Display device

Abstract

To provide a liquid crystal display device having a high aperture ratio and consuming less power.SOLUTION: A display device includes a transistor and a capacitor. The transistor includes a first insulating layer, a first semiconductor layer in contact with the first insulating layer, a second insulating layer in contact with the first semiconductor layer, and a first conductive layer electrically connected to the first semiconductor layer through an aperture provided in the second insulating layer. The first semiconductor layer includes a channel region. The capacitor includes a second conductive layer in contact with the first insulating layer, a second insulating layer in contact with the second conductive layer, and a first conductive layer in contact with the second insulating layer. The second conductive layer has the composition similar to that of the first semiconductor layer. The first conductive layer and the second conductive layer have the function of transmitting visible light.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] One embodiment of the present invention relates to a display device, a manufacturing method thereof, and an electronic device.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. Examples of the semiconductor device include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, Input devices (e.g., touch sensors, etc.), input / output devices (e.g., touch panels, etc.), A driving method thereof or a manufacturing method thereof can be given as an example. [Background technology]

[0003] It is used in many flat panel displays such as liquid crystal displays and light emitting displays. The transistors used are made of amorphous silicon, single crystal silicon, or Alternatively, the semiconductor device is made of a silicon semiconductor such as polycrystalline silicon. Transistors, which use conductors, are also used in integrated circuits (ICs).

[0004] In recent years, metal oxides that exhibit semiconducting properties have been used in transistors instead of silicon semiconductors. In this specification, metal oxides that exhibit semiconducting properties are referred to as oxide semiconductors. For example, Patent Documents 1 and 2 describe oxide semiconductors such as A transistor using In-Ga-Zn oxide or In-Ga-Zn oxide is manufactured. A technique for using a transistor as a switching element of a pixel of a display device has been disclosed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-123861 A [Patent Document 2] JP 2007-96055 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of one embodiment of the present invention is to provide a liquid crystal display device with a high aperture ratio and a manufacturing method thereof. Another embodiment of the present invention is a liquid crystal display device and Another object of the present invention is to provide a manufacturing method thereof. Another object of the present invention is to provide a liquid crystal display device and a manufacturing method thereof. An object of the present invention is to provide a high-definition liquid crystal display device and a manufacturing method thereof. Another embodiment of the present invention is to provide a highly reliable liquid crystal display device and a manufacturing method thereof. Another object of the present invention is to provide a novel liquid crystal display device and a manufacturing method thereof. One of the objectives is to provide.

[0007] Note that the description of these problems does not preclude the existence of other problems. However, it is not necessary to solve all of these problems. It is possible to extract other issues from the description in the section. [Means for solving the problem]

[0008] One embodiment of the present invention is a display device including a transistor and a capacitor, The photoresist includes a first insulating layer, a first semiconductor layer in contact with the first insulating layer, and a second semiconductor layer in contact with the first semiconductor layer. a second insulating layer electrically connected to the first semiconductor layer through an opening provided in the second insulating layer; a first conductive layer electrically connected to the first semiconductor layer, the first semiconductor layer having a channel region and a capacitance The element includes a second conductive layer in contact with the first insulating layer, a second insulating layer in contact with the second conductive layer, and a first conductive layer in contact with the second insulating layer, the second conductive layer being similar to the first semiconductor layer; The first conductive layer and the second conductive layer have a composition of the above-mentioned, and the first conductive layer and the second conductive layer have a function of transmitting visible light. It is a display device.

[0009] In the above embodiment, the first semiconductor layer, the first conductive layer, and the second conductive layer are made of metal. It may have an oxide.

[0010] In the above embodiment, the metal oxide contained in the first semiconductor layer is The metal oxide may contain one or more types of metal elements.

[0011] In the above embodiment, the first conductive layer may include In-Zn oxide.

[0012] In the above embodiment, the second insulating layer may include silicon oxynitride.

[0013] In the above embodiment, the second insulating layer and the third insulating layer are in contact with the first conductive layer. The third insulating layer may have more oxygen than satisfies the stoichiometric composition.

[0014] In the above aspect, the liquid crystal element includes a liquid crystal layer and a pixel electrode. The pixel electrode may be electrically connected to the first conductive layer.

[0015] In the above embodiment, the resistivity of the liquid crystal element is 1.0×10 14 Ω cm or more Good too.

[0016] In the above aspect, the frame frequency of the display device is 0.1 Hz or more and less than 60 Hz. After writing data to the capacitor, the display device turns off the transistor. The memory may have a function of retaining data by this.

[0017] In the above aspect, the frame frequency of the display device is 0.1 Hz or more and less than 20 Hz. It's fine.

[0018] In the above aspect, the scanning line is formed using a metal material. may have a portion that overlaps with a channel region of the transistor.

[0019] In addition, an electronic device including a display device according to one embodiment of the present invention and an operation key is also an embodiment of the present invention. It is.

[0020] Another embodiment of the present invention is a method for manufacturing a display device, the method including: forming a first semiconductor layer and a second semiconductor layer; The method includes the steps of forming a first insulating layer, and forming a first insulating layer that reaches the first semiconductor layer. forming an opening; and forming a first semiconductor layer through the first opening, the first semiconductor layer overlapping the second semiconductor layer. forming a third semiconductor layer in electrical contact with the first insulating layer and forming a second insulating layer in contact with the third semiconductor layer; forming a second opening reaching the third semiconductor layer through the second opening; forming a pixel electrode so as to be electrically connected to the first insulating layer; In the step of forming the first semiconductor layer and the second semiconductor layer, the resistance of each of the first semiconductor layer and the second semiconductor layer is reduced. In the step of forming the second insulating layer, the third semiconductor layer is made to have a low resistance and the second insulating layer is made to have a low resistance. After the formation of the layer, the channel region of the first semiconductor layer, which has been made to have a low resistance, is made to have a high resistance. This is a method for producing the above.

[0021] The first semiconductor layer, the second semiconductor layer, and the third semiconductor layer may also be formed to have a metal oxide. A body layer may be formed.

[0022] The third semiconductor layer may also be formed to include In-Zn oxide.

[0023] In addition, the first insulating layer and the second insulating layer are formed by a CVD method using a deposition gas containing silane. A layer may be formed.

[0024] The deposition gas may also contain nitrogen oxides.

[0025] After the second insulating layer is formed, a heat treatment may be performed.

[0026] Moreover, after forming the pixel electrodes, the liquid crystal layer may be formed. Effect of the Invention

[0027] According to one embodiment of the present invention, a liquid crystal display device with a high aperture ratio and a manufacturing method thereof can be provided. According to one embodiment of the present invention, a liquid crystal display device and a display device having a simplified manufacturing process can be provided. According to one embodiment of the present invention, a liquid crystal display device with low power consumption can be manufactured. According to one embodiment of the present invention, a display device and a manufacturing method thereof can be provided. It is possible to provide a high-definition liquid crystal display device and a manufacturing method thereof. According to the embodiment, a highly reliable liquid crystal display device and a method for manufacturing the same can be provided. According to one embodiment of the present invention, a novel liquid crystal display device and a manufacturing method thereof can be provided. can.

[0028] The description of these effects does not preclude the existence of other effects. However, it is not necessary to have all of these effects. However, it is possible to extract effects other than these. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a display device. [Diagram 2] FIG. 1 is a cross-sectional view showing an example of a display device. [Diagram 3] 1A and 1B are a top view and a cross-sectional view illustrating an example of a display device. [Figure 4] FIG. 1 is a cross-sectional view showing an example of a display device. [Diagram 5] FIG. 1 is a perspective view showing an example of a display device. [Figure 6] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 7] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 8] 1A to 1C are cross-sectional views illustrating an example of a method for manufacturing a display device. [Figure 9] 1A to 1C are cross-sectional views illustrating an example of a method for manufacturing a display device. [Figure 10] 1A and 1B are diagrams showing examples of pixel arrangement and configuration; [Figure 11] FIG. 1 is a perspective view showing an example of a display device. [Figure 12] FIG. 1 is a cross-sectional view showing an example of a display device. [Figure 13] 2A and 2B are diagrams showing an example of the configuration and operation mode of a pixel; [Figure 14] 1A and 1B are a block diagram and a timing chart of a touch sensor. [Figure 15] 1A and 1B are a block diagram and a timing chart of a display device. [Figure 16] 1A to 1C are diagrams illustrating operations of a display device and a touch sensor. [Figure 17] 1A to 1C are diagrams illustrating operations of a display device and a touch sensor. [Figure 18] 1A and 1B are diagrams illustrating examples of electronic devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The embodiment will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention may be modified in various ways in form and detail without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be modified in various ways. The present disclosure is not to be construed as being limited to the contents of the description of the embodiment.

[0031] 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 the repeated explanations are omitted. When referring to a function, the hatch pattern may be the same and no particular symbol may be used.

[0032] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily the same as the actual components for ease of understanding. The position, size, range, etc. may not be shown. Therefore, the disclosed invention may not necessarily be The present invention is not limited to the position, size, range, etc. disclosed in the drawings.

[0033] The words "membrane" and "layer" may be interchangeable depending on the situation. For example, the term "conductive layer" can be used interchangeably with the term "conductive film." ". Alternatively, for example, the term "insulating film" may be changed to It is possible to change the term to "insulating layer."

[0034] In this specification, the term "metal oxide" refers to a metal oxide in a broad sense. Metal oxides are oxide insulators and oxide conductors (including transparent oxide conductors). , oxide semiconductors (also called oxide semiconductors or simply OS), etc. For example, when a metal oxide is used for the semiconductor layer of a transistor, the metal oxide is In other words, when describing an OS FET, In other words, the transistor can be a transistor including a metal oxide or an oxide semiconductor.

[0035] In the present specification and the like, metal oxides having nitrogen are also referred to as metal oxides. Nitrogen-containing metal oxides are also called metal oxynitrides (met de). It may also be called tetrahydrofuran (tetrahydrofuran) oxynitride.

[0036] (Embodiment 1) In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS. .

[0037] <1. Display device configuration example 1> First, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0038] A display device according to one embodiment of the present invention includes a display element, a transistor, and a capacitor. The element may be, for example, a liquid crystal element. Hereinafter, the display element will be described as a liquid crystal element. However, a display element to which one embodiment of the present invention can be applied is not limited to a liquid crystal element. The light-emitting element may be, for example, an organic electroluminescence (EL) element. Children, inorganic EL elements, LEDs (Light Emitting Diodes), QLEDs ( Quantum-dot Light Emitting Diode, semiconductor laser As the light emitting element, a backlight or a sidelight can be used. Alternatively, a light source such as a liquid crystal display may be combined with a transmission type liquid crystal display. Alternatively, both a liquid crystal element and a light emitting element may be used.

[0039] The liquid crystal element includes a pixel electrode, a liquid crystal layer, and a common electrode. The pixel electrode, the common electrode, and the capacitance element are electrically connected to the pixel electrode. The visible light passes through the liquid crystal element and is emitted to the outside of the display device. do.

[0040] In the display device of one embodiment of the present invention, a capacitor element has a region through which visible light passes. The capacitance element can be provided in the display region. This increases the aperture ratio of the pixel, and the display device It is possible to reduce power consumption and to realize a high-definition display device.

[0041] The transistor included in the display device of one embodiment of the present invention has a channel-protective structure. By adopting this structure, the channel protection layer of the transistor and the dielectric constant of the capacitor element can be reduced. This allows the layers to be formed in the same process, improving the reliability of the transistor. This can simplify the manufacturing process of the display device of one embodiment of the present invention.

[0042] The display device according to one embodiment of the present invention further includes scanning lines and signal lines. The lines are electrically connected to the transistors. The scanning lines and the signal lines are By using a metal layer for the scanning lines and the signal lines, The resistance value can be reduced.

[0043] In addition, it is preferable that the scan line has a portion overlapping with a channel region of the transistor. Depending on the material used in the channel region of a transistor, it may become a transistor when irradiated with light. The characteristics of the transistor may vary. This makes it possible to prevent external light or backlight light from irradiating the channel area. This can improve the reliability of the transistor.

[0044] The display device 10A shown in FIG. 1A includes a substrate 11, a substrate 12, a transistor 14, and a liquid crystal element. 15, a capacitance element 16, etc. A backlight unit is provided on the substrate 12 side of the display device 10A. 13 is placed.

[0045] The liquid crystal element 15 includes a pixel electrode 21, a liquid crystal layer 22, and a common electrode 23. 1 is electrically connected to the transistor 14 through an opening provided in the insulating layer 26. On the insulating layer 26, a pixel electrode 21 is formed by the same process and using the same material. A conductive layer 25 is provided. The conductive layer 25 is electrically connected to the common electrode 23 via a connector 29. are actively connected.

[0046] Light 45a from the backlight unit 13 passes through the substrate 12, the insulating layer 26, the pixel electrodes 21, the liquid crystal display 22, and the liquid crystal display 24. The light is emitted to the outside of the display device 10A through the crystal layer 22, the common electrode 23, and the substrate 11. The materials of these layers through which the light 45a passes are materials that transmit visible light.

[0047] Light 45b from the backlight unit 13 passes through the substrate 12, the transistor 14, the pixel electrode 2 1, the liquid crystal layer 22, the common electrode 23, and the substrate 11 are emitted to the outside of the display device 10A. In this embodiment, the transistor 14 electrically connected to the liquid crystal element 15 is Therefore, the transistor 14 is provided. The area that is covered by the LCD can also be used as a display area. This increases the aperture ratio of the pixels. The higher the aperture ratio, the higher the light extraction efficiency. It is possible to reduce power consumption and realize a high-definition display device.

[0048] The light 45c from the backlight unit 13 passes through the substrate 12, the capacitance element 16, the pixel electrode 21, The light is emitted to the outside of the display device 10A through the liquid crystal layer 22, the common electrode 23, and the substrate 11. In this embodiment, the capacitance element 16 has a region that transmits visible light. Therefore, the area where the capacitance element 16 is provided can also be used as a display area. This allows the aperture ratio of the pixel to be increased. The higher the aperture ratio, the greater the light extraction efficiency. Since the display efficiency can be increased, the power consumption of the display device can be reduced. This allows for the realization of a thin display device.

[0049] In the display device 10B shown in FIG. 1(B), a backlight unit 13 is disposed on the substrate 11 side. The other configurations are the same as those of the display device 10A. Therefore, the description will be omitted.

