Semiconductor device

Abstract

To provide a flexible and thinned touch panel with high detection sensitivity.SOLUTION: A touch panel includes a first flexible substrate, a first insulating layer over the first substrate, a transistor and a light-emitting element over the first insulating layer, a color filter over the light-emitting element, a pair of sensor electrodes over the color filter, a second insulating layer over the sensor electrodes, a second flexible substrate over the second insulating layer, and a protective layer over the second substrate. A first bonding layer is between the light-emitting element and the color filter. A thickness of the first substrate and the second substrate is each 1 μm to 200 μm. The first bonding layer includes a region with a thickness of 50 nm to 10 μm.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] One aspect of the present invention relates to a display device. In particular, the display device has flexibility and can be bent. The present invention relates to a display device. Furthermore, one embodiment of the present invention relates to a touch panel. In particular, The present invention relates to a touch panel that can be bent.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect relates to an article, a method, or a manufacturing method. One aspect of the present invention is a process, machine, manufacture, or composition. Therefore, the invention disclosed herein more specifically relates to The technical field of one embodiment of the present invention is a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, Examples include their driving methods and their manufacturing methods. [Background technology]

[0003] In recent years, display devices are expected to be used in a variety of applications, and diversification is required. For example, the thin type of smartphones and tablet devices equipped with touch panels as mobile information terminals They are becoming increasingly sophisticated, high-performance, and multifunctional.

[0004] In addition, Patent Document 1 discloses a film substrate on which transistors and other elements serving as switching elements are mounted. A flexible active matrix light emitting device having an organic EL element is disclosed. do. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-174153 Summary of the Invention [Problem to be solved by the invention]

[0006] The display device is thin enough to be flexible, and the screen is used as a user interface. There is a demand for a touch panel that has an input function that can be performed by touching it with a finger or the like.

[0007] An object of one embodiment of the present invention is to provide a flexible touch panel. Another objective is to achieve both a thinner touch panel and high detection sensitivity.

[0008] Another object is to provide a novel display device. One of the objectives is to provide a touch panel. It shall be one of the following.

[0009] The description of these problems does not preclude the existence of other problems. It is not necessary to solve all of these problems. It will be clear from the description of the specification, etc. that there are other problems than those mentioned above. It is possible to extract it. [Means for solving the problem]

[0010] One aspect of the present invention is a flexible first substrate, a first insulating layer on the first substrate, and a second insulating layer. A transistor and a light-emitting element are formed on the insulating layer 1, and a color filter and a color filter are formed on the light-emitting element. A pair of sensor electrodes on the filter, a second insulating layer on the sensor electrodes, and a second insulating layer on the second insulating layer. a touch panel including a flexible second substrate and a protective layer on the second substrate; In addition, a first adhesive layer is provided between the light emitting element and the color filter, and the first substrate and the second substrate are bonded to each other. The thickness of the second substrate is 1 μm or more and 200 μm or less, and the thickness of the first adhesive layer is 50 nm or more. It has an area of 10 μm or less above.

[0011] Further, a first conductive film is provided on the first insulating layer, and one of the sensor electrodes and It is preferable that the first conductive film is electrically connected via a conductive connector.

[0012] Another embodiment of the present invention is a semiconductor device including a first substrate having flexibility and a pair of cells provided on the first substrate. a sensor electrode, a first insulating layer on the sensor electrode, a transistor and a a light-emitting element, a color filter below the light-emitting element, and a second insulating layer above the light-emitting element; A flexible second substrate is provided on the second insulating layer, and a protective layer is provided below the first substrate. The touch panel further includes a first adhesive layer between the light-emitting element and the second insulating layer, The thickness of the first substrate and the second substrate is 1 μm or more and 200 μm or less, and the thickness of the first adhesive layer is The thickness has a region of 50 nm or more and 10 μm or less.

[0013] In addition, a semiconductor layer in which a channel of the transistor is formed may contain an oxide semiconductor. It is preferable that:

[0014] Further, the semiconductor layer in which the channel of the transistor is formed has polycrystalline silicon. It's fine.

[0015] The protective layer preferably contains aluminum oxide or yttrium oxide. stomach.

[0016] A second adhesive layer is provided between the first insulating layer and the first substrate, and the thickness of the second adhesive layer is The thickness is preferably 50 nm or more and 10 μm or less.

[0017] A third adhesive layer is provided between the second insulating layer and the second substrate, and the thickness of the third adhesive layer is The thickness is preferably 50 nm or more and 10 μm or less. [Effects of the Invention]

[0018] According to one aspect of the present invention, a flexible touch panel can be provided. This makes it possible to achieve both a thinner panel and high detection sensitivity.

[0019] Alternatively, a novel display device, touch sensor, or touch panel can be provided. The description of these effects does not preclude the existence of other effects. It is not necessary to have all of these effects. Effects other than these may be included in the description. The above is self-evident from the description, drawings, claims, etc. From the above descriptions, it is possible to extract other effects. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 2] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 3] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 5] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 6] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 7] FIG. 1 is a diagram showing an example of the configuration of a touch panel. [Figure 8]1A and 1B are a block diagram and a timing chart of a touch sensor; [Figure 9] Circuit diagram of a touch sensor. [Figure 10] 1A and 1B are a block diagram and a timing chart of a display device. [Figure 11] 1A to 1C are diagrams illustrating operations of a display device and a touch sensor. [Figure 12] 1A to 1C are diagrams illustrating operations of a display device and a touch sensor. [Figure 13] Block diagram of a touch panel. [Figure 14] Circuit diagram of a pixel. [Figure 15] FIG. 2 is a timing chart illustrating the operation of the display device. [Figure 16] 1 is a cross-sectional view of the device and a perspective view of the nozzle. [Figure 17] An example of the configuration of electronic devices. [Figure 18] An example of the configuration of electronic devices. [Figure 19] Cs-corrected high-resolution TEM image of a cross section of CAAC-OS, and a schematic cross-sectional diagram of CAAC-OS. [Figure 20] Cs-corrected high-resolution TEM image of the CAAC-OS in the plane. [Figure 21] 10A and 10B illustrate structural analyses of a CAAC-OS and a single-crystal oxide semiconductor by XRD. [Figure 22] Electron diffraction pattern of CAAC-OS. [Figure 23] FIG. 1 shows the change in the crystalline part of an In-Ga-Zn oxide due to electron irradiation. DETAILED DESCRIPTION OF THE INVENTION

[0021] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiments, and various changes and modifications may be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention is based on the following embodiments. The present disclosure should not be construed as being limited to the contents of the preceding paragraph.

[0022] In the configuration of the invention described below, the same parts or parts having similar functions are The same reference numerals are used in common between different drawings, and repeated explanations thereof will be omitted. When referring to a function, the hatch pattern may be the same and no particular symbol may be assigned.

[0023] In each figure described in this specification, the size, layer thickness, or area of each component is The figures may be exaggerated for clarity and are not necessarily limited to that scale. stomach.

[0024] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. The number is not a numerical limitation.

[0025] (Embodiment 1) In this embodiment, a configuration example of a touch panel according to one embodiment of the present invention will be described with reference to the drawings. explain.

[0026] [Touch panel configuration example] FIG. 1A is a schematic perspective view of a touch panel 100 exemplified below.

[0027] The touch panel 100 is formed between a flexible substrate 101 and a flexible substrate 102. , includes at least a display device 110 and a touch sensor 120.

[0028] FIG. 1(B) is a perspective schematic diagram showing the touch sensor 120 in FIG. 1(A), and FIG. 1(C) is a perspective schematic diagram showing the touch sensor 120 in FIG. ) is a configuration including the display device 110, the wiring 131, the wiring 132, and the wiring 144 in FIG. FIG.

[0029] The touch sensor 120 may be, for example, a capacitance type touch sensor. Capacitive touch panels include surface capacitive touch panels and projected capacitive touch panels. There are two types of methods, self-capacitance and mutual capacitance, which mainly differ in the driving method. The capacitance method is preferable because it allows simultaneous multipoint detection.

[0030] The following describes a case where a projected capacitive touch sensor is applied.

[0031] In addition, various sensors (e.g., Applying optical sensors using photoelectric conversion elements, pressure-sensitive sensors using pressure-sensitive elements, etc. It is also possible.

[0032] The touch sensor 120 has a plurality of electrodes 121 and a plurality of electrodes 122. The electrodes 121 are , and the electrode 122 is electrically connected to one of the plurality of wirings 132. The wiring 131 is electrically connected to the FPC 142. An FPC 143 is electrically connected to 132.

[0033] The electrode 121 has a shape that extends in one direction. The electrode 122 intersects with the electrode 121. In addition, a dielectric layer is provided between the electrodes 121 and 122. A capacitance is formed at the intersection of these electrodes. A plurality of capacitance elements are arranged in a matrix by a plurality of electrodes 122 and a dielectric layer between them. It has a structure.

[0034] The electrodes 121 and 122 preferably have light-transmitting properties. As shown in (B), the electrodes 121 and 122 are arranged so that there is as little gap as possible between them. It is preferable to arrange the electrodes 121 or 122 in the gaps. A dummy electrode including the same conductive film as the electrode 122 may be provided. By minimizing the gap between the film 122 and the substrate 122, the unevenness of the transmittance can be reduced. As a result, unevenness in brightness of light passing through the touch sensor 120 can be reduced.

[0035] The display device 110 includes a display unit 111 including at least a plurality of pixels, and a signal The display unit 111 includes wiring 144 for supplying light and power. The display element is preferably an organic electroluminescence (EL) element. can be used.

[0036] In addition, in FIG. 1, the display device 110 includes not only a display unit 111 but also a drive circuit 112. The driving circuit 112 may be, for example, a scanning line driving circuit, a signal line driving circuit, etc. A circuit that functions as

[0037] The FPC 141 is electrically connected to the wiring 144. Signals and power for driving the display device 110 can be supplied via this.

[0038] In addition, in FIG. 1, IC 114 mounted on FPC 141 by COF method is provided. The IC 114 is, for example, a scanning line driving circuit or a signal line driving circuit. It should be noted that the display device 110 may include an IC that functions as a scanning line driving circuit and a signal In some cases, a circuit that functions as a scanning line driver circuit or a signal line driver circuit is provided. A functioning circuit is provided externally, and a signal for driving the display device 110 is transmitted via the FPC 141. In such a case, the IC 114 may not be provided.

[0039] In FIG. 1, a display device 110, wiring 131, and wiring 132 are provided on the first substrate 101 side. 10, and a touch sensor 120 is provided on the second substrate 102 side.

[0040] [Cross-section example] In FIG. 2(A), the cutting lines A1-A2, B1-B2, C1-C2, 2A and 2B show an example of a cross-sectional configuration of the display unit 111. As an example, a cross section of one pixel included in the display unit 111 is shown.

[0041] The first substrate 101 and the second substrate 102 are bonded together by a first adhesive layer 151. The first adhesive layer 151 is also provided between the light emitting element 180 and the color filter 184. That's fine.

[0042] The first substrate 101 and the second substrate 102 are flexible and have a thickness of, for example, 1 μm. ≧200 μm, preferably ≧3 μm and ≦100 μm, more preferably ≧5 μm It is preferable that the thickness is 50 μm or less, and typically, it is about 20 μm. If the thickness is less than 1 / 2 m, the mechanical strength of the touch panel 100 is insufficient, which may cause damage. Furthermore, if the thickness is greater than 200 μm, the flexibility will be poor and The bending stress generated when the substrate is bent increases, and the substrate itself or the components provided on the substrate There is a risk that the wiring and elements connected to the device may be damaged.

[0043] The first substrate 101 and the second substrate 102 have the same or approximately the same thickness. It is preferable that the thickness of the first substrate 101 and the second substrate 102 be the same. The display device 110 and the touch sensor 120 are placed in the center of the touch panel. As a result, the influence of bending stress that occurs when the touch panel is bent can be displayed. Since the influence of the bending on the device 110 and the touch sensor 120 is suppressed, problems such as damage due to bending can be prevented. This can suppress the occurrence of such a problem, thereby realizing a highly reliable touch panel 100. The smaller of the thicknesses of the first substrate 101 and the second substrate 102 is 80% of the larger thickness. It is sufficient to set the content at 90% or more, preferably 90% or more, and more preferably 95% or more.

[0044] The first substrate 101 and the second substrate 102 have the same or approximately the same linear thermal expansion coefficient. It is preferable to use materials with the same linear thermal expansion coefficient. Even if the touch panel 100 is subjected to heat or the temperature changes during use, It also prevents bending of the touch panel. The range of the second substrate 101 can be widened by adjusting the linear thermal expansion coefficient of the material used for the first substrate 101. The difference in the linear thermal expansion coefficient of the material used for the substrate 102 is, for example, in the range of 0°C to 200°C. 10 ppm / K or less, preferably 5 ppm / K or less, more preferably 2 ppm / K or less It is preferable that there is.

[0045] In FIG. 2A, the transistor 161 and the transistor 162 included in the driver circuit 112 are 62, and the transistor 163 and the transistor 164 included in the pixel of the display unit 111. 64. Each transistor is provided on a first insulating layer 171.

[0046] In FIG. 1 and FIG. 2A, the driving circuit is formed on the first insulating layer 171 on which the display section 111 is formed. The diagram shows the configuration of a driver-integrated display device in which a circuit 112 is formed, but the display unit 111 is formed. Apart from the insulating surface, one of the circuits that functions as a scanning line driver circuit or a signal line driver circuit Or, both may be provided. For example, the drive circuit IC is mounted by the COG method. Alternatively, an FPC (Flexible Printed Circuit) on which a driver circuit IC is mounted using the COF method may be used. ble Printed Circuit) may be implemented.

[0047] In FIG. 2A, examples of transistors provided in the driver circuit 112 and the display portion 111 include , which shows a bottom-gate transistor.

[0048] Here, the pixels included in the display unit 111 provided in the display device 110, the drive circuit 112, etc. As a transistor used in this application, an oxide semiconductor is used in the semiconductor layer where the channel is formed. In particular, it is preferable to use an oxide semiconductor having a larger band gap than silicon. It is preferable that the semiconductor has a wider band gap than silicon and a lower carrier density. The use of a conductive material is preferable because it can reduce the current when the transistor is in an off state.

