Semiconductor device

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 channel forming region is made of a thin film transistor (hereafter referred to as TFT) using an oxide semiconductor film. The present invention relates to a semiconductor device having a circuit formed thereon, and a manufacturing method thereof. and light-emitting display devices having organic light-emitting elements as components. 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 the channel layer are widely used. Thin film transistors using amorphous silicon have low field effect mobility, but they are This has the advantage that it can accommodate larger areas of 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 of applying it to devices and optical devices is attracting attention. It is known that tin oxide, indium oxide, zinc oxide, etc. 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. 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 are being 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 larger display devices and application to mobile devices, Therefore, there is a demand for further reduction in power consumption as well as 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 is wired so that it overlaps with the transparent electrode 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 additional capacitance electrode (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, Uses metal electrodes such as Mo, Au, Ti, Ta, or alloy electrodes containing these metals. 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 the 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] JP 2004-103957 A [Patent Document 2] JP 2007-81362 A [Patent Document 3] Japanese Patent Application Publication No. 2-82221 [Patent Document 4] Japanese Patent Application Publication No. 2-310536 [Patent Document 5] JP 2008-243928 A [Patent Document 6] JP 2007-109918 A [Patent Document 7] JP 2007-115807 A 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 having low wiring resistance. An object of one embodiment of the present invention is to provide a semiconductor device that can be manufactured at reduced cost. An object of one embodiment of the present invention is to provide a semiconductor device having high transmittance. An object of one embodiment of the present invention is to provide a high-definition semiconductor device. Another object 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 having a 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 first electrode connected thereto, and a semiconductor layer and a first electrode are formed so as 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 a 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 the following features.

[0013] Another embodiment of the present invention is a semiconductor layer provided over a substrate having an insulating surface, A first wiring including a first electrode connected to the semiconductor layer and a first insulating film 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; 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 and The third wiring has a fourth conductive layer, and the third wiring has a fifth conductive layer and a sixth conductive layer. The semiconductor device is as follows.

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

[0015] In the above, the semiconductor layer is an oxide semiconductor containing indium, gallium, or zinc. It is preferably 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 A 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 shows the case of Ga alone. In addition, the above metal elements other than Ga may be selected, such as Ga and Ni, Ga and Fe, etc. In addition, in the above oxide semiconductor, in addition to the metal element contained as M, 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 In-Ga-Zn-O oxide semiconductor is called an In-Ga-Zn-O-based oxide semiconductor, and a thin film using 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, other 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 as the oxide semiconductors having a non-crystalline structure that suppresses crystallization. By adding impurities that maintain the amorphous state, the characteristics of thin film transistors are stabilized. It is possible to do so.

[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 , microcrystal semiconductors, organic semiconductors, etc. may be used.

[0019] Furthermore, in the above, a multi-tone mask is used for processing 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 with low light transmittance). This allows the light-transmitting region (region with high light transmittance) to be formed without increasing the number of masks. In addition, a region having light blocking properties (region having 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 Also refers to connectors, such as FPC (Flexible Printed Circuit). inted circuit) or TAB (Tape Automated Bon ding tape or TCP (Tape Carrier Package) is used. Modules with printed wiring boards attached to the ends of TAB tape or TCP The display element is made of IC (Integrated Circuit) by COG (Chip On Glass) method. ) is also included in the display device.

[0022] The switch may take various forms. For example, an electrical switch may be used. In other words, anything that can control the flow of electric 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) (uctor) diodes, diode-connected transistors, etc. Alternatively, a logic circuit that combines these can be used as a switch.

[0023] An example of a mechanical switch is the Digital Micromirror Device (DMD). 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 causes The transistor operates by controlling conduction and non-conduction.

[0024] When a transistor is used as a switch, the transistor acts simply as a switch. However, the polarity (conductivity type) of the transistor is not particularly limited. To suppress the off-state current, it is desirable to use a transistor with a polarity that reduces the off-state current. As transistors with low current, transistors with LDD regions and multi-gate structures are There are transistors with a structure that operates 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.). In this case, it is preferable to use an N-channel transistor. 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 preferable to use an N-channel transistor because the source terminal is low. When operating at a potential close to that of the potential side power supply, the source terminal of a P-channel transistor When operating close to the high-potential power supply, the absolute value of the gate-source voltage is increased. This is because the switch can operate more accurately because the distance between the switch and the switch can be reduced. Since the transistor rarely operates as a source follower, the output voltage is This is because it is unlikely that the value will become small.

[0025] In addition, CMOS transistors are used to realize a A CMOS switch can be used as the switch. Either the N-channel transistor or the N-channel transistor is conductive. If the input voltage to the switch is 1 V, a current will flow, making it easier to function as a switch. Whether the signal voltage is high or low, the voltage can be appropriately output. In addition, the voltage amplitude of the signal for turning the switch on or off can be reduced. Therefore, power consumption can be reduced.

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

[0027] In addition, when it is explicitly stated that A and B are connected, it means that A and B are electrically connected. A and B are connected functionally, A and B are directly connected, Here, A and B are objects (e.g., devices, elements, circuits, etc.). , wiring, electrodes, terminals, conductive films, layers, etc.). Therefore, a given connection relationship, For example, the present invention is not limited to the connection relationships shown in the drawings or text, and may be modified in any way without departing from the spirit or scope of the present invention. This also includes matters other than those involved.

[0028] For example, if A and B are electrically connected, then the following can be used to electrically connect A and B: The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more electrodes (e.g., anode) 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, (e.g. step-down circuits, level shifter circuits that change the potential level of signals, etc.), voltage sources, current sources, Switching circuits, amplifier circuits (circuits that can increase the signal amplitude or current, etc., operational amplifiers, Differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, control One or more control circuits, etc., may be connected between A and B. For example, If the signal output from A is transmitted to B, even if there is another circuit between A and B, 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 directly (when they are functionally connected across a circuit) (i.e., when A and B are connected without any other element or circuit between them) In other words, when it is explicitly stated that something is electrically connected, it should simply be "" is the same as if it were expressly stated that the

[0030] Note that the following elements may be used: a display element, a display device having a display element, a light-emitting element, and a device having a light-emitting element. The light emitting device can have a variety of configurations and elements. For example, As the display element, the display device, the light-emitting element or the light-emitting device, EL (electroluminescence EL elements (EL elements containing organic and inorganic materials, organic EL elements, inorganic EL elements), LED (white LED, red LED, green LED, blue LED, etc.), transistor (depending on current) transistors that emit light when exposed to light, electron emitters, liquid crystal elements, electronic ink, electrophoretic elements, grayscale 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 emission elements, a field emission display (F ED) and SED type flat panel displays (SED: Surface-conductio Display devices using liquid crystal elements, such as LC Electron Emitter Displays The display can be a liquid crystal display (transmissive liquid crystal display, semi-transmissive liquid crystal display, reflective liquid crystal display, etc.). projection type liquid crystal display, direct view type liquid crystal display, projection type liquid crystal display), electronic ink An example of a display device using a liquid crystal display or an electrophoretic element is electronic paper.

[0031] The EL element is a device having an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. The EL layer is made up of three types of layers: 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 of them use light emitted from triplet excitons (phosphorescence), while others use organic materials. Those formed by inorganic matter, those formed by organic matter, and those formed by inorganic matter. Materials formed by the structure, including polymeric materials, low molecular weight materials, polymeric materials However, the present invention is not limited to the above, and may include materials including low molecular weight materials. There can be a variety of L elements.

[0032] An electron-emitting device is a device 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- Metal-insulator-metal (MIM) type, which is a laminate of metals, 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 device is not limited to this, and various types of electron emission devices may be used. It is possible to 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. The liquid crystal is a device that consists of a pair of electrodes and liquid crystal. Controlled by the electric field applied to the crystal (including the transverse 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, 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 crystal, plasma-addressed liquid crystal (PALC), and banana-shaped liquid crystal. The liquid crystal display is driven by a Twisted Nematic (TN) mode. mode, STN (Super Twisted Nematic) mode, IPS (In- Plane-Switching mode, FFS (Fringe Field Switching) mode tching) mode, MVA (Multi-domain Vertical Ali 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 Birefring ngence) mode, FLC (Ferroelectric Liquid Crys tal) mode, AFLC(AntiFerroelectric Liquid Cr ystal) mode, PDLC (Polymer Dispersed Liquid 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 of filters 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.), Those that are displayed by the movement of one end of the film, and those that are displayed by coloring / phase changes of molecules. Some are displayed by molecular light absorption, while others are displayed by spontaneous light emission caused by the combination of electrons and holes. For example, one method of displaying electronic paper is microcapsule 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 of ), magnetophoretic type, magnetic thermal type, electrowetting, light scattering (transparent / white Clouding), cholesteric liquid crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid Crystals, ferroelectric liquid crystals, dichroic dyes and liquid crystal dispersions, movable films, color development and erasure by leuco dyes, 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 makes it possible to solve the problems of aggregation and precipitation of electrophoretic particles, which are drawbacks of the electrophoretic method. Electronic liquid powders have many advantages, such as high speed response, high reflectance, wide viewing angle, low power consumption, and memory properties. It has a lit.

[0035] A plasma display panel is made up of a substrate on which electrodes are formed, and a substrate having electrodes and minute grooves. A substrate having a surface on which a phosphor layer is formed and a phosphor layer formed in the grooves is placed opposite to the substrate at a narrow distance, 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 two film electrodes from above and below. A lamp is a glass tube that is filled with discharge gas and RGB phosphors. By applying a voltage between the electrodes, ultraviolet light is generated, causing the phosphor to glow. The display can be done by using a DC type PD The driving method of the plasma display panel is as follows: AWS (Address While Sustain) drive, reset subframe ADS (Address Display Status) is divided into a period, an address period, and a 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 A variety of driving methods can be used for 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), Using luminescence, cold cathode tubes, hot cathode tubes, LEDs, laser light sources, mercury lamps, etc. However, the present invention is not limited to this, and various light sources can be used as the light source. do.

[0037] Note that various types of transistors can be used as the transistor. There is no limitation on the type of transistor to be 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 TFT. For example, Since it can be manufactured at a lower temperature than crystalline silicon, it reduces manufacturing costs and the manufacturing equipment. It is possible to increase the size of the device. Since the manufacturing equipment can be enlarged, it is possible to manufacture the device 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 having a light-transmitting property. The light transmission through the display element can be controlled by using the film thickness of the transistor. Because the film is thin, some of the films that make up the transistor can transmit light. Therefore, the aperture ratio can be improved.

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

[0039] In addition, when manufacturing microcrystalline silicon, a catalyst (such as nickel) is used to form the crystal. This makes it possible to further improve the crystallinity and manufacture transistors with good electrical characteristics. In some cases, the crystallinity can be improved by simply applying heat treatment without laser irradiation. As a result, part of the source driver circuit (analog switches, etc.) and the gate The gate driver circuit (scanning line driver circuit) can be formed integrally on the substrate. If laser irradiation is not performed for the purpose of crystallization, the unevenness of the silicon crystallinity can be suppressed. Therefore, it is possible to display an image with improved image 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 can improve the overall panel quality. It is preferable to perform the process in a region other than the region of the panel, but it is not limited to this. The crystallinity of the contact may be improved. The crystallinity can be improved by selectively applying a laser beam. For example, the peripheral circuit area, which is an area other than the pixels, can be selectively irradiated. Alternatively, the gate driver circuit, the source driver circuit, and the Alternatively, the laser light may be irradiated only to a region such as a path. (e.g., an analog switch) may be irradiated with laser light. It is possible to improve the crystallization of silicon only in areas where high-speed circuitry 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 problems because the area that needs to be improved in crystallinity is small. The manufacturing process can be shortened, throughput can be improved, and manufacturing costs can be reduced. The number of manufacturing devices required is small, which reduces manufacturing costs. It is possible to do so.

[0042] Alternatively, a transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. As a result, there is little variation in characteristics, size, shape, etc., and the current supply capacity is high and the size These transistors can be used to fabricate transistors with small capacitances. It is possible to achieve low power consumption or high circuit integration.

[0043] Or ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO, SnO, Compound semiconductors such as TiO, AlZnSnO (AZTO) or oxide semiconductors Thin-film transistors are also available, which are made by thinning these compound semiconductors or oxide semiconductors. These can lower the manufacturing temperature, for example, at room temperature. As a result, it is possible to manufacture transistors on substrates with low heat resistance, such as 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 material can be used as a resistor element, a pixel electrode, and an electrode having light-transmitting properties. Since these can be deposited or formed simultaneously with the transistors, costs can be reduced.

[0044] Alternatively, a transistor formed by inkjet or printing method 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, the film is applied only to the necessary parts, so the entire 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, transistors having organic semiconductors or carbon nanotubes 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 shock.

