Semiconductor Devices

Abstract

To provide a semiconductor device with high aperture ratio or a manufacturing method thereof, and to provide a semiconductor device with low power consumption or a manufacturing method thereof.SOLUTION: A semiconductor device includes: a semiconductor layer over a substrate having an insulating surface; a gate insulating film covering the semiconductor layer; gate wiring including a gate electrode, which is provided over the gate insulating film and is formed by stacking a first conductive layer and a second conductive layer; an insulating film covering the semiconductor layer and the gate wiring including the gate electrode; and source wiring including a source electrode, which is disposed on the insulating film, is electrically connected to the semiconductor layer, and is formed by stacking a third conductive layer and a fourth conductive layer. The gate electrode is formed by the first conductive layer. The gate wiring is formed by the first conductive layer and the second conductive layer. The source electrode is formed using the third conductive layer. The source wiring is formed by the third conductive layer and the fourth conductive layer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device, a display device, a light-emitting device, or a manufacturing method thereof. The device is constructed with a thin film transistor (hereinafter referred to as TFT) that uses an oxide semiconductor film in the channel forming region. The present invention relates to a semiconductor device having a circuit formed thereon and a manufacturing method thereof, for example, a liquid crystal display panel. and light-emitting display devices having organic light-emitting elements. Regarding child devices. [Background technology]

[0002] Amorphous silicon and other materials are used as switching elements in display devices such as liquid crystal display devices. Thin film transistors (TFTs) that use a silicon layer as a channel layer are widely used. Thin film transistors using amorphous silicon have low field effect mobility, but This has the advantage of being able to accommodate larger area glass substrates.

[0003] Recently, thin film transistors have been fabricated using metal oxides that exhibit semiconducting properties, and electronic devices have been developed. For example, among metal oxides, the technology for applying it to electronic devices and optical devices is attracting attention. It is known that oxides such as tungsten, tin oxide, indium oxide, and zinc oxide exhibit semiconductor properties. A thin film transistor in which a transparent semiconductor layer made of such a metal oxide is used as a channel forming region is used. A transistor is disclosed in Patent Document 1.

[0004] In addition, a channel layer of the transistor is formed using a light-transmitting oxide semiconductor layer, The gate electrode, source electrode, and drain electrode are also formed of a transparent conductive film having light-transmitting properties. Therefore, techniques for improving the aperture ratio have been studied (Patent Document 2).

[0005] By improving the aperture ratio, the light utilization efficiency is improved, and the power consumption and size of the display device are reduced. On the other hand, from the viewpoint of increasing the size of display devices and application to mobile devices, Therefore, there is a demand for further reduction in power consumption along with an improvement in aperture ratio.

[0006] As a method for wiring metal auxiliary wiring to the transparent electrodes of the electro-optical element, In either case, the metal auxiliary wiring and the transparent electrode are wired so that they overlap to provide electrical continuity with the transparent electrode. It is known that such a method is used (see, for example, Patent Document 3).

[0007] The additional capacitance electrodes provided on the active matrix substrate are made of transparent material such as ITO or SnO2. The electrode for the additional capacitance is made of a transparent conductive film, and in order to reduce the electrical resistance of the electrode for the additional capacitance, the electrode is made of a metal film. A configuration is known in which an auxiliary wiring is provided in contact with an electrode for additional capacitance (see, for example, Patent Document 4). (see).

[0008] In a field-effect transistor using an amorphous oxide semiconductor film, The materials used to form the source and drain electrodes are indium tin oxide (ITO), Transparent electrodes such as indium zinc oxide, ZnO, SnO2, and Al, Ag, Cr, Ni, Metal electrodes such as Mo, Au, Ti, Ta, etc., or alloy metal electrodes containing these are used. Two or more layers of these can be stacked to reduce contact resistance or improve interface strength. It is known that this is effective (see, for example, Patent Document 5).

[0009] In addition, the source electrode, drain electrode and The materials for the gate electrode and auxiliary capacitance electrode are indium (In), aluminum (Al), and gold ( Metals such as Au, silver (Ag), indium oxide (In2O3), and tin oxide (SnO2) , zinc oxide (ZnO), cadmium oxide (CdO), cadmium indium oxide (CdI n2O4), cadmium tin oxide (Cd2SnO4), zinc tin oxide (Zn2SnO4) The materials for the gate electrode, source electrode, and drain electrode can be It is known that all of the above may be the same or different (see, for example, Patent Documents 6 and 7). ). [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-103957 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-81362 [Patent Document 3] Japanese Patent Application Publication No. 2-82221 [Patent Document 4] Japanese Patent Application Publication No. 2-310536 [Patent Document 5] Japanese Patent Application Laid-Open No. 2008-243928 [Patent Document 6] Japanese Patent Application Laid-Open No. 2007-109918 [Patent Document 7] Japanese Patent Application Laid-Open No. 2007-115807 Summary of the Invention [Problem to be solved by the invention]

[0011] An object of one embodiment of the present invention is to provide a semiconductor device with low power consumption. An object of one embodiment of the present invention is to provide a semiconductor device with low wiring resistance. An object of one embodiment of the present invention is to provide a semiconductor device that can be manufactured at low cost. An object of one embodiment of the present invention is to provide a semiconductor device with high transmittance. An object of one embodiment of the present invention is to provide a high-definition semiconductor device. Another object of one embodiment of the present invention is to provide a semiconductor device with a high aperture ratio. Another object of the present invention is to provide a semiconductor device having a large storage capacitance. Another object of the present invention is to provide a semiconductor device with reduced light leakage. The object of the present invention is to provide a semiconductor device with reduced feedthrough voltage. An object of one embodiment of the present invention is to provide a semiconductor device in which a depletion layer is easily formed. [Means for solving the problem]

[0012] One embodiment of the present invention is a semiconductor layer provided over a substrate having an insulating surface, A first wiring including a connected first electrode, and a semiconductor layer and a first electrode formed to cover the first wiring and the semiconductor layer and the first electrode. and a second wiring including a second electrode provided on the semiconductor layer via the insulating film. The first electrode has a first conductive layer, and the first wiring has the first conductive layer and the second conductive layer. The second electrode has a third conductive layer, and the second wiring has a third conductive layer and a fourth conductive layer. The semiconductor device is characterized by having:

[0013] Another embodiment of the present invention is a semiconductor layer provided over a substrate having an insulating surface, and a semiconductor layer in contact with the semiconductor layer. a first wiring including a first electrode connected to the semiconductor layer; and a wiring formed to cover the semiconductor layer and the first electrode. an insulating film; a second wiring including a second electrode provided on the semiconductor layer via the insulating film; and a third The first electrode has a first conductive layer, and the first wiring is connected to the first conductive layer and the first The second electrode has a third conductive layer, and the second wiring has a third conductive layer. The third wiring has a fourth conductive layer, and the third wiring has a fifth conductive layer and a sixth conductive layer. This is a semiconductor device.

[0014] In the above, the first conductive layer and the third conductive layer preferably have light-transmitting properties. The second conductive layer and the fourth conductive layer are the first conductive layer, the third conductive layer, or a light-transmitting layer. The conductivity of the second conductive layer is preferably higher than that of the fourth conductive layer. It is preferable that the polymer has the following properties.

[0015] In the above, the semiconductor layer is an oxide semiconductor containing indium, gallium, or zinc. Preferably, it is a layer.

[0016] An example of an oxide semiconductor that can be used in this specification is InMO3(ZnO). m (m>0), where M is gallium (Ga), iron (Fe), nickel (Ni), and One metal element selected from nickel (Ni), manganese (Mn) and cobalt (Co), or It shows multiple metal elements. For example, when Ga is selected as M, it means that only Ga is selected. Other examples include combinations of Ga and Ni, Ga and Fe, and other metal elements other than Ga. In addition to the metal element contained as M in the oxide semiconductor, Some contain Fe, Ni or other transition metal elements, or oxides of these transition metals. In this specification, among the above oxide semiconductors, those containing at least gallium as M are The material is called an In-Ga-Zn-O oxide semiconductor, and a thin film made of this material is called an In-Ga- It is sometimes called a Zn-O-based non-single crystal film.

[0017] In addition to the above, oxide semiconductors include In-Sn-Zn-O and In-Al-Zn-O. , Sn-Ga-Zn-O system, Al-Ga-Zn-O system, Sn-Al-Zn-O system, In- Zn-O series, Sn-Zn-O series, Al-Zn-O series, In-O series, Sn-O series, Zn-O These oxide semiconductors can be used to suppress crystallization and to provide non-crystalline structures. By adding impurities that maintain the amorphous state, the characteristics of thin film transistors are stabilized. It can be done.

[0018] Note that the semiconductor layer used in one embodiment of the present invention only needs to have a light-transmitting property. For example, an oxide semiconductor can be used as the semiconductor layer. crystalline semiconductors (single crystal semiconductors or polycrystalline semiconductors), amorphous semiconductors, and microcrystalline semiconductors Any of semiconductors such as microcrystalline semiconductors and organic semiconductors may be used.

[0019] Furthermore, in the above, a multi-tone mask is used to process the first conductive layer and the second conductive layer. By using a single mask (reticle), it is possible to obtain a transparent region (a region with high light transmittance). It is possible to form a light-shielding area (a light-transmitting area) and a light-shielding area (a light-transmitting area). This allows for the formation of transparent regions (regions with high light transmittance) without increasing the number of masks. , and a region having light blocking properties (region with low light transmittance) can be formed.

[0020] In this specification, a semiconductor device is a device that can function by utilizing semiconductor characteristics. This refers to semiconductor circuits, display devices, electro-optical devices, light-emitting display devices, and electronic devices. Included in the conductor device.

[0021] In this specification, the term "display device" refers to an image display device, a light-emitting device, or a light It also refers to connectors, such as FPC (Flexible Printed Circuit) integrated circuit) or TAB (Tape Automated Bon ding) tape or TCP (Tape Carrier Package) Modules with printed wiring boards attached to the end of TAB tape or TCP The display element is an integrated circuit (IC) using the COG (Chip On Glass) method. ) is also included in the display device.

[0022] The switch may take various forms, for example, an electrical switch. There are various types of switches, such as switches and mechanical switches. In other words, anything that can control the flow of current is sufficient. There is no particular limitation. For example, a transistor (e.g., a bipolar transistor) can be used as a switch. transistors, MOS transistors, etc.), diodes (e.g., PN diodes, P IN diode, Schottky diode, MIM (Metal Insulator Metal diode, MIS (Metal Insulator Semiconductor) diodes, diode-connected transistors, etc. Alternatively, a logic circuit that combines these can be used as a switch.

[0023] Examples of mechanical switches include digital micromirror devices (DMDs), There are switches that use MEMS (microelectromechanical systems) technology. The switch has an electrode that can be mechanically moved, and the movement of the electrode The transistor operates by controlling conduction and non-conduction.

[0024] When a transistor is used as a switch, the transistor acts as a simple switch. However, the polarity (conductivity type) of the transistor is not particularly limited. To suppress this, it is desirable to use a transistor with a polarity that reduces the off-state current. As a transistor with low current, a transistor with LDD region or a multi-gate structure There are transistors with a structure such as a switch. The potential of the source terminal operates at a value close to the potential of the low-potential power supply (Vss, GND, 0V, etc.). On the other hand, if the potential of the source terminal is However, when it operates at a potential close to the high-potential power supply (such as Vdd), it is a P-channel transistor. It is desirable to use an N-channel transistor because the source terminal is low. When operating at a potential close to that of the power supply, the source terminal of a P-channel transistor When operating at a potential close to that of the high-potential power supply, the absolute value of the voltage between the gate and source is large. This is because the switch can operate more accurately. , the transistor rarely operates as a source follower, so the output voltage This is because it is unlikely that

[0025] In addition, CMOS transistors are used to implement both N-channel and P-channel transistors. A CMOS switch can be used as the switch. Either the N-channel transistor or the N-channel transistor is conducting. If the input voltage to the switch is 0.05V, a current will flow, making it easier to function as a switch. Whether the signal voltage is high or low, the voltage can be output appropriately. In addition, the voltage amplitude of the signal for turning the switch on or off can be reduced. Therefore, power consumption can also be reduced.

[0026] When using a transistor as a switch, the switch must be connected to the input terminal (source terminal or the other of the source and drain terminals), the output terminal (the other of the source and drain terminals), and the The diode is used as a switch. In some cases, the switch may not have a terminal that controls conduction. Using diodes as switches rather than transistors reduces the amount of wiring required to control the terminals. It can be eliminated.

[0027] When it is explicitly stated that A and B are connected, it means that A and B are electrically connected. A and B are functionally connected, A and B are directly connected, Here, A and B are objects (e.g., devices, elements, circuits) , wiring, electrodes, terminals, conductive films, layers, etc.). Therefore, a predetermined connection relationship, For example, the present invention is not limited to the connection relationships shown in the drawings or text, but may be modified to include the connection relationships shown in the drawings or text. This also includes matters other than those in charge.

[0028] For example, if A and B are electrically connected, the electrical connection between A and B can be The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more electrodes (such as a diode) may be connected between A and B. Alternatively, A and B may In the case of functional connection, a circuit that allows the functional connection between A and B (e.g. , logic circuits (inverters, NAND circuits, NOR circuits, etc.), signal conversion circuits (DA conversion circuits circuits, AD conversion circuits, gamma correction circuits, etc.), potential level conversion circuits (power supply circuits (boosting circuits, voltage sources, current sources, Switching circuits, amplifier circuits (circuits that can increase signal amplitude or current, etc.), operational amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, signal generation circuits, memory circuits, control One or more control circuits may be connected between A and B. For example, Even if there is another circuit between them, if the signal output from A is transmitted to B, then A and B are It is assumed that they are functionally connected.

[0029] In addition, when it is explicitly stated that A and B are electrically connected, it means that A and B are electrically When A and B are directly connected (i.e., when another element or circuit is placed between A and B), A and B are functionally connected (i.e., there is another When A and B are connected functionally across a circuit, and when A and B are connected directly ( (i.e., when A and B are connected without any other element or circuit between them) In other words, when explicitly stating that something is electrically connected, it simply means that it is connected. is the same as if it were expressly stated only that the

[0030] Note that the term "display element," "display device having a display element," "light-emitting element," and "device having a light-emitting element" may be used interchangeably. The light emitting device can have various forms and various elements. The display element, display device, light-emitting element or light-emitting device may be an EL (electroluminescence) EL elements (EL elements including organic and inorganic materials, organic EL elements, inorganic EL elements), LED (white LED, red LED, green LED, blue LED, etc.), transistor (depending on the current) transistors that emit light by electrons, electron-emitting devices, liquid crystal devices, electronic ink, electrophoretic devices, lighting light valve (GLV), plasma display panel (PDP), digital Micromirror device (DMD), piezoelectric ceramic display, carbon nanotube The contrast, brightness, reflectance, transmittance, etc. change due to electromagnetic effects. The display device may have a display medium. As a display device using electron-emitting devices, a field emission display (F ED) and SED type flat panel displays (SED: Surface-conductive n Electron-emitter Display) and other displays using liquid crystal elements The devices include LCD displays (transmissive LCD displays, semi-transmissive LCD displays, and reflective LCD displays). projection type LCD display, direct view LCD display, projection type LCD display), electronic An example of a display device using a liquid crystal display or an electrophoretic element is electronic paper.

[0031] The EL element is an element having an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. The EL layer is made up of a number of types, including those that utilize light emission (fluorescence) from singlet excitons, Those that utilize light emission from doublet excitons (phosphorescence) and those that utilize light emission from singlet excitons (fluorescence). Some utilize light emission from triplet excitons (phosphorescence), while others utilize organic materials. formed by inorganic matter, formed by organic matter and formed by inorganic matter. Materials formed by organic materials, including polymeric materials, low molecular weight materials, and polymeric materials However, it is not limited to this, and E There can be a variety of L elements.

[0032] An electron-emitting device is an element that extracts electrons by concentrating a high electric field on a cathode. For example, As electron emitters, Spindt type, carbon nanotube (CNT) type, metal-insulator- MIM (Metal-Insulator-Metal) type with metal layers, metal-insulator MIS (Metal-Insulator-Semiconductor) tor type, MOS type, silicon type, thin film diode type, diamond type, metal-insulator -Semiconductor-metal thin film type, HEED type, EL type, porous silicon type, surface conduction (S However, the electron emission element is not limited to this, and various types of electron emission elements may be used. It can have a variety of things.

[0033] A liquid crystal element is a device that controls the transmission or non-transmission of light by the optical modulation action of liquid crystals. It is composed of a pair of electrodes and liquid crystal. Controlled by the electric field applied to the crystal (including the horizontal electric field, the vertical electric field, or the diagonal electric field) The liquid crystal elements include nematic liquid crystal, cholesteric liquid crystal, smectic Liquid crystal, discotic liquid crystal, thermotropic liquid crystal, lyotropic liquid crystal, low molecular weight liquid crystal, Polymer liquid crystal, polymer dispersed liquid crystal (PDLC), ferroelectric liquid crystal, antiferroelectric liquid crystal, main chain liquid crystal, Examples include side-chain polymer liquid crystals, plasma-addressed liquid crystals (PALCs), and banana-shaped liquid crystals. The liquid crystal driving method is Twisted Nematic (TN). mode, STN (Super Twisted Nematic) mode, IPS (In- Plane-Switching mode, FFS (Fringe Field Switching) mode tching) mode, MVA (Multi-domain Vertical Alignment gnment) mode, PVA(Patterned Vertical Alignm) ent) mode, ASV (Advanced Super View) mode, ASM ( Axially Symmetrically aligned Micro-cell) mode , OCB (Optically Compensated Birefringence) ) mode, ECB (Electrically Controlled Birefringence ngence) mode, FLC (Ferroelectric Liquid Crystal tal) mode, AFLC(AntiFerroelectric Liquid Cr systal mode, PDLC (Polymer Dispersed Liquid Crystal Crystal mode, guest host mode, Blue Phase mode However, the present invention is not limited to this, and the liquid crystal element and its driving method can be used. A variety of different types can be used.

[0034] In addition, electronic paper is displayed by molecules (optical anisotropy, dye molecule orientation, etc.). (electrophoresis, particle migration, particle rotation, phase change, etc.), It is displayed by the movement of one end of the film, and by the color / phase change of the molecules. Some are displayed by molecular light absorption, and others by spontaneous light emission caused by electron-hole combinations. For example, one method of displaying electronic paper is to use microcapsules. Horizontally moving electrophoresis, vertically moving electrophoresis, spherical twist ball, magnetic twist twist ball, cylindrical twist ball method, charged toner, electronic liquid powder (Bridgestone Corporation) registered trademark), magnetophoretic type, magnetic heat sensitive type, electrowetting, light scattering (transparent / white Cloudiness change), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid Crystal, ferroelectric liquid crystal, dichroic dye / liquid crystal dispersion type, movable film, color development and decolorization by leuco dye, Photochromic, electrochromic, electrodeposition, flexible organic EL, etc. can be used. However, it is not limited to this, and electronic paper and its display can also be used. Various methods can be used. Here, microcapsule electrophoresis is used. This solves the problems of electrophoresis, such as aggregation and precipitation of electrophoretic particles. Electronic liquid powders have merits such as high speed response, high reflectivity, wide viewing angle, low power consumption, and memory function. It has a lit.

[0035] The plasma display panel is made up of a substrate on which electrodes are formed, and a substrate on which electrodes and minute grooves are formed. A substrate having a surface on which a phosphor layer is formed and a groove in which a phosphor layer is formed is placed opposite to the substrate at a narrow interval, and a rare gas is introduced. Alternatively, the plasma display panel may have a plasma tube. It is also possible to sandwich the plasma between film electrodes from above and below. It is a glass tube that contains discharge gas, RGB phosphors, etc. By applying a voltage between the electrodes, ultraviolet light is generated, causing the phosphor to glow. The plasma display panel can be a DC type PD The plasma display panel may be a PDP or an AC PDP. AWS (Address While Sustain) drive, subframe reset ADS (Address Display Status) is divided into period, address period, and sustain period. Separated drive, CLEAR (HI-CONTRAST & LOW ENERGY) ADDRESS&REDUCTION OF FALSE CONTOUR SEQU ENCE) drive, ALIS (Alternate Lighting of Surfa ces) method, TERES (Technology of Reciprocal Su However, it is not limited to this, and plasma Various methods can be used to drive the display panel.

[0036] In addition, display devices that require a light source, such as liquid crystal displays (transmissive liquid crystal displays), , Transflective LCD, Reflective LCD, Direct-view LCD, Projection LCDs, display devices using grating light valves (GLVs), digital As a light source for a display device using a digital micromirror device (DMD), an electroluminescent Using luminescence, cold cathode tube, hot cathode tube, LED, laser light source, mercury lamp, etc. However, the light source is not limited to this, and various light sources can be used. do.

[0037] Note that various types of transistors can be used as the transistor. There is no limitation on the type of transistor used. For example, amorphous silicon, polycrystalline silicon, microcrystalline silicon, Crystalline (also called microcrystalline, nanocrystalline, or semi-amorphous) silicon, etc. Thin film transistors (TFTs) having non-single crystal semiconductor films and single crystal semiconductor films, such as There are various advantages to using TFTs. For example, It can be manufactured at a lower temperature than crystalline silicon, reducing manufacturing costs and reducing the manufacturing equipment. It is possible to increase the size of the manufacturing equipment, so it is possible to manufacture on a large substrate. Therefore, a large number of display devices can be manufactured at the same time, resulting in low manufacturing costs. Since the manufacturing temperature is low, a substrate with low heat resistance can be used. A transistor can be manufactured on a substrate that has light-transmitting properties. The light transmission through the display element can be controlled by using the film thickness of the transistor. Because the film is thin, a part of the film that constitutes the transistor can transmit light. Therefore, the aperture ratio can be improved.

[0038] When producing polycrystalline silicon, a catalyst (such as nickel) is used to This will further improve the crystallinity and make it possible to manufacture transistors with good electrical characteristics. As a result, gate driver circuits (scanning line driver circuits) and source driver circuits (signal line driver circuits) , signal processing circuits (signal generation circuit, gamma correction circuit, DA conversion circuit, etc.) are integrated on the board It can be achieved.

[0039] When manufacturing microcrystalline silicon, a catalyst (such as nickel) is used to This further improves the crystallinity, making it possible to manufacture transistors with good electrical characteristics. In this case, the crystallinity can be improved by simply applying heat treatment without laser irradiation. As a result, part of the source driver circuit (analog switch, etc.) and gate The gate driver circuit (scanning line driving circuit) can be formed integrally on the substrate. If laser irradiation is not performed for the purpose of crystallization, unevenness in the crystallinity of silicon can be suppressed. Therefore, it is possible to display an image with improved quality.

[0040] However, polycrystalline silicon and microcrystalline silicon are produced without using a catalyst (such as nickel). It is possible.

[0041] In addition, improving the crystallinity of silicon to polycrystalline or microcrystalline allows the entire panel to be It is desirable to perform this in a partial area of ​​the panel, but it is not limited to this. The crystallinity of the crystalline silicon may be improved. For example, the peripheral circuit area, which is an area other than the pixel area, can be selectively irradiated. Alternatively, the laser light may be irradiated only on the gate driver circuit, the source driver circuit, and the Alternatively, the laser light may be irradiated only on a region such as a path. The laser light may be irradiated only on the area of ​​the semiconductor device (for example, an analog switch). It is possible to improve the crystallization of silicon only in areas where high-speed circuit operation is required. Since there is little need for high-speed operation in the pixel area, there is no problem even if the crystallinity is not improved. The pixel circuit can be operated without any problems. The manufacturing process can be shortened, throughput can be improved, and manufacturing costs can be reduced. The number of manufacturing devices required is also small, which reduces manufacturing costs. It can be done.

[0042] Alternatively, a transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. This allows for less variation in characteristics, size, and shape, a high current supply capacity, and a small size. These transistors can be used to fabricate transistors with small capacitances. This allows for lower power consumption and higher circuit integration.

[0043] Or ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO, SnO, Compound semiconductors or oxide semiconductors such as TiO, AlZnSnO (AZTO) transistors, and thin-film transistors made by thinning these compound semiconductors or oxide semiconductors. These can lower the manufacturing temperature, for example, to room temperature. As a result, it is possible to manufacture transistors on substrates with low heat resistance, such as plastic. Transistors can be formed directly on stick or film substrates. By simply using the compound semiconductor or oxide semiconductor in the channel formation region of a transistor, For example, these compound semiconductors or oxides can be used for other purposes. The semiconductor can be used as a resistor element, a pixel electrode, or a light-transmitting electrode. Since these can be deposited or formed simultaneously with the transistors, costs can be reduced.

[0044] Alternatively, a transistor formed by inkjet or printing can be used. These allow fabrication at room temperature, in a low vacuum, or on a large substrate. Since it is possible to manufacture without using a mask (reticle), The layout can be easily changed. Furthermore, since there is no need to use a resist, The cost of materials is reduced and the number of processes can be reduced. Furthermore, since the film is applied only to the necessary parts, This method is less wasteful and less costly than the method of forming a film on a surface and then etching it. can.

[0045] Alternatively, a transistor having an organic semiconductor or a carbon nanotube may be used. These features make it possible to form transistors on a flexible substrate. A semiconductor device using such a substrate can be made resistant to shocks.

[0046] Furthermore, transistors of various structures can be used. For example, MOS transistors The use of transistors such as junction transistors and bipolar transistors as transistors By using MOS transistors, the size of the transistors can be reduced. Therefore, multiple transistors can be mounted. By using a transistor, a large current can be passed through, which allows the circuit to operate at high speed. It can be made to work.

[0047] In addition, MOS transistors, bipolar transistors, etc. can be mixed and formed on a single substrate. This can achieve low power consumption, compact size, high speed operation, etc. .

[0048] In addition, various other transistors can be used.

