Display device

Abstract

To provide a display device providing a pixel having a memory in the pixel.SOLUTION: In a display device, a pixel includes at least a display element 1613, a capacitance element 1612, an inverter 1603, and switches 1602, 1606, 1607, and supplies a voltage to the display element by controlling the switches using a signal stored in the capacitance element and a signal outputted from the inverter. The inverter and the switches may be configured with transistors having the same polarity and a semiconductor layer forming the pixel may be composed of a material having light transmissivity. A gate electrode, a drain electrode, and a capacitance electrode may be formed using a conductive layer having light transmissivity. By forming the pixel with light transmissive material, the display device can be transmissive type while having a pixel with memory arranged.SELECTED DRAWING: Figure 16

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 panel forming region has a circuit composed of thin film transistors using a light-transmitting semiconductor film. The present invention relates to a semiconductor device, a display device, a light-emitting device, and a manufacturing method thereof, in particular, a channel type US20130232633A1 - Semiconductor device having a circuit formed of thin film transistors using an oxide semiconductor film in a ... - Google Patents The present invention relates to a display device, a light-emitting device, or a manufacturing method thereof. [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 having a transparent semiconductor layer made of such a metal oxide as a channel forming region is used. A transistor is disclosed (see, for example, Patent Document 1).

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

[0005] By improving the aperture ratio, the light utilization efficiency is improved, leading to power saving and miniaturization of display devices. On the other hand, in view of the increasing size of display devices and application to mobile devices, From this viewpoint, there is a demand for further reduction in power consumption as well as improvement in aperture ratio.

[0006] In addition, as metal auxiliary wiring for the transparent electrode of the electro-optical element, A metal auxiliary wiring is provided so that it overlaps with the transparent electrode so as to be electrically connected to the transparent electrode. is known (see, for example, Patent Document 3).

[0007] In addition, the additional capacitance electrodes provided on the active matrix substrate are made of transparent materials such as ITO and SnO2. Auxiliary wiring made of a metal film is used to reduce the electrical resistance of the additional capacitance electrode. is provided in contact with an electrode for additional capacitance (see, for example, Patent Document 4).

[0008] In a field effect transistor using an amorphous oxide semiconductor film, The materials forming the electrode and drain electrode are indium tin oxide (ITO), indium tin oxide (ITO), Transparent electrodes made of zinc oxide, ZnO, SnO2, etc., and Al, Ag, Cr, Ni, Mo, Metal electrodes such as Au, Ti, Ta, etc., or alloy metal electrodes containing these can be used. By stacking two or more layers of films made of these materials, the contact resistance can be reduced and the interface strength can be improved. It is known that the above-mentioned method can improve the stability of the oxidized organic compound (for example, see 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) In addition, the gate electrode, the source electrode and the drain electrode may be made of an oxide material such as It is known that the materials of the poles may all be the same or may be different (see, for example, patent literature 1). See 6, 7).

[0010] On the other hand, in order to reduce power consumption, display devices with memory arranged within pixels are being considered. (For example, see Patent Documents 8 and 9.) In addition, the display devices of Patent Documents 8 and 9 have light reflective pixels. Electrodes are used. [Prior art documents] [Patent documents]

[0011] [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 [Patent Document 8] JP 2001-264814 A [Patent Document 9] JP 2003-076343 A Summary of the Invention [Problem to be solved by the invention]

[0012] One of the objectives of one aspect of the present invention is to provide a technique for a pixel having a memory. Another object of one embodiment of the present invention is to improve the aperture ratio of a pixel.

[0013] In addition, the description of a plurality of problems does not preclude the existence of other problems. It is not necessary for the method to solve all of the above problems. [Means for solving the problem]

[0014] For example, one embodiment of the present invention is a circuit including a first circuit having a function of controlling input of a video signal, A second circuit having a function of holding a signal and controlling the polarity of a voltage supplied to a display element The display device includes a third circuit having a function and a display element having a pixel electrode. In this embodiment, a pixel having a memory can be provided. The first to third circuits are made of a material having light-transmitting properties, and the pixel electrodes are It may be placed at the top.

