JP2018010229A - Display device, display module, electronic apparatus, and method of making display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device having high visibility regardless of the surrounding brightness, and provide a highly reliable display device.SOLUTION: A display device has a first display element, a second display element, a first insulating layer, and a second insulating layer. The first display element has a first pixel electrode configured to reflect visible light, and a liquid crystal layer. The second display element is configured to emit visible light. The second display element has a second pixel electrode and a common electrode. The common electrode is on the opposite side of the second insulating layer across the second pixel electrode. The first pixel electrode is on the opposite side of the second pixel electrode across the second insulating layer. The first pixel electrode is between the first insulating layer and the second insulating layer. The first pixel electrode is on the opposite side of the liquid crystal layer across the first insulating layer.SELECTED DRAWING: Figure 2

Description

One embodiment of the present invention relates to a display device, a display module, an electronic device, and a method for manufacturing the 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, a power storage device, a memory device, an electronic device, a lighting device, an input device (eg, a touch sensor), an input / output device (eg, a touch panel) ), A driving method thereof, or a manufacturing method thereof can be given as an example.

In recent years, display devices are expected to be applied to various uses. As a display device, for example, a light emitting device having a light emitting element, a liquid crystal display device having a liquid crystal element, and the like have been developed.

For example, Patent Document 1 discloses a flexible light emitting device to which an organic EL (Electroluminescence) element is applied.

Patent Document 2 has a region that reflects visible light and a region that transmits visible light, and can be used as a reflective liquid crystal display device in an environment where sufficient external light is obtained. A transflective liquid crystal display device that can be used as a transmissive liquid crystal display device in an environment where the above cannot be obtained is disclosed.

JP 2014-197522 A JP 2011-191750 A

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 an all-weather display device. 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 novel display device, an input / output device, an electronic device, or the like.

An object of one embodiment of the present invention is to provide a method for manufacturing a novel display device. An object of one embodiment of the present invention is to provide a method for manufacturing a display device in which a manufacturing process is simplified. 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.

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.

The display device of one embodiment of the present invention includes a first display element, a second display element, a first insulating layer, and a second insulating layer. The first display element includes a first pixel electrode having a function of reflecting visible light and a liquid crystal layer. The second display element has a function of emitting visible light. The second display element has a second pixel electrode and a common electrode. The common electrode is located on the opposite side of the second insulating layer with the second pixel electrode interposed therebetween. The first pixel electrode is located on the opposite side of the second pixel electrode with the second insulating layer interposed therebetween. The first pixel electrode is located between the first insulating layer and the second insulating layer. The first pixel electrode is located on the opposite side of the liquid crystal layer with the first insulating layer interposed therebetween. The display device preferably includes a first transistor and a second transistor. The first transistor has a function of controlling driving of the first display element. The second transistor has a function of controlling driving of the second display element. The second insulating layer has a portion that functions as a gate insulating layer of the first transistor and a portion that functions as a gate insulating layer of the second transistor.

The display device of one embodiment of the present invention includes a first display element, a second display element, a first insulating layer, a second insulating layer, a third insulating layer, a first transistor, and a second transistor. Have The first transistor has a function of controlling driving of the first display element. The second transistor has a function of controlling driving of the second display element. The first display element includes a first pixel electrode having a function of reflecting visible light and a liquid crystal layer. The second display element has a function of emitting visible light. The second display element has a second pixel electrode and a common electrode. The first transistor and the second transistor are respectively located between the second insulating layer and the third insulating layer. The first transistor is electrically connected to the first pixel electrode through an opening provided in the second insulating layer. The second transistor is electrically connected to the second pixel electrode through an opening provided in the third insulating layer. The common electrode is located on the opposite side of the third insulating layer with the second pixel electrode interposed therebetween. The first pixel electrode is located on the opposite side of the second pixel electrode with the second insulating layer interposed therebetween. The first pixel electrode is located between the first insulating layer and the second insulating layer. The first pixel electrode is located on the opposite side of the liquid crystal layer with the first insulating layer interposed therebetween.

One or both of the first transistor and the second transistor preferably include an oxide semiconductor in a channel formation region.

The first pixel electrode may have an opening. The second display element has a portion overlapping with the opening. The second display element has a function of emitting visible light toward the opening.

The thickness of the first insulating layer is preferably 50 nm or more and 600 nm or less.

One embodiment of the present invention is a display module including any one of the above-described structures and a circuit board such as a flexible printed circuit board (FPC).

One embodiment of the present invention is an electronic device including the display module and at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button.

One embodiment of the present invention is a method for manufacturing a display device including a first display element and a second display element. The first display element includes a first pixel electrode having a function of reflecting visible light, a liquid crystal layer, and a first common electrode having a function of transmitting visible light. The second display element includes a second pixel electrode having a function of transmitting visible light, a light emitting layer, and a second common electrode having a function of reflecting visible light. The first common electrode is formed over the first substrate, the first insulating layer is formed over the manufacturing substrate, the second insulating layer is formed over the first insulating layer, and the second insulating layer is formed. A peeling layer is formed over the insulating layer, plasma treatment is performed on the surface of the peeling layer, a third insulating layer is formed over the peeling layer, and the first pixel electrode is formed over the third insulating layer. Then, a fourth insulating layer is formed over the first pixel electrode. Heat treatment is performed after the third insulating layer is formed and before the second display element is formed. A second display element is formed by forming a second pixel electrode, a light emitting layer, and a second common electrode in this order on the fourth insulating layer. The manufacturing substrate and the second substrate are attached to each other using an adhesive. The manufacturing substrate and the third insulating layer are separated. A liquid crystal layer is disposed between the first common electrode and the exposed third insulating layer, and the first substrate and the second substrate are bonded together using an adhesive, whereby the first display element Form.

In the above method for manufacturing a display device, after the first pixel electrode is formed, an opening may be provided in the first pixel electrode, and the second display element may be formed at a position overlapping the opening.

In the above method for manufacturing a display device, the adhesive used when the first substrate and the second substrate are bonded to each other preferably contains conductive particles. The same conductive film is processed to form a first pixel electrode and a conductive layer. After the manufacturing substrate and the third insulating layer are separated, the third insulating layer is processed to expose the conductive layer. By bonding the first substrate and the second substrate, the first common electrode and the conductive layer are electrically connected by conductive particles.

In the above method for manufacturing a display device, the first insulating layer and the third insulating layer each preferably contain silicon and nitrogen, and more preferably contain silicon nitride. The first insulating layer and the third insulating layer may be formed under the same film formation conditions.

In the above method for manufacturing a display device, each of the first insulating layer and the third insulating layer preferably has a function of blocking hydrogen.

In the above method for manufacturing a display device, the second insulating layer preferably contains silicon and oxygen, and more preferably contains silicon oxynitride.

In the above method for manufacturing a display device, the second insulating layer preferably has a function of releasing hydrogen when heated.

In the above method for manufacturing a display device, the plasma treatment is preferably performed in an atmosphere containing nitrous oxide, and more preferably in an atmosphere containing nitrous oxide and silane. An oxide layer may be formed over the separation layer by performing plasma treatment. The oxide layer includes at least one of the materials included in the release layer.

In the above method for manufacturing a display device, an oxide layer containing tungsten and oxygen may be formed by forming a peeling layer containing tungsten and performing plasma treatment.

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, an all-weather display device 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 novel display device, an input / output device, an electronic device, or the like can be provided.

According to one embodiment of the present invention, a novel method for manufacturing a display device can be provided. According to one embodiment of the present invention, a method for manufacturing a display device in which a manufacturing process is simplified can be provided. According to one embodiment of the present invention, a method for manufacturing a display device with low cost and high productivity 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. 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. 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 transistor. 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 figure which shows an example of a display module. 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 circumstances 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.

Moreover, in this specification etc., it may describe as CAAC (c-axis aligned crystal) and CAC (cloud aligned complementary). Note that CAAC represents an example of a crystal structure, and CAC represents an example of a function or a material structure.

An example of a crystal structure of an oxide semiconductor or a metal oxide will be described. Note that in the following, an example of an oxide semiconductor film formed by a sputtering method using an In—Ga—Zn oxide target (In: Ga: Zn = 4: 2: 4.1 [atomic ratio]) is described. Will be described. An oxide semiconductor formed by a sputtering method with a substrate temperature of 100 ° C. to 130 ° C. using the target is referred to as sIGZO, and the substrate temperature is set to room temperature (RT) using the target. An oxide semiconductor formed by the method is referred to as tIGZO. For example, sIGZO has a crystal structure of one or both of nc (nano crystal) and CAAC. TIGZO has an nc crystal structure. Note that the room temperature (RT) here includes a temperature when the substrate is not intentionally heated.

In this specification and the like, a CAC-OS or a CAC-metal oxide has a function of a conductor in part of a material and a function of a dielectric (or insulator) in part of the material. As a whole, it has a function as a semiconductor. Note that in the case where a CAC-OS or a CAC-metal oxide is used for a semiconductor layer of a transistor, the conductor has a function of flowing electrons (or holes) serving as carriers, and the dielectric does not flow electrons serving as carriers. It has a function. By causing the function as a conductor and the function as a dielectric to act complementarily, a switching function (function to turn on / off) can be given to the CAC-OS or CAC-metal oxide. In CAC-OS or CAC-metal oxide, by separating each function, both functions can be maximized.

In this specification and the like, a CAC-OS or a CAC-metal oxide includes a conductor region and a dielectric region. The conductor region has the above-described conductor function, and the dielectric region has the above-described dielectric function. In the material, the conductor region and the dielectric region may be separated at the nanoparticle level. In addition, the conductor region and the dielectric region may be unevenly distributed in the material, respectively. In addition, the conductor region may be observed with the periphery blurred and connected in a cloud shape.

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

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

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

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

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

A light-emitting element is preferably used for the second display element. Light emitted from the light-emitting element is not affected by external light in luminance or chromaticity, and thus color reproducibility (wide color gamut) is high, and high-contrast and vivid display can be performed.

As the second display element, for example, a self-luminous light emitting element such as an OLED (Organic Light Emitting Diode), an LED (Light Emitting Diode), a QLED (Quantum-Dot Light Emitting Diode), or a semiconductor laser can be used.

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 light emission 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 reflected light from the first display element and light emission 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. Further, by using light in which reflected light and light emission are mixed, it is possible to display an image that makes it feel as if you are looking at a painting.

