the conductive layer 112a, and a conductive layer 129a over the conductive layer 126 a.

The light emitting device 130G includes a conductive layer 112b, a conductive layer 126b over the conductive layer 112b, and a conductive layer 129b over the conductive layer 126 b.

The conductive layers 112a, 112b, 112c, 126a, 126b, 126c, 129a, 129b, and 129c are each made of a material having high transparency to visible light. The common electrode 115 preferably uses a material that reflects visible light.

Fig. 22A, 24A, and the like show an example in which the top surface of the layer 128 has a flat portion, but the shape of the layer 128 is not particularly limited. Fig. 24B to 24D show a modified example of the layer 128.

As shown in fig. 24B and 24D, the top surface of the layer 128 may have a concave shape in the center and the vicinity thereof, i.e., a concave curved surface shape, when viewed in cross section.

In addition, as shown in fig. 24C, the top surface of the layer 128 may have a shape in which the center and the vicinity thereof expand, i.e., a shape of a convex curved surface, as seen in cross section.

In addition, the top surface of the layer 128 may have one or both of a convex curved surface and a concave curved surface. The number of the convex curved surfaces and the concave curved surfaces on the top surface of the layer 128 is not limited, and may be one or more.

In addition, the height of the top surface of layer 128 may be uniform or substantially uniform with the height of the top surface of conductive layer 112a, or may be different. For example, the height of the top surface of layer 128 may be lower or higher than the height of the top surface of conductive layer 112 a.

In addition, fig. 24B can also be said to be an example in which the layer 128 is housed inside the concave portion of the conductive layer 112 a. On the other hand, as shown in fig. 24D, the layer 128 may be formed so as to exist outside the concave portion of the conductive layer 112a, in other words, so that the top surface width of the layer 128 is larger than the concave portion.

Embodiment 4

In this embodiment mode, a structure example of a transistor which can be used in a display device according to one embodiment of the present invention will be described. In particular, a case where a transistor including silicon in a semiconductor forming a channel is used will be described.

One embodiment of the present invention is a display device including a light emitting device and a pixel circuit. The display device can realize a full-color display device by including, for example, three light emitting devices that emit light of red (R), green (G), or blue (B).

Further, as all the transistors included in the pixel circuit for driving the light emitting device, a transistor containing silicon in a semiconductor layer in which a channel is formed is preferably used. The silicon may be monocrystalline silicon, polycrystalline silicon, amorphous silicon, or the like. In particular, a transistor (hereinafter, also referred to as LTPS transistor) including low-temperature polysilicon (LTPS (Low Temperature Poly Silicon)) in a semiconductor layer is preferably used. LTPS transistors have high field effect mobility and good frequency characteristics.

By using a transistor using silicon such as an LTPS transistor, a circuit (e.g., a source driver circuit) which needs to be driven at a high frequency and a display portion can be formed over the same substrate. Therefore, an external circuit mounted to the display device can be simplified, and the component cost and the mounting cost can be reduced.

In addition, a transistor (hereinafter, also referred to as an OS transistor) including a metal oxide (hereinafter, also referred to as an oxide semiconductor) in a semiconductor in which a channel is formed is preferably used for at least one of the transistors included in the pixel circuit. The field effect mobility of the OS transistor is very high compared to a transistor using amorphous silicon. In addition, the leakage current between the source and the drain (hereinafter, also referred to as off-state current) in the off state of the OS transistor is extremely low, and the charge stored in the capacitor connected in series with the transistor can be held for a long period of time. In addition, by using an OS transistor, power consumption of the display device can be reduced.

By using LTPS transistors for a part of transistors included in a pixel circuit and OS transistors for other transistors, a display device with low power consumption and high driving capability can be realized. As a more preferable example, an OS transistor is preferably used for a transistor or the like used as a switch for controlling conduction/non-conduction between wirings, and an LTPS transistor is preferably used for a transistor or the like for controlling current.

For example, one of the transistors provided in the pixel circuit is used as a transistor for controlling a current flowing through the light emitting device, and may also be referred to as a driving transistor. One of a source and a drain of the driving transistor is electrically connected to a pixel electrode of the light emitting device. LTPS transistors are preferably used as the driving transistors. Accordingly, a current flowing through the light emitting device in the pixel circuit can be increased.

On the other hand, the other of the transistors provided in the pixel circuit is used as a switch for controlling selection/non-selection of the pixel, and may also be referred to as a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and the drain is electrically connected to a source line (signal line). The selection transistor is preferably an OS transistor. Therefore, the gradation of the pixel can be maintained even if the frame rate is made significantly small (for example, 1fps or less), whereby by stopping the driver when displaying a still image, the power consumption can be reduced.

A more specific structural example will be described below with reference to the drawings.

Structural example 2 of display device

Fig. 25A is a block diagram of the display device 400. The display device 400 includes a display portion 404, a driving circuit portion 402, a driving circuit portion 403, and the like.

The display unit 404 includes a plurality of pixels 430 arranged in a matrix. The pixel 430 includes a subpixel 405R, a subpixel 405G, and a subpixel 405B. The sub-pixels 405R, 405G, 405B each include a light emitting device used as a display device.

The pixel 430 is electrically connected to the wiring GL, the wiring SLR, the wiring SLG, and the wiring SLB. The wirings SLR, SLG, and SLB are each electrically connected to the driver circuit portion 402. The wiring GL is electrically connected to the driving circuit portion 403. The driving circuit portion 402 is used as a source line driving circuit (also referred to as a source driver), and the driving circuit portion 403 is used as a gate line driving circuit (also referred to as a gate driver). The wiring GL is used as a gate line, and each of the wirings SLR, SLG, and SLB is used as a source line.

The subpixel 405R includes a light emitting device that exhibits red light. The subpixel 405G includes a light emitting device that exhibits green light. The subpixel 405B includes a light emitting device that exhibits blue light. Thus, the display device 400 can perform full-color display. Note that the pixel 430 may also include a sub-pixel having a light emitting device that exhibits other colors. For example, the pixel 430 may include a sub-pixel having a light emitting device that emits white light, a sub-pixel having a light emitting device that emits yellow light, or the like, in addition to the above three sub-pixels.

The wiring GL is electrically connected to the sub-pixel 405R, the sub-pixel 405G, and the sub-pixel 405B arranged in the row direction (extending direction of the wiring GL). The wirings SLR, SLG, and SLB are electrically connected to the sub-pixel 405R, the sub-pixel 405G, or the sub-pixel 405B (not shown) arranged in the column direction (extending direction of the wirings SLR, etc.), respectively.

[ Structural example of Pixel Circuit ]

Fig. 25B shows an example of a circuit diagram of the pixel 405 which can be used for the above-described sub-pixel 405R, sub-pixel 405G, and sub-pixel 405B. The pixel 405 includes a transistor M1, a transistor M2, a transistor M3, a capacitor C1, and a light emitting device EL. In addition, the wiring GL and the wiring SL are electrically connected to the pixel 405. The wiring SL corresponds to any of the wirings SLR, SLG, and SLB shown in fig. 25A.

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

The wiring SL is supplied with a data potential. The wiring GL is supplied with a selection signal. The selection signal includes a potential that places the transistor in a conductive state and a potential that places the transistor in a non-conductive state.

The wiring RL is supplied with a reset potential. The wiring AL is supplied with an anode potential. The wiring CL is supplied with a cathode potential. The anode potential in the pixel 405 is higher than the cathode potential. In addition, the reset potential supplied to the wiring RL may be such that the potential difference of the reset potential and the cathode potential is smaller than the threshold voltage of the light emitting device EL. The reset potential may be a potential higher than the cathodic potential, the same potential as the cathodic potential, or a potential lower than the cathodic potential.

The transistor M1 and the transistor M3 are used as switches. The transistor M2 is used as a transistor for controlling the current flowing through the light emitting device EL. For example, it can be said that the transistor M1 is used as a selection transistor and the transistor M2 is used as a driving transistor.

Here, LTPS transistors are preferably used for all of the transistors M1 to M3. Alternatively, it is preferable to use OS transistors for the transistors M1 and M3 and LTPS transistors for the transistor M2.

Or the transistors M1 to M3 may all use OS transistors. At this time, LTPS transistors may be used as one or more of the plurality of transistors included in the driving circuit portion 402 and the plurality of transistors included in the driving circuit portion 403, and OS transistors may be used as the other transistors. For example, OS transistors may be used as the transistors provided in the display portion 404, and LTPS transistors may be used as the transistors in the driving circuit portion 402 and the driving circuit portion 403.

As the OS transistor, a transistor using an oxide semiconductor for a semiconductor layer in which a channel is formed can be used. For example, the semiconductor layer preferably contains 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, as the semiconductor layer of the OS transistor, an oxide containing indium, gallium, and zinc is preferably used. Or preferably oxides comprising indium, tin and zinc are used. Or preferably oxides containing indium, gallium, tin and zinc are used.

A transistor using an oxide semiconductor whose band gap is wider than that of silicon and carrier density is low can realize extremely low off-state current. Because of its low off-state current, the charge stored in the capacitor connected in series with the transistor can be maintained for a long period of time. Therefore, in particular, the transistor M1 and the transistor M3 connected in series with the capacitor C1 are preferably transistors including an oxide semiconductor. By using a transistor including an oxide semiconductor as the transistor M1 and the transistor M3, leakage of charge held in the capacitor C1 through the transistor M1 or the transistor M3 can be prevented. In addition, the charge stored in the capacitor C1 can be held for a long period of time, and thus a still image can be displayed for a long period of time without rewriting the data of the pixel 405.

Note that the transistor is represented as an n-channel type transistor in fig. 25B, but a p-channel type transistor may also be used.

In addition, each transistor included in the pixel 405 is preferably formed over the same substrate in an array.

As a transistor included in the pixel 405, a transistor including a pair of gates overlapping with a semiconductor layer interposed therebetween can be used.

In the case where a transistor including a pair of gates has a structure in which the pair of gates are electrically connected to each other and supplied with the same potential, there are advantages such as an increase in on-state current of the transistor and an improvement in saturation characteristics. Further, a potential for controlling the threshold voltage of the transistor may be supplied to one of the pair of gates. In addition, by supplying a constant potential to one of the pair of gates, stability of the electrical characteristics of the transistor can be improved. For example, one gate of the transistor may be electrically connected to a wiring to which a constant potential is supplied, or one gate of the transistor may be electrically connected to a source or a drain of the transistor itself.

The pixel 405 shown in fig. 25C is an example of a case where a transistor including a pair of gates is used for the transistor M1 and the transistor M3. In each of the transistors M1 and M3, a pair of gates are electrically connected to each other. By adopting such a configuration, the data writing period to the pixel 405 can be shortened.