[0015] Alternatively, one embodiment of the present invention is a first circuit having a first switch, A first capacitance element and a second capacitance element to which a signal is input, and an input terminal is a first capacitance element. the output terminal is electrically connected to the first capacitance element, and the output terminal is electrically connected to the second capacitance element. a second circuit having an inverter, the control terminal of which is electrically connected to the first capacitance element; a second switch having a control terminal electrically connected to the second capacitance element; and a third switch having a control terminal electrically connected to the second capacitance element. a third circuit having a switch; and a second switch electrically connected to the second switch and the third switch. and a display element including a pixel electrode. It is possible to provide a pixel having the above-mentioned characteristics.

[0016] In the above embodiment, the first to third wirings may be provided. The first wiring is electrically connected to the first capacitance element through the first switch, and the inverter The input terminal of the inverter is electrically connected to the first capacitance element, and the output terminal of the inverter is electrically connected to the second capacitance element. The first capacitive element is electrically connected to a control terminal of the second switch. the second capacitance element is electrically connected to the control terminal of the third switch, and the second The line is connected to a third wiring via a second switch and a third switch.

[0017] In this embodiment, first to third switches, first to second capacitance elements, and an inverter The first to third pixel electrodes can be formed using a light-transmitting material. The third switch, the first and second capacitance elements, and the inverter may be disposed above the third switch, the first and second capacitance elements, and the inverter. do.

[0018] In each of the above aspects of the present invention, various types of switches can be used. As an example of the switch, an electrical switch or a mechanical switch can be used. In other words, the switch can be anything that can control the current, and is not limited to a specific type. An example of a switch is a transistor (e.g., a bipolar transistor, M OS transistors, etc.), diodes (e.g., PN diodes, PIN diodes, Hotkey diode, MIM (Metal Insulator Metal) diode MIS (Metal Insulator Semiconductor) Diode These include diodes, diode-connected transistors, and logic circuits that combine these. An example of a mechanical switch is a 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 Thus, the device operates by controlling conduction and non-conduction.

[0019] In each of the above embodiments, when a transistor is used as a switch, the transistor Since the transistor acts simply as a switch, the polarity (conductivity type) of the transistor is not particularly limited. However, if you want to suppress the off-state current, you should use a transistor with a polarity that reduces the off-state current. As an example of a transistor having a low off-state current, There are transistors having a multi-gate structure and transistors having a multi-gate structure.

[0020] In each of the above aspects of the present invention, a transistor is used as a switch, and the transistor The transistor source potential 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 as the switch. The transistor operates with its source voltage close to the voltage of the high-potential power supply (Vdd, etc.). In this case, it is preferable to use a P-channel transistor as the switch. In the case of an N-channel transistor, when the source operates at a potential close to the low-potential power supply, In the case of a P-channel transistor, when the source operates at a potential close to the high-potential power supply, , the absolute value of the voltage between the gate and the source can be increased. This is because it allows for more accurate operation as a transistor. Since the follower operation is unlikely to occur, the output voltage is unlikely to become small. This is because there are few.

[0021] In each of the above aspects of the present invention, the switch may be an N-channel transistor and a P A CMOS type switch may be used by using both a CM channel type transistor and a CM When it is made into an OS type switch, a P-channel transistor and an N-channel transistor are If either one of them is conductive, current will flow, making it easier to function as a switch. This allows the switch to output an appropriate voltage regardless of whether the input signal voltage is high or low. Alternatively, the voltage amplitude value of the signal for turning the switch on or off can be reduced. Since the time required for the power supply to be turned on can be reduced, the power consumption can be reduced.

[0022] When using a transistor as a switch, the switch is connected to the input terminal (source or One of the drain terminals), the output terminal (the other of the source or drain), and the terminal that controls conduction On the other hand, when a diode is used as a switch, A switch may not have a terminal that controls conduction. However, using a diode as a switch reduces the amount of wiring required to control the terminal. can be done.