[0049] Note that the transistor can be formed using various substrates. The substrate is not limited to a single crystal substrate (e.g., silicon). substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate, metal substrate, stainless steel Stainless steel substrate, substrate with stainless steel foil, tungsten substrate, tungsten A substrate with stainless steel foil, a flexible substrate, etc. can be used. An example of a glass substrate Examples of such glass include barium borosilicate glass and aluminoborosilicate glass. Examples of boards include polyethylene terephthalate (PET) and polyethylene naphthalate. (PEN), polyethersulfone (PES), or acrylic Other materials include flexible synthetic resins such as laminated films (polypropylene, etc.). Polyester, vinyl, polyvinyl fluoride, polyvinyl chloride, etc.), including fibrous materials Paper, base film (polyester, polyamide, polyimide, inorganic vapor deposition film, paper, etc.) ) or a transistor is formed on one substrate and then transferred to another substrate. The transistor may be transposed and placed on a different substrate. The substrates used are single crystal substrates, SOI substrates, glass substrates, quartz substrates, and plastic substrates. Board, paper substrate, cellophane substrate, stone substrate, wood substrate, cloth substrate (natural fiber (silk, cotton, linen), Synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate, (including plaster, rayon, recycled polyester, etc.), leather substrate, rubber substrate, stainless steel A substrate with a stainless steel foil, a substrate with a stainless steel foil, etc. can be used. Alternatively, the skin (epidermis, dermis) or subcutaneous tissue of an animal such as a human may be used as the substrate. Alternatively, a transistor may be formed on a substrate, and the substrate may be polished to make it thinner. The substrates that can be polished include single crystal substrates, SOI substrates, glass substrates, quartz substrates, and plastic substrates. Substrates, stainless steel substrates, substrates with stainless steel foil, etc. are used. By using these substrates, it is possible to form transistors with good characteristics and consume Forming low-power transistors, producing durable devices, making them heat-resistant, lightweight, or It is possible to achieve a thinner design.

[0050] The structure of the transistor can take various forms and is not limited to a specific structure. For example, a multi-gate structure with two or more gate electrodes can be applied. In the gate structure, the channel regions are connected in series, so multiple transistors are connected in series. The multi-gate structure reduces the off-state current and increases the breakdown voltage of the transistor. Alternatively, the multi-gate structure can be used to reduce the saturation region. When operating in the low-voltage range, the drain-source current remains constant even if the drain-source voltage changes. The voltage-current characteristic slope is flat. By taking advantage of the flat slope, it is possible to create ideal current source circuits and circuits with very high resistance values. As a result, it is possible to realize an active load with good characteristics, such as a differential circuit or a current mirror circuit. It is possible to realize this path.

[0051] As another example, a structure in which gate electrodes are arranged above and below the channel can be applied. By using a structure in which gate electrodes are arranged above and below the channel, The current value can be increased by increasing the number of gate electrodes above and below the channel. By using a structure in which the depletion layer is easily formed, the S value can be improved. In addition, by arranging gate electrodes above and below the channel, , a configuration in which a plurality of transistors are connected in parallel.

[0052] A structure in which a gate electrode is placed above a channel region, and a structure in which a gate electrode is placed below a channel region Structures in which the channel region is divided into multiple regions, such as a positive staggered structure, a reverse staggered structure, and a The structure may be a structure in which the channel regions are connected in parallel, or a structure in which the channel regions are connected in series. Furthermore, the source electrode and drain electrode are attached to the channel region (or a part of it). An overlapping structure can also be applied. By using a structure in which the gate electrodes overlap, charges accumulate in part of the channel region, This can prevent the operation from becoming unstable. Alternatively, a structure with an LDD region can be appropriately By providing an LDD region, it is possible to reduce the off-current or improve the breakdown voltage of the transistor. Alternatively, by providing an LDD region, it is possible to reduce saturation. When operating in the sum region, the drain-source current remains constant even if the drain-source voltage is changed. does not change much, and the slope of the voltage-current characteristics can be made flat.

[0053] Note that various types of transistors can be used and can be formed using various substrates. Therefore, all the circuits required to realize a given function can be implemented in the same For example, it is possible to form a circuit on a substrate that is necessary to realize a predetermined function. All of these can be mounted on various substrates such as glass, plastic, single crystal, or SOI. It is also possible to form the entire circuit necessary to realize a predetermined function using a substrate. Since all components are formed using the same substrate, the number of components is reduced, resulting in cost reduction. Alternatively, the reliability can be improved by reducing the number of connection points with the circuit components. A part of the circuit required to realize a certain function is formed on a certain substrate, and the It is also possible that another part of the circuitry required to realize the above may be formed on another substrate. In other words, all of the circuits required to realize a given function are formed using the same substrate. For example, some of the circuits required to realize a specific function may be mounted on a glass substrate. Another part of the circuit formed by transistors on the board and required to realize a specified function. The part is formed on a single crystal substrate and is composed of transistors formed using the single crystal substrate. The IC chip is connected to the glass substrate using COG (Chip On Glass). It is also possible to place the IC chip on the board. (Tape Automated Bonding) and printed circuit boards are used to bond glass substrates. In this way, it is possible to connect the two circuits together. This reduces costs by reducing the number of components, and improves signal quality by reducing the number of connections to circuit components. Alternatively, it is possible to improve reliability in areas where the driving voltage is high and the driving frequency is high. The power consumption of the circuitry for these parts is high, so the circuits for these parts are formed on the same board. Instead, for example, a circuit for that part is formed on a single crystal substrate, and the circuit is configured By using an IC chip fabricated in this way, it is possible to prevent an increase in power consumption.

[0054] Note that one pixel refers to one element whose brightness can be controlled. In this case, one pixel refers to one color element, and the brightness is expressed by one color element. Therefore, in the case of a color display device consisting of R (red), G (green), and B (blue) color elements, In this example, the smallest unit of an image is composed of three pixels: an R pixel, a G pixel, and a B pixel. The color elements are not limited to three colors, and more than three colors may be used. Colors may also be used. For example, white may be added to make it RGBW (W is white). Or, for example, yellow, cyan, magenta, emerald green, vermilion, It is also possible to add one or more colors, or for example, at least one of the RGB colors. It is also possible to add a color similar to a single color to RGB. For example, R, G, B1, B 2. B1 and B2 are both blue, but they have slightly different wavelengths. Similarly, it is possible to use R1, R2, G, and B. By using such color elements, By using such color elements, it is possible to display the image more realistically. As another example, multiple regions can be used for one color element. When using this to control brightness, it is possible to use one area as one pixel. For example, when area gradation is performed or when sub-pixels are used, For each color element, there are multiple areas that control brightness, and the overall gradation is expressed. It is also possible to use one pixel for one area for controlling the thickness. Each color element is made up of multiple pixels. Even if there are multiple color elements in one color element, they may be grouped together and one color element may be considered as one pixel. Therefore, in this case, one color element is composed of one pixel. When controlling the brightness of one color element using multiple regions, the display The size of the area that contributes to the display may be different. In the various brightness control areas, the signal supplied to each is slightly different. In other words, for one color element, multiple regions may be used to widen the viewing angle. The potentials of the pixel electrodes of the respective regions may be different. The voltage applied to the molecules varies depending on the pixel electrode, which makes it possible to widen the viewing angle. Cut.

[0055] When explicitly stating one pixel (three colors), the three pixels of R, G, and B are considered to be one pixel. When explicitly describing one pixel (one color), it refers to one color element. In this case, when there are multiple regions, they are considered as one pixel.

[0056] In some cases, pixels are arranged (distributed) in a matrix. The pixels are arranged in a straight line in either the vertical or horizontal direction. This includes cases where they are arranged side by side or in a jagged line. For example, when displaying full color using three color elements (e.g., RGB), the stripes are arranged This also includes cases where the dots of the three color elements are arranged in a delta arrangement. This also includes the case where the dots are arranged in a Bayer pattern. This can reduce power consumption or extend the life of the display element. can.

[0057] In addition, the active matrix type has active elements in the pixels, or the A passive matrix method can be used.

[0058] In the active matrix system, the active element (active element, nonlinear element) is a transistor. Use not only transistors but also various active elements (active elements, nonlinear elements) For example, MIM (Metal Insulator Metal) and TFD ( Thin Film Diodes) can also be used. Since the number of manufacturing steps is small, it is possible to reduce manufacturing costs and improve yields. In addition, the small size of the element allows for an improved aperture ratio, resulting in lower power consumption and higher brightness. It is possible to achieve this.

[0059] In addition to the active matrix method, there are also active elements (active elements, nonlinear It is also possible to use a passive matrix type that does not use active elements. Since it does not use any nonlinear elements, there are fewer manufacturing steps, which reduces manufacturing costs and improves yield. Since no active elements (active elements, non-linear elements) are used, Therefore, the aperture ratio can be improved, and it is possible to achieve low power consumption and high brightness.

[0060] A transistor is a device having at least three terminals including a gate, a drain, and a source. The element has a channel region between the drain region and the source region, A current can flow through the in-region, the channel region, and the source region. The source and drain depend on the transistor structure and operating conditions, so it is difficult to know which is the source or drain. Therefore, it is difficult to define whether the source or drain is the In some cases, the region that functions as a source or drain is not called a source or drain. In this case, they may be referred to as the first terminal and the second terminal, respectively. They may be referred to as the first electrode and the second electrode, or as the first region and the second region. There is.

[0061] The transistor has at least three terminals including a base, an emitter, and a collector. In this case, the emitter and the collector may be connected to the first terminal and the second terminal. It may be referred to as a terminal.

[0062] The gate is a gate electrode and a gate wiring (gate line, gate signal line, scanning line, scanning signal line). The term refers to the whole or part of a gate electrode and The gate insulating film is a part that overlaps the semiconductor that forms the channel region. The gate electrode is partially doped with LDD (Lightly Doped Diode). ed Drain) region or source region (or drain region) and The gate wiring is the gate electrode of each transistor. a wiring for connecting between the gate electrodes of each pixel, or This refers to the wiring that connects the gate electrode to another wiring.

[0063] However, there are areas (regions, conductive layers) that function as both gate electrodes and gate wiring. Such parts (regions, conductive layers, wiring, etc.) are also present. In other words, the gate electrode and the gate wiring However, there are also regions that cannot be clearly distinguished. For example, If a part of the line overlaps with the channel region, the overlapping part (region, conductive layer, wiring ) functions as a gate wiring, but also functions as a gate electrode. Therefore, such a part (region, conductive layer, wiring, etc.) may be called a gate electrode. , which may also be called gate wiring.

[0064] It is made of the same material as the gate electrode and forms the same island as the gate electrode. The connected part (region, conductive layer, wiring, etc.) may also be called a gate electrode. The gate wiring is made of the same material as the gate wiring and is connected to the same island as the gate wiring. The part (region, conductive layer, wiring, etc.) that is connected to the gate may also be called the gate wiring. The part (region, conductive layer, wiring, etc.) does not overlap the channel region in the strict sense. However, there are cases where the gate electrode does not have a function to connect to another gate electrode. Due to manufacturing specifications, the gate electrode or gate wiring is made of the same material. The area (region, Therefore, such parts (regions, conductive layers, wiring, etc.) are also included in the gate. They may also be called gate electrodes or gate wirings.

[0065] For example, in a multi-gate transistor, one gate electrode and another gate In many cases, the electrode is connected to the gate electrode through a conductive layer made of the same material. The necessary parts (regions, conductive layers, wiring, etc.) are parts for connecting gate electrodes. Since it is a component (region, conductive layer, wiring, etc.), it can be called gate wiring, but multi-gate Since the transistors can be considered as one transistor, they can be called gate electrodes. In other words, it is formed of the same material as the gate electrode or gate wiring, and The part (area, conductive layer, wiring, etc.) that forms the same island as the port wiring and is connected The gate electrodes and gate wirings may be called gate electrodes or gate wirings. A conductive layer that is connected to wiring and is different from the gate electrode or gate wiring. The conductive layer formed from the material may also be called a gate electrode or a gate wiring.

[0066] The gate terminal is a part of the gate electrode (region, conductive layer, wiring, etc.) or Regarding the part (area, conductive layer, wiring, etc.) that is electrically connected to the electrode, It is said that.

[0067] Note that a certain wiring may be called a gate wiring, gate line, gate signal line, scanning line, scanning signal line, etc. In some cases, the gate of the transistor may not be connected to the wiring. The gate wiring, gate lines, gate signal lines, scanning lines, and scanning signal lines are the same as the gates of transistors. wiring formed in the same layer as the gate of the transistor, wiring formed in the same material as the gate of the transistor, or It may refer to the wiring deposited at the same time as the gate of a transistor. These include measurement wiring, power supply wiring, and reference potential supply wiring.

[0068] The source includes the source region, the source electrode, and the source wiring (source line, source signal line, It refers to the whole or part of the data line (also called data line, data signal line, etc.). The source region is formed by doping P-type impurities (such as boron or gallium) or N-type impurities (such as phosphorus or arsenic). Therefore, it refers to a semiconductor region that contains a large amount of P-type impurities and N-type impurities. The region containing The source electrode is formed of a material different from the source region and is not included in the source region. The term "conductive layer" refers to the portion of the conductive layer that is electrically connected to the source region. The source electrode is sometimes called the source electrode, including the source region. wiring for connecting the source electrodes of the transistors, and wiring for connecting the source electrodes of each pixel. This refers to a wiring for connecting a source electrode to another wiring, or a wiring for connecting a source electrode to another wiring.

[0069] However, there is a part (area) that functions as both a source electrode and a source wiring. Such parts (regions, conductive layers, wiring, etc.) are also present. It may be called a source electrode or a source wiring. There are also areas where it is difficult to clearly distinguish between lines and objects. If a part of the source wiring overlaps with the source region, that part (region, conductive layer) , wiring, etc.) functions as a source wiring, but also as a source electrode. Therefore, such a part (region, conductive layer, wiring, etc.) can be called a source electrode. That's fine, you can call it source wiring.

[0070] It is made of the same material as the source electrode and forms the same island as the source electrode. Connected parts (regions, conductive layers, wiring, etc.) and connecting source electrodes The part (region, conductive layer, wiring, etc.) that is connected to the source electrode may also be called the source electrode. The overlapping portion of the source line may also be called the source electrode. There are also regions that are made of the same material and form the same island as the source wiring. Such a part (region, conductive layer, wiring, etc.) may be called a source wiring. In some cases, the device may not have the ability to connect to a separate source electrode. Due to specifications, the source electrode or source wiring is made of the same material. There are parts (regions, conductive layers, wiring, etc.) that are connected to the source wiring. Such a part (region, conductive layer, wiring, etc.) may also be called a source electrode or source wiring.

[0071] For example, the conductive layer in the portion connecting the source electrode and the source wiring is A conductive layer formed of a material different from the source electrode or source wiring may also be called a source electrode. Alternatively, it may be called source wiring.

[0072] The source terminal may be a source region, a source electrode, or a terminal electrically connected to the source electrode. It refers to a part of a circuit (such as an area, conductive layer, or wiring).

[0073] A certain wiring may be referred to as a source wiring, a source line, a source signal line, a data line, a data signal line, etc. When a transistor is called a "transistor," the source (drain) of the transistor may not be connected to the wiring. In this case, the source wiring, source line, source signal line, data line, and data signal line are The wiring formed in the same layer as the source (drain) of the transistor, The wiring is made of the same material as the source (drain) of the transistor, or the wiring is made of the same material as the source (drain) of the transistor. Examples include storage capacitor wiring, power supply wiring, and reference voltage wiring. Power supply wiring, etc.

[0074] The drain is the same as the source.

[0075] Semiconductor devices include semiconductor elements (transistors, diodes, thyristors, etc.). It refers to a device that has a circuit. Furthermore, it refers to the entire device that can function by utilizing the characteristics of semiconductors. Generally, a device that has semiconductor material can be called a semiconductor device. say.

[0076] The display device refers to a device having a display element. The display device may include a plurality of pixels including a peripheral circuit for driving the plurality of pixels. The peripheral driving circuit for driving the plurality of pixels may include a driving circuit. The display device may be formed on the same substrate as the element. The peripheral drive circuits arranged on the board by the chip-on-glass (COG) It may include an IC chip connected to the board or an IC chip connected by a tab or the like. The display device may contain IC chips, resistors, capacitors, inductors, transistors, etc. The flexible printed circuit (FPC) may be attached. The display device is connected via a flexible printed circuit (FPC) or the like, and the IC chip Printed wiring with resistors, capacitors, inductors, transistors, etc. attached The display device may include an optical element such as a polarizing plate or a retardation plate. The display device may include a lighting device, a housing, an audio input / output device, a light source, and a display sheet. It may also include a sensor.

[0077] The lighting device includes a backlight unit, a light guide plate, a prism sheet, a diffusion sheet, a reflector, It has a sheet, a light source (LED, cold cathode fluorescent lamp, etc.), a cooling device (water-cooled, air-cooled), etc. is also good.

[0078] The light-emitting device refers to a device having a light-emitting element or the like. When the light-emitting device has an element, it is a specific example of a display device.

[0079] The reflecting device is a device that has a light reflecting element, a light diffracting element, a light reflecting electrode, etc. This refers to

[0080] The liquid crystal display device refers to a display device having a liquid crystal element. There are various types, including visual, projection, transmissive, reflective, and semi-transmissive.

[0081] The driving device refers to a device that has semiconductor elements, electric circuits, and electronic circuits. For example, a transistor (selection transistor) that controls the input of a signal from a source signal line to a pixel (sometimes called a phototransistor or switching transistor) that applies voltage or current to the pixel electrode The transistors that supply voltage or current to the light-emitting element are Furthermore, a circuit for supplying signals to the gate signal lines (gate driver, gate the source signal line driver circuit, and the circuit that supplies signals to the source signal line (source driver A pixel driver (sometimes called a pixel driver or a source line driver circuit) is an example of a driver.

[0082] In addition, display devices, semiconductor devices, lighting devices, cooling devices, light-emitting devices, reflecting devices, driving devices, etc. For example, a display device may have a semiconductor device and a light emitting device. Alternatively, the semiconductor device may have a display device and a driver. This may be the case.

[0083] Note that it is not possible to explicitly say that B is formed on A, or that B is formed on A. When describing, it is not limited to forming B on A in direct contact with it. This also includes cases where there is no object between A and B, i.e., there is another object between A and B. Here, A and B are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layers, etc.).

[0084] Therefore, for example, it is not possible to explicitly state that layer B is formed on top of layer A (or on top of layer A). When the layer is placed on top of the substrate, there are cases where layer B is formed directly on top of layer A, and cases where layer B is formed directly on top of layer A. Another layer (such as layer C or layer D) is formed adjacent to it, and layer B is formed directly on top of it. It should be noted that other layers (such as layer C and layer D) may be formed separately. It may be a single layer or multiple layers.

[0085] Furthermore, the same applies when it is explicitly stated that B is formed above A. This is not limited to B being directly on top of A, but also includes the presence of another object between A and B. For example, if layer B is formed above layer A, In this case, there are two cases: when layer B is formed directly on top of layer A, and when layer B is formed directly on top of layer A. Another layer (such as layer C or layer D) is formed, and layer B is formed directly on top of it. It should be noted that other layers (such as layers C and D) may be single layers. Alternatively, it may be multi-layered.

[0086] In addition, B is formed on A, B is formed on A, or B is formed above A. When explicitly stating that "B" is formed, this also includes the case where B is formed diagonally above. .

[0087] The same applies to the case where B is below A, or B is below A.

[0088] In addition, when something is explicitly stated as singular, it is preferable that it be singular. However, it is not limited to this, and plural numbers are also possible. It is preferable that the items listed are plural. However, this is not limited to this. , it is also possible that it is singular.

[0089] In the drawings, the size, thickness of layers, or areas may be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

[0090] The diagrams are merely diagrams showing ideal examples, and are not limited to the shapes or values ​​shown in the diagrams. For example, variations in shape due to manufacturing technology, variations in shape due to errors, and noise Variations in signals, voltages, or currents due to timing differences, or variations in signals, voltages, Alternatively, it is possible to include variations in current.

[0091] Note that technical terms may be used to describe specific embodiments or examples. Many, but not limited to:

[0092] In addition, undefined terms (including scientific and technical terms such as technical terms or academic terms) are generally It can be used as a meaning equivalent to the general meaning understood by a person of ordinary skill in the art. The terms defined herein shall be construed in a manner consistent with the background of the relevant art. is preferred.

[0093] It should be noted that the terms first, second, third, etc., refer to various elements, members, regions, layers, and sections as distinct from one another. Therefore, the words "first," "second," "third," etc. are used to distinguish between elements, parts, etc. It is not intended to limit the number of materials, regions, layers, areas, etc. It is possible to replace "second" or "third" etc.

[0094] In addition, "up," "upward," "down," "downward," "sideways," "right," "left," Spatial positioning terms such as "diagonally," "in the back," or "in front" may be used to indicate the position of an element or is sometimes used to simply illustrate the relationship of a feature to other elements or features. However, this is not limited to this, and the words and phrases that indicate these spatial arrangements are added to the direction drawn in the drawing. In addition, other orientations are possible. For example, if it is explicitly stated that B is above A, The device shown is not limited to B being above A. It can be flipped or rotated 180 degrees. Since it is possible for B to be under A, it is possible for B to be under A. The phrase "on" can include an orientation of "under" in addition to an orientation of "on." However, the device in the figure is not limited to this and can be rotated in various directions. The term "above" includes the directions "above" and "below," as well as "sideways," "to the right," and "to the left." It is possible to include other directions such as "towards," "diagonally," "behind," or "forward." . [Effects of the Invention]

[0095] In one embodiment of the present invention, a light-transmitting transistor or a light-transmitting capacitor is formed. Therefore, even when a transistor or a capacitor is disposed within a pixel, Even in the case where a transistor or a capacitor is formed, light can be transmitted through the film. Therefore, the aperture ratio can be improved. A wiring that connects a capacitor element to another element (e.g., another capacitor element) The wiring that connects the signal can be formed using a material with low resistivity and high conductivity. This reduces waveform distortion and voltage drop due to wiring resistance. [Brief explanation of the drawings]

[0096] [Figure 1] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 2] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 3] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 4] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 5] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 6] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 7] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 8] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 9] FIG. 1 is a top view according to one embodiment of the present invention. [Figure 10] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 11] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 12] FIG. 1 is a top view according to one embodiment of the present invention. [Figure 13] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 14] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 15] FIG. 1 is a top view according to one embodiment of the present invention. [Figure 16] 1A and 1B are a top view and a cross-sectional view according to one embodiment of the present invention. [Figure 17] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 18] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 19] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 20] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 21] 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 22] FIG. 10 is a diagram illustrating a multi-tone mask. [Figure 23] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 24] FIG. 1 is a block diagram according to one embodiment of the present invention. [Figure 25] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 26] FIG. 1 is a circuit diagram illustrating a semiconductor device according to one embodiment of the present invention. [Figure 27] FIG. 1 is a cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 28] 1A and 1B are a top view and a cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 29] 1A and 1B are a top view and a cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 30] 1A and 1B illustrate a display device according to one embodiment of the present invention. [Figure 31] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Figure 32] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Figure 33] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Figure 34] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Figure 35] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 36] FIG. 1 is a plan view according to one embodiment of the present invention. [Figure 37] FIG. 1 illustrates a circuit according to one embodiment of the present invention. [Figure 38] FIG. 1 illustrates a circuit according to one embodiment of the present invention. [Figure 39] FIG. 1 illustrates a circuit according to one embodiment of the present invention. [Figure 40] 10A and 10B are diagrams illustrating potentials of a display element according to one embodiment of the present invention. [Figure 41] 1A and 1B illustrate a display screen according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0097] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited to the following description, and the embodiments and methods thereof may be modified without departing from the spirit and scope of the present invention. It will be readily apparent to those skilled in the art that various modifications may be made to the details. The present invention should not be construed as being limited to the following description of the embodiments.

[0098] In this specification, the term "film" refers to a film formed over the entire surface and not patterned. And, a "layer" is something that has been patterned into a desired shape using a resist mask or the like. The distinction between "membrane" and "layer" as mentioned above is made for convenience, and the distinction between membrane and layer is not made for convenience. In addition, the terms "film" and "layer" are sometimes used without any distinction between them. They are sometimes used without distinction.

[0099] In addition, in this specification, terms with numerals such as "first," "second," or "third" refer to elements. It is given for convenience to distinguish elements, and is not limited to a specific number. The arrangement and order of steps are not limited to those shown.

[0100] Note that the content (or even a part of the content) described in one embodiment may be used in conjunction with that embodiment. Other content (or even part of content) described in the above, and / or one or more other implementations The content (or part of the content) described in the form of You can do things like:

[0101] The contents described in the embodiments are explained in detail in each embodiment using various drawings. This refers to the content that is stated or the content that is stated using the text in the specification.

[0102] In addition, a drawing (or a part thereof) described in one embodiment may be different from another part of the drawing, Another figure (or a part thereof) described in the embodiment, and / or one or more By combining with the figure (or a part thereof) described in another embodiment of the present invention, , and many more diagrams can be constructed.

[0103] In addition, in a drawing or a sentence described in a certain embodiment, a part thereof may be extracted. Therefore, the drawings and drawings that illustrate certain parts of the invention may be omitted. If a part of a drawing or text is included in the invention, the part of the drawing or text may also be included in the invention. It is disclosed as an embodiment and may constitute an embodiment of the invention. Therefore, for example, active elements (transistors, diodes, etc.), wiring, passive elements (capacitive elements, resistive elements, etc.), conductive layers, insulating layers, semiconductor layers, organic materials, inorganic materials, components, Substrate, module, device, solid, liquid, gas, method of operation, method of manufacture, etc. The drawings (cross-section, plan view, circuit diagram, block diagram, flow chart, process chart, perspective view) , elevation, layout, timing chart, structural diagram, schematic diagram, graph, table, optical path diagram, vector A part of a graph (such as a graph, phase diagram, waveform diagram, photograph, or chemical formula) or text can be extracted. This can constitute one aspect of the invention.

[0104] (Embodiment 1) In this embodiment mode, a semiconductor device and a manufacturing process thereof will be described with reference to FIGS. do.

[0105] 1A and 1B show a semiconductor device according to this embodiment. FIG. 1A is a plan view, and FIG. 1B is a side view. 1(A) is a cross-sectional view taken along line AB in FIG.

[0106] The semiconductor device shown in FIG. 1A has a plurality of wirings (for example, gate wirings) arranged in one direction. and capacitance wiring), and multiple wirings (e.g., source wirings) arranged in two directions, and and a pixel portion having a plurality of transistors near the intersection of the wirings. It is desirable that the wiring arranged in the first direction and the wiring arranged in the second direction are perpendicular to each other. In this specification, the pixel portion is a region surrounded by a plurality of gate wirings and a plurality of source wirings. It refers to the area.

[0107] The transistor 150 shown in FIG. 1 includes a semiconductor layer 103a and a A conductive layer 101 serving as a source electrode or a drain electrode is provided over the semiconductor layer 103a. and conductive layers 106a and 106b serving as source and drain electrodes. a gate insulating film 110 provided on the gate insulating film 6b; and a conductive layer 113a serving as a gate electrode provided between the conductive layers 106a and 106b. Therefore, the transistor 150 is a so-called top gate type transistor. However, even if a gate electrode is disposed below the channel (semiconductor layer 103a), The semiconductor layer 103a preferably contains an oxide. However, the present invention is not limited to this. For example, the semiconductor layer 103a may be made of silicon. Formed using silicon, gallium arsenide, compound semiconductors, organic semiconductors, carbon nanotubes, etc. It is possible to do this.