[0050] In the display device 10A, the light 45b first passes through the transistor 14, which transmits visible light. Then, the light 45b transmitted through the region is incident on the liquid crystal element 15. On the other hand, in the display device 10B, the light 45b first enters the liquid crystal element 15. The light 45b transmitted through the transistor 15 is incident on a region of the transistor 14 that transmits visible light. In this way, the light from the backlight unit 13 passes through the transistor 14 and the liquid crystal element It does not matter which one of the two, 15, the beam enters first.

[0051] In the display device 10A, the light 45c first enters the capacitance element 16. The transmitted light 45c is incident on the liquid crystal element 15. On the other hand, in the display device 10B, the light 45c is First, the light 45c is incident on the liquid crystal element 15. Then, the light 45c transmitted through the liquid crystal element 15 is incident on the capacitive element 16. The light is incident on the region of the backlight unit 16 that transmits visible light. The light from 3 may be incident on either the capacitance element 16 or the liquid crystal element 15 first.

[0052] In addition, the display device of one embodiment of the present invention includes a liquid crystal element, a transistor, a capacitor, and a touch panel. The liquid crystal element includes a pixel electrode, a liquid crystal layer, and a common electrode. The touch sensor is electrically connected to the pixel electrode and the capacitance element. The pixel electrode, the common electrode, and the capacitance element are located closer to the display surface than the transistor. Visible light passes through the capacitor element and the liquid crystal element and is reflected by the display device. is ejected to the outside.

[0053] A display device according to one embodiment of the present invention is a display device (an input / output device or a touch sensor) equipped with a touch sensor. This can be applied to a touch panel.

[0054] The display device 15A shown in FIG. 2A has a touch sensor unit on the substrate 11 side of the display device 10A. The configuration has 31.

[0055] The display device 15B shown in FIG. 2B has a structure in which a semiconductor device is provided between the substrate 11 and the common electrode 23 of the display device 10A. The display device includes a touch sensor unit 31 and an insulating layer 32. The device 15B has a conductive layer 27 and a conductive layer 28 .

[0056] A conductive layer formed on the insulating layer 26 using the same process and material as the pixel electrode 21. A common electrode 27 is provided in contact with the insulating layer 32. The conductive layer 28 is formed of a material. The conductive layer 28 is electrically connected to the conductive layer 27 via the connector 29. This allows one or more FPCs connected to the substrate 12 to be electrically connected to the substrate 12. Therefore, both the signal for driving the liquid crystal element 15 and the signal for driving the touch sensor unit 31 It is not necessary to connect an FPC or the like to the substrate 11 side, and the display device can be configured Compared to the case where FPCs are connected to both the board 11 side and the board 12 side, It is easy to incorporate into electronic devices and reduces the number of parts required.

[0057] In the display device 15B, a touch sensor unit 31 can be provided between the pair of substrates. Therefore, the number of substrates can be reduced, and the display device can be made lighter and thinner.

[0058] The display device 15C shown in FIG. 2C has a structure in which, between the substrate 12 and the insulating layer 26 of the display device 10B, The display device includes a touch sensor unit 31 and an insulating layer 32. 15C has a conductive layer 33.

[0059] In contact with the insulating layer 32, the same process as for one or more conductive layers of the transistor 14; The conductive layer 33 is made of the same material as the touch sensor. In the display device 15C, the display unit 15 is electrically connected to the substrate 11. A signal for driving the liquid crystal element 15 and a signal for driving the touch sensor unit are transmitted by one or more FPCs. Therefore, it is easy to incorporate it into electronic devices. This also reduces the number of parts required.

[0060] In the display device 15C, a touch sensor unit 31 can be provided between the pair of substrates. Therefore, the number of substrates can be reduced, and the display device can be made lighter and thinner.

[0061] [About pixels] Next, a pixel included in the display device of one embodiment of the present invention will be described with reference to FIG.

[0062] FIG. 3(A1) shows a schematic top view of a pixel 900. The pixel 900 shown in FIG. In FIG. 3(A1), the pixel 900 has two sub-pixels vertically and one horizontally. In the example shown, two sub-pixels are arranged. Each sub-pixel is provided with a transmissive liquid crystal element 40 (FIG. 3(A1) 2, a transistor 206, a capacitance element 34, etc. are provided. In FIG. 3(A1), a pixel 900 has two wirings 902 and two wirings 904. In each sub-pixel shown in FIG. 3(A1), a display region 918 (display display area 918R, display area 918G, display area 918B, and display area 918W). is doing.

[0063] The pixel 900 also includes a wiring 902 and a wiring 904. The wiring 902 is, for example, The wiring 904 functions as, for example, a signal line. 02 and wiring 904 have a mutual intersecting portion.

[0064] The transistor 206 functions as a selection transistor. The gate electrode is electrically connected to the wiring 902. Alternatively, one of the drain electrodes is electrically connected to the wiring 904, and the other is connected to the liquid crystal element 40, and is electrically connected to the capacitive element 34.

[0065] Here, the wiring 902 and the wiring 904 have a light-shielding property. The transistor 206, the wiring connected to the transistor 206, the capacitor element 34, etc. A light-transmitting film is preferably used for the layer. The pixel 900 is divided into a transmission region 900t that transmits visible light and a light-shielding region 900s that blocks visible light. In this example, a transistor is fabricated using a light-transmitting film. By forming the liquid crystal display panel in such a manner, the areas other than the areas where the wiring is provided can be made into the transparent area 900t. By overlapping the transparent area of ​​the crystal element with the transistor, the wiring connected to the transistor, the capacitance element, etc. This makes it possible to increase the aperture ratio of the pixel.

[0066] In addition, the higher the ratio of the area of ​​the transmission region to the area of ​​the pixel, the greater the amount of transmitted light. For example, the ratio of the area of ​​the transparent region to the area of ​​the pixel can be set to 1% or more and 95% or less. Preferably, the ratio is 10% or more and 90% or less, and more preferably, 20% or more and 80% or less. It is particularly preferable to set the ratio at 40% or more or 50% or more, and it is preferable to set the ratio at 60% or more and 80% or more. It is more preferable that the ratio is less than or equal to the above.

[0067] Also, a cross-sectional view corresponding to the cut surface of the dashed line AB shown in FIG. 3(A2) is shown in FIG. 3(B) and 4. In addition, in FIG. 3(B) and FIG. 4, the liquid Also shown are cross sections of the crystal element 40, the colored layer 131, the light-shielding layer 132, the drive circuit section 64, etc. The driving circuit section 64 is used as a scanning line driving circuit section or a signal line driving circuit section. The driver circuit portion 64 also includes a transistor 201.

[0068] The transistor 206 is preferably a channel-protective transistor. The semiconductor layer 231 has a channel region and is in contact with the semiconductor layer 231. An insulating layer 261 having an opening is provided. The opening serves as either the source or drain of the transistor 206. The conductive layer 222 and the semiconductor layer 231 are electrically connected to each other. An opening is provided, and the source or drain of the transistor 206 is exposed through the opening. A conductive layer 232 having a function as a gate and the semiconductor layer 231 are electrically connected to each other. In the semiconductor layer 231, the connection portion with the conductive layer 222 and the connection portion with the conductive layer 232 are It is preferable that the portion has a low resistance.

[0069] The capacitance element 34 includes a conductive layer 262, an insulating layer 261, and a conductive layer 232. The insulating layer 261 functions as a first electrode of the capacitor 34. The conductive layer 262 functions as a second electrode of the capacitor element 34. That is, the conductive layer 232 serves as a source or drain of the transistor 206. The insulating layer 261 also functions as a second electrode of the capacitor 34. It functions as a channel protection layer for the transistor 206 and as a dielectric for the capacitance element 34. . The first electrode of the capacitor 34 may be, for example, a lower electrode. The second electrode may be, for example, a top electrode.

[0070] The conductive layer 262 can be formed in the same layer as the semiconductor layer 231. The semiconductor layer is processed by lithography or the like, and then the capacitor element 34 is formed. The conductive layer 262 can be formed by reducing the resistance of the semiconductor layer. The conductive layer 262 has the same composition as the semiconductor layer 231. A resist mask is formed on the thin film to be patterned, and the thin film is processed by etching or other methods to remove the resist. The method is to remove the photomask, and the method is to deposit a photosensitive thin film, then expose and develop it. and a method of processing the thin film into a desired shape.

[0071] As described above, in the display device of one embodiment of the present invention, a channel-protective transistor is used. In forming the source and drain of a transistor, etc., a channel region of a semiconductor layer is etched. This can prevent damage caused by the transistors. This stabilizes the electrical characteristics of the transistor, resulting in a highly reliable transistor.

[0072] In the display device of one embodiment of the present invention, a first electrode of the capacitor is formed using a semiconductor The dielectric layer of the capacitor can be formed in the same process as the channel layer of the transistor. The second electrode of the capacitor can be formed in the same process as the transistor protection layer. The source or drain of the transistor can be formed in the same process. The manufacturing process of the display device of one embodiment can be simplified, and the manufacturing cost can be reduced. Cut.

[0073] As shown in FIG. 3(B) and FIG. 4, the light from the backlight unit 13 is The light from the backlight unit 13 is emitted in the direction indicated by the arrow. The output of the transistor 206 and the capacitor 34 are connected to the outside. It is also preferable that the film forming the capacitor 34 has light-transmitting properties. 206, the larger the area of ​​the light-transmitting region of the capacitance element 34, etc., the 13 light can be used efficiently.

[0074] As shown in FIG. 3B and FIG. 4, the light from the backlight unit 13 is The colored layer 131 may be used to take out the liquid. The color layer 131 can be colored in a desired color. , cyan (C), magenta (M), yellow (Y), etc.

[0075] In FIG. 3B, the light from the backlight unit 13 first passes through the transistor 206, Then, the transistor 206 or the capacitor 34 is The transmitted light is incident on the liquid crystal element 40. The light transmitted through the liquid crystal element 40 is reflected by the colored layer It is taken out via 131.

[0076] In FIG. 4, the light from the backlight unit 13 first enters the colored layer 131. The light that has passed through the colored layer 131 enters the liquid crystal element 40. The transmitted light is extracted to the outside via the transistor 206, the capacitance element 34, or the like.

[0077] The following materials can be used for the transistors, wiring, capacitors, and the like shown in FIG. These materials are semiconductors that transmit visible light in the configuration examples shown in this embodiment. The coating may also be applied to the coating layer and the conductive layer.

[0078] The semiconductor layer of the transistor can be formed using a light-transmitting semiconductor material. As the light-transmitting semiconductor material, a metal oxide or an oxide semiconductor (Oxid The oxide semiconductor is at least indium. It is preferable that the alloy contains indium and zinc. It is particularly preferable that the alloy contains indium and zinc. In addition to these, aluminum, gallium, yttrium, copper, vanadium, beryllium, Boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, Lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium The composition may contain one or more selected from the group consisting of ammonium nitrate, ammonium nitrate, and the like.

[0079] The conductive layers of the transistor and the capacitor are formed using a light-transmitting conductive material. The conductive material having light transmission is selected from the group consisting of indium, zinc, and tin. It is preferable to include one or more of the following: In oxide, In-Sn oxide, etc. In-Zn oxide (also called ITO: Indium Tin Oxide), In- W oxide, In-W-Zn oxide, In-Ti oxide, In-Sn-Ti oxide, In- Examples include Sn--Si oxide, Zn oxide, and Ga--Zn oxide.

[0080] In addition, the conductive layer of the transistor and the capacitor may be doped with an impurity element to reduce the A resistive oxide semiconductor may be used. It can be called an oxide conductor (OC).

[0081] For example, an oxide conductor is formed by forming oxygen vacancies in an oxide semiconductor and adding hydrogen to the oxygen vacancies. By this, a donor level is formed near the conduction band. As a result, the oxide semiconductor becomes highly conductive and becomes a conductor.

[0082] In addition, oxide semiconductors have a large energy gap (for example, an energy gap of 2 0.5 eV or more), it is transparent to visible light. The material conductor is an oxide semiconductor having a donor level near the conduction band. Conductors are less affected by absorption due to donor levels, and exhibit the same level of absorption as oxide semiconductors for visible light. It has a light transmittance of .

[0083] In addition, the oxide conductor may be formed by adding one or more metal elements contained in a semiconductor layer of a transistor. It is preferable that the oxide semiconductors constituting the transistors each have the same metal element. By using this material for two or more layers, the manufacturing equipment (e.g., deposition equipment, processing equipment, etc.) can be reduced by two or more Since it can be commonly used in the above steps, the manufacturing cost can be reduced.

[0084] By using the pixel structure of the display device described in this embodiment, Therefore, the power consumption is suppressed and the light emitted from the An excellent display device can be provided.

[0085] <2. Display device configuration example 2> Next, a display device according to one embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a perspective view of the display device 100. FIG. 6 is a cross-sectional view of the display device 100. In FIG. 61 is shown by a dashed line.

[0086] The display device 100 includes a display unit 62 and a drive circuit unit 64. PC72 and IC73 are implemented.

[0087] The display unit 62 has a plurality of pixels 900 and has a function of displaying an image.

[0088] The pixel 900 has a plurality of sub-pixels. For example, a sub-pixel that exhibits red, a sub-pixel that exhibits green, A pixel is formed by a blue sub-pixel and a blue sub-pixel. It is possible to display full color. The colors displayed by the sub-pixels are red, green, and blue. The pixel may include sub-pixels each having a color such as white, yellow, magenta, or cyan. In this specification and the like, a sub-pixel may be simply referred to as a pixel.

[0089] The display device 100 has one or both of a scanning line driving circuit and a signal line driving circuit. Alternatively, the display device may not have both the scanning line driver circuit and the signal line driver circuit. When the display device 100 has a sensor such as a touch sensor, the display device 100 In the present embodiment, the driving circuit section 64 includes a scanning line driver. The scanning line driver circuit outputs scanning signals to the scanning lines of the display unit 62. It has the function of outputting.

[0090] In the display device 100, the IC 73 is mounted on the substrate 51 by a mounting method such as the COG method. The IC 73 includes, for example, a signal line driver circuit, a scanning line driver circuit, and a sensor driver circuit. It has one or more of the following:

[0091] The display device 100 is electrically connected to an FPC 72. Signals and power are supplied from the outside to the FPC 72 and the drive circuit section 64. A signal can be output from IC73 to the outside via

[0092] An IC may be mounted on the FPC 72. For example, the FPC 72 may include a signal line drive circuit. An IC having one or more of the following circuits is mounted on the board: a scanning line driver circuit, a sensor driver circuit, and a It may be possible.

[0093] Signals and power are supplied to the display unit 62 and the drive circuit unit 64 through wiring 65. The signal and power are input to the wiring 65 from the IC 73 or from the outside via the FPC 72. Be encouraged.