The pixel 405 shown in fig. 25D is an example of a case where a transistor including a pair of gates (hereinafter, sometimes referred to as a first gate and a second gate) is used for the transistor M1 and the transistor M3 as well as the transistor M2. The pair of gates of the transistor M2 are electrically connected to each other. By using such a transistor for the transistor M2, saturation characteristics are improved, and thus control of the emission luminance of the light-emitting device EL is facilitated, and display quality can be improved.

Fig. 25D shows a case where the first gate and the second gate of the transistor M2 are electrically connected, but the present invention is not limited thereto. As shown in fig. 25E, the following structure may be adopted: the first gate of the transistor M2 is electrically connected to the other of the source and the drain of the transistor M1 and one electrode of the capacitor C1, and the second gate of the transistor M2 is electrically connected to the other of the source and the drain of the transistor M2, one of the source and the drain of the transistor M3, the other electrode of the capacitor C1 and one electrode of the light emitting device EL.

[ Structural example of transistor ]

A cross-sectional structure example of a transistor which can be used for the display device is described below.

[ Structural example 1]

Fig. 26A is a cross-sectional view including a transistor 410.

The transistor 410 is a transistor which is provided over the substrate 401 and uses polysilicon in a semiconductor layer. For example, transistor 410 corresponds to transistor M2 of pixel 405. That is, fig. 26A is an example in which one of a source and a drain of the transistor 410 is electrically connected to the conductive layer 431 of the light-emitting device.

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 contains silicon. The semiconductor layer 411 preferably contains polysilicon. A portion of the insulating layer 412 is used as a gate insulating layer. A portion of the conductive layer 413 is used as a gate electrode.

Note that the semiconductor layer 411 may also contain a metal oxide (also referred to as an oxide semiconductor) which shows semiconductor characteristics. At this time, the transistor 410 may be referred to as an OS transistor.

The low-resistance region 411n is a region containing an impurity element. For example, in the case where the transistor 410 is an n-channel transistor, phosphorus, arsenic, or the like may be added to the low-resistance region 411 n. 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 411 n. In addition, in order to control the threshold voltage of the transistor 410, the impurity described above may be added to the channel formation region 411i.

An insulating layer 421 is provided over the substrate 401. The semiconductor layer 411 is provided over the insulating layer 421. The insulating layer 412 is provided so as to cover the semiconductor layer 411 and the insulating layer 421. The conductive layer 413 is provided on the insulating layer 412 at a position overlapping with the semiconductor layer 411.

Further, an insulating layer 422 is provided so as to cover the conductive layer 413 and the insulating layer 412. The insulating layer 422 is provided with a conductive layer 414a and a conductive layer 414b. The conductive layer 414a and the conductive layer 414b are electrically connected to the low-resistance region 411n through openings formed in the insulating layer 422 and the insulating layer 412. A part of the conductive layer 414a is used as one of a source electrode and a drain electrode, and a part of the conductive layer 414b is used as the other of the source electrode and the drain electrode. Further, an insulating layer 423 is provided so as to cover the conductive layer 414a, the conductive layer 414b, and the insulating layer 422.

A conductive layer 431 serving as a pixel electrode is provided over the insulating layer 423. The conductive layer 431 is provided over the insulating layer 423, and is electrically connected to the conductive layer 414b in an opening provided in the insulating layer 423. Although omitted here, an EL layer and a common electrode may be stacked over the conductive layer 431.

[ Structural example 2]

Fig. 26B shows a transistor 410a including a pair of gate electrodes. The transistor 410a shown in fig. 26B is mainly different from that of fig. 26A in that it includes a conductive layer 415 and an insulating layer 416.

The conductive layer 415 is disposed on the insulating layer 421. Further, an insulating layer 416 is provided so as to cover the conductive layer 415 and the insulating layer 421. The semiconductor layer 411 is provided so that at least the channel formation region 411i overlaps with the conductive layer 415 with the insulating layer 416 interposed therebetween.

In the transistor 410a shown in fig. 26B, a part of the conductive layer 413 is used as a first gate electrode, and a part of the conductive layer 415 is used as a second gate electrode. At this time, a portion of the insulating layer 412 is used as a first gate insulating layer, and a portion of the insulating layer 416 is used as a second gate insulating layer.

Here, in the case where 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 formed in the insulating layer 412 and the insulating layer 416 in a region not shown. In the case where the second gate electrode is electrically connected to the source electrode or the drain electrode, the conductive layer 414a or the conductive layer 414b may be electrically connected to the conductive layer 415 through an opening formed in the insulating layer 422, the insulating layer 412, or the insulating layer 416 in a region not shown.

In the case where LTPS transistors are used for all the transistors constituting the pixel 405, the transistor 410 illustrated in fig. 26A or the transistor 410a illustrated in fig. 26B can be employed. In this case, the transistor 410a may be used for all the transistors constituting the pixel 405, the transistor 410 may be used for all the transistors, or the transistor 410a and the transistor 410 may be used in combination.

[ Structural example 3]

Hereinafter, an example of a structure of a transistor including silicon for a semiconductor layer and a transistor including metal oxide for a semiconductor layer is described.

Fig. 26C shows a schematic cross-sectional view including a transistor 410a and a transistor 450.

The transistor 410a can be structured as described above with reference to structural example 1. Note that although an example using the transistor 410a is shown here, a structure including the transistor 410 and the transistor 450, or a structure including all of the transistor 410, the transistor 410a, and the transistor 450 may be used.

The transistor 450 is a transistor using a metal oxide in a semiconductor layer. The structure shown in fig. 26C is an example in which, for example, the transistor 450 corresponds to the transistor M1 of the pixel 405 and the transistor 410a corresponds to the transistor M2. That is, fig. 26C shows an example in which one of a source and a drain of the transistor 410a is electrically connected to the conductive layer 431.

Further, fig. 26C shows an example in which the transistor 450 includes a pair of gates.

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. A portion of the conductive layer 453 is used as a first gate of the transistor 450 and a portion of the conductive layer 455 is used as a second gate of the transistor 450. At this time, a portion of the insulating layer 452 is used as a first gate insulating layer of the transistor 450, and a portion of the insulating layer 422 is used as a second gate insulating layer of the transistor 450.

The conductive layer 455 is disposed on the insulating layer 412. An insulating layer 422 is provided so as to cover the conductive layer 455. The semiconductor layer 451 is provided over the insulating layer 422. An insulating layer 452 is provided so as 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.

Further, an insulating layer 426 is provided so as to cover the insulating layer 452 and the conductive layer 453. Conductive layer 454a and conductive layer 454b are provided over insulating layer 426. Conductive layer 454a and conductive layer 454b are electrically connected to semiconductor layer 451 through openings formed in insulating layer 426 and insulating layer 452. A part of the conductive layer 454a is used as one of a source electrode and a drain electrode, and a part of the conductive layer 454b is used as the other of the source electrode and the drain electrode. Further, an insulating layer 423 is provided so as to cover the conductive layer 454a, the conductive layer 454b, and the insulating layer 426.

Here, the conductive layers 414a and 414b which are electrically connected to the transistor 410a are preferably formed by processing the same conductive film as the conductive layers 454a and 454 b. Fig. 26C shows a structure in which the conductive layer 414a, the conductive layer 414b, the conductive layer 454a, and the conductive layer 454b are formed over the same surface (i.e., in contact with the top surface of the insulating layer 426) and contain the same metal element. At this time, the conductive layer 414a and the conductive layer 414b are electrically connected to the low-resistance region 411n through openings formed in the insulating layer 426, the insulating layer 452, the insulating layer 422, and the insulating layer 412. This is preferable because the manufacturing process can be simplified.

In addition, the conductive layer 413 used as the first gate electrode of the transistor 410a and the conductive layer 455 used as the second gate electrode of the transistor 450 are preferably formed by processing the same conductive film. Fig. 26C shows a structure in which the conductive layer 413 and the conductive layer 455 are formed over 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 the manufacturing process can be simplified.

In fig. 26C, the insulating layer 452 serving as the first gate insulating layer of the transistor 450 covers an end portion of the semiconductor layer 451, but as in the transistor 450a shown in fig. 26D, the insulating layer 452 may be processed so that a top surface thereof matches or substantially matches a top surface of the conductive layer 453.

In this specification and the like, "the top surface shape is substantially uniform" means that at least a part of the edge of each layer in the stack is overlapped. For example, the upper layer and the lower layer are processed by the same mask pattern or a part of the same mask pattern. However, there are cases where the edges do not overlap in practice, and there are cases where the upper layer is located inside the lower layer or outside the lower layer, and this may be said to be "the top surface shape is substantially uniform".

Note that an example in which the transistor 410a corresponds to the transistor M2 and is electrically connected to the pixel electrode is shown here, but is not limited thereto. For example, the transistor 450 or the transistor 450a may also correspond to the transistor M2. At this time, the transistor 410a corresponds to the transistor M1, the transistor M3, or other transistors.

Embodiment 5

In this embodiment, a light-emitting device which can be used in a display device according to one embodiment of the present invention will be described.

As shown in fig. 27A, the light-emitting device includes an EL layer 763 between a pair of electrodes (a lower electrode 761 and an upper electrode 762). The EL layer 763 may be formed of a plurality of layers such as a layer 780, a light-emitting layer 771, and a layer 790.

The light-emitting layer 771 contains at least a light-emitting substance (also referred to as a light-emitting material).

When the lower electrode 761 and the upper electrode 762 are an anode and a cathode, respectively, the layer 780 includes one or more of a layer containing a substance having high hole injection property (a hole injection layer), a layer containing a substance having high hole transport property (a hole transport layer), and a layer containing a substance having high electron blocking property (an electron blocking layer). The layer 790 includes one or more of a layer containing a substance having high electron injection property (an electron injection layer), a layer containing a substance having high electron transport property (an electron transport layer), and a layer containing a substance having high hole blocking property (a hole blocking layer). In the case where the lower electrode 761 and the upper electrode 762 are a cathode and an anode, respectively, the structures of the layer 780 and the layer 790 are reversed as described above.

The structure including the layer 780, the light-emitting layer 771, and the layer 790 which are provided between a pair of electrodes can be used as a single light-emitting unit, and the structure of fig. 27A is referred to as a single structure in this specification.

In addition, fig. 27B shows a modified example of the EL layer 763 included in the light-emitting device shown in fig. 27A. Specifically, the light-emitting device shown in fig. 27B includes a layer 781 over the lower electrode 761, a layer 782 over the layer 781, a light-emitting layer 771 over the layer 782, a layer 791 over the light-emitting layer 771, a layer 792 over the layer 791, and an upper electrode 762 over the layer 792.