[0046] Furthermore, transistors of various structures can be used. For example, MOS transistors 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. This 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 the above. For example, the substrate may be 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 the flexible substrate include barium borosilicate glass and aluminoborosilicate glass. Examples of plates include polyethylene terephthalate (PET) and polyethylene naphthalate. (PEN), polyethersulfone (PES), or acrylic Other examples include laminated films (polypropylene, etc.) Polyester, vinyl, polyvinyl fluoride, polyvinyl chloride, etc.), including fibrous materials Paper, base film (polyester, polyamide, polyimide, inorganic deposition film, paper, etc.) Alternatively, a transistor may be formed on one substrate and then transferred to another substrate. The transistors 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 board, cellophane board, stone board, wood board, cloth board (natural fiber (silk, cotton, hemp), Synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate, (including pla, rayon, recycled polyester, etc.), leather substrate, rubber substrate, stainless steel A substrate having a stainless steel foil, a substrate having 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 to improve consumption. To form low-power transistors, to manufacture devices that are less likely to break, to make them heat-resistant, to make them lighter, or It is possible to achieve a thinner design.

[0050] Note that the structure of the transistor can take various forms and is not limited to a specific structure. For example, a multi-gate structure having two or more gate electrodes can be applied. In the case of a gate structure, the channel regions are connected in series, so multiple transistors are connected in series. The multi-gate structure reduces the off-current and increases the withstand voltage of the transistor. Alternatively, the multi-gate structure can reduce the saturation region. When operating in the low-temperature range, the drain-source current remains constant even if the drain-source voltage changes. The voltage-current characteristic slope does not change much, and the voltage-current characteristic slope can be made 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 a path.

[0051] As another example, a structure in which gate electrodes are arranged above and below the channel can be applied. By arranging the gate electrodes above and below the channel, The current value can be increased by increasing the current density. By using a structure in which the MOSFETs are arranged, it becomes easier for a depletion layer to form, and this leads to an improvement in the S value. 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 disposed above a channel region, and a structure in which a gate electrode is disposed below a channel region Structures in which the channels are arranged, positive staggered structure, reverse staggered structure, channel region divided into multiple regions 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. In addition, the source electrode and the 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. 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 characteristic 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, a circuit required to realize a specific function can be formed on the substrate. All of these can be mounted on a variety of substrates, including glass, plastic, single crystal, and SOI substrates. It is also possible to form the entire circuit necessary to realize a given function using a substrate. Since all components are formed using the same substrate, the number of components is reduced, resulting in lower costs. Alternatively, the reliability can be improved by reducing the number of connection points with the circuit components. A part of the circuitry required to realize a certain function is formed on a certain substrate, and the device performs the specified function. It is possible that other parts of the circuitry required to realize the above-mentioned embodiment are formed on other substrates. 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 certain function may be mounted on a glass substrate. Another part of the circuitry required to realize a given function, formed by transistors on a plate 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 by COG (Chip On Glass) and the glass substrate is It is also possible to place the IC chip on the board. Alternatively, the IC chip can be attached to the TAB (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 allows for cost reduction by reducing the number of components, and signal quality improvement by reducing the number of connections to circuit components. Alternatively, it is possible to improve the reliability of the parts with high drive voltages and parts with high drive frequencies. Since the power consumption of the circuitry for the other parts is large, the circuits for those parts are formed on the same board. Instead, for example, a circuit for that part is formed on a single crystal substrate, and the 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 the color elements R (red), G (green), and B (blue), In this case, 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, it is possible to add white to make it RGBW (W is white). Or, for example, yellow, cyan, magenta, emerald green, red It is possible to add one or more colors, for example, or to add at least one of the colors in RGB. It is also possible to add a color similar to the first 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 for one color element can be used. When using this to control the brightness, it is possible to treat one area as one pixel. For example, when area gradation is performed or when a pixel has sub-pixels, For each color element, there are multiple areas that control the brightness, and the gradation is expressed as a whole, but the brightness It is also possible to use one pixel for one area for controlling the width. The color element is composed of multiple pixels. Even if there are multiple color elements in one color element, they may be grouped together and each color element may be considered as one pixel. Therefore, in this case, one color element is composed of one pixel. Or 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, a plurality of regions may be arranged for one color element 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. This makes it possible to widen the viewing angle. Cut.

[0055] When explicitly stating one pixel (three colors), R, G, and B pixels are considered to be one pixel. When it is explicitly stated as 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 the vertical or horizontal direction. This includes cases where they are arranged side by side or in a jagged line. For example, when performing full-color display using three color elements (e.g., RGB), This also includes cases where the dots of the three color elements are arranged in a delta arrangement. This also includes the Bayer arrangement. Note that the size of the display area for each dot of the color element is This can reduce power consumption or extend the life of the display element. can.

[0057] In addition, the active matrix type in which the pixels have active elements or the A passive matrix method that does not use a reflective layer can be used.

[0058] In the active matrix method, a transistor is used as an active element (active element, nonlinear element). Use not only transistors but also various active elements (active elements, nonlinear elements) For example, MIM (Metal Insulator Metal) and TFD ( It is also possible to use thin film diodes. Since the manufacturing process is few, 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 type, 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 increases yields. It is possible to improve the accuracy. Since no active elements (non-linear elements) are used, Therefore, the aperture ratio can be improved, and low power consumption and high brightness can be achieved.

[0060] A transistor is defined as an element having at least three terminals including a gate, a drain, and a source. The element has a channel region between a drain region and a source region, A current can be passed through the in-region, the channel region, and the source region. Which is the source and which is the drain depends on the transistor structure and operating conditions. Therefore, it is difficult to determine whether the source and drain are In some cases, the regions that function as a source or drain are not called source or drain. In some cases, they are referred to as the first terminal and the second terminal. It may be written as the first electrode and the second electrode. Or, it may be written as the first region and the second region. There is.

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

[0062] The gate is a gate electrode and a gate wiring (gate line, gate signal line, scanning line, scanning signal line, etc.). The term refers to the whole or a part of the 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 a wiring for connecting a gate electrode to another wiring.

[0063] However, there are some areas (regions, conductors) 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 are However, there are also regions that are not clearly distinguishable. For example, If a part of the line overlaps with the channel region, that part (region, conductive layer, wiring ) function as gate wiring, but also as a gate electrode. Therefore, such a part (region, conductive layer, wiring, etc.) may be called a gate electrode. , which may be called a gate wiring.

[0064] In addition, it is made of the same material as the gate electrode and forms the same island as the gate electrode. The connected portion (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. A part (region, conductive layer, wiring, etc.) does not strictly overlap with the channel region. In some cases, 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 single gate wiring, it can be called a 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 main 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 a 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 (such as a region, a conductive layer, or a wiring) or A part of a part (such as an area, conductive layer, or wiring) that is electrically connected to a pole He says.

[0067] Note that a certain wiring may be called a gate wiring, a gate line, a gate signal line, a scanning line, a scanning signal line, etc. In some cases, the gate of the transistor is not connected to the wiring. The gate wiring, gate line, gate signal line, scanning line, and scanning signal line are the same as the gate of the transistor. wiring made of the same material as the transistor gate or wiring made of the same material as the transistor gate In some cases, the term "interconnect" refers to the wiring that is 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, de- This refers to the whole or a part of the data line, including the 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 is 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, 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 portion (area) that functions as both a source electrode and a source wiring. Such parts (areas, conductive layers, wiring, etc.) are also included in the In other words, the source electrode and the source wiring are There are also areas where the lines are not clearly distinguishable. When a part of the source wiring overlaps with the source region, that part (region, conductive layer , wiring, etc.) function as source wiring, but also function as source electrodes. Therefore, such a part (region, conductive layer, wiring, etc.) can be called the source electrode. That's fine, you can call it source wiring.

[0070] In addition, it is made of the same material as the source electrode and forms the same island as the source electrode. Connected parts (areas, 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 may also be called the source electrode. There are also regions that are made of the same material and form the same islands as the source wiring and are connected to it. Such a portion (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 portion (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 the 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 board (such as a region, 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, the source line, the source signal line, the data line, and the 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 transistor source (drain) or is formed at the same time as the transistor source (drain). Examples include storage capacitor wiring, power supply lines, and reference voltage lines. Power supply wiring, etc.

[0074] The drain is similar to the source.

[0075] The semiconductor device includes semiconductor elements (transistors, diodes, thyristors, etc.). It also refers to the whole device that can function by utilizing the properties of semiconductors. Generally, a semiconductor device may be called a semiconductor device. Alternatively, a device that has semiconductor material may be called a semiconductor device. say.

[0076] Note that the display device refers to a device having a display element. The display device may include a plurality of pixels including the above-mentioned. 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 driving circuits arranged on the board by the so-called chip-on-glass (COG) It may include an IC chip connected to the board or an IC chip connected by TAB or the like. The display device is made up of IC chips, resistors, capacitors, inductors, transistors, etc. The flexible printed circuit (FPC) may include a flexible printed circuit (FPC) to which the 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. The display device may include a polarizing plate or a retardation plate. The display device may include a lighting device, a housing, an audio input / output device, a light, and 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, the light emitting device is a specific example of a display device.

[0079] The reflecting device is a device that has a light reflecting element, a light diffractive 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 visual, projection, transmissive, reflective, and semi-transmissive types.

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

[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 include a semiconductor device and a light emitting device. Alternatively, the semiconductor device may have a display device and a driver. There may be cases where this is the case.

[0083] In addition, it is not necessary to explicitly say that B is formed on A, or that B is formed on A. In the case of describing, it is not limited to forming B directly on A. This also includes cases where A and B are not connected in a physical sense, that is, cases where another object is present 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 necessary to explicitly state that layer B is formed on layer A (or on layer A). In the case of a laminated structure, layer B may be formed directly on layer A, or layer A may be formed directly on layer B. Another layer (such as layer C or layer D) is formed adjacent to it, and layer B is formed directly on top of it. In addition, other layers (such as layers C and D) may be formed separately. It may be a 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 A, but includes the case where there is another object between A and B. For example, if a layer B is formed above a layer A, In this case, layer B is formed directly on layer A, and layer B is formed directly on layer A. Another layer (such as layer C or layer D) is formed, and layer B is formed directly on top of it. The case where the other layers (e.g., layers C and D) are single layers is also included. 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, where something is explicitly stated as singular, it is preferable to use the singular. However, this is not limited to this, and plurals are also possible. It is preferable that the items described are plural. However, this is not limited to this. , it is also possible that it is singular.

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

[0090] Note that the diagram is a schematic representation of an ideal example, and is not limited to the shapes or values ​​shown in the diagram. For example, there are variations in shape due to manufacturing techniques, variations in shape due to errors, and noise. Variations in signals, voltages, or currents due to timing differences, or variations in signals, voltages, Or, it is possible to include current variation.

[0091] In addition, technical terms may be used for the purpose of describing a specific embodiment or example. 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 is possible to use the term as meaning equivalent to the general meaning understood by a person skilled in the art. Any words defined herein shall be construed in a manner consistent with the background of the relevant art. is preferred.

[0093] In addition, the terms first, second, third, etc., refer to various elements, members, regions, layers, or sections from one another. Therefore, the words first, second, third, etc. are used to distinguish between elements, parts, etc. The number of materials, regions, layers, areas, etc. is not limited. It is possible to replace "second" or "third" etc.

[0094] In addition, "up," "upward," "down," "downward," "sideways," "right," "left," Spatial location terms such as "diagonally," "in the back," or "in front" refer to an element or may be used to simply illustrate the relationship of a feature to other elements or features in a diagrammatic manner. However, this is not limited to the above, and the terms that indicate these spatial arrangements are added to the direction depicted in the figure. In addition, other orientations are possible. For example, if B is explicitly stated as above A, The device in the figure is not limited to B being above A. 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 can be rotated in various directions, so The word "above" refers to the directions "above" and "below," as well as "sideways," "right," and "left." The orientation may include other orientations such as "towards," "diagonally," "behind," or "forward." . Effect 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 to another element (e.g., another capacitor) The wiring that connects the signal lines can be made of materials with low resistivity and high conductivity. This reduces waveform distortion and voltage drop due to wiring resistance. [Brief description 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. [Diagram 2] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Diagram 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. [Diagram 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] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Figure 22] FIG. 1 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. [Diagram 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. [Diagram 30] 1A and 1B are diagrams illustrating a display device according to one embodiment of the present invention. [Diagram 31] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Diagram 32] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Diagram 33] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Diagram 34] 1A to 1C are diagrams illustrating electronic devices according to one embodiment of the present invention. [Diagram 35] FIG. 1 is a cross-sectional view according to one embodiment of the present invention. [Diagram 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. [Diagram 40] 13A to 13C are diagrams illustrating potentials of a display element according to one embodiment of the present invention. [Diagram 41] 1A and 1B are diagrams illustrating a display screen according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0098] In this specification, the term "film" refers to a film that is formed over the entire surface and is not patterned. And the term "layer" refers to a material 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 membrane and layer are not specifically referred to. In addition, the terms "film" and "layer" are sometimes used without any distinction between the layers of a laminated film. They are sometimes used without distinction.