[0108] The semiconductor layer 103a that constitutes the transistor 150 and the conductive layer 103b that functions as a gate electrode are also formed. the conductive layer 113a and the conductive layers 106a and 106b functioning as a source electrode and a drain electrode, respectively. A part or all of the components are made of a light-transmitting material. A part or all of the semiconductor layers and conductive layers that constitute the transistor 150 are made of a light-transmitting material. By forming the transistor using a material that can transmit light, the transistor can be formed Therefore, the aperture ratio of the pixel portion can be improved.

[0109] Note that the term "light-transmitting" used herein means that at least the conductive layer 109a and the conductive layer 116a This means that it has a higher transmittance of light in the visible range (approximately 400nm to 800nm) compared to Taste.

[0110] Normally, the wiring that connects elements, for example, transistors, is The conductive layer that constitutes the electrode, source electrode, or drain electrode is stretched as it is, and the same island (i Therefore, the gate of a transistor and the gate of another transistor are often formed by a metal pad. The wiring that connects the gate of the transistor and the gate of the transistor (called the gate wiring) They are often made of the same layer structure and materials, and are used to separate the source and The wiring that connects the source of the transistor (called the source wiring) is They are often made of the same layer structure and the same materials. When a light-transmitting material is used as the source electrode or the drain electrode, The wiring and the source wiring are transparent like the gate electrode and the source or drain electrode. The substrate is formed using a material having such properties.

[0111] A light-transmitting material, such as indium tin oxide, indium zinc oxide, indium Tin zinc oxide and the like are used in combination with materials that have light-shielding and reflective properties, such as aluminum and molybdenum. It has lower conductivity than other metals such as buten, titanium, tungsten, neodymium, copper, silver, and chromium. Therefore, when a wiring is formed using a light-transmitting material, the wiring resistance tends to be low. For example, when manufacturing a large display device, the wiring becomes long, and the wiring The resistance becomes very high. When the wiring resistance becomes high, the waveform of the signal propagating through the wiring becomes rough. This causes a voltage drop due to wiring resistance, which reduces the voltage supplied. It becomes difficult to supply accurate voltage and current, and normal display and operation cannot be achieved. It may be difficult.

[0112] Therefore, the gate wiring electrically connected to the gate electrode of the transistor 150 is made of a light-transmitting material. A conductive layer 113a having a light-shielding property and a conductive layer 116a having a light-shielding property are stacked. The source wiring electrically connected to the source electrode or the drain electrode of the transistor 150 is a light-transmitting A conductive layer 106a having a light-shielding property and a conductive layer 109a having a light-shielding property are stacked. The gate electrode of the transistor 150 is formed from a part of the conductive layer 113a having light-transmitting properties. The source electrode or the drain electrode of the transistor 150 is formed of a light-transmitting conductive layer. It is formed from a part of 106a.

[0113] It is desirable that the light transmittance of the conductive layer 113a is sufficiently high. The transmittance is preferably higher than the light transmittance of the conductive layer 116a.

[0114] It is also desirable that the resistivity of the conductive layer 116a is sufficiently low and the conductivity is sufficiently high. It is desirable that the resistivity of the conductive layer 116a be lower than the resistivity of the conductive layer 113a. However, since the conductive layer 116a functions as a conductive layer, the resistivity of the conductive layer 116a is higher than that of the insulating layer. It is desirable that the resistivity be lower than that of

[0115] A gate wiring or a source wiring is formed by stacking a light-transmitting conductive layer and a light-shielding conductive layer. By doing so, it is possible to reduce the wiring resistance. This reduces signal waveform distortion and voltage drop due to wiring resistance. In addition, by reducing the voltage drop caused by wiring resistance, accurate voltage and current can be supplied. This makes it possible to manufacture large-sized display devices. The wiring or source wiring is made of a conductive layer having a light-shielding property, and therefore, the wiring or source wiring is made of a conductive layer having a light-shielding property. In other words, the gate wiring arranged in the row direction and the By using source wiring, the gaps between pixels can be shielded from light without using a black matrix. However, it is possible to use a black matrix.

[0116] In addition, from the perspective of display performance, pixels are required to have large capacitance elements and a high aperture ratio. Each pixel has a high aperture ratio, which improves light utilization efficiency and reduces the energy consumption of the display device. In recent years, pixel size has become smaller, allowing for higher resolution images. However, as pixel size becomes smaller, the amount of transistors per pixel decreases. The area where the stator and wiring are formed is increased, reducing the aperture ratio of the pixel. To obtain a high aperture ratio within the pixel size, it is necessary to efficiently arrange the elements required for the pixel circuit configuration. It is essential to get out.

[0117] The capacitance wiring according to one aspect of the present invention is arranged in the same direction as the gate wiring, and In the source wiring, it is preferable to form the conductive layer 113b having a light-transmitting property. In the overlapping region, a conductive layer 113b having a light-transmitting property for increasing the conductivity and a light-shielding property are formed. The capacitor wiring may be provided with a storage capacitor portion 160. The storage capacitor 160 is formed by connecting the source electrode or the drain electrode of the transistor 150. The storage capacitor 160 is connected to one of the electrodes (conductive layer 106b). The insulating film 110 is a dielectric, and the conductive layer 106b and the conductive layer 113b function as electrodes. In addition, a capacitance is also formed between the pixel electrode and the conductive layer 113b. The capacitance may also be a storage capacitance.

[0118] In this embodiment, an example is shown in which the width of the capacitance wiring and the width of the gate wiring are formed to be the same. However, the width of the capacitance wiring may be different from the width of the gate wiring. It is preferable that the width of the capacitance wiring is wider than that of the storage wiring. The area of ​​the capacitance section 160 can be increased.

[0119] In this way, the storage capacitor 160 is formed by the conductive layer 106b and the conductive layer 113b, which have light-transmitting properties. By configuring the storage capacitor 160 as above, light can be transmitted through the storage capacitor 160. Therefore, the aperture ratio can be improved. By configuring the storage capacitor 160 with a conductive layer having a high electrical conductivity, the storage capacitor 160 can be enlarged without reducing the aperture ratio. Therefore, even when the transistor is turned off, the potential of the pixel electrode is maintained. The characteristics are improved, and the display quality is improved. In addition, the feedthrough potential can be reduced. Alternatively, crosstalk can be reduced due to improved noise resistance. In addition, since the voltage can be set accurately, flickering can also be reduced. This allows the circuit elements required for the circuit configuration to be laid out efficiently.

[0120] The transistor 150 shown in FIG. 1 is typically used in a liquid crystal display device or an EL display device. The present invention can be applied to a pixel transistor provided in a pixel portion of a light-emitting display device. Therefore, in FIG. 1, contact holes 130 are provided in the gate insulating film 110 and the insulating film 117. Pixel electrode layers (light-transmitting conductive layers 119a and 119c) are provided on the insulating film 117. , the pixel electrode 114 is connected to the gate insulating film 110 through a contact hole 130 formed in the insulating film 117. The electrode layer (transparent conductive layer 119a having light-transmitting properties) and the conductive layer 106b are connected. do.

[0121] Next, an example of a manufacturing process of a semiconductor device will be described with reference to FIGS.

[0122] First, an oxide semiconductor film 101 is formed over a substrate 100 having an insulating surface (FIG. 2(A)). , see (B)).

[0123] The substrate 100 having an insulating surface may be, for example, a visible light transmitting substrate used in a liquid crystal display device or the like. The glass substrate may be an alkali-free glass substrate. The alkali-free glass substrate is preferably an aluminosilicate glass substrate. Glass materials such as aluminoborosilicate glass and barium borosilicate glass are used. Other examples of the substrate 100 having an insulating surface include a ceramic substrate, a quartz substrate, and a sapphire substrate. The surface of an insulating substrate made of an insulator such as a silicon substrate, or a semiconductor substrate made of a semiconductor material such as silicon Coated with insulating material, insulating the surface of a conductive substrate made of a conductor such as metal or stainless steel It is possible to use materials coated with PET (polyethylene Plastic bases such as polyethylene terephthalate Plates can also be used.

[0124] An insulating film serving as a base film may be provided on the substrate 100 having an insulating surface. Alkali metals (Li, Cs, Na, etc.) and alkaline earth metals (Ca, Mg, etc.) from 00 It has the function of preventing the diffusion of impurities such as other metal elements. 19 / cm 3Less than 1 × 10 18 / cm 3 The insulating film is a silicon nitride film. , silicon oxide film, silicon nitride oxide film, silicon oxynitride film, aluminum oxide film, nitride a single layer selected from aluminum nitride film, aluminum oxynitride film, and aluminum nitride oxide film The nitride film may be formed by a nitride structure or a laminated structure of multiple films. It is desirable to provide a silicon oxide film on the silicon film. This makes it possible to sufficiently prevent the diffusion of impurities. By doing so, it is possible to prevent the silicon nitride film from coming into contact with the semiconductor layer. This is because when the silicon dioxide film comes into contact with the semiconductor layer, the semiconductor layer may be hydrogenated. However, the present invention is not limited to this, and the silicon nitride film and the semiconductor layer can be in contact with each other.

[0125] The oxide semiconductor forming the oxide semiconductor film 101 is InMO3(ZnO). m (m> It is preferable to use an oxide semiconductor having a structure represented by In-Ga-Zn-O. It is preferable to use a GaN-based oxide semiconductor. M is gallium (Ga), iron (Fe), nickel (Ni), or the like. One metal element selected from nickel (Ni), manganese (Mn) and cobalt (Co), or It indicates multiple metal elements. For example, M can be Ga, Ga and Ni, or G In some cases, the oxide semiconductor may contain the above metal elements other than Ga, such as Ga and Fe. In addition to the metal elements contained as M, Fe, Ni and other transition elements are included as impurity elements. Some of them contain metal elements or oxides of the transition metals. nMO3(ZnO) mAmong oxide semiconductors with a structure expressed as (m>0), M is at least Oxide semiconductors with a structure containing at least Ga are called In-Ga-Zn-O oxide semiconductors. The thin film is also called an In-Ga-Zn-O system non-single crystal film.

[0126] The crystal structure of the In-Ga-Zn-O non-single crystal film was determined by XRD (X-ray diffraction) analysis. The In-Ga-Zn-O non-single crystal structure of the sample used for analysis was The crystal film is formed by sputtering and then heat-treated at 200 to 500°C, typically 300 It is done at ℃ to 400℃ for 10 to 100 minutes.

[0127] By using In-Ga-Zn-O based non-single crystal film as the active layer of thin film transistors, , at a gate voltage of ±20V, the on-off ratio is 10 9 More than 10cm of mobility 2 / V·s A thin film transistor having the above electrical characteristics can be manufactured.

[0128] However, the oxide semiconductor film 101 is InMO3(ZnO) m Structures represented by (m>0) For example, the present invention is not limited to an oxide semiconductor film of indium oxide (InO x ), oxidation Zinc (ZnO x ), tin oxide (SnO), indium zinc oxide (IZO), indium oxide Tin (Indium Tin Oxide: ITO), indium oxide containing silicon oxide Oxide semiconductor films containing tin oxide (ITSO), gallium-doped zinc oxide (GZO), etc. may also be used.

[0129] The thickness of the oxide semiconductor film 101 is set to 50 nm or more, preferably 60 nm to 150 nm. The oxide semiconductor film 101 is used as a source electrode or a drain electrode to be formed later. Between the conductive layers 106a and 106b, which function as a conductive layer, there is provided a conductive layer 106b. This is because the conductive layers 106a and 106b may have a region with a thinner film thickness than the conductive layers 106a and 106b. This is caused by etching a part of the semiconductor layer 103a when etching. Therefore, by making the thickness of the oxide semiconductor film 101 50 nm or more, it is possible to form a channel. This can prevent the area from being lost due to etching.

[0130] The carrier concentration range of the oxide semiconductor film 101 is 1×10 17 / cm 3 Less than (more preferably 1×10 11 / cm 3 The carrier concentration range of the oxide semiconductor film 101 is preferably higher than or equal to 100 nm. If the range is exceeded, the thin film transistor may be normally on.

[0131] The oxide semiconductor film 101 may contain insulating impurities. Insulating oxides such as silicon, germanium oxide, and aluminum oxide, silicon nitride, Silicon, aluminum nitride, and other insulating nitrides, as well as silicon oxynitride and oxynitride An insulating oxynitride such as aluminum oxide is applied.

[0132] These insulating oxides, insulating nitrides, and insulating oxynitrides are used to improve the electrical conductivity of oxide semiconductors. The oxide semiconductor is doped with the fluorine-containing compound at a concentration that does not impair the properties of the oxide semiconductor.

[0133] By adding insulating impurities to the oxide semiconductor film 101, By suppressing the crystallization of the oxide semiconductor film 101, This makes it possible to stabilize the characteristics of the thin film transistor.

[0134] For example, if an In-Ga-Zn-O oxide semiconductor contains impurities such as silicon oxide, By using the oxide semiconductor, the oxide semiconductor can be crystallized or microcrystalline even when heat treatment is performed at 300° C. to 600° C. The formation of crystal grains can be prevented.

[0135] Fabrication of thin-film transistors with In-Ga-Zn-O oxide semiconductors as the channel formation region In the process, the S value (subthreshold swing value) is calculated by heat treatment. e) and field-effect mobility can be improved, but even in such cases, This prevents the thin-film transistor from becoming normally on. Even if thermal stress or bias stress is applied to the transistor, the threshold voltage can be prevented from fluctuating. This can be done.

[0136] In addition to the above, oxide semiconductors that can be used for the oxide semiconductor film 101 include In-Sn-Zn- O-based, In-Al-Zn-O-based, Sn-Ga-Zn-O-based, Al-Ga-Zn-O-based, S n-Al-Zn-O series, In-Zn-O series, Sn-Zn-O series, Al-Zn-O series, In -O-based, Sn-O-based, and Zn-O-based oxide semiconductors can be used. By adding impurities that suppress crystallization and maintain an amorphous state to the oxide semiconductor, The characteristics of the thin film transistor can be stabilized.

[0137] The semiconductor layer used in one embodiment of the present invention is only required to have a light-transmitting property. Crystalline semiconductors (single crystal semiconductors or polycrystalline semiconductors), amorphous semiconductors, microcrystalline semiconductors, Any of microcrystalline semiconductors, organic semiconductors, etc. may be used.

[0138] In addition, when an insulating film is formed on the substrate 100, the insulating film is formed before the oxide semiconductor film 101 is formed. The surface of the insulating film may be subjected to plasma treatment. It is possible to remove dust (particles, etc.) adhering to the surface.

[0139] When performing plasma processing, using a pulsed direct current (DC) power supply can reduce dust and improve film thickness. Furthermore, after the plasma treatment, the cloth is exposed to the atmosphere. By forming the oxide semiconductor film 101 without using the insulating film, the interface between the insulating film and the oxide semiconductor film 101 This can prevent dust and moisture from adhering to the surface.

[0140] In addition, the sputtering equipment is a multi-target sputtering equipment that can install multiple targets of different materials. In a multi-target sputtering device, different films can be stacked in the same chamber. It is also possible to sputter multiple types of materials simultaneously in the same chamber to form a single film. Furthermore, a magnetron sputtering device equipped with a magnetic field generating mechanism inside the chamber is used. method (magnetron sputtering method) and E using plasma generated by microwaves. CR sputtering or the like may also be used. In addition, the target material and the sputtering gas components may be mixed during film formation. Reactive sputtering is a method in which a compound is formed by chemically reacting a substance with a substrate during film formation. Alternatively, a bias sputtering method in which a voltage is applied may be used.

[0141] Next, a resist mask 102 is formed over the oxide semiconductor film 101. The oxide semiconductor film 101 is selectively etched using SiO 2 to form an island-shaped semiconductor layer 103a (See Figure 2(C) and (D)). The resist mask is formed by spin coating. In this case, a large amount of resist material and a large amount of developer are used to improve the uniformity of the resist film. In particular, when the substrate becomes large, the spin coating method is used for the formation of the substrate. In the film method, the mechanism for rotating the large substrate is large-scale, and there is a loss of the material liquid and a large amount of waste liquid. In addition, when spin-coating a rectangular substrate, the rotation axis is Therefore, when using droplet ejection methods such as the inkjet method, circular unevenness around the center tends to occur in the coating film. A resist material film is selectively formed by using a method such as screen printing, and then exposed to light. By selectively forming a resist material film, The amount of resist material used can be reduced, resulting in significant cost reductions. Large sizes such as 1200mm x 1100mm, 1250mm x 1150mm, and 1300mm x 1200mm. It can also be used for area substrates, but is not limited to this.

[0142] In this case, wet etching or dry etching may be used as the etching method. Here, wet etching using a mixture of acetic acid, nitric acid, and phosphoric acid is performed. Unnecessary portions of the oxide semiconductor film 101 are removed to form island-shaped semiconductor layers 103a. After the etching, the resist mask 102 is removed. The etchant used for etching may be any etchant that can etch the oxide semiconductor film 101. In the case of dry etching, a gas containing chlorine or It is preferable to use a gas containing chlorine and oxygen added thereto. By using a gas containing the oxide semiconductor film 101, the insulating film serving as a base film can be easily etched. This is because etching selectivity can be easily achieved and damage to the insulating film can be sufficiently reduced.

[0143] The etching equipment used for dry etching is a reactive ion etching method ( Etching equipment using the RIE method and ECR (Electron Cyclotron Resonance) and ICP (Inductively Coupled Plas) A dry etching apparatus using a high density plasma source such as SiO2 can be used. In addition, compared to ICP etching equipment, dry etching equipment allows for a uniform discharge over a wide area. The etching device is a device in which the upper electrode is grounded and the lower electrode is powered by a 13.56MHz high frequency power source. The lower electrode was connected to an ECCP (Enhanced Ceramic Plate) with a 3.2MHz low frequency power supply grounded. Etching in the (Coupled Capacitively Coupled Plasma) mode In the case of an etching apparatus in this ECCP mode, for example, It can also accommodate the use of 0th generation substrates exceeding 3m in size.

[0144] After that, it is advisable to carry out a heat treatment at 200 to 600°C, typically 300 to 500°C. Here, a heat treatment is performed in a nitrogen atmosphere at 350° C. for 1 hour. Atomic-level rearrangement occurs in the In-Ga-Zn-O oxide semiconductor that constitutes 03a. This heat treatment (including photo-annealing) promotes the movement of carriers in the semiconductor layer 103a. The timing of the above heat treatment is important in that it can release the strain that inhibits the There are no particular limitations as long as it is after the formation of the conductor layer 103a.

[0145] Next, a conductive film 104 is formed on the island-shaped semiconductor layer 103a (see FIGS. 2(E) and 2(F)). ).

[0146] The conductive film 104 is made of indium tin oxide (ITO), indium tin oxide containing silicon oxide, or It uses materials such as ITSO, organic indium, organic tin, zinc oxide (ZnO), and titanium nitride. Indium zinc oxide containing zinc oxide (Indium Zinc Oxide) Oxide:IZO), zinc oxide containing gallium (Ga), tin oxide (SnO2), acid Indium oxide containing tungsten oxide, Indium zinc oxide containing tungsten oxide Indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, etc. are also used. The conductive film 104 may be formed by sputtering the above-mentioned materials to have a single layer structure or two or more layers. However, when a laminated structure is used, all of the multiple films It is desirable that the light transmittance of the entire film is sufficiently high.

[0147] Next, resist masks 105a and 105b are formed over the conductive film 104. The conductive film 104 is selectively etched using the etching masks 105a and 105b to form a source electrode or Conductive layers 106a and 106b functioning as drain electrodes are formed (FIGS. 2(G) and 2(H)). After the etching, the resist masks 105a and 105b are removed. At this time, in order to improve the coverage of the gate insulating film 110 to be formed later and to prevent discontinuities, The conductive layers 106a and 106b functioning as source and drain electrodes have tapered edges. It is preferable to etch the source electrode or the drain electrode so as to have a desired shape. The "substrate" includes electrodes and wirings formed by the conductive film, such as source wirings.

[0148] Next, a conductive film 107 is formed on the island-shaped semiconductor layer 103a and the conductive layers 106a and 106b. (See Figures 3(A) and (B)).

[0149] The conductive film 107 is made of aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), or the like. Ta (Ta), Molybdenum (Mo), Nickel (Ni), Platinum (Pt), Copper (Cu), Gold ( Au), silver (Ag), manganese (Mn), neodymium (Nd), chromium (Cr), antimony Metallic materials such as antimony (Sb), niobium (Nb), cerium (Ce), or these metallic materials A single layer is formed using alloy materials whose main component is a metal or nitrides whose component is a metal material. Alternatively, it can be formed by laminating. It can be formed by using a low resistance conductive material such as aluminum. is desirable.

[0150] When the conductive film 107 is formed on the conductive layers 106a and 106b (or the conductive film 104), For example, if the conductive layers 106a and 106b are made of ITO, the film may react with the conductive layer. If aluminum is used for the conductive film 107, a chemical reaction may occur. Therefore, in order to avoid chemical reactions, the conductive layers 106a and 106b are It is desirable to use a high melting point material between the film 107. For example, the following high melting point material is used: Examples of the metals include molybdenum, titanium, tungsten, tantalum, and chromium. Conductive layers 106a and 106b are formed on the film using a high melting point material using a material with high conductivity. It is preferable to use a multilayer film. Materials with high conductivity include aluminum, copper, and silver. For example, when the conductive layers 106a and 106b are formed in a laminated structure, The first layer is molybdenum, the second layer is aluminum, and the third layer is molybdenum. The first layer is made of molybdenum, the second layer is made of aluminum containing a small amount of neodymium, and the third layer is made of molybdenum. By adopting such a structure, it is possible to prevent the occurrence of hillocks. Note that the thickness of the light-transmitting conductive layer is thinner than that of the light-shielding conductive layer. It is desirable, but not limited to this.

[0151] Next, a resist mask 108 is formed over the conductive film 107. The conductive film 107 is then etched to form a conductive layer 109a (see FIGS. 3(C) and 3(D)). After the etching, the resist mask 108 is removed. 7 is removed except for the portion where the resist mask 108 is formed, and the conductive layer 106a is As a result, the conductive layers 109a and 106a are exposed to the outside. That is, the surface area of ​​the conductive layer 106a is larger than that of the conductive layer 109a. Alternatively, the conductive layer 109a and the conductive layer 106a are larger than the product. The area where the conductive layer 109a and the conductive layer 106a overlap, and the area where the conductive layer 109a and the conductive layer 106a do not overlap. It has a region.

[0152] In the region where the conductive layer 106a and the conductive layer 109a overlap, the conductive layer 106a and the conductive layer 109a functions as a source wiring, and in the region where the conductive layer 106a and the conductive layer 109a do not overlap, The conductive layer 106a functions as a source electrode or a drain electrode. The conductive layer 106a functioning as an electrode is formed using a light-transmitting material. Since light can be transmitted through the area where the source electrode or drain electrode is formed, The aperture ratio of the pixel can be improved. By forming the source wiring from a material with high conductivity, the wiring resistance of the source wiring is reduced, and power consumption is also reduced. In addition, the source wiring is made of a conductive layer having a light-shielding property. This allows light to be shielded between pixels, and also improves contrast. do.

[0153] After forming the conductive layers 106a and 106b, the conductive layer 109a is formed. However, the order of forming the conductive layer 1 which is a part of the source wiring may be reversed. After forming the conductive layers 106a and 109a, the conductive layers 106a and 109b functioning as source and drain electrodes are 06b can also be formed (see Figure 7).

[0154] The conductive layer 106b also functions as an electrode of the storage capacitor 160.

[0155] Next, a gate insulating film 110 is formed to cover the conductive layers 106a and 106b. A film 111 is formed (see FIGS. 3(E) and (F)).

[0156] The gate insulating film 110 may be a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a nitride oxide film. silicon oxide film, aluminum oxide film, aluminum nitride film, aluminum oxynitride film, nitride The gate electrode can be formed as a single layer or a multilayer of an aluminum oxide film or a tantalum oxide film. The gate insulating film 110 is formed by a method such as sputtering or CVD to a thickness of 50 nm to 250 nm. For example, the gate insulating film 110 can be formed by sputtering. A silicon film can be formed to a thickness of 100 nm. Alternatively, oxidation can be performed by sputtering. The aluminum film can be formed to a thickness of 100 nm.

[0157] By forming the gate insulating film 110 as a dense film, the semiconductor layer 103 In addition, the intrusion of moisture and oxygen into the a in the substrate 100 can be prevented. Alkaline metals (Li, Cs, Na, etc.), alkaline earth metals (Ca, Mg, etc.) and other metallic elements It is possible to prevent impurities such as Na from entering the semiconductor layer 103a. , 5×10 19 / cm 3 Less than 1 × 10 18 / cm 3 The following applies: In this way, fluctuations in the semiconductor characteristics of a semiconductor device including an oxide semiconductor can be suppressed. The reliability of the semiconductor device can be improved.

[0158] The gate insulating film 110 is made of silicon oxide, silicon nitride, silicon oxynitride, or silicon nitride oxide. insulating films containing oxygen or nitrogen, such as carbon, and carbon such as DLC (diamond-like carbon) Films containing epoxy, polyimide, polyamide, polyvinylphenol, benzocyclo A film made of an organic material such as butene or acrylic or a siloxane material such as siloxane resin is used. It may be provided in a layer or laminate structure.

[0159] The gate insulating film 110 preferably has light-transmitting properties.

[0160] The conductive film 111 is preferably formed of substantially the same material as the conductive film 104. However, it is not limited to this. "Approximately the same material" means a material with the same main element. At the impurity level, the types and concentrations of elements contained may differ. As shown above, the conductive film 111 is formed by sputtering or vapor deposition using roughly the same material. In this case, there is an advantage that the material can be shared with the conductive film 104. By sharing the material of the film 104, the same manufacturing equipment can be used, and the manufacturing process can be performed smoothly. This allows for smooth flow, improves throughput, and reduces costs. It becomes possible to manifest it.

[0161] Next, resist masks 112a and 112b are formed over the conductive film 111. The conductive film 111 is selectively etched using the etching masks 112a and 112b to form a conductive layer 113a. After the etching, a resist pattern 113b is formed (see FIGS. 4(A) and 4(B)). The masks 112a and 112b are removed.

[0162] Next, a conductive film 114 is formed on the conductive layers 113a and 113b and the gate insulating film 110 (FIG. 4(C), (D)).