In the case where the lower electrode 761 and the upper electrode 762 are an anode and a cathode, respectively, the layers 781, 782, 791, and 792 may be a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer, respectively, for example. In the case where the lower electrode 761 and the upper electrode 762 are a cathode and an anode, respectively, the layers 781, 782, 791, and 792 may be an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer, respectively. By adopting the above layer structure, carriers can be efficiently injected into the light-emitting layer 771, and thus the recombination efficiency of carriers in the light-emitting layer 771 can be improved.

As shown in fig. 27C and 27D, a structure in which a plurality of light-emitting layers (light-emitting layers 771, 772, and 773) are provided between the layer 780 and the layer 790 is also one of single structures. Note that although fig. 27C and 27D show examples including three light-emitting layers, the light-emitting layers in a light-emitting device having a single structure may be two layers or four or more layers. In addition, the light emitting device having a single structure may include a buffer layer between two light emitting layers.

As shown in fig. 27E and 27F, a structure in which a plurality of light emitting units (light emitting units 763a and 763 b) are connected in series with a charge generating layer 785 (also referred to as an intermediate layer) interposed therebetween is referred to as a series structure in this specification. In addition, the series structure may be referred to as a stacked structure. By adopting the series structure, a light-emitting device capable of emitting light with high luminance can be realized. In addition, the series structure can reduce the current required to obtain the same luminance as compared with the single structure, and thus can improve the reliability.

Fig. 27D and 27F show examples in which the display device includes a layer 764 overlapping with the light-emitting device. Fig. 27D shows an example in which a layer 764 is overlapped with the light-emitting device shown in fig. 27C, and fig. 27F shows an example in which a layer 764 is overlapped with the light-emitting device shown in fig. 27E. In fig. 27D and 27F, the upper electrode 762 uses a conductive film that transmits visible light to extract light to the upper electrode 762 side.

One or both of a color conversion layer and a color filter (coloring layer) can be used as the layer 764.

In fig. 27C and 27D, a light-emitting substance which emits light of the same color, or even the same light-emitting substance may be used for the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. For example, a light-emitting substance which emits blue light may be used for the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. Regarding the sub-pixel exhibiting blue light, blue light emitted from the light emitting device may be extracted. In addition, with respect to the sub-pixel that exhibits red light and the sub-pixel that exhibits green light, by providing a color conversion layer as the layer 764 shown in fig. 27D, blue light emitted by the light emitting device can be converted into light of a longer wavelength to be extracted as red light or green light. Further, as the layer 764, both a color conversion layer and a coloring layer are preferably used. A part of light emitted from the light emitting device is sometimes not converted but transmitted through the color conversion layer. The color conversion layer absorbs light of a desired color, and thus the color purity of light emitted from the sub-pixel can be improved. Note that the light-emitting device shown in fig. 27A and 27B may have the same structure as described above. At this time, a light-emitting substance which emits blue light can be used for the light-emitting layer 771 of the light-emitting device shown in fig. 27A and 27B.

In fig. 27C and 27D, light-emitting substances that emit light of different colors may be used for the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. When the light emitted from each of the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 is in a complementary color relationship, white light emission can be obtained. For example, a light-emitting device having a single structure preferably includes a light-emitting layer containing a light-emitting substance that emits blue light and a light-emitting layer containing a light-emitting substance that emits visible light longer than the blue wavelength.

As the layer 764 shown in fig. 27D, a color filter may be provided. The white light is transmitted through the color filter, whereby light of a desired color can be obtained.

For example, in the case where a light-emitting device having a single structure includes three light-emitting layers, it is preferable to include a light-emitting layer containing a light-emitting substance that emits red (R) light, a light-emitting layer containing a light-emitting substance that emits green (G) light, and a light-emitting layer containing a light-emitting substance that emits blue (B) light. As a lamination order of the light emitting layers, an order of laminating R, G, B sequentially from the anode side, an order of laminating R, B, G sequentially from the anode side, or the like can be adopted. In this case, a buffer layer may be provided between R and G or B.

For example, in the case where a light-emitting device having a single structure includes two light-emitting layers, a structure including a light-emitting layer containing a light-emitting substance that emits blue (B) light and a light-emitting layer containing a light-emitting substance that emits yellow (Y) light is preferably employed. This structure is sometimes referred to as a BY single structure.

The light-emitting device that emits white light preferably contains two or more kinds of light-emitting substances. In order to obtain white light emission, the light-emitting substances may be selected so that the respective light emissions of two or more light-emitting substances are in a complementary relationship. For example, by placing the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer in a complementary relationship, a light-emitting device that emits light in white color as a whole can be obtained. In addition, the same applies to a light-emitting device including three or more light-emitting layers.

Note that each of the layers 780 and 790 in fig. 27C and 27D may have a stacked structure of two or more layers as shown in fig. 27B.

In fig. 27E and 27F, a light-emitting substance which emits light of the same color, or even the same light-emitting substance may be used for the light-emitting layer 771 and the light-emitting layer 772. For example, in a light-emitting device included in a sub-pixel which emits light of each color, a light-emitting substance which emits blue light may be used for the light-emitting layer 771 and the light-emitting layer 772. Regarding the sub-pixel exhibiting blue light, blue light emitted from the light emitting device may be extracted. In addition, with respect to the sub-pixel that exhibits red light and the sub-pixel that exhibits green light, by providing a color conversion layer as the layer 764 shown in fig. 27F, blue light emitted by the light emitting device can be converted into light of a longer wavelength to be extracted as red light or green light. Further, as the layer 764, both a color conversion layer and a coloring layer are preferably used.

In fig. 27E and 27F, light-emitting substances that emit light of different colors may be used for the light-emitting layer 771 and the light-emitting layer 772. When the light emitted from the light-emitting layer 771 and the light emitted from the light-emitting layer 772 are in a complementary color relationship, white light emission can be obtained. A color filter may be provided as the layer 764 shown in fig. 27F. The white light is transmitted through the color filter, whereby light of a desired color can be obtained.

Note that although fig. 27E and 27F illustrate an example in which the light emitting unit 763a includes one light emitting layer 771 and the light emitting unit 763b includes one light emitting layer 772, it is not limited thereto. Each of the light emitting units 763a and 763b may include two or more light emitting layers.

In addition, although fig. 27E and 27F show examples of the light emitting device including two light emitting units, it is not limited thereto. The light emitting device may also include three or more light emitting units. In addition, a structure including two light emitting units and a structure including three light emitting units may be referred to as a two-stage series structure and a three-stage series structure, respectively.

In fig. 27E and 27F, the light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a, and the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772, and a layer 790b.

In the case where the lower electrode 761 and the upper electrode 762 are an anode and a cathode, respectively, the layers 780a and 780b each include one or more of a hole injection layer, a hole transport layer, and an electron blocking layer. In addition, each of the layers 790a and 790b includes one or more of an electron injection layer, an electron transport layer, and a hole blocking layer. In the case where the lower electrode 761 and the upper electrode 762 are a cathode and an anode, respectively, the structures of the layer 780a and the layer 790a are inverted from the above, and the structures of the layer 780b and the layer 790b are also inverted from the above.

In the case where the lower electrode 761 and the upper electrode 762 are an anode and a cathode, respectively, for example, the layer 780a includes a hole injection layer and a hole transport layer over the hole injection layer, and may further include an electron blocking layer over the hole transport layer. In addition, the layer 790a includes an electron transport layer, and may further include a hole blocking layer between the light emitting layer 771 and the electron transport layer. In addition, the layer 780b includes a hole transport layer, and may further include an electron blocking layer on the hole transport layer. In addition, the layer 790b includes an electron transport layer and an electron injection layer over the electron transport layer, and may further include a hole blocking layer between the light emitting layer 771 and the electron transport layer. In the case where the lower electrode 761 and the upper electrode 762 are a cathode and an anode, respectively, for example, the layer 780a includes an electron injection layer and an electron transport layer over the electron injection layer, and may further include a hole blocking layer over the electron transport layer. In addition, the layer 790a includes a hole transport layer, and may further include an electron blocking layer between the light emitting layer 771 and the hole transport layer. In addition, the layer 780b includes an electron transport layer, and may further include a hole blocking layer on the electron transport layer. In addition, the layer 790b includes a hole-transporting layer and a hole-injecting layer over the hole-transporting layer, and may further include an electron-blocking layer between the light-emitting layer 771 and the hole-transporting layer.

Further, when a light emitting device having a tandem structure is manufactured, two light emitting units are stacked with a charge generation layer 785 interposed therebetween. The charge generation layer 785 has at least a charge generation region. The charge generation layer 785 has a function of injecting electrons into one of the two light emitting cells and injecting holes into the other when a voltage is applied between the pair of electrodes.

Further, as an example of a light emitting device having a series structure, the structure shown in fig. 28A to 28C can be given.

Fig. 28A shows a structure having three light emitting units. In fig. 28A, a plurality of light emitting units (light emitting unit 763a, light emitting unit 763b, and light emitting unit 763 c) are connected in series to each other through a charge generating layer 785. In addition, the light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a, the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772, and a layer 790b, and the light-emitting unit 763c includes a layer 780c, a light-emitting layer 773, and a layer 790c. Layer 780c may be configured to be used for layers 780a and 780b, and layer 790c may be configured to be used for layers 790a and 790 b.

In fig. 28A, the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773 may contain light-emitting substances that emit light of the same color. Specifically, it is possible to employ: a light-emitting layer 771 the light-emitting layer 772 and the light-emitting layer 773 each include light emission of blue (B) Structure of the substance (so-called B\ B\B three-stage tandem structure). Further, as in the light-emitting device shown in fig. 27F, the structure of the setting layer 764 can be adopted as appropriate. As the layer 764, a color conversion layer or both a color conversion layer and a coloring layer can be used. Note that "a\b" means that a light-emitting unit containing a light-emitting substance that emits light of a is provided with a light-emitting unit containing a light-emitting substance that emits light of b via a charge generation layer, and a and b represent colors.

In addition, in fig. 28A, light-emitting substances which emit light of different colors from each other may be used for part or all of the light-emitting layer 771, the light-emitting layer 772, and the light-emitting layer 773. Examples of the combination of the emission colors of the emission layer 771, the emission layer 772, and the emission layer 773 include: any two are blue (B) and the rest are yellow (Y); and one of them is red (R), the other is green (G), and the other is blue (B). Further, as in the light-emitting device shown in fig. 27F, the structure of the setting layer 764 can be adopted as appropriate. As the layer 764, a color filter may be used.

Note that the light-emitting substances that emit light of the same color are not limited to the above-described structure. For example, as shown in fig. 28B, a tandem-type light-emitting device in which light-emitting units including a plurality of light-emitting layers are stacked may also be employed. Fig. 28B shows a structure in which two light emitting units (a light emitting unit 763a and a light emitting unit 763B) are connected in series through a charge generating layer 785. The light-emitting unit 763a includes a layer 780a, a light-emitting layer 771b, a light-emitting layer 771c, and a layer 790a, and the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b.