[0023] In the invention disclosed in this specification, transistors of various structures are used as transistors. In other words, there is no limitation on the configuration of the transistors used.

[0024] In this specification, a semiconductor device is a semiconductor element (transistor, diode, silicon However, the function of the device is not limited to the semiconductor characteristics. Any device that can be used for semiconductor devices, or any device that has semiconductor material, may be called a semiconductor device. In the specification, a display device refers to a device having a display element.

[0025] In this specification, a driving device refers to a device having semiconductor elements, electric circuits, and electronic circuits. For example, a transistor (selection transistor) that controls the input of a signal from a source signal line to a pixel These transistors are sometimes called driving transistors, switching transistors, etc.) and supply voltage to the pixel electrodes. or a transistor for supplying a current; a transistor for supplying a voltage or a current to a light-emitting element Further, a circuit for supplying a signal to a gate signal line (a gate driver) ), a circuit that supplies signals to the source signal lines ( A source driver, a source line driver circuit, etc. are examples of a driver device. .

[0026] Also, the present invention relates to a display device, a semiconductor device, a lighting device, a cooling device, a light-emitting device, a reflecting device, and a driving device. The above-mentioned devices and the like can be combined with each other, and such devices are also included in the scope of the present invention. For example, a display device may include a semiconductor device and a light emitting device. The body device may have a display device and a driver.

[0027] In each aspect of the present invention, all of the circuits required to realize a predetermined function are implemented in the same A substrate (e.g., a glass substrate, a plastic substrate, a single crystal substrate, an SOI substrate, etc.) In this way, it is possible to reduce the cost by reducing the number of parts, or to reduce the number of circuit parts. This improves reliability by reducing the number of connection points with the product.

[0028] In addition, it is possible to avoid forming all of the circuits required to realize a given function on the same substrate. In other words, part of the circuitry required to realize a given function is formed on a certain substrate. Another part of the circuitry required to realize a given function is formed on a different substrate. For example, some of the circuits required to realize a certain function can be made of glass. Another part of the circuitry required to realize a given function is formed on the single crystal substrate. (or SOI substrate). The single crystal substrate (also called IC chip) on which another part of the circuitry required for the semiconductor device is formed is called COG ( By using the Chip On Glass (Chip On Glass) method, the IC is connected to the glass substrate and then attached to the glass substrate. It is possible to place the chip on the board. Or, the IC chip can be placed on the board using TAB (Tape Auto) omated Bonding), COF(Chip On Film), SMT(Su rface mount technology, or a printed circuit board, etc. It is possible to connect to the substrate.

[0029] In this specification, when it is explicitly stated that X and Y are connected, it means that X and Y are When X and Y are electrically connected, when X and Y are functionally connected, and when X and Y are This includes the case where the two are directly connected. Here, X and Y are the objects (e.g., , elements, circuits, wiring, electrodes, terminals, conductive films, layers, etc.) Connection relationships, for example, are not limited to those shown in the drawings or text, but include those shown in the drawings or text. This also includes relationships other than those mentioned above.

[0030] An example of a case where X and Y are electrically connected is The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more resistors (e.g., diodes) can be connected between X and Y.

[0031] An example of a case where X and Y are functionally connected is a case where a functional connection between X and Y is possible. Circuits that convert Circuits (DA conversion circuits, AD conversion circuits, gamma correction circuits, etc.), potential level conversion circuits (power supply circuits (voltage boost circuit, voltage drop circuit, etc.), level shifter circuit that changes the potential level of the signal, etc.), voltage source , current sources, switching circuits, amplifier circuits (circuits that can increase the signal amplitude or current amount, etc., amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits One or more circuits (e.g., a circuit, a control circuit, etc.) can be connected between X and Y. Even if there is another circuit between X and Y, the signal output from X will be transmitted to Y. If X and Y are functionally connected, then X and Y are functionally connected.