[0094] 6 is a cross-sectional view including a pixel 900 and a driving circuit unit 64. As shown in FIG. The display device 100 includes a substrate 51, a transistor 201, a transistor 206, a liquid crystal element 40, An alignment film 133a, an alignment film 133b, a connection portion 204, an adhesive layer 141, a colored layer 131, and a light-shielding layer 132, an overcoat 121, and a substrate 61.

[0095] The liquid crystal element 40 includes a pixel electrode 111, a common electrode 112, and a liquid crystal layer 113. The alignment of the liquid crystal layer 113 is controlled by the electric field generated between the electrode 111 and the common electrode 112. The liquid crystal layer 113 is located between an alignment film 133a and an alignment film 133b.

[0096] In FIG. 6, the pixel electrode 111 is electrically connected to the conductive layer 232. The conductive layer 232 is connected to the other of the source electrode and the drain electrode of the transistor 206, The second electrode of the capacitor 34 is formed using a material that transmits visible light. In addition, the conductive layer 262 functioning as the first electrode of the capacitor 34 also transmits visible light. As a result, the area where the capacitor element 34 is provided is the display area 91. 8. Therefore, the aperture ratio of the pixel 900 can be increased. This makes it possible to reduce the power consumption of the display device 100.

[0097] 6, an alignment film is provided so as to be in contact with the liquid crystal layer 113. It has a function of controlling the alignment of the liquid crystal layer 113. In FIG. An alignment film 133a is provided, and an alignment film 133b is provided so as to be in contact with the common electrode 112. The alignment film 133a and / or the alignment film 133b may not be provided.

[0098] There are two types of liquid crystal materials: positive type, in which the anisotropy of the dielectric constant (Δε) is positive, and negative type, in which the anisotropy is negative. In one embodiment of the present invention, either material can be used, and the applied model The optimum liquid crystal material can be used depending on the mode and design.

[0099] In one embodiment of the present invention, it is preferable to use a negative type liquid crystal material. The influence of the flexoelectric effect caused by the polarization of molecules can be suppressed, and the transmittance due to polarity can be reduced. Therefore, the flicker is hardly noticeable to the user of the display device. The flexoelectric effect is mainly caused by the molecular shape, and can be suppressed by orientation distortion. This is a phenomenon in which polarization occurs. Negative liquid crystal materials have orientation distortions such as spreading and bending deformation. It's difficult.

[0100] It should be noted that liquid crystal elements to which various modes are applied can be used as the liquid crystal element 40. For example, FFS (Fringe Field Switching) mode, VA (Ver (Twisted Nematic) mode, mode, IPS (In-Plane-Switching) mode, ASM (Axiall y Symmetric aligned Micro-cell) mode, OCB(O (Fptically Compensated Birefringence) mode, LC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) mode, EC B(Electrically Controlled Birefringence) Uses liquid crystal elements that use mode, VA-IPS mode, guest host mode, etc. can be done.

[0101] In addition, the display device 100 may be a normally black type liquid crystal display device, for example, a vertical alignment (VA) A transmissive liquid crystal display device using a vertical alignment mode may be used. VA (Multi-Domain Vertical Alignment) mode, P VA(Patterned Vertical Alignment) mode, ASV( Advanced Super View mode, etc. can be used.

[0102] A liquid crystal element is an element that controls the transmission or non-transmission of light by the optical modulation action of liquid crystal. The optical modulation of liquid crystals is achieved by applying an electric field (horizontal electric field, vertical electric field, or For example, the optical properties of the liquid crystal can be controlled by a lateral electric field. When controlling the dynamic modulation effect, the control method can be called a lateral electric field method. The liquid crystals used are thermotropic liquid crystals, low molecular weight liquid crystals, polymer liquid crystals, and polymer dispersion liquids. Crystal (PDLC: Polymer Dispersed Liquid Crystal) The liquid crystal material may be a ferroelectric liquid crystal, an antiferroelectric liquid crystal, or the like. Therefore, cholesteric phase, smectic phase, cubic phase, chiral nematic phase, etc. Shows dimensions etc.

[0103] In addition, when the in-plane switching system is adopted, liquid crystal that exhibits a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases. When the temperature of a cholesteric liquid crystal is increased, the cholesteric The blue phase appears just before the transition from the crystalline phase to the isotropic phase. In order to improve the temperature range, a liquid crystal composition containing 5% by weight or more of chiral agent is used. The liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent is used for the liquid crystal layer 113. The response speed is short and the liquid crystal exhibits optical isotropy. The crystal composition does not require alignment treatment and has little viewing angle dependency. Since the rubbing process is unnecessary, electrostatic damage caused by the rubbing process is eliminated. This can prevent defects or damage to the liquid crystal display device during the manufacturing process. Cut.

[0104] Since the display device 100 is a transmissive liquid crystal display device, the pixel electrode 111 and the common electrode 1 One or both of the electrodes 12 are made of a conductive material that transmits visible light. One or both of the conductive layers 232 and 262 are made of a conductive material that transmits visible light. There are.

[0105] Examples of conductive materials that transmit visible light include indium (In), zinc (Zn), and tin. It is preferable to use a material containing one or more selected from the group consisting of indium oxide, tin, and tin. Indium, indium tin oxide (ITO), indium zinc oxide, tungsten oxide Indium oxide, indium zinc oxide with tungsten oxide, indium zinc oxide with titanium oxide Indium oxide, indium tin oxide with titanium oxide, indium with silicon oxide Examples include tin oxide (ITSO), zinc oxide, and zinc oxide containing gallium. A graphene-containing film can also be used. The graphene-containing film can be, for example, graphene oxide. The film can be formed by reducing a film containing the metal ions.

[0106] One or more of the conductive layer 232, the conductive layer 262, the pixel electrode 111, and the common electrode 112 It is preferable to use an oxide conductor for at least one of the transistors 20. It is preferable that the semiconductor layer 231 of the sixth embodiment has one or more kinds of metal elements. The conductive layer 262 preferably contains indium, and is preferably an In-M-Zn oxide (where M is Al, T It is more preferred that the film is a Cr film, such as a Cr film, a Ga film, a Y film, a Zr film, a La film, a Ce film, a Nd film, a Sn film, or a Hf film. It is preferable that the conductive layer 232 is an In-Zn oxide film. By using an In-Zn oxide film as the conductive layer 232, the display device 1 can be easily formed. It is possible to suppress the increase in resistance during the manufacturing process of 00.

[0107] One or more of the conductive layer 232, the conductive layer 262, the pixel electrode 111, and the common electrode 112 A plurality of the first and second insulating layers may be formed using an oxide semiconductor. By using this for two or more layers constituting the display device, It is possible to share the same equipment (machining equipment, etc.) for two or more processes, thereby reducing manufacturing costs. It is possible.

[0108] The oxide semiconductor has at least one of the following properties: oxygen vacancies in the film, and the concentration of impurities such as hydrogen and water in the film. The oxide semiconductor is a semiconductor material whose resistance can be controlled by the other. A process that increases oxygen deficiency and / or impurity concentration in the body, or oxygen deficiency By performing treatment to reduce at least one of the impurity concentration and the The resistivity of the oxide semiconductor can be controlled by controlling oxygen vacancies and impurity concentration. The oxide semiconductor is made to have a low resistance by performing a treatment to increase at least one of the above. A conductor can be formed.

[0109] In this manner, an oxide conductor formed using an oxide semiconductor has a high carrier density. The oxide semiconductor may be a low-resistance oxide semiconductor, a conductive oxide semiconductor, or a highly conductive oxide semiconductor. It can also be called the body.

[0110] In addition, by forming the oxide semiconductor and the oxide conductor from the same metal element, the manufacturing cost can be reduced. For example, by using a metal oxide target of the same metal composition, In addition, the manufacturing cost can be reduced by using a metal oxide target having the same metal composition. By using the above, the etching gas or etching solution for processing the oxide semiconductor can be However, the oxide semiconductor body and the oxide conductor may be made of the same metal. For example, during the manufacturing process of a display device, The metal elements in the mixture may be released, resulting in a different metal composition.

[0111] The transistor 206 includes a gate electrode 221, an insulating layer 211, a semiconductor layer 231, and an insulating layer 26. 1, a conductive layer 222, and a conductive layer 232. The semiconductor layer 231 contains indium. It is preferable that In-M-Zn oxide (M is Al, Ti, Ga, Y, Zr, La, Ce) is used. , Nd, Sn, or Hf) films are more preferred.

[0112] The gate electrode 221 has a region overlapping with the semiconductor layer 231 via the insulating layer 211. Specifically, the gate electrode 221 overlaps with the channel region of the semiconductor layer 231 via the insulating layer 211. It has a region as follows.

[0113] A semiconductor layer 231 is provided so as to be in contact with the insulating layer 211. An insulating layer 261 is provided so as to contact the conductive layer 222 and the insulating layer 211. The insulating layer 261 is electrically connected to the semiconductor layer 231 through an opening provided in the insulating layer 261. The conductive layer 232 is electrically connected to the semiconductor layer 231 through an opening provided in the insulating layer 261. is connected.

[0114] The insulating layer 211 functions as a gate insulating layer of the transistor 206. 31 has a channel region. The insulating layer 261 is a channel protection layer for the transistor 206. The conductive layer 222 serves as a source electrode or a drain electrode of the transistor 206. The conductive layer 232 serves as one of the source electrodes of the transistor 206. Alternatively, it has a function as the other of the drain electrodes.

[0115] Also, the gate electrode 221 can be a part of the scanning line. The conductive layer 204 may have a portion overlapping with the channel region of the conductive layer 206. The conductive layer 222 can be a part of the signal line. It is preferable that the electrical resistance of the gate electrode 221 and the electrical layer 222 is sufficiently low. The conductive layer 222 is preferably formed using a metal, an alloy, or the like. For the conductive layer 222, a material having a function of blocking visible light may be used.

[0116] As described above, the conductive layer 232 is made of a material that transmits visible light. That is, in one embodiment of the present invention, the transistor 206 is preferably The conductive layer 232 may be formed using a material different from that of the conductive layer 231 .

[0117] Specifically, conductive materials that transmit visible light and can be used for the conductive layer 232 and the like include copper and and aluminum, which are conductive materials that block visible light. Therefore, in order to prevent signal delay, the bus lines such as the scanning lines and the signal lines are made of visible light having a low resistivity. It is preferable to form the light shielding layer using a conductive material, for example, a metal material such as copper. The gate electrode 221 and the conductive layer 222 are preferably formed using a metal material such as copper. However, depending on the size of the pixel, the width of the bus line, the thickness of the bus line, etc. The lines can be made of a conductive material that transmits visible light.

[0118] In addition, by using a conductive layer that blocks visible light for the gate electrode 221, the light from the backlight is transmitted to the semiconductor This can prevent the semiconductor layer 231 from being irradiated with light. This can suppress the noise and improve the reliability of the transistor.

[0119] A light-shielding layer 132 is provided on the substrate 61 side of the semiconductor layer 231, and a light-shielding layer 132 is provided on the substrate 51 side of the semiconductor layer 231. By providing a gate electrode 221 for blocking visible light, external light and backlight can be blocked. This can prevent the semiconductor layer 231 from being irradiated with light.

[0120] In one embodiment of the present invention, the conductive layer that blocks visible light overlaps a portion of the semiconductor layer 231 and For example, the conductive layer that blocks visible light may not overlap with other parts of the conductive layer 231. Both of them may overlap with the channel region of the semiconductor layer 231 .

[0121] The transistor 206 is covered with an insulating layer 212, an insulating layer 214, and an insulating layer 215. Note that the insulating layer 212, the insulating layer 214, and the insulating layer 215 are formed on the insulating layer 212 of the transistor 206. The insulating layer 215 can also be regarded as a component. The insulating layer 215 functions as a planarization layer.

[0122] The insulating layer 212 may be configured to contain more oxygen than the stoichiometric composition. It is also preferable to form the insulating layer 214 and the insulating layer 215 from oxygen that satisfies the stoichiometric composition. The oxygen contained in the insulating layer 212 or the like can be removed by heat treatment or the like. A part of the electrons passes through the insulating layer 261 and is supplied to the channel region of the semiconductor layer 231. In the case where the channel region of the semiconductor layer 231 is an oxide semiconductor, the oxygen in the channel region As a result, the resistance of the channel region of the semiconductor layer 231 can be increased. This makes it possible to suppress fluctuations in the electrical characteristics of the transistor and improve reliability.

[0123] For example, when an oxide conductor is used as the conductive layer 262, the oxide conductor contained in the insulating layer 212 There is a possibility that oxygen will diffuse into the conductive layer 262, causing the conductive layer 262 to have a high resistance. The conductive layer 232 is made of a material that is difficult for oxygen to permeate. The oxygen contained in the conductive layer 262 is difficult to be supplied to the conductive layer 262. Even when a conductive material is used, the conductive layer 262 can be prevented from becoming high in resistance.

[0124] In the display device 100, a colored layer 131 and a light-shielding layer 13 are provided on the substrate 61 side of the liquid crystal layer 113. The colored layer 131 overlaps at least the display area 918 of the pixel 900. A light-shielding layer 132 is provided in the portion other than the display area 918 (non-display area). The light-shielding layer 132 overlaps at least a portion of the transistor 206.

[0125] An overcoat 121 is provided between the colored layer 131 and the light-shielding layer 132 and the liquid crystal layer 113. The overcoat 121 is preferably provided with a colored layer 131, a light-shielding layer 132, etc. This can prevent impurities contained in the insulating film 111 from diffusing into the liquid crystal layer 113.

[0126] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. A liquid crystal layer 113 is sealed in the area surrounded by 61 and adhesive layer 141 .

[0127] When the display device 100 is made to function as a transmissive liquid crystal display device, the polarizing plate is In FIG. 6, the polarizing plate 130 on the substrate 61 side is shown. The light from the backlight arranged on the outer side of the polarizing plate on the 51 side passes through the polarizing plate. At this time, the liquid crystal is By controlling the orientation of the layer 113, the optical modulation of light can be controlled. The intensity of the light emitted through the colored layer 131 can be controlled. Therefore, light outside of a specific wavelength range is absorbed, and the emitted light is, for example, red, blue, or or green light.

[0128] In addition to the polarizing plate, for example, a circular polarizing plate can be used. For example, a linear polarizing plate and a quarter-wave retardation plate can be laminated. This makes it possible to reduce the viewing angle dependency of the display device.