In fig. 28B, light-emitting substances in a complementary color relationship are selected for each of the light-emitting layers 771a, 771B, and 771c, so that the light-emitting unit 763a has a structure capable of realizing white light emission (W). The light-emitting element 763b has a structure capable of realizing white light emission (W) by selecting light-emitting substances in a complementary color relationship from the light-emitting layer 772a, the light-emitting layer 772b, and the light-emitting layer 772 c. That is, the structure shown in fig. 28B is a W/W two-stage series structure. Note that the order of lamination of the light-emitting substances in the complementary color relationship is not particularly limited. The practitioner can appropriately select the most appropriate lamination sequence. Although not shown, a three-stage or four-or more-stage tandem structure of W/W may be employed.

In addition, in the case of using a light emitting device having a series structure, there can be mentioned: a b\y or y\b two-stage tandem structure including a light emitting unit emitting yellow (Y) light and a light emitting unit emitting blue (B) light; a two-stage tandem structure of R.G\B or B\R.G including a light emitting unit emitting red (R) light and green (G) light and a light emitting unit emitting blue (B) light; the light emitting device comprises a B\Y\B three-stage series structure sequentially comprising a light emitting unit for emitting blue (B) light, a light emitting unit for emitting yellow (Y) light and a light emitting unit for emitting blue (B) light; the light emitting device comprises a light emitting unit for emitting blue (B) light, a light emitting unit for emitting yellow-green (YG) light and a B\YG\B three-stage series structure of the light emitting unit for emitting blue (B) light in sequence; and a b\g\b three-stage tandem structure including a light emitting unit emitting blue (B) light, a light emitting unit emitting green (G) light, and a light emitting unit emitting blue (B) light in this order. Note that "a·b" means that one light-emitting unit includes a light-emitting substance that emits light of a and a light-emitting substance that emits light of b.

Further, as shown in fig. 28C, a light emitting unit including one light emitting layer and a light emitting unit including a plurality of light emitting layers may be combined.

Specifically, in the structure shown in fig. 28C, a plurality of light emitting units (light emitting unit 763a, light emitting unit 763b, and light emitting unit 763C) are connected in series to each other through a charge generating layer 785. In addition, the light-emitting unit 763a includes a layer 780a, a light-emitting layer 771, and a layer 790a, the light-emitting unit 763b includes a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b, and the light-emitting unit 763c includes a layer 780c, a light-emitting layer 773, and a layer 790c.

For example, a b\r·g·yg B three-stage series structure or the like may be employed in the structure shown in fig. 28C, wherein the light emitting unit 763a is a light emitting unit that emits blue (B) light, the light emitting unit 763B is a light emitting unit that emits red (R) light, green (G) light, and yellow-green (YG) light, and the light emitting unit 763C is a light emitting unit that emits blue (B) light.

For example, as the number of stacked layers and the color order of the light emitting units, there may be mentioned a two-stage structure in which B and Y are stacked from the anode side, a two-stage structure in which B and light emitting unit X are stacked, a three-stage structure in which B, Y and B are stacked, a three-stage structure in which B, X and B are stacked, a two-stage structure in which R and Y are stacked from the anode side, a two-stage structure in which R and G are stacked, a two-stage structure in which G and R are stacked, a three-stage structure in which G, R and G are stacked, a three-stage structure in which R, G and R are stacked, or the like may be employed as the number of stacked layers and the color order of the light emitting layers in the light emitting unit X. In addition, another layer may be provided between the two light-emitting layers.

Next, materials that can be used for the light emitting device are described.

As the electrode on the side from which light is extracted out of the lower electrode 761 and the upper electrode 762, a conductive film that transmits visible light is used. Further, a conductive film that reflects visible light is preferably used as the electrode on the side from which light is not extracted. In the case where the display device includes a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits visible light and infrared light as an electrode on the side where light is extracted and use a conductive film that reflects visible light and infrared light as an electrode on the side where light is not extracted.

The electrode on the side not extracting light may be a conductive film transmitting visible light. In this case, the electrode is preferably arranged between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 can be reflected by the reflective layer and extracted from the display device.

As a material for forming a pair of electrodes of the light-emitting device, a metal, an alloy, a conductive compound, a mixture thereof, or the like can be suitably used. Specific examples of the material include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys thereof in suitable combination. Examples of the material include indium tin oxide (also referred to as in—sn oxide or ITO), in—si—sn oxide (also referred to as ITSO), indium zinc oxide (in—zn oxide), and in—w—zn oxide. Examples of the material include silver-containing alloys, aluminum-containing alloys (aluminum alloys) such as aluminum, nickel and lanthanum alloys (al—ni—la), silver and magnesium alloys, and silver, palladium and copper alloys (ag—pd—cu, also referred to as APC), and the like. Examples of the material include rare earth metals such as lithium, cesium, calcium, and strontium, europium, ytterbium, and the like, and alloys and graphene thereof, which are not listed above and belong to group 1 or group 2 of the periodic table.

The light emitting device preferably employs an optical microcavity resonator (microcavity) structure. Therefore, one of the pair of electrodes included in the light-emitting device is preferably an electrode having visible light transmittance and visible light reflectance (semi-transparent-semi-reflective electrode), and the other is preferably an electrode having reflectivity to visible light (reflective electrode). When the light emitting device has a microcavity structure, light emission obtained from the light emitting layer can be made to resonate between the two electrodes, and light emitted from the light emitting device can be improved.

In addition, the semi-transmissive-semi-reflective electrode may also have a stacked structure of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode having transparency to visible light (also referred to as a transparent electrode).

The transparent electrode has a light transmittance of 40% or more. For example, an electrode having a transmittance of 40% or more of visible light (light having a wavelength of 400nm or more and less than 750 nm) is preferably used as the transparent electrode of the light-emitting device. The reflectance of the semi-transmissive-semi-reflective electrode to visible light is 10% or more and 95% or less, preferably 30% or more and 80% or less. The reflectance of the reflective electrode to visible light is 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes is preferably 1×10 ^-2 Ω cm or less.

The light emitting device includes at least a light emitting layer. The light-emitting device may further include, as a layer other than the light-emitting layer, a layer containing a substance having high hole injection property, a substance having high hole transport property, a hole blocking material, a substance having high electron transport property, an electron blocking material, a substance having high electron injection property, a bipolar substance (a substance having high electron transport property and hole transport property), or the like. For example, the light emitting device may include one or more of a hole injection layer, a hole transport layer, a hole blocking layer, a charge generation layer, an electron blocking layer, an electron transport layer, and an electron injection layer in addition to the light emitting layer.

The light-emitting device may use a low-molecular compound or a high-molecular compound, and may further include an inorganic compound. The layer constituting the light-emitting device may be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

The light-emitting layer comprises one or more light-emitting substances. As the light-emitting substance, a substance exhibiting a light-emitting color such as blue, violet, bluish violet, green, yellowish green, yellow, orange, or red is suitably used. Further, as the light-emitting substance, a substance that emits near infrared light may be used.

Examples of the luminescent material include a fluorescent material, a phosphorescent material, a TADF material, and a quantum dot material.

Examples of the fluorescent material 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, naphthalene derivatives, and the like.

Examples of the phosphorescent material include an organometallic complex (particularly iridium complex) having a 4H-triazole skeleton, a 1H-triazole skeleton, an imidazole skeleton, a pyrimidine skeleton, a pyrazine skeleton or a pyridine skeleton, an organometallic complex (particularly iridium complex) having a phenylpyridine derivative having an electron-withdrawing group as a ligand, a platinum complex, a rare earth metal complex, and the like.

The light-emitting layer may contain one or more organic compounds (host material, auxiliary material, etc.) in addition to the light-emitting substance (guest material). As the one or more organic compounds, one or both of a substance having high hole-transporting property (hole-transporting material) and a substance having high electron-transporting property (electron-transporting material) can be used. As the hole transporting material, the following substances having high hole transporting properties which can be used for the hole transporting layer can be used. As the electron transporting material, the following materials having high electron transporting properties which can be used for the electron transporting layer can be used. Furthermore, as one or more organic compounds, bipolar materials or TADF materials may also be used.

For example, the light-emitting layer preferably contains a combination of a phosphorescent material, a hole-transporting material that easily forms an exciplex, and an electron-transporting material. By adopting such a structure, luminescence of ExTET (Exciplex-TRIPLET ENERGY TRANSFER: exciplex-triplet energy transfer) utilizing energy transfer from the exciplex to a light-emitting substance (phosphorescent material) can be obtained efficiently. By selecting a combination of exciplex forming light emission at a wavelength overlapping with the wavelength of the absorption band on the lowest energy side of the light-emitting substance, energy transfer can be made smooth, and light emission can be obtained efficiently. By adopting the above structure, high efficiency, low voltage driving, and long life of the light emitting device can be simultaneously realized.

The hole injection layer is a layer containing a material having high hole injection property, which injects holes from the anode to the hole transport layer. Examples of the material having high hole injection property include an aromatic amine compound and a composite material containing a hole transporting material and an acceptor material (electron acceptor material).

As the hole transporting material, the following material having high hole transporting property which can be used for the hole transporting layer can be used.

As the acceptor material, for example, oxides of metals belonging to groups 4 to 8 of the periodic table can be used. Specifically, molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide may be mentioned. Molybdenum oxide is particularly preferred because it is also stable in the atmosphere, has low hygroscopicity, and is easy to handle. In addition, an organic acceptor material containing fluorine may be used. In addition to the above, organic acceptor materials such as quinone dimethane derivatives, tetrachloroquinone derivatives, hexaazatriphenylene derivatives, and the like can also be used.

For example, a material containing a hole-transporting material and an oxide of a metal belonging to groups 4 to 8 of the periodic table (typically molybdenum oxide) can be used as the material having high hole-injecting property.

The hole transport layer is a layer that transports holes injected from the anode through the hole injection layer to the light emitting layer. The hole transport layer is a layer containing a hole transport material. As the hole transport material, a material having a hole mobility of 1X 10 ^-6cm²/Vs or more is preferably used. Note that as long as the hole transport property is higher than the electron transport property, substances other than the above may be used. As the hole transporting material, a material having high hole transporting property such as a pi-electron rich heteroaromatic compound (for example, a carbazole derivative, a thiophene derivative, a furan derivative, or the like) or an aromatic amine (a compound having an aromatic amine skeleton) is preferably used.

The electron blocking layer is disposed in contact with the light emitting layer. The electron blocking layer is a layer having hole transport property and containing a material capable of blocking electrons. The electron blocking material among the above hole transport materials may be used for the electron blocking layer.