[0049] For example, the oxide semiconductor may contain at least indium (In) or zinc (Zn ) is preferably contained as the oxide semiconductor. is expressed as a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce or Hf) It is more preferable that the oxide contains an oxide having a high solubility in water.

[0050] In particular, the semiconductor layer has a plurality of crystal portions, and the c-axes of the crystal portions are aligned with the surface on which the semiconductor layer is formed. or oriented perpendicular to the upper surface of the semiconductor layer and having no grain boundary between adjacent crystal portions. An oxide semiconductor film is preferably used.

[0051] Such oxide semiconductors have no crystal grain boundaries, so when the display panel is bent, The occurrence of cracks in the oxide semiconductor film due to stress is suppressed. Such oxide semiconductors are suitable for use in flexible display panels that are used in a curved state. You can be there.

[0052] By using such materials for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and reliability is improved. High-performance transistors can be realized.

[0053] In addition, a transistor using an oxide semiconductor for a semiconductor layer has a source and a drain in an off state. Because the leakage current (off-state current) between the transistors is low, the charge stored in the capacitance can be released via the transistor. By applying such a transistor to a pixel, This makes it possible to stop the drive circuit while maintaining the gradation of the image displayed in each display area. As a result, electronic devices with extremely low power consumption can be realized.

[0054] The preferred oxide semiconductors applicable to the semiconductor layer and their forming methods are as follows: This will be explained in detail in a later embodiment.

[0055] It is also preferable to operate the touch sensor 120 during a period when pixel driving is paused. By performing this operation, it is possible to eliminate the influence of noise that occurs when driving pixels. This makes it possible to improve the detection sensitivity of the touch sensor 120. Therefore, the influence of noise can be eliminated, and the touch sensor and the display unit 111 or the drive circuit 11 Specifically, the distance between the light emitting element 180 and the color In the region where the adhesive layer 151 overlaps with the filter 184, the thickness of the adhesive layer 151 is 50 nm or more and 10 μm or less. Preferably, the area is 50 nm or more and 5 μm or less, more preferably 100 nm or more and 3 μm or less. The first substrate 101 and the second substrate 102 can be brought close to each other to such an extent that a gap is formed between the first substrate 101 and the second substrate 102.

[0056] An example of a method for driving the touch sensor 120 and the display device 110 will be described later in the following embodiment. This will be explained in the form of:

[0057] Alternatively, the pixels included in each display region provided in the display device 110 and the driving circuits As a transistor to be used, silicon may be used for a semiconductor layer in which a channel is formed. Although amorphous silicon may be used as the silicon, silicon having crystallinity is particularly preferred. It is preferable to use, for example, microcrystalline silicon, polycrystalline silicon, single crystal silicon, etc. In particular, polycrystalline silicon is formed at a lower temperature than single-crystalline silicon. It has high field effect mobility and high reliability compared to amorphous silicon. By applying such a polycrystalline semiconductor to a pixel, the aperture ratio of the pixel can be improved. Even when the pixels are extremely fine, the gate drive circuit and the source drive circuit are This allows the components to be formed on the same substrate as the electronic device, reducing the number of components that make up the electronic device. can be done.

[0058] The transistor 161 and the transistor 162 are connected to the second For example, the second gate of the transistor 161 may have a gate of the transistor The gate of the transistor 161 may be electrically connected to the gate of the transistor 162, or different potentials may be applied to them. If necessary, the transistor 163 and the transistor 164 may also be provided with a second gate. If not required, the transistors 161 and 162 may be provided. Alternatively, the second gate may not be provided.

[0059] In addition to the gate, source, and drain of the transistor, various wiring that makes up the touch panel Wires and electrodes may be made of aluminum, titanium, chromium, nickel, copper, yttrium, elemental metals consisting of zirconium, molybdenum, silver, tantalum, or tungsten, or The alloy containing this as the main component can be used as a single layer structure or a laminated structure. , a single layer structure of aluminum film containing silicon, and a two-layer structure of aluminum film stacked on titanium film. Layer structure, two-layer structure with aluminum film laminated on tungsten film, copper-magnesium-aluminum Two-layer structure with copper film laminated on aluminum alloy film, two-layer structure with copper film laminated on titanium film, Two-layer structure with copper film laminated on tungsten film, titanium film or titanium nitride film and its titanium An aluminum film or a copper film is laminated on the silicon film or titanium nitride film, and then an aluminum film or a copper film is laminated on top of that. Three-layer structure forming titanium film or titanium nitride film, molybdenum film or molybdenum nitride film Then, an aluminum film or a copper film is laminated on the molybdenum film or the molybdenum nitride film. There are three-layer structures, such as a layer of silicon dioxide and a molybdenum film or molybdenum nitride film formed on top of that. It is also possible to use a transparent conductive material containing indium oxide, tin oxide, or zinc oxide. In addition, copper containing manganese is preferable because it improves the controllability of the shape by etching. .

[0060] Each pixel in the display unit 111 has a switching transistor 163 and a current control transistor 164. The transistor 164 and one electrode (source electrode or drain electrode) of the transistor 164 The first electrode 181 is electrically connected to the insulating layer 176. An insulating layer 175 is provided to cover the edge of the first electrode 181 .

[0061] Here, the structure of the transistors included in the display unit 111, the driver circuit 112, etc. is not limited to the above. For example, a staggered transistor may be used, or an inversely staggered transistor may be used. In addition, the transistor may have either a top gate type or a bottom gate type structure. You may do so.

[0062] In FIG. 3, transistor 161, transistor 162, transistor 163, transistor 1 shows a case where a channel protection type bottom gate structure transistor is provided as the transistor 164. A protective layer is provided to cover the upper surface of the semiconductor layer of the transistor. The semiconductor layer and the source electrode or the drain electrode are electrically connected through the opening. By adopting such a configuration, etching when processing the source electrode and the drain electrode is performed. Therefore, the semiconductor layer can be prevented from becoming thin.

[0063] Also, in FIG. 4, transistor 161, transistor 162, transistor 163, An example in which a transistor with a top gate structure is used as the transistor 164 is shown.

[0064] When an oxide semiconductor is used for the semiconductor layer of a transistor, a bottom-gate structure is used. Oxide semiconductors, which have higher mobility than amorphous silicon, are preferably used at low temperatures. Therefore, the heat resistance of the gate electrode located under the semiconductor layer is not an issue. The range of material options can be expanded. The manufacturing process can be simplified compared to the top gate structure, and manufacturing costs can be reduced.

[0065] In particular, by using CAAC-OS (described later) as an oxide semiconductor, This makes it possible to increase the resistance of the oxide semiconductor to etching during the processing of the rain electrode. Therefore, when the CAAC-OS is used for the semiconductor layer, a channel etch structure is preferably used. This is preferable because it is possible to apply a structure that simplifies the manufacturing process.

[0066] In addition, it is formed by transferring it onto polycrystalline silicon or an insulating layer as a semiconductor layer of a transistor. When single crystal silicon is used, it is preferable to use a top gate structure. By applying a gate-structure transistor, the material for wiring and electrodes above the semiconductor layer can be This allows for the use of materials with low heat resistance, broadening the range of material choices. In addition, when a highly heat-resistant material is used for the gate electrode or when polycrystalline silicon is used at an extremely low temperature ( For example, when the temperature is lower than 450°C, the bottom gate structure described above is used. This is preferable because it reduces the manufacturing process.

[0067] The light emitting element 180 includes a first electrode 181, a second electrode 183, and an E It has an L layer 182. The light emitting element 180 will be described below.

[0068] In the light emitting element 180, the electrode provided on the light emitting side has a A material having light-transmitting properties is used.

[0069] Examples of materials that have transparency include the conductive oxides and graphene mentioned above, as well as gold, silver, and platinum. , magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, Metallic materials such as radium or titanium, or alloy materials containing such metallic materials can be used. Alternatively, nitrides of the metal materials (for example, titanium nitride) may be used. When using metal materials or alloy materials (or their nitrides), they should be made to a degree that they have translucency. Alternatively, a laminated film of the above materials can be used as the conductive layer. For example, By using a laminated film of silver-magnesium alloy and indium tin oxide, the conductivity can be increased. This is preferable because it can

[0070] Such electrodes are formed by vapor deposition or sputtering. It is formed using a discharge method such as the ink jet method, a printing method such as the screen printing method, or a plating method. It can be achieved.

[0071] In addition, when the above-described conductive oxide having light-transmitting properties is formed by a sputtering method, When the conductive oxide is formed in an atmosphere containing argon and oxygen, the light transmittance is improved. It is possible.

[0072] When a conductive oxide film is formed on the EL layer 182, an argon gas having a reduced oxygen concentration is used. a first conductive oxide film formed under an atmosphere containing argon and oxygen; By forming a laminated film of the deposited second conductive oxide film, damage to the EL layer 182 due to film formation is reduced. Here, it is particularly preferable to use the first conductive oxide film. It is preferable that the purity of the argon gas used is high, for example, that the dew point is -70°C or less, preferably - It is preferable to use argon gas at 100°C or less.

[0073] The electrode provided on the side opposite to the light emitting side is made of a material that is reflective to the emitted light.

[0074] Examples of materials that have light reflectivity include aluminum, gold, platinum, silver, nickel, and titanium. Metallic materials such as tin, chromium, molybdenum, iron, cobalt, copper, or palladium, and the like An alloy material containing a metal material can be used. Lanthanum, neodymium, germanium, etc. may be added to the material. Examples of alloy materials include: Aluminum and titanium alloy, aluminum and nickel alloy, aluminum and neodymium Alloys containing aluminum (aluminum alloys), such as silver and copper alloys, silver and para Examples include alloys containing silver, such as an alloy of zinc and copper, and an alloy of silver and magnesium. The alloy containing copper is preferable because it has high heat resistance. By stacking a metal oxide film or a metal oxide film, oxidation of the aluminum-containing film can be suppressed. As a metal material or metal oxide material provided in contact with the aluminum-containing film, Examples of the transparent material include titanium and titanium oxide. A film made of a metal material may be laminated. For example, a laminated film of silver and indium tin oxide, A laminated film of an alloy of silver and magnesium and indium tin oxide can be used.

[0075] Such electrodes are formed by vapor deposition or sputtering. It is formed using a discharge method such as the ink jet method, a printing method such as the screen printing method, or a plating method. It can be achieved.

[0076] The EL layer 182 is a layer containing at least a light-emitting organic compound (hereinafter also referred to as a light-emitting layer). It may be composed of a single layer or a plurality of layers laminated together. The laminated structure includes, from the anode side, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, An example of a structure in which an electron injection layer is laminated on the light emitting layer can be given. These layers do not necessarily have to be provided in the EL layer 182. Specifically, a plurality of light-emitting layers may be stacked in the EL layer 182. In addition, other components such as a charge generating region can be added as appropriate. For example, two or more light-emitting layers that exhibit complementary colors may be stacked. By stacking optical layers, white light can be emitted.

[0077] The EL layer 182 is formed by a vacuum deposition method or a discharge method such as an inkjet method or a dispense method. The conductive layer can be formed by a coating method such as spin coating, or a printing method.

[0078] In this embodiment, a reflective material is used for the first electrode 181, and a reflective material is used for the second electrode 182. A light-transmitting material is used for the light-emitting element 83. Therefore, the light-emitting element 180 is a top-emission type (top-emission type). The light emitting element is a top-emission type, and emits light to the second substrate 102 side.

[0079] The above is the description of the light emitting element 180.

[0080] The second electrode 122 constituting the touch sensor 120 is formed in contact with the second insulating layer 172. In addition, a dielectric layer 123 is provided to cover the second insulating layer 172, and the dielectric layer 123 A first electrode 121 is provided that intersects with a second electrode 122 via a line.

[0081] The first electrode 121 and the second electrode 122 are made of the above-mentioned light-transmitting conductive material. You can be there.

[0082] After forming a film of a light-transmitting conductive material on the insulating layer 172 by sputtering, By using various patterning techniques such as photolithography, unnecessary parts are removed to form the first The electrode 121 and the second electrode 122 can be formed. Alternatively, the graphene oxide may be formed by applying a solution in which the graphene oxide is dispersed and then reducing the solution.

[0083] The material used for the dielectric layer 123 is, for example, a resin such as acrylic or epoxy, or a silicone resin. In addition to resins with SAN bonds, silicon oxide, silicon oxynitride, aluminum oxide, etc. Inorganic insulating materials can also be used.

[0084] The touch sensor 120 includes a first electrode 121, a dielectric layer 123, and a second electrode An insulating layer 125 is provided to cover the touch sensor 122. The insulating layer 125 It functions as a planarizing layer to cover the steps and make the thickness of the color filter 184 uniform. Has.

[0085] The insulating layer 125 also serves to separate the wiring and electrodes that make up the touch sensor 120 from the display device 110. It also has the function of reducing the parasitic capacitance that forms between the wiring and electrodes included in the insulation. It is preferable to use an organic material with a low relative dielectric constant for the insulating layer 125. The thickness is, for example, 1 μm or more and 20 μm or less, preferably 1 μm or more and 10 μm or less. This is preferable because it allows the touch panel 100 to be made thinner and the parasitic capacitance to be reduced at the same time.

[0086] A color filter 184 is formed in the area overlapping the light emitting element 180 on the insulating layer 125. are.

[0087] The color filter 184 is provided for the purpose of adjusting the color of light emitted from the pixel and increasing color purity. For example, when a white light emitting element is provided as the light emitting element 180, By using multiple pixels with color filters, full color display is possible. In this case, three color filters of red (R), green (G), and blue (B) can be used. Or, yellow (Y) can be added to make it four colors. ) and a white (W) pixel may be used to make it four colors (or five colors).

[0088] In addition, a black matrix 185 is provided between adjacent color filters 184. The black matrix 185 blocks light from leaking from adjacent pixels and The black matrix 185 is formed only between adjacent pixels of different luminescent colors. The color filter 184 may be arranged between the edges of the color filter 184 and not between the pixels of the same color. By providing the portion so as to overlap with the black matrix 185, light leakage can be suppressed. The black matrix 185 can be made of a material that blocks light, and can be made of a metal. The film can be formed using a resin material containing a material or a pigment. In this way, the black matrix 185 is provided in an area other than the display section 111 such as the driving circuit 112. This is preferable because it can suppress unintended light leakage due to guided light or the like.