[0129] Moreover, the liquid crystal element 40 is preferably driven using a guest-host liquid crystal mode. When using the guest-host liquid crystal mode, no polarizing plate is required. This reduces the amount of light that can be extracted, improving the light extraction efficiency and making the display brighter. .

[0130] The drive circuit unit 64 includes a transistor 201 .

[0131] The transistor 201 includes a gate electrode 221, an insulating layer 211, a semiconductor layer 231, and an insulating layer 26. 1, conductive layer 224, and conductive layer 225. That is, one functions as a source electrode, and the other functions as a drain electrode. An opening is provided in the insulating layer 261, and the conductive layer 224 and the semiconductor layer 23 are exposed through the opening. 1 is electrically connected to the insulating layer 261. An opening is provided in the insulating layer 261. The conductive layer 225 and the semiconductor layer 231 are electrically connected to each other via the semiconductor layer 231. In 231, the connection portion with the conductive layer 224 and the connection portion with the conductive layer 225 are made to have low resistance. It is preferable to do so.

[0132] The transistors provided in the driver circuit portion 64 do not need to have a function of transmitting visible light. That is, the conductive layer 224 and the conductive layer 225 can be formed using a metal material or the like. Specifically, the conductive layer 222 can be formed using the same material. The conductive layer 224, the conductive layer 225, and the conductive layer 222 can be formed in the same process. .

[0133] In the connection portion 204, the wiring 65 and the conductive layer 251 are connected to each other, and the conductive layer 251 and the connection body 24 2 are connected to each other. That is, in the connection portion 204, the conductive layer 225 is connected to the conductive layer 251. The FPC 72 is electrically connected via the connector 242. Thus, signals and power can be supplied from the FPC 72 to the wiring 65 .

[0134] The wiring 65 is connected to the conductive layer 224, the conductive layer 225, and the The conductive layer 222 of the stator 206 can be formed of the same material and in the same process. The electrode layer 251 is formed of the same material and in the same process as the pixel electrode 111 of the liquid crystal element 40. In this way, the conductive layer constituting the connection portion 204 can be formed on the pixel 900 and the driving circuit If the conductive layer is fabricated using the same material and process as the conductive layer used in the portion 64, an increase in the number of processes can be prevented. This is preferable.

[0135] The transistor 201 and the transistor 206 may have the same structure or may have different structures. That is, the transistors in the driver circuit 64 and the transistors in the pixel 900 may be The transistor may have the same structure or a different structure. For example, the driving circuit section 6 The transistor in 4 does not have to be a channel protection type transistor. For example, Alternatively, the driving circuit section 64 may be a transistor of a multiple structure. The pixel 900 may have a transistor of a plurality of structures. For example, the driving circuit section 64 may be a channel protection type transistor and a channel etch type transistor. For example, the pixel 900 may have a channel protection transistor. The semiconductor device may have a transistor having a channel etch type and a transistor having a channel etch type.

[0136] In addition, the semiconductor layer 231 of the transistor 201 and the semiconductor layer 232 of the transistor 206 For example, the semiconductor layer 231 of the transistor 201 may be formed of a different material. The conductor layer 231 is made of amorphous silicon or low-temperature polysilicon. An oxide semiconductor may be used as the semiconductor layer 231 of the transistor 206. By using amorphous silicon or low-temperature polysilicon for the semiconductor layer of the As a result, the on-state current of the transistor can be increased. Furthermore, it is possible to reduce the area occupied by the circuit portion. By applying transistors with large on-state current, it is possible to make display devices larger or to make them more precise. Even if the number of wirings increases, it is possible to reduce the signal delay in each wiring. By applying such a configuration, it is possible to suppress the unevenness of the display. High-performance transistors can be realized.

[0137] FIG. 7 shows a modified example of the display device 100. The display device 100 shown in FIG. The fact that the stator 206 and the transistor 201 have a gate electrode 223 corresponds to the configuration shown in FIG. This is different from the display device 100 shown in FIG.

[0138] The gate electrode 223 is provided so as to be in contact with the insulating layer 214. The gate electrode 223 is provided so as to have an area overlapping with the semiconductor layer 231. For example, a metal material such as copper can be used as the gate electrode 2. The gate electrode 223 can be made of the same material as the gate electrode 221. For example, the gate electrode 221 and the gate electrode 223 may be formed of different materials. Alternatively, one of the gate electrodes may be made of a material having a light-shielding property, such as a metal material. One of the electrode 221 and the gate electrode 223 may be formed of an oxide conductor.

[0139] The gate electrode 221 and the gate electrode 223 can be electrically connected to each other. A transistor with two gate electrodes electrically connected to each other is It is possible to increase the field effect mobility and the on-current compared to As a result, a circuit capable of high speed operation can be fabricated. By using a transistor with a large on-current, the display Even if the number of wirings increases due to the larger size or higher resolution of the device, the signal delay in each wiring It is possible to reduce the amount of light emitted from the display and to suppress uneven display. By applying this configuration, a highly reliable transistor can be realized.

[0140] Among the transistors included in the display device 100, some of the transistors have a gate electrode 22. 3, and the other transistors may not have the gate electrode 223. For example, the transistor 201 has a gate electrode 223, and the transistor 20 The transistor 206 may not have the gate electrode 223. The transistor 201 has a gate electrode 223, and the transistor 202 does not have a gate electrode 223. In addition, some or all of the transistors included in the display device 100 may be Alternatively, the gate electrode 221 may not be provided.

[0141] Next, materials that can be used for each component of the display device of one embodiment of the present invention will be described in detail. The following description will be given. Note that the description of components that have already been explained may be omitted. In addition, the display device and touch panel described below, as well as their components, are made of the following materials: can be used appropriately.

[0142] <Substrates 51 and 61> There is no particular limitation on the material of the substrate of the display device of one embodiment of the present invention, and various substrates can be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a semiconductor substrate, a ceramic substrate, A metal substrate, a plastic substrate, or the like can be used.

[0143] By using a thin substrate, the display device can be made lighter and thinner. Furthermore, by using a substrate that is thick enough to provide flexibility, a flexible display device can be realized. can.

[0144] In the display device of one embodiment of the present invention, a transistor or the like is formed over a formation substrate, and then a By using a fabrication substrate, the characteristics of Formation of good transistors, formation of transistors with low power consumption, and durable display devices To manufacture, impart heat resistance to a display device, and to reduce the weight or thickness of the display device. The substrate on which the transistor is transferred is a substrate on which a transistor can be formed. Not limited to substrates, paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk , cotton, linen), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (a acetate, cupra, rayon, recycled polyester, etc.), leather substrate, or rubber A substrate or the like can be used.

[0145] Semiconductor layer The semiconductor material used for the semiconductor layer is not particularly limited, and examples thereof include oxide semiconductors, silicon, Germanium, etc. There are no particular limitations on the crystallinity of the semiconductor material used in the semiconductor layer. Semiconductors that are not amorphous or have crystallinity (microcrystalline semiconductors, polycrystalline semiconductors, single crystal semiconductors, etc.) Either a conductor or a semiconductor having a crystalline region in part may be used. The use of a semiconductor is preferable because it is possible to suppress the deterioration of the transistor characteristics.

[0146] For example, Group 14 elements, compound semiconductors, or oxide semiconductors can be used for the semiconductor layer. Typically, a semiconductor containing silicon, a semiconductor containing gallium arsenide, or an indium An oxide semiconductor containing the above can be used for the semiconductor layer.

[0147] An oxide semiconductor is preferably used as a semiconductor in which a channel of a transistor is formed. In particular, it is preferable to use an oxide semiconductor having a band gap larger than that of silicon. If a semiconductor material with a wider band gap and lower carrier density than silicon is used, This is preferable because it is possible to reduce the current in the off state of the transistor.

[0148] For the oxide semiconductor, the above description and Embodiment 4 and the like can be referred to.

[0149] By using an oxide semiconductor, fluctuations in electrical characteristics can be suppressed, resulting in highly reliable transistors. It can be achieved.

[0150] In addition, due to its low off-state current, the charge stored in the capacitance can be released through the transistor for a long period of time. By applying such transistors to pixels, It is also possible to stop the driving circuit while maintaining the gradation of the image displayed. A display device with reduced power consumption can be realized.

[0151] The transistors 201 and 206 are highly purified to suppress the formation of oxygen vacancies. In this way, in the off state of the transistor, The current value (off-state current value) can be reduced. Therefore, when an electric signal such as an image signal is held, The write interval can be set longer when the power is on. Since the frequency of refresh operations can be reduced, power consumption can be reduced. .

[0152] In addition, the transistor 201 and the transistor 206 have a relatively high field effect mobility. Since such a transistor capable of high speed operation can be used in a display device, By using this in a device, the transistors of the display section and the transistors of the drive circuit section can be mounted on the same substrate. That is, a driving circuit can be formed separately using a silicon wafer or the like. Since there is no need to use a semiconductor device that is not electrically connected to the display device, the number of parts in the display device can be reduced. In addition, the display section also uses transistors that can be driven at high speed, enabling high-quality images to be displayed. An image can be provided.

[0153] <Insulating layer> Insulating material that can be used for various insulating layers, overcoats, spacers, etc. in display devices As the insulating material, an organic insulating material or an inorganic insulating material can be used. For example, acrylic resin, epoxy resin, polyimide resin, polyamide resin, polyimide amide resin, siloxane resin, benzocyclobutene resin, and phenol resin. Examples of the inorganic insulating layer include a silicon oxide film, a silicon oxynitride film, and a silicon nitride oxide film. Kon film, silicon nitride film, aluminum oxide film, hafnium oxide film, yttrium oxide film , zirconium oxide film, gallium oxide film, tantalum oxide film, magnesium oxide film, laminar oxide film Examples of the thin film include a titanium oxide film, a cerium oxide film, and a neodymium oxide film.

[0154] <Conductive layer> In addition to the gates, sources, and drains of transistors, various wirings and electrodes of display devices Conductive layers include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, etc. Metals such as tungsten, molybdenum, silver, tantalum, or tungsten, or those mainly composed of these The alloy may be used as a single layer or a multilayer structure. A two-layer structure in which a titanium film is laminated on a tungsten film, a two-layer structure in which a titanium film is laminated on a tungsten film, A two-layer structure with a copper film laminated on a molybdenum film, and an alloy film containing molybdenum and tungsten A two-layer structure with a copper film laminated on top of a copper-magnesium-aluminum alloy film. A layer structure, a titanium film or a titanium nitride film, and an alumina layer on the titanium film or the titanium nitride film. An aluminum film or a copper film is laminated, and then a titanium film or a titanium nitride film is formed on the aluminum film or a copper film. A three-layer structure consisting of a molybdenum film or molybdenum nitride film and a molybdenum film or molybdenum nitride film. An aluminum or copper film is layered on top of the molybdenum film, and then a molybdenum film or For example, when the conductive layer has a three-layer structure, In this case, the first and third layers are titanium, titanium nitride, molybdenum, tungsten, molybdenum, Alloys containing tungsten and tungsten, alloys containing molybdenum and zirconium, or molybdenum nitride The first layer is made of copper, aluminum, gold or silver, or copper and manganese. It is preferable to form a film made of a low resistance material such as a tantalum alloy. Indium oxide with tungsten, indium zinc oxide with tungsten oxide, oxide Indium oxide containing titanium, indium tin oxide containing titanium oxide, indium zinc A light-transmitting conductive material such as oxide or ITSO may be used.

[0155] Note that an oxide conductor may be formed by controlling the resistivity of an oxide semiconductor.

[0156] ≪Adhesive layer 141≫ The adhesive layer 141 is made of a hard material such as a thermosetting resin, a photocurable resin, or a two-liquid mixed type hardening resin. Chemically-compatible resins can be used. For example, acrylic resins, urethane resins, epoxy resins, Alternatively, a siloxane resin or the like can be used.

[0157] <Connector 242> The connector 242 may be, for example, an anisotropic conductive film (ACF). Conductive Film), or Anisotropic Conductive Paste (ACP) For example, a tropic conductive paste can be used.

[0158] ≪Colored layer 131≫ The colored layer 131 is a colored layer that transmits light of a specific wavelength band. Materials that can be used include metal materials, resin materials, and resin materials containing pigments or dyes. etc.

[0159] ≪Light blocking layer 132≫ The light-shielding layer 132 is provided, for example, between adjacent colored layers 131 of different colors. For example, A black matrix formed using a metal material or a resin material containing a pigment or dye. The light-shielding layer 132 may be made of a material other than the driving circuit section 64. It is preferable to provide the same in an area other than the pixel 900, because it is possible to suppress light leakage due to guided light, etc. stomach.

[0160] <3. Example of a method for manufacturing a display device> An example of a method for manufacturing the display device 100 having the configuration shown in FIG. 6 will be described with reference to FIGS. 9(A) and (B) will be used to explain the method. By changing the configuration of the transistors and liquid crystal elements, the display devices according to the present embodiment can be used. It can be made.

[0161] The thin films (insulating film, semiconductor film, conductive film, etc.) that make up the display device are each formed by sputtering. Chemical Vapor Deposition (CVD) method , vacuum deposition, pulsed laser deposition (PLD) ion) method, Atomic Layer Deposition (ALD) The CVD method can be used to form the film. An example of the CVD method is plasma-enhanced chemical vapor deposition (PE Examples of thermal CVD include the metal organic chemical vapor deposition (MOCVD) method and the thermal CVD method. deposition (MOCVD: Metal Organic CVD) method.

[0162] The thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device are formed by spin coating, Dip, spray application, inkjet printing, dispensing, screen printing, offset Printing, doctor knife, slit coat, roll coat, curtain coat, knife coat The film can be formed by a method such as a coating method.

[0163] The thin film constituting the display device can be processed using a lithography method or the like. Alternatively, the island-shaped thin film may be formed by a film formation method using a shielding mask. The thin film may be processed by a lint method, a sandblasting method, a lift-off method, or the like.

[0164] When processing using photolithography, the light used for exposure is, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), and mixtures of these. Other examples include ultraviolet light, KrF laser light, and ArF laser light. Also, the exposure may be performed by immersion exposure. Examples of such light include extreme ultraviolet (EUV) and X-rays. In place of the light used for exposure, an electron beam can also be used. Extreme ultraviolet light, X-rays, or electron beams are preferred because they enable extremely fine processing. In addition, when exposure is performed by scanning a beam such as an electron beam, a photomath No sc is required.

[0165] For etching thin films, there are dry etching, wet etching, and sandblasting methods. etc. can be used.

