JP2018066944A - Method for manufacturing display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display that exhibits high visibility irrespective of an ambient brightness.SOLUTION: A display including a first display device having a first liquid crystal layer and a second display device having a second liquid crystal layer between a first substrate and a second substrate is manufactured. The second display device is formed by forming a first common electrode on the first substrate, forming a second common electrode on the second substrate, forming a first layer on a manufacture substrate, forming a second layer on the first layer, forming a first pixel electrode on the second layer, forming an insulating layer on the first pixel electrode, forming a second pixel electrode on the insulating layer, and laminating the manufacture substrate and second substrate while the second liquid crystal layer is arranged between the second common electrode and second pixel electrode; the first display device is formed by separating the first layer and second layer by irradiating the layers with light, and laminating the first substrate and second substrate while the first liquid crystal layer is arranged between the first common electrode and first pixel electrode.SELECTED DRAWING: Figure 3

Description

One embodiment of the present invention relates to a method for manufacturing a display device.

Note that one embodiment of the present invention is not limited to the above technical field. As a technical field of one embodiment of the present invention, a semiconductor device, a display device, a light-emitting device, an electronic device, a lighting device, a driving method thereof, or a manufacturing method thereof can be given as an example.

Note that in this specification and the like, a semiconductor device refers to any device that can function by utilizing semiconductor characteristics. A transistor, a semiconductor circuit, a display device, a light-emitting device, an arithmetic device, a memory device, or the like is one embodiment of a semiconductor device. In addition, an imaging device, an electro-optical device, a power generation device (including a thin film solar cell, an organic thin film solar cell, and the like) and an electronic device may include a semiconductor device.

Electronic devices typified by mobile devices such as personal computers (PCs), notebook PCs, electronic books, tablets, and smartphones are widespread. Mobile devices are required to display suitable for the brightness of the environment used such as the outdoor environment and indoor environment.

As a display device included in an electronic apparatus, a display device in which a reflective liquid crystal display device and a transmissive liquid crystal display device are combined is proposed. For example, as a liquid crystal display device that takes advantage of the reflective liquid crystal display device and enables use in an environment where ambient illumination light is weak, a part of the incident light is transmitted and the remaining incident light is reflected. A liquid crystal display device using a so-called semi-transmissive reflective film has been proposed (see Patent Document 1).

JP 2002-372710 A

An object of one embodiment of the present invention is to provide a method for manufacturing a display device with low cost and high productivity. An object of one embodiment of the present invention is to manufacture a display device using a large-sized substrate. An object of one embodiment of the present invention is to manufacture a display device at low temperature. An object of one embodiment of the present invention is to provide a novel method for manufacturing a display device.

An object of one embodiment of the present invention is to provide a display device with low power consumption. An object of one embodiment of the present invention is to provide a display device with high visibility regardless of ambient brightness. An object of one embodiment of the present invention is to provide a display device with favorable display quality. An object of one embodiment of the present invention is to provide a highly convenient display device. An object of one embodiment of the present invention is to provide a highly reliable display device. An object of one embodiment of the present invention is to reduce the thickness or weight of a display device. An object of one embodiment of the present invention is to provide a display device having flexibility or a curved surface. An object of one embodiment of the present invention is to provide a display device that is not easily damaged. An object of one embodiment of the present invention is to provide a novel display device, an electronic device, or the like.

Note that the description of these problems does not disturb the existence of other problems. One embodiment of the present invention does not necessarily have to solve all of these problems. Issues other than these can be extracted from the description, drawings, and claims.

One embodiment of the present invention includes a first display element having a first liquid crystal layer and a second display element having a second liquid crystal layer between a first substrate and a second substrate. This is a method for manufacturing a display device.

(1) A method for manufacturing a display device of one embodiment of the present invention includes a step of forming a first common electrode over a first substrate, a step of forming a second common electrode over a second substrate, A step of forming a first layer on a manufacturing substrate, a step of forming a second layer on the first layer, a step of forming a first pixel electrode on the second layer, A step of forming an insulating layer on the pixel electrode; a step of forming a second pixel electrode on the insulating layer; and a second liquid crystal layer disposed between the second common electrode and the second pixel electrode. In the state, the step of forming the second display element by bonding the manufacturing substrate and the second substrate, and the step of separating the first layer and the second layer by irradiating light In the state where the first liquid crystal layer is disposed between the first common electrode and the first pixel electrode, the first substrate and the second substrate are bonded to each other, so that the first display And a step of forming a child, a. A step of forming a functional layer on the first substrate may be included before the step of forming the first common electrode. The functional layer is formed so as to have one or both of the sensing element and the colored layer.

(2) A method for manufacturing a display device of one embodiment of the present invention includes a step of forming a first release layer over a first manufacturing substrate and a step of forming a first common electrode over the first release layer. Forming a second common electrode over the second substrate, forming a second release layer over the second manufacturing substrate, and forming a first pixel electrode over the second release layer. Forming the insulating layer on the first pixel electrode, forming the second pixel electrode on the insulating layer, and between the second common electrode and the second pixel electrode. In the state where the second liquid crystal layer is disposed, the second manufacturing substrate and the second substrate are bonded to each other, and a second display element is formed, and the second separation layer is used to form the second display element. In the state in which the first liquid crystal layer is disposed between the first common electrode and the first pixel electrode, the step of separating the manufacturing substrate and the second substrate, and the first common electrode and the first pixel electrode The step of forming the first display element by bonding the second substrate, the step of separating the first manufacturing substrate and the second substrate using the first release layer, And a step of bonding the first substrate and the second substrate in a state where the first display element is disposed between the first substrate and the second substrate. One or both of the first release layer and the second release layer is formed to have a first layer and a second layer on the first layer. In one or both of the step of separating the second manufacturing substrate and the second substrate and the step of separating the first manufacturing substrate and the second substrate, light irradiation is performed, whereby the first And the second layer are separated.

In the above (2), a step of forming a first functional layer on the first release layer may be included before the step of forming the first common electrode. The first functional layer is formed to have one or both of the sensing element and the colored layer. The first substrate may have a surface on which the second functional layer is provided. The step of bonding the first substrate and the second substrate is performed in a state in which the second functional layer is disposed between the first substrate and the second substrate. The second functional layer is formed so as to have one or both of the light diffusion layer and the polarizing plate.

Alternatively, in the above (2), the method includes a step of forming a third release layer on the third manufacturing substrate, and a step of forming a functional layer on the third release layer. Before the step of bonding the substrate and the second substrate, the third manufacturing substrate and the first substrate with the third peeling layer disposed between the third manufacturing substrate and the first substrate. And a step of separating the third manufacturing substrate and the first substrate using the third peeling layer. The step of bonding the first substrate and the second substrate is performed in a state where the functional layer is disposed between the first substrate and the second substrate. The functional layer is formed so as to have one or a plurality of sensing elements, light diffusion layers, and polarizing plates.

In the above (2), it is preferable to use a glass substrate having a thickness of 0.1 mm or more and less than 0.5 mm as the first substrate. Alternatively, in the above (2), it is preferable to use a resin substrate having a thickness of 1 μm to 200 μm as the first substrate.

In each of the above manufacturing methods, the first pixel electrode is formed to have a function of reflecting visible light, and the second pixel electrode, the first common electrode, and the second common electrode are each visible. It is preferably formed so as to have a function of transmitting light.

In each of the above manufacturing methods, it is preferable that an antireflection member is provided on a surface of the first substrate opposite to the surface on the second substrate side. The antireflection member may be provided to have a convex portion.

In each of the above manufacturing methods, the liquid crystal layer is preferably provided so as to have a dichroic dye.

Each of the above manufacturing methods preferably includes a step of forming a transistor including a metal oxide in a channel formation region over the insulating layer before the step of forming the second display element.

Each of the above manufacturing methods may include a step of removing the second layer remaining on the exposed surface of the stacked body including the second substrate after the step of separating the first layer and the second layer. preferable. Ashing is preferably performed in the step of removing the second layer.

In each of the above manufacturing methods, the second layer is preferably formed to have a region with a thickness of 0.1 μm to 5 μm.

In each of the above manufacturing methods, laser light is used as light, and the laser light is applied to the interface between the first layer and the second layer or the vicinity thereof, whereby the first layer and the second layer are irradiated. And are preferably separated.

In each of the above manufacturing methods, the first layer is preferably formed to include one or more of titanium, molybdenum, aluminum, tungsten, silicon, indium, zinc, gallium, tantalum, and tin. The first layer is preferably formed so as to have one or both of titanium and titanium oxide. The first layer is preferably formed so as to have a laminated structure of titanium and titanium oxide.

In each of the above manufacturing methods, the second layer is preferably formed so as to have a residue of the compound represented by Structural Formula (100).

In each of the above manufacturing methods, the second layer is formed to have an opening, a conductive layer is formed so as to cover the opening, and the first layer and the second layer are separated, so that It is preferred that the layer is exposed.

In each of the above manufacturing methods, light is preferably irradiated so that a wavelength region has a wavelength region of 180 nm to 450 nm. The light is preferably irradiated so that the wavelength region has 308 nm or its vicinity. The light is preferably irradiated using a laser device. The light is preferably irradiated using a linear laser device. The light is preferably irradiated at an energy density of 250 mJ / cm ² or more and 360 mJ / cm ² or less.

According to one embodiment of the present invention, a method for manufacturing a display device with low cost and high productivity can be provided. According to one embodiment of the present invention, a display device can be manufactured using a large-sized substrate. According to one embodiment of the present invention, a display device can be manufactured at low temperature. According to one embodiment of the present invention, a method for manufacturing a novel display device can be provided.

According to one embodiment of the present invention, a display device with low power consumption can be provided. According to one embodiment of the present invention, a display device with high visibility can be provided regardless of ambient brightness. According to one embodiment of the present invention, a display device with favorable display quality can be provided. According to one embodiment of the present invention, a highly convenient display device can be provided. According to one embodiment of the present invention, a highly reliable display device can be provided. According to one embodiment of the present invention, a display device can be reduced in thickness or weight. According to one embodiment of the present invention, a display device having flexibility or a curved surface can be provided. According to one embodiment of the present invention, a display device that is not easily damaged can be provided. According to one embodiment of the present invention, a novel display device, an electronic device, or the like can be provided.

Note that the description of these effects does not disturb the existence of other effects. One embodiment of the present invention need not necessarily have all of these effects. Effects other than these can be extracted from the description, drawings, and claims.

The perspective view which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. FIG. 11 is a flowchart illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. FIG. 11 is a flowchart illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. Sectional drawing which shows an example of a display apparatus. FIG. 11 is a flowchart illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. FIG. 10 is a cross-sectional view illustrating an example of a method for manufacturing a display device. Sectional drawing which shows an example of a display apparatus. Sectional drawing which shows an example of a display apparatus. The figure which shows an example of a laser irradiation unit. The figure which shows an example of a pixel unit. The figure which shows an example of a pixel unit. The figure which shows an example of an operation mode. FIG. 10 illustrates an example of a display device and an example of a pixel. FIG. 10 is a circuit diagram illustrating an example of a pixel circuit of a display device. FIG. 6 is a circuit diagram illustrating an example of a pixel circuit of a display device, and a diagram illustrating an example of a pixel. The block diagram and timing chart figure of a touch sensor. The block diagram and timing chart figure of a display apparatus. FIG. 6 illustrates operations of a display device and a touch sensor. FIG. 6 illustrates operations of a display device and a touch sensor. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

Note that in structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated. In addition, in the case where the same function is indicated, the hatch pattern is the same, and there is a case where no reference numeral is given.

In addition, the position, size, range, and the like of each component illustrated in the drawings may not represent the actual position, size, range, or the like for easy understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, range, or the like disclosed in the drawings.

Note that the terms “film” and “layer” can be interchanged with each other depending on the case or circumstances. For example, the term “conductive layer” can be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” can be changed to the term “insulating layer”.

In this specification and the like, a metal oxide is a metal oxide in a broad expression. Metal oxides are classified into oxide insulators, oxide conductors (including transparent oxide conductors), oxide semiconductors (also referred to as oxide semiconductors or simply OS), and the like. For example, in the case where a metal oxide is used for a semiconductor layer of a transistor, the metal oxide may be referred to as an oxide semiconductor. That is, in the case of describing as an OS FET, it can be said to be a transistor including a metal oxide or an oxide semiconductor.

In this specification and the like, metal oxides containing nitrogen may be collectively referred to as metal oxides. Further, a metal oxide containing nitrogen may be referred to as a metal oxynitride.

(Embodiment 1)
In this embodiment, a display device of one embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.

≪Overview of display device and manufacturing method≫
One embodiment of the present invention is a method for manufacturing a display device including a first display element and a second display element between a first substrate and a second substrate.

The display device of this embodiment includes a first display element that reflects visible light and a second display element that transmits visible light.

The display device of this embodiment has a function of displaying an image by using one or both of light reflected by the first display element and light transmitted by the second display element.

As the first display element, an element that reflects external light for display can be used. Since such an element does not have a light source, power consumption during display can be extremely reduced.

As the first display element, a reflective liquid crystal element can be typically used. Alternatively, as a first display element, in addition to a shutter-type MEMS (Micro Electro Mechanical System) element, an optical interference-type MEMS element, a microcapsule type, an electrophoretic method, an electrowetting method, and an electronic powder fluid (registered trademark) An element to which a method or the like is applied can be used.

As the second display element, an element that transmits and displays light from a light source can be used. As the second display element, a transmissive liquid crystal element can be typically used. A backlight can be used as the light source.

The display device of the present embodiment includes a first mode for displaying an image using only the first display element, a second mode for displaying an image using only the second display element, and a first mode There is a third mode in which an image is displayed using the display element and the second display element, and these modes can be used by switching automatically or manually.

In the first mode, an image is displayed using the first display element and external light. Since the first mode does not require a light source, it is an extremely low power consumption mode. For example, when external light is sufficiently incident on the display device (for example, in a bright environment), display can be performed using light reflected by the first display element. For example, it is effective when the external light is sufficiently strong and the external light is white light or light in the vicinity thereof. The first mode is a mode suitable for displaying characters. In the first mode, light that reflects external light is used, so that it is possible to perform display that is kind to the eyes, and there is an effect that the eyes are less tired.

In the second mode, an image is displayed using the second display element and the light source. In the second mode, an image is displayed using light transmitted by the second display element. Therefore, an extremely vivid display (high contrast and high color reproducibility) can be performed regardless of illuminance and chromaticity of external light. For example, it is effective when the illuminance is extremely low, such as at night or in a dark room. When the surroundings are dark, the user may feel dazzled when performing bright display. In order to prevent this, it is preferable to perform display with reduced luminance in the second mode. Thereby, in addition to suppressing glare, power consumption can also be reduced. The second mode is a mode suitable for displaying vivid images (still images and moving images).

In the third mode, display is performed using both the reflected light from the first display element and the transmitted light from the second display element. While displaying more vividly than in the first mode, it is possible to suppress power consumption as compared with the second mode. For example, it is effective when the illuminance is relatively low, such as under room lighting or in the morning or evening hours, or when the chromaticity of outside light is not white.

With such a configuration, a display device with high visibility and high convenience can be realized regardless of ambient brightness. Specifically, it is possible to realize a display device with high visibility and high convenience both in the outside light and in the room.

In this embodiment, an example in which a reflective liquid crystal element is manufactured as the first display element and a transmissive liquid crystal element is manufactured as the second display element is described.

The first display element includes a first pixel electrode, a first common electrode, and a first liquid crystal layer. The second display element includes a second pixel electrode, a second common electrode, and a second liquid crystal layer.

A method for manufacturing a display device in this embodiment includes a step of forming a first common electrode over a first substrate, a step of forming a second common electrode over a second substrate, and a manufacturing substrate. Forming a first layer; forming a second layer on the first layer; forming a first pixel electrode on the second layer; and on the first pixel electrode Producing in a state in which an insulating layer is formed, a second pixel electrode is formed on the insulating layer, and a second liquid crystal layer is disposed between the second common electrode and the second pixel electrode. A step of forming a second display element by bonding the substrate and the second substrate; a step of separating the first layer and the second layer by irradiating light; The first display element is formed by bonding the first substrate and the second substrate in a state where the first liquid crystal layer is disposed between the common electrode and the first pixel electrode. And a step of, a.

In the display device of this embodiment, the first display element and the second display element are formed independently. Therefore, the degree of freedom in designing each display element can be increased. For example, the first liquid crystal layer can be formed using a liquid crystal material suitable for a reflective display element. Similarly, the second liquid crystal layer can be formed using a liquid crystal material suitable for a transmissive display element. In addition, the cell gap, retardation, and the like can be independently determined for the first display element and the second display element.

In the case where a reflective liquid crystal element and a transmissive liquid crystal element are formed using one liquid crystal layer, alignment defects are likely to occur because regions having different cell gaps are formed in the liquid crystal layer. In this embodiment mode, since each of the two display elements has a liquid crystal layer, such alignment failure can be suppressed and the aperture ratio of the display element can be increased.

Further, the driving method can be independently determined for the first display element and the second display element. For example, the first display element can be driven in a mode suitable for a reflective display element. Similarly, the second display element can be driven in a mode suitable for a transmissive display element. For example, one of a reflective display element and a transmissive display element can be driven in the VA mode, and the other can be driven in the TN mode. Thereby, contrast can be raised.

Here, in the configuration in which the display panel having the first display element and the display panel having the second display element are simply bonded, glass or resin is interposed between the first display element and the second display element. Therefore, it is difficult to reduce the distance between the first display element and the second display element.

On the other hand, in the method for manufacturing a display device in this embodiment, a process of peeling the manufacturing substrate and transferring the first pixel electrode, the second display element, and the transistor or the like from the manufacturing substrate to the second substrate is performed. Have. Then, the first substrate provided with the first common electrode and the second substrate are bonded to each other with the first liquid crystal layer interposed therebetween, whereby the first display element and the second substrate are interposed between the pair of substrates. Display elements can be arranged. Thus, a thick substrate or the like does not exist between the first display element and the second display element, and the distance between the first display element and the second display element can be reduced. For example, when the first display element is a reflective liquid crystal element and the second display element is a transmissive liquid crystal element, the distance in the thickness direction of the two liquid crystal elements is less than 30 μm, preferably less than 10 μm, More preferably, it can be less than 5 μm. Note that the distance in the thickness direction is, for example, the shortest distance between the reflective electrode included in the reflective liquid crystal element and the pixel electrode included in the transmissive liquid crystal element.

The first display element emits reflected light to the first substrate side. The second display element emits transmitted light to the first substrate side. When the distance between the first display element and the second display element is short, the distance between the first substrate and the second display element is also short, and the luminance of the second display element can be increased. In addition, attenuation and extinction of light transmitted through the second display element can be suppressed. Thereby, the light extraction efficiency of the display device can be increased. Alternatively, in the case where display is performed using the first display element and the second display element at the same time, or in the case where display is performed alternately, display using the first display element and display using the second display element. Can be reduced.

In the method for manufacturing a display device of this embodiment mode, it is preferable to first form a first pixel electrode over a manufacturing substrate, and then form a transistor, a second display element, and the like. Accordingly, the first pixel electrode can be formed flat without being affected by unevenness caused by the transistor, the second display element, or the like.

By forming the first pixel electrode flat, variations in the initial alignment of the liquid crystal can be reduced and display defects can be suppressed. Further, in the contact portion between the transistor and the first pixel electrode, since the first pixel electrode is flat, it is possible to suppress the alignment failure of the liquid crystal in the contact portion. Therefore, it is possible to suppress the reduction in the aperture ratio due to the alignment failure of the liquid crystal.

For example, when the region where the initial alignment of the liquid crystal is difficult to align is used for display, contrast may be lowered. In addition, when a region where the initial alignment of the liquid crystal is difficult to align between two adjacent pixels occurs, the contrast can be suppressed by covering the region with a light shielding layer or the like, but the aperture ratio may be decreased. . On the other hand, in the method for manufacturing the display device of this embodiment mode, the first pixel electrode can be formed flat, so that the alignment film can also be formed flat. Defects in alignment processing such as rubbing processing are unlikely to occur, and the initial alignment is easily aligned at the end of the first pixel electrode. It is possible to suppress the occurrence of a region in which the initial alignment of the liquid crystal is hardly aligned between two adjacent pixels. Therefore, the aperture ratio can be increased, and high definition of the display device can be easily achieved.

In addition, in order to suppress the influence of the unevenness, it is not necessary to provide a thick insulating film having a planarization function between the transistor, the second display element, and the like and the first pixel electrode. Therefore, the distance between the first display element and the second display element can be reduced.

Since the distance between the first pixel electrode and the second display element can be reduced, high viewing angle characteristics in the display device and high aperture ratio of the first display element can both be achieved. In addition, the combined aperture ratio of the first display element and the second display element can be increased. In addition, the display device can be thinned.

Alternatively, the method for manufacturing the display device in this embodiment includes a step of forming a first release layer over a first manufacturing substrate, a step of forming a first common electrode over the first release layer, Forming a second common electrode over the second substrate, forming a second peeling layer over the second manufacturing substrate, and forming the first pixel electrode over the second peeling layer. A step of forming an insulating layer on the first pixel electrode; a step of forming a second pixel electrode on the insulating layer; and a second portion between the second common electrode and the second pixel electrode. In the state where the liquid crystal layer is disposed, the second manufacturing substrate and the second substrate are bonded to each other, thereby forming the second display element, and the second manufacturing layer using the second peeling layer. The first manufacturing substrate in a state in which the step of separating the substrate and the second substrate and the first liquid crystal layer are disposed between the first common electrode and the first pixel electrode The step of forming the first display element by bonding the second substrate, the step of separating the first manufacturing substrate and the second substrate using the first release layer, And a step of bonding the first substrate and the second substrate in a state where the first display element is disposed between the first substrate and the second substrate. One or both of the first release layer and the second release layer is formed to have a first layer and a second layer on the first layer. In one or both of the step of separating the second manufacturing substrate and the second substrate and the step of separating the first manufacturing substrate and the second substrate, light irradiation is performed, whereby the first And the second layer are separated.

It is preferable that the thickness of the first substrate which is the substrate on the display surface side is sufficiently thin. For the first substrate, for example, a glass substrate having a thickness of 0.1 mm to less than 0.5 mm, preferably 0.1 mm to 0.3 mm, a resin substrate having a thickness of 1 μm to 200 μm, and the like are preferably used. . Thereby, blurring of the image can be reduced and the image can be clearly displayed.

On the other hand, if the thickness of the first substrate is thin, it may be difficult to transport between or within the manufacturing apparatus during the manufacturing process of the display device, and the manufacturing yield of the display device may be reduced.

In the method for manufacturing a display device of this embodiment mode, after the first display element and the second display element are arranged between the first manufacturing substrate and the second substrate, the first manufacturing substrate is attached to the first manufacturing substrate. The second substrate and the first substrate are bonded to each other. A first common electrode, a detection element, a colored layer, and the like are formed over the first manufacturing substrate, and then transferred to the first substrate. Since the first manufacturing substrate is not a component of the display device, a material having heat resistance suitable for the manufacturing process, such as heat resistance and thickness, and thickness suitable for the manufacturing apparatus can be selected. Therefore, the substrate can be easily transferred in the manufacturing process of the display device, and a high-quality film can be formed at a sufficiently high temperature. In addition, the first substrate with a small thickness can be used, and the display quality of the display device can be improved.

<Optical member>
On the surface (outer surface) opposite to the surface on the second substrate side of the first substrate, as an optical member, a polarizing plate, a retardation plate, a light diffusion layer, an antireflection member, a condensing film, etc. One or more of them can be provided. Examples of the functional member other than the optical member include an antistatic film that suppresses adhesion of dust, a water-repellent film that makes it difficult to adhere dirt, and a hard coat film that suppresses the occurrence of scratches associated with use.

The light diffusion layer has a function of diffusing light reflected by the reflective electrode of the reflective liquid crystal element. With this function, a natural color can be generated even with a reflective liquid crystal element. In addition, it is possible to display a white color close to a blank sheet.