With such a configuration, it is possible to realize a highly visible and highly convenient display device or an all-weather display device regardless of ambient brightness.

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.

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.

Next, a configuration example of the display device of the present embodiment will be described with reference to FIGS.

<Configuration example 1>
FIG. 1 is a schematic perspective view of the display device 300. The display device 300 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 300 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 300. Therefore, the structure illustrated in FIG. 1 can also be referred to as a display module including the display device 300, 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 the light-emitting element 170 on the substrate 351 side of the electrode 311b. Light from the light emitting element 170 is emitted to the substrate 361 side through the opening 451 of the electrode 311b. The area of the light emitting region of the light emitting element 170 and the area of the opening 451 may be equal. One of the area of the light emitting region of the light emitting 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. In particular, the area of the opening 451 is preferably smaller than the area of the light emitting region of the light emitting element 170. When the opening 451 is small, part of light from the light-emitting element 170 may be blocked by the electrode 311b and may not be extracted to the outside. By making the opening 451 sufficiently large, it is possible to prevent the light emission of the light emitting element 170 from being wasted.

2 illustrates an example of a cross section of the display device 300 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 300 illustrated in FIG. 2 includes a transistor 201, a transistor 203, a transistor 205, a transistor 206, a liquid crystal element 180, a light-emitting element 170, an insulating layer 115, an insulating layer 220, a coloring layer 131, and the like between a substrate 351 and a substrate 361. The coloring layer 134 and the like are included. The substrate 361 and the insulating layer 115 are bonded to each other with an adhesive layer 141 interposed therebetween. The substrate 351 and the insulating layer 115 are bonded through an adhesive layer 142.

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 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. In the case where the insulating layer 117 transmits visible light, the insulating layer 117 may be overlapped with the display region of the liquid crystal element 180.

The liquid crystal element 180 is a reflective liquid crystal element. The liquid crystal element 180 emits reflected light to the substrate 361 side. The liquid crystal element 180 has a stacked structure in which the electrode 311a, the liquid crystal layer 112, and the 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 insulating layer 115 is provided in contact with the electrode 311a on the substrate 361 side. An alignment film 133 a is provided between the liquid crystal layer 112 and the insulating layer 115. 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 311a and the electrode 113 have a function of transmitting visible light. Light incident from the substrate 361 side is polarized by the polarizing plate 135, passes through the electrode 113, the liquid crystal layer 112, the insulating layer 115, and the electrode 311a, and is reflected by the electrode 311b. Then, the light passes through the electrode 311a, the insulating layer 115, the liquid crystal layer 112, and the electrode 113 again, and reaches the polarizing plate 135. 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 135 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.

In the connection portion 207, an opening is provided in the insulating layer 220. Therefore, impurities may enter the transistor and the light-emitting element 170 from the liquid crystal layer 112 side through the opening of the insulating layer 220.

Here, the display device 300 includes the insulating layer 115 between the electrode 311 a and the liquid crystal layer 112. Thus, impurities can be prevented from entering the transistor and the light-emitting element 170 from the liquid crystal layer 112 side, and the reliability of the display device can be improved. The insulating layer 115 is preferably provided over the entire display portion 362.

Note that if the insulating layer 115 is too thick, much of the light incident from the substrate 361 side is absorbed by the insulating layer 115. For this reason, the reflectance of the pixel is lowered and the display becomes dark. Further, when the driving voltage of the liquid crystal element 180 is constant, the thicker the insulating layer 115, the weaker the electric field applied to the liquid crystal layer 112, and the display contrast is lowered. In order to increase the display contrast without changing the thickness of the insulating layer 115, the driving voltage of the liquid crystal element 180 needs to be increased.

Therefore, the thickness of the insulating layer 115 is preferably 50 nm to 600 nm, more preferably 100 nm to 500 nm, and still more preferably 100 nm to 400 nm. Thus, the barrier property of the insulating layer 115 can be ensured and good display can be performed using the liquid crystal element 180. Further, since the insulating layer 115 is thin, the thickness of the entire display device can be reduced.

The insulating layer 115 has openings in the connection portion 252 and the connection portion 204.

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 conductive layer 311 d 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 conductive layer 311d and the electrode 311a are obtained by processing the same conductive film.

As the connection body 243, 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. Further, it is preferable to use a material that is elastically deformed or plastically deformed as the connection body 243. At this time, the connection body 243, 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 243 and the conductive layer electrically connected to the connection body 243 can be increased, the contact resistance can be reduced, and the occurrence of problems such as connection failure can be suppressed.

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 disposed after applying a paste or the like to be the adhesive layer 141.

The 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 conductive layer 311 c is exposed on the upper surface of the connection portion 204 through the opening of the insulating layer 115. The conductive layer 311c and the electrode 311a are obtained by processing the same conductive film. The connection layer 242 is preferably provided so as to cover the conductive layer 311c. Accordingly, the connection unit 204 and the FPC 372 can be electrically connected via the connection layer 242.

The light emitting element 170 is a bottom emission type light emitting element. The light-emitting element 170 has a stacked structure in which the electrode 191, the EL layer 192, and the electrode 193 are stacked in this order from the insulating layer 220 side. The electrode 191 functions as a pixel electrode. The EL layer 192 includes at least a light-emitting substance. The electrode 193 functions as a common electrode. The light-emitting element 170 is an electroluminescent element that emits light toward the substrate 361 by applying a voltage between the electrode 191 and the electrode 193.

The electrode 191 is connected to the conductive layer 222b included in the transistor 205 through openings provided in the insulating layer 212, the insulating layer 213, and the insulating layer 214, respectively. The transistor 205 has a function of controlling driving of the light-emitting element 170. An insulating layer 216 covers the end portion of the electrode 191.

The electrode 191 has a function of transmitting visible light. The electrode 193 preferably has a function of reflecting visible light.

The light emitting element 170 is preferably covered with an insulating layer 194. In FIG. 2, the insulating layer 194 is provided in contact with the electrode 193. By providing the insulating layer 194, impurities can be prevented from entering the light-emitting element 170, and the reliability of the light-emitting element 170 can be improved. A substrate 351 is attached to the insulating layer 194 with an adhesive layer 142.

Light emitted from the light-emitting element 170 is emitted to the substrate 361 side through the coloring layer 134, the insulating layer 220, the opening 451, the electrode 311a, and the like.

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

The transistors 201, 203, 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 light emitting 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 electrode 311a which is a pixel electrode of the liquid crystal element 180 is positioned opposite to the electrode 191 which is a pixel electrode of the light-emitting element 170 with a gate insulating layer (insulating layer 211) included in the transistor interposed therebetween.

Here, in the case where the transistor 206 including an oxide semiconductor in the channel formation region and having extremely low off-state current is applied, or in the case where a memory element electrically connected to the transistor 206 is used, the liquid crystal element 180 is used. Thus, even when the writing operation to the pixel is stopped when displaying a still 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.

The transistor 203 is a transistor (also referred to as a switching transistor or a selection transistor) that controls pixel selection / non-selection. The transistor 205 is a transistor (also referred to as a drive transistor) that controls a current flowing through the light-emitting element 170.

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 is provided so as to cover the transistor 206 and the like. The insulating layer 213 is provided so as to cover the transistor 205 and the like. 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 201, the transistor 203, the transistor 205, and the transistor 206 include a conductive layer 221a that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a conductive layer 222a and a conductive layer 222b that function 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.

In addition to the structures of the transistor 203 and the transistor 206, the transistor 201 and the transistor 205 include a conductive layer 223 that functions as a gate.

A structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates is applied to the transistor 201 and the transistor 205. 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. By forming the conductive film included in the conductive layer 223 in an atmosphere containing oxygen, oxygen can be supplied to the insulating layer 212. 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 low-resistance oxide semiconductor. 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 colored layer 134 is provided in contact with the insulating layer 213. The colored layer 134 is covered with the insulating layer 214.

A linear polarizing plate may be used as the polarizing plate 135 disposed on the outer surface of the substrate 361, but a circular polarizing plate may also 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. Thereby, external light reflection can be suppressed. In addition, a desired contrast may be realized by adjusting a cell gap, an alignment, a driving voltage, and the like of the liquid crystal element used for the liquid crystal element 180 in accordance with the type of the polarizing plate.

Various optical members can be arranged outside the substrate 361. Examples of the optical member include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an antireflection layer, and a light collecting film. Further, on the outside of the substrate 361, an antistatic film that suppresses adhesion of dust, a water-repellent film that makes it difficult to adhere dirt, a hard coat film that suppresses generation of scratches due to use, and the like may be arranged.

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. In particular, by using an organic resin for the substrate 351 and the substrate 361, the display device can be reduced in thickness and weight.

As the liquid crystal element 180, for example, a liquid crystal element to which a vertical alignment (VA) mode is applied can be used. 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 180, liquid crystal elements to which various modes are applied can be used. For example, in addition to the VA mode, a TN (Twisted Nematic) mode, an IPS (In-Plane-Switching) mode, an FFS (Fringe Field Switching) mode, an ASM (Axially Symmetrical Aligned Micro-cell) mode, Further, a liquid crystal element to which an FLC (Ferroelectric Liquid Crystal) mode, an AFLC (Antiferroelectric Liquid Crystal) mode, or the like is applied 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). As the liquid crystal used in the liquid crystal element, a thermotropic liquid crystal, a low-molecular liquid crystal, a polymer liquid crystal, a polymer dispersed liquid crystal (PDLC), a ferroelectric 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. .

In the case of using a reflective liquid crystal element, a polarizing plate 135 is provided on the display surface side. Separately from this, it is preferable to arrange a light diffusing plate on the display surface side because the visibility can be improved.

A front light may be provided outside the polarizing plate 135. 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.

As the adhesive layer, 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 these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, and the like. In particular, a material with low moisture permeability such as an epoxy resin is preferable. Alternatively, a two-component mixed resin may be used. Further, an adhesive sheet or the like may be used.

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

The light emitting element 170 includes a top emission type, a bottom emission type, a dual emission type, and the like. A conductive film that transmits visible light is used for the electrode from which light is extracted. In addition, a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

The EL layer 192 includes at least a light-emitting layer. The EL layer 192 is a layer other than the light-emitting layer and is a substance having a high hole-injecting property, a substance having a high hole-transporting property, a hole blocking material, a substance having a high electron-transporting property, a substance having a high electron-injecting property, or a bipolar property A layer containing a substance (a substance having a high electron transporting property and a high hole transporting property) or the like may be further included.