[0166] When manufacturing the display device 100, first, a conductive layer is formed on the substrate 51, and the conductive layer is lithographed. By processing using a roughing method or the like, a wiring 902 and a gate electrode 221 are formed. As described above, the wiring 902 functions as a scanning line. The wiring 902 and the gate electrode 221 have a low resistivity. It is preferable to form the insulating layer using a conductive material that blocks visible light, for example, a metallic material such as copper.

[0167] Next, the insulating layer 211 is formed. As described above, the insulating layer 211 is provided on the display device 100. The insulating layer functions as a gate insulating layer of the transistor.

[0168] Thereafter, a semiconductor layer is formed and processed by lithography or the like. Then, the semiconductor layer 231 and the semiconductor layer 262a are formed (FIG. 8(A)). The display device 100 has a region that functions as a channel region of a transistor. The semiconductor layer 231 and the semiconductor layer 262a are preferably made of an oxide semiconductor. For example, it is preferable to contain indium, and In-M-Zn oxide (wherein M is Al, Ti, More preferably, the film is a film of one of the elements selected from the group consisting of Ga, Y, Zr, La, Ce, Nd, Sn and Hf.

[0169] Next, the insulating layer 261 is formed (FIG. 8(B)). As described above, the insulating layer 261 is A channel protection layer of a transistor provided in the display device 100 and It functions as a dielectric layer of the capacitance element.

[0170] The insulating layer 261 can be, for example, a silicon oxynitride film. For example, the film can be formed by a CVD method, particularly a PECVD method. When forming a film by a CVD method, for example, silane gas is used as a film forming gas, and Nitrogen oxide gas such as nitrous oxide is used. In this case, hydrogen or the like is mixed during the formation of the insulating layer 261. This is supplied to the conductor layer 262a, and the resistance of the semiconductor layer 262a can be reduced. , a conductive layer 262 having a function as a first electrode of a capacitor provided in the display device 100 can be formed.

[0171] The insulating layer 261 formed by the above method contains ammonia. Even if hydrogen or the like supplied to the conductive layer 262 diffuses outward when a heat treatment or the like is performed after the deposition of the conductive layer 262, The ammonia contained in the insulating layer 261 is supplied to the conductive layer 262, whereby the conductive layer 2 It is possible to suppress an increase in the resistivity of 62.

[0172] In addition, hydrogen or the like is supplied to the semiconductor layer 231 during the formation of the insulating layer 261, and the semiconductor layer 231 becomes active. However, the resistance of the channel region where the semiconductor layer is formed may be reduced by a subsequent process. Since the channel region of the insulating layer 231 can be made highly resistant, Therefore, no problem occurs even if the resistance is reduced.

[0173] Next, an opening is provided in the insulating layer 261, which reaches the semiconductor layer 231. Then, the semiconductor layer 232a The semiconductor layer 232a has a region overlapping with the conductive layer 262. The conductor layer 232a is electrically connected to the semiconductor layer 231 through an opening provided in the insulating layer 261. is connected to.

[0174] For example, In-Zn oxide is preferably used as the semiconductor layer 232a. The substrate temperature was set to a temperature that was not intentionally heated by the sputtering method, and argon (Ar) was used. It is preferable to form the In-Zn oxide film in a 100% nitrogen atmosphere. By using In-Zn oxide as the a, the resistance of the semiconductor layer 232a is reduced in a later process. A conductive layer 232 can be formed, and the formed conductive layer 232 can be further The semiconductor layer 232a is made of In-Zn An oxide semiconductor other than the oxide may be used. In this case, the semiconductor layer 232a is It is preferable that the semiconductor layer 232a contains one or more of the metal elements contained in the semiconductor layer 232a. If the metal element in 231 is present in one or more of the following materials, the manufacturing equipment (e.g., film forming equipment, processing equipment, etc.) Since it is possible to share the same equipment for two or more processes, manufacturing costs can be reduced. This can be done.

[0175] Next, an opening is provided in the insulating layer 261 so as to reach the semiconductor layer 231. Then, the conductive layer 222 and the conductive Then, a conductive layer 224, a conductive layer 225, and a wiring 65 are formed (FIG. 8(C)). 22, the conductive layer 224, and the conductive layer 225 are connected to each other through an opening provided in the insulating layer 261. , and is electrically connected to the semiconductor layer 231 .

[0176] As described above, the conductive layer 222 is a source or drain electrode of the transistor 206. The conductive layer 224 functions as a source electrode of the transistor 201. The conductive layer 225 functions as one of the drain electrodes of the transistor 2. The conductive layer 222 serves as the other of the source electrode and the drain electrode of the semiconductor device 220. The conductive layer 222, the conductive layer 224, the conductive layer 225 and the conductive layer 226 may be a part of the signal line. The wiring 65 is made of a conductive material that blocks visible light and has a low resistivity, such as a metal material such as copper. It is preferable to form

[0177] Since the insulating layer 261 functions as a channel protection layer, the conductive layer 222 and the semiconductor Upon formation of layer 232a, conductive layer 224, and conductive layer 225, the channel of semiconductor layer 231 This makes it possible to suppress damage to the region caused by etching. In this way, the electrical characteristics of the transistors included in the display device 100 can be stabilized, and highly reliable transistors can be obtained. It is possible to realize the star.

[0178] After the opening is formed in the insulating layer 261, an inert gas such as argon is introduced into the semiconductor layer 231. By supplying the source voltage of the transistor 206 and / or the transistor 201, The contact portion with the electrode and the contact portion with the drain electrode may be made n-type. For example, sputtering, ion implantation, ion doping, plasma immersion, etc. The method may be an ion implantation method, a plasma treatment, or the like. And / or, the on-state current of the transistor 201 is increased to speed up the operation of the display device 100. It is possible.

[0179] Next, the insulating layer 212 is formed. The insulating layer 212 may be formed of, for example, silicon oxynitride. The insulating layer 212 can be formed by, for example, a CVD method, particularly a PECVD method. When a film containing silicon oxynitride is formed by a CVD method, for example, Silane gas is used as the film forming gas, and nitrogen oxide gas such as nitrous oxide gas is also used. In this case, hydrogen or the like is supplied to the semiconductor layer 232a during the formation of the insulating layer 212, 2a can be made to have a low resistance. A conductive layer having a function as a drain electrode and a function as a second electrode of the capacitor 34. A layer 232 may be formed.

[0180] In addition, the insulating layer 212 may contain more oxygen than the stoichiometric amount. For example, when the insulating layer 212 is formed by a CVD method, oxygen or other gas is preferably used as the film forming gas. Alternatively, a mixture of oxygen and nitrogen oxide gases such as nitrous oxide or nitrogen dioxide may be used. In addition, after the insulating layer 212 is formed, oxygen can be contained in the insulating layer 212. Ion implantation method, ion doping method, plasma immersion ion implantation method, plasma processing, etc. Oxygen may be introduced into the insulating layer 212 by this.

[0181] The oxygen contained in the insulating layer 212 is partially transmitted through the insulating layer 261 by heat treatment or the like and is transferred to the semiconductor layer This supplies the channel region of the semiconductor layer 231 with oxygen. In the case of a semiconductor material, oxygen vacancies in the channel region can be reduced. The channel region of the semiconductor layer 231 can be made highly resistive, and the electrical characteristics of the transistor can be changed. This can suppress vibration and improve reliability.

[0182] For example, when an oxide conductor is used as the conductive layer 262, the oxide conductor contained in the insulating layer 212 There is a possibility that oxygen will diffuse into the conductive layer 262, causing the conductive layer 262 to have a high resistance. The conductive layer 232 is made of a material that is difficult for oxygen to permeate. The oxygen contained in the conductive layer 262 is difficult to be supplied to the conductive layer 262. Even when a conductive material is used, the conductive layer 262 can be prevented from becoming high in resistance.

[0183] Next, the insulating layer 214 is formed. After that, the insulating layer 215 is formed. After that, chemical mechanical polishing (CMP) The insulating layer 215 is subjected to planarization treatment by a method such as (FIG. 9(A)).

[0184] Next, an opening is formed in the insulating layer 215, the insulating layer 214, and the insulating layer 212, reaching the conductive layer 232. An opening is then provided that reaches the wiring 65 and the insulating layer 66. Then, a conductive layer is provided and the conductive layer is lithographed. The pixel electrode 111 and the conductive layer 251 are formed by processing using a roughing method or the like. The pixel electrodes are connected to the insulating layers 215, 214, and 212 through openings. The electrode 111 is electrically connected to the conductive layer 232, and the conductive layer 251 is electrically connected to the wiring 65. As described above, the pixel electrode 111 is made of a material having a function of transmitting visible light. is used.

[0185] Next, an alignment film 133a is formed so as to cover the pixel electrodes 111 (FIG. 9(B)). On the substrate 61, a light-shielding layer 132, a colored layer 131, an overcoat 121, and a common electrode 112 are formed. As described above, the common electrode 112 is formed on the substrate 133b. Therefore, a material that has a function of transmitting visible light is used.

[0186] Furthermore, an adhesive layer 14 is provided between the substrate 51 shown in FIG. 9(B) and the substrate 61 shown in FIG. 1 is used to seal the liquid crystal layer 113. Then, the connector 242, the FPC 72, and the polarizing plate In this manner, the display device 100 shown in FIG. do.

[0187] As described above, in the method for manufacturing a display device according to one embodiment of the present invention, the transistor 206 is The semiconductor layer 231 and the conductive layer 262 of the capacitor 34 are formed in the same process. In addition, an insulating layer having a function as a channel protection layer of the transistor 206 and The insulating layer 261 and the insulating layer having the function as the dielectric layer of the capacitance element 34 are formed in one process. The source electrode or drain electrode of the transistor 206 can be formed of The conductive layer having the function as the other electrode of the capacitance element 34 and the conductive layer having the function as the second electrode of the capacitance element 34 The conductive layer and the conductive layer 232 can be formed in one step. The manufacturing process of the display device 100 can be simplified, and the manufacturing cost of the display device 100 can be reduced. This can be done.

[0188] As described above, the conductive layer 262 and the conductive layer 232 have a function of transmitting visible light. This makes it possible to increase the aperture ratio of the pixel 900 of the display device 100. The higher the aperture ratio, the higher the light extraction efficiency, and therefore the power consumption of the display device 100. In addition, the image displayed by the display device 100 can be made higher definition. can be done.

[0189] <4. Example of pixel arrangement> 10A and 10B show examples of the arrangement of a pixel 900 and sub-pixels included in the pixel 900. In FIG. In FIG. 10(A) and (B), the red subpixel R, the green subpixel G, and the blue subpixel B are 10(A) and 10(B), a plurality of scanning lines 81 are arranged to form one pixel. The scanning lines 81 and the signal lines 82 extend in the x direction and the y direction, respectively. The lines 82 cross.

[0190] As shown in the double-dashed line frame in FIG. 10A, the subpixel includes a transistor 206, a capacitor element 34, and the liquid crystal element 40. The gate electrode of the transistor 206 is connected to the scan line 81. One of the source electrode and the drain electrode of the transistor 206 is electrically connected to The first electrode is electrically connected to the signal line 82, and the second electrode is electrically connected to the second electrode of the capacitance element 34 and the liquid crystal element The first electrode of the capacitor element 34 and the liquid crystal element 40 are electrically connected to each other. A constant potential is applied to each of the first electrodes.

[0191] 10A and 10B show an example in which source line inversion driving is applied. Signals A1 and A2 are signals of the same polarity. Signals B1 and B2 are signals of the same polarity. Signals A2 and B2 are signals with opposite polarities. The number is.

[0192] As the resolution of a display device increases, the distance between sub-pixels becomes narrower. As shown in the dashed line frame in FIG. 1, in the sub-pixel to which the signal A1 is input, the signal B1 is input In the vicinity of the signal line 82, the liquid crystal is easily affected by the potentials of both the signal A1 and the signal B1. This makes the liquid crystal alignment more likely to be poor.

[0193] In FIG. 10A, the direction in which multiple sub-pixels exhibiting the same color are arranged is the y direction. The direction is approximately parallel to the direction in which the signal line 82 extends. A subpixel exhibiting a different color is adjacent to the long side of the subpixel.

[0194] In FIG. 10B, the direction in which multiple sub-pixels exhibiting the same color are arranged is the x direction. As shown in the dashed line frame in FIG. Sub-pixels of the same color are adjacent to each other on the short side of the pixel.

[0195] As shown in FIG. 10B, in the subpixel, a side that is approximately parallel to the direction in which the signal line 82 extends However, when the side is short, the alignment of the liquid crystal is more likely to be poor than when the side is long (FIG. 10(A)). As shown in FIG. 10(B), the alignment defect of the liquid crystal is easily caused. When a convex region is located between subpixels that have the same color, a convex region is located between subpixels that have different colors. In comparison with the case where the display device is turned on (FIG. 10(A)), the display defect is less likely to be visually recognized by the user of the display device. In one embodiment of the present invention, the direction in which a plurality of sub-pixels exhibiting the same color are arranged is a direction along which the signal line It is preferable that 82 intersects the direction of extension.

[0196] <5. Display device configuration example 3> One embodiment of the present invention is a display device (an input / output device or a touch panel) equipped with a touch sensor. The configuration of each of the above-mentioned display devices can be applied to a touch panel. In the present embodiment, an example in which a touch sensor is mounted on the display device 100 will be mainly described. explain.

[0197] There is no limitation on a detection element (also referred to as a sensor element) included in a touch panel of one embodiment of the present invention. Various sensors that can detect the proximity or contact of a detection target such as a finger or stylus, It can be used as a sensing element.

[0198] The sensor type may be, for example, a capacitance type, a resistive film type, a surface acoustic wave type, or an infrared type. Various methods such as a pressure-sensitive method, an optical method, or a pressure-sensitive method can be used.

[0199] In this embodiment, a touch panel having a capacitance type sensing element will be described as an example. .

[0200] The capacitive touch sensor includes a surface capacitive touch sensor and a projected capacitive touch sensor. The electrostatic capacitance type includes the self-capacitance type and the mutual capacitance type. This is preferable because it enables simultaneous multi-point detection.

[0201] The touch panel according to one embodiment of the present invention is formed by bonding a display device and a sensing element that are separately manufactured. A detector element is provided on one or both of a substrate supporting a display element and an opposing substrate. Various configurations can be applied, such as a configuration in which electrodes or the like are provided.

[0202] 11 and 12 show an example of a touch panel. FIG. 11(A) shows a touch panel 35 FIG. 11(B) is a perspective view of FIG. 11(A). For clarity, only representative components are shown. In FIG. 11(B), the substrate 61 and The substrate 162 is shown by a dashed line, with only the outline being shown. FIG. 12 is a cross-sectional view of the touch panel 350. do.