Under strong light such as outdoors in fine weather, external light reflection on the display surface is strong, and the visibility of light (display) emitted from the inside of the display device is reduced. By providing the antireflection member, the external light reflection on the display surface can be sufficiently suppressed under strong light, and the visibility can be further improved.

The antireflection member includes an antireflection layer (also referred to as an AR (Anti-Reflection) layer), a low reflection layer (also referred to as an LR (Low-Reflection) layer), and an antiglare layer (AG (Anti-Glare) layer, non-glare). Also referred to as a layer).

The AR layer has a function of reducing regular reflection (specular reflection) of external light by utilizing light interference action.

The AR layer is formed of a material having a refractive index different from that of the first substrate. The AR layer can be formed as a single layer or a stacked layer using, for example, zirconium oxide, magnesium fluoride, aluminum oxide, silicon oxide, or the like.

The AG layer has a function of reducing regular reflection (specular reflection) by diffusing incident external light.

Examples of the method of forming the AG layer include a method of providing fine irregularities on the surface, a method of mixing materials having different refractive indexes, or a method of combining both. For example, an AG layer can be formed by mixing nanofibers such as cellulose fibers, inorganic beads such as silicon oxide, or resin beads with a light-transmitting resin.

An AG layer may be provided over the AR layer. By providing a stack of the AR layer and the AG layer, it is possible to further enhance the function of preventing reflection or reflection of external light. By using one or both of the AR layer and the AG layer, the external light reflectance of the surface of the display device may be less than 1%, preferably less than 0.3%.

<Channel formation region of transistor>
The display device of this embodiment preferably includes a metal oxide in a channel formation region of the transistor. The metal oxide can function as an oxide semiconductor.

When low temperature polysilicon (LTPS (Low Temperature Poly-Silicon)) is used for the channel formation region of the transistor, it is necessary to apply a temperature of about 500 ° C. to 550 ° C., and thus heat resistance is required for the resin layer. Further, in order to alleviate damage in the laser crystallization process, it may be necessary to increase the thickness of the resin layer.

On the other hand, a transistor using a metal oxide for a channel formation region can be formed at 350 ° C. or lower, further 300 ° C. or lower. Therefore, high heat resistance is not required for the resin layer. Therefore, the heat resistant temperature of the resin layer can be lowered, and the range of selection of materials is widened.

In addition, a transistor using a metal oxide for a channel formation region does not require a laser crystallization process. Compared with the case of using LTPS, the process can be simplified, which is preferable.

Note that the display device of one embodiment of the present invention is not limited to a structure including a metal oxide in a channel formation region of a transistor. For example, in the display device of this embodiment, silicon can be used for a channel formation region of a transistor. As silicon, amorphous silicon or crystalline silicon can be used. Examples of crystalline silicon include microcrystalline silicon, polycrystalline silicon, single crystal silicon, and the like.

When silicon is used for the channel formation region, LTPS is preferably used. Polycrystalline silicon such as LTPS can be formed at a lower temperature than single crystal silicon, and has higher field-effect mobility and higher reliability than amorphous silicon.

<Outline of separation method>
The method for manufacturing the display device in this embodiment includes a separation step using light irradiation. A separation method in this step will be described. Note that the method for manufacturing a display device of one embodiment of the present invention may include a separation step using another separation method. For example, when the separation process is performed a plurality of times, the separation process using light irradiation is performed once or more. By performing all the separation steps by the same separation method, the material, the manufacturing apparatus, and the like can be made the same, and the cost may be reduced. In some cases, a difference in the force required for the separation can be obtained by changing the separation method depending on the separation step. Thereby, it may be possible to control so that separation occurs at a desired interface at a desired timing.

In this embodiment, first, a first material, here, a metal oxide layer is formed over a manufacturing substrate. Next, a second material, here a resin layer, is formed over the metal oxide layer. And a metal oxide layer and a resin layer are isolate | separated by irradiating light.

It is preferable to use light when separating the metal oxide layer and the resin layer. Light is preferably applied to the interface between the metal oxide layer and the resin layer or in the vicinity thereof (also referred to as the interface or the vicinity of the interface). Moreover, light may be irradiated into the metal oxide layer. Moreover, light may be irradiated into the resin layer. In this specification and the like, “the interface between A and B or the vicinity thereof” and “the interface between A and B or the vicinity of the interface” include at least the interface between A and B, and the interface between A and B. To within 20% of the thickness of either A or B.

By irradiating light, the interface between the metal oxide layer and the resin layer (and also in the metal oxide layer and the resin layer) is heated, and the adhesion (adhesion) between the metal oxide layer and the resin layer is increased. Can be lowered. Furthermore, the metal oxide layer and the resin layer can be separated.

<Light irradiation>
Next, light irradiation will be described.

Light can be irradiated using a lamp, a laser device, or the like.

It is preferable to irradiate laser light using a linear laser device. Since a laser apparatus of a production line such as low temperature polysilicon (LTPS (Low Temperature Poly-Silicon)) can be used, these apparatuses can be effectively used. The linear laser is focused in a rectangular shape (formed into a linear laser beam), and irradiates light on the interface between the metal oxide layer and the resin layer.

The light is preferably irradiated so that the wavelength region has 180 nm or more and 450 nm or less. The light is more preferably irradiated so that the wavelength region has 308 nm or its vicinity.

The energy density of the light is preferably from 250 mJ / cm ² or more 400 mJ / cm ² or less, 250 mJ / cm ² or more 360 mJ / cm ² or less being more preferred.

When irradiating light using a laser device, the number of shots of laser light irradiated to the same location can be 1 shot or more and 50 shots or less, preferably more than 1 shot and 10 shots or less, more than 1 shot. 5 shots or less are more preferable.

At both ends in the minor axis direction of the beam, there are portions where the light intensity is low. Therefore, it is preferable to provide an overlapping portion between one shot and the next shot that is equal to or larger than the width of the portion where the light intensity is low. Therefore, the number of shots of laser light is preferably 1.1 shots or more, and more preferably 1.25 shots or more.

Note that in this specification, the number of shots of laser light refers to the number of times laser light is irradiated to a certain point (region), and is determined by the beam width, scan speed, frequency, overlap rate, or the like. Further, there is an overlapping portion between pulses that move the linear beam in a certain scanning direction, that is, between one shot and the next shot, and the overlapping ratio is the overlap ratio. Note that the closer the overlap rate is to 100%, the larger the number of shots, the farther the distance is, the smaller the number of shots, and the faster the scanning speed, the smaller the number of shots.

When the number of shots of the laser beam is 1.1, it means that there is an overlap of about 1/10 width between two consecutive shots, and it can be said that the overlap rate is 10%. Similarly, a 1.25 shot indicates that there is an overlap with a width of about a quarter of the beam between two consecutive shots, and it can be said that the overlap rate is 25%.

Here, the energy density of the light irradiated in the laser crystallization step of LTPS is high, for example, 350 mJ / cm ² or more and 400 mJ / cm ² or less. Also, a large number of laser shots are required, and examples include 10 shots or more and 100 shots or less.

On the other hand, in this embodiment mode, light irradiation for separating the metal oxide layer and the resin layer can be performed with an energy density lower than that used in the laser crystallization step or with a smaller number of shots. . Therefore, the number of substrates that can be processed by the laser device can be increased. In addition, it is possible to reduce the running cost of the laser device, such as reducing the frequency of maintenance of the laser device. Accordingly, manufacturing cost of a display device and the like can be reduced.

Further, since the light irradiation is performed with an energy density lower than that used in the laser crystallization process or with a smaller number of shots, damage to the substrate due to the laser light irradiation can be reduced. For this reason, even if the substrate is used once, the strength is hardly lowered and the substrate can be reused. Therefore, the cost can be suppressed.

In this embodiment, a metal oxide layer is provided between the manufacturing substrate and the resin layer. By using the metal oxide layer, light irradiation may be performed with a lower energy density or a smaller number of shots than in the case where the metal oxide layer is not used.

When irradiating light through the manufacturing substrate, if foreign matter such as dust adheres to the light irradiation surface of the manufacturing substrate, light irradiation unevenness occurs, and a portion having low peelability is formed, and the metal oxide layer and The yield of the process of separating the resin layer may be reduced. Therefore, it is preferable to clean the light irradiation surface before irradiating with light or while irradiating with light. For example, the light irradiation surface of the manufacturing substrate can be cleaned using an organic solvent such as acetone, water, or the like. Moreover, you may spray gas using an air knife. As a result, light irradiation unevenness can be reduced and the separation yield can be improved.

<Resin layer>
By forming the resin layer thin, a display device can be manufactured at low cost. Further, the display device can be reduced in weight and thickness. In addition, the flexibility of the display device can be increased. For example, the thickness of the resin layer may be 0.1 μm or more and 5 μm or less.

The visible light transmittance of the resin layer is not particularly limited. For example, it may be a colored layer or a transparent layer. Here, when the resin layer is positioned on the display surface side of the display device, if the resin layer is colored (colored), the light extraction efficiency decreases, the color of the extracted light changes, and the display quality is improved. In some cases, such as deterioration. When the thickness of the resin layer is thin, it is preferable because the visible light transmittance of the resin layer can be increased.

The resin layer can be removed using a wet etching apparatus, a dry etching apparatus, an ashing apparatus, or the like. In particular, it is preferable to remove the resin layer by performing ashing using oxygen plasma. When the thickness of the resin layer is thin, the time required for the step of removing the resin layer can be shortened, which is preferable.

In this embodiment, a metal oxide layer is provided between the manufacturing substrate and the resin layer. Since the metal oxide layer has a function of absorbing light, the effect of light irradiation can be obtained even if the light absorption rate of the resin layer is low. Therefore, a resin layer having a high visible light transmittance can be used. Therefore, even if the resin layer is located on the display surface side of the display device, high display quality can be realized. Moreover, in order to improve display quality, the process of removing the colored (colored) resin layer can be reduced. Moreover, the range of selection of the material for the resin layer is expanded.

The average value of the transmittance of light in the wavelength range of 450 nm to 700 nm of the resin layer is preferably 70% or more and 100% or less, preferably 80% or more and 100% or less, and more preferably 90% or more and 100% or less.

In this embodiment mode, a transistor or the like is formed at a temperature lower than the heat resistant temperature of the resin layer. The heat resistance of the resin layer can be evaluated by, for example, a weight reduction rate by heating, specifically, a 5% weight reduction temperature. In the peeling method and the manufacturing method of the display device in this embodiment mode, the maximum temperature in the process can be lowered. For example, in this embodiment, the 5% weight reduction temperature of the resin layer may be 200 ° C. or higher and 650 ° C. or lower, 200 ° C. or higher and 500 ° C. or lower, 200 ° C. or higher and 400 ° C. or lower, or 200 ° C. or higher and 350 ° C. or lower. it can. For this reason, the range of selection of materials is widened. The 5% weight reduction temperature of the resin layer may be higher than 650 ° C.

<< Configuration Example 1 of Display Device >>
Hereinafter, the display device 300A will be described with reference to FIGS.

FIG. 1 is a schematic perspective view of the display device 300A. The display device 300A has a structure in which a substrate 351 and a substrate 361 are attached to each other. In FIG. 1, the substrate 361 is clearly indicated by a broken line.

The display device 300A includes a display portion 362, a circuit 364, a wiring 365, and the like. FIG. 1 shows an example in which an IC (integrated circuit) 373 and an FPC 372 are mounted on the display device 300A. Therefore, the structure illustrated in FIG. 1 can also be referred to as a display module including the display device 300A, an IC, and an FPC.

As the circuit 364, for example, a scan line driver circuit can be used.

The wiring 365 has a function of supplying a signal and power to the display portion 362 and the circuit 364. The signal and power are input to the wiring 365 from the outside through the FPC 372 or from the IC 373.

FIG. 1 illustrates an example in which the IC 373 is provided on the substrate 351 by a COG (Chip On Glass) method, a COF (Chip on Film) method, or the like. For example, an IC having a scan line driver circuit or a signal line driver circuit can be used as the IC 373. Note that the display device 100 and the display module may be configured without an IC. Further, the IC may be mounted on the FPC by a COF method or the like.

FIG. 1 shows an enlarged view of a part of the display unit 362. In the display portion 362, electrodes 311b included in the plurality of display elements are arranged in a matrix. The electrode 311b has a function of reflecting visible light, and functions as a reflective electrode of the liquid crystal element 180.

As shown in FIG. 1, the electrode 311 b has an opening 451. Further, the display portion 362 includes a transmissive liquid crystal element 170 on the substrate 351 side of the electrode 311b. Light from the liquid crystal element 170 is emitted to the substrate 361 side through the opening 451 of the electrode 311b. The area of the display region of the liquid crystal element 170 and the area of the opening 451 may be equal. One of the area of the display area of the liquid crystal element 170 and the area of the opening 451 is larger than the other, which is preferable because a margin for positional deviation is increased.

2 illustrates an example of a cross section of the display device 300A illustrated in FIG. 1 when a part of a region including the FPC 372, a part of a region including the circuit 364, and a part of a region including the display portion 362 are cut. Indicates.

A display device 300A illustrated in FIG. 2 includes a transistor 201, a transistor 205, a transistor 206, a liquid crystal element 180, a liquid crystal element 170, an insulating layer 220, a coloring layer 131, and the like between a substrate 351 and a substrate 361. The substrate 361 and the insulating layer 220 are bonded via an adhesive layer 141. The substrate 351 and the insulating layer 220 are bonded through an adhesive layer 142.

2 shows an example in which a polarizing plate 135a is provided outside the substrate 361 and a polarizing plate 135b and a backlight unit 65 are provided outside the substrate 351. For example, a stacked structure from the substrate 351 to the substrate 361 can be referred to as a display device or a display panel. Further, a stacked structure in which the polarizing plate 135a, the polarizing plate 135b, and the backlight unit 65 are added to the stacked structure can be referred to as a display module.

The substrate 361 is provided with a coloring layer 131, a light shielding layer 132, an insulating layer 121, an electrode 113 functioning as a common electrode of the liquid crystal element 180, an alignment film 133b, an insulating layer 117, and the like. A polarizing plate 135 a is provided on the outer surface of the substrate 361. The insulating layer 121 may function as a planarization layer. Since the surface of the electrode 113 can be substantially flattened by the insulating layer 121, the alignment state of the liquid crystal layer 112 can be made uniform. The insulating layer 117 functions as a spacer for maintaining the cell gap of the liquid crystal element 180.

The liquid crystal element 180 is a reflective liquid crystal element. The liquid crystal element 180 has a stacked structure in which an electrode 311 a and an electrode 311 b that function as pixel electrodes, a liquid crystal layer 112, and an electrode 113 are stacked. An electrode 311b that reflects visible light is provided in contact with the substrate 351 side of the electrode 311a. The electrode 311b has an opening 451. The electrode 311a and the electrode 113 transmit visible light. An alignment film 133a is provided between the liquid crystal layer 112 and the electrode 311a. An alignment film 133 b is provided between the liquid crystal layer 112 and the electrode 113.

In the liquid crystal element 180, the electrode 311b has a function of reflecting visible light, and the electrode 113 has a function of transmitting visible light. Light incident from the substrate 361 side is polarized by the polarizing plate 135a, passes through the electrode 113 and the liquid crystal layer 112, and is reflected by the electrode 311b. Then, the light passes through the liquid crystal layer 112 and the electrode 113 again and reaches the polarizing plate 135a. At this time, the alignment of the liquid crystal can be controlled by the voltage applied between the electrode 311b and the electrode 113, and the optical modulation of light can be controlled. That is, the intensity of light emitted through the polarizing plate 135a can be controlled. In addition, light that is not in a specific wavelength region is absorbed by the colored layer 131, so that the extracted light is, for example, red light.

As shown in FIG. 2, the opening 451 is preferably provided with an electrode 311a that transmits visible light. Thereby, since the liquid crystal layer 112 is aligned in the region overlapping with the opening 451 as well as the other regions, it is possible to suppress the occurrence of unintentional light leakage due to poor alignment of the liquid crystal at the boundary between these regions. .

In the connection portion 207, the electrode 311b is electrically connected to the conductive layer 222a included in the transistor 206 through the conductive layer 221b. The transistor 206 has a function of controlling driving of the liquid crystal element 180.

A connection portion 252 is provided in a part of the region where the adhesive layer 141 is provided. In the connection portion 252, the electrode 311 e obtained by processing the same conductive film as the electrode 311 a and a part of the electrode 113 are electrically connected by the connection body 243. Therefore, a signal or a potential input from the FPC 372 connected to the substrate 351 side can be supplied to the electrode 113 formed on the substrate 361 side through the connection portion 252.

The liquid crystal element 170 is a transmissive liquid crystal element. The liquid crystal element 170 has a stacked structure in which an electrode 191 functioning as a pixel electrode, a liquid crystal layer 192, and an electrode 193 are stacked. The electrodes 191 and 193 transmit visible light. An alignment film 153 a is provided between the liquid crystal layer 192 and the electrode 191. An alignment film 153 b is provided between the liquid crystal layer 192 and the electrode 193. The electrode 191 is connected to a conductive layer 222 a included in the transistor 205 through an opening provided in the insulating layer 214. The transistor 205 has a function of controlling driving of the liquid crystal element 170.

A connection portion 253 is provided in a part of the region where the adhesive layer 142 is provided. In the connection portion 253, an electrode 191 a obtained by processing the same conductive film as the electrode 191 and a part of the electrode 193 are electrically connected by a connection body 244. Therefore, a signal or a potential input from the FPC 372 can be supplied to the electrode 193 through the connection portion 253.

In the liquid crystal element 170, the electrode 191 and the electrode 193 have a function of transmitting visible light. Light emitted from the backlight unit 65 is polarized by the polarizing plate 135 b and passes through the electrode 193, the liquid crystal layer 192, and the electrode 191. At this time, the alignment of the liquid crystal can be controlled by the voltage applied between the electrode 191 and the electrode 193, and the optical modulation of light can be controlled. That is, the intensity of light emitted through the polarizing plate 135a can be controlled.

The insulating layer 117 is provided so as to overlap with the opening 451 of the electrode 311b. The insulating layer 117 transmits visible light. The insulating layer 117 is located on the optical path of light that passes through the liquid crystal element 170. Light emitted from the backlight unit 65, polarized by the polarizing plate 135b, and transmitted through the liquid crystal element 170 is transmitted through the insulating layer 117 and reaches the polarizing plate 135a. Thereby, it is possible to prevent the polarization state of the light transmitted through the liquid crystal element 170 from being changed by the liquid crystal layer 112. That is, even if the alignment state of the liquid crystal layer 112 is changed by the voltage applied to the liquid crystal element 180, the display by the liquid crystal element 170 is not affected. Note that the insulating layer 117 may overlap with the display region of the liquid crystal element 180 in order to transmit visible light. Further, the light transmitted through the insulating layer 117 is absorbed by light outside the specific wavelength region by the colored layer 131, so that the extracted light becomes, for example, red light.

With such a configuration, the liquid crystal element 170 and the liquid crystal element 180 can be driven independently, displaying an image only with the liquid crystal element 170, displaying an image only with the liquid crystal element 180, and Displaying images by simultaneously driving both the liquid crystal element 170 and the liquid crystal element 180 can be realized.

The liquid crystal element 180 and the liquid crystal element 170 can exhibit various colors by changing the color of the colored layer depending on the pixel. The display device 300A can perform color display using the liquid crystal element 180 and the colored layer. The display device 300A can perform color display using the liquid crystal element 170 and the colored layer.

In order to realize color display, the color of the colored layer combined with the liquid crystal element 170 and the liquid crystal element 180 may be not only a combination of red, green, and blue, but also a combination of yellow, cyan, and magenta. For example, the color of the colored layer combined with the liquid crystal element 170 may be red, green, and blue, and the color of the colored layer combined with the liquid crystal element 180 may be cyan, magenta, and yellow. What is necessary is just to set the color of the colored layer to combine suitably according to the objective or a use. In the case where the colored layer combined with the liquid crystal element 170 and the colored layer combined with the liquid crystal element 180 have different colors, it is preferable to provide an opening in the colored layer 131 so that the display area of the colored layer 131 and the liquid crystal element 170 do not overlap. In addition, when performing monochrome display or grayscale display using the liquid crystal element 180, the colored layer 131 is not necessarily formed. The colored layer combined with the liquid crystal element 170 can be provided between the insulating layer 213 and the insulating layer 214, for example.

The transistors 201, 205, and 206 are all formed on the surface of the insulating layer 220 on the substrate 351 side. These transistors can be manufactured using the same process.

The circuit electrically connected to the liquid crystal element 180 is preferably formed on the same plane as the circuit electrically connected to the liquid crystal element 170. Thereby, the thickness of the display device can be reduced as compared with the case where the two circuits are formed on different surfaces. Further, since the two transistors can be manufactured in the same process, the manufacturing process can be simplified as compared with the case where the two transistors are formed over different surfaces.

The pixel electrode of the liquid crystal element 180 is positioned opposite to the pixel electrode of the liquid crystal element 170 with a gate insulating layer included in the transistor interposed therebetween.

Here, when a transistor having a metal oxide in the channel formation region and having an extremely low off-state current is used, or when a memory element electrically connected to the transistor is used, a still image using a liquid crystal element is used. Even when the writing operation to the pixel is stopped when displaying the image, the gradation can be maintained. That is, display can be maintained even if the frame rate is extremely small. In one embodiment of the present invention, the frame rate can be extremely small, and driving with low power consumption can be performed.

Insulating layers such as an insulating layer 211, an insulating layer 212, an insulating layer 213, and an insulating layer 214 are provided on the substrate 351 side of the insulating layer 220. A part of the insulating layer 211 functions as a gate insulating layer of each transistor. The insulating layer 212, the insulating layer 213, and the insulating layer 214 are each provided to cover the transistor. The insulating layer 214 functions as a planarization layer. Note that the number of insulating layers covering the transistor is not limited, and may be a single layer or two or more layers.

It is preferable to use a material in which impurities such as water and hydrogen hardly diffuse for at least one of the insulating layers covering each transistor. Thereby, the insulating layer can function as a barrier film. With such a structure, impurities can be effectively prevented from diffusing from the outside with respect to the transistor, and a highly reliable display device can be realized.

The transistor 205 and the transistor 206 include a conductive layer 221a functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, conductive layers 222a and 222b functioning as a source and a drain, and a semiconductor layer 231. Here, the same hatching pattern is given to a plurality of layers obtained by processing the same conductive film.

The transistor 201 includes a conductive layer 223 functioning as a gate in addition to the structures of the transistor 205 and the transistor 206.

A structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates is applied to the transistor 201. With such a structure, the threshold voltage of the transistor can be controlled. The transistor may be driven by connecting two gates and supplying the same signal thereto. Such a transistor can have higher field-effect mobility than other transistors, and can increase on-state current. As a result, a circuit that can be driven at high speed can be manufactured. Furthermore, the area occupied by the circuit portion can be reduced. By applying a transistor with a large on-state current, even if the number of wirings increases when the display device is enlarged or high-definition, signal delay in each wiring can be reduced, and display unevenness is suppressed. can do.

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 to the other of the two gates.

There is no limitation on the structure of the transistor included in the display device. The transistor included in the circuit 364 and the transistor included in the display portion 362 may have the same structure or different structures. The plurality of transistors included in the circuit 364 may have the same structure, or two or more structures may be used in combination. Similarly, the plurality of transistors included in the display portion 362 may have the same structure, or two or more structures may be used in combination.

For the conductive layer 223, a conductive material containing an oxide is preferably used. When the conductive film included in the conductive layer 223 is formed, oxygen can be supplied to the insulating layer 212 by being formed in an atmosphere containing oxygen. The proportion of oxygen gas in the film forming gas is preferably in the range of 90% to 100%. Oxygen supplied to the insulating layer 212 is supplied to the semiconductor layer 231 by a later heat treatment, so that oxygen vacancies in the semiconductor layer 231 can be reduced.