For the EL layer 192, either a low molecular compound or a high molecular compound can be used, and an inorganic compound may be included. The layers constituting the EL layer 192 can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an ink jet method, or a coating method.

The EL layer 192 may include an inorganic compound such as a quantum dot. For example, a quantum dot can be used for a light emitting layer to function as a light emitting material.

Note that light with high color purity can be extracted from the display device by applying a combination of a color filter (colored layer) and a microcavity structure (optical adjustment layer). The film thickness of the optical adjustment layer is changed according to the color of each pixel.

In addition to the gate, source, and drain of the transistor, materials that can be used for conductive layers such as various wirings and electrodes constituting the display device include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, A metal such as tantalum or tungsten, or an alloy containing the same as a main component can be given. A film containing any of these materials can be used as a single layer or a stacked structure.

As the light-transmitting conductive material, conductive oxide such as indium oxide, indium tin oxide (ITO), indium zinc oxide, zinc oxide, zinc oxide containing gallium, or graphene can be used. Alternatively, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or an alloy material containing the metal material can be used. Alternatively, a nitride (eg, titanium nitride) of the metal material may be used. Note that in the case where a metal material or an alloy material (or a nitride thereof) is used, it may be thin enough to have a light-transmitting property. In addition, a stacked film of the above materials can be used as a conductive layer. For example, it is preferable to use a laminated film of an alloy of silver and magnesium and indium tin oxide because the conductivity can be increased. These can also be used for conductive layers such as various wirings and electrodes constituting the display device and conductive layers (conductive layers functioning as pixel electrodes and common electrodes) included in the display element.

Examples of the insulating material that can be used for each insulating layer include inorganic insulating materials such as resins such as acrylic and epoxy, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

Examples of materials that can be used for the colored layer include metal materials, resin materials, resin materials containing pigments or dyes, and the like.

<Configuration example 2>
3 does not include the transistor 201, the transistor 203, the transistor 205, and the transistor 206, but includes the transistor 281, the transistor 284, the transistor 285, and the transistor 286, and is mainly different from the display device 300. The display device 300A illustrated in FIG. .

3 is different from the display device 300 in that the insulating layer 115 is formed in an island shape.

Note that in FIG. 3, the positions of the insulating layer 117 and the connection portion 207 are also different from those in FIG. FIG. 3 illustrates the end portion of the pixel. The insulating layer 117 is disposed so as to overlap the end portion of the colored layer 131. Further, the insulating layer 117 is disposed so as to overlap the end portion of the light shielding layer 132. As described above, at least a part of the insulating layer 117 may be disposed in a portion that does not overlap with the display region (portion that overlaps with the light shielding layer 132).

Like the transistor 284 and the transistor 285, two transistors included in the display device may be partially stacked. Thereby, since the area occupied by the pixel circuit can be reduced, the definition can be increased. In addition, the light emitting area of the light emitting element 170 can be increased and the aperture ratio can be improved. If the light-emitting element 170 has a high aperture ratio, the current density for obtaining necessary luminance can be reduced, so that reliability is improved.

The transistor 281, the transistor 284, and the transistor 286 each include a conductive layer 221a, an insulating layer 211, a semiconductor layer 231, a conductive layer 222a, and a conductive layer 222b. The conductive layer 221a overlaps with the semiconductor layer 231 with the insulating layer 211 interposed therebetween. The conductive layer 222 a and the conductive layer 222 b are electrically connected to the semiconductor layer 231. The transistor 281 includes a conductive layer 223.

The transistor 285 includes a conductive layer 222b, an insulating layer 217, a semiconductor layer 261, a conductive layer 223, an insulating layer 212, an insulating layer 213, a conductive layer 263a, and a conductive layer 263b. The conductive layer 222b overlaps with the semiconductor layer 261 with the insulating layer 217 interposed therebetween. The conductive layer 223 overlaps with the semiconductor layer 261 with the insulating layer 212 and the insulating layer 213 interposed therebetween. The conductive layer 263a and the conductive layer 263b are electrically connected to the semiconductor layer 261.

The conductive layer 221a functions as a gate. The insulating layer 211 functions as a gate insulating layer. The conductive layer 222a functions as one of a source and a drain. The conductive layer 222b included in the transistor 286 functions as the other of the source and the drain.

The conductive layer 222b shared by the transistor 284 and the transistor 285 includes a portion functioning as the other of the source and the drain of the transistor 284 and a portion functioning as the gate of the transistor 285. The insulating layer 217, the insulating layer 212, and the insulating layer 213 function as gate insulating layers. One of the conductive layer 263a and the conductive layer 263b functions as a source, and the other functions as a drain. The conductive layer 223 functions as a gate.

<Configuration example 3>
FIG. 4A shows a cross-sectional view of a display portion of the display device 300B.

The display device 300B is different from the display device 300 in that the display device 300B does not include the colored layer 131. In FIG. 4A, the transistor 203 is not shown. Since other configurations are the same as those of the display device 300, detailed description thereof is omitted.

The liquid crystal element 180 exhibits white. Since the colored layer 131 is not included, the display device 300 can perform display in black and white or gray scale using the liquid crystal element 180.

In the display device 300B, an example in which the electrode 113 is provided over the substrate 361 with the insulating layer 121 interposed therebetween is shown. The insulating layer 121 may not be provided. As in the display device 300 </ b> C illustrated in FIG. 4B, the electrode 113 may be provided in contact with the substrate 361.

<Configuration example 4>
A display device 300C illustrated in FIG. 4B is different from the display device 300B in that the EL layer 192 is separately applied and the coloring layer 134 and the insulating layer 121 are not provided. Since other configurations are the same as those of the display device 300B, detailed description thereof is omitted.

In the light-emitting element 170 to which the separate coating method is applied, at least one layer (typically, a light-emitting layer) among the layers constituting the EL layer 192 is painted separately, and all the layers constituting the EL layer are painted separately. It may be.

<Example of manufacturing method of display device>
Next, a method for manufacturing the display device of this embodiment will be specifically described with reference to FIGS. Hereinafter, an example of a method for manufacturing the display device 300 illustrated in FIG. 2 will be described. 5 to 9, the manufacturing method will be described with particular attention to the display portion 362 and the connection portion 204 of the display device 300. Note that illustration of the transistor 203 is omitted in 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.

First, the first insulating layer 101 is formed over the formation substrate 350, and the second insulating layer 102 is formed over the first insulating layer 101 (FIG. 5A).

The manufacturing substrate 350 has rigidity to an extent that the manufacturing substrate 350 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 350 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 first insulating layer 101 has a function of blocking hydrogen (and nitrogen) released from the second insulating layer 102 in a later heating step.

The first insulating layer 101 preferably contains nitrogen and silicon. As the first insulating layer 101, for example, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used. In particular, a silicon nitride film or a silicon nitride oxide film is preferable.

The first insulating layer 101 can be formed by a film formation method such as a sputtering method or a plasma CVD method. For example, the silicon nitride film included in the first insulating layer 101 is formed by a plasma CVD method using a deposition gas containing silane gas, hydrogen gas, and ammonia (NH ₃ ) gas.

The thickness of the first insulating layer 101 is not particularly limited. For example, the thickness can be set to 50 nm to 600 nm, preferably 100 nm to 300 nm.

Note that in the case where the hydrogen (and nitrogen) blocking property of the formation substrate 350 is sufficiently high, the first insulating layer 101 may not be provided. In that case, the second insulating layer 102 may be provided in contact with the manufacturing substrate 350.

The second insulating layer 102 has a function of releasing hydrogen in a later heating step. In addition, the second insulating layer 102 may have a function of releasing hydrogen and nitrogen in a later heating step.

As the second insulating layer 102, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used. The second insulating layer 102 preferably contains oxygen and silicon. The second insulating layer preferably further contains hydrogen. The second insulating layer preferably further contains nitrogen.

The second insulating layer 102 can be formed by a film formation method such as a sputtering method or a plasma CVD method. In particular, a silicon oxynitride film included in the second insulating layer 102 is formed by a plasma CVD method using a film formation gas containing a silane gas and a nitrous oxide gas, so that a large amount of hydrogen and nitrogen are contained in the film. Since it can be made to contain, it is preferable. Further, it is preferable to increase the proportion of the silane gas in the film forming gas because the amount of released hydrogen is increased in the subsequent heating step.

The thicker the second insulating layer 102 is, the more preferable it is because the amount of released hydrogen and nitrogen increases, but it is preferable to set the thickness in consideration of productivity. The thickness of the second insulating layer 102 is preferably 1 nm to 1 μm, more preferably 50 nm to 800 nm, still more preferably 100 nm to 600 nm, and particularly preferably 200 nm to 400 nm.

At least one of the first insulating layer 101 and the second insulating layer 102 can also serve as a base film. For example, in the case where a glass substrate is used as the manufacturing substrate 350, it is preferable to have a base film between the manufacturing substrate 350 and the separation layer 107 because contamination from the glass substrate can be prevented.

Note that another layer may be provided between the first insulating layer 101 and the second insulating layer 102.

Next, a separation layer 107 is formed over the second insulating layer 102 (FIG. 5B).

An inorganic material can be used for the peeling layer 107. Examples of the inorganic material include tungsten (W), molybdenum (Mo), titanium, tantalum, niobium, nickel, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, and a metal containing an element selected from silicon, An alloy containing an element, a compound containing the element, or the like can be given. The crystal structure of the layer containing silicon may be any of amorphous, microcrystalline, and polycrystalline.

It is preferable to use a refractory metal such as tungsten, titanium, or molybdenum for the separation layer 107 because the degree of freedom in the formation process of the layer to be separated is increased.

The thickness of the peeling layer 107 is 1 nm to 1000 nm, preferably 10 nm to 200 nm, more preferably 10 nm to 100 nm.

In this embodiment, the separation layer 107 is formed using tungsten.

Note that the peeling layer 107 and the second insulating layer 102 do not need to be in contact with each other, and another layer may be provided between the peeling layer 107 and the second insulating layer 102.

Next, plasma treatment is performed on the surface of the separation layer 107 (see an arrow indicated by a dotted line in FIG. 5C).