[0163] The conductive film 114 is made of aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), or the like. Ta (Ta), Molybdenum (Mo), Nickel (Ni), Platinum (Pt), Copper (Cu), Gold ( Au), silver (Ag), manganese (Mn), neodymium (Nd), chromium (Cr), antimony Metallic materials such as antimony (Sb), niobium (Nb), cerium (Ce), or these metallic materials A single layer is formed using alloy materials whose main component is a metal or nitrides whose component is a metal material. Alternatively, it can be formed by laminating. It can be formed by using a low resistance conductive material such as aluminum. is desirable.

[0164] The conductive film 114 is preferably formed of a material different from that of the conductive film 107. Alternatively, the conductive film 114 may have a different stacked structure from that of the conductive film 107. This is because the temperature applied in the manufacturing process of the semiconductor device is This is because the temperature of the conductive film 107 is often different from that of the conductive film 107. Therefore, the conductive film 107 is preferably made of a material having a higher melting point or a laminated structure. Alternatively, it is preferable that the conductive film 107 is made of a material that is less likely to cause hillocks. It is preferable to use a laminated structure. Alternatively, the conductive film 114 may be a signal Since a wire may be formed, a material or a laminated structure having a lower wiring resistance than the conductive film 107 is used. It is preferable to use a light-transmitting conductive layer rather than a light-blocking conductive layer. It is desirable that the film thickness is thin.

[0165] The same as when the conductive film 107 is formed on the conductive layers 106a and 106b (or the conductive film 104). Similarly, when the conductive film 114 is formed on the conductive layers 113a and 113b (or the conductive film 111), In this case, the two films may react with each other. Even when the conductive film 114 is formed on the conductive layers 113a and 113b, the conductive film 11 It is desirable to use a high melting point material between the substrate and the electrode. Examples include bismuth, titanium, tungsten, tantalum, and chromium. On the film using the material, a conductive film 114 is formed as a multilayer film using a material with high conductivity. Materials with high conductivity include aluminum, copper, and silver. .

[0166] Next, a resist mask 115 is formed over the conductive film 114. The conductive film 114 is then etched to form a conductive layer 116a (see FIGS. 4(E) and 4(F)). After the etching, the resist mask 115 is removed. 4 is removed except for the portion where the resist mask 115 is formed, and the conductive layer 113a is As a result, the conductive layers 116a and 113a are exposed to the outside. That is, the surface area of ​​the conductive layer 113a is larger than that of the conductive layer 116a. Alternatively, the conductive layers 116a and 113a are larger than the product of the conductive layers 113a and 116b. The area where the conductive layer 116a and the conductive layer 113a overlap is defined as a region where the conductive layer 116a and the conductive layer 113a do not overlap. Has.

[0167] In the region where the conductive layer 113a and the conductive layer 116a overlap, the conductive layer 113a and the conductive layer 116a functions as a gate wiring, and in the region where the conductive layer 113a and the conductive layer 116a do not overlap, The conductive layer 113a functions as a gate electrode. By forming the gate electrode from a light-transmitting material, Since light can be transmitted, the aperture ratio of the pixel can be improved. The conductive layer 116a, which functions as a wiring, is formed of a material having a higher conductivity than the conductive layer 113a. By doing so, the wiring resistance can be reduced, and power consumption can be reduced. The lines are formed using the conductive layer 116a having a light-shielding property, and therefore, light is shielded between the pixels. That is, the gate wirings arranged in the row direction and the source wirings arranged in the column direction can be This allows the gaps between pixels to be shielded from light without using a black matrix. .

[0168] After forming the conductive layers 113a and 113b, the conductive layer 116a is formed. However, the order of forming the conductive layer functioning as the gate wiring may be reversed. After forming 116a, a conductive layer 113a functioning as a gate electrode may be formed. (See Figure 7.)

[0169] In addition, capacitance wiring is arranged in the same direction as the gate wiring. It is preferable to form the conductive layer 113b having a light-transmitting property. Alternatively, the conductive layer 113b and the conductive layer 116b may be laminated together. By laminating the conductive layer 116b, which has a higher conductivity than the conductive layer 113b, the resistance can be reduced. This can be done (see Figure 1(A)).

[0170] In this embodiment, an example is shown in which the width of the capacitance wiring and the width of the gate wiring are formed to be the same. However, the width of the capacitance wiring may be different from the width of the gate wiring. It is preferable that the width of the storage capacitor 160 is wider than the width of the port wiring. This can be done.

[0171] In this way, by forming the storage capacitor 160 with a conductive layer having light transmission properties, Since light can be transmitted through the portion where the storage capacitor 160 is formed, the aperture ratio can be increased. Furthermore, by forming the storage capacitor 160 from a light-transmitting material, This allows the storage capacitor 160 to be increased, so that the transistor is turned off. Even when the voltage is high, the potential retention characteristics of the pixel electrode are improved, improving the display quality. The loop potential can be reduced.

[0172] In this manner, the transistor 150 and the storage capacitor portion 160 can be manufactured. The transistor 150 and the storage capacitor 160 can be light-transmitting elements.

[0173] After the semiconductor layer 103a is formed, the source electrode and the source wiring are formed, and then the gate insulating film After the formation of the semiconductor layer 103a, or after the formation of the gate electrode and the gate wiring, A process for increasing the conductivity of a part or all of the region may be performed. The hydrogenation treatment is an example of the treatment for forming the semiconductor layer 1. The hydrogenation treatment is performed on the semiconductor layer 103a by applying heat to the semiconductor layer 103a. Alternatively, hydrogenation can be achieved by applying heat in a hydrogen atmosphere. As shown in FIG. 6A, the channel of the semiconductor layer 103a of the transistor 151 By forming a channel protection layer 120a in the region overlapping the formation region, the semiconductor layer 10 3a, regions 121a, 121b with selectively increased conductivity can be formed.

[0174] The channel protection layer 120a is preferably made of silicon oxide. This can reduce the amount of hydrogen entering the channel formation region of the conductor layer 103a. The channel protection layer 120a may be removed after the treatment to increase the conductivity. The channel protection layer 120b can also be formed from a resist (see FIG. 6(B)). In this case, it is preferable to remove the resist after the hydrogenation treatment. By performing a process to increase the conductivity of the semiconductor layer, it becomes easier for current to flow through the transistor. This also reduces the resistance of the capacitance element.

[0175] In FIG. 6A, the channel protection layer 120a of the transistor 151 is formed on the semiconductor layer 103. Although an example in which the gate insulating film 110 is provided in contact with the channel a has been shown, the gate insulating film 110 may also be provided on the channel By adjusting the shape of the protective layer and the conductive layer that functions as the gate electrode, the channel protection layer is more effective than the conductive layer. By making the layer larger, an offset region can be created.

[0176] The channel protection layer 120a prevents the semiconductor from being damaged when etching the conductive layers 106a and 106b. Therefore, the conductor layer 103a can be prevented from being etched. If the semiconductor layer 103a is thin, a depletion layer is less likely to occur. Therefore, the S value can be reduced, and the off-state current can also be reduced.

[0177] Alternatively, as shown in FIG. 6C, a conductive layer having a conductivity greater than that of the semiconductor layer 103a is formed on the semiconductor layer 103a. It is also possible to form transistor 152 with enhanced efficiency regions 121a, 121b. Cut.

[0178] Next, after forming an insulating film 117, a resist mask (not shown) is formed on the insulating film 117. Then, the insulating film 117 is etched using the resist mask, and a contact is formed on the insulating film 117. The insulating film 117 is formed with a through hole 130 (see FIGS. 5(A) and 5(B)). 150, the storage capacitor portion 160, or the surface on which wiring or the like is formed. The transistor 150 and the storage capacitor portion 160 are formed as light-transmitting elements. Therefore, the area where they are arranged can also be used as an opening area. Therefore, unevenness caused by the transistor 150, the storage capacitor 160, or wiring can be reduced. Therefore, it is beneficial to flatten the top surface on which these elements are formed.

[0179] The insulating film 117 also functions as an insulating film that protects the transistor 150 from impurities. The insulating film 117 can be formed of, for example, a film containing silicon nitride. A film containing silicon is preferable because it has a high effect of blocking impurities. The insulating film 117 can be formed of a film containing an organic material. Suitable organic materials include acrylic, polyimide, and polyamide. These organic materials can smooth out uneven surfaces. Therefore, the insulating film 117 is preferably a film containing silicon nitride. When a laminated structure is formed with a film containing an organic material and a film containing silicon nitride on the bottom side, It is preferable to place an insulating film 117 on the upper side and place a film containing an organic material on the upper side. When forming a laminated structure, it is desirable that each film has a sufficiently high light transmittance. In this case, the insulating film 117 is etched, and a photosensitive material can also be used. No contact holes are required.

[0180] The insulating film 117 may also function as a color filter. By providing a color filter on the opposite substrate, there is no need to provide a color filter on the opposite substrate. This eliminates the need for margins to adjust the positions of the two substrates, making panel manufacturing easier. The insulating film 117 may not be formed. The pixel electrodes may be located on the same layer as the port wiring.

[0181] Next, a conductive film 118 is formed on the insulating film 117 and the contact hole 130 (FIG. 5C The conductive film 118 is made of a material that is generally the same as the material of the conductive film 104 and the conductive film 111. It is desirable that the same materials are used. Therefore, when the conductive film 118 is formed by sputtering or vapor deposition, the conductive film 104 and the conductive film 111 The advantage is that materials can be shared with other companies. This allows the manufacturing process to run smoothly and improves throughput. However, the conductive film 118 is made of a conductive material. The conductive film 104 and the conductive film 111 may be formed using a material different from that of the conductive film 104 and the conductive film 111 .

[0182] Next, a resist mask (not shown) is formed over the conductive film 118. The conductive film 118 is selectively etched to form conductive layers 119a, 119b, and 119c. (See Fig. 5(E) and (F)). After the etching, the resist mask is removed. do.

[0183] The conductive layers 119a, 119b, and 119c function as pixel electrodes. a, 119b, and 119c are connected to the source wiring and the source electrode through the contact hole 130. , gate wiring, gate electrodes, pixel electrodes, capacitance wiring, electrodes of the storage capacitance section, etc. are connected to each other. Therefore, the conductive layers 119a to 119c can connect the conductors. The conductive layers 119a to 119c can function as wiring for the source. A light-transmitting conductive layer used for a source wiring including an electrode, or a gate wiring including a gate electrode It is desirable that the thickness of the conductive layer is thinner than that of the light-transmitting conductive layer used in the above embodiment. The thickness of the conductive layers 119a to 119c is not limited to a specific value. A light-transmitting conductive layer or a light-transmitting conductive layer used for a gate wiring including a gate electrode It may be thicker than

[0184] In this manner, the semiconductor device shown in FIGS. The light-transmitting transistor 150 and the light-transmitting storage capacitor 151 are fabricated by the manufacturing method shown in the embodiment. Therefore, a transistor and a capacitor element can be arranged in the pixel. Even when a transistor or a capacitor is formed, light is not transmitted through the transistor or capacitor. Furthermore, the aperture ratio can be improved by increasing the number of transistors and elements. The wiring that connects the transistors (e.g., other transistors) uses materials with low resistivity and high conductivity. This reduces signal waveform distortion and minimizes voltage drops due to wiring resistance. can be reduced.

[0185] Next, another example of the semiconductor device will be described with reference to FIGS. 7 to 15. The semiconductor device shown in FIG. 15 has many parts in common with that shown in FIG. In this section, overlapping parts will be omitted and only differences will be explained.

[0186] 7(A) is a plan view, and FIG. 7(B) is a cross-sectional view taken along line AB in FIG. 7(A). 7(C) is a cross-sectional view taken along line CD in FIG. 7(A). The light-shielding conductive layer is laminated in this order on the light-transmitting conductive layer. However, a conductive layer having a light-shielding property and a conductive layer having a light-transmitting property may be formed in this order. The light-transmitting conductive layer 113a functioning as a gate electrode can be formed as a gate electrode. It is sufficient that the light-shielding conductive layer 116a, which functions as a root wiring, is connected to the light-shielding conductive layer 116a. The light-transmitting conductive layer 106a functioning as a source electrode or a drain electrode is It is only necessary that the light-shielding conductive layer 109a functioning as a line be connected to the light-shielding conductive layer 109a.

[0187] 8(A) is a plan view, and FIG. 8(B) is a cross section taken along line AB in FIG. 8(A). 8(C) is a cross-sectional view taken along line CD in FIG. 8(A). The light-transmitting conductive layer and the light-shielding conductive layer are laminated in this order to form the light wiring and the source wiring. However, the gate wiring and the source wiring may be formed of a conductive layer having a light-shielding property. The light-transmitting conductive layer 113a serving as a gate electrode and the gate It is only necessary that the conductive layer 116a having a light-blocking property and functioning as a light wiring be connected. A light-transmitting conductive layer 106a serving as a source electrode or a drain electrode, It is only necessary that the conductive layer 109a having a light-blocking property and functioning as a line is connected. 8 shows a case where a light-shielding conductive layer and a light-transmitting conductive layer are formed in this order. In this example, the gate wiring and the source wiring are formed of a conductive layer having a light-shielding property. However, the light-transmitting conductive layer and the light-blocking conductive layer may be formed in this order.

[0188] In addition, in this embodiment mode, a transistor can be formed in a pixel. For example, as shown in FIG. 9, the transistor can be made larger than the gate wiring width. A transistor 153 in which the channel width W of the transistor is longer or the channel length L of the transistor is longer By making the transistor larger, its current capability can be increased significantly. This reduces the off-current, thereby shortening the time required to write a signal to the pixel. This reduces the amount of light that can be emitted, and flickering can be reduced. Locations can be provided.

[0189] In addition, in the peripheral driving circuits such as the protection circuit, gate driver, and source driver, Therefore, the pixel area does not need to be transparent to light. The peripheral driver circuit portion is formed of a light-shielding material. (See FIG. 25(A)).

[0190] 10(A) is a plan view, and FIG. 10(B) is a cross-sectional view taken along line AB in FIG. 10(A). 10 is a cross-sectional view of the conductive layer 106c and the conductive layer 113c. The size of the storage capacitor 161 is larger than that of the conductive layer 106b and the conductive layer 113b. It is preferable that the contact area between the pixel electrode and the substrate is 70% or more, or 80% or more of the pixel pitch. The contact is made on the conductive layer 109b on the conductive layer 106c. Since the configuration is the same as that shown in FIG.

[0191] By adopting such a configuration, the storage capacitor 161 having high light transmittance can be formed large. By increasing the storage capacitance 161, the transistor can be turned off. Even when the voltage is high, the potential retention characteristics of the pixel electrodes are improved, improving display quality. In addition, even when the storage capacitor 161 is formed large, However, light can be transmitted through the portion where the storage capacitor 161 is formed. The aperture ratio can be increased, and power consumption can be reduced. Even if the liquid crystal alignment is disturbed due to the unevenness caused by the holes, the conductive layer 10 having the light-shielding property 9b can prevent light leakage.

[0192] 11(A) is a plan view, and FIG. 11(B) is a cross-sectional view taken along line AB in FIG. 11(A). FIG.

[0193] The semiconductor device shown in FIG. 11 has a high conductivity region (n + Both areas and conductive layers 106a and 106b serving as source and drain electrodes. The figure shows a structure in which the gate electrode is not overlapped with the 06b. In the semiconductor layer 103a, the conductive layer 106a and the conductive layer 106b may be provided in a region where the conductive layer 106a and the conductive layer 106b are connected. The region with high conductivity is formed so as to overlap with the gate electrode (conductive layer 113a). They may be provided in such a way that they do not overlap.

[0194] The region with high conductivity is formed by selectively adding hydrogen to the semiconductor layer 103a as described with reference to FIG. Hydrogen can be formed by increasing the conductivity of the semiconductor layer 103a. Just add it where you want it.

[0195] In addition, by providing the source electrode and the drain electrode so that they do not overlap with the gate electrode, This suppresses the parasitic capacitance generated between the source electrode, the drain electrode and the gate electrode. Therefore, feedthrough can be reduced.

[0196] In FIG. 11, the conductivity of a part of the semiconductor layer 103a is increased. In this way, in the transistor 154, the gate electrode and the source or drain electrode There is no need to overlap.

[0197] The source wiring and the gate wiring are each formed of a conductive layer having a light-shielding property and a conductive layer having a light-transmitting property. However, the present invention is not limited to this. The source wiring and the gate wiring have a light-shielding property. or the source electrode and the drain electrode are formed of only a light-transmitting conductive layer. For example, the gate wiring may be made of only a conductive layer having a light-shielding property, and the source wiring may be made of only a conductive layer having a light-shielding property. FIG. 12 shows a case where only a conductive layer having a light-transmitting property is used as the drain electrode. The source wiring is formed only from a conductive layer having a light-shielding property, and the gate wiring is also formed from a conductive layer having a light-shielding property. The capacitor wiring may be formed of a conductive layer having a light-shielding property, or may be formed of a light-transmitting conductive layer. The source electrode may be formed of a conductive layer having a light-transmitting property. A conductive layer having a light-shielding property may be formed in the area overlapping with the port wiring. .

[0198] 13A and 14A show examples of a light-emitting display device as an example of a pixel configuration. The pixel shown in FIG. 3(A) has a gate wiring formed by stacking a conductive layer 106a and a conductive layer 109a in this order. The source wiring and the switching transistor are laminated in this order. the capacitor 150, the driving transistor 155, the storage capacitor 162, the conductive layer 106d and the conductive layer 109c. The pixel shown in FIG. 14(A) has a conductive The gate wiring is formed by stacking the layer 106a and the conductive layer 109a in this order, and the conductive layers 113a and 116a. The source wiring, the switching transistor 150, and the driving transistor are stacked in this order. The capacitor 156, the storage capacitor 164, the conductive layer 106d and the conductive layer 109c are stacked in this order. It has a source line.

[0199] The transistor 150 shown in FIGS. 13A and 14A is formed on a substrate 100 having an insulating surface. A semiconductor layer 103a and a source electrode or a drain electrode provided on the semiconductor layer 103a are provided on the semiconductor layer 103a. Conductive layers 106a and 106c function as electrodes, and a conductive layer 106b is provided on the conductive layers 106a and 106c. a gate insulating film 110 formed on the gate insulating film 110 and a conductive layer 106a, 106b provided on the gate insulating film 110; The conductive layer 113a serving as a gate electrode is provided between the gate electrodes 113c. The driving transistor 155 and the driving transistor 156 have insulating surfaces. A semiconductor layer 103b is formed on the substrate 100, and a source electrode or Conductive layers 106d and 106e functioning as drain electrodes, and a gate insulating film 110 provided on the gate insulating film 110 and a conductive layer 1 A conductive layer 113c or 114c serving as a gate electrode is provided between the gate electrodes 106d and 106e. 13, the storage capacitor 162 is composed of the conductive layer 106e and the conductive layer 113c. In FIG. 14, the storage capacitor 164 is made up of the conductive layer 1 06e and conductive layer 113d.

[0200] As shown in FIG. 13(B), when connecting the gate and the drain, a contact hole is used. The top ITO is connected via the wires 132 and 133, as shown in FIG. 14(B). As shown in FIG. 1, the gate and the drain may be directly connected via a contact hole 131. In this case, the area of ​​the pixel electrode can be increased, improving the aperture ratio. It's easy to make.

[0201] The semiconductor device shown in FIGS. 13 and 14 includes a switching transistor 150, a driving transistor 160, and a Although the case where two transistors, 155 and 156, are used has been described, It is also possible to provide three or more transistors in one pixel.

[0202] In this way, one embodiment of the present invention is a case where two or more transistors are provided in one pixel. However, since light can be transmitted through the area where the transistor is formed, the opening The rate can be increased.

[0203] FIG. 15 shows a transistor having a shape in which the conductive layer 106a surrounds the conductive layer 106b (for example, , U-shaped or C-shaped).

[0204] The transistor 156 shown in FIG. 15 includes a semiconductor layer 103c on a substrate 100 having an insulating surface. and a conductive layer functioning as a source electrode or a drain electrode provided over the semiconductor layer 103c. 106a, 106b, and a gate insulating film 110 provided on the conductive layers 106a, 106b. and a conductive layer 113a that functions as a gate electrode and is provided on the gate insulating film 110. In this way, one of the source electrode and the drain electrode is The source electrode and the drain electrode are formed in a shape that surrounds the other electrode (for example, U-shaped or C-shaped). The distance is kept almost constant.

[0205] By forming the transistor 156 in the above-described shape, the channel width of the transistor can be increased. This allows the area of ​​the region through which carriers move to be increased. It is possible to increase the amount of current and reduce the area of ​​the transistor. The variation in electrical characteristics can be reduced.

[0206] In this embodiment, a configuration in which a capacitance line is provided has been described, but a configuration in which a capacitance line is not provided Alternatively, a storage capacitor can be provided by overlapping the pixel electrode with the adjacent gate wiring via an insulating film. (See Figure 36).

[0207] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0208] (Embodiment 2) In this embodiment mode, an example of a manufacturing process of a semiconductor device will be described with reference to FIGS. Note that the semiconductor device and the manufacturing process thereof in this embodiment mode are mostly the same as those of the conventional semiconductor device. This is common to Form 1. Therefore, in the following, we will omit the overlapping parts and focus on the differences. will be explained in detail.

[0209] 16A and 16B show a semiconductor device according to this embodiment. FIG. 16A is a plan view, and FIG. 16(B) is a cross-sectional view taken along line AB in FIG. 16(A).

[0210] Next, an example of a manufacturing process of the semiconductor device shown in FIG. 16 will be described with reference to FIGS. 17 to 22. In addition, in this embodiment mode, a case where a semiconductor device is manufactured using a multi-tone mask will be described. and explain.

[0211] First, a semiconductor layer 203 is formed on a substrate 200 having an insulating surface (FIG. 17(A), (See (B)).

[0212] The material of the substrate 200 and the material and manufacturing method of the semiconductor layer 203 are the same as those described in Embodiment 1. The substrate 100 and the semiconductor layer 103a can be referred to as a substrate 20 having an insulating surface. An insulating film that functions as a base film may be provided on the insulating film.

[0213] Next, a conductive film 204 and a conductive film 205 are formed on the semiconductor layer 203 (FIGS. 17(C) and 17(D)). )). Materials and manufacturing methods of the conductive films 204 and 205 are the same as those in Embodiment 1. The conductive films 104 and 107 shown in FIG.

[0214] Next, resist masks 206a and 206b are formed over the conductive film 205. 206a and 206b are patterns having regions of different thicknesses formed by using a multi-tone mask. By using a multi-tone mask, it is possible to form a resist mask. This is preferable because the number of sheets of the conductive film is reduced and the manufacturing process is also reduced. A process of forming patterns of the films 204 and 205 and a process of forming patterns of the conductive films 212 and 213 In the step of forming the etched film (see FIGS. 19(C) and 19(D)), a multi-tone mask can be used.

[0215] A multi-tone mask is a mask that can perform exposure with multiple levels of light intensity. Representative examples include: Exposure is performed at three levels of light intensity: exposed area, semi-exposed area, and unexposed area. By doing so, a single exposure and development process can be performed to produce a film having multiple (typically two) thicknesses. A resist mask can be formed. Therefore, by using a multi-tone mask, This allows reducing the number of masks required.

[0216] 22(A-1) and 22(B-1) show cross sections of a typical multi-tone mask. (A-1) shows a gray-tone mask 403, and FIG. 22(B-1) shows a half-tone mask. The mask 414 is shown.

[0217] The gray-tone mask 403 shown in FIG. 22(A-1) is a light-shielding mask on a light-transmitting substrate 400. The light-shielding portion 401 is formed by a light-shielding layer, and the diffraction grating portion 4 is formed by a pattern of the light-shielding layer. It consists of 02.

[0218] The diffraction grating section 402 is made up of slits and dots spaced at intervals equal to or less than the resolution limit of the light used for exposure. The diffraction grating portion 402 has a groove or a mesh, and thereby the transmittance of light is controlled. The slits, dots or meshes provided may be periodic or non-periodic. It may also be something.

[0219] The light-transmitting substrate 400 may be made of quartz or the like. The light-shielding layer constituting the grating portion 402 may be formed using a metal film, preferably chromium. Alternatively, it may be made of chromium oxide or the like.

[0220] When the gray-tone mask 403 is irradiated with light for exposure, the pattern shown in FIG. 22(A-2) is formed. As shown, the light transmittance in the area overlapping the light-shielding portion 401 is 0%, and the light-shielding portion 401 also acts as a diffracting The light transmittance in the area where the grating portion 402 is not provided is 100%. The light transmittance of the portion 402 is in the range of approximately 10% to 70%. This can be adjusted by adjusting the spacing of the slots or mesh.

[0221] The halftone mask 414 shown in FIG. 22(B-1) is a semi-transparent mask formed on a light-transmitting substrate 411. It is composed of a semi-transparent portion 412 formed by a transparent layer and a light-shielding portion 413 formed by a light-shielding layer. It has been done.

[0222] The semi-transparent portion 412 is a layer of MoSiN, MoSi, MoSiO, MoSiON, CrSi, etc. The light-shielding portion 413 can be formed using the same material as the light-shielding layer of the gray-tone mask. It may be formed using a metal film, preferably chromium or chromium oxide.

[0223] When the halftone mask 414 is irradiated with light for exposure, the pattern shown in FIG. 22(B-2) is formed. In this way, the light transmittance in the area overlapping the light-shielding portion 413 is 0%, and the light-shielding portion 413 is also semi-transparent. The light transmittance in the area where the semi-transparent portion 412 is not provided is 100%. The light transmittance of 12 is generally in the range of 10% to 70%, and the type of material or the formation This can be adjusted by the film thickness, etc.

[0224] By using a multi-tone mask, three exposure areas, exposed area, intermediate exposed area, and unexposed area, can be obtained. A light level mask can be formed, and multiple (typically It is possible to form a resist mask having regions of different thicknesses (two types in total). By using a multi-tone mask, the number of photomasks can be reduced.

[0225] The halftone masks shown in FIGS. 17(E) and 17(F) are formed by depositing a semi-transparent layer on a light-transmitting substrate 300. The conductive film 205 is composed of layers 301a and 301b and a light-shielding layer 301c. The resist mask on the area that will later become the source wiring is thick, and the area that will later become the source electrode or drain The resist mask for the area that will become the inner electrode is formed to a thin film (see 17(E), (F)). ).

[0226] Using resist masks 206a and 206b, unnecessary portions of the conductive films 204 and 205 are selected. The conductive layers 207a, 208a and the conductive layers 207b, 208b are formed by selectively etching and removing the conductive layers. (See Figures 18(A) and (B)).