In particular, the conductive layer 223 is preferably formed using a metal oxide with low resistance. At this time, an insulating film from which hydrogen is released, for example, a silicon nitride film or the like is preferably used for the insulating layer 213. Hydrogen is supplied into the conductive layer 223 during the formation of the insulating layer 213 or by a subsequent heat treatment, so that the electrical resistance of the conductive layer 223 can be effectively reduced.

A connection portion 204 is provided in a region of the substrate 351 that does not overlap with the substrate 361. In the connection portion 204, the wiring 365 is electrically connected to the FPC 372 through the connection layer 242. The connection unit 204 has the same configuration as the connection unit 207. The electrode 311c obtained by processing the same conductive film as the electrode 311a is exposed on the upper surface of the connection portion 204. Accordingly, the connection unit 204 and the FPC 372 can be electrically connected via the connection layer 242.

As the connection layer 242, various anisotropic conductive films (ACF: Anisotropic Conductive Film), anisotropic conductive paste (ACP: Anisotropic Conductive Paste), and the like can be used.

As the polarizing plate 135a and the polarizing plate 135b, for example, circular polarizing plates can be used. As a circularly-polarizing plate, what laminated | stacked the linearly-polarizing plate and the quarter wavelength phase difference plate, for example can be used. Further, by adjusting the cell gap, alignment, driving voltage, and the like of the liquid crystal element used for the liquid crystal element 180 according to the type of the polarizing plate, a desired contrast can be realized. Further, depending on the purpose, application, element configuration, etc., a linearly polarizing plate may be used instead of the circularly polarizing plate.

For the substrate 351 and the substrate 361, glass, quartz, ceramic, sapphire, organic resin, or the like can be used, respectively. When a flexible material is used for the substrate 351 and the substrate 361, the flexibility of the display device can be increased.

The thicknesses of the substrates constituting the display device are preferably sufficiently thin. For example, a glass substrate having a thickness of 0.1 mm to less than 0.5 mm, preferably 0.1 mm to 0.3 mm, a resin substrate having a thickness of 1 μm to 200 μm, and the like are preferably used as the substrate. By reducing the thickness of the substrate, the display device can be made thinner and lighter. In addition, by reducing the thickness of the substrate on the display surface side, blurring of the image can be reduced and the image can be clearly displayed.

For example, each of the liquid crystal element 170 and the liquid crystal element 180 is preferably driven using a guest / host liquid crystal mode. When the guest / host liquid crystal mode is used, it is not necessary to use a polarizing plate. Since light absorption by the polarizing plate can be reduced, light extraction efficiency can be increased and display on the display device can be brightened.

For example, in FIG. 2, when the liquid crystal element 170 is driven using the guest / host liquid crystal mode and the liquid crystal element 180 is driven using another mode, the polarizing plate 135b is not necessarily provided.

For example, in FIG. 2, when both the liquid crystal element 170 and the liquid crystal element 180 are driven using the guest / host liquid crystal mode, both the polarizing plate 135a and the polarizing plate 135b are not necessarily provided.

The liquid crystal material preferably has a dichroic dye. A liquid crystal material containing a dichroic dye is referred to as a guest / host liquid crystal. For the guest-host liquid crystal, specifically, a material having a large absorbance in the major axis direction of the molecule and a small absorbance in the minor axis direction orthogonal to the major axis direction can be used for the dichroic dye. Preferably, a material having a dichroic ratio of 10 or more can be used for the dichroic dye, and more preferably, a material having a dichroic ratio of 20 or more can be used for the dichroic dye.

For example, azo dyes, anthraquinone dyes, dioxazine dyes, and the like can be used as dichroic dyes. Alternatively, a structure in which two liquid crystal layers containing homogeneously aligned dichroic dyes are stacked so that the alignment directions are orthogonal to each other can be used for the layer containing the liquid crystal material. Thereby, light can be easily absorbed in all directions. Alternatively, contrast can be increased.

Alternatively, a phase transition type guest-host liquid crystal or a structure in which droplets containing a guest-host liquid crystal are dispersed in a polymer may be used for the liquid crystal material.

The liquid crystal element 170 and the liquid crystal element 180 are not limited to the guest / host liquid crystal mode, and are driven using driving methods such as a TN (Twisted Nematic) mode, an OCB (Optically Compensated Birefringence) mode, and a vertical alignment (VA) mode, respectively. May be.

As the vertical alignment mode, an MVA (Multi-Domain Vertical Alignment) mode, a PVA (Patterned Vertical Alignment) mode, an ASV (Advanced Super View) mode, or the like can be used.

As the liquid crystal element 170 and the liquid crystal element 180, other liquid crystal elements to which various modes are applied can be used. For example, IPS (In-Plane-Switching) mode, VA-IPS mode, FFS (Fringe Field Switching) mode, ASM (Axial Symmetrical aligned Micro-cell) mode, FLC (Ferroelectric Liquid LC mode) Further, a liquid crystal element to which a STN (Super Twisted Nematic) mode, a TBA (Transverse Bend Alignment) mode, an ECB (Electrically Controlled Birefringence) mode, or the like can be used.

The liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal. The optical modulation action of the liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). The liquid crystal used for the liquid crystal element includes a thermotropic liquid crystal, a low molecular liquid crystal, a polymer liquid crystal, a polymer dispersed liquid crystal (PDLC), a polymer network liquid crystal (PNLC), a ferroelectric. A liquid crystal, an antiferroelectric liquid crystal, or the like can be used. These liquid crystal materials exhibit a cholesteric phase, a smectic phase, a cubic phase, a chiral nematic phase, an isotropic phase, and the like depending on conditions.

As the liquid crystal material, either a positive type liquid crystal or a negative type liquid crystal may be used, and an optimal liquid crystal material may be used according to an applied mode or design.

In order to control the alignment of the liquid crystal, an alignment film can be provided. Note that in the case of employing a horizontal electric field mode, liquid crystal exhibiting a blue phase for which an alignment film is unnecessary may be used. The blue phase is one of the liquid crystal phases. When the temperature of the cholesteric liquid crystal is increased, the blue phase appears immediately before the transition from the cholesteric phase to the isotropic phase. Since the blue phase appears only in a narrow temperature range, a liquid crystal composition mixed with several percent by weight or more of a chiral agent is used for the liquid crystal in order to improve the temperature range. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a short response speed and is optically isotropic. In addition, a liquid crystal composition including a liquid crystal exhibiting a blue phase and a chiral agent does not require alignment treatment and has a small viewing angle dependency. Further, since it is not necessary to provide an alignment film, a rubbing process is not required, so that electrostatic breakdown caused by the rubbing process can be prevented, and defects or breakage of the liquid crystal display device during the manufacturing process can be reduced. .

A front light may be provided outside the polarizing plate 135a. As the front light, an edge light type front light is preferably used. It is preferable to use a front light including an LED because power consumption can be reduced.

One or both of the liquid crystal element 170 and the liquid crystal element 180 may have a partition in the liquid crystal layer. The partition has a function of bonding a pair of electrodes (or a pair of alignment films) included in the liquid crystal element. With the partition, the adhesion between the pair of electrodes (or the pair of alignment films) included in the liquid crystal element can be increased. Therefore, the yield of the separation step of the manufacturing substrate performed after manufacturing the liquid crystal element can be increased. It is preferable to dispose a partition wall over the non-display region of the liquid crystal element. As the partition wall, for example, a polymer wall (also referred to as a polymer wall) can be used.

<< Example 1 of Manufacturing Method of Display Device >>
Hereinafter, a method for manufacturing the display device 300A will be described with reference to FIGS.

Note that a thin film (an insulating film, a semiconductor film, a conductive film, or the like) included in the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, or a pulse laser deposition (PLD: Pulse Laser Deposition). ) Method, atomic layer deposition (ALD: Atomic Layer Deposition) method, or the like. The CVD method may be a plasma enhanced chemical vapor deposition (PECVD) method or a thermal CVD method. As an example of the thermal CVD method, a metal organic chemical vapor deposition (MOCVD) method may be used.

Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices are spin coat, dip, spray coating, ink jet, dispense, screen printing, offset printing, doctor knife, slit coat, roll coat, curtain coat, knife It can be formed by a method such as coating.

When a thin film included in the display device is processed, the thin film can be processed using a lithography method or the like. Alternatively, an island-shaped thin film may be formed by a film formation method using a shielding mask. Alternatively, the thin film may be processed by a nanoimprint method, a sand blast method, a lift-off method, or the like. As a photolithography method, a resist mask is formed on a thin film to be processed, the thin film is processed by etching or the like, and the resist mask is removed. After forming a photosensitive thin film, exposure and development are performed. And a method for processing the thin film into a desired shape.

When light is used in the lithography method, for example, light used for exposure can be i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light in which these are mixed. In addition, ultraviolet light, KrF laser light, ArF laser light, or the like can be used. Further, exposure may be performed by an immersion exposure technique. Further, extreme ultraviolet light (EUV: Extreme Ultra-violet) or X-rays may be used as light used for exposure. Further, an electron beam can be used instead of the light used for exposure. It is preferable to use extreme ultraviolet light, X-rays, or an electron beam because extremely fine processing is possible. Note that a photomask is not necessary when exposure is performed by scanning a beam such as an electron beam.

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

[Step S1: Prepare Fabrication Substrate 14]
First, a manufacturing substrate 14 is prepared (FIGS. 3 and 4A).

The manufacturing substrate 14 has rigidity to such an extent that it can be easily transported, and has heat resistance with respect to the temperature required for the manufacturing process. Examples of a material that can be used for the manufacturing substrate 14 include glass, quartz, ceramic, sapphire, resin, semiconductor, metal, and alloy. Examples of the glass include alkali-free glass, barium borosilicate glass, and alumino borosilicate glass.

The thickness of the manufacturing substrate 14 is, for example, not less than 0.5 mm and not more than 1 mm, specifically 0.5 mm and 0.7 mm.

[Step S2: Form Metal Oxide Layer 20]
Next, the metal oxide layer 20 is formed over the manufacturing substrate 14 (FIG. 3 and FIG. 4 (B1)). Alternatively, the metal layer 19 and the metal oxide layer 20 are stacked over the manufacturing substrate 14 (FIG. 4B2).

Various metals, alloys, and the like can be used for the metal layer 19.

Various metal oxides can be used for the metal oxide layer 20. Examples of the metal oxide include titanium oxide (TiO _x ), molybdenum oxide, aluminum oxide, tungsten oxide, indium tin oxide containing silicon (ITSO), indium zinc oxide, and In—Ga—Zn oxide. It is done.

Other metal oxides include indium oxide, indium oxide containing titanium, indium oxide containing tungsten, indium tin oxide (ITO), ITO containing titanium, indium zinc oxide containing tungsten, and zinc oxide (ZnO). ), ZnO containing gallium, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, tin oxide, bismuth oxide, titanate, tantalate, niobic acid Examples include salts.

There is no particular limitation on the method of forming the metal oxide layer 20. For example, it can be formed using a sputtering method, a plasma CVD method, a vapor deposition method, a sol-gel method, an electrophoresis method, a spray method, or the like.

After the metal layer is formed, the metal oxide layer 20 can be formed by introducing oxygen into the metal layer. At this time, only the surface of the metal layer or the entire metal layer is oxidized. In the former case, a stacked structure of the metal layer 19 and the metal oxide layer 20 is formed by introducing oxygen into the metal layer (FIG. 4 (B2)).

For example, the metal layer can be oxidized by heating the metal layer in an atmosphere containing oxygen. It is preferable to heat the metal layer while flowing a gas containing oxygen. The temperature for heating the metal layer is preferably 100 ° C. or higher and 500 ° C. or lower, more preferably 100 ° C. or higher and 450 ° C. or lower, more preferably 100 ° C. or higher and 400 ° C. or lower, and further preferably 100 ° C. or higher and 350 ° C. or lower.

The metal layer is preferably heated below the maximum temperature in the manufacture of the transistor. Thereby, it can prevent that the maximum temperature in manufacture of a display apparatus becomes high. By setting the temperature to be equal to or lower than the maximum temperature in manufacturing a transistor, it is possible to divert a manufacturing apparatus or the like in a transistor manufacturing process, and thus it is possible to suppress additional equipment investment. Therefore, a display device with reduced production costs can be obtained. For example, when the manufacturing temperature of the transistor is up to 350 ° C., the temperature of the heat treatment is preferably 350 ° C. or lower.

Alternatively, the metal layer can be oxidized by performing radical treatment on the surface of the metal layer. In the radical treatment, it is preferable to expose the surface of the metal layer to an atmosphere containing at least one of oxygen radicals and hydroxy radicals. For example, plasma treatment is preferably performed in an atmosphere containing one or both of oxygen and water vapor (H ₂ O).

By including hydrogen, oxygen, hydrogen radical (H ^* ), oxygen radical (O ^* ), hydroxy radical (OH ^* ), or the like on the surface or inside of the metal oxide layer 20, the metal oxide layer 20 and the resin layer The force required for separation from 23 can be reduced. From this point of view, it is preferable to perform radical treatment or plasma treatment to form the metal oxide layer 20.

When the metal layer is oxidized by performing radical treatment or plasma treatment on the surface of the metal layer, a step of heating the metal layer at a high temperature becomes unnecessary. Therefore, it is possible to prevent the maximum temperature in manufacturing the display device from increasing.

Alternatively, the metal oxide layer 20 can be formed in an oxygen atmosphere. For example, the metal oxide layer 20 can be formed by forming a metal oxide film using a sputtering method while flowing a gas containing oxygen. Also in this case, it is preferable to perform radical treatment on the surface of the metal oxide layer 20. In the radical treatment, it is preferable to expose the surface of the metal oxide layer 20 to an atmosphere containing at least one of oxygen radicals, hydrogen radicals, and hydroxy radicals. For example, the plasma treatment is preferably performed in an atmosphere containing one or more of oxygen, hydrogen, and water vapor (H ₂ O).

The radical treatment can be performed using a plasma generator or an ozone generator.

For example, oxygen plasma treatment, hydrogen plasma treatment, water plasma treatment, ozone treatment, or the like can be performed. The oxygen plasma treatment can be performed by generating plasma in an atmosphere containing oxygen. The hydrogen plasma treatment can be performed by generating plasma in an atmosphere containing hydrogen. The water plasma treatment can be performed by generating plasma in an atmosphere containing water vapor (H ₂ O). In particular, performing water plasma treatment is preferable because a large amount of moisture can be contained in the surface or inside of the metal oxide layer 20.

Plasma treatment in an atmosphere containing two or more of oxygen, hydrogen, water (water vapor), and an inert gas (typically argon) may be performed. Examples of the plasma treatment include plasma treatment in an atmosphere containing oxygen and hydrogen, plasma treatment in an atmosphere containing oxygen and water, plasma treatment in an atmosphere containing water and argon, and oxygen and argon. Or a plasma treatment in an atmosphere containing oxygen, water, and argon. Using argon gas as one of the plasma treatment gases is preferable because the plasma treatment can be performed while damaging the metal layer or the metal oxide layer 20.

Two or more plasma treatments may be performed continuously without exposure to the atmosphere. For example, the water plasma treatment may be performed after the argon plasma treatment.

In addition, as a method for introducing oxygen, hydrogen, water, or the like, an ion implantation method, an ion doping method, a plasma immersion ion implantation method, or the like can be used.

The thickness of the metal layer 19 is preferably 1 nm to 100 nm, more preferably 1 nm to 50 nm, and more preferably 1 nm to 20 nm.

The thickness of the metal oxide layer 20 is, for example, preferably 1 nm to 200 nm, more preferably 5 nm to 100 nm, and more preferably 5 nm to 50 nm. In addition, when forming the metal oxide layer 20 using a metal layer, the thickness of the metal oxide layer 20 finally formed may become thicker than the thickness of the formed metal layer.

By supplying a liquid containing water to the interface between the metal oxide layer 20 and the resin layer 23 before or during the separation, the force required for the separation can be reduced.

The metal oxide layer 20 preferably has a low surface tension and high wettability with respect to a liquid containing water. The liquid containing water is spread over the entire surface of the metal oxide layer 20, and the liquid containing water can be easily supplied to the separation interface. Uniform peeling can be achieved by spreading the water over the entire metal oxide layer 20.

The smaller the contact angle between the metal oxide layer 20 and the liquid, the higher the effect of supplying the liquid. Specifically, the contact angle of the metal oxide layer 20 with the liquid containing water is preferably greater than 0 ° and 60 ° or less, and more preferably greater than 0 ° and 50 ° or less. In addition, when the wettability with respect to the liquid containing water is very high (for example, when a contact angle is about 20 degrees or less), acquisition of the exact value of a contact angle may be difficult. Since the metal oxide layer 20 is more suitable as the wettability with respect to the liquid containing water is higher, the wettability with respect to the liquid containing water may be higher as the accurate value of the contact angle cannot be obtained.

For the metal oxide layer 20, titanium oxide, tungsten oxide, or the like is suitable. When titanium oxide is used, cost can be reduced as compared with tungsten oxide, which is preferable.

[Step S3: Form Resin Layer 23]
Next, the first layer 24 is formed over the metal oxide layer 20 (FIG. 4C). And the resin layer 23 is formed by heat-processing with respect to the 1st layer 24 (FIG.3 and FIG.4 (D)).

The first layer 24 can be formed using various resin materials (including a resin precursor).

The first layer 24 is preferably formed using a thermosetting material.

The first layer 24 may be formed using a photosensitive material, or may be formed using a non-photosensitive material (also referred to as a non-photosensitive material).

When a material having photosensitivity is used, a part of the first layer 24 can be removed by photolithography to form the resin layer 23 having a desired shape. Specifically, after the first layer 24 is formed, heat treatment (pre-bake treatment) for removing the solvent is performed, and then exposure is performed using a photomask. Subsequently, unnecessary portions can be removed by performing development processing.

In addition, by forming a mask such as a resist mask or a hard mask on the first layer 24 or the resin layer 23 and performing etching, the resin layer 23 having a desired shape can be formed. This method is particularly suitable when a non-photosensitive material is used.

For example, an inorganic film is formed on the resin layer 23, and a resist mask is formed on the inorganic film. After the inorganic film is etched using the resist mask, the resin layer 23 can be etched using the inorganic film as a hard mask.

Examples of the inorganic film that can be used as the hard mask include various inorganic insulating films, metal films and alloy films that can be used for the conductive layer, and the like.

It is preferable that the mask be formed with a very thin thickness and be removed at the same time as the etching because the number of steps for removing the mask can be reduced.

The first layer 24 is preferably formed using a material containing a polyimide resin or a polyimide resin precursor. The first layer 24 can be formed using, for example, a material containing a polyimide resin and a solvent, or a material containing a polyamic acid and a solvent. Since polyimide is a material that is suitably used for a planarizing film or the like of a display device, the film forming device and the material can be shared. Therefore, no new device or material is required to realize the structure of one embodiment of the present invention.

Specifically, the resin layer 23 preferably has a residue of a compound (oxydiphthalic acid) represented by the structural formula (100).

For the resin layer 23, a polyimide resin obtained by using an acid component containing oxydiphthalic acid or an oxydiphthalic acid derivative and an amine component containing an aromatic amine or an aromatic amine derivative is suitable. Examples of the oxydiphthalic acid derivative include oxydiphthalic anhydride.

In addition, examples of the resin material that can be used for forming the first layer 24 include acrylic resin, epoxy resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene resin, phenol resin, and those resins. A precursor etc. are mentioned.

The first layer 24 is preferably formed using a spin coater. By using the spin coating method, a thin film can be uniformly formed on a large substrate.

The first layer 24 is preferably formed using a solution having a viscosity of 5 cP or more and less than 500 cP, preferably 5 cP or more and less than 100 cP, more preferably 10 cP or more and 50 cP or less. The lower the viscosity of the solution, the easier the application. In addition, the lower the viscosity of the solution, the more air bubbles can be prevented and the better the film can be formed.

In addition, examples of the method for forming the first layer 24 include dip, spray coating, ink jet, dispensing, screen printing, offset printing, doctor knife, slit coat, roll coat, curtain coat, knife coat and the like.

The heat treatment can be performed, for example, while flowing a gas containing one or more of oxygen, nitrogen, and a rare gas (such as argon) inside the chamber of the heating device. Alternatively, the heat treatment can be performed using a chamber of a heating device, a hot plate, or the like in an air atmosphere.

When heating is performed in an air atmosphere or a gas containing oxygen, the resin layer 23 may be colored due to oxidation, and the permeability to visible light may be reduced.

Therefore, it is preferable to perform heating while flowing nitrogen gas. Thereby, the transparency with respect to the visible light of the resin layer 23 can be improved.

By the heat treatment, degassing components (for example, hydrogen, water, etc.) in the resin layer 23 can be reduced. In particular, it is preferable to heat at a temperature equal to or higher than the manufacturing temperature of each layer formed on the resin layer 23. Thereby, degassing from the resin layer 23 in the transistor manufacturing process can be significantly suppressed.

For example, in the case where the transistor manufacturing temperature is up to 350 ° C., the film to be the resin layer 23 is preferably heated at 350 ° C. or higher and 450 ° C. or lower, more preferably 400 ° C. or lower, and even more preferably 375 ° C. or lower. Thereby, degassing from the resin layer 23 in the transistor manufacturing process can be significantly suppressed.

The temperature of the heat treatment is preferably equal to or lower than the maximum temperature in manufacturing the transistor. By setting the temperature to be equal to or lower than the maximum temperature in manufacturing a transistor, it is possible to divert a manufacturing apparatus or the like in a transistor manufacturing process, and thus it is possible to suppress additional equipment investment. Therefore, a display device with reduced production costs can be obtained. For example, when the manufacturing temperature of the transistor is up to 350 ° C., the temperature of the heat treatment is preferably 350 ° C. or lower.

If the maximum temperature in the manufacture of the transistor and the temperature of the heat treatment are made equal, the maximum temperature in the manufacture of the display device can be prevented by performing the heat treatment, and the degassing component of the resin layer 23 can be reduced. preferable.

By extending the treatment time, even in the case where the heating temperature is relatively low, it may be possible to achieve the same peelability as in the case where the heating temperature is higher. Therefore, when the heating temperature cannot be increased due to the configuration of the heating device, it is preferable to increase the treatment time.

The heat treatment time is preferably, for example, 5 minutes to 24 hours, more preferably 30 minutes to 12 hours, and further preferably 1 hour to 6 hours. Note that the heat treatment time is not limited thereto. For example, when the heat treatment is performed using an RTA (Rapid Thermal Annealing) method, it may be less than 5 minutes.

As the heating device, various devices such as an electric furnace and a device for heating an object to be processed by heat conduction or heat radiation from a heating element such as a resistance heating element can be used. For example, an RTA apparatus such as a GRTA (Gas Rapid Thermal Anneal) apparatus or an LRTA (Lamp Rapid Thermal Anneal) apparatus can be used. The LRTA apparatus is an apparatus that heats an object to be processed by radiation of light (electromagnetic waves) emitted from a lamp such as a halogen lamp, a metal halide lamp, a xenon arc lamp, a carbon arc lamp, a high pressure sodium lamp, or a high pressure mercury lamp. The GRTA apparatus is an apparatus that performs heat treatment using a high-temperature gas. Since the processing time can be shortened by using an RTA apparatus, it is preferable for mass production. Further, the heat treatment may be performed using an in-line heating apparatus.

Note that the thickness of the resin layer 23 may change from the thickness of the first layer 24 due to the heat treatment. For example, when the solvent contained in the first layer 24 is removed or the curing proceeds and the density increases, the volume decreases and the resin layer 23 becomes thinner than the first layer 24. There is.

Before performing the heat treatment, heat treatment (also referred to as pre-bake treatment) for removing the solvent contained in the first layer 24 may be performed. The pre-baking temperature can be appropriately determined according to the material used. For example, it can be performed at 50 ° C. or higher and 180 ° C. or lower, 80 ° C. or higher and 150 ° C. or lower, or 90 ° C. or higher and 120 ° C. or lower. Alternatively, the heat treatment may also serve as a pre-bake treatment, and the solvent contained in the first layer 24 may be removed by the heat treatment.

The resin layer 23 has flexibility. The manufacturing substrate 14 is less flexible than the resin layer 23.