By performing plasma treatment on the surface of the release layer 107, the surface state of the release layer 107 is changed. By changing the state of the surface of the separation layer 107, separation can be performed reliably between the separation layer 107 and the insulating layer 115, not between the second insulating layer 102 and the separation layer 107.

The plasma treatment is preferably performed in an atmosphere containing nitrous oxide. Thus, the surface of the release layer 107 is oxidized, and the oxide layer 111 of a material constituting the release layer 107 can be formed over the release layer 107 (FIG. 5D).

The plasma treatment is preferably performed in an atmosphere containing nitrous oxide and silane. According to this method, the oxide layer 111 having a very thin thickness can be formed. The oxide layer 111 may be a thin film that is difficult to confirm by cross-sectional observation using an electron microscope or the like. When the oxide layer 111 has a very thin thickness, a decrease in light extraction efficiency of the display device can be suppressed. Or the characteristic fluctuation | variation of a semiconductor element can be suppressed.

When plasma treatment is performed in an atmosphere containing nitrous oxide and silane, the surface of the peeling layer 107 is oxidized by nitrous oxide, and at the same time, a film (eg, a silicon oxynitride film or a oxynitride film) is formed on the peeling layer 107 by silane. A silicon film) may be formed. For example, an insulating layer with a thickness of 1 nm to 20 nm may be formed during the plasma treatment. By forming an insulating layer over the separation layer 107 during the plasma treatment, the progress of oxidation of the separation layer 107 can be controlled. Accordingly, a thin oxide layer 111 can be formed over the separation layer 107.

By performing analysis using X-ray photoelectron spectroscopy (XPS) or the like on the surface of the peeling layer 107 exposed in the subsequent peeling step or the surface of the layer to be peeled, an oxide can be obtained. The presence of (and nitride) can be confirmed. That is, even if it is difficult to confirm the oxide layer 111 by cross-sectional observation using an electron microscope or the like, it can be confirmed using XPS analysis or the like that the oxide layer 111 has been formed.

The plasma treatment is preferably performed in an atmosphere containing nitrous oxide, silane, and ammonia. By performing this treatment, the amount of hydrogen and nitrogen supplied from the second insulating layer 102 to the separation layer 107 can be reduced, so that the second insulating layer 102 can be thinned and productivity can be improved. it can.

In addition to the above plasma treatment, the oxide layer 111 may be formed by performing thermal oxidation treatment, oxygen plasma treatment, treatment with a solution having strong oxidizing power such as ozone water, or the like.

The oxide layer 111 is a layer including an oxide of a material included in the release layer. In the case where the separation layer 107 includes a metal, the oxide layer 111 is a layer that includes a metal oxide included in the separation layer 107. The oxide layer 111 preferably contains tungsten oxide, titanium oxide, or molybdenum oxide.

Tungsten oxide is generally represented by WO _x (2 ≦ x <3), and is typically a non-stoichiometric compound having various compositions such as WO ₃ , W ₂ O ₅ , W ₄ O ₁₁ , and WO _2. Exists. Titanium oxide and molybdenum oxide are also present as non-stoichiometric compounds.

In this embodiment, the oxide layer 111 includes tungsten oxide.

The thickness of the oxide layer 111 is 1 nm to less than 15 nm, preferably 1 nm to less than 5 nm, more preferably 1 nm to 3 nm. The thickness of the oxide layer 111 may be less than 1 nm. As described above, when the oxide layer 111 is extremely thin, it is difficult to confirm with a cross-sectional observation image.

The oxide layer 111 at this stage is preferably in a state containing a large amount of oxygen. For example in the case of using tungsten as the peeling layer 107 is preferably an oxide layer 111 is tungsten oxide composed mainly of WO _3.

In one embodiment of the present invention, the oxide layer 111 is formed using plasma treatment; therefore, the thickness of the oxide layer 111 can be changed depending on plasma treatment conditions. Note that in one embodiment of the present invention, disilane or trisilane may be used instead of silane.

Next, the insulating layer 115 is formed over the separation layer 107 (or the oxide layer 111) (FIG. 5D).

The insulating layer 115 has a function of blocking hydrogen (and nitrogen) released from the second insulating layer 102 in a later heating step. The insulating layer 115 can be used as a barrier layer that prevents impurities from diffusing into a transistor or a display element to be formed later.

The insulating layer 115 preferably contains nitrogen and silicon.

The material and the deposition method that can be used for the insulating layer 115 are similar to the material and the deposition method that can be used for the first insulating layer 101. The first insulating layer 101 and the insulating layer 115 may be formed under the same film formation conditions.

The thickness of the insulating layer 115 is not particularly limited. For example, the thickness of the insulating layer 115 is preferably 50 nm to 600 nm, more preferably 100 nm to 500 nm, and still more preferably 200 nm to 400 nm.

After the insulating layer 115 is formed over the manufacturing substrate 350, heat treatment is performed. For example, the heat treatment is preferably performed after the insulating layer 115 is formed and before the electrode 311a is formed. Alternatively, a heating step included in the manufacturing process of the transistor may also serve as the heat treatment.

The heat treatment may be performed above the temperature at which hydrogen (and nitrogen) is desorbed from the second insulating layer 102 and below the softening point of the formation substrate 350. In addition, it is preferable that heating be performed at a temperature higher than the temperature at which the metal oxide in the oxide layer 111 is reduced by hydrogen. As the temperature of the heat treatment is higher, the amount of hydrogen (and nitrogen) desorbed from the second insulating layer 102 is increased, so that the subsequent peelability can be improved. Depending on the heating time and the heating temperature, the peelability may be too high, and peeling may occur at an unintended timing. Therefore, when tungsten is used for the peeling layer 107, heating is performed at a temperature of 300 ° C. or higher and lower than 700 ° C., preferably 350 ° C. or higher and 500 ° C. or lower.

The atmosphere in which the heat treatment is performed is not particularly limited, and may be performed in an air atmosphere, but is preferably performed in an inert gas atmosphere such as nitrogen or a rare gas.

By performing heat treatment, hydrogen (and nitrogen) is released from the second insulating layer 102 and supplied to the oxide layer 111. At this time, since the first insulating layer 101 and the insulating layer 115 block released hydrogen (and nitrogen), the hydrogen released from the second insulating layer 102 is converted into the first insulating layer 101 and the insulating layer. 115 hardly penetrates. Therefore, hydrogen (and nitrogen) can be efficiently supplied to the oxide layer 111.

With the hydrogen supplied into the oxide layer 111, the oxide in the oxide layer 111 is reduced, and a plurality of oxides having different oxygen compositions are mixed in the oxide layer 111. For example, when tungsten is contained in the release layer 107, WO ₃ formed by plasma treatment is reduced, and WO _x (2 <x <3) or WO ₂ having a lower oxygen composition than WO ₃ is generated. These are mixed. Such a mixed metal oxide exhibits different crystal structures depending on the composition of oxygen, so that the mechanical strength in the oxide layer 111 is weakened. As a result, a state in which the oxide layer 111 easily collapses is realized, and the peelability in the subsequent peeling step can be improved.

Further, the material supplied to the separation layer 107 and a compound containing nitrogen are also generated by nitrogen supplied to the oxide layer 111. By the presence of such a compound, the mechanical strength of the oxide layer 111 can be further weakened, and the peelability can be improved. In the case where the separation layer 107 includes a metal, a compound containing metal and nitrogen (metal nitride) is generated in the oxide layer 111. For example, when the separation layer 107 includes tungsten, tungsten nitride is generated in the oxide layer.

As more hydrogen is supplied into the oxide layer 111, WO ₃ is more easily reduced, and a plurality of oxides having different oxygen compositions are likely to be mixed in the oxide layer 111, so that the force required for peeling is reduced. be able to. As the amount of nitrogen supplied into the oxide layer 111 increases, the mechanical strength of the oxide layer 111 can be weakened, and the force required for peeling can be reduced.

The thicker the layer having a function of releasing hydrogen (and nitrogen), the more hydrogen (and nitrogen) can be released.

In the case where a layer having a function of releasing hydrogen (and nitrogen) is provided between the separation layer 107 and the insulating layer 115, the layer having a function of releasing hydrogen (and nitrogen) is one of components of the display device. Specifically, a layer having a function of releasing hydrogen (and nitrogen) is disposed between the electrode 311 a and the liquid crystal layer 112. Therefore, the thicker the layer having a function of releasing hydrogen (and nitrogen), the lower the reflectance of the pixel, the lower the contrast, and the higher the driving voltage. Although the thickness of the layer having a function of releasing hydrogen (and nitrogen) can be reduced after peeling, this leads to an increase in the number of steps.

Therefore, in one embodiment of the present invention, the second insulating layer 102 is provided between the formation substrate 350 and the separation layer 107 as described above. Since the second insulating layer 102 is not a layer included in the display device, the second insulating layer 102 can be provided thick. By sufficiently releasing hydrogen from the second insulating layer 102, it is not necessary to provide a layer having a function of releasing hydrogen (and nitrogen) between the separation layer 107 and the insulating layer 115. Therefore, separation can be performed with high yield, and favorable display can be performed using the liquid crystal element 180. In addition, the thickness of the display device can be reduced.

Next, the electrode 311a and the conductive layer 311c are formed over the insulating layer 115, the electrode 311b is formed over the electrode 311a, and the conductive layer 311e is formed over the conductive layer 311c (FIG. 5E). The electrode 311b has an opening 451 on the electrode 311a. The electrodes 311a and the conductive layer 311c can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask. The same applies to the electrode 311b and the conductive layer 311e. 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.

Next, the insulating layer 220 is formed (FIG. 6A). Then, an opening reaching the electrode 311b is provided in the insulating layer 220.

As the insulating layer 220, an inorganic insulating film, a resin, or the like can be used.

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.

As the insulating layer 121, a resin such as acrylic or epoxy may be used.

Next, the connection portion 204, the connection portion 207, the transistor 205, and the transistor 206 are formed over the insulating layer 220.

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, the case where a transistor with a bottom-gate structure including an oxide semiconductor layer as the semiconductor layer 231 is formed as the transistor 206 is described. The transistor 205 has a structure in which a conductive layer 223 and an insulating layer 212 are added to the structure of the transistor 206, and includes two gates.

An oxide semiconductor is preferably used for the semiconductor of the transistor. When a semiconductor material having a wider band gap and lower carrier density than silicon is used, current in an off state of the transistor can be reduced.