[0032] In addition, when it is explicitly stated that X and Y are electrically connected, it means that X and Y are electrically When X and Y are directly connected (i.e., when another element or circuit is placed between X and Y), X and Y are functionally connected (i.e., there is no distinction between X and Y) and When X and Y are connected directly ( In other words, X and Y 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

[0033] In this specification, anything expressly stated as singular shall be deemed to be singular. However, even in this case, multiple instances are possible. It is preferable that anything written as a number should be plural. However, in this case But it can also be singular.

[0034] In the figures of this application, sizes, layer thicknesses, or areas may be exaggerated for clarity. Therefore, the scale is not necessarily limited to that. The figure is a schematic representation of an ideal example. The figures are merely illustrative and are not limited to the shapes or values ​​shown in the figures. For example, the shapes may vary depending on the manufacturing technique. Variation in shape due to error, variation in signal, voltage, or current due to noise or may include variations in signals, voltages, or currents due to timing differences. It is possible.

[0035] In addition, technical terms are often used for the purpose of describing a specific embodiment or example. However, one aspect of the present invention should not be interpreted as being limited by technical terms.

[0036] In addition, undefined terms (including scientific and technical terms such as technical terms or academic terms) are usually It is possible to use the term as meaning equivalent to the general meaning understood by a person skilled in the art. Such defined language shall be construed in a manner consistent with the background of the relevant art. preferable.

[0037] In addition, the terms "first," "second," "third," etc., refer to various elements, members, areas, layers, regions, etc. The terms "first," "second," "third," etc. are used to distinguish between elements, members, etc. The order and number of the regions, layers, sections, etc. are not limited. "The" can be replaced with "the second" or "the third", etc.

[0038] Also, "up," "upward," "down," "downward," "sideways," "right," "left," Spatial arrangement such as "diagonally," "at the back," "in front," "inside," "outside," or "inside" The phrase "show" refers to a simple, graphical depiction of the relationship of one element or feature to another element or feature. However, it is not limited to this usage and may be used to indicate these spatial arrangements. The phrase may include other orientations in addition to those depicted in the drawings. For example, Y above X may be clearly stated. Where shown illustratively, Y is not limited to being above X. The configurations shown may be inverted or It is possible to rotate 180 degrees, so that it is possible to include Y being below X. In this way, the word "on" includes the direction of "under" in addition to the direction of "on." However, the device shown in the figure can be rotated in various directions. Therefore, the word "on" can be used to mean "sideways" in addition to the directions "up" and "down." "To the right," "To the left," "Diagonally," "To the back," "To the front," "Inside," "Outside," or can include other directions such as "inside"; that is, it should be interpreted appropriately depending on the situation. It is possible.

[0039] Note that it is not necessary to explicitly say that Y is formed on X, or that Y is formed on X. In the case of describing, it is not limited to forming Y directly on X. This also includes cases where X and Y are not connected in a physical sense, that is, cases where another object is present between X and Y. Here, X and Y are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, layers, etc.).

[0040] Therefore, for example, it is not necessary to explicitly state that layer Y is formed on layer X (or on layer X). In the cases described, layer Y is formed directly on layer X, and layer X is formed on layer Y. Another layer (such as layer Z) is formed directly on top of it, and layer Y is formed directly on top of it. The other layer (e.g., layer Z) may be a single layer or It may be multi-layered.

[0041] Furthermore, the same applies when it is explicitly stated that Y is formed above X. This is not limited to Y being directly on top of X, but includes the presence of another object between X and Y. For example, if a layer Y is formed above a layer X, In this case, layer Y is formed directly on layer X, and layer X is formed directly on layer Y. If another layer (such as layer Z) is formed and layer Y is formed directly on top of it, The other layer (e.g., layer Z) may be a single layer or a multi-layer. stomach.

[0042] In addition, Y is formed on X, Y is formed on X, or Y is formed above X When explicitly stating that "Y is formed diagonally above X," this also includes the case where Y is formed diagonally above X. do.

[0043] The same applies to the description "Y below X" or "Y below X." Effect of the Invention

[0044] By forming a light-transmitting transistor or a light-transmitting capacitor element, Even when arranging transistors and capacitance elements, As a result, the aperture ratio of the pixel can be improved. In addition, by using such a transistor and a light-transmitting wiring, By providing memory in the pixel, a transmissive display with memory in the pixel can be realized. It becomes possible to do so.