The electron blocking layer has hole transport properties and therefore may also be referred to as a hole transport layer. In addition, a layer having electron blocking property among the hole transport layers may also be referred to as an electron blocking layer.

The electron transport layer is a layer that transports electrons injected from the cathode through the electron injection layer to the light emitting layer. The electron transport layer is a layer containing an electron transport material. As the electron transport material, a material having an electron mobility of 1X 10 ^-6cm²/Vs or more is preferably used. Note that as long as the electron transport property is higher than the hole transport property, substances other than the above may be used. Examples of the electron-transporting material include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, and metal complexes having a thiazole skeleton, and materials having high electron-transporting properties such 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 nitrogen-containing heteroaromatic compounds, which lack pi-electron-type heteroaromatic compounds.

The hole blocking layer is disposed in contact with the light emitting layer. The hole blocking layer is a layer having electron transport property and containing a material capable of blocking holes. The hole blocking material may be used for the hole blocking layer.

The hole blocking layer has electron transport properties and therefore may also be referred to as an electron transport layer. In addition, a layer having hole blocking property among the electron transport layers may also be referred to as a hole blocking layer.

The electron injection layer is a layer containing a material having high electron injection property, which injects electrons from the cathode to the electron transport layer. As the material having high electron injection properties, alkali metal, alkaline earth metal, or a compound thereof can be used. As the material having high electron injection properties, a composite material including an electron transporting material and a donor material (electron donor material) may be used.

Further, it is preferable that LUMO of the material having high electron injection property: the difference between the energy level and the work function value of the material for the cathode is small (specifically, 0.5eV or less).

Examples of the electron injection layer include alkali metals, alkaline earth metals, and their compounds such as lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF _x, X is an arbitrary number), lithium 8- (hydroxyquinoline) (abbreviated as Liq), lithium 2- (2-pyridyl) phenol (abbreviated as LiPP), lithium 2- (2-pyridyl) -3-hydroxypyridine (pyridinolato) (abbreviated as LiPPy), lithium 4-phenyl-2- (2-pyridyl) phenol (abbreviated as LiPPP), lithium oxide (LiO _x), and cesium carbonate. The electron injection layer may have a stacked structure of two or more layers. Examples of the stacked structure include a structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer.

The electron injection layer may also comprise an electron transport material. For example, compounds having an unshared electron pair and having an electron-deficient heteroaromatic ring can be used for the electron transport material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used.

The lowest unoccupied molecular orbital (LUMO: lowest Unoccupied Molecular Orbital) level of an organic compound having an unshared pair of electrons is preferably-3.6 eV or more and-2.3 eV or less. In general, the highest occupied molecular orbital (HOMO: highest Occupied Molecular Orbital) energy level and LUMO energy level of an organic compound can be estimated using CV (cyclic voltammetry), photoelectron spectroscopy, absorption spectroscopy, or reverse-light electron spectroscopy.

For example, 4, 7-diphenyl-1, 10-phenanthroline (abbreviated as BPhen), 2, 9-bis (naphthalen-2-yl) -4, 7-diphenyl-1, 10-phenanthroline (abbreviated as NBPhen), and a diquinoxalino [2,3-a:2',3' -c ] phenazine (abbreviated as HATNA), 2,4, 6-tris [3' - (pyridin-3-yl) biphenyl-3-yl ] -1,3, 5-triazine (abbreviated as TmPPPyTz) and the like are used for organic compounds having an unshared electron pair. In addition, NBPhen has a high glass transition temperature (Tg) as compared with BPhen, and thus has high heat resistance.

As described above, the charge generation layer has at least the charge generation region. The charge generation region preferably includes an acceptor material, and for example, preferably includes a hole transport material and an acceptor material which can be applied to the hole injection layer.

The charge generation layer preferably includes a layer containing a material having high electron injection property. This layer may also be referred to as an electron injection buffer layer. The electron injection buffer layer is preferably disposed between the charge generation region and the electron transport layer. By providing the electron injection buffer layer, the injection barrier between the charge generation region and the electron transport layer can be relaxed, so electrons generated in the charge generation region are easily injected into the electron transport layer.

The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, for example, a compound that may contain an alkali metal or a compound of an alkaline earth metal. Specifically, the electron injection buffer layer preferably contains an inorganic compound containing an alkali metal and oxygen or an inorganic compound containing an alkaline earth metal and oxygen, and more preferably contains an inorganic compound containing lithium and oxygen (lithium oxide (Li ₂ O) or the like). In addition, a material applicable to the above-described electron injection layer can be suitably used as the electron injection buffer layer.

The charge generation layer preferably includes a layer containing a material having high electron-transport property. This layer may also be referred to as an electronic relay layer. The electron relay layer is preferably disposed between the charge generation region and the electron injection buffer layer. When the charge generation layer does not include the electron injection buffer layer, the electron relay layer is preferably disposed between the charge generation region and the electron transport layer. The electron relay layer has a function of suppressing interaction of the charge generation region and the electron injection buffer layer (or the electron transport layer) and smoothly transferring electrons.

As the electron mediator, a phthalocyanine material such as copper (II) phthalocyanine (abbreviated as CuPc) or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

Note that the above-described charge generation region, electron injection buffer layer, and electron relay layer may not be clearly distinguished depending on the cross-sectional shape, characteristics, and the like.

In addition, the charge generation layer may contain a donor material instead of an acceptor material. For example, the charge generation layer may include a layer containing an electron transport material and a donor material which can be applied to the electron injection layer.

When the light emitting units are stacked, the charge generation layer is provided between the two light emitting units, whereby the rise of the driving voltage can be suppressed.

Embodiment 6

In this embodiment, an electronic device according to an embodiment of the present invention will be described with reference to fig. 29 to 31.

The electronic device according to the present embodiment includes the display device according to one embodiment of the present invention in the display portion. The display device according to one embodiment of the present invention is easy to achieve high definition and high resolution, and can achieve high display quality. Therefore, the display device can be used for display portions of various electronic devices.

Examples of the electronic device include electronic devices having a large screen such as a television set, a desktop or notebook personal computer, a display for a computer or the like, a digital signage, a large-sized game machine such as a pachinko machine, and the like, and digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, and audio reproducing devices.

In particular, since the display device according to one embodiment of the present invention can improve the definition, the display device can be suitably used for an electronic apparatus including a small display portion. Examples of such electronic devices include wristwatch-type and bracelet-type information terminal devices (wearable devices), head-mountable wearable devices, VR devices such as head-mounted displays, glasses-type AR devices, and MR (Mixed Reality) devices.

The display device according to one embodiment of the present invention preferably has extremely high resolution such as HD (1280×720 in pixel number), FHD (1920×1080 in pixel number), WQHD (2560×1440 in pixel number), WQXGA (2560×1600 in pixel number), 4K (3840×2160 in pixel number), 8K (7680×4320 in pixel number), or the like. In particular, the resolution is preferably set to 4K, 8K or more. In the display device according to one embodiment of the present invention, the pixel density (sharpness) is preferably 100ppi or more, more preferably 300ppi or more, still more preferably 500ppi or more, still more preferably 1000ppi or more, still more preferably 2000ppi or more, still more preferably 3000ppi or more, still more preferably 5000ppi or more, and still more preferably 7000ppi or more. By using the display device having one or both of high resolution and high definition, the sense of realism, sense of depth, and the like can be further improved in an electronic device for personal use such as a portable device or a home device. The screen ratio (aspect ratio) of the display device according to one embodiment of the present invention is not particularly limited. For example, the display device may adapt to 1:1 (square), 4: 3. 16: 9. 16:10, etc.

The electronic device of the present embodiment may also include a sensor (the sensor has a function of sensing, detecting, measuring, force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electric power, radiation, flow, humidity, inclination, vibration, smell, or infrared ray).

The electronic device of the present embodiment may have various functions. For example, it may have the following functions: a function of displaying various information (still image, moving image, character image, etc.) on the display section; a function of the touch panel; a function of displaying a calendar, date, time, or the like; executing functions of various software (programs); a function of performing wireless communication; a function of reading out a program or data stored in the storage medium; etc.

An example of a wearable device that can be worn on the head is described using fig. 29A to 29D. These wearable devices have one or both of the function of displaying AR content and the function of displaying VR content. In addition, these wearable devices may also have the function of displaying SR (Substitutional Reality) or MR content in addition to AR, VR. When the electronic device has a function of displaying contents of at least one of AR, VR, SR, MR, and the like, the user's sense of immersion can be improved.

The electronic apparatus 700A shown in fig. 29A and the electronic apparatus 700B shown in fig. 29B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

The display panel 751 can be applied to a display device according to one embodiment of the present invention. Therefore, an electronic device capable of displaying with extremely high definition can be realized.

Both the electronic device 700A and the electronic device 700B can project an image displayed by the display panel 751 on the display region 756 of the optical member 753. Since the optical member 753 has light transmittance, the user can see an image displayed in the display region while overlapping the transmitted image seen through the optical member 753. Therefore, both the electronic device 700A and the electronic device 700B are electronic devices capable of AR display.

As an imaging unit, a camera capable of capturing a front image may be provided to the electronic device 700A and the electronic device 700B. Further, by providing the electronic device 700A and the electronic device 700B with an acceleration sensor such as a gyro sensor, it is possible to detect the head orientation of the user and display an image corresponding to the orientation on the display area 756.

The communication unit includes a wireless communication device, and can supply video signals and the like through the wireless communication device. In addition, a connector to which a cable for supplying a video signal and a power supply potential can be connected may be included instead of or in addition to the wireless communication device.

The electronic device 700A and the electronic device 700B are provided with a battery, and can be charged by one or both of a wireless system and a wired system.

The housing 721 may be provided with a touch sensor module. The touch sensor module has a function of detecting whether or not the outer surface of the housing 721 is touched. By the touch sensor module, it is possible to detect a click operation, a slide operation, or the like by the user and execute various processes. For example, processing such as temporary stop and playback of a moving image can be performed by a click operation, and processing such as fast forward and fast backward can be performed by a slide operation. In addition, by providing a touch sensor module for each of the two housings 721, the operation range can be enlarged.

As the touch sensor module, various touch sensors can be used. For example, various methods such as a capacitance method, a resistive film method, an infrared method, an electromagnetic induction method, a surface acoustic wave method, and an optical method can be used. In particular, a capacitive or optical sensor is preferably applied to the touch sensor module.

In the case of using an optical touch sensor, a photoelectric conversion device (also referred to as a photoelectric conversion element) can be used as a light receiving device (also referred to as a light receiving element). One or both of an inorganic semiconductor and an organic semiconductor may be used for the active layer of the photoelectric conversion device.

The electronic apparatus 800A shown in fig. 29C and the electronic apparatus 800B shown in fig. 29D each include a pair of display portions 820, a housing 821, a communication portion 822, a pair of attachment portions 823, a control portion 824, a pair of imaging portions 825, and a pair of lenses 832.