[0089] As shown in FIG. 2A, the first substrate 102 is provided with a touch sensor 120. The electrode 121 and the second electrode 122 are arranged, and the color filter is arranged on the side closer to the light emitting element 180. It is preferable to arrange the touch sensor 120 and the touch panel 184. The sensitivity of the touch sensor 120 can be improved by reducing the distance between the touch sensor and the touch surface. By reducing the distance between the filter 184 and the light emitting element 180, This can prevent light from leaking into the color filter 184 of an adjacent pixel.

[0090] The insulating layers 171 and 172 are made of a material that suppresses the diffusion of impurities from the outside. For example, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride oxides, nitrides or oxynitrides of semiconductors such as silicon, aluminum oxide, aluminum nitride, etc. Inorganic insulating materials such as metal oxides, metal nitrides, and metal oxynitrides, such as aluminum and aluminum oxide nitride. Alternatively, a laminated film of such inorganic insulating material or an inorganic insulating material is preferably used. A laminated film of an insulating material and an organic insulating material may also be used.

[0091] The wiring 132 is provided on the insulating layer 171. The insulating layer 176 and the wiring 132 are provided on the insulating layer 171. A conductive layer 166 is provided. The conductive layer 166 is connected to the insulating layer 176 through an opening. 2A, the wiring 132 is electrically connected to the transistor 132. The conductive layer 166 is formed by processing the same conductive film as the source and drain electrodes of the transistor. 1 shows an example in which the same conductive film as the first electrode 181 of the light emitting element 180 is processed and formed. In addition, it is preferable that the wiring 131 in FIG. stomach.

[0092] On the second substrate 102 side, the electrode 121 of the touch sensor 120 is connected to the conductive layer 1. 66, and its upper surface (the surface facing the conductive layer 166) is , including a portion where no structure other than the adhesive layer is provided. The same applies to

[0093] The electrode 121 of the touch sensor 120 and the conductive layer 166 are electrically connected by the conductive particles 165. The conductive particles 165 are provided so as to be dispersed in the adhesive layer 151. Therefore, the electrode 121 and the wiring 132 are connected by the conductive particles 165 and the conductive layer 166. Similarly, the electrode 122 and the wiring 131 in FIG. They are electrically connected by conductive particles 165 .

[0094] The conductive particles 165 are made of organic resin or silica particles, and the surface of the particles is covered with a metal material or an alloy material. It is preferable to use a material coated with a conductive material such as nickel or gold as the metal material. It is preferable to use a nickel-based alloy because it can reduce contact resistance. It is preferable to use particles coated with layers of two or more metal materials. The particles 165 may be particles of a conductive material.

[0095] The conductive particles 165 sandwiched between the electrode 121 and the conductive layer 166 are subjected to pressure acting in the vertical direction. It is preferable that the conductive member is deformed into a crushed shape by the electric current. The contact area between the conductive particles 165 and the electrode 121 (or electrode 122) or the conductive layer 166 increases. In order to increase the size of the wiring, the electrical resistance in these connections can be reduced. In the cross-sectional schematic diagram shown in FIG. 1, for convenience, the cross-sectional shape of the conductive particles 165 is shown perpendicular to the substrate. Although the cross section is shown as an ellipse having a long axis, in many cases the cross section is actually a circle. Or, the conductive particles have an elliptical shape with the major axis component parallel to the substrate. An example is shown in which the cross section of 165 is an ellipse having a major axis component parallel to the substrate.

[0096] At the outer periphery of the substrate 101, a part of the wiring 132 forms a connection terminal 156. In FIG. 2(A), a part of the wiring 132 and a gate electrode of a transistor are used as the connection terminal 156. The example shows a case where a laminated structure of conductive layers is formed by processing the same conductive film as the conductive film. In addition, by using a laminated structure of multiple layers as the connection terminal 156, when crimping the FPC 143, The connection terminal 156 and the FPC 143 are connected by the connection layer 157. The connection layer 157 is electrically connected via an anisotropic conductive film (ACF :Anisotropic Conductive Film) and anisotropic conductive paste (ACP: Anisotropic Conductive Paste) It is possible.

[0097] In addition, wiring 144 electrically connected to the display unit 111 or the drive circuit 112 is provided on the substrate 10 The wiring 144 is routed to the other outer periphery of the substrate 101. A part of the connecting terminal 155 is formed as the connecting terminal 155. The connection terminal 155 can be connected to the FP 56 via a connection layer 158. It is electrically connected to C141.

[0098] Here, the first substrate 101 and the insulating layer 171 are bonded together by an adhesive layer 152 . The second substrate 102 and the insulating layer 172 are bonded together by an adhesive layer 153 .

[0099] The adhesive layers 152 and 153 may be made of the same material as the adhesive layer 151. Each adhesive layer is made of a hardening resin such as a thermosetting resin, a photo-curing resin, or a two-component mixed hardening resin. For example, acrylic, urethane, epoxy, or siloxane resins can be used. Resins having such a structure can be used.

[0100] Here, at least two of the adhesive layers 151, 152, and 153 are preferably It is preferable to use the same material for all of these adhesive layers. This makes it possible to equalize the coefficient of linear thermal expansion, and the heat generated during the manufacturing process and the temperature during use Even when the angle changes, the touch panel 100 is prevented from unintentionally bending. It also expands the temperature range in which stable operation of the touch panel is guaranteed. .

[0101] In addition, at least two of the adhesive layers 151, 152, and 153, preferably It is preferable that the thicknesses of the two adhesive layers are approximately equal. The thickness of the smaller one is 50% or more, preferably 80% or more, more preferably 100% or more, of the thickness of the larger one. should be 90% or more.

[0102] The adhesive layers 152 and 153 have a thickness of 50 nm or more, similar to the adhesive layer 151. μm or less, preferably 50 nm or more and 5 μm or less, more preferably 100 nm or more and 3 μm or less It is preferable that the thickness of these three adhesive layers is thin enough to have a lower area. As a result, the thickness of the touch panel 100 can be reduced, and a touch panel with excellent flexibility can be realized.

[0103] Here, the structure in which either or both of the adhesive layer 152 and the adhesive layer 153 are not provided is also possible. 5 shows a case where neither adhesive layer 152 nor adhesive layer 153 is provided. In FIG. 5, an insulating layer 171 is provided in contact with the upper surface of a flexible first substrate 101. An insulating layer 172 is provided in contact with the upper surface of the second substrate 102. 2(A) shows a configuration without adhesive layer 152 and adhesive layer 153. However, in the configurations shown in FIGS. 2(A), 3, 4, etc., either the adhesive layer 152 or the adhesive layer 153 Either one or both may be omitted.

[0104] A protective layer 178 is preferably provided on the surface of the substrate 102. This can also be called a ceramic coating, and it prevents the touch panel 100 from being touched by a finger or stylus. The protective layer 178 has a function of protecting the surface of the substrate 102 during operation. Examples include silicon oxide, aluminum oxide, yttrium oxide, and yttria-stabilized zirconia ( The protective layer 178 can be formed by sputtering or the like. It can be formed by a sol-gel method or the like. In particular, it can be formed by using the aerosol deposition method described later. By forming the protective layer 178, a highly dense film can be formed, and the mechanical strength can be increased. This is preferable.

[0105] A method for forming a flexible touch panel will now be described.

[0106] For convenience, the components including pixels and drive circuits, and the components including optical members such as color filters are used here. Alternatively, a structure including a touch sensor will be referred to as an element layer. In addition to the display element, wiring electrically connected to the display element, transistors used in pixels and circuits The device may also include elements such as:

[0107] Here, the support having an insulating surface on which the element layer is formed is referred to as a substrate. Let's say.

[0108] As a method for forming an element layer on a substrate having a flexible insulating surface, a method for forming a layer directly on the substrate can be used. A method for forming a contact element layer and a method for forming an element layer on a support substrate having a different rigidity from the substrate. Thereafter, the element layer is peeled off from the support base material and transferred onto the base material.

[0109] If the material constituting the base material is heat resistant to the heat applied in the process of forming the element layer, It is preferable to form the element layer directly on the substrate, since this simplifies the process. When the element layer is formed in a state where the element is fixed to the support substrate, it is easy to transport the element within and between devices. This is preferable because it makes things easier.

[0110] In addition, when a method is used in which an element layer is formed on a supporting substrate and then transferred to a substrate, the supporting substrate is first A release layer and an insulating layer are laminated on the support substrate, and an element layer is formed on the insulating layer. The support substrate and the element layer are peeled off and transferred to the substrate. The material may be selected so that release occurs at the interface of the edge layer or in the release layer.

[0111] For example, a layer containing a high melting point metal material such as tungsten as a peeling layer and an oxide layer of the metal material A layer containing a silicon nitride layer or a silicon oxynitride layer is stacked on the peeling layer as an insulating layer. It is preferable to use a layer in which a plurality of high melting point metal materials are stacked. This is preferable because it increases the degree of freedom.

[0112] Peeling can be achieved by applying mechanical force, etching the peeling layer, or by breaking down the peeling interface. The peeling may be performed by dropping a liquid onto a portion of the surface and allowing it to penetrate the entire peeling interface. Alternatively, the peeling may be performed by applying heat to the peeling interface, taking advantage of the difference in thermal expansion.

[0113] Furthermore, if peeling is possible at the interface between the support substrate and the insulating layer, it is not necessary to provide a peel layer. For example, glass is used as the support substrate and an organic resin such as polyimide is used as the insulating layer. A part of the organic resin is locally heated using a laser beam or the like to form a peeling starting point. Alternatively, the separation may be performed at the interface between the glass and the insulating layer. A metal layer is provided between the edge layers, and an electric current is passed through the metal layer to heat the metal layer, The separation may be performed at the interface between the metal layer and the insulating layer. It can be used as a substrate.

[0114] Examples of flexible substrates include polyethylene terephthalate (PET), poly Polyester resins such as ethylene naphthalate (PEN), polyacrylonitrile resins, Polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethylene Polyethersulfone (PES) resin, polyamide resin, cycloolefin resin, polystyrene Resins, polyamide-imide resins, polyvinyl chloride resins, etc. In particular, the linear thermal expansion coefficient It is preferable to use a material with a low coefficient of linear thermal expansion, for example, 30 ppm / K or less. Polyamide-imide resin, polyimide resin, PET, etc. can be suitably used. Substrates made of resin-impregnated fibers (also called prepregs) and inorganic fillers mixed with organic resins are also used. It is also possible to use a substrate having a reduced linear thermal expansion coefficient.

[0115] When the above materials contain fibrous bodies, the fibrous bodies are made of high strength organic or inorganic compounds. High strength fibers are specifically fibers with high tensile modulus or Young's modulus. Representative examples include polyvinyl alcohol fibers, polyester fibers, and polyamide fibers. Mid fiber, polyethylene fiber, aramid fiber, polyparaphenylene benzobisoxide Examples of the fiber include Sasol fiber, glass fiber, and carbon fiber. Examples of glass fibers include those made from glass, S-glass, D-glass, and Q-glass. Alternatively, the fiber is used in the form of a nonwoven fabric, and the resin is impregnated into the fiber, and the resin is hardened to form a flexible structure. As a flexible substrate, a substrate made of a fiber body and a resin may be used. The use of a structure is preferable because it improves reliability against damage due to bending or local pressure. stomach.

[0116] The touch panel 100 according to one embodiment of the present invention includes a display device 1 between a pair of flexible substrates. 10 and a touch sensor 120. The sensor 120 can be disposed at the center of the thickness of the touch panel 100. As a result, the influence of bending stress that occurs when the touch panel 100 is bent is reduced. Since the bending of the device 110 and the touch sensor 120 is suppressed, defects such as breakage due to bending can be prevented. This can suppress the occurrence of such a problem, thereby realizing a highly reliable touch panel 100.

[0117] Furthermore, the touch panel 100 according to one embodiment of the present invention has a wiring of the touch sensor 120 and an FPC. The terminals for connecting the above are arranged on the substrate side on which the display device 110 is provided. Furthermore, the terminal is connected to the area where the drive circuit of the display device 110 is provided on the periphery of the touch panel. By placing the FPC in a different area from the other area, the degree of freedom in the FPC placement position can be increased. do.

[0118] The positions of FPC141, FPC142, and FPC143 are limited to the configuration shown in Figure 1. The touch panel 100 is not necessarily mounted on a single board, but can be appropriately changed to suit the shape and specifications of the housing of an electronic device or the like into which the touch panel 100 is to be incorporated. For example, as shown in FIG. 6A, an FPC electrically connected to the wiring 131 may be 142 may be arranged on the side where the FPC 143 is provided. In the example shown in FIG. 6B, the FPC 142 and the FPC 143 are individually provided. In this way, these may be integrated into one FPC 140. 142 and FPC 143 are disposed on the side of the first substrate 101 where the FPC 141 is provided. That's fine.

[0119] Note that the display device of one embodiment of the present invention is an active matrix display device having active elements in pixels. Alternatively, a passive matrix system in which pixels do not have active elements can be used.

[0120] In the active matrix system, the active element (active element, nonlinear element) is a transistor. By using not only transistors but also various active elements (active elements, nonlinear elements), For example, MIM (Metal Insulator Metal) or T It is also possible to use FD (Thin Film Diode) and other elements. Since the number of manufacturing steps is small, it is possible to reduce manufacturing costs and improve yields. Alternatively, these elements can improve the aperture ratio due to their small size. This makes it possible to achieve low power consumption and high brightness.

[0121] Other than the active matrix type, active elements (active elements, nonlinear elements) It is also possible to use a passive matrix type that does not use active elements (active elements). Since it does not use any nonlinear elements, there are fewer manufacturing steps, which reduces manufacturing costs and improves yield. Alternatively, active elements (active elements, non-linear elements) can be used. Since the aperture ratio is not increased, it is possible to achieve low power consumption or high brightness. This can be done.

[0122] [Variations] The following describes the configuration of a touch panel that is partially different from the above configuration. Explanation of the parts that overlap with the above will be omitted, and only the main differences will be explained.

[0123] FIG. 7(A) shows a schematic cross-sectional view of a touch panel exemplified below.

[0124] The configuration shown in FIG. 7(A) has a bottom emission type light emitting element and is touch sensitive. The main difference from the configuration illustrated in FIG. 2(A) is the position of the sensor.