Specifically, first, the conductive layer 221a, the conductive layer 221b, and the conductive layer 221c are formed over the insulating layer 220. The conductive layers 221a, 221b, and 221c can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask. Here, in the connection portion 207, the conductive layer 221 b and the electrode 311 b are connected through the opening of the insulating layer 220. In the connection portion 204, the conductive layer 311 e and the conductive layer 221 c are connected through an opening in the insulating layer 220.

Subsequently, the insulating layer 211 is formed.

As the insulating layer 211, 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.

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 inorganic insulating film is preferably room temperature (25 ° C.) or higher and 350 ° C. or lower, more preferably 100 ° C. or higher and 300 ° C. or lower.

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

The substrate temperature at the time of forming the oxide semiconductor film is preferably 350 ° C. or lower, more preferably room temperature or higher and 200 ° C. or lower, and further preferably room temperature or higher and 130 ° C. or lower.

The oxide semiconductor 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 oxygen flow rate ratio (oxygen partial pressure) in forming the oxide semiconductor film. However, in the case of obtaining a transistor with high field-effect mobility, the flow rate ratio of oxygen (oxygen partial pressure) during formation of the oxide semiconductor film is preferably 0% or more and 30% or less, and is preferably 5% or more and 30% or less. Is more preferably 7% or more and 15% or less.

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

The oxide semiconductor preferably has an energy gap of 2 eV or more, and 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 an oxide semiconductor with a wide energy gap.

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

Note that an example of an oxide semiconductor is described in Embodiment 3.

Subsequently, a conductive layer 222a, a conductive layer 222b, and a wiring 365 are formed. The conductive layer 222a, the conductive layer 222b, and the wiring 365 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask. 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. In the connection portion 204, the conductive layer 311e and the wiring 365 are electrically connected through the conductive layer 221c.

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 206 can be manufactured (FIG. 6A). In the transistor 206, part of the conductive layer 221a functions as a gate, part of the insulating layer 211 functions as a gate insulating layer, and the conductive layer 222a and the conductive layer 222b function as a source or a drain, respectively.

Next, the insulating layer 212 that covers the transistor 206 is formed, and the 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.

The conductive layer 223 included in the transistor 205 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask.

As described above, the transistor 205 can be manufactured (FIG. 6A). In the transistor 205, part of the conductive layer 221a and part of the conductive layer 223 function as a gate, part of the insulating layer 211 and part of the insulating layer 212 function as a gate insulating layer, and the conductive layer 222a and the conductive layer Each of 222b functions as a source or a drain.

Next, the insulating layer 213 is formed (FIG. 6A). 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 oxide semiconductor layer. As a result, oxygen vacancies in the oxide semiconductor layer and defects at the interface between the oxide semiconductor layer and the insulating layer 212 can be repaired, and the defect level can be reduced. Thereby, a display device with extremely high reliability can be realized.

Next, the coloring layer 134 is formed over the insulating layer 213 (FIG. 6A), and then the insulating layer 214 is formed (FIG. 6B).

The colored layer 134 can be processed into an island shape by a photolithography method or the like by being formed using a photosensitive material.

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 222b included in the transistor 205 is formed in the insulating layer 212, the insulating layer 213, and the insulating layer 214.

Next, the electrode 191 is formed (FIG. 6B). The electrode 191 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask. Here, the conductive layer 222b included in the transistor 205 and the electrode 191 are connected. The electrode 191 is formed using a conductive material that transmits visible light.

Next, an insulating layer 216 that covers an end portion of the electrode 191 is formed (FIG. 6B). As the insulating layer 216, a resin or an inorganic insulating film that can be used for the insulating layer 121 can be used. The insulating layer 216 has an opening in a portion overlapping with the electrode 191.

Next, an EL layer 192 and an electrode 193 are formed (FIG. 6C). A part of the electrode 193 functions as a common electrode of the light-emitting element 170. The electrode 193 is formed using a conductive material that reflects visible light.

The EL layer 192 can be formed by a method such as an evaporation method, a coating method, a printing method, or a discharge method. In the case where the EL layer 192 is separately formed for each pixel, the EL layer 192 can be formed by an evaporation method using a shadow mask such as a metal mask or an ink jet method. In the case where the EL layer 192 is not formed for each pixel, an evaporation method that does not use a metal mask can be used.

For the EL layer 192, either a low molecular compound or a high molecular compound can be used, and an inorganic compound may be included.

Each step performed after the formation of the EL layer 192 is performed so that the temperature applied to the EL layer 192 is equal to or lower than the heat resistant temperature of the EL layer 192. The electrode 193 can be formed by an evaporation method, a sputtering method, or the like.

As described above, the light-emitting element 170 can be formed (FIG. 6C). The light-emitting element 170 has a structure in which an electrode 191 that partially functions as a pixel electrode, an EL layer 192, and an electrode 193 that partially functions as a common electrode are stacked. The light-emitting element 170 is manufactured so that the light-emitting region overlaps with the colored layer 134.

Although an example in which a bottom emission light-emitting element is manufactured as the light-emitting element 170 is described here, one embodiment of the present invention is not limited thereto.

The light emitting element may be any of a top emission type, a bottom emission type, and a dual emission type. A conductive film that transmits visible light is used for the electrode from which light is extracted. In addition, a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

Next, an insulating layer 194 is formed so as to cover the electrode 193 (FIG. 6C). The insulating layer 194 functions as a protective layer that suppresses diffusion of impurities such as water into the light-emitting element 170. The light emitting element 170 is sealed with the insulating layer 194. After the electrode 193 is formed, the insulating layer 194 is preferably formed without being exposed to the atmosphere.

As the insulating layer 194, for example, an inorganic insulating film that can be used for the above-described insulating layer 211 can be used. In particular, an inorganic insulating film having a high barrier property is preferably included. Alternatively, an inorganic insulating film and an organic insulating film may be stacked.

The substrate temperature when the insulating layer 194 is formed is preferably equal to or lower than the heat resistance temperature of the EL layer 192. The insulating layer 194 can be formed by an ALD method, a sputtering method, or the like. The ALD method and the sputtering method are preferable because they can be formed at a low temperature. Use of the ALD method is preferable because coverage of the insulating layer 194 is favorable.

Next, the substrate 351 is attached to the surface of the insulating layer 194 with the use of the adhesive layer 142 (FIG. 7A).

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. Further, an adhesive sheet or the like may 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.

Next, the manufacturing substrate 350 is peeled off (FIG. 7B).

As a separation method, for example, the manufacturing substrate 350 or the substrate 351 is fixed to an adsorption stage, and a separation starting point is formed between the separation layer 107 and the insulating layer 115. For example, the starting point of peeling may be formed by inserting a sharp tool such as a blade between them. Alternatively, the starting point of peeling may be formed by irradiating a part of the peeling layer 107 with laser light irradiation. Further, a liquid (for example, alcohol, water, water containing carbon dioxide, or the like) is dropped on, for example, an end portion of the separation layer 107 or the insulating layer 115, and the liquid is removed between the separation layer 107 and the insulating layer 115 by using a capillary phenomenon. The starting point of peeling may be formed by infiltrating into.

Next, gently apply a physical force in a direction substantially perpendicular to the contact surface at the part where the peeling start point is formed (the process of peeling with a human hand or jig, or separation while rotating the roller). Can be peeled without damaging the layer to be peeled. For example, the separation may be performed by attaching a tape or the like to the manufacturing substrate 350 or the substrate 351 and pulling the tape in the above direction, or the hook-shaped member may be pulled on the edge of the manufacturing substrate 350 or the substrate 351 to be separated. May be performed. Alternatively, the peeling may be performed by adhering an adhesive member or a member capable of vacuum suction to the back surface of the manufacturing substrate 350 or the substrate 351 and pulling it.

Here, at the time of peeling, a liquid containing water, such as water or an aqueous solution, is added to the peeling interface, and peeling is performed so that the liquid penetrates the peeling interface, whereby the peelability can be improved. In addition, static electricity generated at the time of peeling can be prevented from adversely affecting the transistor and the light-emitting element 170 (for example, the semiconductor element is destroyed by static electricity).

Peeling occurs mainly inside the oxide layer 111 and at the interface between the oxide layer 111 and the peeling layer 107. Therefore, as illustrated in FIG. 7B, part of the oxide layer 111 may be attached to the surface of the separation layer 107 and the surface of the insulating layer 115 after separation. In one embodiment of the present invention, a very thin oxide layer is formed; therefore, even when the oxide layer 111 remains on the surface of the insulating layer 115 after separation, reduction in light extraction efficiency of the display device can be suppressed. . Or the characteristic fluctuation | variation of a semiconductor element can be suppressed. Note that the oxide layer 111 is not shown in the subsequent steps.

Through the above method, the manufacturing substrate 350 can be peeled with a high yield.

The insulating layer 115 is exposed by peeling the manufacturing substrate 350 (FIG. 8A).

Next, the conductive layer 311c is exposed in the connection portion 204 by processing the insulating layer 115 (FIG. 8B). The insulating layer 115 can be formed by overlaying a mask on a portion where the insulating layer 115 is to be left and etching an unnecessary portion of the insulating layer 115. For the processing of the insulating layer 115, either wet etching or dry etching can be used, and dry etching is particularly preferable.

As shown in FIG. 2, in addition to the connecting portion 204, the insulating layer 115 is also removed at the connecting portion 252 to expose the conductive layer 311d. Note that an opening may be provided in the insulating layer 115 as shown in FIG. 2, or the insulating layer 115 may be processed into an island shape as shown in FIG.

Next, an alignment film 133a is formed over the insulating layer 115 (FIG. 9A). The alignment film 133a can be formed by performing a rubbing process after forming a thin film of resin or the like.

Independent of the steps from FIG. 5A to FIG. 9A, the colored layer 131 to the alignment film 133b are formed in order on the substrate 361 (see FIG. 2).

Specifically, in the display portion 362, the colored layer 131 is provided in contact with the substrate 361, and in the circuit 364 or the like, the light shielding layer 132 is provided in contact with the substrate 361. Then, the insulating layer 121 is formed over the colored layer 131 and the light shielding layer 132. For the insulating layer 121, a material that can be used for the insulating layer 220 can be used. Then, an electrode 113 is provided so as to overlap with the insulating layer 121. The electrode 113 can be formed by forming a conductive film, forming a resist mask, etching the conductive film, and then removing the resist mask. The electrode 113 is formed using a conductive material that transmits visible light. Then, an insulating layer 117 is formed so as to overlap with the electrode 113. As the insulating layer 117, an organic insulating film is preferably used, and a resin such as acrylic or epoxy can be preferably used. Next, the alignment film 133 b is formed so as to overlap with 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.