The display unit 820 can be applied to a display device according to one embodiment of the present invention. Therefore, an electronic device capable of displaying with extremely high definition can be realized. Thus, the user can feel a high immersion.

The display unit 820 is provided in a position inside the housing 821 and visible through the lens 832. In addition, by displaying different images on each of the pair of display portions 820, three-dimensional display using parallax can be performed.

Both electronic device 800A and electronic device 800B may be referred to as VR-oriented electronic devices. A user who mounts the electronic apparatus 800A or the electronic apparatus 800B can see an image displayed on the display unit 820 through the lens 832.

The electronic device 800A and the electronic device 800B preferably have a mechanism in which the left and right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are positioned at the most appropriate positions according to the positions of eyes of the user. Further, it is preferable to have a mechanism in which the focus is adjusted by changing the distance between the lens 832 and the display portion 820.

The user can mount the electronic apparatus 800A or the electronic apparatus 800B on the head using the mounting portion 823. In fig. 29C and the like, the attachment portion 823 is illustrated as having a shape like a temple of an eyeglass (also referred to as a joint, temple, or the like), but is not limited thereto. The mounting portion 823 may have, for example, a helmet-type or belt-type shape as long as the user can mount it.

The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging section 825 may be output to the display section 820. An image sensor may be used in the imaging section 825. In addition, a plurality of cameras may be provided so as to be able to correspond to various angles of view such as a telephoto angle and a wide angle.

Note that, here, an example including the imaging unit 825 is shown, and a distance measuring sensor (hereinafter, also referred to as a detection unit) capable of measuring a distance from the object may be provided. In other words, the imaging section 825 is one mode of the detecting section. As the Detection unit, for example, an image sensor or a LIDAR (Light Detection AND RANGING) equidistant image sensor can be used. By using the image acquired by the camera and the image acquired by the range image sensor, more information can be acquired, and a posture operation with higher accuracy can be realized.

The electronic device 800A may also include a vibration mechanism that is used as a bone conduction headset. For example, a structure including the vibration mechanism may be employed as any one or more of the display portion 820, the frame 821, and the mounting portion 823. Thus, it is not necessary to provide an acoustic device such as a headphone, an earphone, or a speaker, and only the electronic device 800A can enjoy video and audio.

The electronic device 800A and the electronic device 800B may each include an input terminal. A cable supplying an image signal from an image output apparatus or the like, power for charging a battery provided in the electronic apparatus, or the like may be connected to the input terminal.

The electronic device according to an embodiment of the present invention may have a function of wirelessly communicating with the headset 750. The headset 750 includes a communication section (not shown), and has a wireless communication function. The headset 750 may receive information (e.g., voice data) from an electronic device via a wireless communication function. For example, the electronic device 700A shown in fig. 29A has a function of transmitting information to the headphones 750 through a wireless communication function. In addition, the electronic device 800A shown in fig. 29C, for example, has a function of transmitting information to the headphones 750 through a wireless communication function.

In addition, the electronic device may also include an earphone portion. The electronic device 700B shown in fig. 29B includes an earphone portion 727. For example, a structure may be employed in which the earphone portion 727 and the control portion are connected in a wired manner. A part of the wiring connecting the earphone portion 727 and the control portion may be disposed inside the housing 721 or the mounting portion 723.

Also, the electronic device 800B shown in fig. 29D includes an earphone portion 827. For example, a structure may be employed in which the earphone part 827 and the control part 824 are connected in a wired manner. A part of the wiring connecting the earphone unit 827 and the control unit 824 may be disposed inside the housing 821 or the mounting unit 823. The earphone part 827 and the mounting part 823 may include magnets. This is preferable because the earphone part 827 can be fixed to the mounting part 823 by magnetic force, and easy storage is possible.

Note that the electronic device may also include a sound output terminal that can be connected to an earphone, a headphone, or the like. The electronic device may include one or both of the audio input terminal and the audio input means. As the sound input means, for example, a sound receiving device such as a microphone can be used. By providing the sound input mechanism to the electronic apparatus, the electronic apparatus can be provided with a function called a headset.

As described above, both of the glasses type (electronic device 700A, electronic device 700B, and the like) and the goggle type (electronic device 800A, electronic device 800B, and the like) are preferable as the electronic device according to the embodiment of the present invention.

In addition, the electronic device of one embodiment of the present invention may send information to the headset in a wired or wireless manner.

The electronic device 6500 shown in fig. 30A is a portable information terminal device that can be used as a smartphone.

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.

The display portion 6502 can use a display device according to one embodiment of the present invention.

Fig. 30B is a schematic cross-sectional view of an end portion on the microphone 6506 side including a housing 6501.

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

The display device 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 using an adhesive layer (not shown).

In an area outside the display portion 6502, a part of the display device 6511 is overlapped, and the overlapped part is connected to the FPC6515. The FPC6515 is mounted with an IC6516. The FPC6515 is connected to terminals provided on the printed circuit board 6517.

The display device 6511 can use a flexible display according to one embodiment of the present invention. Thus, an extremely lightweight electronic device can be realized. Further, since the display device 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic apparatus. Further, by folding a part of the display device 6511 to provide a connection portion with the FPC6515 on the back surface of the pixel portion, a narrow-frame electronic apparatus can be realized.

Fig. 30C shows an example of a television apparatus. In the television device 7100, a display unit 7000 is incorporated in a housing 7101. Here, a structure in which the housing 7101 is supported by a bracket 7103 is shown.

The display unit 7000 may be a display device according to an embodiment of the present invention.

The operation of the television device 7100 shown in fig. 30C can be performed by using an operation switch provided in the housing 7101 and a remote control operation device 7111 provided separately. Alternatively, the display 7000 may be provided with a touch sensor, or the television device 7100 may be operated by touching the display 7000 with a finger or the like. The remote controller 7111 may be provided with a display unit for displaying data outputted from the remote controller 7111. By using the operation keys or touch panel provided in the remote control unit 7111, the channel and volume can be operated, and the video displayed on the display unit 7000 can be operated.

The television device 7100 includes a receiver, a modem, and the like. A general television broadcast may be received by using a receiver. Further, the communication network is connected to a wired or wireless communication network via a modem, and information communication is performed in one direction (from a sender to a receiver) or in two directions (between a sender and a receiver, between a receiver and a receiver, or the like).

Fig. 30D shows an example of a notebook personal computer. The notebook personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. The display unit 7000 is incorporated in the housing 7211.

Fig. 30E and 30F show an example of the digital signage.

The digital signage 7300 shown in fig. 30E includes a housing 7301, a display portion 7000, a speaker 7303, and the like. Further, an LED lamp, an operation key (including a power switch or an operation switch), a connection terminal, various sensors, a microphone, and the like may be included.

Fig. 30F shows a digital signage 7400 disposed on a cylindrical post 7401. The digital signage 7400 includes a display 7000 disposed along a curved surface of the post 7401.

In fig. 30E and 30F, a display device according to an embodiment of the present invention can be used for the display unit 7000.

The larger the display unit 7000 is, the larger the amount of information that can be provided at a time is. The larger the display unit 7000 is, the more attractive the user can be, for example, to improve the advertising effect.

By using the touch panel for the display unit 7000, not only a still image or a moving image can be displayed on the display unit 7000, but also a user can intuitively operate the touch panel, which is preferable. In addition, in the application for providing information such as route information and traffic information, usability can be improved by intuitive operations.

As shown in fig. 30E and 30F, the digital signage 7300 or 7400 can preferably be linked to an information terminal device 7311 or 7411 such as a smart phone carried by a user by wireless communication. For example, the advertisement information displayed on the display portion 7000 may be displayed on the screen of the information terminal device 7311 or the information terminal device 7411. Further, by operating the information terminal device 7311 or the information terminal device 7411, the display of the display portion 7000 can be switched.

Further, a game may be executed on the digital signage 7300 or the digital signage 7400 with the screen of the information terminal apparatus 7311 or the information terminal apparatus 7411 as an operation unit (controller). Thus, a plurality of users can participate in the game at the same time without specifying the users, and enjoy the game.

The electronic apparatus shown in fig. 31A to 31G includes a housing 9000, a display portion 9001, a speaker 9003, an operation key 9005 (including a power switch or an operation switch), a connection terminal 9006, a sensor 9007 (which has a function of sensing, detecting, measuring, or the like force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, an electric field, current, voltage, electric power, radiation, flow, humidity, inclination, vibration, smell, or infrared ray), a microphone 9008, or the like.

In fig. 31A to 31G, a display device according to one embodiment of the present invention can be used for the display portion 9001.

The electronic devices shown in fig. 31A to 31G have various functions. For example, it may have the following functions: a function of displaying various information (still image, moving image, character image, etc.) on the display unit; a function of the touch panel; a function of displaying a calendar, date, time, or the like; functions of controlling processing by using various software (programs); a function of performing wireless communication; a function of reading out and processing the program or data stored in the storage medium; etc. Note that the functions of the electronic apparatus are not limited to the above functions, but may have various functions. The electronic device may include a plurality of display portions. In addition, a camera or the like may be provided in the electronic device so as to have the following functions: a function of capturing a still image or a moving image, and storing the captured image in a storage medium (an external storage medium or a storage medium built in a camera); a function of displaying the photographed image on a display section; etc.

Next, the electronic devices shown in fig. 31A to 31G are described in detail.

Fig. 31A is a perspective view showing the portable information terminal 9101. The portable information terminal 9101 can be used as a smart phone, for example. Note that in the portable information terminal 9101, a speaker 9003, a connection terminal 9006, a sensor 9007, and the like may be provided. Further, as the portable information terminal 9101, text or image information may be displayed on a plurality of surfaces thereof. An example of displaying three icons 9050 is shown in fig. 31A. In addition, information 9051 shown in a rectangle of a broken line may be displayed on the other surface of the display portion 9001. As an example of the information 9051, information indicating the receipt of an email, SNS, a telephone, or the like can be given; a title of an email, SNS, or the like; sender name of email or SNS; a date; time; a battery balance; and radio wave intensity. Or an icon 9050 or the like may be displayed at a position where the information 9051 is displayed.

Fig. 31B is a perspective view showing the portable information terminal 9102. The portable information terminal 9102 has a function of displaying information on three or more surfaces of the display portion 9001. Here, examples are shown in which the information 9052, the information 9053, and the information 9054 are displayed on different surfaces. For example, in a state where the portable information terminal 9102 is placed in a coat pocket, the user can confirm the information 9053 displayed at a position seen from above the portable information terminal 9102. For example, the user can confirm the display without taking out the portable information terminal 9102 from the pocket, whereby it can be determined whether to answer a call.