[0227] Next, the resist masks 206a and 206b are ashed with oxygen plasma. The resist masks 206a and 206b are ashed with oxygen plasma. As a result, the resist mask 206b is removed and the conductive layer 207b is exposed. The resist mask 206a shrinks and remains as a resist mask 209 (FIG. 18(C), ( D). In this way, by using a resist mask formed with a multi-tone mask, Since an additional resist mask is not required, the process can be simplified.

[0228] Next, the conductive layers 207a and 207b are etched using the resist mask 209. After the etching, the conductive layer 210a is formed (see FIGS. 18(E) and 18(F)). The resist mask 209 is removed. As a result, the conductive layer 207b is removed, and the conductive layer 208 is The conductive layer 207a is exposed in the area where the resist mask 209 is formed. The conductive layer 208a is exposed by etching. The surface area of ​​the layer 210a and the conductive layer 208a is significantly different. Therefore, the surface area of ​​the conductive layer 208a is larger than the surface area of ​​the conductive layer 210a. Alternatively, the conductive layer 210a and the conductive layer 208a may be overlapped with each other. and a region where the conductive layer 210a and the conductive layer 208a do not overlap.

[0229] In the region where the conductive layer 208a and the conductive layer 210a overlap, the conductive layer 208a and the conductive layer 210 a functions as a source wiring, and is a region where the conductive layer 208a and the conductive layer 210a do not overlap. In this case, the conductive layer 208a functions as a source electrode or a drain electrode. The conductive layer 208a functioning as an inner electrode is formed using a light-transmitting material. The aperture ratio of the pixel can be improved. By laminating the conductive layer 208a and the conductive layer 210a having a higher conductivity than the conductive layer 208a, This reduces the wiring resistance and power consumption. Since the conductive layer 210a is configured using the conductive layer 210a, it is possible to block light between pixels.

[0230] In this way, by using a multi-tone mask, it is possible to obtain a transparent region ( forming a region with high light transmittance and a region with light blocking properties (region with low light transmittance) This allows the area having light transmittance (light transmittance) to be increased without increasing the mask. It is possible to form a light-shielding region (region with high light transmittance) and a light-shielding region (region with low light transmittance).

[0231] Next, after forming a gate insulating film 211 on the conductive layers 208a and 208b, Conductive films 212 and 213 are formed on the conductive film 212 (see FIGS. 19A and 19B). The material and the formation method of the conductive film 213 are the same as those of the gate insulating film 110 described in Embodiment 1. , the conductive film 111, and the conductive film 114 can be referred to.

[0232] Next, resist masks 214a and 214b are formed on the conductive film 213 using a half-tone mask. The halftone mask is formed by forming a semi-transmitting layer 303a on a light-transmitting substrate 302, 303b and light-shielding layers 303c and 303d. In this case, the resist mask in the area that will later become the gate wiring is thick, and the area that will later become the gate electrode is thick. The resist mask in this area is formed to have a thin film thickness (see FIGS. 19(C) and (D)).

[0233] Using resist masks 214a and 214b, unnecessary portions of the conductive films 212 and 213 are selected. The conductive layers 215a, 216a and the conductive layers 215b, 216b are selectively etched away. (See Figures 20(A) and (B)).

[0234] Next, the resist masks 214a and 214b are ashed with oxygen plasma. The resist masks 214a and 214b are ashed with oxygen plasma. As a result, the resist masks 214a and 214b are shrunk, and the resist masks 217a and 217b are shrunk. 20(C) and (D)). By using the resist mask, it is possible to eliminate the need for an additional resist mask. This simplifies the process.

[0235] Next, the conductive layers 215a and 215b are patterned using resist masks 217a and 217b. As a result, the conductive layers 215a and 215b are etched. , and the resist masks 217a and 217b are removed except for the portions where they are formed. The conductive layers 218a and 218b formed by this are conductive. The surface areas of the layers 216a and 216b are significantly different. The surface area of ​​the conductive layers 16a and 216b is larger than the surface area of ​​the conductive layers 218a and 218b. Alternatively, the conductive layer 216a and the conductive layer 218a may be and a region where the conductive layer 216a and the conductive layer 218a do not overlap. After the etching, the resist masks 217a and 217b are removed.

[0236] At least the area where the conductive layer 218a is present functions as a gate wiring, and the conductive layer 216a In one region, the conductive layer 216a functions as a gate electrode. By forming the conductive layer having a light-transmitting property, the aperture ratio of the pixel can be improved. In addition, the conductive layer 216a and the conductive layer 218a functioning as gate wirings are a and the conductive layer 218a, which has a higher conductivity than the conductive layer 216a, are laminated together. The resistance can be reduced, and power consumption can be reduced. Since the conductive layer 218a is used, light can be shielded between pixels. The black pixels are formed by gate wiring arranged in the row direction and source wiring arranged in the column direction. The gaps between pixels can be shielded from light without using a matrix.

[0237] In addition, the capacitance wiring is arranged in the same direction as the gate wiring. and conductive layer 218b, which has a higher conductivity than conductive layer 216b. By forming the wiring in this manner, it is possible to reduce the wiring resistance and the power consumption. The conductive layer 216b also functions as an electrode of the storage capacitor 260. The portion 260 has a conductive layer 208b that functions as an electrode, with the gate insulating film 211 as a dielectric. and a conductive layer 216b.

[0238] In this way, by configuring the storage capacitor 260 with a light-transmitting conductive layer, Since light can be transmitted through the portion where the storage capacitor 260 is formed, the aperture ratio can be increased. Furthermore, by forming the storage capacitor 260 from a light-transmitting material, This allows the storage capacitor 260 to be increased, so that the transistor is turned off. Even when the voltage is high, the potential retention characteristics of the pixel electrode are improved, improving the display quality. The loop potential can be reduced.

[0239] Through the above steps, the transistor 250 and the storage capacitor portion 260 shown in FIG. 16 can be manufactured. do.

[0240] Next, after forming an insulating film 219, a resist mask (not shown) is formed on the insulating film 219. Then, the insulating film 219 is etched using the resist mask, and a contact is formed on the insulating film 219. Next, an insulating film 219 and a contact hole are formed (see FIGS. 21(A) and 21(B)). A conductive film 220 is formed over the hole. The materials and manufacturing method of the insulating film 219 and the conductive film 220 are as follows: The insulating film 117 and the conductive film 118 in Embodiment 1 can be referred to. 19 may not be formed. Even if the pixel electrode is on the same layer as the gate electrode and gate wiring, good.

[0241] Next, a resist mask (not shown) is formed over the conductive film 220. The conductive film 220 is selectively etched to form conductive layers 221a, 221b, and 221c. (See FIGS. 21C and 21D). The conductive layers 221a, 221b, and 221c are After the etching, the resist mask is removed.

[0242] In this manner, a semiconductor device can be manufactured. It is possible to create a mask with three exposure levels: exposed, intermediately exposed, and unexposed. A single exposure and development process can produce a multi-thickness region (typically two types). A resist mask can be formed. Therefore, by using a multi-tone mask, In addition, the manufacturing method shown in this embodiment mode can reduce the number of transparent masks. The transistor 250 having a light-transmitting property and the storage capacitor portion 260 having a light-transmitting property are formed. Therefore, it is possible to connect a transistor and an element (for example, another transistor) within a pixel. The wiring that connects the signal can be formed using a material with low resistivity and high conductivity. This reduces waveform distortion and voltage drop due to wiring resistance.

[0243] In addition, in the peripheral driving circuits such as the protection circuit, gate driver, and source driver, Therefore, the pixel area does not need to have a transparent transistor or capacitor. The peripheral drive circuit area may be formed of a light-shielding material. Good (see Figure 25(B)).

[0244] In this embodiment, in forming a source wiring, a source electrode, a gate wiring, or a gate electrode, Although the case where a multi-tone mask is used has been described, one embodiment of the present invention is not limited to this. For example, multi-tone masks are used in forming semiconductor films, source wiring, and source electrodes. In this embodiment, a process for forming a gate wiring and a process for forming a source wiring are performed. The case where a multi-tone mask is used in both processes has been described. This step may be used in either the step of forming the semiconductor layer or the step of forming the source wiring. A multi-tone mask can also be used in the process of forming source wiring. FIG. 23(A) shows a case where the source wiring and the source electrode are formed using a multi-tone mask.

[0245] In addition, the semiconductor layer, the source wiring, and the source electrode are formed using a multi-tone mask, and a storage capacitor is formed. FIG. 23(B) shows the case where a channel portion is formed on the channel forming region of the semiconductor film. Even when a protective film is formed, a multi-tone mask can be used (see FIG. 23(C)). 23B and 23C, the semiconductor layer of the transistor 250 and the storage capacitor The oxide semiconductor layer 260 was made into one island, so that the oxide semiconductor layer In addition, the number of contact holes can be reduced, The contact resistance can be reduced, and contact failures can be reduced. .

[0246] Next, the semiconductor layer 203b and the conductive layer 210a functioning as a source wiring are formed using a multi-tone mask. 35(A) shows the case where the semiconductor layer 203b and the source electrode or the drain electrode are formed. When the conductive layers 208c and 208d functioning as the gate electrodes are formed using a multi-tone mask, is shown in Figure 35(B).

[0247] This embodiment mode can be implemented in appropriate combination with other embodiment modes.

[0248] (Embodiment 3) In this embodiment, in the display device, at least a part of the driver circuit and a pixel An example of fabricating a thin film transistor disposed in a portion will be described below.

[0249] FIG. 24 shows an example of a block diagram of an active matrix liquid crystal display device, which is an example of a display device. The display device shown in FIG. 24A is a pixel display device having a display element on a substrate 5300. a pixel portion 5301 having a plurality of pixels, a scanning line driver circuit 5302 for selecting each pixel, and a It also has a signal line driver circuit 5303 that controls input of a video signal to the pixel.

[0250] The light-emitting display device shown in FIG. 24(B) has a plurality of pixels each having a display element over a substrate 5400. A pixel portion 5401 for selecting each pixel, a first scanning line driver circuit 5402 for selecting each pixel, and a second scanning line driver circuit 5403 for selecting each pixel. A driver circuit 5404 and a signal line driver circuit 5405 for controlling the input of a video signal to a selected pixel 403 and

[0251] When a video signal input to a pixel of the light-emitting display device shown in FIG. 24(B) is in a digital format, When a pixel is turned on, it emits light or does not emit light by switching the transistor on or off. Therefore, gray scale display can be performed using area gray scale or time gray scale. The stacked gray scale method divides one pixel into multiple sub-pixels, and each sub-pixel is independently driven based on a video signal. The time gray scale method is a driving method that displays gray scales by moving the pixel. This is a driving method that displays gradation by controlling the period during which the light is turned on.

[0252] Light-emitting elements have a faster response speed than liquid crystal elements, so they are more suitable for time gray scale modulation than liquid crystal elements. When displaying using the time gray scale method, one frame period is divided into multiple sub-frame periods. Then, in accordance with the video signal, the light emitting element of the pixel emits light in each sub-frame period. By dividing the period into multiple subframes, one frame can be The total length of the period during which the pixel emits light during the frame period can be controlled by a video signal, It is possible to display gradations.

[0253] In the light-emitting display device shown in FIG. 24B, two switching TFTs are provided for one pixel. In the case where the first scanning line which is the gate wiring of one of the switching TFTs is arranged, The signal to be input to the first scanning line driver circuit 5402 is generated by the first scanning line driver circuit 5402, and the other switching TFT A signal input to the second scanning line, which is the gate wiring of the second scanning line, is generated by a second scanning line driver circuit 5404. The example shows a signal input to the first scanning line and a signal input to the second scanning line. The signal may be generated by one scanning line driving circuit. The operation of the switching element is controlled by the number of switching TFTs that each pixel has. In this case, multiple scan lines may be provided for each pixel. The signals input to the scanning lines may all be generated by one scanning line driving circuit, or may be generated by a plurality of scanning line driving circuits. It may also be generated by the scan line driver circuit.

[0254] The thin film transistor to be disposed in the pixel portion of the liquid crystal display device is the same as that of the first embodiment or the second embodiment. The thin film transistors shown in Embodiment Modes 1 and 2 are formed in accordance with the following. Since it is a n-channel TFT, the driver circuit can be configured with n-channel TFTs. A part of the driver circuit is formed on the same substrate as the thin film transistor of the pixel portion.

[0255] In addition, in the light-emitting display device, the driver circuit may be configured with an n-channel TFT. A part of the driver circuit can be formed on the same substrate as the thin film transistor of the pixel portion. In addition, the signal line driver circuit and the scanning line driver circuit are formed by the n-channel TF shown in Embodiments 1 and 2. It is also possible to make it using only T.

[0256] In addition, in the peripheral driving circuits such as the protection circuit, gate driver, and source driver, Therefore, the pixel area does not need to be transparent to light. In the peripheral driving circuit section, the transistors do not transmit light. It's okay.

[0257] FIG. 25(A) shows the case where a thin film transistor is formed without using a multi-tone mask, and FIG. 25(B) shows the case where a thin film transistor is formed without using a multi-tone mask. ) shows the case where a thin film transistor is formed using a multi-tone mask. The thin film transistor formed without the insulating layer is a semiconductor layer provided on a substrate 100 having an insulating surface. a semiconductor layer 171 and a gate electrode 172 that functions as a source electrode or a drain electrode provided on the semiconductor layer 171; a conductive layer 172 formed on the gate insulating film 110; 10 and a conductive layer 174 that functions as a gate electrode. The conductive layer 174 functions as an electrode, and the conductive layer 175 functions as a source electrode or a drain electrode. The gate electrode 72 can be formed of a conductive layer having a light-shielding property (see FIG. 25(A)). An insulating film 175 is formed on a conductive layer 174 that functions as a gate electrode.

[0258] The thin film transistor formed using a multi-tone mask is formed on a substrate 200 having an insulating surface. The semiconductor layer 271 and the source electrode or the drain electrode provided on the semiconductor layer 271 are Conductive layers 272 and 273 functioning as electrodes, and a gate insulating film provided on the conductive layer 273; and conductive layers 275 and 276 that function as gate electrodes provided on the gate insulating film. The gate electrode, the source electrode, and the drain electrode are each made of a light-transmitting conductive material. The insulating layer and the light-shielding conductive layer can be stacked (see FIG. 25(B)). In addition, an insulating film 277 is formed on the conductive layers 275 and 276 that function as gate electrodes. .

[0259] In peripheral driving circuits such as protection circuits, gate drivers, and source drivers, transistors Therefore, the semiconductor layer used in one embodiment of the present invention does not need to transmit light. In addition to oxide semiconductors, crystalline semiconductors (single crystal semiconductors or polycrystalline semiconductors), amorphous semiconductors, Any of conductors, microcrystalline semiconductors, microcrystalline semiconductors, organic semiconductors, etc. may be used. .

[0260] The above-mentioned driving circuit is not limited to liquid crystal display devices and light-emitting display devices, but may also be used in It may also be used in electronic paper, which uses electrically connected elements to drive electronic ink. Electronic paper includes electrophoretic display devices (electrophoretic displays) that have the same readability as paper. It is possible to realize a low-cost display that consumes less power than other display devices, and is also thin and lightweight. It is Noh.

[0261] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0262] (Fourth embodiment) Next, a structure of a display device, which is one embodiment of a semiconductor device, will be described. As a display device, a light-emitting display device having a light-emitting element that utilizes electroluminescence The light-emitting element that utilizes electroluminescence is made of an organic compound as the light-emitting material. Generally, the former is an organic EL element, and the latter is an inorganic compound. These are called inorganic EL elements.

[0263] In an organic EL element, electrons and holes are released from a pair of electrodes by applying a voltage to the light-emitting element. are injected into the layers containing the light-emitting organic compounds, causing a current to flow. The recombination of the electrons and holes creates an excited state in the light-emitting organic compound. The excited state is then converted to the ground state, at which point light is emitted. Such a light-emitting element is called a current-excited light-emitting element.

[0264] Inorganic EL elements are divided into dispersion-type inorganic EL elements and thin-film-type inorganic EL elements depending on the element structure. Dispersion-type inorganic EL elements have a light-emitting layer in which particles of a light-emitting material are dispersed in a binder. The emission mechanism is a donor-acceptor interaction that utilizes the donor and acceptor levels. Thin-film inorganic EL devices sandwich the light-emitting layer between dielectric layers. Furthermore, this structure is sandwiched between electrodes, and the light emission mechanism utilizes the inner-shell electron transition of metal ions. In this example, the light-emitting element is an organic EL element. do.

[0265] Next, a pixel configuration and pixel operation to which digital time gray scale driving can be applied will be described. 26 is a diagram showing an example of a pixel configuration to which digital time gray scale driving can be applied. Two n-channel transistors, each of which uses a conductor layer as the channel formation region, are used in one pixel. Here is an example:

[0266] A pixel 6400 shown in FIG. 26(A) includes a switching transistor 6401, a driving transistor 6402, and a The switching element 6402 includes a transistor 6402, a light-emitting element 6404, and a capacitor element 6403. The gate of the scanning transistor 6401 is connected to the scanning line 6406, and the first electrode (source electrode and The second electrode (one of the source electrode and drain electrode) is connected to a signal line 6405, and the second electrode (one of the source electrode and drain electrode) is connected to a signal line 6406. The other of the gate electrodes is connected to the gate of the driving transistor 6402. The gate of the transistor 6402 is connected to a power supply line 6407 via a capacitor element 6403. The electrode is connected to a power line 6407, and the second electrode is the first electrode (pixel electrode) of the light emitting element 6404. The second electrode of the light emitting element 6404 corresponds to the common electrode 6408.

[0267] A low power supply potential is set to the second electrode (common electrode 6408) of the light emitting element 6404. The low power supply potential is a low power supply potential with respect to the high power supply potential set to the power supply line 6407. Potential < High power supply potential. For example, GND, 0V, etc. are set as low power supply potential. The potential difference between the high power supply potential and the low power supply potential is applied to the light emitting element 6404. Then, in order to make the light emitting element 6404 emit light by passing a current through the light emitting element 6404, a high power supply potential and the low power supply potential becomes equal to or greater than the forward threshold voltage (Vth) of the light emitting element 6404. The respective potentials are set as follows.

[0268] The capacitor element 6403 is omitted by substituting the gate capacitance of the driving transistor 6402. The gate capacitance of the driving transistor 6402 is determined by the channel region A capacitance may be formed between the gate electrode and the transistor.

[0269] In the case of a voltage input voltage driving method, the gate of the driving transistor 6402 is connected to The driving transistor 6402 is either fully on or off. A video signal is input, that is, the driving transistor 6402 is operated in a linear region. The driving transistor 6402 is operated in a linear region, so that the voltage of the driving transistor 6402 is higher than the voltage of the power supply line 6407. A high voltage is applied to the gate of the driving transistor 6402. The signal line 6405 is connected to A voltage equal to or greater than (power supply line voltage+Vth of the driving transistor 6402) is applied.

[0270] Furthermore, when analog grayscale driving is performed instead of digital time grayscale driving, the input of the signal is different. By doing so, the same pixel configuration as in FIG. 26(A) can be used.

[0271] When analog gradation driving is performed, a light emitting element 6404 is connected to the gate of a driving transistor 6402. A voltage equal to or greater than the forward voltage of the light emitting element 64 and the Vth of the driving transistor 6402 is applied. The forward voltage in 04 refers to the voltage required to achieve the desired brightness, and It should be noted that the driving transistor 6402 is designed to operate in the saturation region. By inputting an optical signal, a current can be passed through the light emitting element 6404. In order to operate the transistor 6402 in the saturation region, the potential of the power supply line 6407 is The potential of the light emitting element is made higher than the gate potential of the capacitor 6402. A current corresponding to a video signal is passed through 6404, enabling analog gradation driving.

[0272] It should be noted that the pixel configuration shown in FIG. 26(A) is not limited to this. A switch, a resistor, a capacitor, a transistor, or a logic circuit is newly added to the pixel. For example, the configuration shown in FIG. 26(B) may be used. 10 is a switching transistor 6401, a driving transistor 6402, a light emitting element The switching transistor 6401 has a gate The port is connected to a scanning line 6406, and the first electrode (one of the source electrode and the drain electrode) is connected to a signal line. The second electrode (the other of the source electrode and the drain electrode) is connected to the driving transistor 6405. The driving transistor 6402 has a gate connected to The capacitor 6403 is connected to a first electrode (pixel electrode) of the light emitting element 6404. The first electrode is connected to a wiring 6426 that applies a pulse voltage, and the second electrode is connected to the first electrode of the light emitting element 6404. The second electrode of the light emitting element 6404 corresponds to the common electrode 6408. Of course, in this configuration, a switch, a resistor, a capacitor, a transistor, or A logic circuit or the like may be added.

[0273] Next, the configuration of the light emitting element will be explained with reference to FIGS. 27(A), 27(B), and 27(C). Here, the case where the driving TFT is the transistor 150 shown in FIG. The cross-sectional structure of the pixel will now be described. The driving TFTs used in the device, TFT7001, 7011, and 7021, are The transistor can be manufactured in the same manner as in the transistors described in the first and second embodiments. It is a thin film transistor with excellent electrical characteristics.

[0274] The light emitting element only needs to have at least one of the anode and cathode transparent in order to extract light. Then, a thin film transistor and a light emitting element are formed on the substrate, and light is taken from the surface opposite to the substrate. Top emission, bottom emission, and top emission. There are light-emitting devices with a double-sided emission structure in which light is emitted from the side surface. The present invention can also be applied to a light emitting element with an injection structure.

[0275] A light emitting element with a top emission structure will be described with reference to FIG.

[0276] 27A, a TFT 7001, which is a driving TFT, is the transistor 150 shown in FIG. When light emitted from the light emitting element 7002 passes through the anode 7005 side, the cross section of the pixel is 27A shows a plan view of the cathode 7003 of the light-emitting element 7002 and the driving TFT 7004. The TFT 7001 is electrically connected, and the light-emitting layer 7004 is formed on the cathode 7003, and the anode 70 The cathode 7003 is a conductive material with a low work function and a high reflectivity. Various materials can be used for the conductive film. For example, Ca, Al, MgAg, AlL The light-emitting layer 7004 may be composed of a single layer or a plurality of layers. If it is made up of multiple layers, the cathode 7003, an electron injection layer, an electron transport layer, a light-emitting layer, a hole transport layer, and a hole injection layer are laminated in this order. It is not necessary to provide all of these layers. The anode 7005 has a light-transmitting property. The conductive material may be, for example, indium oxide containing tungsten oxide. Indium zinc oxide with tungsten oxide, indium oxide with titanium oxide, acid Indium tin oxide containing titanium dioxide, indium tin oxide (hereinafter referred to as ITO), Translucent conductive materials such as indium zinc oxide and indium tin oxide doped with silicon oxide A conductive film may also be used.

[0277] The region where the light-emitting layer 7004 is sandwiched between the cathode 7003 and the anode 7005 is the light-emitting element 7002. In the case of the pixel shown in FIG. 27(A), the light emitted from the light emitting element 7002 is The light is emitted toward the anode 7005 as shown by the mark.

[0278] In addition, the gate electrode provided on the semiconductor layer in the driver circuit is made of the same material as the cathode 7003. It is preferable to form an insulating film on the anode because this simplifies the process. For example, SiNx and SiOx have hygroscopic properties, which can prevent deterioration of EL elements. In addition, the cathode is made of a semi-transparent film (transmittance 30-80%, reflectance 30-60%), By using a cavity structure (microresonator), color purity can be improved.

[0279] Next, a light emitting element with a bottom emission structure will be described with reference to FIG. The driving TFT 7011 is the transistor 150 shown in FIG. 27(B) shows a cross-sectional view of a pixel when light emitted from the cathode 7013 is emitted to the cathode 7013 side. Then, on the conductive layer 7017 having light transmitting property and electrically connected to the driving TFT 7011, A cathode 7013 of the light emitting element 7012 is formed as a film. A light emitting layer 7014 is formed on the cathode 7013. In addition, when the anode 7015 is transparent, A shielding film 7016 for reflecting or blocking light may be formed to cover the surface. As in the case of FIG. 27(A), the cathode 7013 can be made of various conductive materials with a small work function. However, the thickness of the film should be such that it transmits light (preferably For example, an aluminum film having a thickness of 20 nm is used as the cathode. 7013. The light-emitting layer 7014 can be formed as shown in FIG. It can be made up of a single layer or multiple layers stacked together. The anode 7015 does not need to transmit light, but it may have light-transmitting properties as in FIG. The shielding film 7016 can be formed using a conductive material that can However, the present invention is not limited to a metal film. For example, a black pigment may be used. It is also possible to use an added resin or the like.

[0280] The region where the light-emitting layer 7014 is sandwiched between the cathode 7013 and the anode 7015 is the light-emitting element 7012. In the case of the pixel shown in FIG. 27(B), the light emitted from the light-emitting element 7012 corresponds to The light is emitted toward the cathode 7013 as shown by the arrow.

[0281] The gate electrode provided on the semiconductor layer in the driver circuit is made of the same material as the cathode 7013. This is preferable because it simplifies the process.

[0282] Next, a light emitting element with a dual emission structure will be described with reference to FIG. 27(C). Then, on the conductive layer 7027 having light transmitting property and electrically connected to the driving TFT 7021, A cathode 7023 of the light-emitting element 7022 is formed as a film. A light-emitting layer 7024 is formed on the cathode 7023. The cathode 7023 is laminated in the same manner as in FIG. Various conductive materials with small electrical conductivity can be used. For example, Al having a thickness of 20 nm is used as the cathode 7023. The light-emitting layer 7024 can be formed of a single layer, as in FIG. The anode 70 may be formed by laminating a plurality of layers. 25 can be formed using a light-transmitting conductive material, similar to FIG. 27(A). do.

[0283] The overlapping portion of the cathode 7023, the light-emitting layer 7024, and the anode 7025 is the light-emitting element 70. In the case of the pixel shown in FIG. 27(C), the light emitted from the light emitting element 7022 is emitted to both the anode 7025 side and the cathode 7023 side as shown by the arrows.

[0284] Note that the gate electrode provided over the semiconductor layer in the driver circuit is made of the same material as the conductive layer 7027. It is preferable to form the semiconductor layer on the driver circuit because the process can be simplified. When the gate electrode is laminated using the same material as the conductive layer 7027 and the cathode 7023, In addition to simplifying the process, lamination can reduce wiring resistance, which is preferable. I wish.

[0285] Although organic EL elements have been described as light-emitting elements here, inorganic EL elements can also be used as light-emitting elements. It is also possible to provide an L element. The anode is common to all pixels, and the cathode is patterned. It may also be used as a pixel electrode.