[0203] The touch panel 350 is constructed by bonding a display device and a sensing element that are separately manufactured. do.

[0204] The touch panel 350 includes an input device 375 and a display device 370, which are stacked on top of each other. It is being done.

[0205] The input device 375 includes a substrate 162, an electrode 127, an electrode 128, a plurality of wirings 137, and a plurality of The FPC 72b has a plurality of wirings 137 and a plurality of wirings 138. Each is electrically connected to the other. IC 73b is provided on FPC 72b.

[0206] The display device 370 has a substrate 51 and a substrate 61 disposed opposite each other. The substrate 51 has a display section 62 and a driving circuit section 64. Wiring 65 and the like are provided on the substrate 51. The FPC 72a is electrically connected to the wiring 65. The FPC 72a is provided with an IC 73a. is provided.

[0207] Signals and power are supplied to the display unit 62 and the drive circuit unit 64 through wiring 65. The signal and power are input to the wiring 65 from the outside or IC 73a via the FPC 72a. will be done.

[0208] FIG. 12 shows a region including a pixel 900, a driving circuit section 64, and an FPC 72a, and an FPC 72b. 1 is a cross-sectional view of a region including the above.

[0209] The substrate 51 and the substrate 61 are bonded together by an adhesive layer 141. The substrate 51 and the substrate 61 are attached to each other by an adhesive layer 169. Each layer in the figure corresponds to a display device 370. In addition, each layer from the substrate 162 to the electrode 124 This corresponds to the input device 375. In other words, the adhesive layer 169 is It can be said that the two are pasted together.

[0210] The configuration of the display device 370 shown in FIG. 12 is similar to that of the display device 100 shown in FIG. Therefore, detailed description will be omitted.

[0211] A polarizing plate 165 is attached to the substrate 51 by an adhesive layer 167. A backlight 161 is attached to the substrate 5 via an adhesive layer 163.

[0212] The backlight 161 may be a direct-light type backlight or an edge-light type backlight. When using a direct-type backlight with LEDs, complex local This is preferable because it allows dimming and enhances contrast. By using a backlight of the reflective type, the thickness of the module including the backlight can be reduced. In addition, quantum dots may be used as the backlight 161.

[0213] Quantum dots are semiconductor nanocrystals with a size of a few nm, and are about 1×10 3 1×10 6 Quantum dots are composed of about 100 atoms. The energy shift of quantum dots depends on their size. Therefore, even if quantum dots are made of the same material, their emission wavelengths differ depending on their size. The emission wavelength can be easily adjusted by changing the size of the quantum dots used. can.

[0214] In addition, quantum dots have a narrow emission spectrum peak width, making it possible to obtain light emission with good color purity. Furthermore, the theoretical external quantum efficiency of quantum dots is said to be nearly 100%. This is much higher than the 25% of organic compounds that emit fluorescent light, and the percentage of organic compounds that emit phosphorescent light is This shows that the quantum dots used as luminescent materials can In addition, quantum dots, which are inorganic compounds, can be used to obtain light-emitting devices with high luminous efficiency. Since the intrinsic stability is also excellent, it is possible to obtain a light-emitting element that is favorable from the viewpoint of life. can be done.

[0215] The materials that make up quantum dots are elements in Group 14 of the periodic table, elements in Group 15 of the periodic table, Group 16 elements, compounds consisting of multiple Group 14 elements, Groups 4 to 1 Compounds of Group 4 elements and Group 16 elements of the periodic table, Compounds of Group 2 elements and Group 16 elements of the periodic table Compounds with elements, compounds with elements in group 13 and group 15, compounds with elements in group 13 Compounds of elements and elements of group 17 of the periodic table, compounds of elements of group 14 of the periodic table and elements of group 15 of the periodic table compounds of elements in Group 11 and Group 17 of the periodic table; iron oxides; titanium oxides; Examples include chalcogenide spinels and various semiconductor clusters.

[0216] Specifically, cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide , zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, arsenide Indium, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride Lithium, indium antimonide, gallium antimonide, aluminum phosphide, arsenide Aluminum, aluminum antimonide, lead selenide, lead telluride, lead sulfide, lead selenide Indium, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, selenium arsenic sulphide, arsenic telluride, antimony sulphide, antimony selenide, antimony telluride, sulphide Bismuth carbide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium , tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, boron arsenide, Aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride Calcium, calcium sulfide, calcium selenide, calcium telluride, beryllium sulfide, selenium Beryllium telluride, beryllium sulfide, magnesium selenide, sulfur Germanium sulphide, germanium selenide, germanium telluride, tin sulfide, tin selenide, Tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, copper oxide Nickel, cobalt oxide, cobalt sulfide, triiron tetroxide, iron sulfide, manganese oxide, molybdenum sulfide Butane, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide , silicon nitride, germanium nitride, aluminum oxide, barium titanate, selenium and Compounds of zinc and cadmium, compounds of indium, arsenic and phosphorus, compounds of cadmium, selenium and sulfur Yellow Compound, Cadmium, Selenium, and Tellurium Compound, Indium, Gallium, and Arsenic Compound compounds of indium, gallium and selenium compounds of indium, selenium and sulfur compounds of copper and Examples of the compound include, but are not limited to, compounds of indium and sulfur and combinations thereof. In addition, the composition is expressed in an arbitrary ratio, so-called alloy type quantum dots For example, alloy quantum dots of cadmium, selenium, and sulfur may be used. By changing the ratio, the emission wavelength can be changed, which is effective for obtaining blue light. It is one of the means.

[0217] Quantum dot structures include core type, core-shell type, and core-multishell type. Either of these can be used, but another inorganic material with a wider band gap can be placed over the core. By forming a shell with , defects and dangling bonds on the nanocrystal surface can be eliminated. This can reduce the effect of the core- It is preferable to use shell-type or core-multishell type quantum dots. Examples include zinc sulfide and zinc oxide.

[0218] In addition, quantum dots have a high proportion of surface atoms, making them highly reactive and prone to aggregation. Therefore, a protective agent or a protective group is attached to the surface of the quantum dots. It is preferable that the protecting agent is attached or the protecting group is provided. This prevents aggregation and increases solubility in solvents. It also reduces reactivity and improves electrical conductivity. It is also possible to improve the mechanical stability. Examples of the protecting agent (or protecting group) include poly(phenylene ether). Polyoxyethylene lauryl ether, Polyoxyethylene stearyl ether, Polyoxyethylene Polyoxyethylene alkyl ethers such as diethylene oleyl ether, tripropyl Phosphine, tributylphosphine, trihexylphosphine, trioctylphosphine Trialkylphosphines such as polyoxyethylene n-octylphenyl ether, poly Polyoxyethylene alkyl phenyl ether, etc. Ethers, tri(n-hexyl)amine, tri(n-octyl)amine, tri(n-decyl)amine tertiary amines such as tripropylphosphine oxide, tributylphosphine oxide, etc. phosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, Organophosphorus compounds such as decylphosphine oxide, polyethylene glycol dilaurate polyethylene glycol diesters such as polyethylene glycol distearate, In addition, organic nitrogenation of nitrogen-containing aromatic compounds such as pyridine, lutidine, collidine, and quinolines Compounds, hexylamine, octylamine, decylamine, dodecylamine, tetradecyl Aminoalkanes such as amine, hexadecylamine, octadecylamine, dibutylsulfate, dialkyl sulfides such as dimethyl sulfoxide and dibutyl sulfoxide Dialkyl sulfoxides, sulfur-containing aromatic compounds such as thiophene, and other organic sulfur compounds, Higher fatty acids such as lumetic acid, stearic acid, and oleic acid, alcohols, and sorbitan fats Acid esters, fatty acid modified polyesters, tertiary amine modified polyurethanes, polyethylene Examples of suitable amines include imines.

[0219] As quantum dots become smaller, their band gaps become larger, so they can emit light at the desired wavelength. The size of the crystal is adjusted accordingly to obtain the desired amount of light. The emission of the quantum dots is shifted to the blue side, i.e., to higher energy, so By varying the size, the wavelength range of the spectrum can be expanded to include the ultraviolet, visible, and infrared regions. The emission wavelength can be adjusted over a wide range. The size (diameter) of quantum dots is 0. A range of 5 nm to 20 nm, preferably 1 nm to 10 nm, is usually used. In addition, the narrower the size distribution of quantum dots, the narrower the emission spectrum becomes and the higher the color purity becomes. The shape of the quantum dots is not particularly limited, and may be spherical, The quantum dots may be rod-shaped, disk-shaped, or have other shapes. Since the quantum rods emit light with a polarized light direction along the c-axis, This makes it possible to obtain a light emitting device with better external quantum efficiency.

[0220] A polarizing plate 166 is attached to the substrate 162 by an adhesive layer 168. A protection substrate 160 is attached to the substrate 66 by an adhesive layer 164. When the touch panel 350 is assembled, the protection board 160 is placed on the touch panel 350 so that the object to be detected, such as a finger or a stylus, The protective substrate 160 may be used as a substrate that is directly touched. The protective substrate 160 can be a substrate 51 and a A structure in which a protective layer is formed on the surface of a substrate that can be used for the substrate 61, etc., or a reinforced glass It is preferable to use a protective layer such as a ceramic coating. Alternatively, the protective layer may be made of silicon oxide, aluminum oxide, yttrium oxide, yttrium oxide, or yttrium oxide. It can be formed using an inorganic insulating material such as thoria-stabilized zirconia (YSZ).

[0221] A polarizing plate 166 may be disposed between the input device 375 and the display device 370. In that case, as shown in FIG. 2, the protection substrate 160, the adhesive layer 164, and the adhesive layer 168 may not be provided. In this case, the substrate 162 may be located on the top surface of the touch panel 350. It is preferable to use a material that can be used for the protection substrate 160 described above for 62 .

[0222] An electrode 127 and an electrode 128 are provided on the substrate 61 side of the substrate 162. 7 and electrode 128 are formed on the same plane. The electrode 124 is disposed so as to cover the electrode 128. The electrode 124 is disposed through an opening in the insulating layer 125. The electrode 127 is electrically connected to two electrodes 128 disposed on either side of the electrode 127 via the .

[0223] Among the conductive layers of the input device 375, the conductive layers overlapping the display area 918 (electrodes 127, 1 28, etc.) are made of a material that transmits visible light.

[0224] The wiring 137 obtained by processing the same conductive layer as the electrodes 127 and 128 is the same as the electrode 124. The conductive layer 126 is connected to the conductive layer 126 obtained by processing the conductive layer of the connecting body 24. 2b and is electrically connected to FPC 72b.

[0225] This embodiment mode can be appropriately combined with other embodiment modes. In the case where a plurality of configuration examples are shown in one embodiment, the configuration examples may be appropriately combined. It is possible to do this.

[0226] (Embodiment 2) In this embodiment, operation modes that can be performed in a display device according to one embodiment of the present invention will be described. 13 will be used to explain.

[0227] In the following, we will assume that the device operates at a normal frame frequency (typically 60 Hz or higher and 240 Hz or lower). There are two operating modes: Normal mode, which operates at a slower frame rate, and Low mode, which operates at a slower frame rate. The idle stop (IDS) driving mode will be explained as an example.

[0228] In the IDS drive mode, the image data is written and then the image data is written. This is a driving method that stops switching of the image data. By extending the interval between writing the image data, the time required to write the image data during that time is reduced. The IDS drive mode can reduce the power consumption by the amount of power consumed by the IDS. The frame frequency can be set to about 1 / 100 to 1 / 10 of the normal frame rate. The video signal is the same between frames. Therefore, the IDS driving mode can display still images. This is particularly effective when displaying images using IDS driving, which reduces power consumption. This reduces noise and screen flicker, helping to reduce eye strain.

[0229] 13(A), (B), and (C) show the pixel circuit and the normal drive mode and the IDS drive mode. 13A is a timing chart for explaining the operation of the first display element 50. 1 (here, a reflective liquid crystal element) and a pixel circuit electrically connected to the first display element 501. In the pixel circuit 506 shown in FIG. a gate line GL; a transistor M1 connected to the signal line SL and the gate line GL; Capacitance element Cs connected to transistor M1 LC In addition, the first display element One electrode of 501, one of the source and drain of the transistor M1, and a capacitance element Cs LC The node to which is connected is called node ND1.

[0230] The transistor M1 is connected to the capacitance element Cs LC This can be a leak path for data D1 stored in Therefore, it is preferable that the off-state current of the transistor M1 is as small as possible. In the present invention, it is preferable to use a transistor having a metal oxide in a semiconductor layer in which a channel is formed. It is preferable that the metal oxide has at least one of an amplifying function, a rectifying function, and a switching function. When the metal oxide has a metal oxide semiconductor, conductor) or oxide semiconductor Here, we will introduce a typical example of a transistor in which a channel is formed. A transistor using an oxide semiconductor for a semiconductor layer (also called an OS transistor) The OS transistor is a transistor that uses polycrystalline silicon, etc. The transistor M1 also has the characteristic of having an extremely low leakage current (off-state current) when in a non-conducting state. By using an OS transistor, the charge supplied to the node ND1 can be retained for a long period of time. can be done.

[0231] In the circuit diagram shown in FIG. 13A, the liquid crystal element LC serves as a leak path for the data D1. Therefore, to perform the IDS drive properly, the resistivity of the liquid crystal element LC must be set to 1.0×10 1 4 It is preferable to set the resistance at Ω·cm or more.

[0232] The channel region of the OS transistor is formed of, for example, In-Ga-Zn oxide, I In-Ga-Zn oxide can be preferably used. Typically, a composition of In:Ga:Zn=4:2:4.1 (atomic ratio) is used. It is possible.

[0233] FIG. 13B shows the signals applied to the signal line SL and the gate line GL in the normal drive mode. 1 is a timing chart showing the waveform of a signal. In the normal drive mode, the normal frame frequency ( For example, 60 Hz. If one frame period is represented by periods T1 to T3, each frame During the scan period, a scanning signal is applied to the gate line GL, and data D1 is sent from the signal line SL to the node ND1. This operation is performed when the same data D1 is written from the period T1 to T3. The same is true when writing different data.

[0234] On the other hand, FIG. 13C shows that the signal line SL and the gate line GL in the IDS drive mode are 1 is a timing chart showing the waveforms of signals applied to the IDS drive. The frequency of one frame is represented as T1, and the data The write period is T W , the data retention period is period T RET The IDS drive mode is , period T W A scanning signal is applied to the gate line GL, and data D1 of the signal line SL is transferred to the capacitance element Cs L C Write to period T RET The gate line GL is fixed to a low level voltage, and the transistor M1 is set to a non-conductive state, and the data D1 that was written once is transferred to the capacitance element Cs LC Actions to be held in The low frame frequency is, for example, 0.1 Hz or more and less than 60 Hz. Alternatively, for example, the frequency may be set to be equal to or higher than 0.1 Hz and lower than 20 Hz.