The thickness of the resin layer 23 is preferably 0.01 μm or more and less than 10 μm, more preferably 0.1 μm or more and 5 μm or less, and further preferably 0.5 μm or more and 3 μm or less. By forming the resin layer thin, a display device can be manufactured at low cost. Further, the display device can be reduced in weight and thickness. In addition, the flexibility of the display device can be increased. By using a low viscosity solution, it becomes easy to form the resin layer 23 thin. However, it is not limited to this, The thickness of the resin layer 23 is good also as 10 micrometers or more. For example, the thickness of the resin layer 23 may be 10 μm or more and 200 μm or less. Setting the thickness of the resin layer 23 to 10 μm or more is preferable because the rigidity of the display device can be increased.

The thermal expansion coefficient of the resin layer 23 is preferably 0.1 ppm / ° C. or more and 50 ppm / ° C. or less, more preferably 0.1 ppm / ° C. or more and 20 ppm / ° C. or less, and 0.1 ppm / ° C. or more and 10 ppm / ° C. or less. More preferably, it is not higher than ° C. As the coefficient of thermal expansion of the resin layer 23 is lower, it is possible to suppress the generation of cracks in the layer constituting the transistor or the like, or the damage of the transistor or the like due to heating.

[Step S4: Form a transistor]
Next, a layer to be peeled including a transistor is formed over the resin layer 23.

As the layer to be peeled, for example, an insulating layer or a functional element (a transistor, a display element, or the like) can be provided.

The peeled layer is formed at a temperature lower than the heat resistance temperature of the resin layer 23. It is preferable to form at a temperature lower than the temperature of the heat treatment.

The insulating layer 31 is preferably formed over the resin layer 23 (FIG. 4E).

The insulating layer 31 can be used as a barrier layer that prevents impurities contained in the resin layer 23 from diffusing into transistors and display elements to be formed later. For example, the insulating layer 31 preferably prevents diffusion of moisture or the like contained in the resin layer 23 into the transistor or the display element when the resin layer 23 is heated. Therefore, the insulating layer 31 preferably has a high barrier property.

As the insulating layer 31, an oxide insulating film, a nitride insulating film, an oxynitride insulating film, a nitrided oxide insulating film, or the like can be used. The insulating layer 31 can be formed as a single layer or a stacked layer. Examples of the oxide insulating film include a silicon oxide film, an aluminum oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. . Examples of the nitride insulating film include a silicon nitride film and aluminum nitride. As the oxynitride insulating film, a silicon oxynitride film or the like can be given. Examples of the nitrided oxide insulating film include a silicon nitride oxide film. In particular, it is preferable to form a silicon nitride film on the resin layer 23 and form a silicon oxide film on the silicon nitride film.

Note that in this specification and the like, “silicon oxynitride” refers to a material having a higher oxygen content than nitrogen. In this specification and the like, “silicon nitride oxide” refers to a material whose content is higher in nitrogen than oxygen.

The inorganic insulating film is denser and has a higher barrier property as the deposition temperature is higher, and thus it is preferable to form the inorganic insulating film at a high temperature. The substrate temperature during the formation of the insulating layer 31 is preferably room temperature (25 ° C.) or higher and 350 ° C. or lower, more preferably 100 ° C. or higher and 300 ° C. or lower.

A functional element may be formed directly on the resin layer 23 without providing the insulating layer 31.

Next, the electrode 311a, the electrode 311c, and the electrode 311e are formed over the insulating layer 31 (FIG. 5A). Then, an electrode 311b is formed on the electrode 311a, an electrode 311d is formed on the electrode 311c, and an electrode 311f is formed on the electrode 311e. The electrode 311b has an opening 451 on the electrode 311a. The electrode 311a is formed using a conductive material that transmits visible light. The electrode 311b is formed using a conductive material that reflects visible light.

Each of the electrode and the conductive layer included in the display device can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

The electrode and the conductive layer included in the display device are each a single layer of a metal such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, or tungsten, or an alloy containing the same as a main component. It can be used as a structure or a laminated structure. Or indium oxide, indium tin oxide (ITO), indium oxide containing tungsten, indium zinc oxide containing tungsten, indium oxide containing titanium, ITO containing titanium, indium zinc oxide, zinc oxide (ZnO) Alternatively, a light-transmitting conductive material such as ZnO containing gallium or ITO containing silicon may be used. Alternatively, a semiconductor such as polycrystalline silicon or an oxide semiconductor, or a silicide such as nickel silicide, which has been reduced in resistance by containing an impurity element or the like, may be used. Alternatively, a film containing graphene can be used. The film containing graphene can be formed, for example, by reducing a film containing graphene oxide formed in a film shape. Alternatively, a semiconductor such as an oxide semiconductor containing an impurity element may be used. Alternatively, a conductive paste such as silver, carbon, or copper, or a conductive polymer such as polythiophene may be used. The conductive paste is preferable because it is inexpensive. The conductive polymer is preferable because it is easy to apply.

Next, the insulating layer 220 is formed (FIG. 5A). Then, an opening reaching the electrode 311b and an opening reaching the electrode 311d are provided in the insulating layer 220.

As the insulating layer 220, an inorganic insulating film that can be used for the insulating layer 31 can be used. Moreover, you may use resin, such as an acryl and an epoxy.

Next, the transistor 201, the transistor 205, and the transistor 206 are formed over the insulating layer 220 (FIGS. 3 and 5A). In addition, a connection portion 204 and a connection portion 207 are also formed over the insulating layer 220 (FIG. 5A).

There is no particular limitation on the structure of the transistor included in the display device. For example, a planar transistor, a staggered transistor, or an inverted staggered transistor may be used. Further, any transistor structure of a top gate structure or a bottom gate structure may be employed. Alternatively, gate electrodes may be provided above and below the channel.

A semiconductor material used for the transistor is not particularly limited, and for example, a Group 14 element, a compound semiconductor, or an oxide semiconductor can be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used.

Here, a case of manufacturing a bottom-gate transistor having a metal oxide layer as the semiconductor layer 231 is described. The metal oxide can function as an oxide semiconductor.

In this embodiment, an oxide semiconductor is used as a semiconductor of the transistor. It is preferable to use a semiconductor material with a wider band gap and lower carrier density than silicon because current in an off state of the transistor can be reduced.

In the transistors 205 and 206, part of the conductive layer 221a functions as a gate, part of the insulating layer 211 functions as a gate insulating layer, and part of the conductive layer 222a functions as one of a source and a drain, Part of the conductive layer 222b functions as the other of the source and the drain. The transistor 201 has a structure in which a conductive layer 223 and an insulating layer 212 are added to the structures of the transistor 205 and the transistor 206, and includes two gates. In the transistor 201, part of the conductive layer 221a and part of the conductive layer 223 function as a gate, and part of the insulating layer 211 and part of the insulating layer 212 function as a gate insulating layer.

A method for manufacturing each transistor and each connection portion will be specifically described.

First, the conductive layer 221a, the conductive layer 221b, and the conductive layer 221c are formed over the insulating layer 220. Here, the conductive layer 221b and the electrode 311b are connected through the opening of the insulating layer 220, and the conductive layer 221c and the electrode 311d are connected.

Subsequently, the insulating layer 211 is formed. As the insulating layer 211, an inorganic insulating film that can be used for the insulating layer 31 can be used.

Subsequently, the semiconductor layer 231 is formed. In this embodiment, a metal oxide layer is formed as the semiconductor layer 231. The metal oxide layer can be formed by forming a metal oxide film, forming a resist mask, etching the metal oxide film, and then removing the resist mask.

The substrate temperature during the formation of the metal oxide film is preferably 350 ° C. or less, more preferably from room temperature to 200 ° C., and further preferably from room temperature to 130 ° C.

The metal oxide film can be formed using one or both of an inert gas and an oxygen gas. Note that there is no particular limitation on the flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film. However, in the case of obtaining a transistor with high field effect mobility, the flow rate ratio of oxygen (oxygen partial pressure) during the formation of the metal oxide film is preferably 0% or more and 30% or less, and 5% or more and 30% or less. Is more preferably 7% or more and 15% or less.

The metal oxide film preferably contains at least indium or zinc. In particular, it is preferable to contain indium and zinc.

The metal oxide preferably has an energy gap of 2 eV or more, more preferably 2.5 eV or more. More preferably, it is 3 eV or more. In this manner, off-state current of a transistor can be reduced by using a metal oxide having a wide energy gap.

The metal oxide film can be formed by a sputtering method. In addition, a PLD method, a PECVD method, a thermal CVD method, an ALD method, a vacuum evaporation method, or the like may be used.

Subsequently, a conductive layer 222a, a conductive layer 222b, and a wiring 365 are formed. The conductive layer 222a and the conductive layer 222b are each connected to the semiconductor layer 231. Here, the conductive layer 222a included in the transistor 206 is electrically connected to the conductive layer 221b. Accordingly, in the connection portion 207, the electrode 311b and the conductive layer 222a can be electrically connected. The wiring 365 is electrically connected to the conductive layer 221c. Thereby, in the connection part 204, the wiring 365 and the electrode 311d can be electrically connected.

Note that when the conductive layers 222a and 222b are processed, part of the semiconductor layer 231 which is not covered with the resist mask may be thinned by etching.

As described above, the transistor 205, the transistor 206, the connection portion 204, and the connection portion 207 can be manufactured.

Next, an insulating layer 212 that covers the transistor 206 and the like is formed, and a conductive layer 223 is formed over the insulating layer 212.

The insulating layer 212 can be formed by a method similar to that of the insulating layer 211.

As described above, the transistor 201 can be manufactured.

Next, the insulating layer 213 is formed. The insulating layer 213 can be formed by a method similar to that of the insulating layer 211.

For the insulating layer 212, an oxide insulating film such as a silicon oxide film or a silicon oxynitride film formed in an atmosphere containing oxygen is preferably used. Further, an insulating film that hardly diffuses and transmits oxygen such as a silicon nitride film is preferably stacked as the insulating layer 213 over the silicon oxide film or the silicon oxynitride film. An oxide insulating film formed in an atmosphere containing oxygen can be an insulating film from which a large amount of oxygen is easily released by heating. By performing heat treatment in a state where such an oxide insulating film that releases oxygen and an insulating film that hardly diffuses and transmits oxygen are stacked, oxygen can be supplied to the metal oxide layer. As a result, oxygen vacancies in the metal oxide layer and defects at the interface between the metal oxide layer and the insulating layer 212 can be repaired, and the defect level can be reduced. Thereby, a highly reliable display device can be realized.

Next, the insulating layer 214 is formed over the insulating layer 213 (FIG. 5B).

The insulating layer 214 is a layer having a formation surface of a display element to be formed later, and thus preferably functions as a planarization layer. As the insulating layer 214, a resin or an inorganic insulating film that can be used for the insulating layer 220 can be used.

Next, an opening reaching the conductive layer 222a included in the transistor 205 is formed in the insulating layer 212, the insulating layer 213, and the insulating layer 214.

[Step S5: Form Liquid Crystal Element 170]
Next, the liquid crystal element 170 is formed (FIGS. 3, 5B, and 6). The liquid crystal element 170 is formed by bonding the manufacturing substrate 14 and the substrate 351 with a liquid crystal layer disposed between the common electrode and the pixel electrode.

Over the manufacturing substrate 14, an electrode 191 and an electrode 191 a that function as pixel electrodes of the liquid crystal element 170 are formed. Here, the conductive layer 222a included in the transistor 205 and the electrode 191 are connected. The electrodes 191 and 191a are formed using a conductive material that transmits visible light. Then, an alignment film 153a is formed over the electrode 191.

In addition, an electrode 193 that functions as a common electrode of the liquid crystal element 170 is formed over the substrate 351. The electrode 193 is formed using a conductive material that transmits visible light. Then, an alignment film 153 b is formed over the electrode 193.

The alignment film 153a and the alignment film 153b can be formed by performing a rubbing process after forming a thin film such as a resin.

The manufacturing substrate 14 and the substrate 351 in which the above steps are completed are attached to each other using the adhesive layer 142 (FIG. 6). The manufacturing substrate 14 and the substrate 351 are attached to each other with the liquid crystal layer 192 sandwiched between the alignment film 153a and the alignment film 153b.

A liquid crystal element 170 illustrated in FIG. 6 has a structure in which an electrode 191 partly functioning as a pixel electrode, a liquid crystal layer 192, and an electrode 193 partly functioning as a common electrode are stacked. The liquid crystal element 170 is manufactured so that the opening 451 of the electrode 311b and the display region overlap.

In the connection portion 253, the electrode 193 and the electrode 191a are electrically connected through the connection body 244.

For the adhesive layer 142, various curable adhesives such as an ultraviolet curable photocurable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used.

Examples of the substrate 351 include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES). ) Resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) Resin, ABS resin, cellulose nanofiber, etc. can be used. Various materials such as glass, quartz, resin, metal, alloy, and semiconductor may be used for the substrate 351. For the substrate 351, various materials such as glass, quartz, resin, metal, alloy, and semiconductor having a thickness enough to be flexible may be used.

As the connection body 244, for example, conductive particles can be used. As the conductive particles, those obtained by coating the surface of particles such as organic resin or silica with a metal material can be used. It is preferable to use nickel or gold as the metal material because the contact resistance can be reduced. In addition, it is preferable to use particles in which two or more kinds of metal materials are coated in layers, such as further coating nickel with gold. It is preferable to use a material that is elastically deformed or plastically deformed as the connection body 244. At this time, the connection body 244, which is a conductive particle, may have a shape crushed in the vertical direction as shown in FIG. By doing so, the contact area between the connection body 244 and the conductive layer electrically connected to the connection body 244 can be increased, the contact resistance can be reduced, and the occurrence of problems such as poor connection can be suppressed.

The connection body 244 is preferably arranged so as to be covered with the adhesive layer 142. For example, the connection body 244 may be dispersed in the adhesive layer 142 before curing.

As described above, the liquid crystal element 170 can be formed (FIGS. 3 and 6).

[Step S6: Irradiate / Separate Light]
Next, the metal oxide layer 20 and the resin layer 23 are separated (FIGS. 3, 7, and 8). Accordingly, the transistor, the liquid crystal element 170, and the like manufactured over the manufacturing substrate 14 can be transferred to the substrate 351.

FIG. 7 shows an example in which the laser beam 55 is irradiated. For example, in FIG. 7, the laser beam 55 is a linear laser beam scanned from the left side to the right side, and its major axis is perpendicular to the scanning direction and the incident direction (from top to bottom). In the laser device, the stacked body is arranged so that the manufacturing substrate 14 is on the upper side. The laminated body is irradiated with laser light 55 from the upper side of the laminated body (production substrate 14).

The laser beam 55 is preferably applied to the interface between the metal oxide layer 20 and the resin layer 23 or the vicinity thereof through the manufacturing substrate 14. Further, the laser beam 55 may be irradiated into the metal oxide layer 20 or may be irradiated into the resin layer 23.

The metal oxide layer 20 absorbs the laser light 55. The resin layer 23 may absorb the laser light 55.

The absorption rate of the laser beam 55 in the stacked structure of the manufacturing substrate 14 and the metal oxide layer 20 is preferably 50% or more and 100% or less, more preferably 75% or more and 100% or less, and further preferably 80% or more and 100% or less. The laminated structure absorbs most of the laser light 55, so that it can be reliably peeled off at the interface between the metal oxide layer 20 and the resin layer 23. Moreover, the damage which the resin layer 23 receives from light can be reduced.

By the irradiation with the laser beam 55, the adhesion or adhesiveness between the metal oxide layer 20 and the resin layer 23 is lowered. The resin layer 23 may be weakened by the irradiation with the laser beam 55.

As the laser light 55, light having a wavelength that is at least partially transmitted through the manufacturing substrate 14 and absorbed by the metal oxide layer 20 is selected and used. The laser light 55 is preferably light in the wavelength region from visible light to ultraviolet light. For example, light having a wavelength of 180 nm to 450 nm, preferably 200 nm to 400 nm, more preferably light having a wavelength of 250 nm to 350 nm can be used.

The laser beam 55 preferably has an energy higher than the energy gap of the metal oxide layer 20. For example, the energy gap of titanium oxide is about 3.2 eV. Therefore, when titanium oxide is used for the metal oxide layer 20, the light preferably has an energy higher than 3.2 eV.

In particular, it is preferable to use an excimer laser having a wavelength of 308 nm because the productivity is excellent. Since the excimer laser is also used for laser crystallization in LTPS, an existing LTPS production line device can be used, and new equipment investment is not required, which is preferable. The energy of light having a wavelength of 308 nm is about 4.0 eV. That is, when titanium oxide is used for the metal oxide layer 20, an excimer laser with a wavelength of 308 nm is suitable. Alternatively, a solid-state UV laser (also referred to as a semiconductor UV laser) such as a UV laser having a wavelength of 355 nm, which is the third harmonic of the Nd: YAG laser, may be used. Since a solid-state laser does not use a gas, it can reduce a running cost and is preferable to an excimer laser. Further, a pulse laser such as a picosecond laser may be used.

In the case of using a linear laser beam as the laser beam 55, the laser beam 55 is scanned by moving the manufacturing substrate 14 and the light source relatively, and the laser beam 55 is irradiated over a region to be peeled off.

FIG. 8 shows an example in which separation occurs at the interface between the metal oxide layer 20 and the resin layer 23. Separation occurs at the interface between the metal oxide layer 20 and the resin layer 23 due to a decrease in adhesion or adhesion between the metal oxide layer 20 and the resin layer 23. Moreover, separation may occur in the weakened resin layer 23.

Here, at the time of separation, separation can be easily performed by adding a liquid containing water such as water or an aqueous solution to the separation interface and performing separation so that the liquid penetrates the separation interface. In addition, static electricity generated at the time of separation can be prevented from adversely affecting a functional element such as a transistor (a semiconductor element is destroyed by static electricity).

Examples of the liquid to be supplied include water (preferably pure water), a neutral, alkaline, or acidic aqueous solution, and an aqueous solution in which a salt is dissolved. Moreover, ethanol, acetone, etc. are mentioned. Various organic solvents may be used.

When the liquid is supplied to the separation interface, the surface of the layer to be peeled exposed by the separation may be dried.

A separation starting point may be formed by separating a part of the resin layer 23 from the manufacturing substrate 14 before separation. For example, the starting point of separation may be formed by inserting a sharp-shaped instrument such as a blade between the production substrate 14 and the resin layer 23. Alternatively, the resin layer 23 may be cut from the substrate 351 side with a sharp tool to form the separation starting point. Alternatively, the separation starting point may be formed by a method using a laser such as a laser ablation method.

[Step S7-1: Determine whether to remove the resin layer 23]
When the resin layer 23 is removed after the separation, the process proceeds to step S7-2. If the resin layer 23 is not removed, the process proceeds to step 8. When the resin layer 23 is not removed, the number of steps can be reduced.

In this manufacturing method example 1, a case where the resin layer 23 is removed will be described. The resin layer 23 is preferably removed when one or more of the electrodes 311a, 311c, and 311e need to be exposed.

[Step S7-2: Remove the resin layer 23]
Next, the resin layer 23 is removed (FIGS. 3 and 9A). Further, the insulating layer 31 may be removed (FIG. 9A).

By removing the resin layer 23 and the insulating layer 31, the display device can be made thinner and lighter.

If the resin layer 23 and the insulating layer 31 are provided thick, most of the light incident on the display device is absorbed by the resin layer 23. For this reason, the reflectance of the pixel is lowered and the display becomes dark. When the driving voltage of the reflective liquid crystal element is constant, the thicker the resin layer 23 and the insulating layer 31, the weaker the electric field applied to the liquid crystal layer and the lower the display contrast. In order to increase the display contrast without changing the thickness of the resin layer 23 and the insulating layer 31, it is necessary to increase the driving voltage of the reflective liquid crystal element. Therefore, it is preferable to remove the resin layer 23 and the insulating layer 31.

In some cases, such as when the resin layer 23 and the insulating layer 31 are sufficiently thin, the resin layer 23 and the insulating layer 31 may not be completely removed.

In the case where the insulating layer 31 has high barrier properties, by leaving the insulating layer 31, impurities can be prevented from entering the transistor and the liquid crystal element 170, and the reliability of the display device can be improved. The thickness of the insulating layer 31 is preferably 50 nm to 300 nm, and more preferably 100 nm to 200 nm.

For example, as shown in FIG. 9B, part of the insulating layer 31 may be removed so that the electrode 311c and the electrode 311e are exposed.

Further, before bonding to the substrate 361, an alignment film 133a is formed over the substrate 351 so as to overlap with the electrode 311b functioning as the pixel electrode of the liquid crystal element 180. The alignment film 133a is a layer that comes into contact with the liquid crystal layer 112 later. The alignment film 133a can be formed by performing a rubbing process after forming a thin film such as a resin.

[Step S8: Form Liquid Crystal Element 180]
Next, the liquid crystal element 180 is formed (FIG. 3). The liquid crystal element 180 is formed by bonding the substrate 351 and the substrate 361 with a liquid crystal layer disposed between the common electrode and the pixel electrode.

Before being attached to the substrate 351, the electrode 113 or the like that functions as a common electrode of the liquid crystal element 180 is formed over the substrate 361.

A process for forming the electrode 113 and the like over the substrate 361 will be described with reference to FIGS.

First, the colored layer 131 and the light shielding layer 132 are formed over the substrate 361. In the display portion 362, the colored layer 131 can be processed into an island shape by a photolithography method or the like by being formed using a photosensitive material. The light shielding layer 132 can be formed using metal, resin, or the like. Note that after an insulating layer having a high barrier property is formed over the substrate 361, the coloring layer 131 and the light-blocking layer 132 may be formed over the insulating layer.

The substrate 361 is a substrate located on the display surface side. Therefore, a material that transmits visible light is used for the substrate 361. For example, among materials that can be used for the manufacturing substrate 14 or the substrate 351 described above, a material that transmits visible light can be used.

Next, the insulating layer 121 is formed over the coloring layer 131 and the light shielding layer 132.

The insulating layer 121 preferably functions as a planarization layer. For the insulating layer 121, a resin such as acrylic or epoxy can be preferably used.

An inorganic insulating film may be applied to the insulating layer 121. As the insulating layer 121, for example, an inorganic insulating film such as a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, or an aluminum nitride film can be used. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, a neodymium oxide film, or the like may be used. Two or more of the above insulating films may be stacked.

Next, the electrode 113 is formed. The electrode 113 is formed using a conductive material that transmits visible light.

Next, the insulating layer 117 is formed over the electrode 113. An organic insulating film is preferably used for the insulating layer 117.

Next, an alignment film 133 b is formed over the electrode 113 and the insulating layer 117. The alignment film 133b can be formed by performing a rubbing process after forming a thin film such as a resin.

The substrate 361 and the substrate 351 that have been subjected to the above steps are bonded using the adhesive layer 141 (FIG. 11). The substrate 361 and the substrate 351 are attached to each other with the liquid crystal layer 112 sandwiched between the alignment film 133a and the alignment film 133b. A material that can be used for the adhesive layer 142 can be used for the adhesive layer 141.

A liquid crystal element 180 illustrated in FIG. 11 has a structure in which electrodes 311a and 311b, part of which functions as pixel electrodes, a liquid crystal layer 112, and an electrode 113, part of which functions as a common electrode, are stacked. The liquid crystal element 180 is manufactured so as to overlap with the colored layer 131.

In the connection portion 252, the electrode 113 and the electrode 311 e are electrically connected through the connection body 243.

A material that can be used for the connection body 244 can be used for the connection body 243. The connection body 243 is preferably disposed so as to be covered with the adhesive layer 141. For example, the connection body 243 may be dispersed in the adhesive layer 141 before curing.

[Step S9: Implement]
After that, an FPC 372, an IC, or the like can be electrically connected. In addition, optical members such as a polarizing plate 135a and a polarizing plate 135b can be provided.

Through the above steps, the display device 300A illustrated in FIG. 2 can be manufactured.

<< Display device configuration example 2 >>
Hereinafter, a display device having a configuration different from that of the display device 300A will be described with reference to FIGS. Detailed description of the same parts as those of the display device 300A will be omitted.