[0286] In this embodiment, a thin film transistor (driving TFT) for controlling the driving of a light emitting element is used. In the example shown, the light emitting element is electrically connected to the driving TFT. A current control TFT may be connected.

[0287] Note that the semiconductor device described in this embodiment mode has the same structure as that shown in FIGS. The present invention is not limited to the configuration shown, and various modifications based on the disclosed technical idea are possible. be.

[0288] Next, the upper surface and the lower surface of a light-emitting display panel (also referred to as a light-emitting panel), which corresponds to one mode of a semiconductor device, The cross section will be explained using Figures 28(A) and 28(B). Figure 28(A) shows the first The thin film transistor and the light emitting element formed on the substrate are sandwiched between the second substrate and the substrate by a sealing material. 28(B) is a top view of the panel sealed by the HI in FIG. 28(A). This corresponds to a cross-sectional view.

[0289] A pixel portion 4502, a signal line driver circuit 4503a, and a signal line driver circuit 4504 are provided on a first substrate 4501. 3b and the scanning line driver circuits 4504a and 4504b. In addition, a pixel portion 4502, signal line driver circuits 4503a and 4503b, and A second substrate 4506 is provided on the scanning line driver circuits 4504a and 4504b. The pixel portion 4502, the signal line driver circuits 4503a and 4503b, and the scanning line driver circuit 45 4504a and 4504b are a first substrate 4501, a sealing material 4505, and a second substrate 4506. The seal is sealed together with the filler 4507 by the sealant. Highly airtight protective film with little outgassing (lamination film, UV curable resin film) It is preferable to package (enclose) the product in a protective film (such as a film) or a cover material.

[0290] In addition, a pixel portion 4502, a signal line driver circuit 4503a, 4503b and the scanning line driver circuits 4504a and 4504b have a plurality of thin film transistors. In FIG. 28B, a thin film transistor 4510 included in a pixel portion 4502 and A thin film transistor 4509 included in the signal line driver circuit 4503a is shown as an example. The transistors 4509 and 4510 are highly reliable devices that include an oxide semiconductor as a semiconductor layer. The thin film transistors shown in the first and second embodiments can be applied.

[0291] In addition, in the peripheral driving circuits such as the protection circuit, gate driver, and source driver, Therefore, in the pixel portion 4502, the transistor The capacitors and capacitor elements are formed from a light-transmitting material, and the peripheral driver circuit portion is formed from a light-shielding material. It may be formed of a material.

[0292] Further, 4511 corresponds to a light-emitting element, and a first electrode which is a pixel electrode of the light-emitting element 4511 is The electrode layer 4517 is electrically connected to the source electrode layer or the drain electrode layer of the thin film transistor 4510. The light-emitting element 4511 is configured by a first electrode layer 4517, an electric field generating layer 4518, and a second electrode layer 4519. The structure shown in this embodiment is a stacked structure of the light emitting layer 4512 and the second electrode layer 4513. The light emitting element 4511 may be arranged in accordance with the direction of light to be extracted from the light emitting element 4511. The configuration of 1 can be changed as needed.

[0293] The partition wall 4520 is formed using an organic resin film, an inorganic insulating film, or organic polysiloxane. In particular, a photosensitive material is used to form an opening on the first electrode layer 4517, and the sidewall of the opening It is preferable to form the inclined surface so that the inclined surface has a continuous curvature.

[0294] The electroluminescent layer 4512 may be composed of a single layer or a plurality of layers stacked. It doesn't matter whether it's done or not.

[0295] The second electrode layer is formed to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4511. A protective film may be formed on the partition wall 4513 and the partition wall 4520. The protective film may be formed of silicon nitride. It is possible to form a silicon nitride oxide film, a DLC film, etc.

[0296] In addition, signal line driver circuits 4503a and 4503b, scanning line driver circuits 4504a and 4504b Various signals and potentials applied to the pixel portion 4502 are transmitted through the FPC 4518a, 4518b, and It is supplied by b.

[0297] The connection terminal electrode 4515 is formed of the same conductive film as the first electrode layer 4517 of the light-emitting element 4511. The terminal electrode 4516 is formed from the source of the thin film transistors 4509 and 4510. The source electrode layer and the drain electrode layer may be formed from the same conductive film.

[0298] The connection terminal electrode 4515 is connected to the terminal of the FPC 4518a via the anisotropic conductive film 4519. are electrically connected to each other.

[0299] The second substrate located in the direction of light extraction from the light emitting element 4511 must be transparent. In that case, use a glass plate, plastic plate, polyester film or acrylic A light-transmitting material such as a film is used.

[0300] In addition to inert gases such as nitrogen and argon, filler 4507 can also be used as UV-curable resin. It can be made of oil or thermosetting resin, and PVC (polyvinyl chloride), acrylic, Polyimide, epoxy resin, silicone resin, PVB (polyvinyl butyral) or EV A (ethylene vinyl acetate) can be used.

[0301] If necessary, a polarizing plate or a circular polarizing plate (including an elliptical polarizing plate) may be provided on the light-emitting surface of the light-emitting element. Optical films such as retardation plates (λ / 4 plates, λ / 2 plates) and color filters may be provided as appropriate. In addition, an anti-reflection film may be provided on the polarizing plate or the circular polarizing plate. Anti-glare treatment can be applied to diffuse reflected light and reduce glare.

[0302] The signal line driver circuits 4503a and 4503b and the scanning line driver circuits 4504a and 4504b are A single crystal semiconductor substrate or a polycrystalline semiconductor film is formed on an insulating substrate. Alternatively, the signal line driver circuit may be implemented as a drive circuit formed by a thin film. Alternatively, only a part of the scanning line driver circuit or only a part of the scanning line driver circuit may be separately formed and mounted. This embodiment is not limited to the configurations of FIGS. 28(A) and 28(B).

[0303] Through the above steps, a light-emitting display device can be manufactured at reduced costs.

[0304] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0305] (Embodiment 5) Next, another structure of a display device, which is one embodiment of a semiconductor device, will be described. A liquid crystal display device having a liquid crystal element will be described as a display device.

[0306] First, the top and cross-sectional views of a liquid crystal display panel (also called a liquid crystal panel), which is one type of liquid crystal display device, will be described. The surface will be explained using Figures 29(A1), 29(A2), and 29(B). 29(A1) and 29(A2) show the structure shown in the first and second embodiments formed on a first substrate 4001. thin film transistors 4010 and 4011 including an oxide semiconductor as a semiconductor layer, and a liquid crystal display The element 4013 is sealed between the second substrate 4006 and the panel 4008 by a sealant 4005. 29(A1) and 29(A2) are top views of the MN. This corresponds to a cross-sectional view.

[0307] A pixel portion 4002 and a scanning line driver circuit 4004 are provided on a first substrate 4001. In this way, a sealing material 4005 is provided. A second substrate 4006 is provided on the path 4004. The line driver circuit 4004 is made up of a first substrate 4001, a sealing material 4005, and a second substrate 4006. The first substrate 4001 is sealed together with the liquid crystal layer 4008. In a region different from the region surrounded by the material 4005, a single crystal is formed on a separately prepared substrate. A signal line driver circuit 4003 formed of a semiconductor film or a polycrystalline semiconductor film is mounted.

[0308] The method of connecting the separately formed drive circuit is not particularly limited, and may be a COG method, Wire bonding or TAB method can be used. is an example of mounting a signal line driver circuit 4003 by the COG method, and FIG. 29(A2) shows This is an example in which a signal line driver circuit 4003 is mounted by the TAB method.

[0309] In addition, a pixel portion 4002 and a scanning line driver circuit 4004 are provided on a first substrate 4001. 29(B), the thin film transistor included in the pixel portion 4002 a thin film transistor 4010 and a thin film transistor 401 included in a scanning line driver circuit 4004 An insulating layer 4021 is provided on the thin film transistors 4010 and 4011. The thin film transistors 4010 and 4011 each contain an oxide semiconductor as a semiconductor layer. The thin film transistors shown in the first and second embodiments can be applied.

[0310] In addition, in the peripheral driving circuits such as the protection circuit, gate driver, and source driver, Therefore, in the pixel portion 4002, the transistor does not need to transmit light. The capacitors and capacitor elements are formed from a light-transmitting material, and the peripheral driver circuit portion is formed from a light-shielding material. It may be formed of a material.

[0311] The pixel electrode 4030 of the liquid crystal element 4013 is electrically connected to the thin film transistor 4010. The counter electrode layer 4031 of the liquid crystal element 4013 is electrically connected to the second substrate 400. The pixel electrode 4030, the counter electrode layer 4031, and the liquid crystal layer 4008 are overlapped. The portion where the pixel electrode 4030 and the counter electrode layer 4031 are formed corresponds to the liquid crystal element 4013. The insulating layers 4032 and 4033 functioning as alignment films are provided on the insulating layer 4031. A liquid crystal layer 4008 is sandwiched between 4032 and 4033 .

[0312] In the pixel section 4002, the grid-like wiring portion does not transmit light, but the other portions transmit light. Furthermore, the gap between each pixel electrode can be increased. A gap is necessary, and no electric field is applied to the liquid crystal in the gap. Therefore, the grid-like wiring part is made into a black matrix. It can be used.

[0313] The first substrate 4001 and the second substrate 4006 may be made of glass or metal (typically, stainless steel). Stainless steel, ceramics, and plastics can be used. , FRP (Fiberglass-Reinforced Plastics) board, PV F (polyvinyl fluoride) film, polyester film or acrylic resin film Aluminum foil can also be used with PVF film or polyester film. A sheet sandwiched between films can also be used.

[0314] 4035 is a columnar spacer obtained by selectively etching the insulating film. In order to control the distance (cell gap) between the pixel electrode 4030 and the counter electrode layer 4031 A spherical spacer may be used. The counter electrode layer 4031 is , which is electrically connected to a common potential line provided on the same substrate as the thin film transistor 4010. The common connection portion is used to connect the counter electrode layer 403 via conductive particles disposed between the pair of substrates. The conductive particles can electrically connect the sealing material 400 to the common potential line. Include in 5.

[0315] Alternatively, a 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 cholesteric liquid crystal is increased, the phase immediately transitions from the cholesteric phase to the isotropic phase. The blue phase appears only in a narrow temperature range, so the temperature range needs to be improved. In order to achieve this, a liquid crystal composition containing 5% by weight or more of a chiral agent is used for the liquid crystal layer 4008. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent has a response speed of 10 μs to It is optically isotropic, requiring no alignment treatment, and has little viewing angle dependency. stomach.

[0316] Although the liquid crystal display device shown in this embodiment is an example of a transmissive liquid crystal display device, a reflective liquid crystal display device may also be used. The present invention can be applied to both display devices and semi-transmissive liquid crystal display devices.

[0317] In addition, in the liquid crystal display device described in this embodiment mode, a polarizing plate is provided on the outer side (viewing side) of the substrate, and In the example shown in Fig. 1, a colored layer and an electrode layer used for a display element are provided in this order, but the polarizing plate is provided on the inner side of the substrate. The laminated structure of the polarizing plate and the colored layer is not limited to the present embodiment, and the polarizing plate and the colored layer may be provided. The black matrix may be appropriately set depending on the material of the colored layer and the manufacturing process conditions. A light-shielding film that functions as a light-shielding film may be provided.

[0318] In this embodiment, in order to reduce the surface unevenness of the thin film transistor, In order to improve the reliability of the thin film transistor obtained in the first and second embodiments, The insulating layer 402 is covered with an insulating layer 4021 which functions as a planarization insulating film. The protective film 1 can be formed in a single layer or a laminated structure of two or more layers. It is designed to prevent the intrusion of polluting impurities such as floating organic matter, metals, and water vapor. The protective film is preferably a silicon oxide film, a silicon nitride film, or an oxide film, which is formed by sputtering. Silicon nitride film, silicon oxynitride film, aluminum oxide film, aluminum nitride film, oxide The insulating film 11 may be formed of a single layer or a stack of aluminum nitride films or aluminum nitride oxide films. In this embodiment, an example of forming the protective film by sputtering is shown, but there is no particular limitation thereto. It may be formed by various methods such as the VD method.

[0319] The protective film can be formed of an insulating layer having a laminated structure. In this case, a silicon oxide film is formed as the first layer of the protective film by using, for example, a sputtering method. When a silicon oxide film is used as the protective film, the silicon dioxide film used as the source electrode layer and the drain electrode layer can be It is effective in preventing hillocks on aluminum films.

[0320] Furthermore, as the second layer of the protective film, a silicon nitride film is formed by, for example, sputtering. When a silicon nitride film is used as a protective film, mobile ions such as sodium penetrate into the semiconductor region. As a result, it is possible to suppress changes in the electrical characteristics of the TFT.

[0321] After forming the protective film, the semiconductor layer may be annealed (at 300°C to 400°C). stomach.

[0322] An insulating layer 4021 is formed as a planarization insulating film. Heat-resistant organic compounds such as amide, acrylic, benzocyclobutene, polyamide, and epoxy. In addition to the above organic materials, low-k materials can also be used. , siloxane resin, PSG (phosphorus glass), BPSG (borophosphorus glass), etc. In addition, by stacking multiple insulating films made of these materials, it is possible to obtain an insulating layer. 4021 may be formed.

[0323] Siloxane-based resin is a Si-OS compound formed using siloxane-based materials as starting materials. The siloxane resin corresponds to a resin containing an i bond. Alternatively, an organic group having a fluoro group may be used. That's fine.

[0324] The method for forming the insulating layer 4021 is not particularly limited, and may be a sputtering method, an SOG method, or the like, depending on the material. , spin coating, dip coating, spray coating, droplet ejection method (inkjet method, screen printing, offset printing, etc.), doctor knife, roll coater, curtain coater, knife When the insulating layer 4021 is formed using a material liquid, The semiconductor layer may be annealed (at 300° C. to 400° C.) simultaneously with the baking step. By combining the baking process of the insulating layer 4021 with the annealing process of the semiconductor layer, a semiconductor device can be efficiently manufactured. It becomes possible to manufacture

[0325] The pixel electrode 4030 and the counter electrode layer 4031 are made of indium oxide containing tungsten oxide. Indium zinc oxide with tungsten oxide, indium oxide with titanium oxide, acid Indium tin oxide containing titanium dioxide, indium tin oxide (hereinafter referred to as ITO), Translucent conductive materials such as indium zinc oxide and indium tin oxide doped with silicon oxide Conductive materials can be used.

[0326] The pixel electrode 4030 and the counter electrode layer 4031 are made of a conductive polymer ( The conductive composition may be used to form the conductive layer. The pixel electrode has a sheet resistance of 10000Ω / □ or less and a light transmittance of 550nm. It is preferable that the sheet resistance is 70% or more. It is preferable that the sheet resistance is lower. The resistivity of the conductive polymer contained in the conductive composition is preferably 0.1 Ω·cm or less.

[0327] As the conductive polymer, a so-called π-electron conjugated conductive polymer can be used. For example, polyaniline or its derivatives, polypyrrole or its derivatives, polythiophene or or a derivative thereof, or a copolymer of two or more of these.

[0328] A signal line driver circuit 4003 and a scanning line driver circuit 4004 or a pixel section 4 Various signals and potentials applied to 002 are supplied from FPC4018.

[0329] The connection terminal electrode 4015 is made of the same conductive film as the pixel electrode 4030 of the liquid crystal element 4013. The terminal electrode 4016 is formed on the source electrode layers of the thin film transistors 4010 and 4011. The drain electrode layer may be formed of the same conductive film as the drain electrode layer.

[0330] The connection terminal electrode 4015 is connected to the terminal of the FPC 4018 via the anisotropic conductive film 4019. are electrically connected.

[0331] In addition, in FIG. 29(A1) and FIG. 29(A2), a signal line driver circuit 4003 is separately formed. Although an example in which the first substrate 4001 is mounted is shown, this embodiment is not limited to this configuration. The scanning line driver circuit may be formed separately and mounted, or a part of the signal line driver circuit may be mounted. Alternatively, only a part of the scanning line driving circuit may be separately formed and mounted.

[0332] FIG. 30 shows a liquid crystal display module constructed as a semiconductor device using a TFT substrate 2600. An example is shown.

[0333] FIG. 30 shows an example of a liquid crystal display module, in which a TFT substrate 2600 and an opposing substrate 2601 are connected. The substrate is fixed by a bonding material 2602, and a pixel portion 2603 including a TFT and the like and a liquid crystal layer are disposed between the substrate and the bonding material 2602. A display element 2604, a colored layer 2605, and a polarizing plate 2606 are provided to form a display area. The coloring layer 2605 is necessary for color display. In the case of the RGB system, it contains red, green, A colored layer corresponding to each color of blue is provided for each pixel. On the outer side of the substrate 2601, a polarizing plate 2606, a polarizing plate 2607, and a diffusion plate 2613 are arranged. The light source is composed of a cold cathode fluorescent lamp 2610 and a reflector 2611, and the circuit board 2612 is , and connected to the wiring circuit section 2608 of the TFT substrate 2600 by a flexible wiring substrate 2609. It also incorporates external circuits such as a control circuit and a power supply circuit. The liquid crystal layer may be laminated with a retardation plate interposed therebetween.

[0334] The LCD module is available in TN (Twisted Nematic) mode, IPS (In-Plane Switching) mode, n-Plane-Switching mode, FFS (Fringe Field Switching) Switching mode, MVA (Multi-domain Vertical A alignment) mode, PVA(Patterned Vertical Alignment) mode nment) mode, ASM(Axially Symmetric aligned Micro-cell mode, OCB (Optically Compensated) Birefringence mode, FLC (Ferroelectric Liquid Crystal uid Crystal) mode, AFLC(AntiFerroelectric L Liquid Crystal) can be used.

[0335] Through the above steps, a liquid crystal display device can be manufactured at reduced manufacturing costs.

[0336] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0337] (Sixth embodiment) Next, we will explain electronic paper, which is one type of semiconductor device. Achieve the same readability while consuming less power than other display devices, and being thinner and lighter. It is possible.

[0338] FIG. 31 shows an active matrix electronic paper as one mode of a semiconductor device. The thin film transistor 581 used in the pixel portion of the semiconductor device is the same as that shown in the above embodiment. It can be manufactured in the same way as the thin film transistor in the pixel section, and is a thin film transistor containing an oxide semiconductor as a semiconductor layer. It is a transistor.

[0339] The electronic paper shown in FIG. 31 is an example of a display device that uses a twisting ball display method. The istball display method is an electrode layer that uses spherical particles painted in black and white as display elements. and a first electrode layer and a second electrode layer, This is a method of displaying by creating a potential difference and controlling the orientation of spherical particles.

[0340] The thin film transistor 581 provided on the substrate 580 is a thin film transistor with a top gate structure. The source electrode layer or the drain electrode layer is formed on the first electrode layer 587 and the insulating layer 585. The first electrode layer 587 and the substrate 586 are in contact with each other through an opening formed therebetween and are electrically connected. Between the second electrode layer 588 and the black area 590a and the white area 590b, A spherical particle 589 is provided, which includes a cavity 594 filled with a liquid. The periphery of the shaped particle 589 is filled with a filler 595 such as a resin (see FIG. 31).

[0341] Also, instead of the twist ball, an electrophoretic display element can be used. Liquid, positively or negatively charged white particles, and black particles charged with the opposite polarity to the white particles. The first electrode layer is a microcapsule with a diameter of about 10 μm to 200 μm that contains the above. The microcapsules provided between the first electrode layer and the second electrode layer Therefore, when an electric field is applied, the white particles and the black particles move in opposite directions, and the white or Black can be displayed. A display element that applies this principle is an electrophoretic display element. The electrophoretic display element has a higher reflectivity than the liquid crystal element, so auxiliary lights are not required. It consumes little power and the display can be seen even in dimly lit places. Even if power is not supplied, the image displayed can be retained. Even if the electronic paper is moved away from the power supply source (e.g., a radio wave source), the display It is possible to save the captured image.

[0342] Through the above steps, electronic paper can be produced at reduced manufacturing costs.

[0343] This embodiment mode can be implemented by being appropriately combined with the configurations described in other embodiments. is.

[0344] (Embodiment 7) The semiconductor device according to this embodiment can be applied to various electronic devices (including game machines). The electronic device can be, for example, a television device (television or television receivers), computer monitors, digital cameras, digital video cameras digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable Examples include game machines, mobile information terminals, sound reproduction devices, and large game machines such as pachinko machines. do.

[0345] FIG. 32(A) shows an example of a mobile information terminal device 9200. The 00 has a built-in computer and is capable of performing various data processing. Such portable information terminal devices 9200 include PDAs (Personal Digital Assistants) Assistance).

[0346] The mobile information terminal device 9200 is composed of two housings, a housing 9201 and a housing 9203. The housing 9201 and the housing 9203 are foldably connected to each other at a connecting portion 9207. A display unit 9202 is incorporated in a housing 9201, and a keyboard 9203 is incorporated in a housing 9203. Of course, the configuration of the mobile information terminal device 9200 is not limited to the above. However, as long as the thin film transistor described in the first or second embodiment is included, It is sufficient to have other auxiliary equipment installed as appropriate. By forming a circuit and a pixel part, manufacturing costs are reduced, and thin film transistors with high electrical properties are used. It is possible to realize a portable information terminal device having such a device.

[0347] FIG. 32B shows an example of a digital video camera 9500. The META 9500 has a display unit 9503 built into a housing 9501, and various operation units are also installed. The configuration of the digital video camera 9500 is not particularly limited, and at least Any other configuration may be used as long as it includes the thin film transistor described in the first or second embodiment. The drive circuit and pixel section are formed on the same substrate. This reduces manufacturing costs and allows for the development of digital devices with thin film transistors with high electrical characteristics. This makes it possible to create a real video camera.

[0348] FIG. 32C shows an example of a mobile phone 9100. The mobile phone 9100 has a housing It consists of two housings, 9104 and housing 9101, and is foldable by connecting part 9103. The display unit 9102 is incorporated in the housing 9104. The body 9101 is provided with operation keys 9106. The mobile phone 9100 is configured as follows: There is no particular limitation, and the structure includes at least the thin film transistor described in the first or second embodiment. Any other auxiliary equipment may be provided as needed. By forming the driver circuit and pixel part on the substrate, manufacturing costs can be reduced, and a thin film transistor with high electrical properties can be used. A mobile phone having a transistor can be realized.

[0349] FIG. 32(D) shows an example of a portable computer 9800. The device 800 includes a housing 9801 and a housing 9804 that are connected in an openable and closable manner. The display unit 9802 is built into the housing 9801, and the housing 9801 is equipped with a keyboard 9803, etc. The configuration of the computer 9800 is not particularly limited, and is at least as described in the first embodiment or It is sufficient that the configuration includes the thin film transistor described in 2, and other auxiliary equipment is provided as appropriate. The manufacturing process can be simplified by forming the driver circuit and the pixel section on the same substrate. This reduces costs and enables the realization of computers with thin film transistors with excellent electrical properties. .

[0350] FIG. 33(A) shows an example of a television device 9600. The display unit 9603 is incorporated in the housing 9601. In this case, the housing 9601 is supported by a stand 9605. This shows a configuration in which the above is supported.

[0351] The television device 9600 can be operated using an operation switch on the housing 9601 or a separate remote control. This can be done by the remote control operation device 9610. The channel and volume can be controlled by the 9609, and the information displayed on the display 9603 is In addition, the remote control operation device 9610 can operate the video. A display portion 9607 for displaying information output from 9610 may be provided.

[0352] The television device 9600 is configured to include a receiver, a modem, and the like. It can receive more general TV broadcasts and can also receive them via wired or wireless modems. By connecting to a communication network, it can be one-way (sender to receiver) or two-way. It is also possible to communicate information (between a sender and a receiver, or between receivers).

[0353] FIG. 33(B) shows an example of a digital photo frame 9700. The photo frame 9700 has a display unit 9703 built into a housing 9701. The unit 9703 is capable of displaying various images, for example, images taken with a digital camera. By displaying the image data, it can function like a normal photo frame.

[0354] The Digital Photo Frame 9700 has an operation panel, external connection terminals (USB terminal, US A terminal that can be connected to various cables such as B cable, etc., and a recording medium insertion section. These components may be incorporated on the same surface as the display unit, but they may be incorporated on the side or back. It is preferable to have a recording medium for a digital photo frame as it improves the design. A memory that stores image data taken with a digital camera is inserted into the body insertion section. The image data can be captured and the captured image data can be displayed on the display portion 9703 .

[0355] The digital photo frame 9700 may also be configured to be capable of transmitting and receiving information wirelessly. It is also possible to configure the device so that desired image data can be wirelessly acquired and displayed.

[0356] FIG. 34(A) shows an example of a mobile phone 1000 different from the mobile phone of FIG. 32(C). The mobile phone 1000 includes a display unit 1002 built into a housing 1001, an operation unit 1003, a display unit 1004, a display unit 1005, a display unit 1006, a display unit 1007, a display unit 1008, a display unit 1009, a display unit 1010, a display unit 1011, a display unit 1012, a display unit 1013, a operation button 1003, external connection port 1004, speaker 1005, microphone 1006, etc. It is prepared.

[0357] The mobile phone 1000 shown in FIG. 34(A) displays information by touching the display unit 1002 with a finger or the like. In addition, operations such as making a phone call or sending an email can be performed using the display unit 1. This can be done by touching 002 with a finger or the like.

[0358] The screen of the display unit 1002 has three main modes. The first is a display mode that mainly displays images. The first mode is a display mode, and the second mode is an input mode that mainly inputs information such as characters. This is a display + input mode that combines two modes: display mode and input mode.

[0359] For example, when making a call or creating an email, the display unit 1002 is used to input characters. This is the main character input mode, and you can input characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display unit 1002. I wish.

[0360] In addition, the mobile phone 1000 may include a sensor for detecting tilt, such as a gyro or an acceleration sensor. By providing a detection device having the above configuration, the orientation of the mobile phone 1000 (portrait or landscape) can be determined and the display The screen display of the display unit 1002 can be automatically switched.

[0361] The screen mode can be switched by touching the display unit 1002 or by operating the housing 1001. This is done by operating the button 1003. Also, depending on the type of image displayed on the display unit 1002, For example, if the image signal to be displayed on the display unit is a video signal, If it is data, the display mode is switched to, and if it is text data, the input mode is switched to.

[0362] In the input mode, the optical sensor of the display unit 1002 detects a signal and displays it. If there is no input by touch operation of the part 1002 for a certain period of time, the screen mode is changed to the input mode. Alternatively, the display mode may be switched from the normal mode to the display mode.