[0099] In addition, in this specification, terms with numerals such as "first," "second," and "third" refer to The numbers are given for convenience in order to distinguish elements, and are not limited in number. The arrangement and order of steps are not intended to be limiting.

[0100] In addition, the contents (or even a part of the contents) described in one embodiment may be used in the embodiment. Another content (or a part of the content) described in the embodiment, and / or one or more other embodiments The application, combination, or replacement of the contents (or part of the contents) described in the form It is possible to do the following:

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

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

[0103] In addition, in a drawing or text described in a certain embodiment, a part of it may be taken out. It is possible to constitute an embodiment of the invention by using the above-mentioned parts. If the invention contains text, the contents of a part of the figure or text may also be considered as part of the invention. It is disclosed as an embodiment and may constitute an aspect of the invention. 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, parts, Substrate, module, device, solid, liquid, gas, method of operation, method of manufacture, etc. The drawings (cross-sectional view, 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, phase diagram, waveform diagram, photograph, chemical formula, etc., or text It is possible to 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] FIG. 1 shows a semiconductor device according to this embodiment. FIG. 1(A) is a plan view, and FIG. 1(B) is a schematic view. FIG. 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 (e.g., gate wirings) arranged in one direction. and capacitance wiring), a plurality of wirings (e.g., source wirings) arranged in two directions, and The pixel portion includes a plurality of transistors disposed 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, a 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 functioning as a source electrode or a drain electrode is provided on the semiconductor layer 103a. and conductive layers 106a and 106b functioning as source and drain electrodes. A gate insulating film 110 is provided on the gate insulating film 6b. A conductive layer 113a serving as a gate electrode is 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 under 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 so.

[0108] In addition, a semiconductor layer 103a constituting the transistor 150 and a conductive layer functioning as a gate electrode The conductive layer 113a and the conductive layers 106a and 106b functioning as a source electrode and a drain electrode. A part or the whole of the light-transmitting material is used. A part or the whole of the semiconductor layer and the conductive layer that constitute the transistor 150 is made of a light-transmitting material. By forming the transistor using a material that can transmit light, Therefore, the aperture ratio of the pixel portion can be improved.

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

[0110] Usually, the wiring that connects elements, for example, transistors, is The conductive layer constituting the electrode, source electrode or drain electrode is stretched as it is, and the same island ( Therefore, the gate of a transistor and the 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 the source of a transistor is different from the source of a transistor. The wiring that connects the source of the transistor (called the source wiring) is In many cases, the gate electrodes and source electrodes are formed of the same layer structure and the same materials. When a light-transmitting material is used as the source electrode or 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 with materials that have light-shielding and reflective properties, such as aluminum and molybdenum. It has a lower electrical conductivity than other metals such as butanol, titanium, tungsten, neodymium, copper, silver, and chromium. Therefore, when a wiring is formed using a light-transmitting material, the wiring resistance tends to be high. For example, when manufacturing a large display device, the wiring becomes long, so 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 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 laminated. The gate electrode of the transistor 150 is formed of 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 conductive layer 113a has a sufficiently high light transmittance. The transmittance is preferably higher than the light transmittance of the conductive layer 116a.

[0114] In addition, it is 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 conductive layer having a light-transmitting property and a conductive layer having a light-shielding property. By doing so, it is possible to reduce the wiring resistance. This reduces the distortion of the signal waveform and the 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 a large display device. The wiring or source wiring is made of a conductive layer having a light-shielding property, so that the pixels are shielded. In other words, the gate wiring arranged in the row direction and the By using the 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 terms 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, enabling higher resolution images. However, as pixel size becomes smaller, the amount of transistors per pixel decreases. The area of ​​the stator and wiring is increased, reducing the aperture ratio of the pixel. In order to obtain a high aperture ratio within the pixel size, the elements required for the pixel circuit configuration must be arranged efficiently. 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 region, it is preferable to form the light-transmitting conductive layer 113b. In the region overlapping with the conductive layer 113b, a conductive layer 113b having a light-transmitting property is used to increase the conductivity, and a conductive layer 113b having a light-shielding property is used to A conductive layer 116b having a capacitance of 160 may be laminated on the capacitance wiring. 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 gate 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 is the same as that of the gate wiring. However, the width of the capacitance wiring may be different from the width of the gate wiring. It is preferable to make the width of the capacitance line wider than the width of the storage line. The area of ​​the capacitance section 160 can be increased.

[0119] In this manner, the storage capacitor 160 is formed by the conductive layer 106b and the conductive layer 113b having 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 forming the storage capacitor 160 from a conductive layer having a large 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 feed-through 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 be reduced. This makes it possible to efficiently lay out the circuit elements required for the circuit configuration.

[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, a contact hole 130 is provided in the gate insulating film 110 and the insulating film 117. A pixel electrode layer (light-transmitting conductive layers 119a and 119c) is provided on the insulating film 117. , through a contact hole 130 provided in the gate insulating film 110 and the insulating film 117. The base 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. 2A). , see (B)).

[0123] The substrate 100 having an insulating surface is, for example, a visible light transmitting substrate used in a liquid crystal display device or the like. The glass substrate may be a non-alkali glass substrate. The non-alkali glass substrate is preferably, for example, 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 an aluminum substrate, or a semiconductor substrate made of a semiconductor material such as silicon The surface of a conductive substrate made of a conductor such as metal or stainless steel, coated with an insulating material, is insulated. Materials covered with PET (polyethylene Plastic bases such as polyethylene terephthalate A plate may also be used.

[0124] An insulating film serving as a base film may be provided on a substrate 100 having an insulating surface. Alkaline 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 or equal to 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, nitrogen A single layer selected from the group consisting of an aluminum nitride film, an aluminum oxynitride film, and an aluminum nitride oxide film. The nitride film may be formed by a nitride structure or a laminate structure of a plurality of films. It is preferable to provide a silicon oxide film on the silicon film. This can sufficiently prevent the diffusion of impurities. By so doing, it is possible to prevent the silicon nitride film from coming into contact with the semiconductor layer. This is because when the silicon hydride film comes into contact with the semiconductor layer, the semiconductor layer may be hydrogenated. However, the present invention is not limited to this, and it is possible for the silicon nitride film and the semiconductor layer to be in contact with each other.

[0125] The oxide semiconductor film 101 is formed of an oxide semiconductor such as InMO3(ZnO). m (m> 0), and in particular, 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. A 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-mentioned metal elements other than Ga, such as a and Fe. In addition to the metal elements contained as M, Fe, Ni and other transition elements are included as impurity elements. In the present specification, the term "I" refers to a metal element or an oxide of the transition metal. nMO3(ZnO) mAmong oxide semiconductors with a structure represented by (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-monocrystalline structure of the sample used in the analysis was The crystal film is formed by sputtering and then heat-treated at 200°C to 500°C, typically 300°C. The heating is performed at temperatures between ℃ and 400℃ for 10 to 100 minutes.

[0127] By using In-Ga-Zn-O 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 movement 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 Structure represented as (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 film 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 region overlapping the conductive layers 106a and 106b. This is because the conductive layers 106a, 106b may have regions with a thinner thickness than the conductive layers 106a, 106b. This is caused by etching a part of the semiconductor layer 103a when etching the semiconductor layer 103a. Therefore, when the thickness of the oxide semiconductor film 101 is 50 nm or more, 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 oxide semiconductor film 101 preferably has a carrier concentration range of 100 or more. If the above 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, etc. 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 improve the electrical conductivity of oxide semiconductors. The oxide semiconductor is doped with the fluorine atom at a concentration that does not impair the semiconductor's properties.

[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, impurities such as silicon oxide are added to an In-Ga-Zn-O oxide semiconductor. By using the above-mentioned method, the oxide semiconductor is not crystallized or crystallized even when heat treatment is performed at a temperature of 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 semiconductor 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, In addition, the thin-film transistor can be prevented 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, the oxide semiconductor film 101 can be made of 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 Sn-O, Sn-O, and Zn-O oxide semiconductors can be used. By adding impurities that suppress crystallization and maintain the 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 microcrystal semiconductors, organic semiconductors, etc. may be used.

[0138] In addition, when an insulating film is formed on the substrate 100, the insulating film is removed before the oxide semiconductor film 101 is formed. The surface of the insulating film may be subjected to a plasma treatment. It is possible to remove dirt (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. In addition, after the above-mentioned plasma treatment, the cloth is exposed to the air. By forming the oxide semiconductor film 101 without using any 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 of the substrate.

[0140] In addition, the sputtering equipment is a multi-target sputtering equipment that can accommodate 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. In addition, 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 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 with a metal. 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. 02, the oxide semiconductor film 101 is selectively etched to form an island-shaped semiconductor layer 103a (See Figure 2 (C) and (D)). The resist mask is formed using the spin coating method. 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. This results in a large amount of wasted material. In the film method, the mechanism for rotating the large substrate is large-scale, and the loss of the material liquid and the amount of waste liquid are large. In addition, when spin-coating a rectangular substrate, the rotation axis is located at the center. Therefore, the inkjet method and other droplet ejection methods tend to produce circular unevenness around the center of the coating film. A resist material film is selectively formed by using a method such as screen printing, and then exposed to light. It is preferable to form a resist mask 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 1400mm. It can also be used for area substrates, but is not limited to this.

[0142] In this case, wet etching or dry etching is used as the etching method. Here, the etching is done by using a mixture of acetic acid, nitric acid, and phosphoric acid. Unnecessary portions of the oxide semiconductor film 101 are removed to form island-shaped semiconductor layers 103a. After the above 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. By using a gas having such a property, an insulating film serving as a base film and the oxide semiconductor film 101 can be easily bonded to each other. This is because an etching selection ratio can be easily achieved and damage to the insulating film can be sufficiently reduced.

[0143] In addition, 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 is easier to obtain uniform discharge over a wide area. The etching device is a 13.56MHz high-frequency power source connected to the lower electrode and grounded to the upper electrode. The lower electrode is connected to a 3.2MHz low-frequency power supply grounded ECCP (Enhanced Ceramic Plate). ced Capacitively Coupled Plasma Mode Etching In the case of an etching apparatus in this ECCP mode, for example, It can also accommodate the use of 0th generation substrates that are larger than 3m.

[0144] After that, it is advisable to carry out a heat treatment at 200°C to 600°C, typically 300°C to 500°C. In this example, a heat treatment is performed in a nitrogen atmosphere at 350° C. for 1 hour. The atomic level rearrangement of the In-Ga-Zn-O oxide semiconductor that constitutes 03a occurs. This heat treatment (including photo-annealing) accelerates the movement of carriers in the semiconductor layer 103a. The above heat treatment is important because it can release the strain that inhibits the growth of the crystal. There is no particular limitation 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 the like. It uses materials such as ITSO, organic indium, organic tin, zinc oxide (ZnO), and titanium nitride. Indium zinc oxide (InZinc 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 the laminated structure is used, all of the multiple films are 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 above 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 discontinuity, The conductive layers 106a and 106b functioning as a source electrode and a drain electrode have tapered ends. It is preferable to etch the source electrode or the drain electrode so as to have a shape similar to that of the first embodiment. The conductive film includes electrodes and wirings 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 (Ant) 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 material, or nitrides whose component is a metal material. It can be formed of 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. When 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 multi-layer film. Materials with high electrical 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 using such a structure, the occurrence of hillocks can be prevented. Note that the conductive layer having a light-transmitting property has a smaller thickness than the conductive layer having a light-shielding property. It is preferable, 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. A region where the conductive layer 109a and the conductive layer 106a overlap, and a region 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, functions as a source wiring, and in a 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, which functions as an electrode, is formed of a light-transmitting material. Since light can be transmitted through the area where the source electrode or drain electrode is formed, In addition, the conductive layer 109a is formed to be thicker than the conductive layer 106a. By forming the source wiring from a material with high conductivity, the wiring resistance of the source wiring is reduced, and power consumption is reduced. In addition, the source wiring is formed using a conductive layer having a light-shielding property. This allows light shielding between pixels, and improves contrast. do.