Fig. 31C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 may execute various application software such as reading and editing of mobile phones, emails and articles, playing music, network communications, computer games, and the like. The tablet terminal 9103 includes a display portion 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front face of the housing 9000, operation keys 9005 serving as operation buttons on the left side face of the housing 9000, and connection terminals 9006 on the bottom face.

Fig. 31D is a perspective view showing the wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used as a smart watch (registered trademark), for example. The display surface of the display portion 9001 is curved, and can display along the curved display surface. Further, the portable information terminal 9200 can perform handsfree communication by, for example, communicating with a headset capable of wireless communication. Further, by using the connection terminal 9006, the portable information terminal 9200 can perform data transmission or charging with other information terminals. Charging may also be performed by wireless power.

Fig. 31E to 31G are perspective views showing the portable information terminal 9201 that can be folded. Fig. 31E is a perspective view showing a state in which the portable information terminal 9201 is unfolded, fig. 31G is a perspective view showing a state in which it is folded, and fig. 31F is a perspective view showing a state in the middle of transition from one of the state in fig. 31E and the state in fig. 31G to the other. The portable information terminal 9201 has good portability in a folded state and has a large display area with seamless splicing in an unfolded state, so that the display has a strong browsability. The display portion 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. The display portion 9001 can be curved in a range of, for example, 0.1mm to 150mm in radius of curvature.

Examples

In this example, the pixel electrode 111 was manufactured by the method shown in fig. 9A to 9E, the EL layer 113 was manufactured on the pixel electrode 111 by the method shown in fig. 7A and 7B, and a scanning transmission electron microscope (STEM: scanning Transmission Electron Microscopy) was used: and (5) observing results.

In this example, samples 1A, 1B, 1C, and 1D having the EL layer 113 formed on the pixel electrode 111 were manufactured by the method described in the above embodiment mode. Samples 1A and 1B are deep samples of the depth of the recess formed in the insulating layer 255C, and samples 1C and 1D are samples of large thickness of the pixel electrode 111.

Hereinafter, the method for producing samples 1A to 1D will be described. First, a method of manufacturing the pixel electrode 111 is described with reference to fig. 9A to 9E.

First, in samples 1A to 1D, as shown in fig. 9A, an insulating layer 255c, a conductive film 11aA, a conductive film 11bA, a conductive film 11cA, and a conductive film 11dA are sequentially deposited on a silicon substrate.

The insulating layer 255c is a silicon oxide film deposited by a PECVD method. In addition, the conductive film 11aA is a 50nm thick titanium film deposited by a DC sputtering method. In addition, the conductive film 11bA is an aluminum film deposited by a DC sputtering method. In addition, the conductive film 11cA is a 6nm thick titanium film deposited by a DC sputtering method. The conductive film 11aA, the conductive film 11bA, and the conductive film 11cA are continuously deposited in a state of not being exposed to the atmosphere. After the deposition, the conductive film 11aA, the conductive film 11bA, and the conductive film 11cA were subjected to heat treatment at 300 ℃ for 1 hour in an atmosphere, whereby the conductive film 11cA was oxidized to form titanium oxide.

Here, in sample 1A and sample 1B, a conductive film 11bA with a target thickness of 70nm was deposited, in sample 1C, a conductive film 11bA with a target thickness of 100nm was deposited, and in sample 1D, a conductive film 11bA with a target thickness of 180nm was deposited. Thus, the thicknesses of the pixel electrodes 111 of the samples 1C and 1D are greater than those of the samples 1A and 1B, and the thickness of the pixel electrode 111 of the sample 1D is greater than that of the sample 1C.

The conductive film 11dA is a 10nm thick indium tin oxide film containing silicon. The conductive film 11dA was deposited using an indium tin oxide target containing 5wt% silicon oxide and using a DC sputtering method.

Next, in samples 1A to 1D, as shown in fig. 9A, a resist mask 12 was formed over the conductive film 11 dA. As the resist mask 12, a positive type photoresist having a thickness of 1.5 μm was used.

Next, in samples 1A to 1D, as shown in fig. 9B, the conductive film 11dA was wet etched to form a conductive layer 11D. ITO-07N (manufactured by Kanto chemical Co., ltd.) was used for wet etching of the conductive film 11 dA.

Next, in samples 1A to 1D, as shown in fig. 9C, the conductive films 11cA, 11bA, and 11aA are dry etched to form the conductive layers 11C, 11b, and 11A. In dry etching of the conductive film 11cA, the conductive film 11bA, and the conductive film 11aA, BCl ₃ gas 60sccm and Cl ₂ gas 20sccm were used as etching gases, the pressure was 1.9pa, the icp power was 450W, the bias power was 100W, and the substrate temperature was 70 ℃. Note that the thickness of the conductive film 11bA differs between the samples 1A to 1D, and thus the etching times of the samples 1A to 1D are appropriately set.

Here, in the above conditions, the etching rates of the conductive film 11cA, the conductive film 11bA, and the conductive film 11aA are different from each other. Thus, as shown in fig. 9C, the side surfaces of the conductive layers 11a and 11C protrude from the side surface of the conductive layer 11 b.

Next, in samples 1A to 1D, as shown in fig. 9D, the exposed insulating layer 255c is dry etched to form a recess in the insulating layer 255 c. In dry etching of the insulating layer 255c, CF ₄ gas of 80sccm, pressure of 2.0pa, icp power of 500W, bias power of 50W, and substrate temperature of 70 ℃.

Here, in the etching step according to fig. 9D, the processing time in sample 1A was set to 60 seconds, the processing time in sample 1B was set to 120 seconds, and the processing time in samples 1C and 1D was set to 15 seconds. Thus, in sample 1A, the depth T2 of the recess of the insulating layer 255C is deeper than that of samples 1C and 1D, and in sample 1B, the depth T2 of the recess of the insulating layer 255C is deeper than that of sample 1A.

Next, as shown in fig. 9E, in samples 1A to 1D, the resist mask 12 on the conductive layer 11D was removed by plasma ashing and wet etching with oxygen gas. Thus, in samples 1A to 1D, the pixel electrode 111 (the conductive layer 11A, the conductive layer 11b, the conductive layer 11c, and the conductive layer 11D) can be formed over the insulating layer 255 c.

In this way, as shown in fig. 7A, in the samples 1A to 1D, a plurality of pixel electrodes 111 can be formed. Next, in samples 1A to 1D, an EL film was deposited on the insulating layer 255c and the pixel electrode 111. The EL film having a target thickness of 180nm was deposited by vapor deposition.

As shown in fig. 7B, the EL film has a first layer 113a on the pixel electrode 111a, a second layer 113B on the pixel electrode 111B, and a fourth layer 113d between the pixel electrode 111a and the pixel electrode 111B.

Further, an aluminum oxide film having a thickness of 15nm was deposited by an ALD method so as to cover the EL film.

Cross-sectional STEM images of the samples 1A to 1D manufactured through the above steps were photographed. The sectional STEM images of samples 1A to 1D were photographed at an acceleration voltage of 200kV using "HD-2300" manufactured by Hitachi high technology Co.

Fig. 32A to 32D show cross-sectional STEM images of samples 1A to 1D. Fig. 32A is a cross-sectional STEM image of sample 1A, fig. 32B is a cross-sectional STEM image of sample 1B, fig. 32C is a cross-sectional STEM image of sample 1C, and fig. 32D is a cross-sectional STEM image of sample 1D.

As shown in fig. 32A to 32D, in each of the samples 1A to 1D, the first layer 113a is formed on the pixel electrode 111A, and the second layer 113b is formed on the pixel electrode 111 b. In addition, the fourth layer 113d is formed in a region where a recess is formed in the insulating layer 255c between the pixel electrode 111a and the pixel electrode 111 b.

Here, a region surrounded by a broken line in fig. 32A to 32D represents a region in which the first layer 113a and the fourth layer 113D or the second layer 113b and the fourth layer 113D are divided. In other words, in the sample 1A, the second layer 113B and the fourth layer 113D are divided, in the sample 1B, the first layer 113a and the fourth layer 113D are divided, and in the sample 1C and the sample 1D, the first layer 113a and the second layer 113B and the fourth layer 113D are divided.

Table 1 shows the sum of the thicknesses T1A of the conductive layers 11A and 11b, the depth T2 of the concave portion of the insulating layer 255c, the thicknesses T1A, and the depth T2 in the samples 1A to 1D, and the thickness T3 of the fourth layer 113D.

TABLE 1

As shown in table 1, the sum of the thickness T1A and the depth T2 in the samples 1A to 1D is equal to or greater than the thickness T3. In other words, if the sum of the thickness T1a and the depth T2 is equal to or greater than the thickness T3, it is confirmed that at least one of the first layer 113a and the fourth layer 113d and the second layer 113b and the fourth layer 113d is divided.

Thus, by increasing the step formed by the concave portions of the pixel electrode 111 and the insulating layer 255c, the EL layer 113 formed on the pixel electrode 111 and the fourth layer 113d formed between the pixel electrodes 111 can be divided. Accordingly, leakage current between light emitting devices can be suppressed or sufficiently reduced.

[ Description of the symbols ]