[0235] This embodiment mode can be combined with other embodiment modes as appropriate.

[0236] (Embodiment 3) In this embodiment, an example of a method for driving a touch sensor will be described with reference to the drawings.

[0237] <Example of sensor detection method> FIG. 14A is a block diagram showing the configuration of a mutual capacitance type touch sensor. In FIG. 14(A), a pulse voltage output circuit 551 and a current detection circuit 552 are shown. In A), an electrode 521 to which a pulse voltage is applied and an electrode 522 to which a change in current is detected are arranged. Each of these is shown as six wires, X1 to X6 and Y1 to Y6. 5A illustrates a capacitance 553 formed by overlapping an electrode 521 and an electrode 522. The functions of the electrodes 521 and 522 may be interchangeable.

[0238] The pulse voltage output circuit 551 is a circuit for applying a pulse voltage to the wirings X1 to X6 in order. A pulse voltage is applied to the wirings X1 to X6 to form a capacitance 553. An electric field is generated between the electrodes 521 and 522. The electric field generated between the wirings is prevented by shielding, etc. The proximity or contact of the object to be detected is detected by causing a change in the mutual capacitance of the capacitance 553. It can be put out.

[0239] The current detection circuit 552 detects the current in the wirings Y1 to Y6 due to a change in mutual capacitance in the capacitor 553. This is a circuit for detecting changes in current. The wiring from Y1 to Y6 detects the proximity or When there is no contact, the detected current value does not change, but when the object to be detected approaches or comes into contact with the object, When the mutual capacitance decreases, the change in the current value is detected. This can be achieved by using an integrating circuit or the like.

[0240] In addition, one or both of the pulse voltage output circuit 551 and the current detection circuit 552 may be For example, the display section 62 and the driving circuit section 63 may be formed on the substrate 51 or the substrate 61 shown in FIG. 64, etc., can simplify the process and can also be used to drive the touch sensor. This is preferable because it reduces the number of components required. One or both of the current sensing circuits 552 may be implemented in IC73.

[0241] In particular, as a transistor formed on the substrate 51, a multi-layered semiconductor layer in which a channel is formed is formed. When crystalline silicon such as crystalline silicon or single crystal silicon is used, the pulse voltage output circuit 551 The driving capability of the circuits such as the current detection circuit 552 is improved, and the sensitivity of the touch sensor is improved. This can be done.

[0242] FIG. 14B shows input / output waveforms in the mutual capacitance type touch sensor shown in FIG. 14A. FIG. 14B shows a timing chart of the detection of the object in each row and column during one frame period. In FIG. 14(B), the detection of the object to be detected is performed. The two cases shown are when detecting the object (touch) and when detecting the object (sensor). For the wiring to Y6, a waveform is shown in which the voltage value corresponds to the detected current value.

[0243] A pulse voltage is applied to the wires X1-X6 in sequence, and Y1 through The waveform on the Y6 wire changes. When there is no proximity or contact of the object to be detected, the waveform on the Y6 wire changes. The waveforms of Y1 to Y6 change uniformly in response to the change in the voltage of the wire 6. In areas where they are close to each other or in contact, the current value decreases, and the corresponding voltage waveform also changes. To become.

[0244] In this way, the proximity or contact of a sensing object can be detected by detecting the change in mutual capacitance. It is possible.

[0245] <Example of a method for driving a display device> FIG. 15(A) is a block diagram showing a configuration example of a display device. A driving circuit GD (scanning line driving circuit), a source driving circuit SD (signal line driving circuit), a plurality of pixels p ix. In FIG. 15(A), the gate drive circuit GD is electrically The gate lines x_1 to x_m (m is a natural number) connected to the source driver circuit SD are electrically connected to the In the pixel pix, corresponding to the connected source lines y_1 to y_n (n is a natural number), They are numbered (1,1) through (n,m).

[0246] FIG. 15B shows the current applied to the gate lines and source lines in the display device shown in FIG. FIG. 15B is a timing chart of a data signal for each frame period. The diagram shows two cases: when the data signal is rewritten and when the data signal is not rewritten. 15(B) does not take into account periods such as blanking periods.

[0247] When the data signal is rewritten every frame period, the gate lines x_1 to x_m are In the horizontal scanning period 1H during which the scanning signal is at H level, A data signal D is applied to the column source lines y_1 to y_n.

[0248] When the data signal is not rewritten every frame period, the gate lines x_1 to x_m are In the horizontal scanning period 1H, the scanning signal to the source lines y_1 to y_n of each column is stopped. Stop providing data signals.

[0249] The driving method in which the data signal is not rewritten every frame period is particularly Effective when using an oxide semiconductor in the semiconductor layer in which a channel is formed as a transistor A transistor using an oxide semiconductor is different from a transistor using a semiconductor such as silicon. It is possible to reduce the off-state current significantly compared to that of a conventional transistor. The data signal written in the previous period is retained without rewriting the data signal for each period. For example, the gradation of a pixel can be maintained for 1 second or more, preferably 5 seconds or more. It is also possible.

[0250] In addition, a polycrystalline silicon is used as a semiconductor layer in which a channel is formed as a transistor of the pixel pix. When applying a recon, the size of the storage capacitance of the pixel is increased in advance. The larger the storage capacitance, the longer the grayscale of the pixel can be maintained. The size of the storage capacitor can be determined by the size of the transistor and the display element that are electrically connected to the storage capacitor. For example, the storage capacitance per pixel should be set to 5fF or more. F or less, preferably 10 fF to 5 pF, and more preferably 20 fF to 1 pF. Then, the data signal is not rewritten every frame period, and the data written in the previous period is retained. The data signal can be held for a period of, for example, several frames or several tens of frames. This makes it possible to maintain the gradation of the pixel.

[0251] <Example of how to drive the display and touch sensor> 16A to 16D are diagrams showing an example of the touch sensor described in FIG. 14A and FIG. When the display unit described in FIG. 15(A) and (B) is driven for 1 second, FIG. 16(A) is a diagram for explaining the operation during a frame period in which one of the display units Frame period is 16.7 ms (frame frequency: 60 Hz), one frame of the touch sensor The period is shown to be 16.7 ms (frame frequency: 60 Hz).

[0252] In the display device according to one embodiment of the present invention, the operation of the display unit and the operation of the touch sensor are independent of each other. In this case, a touch detection period can be provided in parallel with a display period. As shown in the figure, the frame period of both the display and touch sensor is set to 16.7 ms (frame period The frame frequency of the touch sensor and the display can be set to 60Hz. For example, as shown in FIG. 16B, one frame period of the display unit may be set to 8. .3ms (frame frequency: 120Hz), and the frame period of the touch sensor is set to 1 It is also possible to set the frame frequency to 6.7 ms (frame frequency: 60 Hz). The frame frequency of the display unit may be set to 33.3 ms (frame frequency: 30 Hz).

[0253] The frame frequency of the display unit is switchable, and when displaying moving images, the frame Increase the frequency (for example, 60Hz or more or 120Hz or more) when displaying a still image. reduce the frame frequency (for example, 60Hz or less, 30Hz or less, or 1Hz or less). By doing so, the power consumption of the display device can be reduced. The frame frequency can be switched between standby and when a touch is detected. It is okay to do so.

[0254] In addition, the display device of one embodiment of the present invention can display the previous image without rewriting a data signal in a display portion. By holding the rewritten data signal for the period, one frame period of the display is extended to 16.7ms. Therefore, as shown in FIG. 16(C), The frame period is set to 1 sec. (frame frequency: 1 Hz), and the touch sensor The frame period can also be set to 16.7 ms (frame frequency: 60 Hz).

[0255] In addition, the data signal rewritten in the previous period is not rewritten in the display unit. For the configuration to hold the signal, refer to the IDS drive mode described above. In the IDS drive mode, the rewriting of data signals in the display is limited to a specific area. A partial IDS driving mode may be used in which only the display part is driven. The data signal that is to be written is rewritten only in a specific area, and in other areas, the data signal is written to the previous period. This is a configuration for holding the rewritten data signal.

[0256] According to the touch sensor driving method disclosed in the present embodiment, the driving method shown in FIG. When the touch sensor is operated, the touch sensor can be driven continuously. ) at the timing when the touch sensor detects the proximity or contact of the object to be detected. It is also possible to rewrite the data signals on the display unit.

[0257] Here, if a data signal rewrite operation is performed on the display unit during the sensing period of the touch sensor, Noise generated when rewriting data signals is transmitted to the touch sensor, causing the Therefore, the rewriting period of the data signal on the display unit and It is preferable to drive the touch sensor so that the sensing period of the touch sensor is shifted from the sensing period of the touch sensor.

[0258] In FIG. 17(A), the rewriting of the data signal of the display unit and the sensing of the touch sensor are interchanged. FIG. 17B shows an example in which the rewriting operation of the data signal on the display unit is performed. This shows an example in which the touch sensor is sensed once for every two times. A configuration in which the touch sensor is sensed once for every three or more rewrite operations. It is also possible to use the following.

[0259] In addition, the transistor applied to the pixel pix has an oxide in the semiconductor layer in which the channel is formed. When using semiconductors, it is possible to reduce the off-current significantly, making it possible to rewrite data signals. Specifically, after the data signal is rewritten, Therefore, it is possible to provide a sufficiently long pause before the data signal is rewritten next time. 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 limited by the capacitance connected to the transistor and the leakage current of the display element, etc. For example, it may be 1 minute or less, 10 minutes or less, 1 hour or less, or 1 day or less. can.

[0260] FIG. 17C shows an example in which the data signal of the display is rewritten once every 5 seconds. In FIG. 17(C), the display unit rewrites the data signal and then writes the next data signal. Before the rewrite operation, a pause period is provided during which the rewrite operation is stopped. So, the touch sensor operates at a frame frequency of iHz (i is the frame frequency of the display device or higher, In addition, as shown in Figure 17(C), the touch panel can be driven at a frequency of 0.2 Hz or higher. The sensor performs sensing during the rest period, and does not perform sensing during the period when the data signal of the display is being rewritten. This is preferable because it is possible to improve the sensitivity of the touch sensor. As shown in Fig. 1, the data signal of the display unit is rewritten and the touch sensor is sensed at the same time. This allows the driving signals to be simplified.

[0261] In addition, during the pause period when the data signal of the display unit is not rewritten, the data signal to the display unit is In addition to stopping the supply of the signal to either the gate driver GD or the source driver SD, In addition, the gate driver GD and the source driver S may be turned off. You can also stop the power supply to one or both of D. This will reduce noise. The touch sensor can be made more sensitive by reducing the noise generated by the touch sensor. The power consumption can be further reduced.

[0262] The display device according to one embodiment of the present invention has a structure in which a display unit and a touch sensor are sandwiched between two substrates. Therefore, the distance between the display unit and the touch sensor can be made extremely short. Noise generated when the display is in operation is easily transmitted to the touch sensor, reducing the sensitivity of the touch sensor. By applying the driving method exemplified in this embodiment, it is possible to achieve a thin and high It is therefore possible to realize a display device having a touch sensor that achieves both high detection sensitivity and high image quality.

[0263] This embodiment mode can be combined with other embodiment modes as appropriate.

[0264] (Embodiment 4) In this embodiment, the present invention can be used for a semiconductor layer of a transistor disclosed in one embodiment of the present invention. In addition, a metal oxide is used for the semiconductor layer of a transistor. In this case, the metal oxide may be interpreted as an oxide semiconductor.

[0265] Oxide semiconductors are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. As a crystalline oxide semiconductor, CAAC-OS (c-axis-aligned crystal-like oxide semiconductor) talline oxide semiconductor), polycrystalline oxide semiconductor, n c-OS(nanocrystalline oxide semiconductor ), pseudo-amorphous oxide semiconductor (a-like OS) xide semiconductor, and amorphous oxide semiconductor.

[0266] In addition, the semiconductor layer of the transistor disclosed in one embodiment of the present invention may include CAC-OS (Clo ud-Aligned Composite oxide semiconductor ) may also be used.

[0267] Note that the semiconductor layer of the transistor disclosed in one embodiment of the present invention is preferably a semiconductor layer formed of the above-described non-single-crystal oxide. In addition, a non-single-crystal oxide semiconductor or a CAC-OS can be preferably used. As the OS, nc-OS or CAAC-OS can be preferably used.

[0268] Note that in one embodiment of the present invention, CAC-OS is preferably used for a semiconductor layer of a transistor. By using CAC-OS, it is possible to provide transistors with high electrical characteristics and high reliability. It can be granted.

[0269] The following provides details about CAC-OS.

[0270] CAC-OS or CAC-metal oxide is a material that has the function of electrical conductivity. A part of the material has an insulating function, and the material as a whole has a semiconductor function. Note that CAC-OS or CAC-metal oxide is used as the channel of a transistor. When used in a region, the function of conductivity is to allow the flow of electrons (or holes) that serve as carriers. The insulating function is to prevent the flow of electrons, which act as carriers. The function of switching (On / Off) is achieved by making the function of the sensor and the sensor's sensitivity work in a complementary manner. This function is added to CAC-OS or CAC-metal oxide. In the case of CAC-OS or CAC-metal oxide, By separating the functions, the functionality of both can be maximized.

[0271] In addition, CAC-OS or CAC-metal oxide is used in conductive areas and insulating areas. The conductive region has the above-mentioned conductive function, and the insulating region has the above-mentioned insulating function. In addition, the conductive region and the insulating region in the material are formed by nanoparticle layers. The conductive and insulating regions may be separated by a gap in the material. In addition, the conductive regions are observed as connected clouds with blurred edges. This may be the case.

[0272] In addition, in the CAC-OS or CAC-metal oxide, the conductive region and the insulating region are The peripheral region is 0.5 nm to 10 nm, preferably 0.5 nm to 3 nm. The following sizes may be present in the material:

[0273] In addition, CAC-OS or CAC-metal oxide has different band gaps. For example, CAC-OS or CAC-metal oxi de is a component with a wide gap due to the insulating region and a component with a narrow gap due to the conductive region. In the case of this configuration, when a carrier flows, In the narrow gap component, carriers mainly flow. The component having a narrow gap acts complementary to the component having a wide gap. Carriers also flow to the wide gap component in conjunction with the component with a large gap. AC-OS or CAC-metal oxide is used for the channel region of the transistor. In this case, the transistor has a high current drive capability in the on-state, i.e., a large on-state current, and Therefore, a high field effect mobility can be obtained.