[0125] An insulating layer 172 is provided on the first substrate 101 via an adhesive layer 192. 2, electrodes 121, 122, a dielectric layer 123, etc. constituting a touch sensor 120 are provided on the upper surface of the substrate 2. The electrodes 121, 122, and the dielectric layer 123 are bonded to the adhesive layer 191. 7A. The panel has a configuration in which a touch sensor 120 is provided between a display device 110 and a first substrate 101. It has the following characteristics.

[0126] In addition, the light emitting element 180 in FIG. 7(A) is a bottom emission type light emitting element. That is, light emitted from the light emitting element 180 is extracted to the first substrate 101 side. The color filter 184 is disposed closer to the first substrate 101 than the light emitting element 180. A) shows an example in which the insulating layer 176 is disposed between the inorganic insulating layer covering the transistor. A black matrix may be provided to cover the transistors and wiring.

[0127] The first substrate 101 is provided with an electrode 121 of the touch sensor 120 and an FPC 143 (or an electrode 122 and FPC 142) are provided with a connection terminal 156. In the area to be covered, there is no adhesive layer 191 and no structure above the adhesive layer 191, and at least As shown in FIG. 7(A), the first substrate 101 is , extending at least outward from the second substrate 102 in the direction in which the connection terminals 156 are provided. It is preferable that the thickness is elongated.

[0128] An insulating layer 173 is provided on the lower surface (the surface on the light emitting element 180 side) of the second substrate 102. The insulating layer 173 is preferably an inorganic insulating material similar to the insulating layers 171 and 172. It is preferable to use materials.

[0129] Since the first substrate 101 side is the display surface and the operation surface, the surface of the first substrate 101 is protected. A protective layer 178 is preferably provided.

[0130] As shown in FIG. 7B, the adhesive layer 19 between the first substrate 101 and the insulating layer 172 2 is not provided, and the insulating layer 172 is formed directly on the upper surface of the first substrate 101. That's fine.

[0131] The adhesive layer 191 and the adhesive layer 192 are the same as the adhesive layer 152 or the adhesive layer 153 described above. This can be configured as follows.

[0132] The configuration of the transistor and its surroundings is not limited to the configuration shown in FIG. 7, and may be the same as that shown in FIGS. The transistor structure and its surrounding insulation, such as the transistor configuration shown in A laminated structure such as a layer can be used.

[0133] The above is a description of the modified example.

[0134] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0135] (Embodiment 2) In this embodiment, an example of a method for driving a touch panel according to one embodiment of the present invention will be described with reference to the drawings. This will be explained in light of the above.

[0136] [Example of sensor detection method] FIG. 8(A) is a block diagram showing the configuration of a mutual capacitance type touch sensor. ) shows a pulse voltage output circuit 501 and a current detection circuit 502. The electrode 121 to which the pulse voltage is applied and the electrode 122 to which the change in current is detected are respectively , X1-X6, Y1-Y6 are shown as six wires each. The figure shows a capacitance 503 formed by overlapping the electrode 121 and the electrode 122. The functions of the electrodes 121 and 122 may be interchangeable.

[0137] The pulse voltage output circuit 501 is a circuit for applying a pulse voltage to the wires X1 to X6 in order. When a pulse voltage is applied to the wirings X1-X6, a current that forms a capacitance 503 is generated. An electric field is generated between the electrodes 121 and 122. The electric field generated between the electrodes is capacitively By using the change in the mutual capacitance of 503, the proximity or contact of the object to be detected is detected. It can be put out.

[0138] The current detection circuit 502 detects the change in mutual capacitance in the capacitor 503 and detects the change in the wiring of Y1 to Y6. The wiring of Y1 to Y6 detects the proximity of the object to be detected, Or, if there is no contact, the detected current value will not change, but the proximity of the object to be detected, or When the mutual capacitance decreases due to contact, a decrease in the current value is detected. The detection may be performed using an integrating circuit or the like.

[0139] In the first embodiment, the pulse voltage output circuit 501 and the current detection circuit 50 2 or both may be formed on the first substrate 101. For example, When the touch panel 111 and the driving circuit 112 are formed at the same time, the process can be simplified and the touch panel 111 and the driving circuit 112 can be formed at the same time. This is preferable because it reduces the number of components in the electronic device to which the panel 100 is applied. Either or both of the pulse voltage output circuit 501 and the current detection circuit 502 are connected to the FPC (FPC142, FPC143 (or FP)) electrically connected to the touch sensor 120 C140)) may be mounted using the COF method.

[0140] In particular, as a transistor formed on the first substrate 101, a semiconductor in which a channel is formed is When crystalline silicon such as polycrystalline silicon or single crystal silicon is used for the conductor layer, the pulse voltage The driving capability of the output circuit 501, the current detection circuit 502, and other circuits is improved, and the sensitivity of the touch sensor is improved. can be improved.

[0141] Next, FIG. 8(B) shows the input / output of the mutual capacitance type touch sensor shown in FIG. 8(A). The timing chart of the waveform is shown in Fig. 8(B). In addition, in Fig. 8(B), when no object is detected (non-touch ) and when detecting an object to be detected (touch). For the wire Y6, a waveform is shown in which the voltage value corresponds to the detected current value.

[0142] A pulse voltage is applied to the wires X1-X6 in order, and the The waveform in the Y6 wiring changes. When there is no proximity or contact of the object to be detected, X1-X6 The waveforms of Y1-Y6 change uniformly according to the change in the voltage of the wiring. Or, at the contact point, the current value decreases, and the corresponding voltage waveform also changes. do.

[0143] In this way, by detecting the change in mutual capacitance, the proximity or contact of the object to be detected can be detected. It is possible.

[0144] In addition, in FIG. 8(A), a package in which only a capacitor 503 is provided at the intersection of the wiring as a touch sensor is used. The configuration of the touch sensor of the sub-matrix type has been shown, but the An active matrix touch sensor may also be used. 1 shows an example of one sensor circuit included in the touch sensor.

[0145] The sensor circuit includes a capacitor 503, a transistor 511, a transistor 512, and a transistor The transistor 513 has a gate to which a signal G2 is applied, and a source or A voltage VRES is applied to one of the drains, and the other is connected to one electrode of the capacitor 503 and the transistor. The transistor 511 is electrically connected to the gate of the transistor 511. One is electrically connected to one of the source and drain of the transistor 512, and the other is connected to a voltage V The transistor 512 receives a signal G1 at its gate and a signal SS at its source or drain. The other electrode of the capacitor 503 is electrically connected to the wiring ML. can be obtained.

[0146] Next, the operation of the sensor circuit will be described. First, the signal G2 is output from the transistor 513. When a potential is applied to turn on the transistor 511, the gate of the transistor 511 is connected to the node A potential corresponding to the voltage VRES is applied to node n. By applying a potential that turns off 513, the potential of the node n is maintained.

[0147] Next, the mutual capacitance of the capacitor 503 changes when a detected object such as a finger approaches or touches the sensor. As a result, the potential of the node n changes from VRES.

[0148] The read operation applies a potential to the signal G1 that turns on the transistor 512. The current flowing through the transistor 511 in accordance with the potential of the node n, that is, the current flowing through the wiring ML, is By detecting this current, it is possible to detect the proximity or contact of an object to be detected. can.

[0149] The transistors 511, 512, and 513 have channels It is preferable to use a transistor in which an oxide semiconductor is used for a semiconductor layer to be formed. In addition, an oxide semiconductor is used for a semiconductor layer forming a channel of the transistor 513. This makes it possible to maintain the potential of node n for a long period of time, and VRES is applied to node n. The frequency of the resupply operation (refresh operation) can be reduced.

[0150] [Example of display device driving method] FIG. 10A is a block diagram showing an example of the configuration of a display device. indicates the gate drive circuit GD, the source drive circuit SD, and the pixel pix. ), the gate lines x_1 to x_m (m is a natural number) electrically connected to the gate drive circuit GD. the number of source lines y_1 to y_n (n is a natural number) electrically connected to the source driver circuit SD; ) are assigned symbols (1,1) to (n,m) in the pixels pix. .

[0151] Next, FIG. 10B shows the gate lines and source lines in the display device shown in FIG. 10B is a timing chart of the signal given to the The diagram shows two cases: when the data signal is rewritten and when it is not. Note that Fig. 10(B) does not take into account periods such as blanking periods.

[0152] When rewriting the data signal every frame period, the gate lines x_1 to x_m are In the horizontal scanning period 1H in which the scanning signal is at H level, A data signal D is applied to the source lines y_1 to y_n of each column.

[0153] When the data signal is not rewritten every frame period, the data signal is applied to the gate lines x_1 to x_m. In the horizontal scanning period 1H, the scanning signals for the source lines y_1 to y_n in each column are stopped. Stop giving data signals to

[0154] A driving method that does not rewrite data signals every frame period is particularly This is effective when an oxide semiconductor is used as a transistor in a semiconductor layer where a channel is formed. Transistors that use oxide semiconductors are different from transistors that use semiconductors such as silicon. Therefore, the off-state current can be reduced significantly compared to that of the conventional photodiode. The data signal written in the previous period is retained without being rewritten in each period. For example, the gradation of a pixel can be maintained for 1 second or more, preferably 5 seconds or more. do.

[0155] In addition, polycrystalline silicon is used in the semiconductor layer in which the channel is formed as a transistor included in the pixel. When applying this technology, it is necessary to increase the size of the storage capacitance of the pixel in advance. The larger the storage capacitance, the longer the grayscale of the pixel can be maintained. The size of the storage capacitor depends on the leakage current of the transistor and display element electrically connected to the storage capacitor. It can be set according to the current, but for example, the storage capacitance per pixel should be between 5fF and 5pF. , preferably 10 fF or more and 5 pF or less, and more preferably 20 fF or more and 1 pF or less. The data signal is not rewritten for each frame period, and the data signal written in the previous period is The signal can be held for example over a period of several frames or several tens of frames. It is possible to maintain the gradation.

[0156] [Example of display device and touch sensor driving method] 11A to 11D show an example of the touch sensor described in FIGS. 8A and 8B. When the display device described in FIGS. 10(A) and 10(B) is driven for 1 second, 11A is a diagram illustrating the operation of a display device during successive frame periods. The frame period of the touch sensor is set to 16.7 ms (frame frequency: 60 Hz). The frame period is set to 16.7 ms (frame frequency: 60 Hz). .

[0157] In the touch panel of this embodiment, the operations of the display device and the touch sensor are independent of each other. Therefore, the touch detection period can be set in parallel with the display period. As shown in the figure, one frame period of both the display device and the touch sensor is set to 16.7 ms (frame The frame frequency of the touch sensor and the display device can be set to 60Hz. For example, as shown in FIG. 11B, in one frame period of the display device, is set to 8.3 ms (frame frequency: 120 Hz), and one frame period of the touch sensor It is also possible to set the frame rate to 16.7 ms (frame frequency: 60 Hz). The frame frequency of the display device may be set to 33.3 ms (frame frequency: 30 Hz). .

[0158] The display device is also configured to be switchable in frame frequency, so that the frame rate can be adjusted when displaying moving images. Increase the frame rate (for example, 60Hz or higher or 120Hz or higher) to minimize the effect of static image display. In this case, reduce the frame frequency (for example, 60Hz or less, 30Hz or less, or 1Hz or less). ) can reduce the power consumption of the display device. The frequency can be switched between standby and when a touch is detected. They may be different.

[0159] The touch panel of the present embodiment also allows rewriting of data signals in the display device. By holding the data signal rewritten in the previous period without performing the above operation, the display device can Therefore, as shown in Figure 11(C), As shown in the figure, the frame period of the display device is set to 1 sec. (frame frequency: 1 Hz), and the timing The frame period of the touch sensor can be set to 16.7 ms (frame frequency: 60 Hz). can.

[0160] Furthermore, when the touch panel of this embodiment is driven as shown in FIG. 11(C), Therefore, as shown in FIG. 11(D), the touch sensor can be driven continuously. When the touch sensor detects the proximity or contact of an object to be detected, the data on the display device is It is also possible to rewrite the data signal.

[0161] Here, the data signal of the display device is rewritten during the sensing period of the touch sensor. When the display device is driven, noise is transmitted to the touch sensor, causing the Therefore, it is necessary to rewrite the data signal of the display device. It is preferable to drive the touch sensor so that the period is shifted from the sensing period of the touch sensor.

[0162] In FIG. 12A, the rewriting of the data signal of the display device and the sensing of the touch sensor are performed. 12B shows an example in which the rewriting of the data signal of the display device is performed alternately. This example shows that the touch sensor performs sensing once for every two touch actions. This is not limited to this, but the touch sensor sensing is performed once every three or more rewrite operations. The following configuration may also be used.

[0163] In addition, a transistor used in a pixel of a display device has a semiconductor layer in which a channel is formed. When an oxide semiconductor is used, the off-state current can be significantly reduced. The frequency of rewriting can be sufficiently reduced. After the data signal is written, a sufficiently long pause can be provided before the data signal is rewritten. The pause period can be, for example, 0.5 seconds or more, 1 second or more, or 5 seconds or more. The upper limit of the pause period is determined by the capacitance connected to the transistor and the leakage current of the display element, etc. For example, it may be limited to 1 minute or less, 10 minutes or less, 1 hour or less, or 1 day or less. It is possible.

[0164] FIG. 12C shows an example in which the data signal of the display device is rewritten once every five seconds. In FIG. 12(C), the display device rewrites the data signal and then writes the next data signal. A pause period is provided during which the operation is stopped until the rewrite operation. The touch sensor operates at a frame frequency of iHz (i is the frame frequency of the display device or higher, here 0 As shown in Figure 12(C), the touch sensor The sensing is performed during the rest period and not during the period when the data signal of the display device is rewritten. This is preferable because it is possible to improve the sensitivity of the touch sensor. As shown in the figure, the data signal of the display device is rewritten and the touch sensor is sensed at the same time. This allows the driving signals to be simplified.

[0165] In addition, during the pause period when the data signal of the display device is not rewritten, the signal to the drive circuit is It is possible to stop the supply of only the signal, or to stop the supply of the power supply potential in addition to this. Power consumption can be reduced.

[0166] As described in Embodiment 1, the touch panel of one embodiment of the present invention has two flexible The display device and the touch sensor are sandwiched between the substrates, and the distance between the display device and the touch sensor is In this case, noise generated when the display device is driven is transmitted to the touch sensor. This may cause a decrease in the sensitivity of the touch sensor. By applying the driving method exemplified in , it is possible to create a touch panel that is both thin and highly sensitive. It can be achieved.