[0153] After forming the conductive layers 106a and 106b, the conductive layer 109a is formed. However, the order of formation may be reversed. After forming the conductive layers 106a and 109a, which function as source and drain electrodes, 06b can also be formed (see FIG. 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 insulating layer may be a single layer or a multilayer of an aluminum oxide film or a tantalum oxide film. The gate insulating film 110 is formed to a thickness of 50 nm to 250 nm by sputtering, CVD, or the like. For example, the gate insulating film 110 can be formed by sputtering. A silicon film can be formed to a thickness of 100 nm. Or, it can be oxidized 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 a contained in the substrate 100 can be prevented from being invaded by moisture or oxygen. 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 or equal to 1×10 18 / cm 3 The following is the case. Therefore, 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 Cr, and carbon such as DLC (Diamond-Like Carbon) Films containing epoxy, polyimide, polyamide, polyvinylphenol, benzocyclo A film made of organic materials such as butene and acrylic, or siloxane materials such as siloxane resin, is 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 component element. At the impurity level, the types and concentrations of elements contained may differ. By using roughly the same material, the conductive film 111 is formed by sputtering or deposition. 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 streamlined. This allows for smooth flow, improving throughput and reducing costs. It becomes possible to realize this.

[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 above 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), or tantalum. Ta (Ta), Molybdenum (Mo), Nickel (Ni), Platinum (Pt), Copper (Cu), Gold ( Au), silver (Ag), manganese (Mn), neodymium (Nd), chromium (Cr), antimony (Ant) 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 material, or nitrides whose component is a metal material. It can be formed of a low resistance conductive material such as aluminum. is desirable.

[0164] In addition, it is preferable that the conductive film 114 is formed of a material different from that of the conductive film 107. Alternatively, the conductive film 114 may be formed to have a layered structure different 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 has a laminated structure. Alternatively, it is preferable to use a material that is less susceptible to hillocks for the conductive film 107. It is preferable to use a laminated structure. Alternatively, the conductive film 114 is 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 conductive layer having a light-transmitting property rather than a conductive layer having a light-shielding property. It is desirable for the film thickness to be 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, It is desirable to use a high melting point material between the substrate and the substrate 4. For example, Examples include carbide, titanium, tungsten, tantalum, and chromium. On the film using the material, a conductive film 114 is formed as a multi-layer film using a material having high conductivity. Materials with high electrical 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 conductive layer 113a and the conductive layer 11 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. Yes.

[0167] In the region where the conductive layer 113a and the conductive layer 116a overlap, functions as a gate wiring, and in a 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 through the glass, 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 makes it possible to shield the gaps between pixels from light without using a black matrix. .

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

[0169] In addition, the 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. By laminating the conductive layer 116b having a higher conductivity than the conductive layer 113b, the resistance can be reduced. (See Figure 1(A)).

[0170] In this embodiment, an example is shown in which the width of the capacitance wiring is the same as that of the gate wiring. 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, the storage capacitor 160 is formed of a conductive layer having light transmission properties. Since light can be transmitted through the portion where the capacitance storage section 160 is formed, the aperture ratio is In addition, by forming the storage capacitor 160 from a light-transmitting material, This allows the storage capacitor 160 to be made larger, so that the transistor is turned off. Even when the pixel electrode is turned on, the potential retention characteristic of the pixel electrode is improved, and the display quality is improved. 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 may 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 is After the formation of the gate electrode and the gate wiring, the semiconductor layer 103a A process for increasing the electrical conductivity of some or all of the regions may be performed. The hydrogenation process is one example of a process 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 A channel protection layer 120a is formed in the region overlapping the formation region, thereby forming a semiconductor layer 10 3a, regions 121a, 121b having selectively enhanced electrical conductivity can be formed.

[0174] The channel protection layer 120a is preferably made of silicon oxide. This can reduce hydrogen from 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 of 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. As a result, the resistance of the capacitance element can be reduced.

[0175] In FIG. 6A, the channel protection layer 120a of the transistor 151 is a 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 be provided thereon. 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 formed.

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

[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 a transistor 152 having regions 121a, 121b with enhanced efficiency. Cut.

[0178] Next, after forming the 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 160, or the surface on which wiring or the like is formed functions as an insulating film for flattening the surface. 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, wiring, etc. can be reduced. Therefore, it is beneficial to have a flat top surface on which these elements are formed.

[0179] The insulating film 117 functions as an insulating film for protecting the transistor 150 from impurities and the like. 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 polyacrylic, polyimide, and polyamide. These organic materials can smooth out uneven surfaces. Therefore, the insulating film 117 is preferably a film having silicon nitride. In the case of forming a laminated structure with a film having an organic material, the film having silicon nitride is placed on the lower side. It is preferable to place an insulating film 117 on the upper side and place a film having an organic material on the upper side. When forming the film in a laminated structure, it is desirable that each film has a sufficiently high light transmittance. In this case, the insulating film 117 is etched, There is no need to form contact holes.

[0180] The insulating film 117 may function as a color filter. By providing a color filter on the opposite substrate, it is not necessary to provide a color filter on the opposite substrate. This eliminates the need for margins to adjust the position 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 gate 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 substantially similar to that of the conductive films 104 and 111. It is desirable to use the same materials. Therefore, when the conductive film 118 is formed by sputtering or vapor deposition, the conductive film 104 and the conductive film 111 The advantage of being able to share materials is that the same manufacturing equipment can be used. This allows the manufacturing process to run smoothly and improves throughput. This makes it possible to reduce costs. The conductive film 104 and the conductive film 111 may be formed using a material different from that of the conductive film 104 .

[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 above 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. , the gate wiring, the gate electrode, the pixel electrode, the capacitance wiring, the 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 preferable 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 that.

[0184] In this manner, the semiconductor device shown in FIGS. The light-transmitting transistor 150 and the light-transmitting storage capacitor Therefore, a transistor and a capacitor element can be arranged in the pixel. Even when the transistor and the capacitor are formed, the light is not transmitted through the area. This allows the aperture ratio to be improved. The wiring that connects the device to another transistor (e.g., another transistor) is made of a material with low resistivity and high conductivity. This reduces the distortion of the signal waveform and reduces the voltage drop caused by 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. Here, overlapping parts will be omitted and only the differences will be explained.

[0186] FIG. 7(A) is a plan view, and FIG. 7(B) is a cross-sectional view taken along line AB in FIG. 7(A). FIG. 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 gate 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 is connected.

[0187] FIG. 8(A) is a plan view, and FIG. 8(B) is a cross-sectional view taken along line AB in FIG. 8(A). FIG. 8(C) is a cross-sectional view taken along line CD in FIG. 8(A). A light-transmitting conductive layer and a light-shielding conductive layer are laminated in this order to form a gate wiring and a source wiring. However, the gate wiring and the source wiring may be formed of a conductive layer having a light-shielding property. A light-transmitting conductive layer 113a serving as a gate electrode and a gate It is only necessary that the conductive layer 116a having a light-shielding property and functioning as a light wiring be connected. A light-transmitting conductive layer 106a serving as a source electrode or a drain electrode and a source It is only necessary that the conductive layer 109a having a light-shielding property and functioning as a line is connected. In the case where a light-shielding conductive layer and a light-transmitting conductive layer are formed in this order, as shown in FIG. In the following description, the gate wiring and the source wiring are formed of a conductive layer having a light-shielding property. However, a light-transmitting conductive layer and a light-shielding 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 width can be made larger than the gate line width. A transistor 153 having a longer channel width W or a longer channel length L By making the transistor larger, the current capacity can be increased sufficiently. This can reduce the time required to write a signal to the pixel. This can reduce flickering and other issues, making it possible to achieve high-definition display devices. Locations can be provided.

[0189] In addition, in the peripheral driving circuits such as the protection circuits, gate drivers, and source drivers, There is no need for light to pass through the transistors and capacitors in the pixel area. The peripheral driver circuit portion is formed of a material having a light-transmitting property. (See FIG. 25(A)).

[0190] FIG. 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 pixel electrode 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 similar to 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 size of the storage capacitor 161, the transistor can be turned off. Even when the pixel electrode is turned on, the potential retention characteristic of the pixel electrode is improved, improving display quality. In addition, when the storage capacitor 161 is formed large, However, light can also pass 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 has a light-shielding property. The light leakage can be prevented by 9b.

[0192] FIG. 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 + Area 1) is provided, and conductive layers 106a and 106b functioning as source and drain electrodes are provided. The figure shows a structure in which 06b is arranged so as not to overlap with the gate electrode. In the semiconductor layer 103a, the conductive layer 106a and the conductive layer 106b may be provided in the 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 so as not to overlap each other.

[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 electrical conductivity of the semiconductor layer 103a. Just add it where you want it.

[0195] In addition, the source electrode and the drain electrode are provided so as not to overlap with the gate electrode. This suppresses the parasitic capacitance generated between the source electrode and the drain electrode and the gate electrode. Therefore, the feedthrough can be reduced.

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

[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 each 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 of a conductive layer having a light-shielding property, and the gate wiring is also formed of 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 Note that the light-transmitting conductive layer that forms the source electrode and the gate electrode may be formed of a conductive layer having a light-transmitting property. A light-shielding conductive layer may be formed in the area overlapping the port wiring. .

[0198] 13A and 14A show an example of a light-emitting display device as an example of a pixel configuration. The pixel shown in FIG. 3(A) has a gate wiring in which a conductive layer 106a and a conductive layer 109a are laminated in this order. The source wiring and the switching transistor are laminated in this order. the capacitor 162; the conductive layer 106d; The pixel shown in FIG. 14A has a power supply line that is laminated in the order of 109c. 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 FIG. 13A and FIG. 14A is a transistor including 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 functioning as electrodes, and a A gate insulating film 110 and conductive layers 106a and 106b are provided on the gate insulating film 110. The conductive layer 113a serving as a gate electrode is provided between the gate electrodes 06c. In addition, the driving transistor 155 and the driving transistor 156 have an insulating surface. A semiconductor layer 103b is provided on a substrate 100, and a source electrode or Conductive layers 106d and 106e functioning as drain electrodes, and A gate insulating film 110 is provided on the gate insulating film 110 and a conductive layer 1 A conductive layer 113c or 1106d or 106e serving as a gate electrode is provided between the gate electrodes 113a and 113b. 13, the storage capacitor 162 is composed of a conductive layer 106e 14, the storage capacitor 164 is composed of the conductive layer 1 06e and the conductive layer 113d.

[0200] As shown in FIG. 13B, when the gate and drain are connected, a contact hole is used. The uppermost ITO is connected via the wires 132 and 133, as shown in FIG. As shown in FIG. 1, the gate and the drain may be directly connected through 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 FIG. 13 and FIG. 14 includes a switching transistor 150 and a driving transistor 151. Although the case where the transistor 155 or 156 is provided has been described, It is also possible to provide three or more transistors in one pixel.

[0202] In this manner, 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 (e.g., , 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 on 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 surrounded by a shape (e.g., 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 is increased. This makes it possible to reduce the size of the region through which carriers move, thereby increasing the area of ​​the region through which carriers move. 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 the present embodiment, a configuration in which a capacitance line is provided has been described. 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 used 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 largely the same as those described above. This is common to form 1. Therefore, in the following, the overlapping parts will be omitted and the differences will be explained. will be explained in detail.

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

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

[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 shown in Embodiment 1. The substrate 100 and the semiconductor layer 103a can be seen. Also, the substrate 20 having an insulating surface An insulating film functioning as a base film may be provided on the insulating film 0.

[0213] Next, a conductive film 204 and a conductive film 205 are formed on the semiconductor layer 203 (FIGS. 17(C) and 17(D)). The materials and manufacturing methods of the conductive films 204 and 205 are described in Embodiment 1. 1 and 2. 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, the photomask to be used can be This is preferable because the number of sheets 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 portion (see FIGS. 19C and 19D), 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 with three levels of light intensity: exposed area, half-exposed area, and unexposed area. A multi-tone mask is used. By this, it is possible to produce a film having multiple (typically two) thicknesses by a single exposure and development process. A resist mask can be formed. Therefore, by using a multi-tone mask, This allows the number of masks to be reduced.

[0216] 22(A-1) and 22(B-1) show cross sections of a typical multi-tone mask. FIG. 22(A-1) shows a graytone mask 403, and FIG. 22(B-1) shows a halftone 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 light-shielding layer pattern. 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. By providing the grating 402 with a groove or mesh, the light transmittance can be controlled. The slits, dots or meshes 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, and 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 following is obtained: As shown in the figure, the light transmittance in the area overlapping the light shielding portion 401 is 0%, and the light shielding portion 401 also has a diffraction 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 about 10% to 70%, and the slits and dots of the diffraction grating This can be adjusted by changing the spacing of the mesh or the like.

[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 from a transparent layer and a light-shielding portion 413 formed from 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 a material similar to the light-shielding layer of a gray-tone mask. It may be formed using a metal film, and is preferably formed using chromium or chromium oxide or the like.