[0363] The display unit 1002 can also function as an image sensor. By touching the palm or fingers to the sensor 02, the palm print, fingerprint, etc. can be captured and identity authentication can be performed. In addition, the display unit may be equipped with a backlight that emits near-infrared light or a sensor that emits near-infrared light. By using a scanning light source, it is also possible to capture images of finger veins, palm veins, etc.

[0364] FIG. 34B is also an example of a mobile phone. The mobile phone in FIG. 34B has a housing 9411. A display device 9410 including a display portion 9412 and an operation button 9413 is mounted on a housing 9401. An operation button 9402, an external input terminal 9403, a microphone 9404, a speaker 9405, and The communication device 9400 includes a light emitting unit 9406 that emits light when an incoming call is received, and has a display function. The display device 9410 can be attached to and detached from the communication device 9400 having a telephone function in two directions as shown by the arrows. Therefore, the display device 9410 and the communication device 9400 can be attached to each other with their short axes facing each other. The display device 9410 and the communication device 9400 can be attached to each other with their long axes facing each other. When only the function is required, the display device 9410 is removed from the communication device 9400. The communication device 9400 and the display device 9410 can be used independently. Images or input information can be sent and received via wired or wireless communication, and each can be recharged with a battery. Having Terry.

[0365] (Embodiment 8) In this embodiment, a pixel configuration and pixel operation applicable to a liquid crystal display device will be described. In this embodiment, the liquid crystal element operates in a twisted twist (TN) mode. ed Nematic mode, IPS (In-Plane-Switching) mode Mode, FFS (Fringe Field Switching) mode, MVA (Multiple ti-domain Vertical Alignment) mode, PVA(Pat terned Vertical Alignment) mode, ASM (Axiall y Symmetric aligned Micro-cell) mode, OCB(O (Ptically Compensated Birefringence) mode, F LC (Ferroelectric Liquid Crystal) mode, AFLC (AntiFerroelectric Liquid Crystal) It is possible.

[0366] FIG. 37A is a diagram showing an example of a pixel configuration that can be applied to a liquid crystal display device. The pixel 5080 includes a transistor 5081, a liquid crystal element 5082, and a capacitor 5083. The gate of the transistor 5081 is electrically connected to a wiring 5085. The first terminal of the transistor 5081 is electrically connected to a wiring 5084. The first terminal of the liquid crystal element 5082 is electrically connected to the wiring. The first terminal of the capacitor 5083 is electrically connected to the first terminal of the liquid crystal element 5082. The second terminal of the capacitor 5083 is electrically connected to the wiring 5086. The first terminal of a transistor is either the source or the drain. The second terminal of the transistor is the other of the source and drain. If the first terminal of the transistor is the source, then the second terminal of the transistor is the drain. Similarly, if the first terminal of the transistor is the drain, then the second terminal of the transistor is is the source.

[0367] The wiring 5084 can function as a signal line. The signal line is input from outside the pixel. The wiring 5085 is a wiring for transmitting the signal voltage to the pixel 5080. The scan line is used to control the on / off of the transistor 5081. The wiring 5086 can function as a capacitance line. This is a wiring for applying a predetermined voltage to the second terminal of the transistor 5083. The capacitor 5083 can function as a storage capacitor. The storage capacitor can store the signal voltage even when the switch is off. The wiring 5087 is a capacitor element for keeping the voltage applied to the capacitor 082. The counter electrode applies a predetermined voltage to the second terminal of the liquid crystal element 5082. The functions that each wiring can have are not limited to these. For example, by changing the voltage applied to the capacitance line, The voltage applied to the liquid crystal element can also be adjusted. Since it is only necessary for the transistor 5081 to function as a P-channel type, the polarity of the transistor 5081 may be a P-channel type. Alternatively, it may be an N-channel type.

[0368] FIG. 37(B) is a diagram showing an example of a pixel configuration that can be applied to a liquid crystal display device. 37(A), the pixel configuration example shown in FIG. 37(B) is different from the pixel configuration example shown in FIG. 37(A) in that the wiring 5087 is omitted. The second terminal of the liquid crystal element 5082 and the second terminal of the capacitor element 5083 are electrically connected. The pixel configuration is the same as that shown in FIG. 37(A), except that the pixel is connected to the The pixel configuration example shown in FIG. 37(B) is particularly suitable for liquid crystal elements in a horizontal electric field mode (IP This is applicable when the liquid crystal element is horizontally shifted (including S mode and FFS mode). In the field mode, the second terminal of the liquid crystal element 5082 and the second terminal of the capacitor element 5083 are Since they can be formed on the same substrate, the second terminal of the liquid crystal element 5082 and the capacitor element 50 This is because it is easy to electrically connect the second terminal of the first terminal 83 to the second terminal of the second terminal 83. By using such a pixel configuration, the wiring 5087 can be omitted, and the manufacturing process can be simplified. This can reduce the manufacturing cost.

[0369] The pixel configuration shown in FIG. 37(A) or FIG. 37(B) is arranged in a matrix. In this way, a display section of a liquid crystal display device is formed, and various images can be displayed. FIG. 37(C) shows a pixel configuration in which a plurality of pixels shown in FIG. 37(A) are arranged in a matrix. The circuit configuration shown in FIG. 37(C) is a diagram showing a circuit configuration when the display unit has The figure shows four pixels extracted from the multiple pixels. j is a natural number), the pixel located at the The wiring 5084_i, wiring 5085_j, and wiring 5086_j are electrically connected to Similarly, for the pixel 5080_i+1,j, a wiring 5084_i+1 and a wiring 5085_j and the wiring 5086_j are electrically connected. For +1, wire 5084_i, wire 5085_j+1, wire 5086_j+1 and Similarly, for pixel 5080_i+1,j+1, the wiring 5084_ i+1, a wiring 5085_j+1, and a wiring 5086_j+1. A wiring can be shared by multiple pixels belonging to the same column or row. In the pixel configuration shown in FIG. 37(C), the wiring 5087 is a counter electrode. Since the elements are common, the notation for wiring 5087 using natural numbers i or j is It is also possible to use the pixel configuration shown in FIG. Therefore, even if the wiring 5087 is shown in the configuration, the wiring 5087 is not essential, and other wiring It can be omitted by being shared with a line, etc.

[0370] The pixel configuration shown in FIG. 37(C) can be driven in various ways. The liquid crystal display is driven by a method called current driving, which prevents deterioration of the liquid crystal element (burn-in). FIG. 37(D) shows the state where dot inversion driving, which is one of AC driving, is performed. When the timing of the voltage applied to each wiring in the pixel configuration shown in FIG. 1 is a diagram showing a dot inversion driving method and a dot inversion driving method. This can suppress the flicker that is visible when the display is turned on.

[0371] In the pixel configuration shown in FIG. 37C, the pixel The switch in the jth gate selection period is in the selected state (on state) during one frame period. In the other periods, it is in the non-selected state (off state). After the j+1 gate selection period, the j+1 gate selection period is provided. In this way, sequential scanning is performed. As a result, all pixels are selected in sequence within one frame period. In the timing chart, when the voltage is in a high state (high level), The switch is in the selected state, and when the voltage is low (low level), it is in the unselected state. This is the case when the transistor in each pixel is an N-channel type, and when it is a P-channel type When a transistor of this type is used, the relationship between voltage and selection state is different from that of the N-channel type. The opposite is true.

[0372] In the timing chart shown in FIG. 37(D), the jth pulse in the kth frame (k is a natural number) During the gate selection period, a positive signal voltage is applied to the wiring 5084_i used as a signal line. A negative signal voltage is applied to the wiring 5084_i+1. In the j+1-th gate selection period, a negative signal voltage is applied to the wiring 5084_i, and the wiring 5 A positive signal voltage is applied to 084_i+1. After that, each signal line As a result, in the kth frame, A positive signal voltage is applied to the pixel 5080_i,j, and a negative signal voltage is applied to the pixel 5080_i+1,j. A negative signal voltage is applied to the pixel 5080_i,j+1, and a positive signal voltage is applied to the pixel 5080_i+1,j+1. Then, in the k+1-th frame, the signal voltages are added as follows: In each pixel, a signal of the opposite polarity to the signal voltage written in the k-th frame is written. As a result, in the k+1th frame, the pixel 5080_i,j A negative signal voltage is applied to pixel 5080_i+1,j, a positive signal voltage is applied to pixel 5080_i,j A positive signal voltage is applied to pixel +1, and a negative signal voltage is applied to pixel 5080_i+1,j+1. In this way, adjacent pixels in the same frame have different polarities. A signal voltage of a certain value is applied to each pixel, and a signal voltage The dot inversion driving method is a driving method in which the polarity of the liquid crystal is inverted. This is visible when the entire or part of the displayed image is uniform while suppressing deterioration of the element. Flicker can be reduced. The voltage applied to all the wirings 5086 including the wirings 5086 can be a constant voltage. The signal voltage in the 5084 timing chart only shows the polarity. can take on various signal voltage values ​​in the polarity shown. The case where the polarity is inverted for each pixel has been described, but the present invention is not limited to this. For example, the polarity of the signal voltage written every two gate selection periods can be reversed. By reversing the polarity, it is possible to reduce the power consumption required to write the signal voltage. In addition, it is possible to invert the polarity for each column (source line inversion), or for each row The polarity can also be reversed (gate line inversion).

[0373] The second terminal of the capacitor 5083 in the pixel 5080 is connected to a capacitor in one frame period. A constant voltage is sufficient. The voltage applied is low for most of the frame period, and a nearly constant voltage is applied. Therefore, the second terminal of the capacitor element 5083 in the pixel 5080 is connected to the wiring 5 085. FIG. 37(E) is a diagram showing an example of a pixel configuration that can be applied to a liquid crystal display device. The pixel configuration shown in FIG. 37(E) has a wiring configuration different from that shown in FIG. 37(C). 5086 is omitted, and the second terminal of the capacitance element 5083 in the pixel 5080 and the The wiring 5085 in the row is electrically connected. In the range shown in FIG. 37(E), the pixel 5080_i,j+1 and the pixel The second terminal of the capacitance element 5083 in 5080_i+1,j+1 is connected to the wiring 5085_j. In this way, the second terminal of the capacitor element 5083 in the pixel 5080 and the By electrically connecting the wiring 5085 in the previous row, the wiring 5086 is omitted. Since the second terminal of the capacitor 5083 can be connected to the The destination may be the wiring 5085 in another row, not just the wiring 5085 in the previous row. The driving method of the pixel configuration shown in FIG. 37(E) is the same as that of the pixel configuration shown in FIG. 37(C). The same method of movement can be used.

[0374] The capacitor 5083 and the wiring electrically connected to the second terminal of the capacitor 5083 are By using this, it is possible to reduce the voltage applied to the wiring 5084 used as a signal line. The pixel configuration and driving method in this case will be explained using Figures 37(F) and 37(G). The pixel configuration shown in FIG. 37(F) has the wiring 5 compared to the pixel configuration shown in FIG. 086 are provided as two per pixel column, and the second The feature of this method is that the electrical connection to the terminals is made alternately between adjacent pixels. The two wires 5086 are referred to as wire 5086-1 and wire 5086-2, respectively. Specifically, in the range shown in FIG. 37(F), pixel 5080_i , j, the second terminal of the capacitance element 5083 is electrically connected to the wiring 5086-1_j. The second terminal of the capacitor 5083 in the pixel 5080_i+1,j is connected to the wiring 5086-2 _j, and the second terminal of the capacitance element 5083 in the pixel 5080_i,j+1 The pixel is electrically connected to the wiring 5086-2_j+1 and is connected to the pixel 5080_i+1,j+1. A second terminal of the capacitor 5083 in the .

[0375] For example, as shown in FIG. 37(G), in the k-th frame, pixel 5080_i, When a signal voltage of positive polarity is written to j, the wiring 5086-1_j is connected to the j-th gate selection period, and changes to high level after the jth gate selection period ends. Then, it maintains a high level for one frame period, and After a signal voltage of negative polarity is written during the j-th gate selection period, the signal voltage is changed to a low level. In this way, after a signal voltage of positive polarity is written to the pixel, the second By changing the voltage of the wiring electrically connected to the terminal in the positive direction, the voltage applied to the liquid crystal element The voltage written to the pixel can be changed by a predetermined amount in the positive direction. The power consumption required for signal writing can be reduced because the signal voltage can be reduced. In addition, when a signal voltage of negative polarity is written in the j-th gate selection period, After a signal voltage of negative polarity is written to the pixel, the second terminal of the capacitor 5083 is electrically connected to the By changing the voltage of the wiring connected to the liquid crystal element in the negative direction, the voltage applied to the liquid crystal element The negative polarity can be changed by a predetermined amount, so that the pixel That is, the signal voltage to be written can be reduced. The electrically connected wiring is connected to the same row of the same frame when a positive polarity signal voltage is applied. The pixels to which a negative signal voltage is applied have different wiring. FIG. 37(F) shows a case where a signal voltage of positive polarity is written in the k-th frame. A wiring 5086-1 is electrically connected to the pixel, and a signal voltage of negative polarity is applied in the k-th frame. In this example, the wiring 5086-2 is electrically connected to the pixel to which the voltage is written. This is just an example. For example, a pixel to which a signal voltage of a positive polarity is written and a pixel to which a signal voltage of a negative polarity is written may be In the case of a driving method in which pixels to which light is written appear every two pixels, the wiring 5086-1 and The electrical connection of the wiring 5086-2 is also performed alternately every two pixels. Furthermore, it is preferable that signal voltages of the same polarity are written to all pixels in one row (gain In this case, one wiring 5086 per row is sufficient. That is, even in the pixel configuration shown in FIG. 37(C), the same applies as in FIG. 37(F) and FIG. 37(G). As explained above, a driving method for reducing the signal voltage written to the pixel can be used. do.

[0376] Next, the liquid crystal element is a vertical alignment (VA) liquid crystal display, typically an MVA mode or a PVA mode. This section describes a pixel configuration and driving method that are particularly preferable for the VA mode. The LCD panel has many advantages, such as no rubbing process required during manufacturing, minimal light leakage during black display, and low driving voltage. However, the image quality deteriorates when the screen is viewed from an angle (narrow viewing angle). In order to widen the viewing angle in the VA mode, the following problems are encountered: As shown in (B), a pixel configuration having multiple sub-pixels in one pixel is used. In the pixel configuration shown in FIG. 38(A) and FIG. 38(B), the pixel 5080 is 5 shows an example of a case where two sub-pixels (sub-pixel 5080-1 and sub-pixel 5080-2) are included. The number of sub-pixels in one pixel is not limited to two, and various numbers of sub-pixels can be used. The larger the number of sub-pixels, the wider the viewing angle can be. The sub-pixels can have the same circuit configuration as each other. In this case, all the sub-pixels are the same as those shown in FIG. The circuit configuration of the first subpixel 5080-1 is the same as that shown in A). A device having a transistor 5081-1, a liquid crystal element 5082-1, and a capacitor element 5083-1 The connections between the various components are in accordance with the circuit configuration shown in FIG. The second subpixel 5080-2 includes a transistor 5081-2, a liquid crystal element 5082-2, a capacitor The circuit configuration shown in FIG. 37(A) is used. shall be in accordance with the following.

[0377] The pixel configuration shown in FIG. 38(A) is a configuration in which two sub-pixels constituting one pixel are used as scanning lines. There are two wires 5085 (wire 5085-1 and wire 5085-2) that are used as signal lines. 5084 is used as a capacitor line, and one wiring 5086 is used as a capacitor line. In this way, by sharing the signal line and the capacitance line between two sub-pixels, The throughput can be improved and the signal line driver circuit can be simplified. This reduces manufacturing costs and the number of connections between the LCD panel and the driver circuit IC. The pixel configuration shown in FIG. 38(B) is a pixel configuration in which two sub-pixels make up one pixel. For each pixel, there is one wiring 5085 used as a scanning line, and one wiring 50 The wiring 5084 has two wirings 5084 (wiring 5084-1 and wiring 5084-2) and is used as a capacitance line. In this way, the scanning lines and the capacitance lines are connected to two sub-pixels. By sharing the same element, the aperture ratio can be improved, and the total number of scanning lines can be reduced. This allows for a sufficient gate line selection period even in high-resolution LCD panels. This allows the appropriate signal voltage to be written to each pixel.

[0378] 38(C) and 38(D) show the pixel configuration shown in FIG. 38(B) in which the liquid crystal element is This is an example in which the electrical connection state of each element is represented in a schematic manner by replacing it with the shape of a pixel electrode. In FIG. 38(C) and FIG. 38(D), 5088-1 represents the first pixel electrode, 88-2 represents the second pixel electrode. In FIG. 38(C), the first pixel electrode 50 88-1 corresponds to the first terminal of the liquid crystal element 5082-1 ​​in FIG. 38(B), and The electrode 5088-2 corresponds to the first terminal of the liquid crystal element 5082-2 in FIG. 38(B). That is, the first pixel electrode 5088-1 is connected to the source or drain of the transistor 5081-1. The second pixel electrode 5088-2 is electrically connected to one of the drains of the transistor 5081. On the other hand, in FIG. 38(D), In other words, the first pixel electrode 5088- 1 is electrically connected to one of the source and drain of the transistor 5081-2, The pixel electrode 5088-2 is connected to either the source or the drain of the transistor 5081-1. It shall be electrically connected.

[0379] The pixel configurations shown in FIG. 38(C) and FIG. 38(D) are arranged alternately in a matrix. By doing so, a special effect can be obtained. An example is shown in Figure 39(A) and Figure 39(B). The pixel configuration shown in Figure 39(A) is The part corresponding to pixel 5080_i,j and pixel 5080_i+1,j+1 is shown in FIG. The configuration shown in FIG. 1 is a block diagram of a pixel 5080_i+1,j and a pixel 5080_i,j+1. In this configuration, the part shown in FIG. When driven as shown in the timing chart, during the jth gate selection period of the kth frame, The first pixel electrode of the pixel 5080_i,j and the second pixel electrode of the pixel 5080_i+1,j A signal voltage of positive polarity is written, and the second pixel electrode of the pixel 5080_i,j and the pixel 50 A signal voltage of negative polarity is written to the first pixel electrode of 80_i+1,j. In the j+1-th gate selection period of the frame, the second pixel electrode and and a signal voltage of positive polarity is written to the first pixel electrode of the pixel 5080_i+1,j+1, The first pixel electrode of the pixel 5080_i,j+1 and the second pixel electrode of the pixel 5080_i+1,j+1 In the (k+1)th frame, a signal voltage of negative polarity is written to each pixel. By doing so, the polarity of the signal voltage is inverted in the pixel configuration including the sub-pixel. This realizes a drive equivalent to dot inversion drive, while changing the polarity of the voltage applied to the signal line by one frame. Since the same voltage can be used within a period, the power consumption required for writing the signal voltage to the pixel can be reduced. The force can be significantly reduced. The voltage applied to all the wirings 5086 including the wiring 5086 can be a constant voltage.

[0380] Furthermore, by using the pixel configuration and driving method shown in FIG. 39(C) and FIG. 39(D), The magnitude of the signal voltage written to the pixel can be reduced. The capacitance lines electrically connected to the plurality of sub-pixels of the pixel are different for each sub-pixel. That is, the pixel configuration and driving method shown in FIG. 39(C) and FIG. 39(D) Therefore, for sub-pixels to which the same polarity is written in the same frame, the capacitances in the same row are For sub-pixels that share a common line and have different polarities written in the same frame, Then, when writing to each row is completed, The voltage of the positive polarity signal voltage is written to the sub-pixel in the positive direction, and the voltage of the negative polarity signal voltage is written to the By changing the signal voltage written to the pixel in the negative direction, Specifically, the wiring 5086 used as the capacitance line is There are two lines (wiring 5086-1 and wiring 5086-2), and the first pixel of pixel 5080_i,j The electrode and the wiring 5086-1_j are electrically connected via a capacitor, and the pixel 5080 The second pixel electrode of pixel _i,j is electrically connected to the wiring 5086-2_j via a capacitance element. The first pixel electrode of the pixel 5080_i+1,j and the wiring 5086-2_j form a capacitance element. The second pixel electrode of the pixel 5080_i+1,j is electrically connected to the wiring 508 6-1_j is electrically connected to the first pixel 5080_i,j+1 through a capacitance element. The pixel electrode and the wiring 5086-2_j+1 are electrically connected via a capacitance element, and the pixel The second pixel electrode 5080_i,j+1 and the wiring 5086-1_j+1 are connected via a capacitance element. The first pixel electrode of the pixel 5080_i+1,j+1 and the wiring 5086 are electrically connected to each other. -1_j+1 are electrically connected to the pixel 5080_i+1,j+1 via a capacitance element. The second pixel electrode and the wiring 5086-2_j+1 are electrically connected via a capacitor element. However, this is just an example. For example, if a pixel is written with a positive signal voltage and a pixel is written with a negative signal voltage, In the case of a driving method in which a pixel to which a signal voltage of the polarity is written appears every two pixels, wiring 5 The electrical connections of 086-1 and wiring 5086-2 are also made alternately every two pixels. Furthermore, it is preferable that signal voltages of the same polarity are written to all pixels in one row. In this case, the wiring 5086 is connected to one row. In other words, even in the pixel configuration shown in FIG. 39(A), As explained using 39(D), a driving method for reducing the signal voltage written to the pixel is used. You can be there.

[0381] (Embodiment 9) Next, another example of the configuration of the display device and a method of driving the same will be described. In this case, a display device using a display element with a slow response time (long response time) in brightness to signal writing is used. In this embodiment, a liquid crystal display (LCD) is used as a display element with a long response time. However, the display element in this embodiment is not limited to this, and may be any suitable element. Various display elements can be used that have a slow response of brightness to interference.

[0382] In the case of a general liquid crystal display device, the response of brightness to signal writing is slow, and the signal current is not applied to the liquid crystal element. Even if pressure is applied continuously, it may take more than one frame period for the response to complete. Even if a moving image is displayed on such a display device, it is not possible to faithfully reproduce the moving image. Furthermore, in the case of active matrix driving, the time required to write a signal to one liquid crystal element is Usually, the signal writing period (one frame period or one sub-frame period) is divided by the number of scanning lines. The time it takes to select a scan line is only a short time (one scan line selection period), and the liquid crystal element cannot respond within this short time. Therefore, most of the response of the liquid crystal element occurs during the period when no signal is written. Here, the dielectric constant of the liquid crystal element changes according to the transmittance of the liquid crystal element. However, the fact that the liquid crystal element responds during the period when no signal is written means that the liquid crystal element The dielectric constant of the liquid crystal element changes when there is no charge exchange with the outside (constant charge state). In other words, in the equation (charge) = (capacity) · (voltage), when the charge is constant, The capacitance changes depending on the voltage applied to the liquid crystal element. Therefore, the voltage at the time of signal writing changes. When a liquid crystal element with slow brightness response is driven by an active matrix, In principle, the voltage cannot reach the voltage at the time of signal writing.

[0383] The display device of this embodiment is configured to make the display element respond to a desired luminance within a signal writing period. In order to achieve this, the signal level at the time of signal writing is corrected in advance (correction signal). Furthermore, the response time of the liquid crystal element is increased as the signal level increases. The larger the value, the shorter the response time of the liquid crystal element. This type of driving method that adds a correction signal is also called overdrive. In the overdrive of this embodiment, the signal writing period is input to the display device. The period of the input image signal (input image signal period T in ), even if the signal writing period is shorter than By correcting the signal level according to the period, the display element can be displayed at the desired brightness within the signal writing period. The signal writing period is equal to the input image signal period T in In cases where For example, the case where one original image is divided into multiple sub-images and the multiple sub-images are combined into one frame is called the case where one original image is divided into multiple sub-images and the multiple sub-images are combined into one frame. For example, the images may be displayed sequentially within a certain period.

[0384] Next, a method for correcting a signal level when writing a signal in an active matrix drive display device is described. An example of the method will be described with reference to Figures 40(A) and (B). The horizontal axis represents time and the vertical axis represents the signal level at the time of signal writing. 40(B) is a graph showing a schematic representation of the change in luminance of the signal level over time when the The horizontal axis is time and the vertical axis is the display level. The change in the display level over time for one display element. In addition, when the display element is a liquid crystal element, the signal The signal level can be expressed as the voltage, and the display level can be expressed as the transmittance of the liquid crystal element. The vertical axis of FIG. 40(A) represents voltage, and the vertical axis of FIG. 40(B) represents transmittance. In the embodiment, the overdrive is performed when the signal level is other than the voltage (duty ratio, current, etc.) ) is also included. In the present embodiment, the overdrive is This also includes cases other than transmittance (brightness, current, etc.). Normally black type (e.g. VA mode, IPS mode, etc.) which displays black, and There are normally white types (e.g. TN mode, OCB mode, etc.) that sometimes display white. However, the graph shown in Figure 40(B) corresponds to both, and in the case of a normally black type The transmittance increases as you move up the graph. The transmittance may be increased toward the bottom of the film. The liquid crystal mode may be a normally black type or a normally white type. The timing of signal writing is indicated by a dotted line on the time axis, and the next The period until the signal is written is called the retention period F i In this embodiment, In Figure 40, i is an integer that represents the index of each retention period. In (A) and (B), i is shown as 0 to 2, but i may be any other value. It can also be an integer (values ​​other than 0 to 2 are not shown). i In The transmittance that realizes the brightness corresponding to the image signal is T i In the steady state, the transmittance T i Give The voltage that is applied is V i The broken line 5101 in FIG. 40(A) indicates the area where overdrive is performed. The solid line 5102 represents the time change of the voltage applied to the liquid crystal element when the liquid crystal element is not This shows the time change in the voltage applied to the liquid crystal element when overdriving is performed. Similarly, the dashed line 5103 in FIG. 40(B) represents the liquid crystal element when no overdrive is performed. The solid line 5104 represents the time change in transmittance when overdrive is performed in this embodiment. The graph shows the time change in the transmittance of the liquid crystal element when the hold period Fi At the end of , the desired transmittance T i The difference between the actual transmittance and the measured transmittance is called the error α i It will be written as follows.