[0167] (Embodiment 3) In this embodiment, an example of a structure and a driving method of a touch panel according to one embodiment of the present invention will be described. , will be explained with reference to the drawings.

[0168] [Touch panel configuration] FIG. 13 is a block diagram showing an example of the configuration of a touch panel exemplified below. As shown in the figure, the touch panel 80 includes a display device 800, a control circuit 810, a counter circuit 820, It has a touch sensor 850.

[0169] The touch panel 80 receives an image signal (Video) which is digital data, and a display device. A synchronization signal (SYNC) is input to control the rewriting of the screen of the device 800. Examples of signals include a horizontal synchronization signal (Hsync), a vertical synchronization signal (Vsync), and There is a reference clock signal (CLK), etc.

[0170] The display device 800 includes a display unit 801, a gate driver 802, and a source driver 803. The display unit 801 has a plurality of pixels PIX. The pixels PIX in the same row are shared The gate line L_X is connected to the gate driver 802, and the pixels PIX in the same column are connected to a common It is connected to the source driver 803 by a source line L_Y.

[0171] The display device 800 has a high level potential (VH), a low level potential (VL), and a power supply High power supply potential (VDD) and low power supply potential (VSS) are supplied as potentials. The potential (VH) is supplied to each pixel PIX of the display unit 801 via the wiring L_H. The low level potential (VL) is supplied to each pixel PIX of the display unit 801 via the wiring L_L. will be done.

[0172] The source driver 803 processes the input image signal, generates a data signal, and outputs the source signal. The gate driver 802 outputs a data signal to the line L_Y. A scanning signal for selecting the pixel PIX is output to the gate line L_X.

[0173] The pixel PIX is a switch whose electrical connection with the source line L_Y is controlled by a scanning signal. When the switching element is turned on, a current flows from the source line L_Y to the pixel PIX. The data signal is written.

[0174] The control circuit 810 is a circuit that controls the entire touch panel 80. It includes a circuit for generating control signals for the constituent circuits.

[0175] The control circuit 810 controls the gate driver 802 and the source driver 803 from the synchronization signal (SYNC). The gate driver 802 has a control signal generating circuit that generates a control signal for the gate driver 803. The control signals include a start pulse (GSP) and a clock signal (GCLK). The control signals for the switch driver 803 are a start pulse (SSP), a clock signal (SCL For example, the control circuit 810 may generate clock signals (GCLK, SCLK) , generate multiple clock signals with the same period but shifted phases.

[0176] The control circuit 810 also receives an image signal (Video ) to the source driver 803.

[0177] The control circuit 810 also controls the sensor signal (S_touch) input from the touch sensor 850. ch) is input, and the image signal is corrected according to the sensor signal. Although it differs depending on the sensor signal, image processing according to the touch is performed.

[0178] The source driver 803 is connected to a digital / analog conversion circuit 804 (hereinafter referred to as a DA conversion circuit The DA conversion circuit 804 converts the image signal into an analog signal. Generates a time signal.

[0179] If the image signal input to the touch panel 80 is an analog signal, the control circuit The signal is converted into a digital signal at 810 and output to a display device 800 .

[0180] The image signal is made up of image data for each frame. The control circuit 810 processes the image data. Based on the information obtained from this processing, the output of the image signal to the source driver 803 is controlled. Therefore, the control circuit 810 processes the image data to generate a frame image. The motion detector 811 detects motion from image data for each object. In this case, the image signal is corrected based on the image data according to the sensor signal. .

[0181] When the motion detector 811 determines that there is motion, the control circuit 810 On the other hand, if it is determined that there is no movement, the control circuit 810 stops the output of the image signal to the source driver 803. If there is any movement again, If so, the output of the image signal is resumed.

[0182] The control circuit 810 determines whether or not a moving image is displayed (moving image display) based on the determination of the motion detection unit 811. The first mode is for displaying a still image (a moving image), and the second mode is for displaying a still image (a moving image). The display on the display unit 801 can be controlled by switching between two modes. For example, if the vertical synchronization signal (Vsync) is 60Hz, the frame frequency must be set to 60Hz or less. The second mode is a mode in which the vertical synchronization signal (Vsync) is 60 Hz, this is a mode in which the frame frequency is less than 60 Hz.

[0183] In the second mode, the frame frequency is set in advance according to the voltage holding characteristics of the pixel. For example, if the motion detection unit 811 determines that there is no motion for a certain period of time, When the output of the image signal to the source driver 803 is stopped, the pixel PIX is written Therefore, the voltage corresponding to the gradation of the image signal will decrease. The voltage corresponding to the gray level is written (refreshed) at each frame frequency cycle. This refresh timing (also called refresh rate) is desirable. For example, the counter circuit 820 counts the H level of the vertical synchronization signal (Vsync) It may be configured to perform the counting at regular intervals based on the signal obtained by counting.

[0184] When the refresh rate is set to once per second by the counter circuit 820, If the frequency of the vertical sync signal (Vsync) is 60Hz, Based on the count signal (Count) obtained by counting the H level 60 times, the refresh If the refresh rate is set to once every 5 seconds, the vertical sync signal If the frequency of the vertical sync signal (Vsync) is 60Hz, The refresh rate is calculated based on the count signal (Count) obtained by counting the bell 300 times. The counter circuit 820 may also receive a sensor signal from the touch sensor 850. When a signal is input, the second mode is forcibly changed to the first mode in response to the sensor signal. A switchable configuration may also be used.

[0185] There are no particular restrictions on the image processing for motion detection performed by the motion detection unit 811. For example, a motion detection method may be to use the difference between image data of two consecutive frames. There is a way to obtain minute data. The difference data obtained can be used to determine whether there is movement or not. There are also methods for detecting motion vectors.

[0186] The touch sensor 850 can apply the operation and structure described in the above embodiment. do.

[0187] In this embodiment, the operation of the display device and the operation of the touch sensor 850 are independent of each other. Therefore, the touch sensing period can be set in parallel with the display period. Therefore, even if the control circuit 810 is configured to switch between the first mode and the second mode, The operation of the display device 800 and the touch sensor 85 can be controlled independently. 0, and the rewriting operation of the data signal of the display device 800 and the touch sensor 850 are synchronized. By performing the sensing operations at different periods, the sensitivity of the sensing can be increased.

[0188] [Pixel configuration example] 14A is a circuit diagram showing an example of the configuration of a pixel PIX. It includes TR1, a transistor TR2, a light-emitting element EL, and a capacitance element CAP.

[0189] The transistor TR1 is electrically connected to the source line L_Y and the gate of the transistor TR2. The transistor TR1 functions as a switching element to control the The transistor TR2 is turned on and off by a detection signal. It functions as a switching element for controlling

[0190] The transistors TR1 and TR2 each have a semiconductor layer in which a channel is formed. It is preferable to use an oxide semiconductor or polycrystalline silicon for the insulating layer.

[0191] The light-emitting element EL has an EL layer containing a light-emitting organic compound sandwiched between two electrodes. The brightness of the light emitted from the light-emitting element changes depending on the current flowing between the two electrodes. One electrode of the transistor is given a low level potential from the wiring L_L, and the other electrode of the transistor is given a low level potential from the wiring L_L. A high level potential is applied from the line L_H via TR2.

[0192] The capacitance element CAP has a function of holding the potential of the gate of the transistor TR2.

[0193] FIG. 14B shows an example of a pixel PIX having a liquid crystal element. It has a capacitor TR, a liquid crystal element LC, and a capacitor element CAP.

[0194] The transistor TR controls the electrical connection between one electrode of the liquid crystal element LC and the source line L_Y. It is a switching element that controls the on / off state by the scanning signal input from its gate. To be controlled.

[0195] Note that the transistor TR has a semiconductor layer in which a channel is formed, which is made of an oxide semiconductor or Preferably, polycrystalline silicon is applied.

[0196] The liquid crystal element LC has two electrodes and liquid crystal. The liquid crystal is induced by the action of an electric field between these two electrodes. The orientation changes depending on the application of the transistor TR. One electrode connected to the source line L_Y corresponds to the pixel electrode, and Vcom is applied to it. The other electrode connected to the common line L_com corresponds to the common electrode.

[0197] The capacitance element CAP is connected in parallel with the liquid crystal element LC. The electrode of the capacitor is connected to the source or drain of the transistor TR, and the other electrode of the capacitor is connected to the capacitor line. It is connected to a capacitance line L_cap to which a voltage is applied.

[0198] Here, examples in which a liquid crystal element LC or a light-emitting element EL is used as a display element will be described. However, one aspect of the present invention is not limited thereto.

[0199] For example, in this specification, a display element, a display device which is a device having a display element, a light-emitting device, A light-emitting device, which is a device having an element and a light-emitting element, can be used in various forms or in various Examples of a display element, a display device, a light-emitting element, or a light-emitting device include is an EL (electroluminescence) element (EL element including organic and inorganic materials, organic EL EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc. etc.), transistors (transistors that emit light according to the current), electron-emitting elements, liquid crystal elements, Electronic ink, electrophoretic element, grating light valve (GLV), plasma display ray (PDP), MEMS (Micro-Electro-Mechanical Systems) based display Display element, Digital Micromirror Device (DMD), DMS (Digital Micromirror Scatter), MIRASOL (registered trademark), IMOD (Interference Module shutter-type MEMS display element, optical interference-type MEMS display element, Electrowetting elements, piezoelectric ceramic displays, carbon nanotubes, Displays whose contrast, brightness, reflectance, transmittance, etc. change due to electromagnetic effects, such as An example of a display device using an EL element is an EL display. An example of a display device using electron-emitting devices is a field emission device. Flat panel display (FED) or SED type flat panel display (SED: Surface-c Induction Electron-emitter Display An example of a display device using a liquid crystal element is a liquid crystal display (transmissive liquid crystal display). Transflective LCD displays, reflective LCD displays, direct-view LCD displays, projection LCD displays A type of display device that uses electronic ink or electrophoretic elements. Examples include electronic paper. When realizing a display, part or all of the pixel electrodes function as reflective electrodes. For example, a part or the whole of the pixel electrode may be made of aluminum. In this case, the reflective electrode may have a metal such as SRAM. This allows further reduction in power consumption. can be done.

[0200] [Touch panel driving method example] Hereinafter, the first mode for displaying moving images and the second mode for displaying still images will be explained using the timing chart shown in FIG. The operation of touch panel 80 for displaying in the second mode for displaying still images will now be described. 5, a vertical synchronization signal (Vsync) and a source line L_Y from the source driver 803. 1 shows the signal waveform of the data signal (Vdata) output to

[0201] FIG. 15 shows an example of a case where a moving image is displayed, then a still image is displayed, and then a moving image is displayed again. 10 is a timing chart of the touch panel 80. Here, the timing chart is from the first frame to the kth frame. Assume that there is motion in the image data up to the first frame. Then, from the (k+1)th frame to the (k+3)th frame, Assume that there is no movement in the image data up to the (k+4)th frame. The image data is assumed to contain motion, where k is an integer greater than or equal to 2.

[0202] During the first moving image display period, the motion detector 811 detects motion in the image data of each frame. Therefore, the touch panel 80 operates in the first mode. In 10, the frame frequency is set to be equal to or higher than the vertical sync signal frequency, here frame frequency f1. Then, the image signal (Video) is output to the source driver 803. The output of the data signal (Vdata) to the source line L_Y is continuously performed by the output of the data signal (Vdata). The length of one frame period during the moving image display period is expressed as 1 / f1 (seconds).

[0203] Next, during the still image display period, the motion detection unit 811 performs image processing for motion detection. Therefore, it is determined that there is no movement in the image data of the (k+1)th frame. 0 operates in the second mode. The control circuit 810 controls the frame frequency to The frequency is less than the frame frequency f2 in this case, and is output to the source driver 803. The source driver 803 controls the output of the data signal (Vdata) to the source line L_Y. The length of one frame period during the still image display period is 1 / f2 (seconds) )

[0204] The source driver 803 can output the data signal (Vdata) intermittently. Therefore, the control signal (start pulse) to the gate driver 802 and the source driver 803 The gate driver 8 may also be supplied intermittently with the gate driver 8 (signal, clock signal, etc.). 02 and source driver 803 can be stopped.

[0205] In the second mode, the data signal (Vdata) is intermittently output to the source line L_Y. As an example, as shown in FIG. At this point, the control circuit 810 controls the gate driver 802 and the source driver 803. The image signal VIDE is output to the source driver 803 at a frame frequency of f2. The source driver 803 outputs the data signal written in the previous period, i.e., In the k-th frame, the data signal (k_data) output to the source line L_Y is In this way, during the still image display period, the data written in the previous period is output to the line L_Y. A signal (k_data) is repeatedly written to the source line L_Y every period 1 / f2 (seconds). Therefore, it is possible to refresh the voltage corresponding to the gradation of the image signal of the same image. By refreshing periodically, the gray scale deviation caused by the voltage drop can be reduced. Flicker can be reduced, resulting in a touch panel with improved display quality. do.

[0206] Then, in the control circuit 810, the motion detection unit 811 determines that there is motion in the image data. The system operates in the second mode until a result is obtained or a sensor signal is input.

[0207] Then, the motion detector 811 detects motion in the image data from the (k+4)th frame onwards. If it is determined that the touch panel 80 is in the first mode, the control circuit 810 operates in the first mode again. So, let's set the frame frequency to be equal to or higher than the vertical sync signal frequency, here frame frequency f1. , and outputs an image signal (Video) to the source driver 803. 03 is to continuously output the data signal (Vdata) to the source line L_Y. .

[0208] As described in Embodiment 1, the touch panel of one embodiment of the present invention has two flexible The display device and the touch sensor are sandwiched between the substrates, and the distance between the display device and the touch sensor is In this case, noise generated when the display device is driven is transmitted to the touch sensor. This may cause a decrease in the sensitivity of the touch sensor. By applying the driving method exemplified in , it is possible to create a touch panel that is both thin and highly sensitive. It can be achieved.

[0209] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0210] (Fourth embodiment) In this embodiment, a protective film or the like is aerosol-deposited on the surface of a member such as the touch panel. An example of film formation by the deposition method is shown below.

[0211] Aerosol deposition (AD) is a method for depositing films without heating the substrate. An aerosol is a small particle dispersed in a gas.