[0223] When the halftone mask 414 is irradiated with light for exposure, the light shown in FIG. 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 depends on 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, an exposed area, an intermediate exposed area, and an unexposed area, are obtained. A light level mask can be formed, and multiple (typically It is possible to form a resist mask having a region of thickness (two types in thickness). 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 semi-transparent layers formed on a light-transmitting substrate 300. The conductive film 205 is made up of layers 301a, 301b and a light-shielding layer 301c. The resist mask on the upper portion that will later become the source wiring is thick, and the The resist mask in the area that will become the doped electrode is formed to be thin (see 17(E) and (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 207a, 208a and the conductive layers 207b, 208b. (See Figures 18(A) and (B)).

[0227] Next, the resist masks 206a and 206b are ashed using 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 photoresist 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. Then, the conductive layer 210a is formed (see FIGS. 18(E) and (F)). After the above etching, The resist mask 209 is removed. As a result, the conductive layer 207b is removed, and the conductive layer 208 is b is exposed. In addition, 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. 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 are overlapped with each other. and regions where conductive layer 210a and 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 of a light-transmitting material. The aperture ratio of the pixel can be improved. The conductive layer 208a and the conductive layer 210a having a higher conductivity than the conductive layer 208a are laminated to form a conductive layer 210a. This reduces the wiring resistance and power consumption. Since the conductive layer 210a is configured to have the above structure, light can be shielded between pixels.

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

[0231] Next, a gate insulating film 211 is formed on the conductive layers 208a and 208b. A conductive film 212 and a conductive film 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 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 the case of the resist mask, the thickness of the resist mask is thick in the area that will later become the gate wiring, and the thickness of the resist mask is thick in the area that will later become the gate electrode. The resist mask in this area is formed to have a small 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 using 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 21 20(C) and (D)). In this way, the multi-tone mask is formed. By using the resist mask, it is possible to eliminate the need for an additional resist mask. Therefore, the process can be simplified.

[0235] Next, the conductive layers 215a and 215b are As a result, the conductive layers 215a and 215b are The resist masks 217a and 217b are removed from the conductive layer 2. 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 above 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 insulating film using a light-transmitting conductive layer, 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 a conductive layer 218a having a higher conductivity than the conductive layer 216a. The resistance can be reduced, and power consumption can be reduced. Since the conductive layer 218a is used, light can be shielded between the 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 a conductive layer 218b having a higher conductivity than the conductive layer 216b. By forming the wiring in this manner, the wiring resistance can be reduced, and power consumption can be reduced. The conductive layer 216b also functions as an electrode of the storage capacitor 260. The portion 260 is 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, the storage capacitor 260 is formed of a conductive layer having light transmission properties. Since light can be transmitted through the portion where the storage capacitor 260 is formed, the aperture ratio is In addition, by forming the storage capacitor 260 from a light-transmitting material, This allows the storage capacitor 260 to be made larger, so that the transistor is turned off. Even when the pixel electrode is turned on, the potential retention characteristic of the pixel electrode is improved, and the display quality is improved. The loop potential can be reduced.

[0239] In this manner, 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 FIG. 21C and FIG. 21D). The conductive layers 221a, 221b, and 221c are pixel electrodes. After the above 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. By a single exposure and development process, it is possible to 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 (e.g., another transistor) within a pixel. The wiring that connects the signal lines can be made of materials 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 circuits, gate drivers, and source drivers, Therefore, the pixel area does not need to have a transistor or a capacitor. The upper part may be made of a light-transmitting material, while the peripheral driving circuitry may be made 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 the formation of 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. Alternatively, the step of forming the semiconductor layer and the step of forming the source wiring may be used. A multi-tone mask can also be used in the process of forming the source wiring. FIG. 23A 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 FIG. 23(B) shows a case where a channel portion is formed on the channel forming region of the semiconductor film. Even if a protective film is formed, a multi-tone mask can be used (FIG. 23(C) 23B and 23C, the semiconductor layer of the transistor 250 and the storage capacitor The oxide semiconductor layer 260 is formed into one island. 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 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 used in appropriate combination with other embodiment modes.

[0248] (Embodiment 3) In this embodiment, in a display device, at least a part of a driver circuit and a pixel An example of manufacturing 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 type liquid crystal display device, which is an example of a display device. The display device shown in FIG. 24A has a pixel structure including 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 signal line driver circuit 5303 for controlling input of a video signal to the pixel.

[0250] The light-emitting display device shown in FIG. 24B 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.

[0251] In the case where 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, the transistor is switched on and off to make it either emitting light or not. 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 changing the time when the pixel emits light. This is a driving method that displays gradations by controlling the period during which the liquid crystal display 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 using the time gray scale method, one frame period is divided into multiple subframe periods. Then, in accordance with the video signal, the light emitting element of the pixel is made to emit light in each sub-frame period. By dividing the period into multiple subframes, one frame can be The total length of time that a pixel emits light during a 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 other switching TFT is generated by the first scanning line driver circuit 5402. A signal input to the second scanning line, which is the gate wiring of the second pixel, is generated by a second scanning line driver circuit 5404. In this example, a signal input to the first scanning line and a signal input to the second scanning line are 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 some cases, each pixel may have a plurality of scanning lines for use in the above-described purpose. The signals input to the scanning lines may all be generated by one scanning line driver circuit, or may be generated by a plurality of scanning line drivers. It may 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 in the first embodiment or the second embodiment. The thin film transistors shown in the first and second embodiments are formed according to the following procedure. Since it is a n-channel TFT, the driver circuit can be configured with n-channel TFTs. A part of the driver circuit that can display the pixel region is formed on the same substrate as the thin film transistor in the pixel portion.

[0255] In addition, in the light-emitting display device, the driver circuit may be configured with n-channel TFTs. 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 of the n-channel TF shown in the first and second embodiments. It is also possible to make it using only T.

[0256] In addition, in the peripheral driving circuits such as the protection circuits, gate drivers, and source drivers, In the case of a transistor, there is no need to transmit light. Therefore, the pixel area does not include transistors and capacitors. In the peripheral driving circuit section, the transistors do not transmit light. It's okay.

[0257] FIG. 25(A) shows a case where a thin film transistor is formed without using a multi-tone mask, and FIG. 25(B) shows a 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 use of a semiconductor layer is formed on a substrate 100 having an insulating surface. A semiconductor layer 171 and a gate electrode functioning as a source electrode or a drain electrode provided on the semiconductor layer 171. A conductive layer 172 is 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 which 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. A semiconductor layer 271 and a source electrode or a drain electrode provided on the semiconductor layer 271 Conductive layers 272 and 273 functioning as electrodes, a gate insulating film provided on the conductive layer 273, The gate insulating film is provided with conductive layers 275 and 276 that function as gate electrodes. 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 together (see FIG. 25B). In addition, an insulating film 277 is formed on the conductive layers 275 and 276 that function as gate electrodes. .

[0259] In the peripheral driving circuits such as protection circuits, gate drivers, and source drivers, 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 devices with switching elements and It may also be used in electronic paper, where electrically connected elements are used to drive electronic ink. Electronic paper includes electrophoretic displays (electrophoretic displays) and other types of displays that have the same reading quality as paper. It is easy to use, consumes less power than other display devices, and is thin and lightweight. It is Noh.

[0261] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiments. It is.

[0262] (Embodiment 4) Next, a structure of a display device, which is one embodiment of a semiconductor device, will be described. The display device is a light-emitting display device having a light-emitting element that utilizes electroluminescence. The light-emitting element that utilizes electroluminescence is an organic compound that is used as a light-emitting material. Generally, the former are organic EL elements, the latter are inorganic compounds. 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 layers containing light-emitting organic compounds, causing a current to flow. The rears (electrons and holes) recombine to form an excited state in the light-emitting organic compound. When the excited state returns to the ground state, light is emitted. Such a light-emitting element is called a current-excitation type light-emitting element.

[0264] Inorganic EL elements are divided into dispersion-type inorganic EL elements and thin-film-type inorganic EL elements according to their 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 reaction that utilizes the donor and acceptor levels. Thin-film inorganic EL elements are made by sandwiching a light-emitting layer between dielectric layers. The 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 using a conductor layer as the channel formation region are used in one pixel. Here is an example.

[0266] A pixel 6400 shown in FIG. 26A includes a switching transistor 6401, a driving transistor The switching element 6402 includes 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 (the source electrode and The second electrode (the source electrode and the drain electrode) is connected to a signal line 6405, and the second electrode (the source electrode and the drain electrode) is connected to a signal line 6405. 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 a common electrode 6408.

[0267] A low power supply potential is set to the second electrode (common electrode 6408) of the light emitting element 6404. Note that 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. 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 6403 is omitted by substituting the gate capacitance of the driving transistor 6402. It is also possible to set the gate capacitance of the driving transistor 6402 as follows: A capacitance may be formed between the gate electrode and the second electrode.

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

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

[0271] In the case of performing analog gradation driving, a light emitting element 6404 is connected to the gate of a driving transistor 6402. A voltage equal to or higher than the forward voltage of the light emitting element 6401 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 should be at least 100% forward voltage. In addition, the video 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 gate potential of the light emitting element 6402 is set higher than that of the gate of the transistor 6403. Analog gradation drive can be performed by passing a current corresponding to a video signal through 6404.

[0272] Note 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 added to the pixel. For example, the configuration shown in FIG. 26(B) may be used. 10, a switching transistor 6401, a driving transistor 6402, a light emitting element The switching transistor 6401 has a gate The first electrode (one of the source electrode and the drain electrode) is connected to a signal line 6406. 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 gate of the driving transistor 6402. The first electrode (pixel electrode) of the light-emitting element 6404 is connected to the first electrode (pixel electrode) of the light-emitting element 6404 through the capacitor element 6403. 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 described with reference to FIG. 27(A), FIG. 27(B), and FIG. 27(C). Here, the case where the driving TFT is a transistor 150 shown in FIG. The cross-sectional structure of the pixel will now be described. The driving TFTs TFT7001, 7011, and 7021 used in the device are The transistor can be manufactured in a similar manner to that 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 side emission. There are light-emitting elements with a double-sided emission structure in which light is emitted from the side of the pixel. The present invention can also be applied to a light emitting element having an injection structure.

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

[0276] In FIG. 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 pixel cross section is FIG. 27A shows a cathode 7003 of a light-emitting element 7002 and a driving TFT. The TFT 7001 is electrically connected, and the light-emitting layer 7004 is disposed on the cathode 7003, and the anode 70 The cathode 7003 is a conductive material with a small work function and a light reflecting property. 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), Conductive materials with translucency such as indium zinc oxide and indium tin oxide doped with silicon oxide A conductive film may be used.

[0277] The region where the light-emitting layer 7004 is sandwiched between the cathode 7003 and the anode 7005 constitutes 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 indicated 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 the process can be simplified. For example, SiNx and SiOx are hygroscopic, so they 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), it is possible to improve color purity.

[0279] Next, a light emitting element having a bottom emission structure will be described with reference to FIG. The driving TFT 7011 is the transistor 150 shown in FIG. FIG. 27(B) shows a cross-sectional view of a pixel in the case where light emitted from the cathode 7013 is emitted to the cathode 7013 side. Then, on a conductive layer 7017 having a light transmitting property and electrically connected to a driving TFT 7011, A cathode 7013 of the light emitting element 7012 is formed, and 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 so as to cover the above. The cathode 7013 may be made of any conductive material having a small work function, as in the case of FIG. 27(A). Various materials can be used. However, the thickness of the film must be such that it transmits light (preferably, For example, an aluminum film having a thickness of 20 nm is used as the cathode. The light-emitting layer 7014 can be used as the light-emitting layer 7013 in the same manner as 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 may have light-transmitting properties as in FIG. The shielding film 7016 can be formed of a conductive material that can be used for the light. A metal that reflects light can be used, but is not limited to a metal film. For example, a black pigment can be used. Additives such as resins can also be used.

[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. 27B, 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] In addition, 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 having a dual emission structure will be described with reference to FIG. Then, on a conductive layer 7027 having a light transmitting property and electrically connected to a driving TFT 7021, A cathode 7023 of the light-emitting element 7022 is formed, and a light-emitting layer 7024 is formed on the cathode 7023. The anode 7025 is laminated in order. The cathode 7023 is, as in the case of FIG. Various conductive materials with small thermal coefficients can be used. However, the thickness of the material should be For example, the cathode 7023 is made of Al having a thickness of 20 nm. The light-emitting layer 7024 can be formed of a single layer, as in FIG. The anode 70 may be configured as a single layer or as a laminate of multiple layers. 25 can be formed using a conductive material having light transmitting properties, similarly to FIG. do.