[0274] That is, CAC-OS or CAC-metal oxide is a matrix composite material. (matrix composite) or metal matrix composite (metal matrix It can also be called atrix composite.

[0275] For example, the elements constituting the metal oxide in the CAC-OS are 0.5 nm or more and 10 nm or less. Preferably, the material is unevenly distributed in a size range of 1 nm to 2 nm or in the vicinity thereof. In the following, it is assumed that one or more metal elements are unevenly distributed in a metal oxide. The region having the metal element has a size of 0.5 nm to 10 nm, preferably 1 nm to 2 nm. A mixed state in which the size is less than or close to one m is also called a mosaic or patch pattern.

[0276] The metal oxide preferably contains at least indium. In addition to these, aluminum, gallium, yttrium, zinc, etc. are preferably contained. Lithium, Copper, Vanadium, Beryllium, Boron, Silicon, Titanium, Iron, Nickel, Gel Manium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum It contains one or more selected from tantalum, tungsten, magnesium, etc. It's fine.

[0277] For example, CAC-OS made of In-Ga-Zn oxide (In-Ga-Zn oxide is one of the CAC-OS) a-Zn oxide may be specifically referred to as CAC-IGZO. (Hereinafter, InO X1 (X1 is a real number greater than 0.) or indium zinc oxide In X2 Zinc Y2 O Z2 (X2, Y2, and Z2 are real numbers greater than 0) ) and gallium oxide (GaO X3 (X3 is a real number greater than 0) . ) or gallium zinc oxide (Ga X4 ZincY4 O Z4 (X4, Y4, and Z4 is a real number greater than 0. The material is separated into the mosaic shape. , mosaic InO X1 , or In X2 Zinc Y2 O Z2 The structure is uniformly distributed in the film. It is structured like a cloud (hereinafter, also referred to as a cloud-like structure).

[0278] In other words, CAC-OS is X3 The region where In is the main component and X2 Zinc Y2 O Z2 , or InO X1 A composite metal oxide having a structure in which a region in which In this specification, for example, the atomic ratio of In to the element M in the first region is The first region has an atomic ratio of In to the element M in the second region that is greater than the atomic ratio of In in the second region. The concentration of In is higher than in the region

[0279] IGZO is a common name and refers to a compound made of In, Ga, Zn, and O. A typical example is InGaO3(ZnO). m1 (m1 is a natural number), or In ( 1+x0) Ga (1-x0) O3(ZnO) m0 (-1≦x0≦1, m0 is an arbitrary number) Examples of the crystalline compounds include those which are

[0280] The crystalline compounds may have a single crystal structure, a polycrystalline structure, or a c-axis aligned crystal structure (CAAC). The CAAC structure is a structure in which multiple IGZO The nanocrystals have a c-axis orientation and are connected in ab-plane without being oriented. do.

[0281] On the other hand, CAC-OS is a material structure of metal oxide. CAC-OS is a material structure of In, Ga In a material composition containing Zn and O, nanoparticles mainly composed of Ga were observed in some areas. The regions where the In is mainly contained are observed as nanoparticles, and the regions where the In is mainly contained as nanoparticles are observed. Therefore, in the CAC-OS, the crystal structure is Construction is a secondary element.

[0282] It should be noted that the CAC-OS does not include a laminated structure of two or more films having different compositions. For example, a structure consisting of two layers, a film mainly made of In and a film mainly made of Ga, is not included. do not have.

[0283] In addition, GaO X3 The region where In is the main component and X2 Zinc Y2 O Z2 , or InO X1 but In some cases, a clear boundary between the region of the main component and the region of the main component may not be observed.

[0284] Instead of gallium, aluminum, yttrium, copper, vanadium, and beryllium can be used. , boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum , lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium If one or more selected elements from the group consisting of uranium, sodium, etc. are included, CAC-OS will The region observed is a nanoparticle of the metal element as the main component, and the other region is a nanoparticle of In as the main component. The regions observed as particles are randomly distributed in a mosaic pattern. cormorant.

[0285] CAC-OS is formed by sputtering without intentionally heating the substrate. In addition, when the CAC-OS is formed by a sputtering method, the deposition gas and The gas is selected from an inert gas (typically argon), oxygen gas, and nitrogen gas. One or more of these may be used. The lower the flow rate ratio of the gas, the more preferable. For example, the flow rate ratio of oxygen gas is preferably 0% or more and less than 30%. Or, it is preferable to set it to 0% or more and 10% or less.

[0286] CAC-OS is a type of X-ray diffraction (XRD) measurement method. When measured using the θ / 2θ scan by the out-of-plane method, In other words, no clear peaks are observed in the measurement region from the X-ray diffraction. It can be seen that no orientation in the ab plane direction or the c-axis direction is observed.

[0287] In addition, the CAC-OS uses an electron beam with a probe diameter of 1 nm (also called a nano-beam electron beam). In the electron beam diffraction pattern obtained by irradiating the sample with electrons, a ring-shaped region of high brightness and the Therefore, the electron diffraction pattern indicates that the CAC-OS The crystal structure has no orientation in the planar and cross-sectional directions. It can be seen that it has a crystal structure.

[0288] For example, in the case of CAC-OS made of In-Ga-Zn oxide, energy dispersive X-ray Spectroscopy (EDX: Energy Dispersive X-ray spectroscopy) The EDX mapping obtained using a GaO X3 The region where is the main component and , InX2 Zinc Y2 O Z2 , or InO X1 The areas where the main component is It can be confirmed that the compound has the structure shown in FIG.

[0289] CAC-OS has a structure different from that of IGZO compounds in which metal elements are uniformly distributed. It has different properties from ZO compounds. That is, CAC-OS is GaO X3 The main components are The area where X2 Zinc Y2 O Z2 , or InO X1 The area where is the principal component and It has a phase-separated structure with a mosaic of regions each consisting of one element as the main component.

[0290] Here, In X2 Zinc Y2 O Z2 , or InO X1 The area where GaO is the main component X3 This region has a higher electrical conductivity than the region where In is the main component. X2 Zinc Y2 O Z2 , or InO X1 The carriers flow through the area where the oxide is the main component. The conductivity of a semiconductor is expressed. X2 Zinc Y2 O Z2 , or InO X1 The region mainly composed of ZnO is distributed in a cloud-like shape in the oxide semiconductor, which leads to a high field effect transition. Mobility (μ) can be achieved.

[0291] On the other hand, GaO X3 The region where In etc. are the principal components is X2 Zinc Y2 O Z2 , or InO X1 This region has higher insulating properties than the region where GaO is the main component. X3 The main components are The distribution of the regions with the junction structure in the oxide semiconductor suppresses leakage current and provides good switching performance. This allows for realizing a matching operation.

[0292] Therefore, when CAC-OS is used in a semiconductor device, GaO X3 The insulation caused by I n X2 Zinc Y2 O Z2 , or InO X1 The conductivity caused by the This allows for a high on-state current (I on ) and high field-effect mobility (μ). Cut.

[0293] In addition, semiconductor devices using CAC-OS have high reliability. It is ideal for a variety of semiconductor devices, including displays.

[0294] This embodiment mode can be combined with other embodiment modes as appropriate.

[0295] (Embodiment 5) In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0296] Examples of electronic devices include television sets, desktop or notebook PCs, etc. Computers, computer monitors, digital cameras, digital video cameras digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio playback equipment Examples of such machines include large gaming machines such as pachinko machines.

[0297] FIG. 18A shows a notebook personal computer, which includes a housing 8111 and a display unit 811 2, a keyboard 8113, a pointing device 8114, etc.

[0298] The display device of one embodiment of the present invention can be applied to the display portion 8112. It is possible to provide a notebook personal computer having a display with high color resolution.

[0299] Figure 18 (B) and (C) show digital signage. The digital signage includes a housing 8000, a display unit 8001, and a screen. It also has an LED lamp, operation keys (power switch, or operation It may have a contact, a connection terminal, various sensors, a microphone, etc. .

[0300] FIG. 18(C) shows a digital signage mounted on a cylindrical pillar.

[0301] The display device according to one embodiment of the present invention is provided in the display portion 8001 shown in FIGS. This makes it possible to provide a digital signage having a display section with a high aperture ratio. can be done.

[0302] The larger the display unit 8001 is, the more information can be displayed at one time. The wider the part 8001, the more noticeable it is, and for example, the more effective the advertising can be. Cut.

[0303] By applying a touch panel to the display unit 8001, images or videos can be displayed on the display unit 8001. It is preferable because it not only shows the route information but also allows the user to operate it intuitively. When used to provide information such as traffic information, the user can intuitively operate the device. This can improve accessibility.

[0304] FIG. 18(D) shows the appearance of the automobile 7900. FIG. 18(E) shows how to drive the automobile 7900. The seat is shown. The automobile 7900 includes a body 7901, wheels 7902, a windshield 7903, It has lights 7904, fog lights 7905, etc.

[0305] The display device of one embodiment of the present invention can be used for a display portion of an automobile 7900 or the like. For example, The display portions 7910 to 7917 shown in FIG. 18E each include a display device according to one embodiment of the present invention. This makes it possible to provide a vehicle having a display with a high aperture ratio. can be done.

[0306] The display unit 7910 and the display unit 7911 are provided on a windshield 7903 of the automobile 7900. In one embodiment of the present invention, an electrode included in a display device is formed using a light-transmitting conductive material. By fabricating this, it is possible to create a so-called see-through display device, where the other side can be seen through. If the display device is in a see-through state, the field of view can be improved even when driving a car 7900. Therefore, the display device 10 according to one embodiment of the present invention is The display device can be provided on a windshield 7903. In the case where the transistor is provided, an organic transistor using an organic semiconductor material or an oxide semiconductor is used. For example, a light-transmitting transistor such as a transistor having a light-transmitting property may be used.

[0307] The display unit 7912 is provided on the pillar portion. The display unit 7913 is provided on the dashboard portion. The display unit 7914 is provided in the door section. For example, By projecting an image from the imaging means on the display unit 7912, the image not blocked by the pillars can be displayed. Similarly, the display unit 7913 can display the view that is blocked by the dashboard. The display unit 7914 can complement the view blocked by the door. That is, by projecting an image from an imaging means provided on the outside of the automobile, This can compensate for blind spots and increase safety. By projecting the image, safety checks can be performed more naturally and without any awkwardness.

[0308] The display unit 7917 is provided on the handle. , or display unit 7917 displays navigation information, speedometer, tachometer, It can provide various information such as distance traveled, fuel amount, gear status, air conditioning settings, etc. In addition, the display items and layout displayed on the display can be adjusted to suit the user's preferences. The above information can be displayed on the display units 7910 to 7914. It can be displayed.

[0309] Note that the display portions 7910 to 7917 can also be used as lighting devices.

[0310] This embodiment mode can be combined with other embodiment modes as appropriate. [Explanation of symbols]

[0311] 10 Display device 10A display device 10B Display device 11 Substrate 12 Substrate 13 Backlight unit 14 Transistor 15 Liquid crystal elements 15A display device 15B Display device 15C Display device 16 Capacitive element 21 Pixel electrode 22 Liquid crystal layer 23 Common electrode 25 Conductive Layer 26 Insulating layer 27 Conductive Layer 28 Conductive Layer 29 Connectors 31 Touch sensor unit 32 Insulating layer 33 Conductive layer 34 Capacitive element 40 Liquid crystal element 45a light 45b light 45c Light 51 Substrate 61 Substrate 62 Display section 64 Drive circuit section 65 Wiring 72 FPC 72a FPC 72b FPC 73 IC 73a IC 73b IC 81 scan lines 82 Signal Line 100 display device 111 Pixel electrode 112 Common electrode 113 Liquid crystal layer 121 Overcoat 124 electrodes 125 Insulating layer 126 Conductive Layer 127 Electrode 128 electrode 130 Polarizing Plate 131 Colored layer 132 Light blocking layer 133a Alignment film 133b Alignment film 137 Wiring 138 Wiring 141 Adhesive layer 160 Protection Board 161 Backlight 162 Substrate 163 Adhesive layer 164 Adhesive layer 165 Polarizing Plate 166 Polarizing Plate 167 Adhesive layer 168 Adhesive layer 169 Adhesive layer 201 Transistor 204 Connection 206 Transistor 211 Insulating layer 212 Insulating layer 214 Insulating layer 215 Insulating Layer 221 Gate electrode 222 Conductive Layer 223 Gate electrode 224 Conductive Layer 225 Conductive Layer 231 Semiconductor Layer 232 Conductive Layer 232a Semiconductor layer 242 Connectors 242b Connection 251 Conductive Layer 261 Insulating Layer 262 Conductive Layer 262a Semiconductor layer 350 Touch Panel 370 Display device 375 Input Device 501 Display element 506 Pixel Circuit 521 Electrode 522 Electrode 551 Pulse voltage output circuit 552 Current detection circuit 553 capacity 900 pixels 900s shading area 900t transmission area 902 Wiring 904 Wiring 918 Display area 918B Display area 918G display area 918R display area 7900 Automobiles 7901 Body 7902 Wheel 7903 Windshield 7904 Light 7905 Fog Lamp 7910 Display section 7911 Display section 7912 Display section 7913 Display section 7914 Display section 7915 Display section 7916 Display section 7917 Display section 8000 Chassis 8001 Display section 8003 Speaker 8111 Case 8112 Display section 8113 Keyboard 8114 Pointing Device

Claims

[Claim 1] a first semiconductor layer on the first insulating layer; a first conductive layer on the first insulating layer; a second insulating layer having a region located on the first semiconductor layer and a region located on the first conductive layer; a second conductive layer having a region located on the second insulating layer and electrically connected to the first semiconductor layer through a first opening of the second insulating layer; a third insulating layer having a region located on the second insulating layer and a region located on the second conductive layer; A scan line, A display device having the first semiconductor layer has a channel region of a transistor; the second insulating layer has a region in contact with the channel region, the third insulating layer has a region overlapping the channel region and in contact with the second insulating layer; the first conductive layer has a region that functions as a first electrode of a capacitor element; the second insulating layer has a region that functions as a dielectric layer of the capacitive element; the second conductive layer has a region that functions as a second electrode of the capacitor element, the first semiconductor layer and the first conductive layer comprise a metal oxide; the scan line comprises a metallic material; the scan line has an area overlapping the channel area, The display device has a function of holding data by writing the data to the capacitor and then turning off the transistor.

Images