Then, the substrate 361 on which the coloring layer 131 to the alignment film 133b are formed and the substrate 351 after the steps up to FIG. 9A are bonded to each other with the liquid crystal layer 112 interposed therebetween (FIG. 9B). The substrate 351 and the substrate 361 are attached to each other with an adhesive layer 141. A material that can be used for the adhesive layer 142 can be used for the adhesive layer 141. Note that in the connection portion 252 illustrated in FIG. 2, the adhesive layer 141 includes conductive particles. Therefore, by bonding the substrate 351 and the substrate 361, the electrode 113 and the conductive layer 311d can be electrically connected.

A liquid crystal element 180 illustrated in FIG. 9B has a structure in which an electrode 311a partly functioning as a pixel electrode, a liquid crystal layer 112, and an electrode 113 partly functioning as a common electrode are stacked. The liquid crystal element 180 is manufactured so as to overlap with the colored layer 131.

Through the above steps, the display device 300 can be manufactured.

Note that a polarizing plate 135 is provided on the outer surface of the substrate 361.

Further, the wiring 365 and the FPC 372 are electrically connected through the connection layer 242.

As described above, in the method for manufacturing the display device in this embodiment, the insulating layer (second insulating layer 102) having a function of releasing hydrogen when heated between the manufacturing substrate 350 and the separation layer 107. Form. Accordingly, an insulating layer positioned between the electrode 311a and the liquid crystal layer 112 can be formed thin.

Further, by changing the state of the surface of the release layer 107 in contact with the insulating layer 115 by plasma treatment or the like, the state is not between the release layer 107 and the second insulating layer 102 but between the release layer 107 and the insulating layer 115. It is possible to perform peeling reliably.

By using the manufacturing method of the display device of this embodiment mode, separation can be performed with high yield and favorable display can be performed using the liquid crystal element 180. In addition, the thickness of the display device can be reduced.

<Example of transistor structure>
In one embodiment of the present invention, the structure of the transistor included in the display device is not particularly limited. 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.

10A to 10E illustrate structural examples of transistors.

A transistor 110a illustrated in FIG. 10A is a top-gate transistor.

The transistor 110a includes a conductive layer 221, an insulating layer 211, a semiconductor layer 231, an insulating layer 212, a conductive layer 222a, and a conductive layer 222b. The semiconductor layer 231 is provided over the insulating layer 151. The conductive layer 221 overlaps with the semiconductor layer 231 with the insulating layer 211 interposed therebetween. The conductive layers 222 a and 222 b are electrically connected to the semiconductor layer 231 through openings provided in the insulating layers 211 and 212.

The conductive layer 221 functions as a gate. The insulating layer 211 functions as a gate insulating layer. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

In the transistor 110a, the physical distance between the conductive layer 221 and the conductive layer 222a or the conductive layer 222b can be easily increased, so that the parasitic capacitance between them can be reduced.

A transistor 110b illustrated in FIG. 10B includes a conductive layer 223 and an insulating layer 218 in addition to the structure of the transistor 110a. The conductive layer 223 is provided over the insulating layer 151 and overlaps with the semiconductor layer 231. The insulating layer 218 is provided so as to cover the conductive layer 223 and the insulating layer 151.

The conductive layer 223 functions as one of a pair of gates. Therefore, the on-state current of the transistor can be increased, the threshold voltage can be controlled, and the like.

FIGS. 10C to 10E show examples of structures in which two transistors are stacked. The structures of the two stacked transistors can be determined independently, and are not limited to the combinations shown in FIGS.

FIG. 10C illustrates a structure in which the transistor 110c and the transistor 110d are stacked. The transistor 110c has two gates. The transistor 110d has a bottom gate structure. Note that the transistor 110c may include one gate (top gate structure). The transistor 110d may have two gates.

The transistor 110c includes a conductive layer 223, an insulating layer 218, a semiconductor layer 231, a conductive layer 221, an insulating layer 211, a conductive layer 222a, and a conductive layer 222b. The conductive layer 223 is provided over the insulating layer 151. The conductive layer 223 overlaps with the semiconductor layer 231 with the insulating layer 218 interposed therebetween. The insulating layer 218 is provided so as to cover the conductive layer 223 and the insulating layer 151. The conductive layer 221 overlaps with the semiconductor layer 231 with the insulating layer 211 interposed therebetween. FIG. 10C illustrates an example in which the insulating layer 211 is provided only in a portion overlapping with the conductive layer 221, but the insulating layer 211 covers an end portion of the semiconductor layer 231 as illustrated in FIG. It may be provided as follows. The conductive layer 222 a and the conductive layer 222 b are electrically connected to the semiconductor layer 231 through an opening provided in the insulating layer 212.

The transistor 110d includes a conductive layer 222b, an insulating layer 213, a semiconductor layer 261, a conductive layer 263a, and a conductive layer 263b. The conductive layer 222 b includes a region overlapping with the semiconductor layer 261 with the insulating layer 213 interposed therebetween. The insulating layer 213 is provided so as to cover the conductive layer 222b. The conductive layer 263a and the conductive layer 263b are electrically connected to the semiconductor layer 261.

The conductive layer 221 and the conductive layer 223 each function as a gate of the transistor 110c. The insulating layer 218 and the insulating layer 211 function as a gate insulating layer of the transistor 110c. The conductive layer 222a functions as one of a source and a drain of the transistor 110c.

The conductive layer 222b includes a portion functioning as the other of the source and the drain of the transistor 110c and a portion functioning as the gate of the transistor 110d. The insulating layer 213 functions as a gate insulating layer of the transistor 110d. One of the conductive layer 263a and the conductive layer 263b functions as a source of the transistor 110d, and the other functions as a drain of the transistor 110d.

The transistors 110c and 110d are preferably applied to the pixel circuit of the light-emitting element 170. For example, the transistor 110c can be used as a selection transistor, and the transistor 110d can be used as a driving transistor.

The conductive layer 263b is electrically connected to an electrode 191 functioning as a pixel electrode of the light-emitting element through an opening provided in the insulating layer 217 and the insulating layer 214.

FIG. 10D illustrates a structure in which the transistor 110e and the transistor 110f are stacked. The transistor 110e has a bottom gate structure. The transistor 110f has two gates. The transistor 110e may have two gates.

The transistor 110e includes a conductive layer 221, an insulating layer 211, a semiconductor layer 231, a conductive layer 222a, and a conductive layer 222b. The conductive layer 221 is provided over the insulating layer 151. The conductive layer 221 overlaps with the semiconductor layer 231 with the insulating layer 211 interposed therebetween. The insulating layer 211 is provided to cover the conductive layer 221 and the insulating layer 151. The conductive layer 222 a and the conductive layer 222 b are electrically connected to the semiconductor layer 231.

The transistor 110f includes a conductive layer 222b, an insulating layer 212, a semiconductor layer 261, a conductive layer 223, an insulating layer 218, an insulating layer 213, a conductive layer 263a, and a conductive layer 263b. The conductive layer 222 b includes a region overlapping with the semiconductor layer 261 with the insulating layer 212 interposed therebetween. The insulating layer 212 is provided so as to cover the conductive layer 222b. The conductive layers 263 a and 263 b are electrically connected to the semiconductor layer 261 through openings provided in the insulating layer 213. The conductive layer 223 overlaps with the semiconductor layer 261 with the insulating layer 218 provided therebetween. The insulating layer 218 is provided in a portion overlapping with the conductive layer 223.

The conductive layer 221 functions as the gate of the transistor 110e. The insulating layer 211 functions as a gate insulating layer of the transistor 110e. The conductive layer 222a functions as one of a source and a drain of the transistor 110e.

The conductive layer 221b includes a portion functioning as the other of the source and the drain of the transistor 110e and a portion functioning as the gate of the transistor 110f. The conductive layer 223 functions as the gate of the transistor 110f. The insulating layer 212 and the insulating layer 218 each function as a gate insulating layer of the transistor 110f. One of the conductive layer 263a and the conductive layer 263b functions as a source of the transistor 110f, and the other functions as a drain of the transistor 110f.

The conductive layer 263b is electrically connected to an electrode 191 functioning as a pixel electrode of the light-emitting element through an opening provided in the insulating layer 214.

FIG. 10E illustrates a structure in which the transistor 110g and the transistor 110h are stacked. The transistor 110g has a top gate structure. The transistor 110h has two gates. Note that the transistor 110g may include two gates.

The transistor 110g includes a semiconductor layer 231, a conductive layer 221, an insulating layer 211, a conductive layer 222a, and a conductive layer 222b. The semiconductor layer 231 is provided over the insulating layer 151. The conductive layer 221 overlaps with the semiconductor layer 231 with the insulating layer 211 interposed therebetween. The insulating layer 211 is provided so as to overlap with the conductive layer 221. The conductive layer 222 a and the conductive layer 222 b are electrically connected to the semiconductor layer 231 through an opening provided in the insulating layer 212.

The transistor 110h includes a conductive layer 222b, an insulating layer 213, a semiconductor layer 261, a conductive layer 223, an insulating layer 218, an insulating layer 217, a conductive layer 263a, and a conductive layer 263b. The conductive layer 222 b includes a region overlapping with the semiconductor layer 261 with the insulating layer 213 interposed therebetween. The insulating layer 213 is provided so as to cover the conductive layer 222b. The conductive layers 263 a and 263 b are electrically connected to the semiconductor layer 261 through openings provided in the insulating layer 213. The conductive layer 223 overlaps with the semiconductor layer 261 with the insulating layer 218 provided therebetween. The insulating layer 218 is provided in a portion overlapping with the conductive layer 223.

The conductive layer 221 functions as the gate of the transistor 110g. The insulating layer 211 functions as a gate insulating layer of the transistor 110g. The conductive layer 222a functions as one of a source and a drain of the transistor 110g.

The conductive layer 221b includes a portion functioning as the other of the source and the drain of the transistor 110g and a portion functioning as the gate of the transistor 110h. The conductive layer 223 functions as the gate of the transistor 110h. The insulating layer 212 and the insulating layer 218 each function as a gate insulating layer of the transistor 110h. One of the conductive layer 263a and the conductive layer 263b functions as a source of the transistor 110h, and the other functions as a drain of the transistor 110h.