[0283] The overlapping portion of the cathode 7023, the light-emitting layer 7024, and the anode 7025 constitutes the light-emitting element 70. In the case of the pixel shown in FIG. 27C, the light emitted from the light emitting element 7022 is is emitted toward both the anode 7025 side and the cathode 7023 side as indicated 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, stacking the layers reduces wiring resistance, which is preferable. I wish.

[0285] Although the organic EL element has been described as the light-emitting element here, inorganic EL elements can also be used as the light-emitting element. 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 In the above example, the driving TFT and the light-emitting element are electrically connected. A current-controlling TFT may be connected.

[0287] The semiconductor device shown in this embodiment mode is shown in FIG. The present invention is not limited to the configuration shown, and various modifications based on the disclosed technical concept are possible. be.

[0288] Next, a top surface of a light-emitting display panel (also called a light-emitting panel) which corresponds to one embodiment of a semiconductor device and The cross section will be described with reference to Fig. 28(A) and Fig. 28(B). Fig. 28(A) shows the first The thin film transistor and the light emitting element formed on the substrate are sandwiched between the substrate and the second substrate by a sealant. FIG. 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. A sealant 4505 is formed to surround the gate 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 sealant 4505, and a second substrate 4506. The filling material 4507 is sealed with the sealing material 4507. Highly sealed protective film with little outgassing (lamination film, UV curable resin film) It is preferable to package (enclose) the package in a material such as a film or a cover material.

[0290] In addition, a pixel portion 4502, a signal line driver circuit 4503a, The scanning line driver circuits 4503a and 4504b each 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 a signal line driver circuit 4503a is illustrated. 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 circuits, gate drivers, and source drivers, There is no need to transmit light through the transistor portion. The capacitors and capacitor elements are formed from a material having light-transmitting properties, and the peripheral driver circuit portion is formed from a material having light-shielding properties. The material may be formed.

[0292] In addition, 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 as a first electrode layer 4517, an electric field generating layer 4518, and a second electrode layer 4519. The laminated structure of the light emitting layer 4512 and the second electrode layer 4513 is the same as that shown in this embodiment. The light emitting element 4511 may be arranged in accordance with the direction of the light to be extracted from the light emitting element 4511. The configuration of 1 can be changed as appropriate.

[0293] The partition 4520 is formed using an organic resin film, an inorganic insulating film, or an 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 that the inclined surface is formed so as to have a continuous curvature.

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

[0295] In order to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4511, the second electrode layer 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 oxide nitride 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 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. The electrodes are electrically connected to each other.

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

[0300] In addition, filler 4507 can be inert gas such as nitrogen or argon, or ultraviolet-curing resin. It can be made of oil or thermosetting resin, and can be made of 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, the polarizing plate or the circular polarizing plate may be provided with an anti-reflection film. 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 film or a polycrystalline semiconductor film is formed on a separately prepared single crystal semiconductor substrate or an insulating substrate. Alternatively, the signal line driver circuit may be implemented as a driver 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 formed separately 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 in appropriate combination with the configurations described in other embodiments. It 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 as a display device will be described.

[0306] First, the top and cross-sectional views of a liquid crystal display panel (also called a liquid crystal panel), which is one form of liquid crystal display device, will be described. The surface will be described with reference to Figs. 29(A1), 29(A2), and 29(B). 29(A1) and 29(A2) show the structure of the first and second embodiments formed on a first substrate 4001. Thin film transistors 4010 and 4011 each including a semiconductor layer made of an oxide semiconductor, and a liquid crystal display The element 4013 is sealed between the second substrate 4006 and the panel 4007 by a sealant 4005. FIG. 29(B) is a top view of the MN in FIG. 29(A1) and FIG. 29(A2). 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 manner, a sealant 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 sealant 4005, and a second substrate 4006. The liquid crystal layer 4008 is sealed together with the first substrate 4001. 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, A wire bonding method, a TAB method, or the like can be used. FIG. 29(A2) shows an example of mounting a signal line driver circuit 4003 by the COG method. 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. In FIG. 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 include 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 circuits, gate drivers, and source drivers, There is no need to transmit light through the transistor portion. 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. The material may be formed.

[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 connected to the second substrate 400. 6. 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 arranged corresponds to the liquid crystal element 4013. 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 rest transmits light. Since the pixel electrodes can be spaced apart from each other, the aperture ratio can be improved. A gap is necessary, and no electric field is applied to the liquid crystal in the gap. Therefore, the grid-like wiring 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 Alternatively, you can use aluminum foil with a PVF film or polyester film. A sheet having a structure sandwiched between films can also be used.

[0314] Also, 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. Using the common connection portion, the counter electrode layer 403 is connected to the 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 it is necessary to improve the temperature range. 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. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a response speed of 10 μs to It is short at 100μs, has optical isotropy so no alignment treatment is required, and has small viewing angle dependency. stomach.

[0316] Note that the liquid crystal display device shown in this embodiment is an example of a transmissive liquid crystal display device, but 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 shown in this embodiment mode, a polarizing plate is provided on the outer side (the viewing side) of the substrate, and In the example shown in FIG. 1, a color layer and an electrode layer for a display element are provided in that order. The laminated structure of the polarizing plate and the colored layer is not limited to the 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 transistor, the thin film transistor obtained in the first and second embodiments is protected. The insulating layer 402 is covered with an insulating layer 4021 which functions as a planarizing insulating film. The protective film 1 can be formed in a one-layer structure or a laminated structure of two or more layers. It is designed to prevent the intrusion of contaminating 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 multilayer of an aluminum nitride film or an aluminum nitride oxide film. In this embodiment, the protective film is formed by a sputtering method. 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, for example, a sputtering method. When a silicon oxide film is used as the protective film, the a It is effective in preventing hillocks in aluminum films.

[0320] In addition, a silicon nitride film is formed as the second layer of the protective film by using, for example, a sputtering method. When a silicon nitride film is used as a protective film, mobile ions such as sodium ions 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] In addition, 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 be used. , siloxane resin, PSG (phosphorus glass), BPSG (borophosphorus glass), etc. are used. In addition, by stacking a plurality of insulating films made of these materials, an insulating layer can be formed. 4021 may be formed.

[0323] Siloxane-based resin is a type of Si-OS formed using siloxane-based materials as starting materials. The siloxane resin corresponds to a resin containing an i bond. Alternatively, the organic group may have a fluoro group. 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 during the baking process. 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 will be 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), Conductive materials with translucency 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 10,000 Ω / □ or less and a light transmittance of 550 nm. It is preferable that the sheet resistance is lower. It is preferable that the resistivity of the conductive polymer contained in the conductive composition is 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 are applied to 002 via 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 a terminal of the FPC 4018 via an anisotropic conductive film 4019. The electrodes are electrically connected to each other.

[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, the present 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 driver circuit may be formed separately 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 2602 is fixed to the substrate 2601 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 2601 and the substrate 2602. A display element 2604, a colored layer 2605, and a polarizing plate 2606 are provided to form a display area. The color layer 2605 is necessary for color display. In the case of the RGB method, it is red, green, A colored layer corresponding to each color of blue and blue is provided for each pixel. A polarizing plate 2606, a polarizing plate 2607, and a diffusion plate 2613 are disposed on the outer side of the optical substrate 2601. The light source is composed of a cold cathode fluorescent lamp 2610 and a reflector 2611. The circuit board 2612 is , and is connected to a wiring circuit section 2608 of the TFT substrate 2600 via a flexible wiring substrate 2609. It also includes 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 uid Crystal) mode, AFLC(AntiFerroelectric L iquid Crystal) can be used.

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

[0336] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiments. It is.

[0337] (Embodiment 6) Next, electronic paper, which is one type of semiconductor device, will be described. 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 type 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 area, and is a thin-film transistor that contains 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 isbball display method uses black and white spherical particles as the display element for the electrode layer. and a second electrode layer is disposed between the first electrode layer and the second electrode layer. This is a method of displaying information by creating a potential difference to control the orientation of spherical particles.

[0340] A thin film transistor 581 provided on a substrate 580 is a thin film transistor having 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 to each other. Between the second electrode layer 588 and the black area 590a and the white area 590b, A spherical particle 589 is provided that includes a cavity 594 therein that is filled with a liquid, The surroundings of the shaped particle 589 are 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 with the opposite polarity to the white particles. The first electrode layer is a microcapsule having a diameter of about 10 μm to 200 μm. The microcapsules provided between the first electrode layer and the second electrode layer are Therefore, when an electric field is applied, the white particles and the black particles move in opposite directions, resulting in a white or Black can be displayed. The display element that applies this principle is the electrophoretic display element. Since electrophoretic display elements have a higher reflectivity than liquid crystal elements, 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., the source of radio waves), the display It is possible to store the captured image.

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

[0343] This embodiment mode can be implemented in appropriate combination with the configurations described in other embodiments. It 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); Examples include game machines, mobile information terminals, audio playback devices, and large game machines such as pachinko machines. do.

[0345] FIG. 32A 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 operations. Such a portable information terminal device 9200 includes a PDA (Personal Digital Audio Player). 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 connected to each other at a connecting portion 9207 so as to be foldable. 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, Other auxiliary equipment may be provided as appropriate. By forming a circuit and a pixel section, manufacturing costs are reduced, and thin-film transistors with high electrical characteristics 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 Mela 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. Any other configuration may be used as long as it includes the thin film transistor described in the first or second embodiment. The driving circuit and the pixel section are formed on the same substrate. This reduces manufacturing costs and enables the development of digital devices having thin film transistors with excellent electrical characteristics. This makes it possible to realize a single-lens video camera.

[0348] FIG. 32C shows an example of a mobile phone 9100. The mobile phone 9100 has a housing It is composed of two housings, 9104 and housing 9101, and is foldable by the connecting part 9103. The display unit 9102 is incorporated in the housing 9104. The body 9101 is provided with an operation key 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 section on the same substrate, manufacturing costs are reduced, and a thin film transistor with high electrical properties is used. It is possible to realize a mobile phone having a transistor.

[0349] FIG. 32D shows an example of a portable computer 9800. The electronic device 800 includes a housing 9801 and a housing 9804 that are connected in an openable and closable manner. The display unit 9802 is incorporated in the display unit 9804, and the housing 9801 is equipped with a keyboard 9803, etc. The configuration of the computer 9800 is not particularly limited, and may be at least as described in the first embodiment or As long as the device is equipped with the thin film transistor described in 2, other auxiliary equipment may be provided as appropriate. The manufacturing process can be carried out by forming the driver circuit and the pixel section on the same substrate. This allows for the realization of computers with thin-film transistors that are less expensive and have better electrical properties. .

[0350] FIG. 33A shows an example of a television device 9600. The display unit 9603 is incorporated in the housing 9601. In addition, the stand 9605 supports the housing 9601. 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 display 9603 shows In addition, the remote control unit 9610 can control the video. A display portion 9607 for displaying information output from 9610 may be provided.

[0352] The television device 9600 includes a receiver and a modem. It can receive more general television broadcasts, and can also be connected to a modem via wired or wireless connection. By connecting to a network, communication 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. 33B shows an example of a digital photo frame 9700. The photo frame 9700 includes a display unit 9703 built into a housing 9701. The unit 9703 is capable of displaying various images, for example images captured by a digital camera. By displaying the image data, it can function like a normal photo frame.

[0354] The Digital Photo Frame 9700 is equipped with an operation unit, 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, etc. These components may be installed on the same surface as the display unit, but they may be installed on the side or back. It is preferable to have a digital photo frame with a built-in memory card because it improves the design. A memory that stores image data taken with a digital camera is inserted into the body insertion section. The captured image data can be displayed on the display portion 9703 .

[0355] The digital photo frame 9700 may also be configured to transmit and receive information wirelessly. It is also possible to wirelessly import and display desired image data.

[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 A button 1003, an external connection port 1004, a speaker 1005, a microphone 1006, etc. It is prepared.

[0357] The mobile phone 1000 shown in FIG. 34A 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 e-mail can be performed by 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 is mainly used for displaying images. The first mode is a display mode, the second is an input mode for inputting information such as characters, and the third mode is a display mode. This is a display + input mode that combines the display mode and the input mode.

[0359] For example, when making a call or composing an e-mail, the display unit 1002 is used for inputting characters. The main character input mode is to 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, a sensor for detecting tilt, such as a gyro or an acceleration sensor, is installed inside the mobile phone 1000. 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 changed 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, the image signal to be displayed on the display unit is a moving image. If it is data, the mode is switched to display mode, and if it is text data, the mode is switched to input mode.

[0362] In the input mode, the optical sensor of the display unit 1002 detects a signal and displays 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 image 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 and 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 the two directions 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, and the display device The communication device 9400 and the display device 9410 may be used alone. Images or input information can be sent and received via wireless or wired communication, and each can be recharged with a rechargeable battery. Has Terry.