[0212] FIG. 16(A) shows an example of the cross-sectional structure of a film forming apparatus for forming a film using an aerosol.

[0213] The film forming apparatus includes a chamber 53 and a film-forming object (for example, a substrate) placed in the chamber 53. a stage 59 for holding the plate 60, etc., and a pump (mechanical pump) for evacuating the chamber 53. an exhaust device 55 such as a mechanical booster pump, a rotary pump, etc., and a spraying means (such as nozzle 56), a raw material container 63 connected to the spraying means via a supply line, It has at least a gas line for introducing a carrier gas and a gas tank 51. .

[0214] First, the raw material powder in the raw material container 63 is vibrated (by ultrasonic waves, etc.) by the vibrator 62. In addition, the moisture in the raw material container 63 is removed by heating, and the moisture is released through the exhaust line. The air is exhausted by an exhaust device 54 .

[0215] Next, a carrier gas is introduced into the raw material container 63 via a gas line to aerosolize the raw material powder. The carrier gas can be dry air, oxygen, inert gas (nitrogen, helium gas, The flow rate of the carrier gas is adjusted by a flow meter 52. can.

[0216] In the chamber 53, which has been decompressed by the exhaust device 55, inorganic fine particles (50 nm or more) The aerosol containing the particles (500 nm or less) is ejected from the nozzle 56 and sprayed onto the substrate 60. The aerosol is solidified by impacting the particles to form an inorganic material layer on the surface of the substrate 60. The film formation method that can form the film is called the AD method. The beam impinges on the object to be coated (such as the substrate 60) at a certain incident angle θ (θ=0° or more and 90° or less). The positions of the object to be film-formed (for example, the substrate 60) and the nozzle 56 are appropriately set so that the object is projected. As the incident angle increases, the impact force when the particles collide with the surface of the substrate 60 increases. On the other hand, when the incident angle becomes smaller, the impact force of the particles on the surface of the substrate 60 becomes smaller. Depending on the material of the particles used, the film formation object (e.g., substrate) The optimum incident angle θ for ejecting the aerosol may differ depending on the It is important to appropriately set the incident angle θ.

[0217] In the device of FIG. 16(A), an example is shown in which the incident angle θ is fixed by angle adjusting means 61. However, there is no particular limitation. The nozzle is fixed and the angle of the stage 59 can be changed as needed. It may also be configured as a stationary configuration.

[0218] 16(B) shows an enlarged perspective view of the tip of the nozzle 56. Although a small nozzle opening 57 is shown in the figure, it is not particularly limited, and a nozzle having a plurality of nozzle openings may be used. may also be used.

[0219] In addition, a mask having an opening is placed between the nozzle 56 and the substrate 60 to selectively form a film. Also, the driving device 58 that moves the stage 59 in the X direction or the Y direction can be used. Therefore, the substrate 60 can be moved in the X or Y direction to form a film over a wide area. .

[0220] The fine particles used in the AD method include aluminum oxide, yttrium oxide, and aluminum nitride. Examples of suitable inorganic materials include aluminum, silicon carbide, silicon nitride, and titanium oxide.

[0221] By using the aerosol deposition (AD) method, it is possible to form a resin substrate or an organic material layer on the surface. The aerosol deposition (AD) method allows deposition of fine particles on a substrate at low temperatures such as room temperature. After impacting the substrate surface, the particles undergo plastic deformation and may be crushed and pressed onto the substrate. The particles are kicked up and adhere to the surface, and as this phenomenon is repeated, the film grows.

[0222] In this embodiment, a film formed by, for example, an aerosol deposition method is used as the touch panel. It can be used for the protective layer 178 applied to the surface of the substrate on the touch sensor side of the panel 100. For example, a 10 mm thick film can be deposited on an aramid film by aerosol deposition. An aluminum oxide film having a thickness of 0 nm to 200 nm is formed as the protective layer 178. The film obtained by the sol deposition method is dense, and fine particles are formed on the film surface at the same time as the film is formed. This provides a protective film with strong adhesion.

[0223] (Embodiment 5) In this embodiment, an electronic device that can be manufactured by using a touch panel according to one embodiment of the present invention will be described. This will be explained with reference to FIGS. 17 and 18.

[0224] Examples of electronic devices include television sets (also known as televisions or television receivers). (hereinafter referred to as "computer monitors"), digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game consoles, Examples include portable information terminals, audio playback devices, and large game machines such as pachinko machines.

[0225] Furthermore, since the device according to one embodiment of the present invention is flexible, it can be applied to the interior or exterior walls of houses or buildings, Alternatively, it may be incorporated along the curved surfaces of the interior or exterior of the vehicle.

[0226] FIG. 17A shows an example of a mobile phone. The mobile phone 7400 has a housing 740 1, in addition to the display unit 7402, operation buttons 7403, and external connection port 7404 , a speaker 7405, a microphone 7406, etc. A display device manufactured according to one embodiment of the present invention is used for the display portion 7402. According to one aspect of the present invention, a highly reliable mobile phone having a curved display is provided. It can be provided with good yield.

[0227] In the mobile phone 7400 shown in FIG. 17A, when a user touches the display portion 7402 with a finger or the like, You can also make calls, enter text, and perform other functions. The operation can be performed by touching the display portion 7402 with a finger or the like.

[0228] In addition, by operating the operation button 7403, the power can be turned on and off, and the display unit 7402 For example, from the email creation screen, you can change the type of image displayed. You can switch to the main menu screen.

[0229] FIG. 17B shows an example of a wristwatch-type portable information terminal. The watch includes a housing 7101, a display unit 7102, a band 7103, a buckle 7104, and an operation button 7 105, input / output terminal 7106, etc.

[0230] The mobile information terminal 7100 is capable of performing functions such as mobile phone calls, e-mails, document viewing and creation, music playback, internet It can run various applications such as internet communication and computer games. Cut.

[0231] The display surface of the display unit 7102 is curved, and displays information along the curved display surface. The display portion 7102 is provided with a touch sensor, and the screen can be touched with a finger or a stylus. For example, the icon 7 displayed on the display unit 7102 can be operated by touching it. You can launch the application by touching 107.

[0232] The operation button 7105 is used to set the time, turn the power on and off, and turn wireless communication on and off. It has various functions such as auto-start, silent mode activation and deactivation, power saving mode activation and deactivation, etc. For example, an operation system built into the mobile information terminal 7100 can be The function of the operation button 7105 can also be freely set using the stem.

[0233] In addition, the mobile information terminal 7100 is capable of performing short-distance wireless communication according to a communication standard. For example, by communicating with a wireless headset, hands-free You can also make calls.

[0234] The portable information terminal 7100 also has an input / output terminal 7106, and can be connected to other information terminals via a connector. Data can be exchanged directly through the input / output terminal 7106. The charging operation can be performed by wireless power supply without going through the input / output terminal 7106. You may go.

[0235] The display portion 7102 of the portable information terminal 7100 is provided with a display device manufactured by applying one embodiment of the present invention. According to one aspect of the present invention, a display device having a curved display and high reliability is provided. This makes it possible to provide high-quality portable information terminals with a high yield.

[0236] FIG. 17C shows an example of a portable display device. 7301, display unit 7302, operation button 7303, drawer member 7304, control unit 730 Equipped with 5.

[0237] The display device 7300 is a flexible display device wound in a roll in a cylindrical housing 7301. It has a part 7302.

[0238] The display device 7300 can receive a video signal through the control unit 7305, and can display the received video signal. The image can be displayed on the display unit 7302. The control unit 7305 is equipped with a battery. In addition, a terminal section for connecting a connector to the control section 7305 is provided, and a video signal and power are transmitted. It may also be configured to be supplied directly from the outside via a line.

[0239] In addition, the operation button 7303 can be used to turn the power on and off and to switch the displayed image. It is possible to carry out such tasks.

[0240] FIG. 17D shows a state in which the display unit 7302 is pulled out by the pull-out member 7304. In this state, an image can be displayed on the display unit 7302. The operation button 7303 arranged on the surface of the housing 7301 allows for easy operation with one hand. 17C, the operation button 7303 can be attached to the center of the housing 7301. By placing it to one side, it can be easily operated with one hand.

[0241] When the display unit 7302 is pulled out, the display surface of the display unit 7302 is flat. To fix the display portion 7302, a frame for reinforcing the display portion 7302 may be provided on the side of the display portion 7302.

[0242] In addition to this configuration, a speaker is provided on the housing, and the audio signal received together with the video signal is output. The configuration may be such that sound is output.

[0243] 18(A) to 18(C) show a foldable mobile information terminal 310. 18(B) shows the portable information terminal 310 in the unfolded state. The mobile information terminal 310 is shown in a state in which it is changing from one folded state to the other. Fig. 3C) shows the portable information terminal 310 in a folded state. When folded, it is highly portable, and when unfolded, it has a seamless, wide display area for easy viewing. Excellent overview.

[0244] The display panel 312 is supported by three housings 315 connected by hinges 313. The two housings 315 are bent via the hinge 313, and the portable information terminal 3 10 can be reversibly transformed from the unfolded state to the folded state. A display device manufactured according to one embodiment can be used for the display panel 312. For example, A display device that can be bent with a curvature radius of 1 mm or more and 150 mm or less can be applied.

[0245] 18(D) and (E) show a foldable mobile information terminal 320. 1 shows the portable information terminal 320 in a folded state with the display unit 322 facing outward. 8(E), the portable information terminal 320 is folded so that the display unit 322 faces inward. When the mobile information terminal 320 is not in use, the non-display section 325 can be folded outward. This can prevent the display portion 322 from being soiled or scratched. The device can be used for the display unit 322 .

[0246] Fig. 18(F) is a perspective view illustrating the external shape of the mobile information terminal 330. 18(H) is a top view of the portable information terminal 330. FIG. 18(H) is a top view of the portable information terminal 340. FIG.

[0247] The portable information terminals 330 and 340 are selected from, for example, telephones, notebooks, information viewing devices, etc. It has one or more functions. Specifically, it can be used as a smartphone. can.

[0248] The mobile information terminals 330 and 340 can display text and image information on multiple surfaces. For example, three operation buttons 339 can be displayed on one surface (see FIG. 18(F)). (H)). Also, information 337 shown in the dashed rectangle can be displayed on another surface (see FIG. 18). (G), (H)). Examples of information 337 include email and social media (SNS). Displays to notify you of incoming calls, e-mails, SNS, etc. The subject, sender name of email or SNS, date and time, time, remaining battery level, antenna Or, instead of information 337, Alternatively, operation buttons 339, icons, etc. may be displayed. Although an example in which information 337 is displayed on the upper side has been shown, one aspect of the present invention is not limited to this. For example, as shown in FIG. 18(H), the mobile information terminal 340 is displayed on the side. Good too.

[0249] For example, the user of the mobile information terminal 330 may store the mobile information terminal 330 in a breast pocket of his / her clothes. When the item is stored, the display (information 337 in this example) can be confirmed.

[0250] Specifically, the telephone number or name of the caller of the incoming call is displayed on the mobile information terminal 330. The user takes the mobile information terminal 330 out of his pocket and You can check the display and decide whether to answer the call without having to turn your phone over.

[0251] The housing 335 of the portable information terminal 330 and the housing 336 of the portable information terminal 340 each have A display device manufactured according to one embodiment of the present invention can be used for the display portion 333. According to one embodiment of the present invention, a display device having a curved display portion and high reliability can be manufactured with high yield. It can be provided well.

[0252] In addition, even if information is displayed on three or more screens, as in the case of a portable information terminal 345 shown in FIG. 18(I), Here, information 355, information 356, and information 357 are displayed on different surfaces. Here is an example:

[0253] One embodiment of the present invention is applied to a display portion 358 included in a housing 351 of a portable information terminal 345. According to one embodiment of the present invention, a display device having a curved display portion can be used. This makes it possible to provide highly reliable display devices with a high yield.

[0254] The touch panel of one embodiment of the present invention can be applied to the display portion of the electronic device described above. Therefore, electronic devices can be made thinner, lighter, and more multifunctional, while also achieving high detection sensitivity. The electronic device can be realized in this way.

[0255] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination.

[0256] (Sixth embodiment) In this embodiment, a semiconductor layer of a semiconductor device that can be used for a display panel of one embodiment of the present invention An oxide semiconductor that can be suitably used will be described.

[0257] Oxide semiconductors have a large energy gap of 3.0 eV or more, making them suitable for The oxide semiconductor film obtained by processing under suitable conditions and sufficiently reducing the carrier density is applied. In the transistors using this material, the off-state current is It can be made extremely low.

[0258] As applicable oxide semiconductors, at least indium (In) or zinc (Zn ) is preferably contained. In particular, it is preferably contained In and Zn. As a stabilizer to reduce the variation in the electrical characteristics of transistors using In addition to gallium (Ga), tin (Sn), hafnium (Hf), and zirconium (Zr) , titanium (Ti), scandium (Sc), yttrium (Y), lanthanides (e.g. , cerium (Ce), neodymium (Nd), gadolinium (Gd), or It is preferable that one or more types are contained.

[0259] For example, oxide semiconductors include indium oxide, tin oxide, zinc oxide, and In-Zn oxide. compounds, Sn-Zn oxides, Al-Zn oxides, Zn-Mg oxides, Sn-Mg acids oxides, In-Mg oxides, In-Ga oxides, In-Ga-Zn oxides (IGZO (also written as In-Al-Zn oxide, In-Sn-Zn oxide, Sn-Ga- Zn-based oxide, Al-Ga-Zn-based oxide, Sn-Al-Zn-based oxide, In-Hf-Z n-based oxides, In-Zr-Zn-based oxides, In-Ti-Zn-based oxides, In-Sc-Zn In-Y-Zn oxide, In-La-Zn oxide, In-Ce-Zn oxide oxides, In-Pr-Zn oxides, In-Nd-Zn oxides, In-Sm-Zn oxides In-Eu-Zn oxides, In-Gd-Zn oxides, In-Tb-Zn oxides , In-Dy-Zn oxide, In-Ho-Zn oxide, In-Er-Zn oxide, In-Tm-Zn oxide, In-Yb-Zn oxide, In-Lu-Zn oxide, I n-Sn-Ga-Zn oxide, In-Hf-Ga-Zn oxide, In-Al-Ga- Zn-based oxides, In-Sn-Al-Zn-based oxides, In-Sn-Hf-Zn-based oxides, I n-Hf-Al-Zn oxides can be used.