The conductive layer 263b is electrically connected to an electrode 191 functioning as a pixel electrode of the light-emitting element through an opening provided in the insulating layer 214.

As described above, the display device in this embodiment includes an insulating layer between a reflective electrode of a liquid crystal element and a liquid crystal layer. Therefore, impurities can be prevented from entering the transistor and the light-emitting element from the liquid crystal layer side, and the reliability of the display device can be improved. The thickness of the insulating layer can be such that a barrier property is ensured and good display can be performed using a liquid crystal element.

In the display device manufacturing method of this embodiment, an insulating layer (second insulating layer) having a function of releasing hydrogen by being heated is formed between the manufacturing substrate and the separation layer. Thereby, the insulating layer located between the reflective electrode of the liquid crystal element and the liquid crystal layer can be formed thin.

Moreover, the peeling interface can be reliably controlled by performing plasma treatment or the like on the surface of the peeling layer.

By using the method for manufacturing the display device of this embodiment mode, separation can be performed with high yield and favorable display can be performed. In addition, the thickness of the display device can be reduced.

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 more specific structure example of the display device described in Embodiment 1 will be described with reference to FIGS.

FIG. 11A is a block diagram of the display device 400. The display device 400 includes a display unit 362, a circuit GD, and a circuit SD. The display portion 362 includes a plurality of pixels 410 arranged in a matrix.

The display device 400 includes a plurality of wirings G1, a plurality of wirings G2, 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 G1, the plurality of wirings G2, the plurality of wirings ANO, and the plurality of wirings CSCOM are electrically connected to the plurality of pixels 410 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 410 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, the circuit GD and the circuit SD that drive the liquid crystal element and the circuit GD and the circuit SD that drive the light emitting element are separately provided. May be provided.

The pixel 410 includes a reflective liquid crystal element and a light-emitting element.

FIGS. 11B1 to 11B4 illustrate configuration examples of the electrode 311 included in the pixel 410. FIG. The electrode 311 functions as a reflective electrode of the liquid crystal element. An opening 451 is provided in the electrode 311 in FIGS. 11B1 and 11B2.

In FIGS. 11B1 and 11B2, the light-emitting element 360 located in a region overlapping with the electrode 311 is indicated by a broken line. The light emitting element 360 is disposed so as to overlap with the opening 451 included in the electrode 311. Thereby, the light emitted from the light emitting element 360 is emitted to the display surface side through the opening 451.

In FIG. 11 (B1), the pixels 410 adjacent in the direction indicated by the arrow R are pixels corresponding to different colors. At this time, as shown in FIG. 11B1, in two pixels adjacent to each other in the direction indicated by the arrow R, it is preferable that the openings 451 are provided at different positions so as not to be arranged in a line. Accordingly, the two light-emitting elements 360 can be separated from each other, and a phenomenon (also referred to as crosstalk) in which light emitted from the light-emitting elements 360 enters the colored layer of the adjacent pixel 410 can be suppressed. In addition, since the two adjacent light emitting elements 360 can be arranged apart from each other, a display device with high definition can be realized even when the EL layer of the light emitting element 360 is separately formed using a shadow mask or the like.

In FIG. 11 (B2), adjacent pixels 410 in the direction indicated by arrow C are pixels corresponding to different colors. Similarly in FIG. 11B2, it is preferable that the openings 451 are provided at different positions in the electrode 311 so that the two pixels adjacent in the direction indicated by the arrow C are not arranged in a line.

The smaller the value of the ratio of the total area of the openings 451 to the total area of the non-openings, the brighter the display using the liquid crystal element. In addition, as the value of the ratio of the total area of the openings 451 to the total area of the non-openings is larger, the display using the light emitting element 360 can be brightened.

The shape of the opening 451 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 451 may be arranged close to adjacent pixels. Preferably, the opening 451 is arranged close to other pixels displaying the same color. Thereby, crosstalk can be suppressed.

In addition, as illustrated in FIGS. 11B3 and 11B4, the light emitting region of the light emitting element 360 may be located in a portion where the electrode 311 is not provided. Thereby, the light emitted from the light emitting element 360 is emitted to the display surface side.

In FIG. 11 (B3), the light emitting elements 360 are not arranged in a line in the two pixels 410 adjacent in the direction indicated by the arrow R. In FIG. 11B4, the light emitting elements 360 are arranged in a line in two pixels adjacent in the direction indicated by the arrow R.

In the structure in FIG. 11B3, the light-emitting elements 360 included in the two adjacent pixels 410 can be separated from each other. Therefore, as described above, crosstalk can be suppressed and higher definition can be achieved. 11B4, since the electrode 311 is not positioned on the side parallel to the arrow C of the light-emitting element 360, light from the light-emitting element 360 can be prevented from being blocked by the electrode 311, and a high viewing angle can be obtained. The characteristics can be realized.

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 410.

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 410 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. 12 is an example of a circuit diagram of the pixel 410. In FIG. 12, two adjacent pixels 410 are shown.

The pixel 410 includes a switch SW1, a capacitor C1, a liquid crystal element 340, a switch SW2, a transistor M, a capacitor C2, a light emitting element 360, and the like. In addition, a wiring G1, a wiring G2, a wiring ANO, a wiring CSCOM, a wiring S1, and a wiring S2 are electrically connected to the pixel 410. In FIG. 12, a wiring VCOM1 electrically connected to the liquid crystal element 340 and a wiring VCOM2 electrically connected to the light emitting element 360 are illustrated.

FIG. 12 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 G1. 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 340. The other electrode of the capacitive element C1 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 340 is connected to the wiring VCOM1.

The gate of the switch SW2 is connected to the wiring G2. 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 the gate of the transistor M. The other electrode of the capacitor C2 is connected to one of the source and the drain of the transistor M and the wiring ANO. The other of the source and the drain of the transistor M is connected to one electrode of the light emitting element 360. The other electrode of the light emitting element 360 is connected to the wiring VCOM2.

FIG. 12 shows an example in which the transistor M has two gates sandwiching a semiconductor and these are connected. As a result, the current that can be passed by the transistor M can be increased.

A signal for controlling the switch SW1 to be in a conductive state or a non-conductive state can be supplied to the wiring G1. 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 340 can be supplied to the wiring S1. A predetermined potential can be applied to the wiring CSCOM.

A signal for controlling the switch SW2 to be in a conductive state or a non-conductive state can be supplied to the wiring G2. The wiring VCOM2 and the wiring ANO can each be supplied with a potential at which a potential difference generated by the light emitting element 360 emits light. A signal for controlling the conduction state of the transistor M can be supplied to the wiring S2.

For example, when performing display in a reflection mode, the pixel 410 illustrated in FIG. 12 can be driven by a signal supplied to the wiring G1 and the wiring S1 and can display using optical modulation by the liquid crystal element 340. In the case where display is performed in the transmissive mode, display can be performed by driving the light-emitting element 360 by driving with signals supplied to the wiring G2 and the wiring S2. In the case of driving in both modes, the driving can be performed by signals given to the wiring G1, the wiring G2, the wiring S1, and the wiring S2.

Note that although FIG. 12 illustrates an example in which one pixel 410 includes one liquid crystal element 340 and one light emitting element 360, the present invention is not limited thereto. FIG. 13A illustrates an example in which one pixel 410 includes one liquid crystal element 340 and four light-emitting elements 360 (light-emitting elements 360r, 360g, 360b, and 360w). A pixel 410 illustrated in FIG. 13A can perform full-color display using a light-emitting element in one pixel, unlike FIG.

In FIG. 13A, in addition to the example in FIG. 12, a wiring G3 and a wiring S3 are connected to the pixel 410.

In the example illustrated in FIG. 13A, for example, light emitting elements exhibiting red (R), green (G), blue (B), and white (W) can be used as the four light emitting elements 360, respectively. As the liquid crystal element 340, a reflective liquid crystal element exhibiting white can be used. Thereby, when displaying in reflection mode, white display with high reflectance can be performed. In addition, when display is performed in the transmissive mode, display with high color rendering properties can be performed with low power.

FIG. 13B illustrates a configuration example of the pixel 410 corresponding to FIG. The pixel 410 includes a light-emitting element 360 w that overlaps with an opening included in the electrode 311, and a light-emitting element 360 r, a light-emitting element 360 g, and a light-emitting element 360 b that are disposed around the electrode 311. The light emitting element 360r, the light emitting element 360g, and the light emitting element 360b preferably have substantially the same light emitting area.

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

(Embodiment 3)
In this embodiment, a structure of a CAC (Cloud Aligned Complementary) -OS that can be used for the transistor disclosed in one embodiment of the present invention will be described.

The CAC-OS is one structure of a material in which an element included in an oxide semiconductor is unevenly distributed with a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. Note that in the following, in an oxide semiconductor, one or more metal elements are unevenly distributed, and a region including the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm, or the vicinity thereof. The state mixed with is also referred to as a mosaic or patch.

Note that the oxide semiconductor 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 selected from the above or a plurality of kinds 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 Also referred to as a cloud-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 oxide semiconductor 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 may refer 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 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 an oxide semiconductor. CAC-OS refers to a region observed in the form of nanoparticles mainly composed of Ga in a material structure including In, Ga, Zn and O, and nanoparticles mainly composed 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. For example, the flow rate ratio of the oxygen gas is 0% to less than 30%, preferably 0% to 10%. .

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 each region is mainly composed of each element. 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 4)
In this embodiment, a display module and an electronic device of one embodiment of the present invention will be described.

A display module 8000 illustrated in FIG. 14 includes a touch panel 8004 connected to the FPC 8003, a display panel 8006 connected to the FPC 8005, a frame 8009, a printed circuit board 8010, and a battery 8011 between an upper cover 8001 and a lower cover 8002. .

The display device of one embodiment of the present invention can be used for the display panel 8006, for example. Accordingly, a display module with high visibility can be manufactured regardless of the surrounding brightness. In addition, a display module with low power consumption can be manufactured. In addition, a highly reliable display module can be manufactured.

The shapes and dimensions of the upper cover 8001 and the lower cover 8002 can be changed as appropriate in accordance with the sizes of the touch panel 8004 and the display panel 8006.