[0365] (Embodiment 8) In this embodiment, a pixel configuration and pixel operation applicable to a liquid crystal display device will be described. In the present embodiment, the liquid crystal element is operated in a Twist (TN) mode. ed Nematic mode, IPS (In-Plane-Switching) mode FFS (Fringe Field Switching) mode, MVA (Multi-Voltage Auto-Voltage ti-domain Vertical Alignment) mode, PVA(Pat terned Vertical Alignment) mode, ASM (Axiall y Symmetric aligned Micro-cell) mode, OCB(O (Fptically Compensated Birefringence) mode, 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 circuit 5080 includes a transistor 5081, a liquid crystal element 5082, and a capacitor element 5083. The gate of the transistor 5081 is electrically connected to the wiring 5085. The first terminal of the transistor 5081 is electrically connected to the 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 a 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 the is the source.

[0367] The wiring 5084 can function as a signal line. The signal line is input from the outside of 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 for continuously adding to the capacitor 082. The counter electrode can be used to apply a predetermined voltage to the second terminal of the liquid crystal element 5082. However, 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 the transistor 5081 only needs to function as a P-channel type, the polarity of the transistor 5081 may be a P-channel type. Alternatively, the transistor may be of 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) in which the wiring 5087 is omitted. The second terminal of the liquid crystal element 5082 and the second terminal of the capacitance 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 lateral 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 adopting such a pixel configuration, the wiring 5087 can be omitted, and the manufacturing process can be simplified. This allows the manufacturing cost to be reduced.

[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. 37C shows a pixel arrangement in which a plurality of pixel configurations shown in FIG. 37A are arranged in a matrix. The circuit configuration shown in FIG. 37(C) is a diagram showing a circuit configuration in the case where the display unit has The figure shows four pixels extracted from the multiple pixels. The pixel located at the position (j is a natural number) is represented as pixel 5080_i,j. The wiring 5084_i, the wiring 5085_j, and the wiring 5086_j are electrically connected to Similarly, for the pixel 5080_i+1,j, a wiring 5084_i+1, a wiring 5085_j is electrically connected to the wiring 5086_j. For +1, wire 5084_i, wire 5085_j+1, wire 5086_j+1 and Similarly, for the pixel 5080_i+1, j+1, a wiring 5084_ i+1, a wiring 5085_j+1, and a wiring 5086_j+1. A wiring can be shared by multiple pixels in 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 may 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 flow driving, which prevents deterioration of the liquid crystal element (burn-in). FIG. 37(D) shows a case where dot inversion driving, which is one of the AC driving methods, is used. When the pixel configuration shown in FIG. 37(C) is used, the timing of the voltage applied to each wiring is FIG. 1 is a diagram showing a pixel timing chart of a pixel in which dot inversion driving is performed and AC driving is performed. This can suppress the flicker that is visible when a light source is turned on.

[0371] In the pixel configuration shown in FIG. 37C, The switch in is in the selected state (on state) during the j-th gate selection period in one frame period. In the other period, it is in the non-selected state (off state). After the j+1-th gate selection period, the j+1-th gate selection period is provided. In this manner, 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 the voltage is low (low level) to deselect the switch. Note that this is the case when the transistors in each pixel are N-channel type, and not P-channel type. When a N-channel transistor is used, the relationship between the voltage and the 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, A positive signal voltage is applied to 084_i+1. After that, each signal line is In each selection period, a signal with the polarity inverted is added alternately. 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 pixel 5080_i, j+1, and a positive signal voltage is applied to pixel 5080_i+1, j+1. In the k+1-th frame, the signal voltages are added as follows: In each pixel, a signal voltage of the opposite polarity to the signal voltage written in the kth 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 having a specific polarity is applied to each pixel, and a signal voltage The dot inversion driving method inverts the polarity of the liquid crystal. 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 wiring 5086 can be a constant voltage. The signal voltage in the 5084 timing chart is only indicated as polarity. can have various signal voltage values ​​in the polarity shown. The polarity is inverted for every pixel. However, the present invention is not limited to this. For example, the polarity may be inverted for every multiple pixels. For example, the polarity of the signal voltage written every two gate selection periods can be inverted. By inverting 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. It is also possible to invert the polarity (gate line inversion).

[0373] In addition, the second terminal of the capacitor 5083 in the pixel 5080 is A constant voltage is sufficient. Here, the voltage applied to the wiring 5085 used as the scanning line is 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 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 to the 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 manner, the second terminal of the capacitance element 5083 in the pixel 5080 and 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. The same movement method can be used.

[0374] The capacitor 5083 and the wiring electrically connected to the second terminal of the capacitor 5083 are By using this, the voltage applied to the wiring 5084 used as a signal line can be reduced. The pixel configuration and driving method in this case will be described with reference to FIG. 37(F) and FIG. 37(G). The pixel configuration shown in FIG. 37(F) has a wiring 5 compared to the pixel configuration shown in FIG. 086 is provided for each pixel column, and the second The feature of this type 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. , j, the second terminal of the capacitance element 5083 is electrically connected to the wiring 5086-1_j. The second terminal of the capacitance element 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 element 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. 37G, in the k-th frame, pixel 5080_i, When a positive signal voltage is written to j, the wiring 5086-1_j is the jth gate selection During the jth gate selection period, the signal is kept at a low level, and after the jth gate selection period ends, the signal is changed to a high level. Then, it maintains the high level for one frame period, and in the k+1th frame In the jth gate selection period, a signal voltage of negative polarity is written, and then 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, This allows the voltage written to the pixel to be changed in the positive direction by a specified amount. This reduces the power consumption required for signal writing. 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 capacitance element 5083 is electrically connected to the By changing the voltage of the wiring connected to the liquid crystal display in the negative direction, the voltage applied to the liquid crystal element is Since the voltage can be changed by a given amount in the negative direction, the pixel The signal voltage to be written can be made small. 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 positive polarity 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 one 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 In the case of a driving method in which pixels to which light is written appear every two pixels, the wiring 5086-1 and Accordingly, the electrical connection of the wiring 5086-2 is also performed alternately every two pixels. It is preferable that the signal voltage of the same polarity is written to all pixels in one row (gain In this case, one wiring 5086 may be provided per row. That is, even in the pixel configuration shown in FIG. 37(C), the same applies when FIGS. 37(F) and 37(G) are used. 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) type, typically represented by MVA mode or PVA mode. A pixel configuration and a driving method thereof that are particularly preferable in the VA mode will be described. This LCD has many advantages, such as no rubbing process required during manufacturing, little light leakage during black display, and low driving voltage. However, the image quality deteriorates when the screen is viewed at an angle (the viewing angle is narrow). In order to widen the viewing angle in the VA mode, the following problems are solved: 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 in which the subpixels are two (subpixel 5080-1 and subpixel 5080-2). 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. In this case, all the sub-pixels are shown in FIG. The circuit configuration of the first subpixel 5080-1 is the same as that shown in FIG. A transistor 5081-1, a liquid crystal element 5082-1, and a capacitor element 5083-1 The connections of each are based on the circuit configuration shown in FIG. The second subpixel 5080-2 includes a transistor 5081-2, a liquid crystal element 5082-2, and a capacitor The circuit configuration shown in FIG. 37A is that the elements 5083-2 are included, and the connections are as shown in FIG. shall be governed by the same.

[0377] The pixel configuration shown in FIG. 38(A) is used as a scanning line for two sub-pixels that make up one pixel. The two wirings 5085 (wiring 5085-1 and wiring 5085-2) are used as signal lines. The wiring 5084 is used as a capacitor line, and the wiring 5086 is used as a capacitor line. In this way, the signal line and the capacitance line are shared by 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 liquid crystal panel and the driver 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 divided into two sub-pixels. By sharing the same pixel, the aperture ratio can be improved and the total number of scanning lines can be reduced. This allows the gate line selection period to be sufficiently long even in high-resolution LCD panels. It is possible to lengthen the length so that an appropriate signal voltage can 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 diagrammatically in terms of 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 second pixel 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 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 the second embodiment, the connection relationship between the pixel electrode and the transistor is reversed. That is, 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 drain of the transistor 5081-1. It is assumed that they are 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 FIG. 39(A) and FIG. 39(B). The pixel configuration shown in FIG. 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 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 A positive signal voltage 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 A signal voltage of negative polarity is written to the pixel electrode. In the (k+1)th frame, In this way, 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 value can be set for the entire period, the power consumption required for writing the signal voltage to the pixel can be reduced. The force required for the wiring 5086_j and the wiring 5086_j+1 can be significantly reduced. The voltage applied to all wirings 5086 including the wiring 5085 can be a constant voltage.

[0380] Furthermore, by using the pixel configuration and the driving method thereof 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 sub-pixels of the pixel are different for each sub-pixel. That is, the pixel configuration and the driving method thereof shown in FIG. 39(C) and FIG. 39(D) are used. Therefore, for sub-pixels to which the same polarity is written in the same frame, the capacitance Sub-pixels that share a common line and have different polarities written in the same frame are Then, when writing to each row is completed, The voltage of the positive polarity signal voltage is written to the subpixel in the positive direction, and the voltage of the negative polarity signal voltage is written to the In the subpixel where a signal voltage is written, the signal voltage written to the pixel is changed in the negative direction. Specifically, the wiring 5086 used as the capacitance line is arranged in each row. The first pixel of pixel 5080_i,j is connected to two lines (line 5086-1 and line 5086-2). The electrode and the wiring 5086-1_j are electrically connected through a capacitor. 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 capacitive 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 via a capacitance element. The pixel electrode and the wiring 5086-2_j+1 are electrically connected via a capacitance element. 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 is 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 through a capacitance element. However, this is just an example. For example, if a pixel to which a signal voltage of positive polarity is written and a pixel to which a signal voltage of negative polarity is written are In the case of a driving method in which a pixel to which a signal voltage of the same polarity is written appears every two pixels, wiring 5 The electrical connections of the wiring 5086-1 and wiring 5086-2 are also made alternately every two pixels. Moreover, 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. That is, even in the pixel configuration shown in FIG. 39(A), As explained with reference to 39(D), a driving method for reducing the signal voltage written to the pixel is used. There can be.

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

[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 when pressure is applied continuously, it may take more than one frame period for the response to complete. Even if moving images are displayed on such a display device, they cannot be reproduced faithfully. 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 subframe period) is divided by the number of scanning lines. The time it takes for the liquid crystal element to respond is only one scan line selection period. 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 dielectric constant of the liquid crystal element changes when no charge is exchanged with the outside (constant charge state). In other words, in the equation (charge) = (capacity) · (voltage), the charge is in a constant state. Since the capacitance changes depending on the voltage applied to the liquid crystal element, the voltage applied to the liquid crystal element changes according to the response of the liquid crystal element. Therefore, the voltage at the time of signal writing changes. When driving a liquid crystal element with a slow luminance response using an active matrix, In principle, the voltage cannot reach the voltage at the time of signal writing.

[0383] The display device of the present 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 pre-compensated (compensation signal). Furthermore, the response time of the liquid crystal element increases as the signal level increases. The larger the response time, the shorter the response time of the liquid crystal element. This driving method of adding a correction signal is also called overdrive. In the overdrive of the present embodiment, the signal writing period is input to the display device. The period of the 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 made to have the desired brightness within the signal writing period. The signal writing period is equal to or shorter than the input image signal period T in In the case where For example, an original image is divided into multiple sub-images, and the multiple sub-images are arranged in a single frame. For example, the images may be displayed sequentially within a certain period of time.

[0384] Next, a method for correcting a signal level when writing a signal in an active matrix display device is described. An example of the method will be described with reference to Figures 40(A) and (B). The horizontal axis is time and the vertical axis is the signal level at the time of signal writing. FIG. 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, and the change in the display level of one display element over time. 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. In the present embodiment, the overdrive is also applicable when the display level is transparent. This also includes cases other than transmittance (brightness, current, etc.). Normally black type (e.g. VA mode, IPS mode, etc.) and normally black type (e.g. 0V, 100V, 200V, 500V, 1000V, 1000V, 20 ...2000V, 2000V, 2000V, 2000V, There are normally white types (e.g. TN mode, OCB mode, etc.) that sometimes display white. However, the graph in Figure 40(B) corresponds to both, and in the case of normally black type The transmittance increases toward the top of the graph. The transmittance may be increased toward the bottom of the plate. 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 hold 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 can 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 In addition, the broken line 5101 in FIG. 40(A) indicates the overdrive. The solid line 5102 represents the change over time of the voltage applied to the liquid crystal element when the liquid crystal element is not turned on. This shows the change in voltage over time applied to the liquid crystal element when overdriving is performed in the same manner. Similarly, the dashed line 5103 in FIG. 40(B) represents the liquid crystal element when overdrive is not performed. The solid line 5104 represents the time change in transmittance when overdrive is performed in this embodiment. The graph shows the change in the transmittance of the liquid crystal element over time when the hold period Fi At the end of , the desired transmittance T i The difference between the measured transmittance and the actual transmittance is called the error α i It will be written as follows.