FIG. 12 is a cross-sectional view of the display device 300B. The display device 300B does not include the substrate 361, the polarizing plate 135a, and the polarizing plate 135b but includes the adhesive layer 392, the substrate 390, and the antireflection member 396. Other configurations are the same as those of the display device 300A. The display device 300 </ b> B is a configuration example in the case where a liquid crystal material that operates in a guest / host liquid crystal mode is used for both the liquid crystal element 170 and the liquid crystal element 180.

FIG. 13 is a cross-sectional view of the display device 300C. The display device 300 </ b> C does not include the substrate 361 but includes the adhesive layer 392, the light diffusion layer 136, the substrate 390, and the antireflection member 396. The display device 300C is different from the display device 300A in the position of the polarizing plate 135a. Other configurations are the same as those of the display device 300A. The display device 300C is a configuration example in the case where a liquid crystal material that operates in a TN mode is used for both the liquid crystal element 170 and the liquid crystal element 180.

It is preferable that the thickness of the substrate (here, the substrate 390) which is the display surface side substrate is sufficiently thin. As the substrate 390, for example, a glass substrate having a thickness of 0.1 mm to less than 0.5 mm, preferably 0.1 mm to 0.3 mm, a resin substrate having a thickness of 1 μm to 200 μm, and the like are preferably used. Thereby, blurring of the image can be reduced and the image can be clearly displayed.

In the display device 300 </ b> B and the display device 300 </ b> C, the coloring layer 131, the electrode 113, and the like are formed over the manufacturing substrate, transferred from the manufacturing substrate to the substrate 351, and then bonded to the substrate 351 with the adhesive layer 392. It is produced by. Therefore, the substrate 390 is not required to have high heat resistance and high rigidity that can withstand the manufacturing process. In addition, the process of thinning the substrate, typically the polishing process, can be reduced. By reducing the polishing step, the yield of manufacturing the display device can be increased.

Note that the above-described display device 300A has a structure in which the coloring layer 131, the electrode 113, and the like are formed directly over the substrate 361. In such a structure, after the substrate 351 and the substrate 361 are bonded together, it is preferable to reduce the thickness of the substrate 361 by polishing or the like.

By using a liquid crystal material that operates in the guest / host liquid crystal mode for both the liquid crystal element 170 and the liquid crystal element 180, the light diffusion layer and the polarizing plate can be omitted. Thus, productivity of the display device can be increased. Moreover, the display of a display apparatus can be brightened by not providing a light-diffusion layer and a polarizing plate. Therefore, the visibility of the display device can be increased.

FIG. 14 shows a cross-sectional view of the display device 300D. The display device 300D does not include the substrate 361, the polarizing plate 135a, and the polarizing plate 135b, but includes a touch sensor, an adhesive layer 392, a substrate 390, and an antireflection member 396. Other configurations are the same as those of the display device 300A. Note that one or both of the polarizing plate and the light diffusion layer are provided depending on the operation mode of the liquid crystal element 170 and the liquid crystal element 180.

In one embodiment of the present invention, a display device (also referred to as an input / output device or a touch panel) including a touch sensor can be manufactured.

The touch sensor included in the display device can also be referred to as an example of the input device. The input device is provided so as to overlap with the display unit, and has a function of converting an operation in which the user touches the display unit into an electric signal and outputting the electric signal.

There is no limitation on a detection element (also referred to as a sensor element) included in the display device of one embodiment of the present invention. Various sensors that can detect the proximity or contact of an object to be detected, such as a finger or a stylus, can be used as the detection element.

For example, various methods such as a capacitance method, a resistance film method, a surface acoustic wave method, an infrared method, an optical method, and a pressure-sensitive method can be used as a sensor method.

In this embodiment, a display device including a capacitance type detection element is described as an example.

Examples of the electrostatic capacity method include a surface electrostatic capacity method and a projection electrostatic capacity method. In addition, examples of the projected capacitance method include a self-capacitance method and a mutual capacitance method. Use of the mutual capacitance method is preferable because simultaneous multipoint detection is possible.

The display device of one embodiment of the present invention includes a structure in which a separately manufactured display panel and a detection element are attached, a structure in which an electrode or the like that configures the detection element is provided on one or both of a pair of substrates included in the display panel, and the like. Various configurations can be applied.

A conductive layer that transmits visible light can be used as the wiring and electrodes of the sensing element. In addition, it is preferable to use a metal mesh having lower resistance and applicable to a large display device as the wiring and the electrode. In general, metal is a material having a high reflectance, but it can be darkened by performing an oxidation treatment or the like. Therefore, even when viewed from the substrate 390 side, it is possible to suppress a decrease in visibility due to reflection of external light.

Alternatively, the wiring and the electrode may be formed using a stack of a metal layer and a layer with low reflectance (also referred to as a “dark color layer”). Examples of the dark color layer include a layer containing copper oxide and a layer containing copper chloride or tellurium chloride. In addition, the dark color layer is formed using fine metal particles such as Ag particles, Ag fibers, and Cu particles, nanocarbon particles such as carbon nanotubes (CNT) and graphene, and conductive polymers such as PEDOT, polyaniline, and polypyrrole. May be.

Since the input device can be manufactured through a process different from the manufacturing process of at least one of the transistor, the liquid crystal element 180, and the liquid crystal element 170, the yield of each element can be improved.

A display device 300D illustrated in FIG. 14 includes a conductive layer 331, an insulating layer 332, a conductive layer 333, a conductive layer 334, an electrode 113a, an electrode 311g, an electrode 311h, and the like.

Two conductive layers 333 provided with the conductive layer 334 interposed therebetween are electrically connected to each other through the conductive layer 331. The conductive layer 331 and the conductive layer 334 are electrically insulated from each other by the insulating layer 332.

The conductive layer 333 is electrically connected to the electrode 113a. The electrode 113a can be formed using the same conductive film and the same process as the electrode 113. In the connection portion 254, the electrode 113a is electrically connected to the electrode 311g through the connection body 243. Accordingly, a signal or a potential input from an FPC (FPC 372 or a different FPC) connected to the substrate 351 side can be supplied to the touch sensor provided on the substrate 390 side via the connection portion 254. .

<< Example 2 of Manufacturing Method of Display Device >>
The display device 300B, the display device 300C, and the display device 300D can be manufactured by changing the process of step S8 among the processes from step S1 to step S9 described in the display device manufacturing method example 1. When the display device 300B, the display device 300C, and the display device 300D are manufactured, step S8 includes the following steps S11 to S18. Hereinafter, a method for manufacturing the display device 300D will be described with reference to FIGS. Note that detailed description of the same portions as the manufacturing method of the display device 300A is omitted.

[Step S11: Prepare Fabrication Substrate 94]
First, similarly to step S1 (FIGS. 3 and 4A), a manufacturing substrate 94 is prepared (FIG. 15).

[Step S12: Form Metal Oxide Layer 90]
Next, as in step S2 (FIGS. 3 and 4B1), a metal oxide layer 90 is formed over the manufacturing substrate 94 (FIG. 15).

[Step S13: Form Resin Layer 93]
Next, as in step S3 (FIGS. 3, 4C, and 4D), a first layer is formed over the metal oxide layer 90, and heat treatment is performed, whereby a resin layer is formed. 93 is formed (FIG. 15).

[Step S14: Form a functional layer]
Next, a functional layer is formed over the resin layer 93 (FIGS. 15 and 16A). Note that FIG. 16B is a cross-sectional view in the case of manufacturing the display device 300B or the display device 300C. FIG. 16B can also be regarded as a cross-sectional view in the case where the functional layer does not include a detection element.

First, as illustrated in FIG. 16A, a conductive layer 331 is formed over the resin layer 93. Note that after an insulating layer having a high barrier property is formed over the resin layer 93, the conductive layer 331 may be formed over the insulating layer.

Then, an insulating layer 332 that covers the conductive layer 331 is formed. Next, an opening reaching the conductive layer 331 is formed in the insulating layer 332. Then, a conductive layer 333 and a conductive layer 334 are formed over the insulating layer 332. The conductive layer 333 is electrically connected to the conductive layer 331 through the opening of the insulating layer 332.

Here, in order to show an example in which a metal mesh is used for the wiring and electrodes of the detection element, the detection element is formed in a portion other than the display region using the liquid crystal element 180 and the liquid crystal element 170. Note that in the case where the wiring and the electrode of the detection element are formed using a conductive material that transmits visible light, the wiring and the electrode may be arranged in the display region.

Next, the insulating layer 335 which covers the conductive layer 333 and the conductive layer 334 is formed. As the insulating layer 332 and the insulating layer 335, an inorganic insulating film, a resin, or the like can be used, respectively.

Next, the coloring layer 131 and the light shielding layer 132 are formed over the insulating layer 335. Note that as illustrated in FIG. 16B, in the case where the detection element is not provided in the functional layer, the coloring layer 131 and the light shielding layer 132 are formed over the resin layer 93.

Note that an inorganic insulating film having a high barrier property may be formed over the resin layer 93, and a detection element, a colored layer, a light shielding layer, or the like may be formed over the inorganic insulating film.

Next, the insulating layer 121 is formed over the coloring layer 131 and the light shielding layer 132. Next, an opening reaching the conductive layer 333 is formed in the insulating layer 121 and the insulating layer 335.

Next, the electrode 113 and the electrode 113a are formed. The electrode 113a is electrically connected to the conductive layer 333 through the openings of the insulating layer 121 and the insulating layer 335.

Next, the insulating layer 117 is formed over the electrode 113.

Next, an alignment film 133 b is formed over the electrode 113 and the insulating layer 117. The alignment film 133b can be formed by performing a rubbing process after forming a thin film such as a resin.

[Step S15: Sealing Liquid Crystal Layer 112]
The manufacturing substrate 94 in which the above steps are completed and the substrate 351 in which the steps up to Step S8 are completed are bonded together using the adhesive layer 141 (FIGS. 14 and 17). The manufacturing substrate 94 and the substrate 351 are attached to each other with the liquid crystal layer 112 sandwiched between the alignment film 133a and the alignment film 133b.

In the connection portion 254, the electrode 113a and the electrode 311g are electrically connected through the connection body 243.

[Step S16: Light Irradiation / Separation]
Next, as in step S7 (FIGS. 3, 7, and 8), the metal oxide layer 90 and the resin layer 93 are separated (FIGS. 15 and 18). Accordingly, the detection element, the coloring layer 131, and the like manufactured over the manufacturing substrate 94 can be transferred to the substrate 351.

Note that in the liquid crystal element 180, the adhesion between the electrode and the liquid crystal layer may be low. Therefore, if the manufacturing substrate 94 is peeled off using a human hand, a jig, a roller, or the like, film peeling occurs in the liquid crystal element 180, and the liquid crystal element 180 may be destroyed. In this embodiment, the metal oxide layer 90 and the resin layer 93 can be separated by light irradiation. Since there is no need to peel off the manufacturing substrate 94 with a strong force, peeling of the film in the liquid crystal element 180 can be suppressed and the yield of separation can be increased.

[Step S17-1: Determine whether to remove resin layer 93]
When the resin layer 93 is removed after the separation, the process proceeds to step S17-2. If the resin layer 93 is not removed, the process proceeds to step 18. Since the resin layer 93 is a layer positioned closer to the display surface than the display element, the display quality of the display device may be improved by removing the resin layer 93 in some cases. Depending on the degree of translucency and thickness of the resin layer 93, the resin layer 93 may not be removed.

In this manufacturing method example 2, a case where the resin layer 93 is removed will be described.

[Step S17-2: Remove the resin layer 93]
The resin layer 93 can be removed by the same method as in step S8-2 (FIGS. 3 and 9A) (FIG. 15).

[Step S18: Laminate Substrate 390]
Next, the substrate 351 and the substrate 390 are attached to each other using the adhesive layer 392 (FIGS. 15 and 19). The substrate 390 provided with the antireflection member 396 can be attached to the substrate 351. Alternatively, the antireflection member 396 may be provided over the substrate 390 after the substrate 351 and the substrate 390 are bonded to each other.

As described above, step S11 to step S18 in FIG. 15 are performed in step S8 in FIG.

Thereafter, in step S9 (FIG. 3), the FPC 372, the IC, and the like can be electrically connected.

Through the above steps, the display device 300D illustrated in FIG. 14 can be manufactured.

<< Configuration Example 3 of Display Device >>
Hereinafter, a display device having a configuration different from that of the display device 300A will be described with reference to FIG. Detailed description of the same parts as those of the display device 300A will be omitted.

FIG. 20 shows a cross-sectional view of the display device 300E. The display device 300E does not include the substrate 361, the polarizing plate 135a, and the polarizing plate 135b, but includes the insulating layer 91a, the adhesive layer 97, the insulating layer 91b, the touch sensor, the adhesive layer 392, the substrate 390, and the antireflection member 396. . The display device 300E includes at least two FPCs and connection bodies (FPC 372a, FPC 372b, a connection layer 242a, and a connection layer 242b). Other configurations are the same as those of the display device 300A. Note that one or both of the polarizing plate and the light diffusion layer are provided depending on the operation mode of the liquid crystal element 170 and the liquid crystal element 180.

The display device 300E includes a conductive layer 331, an insulating layer 332, a conductive layer 333, a conductive layer 334, a conductive layer 336, and the like.

Two conductive layers 333 provided with the conductive layer 334 interposed therebetween are electrically connected to each other through the conductive layer 331. The conductive layer 331 and the conductive layer 334 are electrically insulated from each other by the insulating layer 332.

The conductive layer 333 is electrically connected to the conductive layer 336. The conductive layer 336 can be formed using the same conductive film and the same process as the conductive layer 331. The conductive layer 336 is electrically connected to the FPC 372b through the connection layer 242b.

<< Example 3 of Manufacturing Method of Display Device >>
Hereinafter, a method for manufacturing the display device 300E will be described with reference to FIGS. Note that detailed description of the same portions as the manufacturing method of the display device 300A is omitted.

The display device 300E can be manufactured by changing the process of step S8 among the processes from step S1 to step S9 described in the display device manufacturing method example 1. When manufacturing the display device 300E, step S8 includes a process from step S21 to step S27, a process from step S31 to step S37, and a process of step S28. The process from step S21 to step S27 and the process from step S31 to step S37 can be performed independently. Step S28 is performed after step S27 and step S37.

[Step S21: Prepare Fabrication Substrate 94a]
First, similarly to step S1 (FIGS. 3 and 4A), a production substrate 94a is prepared (FIG. 21).

[Step S22: Form Metal Oxide Layer 90a]
Next, as in step S2 (FIGS. 3 and 4B1), a metal oxide layer 90a is formed over the manufacturing substrate 94a (FIG. 21).

[Step S23: Form Resin Layer 93a]
Next, similarly to Step S3 (FIGS. 3, 4C, and 4D), a first layer is formed over the metal oxide layer 90a, and heat treatment is performed, whereby a resin layer is formed. 93a is formed (FIG. 21).

[Step S24: Form first functional layer]
Next, a first functional layer is formed on the resin layer 93a (FIGS. 21 and 22).

First, the insulating layer 91a is preferably formed over the resin layer 93a. The insulating layer 91a is preferably formed so as to have an inorganic insulating film with high barrier properties.

Next, the coloring layer 131 and the light shielding layer 132 are formed over the insulating layer 91a. Next, the insulating layer 121 is formed over the coloring layer 131 and the light shielding layer 132. Next, the electrode 113 is formed. Next, the insulating layer 117 is formed over the electrode 113. Next, an alignment film 133 b is formed over the electrode 113 and the insulating layer 117. Details of these forming methods can be referred to the manufacturing method example 1.

[Step S25: Sealing Liquid Crystal Layer 112]
The manufacturing substrate 94a in which the process in step S24 is completed and the substrate 351 in which the process up to step S8 is completed are bonded together using the adhesive layer 141 (FIGS. 21 and 23). The manufacturing substrate 94a and the substrate 351 are attached to each other with the liquid crystal layer 112 sandwiched between the alignment film 133a and the alignment film 133b.

[Step S26: Irradiate / Separate Light]
Next, similarly to step S7 (FIGS. 3, 7, and 8), the metal oxide layer 90a and the resin layer 93a are separated (FIGS. 21 and 24).

[Step S27-1: Determine whether to remove the resin layer 93a]
When the resin layer 93a is removed after the separation, the process proceeds to step S27-2. If the resin layer 93a is not removed, the process proceeds to step 28. Since the resin layer 93a is a layer positioned closer to the display surface than the display element, the display quality of the display device may be improved by removing the resin layer 93a. Depending on the degree of translucency and thickness of the resin layer 93a, the resin layer 93a may not be removed.

In this manufacturing method example 3, a case where the resin layer 93a is removed will be described.

[Step S27-2: Remove resin layer 93a]
The resin layer 93a can be removed by the same method as in step S8-2 (FIGS. 3 and 9) (FIG. 25).

As described above, by performing Step S21 to Step S27, the electrode 113, the colored layer 131, and the like manufactured over the manufacturing substrate 94a can be transferred to the substrate 351.

In addition, the following steps S31 to S37 are performed independently of steps S21 to S27.

[Step S31: Prepare Fabrication Substrate 94b]
First, similarly to step S1 (FIGS. 3 and 4A), a manufacturing substrate 94b is prepared (FIG. 21).

[Step S32: Form Metal Oxide Layer 90b]
Next, as in step S2 (FIGS. 3 and 4B1), a metal oxide layer 90b is formed over the formation substrate 94b (FIG. 21).

[Step S33: Form Resin Layer 93b]
Next, similarly to Step S3 (FIGS. 3, 4C, and 4D), a first layer is formed over the metal oxide layer 90b and heat treatment is performed, whereby a resin layer is formed. 93b is formed (FIG. 21).

[Step S34: Form Second Functional Layer]
Next, a second functional layer is formed over the resin layer 93b (FIGS. 21 and 26A).

First, the insulating layer 91b is preferably formed over the resin layer 93b. The insulating layer 91b is preferably formed so as to have an inorganic insulating film with high barrier properties.

Next, the conductive layer 331 and the conductive layer 336 are formed over the insulating layer 91b. Then, an insulating layer 332 that covers the conductive layer 331 and the conductive layer 336 is formed. Next, an opening reaching the conductive layer 331 and the conductive layer 336 is formed in the insulating layer 332. Then, a conductive layer 333 and a conductive layer 334 are formed over the insulating layer 332. The conductive layer 333 is electrically connected to the conductive layer 331 through the opening of the insulating layer 332. In addition, the conductive layer 333 is electrically connected to the conductive layer 336 through the opening of the insulating layer 332.

In the case where one or both of a polarizing plate and a light diffusion layer are provided in the display device, a light diffusion layer 136 is provided over the insulating layer 332, the conductive layer 331, and the conductive layer 336 as illustrated in FIG. The polarizing plate 135 a can be provided over the light diffusion layer 136.

[Step S35: Bonding Substrate 390]
Next, the formation substrate 94b and the substrate 390 are attached to each other using the adhesive layer 392 (FIGS. 21 and 27A). Here, a substrate 390 provided with an antireflection member 396 is used.

[Step S36: Irradiate / Separate Light]
Next, as in step S7 (FIGS. 3, 7, and 8), the metal oxide layer 90b and the resin layer 93b are separated (FIGS. 21, 27B, and 28A). .

[Step S37-1: Determine whether to remove resin layer 93b]
When the resin layer 93b is removed after the separation, the process proceeds to step S37-2. If the resin layer 93b is not removed, the process proceeds to step 28. Since the resin layer 93b is a layer positioned closer to the display surface than the display element, the display quality of the display device may be improved by removing the resin layer 93b. Depending on the degree of translucency and thickness of the resin layer 93b, the resin layer 93b may not be removed.

In this manufacturing method example 3, a case where the resin layer 93b is removed will be described.

[Step S37-2: Remove the resin layer 93b]
The resin layer 93b can be removed by the same method as in step S8-2 (FIGS. 3 and 9) (FIG. 28B).

As described above, by performing Step S31 to Step S37, the detection element manufactured on the manufacturing substrate 94b can be transferred to the substrate 390.

[Step S28: Bonding the first functional layer and the second functional layer]
The substrate 351 completed up to step S27 and the substrate 390 completed up to step S37 are bonded together using the adhesive layer 141 (FIGS. 21 and 29).

As described above, the step shown in FIG. 21 is performed in step S8 of FIG.

Thereafter, in step S9 (FIG. 3), the FPC 372a, the FPC 372b, the IC, and the like can be electrically connected.

Through the above steps, the display device 300E illustrated in FIG. 20 can be manufactured.

<< Display device configuration example 4 >>
Hereinafter, a display device having a configuration different from that of the display device 300 </ b> A will be described with reference to FIGS. 30 and 31. Detailed description of the same parts as those of the display device 300A will be omitted.

FIG. 30 is a cross-sectional view of the display device 300F. The display device 300F includes a resin layer 23 and an insulating layer 31. The electrode 311 c is electrically connected to the connection layer 242 through an opening provided in the resin layer 23 and the insulating layer 31. Similarly, the electrode 311 e is electrically connected to the connection body 243 through an opening provided in the resin layer 23 and the insulating layer 31. Other configurations are the same as those of the display device 300A. Note that one or both of the polarizing plate and the light diffusion layer are provided depending on the operation mode of the liquid crystal element 180.

FIG. 31 is a cross-sectional view of the display device 300G. In the display device 300G, the resin layer 23 is thinner than the display device 300F. Further, the display device 300G does not have the alignment film 133a. Other configurations are the same as those of the display device 300F. In the display device 300G, the resin layer 23 functions as an alignment film. The electrode 311 c passes through openings provided in the resin layer 23 and the insulating layer 31 and is electrically connected to the connection layer 242. Similarly, the electrode 311 e passes through openings provided in the resin layer 23 and the insulating layer 31 and is electrically connected to the connection body 243. The electrode 311c and the electrode 311e protrude from the surface of the resin layer 23.

<< Example 4 of Manufacturing Method of Display Device >>
A method for manufacturing the display device 300F and the display device 300G will be described below with reference to FIGS. Note that detailed description of the same portions as the manufacturing method of the display device 300A is omitted.

[Step S1: Prepare Fabrication Substrate 14]
First, the production substrate 14 is prepared (FIG. 3).

[Step S2: Form Metal Oxide Layer 20]
Next, the metal oxide layer 20 is formed over the manufacturing substrate 14 (FIG. 3).

[Step S3: Form Resin Layer 23]
Next, a first layer is formed on the metal oxide layer 20. And the resin layer 23 is formed by heat-processing with respect to a 1st layer (FIG.3 and FIG.32 (A)).

Here, an opening reaching the metal oxide layer 20 is provided in the resin layer 23.

As described later, separation occurs at the interface between the metal oxide layer 20 and the conductive layer in the portion where the opening is provided in the resin layer 23. As the size of one opening of the resin layer 23 is smaller, separation at the interface between the metal oxide layer 20 and the conductive layer becomes easier, and the yield can be increased. For example, the area of one opening provided in the resin layer 23 is preferably smaller than 10 μm square, more preferably 5 μm square or less, and further preferably 3 μm square or less. When a plurality of openings are provided in the resin layer 23, the longer the shortest distance between two adjacent openings, the easier the separation at the interface between the metal oxide layer 20 and the conductive layer, and the yield can be increased. For example, the shortest distance between two adjacent openings is preferably 1 μm or more, more preferably 5 μm or more, more preferably 10 μm or more, more preferably 50 μm or more, and further preferably 200 μm or more.

In FIG. 32A, one opening is illustrated in the resin layer 23, but a plurality of small openings may be provided in the opening. The plurality of openings may be arranged regularly, such as in a matrix, or may be arranged irregularly.

In the case of using a photosensitive material, for example, the resin layer 23 having a desired shape can be formed by using a photolithography method.

In the case of using a non-photosensitive material, for example, the resin layer 23 having a desired shape can be formed by etching using a mask.

[Step S4: Form a transistor]
Next, a layer to be peeled including a transistor is formed over the resin layer 23.

An insulating layer 31 is preferably formed over the resin layer 23 (FIG. 32B).