As the touch panel 8004, a resistive film type or capacitive type touch panel can be used by being overlapped with the display panel 8006. Alternatively, the touch panel 8004 may be omitted, and the display panel 8006 may have a touch panel function.

The frame 8009 has a function as an electromagnetic shield for blocking electromagnetic waves generated by the operation of the printed board 8010 in addition to a protective function of the display panel 8006. The frame 8009 may have a function as a heat sink.

The printed board 8010 includes a power supply circuit, a signal processing circuit for outputting a video signal and a clock signal. As a power supply for supplying power to the power supply circuit, an external commercial power supply may be used, or a power supply using a battery 8011 provided separately may be used. The battery 8011 can be omitted when a commercial power source is used.

The display module 8000 may be additionally provided with a member such as a polarizing plate, a retardation plate, or a prism sheet.

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. 15A and 15B includes a housing 801, a housing 802, a display portion 803, a display portion 804, 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. 15A) as shown in FIG. 15B.

The display device of one embodiment of the present invention can be used for at least one of the display portion 803 and the display portion 804. Accordingly, a highly visible portable information terminal can be manufactured regardless of the surrounding brightness. In addition, a portable information terminal with low power consumption can be manufactured. In addition, a highly reliable portable information terminal can be manufactured.

Each of the display unit 803 and the display unit 804 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.

Since the portable information terminal 800 can be folded, it has high portability and excellent versatility.

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.

A portable information terminal 810 illustrated in FIG. 15C 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.

The display device of one embodiment of the present invention can be used for the display portion 812. Accordingly, a highly visible portable information terminal can be manufactured regardless of the surrounding brightness. In addition, a portable information terminal with low power consumption can be manufactured. In addition, a highly reliable portable information terminal can be manufactured.

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. 15D 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.

The display device of one embodiment of the present invention can be used for the display portion 822. The convenience of the camera can be enhanced by having a display portion with high visibility regardless of ambient brightness. In addition, a camera with low power consumption can be manufactured. In addition, a highly reliable camera can be manufactured.

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.

16A to 16E are diagrams illustrating 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, Includes functions to measure rotation speed, distance, light, liquid, magnetism, temperature, chemical, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared ), A microphone 9008 and the like.

The display device of one embodiment of the present invention can be favorably used for the display portion 9001. Accordingly, an electronic device having a display portion with high visibility can be manufactured regardless of ambient brightness. In addition, an electronic device with low power consumption can be manufactured. In addition, a highly reliable electronic device can be manufactured.

The electronic devices illustrated in FIGS. 16A to 16E 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. 16A to 16E are not limited to these, and may have other functions.

16A is a perspective view illustrating a wristwatch-type portable information terminal 9200, and FIG. 16B is a perspective view illustrating a wristwatch-type portable information terminal 9201.

A portable information terminal 9200 illustrated in FIG. 16A can execute various applications such as a mobile phone, electronic 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 mobile information terminal 9201 illustrated in FIG. 16B is different from the mobile information terminal illustrated in FIG. 16A in that the display surface of the display portion 9001 is not curved. In addition, the external shape of the display portion of the portable information terminal 9201 is a non-rectangular shape (a circular shape in FIG. 16B).

FIGS. 16C to 16E are perspective views showing a foldable portable information terminal 9202. FIG. Note that FIG. 16C is a perspective view of a state in which the portable information terminal 9202 is expanded, and FIG. 16D is a state in which the portable information terminal 9202 is expanded or changed from one of the folded state to the other. FIG. 16E 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.

ANO wiring C1 capacitive element C2 capacitive element CSCOM wiring G1 wiring G2 wiring G3 wiring GD circuit S1 wiring S2 wiring S3 wiring SD circuit SW1 switch SW2 switch VCOM1 wiring VCOM2 wiring 100 display device 101 first insulating layer 102 second insulating layer 107 Peeling layer 110a Transistor 110b Transistor 110c Transistor 110d Transistor 110e Transistor 110f Transistor 110g Transistor 110h Transistor 111 Oxide layer 112 Liquid crystal layer 113 Electrode 115 Insulating layer 117 Insulating layer 121 Insulating layer 131 Colored layer 132 Light shielding layer 133a Oriented film 133b Oriented film 134 Colored Layer 135 Polarizing plate 141 Adhesive layer 142 Adhesive layer 151 Insulating layer 170 Light emitting element 180 Liquid crystal element 191 Electrode 192 EL layer 193 Electrode 94 Insulating layer 201 Transistor 203 Transistor 204 Connection part 205 Transistor 206 Transistor 207 Connection part 211 Insulating layer 212 Insulating layer 214 Insulating layer 216 Insulating layer 217 Insulating layer 218 Insulating layer 220 Insulating layer 221 Conducting layer 221a Conducting layer 221b Conducting layer 221c conductive layer 222a conductive layer 222b conductive layer 223 conductive layer 231 semiconductor layer 242 connection layer 243 connection body 252 connection portion 261 semiconductor layer 263a conductive layer 263b conductive layer 281 transistor 284 transistor 285 transistor 286 transistor 300 display device 300A display device 300B display device 300C Display device 311 Electrode 311a Electrode 311b Electrode 311c Conductive layer 311d Conductive layer 311e Conductive layer 340 Liquid crystal element 350 Fabrication substrate 351 Base 360 light-emitting element 360b emitting element 360g emitting element 360r emitting element 360w emitting element 361 substrate 362 display unit 364 circuit 365 wiring 372 FPC
373 IC
400 Display device 410 Pixel 451 Opening 800 Portable information terminal 801 Case 802 Case 803 Display unit 804 Display unit 805 Hinge unit 810 Portable information terminal 811 Case 812 Display unit 813 Operation button 814 External connection port 815 Speaker 816 Microphone 817 Camera 820 Camera 821 Housing 822 Display unit 823 Operation button 824 Shutter button 826 Lens 8000 Display module 8001 Upper cover 8002 Lower cover 8003 FPC
8004 Touch panel 8005 FPC
8006 Display panel 8009 Frame 8010 Printed circuit board 8011 Battery 9000 Housing 9001 Display unit 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9055 Hinge 9200 Portable information terminal 9201 Portable information terminal 9202 Portable information terminal

Claims (11)

A first display element, a second display element, a first insulating layer, and a second insulating layer;
The first display element includes a first pixel electrode having a function of reflecting visible light and a liquid crystal layer,
The second display element has a function of emitting visible light,
The second display element has a second pixel electrode and a common electrode,
The common electrode is located on the opposite side of the second insulating layer across the second pixel electrode,
The first pixel electrode is located on the opposite side of the second pixel electrode with the second insulating layer in between.
The first pixel electrode is located between the first insulating layer and the second insulating layer,
The display device, wherein the first pixel electrode is located on the opposite side of the liquid crystal layer with the first insulating layer interposed therebetween. In claim 1,
Having a first transistor and a second transistor;
The first transistor has a function of controlling driving of the first display element,
The second transistor has a function of controlling driving of the second display element,
The display device, wherein the second insulating layer includes a portion that functions as a gate insulating layer of the first transistor and a portion that functions as a gate insulating layer of the second transistor. A first display element, a second display element, a first insulating layer, a second insulating layer, a third insulating layer, a first transistor, and a second transistor;
The first transistor has a function of controlling driving of the first display element,
The second transistor has a function of controlling driving of the second display element,
The first display element includes a first pixel electrode having a function of reflecting visible light and a liquid crystal layer,
The second display element has a function of emitting visible light,
The second display element has a second pixel electrode and a common electrode,
The first transistor and the second transistor are located between the second insulating layer and the third insulating layer, respectively.
The first transistor is electrically connected to the first pixel electrode through an opening provided in the second insulating layer,
The second transistor is electrically connected to the second pixel electrode through an opening provided in the third insulating layer,
The common electrode is located on the opposite side of the third insulating layer across the second pixel electrode,
The first pixel electrode is located on the opposite side of the second pixel electrode with the second insulating layer in between.
The first pixel electrode is located between the first insulating layer and the second insulating layer,
The display device, wherein the first pixel electrode is located on the opposite side of the liquid crystal layer with the first insulating layer interposed therebetween. In claim 3,
One or both of the first transistor and the second transistor includes an oxide semiconductor in a channel formation region. In any one of Claims 1 thru | or 4,
The first pixel electrode has an opening,
The second display element has a portion overlapping the opening,
The display device, wherein the second display element has a function of emitting visible light toward the opening. In any one of Claims 1 thru | or 5,
The display device, wherein the first insulating layer has a thickness of 50 nm to 600 nm. A display device according to any one of claims 1 to 6;
A display module. A display module according to claim 7;
An electronic device having at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button. A method for manufacturing a display device having a first display element and a second display element,
The first display element includes a first pixel electrode having a function of reflecting visible light, a liquid crystal layer, and a first common electrode having a function of transmitting visible light,
The second display element includes a second pixel electrode having a function of transmitting visible light, a light emitting layer, and a second common electrode having a function of reflecting visible light,
Forming the first common electrode on a first substrate;
Forming a first insulating layer over a manufacturing substrate;
Forming a second insulating layer on the first insulating layer;
Forming a release layer on the second insulating layer;
Plasma treatment is performed on the surface of the release layer,
Forming a third insulating layer on the release layer;
Forming the first pixel electrode on the third insulating layer;
Forming a fourth insulating layer on the first pixel electrode;
After forming the third insulating layer and before forming the second display element, heat treatment is performed,
On the fourth insulating layer, the second display element is formed by forming the second pixel electrode, the light emitting layer, and the second common electrode in this order,
Bonding the production substrate and the second substrate using an adhesive,
Separating the fabrication substrate and the third insulating layer;
By disposing the liquid crystal layer between the first common electrode and the exposed third insulating layer, and bonding the first substrate and the second substrate using an adhesive, A method for manufacturing a display device, wherein the first display element is formed. In claim 9,
After forming the first pixel electrode, an opening is provided in the first pixel electrode,
A method for manufacturing a display device, wherein the second display element is formed at a position overlapping with the opening. In claim 9 or 10,
The adhesive used for bonding the first substrate and the second substrate includes conductive particles,
Processing the same conductive film to form the first pixel electrode and the conductive layer;
After separating the manufacturing substrate and the third insulating layer, the third insulating layer is processed to expose the conductive layer,
A method for manufacturing a display device, wherein the first common electrode and the conductive layer are electrically connected by the conductive particles by bonding the first substrate and the second substrate.

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