[0385] In the graph shown in FIG. 40A, during the retention period F0, the dashed line 5101 and the solid line 510 The desired voltage V0 is applied to both of them, and the dashed line in the graph shown in FIG. It is assumed that the desired transmittance T0 is obtained for both 5103 and solid line 5104. If overdrive is not performed, as shown by the dashed line 5101, The desired voltage V1 is applied to the liquid crystal element during the period in which the signal is written, as described above. 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 liquid crystal element is gradually charged 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 so that the voltage V1 is 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, In anticipation of the gradual change in the voltage applied to the liquid crystal element, at the end of the hold period F2, 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 can be 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 tail. Note that, as in the hold period F1, V 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 It is preferable to correct the hold period F2 as follows. i V i-1 Compared to If the voltage becomes smaller, 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 characteristic of the liquid crystal element in advance. The method of implementing it in the device is to formulate a correction formula and The correction values ​​are stored in memory as a look-up table. , a method of reading out a correction value as necessary, etc. can be used.

[0386] When the overdrive in this embodiment is actually realized as a device, There are various constraints. For example, voltage compensation must be performed within the rated voltage range of the source driver. That is, the desired voltage must be large to begin with, and the ideal correction voltage must be If the voltage exceeds the rated voltage of the source driver, the correction cannot be performed. The problems in such a case will be described 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 the FIG. 40(D) ​​is a graph showing a schematic diagram of the change in voltage over time as a solid line 5105. As in FIG. 40B, the horizontal axis is time and the vertical axis is transmittance. This is a graph in which the change in transmittance over time is shown as a solid line 5106. The notation method is the same as that 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' = V1 must be set. This indicates that the correction is insufficient. The transmittance obtained by the measurement is a value that differs from the desired transmittance T1 by an error α1. Since α1 is large only when the desired voltage is originally large, the error α1 In many cases, the degradation of image quality caused by the occurrence of the error α1 is 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 is significantly degraded. 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 ´ exceeds the rated voltage of the source driver Period F i The error at the end of i Estimate the error α i Considering the size of F i+1 This allows the correction voltage at i It has become bigger. However, the error α i+1 This minimizes the impact on In the overdrive of the present 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) further shows the correction voltage V2' of the graph shown in FIG. 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 according to 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 as shown in the graph in FIG. In the solid line 5108 in Fig. 1, the correction voltage V2´´ is adjusted taking into account the error α1. Overcorrection is suppressed and the error α2 is minimized. The specific correction value is subject to change without notice. This can be derived by measuring the response characteristics of the liquid crystal element. The method is to formulate the correction formula and incorporate it into the logic circuit, or to use the correction value as a lookup table. The correction values ​​can be read out as necessary, 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 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] In addition, the error α i The shorter the signal writing period, the larger the The response time of the element must also be shortened, which requires a larger compensation voltage. Furthermore, the required correction voltage becomes larger, and as a result, the correction voltage is The frequency of exceeding the rated voltage of the i The frequency of occurrence is also high. Therefore, the overdrive in this embodiment is effective when the signal write period is short. Specifically, we divide an original image into multiple sub-images and When the plurality of sub-images are displayed in sequence within one frame period, the image is A motion of the plurality of images is detected, and an intermediate image of the plurality of images is generated. When inserting and driving (so-called motion compensation double speed drive), or when combining these When the driving method such as the above is performed, the overdrive of this embodiment is used. That will have a tremendous 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, even in this case, the holding period F i At the end of The error α i Estimate the error α i Considering the size of the retention 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 it is possible to apply a large voltage (negative voltage), 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 voltage applied to the liquid crystal element is the desired voltage V i It can be adjusted to a voltage close to do.

[0389] In order 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, a so-called inversion drive can be implemented in combination with an overdrive. That is, the overdrive in this embodiment includes a 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 Reverse polarity if the and the input image signal period T in If the polarity of the signal is about the same, the writing of a positive signal and the writing of a negative signal The writing of the positive signal is alternated every two times. By making the period of charge and discharge longer than the signal writing period, the frequency of charging and discharging the pixels can be reduced. This reduces power consumption. However, if the polarity reversal period is too long, the polarity difference The difference in brightness caused by the polarity of the input signal may be perceived as flicker. The period for which the signal is input is 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 A display device generates an image based on an input image, and compares the generated image with the input image. The method of displaying the generated image by sequentially adding the motion of the input image will be described. By making the image appear to move in a certain direction, the movement of the video can be made smoother. This improves the problem of image retention and other issues that cause video quality to decrease due to video compensation. The display of moving images ideally requires 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 number of paths becomes huge, the wiring space becomes an issue, and the amount of input image data becomes huge. 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 / 60th of a second, and the PAL standard is 1 Even with this period, the impulse type display device, the CRT, is not affected by the movement. However, there were no problems with the image display. If a video conforming to the above is displayed as is, the display may be blurred due to afterimages caused by the hold type. This causes a problem called hold blur. Blurring occurs when the human eye compensates for unconscious movements and the display does not match the hold type. Since it is recognized by discrepancy, the input image signal is smaller than that of the conventional standard. This can be reduced by shortening the signal cycle (approaching real-time individual control of pixels). However, shortening the input image signal period 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, the hold function can be used 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 an input image is called video interpolation.

[0391] The moving image interpolation method according to the present 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 certain 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. 1B is a schematic diagram for explaining 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. This represents the timing at which two images are input. The image 5121 and the image 5122 are focused on. 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, An example of a method for interpolating moving images in this form can be realized.

[0392] In the present embodiment, an example of a method for interpolating a moving image is shown in FIG. A generated image is generated based on two adjacent input images. The two input images are displayed. 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. However, 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, the video can be displayed 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. Various numbers can be used, for example, three (or more than three) adjacent in time. If an image is generated based on the first input image, the accuracy will be higher 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 be 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, You can delay the display timing for the sync by one or more frames. Since the display timing of the generated image 5123 can be delayed, 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 delayed relative to the input timing, The image storage period will be longer, 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 is.

[0393] Here, the specific image 5123 generated based on the image 5121 and the image 5122 is In order to interpolate a moving image, the motion of the input image is detected. However, 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) to 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 all rectangular in shape, as shown in Figure 41(A). It can be, but is not limited to, various things (shape or size can be changed 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 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 assumed to have been searched. Note that when searching within image 5121, the search range is limited. In the example of FIG. 41(A), the search range is preferably set to an area 5124. The area 5125 is set to be about four times the area of ​​the By making it larger, the detection accuracy can be improved even in fast-moving videos. However, if the search is too broad, the search time will be enormous, and the detection of motion will be difficult. Since this would be difficult to realize, the area of ​​the region 5125 is set to about 2 to 6 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 motion vector 5127 is calculated. 7 represents the movement of image data in the region 5124 during one frame period. To generate an image that represents an intermediate state of motion, the motion vectors are scaled while keeping their orientation unchanged. A modified image generation vector 5128 is created, and the region 5126 in the image 5121 is The image data is moved according to the image generation vector 5128 to generate the image 5123. This series of processing is called image 512 By performing this for all the regions in 2, an image 5123 can be generated. Then, the input image 5121, the generated image 5123, and the input image 5122 are sequentially displayed, It is possible to interpolate a moving image. Note that an object 5130 in the image is not included in the image 5121 and the image The position is different (i.e., moving) in 5122, but the generated image 5123 The point 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 can be 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 staging is at 2 / 3, the size can be set to 2 / 3.

[0395] In this way, multiple regions with various motion vectors are moved to create a new image. When creating an image, the area to be moved may contain overlapping areas, or it may be possible to move the area to another area. There may be some blank areas that are not moved from the area. As a method for correcting the overlapping portion, for example, Priority is assigned based on the average method, the direction of the motion vector, etc., and data with high priority is generated. The method of making the data in the generated image, where either color (or brightness) is given priority, but brightness (or For example, the method of taking 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. A method for obtaining the average of image data at the corresponding position of the image 5121 or the image 5122. Then, the generated image 5123 can be used as a method for generating an image. By displaying the vector 5128 at a timing that matches its size, the movement of the video becomes smoother. Furthermore, the problem of image retention caused by hold drive resulting in reduced video quality can be eliminated. You can improve the problem.

[0396] Another example of the moving image interpolation method according to the present embodiment is a time-domain interpolation method as shown in FIG. A generated image is generated based on two input images that are adjacent to each other. 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 several parts and displaying them, it is possible to perform video interpolation. 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 that of the power cycle. In the example of FIG. 41(B), the “input” and “generation” can be further improved by the Since the same processing as in the example of FIG. 1(A) can be performed, the explanation will be omitted. In the example, "display" means splitting one input image and / or generated image into multiple sub-images. Specifically, as shown in FIG. 41(B), an image 5121 can be displayed. 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 sub-images 5123a and 512 By dividing the image into 3b and displaying them sequentially, the human eye perceives the image as 5123. and dividing the image 5122 into sub-images 5122a and 5122b and displaying them in sequence. The human eye perceives the image 5122 as being displayed. The image to be displayed is the same as that shown in FIG. 41(A), but the display method is impulse type. This makes it possible to further improve the blurring of moving images caused by afterimages, etc. 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 FIG. ) are displayed at equal intervals (1 / 2), but this 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 The method can be made closer to the impulse type, which reduces blurring of moving images caused by afterimages, etc. Or, the timing of displaying the dark sub-image can be delayed (specifically, 1 / 2 to 3 / 4 of the time) to extend the period during which bright images are displayed. Therefore, the display efficiency can be improved and the power consumption can be reduced.

[0397] Another example of the moving image 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 in the same way as the example in FIG. 41(B), but the displayed content is This shows the case of moving text (also called scrolling text, subtitles, telop, etc.). In addition, the "input" and "generation" may be the same as those in FIG. 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 text is moving. This is because when reading moving text, your eyes will inevitably follow the text. This is because hold blurring is likely to occur. Furthermore, characters have clear outlines. This can further accentuate the blur caused by hold blur. That is, it is necessary to determine whether an object moving in an image is a character or not, and if so, to perform further special processing. This is effective for reducing hold blur. Contour and / or pattern detection is performed on the object to determine whether the object is a character. If it is determined that there is a motion, motion compensation is not performed even if the sub-images are divided from the same image. By displaying intermediate states of the object's movement, the object's movement can be made 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 one, the position of the moving object can be displayed without changing. In the example shown in FIG. 1, an area 5131 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 is true for 22b. This makes it possible to reduce the blurring caused by the hold effect. For text, this makes the movement even smoother than with normal motion compensation double speed drive. Therefore, blurring of moving images caused by afterimages or the like can be further improved. [Explanation of symbols]

[0398] 100 Substrates 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 Transistor 152 Transistor 153 Transistor 154 Transistor 155 Transistor 156 Transistor 160 Holding capacity section 161 Holding capacity section 162 Holding capacity section 164 Holding capacity section 170 Substrate 171 Semiconductor Layer 172 Conductive Layer 173 Gate insulating film 174 Conductive Layer 175 Insulating Film 200 Substrates 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 Substrate 271 Semiconductor Layer 272 Conductive Layer 273 Conductive Layer 274 Gate insulating film 275 Conductive Layer 276 Conductive Layer 277 Insulating Film 300 Substrates 301a Semi-transparent layer 301c light shielding layer 302 Substrate 303a semi-transparent layer 303c light shielding layer 400 Substrates 401 Shading part 402 Diffraction grating section 403 Gray Tone Mask 411 Substrate 412 Semi-transparent part 413 Shading part 414 Halftone Mask 580 Substrate 581 Thin Film Transistor 585 Insulation Layer 586 Board 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 Substrate 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 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 Capacitive element 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 Driving transistor 6403 Capacitor 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 Case 9102 Display section 9103 Connection section 9104 Case 9106 Operation key 9200 Portable information terminal equipment 9201 Case 9202 Display section 9203 Case 9205 Keyboard 9207 Connection section 9400 Communication Equipment 9401 Case 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 Case 9503 Display section 9600 Television Equipment 9601 Case 9603 Display section 9605 Stand 9607 Display section 9609 Operation key 9610 Remote control device 9700 Digital Photo Frame 9701 Case 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 an 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 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 an 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 an 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 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 an 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 2, The semiconductor device, wherein the semiconductor layer contains indium, gallium, and zinc.

Images