As shown in FIG. 32B, an opening reaching the metal oxide layer 20 is formed in the insulating layer 31.

Next, the electrode 311a, the electrode 311c, and the electrode 311e are formed over the insulating layer 31 (FIG. 32B). Then, an electrode 311b is formed on the electrode 311a, an electrode 311d is formed on the electrode 311c, and an electrode 311f is formed on the electrode 311e. The electrode 311b has an opening 451 on the electrode 311a.

The electrode 311c and the electrode 311e are in contact with the metal oxide layer 20 through openings provided in the resin layer 23 and the insulating layer 31, respectively.

After that, the layers from the insulating layer 220 to the insulating layer 214 are formed. For details of these steps, the manufacturing method example 1 can be referred to.

[Step S5: Form Liquid Crystal Element 170]
Next, the liquid crystal element 170 is formed (FIG. 3). Thus, the stacked structure illustrated in FIG. 32C can be manufactured.

[Step S6: Irradiate / Separate Light]
Next, the metal oxide layer 20 and the resin layer 23 are separated (FIGS. 3 and 33). In the opening of the resin layer 23, separation occurs at the interface between the metal oxide layer 20 and the electrode 311c and at the interface between the metal oxide layer 20 and the electrode 311e. Accordingly, the transistor, the liquid crystal element 170, and the like manufactured over the manufacturing substrate 14 can be transferred to the substrate 351.

[Step S7-1: Determine whether to remove the resin layer 23]
When the resin layer 23 is removed after the separation, the process proceeds to step S7-2. If the resin layer 23 is not removed, the process proceeds to step 8.

In the case of manufacturing the display device 300F, the process of removing the resin layer 23 is not necessary.

When the display device 300G is manufactured, a part of the resin layer 23 may be removed. Specifically, the resin layer 23 may be thinned to a thickness suitable for functioning as an alignment film.

[Step S7-2: Remove the resin layer 23]
FIG. 34 shows an example in which a part of the resin layer 23 is removed and the thickness of the resin layer 23 is reduced. By removing a part of the resin layer 23, a part of the electrode 311c and a part of the electrode 311e protrude.

[Step S8: Form Liquid Crystal Element 180]
Next, the liquid crystal element 180 is formed (FIG. 3).

[Step S9: Implement]
After that, an FPC 372, an IC, or the like can be electrically connected. In addition, optical members such as a polarizing plate 135a and a polarizing plate 135b can be provided.

Through the above steps, the display device 300F illustrated in FIG. 30 and the display device 300G illustrated in FIG. 31 can be manufactured.

«Display device configuration example 5»
Hereinafter, a display device having a configuration different from that of the display device 300A will be described with reference to FIG. Detailed description of the same parts as those of the display device 300A will be omitted.

FIG. 35 shows a cross-sectional view of the display device 300H. The display device 300H is different from the display device 300A in transistor structure. Other configurations are the same as those of the display device 300A.

The transistor 205 and the transistor 206 included in the display device 300 </ b> A are a BGTC (Bottom Gate Top Contact) type. On the other hand, the transistor 205 and the transistor 206 included in the display device 300H are of a (Top Gate Self Align) type.

Specifically, the transistor 205 and the transistor 206 included in the display device 300H include a conductive layer 223 that functions as a gate, an insulating layer 211b that functions as a gate insulating layer, a conductive layer 222a and a conductive layer 222b that function as a source and a drain, The semiconductor layer 231 is included.

The transistor 201 included in the display device 300H includes a conductive layer 221a functioning as a gate and an insulating layer 211a functioning as a gate insulating layer in addition to the structures of the transistor 205 and the transistor 206.

<< Display device configuration example 6 >>
Hereinafter, a display device having a configuration different from that of the display device 300A will be described with reference to FIG. Detailed description of the same parts as those of the display device 300A will be omitted.

FIG. 36 shows a cross-sectional view of the display device 300J.

The substrate 351 and the substrate 361 are attached so that the liquid crystal layer 112 is sandwiched between the alignment film 133a and the alignment film 133b. The liquid crystal element 180 includes an electrode 311a, an electrode 311b, an electrode 311c, a liquid crystal layer 112, and an electrode 113.

As a pixel electrode of the liquid crystal element 180, an electrode 311a, an electrode 311b, and an electrode 311c are stacked in this order from the alignment film 133a side. The end portion of the electrode 311a and the end portion of the electrode 311c are located outside the end portion of the electrode 311b and are in contact with each other. A conductive film that transmits visible light is used for the electrode 311a and the electrode 311c. A conductive film that reflects visible light is used for the electrode 311b. An opening 451 is provided in the electrode 311b. The opening 451 overlaps the display area of the liquid crystal element 170.

An insulating layer 115 is formed between the alignment film 133a and the pixel electrode of the liquid crystal element 180. The insulating layer 115 preferably has a high barrier property. The insulating layer 115 is preferably a silicon film containing nitrogen such as a silicon nitride film or a silicon oxynitride film.

The electrode 311c and the conductive layer 224 overlap with each other with the insulating layer 220a interposed therebetween. The conductive layer 224 is electrically connected to the conductive layer 203 through an opening provided in the insulating layer 220b. The conductive layer 224 and the conductive layer 203 function as one electrode of the capacitor. The conductive layer 224 overlaps with the transistor 205 and the transistor 206 with the insulating layer 220b provided therebetween. A source or a drain of the transistor 206 is electrically connected to the electrode 311c at the connection portion 207. The source or drain of the transistor 205 is electrically connected to the electrode 191 of the liquid crystal element 170 through the conductive layer 228. Each transistor is covered with an insulating layer 212, an insulating layer 213, an insulating layer 214, an insulating layer 225, and an insulating layer 215. Of these, one or more insulating layers preferably have high barrier properties. FIG. 36 illustrates an example in which a material having a high barrier property is used for the insulating layer 213 and the insulating layer 225. The insulating layer 213 is provided to cover end portions of openings provided in the insulating layer 220a, the insulating layer 220b, the insulating layer 212, and the like. The insulating layer 225 is provided so as to cover an end portion of the opening provided in the insulating layer 214. The coating film 226 is a film that reflects visible light. The coating film 226 has a function of reflecting part of the transmitted light from the liquid crystal element 170 and supplying the reflected light to the opening 451 side. The lens 227 has a function of transmitting the transmitted light from the liquid crystal element 170. The lens 227 overlaps with the display area of the liquid crystal element 170. The liquid crystal element 170 includes an electrode 191, a liquid crystal layer 192, and an electrode 193. The liquid crystal layer 192 is sandwiched between the alignment film 153a and the alignment film 153b. Light is incident on the liquid crystal element 170 from the backlight unit 65 through the substrate 351.

The display device includes a number of insulating films from the insulating layer 115 to the insulating layer 215. Thus, the number of layers through which light transmitted from the liquid crystal element 170 enters can be reduced by forming openings in one or more insulating layers so as to overlap with the openings 451. Thereby, the extraction efficiency of transmitted light can be improved. It is preferable that an interface having a large difference in refractive index does not occur in a region through which transmitted light passes. FIG. 36 illustrates an example in which openings that overlap with the openings 451 are formed in the insulating layer 220a, the insulating layer 220b, and the like.

A colored layer 131, an insulating layer 121, an insulating layer 232, an electrode 113, an insulating layer 117, and an alignment film 133b are provided on one surface of the substrate 361. The insulating layer 121 functions as an overcoat. For the insulating layer 232, an insulating film with high barrier properties is preferable. The electrode 113 functions as a common electrode for the liquid crystal element 180. The insulating layer 117 functions as a spacer for maintaining the cell gap of the liquid crystal element 180. The insulating layer 117 transmits visible light. The insulating layer 117 transmits the transmitted light from the liquid crystal element 170.

<Laser irradiation unit>
Next, an example of a laser irradiation unit will be described with reference to FIGS.

A stacked body 56 shown in FIGS. 37A and 37B has a configuration in which, for example, an object to be peeled 56a and a support 56b are stacked. The laminate 56 is peeled between the peeled body 56a and the support 56b. The peeled body 56a has, for example, a resin layer, and the support 56b has, for example, a manufacturing substrate.

The transport roller 644 can transport the stacked body 56. The transport mechanism that transports the stacked body 56 is not limited to the transport roller, and a belt conveyor, a transport robot, or the like may be used. Moreover, you may arrange | position the laminated body 56 on the stage on a conveyance mechanism.

The laser irradiation unit 610 is a unit that irradiates the laminated body 56 with a laser. As the laser, for example, an excimer laser that outputs ultraviolet light having a wavelength of 308 nm can be used. Further, a high pressure mercury lamp, a UV-LED, or the like may be used.

As shown in FIG. 37A, the stacked body 56 is conveyed to the laser irradiation unit 610 in a state where the support body 56b is positioned on the upper side.

The excimer laser is a high-power pulse laser, and the beam can be shaped into a linear shape by an optical system. By moving the substrate at the irradiation position of the laser beam of the linear beam, the entire substrate or a necessary portion can be irradiated with the laser beam. Note that if the linear beam has a length equal to or longer than one side of the substrate to be used, the entire substrate can be irradiated with laser light only by moving the substrate in one direction. The oscillation frequency of the pulse laser is preferably 1 Hz or more and 300 Hz or less, and more preferably around 60 Hz.

As an excimer laser device, in addition to a device equipped with one laser oscillator, a device equipped with two or more laser oscillators may be used. In an apparatus equipped with a plurality of laser oscillators, a laser beam having a high energy density can be obtained by combining (superimposing) laser beams output in synchronization from the respective laser oscillators in an optical system. Therefore, in the application of the present embodiment, 3.5th generation (600 mm × 720 mm) or more, 6th generation glass substrate (1500 mm × 1850 mm) or more, 7th generation (1870 mm × 2200 mm) or more, or 8th generation glass. Processing of a size larger than the substrate (2160 mm × 2460 mm) can also be performed. Further, in an apparatus equipped with a plurality of laser oscillators, the laser beams output from the respective laser oscillators complement each other in output variations, so that intensity variations for each pulse are reduced, and high-yield processing can be performed. . A plurality of excimer laser devices may be used instead of the plurality of oscillators.

FIG. 37A shows an example of a laser irradiation unit 610 using an excimer laser. Laser beams 610 a and 610 b output from an excimer laser device 660 having two laser oscillators are combined by an optical system 635. Further, the laser beam 610 c that is expanded horizontally by the optical system 635 enters the lens 680 via the mirror 650. The laser beam 610d transmitted through the lens 680 is reduced as compared with the laser beam 610c. At this time, the laser beam 610d is irradiated to the processing region 640 included in the stacked body 56 through the support 56b (for example, a glass substrate). Hereinafter, a portion of the laser beam 610d that is irradiated onto the processing region 640 is referred to as a linear beam 610e.

Although an example in which two laser oscillators are provided is shown here, a configuration having one laser oscillator may be used, thereby simplifying the apparatus. Moreover, it is good also as a structure which has three or more laser oscillators, and can raise the intensity | strength of the linear beam 610e by this.

Then, the linear beam 610e can be irradiated to the processing region 640 by moving the stacked body 56 in the direction of the arrow in the drawing by the transport roller 644.

As shown in FIG. 37A, the process time can be shortened by irradiating the linear beam 610e while transporting the laminated body 56 at a constant speed by the transport roller 644. Note that the stacked body 56 may be arranged on a stage movable in at least one direction, and the linear beam 610e may be irradiated while moving the stage. In the case of using a stage, it is preferable to use a stage that can move in the horizontal direction and the height direction with respect to the traveling direction, and to adjust the focal position and depth of the linear beam 610e. Note that in FIG. 37A, the structure in which the linear beam 610e is irradiated by moving the stacked body 56 is illustrated; however, the present invention is not limited to this. For example, the stacked body 56 may be fixed, the excimer laser device 660 and the like may be moved, and the stacked body 56 may be irradiated with the linear beam 610e.

FIG. 37A shows an example in which the processing region 640 irradiated with the linear beam 610e is positioned inside the end portion of the stacked body 56. Thereby, since the area | region outside the process area | region 640 maintains a state with high adhesiveness, it can suppress that peeling arises at the time of conveyance. The width of the linear beam 610e may be equal to the width of the stacked body 56 or may be larger than the width of the stacked body 56. In that case, the entire stacked body 56 can be irradiated with the linear beam 610e.

FIG. 37B shows a state in which the linear beam 610e is irradiated onto the processing region 640 of the stacked body 56. The stacked body 56 includes a manufacturing substrate 58, a first layer 57a, and a second layer 57b. Here, a portion including the manufacturing substrate 58 and the second layer 57b corresponds to the support 56b, and a portion including the first layer 57a corresponds to the peeled body 56a.

For example, the first layer 57 a corresponds to the resin layer 23 and the second layer 57 b corresponds to the metal oxide layer 20.

The laser light 610d is transmitted through the manufacturing substrate 58, and the linear beam 610e is preferably applied to the interface between the first layer 57a and the second layer 57b or in the vicinity thereof. In particular, the linear beam 610e preferably has a focal point at or near the interface between the first layer 57a and the second layer 57b.

In addition, since the focal point of the linear beam 610e is positioned at the interface between the first layer 57a and the second layer 57b, water that may exist at the interface between the first layer 57a and the second layer 57b is removed. And the water volume may expand rapidly. In this case, it is presumed that a peeling phenomenon occurs at or near the interface between the first layer 57a and the second layer 57b as the volume of water expands.

There is a technique for crystallizing an amorphous silicon film by irradiating the amorphous silicon film with laser light. In the case of this technique, the laser beam is focused inside the amorphous silicon film. However, in one embodiment of the present invention, as illustrated in FIG. 37B, the focal point of the laser light (here, the linear beam 610e) is the interface between the first layer 57a and the second layer 57b. Or its vicinity. As described above, one embodiment of the present invention is different from the technique in which the focal position of the laser light is used to crystallize the amorphous silicon film.

Further, when the focal depth of the linear beam 610e is sufficiently large (deep), not only the interface between the first layer 57a and the second layer 57b or the vicinity thereof, but also the entire thickness direction of the first layer 57a, the first The focal point of the linear beam 610e may be located over the entire thickness direction of the second layer 57b or the entire thickness direction of both the first layer 57a and the second layer 57b.

As the excimer laser, it is preferable to use a laser having a wavelength of 308 nm or longer. When the wavelength is 308 nm or more, even when a glass substrate is used for the support 56b, the laser light necessary for processing can be sufficiently transmitted.

<Other separation methods>
Other separation methods that can be used in the method for manufacturing the display device of this embodiment will be described.

For example, when a separation method using light irradiation is used, a resin layer may be directly formed over a manufacturing substrate without providing a metal oxide layer.

Alternatively, a physical separation method may be used. At this time, for example, it is preferable to form a separation layer over the manufacturing substrate and form a layer to be separated over the separation layer. As the separation layer, for example, a stacked structure of a layer containing a refractory metal material such as tungsten and a layer containing an oxide of the metal material can be used. For example, the stacked structure can be formed by forming a metal layer containing a refractory metal material and oxidizing the surface of the metal layer by oxygen plasma treatment or the like.

Of the layer to be peeled, an inorganic insulating film is preferably formed as a layer in contact with the peeling layer. And it is preferable to form a functional element on an inorganic insulating film. The peeling layer and the inorganic insulating film can be separated by applying a pulling force in the vertical direction to the supporting substrate on which the peeling layer and the inorganic insulating film are formed.

Even in the method of physical separation, at the time of separation, a liquid containing water, such as water or an aqueous solution, is added to the separation interface, and separation is performed so that the liquid penetrates the separation interface. Can do. In addition, static electricity generated at the time of separation can be prevented from adversely affecting a functional element such as a transistor (a semiconductor element is destroyed by static electricity).

As described above, with the use of the method for manufacturing a display device of this embodiment, a display device with high visibility and high convenience can be manufactured regardless of surrounding brightness. In the method for manufacturing a display device in this embodiment, a metal oxide layer and a resin layer are stacked over a manufacturing substrate and light is irradiated to control the peelability of the resin layer from the metal oxide layer. Therefore, a display device can be manufactured with high yield.

This embodiment can be combined with any of the other embodiments as appropriate. In this specification, in the case where a plurality of structure examples are given in one embodiment, any of the structure examples can be combined as appropriate.

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

<Concept of display device>
As a display device which can be manufactured by applying one embodiment of the present invention, for example, a hybrid display can be given. The hybrid display can perform a hybrid display.

Hybrid display is a method of displaying characters or images in one panel by using reflected light and transmitted light together and complementing color tone or light intensity. Alternatively, the hybrid display is a method of displaying characters and / or images using light from a plurality of display elements in the same pixel or the same sub-pixel. However, when a hybrid display that performs hybrid display is viewed locally, the display is performed using a pixel or sub-pixel displayed using any one of a plurality of display elements and two or more of the plurality of display elements. A pixel or a sub-pixel.

Note that in this specification and the like, a display that satisfies any one or a plurality of expressions of the above configuration is referred to as a hybrid display.

The hybrid display has a plurality of display elements in the same pixel or the same sub-pixel. Examples of the plurality of display elements include a reflective element that reflects light and a transmissive element that transmits light. The reflective element and the transmissive element can be controlled independently. The hybrid display has a function of displaying characters and / or images using either one or both of reflected light and transmitted light in the display unit.

<Configuration example of display device>
The display device of this embodiment includes a plurality of first pixels each including a first display element and a plurality of second pixels each including a second display element. The first pixels and the second pixels are preferably arranged in a matrix.

It is preferable that the first pixel and the second pixel are arranged in the display area with the same number and the same pitch. At this time, the adjacent first pixel and second pixel can be collectively referred to as a pixel unit. Thereby, as will be described later, an image displayed with only the plurality of first pixels, an image displayed with only the plurality of second pixels, and both the plurality of first pixels and the plurality of second pixels. Each of the images displayed in can be displayed in the same display area. Note that the number and the pitch of the first pixel and the second pixel may be different from each other.

Each of the first pixel and the second pixel can include one or more subpixels. For example, the pixel has a configuration with one subpixel (white (W), etc.), a configuration with three subpixels (red (R), green (G), and blue (B), or three colors, or Yellow (Y), cyan (C), magenta (M), etc.) or a configuration having four sub-pixels (red (R), green (G), blue (B), white (W) Or four colors of red (R), green (G), blue (B), yellow (Y), etc.) can be applied.

The display device of this embodiment can be configured to perform full-color display in both the first pixel and the second pixel. Alternatively, the display device in this embodiment can have a structure in which the first pixel performs monochrome display or grayscale display, and the second pixel performs full color display. The monochrome display or grayscale display using the first pixel is suitable for displaying information that does not require color display, such as document information.

The display device of one embodiment of the present invention can reproduce color gamuts of various standards. For example, PAL (Phase Alternating Line) and NTSC (National Television System Committee) standards used in television broadcasting, sRGB (standard RGB) widely used in display devices used in electronic devices such as personal computers, digital cameras, and printers ITU-R BT., Which is used in the standard, Adobe RGB standard, HDTV (also known as High Definition Television). 709 (International Telecommunication Union Radiocommunication Sector Broadcasting Service (Television) 709) Standard, DCI-P3 (Digital CinitiitiPUU standard used in digital cinema projection) R BT. A color gamut such as 2020 (REC. 2020 (Recommendation 2020)) standard can be reproduced.

FIG. 38A is a block diagram of the display device 10A.

The display device 10A includes a display unit 14A. The display unit 14A includes a plurality of pixel units 30A arranged in a matrix. The pixel unit 30A includes a first pixel 31p and a second pixel 32p.

FIG. 38A illustrates an example in which the first pixel 31p includes the display element 31W corresponding to white (W). The display element 31W is a display element that utilizes reflection of external light.

FIG. 38A illustrates an example in which the second pixel 32p includes display elements corresponding to three colors of red (R), green (G), and blue (B).

A second pixel 32p illustrated in FIG. 38A includes a display element 32R corresponding to red (R), a display element 32G corresponding to green (G), and a display element 32B corresponding to blue (B). The display elements 32R, 32G, and 32B are display elements that transmit light from the light source.

FIG. 38B is a block diagram of the display device 10B.

The display device 10B includes a display unit 14B. The display unit 14B has a plurality of pixel units 30B arranged in a matrix. The pixel unit 30B includes a first pixel 31p and a second pixel 32p.

FIG. 38B illustrates an example in which the first pixel 31p includes display elements corresponding to three colors of red (R), green (G), and blue (B).

A first pixel 31p illustrated in FIG. 38B includes a display element 31R corresponding to red (R), a display element 31G corresponding to green (G), and a display element 31B corresponding to blue (B). The display element 31R, the display element 31G, and the display element 31B are elements that reflect and display external light. The display element 31R reflects external light and emits red light Rr to the display surface side. Similarly, the display element 31G and the display element 31B respectively emit green light Gr or blue light Br to the display surface side.

The structure of the second pixel 32p shown in FIG. 38B is similar to that in FIG. Therefore, detailed description is omitted.

<Configuration example of pixel unit>
FIG. 38C is a schematic diagram illustrating a configuration example of the pixel unit 30A.

The first pixel 31p has a display element 31W. The display element 31W is an element that reflects and displays external light. The display element 31W reflects external light and emits white light Wr to the display surface side.

The second pixel 32p includes a display element 32R, a display element 32G, and a display element 32B. The display element 32R, the display element 32G, and the display element 32B are elements that transmit visible light. The display element 32R emits red light Rt to the display surface side. Similarly, the display element 32G and the display element 32B respectively emit green light Gt or blue light Bt to the display surface side.

Subsequently, a display mode by the pixel unit 30A will be described with reference to FIGS.

FIG. 39A corresponds to a mode (first mode) in which display is performed using only reflected light by driving the first pixel 31p. For example, when the illuminance of outside light is sufficiently high, the pixel unit 30A uses only the light from the first pixel 31p without driving the second pixel 32p, thereby generating the light 35r that is reflected light. It can be emitted to the display surface side. Thereby, driving with extremely low power consumption can be performed. In addition, display that is kind to the eyes can be performed.

FIG. 39B corresponds to a mode (second mode) in which display is performed using only transmitted light by driving the second pixels 32p. For example, when the illuminance of outside light is extremely small, the pixel unit 30 does not drive the first pixel 31p, and only mixes light (light Rt, light Gt, and light Bt) from the second pixel 32p. By doing so, light 35t of a predetermined color can be emitted to the display surface side. Thereby, a vivid display can be performed. Further, by reducing the luminance when the illuminance of outside light is small, it is possible to suppress glare that the user feels and to reduce power consumption.

FIG. 39C corresponds to a mode (third mode) in which display is performed by driving both the first pixel 31p and the second pixel 32p within the same period. The pixel unit 30 emits light 35tr of a predetermined color in which reflected light and transmitted light are mixed to the display surface side by mixing the light Wr, the light Rt, the light Gt, and the light Bt. be able to.

FIG. 38D is a schematic diagram illustrating a configuration example of the pixel unit 30B. Also in the pixel unit 30B, the above three types of display modes can be performed.

FIG. 38D corresponds to a mode (third mode) in which display is performed by driving both the first pixel 31p and the second pixel 32p. The pixel unit 30B displays the light 35tr of a predetermined color in which reflected light and transmitted light are mixed by mixing the six lights of light Rr, light Gr, light Br, light Rt, light Gt, and light Bt. Can be injected to the surface side.

At this time, there are many combinations of the brightness of each of the six lights, light Rr, light Gr, light Br, light Rt, light Gt, and light Bt, so that the light 35tr becomes light of a predetermined brightness and chromaticity. To do. Therefore, among the combinations of the luminance (gradation) of each of the six lights that realize the light 35tr having the same luminance and chromaticity, the luminance (gradation) of the light Rr, the light Gr, and the light Br emitted from the first pixel 31p. It is preferable to select a combination that yields the largest value. Thereby, power consumption can be reduced without sacrificing color reproducibility.

<Operation mode of display device>
Next, operation modes that can be performed in the first display element and the second display element are described with reference to FIGS.