[0385] In the graph shown in FIG. 40(A), the dashed line 5101 and the solid line 510 2, the desired voltage V0 is applied, and in the graph shown in FIG. 40(B), the dashed line It is assumed that the desired transmittance T0 is obtained for both 5103 and solid line 5104. If no overdrive is performed, as shown by the dashed line 5101, The desired voltage V1 is applied to the liquid crystal element, but as already mentioned, during the period when the signal is written is extremely short compared to the retention period, and most of the retention period is in a constant charge state, During the hold period, the voltage applied to the liquid crystal element changes along with the change in transmittance. At the end of F1, the voltage becomes significantly different from the desired voltage V1. The dashed line 5103 in the graph shown in FIG. 40(B) also differs greatly from the desired transmittance T1. As a result, it is not possible to display the image faithfully to the image signal, and the image quality deteriorates. On the other hand, when the overdrive of this embodiment is performed, the solid line 510 As shown in FIG. 2, at the beginning of the hold period F1, a voltage V1' that is larger than the desired voltage V1 is applied. In other words, the voltage is gradually applied to the liquid crystal element during the hold period F1. In anticipation of this change in voltage, the voltage applied to the liquid crystal element at the end of the hold period F1 is At the beginning of the hold period F1, the desired voltage V1 is set to a value close to the desired voltage V1. By applying the corrected voltage V1' to the liquid crystal element, the desired voltage V1 can be accurately applied to the liquid crystal element. In this case, the solid line 5104 in the graph shown in FIG. As shown in Fig. 1, the desired transmittance T1 is obtained at the end of the holding period F1. Although the charge state is constant for most of the duration, Next, during the hold period F2, the desired voltage V2 is set higher than V1. In this case, as in the case of the retention period F1, At the end of the hold period F2, the voltage applied to the liquid crystal element is gradually changed. At the beginning of the hold period F2, the voltage applied to the liquid crystal element is set to a voltage close to the desired voltage V2. In this case, a voltage V2' corrected from the desired voltage V2 is applied to the liquid crystal element. As shown by the solid line 5104 in the graph of FIG. 40(B), at the end of the holding period F2, The desired transmittance T2 is obtained at the end of the hold period F1. i V i-1 If it is larger than the corrected voltage V i ´ is the desired voltage V i It will be bigger than Furthermore, it is preferable to correct the hold period F2 as follows: i V i-1 Compared to If the voltage is smaller than the corrected voltage V i ´ is the desired voltage V i Compensated to be smaller than It is preferable that the specific correction value is determined by calculating the response characteristics of the liquid crystal element in advance. It can be derived by measuring the and incorporate the correction values ​​into the logic circuit. , a method of reading out correction values ​​as needed, etc. can be used.

[0386] When the overdrive in this embodiment is actually realized as a device, There are various constraints. For example, voltage correction must be performed within the rated voltage range of the source driver. That is, the desired voltage must be large enough to be an ideal correction voltage. If the voltage exceeds the rated voltage of the source driver, the voltage cannot be fully corrected. The problem in such a case will be explained with reference to Figures 40(C) and (D). C) is the same as in Figure 40(A), with the horizontal axis being time and the vertical axis being voltage, and 40(D) ​​is a graph showing the change in voltage over time as a solid line 5105. As in FIG. 40(B), the horizontal axis is time and the vertical axis is transmittance. This is a graph in which the time change in transmittance is schematically shown as a solid line 5106. The notation method is the same as in Figures 40(A) and (B), so the explanation will be omitted. (C) and (D) are correction voltages for achieving a desired transmittance T1 during the hold period F1. Since the voltage V1' exceeds the rated voltage of the source driver, V1' must be set to V1. This indicates that the correction is insufficient. The transmittance obtained will be a value that differs from the desired transmittance T1 by an error α1. The error α1 is large only when the desired voltage is originally large. However, the image quality degradation caused by the error α1 is often within the acceptable range. As the voltage becomes larger, the error in the voltage correction algorithm also becomes larger. In the voltage correction algorithm, it is assumed that the desired transmittance is obtained at the end of the hold period. When the error α1 is set, the error α1 is actually large, but the error α1 is small. Since the voltage is corrected as As a result, the error α2 also becomes larger. Furthermore, if the error α2 becomes larger, The next error, α3, becomes even larger, and so on, causing the error to grow in a chain reaction. As a result, the image quality deteriorates significantly. In drives, in order to prevent errors from increasing in a chain reaction like this, , retention period F i At the correction voltage V i When ´ exceeds the rated voltage of the source driver, Period F i The error α at the end of i and estimate the error α i Considering the size of F i+1 This allows us to adjust the correction voltage at i It has become bigger However, the error α i+1 This minimizes the impact on In the overdrive of this embodiment, An example of minimizing the error α2 will be described with reference to FIGS. 40(E) and (F). The graph shown in FIG. 40(E) is a further example of the correction voltage V2' in the graph shown in FIG. 40(C). The time change of the voltage when the correction voltage is V2'' is shown as a solid line 5107. The graph shown in FIG. 40(F) is obtained by correcting the voltage using the graph shown in FIG. 40(E). The solid line 51 in the graph shown in FIG. In 06, over-correction occurs due to the correction voltage V2', but the graph shown in Figure 40(F) The solid line 5108 in Fig. 5 shows the result of the correction voltage V2' adjusted to take into account the error α1. Overcorrection is suppressed and the error α2 is minimized. This can be derived by measuring the response characteristics of the liquid crystal element. The methods include formulating a correction formula and incorporating it into a logic circuit, and using a look-up table to calculate the correction value. The correction values ​​can be read out as needed, for example. These methods are then used to calculate the correction voltage V i ´ is added separately from the part to be calculated, or supplemented Positive voltage V i It can be incorporated into the part that calculates the error α i―1 Considering The adjusted correction voltage V i The correction amount (desired voltage V i The difference between i ´ correction amount It is preferable to make it small. That is, |V i ´´-V i |<|V i ´-V i |Tosu It is preferable that

[0387] Note that the error α i The shorter the signal writing period, the larger the The response time of the element must also be short, which results in a larger compensation voltage being required. Furthermore, the required correction voltage is increased, resulting in the correction voltage being The frequency of exceeding the rated voltage of i The frequency of occurrence is also high. Therefore, the overdrive in this embodiment is effective when the signal writing period is short. Specifically, it is possible to divide an original image into multiple sub-images and When the plurality of sub-images are displayed sequentially within one frame period, the image included in the plurality of images is A motion occurring in the image is detected, an intermediate image of the plurality of images is generated, and an intermediate image of the plurality of images is generated. When inserting and driving (so-called motion compensated double speed driving), or when combining these When the driving method such as the above is performed, the overdrive of this embodiment is used. This will have a significant effect.

[0388] In addition to the upper limit, the rated voltage of the source driver also has a lower limit. In this case, the voltage applied cannot be smaller than 0. Similarly, an ideal correction voltage cannot be applied, so the error α i It's getting bigger However, in this case, as in the above-mentioned method, the holding period F i At the end of The error α i and estimate the error α i Considering the magnitude of the holding period F i+1 Correction in The voltage can be adjusted. Note that the rated voltage of the source driver is set to a value less than 0. If a large voltage (negative voltage) can be applied, a negative voltage can be applied to the liquid crystal element as a correction voltage. In this way, the holding period F i At the end of the i It can be adjusted to a voltage close to do.

[0389] To prevent deterioration of the liquid crystal element, the polarity of the voltage applied to the liquid crystal element is periodically reversed. In other words, so-called inversion driving can be performed in combination with overdriving. That is, the overdrive in this embodiment includes the case where it is performed simultaneously with the inversion drive. For example, if the signal writing period is equal to the input image signal period T in If the polarity is 1 / 2 of and the input image signal period T in If the polarity of the signal is about the same as that of the signal written in the positive polarity, In this way, the polarity of the signal is reversed. By making the period of charge and discharge longer than the signal writing period, the frequency of pixel charging and discharging can be reduced. Power consumption can be reduced. However, if the polarity reversal period is too long, the difference in polarity The difference in brightness caused by the polarity of the The period is the input image signal period T in It is preferable that the length is equal to or shorter than the length.

[0390] (Embodiment 10) Next, another example of the configuration of the display device and a method of driving the same will be described. In this case, an image that interpolates the movement of an image (input image) input from outside the display device is generated by multiple The image is generated inside the display device based on the input image, and the generated image (generated image) and the input The generated image is displayed by compensating for the movement of the input image. By creating an image that looks like it is moving at a certain time, the movement of the video can be made smoother, and the hole This can improve the problem of video quality being reduced by afterimages caused by video drive. The display of moving images ideally involves changing the brightness of each pixel in real time. This is achieved by controlling the pixels in real time, but the real-time individual control of the pixels is The problem of the huge number of paths, the problem of wiring space, and the huge amount of input image data Therefore, it is difficult to realize the display of moving images on a display device. The display is made to look like a moving image by displaying multiple still images in sequence at a regular interval. This period (called the input image signal period in this embodiment, T in and For example, the NTSC standard is 1 / 60 seconds, and the PAL standard is 1 Even with this period, the CRT, which is an impulse type display device, shows no movement. However, there were no problems with the image display. If a video conforming to this standard is displayed as is, it may be displayed incorrectly due to afterimages caused by the fact that it is a hold type. This causes a problem called hold blur. Blurred images are caused by the inconsistency between the human eye's unconscious movement interpolation and the hold-type display. Since it is recognized by discrepancy, it is easier to recognize input image signals than conventional standards. This can be reduced by shortening the signal cycle (approaching real-time individual control of pixels). However, shortening the input image signal cycle will require changes to the standard and will also increase the amount of data. However, it is difficult to do this based on a standardized input image signal. An image that interpolates the movement of the input image is generated inside the display device, and the generated image By interpolating the input image and displaying it, it is possible to hold the image without changing the standard or increasing the amount of data. In this way, the image signal is generated inside the display device based on the input image signal. The process of interpolating the motion of the input image is called video interpolation.

[0391] The moving image interpolation method according to this embodiment can reduce the blurring of the moving image. The moving image interpolation method in the embodiment can be divided into an image generation method and an image display method. And, for specific patterns of movement, different image generation methods and / or image display methods are used. By using this method, motion blur can be effectively reduced. FIG. 10B is a schematic diagram illustrating an example of a moving image interpolation method according to the present embodiment. In Figures 41(A) and (B), the horizontal axis represents time, and the horizontal position represents The part marked "Input" indicates the timing at which each image is handled. Here, the two images that are adjacent in time are The focus is on the image 5121 and the image 5122. The input image has a period T in Enter at intervals of In addition, the period T in The length of one frame is referred to as one frame period. The part marked "Generation" indicates the timing at which a new image is generated from the input image signal. Here, the generated image is based on the image 5121 and the image 5122. The part marked "display" indicates that the image is displayed on the display device. This shows the timing when the image is displayed. Although it is only indicated by a dashed line, by treating it in the same way as the image of interest, This is an example of a method for interpolating moving images in this form.

[0392] An example of a moving image interpolation method in this embodiment is shown in FIG. The generated image is generated based on two adjacent input images. By displaying the video in the gap between the two, it is possible to interpolate the video. It is preferable that the display period of the display image is half the input period of the input image. The display period is not limited to this, and various display periods can be used. For example, the display period is set to the input period. By making it shorter than 1 / 2, you can display the video more smoothly. By making the period longer than half, power consumption can be reduced. The image is generated based on two input images, but the input images are limited to two. For example, three (or more than three) time-adjacent If an image is generated based on the input image (i.e., the image is generated more accurately than if it is generated based on two input images), It is to be noted that the display timing of the image 5121 is set to the same as that of the image 5 The same time as the input timing of 122, that is, the display timing for the input timing is 1 Although it is a frame delay, the display timing in the video interpolation method of this embodiment is The timing is not limited to this, and various display timings can be used. For example, This allows you to delay the display timing for the , the display timing of the generated image 5123 can be delayed, so that the image 51 This allows for more time for the generation of 23, reducing power consumption and manufacturing costs. If the display timing is too slow relative to the input timing, The image will be stored for a longer period of time, and the memory capacity required for storage will increase. The display timing relative to the input timing is preferably delayed by about one to two frames. It's nice.

[0393] Here, the specific image 5123 generated based on the image 5121 and the image 5122 is In order to interpolate the moving image, the motion of the input image is detected. In this embodiment, a block map is used to detect the motion of the input image. However, there are various methods that can be used without being limited to this. (Methods such as taking the difference between image data and using Fourier transform) can be used. In the block matching method, first, the image data of one input image (here, the image 5121) into a data storage means (semiconductor memory, RAM, or other storage circuit, etc.) Then, the image in the next frame (image 5122 in this example) is stored in memory. The divided areas are rectangular with the same shape, as shown in Figure 41(A). It can be, but is not limited to, various things (shape or size depending on the image) Then, for each divided area, the data stored in the data storage means can be The data is compared with the image data of the previous frame (here, the image data of image 5121). In the example of FIG. 41(A), the image 5122 has a similar image data. A region similar in data to the region 5124 in the image 5121 is searched for, and the region 512 6 is searched. When searching within image 5121, the search range is limited. In the example of FIG. 41(A), the search range is set to area 5124. The area 5125 is set to be about four times the area of ​​the By increasing the size, it is possible to improve the detection accuracy even in fast-moving videos. However, if the search is too broad, the search time will be enormous, and the detection of movement will be difficult. Therefore, the area of ​​the region 5125 is set to be about two to six times the area of ​​the region 5124. Then, the searched region 5126 and the region in the image 5122 are compared. The difference in position between the area 5124 and the area 5125 is calculated as a motion vector 5127. 7 represents the movement of image data in the region 5124 during one frame period. To generate an image that represents the intermediate state of motion, the direction of the motion vector is kept the same but the size is changed. A modified image generation vector 5128 is created, and the vector 5128 is included in the region 5126 in the image 5121. The image data is moved according to the image generation vector 5128 to generate the image 5123. This series of processes is called image 512 By performing this for all areas in 2, image 5123 can be generated. Then, by sequentially displaying the input image 5121, the generated image 5123, and the input image 5122, It is possible to interpolate moving images. Note that an object 5130 in the image is not included in the image 5121 and the image 5122. The position is different (i.e., moving) in 5122, but the generated image 5123 is the midpoint of the object in the image 5121 and the image 5122. By displaying the image, the movement of the video can be made smoother, and blurred video caused by afterimages etc. can be prevented. This can improve the quality of the product.

[0394] The size of the image generation vector 5128 is determined according to the display timing of the image 5123. In the example of FIG. 41(A), the display timing of the image 5123 is determined as follows: Since the timing is set to the midpoint (1 / 2) of the display timing of the image 5121 and the image 5122, The size of the image generation vector 5128 is half that of the motion vector 5127. For example, if the display timing is 1 / 3, the size is set to 1 / 3. If the volume is 2 / 3, the size can be set to 2 / 3.

[0395] In this way, multiple regions with various motion vectors can be moved to create a new image. When creating an image, it is necessary to consider whether there are overlapping areas within the destination area where other areas have already been moved, or whether there are any overlapping areas within the destination area. There may be some blank areas that are not moved from the area. As a method for correcting the overlapping portion, for example, the overlapping data can be corrected by Priority is assigned based on the average method, the direction of the motion vector, etc., and high-priority data is generated. The method of using the data in the generated image, color (or brightness) is given priority, but brightness (or For example, the average of the number of pixels (or color) can be used. The image data at the corresponding position of the image 5121 or 5122 is directly used as the data in the generated image. The method of taking the average of the image data at the position of the image 5121 or the image 5122 Then, the generated image 5123 can be used as an image generation method. By displaying the timing according to the size of the vector 5128, the movement of the video becomes smoother. Furthermore, the problem of image retention caused by hold drive can be eliminated. You can improve the problem.

[0396] Another example of the moving image interpolation method in this embodiment is a time interpolation method as shown in FIG. A generated image generated based on two input images that are adjacent to each other is generated based on the two input images. When displaying the images in the gaps between the displayed images, each image is further divided into multiple sub-images. By dividing the image into multiple images and displaying them, it is possible to interpolate moving images. In addition to the benefits of shorter time, dark images are periodically displayed (the display method is This also provides the advantage of the image display period being closer to the image input period. This reduces blurring of the video due to afterimages, etc., compared to when the length is only half the power cycle. In the example of FIG. 41(B), the “input” and “generation” can be further improved. Since the same processing as in the example of 1(A) can be performed, the explanation will be omitted. In the example, "display" means dividing one input image and / or generated image into multiple sub-images. Specifically, as shown in FIG. 41(B), an image 5121 can be displayed as By dividing the image into sub-images 5121a and 5121b and displaying them sequentially, the image appears to the human eye as 5121 is perceived as being displayed, and image 5123 is perceived as being displayed as sub-images 5123a and 512 By dividing the image into 3b and displaying them sequentially, the human eye perceives it as if image 5123 is displayed. The image 5122 is divided into sub-images 5122a and 5122b and displayed sequentially. The human eye perceives the image 5122 as being displayed. The image to be perceived is the same as the example in Figure 41(A), but the display method is impulse type. Since the image can be made closer to the original image, blurring of moving images due to afterimages and the like can be further improved. The number of divided sub-images is two in FIG. 41(B), but is not limited to this and may be various. The timing at which the sub-image is displayed is as shown in Figure 41 (B ) are set at equal intervals (1 / 2), but it is not limited to this and various display timings can be used. For example, the dark sub-images (5121b, 5122b, 5123b) By speeding up the display timing (specifically, from 1 / 4 to 1 / 2), the display Since the method can be made closer to the impulse type, blurring of moving images due to afterimages etc. can be reduced. Or, you can delay the timing of displaying the dark sub-image (specifically, 1 / 2 to 3 / 4 of the time), the period during which the bright image is displayed can be extended. , the display efficiency can be improved and the power consumption can be reduced.

[0397] Another example of the video interpolation method according to the present embodiment is to detect the shape of an object moving in an image. This is an example in which different processing is performed depending on the shape of the moving object. indicates the timing of display, similar to the example in Figure 41(B), but the displayed content is , and moving text (also called scrolling text, subtitles, tickers, etc.) In addition, "input" and "generation" may be the same as in Figure 41(B). The blurring of moving images during hold driving is due to the nature of the moving object. This is especially noticeable when the characters are moving. This is because when reading moving text, your eyes inevitably follow the text, This is because hold blurring is likely to occur. Furthermore, characters should have clear outlines. This can further accentuate the blur caused by the hold blur. That is, it determines whether an object moving in the image is a character, and if so, performs further special processing. This is effective for reducing hold blur. Contour detection and / or pattern detection are performed on the object to determine whether the object is a character. If it is determined that there is a motion error, motion interpolation is performed even for sub-images divided from the same image. Therefore, the intermediate state of the movement can be displayed to make the movement smoother. If it is determined that the character is not a character, it is divided into two parts from the same image, as shown in Figure 41(B). If the sub-image is a moving object, the position of the moving object can be displayed without changing. In the example shown in Figure 1, the area 5131 that is determined to be a character is moving upward. However, the position of the region 5131 is different between the sub-image 5121a and the sub-image 5121b. Sub-image 5123a and sub-image 5123b, sub-image 5122a and sub-image 51 The same applies to 22b. This allows for a more noticeable blurring of the moving object. For text, this makes the movement even smoother than with normal motion compensation double speed drive. Therefore, blurring of moving images due to afterimages or the like can be further improved. [Explanation of symbols]

[0398] 100 boards 101 Semiconductor film 102 Resist mask 103a Semiconductor layer 103b Semiconductor layer 103c Semiconductor layer 104 Conductive film 105a Resist mask 106a Conductive layer 106b Conductive layer 106c conductive layer 106d Conductive layer 106e conductive layer 107 Conductive film 108 Resist Mask 109a conductive layer 109b Conductive layer 109c Conductive layer 110 Gate insulating film 111 Conductive film 112a Resist mask 113a conductive layer 113b Conductive layer 113c conductive layer 113d conductive layer 114 Conductive film 115 Resist mask 116a conductive layer 116b Conductive layer 117 Insulating film 118 Conductive film 119a Conductive layer 120a Channel protection layer 120b Channel protection layer 121a area 130 Contact Hole 131 Contact Hole 132 Contact Hole 150 transistors 151 transistors 152 transistors 153 Transistor 154 transistors 155 transistors 156 transistors 160 Holding capacity section 161 Holding capacity section 162 Holding capacity section 164 Holding capacity section 170 PCB 171 Semiconductor layer 172 Conductive layer 173 Gate insulating film 174 Conductive Layer 175 insulating film 200 boards 203 Semiconductor layer 203a Semiconductor layer 203b Semiconductor layer 204 Conductive film 205 Conductive Film 206a Resist mask 206b Resist mask 207a Conductive layer 207b Conductive layer 208a conductive layer 208b Conductive layer 208c conductive layer 209 Resist Mask 210a conductive layer 211 Gate insulating film 212 Conductive film 213 Conductive Film 214a Resist mask 215a conductive layer 215b Conductive layer 216a conductive layer 216b Conductive layer 217a Resist mask 218a conductive layer 218b Conductive layer 219 Insulating Film 220 Conductive film 221a Conductive layer 250 transistors 260 Holding capacity section 270 PCB 271 Semiconductor Layer 272 Conductive Layer 273 Conductive Layer 274 Gate insulating film 275 Conductive Layer 276 Conductive Layer 277 Insulating Film 300 boards 301a Semi-transparent layer 301c light shielding layer 302 Substrate 303a semi-transparent layer 303c light shielding layer 400 boards 401 Light blocking part 402 Diffraction grating section 403 Gray Tone Mask 411 Substrate 412 Semi-transparent part 413 Light blocking part 414 Halftone Mask 580 board 581 Thin-film transistor 585 Insulation Layer 586 PCB 587 Electrode layer 588 Electrode layer 589 Spherical particles 590a black area 590b White area 594 Cavity 595 Filling material 1000 mobile phones 1001 Case 1002 Display section 1003 Operation button 1004 External connection port 1005 Speaker 1006 Mike 2600 TFT substrate 2601 Opposing substrate 2602 Sealing material 2603 Pixel section 2604 Display element 2605 Colored layer 2606 Polarizing plate 2607 Polarizing plate 2608 Wiring circuit section 2609 Flexible wiring board 2610 cold cathode tube 2611 Reflector 2612 Circuit Board 2613 Diffuser 4001 board 4002 Pixel section 4003 Signal line driver circuit 4004 Scanning line driver circuit 4005 Sealing material 4006 board 4008 Liquid crystal layer 4010 Thin Film Transistor 4011 Thin-film transistor 4013 Liquid crystal element 4015 Connection terminal electrode 4016 Terminal electrode 4018 FPC 4019 Anisotropic conductive film 4020 Insulation layer 4021 Insulation layer 4030 pixel electrode 4031 Counter electrode layer 4032 Insulation layer 4033 Insulation layer 4035 Spacer 4501 Circuit Board 4502 Pixel section 4503a Signal line driver circuit 4504a Scanning line driver circuit 4505 Sealing material 4506 board 4507 Filling material 4509 Thin-film transistor 4510 Thin-film transistor 4511 Light-emitting element 4512 Electroluminescent layer 4513 Electrode layer 4515 Connection terminal electrode 4516 Terminal electrode 4517 Electrode layer 4518a FPC 4519 Anisotropic conductive film 4520 Bulkhead 5080 pixels 5081 Transistor 5082 Liquid crystal element 5083 Capacitor 5088 pixel electrode 5124 area 5125 area 5126 area 5129 area 5131 area 5300 board 5301 Pixel unit 5302 Scanning line driver circuit 5303 Signal line driver circuit 5400 board 5401 Pixel unit 5402 Scanning line driver circuit 5403 Signal line driver circuit 5404 Scanning line driver circuit 6400 pixels 6401 Switching transistor 6402 Drive transistor 6403 Capacitor element 6404 Light-emitting element 6405 signal line 6406 scan lines 6407 Power line 6408 Common electrode 6410 pixels 7001 TFT 7002 Light-emitting element 7003 Cathode 7004 Light-emitting layer 7005 Anode 7011 Driving TFT 7012 Light-emitting element 7013 Cathode 7014 Light-emitting layer 7015 Anode 7016 Shielding membrane 7017 Conductive layer 7021 Driving TFT 7022 Light-emitting element 7023 Cathode 7024 Light-emitting layer 7025 Anode 7027 Conductive layer 9100 Mobile Phone 9101 Housing 9102 Display section 9103 Connection section 9104 Housing 9106 Operation key 9200 Portable information terminal equipment 9201 Case 9202 Display section 9203 Housing 9205 keyboard 9207 Connection section 9400 Communication Equipment 9401 Housing 9402 Operation button 9403 External input terminal 9404 Microphone 9405 Speaker 9406 Light-emitting part 9410 Display device 9411 Housing 9412 Display section 9413 Operation button 9500 Digital Video Camera 9501 Housing 9503 Display section 9600 Television Equipment 9601 Housing 9603 Display section 9605 Stand 9607 Display section 9609 Operation Key 9610 Remote Control Machine 9700 Digital Photo Frame 9701 Housing 9703 Display section 9800 Computer 9801 Case 9802 Display section 9803 keyboard 9804 Case

Claims

1. a semiconductor layer having a channel formation region; a first electrode having a region in contact with an upper surface of the semiconductor layer; a second electrode having a region in contact with the upper surface of the semiconductor layer; a first insulating film having a region located above the semiconductor layer, a region located above the first electrode, and a region located above the second electrode; a third electrode having a region located above the first insulating film and overlapping with the channel formation region; a fourth electrode having a region in contact with an upper surface of the first insulating film and a region in contact with a lower surface of the third electrode; a second insulating film having a region in contact with an upper surface of the third electrode; a fifth electrode having a region in contact with an upper surface of the second insulating film and a region overlapping the channel formation region via the third electrode; a sixth electrode having a region in contact with an upper surface of the second insulating film and a region overlapping the second electrode; a seventh electrode having a region in contact with the upper surface of the second insulating film and a region overlapping with the third electrode; the third electrode has an area overlapping with the second electrode, the third electrode has an area overlapping with the fifth electrode, The fifth electrode has a region that contacts the first electrode through an opening provided in the second insulating film.

2. a semiconductor layer having a channel formation region; a first electrode having a region in contact with an upper surface of the semiconductor layer; a second electrode having a region in contact with the upper surface of the semiconductor layer; a first insulating film having a region located above the semiconductor layer, a region located above the first electrode, and a region located above the second electrode; a third electrode having a region located above the first insulating film and overlapping with the channel formation region; a fourth electrode having a region in contact with an upper surface of the first insulating film and a region in contact with a lower surface of the third electrode; a second insulating film having a region in contact with an upper surface of the third electrode; a fifth electrode having a region in contact with an upper surface of the second insulating film and a region overlapping the channel formation region via the third electrode; a sixth electrode having a region in contact with an upper surface of the second insulating film and a region overlapping the second electrode; a seventh electrode having a region in contact with the upper surface of the second insulating film and a region overlapping with the third electrode; the third electrode has an area overlapping with the second electrode, the third electrode has an area overlapping with the fifth electrode, the fourth electrode has an area overlapping with the fifth electrode, The fifth electrode has a region that contacts the first electrode through an opening provided in the second insulating film.

3. In claim 1 or claim 2, The semiconductor device, wherein the semiconductor layer contains indium, gallium, and zinc.

Images