[0260] Here, the In-Ga-Zn oxide is an oxide having In, Ga, and Zn as its main components. The ratio of In, Ga, and Zn does not matter. The metal elements may be included.

[0261] In addition, as an oxide semiconductor, InMO3(ZnO) m (m>0 and m is not an integer ) may be used, where M is selected from Ga, Fe, Mn and Co. It indicates one or more metal elements, or the above-mentioned stabilizer elements. In addition, as an oxide semiconductor, In2SnO5(ZnO) n (n>0 and n is an integer) Materials expressed as follows may also be used.

[0262] For example, In:Ga:Zn=1:1:1, In:Ga:Zn=1:3:2, In:Ga :Zn=1:3:4, In:Ga:Zn=1:3:6, In:Ga:Zn=3:1:2A Or In-Ga-Zn oxide with an atomic ratio of In:Ga:Zn=2:1:3 and its composition It is preferable to use an oxide in the vicinity of

[0263] When a large amount of hydrogen is contained in the oxide semiconductor film, the hydrogen is bonded to the oxide semiconductor. Some of the elements become donors and generate electrons, which are carriers. Therefore, the threshold voltage of the oxide semiconductor film is shifted in the negative direction. After that, dehydration treatment (dehydrogenation treatment) is performed to remove hydrogen or moisture from the oxide semiconductor film. It is preferable to remove impurities to achieve high purity so that the impurities are not included as much as possible.

[0264] Note that dehydration treatment (dehydrogenation treatment) of the oxide semiconductor film Oxygen may also decrease at the same time. A process of adding oxygen to an oxide semiconductor film to compensate for oxygen vacancies increased by the oxidation treatment. In this specification and the like, when oxygen is supplied to an oxide semiconductor film, Alternatively, oxygen contained in the oxide semiconductor film may be added to the oxide semiconductor film in a stoichiometric manner. When the amount of oxygen used is greater than the amount of oxygen used, it is sometimes referred to as hyperoxygenation treatment.

[0265] In this way, the oxide semiconductor film is dehydrated by dehydration treatment (dehydrogenation treatment). By removing oxygen and filling the oxygen vacancies through oxygen addition treatment, the i-type (intrinsic) or The oxide semiconductor film can be an oxide semiconductor film that is very close to i-type and is substantially i-type (intrinsic). Note that the term "substantially intrinsic" means that the carrier density of the oxide semiconductor layer is 1×10 17 / cm 3 less than Preferably 1 x 10 15 / cm 3 More preferably, it should be less than 1×1 0 13 / cm 3 less than 8 × 10 11 / cm 3 less than 1 x10 11 / cm 3 less than 1×10 10 / cm 3 Less than 1 x 10 -9 / cm 3 It means that it is more than that.

[0266] In addition, a transistor including an i-type or substantially i-type oxide semiconductor film can be For example, a transistor using an oxide semiconductor film can be The drain current when the capacitor is off is 1×10 at room temperature (approximately 25°C). -18 Below A, Preferably 1 x 10 -21 A or less, more preferably 1×10 -24 A or below, or 85 1 x 10 at °C -15 A or less, preferably 1×10 -18 A or less, more preferably 1x 10 -21 A or less. Note that the transistor being in the off state is an n-channel In the case of a transistor of this type, this refers to a state in which the gate voltage is sufficiently smaller than the threshold voltage. In general, if the gate voltage is 1V or more, 2V or more, or 3V or more less than the threshold voltage, , the transistor is turned off.

[0267] The structure of the oxide semiconductor film will be described below.

[0268] In this specification, "parallel" means that two straight lines are at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Almost parallel" means that two straight lines are arranged at an angle of between -30° and 30°. "Perpendicular" means that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, it also includes the case where the angle is between 85° and 95°. This refers to a state in which two straight lines are arranged at an angle of 60° or more and 120° or less.

[0269] In this specification, when the crystal is a trigonal or rhombohedral crystal, it is represented as a hexagonal crystal system. vinegar.

[0270] Oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, CAAC-OS (C Axis Aligned Crystalline Oxide Semiconductor, polycrystalline oxide Examples of the oxide semiconductor include a semiconductor, a microcrystalline oxide semiconductor, and an amorphous oxide semiconductor.

[0271] From another point of view, oxide semiconductors are classified into amorphous oxide semiconductors and other crystalline oxides. Crystalline oxide semiconductors are divided into single-crystal oxide semiconductors, CAAC- Examples of such oxide semiconductors include OS, polycrystalline oxide semiconductors, and microcrystalline oxide semiconductors.

[0272] First, let me explain about CAAC-OS. Axis-Aligned Nanocrystals It can also be done as follows.

[0273] CAAC-OS is an oxide having multiple crystal parts (also called pellets) aligned along the c-axis. It is a type of semiconductor.

[0274] Transmission Electron Microscope (TEM) A combined analysis image (high resolution) of the bright-field image and diffraction pattern of CAAC-OS was obtained by using a microscope. When observing a high-resolution TEM image, multiple pellets can be confirmed. On the other hand, high-resolution TEM images reveal the boundaries between pellets, i.e., grain boundaries. Therefore, the CAAC-OS is not clearly characterized by the grain boundaries. It can be said that the resulting decrease in electron mobility is unlikely to occur.

[0275] Below, we will explain the CAAC-OS observed by TEM. 1 shows a high-resolution TEM image of a cross section of CAAC-OS observed from a direction approximately parallel to the sample surface. For high-resolution TEM imaging, spherical aberration correction is required. The spherical aberration correction function was used to obtain high-resolution TEM images. , specifically referred to as a Cs-corrected high-resolution TEM image. Cs-corrected high-resolution TEM images can be obtained, for example, This is performed using an atomic resolution analytical electron microscope such as the JEM-ARM200F manufactured by JEOL Ltd. It is possible.

[0276] An enlarged Cs-corrected high-resolution TEM image of area (1) in Figure 19(A) is shown in Figure 19(B). From Figure 19(B), it can be seen that the metal atoms are arranged in layers in the pellet. The arrangement of each metal atom layer is determined by the surface on which the CAAC-OS film is to be formed (also referred to as the surface on which the film is to be formed). Or it reflects the unevenness of the top surface and is parallel to the surface on which the CAAC-OS is formed or the top surface.

[0277] As shown in Figure 19(B), CAAC-OS has a characteristic atomic arrangement. ) shows the characteristic atomic arrangement with auxiliary lines. ) the size of each pellet is about 1 nm to 3 nm, and the size of each pellet is about 1 nm to 3 nm. It can be seen that the size of the gap caused by the tilt is about 0.8 nm. The pellets may also be referred to as nanocrystals (nc).

[0278] Here, based on the Cs-corrected high-resolution TEM image, the pellets of CAAC-OS on the substrate 5120 were The layout of the 5100 is shown diagrammatically as a stack of bricks or blocks. (See FIG. 19(D)). Between the pellets observed in FIG. 19(C), The portion where the tilt occurs corresponds to the region 5161 shown in FIG. 19(D).

[0279] In addition, FIG. 20(A) shows the C of the plane of the CAAC-OS observed from a direction approximately perpendicular to the sample surface. The s-corrected high-resolution TEM images are shown. Regions (1), (2), and (3) in Figure 20(A). ) are enlarged Cs-corrected high-resolution TEM images shown in Fig. 20(B), Fig. 20(C), and Fig. 20(D), respectively. As shown in Figure 20(D), Figure 20(B), Figure 20(C) and Figure 20(D) show that the pellet It can be seen that the metal atoms are arranged in a triangular, quadrangular or hexagonal shape. However, no regularity is observed in the arrangement of metal atoms among different pellets.

[0280] Next, C analyzed by X-ray diffraction (XRD) For example, CAAC-O with InGaZnO4 crystals When S is subjected to structural analysis using the out-of-plane method, the results are as shown in Figure 21(A). As shown in the figure, a peak may appear at a diffraction angle (2θ) of around 31°. Since this is attributed to the (009) plane of the ZnO4 crystal, it is believed that the CAAC-OS crystal is c-axis oriented. It can be seen that the c-axis is oriented in a direction substantially perpendicular to the surface on which the film is formed or the upper surface.

[0281] In addition, in the structural analysis of CAAC-OS using the out-of-plane method, 2θ is 31 In addition to the peak around 2θ of 36°, a peak may also appear around 2θ of 36°. The peaks in the vicinity indicate that some of the CAAC-OS crystals do not have a c-axis orientation. The more preferable CAAC-OS is a structure produced by the out-of-plane method. The analysis shows a peak at 2θ around 31°, but no peak at 2θ around 36°.

[0282] On the other hand, in-pla, X-rays are incident on the CAAC-OS from a direction almost perpendicular to the c-axis. When structural analysis is performed using the NE method, a peak appears at 2θ around 56°. This peak is due to I It is attributed to the (110) plane of the nGaZnO4 crystal. In the case of CAAC-OS, 2θ is set to 5 The sample is fixed at approximately 6° and analyzed while rotating around the normal vector of the sample surface (φ axis). Even if a φ scan is performed, no clear peak appears, as shown in Figure 21(B). On the other hand, in the case of a single crystal oxide semiconductor such as InGaZnO4, 2θ is fixed at around 56° and φ When scanned, it is assigned to a crystal plane equivalent to the (110) plane as shown in Figure 21(C). Six peaks are observed. Therefore, from the structural analysis using XRD, CAAC-OS It can be seen that the orientation of the a-axis and b-axis is irregular.

[0283] Next, we will explain the CAAC-OS analyzed by electron diffraction. For CAAC-OS with ZnO4 crystals, the probe diameter is 300 nm parallel to the sample surface. When an electron beam is incident on the sample, a diffraction pattern (selected area transmission electron diffraction) as shown in FIG. This diffraction pattern may appear due to the presence of InGaZnO4 This includes spots due to the (009) plane of the crystal. The pellets contained in the CAAC-OS have a c-axis orientation, and the c-axis faces the surface to be formed or the upper surface. On the other hand, when the probe was applied to the same sample perpendicular to the sample surface, The diffraction pattern when an electron beam with a diameter of 300 nm was incident is shown in Figure 22(B). 2(B) shows a ring-shaped diffraction pattern. It can be seen that the a-axis and b-axis of the pellets contained in CAAC-OS do not have any orientation. The first ring in FIG. 22(B) is the (010) plane of the InGaZnO4 crystal. This is thought to be due to the (100) plane and the like. This is thought to be due to the (110) surface.

[0284] In addition, the CAAC-OS is an oxide semiconductor with a low density of defect states. Defects include, for example, defects caused by impurities and oxygen vacancies. AC-OS can also be considered an oxide semiconductor with a low impurity concentration. S can also be said to be an oxide semiconductor with few oxygen vacancies.

[0285] Impurities contained in oxide semiconductors can act as carrier traps or as carrier generation sources. In addition, oxygen vacancies in an oxide semiconductor may become carrier traps or By capturing hydrogen, it may become a carrier generation source.

[0286] The impurities are elements other than the main components of the oxide semiconductor, such as hydrogen, carbon, silicon, and transition metals. For example, metal elements such as silicon are more oxidative than metal elements that constitute oxide semiconductors. Elements with strong bonding strength with the oxide semiconductor remove oxygen from the oxide semiconductor, which changes the atomic arrangement of the oxide semiconductor. In addition, heavy metals such as iron and nickel, argon, Carbon dioxide and other molecules have a large atomic radius (or molecular radius), so the atomic arrangement of oxide semiconductors This disrupts the structure and reduces the crystallinity.

[0287] In addition, oxide semiconductors with low defect state density (few oxygen vacancies) have low carrier density. Such an oxide semiconductor can be a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. CAAC-OS has a low impurity concentration and a low density of defect states. Therefore, the oxide semiconductor is likely to be a highly pure intrinsic or substantially highly pure intrinsic oxide semiconductor. A transistor using AC-OS has electrical characteristics in which the threshold voltage is negative (normal It is also called "on." It is rare for it to become a high-purity intrinsic or substantially high-purity intrinsic Oxide semiconductors have few carrier traps. The charge that is trapped takes a long time to be released and behaves like a fixed charge. Therefore, transistors using oxide semiconductors with high impurity concentrations and high defect state densities are being developed. On the other hand, transistors using CAAC-OS can have unstable electrical characteristics. The resulting transistor has little fluctuation in electrical characteristics and is highly reliable.

[0288] In addition, CAAC-OS has a low defect level density, so it is possible to generate Therefore, the carriers are less likely to be captured by the defect level. The electrical characteristics of a transistor are less susceptible to change when irradiated with visible light or ultraviolet light.

[0289] Next, a microcrystalline oxide semiconductor will be described.

[0290] Microcrystalline oxide semiconductors have regions where crystals can be confirmed in high-resolution TEM images. The microcrystalline oxide semiconductor has a crystal structure including a region where a crystal part is clearly visible and a region where a crystal part is not clearly visible. The crystal part contained is between 1 nm and 100 nm, or between 1 nm and 10 nm in size. In particular, fine crystals of 1 nm to 10 nm or 1 nm to 3 nm are often The oxide semiconductor with nanocrystalline structure is called nc-OS (nanocrystalline silicon). nc-OS is called NC-Oxide Semiconductor. In some cases, the grain boundaries cannot be clearly identified in the TEM images. It is possible that the origin of the pellets in C-OS is the same as that of the pellets in C-OS. The crystalline part of the OS is sometimes called a pellet.

[0291] nc-OS is a material that can be used in microscopic areas (e.g., areas between 1 nm and 10 nm, especially areas between 1 nm and 10 nm). The atomic arrangement is periodic in the region of 3 nm or less. There is no regularity in the crystal orientation between the layers. Therefore, no orientation is observed throughout the film. Therefore, depending on the analysis method, nc-OS may be indistinguishable from amorphous oxide semiconductors. For example, an XRD apparatus using an X-ray beam with a diameter larger than that of the pellet is used for nc-OS. When structural analysis is performed using the out-of-plane method, the crystal plane is shown. In addition, the probe diameter ( For example, electron diffraction (also called selected area electron diffraction) is performed using an electron beam of 50 nm or more. On the other hand, for nc-OS, a halo-like diffraction pattern is observed. Nanobeam electron circuits use electron beams with a probe diameter close to the pellet size or smaller than the pellet. When the nc-OS is subjected to nanobeam electron diffraction, spots are observed. When the light is too bright, a circular (ring-shaped) area of high brightness may be observed. Multiple spots may be observed within a ring-like region.