In the following, a normal operation mode (Normal mode) that operates at a normal frame frequency (typically 60 Hz to 240 Hz or less) and an idling stop (IDS) drive mode that operates at a low frame frequency will be exemplified. To explain.

Note that the IDS driving mode refers to a driving method in which image data rewriting is stopped after image data writing processing is executed. Once the image data is written and then the interval until the next image data is written is extended, the power consumption required for writing the image data during that time can be reduced. The IDS drive mode can be set to a frame frequency of about 1/100 to 1/10 of the normal operation mode, for example. A still image has the same video signal between consecutive frames. Therefore, the IDS drive mode is particularly effective when displaying a still image. By displaying an image using IDS driving, power consumption is reduced, flickering of the screen is suppressed, and eye strain can be reduced.

40A to 40C are timing charts illustrating the pixel circuit and the normal drive mode and the IDS drive mode. Note that FIG. 40A illustrates a first display element 501 (here, a reflective liquid crystal element) and a pixel circuit 506 electrically connected to the first display element 501. In the pixel circuit 506 illustrated in FIG. 40A, the signal line SL, the gate line GL, the transistor M1 connected to the signal line SL and the gate line GL, and the capacitor Cs _LC connected to the transistor M1 Is shown.

Transistor M1 may become a leak path data _{D 1.} Therefore, the off-state current of the transistor M1 is preferably as small as possible. As the transistor M1, a transistor including a metal oxide in a semiconductor layer where a channel is formed is preferably used. When the metal oxide has at least one of an amplifying function, a rectifying function, and a switching function, the metal oxide is referred to as a metal oxide semiconductor or an oxide semiconductor, or OS for short. be able to. Hereinafter, as a typical example of a transistor, a transistor in which an oxide semiconductor is used for a semiconductor layer in which a channel is formed (also referred to as an “OS transistor”) is described. The OS transistor has a feature that leakage current (off-state current) in a non-conduction state is extremely lower than that of a transistor using polycrystalline silicon or the like. By using an OS transistor as the transistor M1, the charge supplied to the node ND1 can be held for a long time.

Note that in the circuit diagram shown in FIG. 40 (A), the liquid crystal element LC is the leak path of the data _{D 1.} Therefore, in order to appropriately perform IDS driving, it is preferable that the resistivity of the liquid crystal element LC is 1.0 × 10 ¹⁴ Ω · cm or more.

Note that an In—Ga—Zn oxide, an In—Zn oxide, or the like can be preferably used for the channel region of the OS transistor, for example. As the In—Ga—Zn oxide, a composition in the vicinity of In: Ga: Zn = 4: 2: 4.1 [atomic ratio] can be typically used.

FIG. 40B is a timing chart showing waveforms of signals supplied to the signal line SL and the gate line GL in the normal drive mode. In the normal drive mode, it operates at a normal frame frequency (for example, 60 Hz). When one frame period is represented by periods T ₁ to T ₃ , an operation of applying a scanning signal to the gate line GL and writing data D ₁ from the signal line SL to the node ND ₁ in each frame period is performed. This operation is the same even when writing the same data D ₁ in the period T ₁ to T ₃ or writing different data.

On the other hand, FIG. 40C is a timing chart showing waveforms of signals supplied to the signal line SL and the gate line GL in the IDS driving mode, respectively. In the IDS drive, it operates at a low frame frequency (for example, 1 Hz). Represents one frame period in the period T _1, representing the period T _W a write period of data _therein, the data retention period in the period T _RET. IDS drive mode gives a scanning signal to the gate line GL in a period _{T W,} write data _{D 1} of the signal line SL, and a gate line GL is fixed to the low level of the voltage in the period _{T RET,} nonconductive transistor M1 It performs an operation of holding temporarily the data D ₁ written as. In addition, what is necessary is just to set it as 0.1 Hz or more and less than 60 Hz as a low-speed frame frequency, for example.

The IDS drive mode is effective because it can further reduce power consumption by combining with the above-described first mode, second mode, or third mode.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 3)
In this embodiment, a more specific structure example of the display device of one embodiment of the present invention will be described with reference to FIGS.

FIG. 41A is a block diagram of the display device 700. FIG. The display device 700 includes a display unit 701, a circuit GD, and a circuit SD. The display portion 701 includes a plurality of pixels 710 arranged in a matrix.

The display device 700 includes a plurality of wirings G11, a plurality of wirings G12, a plurality of wirings ANO, a plurality of wirings CSCOM, a plurality of wirings S1, and a plurality of wirings S2. The plurality of wirings G11, the plurality of wirings G12, the plurality of wirings ANO, and the plurality of wirings CSCOM are electrically connected to the plurality of pixels 710 and the circuit GD arranged in the direction indicated by the arrow R, respectively. The plurality of wirings S1 and the plurality of wirings S2 are electrically connected to the plurality of pixels 710 and the circuit SD arranged in the direction indicated by the arrow C, respectively.

Note that, here, for the sake of simplicity, a configuration including one circuit GD and one circuit SD is shown; however, a circuit GD and a circuit SD that drive a reflective liquid crystal element, a circuit GD that drives a transmissive liquid crystal element, and The circuit SD may be provided separately.

The pixel 710 includes a reflective liquid crystal element and a transmissive liquid crystal element.

41B1 and 41B2 illustrate configuration examples of the electrode 761 included in the pixel 710. FIG. The electrode 761 functions as a reflective electrode of a reflective liquid crystal element. An opening 751 is provided in the electrode 761.

In FIGS. 41B1 and 41B2, the transmissive liquid crystal element 760 located in a region overlapping with the electrode 761 is indicated by a broken line. The transmissive liquid crystal element 760 is disposed so as to overlap with the opening 751 included in the electrode 761. Accordingly, light transmitted through the transmissive liquid crystal element 760 is emitted to the display surface side through the opening 751.

In FIG. 41 (B1), the pixel 710 adjacent in the direction indicated by the arrow R is a sub-pixel corresponding to a different color.

In FIG. 41 (B2), the pixel 710 adjacent in the direction indicated by the arrow C is a sub-pixel corresponding to a different color.

The smaller the value of the ratio of the total area of the openings 751 to the total area of the non-openings, the brighter the display using the reflective liquid crystal element. In addition, the larger the value of the ratio of the total area of the openings 751 to the total area of the non-openings, the brighter the display using the transmissive liquid crystal element 760.

The shape of the opening 751 can be, for example, a polygon, a rectangle, an ellipse, a circle, a cross, or the like. Moreover, it is good also as an elongated streak shape, a slit shape, and a checkered shape. Further, the opening 751 may be arranged close to adjacent pixels.

Various sequential circuits such as a shift register can be used for the circuit GD. A transistor, a capacitor, or the like can be used for the circuit GD. A transistor included in the circuit GD can be formed in the same process as the transistor included in the pixel 710.

The circuit SD is electrically connected to the wiring S1. For the circuit SD, for example, an integrated circuit can be used. Specifically, an integrated circuit formed on a silicon substrate can be used for the circuit SD.

For example, the circuit SD can be mounted on a pad electrically connected to the pixel 710 by using a COG method, a COF method, or the like. Specifically, an integrated circuit can be mounted on the pad using an anisotropic conductive film.

FIG. 42 is a circuit diagram illustrating a configuration example of the pixel 710. In FIG. 42, two adjacent pixels 710 are shown.

The pixel 710 includes a switch SW1, a capacitor C1, a liquid crystal element 740, a switch SW2, a switch SW2, a capacitor C2, a liquid crystal element 760, and the like. In addition, the pixel 710 is electrically connected to the wiring G11, the wiring G12, the wiring CSCOM, the wiring S1, and the wiring S2. In FIG. 42, a wiring VCOM1 electrically connected to the liquid crystal element 740 and a wiring VCOM2 electrically connected to the liquid crystal element 760 are illustrated.

FIG. 42 shows an example in which transistors are used for the switch SW1 and the switch SW2.

The gate of the switch SW1 is connected to the wiring G11. One of the source and the drain of the switch SW1 is connected to the wiring S1, and the other is connected to one electrode of the capacitor C1 and one electrode of the liquid crystal element 740. The other electrode of the capacitive element C1 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 740 is connected to the wiring VCOM1.

The gate of the switch SW2 is connected to the wiring G12. One of the source and the drain of the switch SW2 is connected to the wiring S2, and the other is connected to one electrode of the capacitor C2 and one electrode of the liquid crystal element 760. The other electrode of the capacitive element C2 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 760 is connected to the wiring VCOM2.

The wiring G11 can be supplied with a signal for controlling the switch SW1 to be in a conductive state or a non-conductive state. A predetermined potential can be applied to the wiring VCOM1. A signal for controlling the alignment state of the liquid crystal included in the liquid crystal element 740 can be supplied to the wiring S1. A predetermined potential can be applied to the wiring CSCOM.

The wiring G12 can be supplied with a signal for controlling the switch SW2 to be in a conductive state or a non-conductive state. A predetermined potential can be applied to the wiring VCOM2. A signal for controlling the alignment state of the liquid crystal included in the liquid crystal element 760 can be supplied to the wiring S2.

For example, in the case of performing reflection mode display, the pixel 710 illustrated in FIG. 42 is driven by a signal supplied to the wiring G11 and the wiring S1, and can display using optical modulation by the liquid crystal element 740. Further, in the case where display is performed in the transmissive mode, display can be performed by driving with a signal applied to the wiring G12 and the wiring S2 and using optical modulation by the liquid crystal element 760. In the case of driving in both modes, the driving can be performed by signals given to the wiring G11, the wiring G12, the wiring S1, and the wiring S2.

Note that FIG. 42 illustrates an example in which one pixel 710 includes one liquid crystal element 740 and one liquid crystal element 760. At this time, the pixel 710 functions as one subpixel. Alternatively, when the liquid crystal element 760 is driven by a time gray scale method, a single pixel 710 can display full color when displaying in the transmission mode or both modes.

FIG. 43 illustrates an example in which one pixel 710 includes one reflective liquid crystal element 740 and three transmissive liquid crystal elements (a liquid crystal element 760r, a liquid crystal element 760g, and a liquid crystal element 760b). The liquid crystal elements 760r, 760g, and 760b are transmissive liquid crystal elements that transmit red (R), green (G), and blue (B) light, respectively. The pixel 710 shown in FIG. 43 can display in full color with three transmissive liquid crystal elements when displaying in the transmissive mode or both modes.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 4)
In this embodiment, an example of a touch sensor driving method will be described with reference to drawings.

<Example of sensor detection method>
FIG. 44A is a block diagram illustrating a structure of a mutual capacitive touch sensor. In FIG. 44A, a pulse voltage output circuit 551 and a current detection circuit 552 are shown. Note that in FIG. 44A, an electrode 521 to which a pulse voltage is applied and an electrode 522 for detecting a change in current are illustrated as six wirings of X1-X6 and Y1-Y6, respectively. FIG. 44A illustrates a capacitor 553 which is formed by overlapping the electrode 521 and the electrode 522. Note that the functions of the electrode 521 and the electrode 522 may be interchanged.

The pulse voltage output circuit 551 is a circuit for sequentially applying a pulse voltage to the X1-X6 wirings. When a pulse voltage is applied to the wiring of X1-X6, an electric field is generated between the electrode 521 and the electrode 522 forming the capacitor 553. By utilizing the fact that the electric field generated between the electrodes changes the mutual capacitance of the capacitor 553 by shielding or the like, the proximity or contact of the detection target can be detected.

The current detection circuit 552 is a circuit for detecting a change in current in the wirings Y1 to Y6 due to a change in mutual capacitance in the capacitor 553. In the wirings Y1 to Y6, there is no change in the current value detected when there is no proximity or contact with the detected object. However, when the mutual capacitance decreases due to the proximity or contact with the detected object, the current value decreases. Detect changes that occur. Note that current detection may be performed using an integration circuit or the like.

Note that one or both of the pulse voltage output circuit 551 and the current detection circuit 552 may be formed over the substrate 351 or the substrate 361 illustrated in FIG. For example, it is preferable to form the display portion 362, the circuit 364, and the like at the same time because the number of components used for driving the touch sensor can be reduced in addition to simplifying the process. One or both of the pulse voltage output circuit 551 and the current detection circuit 552 may be mounted on the IC 373.

In particular, when crystalline silicon such as polycrystalline silicon or single crystal silicon is used for a semiconductor layer in which a channel is formed as a transistor formed on the substrate 351, circuits such as the pulse voltage output circuit 551 and the current detection circuit 552 are driven. The ability is improved and the sensitivity of the touch sensor can be improved.

FIG. 44B shows a timing chart of input / output waveforms in the mutual capacitive touch sensor shown in FIG. In FIG. 44B, it is assumed that the detection target is detected in each matrix in one frame period. FIG. 44B shows two cases, that is, a case where the detected object is not detected (non-touch) and a case where the detected object is detected (touch). In addition, about the wiring of Y1-Y6, the waveform made into the voltage value corresponding to the detected electric current value is shown.

A pulse voltage is sequentially applied to the X1-X6 wiring, and the waveform of the Y1-Y6 wiring changes according to the pulse voltage. When there is no proximity or contact of the detection object, the waveform of Y1-Y6 changes uniformly according to the change of the voltage of the wiring of X1-X6. On the other hand, since the current value decreases at the location where the detection object is close or in contact, the waveform of the voltage value corresponding to this also changes.

In this way, by detecting the change in mutual capacitance, the proximity or contact of the detection target can be detected.

<Example of driving method of display device>
FIG. 45A is a block diagram illustrating a structure example of a display device. FIG. 45A shows a display portion having a gate driving circuit GD (scanning line driving circuit), a source driving circuit SD (signal line driving circuit), and a plurality of pixels pix. In FIG. 45A, gate lines x_1 to x_m (m is a natural number) electrically connected to the gate driver circuit GD, and source lines y_1 to y_n (n is a natural number) electrically connected to the source driver circuit SD. ) Corresponding to (1, 1) to (n, m) in the pixel pix.

FIG. 45B is a timing chart of signals supplied to the gate lines and the source lines in the display device illustrated in FIG. FIG. 45B shows a case where the data signal is rewritten for each frame period and a case where the data signal is not rewritten. Note that in FIG. 45B, a period such as a blanking period is not considered.

When the data signal is rewritten every frame period, scanning signals are sequentially applied to the gate lines x_1 to x_m. In the horizontal scanning period 1H in which the scanning signal is at the H level, the data signal D is supplied to the source lines y_1 to y_n of each column.

When the data signal is not rewritten every frame period, the scanning signal applied to the gate lines x_1 to x_m is stopped. In the horizontal scanning period 1H, the data signal applied to the source lines y_1 to y_n in each column is stopped.

A driving method in which a data signal is not rewritten every frame period is particularly effective when an oxide semiconductor is applied to a semiconductor layer in which a channel is formed as a transistor included in the pixel pix. A transistor to which an oxide semiconductor is applied can have extremely low off-state current compared to a transistor to which a semiconductor such as silicon is applied. Therefore, the data signal written in the previous period can be held without rewriting the data signal every frame period. For example, the gradation of the pixel is held for 1 second or more, preferably 5 seconds or more. You can also.

Further, in the case where polycrystalline silicon or the like is applied to a semiconductor layer in which a channel is formed as a transistor included in the pixel pix, it is preferable that the size of the storage capacitor included in the pixel is increased in advance. The larger the storage capacity, the longer the pixel gradation can be stored. The size of the storage capacitor may be set according to the leakage current of a transistor or a display element electrically connected to the storage capacitor. For example, the storage capacitor per pixel is 5 fF or more and 5 pF or less, preferably 10 fF or more and 5 pF. In the following, more preferably 20 fF or more and 1 pF or less, the data signal written in the previous period can be held without rewriting the data signal every frame period. For example, in a period of several frames or several tens frames It is possible to maintain the gradation of the pixels throughout.

<Example of driving method of display unit and touch sensor>
46A to 46D show an example in which the touch sensor described in FIGS. 44A and 44B and the display unit described in FIGS. 45A and 45B are 1 sec. It is a figure explaining the operation | movement of a continuous frame period when driving (for 1 second). FIG. 46A shows a case where one frame period of the display portion is 16.7 ms (frame frequency: 60 Hz) and one frame period of the touch sensor is 16.7 ms (frame frequency: 60 Hz).

In the display device of one embodiment of the present invention, the operation of the display portion and the operation of the touch sensor are independent from each other, and the touch detection period can be provided in parallel with the display period. Therefore, as shown in FIG. 46A, one frame period of the display portion and the touch sensor can be set to 16.7 ms (frame frequency: 60 Hz). Further, the frame frequency of the touch sensor and the display unit may be different. For example, as shown in FIG. 46B, one frame period of the display unit is set to 8.3 ms (frame frequency: 120 Hz), and one frame period of the touch sensor is set to 16.7 ms (frame frequency: 60 Hz). You can also. Although not shown, the frame frequency of the display unit may be 33.3 ms (frame frequency: 30 Hz).

In addition, the frame frequency of the display unit can be switched, the frame frequency is increased (for example, 60 Hz or more or 120 Hz or more) when displaying a moving image, and the frame frequency is decreased (for example, 60 Hz) when displaying a still image. The power consumption of the display device can be reduced by adjusting the frequency to 30 Hz or lower or 1 Hz or lower. In addition, the frame frequency of the touch sensor may be switched, and the frame frequency may be different depending on whether the touch sensor detects a touch.

In addition, in the display device of one embodiment of the present invention, the data signal rewritten in the previous period is held without rewriting the data signal in the display portion, so that one frame period of the display portion is longer than 16.7 ms. It can be a period. Therefore, as shown in FIG. 46C, one frame period of the display portion is 1 sec. (Frame frequency: 1 Hz) can be set, and one frame period of the touch sensor can be set to 16.7 ms (frame frequency: 60 Hz).

Note that the IDS driving mode described above can be referred to for a configuration in which the data signal rewritten in the previous period is held without rewriting the data signal in the display portion. Note that the IDS drive mode may be a partial IDS drive mode in which the data signal in the display unit is rewritten only in a specific area. The partial IDS drive mode is a configuration in which the data signal is rewritten only in a specific area in the display portion, and the data signal rewritten in the previous period is held in other areas.

Further, according to the touch sensor driving method disclosed in this embodiment, when the driving illustrated in FIG. 46C is performed, the touch sensor can be continuously driven. Therefore, as shown in FIG. 46D, the data signal of the display portion can be rewritten at the timing when the proximity or contact of the detection target in the touch sensor is detected.

Here, if the rewriting operation of the data signal of the display unit is performed during the sensing period of the touch sensor, noise generated during the rewriting of the data signal is transmitted to the touch sensor, which may reduce the sensitivity of the touch sensor. Therefore, it is preferable to drive so that the data signal rewriting period of the display unit is shifted from the sensing period of the touch sensor.

FIG. 47A shows an example in which rewriting of the data signal of the display portion and sensing of the touch sensor are alternately performed. FIG. 47B shows an example in which sensing of the touch sensor is performed once every time the data signal rewriting operation of the display portion is performed twice. Note that the present invention is not limited to this, and the touch sensor may be sensed once every time the rewrite operation is performed three times or more.

In addition, when an oxide semiconductor is used for a semiconductor layer in which a channel is formed in a transistor applied to the pixel pix, off-state current can be extremely reduced, and thus the frequency of data signal rewriting can be sufficiently reduced. Can do. Specifically, it is possible to provide a sufficiently long pause period after the data signal is rewritten until the next data signal is rewritten. The pause period can be, for example, 0.5 seconds or more, 1 second or more, or 5 seconds or more. The upper limit of the rest period is limited by the capacitance connected to the transistor and the leakage current of the display element, etc., and can be, for example, 1 minute or less, 10 minutes or less, 1 hour or less, or 1 day or less.

FIG. 47C shows an example in which the data signal of the display portion is rewritten at a frequency of once every 5 seconds. In FIG. 47C, after the data signal is rewritten in the display portion, a rest period in which the rewrite operation is stopped is provided until the next data signal rewrite operation. In the rest period, the touch sensor can be driven at a frame frequency iHz (i is equal to or higher than the frame frequency of the display device, here 0.2 Hz or higher). In addition, as shown in FIG. 47C, it is preferable that sensing of the touch sensor be performed in the pause period and not in the rewriting period of the data signal of the display portion because sensitivity of the touch sensor can be improved. In addition, as illustrated in FIG. 47D, when rewriting of the data signal of the display portion and sensing of the touch sensor are performed at the same time, a signal for driving can be simplified.

Further, in the idle period in which the data signal rewriting operation of the display portion is not performed, not only the supply of the data signal to the display portion is stopped, but also the operation of one or both of the gate driving circuit GD and the source driving circuit SD is stopped. May be. Further, power supply to one or both of the gate drive circuit GD and the source drive circuit SD may be stopped. By doing so, noise can be further reduced and the sensitivity of the touch sensor can be further improved. In addition, power consumption of the display device can be further reduced.

When the hybrid display described above is used as the display device, the above-described IDS drive mode or partial IDS drive mode can be combined with the above-described touch sensor drive method. In the case of using a hybrid display, the plurality of display elements can independently perform the IDS drive mode or the partial IDS drive mode. When a hybrid display is used, the following driving method can be realized.

For example, when the hybrid display includes a reflective element and a transmissive element, a monochrome image is displayed on the reflective element. Thereafter, the reflective element is set to the IDS drive mode, and power supply to one or both of the gate drive circuit GD and the source drive circuit SD is stopped. Thereafter, sensing of the touch sensor is performed, and the reflective element in the area where the sensing is not performed is shifted to the partial IDS drive mode. Thereafter, the transmissive element in the region where the partial IDS drive mode is not performed is driven. Thereafter, the power supply to one or both of the gate drive circuit GD and the source drive circuit SD driving the transmissive element is stopped, and the transmissive element is shifted to the partial IDS drive mode.

By performing the driving method as described above, it is possible to realize an excellent display device in which power consumption is reduced and detection sensitivity of the touch sensor is increased.

The display device of one embodiment of the present invention has a structure in which a display portion and a touch sensor are sandwiched between two substrates. Therefore, the distance between the display unit and the touch sensor can be extremely reduced. At this time, noise at the time of driving the display unit easily propagates to the touch sensor, and the sensitivity of the touch sensor may be reduced. By applying the driving method exemplified in this embodiment, a display device having a touch sensor that achieves both reduction in thickness and high detection sensitivity can be realized.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 5)
In this embodiment, a metal oxide that can be used for the transistor disclosed in one embodiment of the present invention will be described. In particular, details of the metal oxide and CAC (Cloud-Aligned Composite) will be described below.

The CAC-OS or the CAC-metal oxide has a conductive function in part of the material and an insulating function in part of the material, and has a function as a semiconductor in the whole material. Note that in the case where a CAC-OS or a CAC-metal oxide is used for a channel formation region of a transistor, the conductive function is a function of flowing electrons (or holes) serving as carriers and the insulating function is a carrier. This function prevents electrons from flowing. By performing the conductive function and the insulating function in a complementary manner, a switching function (function to turn on / off) can be given to the CAC-OS or the CAC-metal oxide. In CAC-OS or CAC-metal oxide, by separating each function, both functions can be maximized.

Further, the CAC-OS or the CAC-metal oxide has a conductive region and an insulating region. The conductive region has the above-described conductive function, and the insulating region has the above-described insulating function. In the material, the conductive region and the insulating region may be separated at the nanoparticle level. In addition, the conductive region and the insulating region may be unevenly distributed in the material, respectively. In addition, the conductive region may be observed with the periphery blurred and connected in a cloud shape.

In CAC-OS or CAC-metal oxide, the conductive region and the insulating region are each dispersed in a material with a size of 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm. There is.

Further, CAC-OS or CAC-metal oxide is composed of components having different band gaps. For example, CAC-OS or CAC-metal oxide includes a component having a wide gap caused by an insulating region and a component having a narrow gap caused by a conductive region. In the case of the configuration, when the carrier flows, the carrier mainly flows in the component having the narrow gap. In addition, the component having a narrow gap acts in a complementary manner to the component having a wide gap, and the carrier flows through the component having the wide gap in conjunction with the component having the narrow gap. Therefore, when the CAC-OS or the CAC-metal oxide is used for a channel formation region of a transistor, high current driving capability, that is, high on-state current and high field-effect mobility can be obtained in the on-state of the transistor.