AL: wiring, CL: wiring, GL: wiring, RL: wiring, SL: wiring, SLB: wiring, SLG: wiring, SLR: wiring, 11a: conductive layer, 11aA: conductive film, 11b: conductive layer, 11bA: conductive film, 11c: conductive layer, 11cA: conductive film, 11d: conductive layer, 11dA: conductive film, 12: resist mask, 100A: display device, 100B: display device, 100C: display device, 100D: display device, 100E: display device, 100F: display device, 100G: display device, 100H: a display device, 100: display device, 101: substrate, 102: substrate, 107: adhesive layer, 108: light shielding layer, 109a: protrusion, 109b: protrusion, 110a: sub-pixels, 110B: sub-pixels, 110b: sub-pixels, 110c: sub-pixels, 110d: sub-pixels, 110G: sub-pixels, 110R: sub-pixels, 110: pixel, 111a: pixel electrode, 111b: pixel electrode, 111c: pixel electrode, 111: pixel electrode, 112a: conductive layer, 112b: conductive layer, 112c: conductive layer, 113a: a first layer, 113b: second layer, 113c: third layer, 113d: fourth layer, 113: EL layer, 114: public layer, 115: common electrode, 123: conductive layer, 124a: pixel, 124b: pixel, 125A: insulating film, 125: insulating layer, 126a: conductive layer, 126b: conductive layer, 126c: conductive layer, 127A: insulating layer, 127: insulating layer, 128: layer, 129a: conductive layer, 129b: conductive layer, 129c: conductive layer, 130a: light emitting device, 130B: light emitting device, 130b: light emitting device, 130c: a light emitting device, 130G: light emitting device, 130R: light emitting device, 130: light emitting device, 131: protective layer, 132a: coloring layer, 132b: coloring layer, 132c: coloring layer, 132: coloring layer, 140: connection portion, 147: resin layer, 151: substrate, 152: substrate, 153: insulating layer, 162: display unit, 164: circuit, 165: wiring, 166: conductive layer, 172: FPC, 173: IC. 201: transistor, 204: connection part, 205: transistor, 209: transistor, 210: transistor, 211: an insulating layer, 213: insulating layer, 214: insulating layer, 215: insulating layer, 218: insulating layer, 221: conductive layer, 222a: conductive layer, 222b: conductive layer, 223: conductive layer, 225: insulating layer, 231i: channel formation region, 231n: low resistance region, 231: semiconductor layer, 240: capacitor, 241: conductive layer, 242: connection layer, 243: insulating layer, 245: conductive layer, 251: conductive layer, 252: conductive layer, 254: insulating layer, 255a: insulating layer, 255b: insulating layer, 255c: insulating layer, 256: a plug(s), 261: insulating layer, 262: insulating layer, 263: insulating layer, 264: insulating layer, 265: insulating layer, 271: plug, 274a: conductive layer, 274b: conductive layer, 274: plug, 280: display module, 281: display unit, 282: circuit part, 283a: pixel circuit, 283: pixel circuit sections 284a: pixel, 284: pixel unit, 285: terminal portion 286: wiring section 290: FPC, 291: substrate, 292: substrate, 301A: substrate, 301B: substrate, 301: substrate, 310A: a transistor(s), 310B: transistor, 310: transistor, 311: conductive layer, 312: low resistance region, 313: insulating layer, 314: insulating layer, 315: element separation layer, 320A: transistor, 320B: transistor, 320: transistor, 321: semiconductor layer, 323: insulating layer, 324: conductive layer, 325: conductive layer, 326: insulating layer 327: conductive layer, 328: insulating layer, 329: insulating layer, 331: substrate, 332: insulating layer, 335: insulating layer, 336: insulating layer, 341: conductive layer, 342: conductive layer 343: a plug(s), 344: insulating layer, 345: insulating layer, 346: insulation layer, 347: bump, 348: adhesive layer, 400: display device, 401: substrate, 402: drive circuit unit, 403: drive circuit unit, 404: display unit, 405B: sub-pixels, 405G: sub-pixels, 405R: sub-pixels, 405: pixel, 410a: transistor, 410: transistor, 411i: channel formation region, 411n: low resistance region, 411: semiconductor layer, 412: insulating layer, 413: conductive layer, 414a: conductive layer, 414b: conductive layer, 415: a conductive layer, 416: insulating layer 421: insulating layer, 422: insulating layer 423: insulating layer, 426: insulating layer, 430: pixel, 431: conductive layer, 450a: transistor, 450: transistor, 451: semiconductor layer, 452: insulating layer, 453: conductive layer, 454a: conductive layer, 454b: conductive layer, 455: conductive layer, 700A: electronic device, 700B: electronic device, 721: a frame body 723: mounting portion, 727: earphone part, 750: earphone, 751: display panel, 753: optical member 756: display area, 757: a frame(s), 758: nose pad, 761: a lower electrode 762: upper electrode, 763a: light emitting unit, 763b: light emitting unit, 763c: light emitting unit, 763: EL layer, 764: layer, 771a: light emitting layer, 771b: light emitting layer, 771c: light emitting layer, 771: a light emitting layer 772a: light emitting layer 772b: light emitting layer 772c: a light emitting layer, 772: light emitting layer, 773: light emitting layer, 780a: layer, 780b: layer, 780c: layer, 780: layer, 781: layer, 782: layer, 785: charge generation layer, 790a: a layer(s), 790b: layer 790c: layer, 790: layer, 791: layer, 792: layer, 800A: electronic device, 800B: electronic device, 820: display unit 821: a frame body 822: communication unit 823: mounting portion, 824: control unit 825: imaging unit 827: earphone part 832: lens, 6500: electronic device, 6501: frame body, 6502: display unit, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source, 6510: a protective member, 6511: display device, 6512: optical member, 6513: touch sensor panel, 6515: FPC, 6516: IC. 6517: printed circuit board, 6518: battery, 7000: display unit, 7100: television apparatus, 7101: frame body, 7103: support, 7111: remote control operation machine, 7200: notebook personal computer, 7211: frame, 7212: keyboard, 7213: pointing device, 7214: external connection port, 7300: digital signage, 7301: frame body, 7303: speaker, 7311: information terminal equipment, 7400: digital signage, 7401: column, 7411: information terminal apparatus, 9000: frame body, 9001: display unit, 9002: camera, 9003: speaker, 9005: operation key, 9006: connection terminal, 9007: sensor, 9008: microphone, 9050: icon, 9051: information, 9052: information, 9053: information, 9054: information, 9055: hinge, 9101: portable information terminal, 9102: portable information terminal, 9103: tablet terminal, 9200: portable information terminal, 9201: a portable information terminal.

Claims

1. A display device, comprising:

A first light emitting device;

a second light emitting device;

a first coloring layer;

a second coloring layer; and

A first insulating layer is provided over the first insulating layer,

Wherein the first light emitting device includes a first pixel electrode on the first insulating layer, a first EL layer on the first pixel electrode, and a common electrode on the first EL layer,

The second light emitting device includes a second pixel electrode on the first insulating layer, a second EL layer on the second pixel electrode, and the common electrode on the second EL layer,

The first coloring layer is disposed in such a manner as to overlap the first light emitting device,

The second coloring layer is disposed in such a manner as to overlap the second light emitting device,

The wavelength regions of the transmitted light of the second coloring layer and the first coloring layer are different from each other,

The first insulating layer has a recess between the first pixel electrode and the second pixel electrode,

A third EL layer is disposed in the recess of the first insulating layer,

The first EL layer, the second EL layer and the third EL layer comprise the same material,

And a sum of a thickness of the first pixel electrode and a depth of the recess is equal to or greater than a thickness of the third EL layer.

2. The display device according to claim 1,

Wherein the third EL layer is in contact with the bottom and side surfaces of the recess of the first insulating layer, the side surfaces of the first pixel electrode, and the side surfaces of the second pixel electrode.

3. The display device according to claim 1,

Wherein the thickness of the first pixel electrode is greater than or equal to the thickness of the third EL layer.

4. The display device according to claim 1,

Wherein the depth of the recess is greater than the thickness of the third EL layer,

And the third EL layer is not in contact with the first pixel electrode and the second pixel electrode.

5. The display device according to claim 1,

Wherein the first pixel electrode and the second pixel electrode each include a first conductive layer on the first insulating layer and a second conductive layer on the first conductive layer,

And the side surface of the second conductive layer protrudes from the side surface of the first conductive layer.

6. The display device according to claim 5,

Wherein a sum of a thickness below a bottom surface of the second conductive layer and a depth of the recess in the first pixel electrode is equal to or greater than a thickness of the third EL layer.

7. The display device according to claim 5,

Wherein the first pixel electrode and the second pixel electrode each comprise a third conductive layer under the first conductive layer,

The first conductive layer is reflective and,

And the second conductive layer and the third conductive layer have a function of protecting the first conductive layer.

8. The display device according to claim 7,

Wherein the first conductive layer comprises aluminum.

9. The display device according to claim 8,

Wherein the second conductive layer comprises titanium oxide.

10. The display device according to claim 9,

Wherein the third conductive layer comprises titanium.

11. The display device according to claim 10,

Wherein the first pixel electrode and the second pixel electrode each comprise a fourth conductive layer on the second conductive layer,

The fourth conductive layer has a work function greater than that of the second conductive layer,

The second conductive layer and the fourth conductive layer have light transmittance,

And the fourth conductive layer contains an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon.

12. The display device according to claim 1, further comprising:

a second insulating layer on the third EL layer; and

A third insulating layer on the second insulating layer,

Wherein the second insulating layer comprises an inorganic material,

The third insulating layer comprises an organic material,

A part of the second insulating layer and a part of the third insulating layer are arranged at positions sandwiched between the side surface of the first EL layer and the side surface of the first pixel electrode and the side surface of the second EL layer and the second pixel electrode,

And the other part of the third insulating layer overlaps with a part of the top surface of the first EL layer and a part of the top surface of the second EL layer with the second insulating layer interposed therebetween.

13. The display device according to claim 12,

Wherein the second insulating layer is in contact with a side surface of the first pixel electrode and a side surface of the second pixel electrode.

14. The display device according to claim 12,

Wherein the common electrode is disposed on the third insulating layer.

15. The display device according to claim 12,

Wherein the first light emitting device includes a common layer disposed between the first EL layer and the common electrode,

And the second light emitting device includes the common layer disposed between the second EL layer and the common electrode.

16. The display device according to claim 12,

Wherein the first coloring layer and the second coloring layer are disposed on the common electrode.

17. The display device according to any one of claims 1 to 16,

Wherein the first EL layer includes a first light emitting unit on the first pixel electrode, a first charge generating layer on the first light emitting unit, and a second light emitting unit on the first charge generating layer,

The second EL layer includes a third light emitting unit on the second pixel electrode, a second charge generating layer on the third light emitting unit, and a fourth light emitting unit on the second charge generating layer,

And the third EL layer includes a fifth light emitting unit on the first insulating layer, a third charge generating layer on the fifth light emitting unit, and a sixth light emitting unit on the third charge generating layer.

18. The display device according to claim 17,

Wherein the first light emitting unit, the third light emitting unit and the fifth light emitting unit comprise the same material,

The first charge generation layer, the second charge generation layer, and the third charge generation layer comprise the same material,

And the second light emitting unit, the fourth light emitting unit, and the sixth light emitting unit comprise the same material.

19. A method of manufacturing a display device, comprising the steps of:

In the manufacture of a display device having a plurality of pixel electrodes including a first conductive layer, a second conductive layer, and a third conductive layer:

Sequentially depositing a first conductive film, a second conductive film and a third conductive film on the insulating layer;

Processing the third conductive film, the second conductive film, and the first conductive film into the third conductive layer, the second conductive layer, and the first conductive layer by first dry etching;

anisotropically etching a side surface of the second conductive layer;

Forming a recess in a region of the insulating layer not overlapping the plurality of pixel electrodes by second dry etching; and

An EL film is formed by a vapor deposition method,

Wherein in the anisotropic etching, an etching rate of the second conductive layer is greater than an etching rate of the third conductive layer,

The EL film is divided into a first EL layer formed on the plurality of pixel electrodes and a second EL layer formed between the plurality of pixel electrodes in a self-aligned manner.

20. The method for manufacturing a display device according to claim 19,

Wherein a gas comprising chlorine is used in the anisotropic etching.