[0292] In this way, the crystal orientation between the pellets (nanocrystals) is not regular, so nc -OS with RANC (Random Aligned nanocrystals) oxide semiconductors, or NANCs (Non-Aligned Nanocrystals) The semiconductor may also be referred to as an oxide semiconductor having a structure (s).

[0293] The nc-OS is an oxide semiconductor with higher order than an amorphous oxide semiconductor. However, the density of defect states in nc-OS is lower than that in amorphous oxide semiconductors. There is no regularity in the crystal orientation between different pellets in S. Therefore, nc-OS is The defect density is higher than that of AAC-OS.

[0294] Next, the amorphous oxide semiconductor will be described.

[0295] Amorphous oxide semiconductors are oxides in which the atomic arrangement within the film is irregular and does not have crystalline parts. An example is an oxide semiconductor that has an amorphous state, such as quartz.

[0296] In amorphous oxide semiconductors, no crystalline parts can be observed in high-resolution TEM images.

[0297] When structural analysis is performed on amorphous oxide semiconductors using an XRD device, out-of-p In the analysis by the Lane method, no peaks indicating crystal planes were detected. When electron diffraction is performed on a conductor, a halo pattern is observed. When nanobeam electron diffraction is performed on the sample, no spots are observed, and only a halo pattern is observed. It is observed.

[0298] There are various views on amorphous structures. For example, A structure that does not have this property is called a completely amorphous structure. The distance between the nearest neighboring atoms or the second nearest neighboring atoms is also called the structure. A structure that has order at the interface but does not have long-range order is sometimes called an amorphous structure. Therefore, according to the strictest definition, an oxide semiconductor that has even a slight degree of order in its atomic arrangement is called a non-metallic oxide semiconductor. Furthermore, it cannot be called an crystalline oxide semiconductor. Therefore, since the semiconductor has crystalline parts, it cannot be called an amorphous oxide semiconductor. For example, CAAC-OS and nc-OS are used as amorphous oxide semiconductors or completely amorphous It cannot be called an oxide semiconductor.

[0299] Note that an oxide semiconductor may have a structure between an nc-OS and an amorphous oxide semiconductor. An oxide semiconductor having such a structure is particularly called an amorphous-like oxide semiconductor (aluminum oxide). ike OS:amorphous-like Oxide Semiconducto It is called r).

[0300] In a-like OS, voids (also called voids) are observed in high-resolution TEM images. In addition, crystals can be clearly seen in high-resolution TEM images. and regions where no crystalline portions can be identified.

[0301] Because of the porosity, the a-like OS has an unstable structure. e OS has an unstable structure compared with CAAC-OS and nc-OS. This shows the structural changes caused by electron irradiation.

[0302] The samples to be irradiated with electrons were a-like OS (referred to as sample A), nc-OS (hereinafter referred to as Sample B) and CAAC-OS (hereinafter referred to as Sample C) are prepared. Both samples are In-Ga-Zn oxides.

[0303] First, high-resolution cross-sectional TEM images of each sample are acquired. It can be seen that all the materials have crystalline parts.

[0304] The determination of which part is to be regarded as one crystal part can be made as follows. For example, The unit cell of the InGaZnO4 crystal has three In-O layers and one Ga-Zn-O layer. It is known that the structure has a total of nine layers, six of which are stacked in layers in the c-axis direction. The spacing between these adjacent layers is approximately the same as the lattice spacing (also called the d value) of the (009) plane. The value is calculated to be 0.29 nm from crystal structure analysis. The areas where the spacing is 0.28 nm or more and 0.30 nm or less are considered to be InGaZnO4 crystal parts. The lattice fringes correspond to the ab plane of the InGaZnO4 crystal.

[0305] Figure 23 shows an example of investigating the average size of the crystal parts (22 to 45 locations) of each sample. However, the length of the lattice fringes mentioned above is the size of the crystal part. It can be seen that the crystalline part of ke OS grows in size according to the cumulative amount of electron irradiation. Specifically, as shown in Figure 23 (1), the initial TEM observation showed a size of about 1.2 nm. The crystal part (also called the initial nucleus) was 4.2 × 10 8 e - / n m 2 On the other hand, in the nc-O For S and CAAC-OS, the cumulative electron irradiation dose from the start of electron irradiation was 4.2 × 10 8 e - / nm 2 It can be seen that there is no change in the size of the crystal part within the range of As shown in (2) and (3) in Figure 23, regardless of the cumulative electron dose, the nc-OS and The sizes of the crystal parts of the CAAC-OS and CAAC-OS are approximately 1.4 nm and 2.1 nm, respectively. It can be seen that...

[0306] In this way, the growth of crystalline parts can be observed in a-like OS due to electron irradiation. On the other hand, in nc-OS and CAAC-OS, the growth of the crystals by electron irradiation is almost nonexistent. In other words, a-like OS is not as good as nc-OS and CAAC- It is clear that it has an unstable structure compared to the OS.

[0307] In addition, due to its porosity, a-like OS is more flexible than nc-OS and CAAC-OS. Specifically, the density of a-like OS is lower than that of a single crystal of the same composition. The density of the nc-OS is 78.6% or more and less than 92.3% of that of the normal crystal. The density of C-OS is 92.3% or more but less than 100% of the density of a single crystal of the same composition. It is difficult to form a film of an oxide semiconductor having a crystal density of less than 78%.

[0308] For example, in an oxide semiconductor having an atomic ratio of In:Ga:Zn=1:1:1, The density of single-crystal InGaZnO4 with a rhombohedral crystal structure is 6.357 g / cm 3 It becomes. For example, in an oxide semiconductor that satisfies the atomic ratio of In:Ga:Zn=1:1:1, The density of a-like OS is 5.0 g / cm 3 More than 5.9g / cm 3 It will be less than For example, in an oxide semiconductor having an atomic ratio of In:Ga:Zn=1:1:1, , the density of nc-OS and the density of CAAC-OS are 5.9 g / cm 3 More than 6.3g / cm 3 It will be less than.

[0309] In some cases, single crystals with the same composition do not exist. In such cases, crystals with different compositions may be used in any proportion. By combining single crystals with the desired composition, the density equivalent to that of a single crystal can be estimated. The density corresponding to a single crystal of a desired composition can be obtained by combining single crystals of different compositions. The density should be as low as possible. It is preferable to estimate by combining different types of single crystals.

[0310] As described above, oxide semiconductors have various structures, each of which has various characteristics. The oxide semiconductor may be, for example, an amorphous oxide semiconductor, an a-like OS, or a microcrystalline oxide semiconductor. The layer may be a laminated film containing two or more of a compound semiconductor and a CAAC-OS.

[0311] The CAAC-OS film can be formed, for example, by the following method.

[0312] The CAAC-OS film can be formed by sputtering a polycrystalline oxide semiconductor target. The film is formed by sputtering.

[0313] By increasing the substrate temperature during film formation, migration of sputtered particles after reaching the substrate is prevented. Specifically, the substrate temperature is set to 100°C or higher and 740°C or lower, preferably 200°C or higher. The film is formed at a temperature of 500°C or less. By increasing the substrate temperature during film formation, the sputtering particles When the particles reach the substrate, migration occurs on the substrate, and the sputtered particles are flattened. At this time, the sputtering particles are positively charged, The ring particles repel each other while adhering to the substrate, resulting in uneven sputtering. Therefore, a CAAC-OS film with a uniform thickness can be formed without overlapping.

[0314] By reducing the amount of impurities mixed in during film formation, it is possible to prevent the crystal state from being destroyed by impurities. For example, the concentration of impurities (hydrogen, water, carbon dioxide, nitrogen, etc.) present in the film formation chamber can be In addition, the impurity concentration in the deposition gas can be reduced. A deposition gas at a temperature of -80°C or lower, preferably -100°C or lower, is used.

[0315] In addition, by increasing the oxygen ratio in the deposition gas and optimizing the power, plasma damage during deposition can be reduced. The oxygen ratio in the film forming gas is 30% by volume or more, preferably 100% by volume or more. Expressed as volume %.

[0316] Alternatively, the CAAC-OS film is formed by the following method.

[0317] First, a first oxide semiconductor film is formed to a thickness of 1 nm or more and less than 10 nm. The semiconductor film is formed by sputtering. Specifically, the substrate temperature is set to 100°C or higher. The temperature is set to 500°C or less, preferably 150°C to 450°C, and the oxygen ratio in the deposition gas is set to 30 The film is formed at a concentration of at least 100% by volume, preferably 100% by volume.

[0318] Next, heat treatment is performed to convert the first oxide semiconductor film into a first CAAC-OS film having high crystallinity. The temperature of the heat treatment is 350°C or higher and 740°C or lower, preferably 450°C or higher and 650°C or lower. The heat treatment time is 1 minute to 24 hours, preferably 6 minutes to 4 hours. The heat treatment may be carried out in an inert atmosphere or an oxidizing atmosphere. Alternatively, heat treatment is performed in an inert atmosphere, and then heat treatment is performed in an oxidizing atmosphere. By the heat treatment in the atmosphere, the impurity concentration of the first oxide semiconductor film can be reduced in a short time. On the other hand, oxygen vacancies are generated in the first oxide semiconductor film by heat treatment in an inert atmosphere. In this case, the oxygen deficiency can be reduced by heat treatment in an oxidizing atmosphere. Heat treatment can be carried out at a pressure of 1000 Pa or less, 100 Pa or less, 10 Pa or less, or The step of removing the oxide semiconductor film from the first oxide semiconductor film may be performed under a reduced pressure of 1 Pa or less. can be reduced in an even shorter time.

[0319] The first oxide semiconductor film has a thickness of 1 nm or more and less than 10 nm. Compared with a thickness of 0 nm or more, it can be easily crystallized by heat treatment.

[0320] Next, a second oxide semiconductor film having the same composition as the first oxide semiconductor film is formed to a thickness of 10 nm or more. The second oxide semiconductor film is formed to a thickness of 0 nm or less by sputtering. Specifically, the substrate temperature is set to 100°C or higher and 500°C or lower, preferably 150°C or higher and 450°C or lower. The temperature is set to 0°C or lower, and the oxygen ratio in the film-forming gas is set to 30% by volume or more, preferably 100% by volume. To film.

[0321] Next, heat treatment is performed to form a second oxide semiconductor film from the first CAAC-OS film by solid-phase growth. The second CAAC-OS film was obtained by heating at a temperature of 350 The temperature is set to 740°C or higher, preferably 450°C or higher and 650°C or lower. The heating time is from 1 minute to 24 hours, preferably from 6 minutes to 4 hours. The heat treatment may be carried out in an inert atmosphere or an oxidizing atmosphere. Preferably, the heat treatment is carried out in an inert atmosphere. After that, heat treatment is performed in an oxidizing atmosphere. The impurity concentration of the nitride semiconductor film can be reduced in a short time. Oxygen vacancies may be generated in the second oxide semiconductor film by the heat treatment. The oxygen deficiency can be reduced by heat treatment in a reactive atmosphere. It may be carried out under reduced pressure of 000 Pa or less, 100 Pa or less, 10 Pa or less, or 1 Pa or less. Under reduced pressure, the impurity concentration of the second oxide semiconductor film can be reduced in a shorter time. Cut.

[0322] In this manner, a CAAC-OS film having a total thickness of 10 nm or more is formed. can be done.

[0323] This embodiment may be combined, at least in part, with other embodiments described in this specification. It can be implemented in combination. [Explanation of symbols]

[0324] 51 Gas Tank 52 Flow meter 53 Chamber 54 Exhaust system 55 Exhaust system 56 nozzles 57 Nozzle mouth 58 Drive Unit 59 Stages 60 boards 61 Angle adjustment means 62 Vibrator 63 Raw material container 80 Touch Panel 100 Touch Panel 101 Substrate 102 Circuit Board 110 Display device 111 Display section 112 Drive circuit 114 IC 120 Touch Sensor 121 Electrode 122 electrodes 123 Dielectric Layer 125 Insulating Layer 131 Wiring 132 Wiring 140 FPC 141 FPC 142 FPC 143 FPC 144 Wiring 151 Adhesive layer 152 Adhesive layer 153 Adhesive layer 155 connection terminal 156 connection terminal 157 Connection Layer 158 Connection Layer 161 transistors 162 transistors 163 transistors 164 transistors 165 Conductive particles 166 Conductive Layer 171 Insulating layer 172 Insulating layer 173 Insulating Layer 175 Insulating Layer 176 Insulating Layer 178 Protective layer 180 Light-emitting element 181 Electrode 182 EL layer 183 Electrode 184 Color Filter 185 Black Matrix 191 Adhesive layer 192 Adhesive layer 310 Mobile Information Terminals 312 Display Panel 313 Hinge 315 Case 320 Mobile Information Terminals 322 Display section 325 Hidden part 330 Mobile Information Terminals 333 Display section 335 Case 336 Case 337 Information 339 Operation Button 340 Mobile Information Terminals 345 Mobile Information Terminals 351 Case 355 Information 356 Information 357 Information 358 Display section 501 Pulse voltage output circuit 502 Current detection circuit 503 capacity 511 Transistor 512 transistors 513 Transistor 800 display device 801 Display section 802 Gate Driver 803 Source Driver 804 DA conversion circuit 810 Control circuit 811 Detector 820 Counter Circuit 850 Touch Sensor 5100 pellets 5120 board 5161 area 7100 Mobile Information Terminal 7101 Housing 7102 Display section 7103 Band 7104 Buckle 7105 Operation button 7106 Input / output terminal 7107 Icon 7300 display device 7301 Housing 7302 Display section 7303 Operation button 7304 Materials 7305 Control Unit 7400 mobile phone 7401 Housing 7402 Display section 7403 Operation button 7404 External connection port 7405 Speaker 7406 Microphone

Claims

[Claim 1] a first substrate; a first insulating layer having a region overlying the first substrate; an adhesive layer having a region overlying the first insulating layer; a second substrate having an area located above the adhesive layer; the first insulating layer has an opening; the adhesive layer has a plurality of conductive particles; one of the plurality of conductive particles has a region overlapping with the first insulating layer; Another one of the plurality of conductive particles is located inside the opening.

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