That is, CAC-OS or CAC-metal oxide can also be referred to as a matrix composite or a metal matrix composite.

The CAC-OS is one structure of a material in which an element constituting a metal oxide is unevenly distributed with a size of 0.5 nm to 10 nm, preferably, 1 nm to 2 nm or near. In the following, in a metal oxide, one or more metal elements are unevenly distributed, and a region having the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm or near. The mixed state is also called mosaic or patch.

Note that the metal oxide preferably contains at least indium. In particular, it is preferable to contain indium and zinc. In addition, aluminum, gallium, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, etc. One kind or plural kinds selected from may be included.

For example, a CAC-OS in In-Ga-Zn oxide (In-Ga-Zn oxide among CAC-OSs may be referred to as CAC-IGZO in particular) is an indium oxide (hereinafter referred to as InO). _X1 (X1 is greater real than 0) and.), or indium zinc oxide _{(hereinafter, in X2 Zn Y2 O Z2 (} X2, Y2, and Z2 is larger real than 0) and a.), gallium An oxide (hereinafter referred to as GaO _X3 (X3 is a real number greater than 0)) or a gallium zinc oxide (hereinafter referred to as Ga _X4 Zn _Y4 O _Z4 (where X4, Y4, and Z4 are greater than 0)) to.) and the like, the material becomes mosaic by separate into, mosaic _{InO X1} or _in X2 _Zn Y2 _{O Z2,} is a configuration in which uniformly distributed in the film (hereinafter, click Also called Udo-like.) A.

That, CAC-OS includes a region _{GaO X3} is the main _component, and In _{X2 Zn} Y2 _{O Z2,} or _{InO X1} is the main component region is a composite metal oxide having a structure that is mixed. Note that in this specification, for example, the first region indicates that the atomic ratio of In to the element M in the first region is larger than the atomic ratio of In to the element M in the second region. It is assumed that the concentration of In is higher than that in the second region.

Note that IGZO is a common name and sometimes refers to one compound of In, Ga, Zn, and O. As a typical example, InGaO ₃ (ZnO) _m1 (m1 is a natural number) or In _{(1 + x0)} Ga _(1-x0) O ₃ (ZnO) _m0 (−1 ≦ x0 ≦ 1, m0 is an arbitrary number) A crystalline compound may be mentioned.

The crystalline compound has a single crystal structure, a polycrystalline structure, or a CAAC (c-axis aligned crystal) structure. The CAAC structure is a crystal structure in which a plurality of IGZO nanocrystals have c-axis orientation and are connected without being oriented in the ab plane.

On the other hand, CAC-OS relates to a material structure of a metal oxide. CAC-OS refers to a region that is observed in the form of nanoparticles mainly composed of Ga in a material structure including In, Ga, Zn, and O, and nanoparticles that are partially composed mainly of In. The region observed in a shape is a configuration in which the regions are randomly dispersed in a mosaic shape. Therefore, in the CAC-OS, the crystal structure is a secondary element.

Note that the CAC-OS does not include a stacked structure of two or more kinds of films having different compositions. For example, a structure composed of two layers of a film mainly containing In and a film mainly containing Ga is not included.

Incidentally, a region _{GaO X3} is the main _component, and In _{X2 Zn} Y2 _{O Z2} or _{InO X1} is the main component region, in some cases clear boundary can not be observed.

In place of gallium, aluminum, yttrium, copper, vanadium, beryllium, boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium are selected. In the case where one or a plurality of types are included, the CAC-OS includes a region that is observed in a part of a nanoparticle mainly including the metal element and a nanoparticle mainly including In. The region observed in the form of particles refers to a configuration in which each region is randomly dispersed in a mosaic shape.

The CAC-OS can be formed by a sputtering method under a condition where the substrate is not intentionally heated, for example. In the case where a CAC-OS is formed by a sputtering method, any one or more selected from an inert gas (typically argon), an oxygen gas, and a nitrogen gas may be used as a deposition gas. Good. Further, the flow rate ratio of the oxygen gas to the total flow rate of the deposition gas during film formation is preferably as low as possible. .

The CAC-OS is characterized in that no clear peak is observed when it is measured using a θ / 2θ scan by the out-of-plane method, which is one of the X-ray diffraction (XRD) measurement methods. Have. That is, it can be seen from X-ray diffraction that no orientation in the ab plane direction and c-axis direction of the measurement region is observed.

In addition, in the CAC-OS, an electron diffraction pattern obtained by irradiating an electron beam with a probe diameter of 1 nm (also referred to as a nanobeam electron beam) has a ring-like region having a high luminance and a plurality of bright regions in the ring region. A point is observed. Therefore, it can be seen from the electron beam diffraction pattern that the crystal structure of the CAC-OS has an nc (nano-crystal) structure having no orientation in the planar direction and the cross-sectional direction.

Further, for example, in a CAC-OS in an In—Ga—Zn oxide, a region in which GaO _X3 is a main component is obtained by EDX mapping obtained by using energy dispersive X-ray spectroscopy (EDX). It can be confirmed that a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component is unevenly distributed and mixed.

The CAC-OS has a structure different from that of the IGZO compound in which the metal element is uniformly distributed, and has a property different from that of the IGZO compound. That is, in the CAC-OS, a region in which GaO _X3 or the like is a main component and a region in which In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component are phase-separated from each other, and a region in which each element is a main component. Has a mosaic structure.

Here, the region containing In _X2 Zn _Y2 O _Z2 or InO _X1 as a main component is a region having higher conductivity than a region containing GaO _X3 or the like as a main component. _That, In _{X2 Zn} Y2 _{O Z2} or _{InO X1,} is an area which is the main component, by carriers flow, expressed the conductivity of the oxide semiconductor. Accordingly, a region where In _X2 Zn _Y2 O _Z2 or InO _X1 is a main component is distributed in a cloud shape in the oxide semiconductor, whereby high field-effect mobility (μ) can be realized.

On the other hand, areas such as _{GaO X3} is the main _component, as compared to the In _{X2 Zn} Y2 _{O Z2} or _{InO X1} is the main component area, it is highly regions insulating. That is, a region containing GaO _X3 or the like as a main component is distributed in the oxide semiconductor, whereby leakage current can be suppressed and good switching operation can be realized.

Therefore, when CAC-OS is used for a semiconductor element, the insulating property caused by GaO _{X3 and the} like and the conductivity caused by In _X2 Zn _Y2 O _Z2 or InO _X1 act in a complementary manner, resulting in high An on-current (I _on ) and high field effect mobility (μ) can be realized.

In addition, a semiconductor element using a CAC-OS has high reliability. Therefore, the CAC-OS is optimal for various semiconductor devices including a display.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 6)
In this embodiment, an electronic device of one embodiment of the present invention will be described.

According to one embodiment of the present invention, a highly reliable electronic device having a flat surface can be manufactured. According to one embodiment of the present invention, a highly reliable electronic device having a curved surface can be manufactured. Further, according to one embodiment of the present invention, an electronic device having flexibility and high reliability can be manufactured.

Electronic devices include, for example, television devices, desktop or notebook personal computers, monitors for computers, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio devices Large game machines such as playback devices and pachinko machines are listed.

In addition, the display device of one embodiment of the present invention can achieve high visibility regardless of the intensity of external light. Therefore, it can be suitably used for a portable electronic device, a wearable electronic device (wearable device), an electronic book terminal, and the like.

A portable information terminal 800 illustrated in FIGS. 48A and 48B includes a housing 801, a housing 802, a display portion 803, a hinge portion 805, and the like.

The housing 801 and the housing 802 are connected by a hinge portion 805. The portable information terminal 800 can be developed from the folded state (FIG. 48A) as shown in FIG. Thereby, when carrying, it is excellent in portability, and when using, it is excellent in visibility by a large display area.

The portable information terminal 800 is provided with a flexible display portion 803 across a housing 801 and a housing 802 connected by a hinge portion 805.

A display device manufactured using one embodiment of the present invention can be used for the display portion 803. Thereby, a portable information terminal can be manufactured with a high yield.

The display unit 803 can display at least one of document information, a still image, a moving image, and the like. When displaying document information on the display unit, the portable information terminal 800 can be used as an electronic book terminal.

When the portable information terminal 800 is deployed, the display unit 803 is held in a greatly curved form. For example, the display portion 803 is held including a curved portion with a curvature radius of 1 mm to 50 mm, preferably 5 mm to 30 mm. Part of the display portion 803 can display a curved surface by continuously arranging pixels from the housing 801 to the housing 802.

The display portion 803 functions as a touch panel and can be operated with a finger, a stylus, or the like.

The display unit 803 is preferably composed of one flexible display. Accordingly, continuous display can be performed between the housings 801 and 802 without interruption. Note that each of the housing 801 and the housing 802 may have a display.

The hinge portion 805 preferably has a lock mechanism so that the angle between the housing 801 and the housing 802 does not become larger than a predetermined angle when the portable information terminal 800 is deployed. For example, it is preferable that the angle at which the lock is applied (not opened further) is 90 degrees or more and less than 180 degrees, typically 90 degrees, 120 degrees, 135 degrees, 150 degrees, or 175 degrees. be able to. Thereby, the convenience, safety | security, and reliability of the portable information terminal 800 can be improved.

When the hinge portion 805 has a lock mechanism, the display portion 803 can be prevented from being damaged without applying excessive force to the display portion 803. Therefore, a highly reliable portable information terminal can be realized.

The housing 801 and the housing 802 may include a power button, an operation button, an external connection port, a speaker, a microphone, and the like.

One of the housing 801 and the housing 802 is provided with a wireless communication module, and data is transmitted through a computer network such as the Internet, a LAN (Local Area Network), and Wi-Fi (Wireless Fidelity: registered trademark). It is possible to send and receive.

A portable information terminal 810 illustrated in FIG. 48C includes a housing 811, a display portion 812, operation buttons 813, an external connection port 814, a speaker 815, a microphone 816, a camera 817, and the like.

A display device manufactured using one embodiment of the present invention can be used for the display portion 812. Thereby, a portable information terminal can be manufactured with a high yield.

The portable information terminal 810 includes a touch sensor in the display unit 812. Any operation such as making a call or inputting characters can be performed by touching the display portion 812 with a finger or a stylus.

In addition, by operating the operation button 813, the power can be turned on and off, and the type of image displayed on the display portion 812 can be switched. For example, the mail creation screen can be switched to the main menu screen.

Further, by providing a detection device such as a gyro sensor or an acceleration sensor inside the portable information terminal 810, the orientation (portrait or landscape) of the portable information terminal 810 is determined, and the screen display orientation of the display unit 812 is changed. It can be switched automatically. The screen display orientation can also be switched by touching the display portion 812, operating the operation buttons 813, or inputting voice using the microphone 816.

The portable information terminal 810 has one or more functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, it can be used as a smartphone. The portable information terminal 810 can execute various applications such as mobile phone, electronic mail, text browsing and creation, music playback, video playback, Internet communication, and games.

A camera 820 illustrated in FIG. 48D includes a housing 821, a display portion 822, operation buttons 823, a shutter button 824, and the like. A removable lens 826 is attached to the camera 820.

A display device manufactured using one embodiment of the present invention can be used for the display portion 822. Thereby, a camera can be manufactured with a high yield.

Here, the camera 820 is configured such that the lens 826 can be removed from the housing 821 and replaced, but the lens 826 and the housing 821 may be integrated.

The camera 820 can capture a still image or a moving image by pressing the shutter button 824. In addition, the display portion 822 has a function as a touch panel and can capture an image by touching the display portion 822.

The camera 820 can be separately attached with a strobe device, a viewfinder, and the like. Alternatively, these may be incorporated in the housing 821.

49A to 49E illustrate electronic devices. These electronic devices include a housing 9000, a display portion 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), a connection terminal 9006, and a sensor 9007 (force, displacement, position, speed, acceleration, angular velocity, rotation) Number, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, smell, or infrared) And a microphone 9008 and the like.

A display device manufactured using one embodiment of the present invention can be favorably used for the display portion 9001. Thereby, an electronic device can be manufactured with a high yield.

The electronic devices illustrated in FIGS. 49A to 49E can have various functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function for displaying a calendar, date or time, a function for controlling processing by various software (programs), Wireless communication function, function for connecting to various computer networks using the wireless communication function, function for transmitting or receiving various data using the wireless communication function, and reading and displaying the program or data recorded on the recording medium It can have a function of displaying on the section. Note that the functions of the electronic devices illustrated in FIGS. 49A to 49E are not limited to these, and may have other functions.

49A is a perspective view illustrating a wristwatch-type portable information terminal 9200, and FIG. 49B is a perspective view illustrating a wristwatch-type portable information terminal 9201.

A portable information terminal 9200 illustrated in FIG. 49A can execute various applications such as a mobile phone, e-mail, text browsing and creation, music playback, Internet communication, and computer games. Further, the display portion 9001 is provided with a curved display surface, and can perform display along the curved display surface. In addition, the portable information terminal 9200 can execute short-range wireless communication with a communication standard. For example, it is possible to talk hands-free by communicating with a headset capable of wireless communication. In addition, the portable information terminal 9200 includes a connection terminal 9006 and can directly exchange data with other information terminals via a connector. Charging can also be performed through the connection terminal 9006. Note that the charging operation may be performed by wireless power feeding without using the connection terminal 9006.

A portable information terminal 9201 illustrated in FIG. 49B is different from the portable information terminal illustrated in FIG. 49A in that the display surface of the display portion 9001 is not curved. Further, the external shape of the display portion of the portable information terminal 9201 is a non-rectangular shape (a circular shape in FIG. 49B).

49C to 49E are perspective views illustrating a foldable portable information terminal 9202. FIG. Note that FIG. 49C is a perspective view of a state in which the portable information terminal 9202 is expanded, and FIG. 49D is a state in which the portable information terminal 9202 is expanded or changed from one of the folded state to the other. FIG. 49E is a perspective view of the portable information terminal 9202 folded.

The portable information terminal 9202 is excellent in portability in the folded state, and in the expanded state, the portable information terminal 9202 is excellent in display listability due to a seamless wide display area. A display portion 9001 included in the portable information terminal 9202 is supported by three housings 9000 connected by a hinge 9055. By bending between the two housings 9000 via the hinge 9055, the portable information terminal 9202 can be reversibly deformed from the expanded state to the folded state. For example, the portable information terminal 9202 can be bent with a curvature radius of 1 mm to 150 mm.

This embodiment can be combined with any of the other embodiments as appropriate.

10A Display device 10B Display device 14 Fabrication substrate 14A Display unit 14B Display unit 19 Metal layer 20 Metal oxide layer 23 Resin layer 24 First layer 30 Pixel unit 30A Pixel unit 30B Pixel unit 31 Insulating layer 31B Display element 31G Display element 31W Display element 31p Pixel 31R Display element 32B Display element 32G Display element 32p Pixel 32R Display element 35r Light 35t Light 35tr Light 55 Laser light 56 Laminated body 56a Separation body 56b Support body 57a First layer 57b Second layer 58 Fabrication substrate 65 Backlight unit 90 Metal oxide layer 90a Metal oxide layer 90b Metal oxide layer 91a Insulating layer 91b Insulating layer 93 Resin layer 93a Resin layer 93b Resin layer 94 Fabrication substrate 94a Fabrication substrate 94b Fabrication substrate 97 Adhesive layer 100 Display device 112 Liquid crystal layer 113 Electrode 113a Electrode 115 Insulating layer 117 Insulating layer 121 Insulating layer 131 Colored layer 132 Light shielding layer 133a Alignment film 133b Alignment film 135a Polarizing plate 135b Polarizing plate 136 Light diffusion layer 141 Adhesive layer 142 Adhesive layer 153a Alignment film 153b Alignment film 170 Liquid crystal element 180 Liquid crystal element 191 electrode 191a electrode 192 liquid crystal layer 193 electrode 201 transistor 203 conductive layer 204 connection part 205 transistor 206 transistor 207 connection part 211 insulating layer 211a insulating layer 211b insulating layer 212 insulating layer 213 insulating layer 214 insulating layer 215 insulating layer 220 insulating layer 220a insulating Layer 220b Insulating layer 221a Conductive layer 221b Conductive layer 221c Conductive layer 222a Conductive layer 222b Conductive layer 223 Conductive layer 224 Conductive layer 225 Insulating layer 226 Covering film 227 Lens 228 Conductive layer 231 Semiconductor layer 2 2 Insulating layer 242 Connection layer 242a Connection layer 242b Connection layer 243 Connection body 244 Connection body 252 Connection section 253 Connection section 254 Connection section 300A Display device 300B Display device 300C Display device 300D Display device 300F Display device 300G Display device 300H Display Device 300J Display device 311a Electrode 311b Electrode 311c Electrode 311d Electrode 311e Electrode 311f Electrode 311g Electrode 311h Electrode 331 Conductive layer 332 Insulating layer 333 Conductive layer 334 Conductive layer 335 Insulating layer 336 Conductive layer 351 Substrate 361 Substrate 362 Display unit 364 Circuit 365 FPC
372a FPC
372b FPC
373 IC
390 Substrate 392 Adhesion layer 396 Antireflection member 451 Opening 501 Display element 506 Pixel circuit 521 Electrode 522 Electrode 551 Pulse voltage output circuit 552 Current detection circuit 553 Capacitor 610 Laser irradiation unit 610a Laser beam 610b Laser beam 610c Laser beam 610d Laser beam 610e Line Beam 635 Optical system 640 Processing region 644 Transport roller 650 Mirror excimer laser device 680 Lens 700 Display device 701 Display unit 710 Pixel 740 Liquid crystal element 751 Opening 760 Liquid crystal element 760b Liquid crystal element 760g Liquid crystal element 760r Liquid crystal element 761 Electrode 800 Portable information terminal 801 Housing 802 Housing 803 Display unit 805 Hinge unit 810 Portable information terminal 811 Housing 812 Display unit 813 Operation button 814 External connection port 815 Speaker 81 Microphone 817 Camera 820 Camera 821 Case 822 Display unit 823 Operation button 824 Shutter button 826 Lens 9000 Case 9001 Display unit 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9055 Hinge 9200 Mobile information terminal 9201 Mobile information terminal 9202 Mobile information Terminal

Claims (20)

A method for manufacturing a display device including a first display element having a first liquid crystal layer and a second display element having a second liquid crystal layer between a first substrate and a second substrate. ,
Forming a first common electrode on the first substrate;
Forming a second common electrode on the second substrate;
Forming a first layer on the manufacturing substrate;
Forming a second layer on the first layer;
Forming a first pixel electrode on the second layer;
Forming an insulating layer on the first pixel electrode;
Forming a second pixel electrode on the insulating layer;
In the state where the second liquid crystal layer is disposed between the second common electrode and the second pixel electrode, the manufacturing substrate and the second substrate are bonded to each other, so that the second display is performed. Forming an element;
Separating the first layer and the second layer by irradiating with light;
The first substrate and the second substrate are bonded together in a state where the first liquid crystal layer is disposed between the first common electrode and the first pixel electrode. Forming a display element. A method for manufacturing a display device. In claim 1,
A step of forming a functional layer on the first substrate before the step of forming the first common electrode;
The method for manufacturing a display device, wherein the functional layer is formed to have one or both of a sensing element and a colored layer. A method for manufacturing a display device including a first display element having a first liquid crystal layer and a second display element having a second liquid crystal layer between a first substrate and a second substrate. ,
Forming a first release layer on a first manufacturing substrate;
Forming a first common electrode on the first release layer;
Forming a second common electrode on the second substrate;
Forming a second release layer on the second manufacturing substrate;
Forming a first pixel electrode on the second release layer;
Forming an insulating layer on the first pixel electrode;
Forming a second pixel electrode on the insulating layer;
By bonding the second manufacturing substrate and the second substrate in a state where the second liquid crystal layer is disposed between the second common electrode and the second pixel electrode, Forming a display element of 2;
Separating the second preparation substrate and the second substrate using the second release layer;
In the state where the first liquid crystal layer is disposed between the first common electrode and the first pixel electrode, the first manufacturing substrate and the second substrate are bonded to each other. Forming a display element of 1;
Separating the first manufacturing substrate and the second substrate using the first release layer;
Bonding the first substrate and the second substrate with the first display element disposed between the first substrate and the second substrate, and
One or both of the first release layer and the second release layer are formed to have a first layer and a second layer on the first layer,
Light is irradiated in one or both of the step of separating the second manufacturing substrate and the second substrate and the step of separating the first manufacturing substrate and the second substrate. Thus, the method for manufacturing a display device, in which the first layer and the second layer are separated. In claim 3,
A step of forming a first functional layer on the first release layer before the step of forming the first common electrode;
The method for manufacturing a display device, wherein the first functional layer is formed to include one or both of a detection element and a colored layer. In claim 3 or 4,
The first substrate has a surface on which a second functional layer is provided,
The step of bonding the first substrate and the second substrate is performed with the second functional layer disposed between the first substrate and the second substrate,
The method for manufacturing a display device, wherein the second functional layer is formed to have one or both of a light diffusion layer and the polarizing plate. In claim 3,
Forming a third release layer on a third manufacturing substrate;
Forming a functional layer on the third release layer, and
Before the step of bonding the first substrate and the second substrate, the third release layer is disposed between the third manufacturing substrate and the first substrate, A step of bonding the third production substrate and the first substrate, and a step of separating the third production substrate and the first substrate using the third release layer,
The step of bonding the first substrate and the second substrate is performed in a state where the functional layer is disposed between the first substrate and the second substrate,
The method for manufacturing a display device, wherein the functional layer is formed to include one or more of a sensing element, a light diffusion layer, and a polarizing plate. In any one of Claims 3 thru | or 6,
A manufacturing method of a display device, wherein a glass substrate having a thickness of 0.1 mm or more and less than 0.5 mm is used for the first substrate. In any one of Claims 3 thru | or 6,
A method for manufacturing a display device, wherein a resin substrate with a thickness of 1 μm to 200 μm is used for the first substrate. In any one of Claims 1 thru | or 8,
The first pixel electrode is formed to have a function of reflecting visible light,
The display device manufacturing method, wherein each of the second pixel electrode, the first common electrode, and the second common electrode has a function of transmitting visible light. In any one of Claims 1 thru | or 9,
A method for manufacturing a display device, wherein an antireflection member is provided on a surface of the first substrate opposite to the surface on the second substrate side. In claim 10,
The method for manufacturing a display device, wherein the antireflection member is provided to have a convex portion. In any one of Claims 1 thru | or 11,
The method for manufacturing a display device, wherein the liquid crystal layer is provided so as to have a dichroic dye. In any one of Claims 1 thru | or 12,
A method for manufacturing a display device, including a step of forming a transistor including a metal oxide in a channel formation region over the insulating layer before the step of forming the second pixel electrode. In any one of Claims 1 thru | or 13,
Manufacturing of a display device, comprising a step of removing the second layer remaining on an exposed surface of the stacked body including the second substrate after the step of separating the first layer and the second layer. Method. In claim 14,
A method for manufacturing a display device, wherein ashing is performed in the step of removing the second layer. In any one of Claims 1 thru | or 15,
The method for manufacturing a display device, wherein the second layer is formed to have a region with a thickness of 0.1 μm to 5 μm. In any one of Claims 1 thru | or 16,
Laser light is used as the light,
A method for manufacturing a display device, wherein the first layer and the second layer are separated by irradiating the laser beam to an interface between the first layer and the second layer or the vicinity thereof. . In any one of Claims 1 thru | or 17,
The method for manufacturing a display device, wherein the first layer is formed to include one or both of titanium and titanium oxide. In any one of Claims 1 thru | or 18,
The method for manufacturing a display device, wherein the second layer is formed so as to have a residue of the compound represented by Structural Formula (100).
In any one of Claims 1 thru | or 19,
The second layer is formed to have an opening;
A conductive layer is formed so as to cover the opening,
A method for manufacturing a display device, wherein the conductive layer is exposed by separating the first layer and the second layer.