[0045] Also, wiring that connects a transistor to an element (for example, another transistor), or a capacitance The wiring that connects elements (e.g., other capacitive elements) is made of a material with low resistivity and high conductivity. By using a material that reduces distortion of the signal waveform and voltage drop due to wiring resistance, It is possible. [Brief description of the drawings]

[0046] [Figure 1] 1 is a cross-sectional view illustrating a configuration example of a display device. [Diagram 2] 1 is a cross-sectional view illustrating a configuration example of a display device. [Diagram 3] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 4] 1 is a cross-sectional view illustrating a configuration example of a display device. [Diagram 5] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 6] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 7] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 8] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 9] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 10] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 11] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 12] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 13] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 14] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 15] FIG. 1 is a block diagram illustrating a configuration example of a display device. [Figure 16] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Figure 17] 17A to 17C are circuit diagrams illustrating an example of the operation of the display device of FIG. 16. [Figure 18] 17A to 17C are circuit diagrams illustrating an example of the operation of the display device of FIG. 16. [Figure 19] 17A to 17C are circuit diagrams illustrating an example of the operation of the display device of FIG. 16. [Figure 20] 17A to 17C are circuit diagrams illustrating an example of the operation of the display device of FIG. 16. [Figure 21] 5A to 5E are circuit diagrams illustrating configuration examples of a display device. [Figure 22] 4A to 4D are circuit diagrams illustrating configuration examples of a display device. [Diagram 23] FIG. 13 is a circuit diagram illustrating an example of the operation of a display device. [Figure 24] FIG. 13 is a circuit diagram illustrating an example of the operation of a display device. [Diagram 25] FIG. 13 is a circuit diagram illustrating an example of the operation of a display device. [Figure 26] FIG. 13 is a circuit diagram illustrating an example of the operation of a display device. [Figure 27] FIG. 13 is a circuit diagram illustrating an example of the operation of a display device. [Figure 28] 4A to 4D are circuit diagrams illustrating configuration examples of a display device. [Figure 29]FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Diagram 30] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Diagram 31] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Diagram 32] FIG. 1 is a plan view illustrating a configuration example of a display device. [Diagram 33] FIG. 1 is a plan view illustrating a configuration example of a display device. [Diagram 34] 1A is a plan view illustrating a configuration example of a display device, and B and C are cross-sectional views of the same. [Diagram 35] 1 is a cross-sectional view illustrating a configuration example of a display device. [Diagram 36] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 37] A-1 and A-2 are plan views for explaining a configuration example of a display device. B and C are cross-sectional views of the same. [Figure 38] AF are cross-sectional views illustrating an example of a method for manufacturing a display device. [Figure 39] 5A to 5E are cross-sectional views illustrating an example of a method for manufacturing a display device. [Diagram 40] 1A to 1H are diagrams for explaining configuration examples of electronic devices. [Diagram 41] 4A to 4D are diagrams for explaining configuration examples of electronic devices, and E to H are diagrams for explaining application examples of a display device. [Diagram 42] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Diagram 43] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The embodiments of the present invention will be described below. The aspects of the invention described in this specification include, for example, the following: The following problems can be solved. Note that the description of multiple problems does not preclude the existence of other problems. In addition, each aspect of the present invention does not necessarily solve all of the problems described below.

[0048] The challenges include, for example, providing technology related to pixels with memory, and increasing the aperture ratio of pixels. Improve the wiring resistance, reduce the contact resistance, and reduce the voltage drop. To reduce power consumption, improve display quality, and reduce the off-current of transistors. Examples of measures include reducing

[0049] Furthermore, the present invention can be embodied in many different ways. It will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiment. In the configurations described below, the same parts or parts having similar functions are different. The same reference numerals are used in the drawings, and the detailed description of the same parts or parts having similar functions will be omitted. Omitted.

[0050] In addition, the contents (or even a part of the contents) described in one embodiment may be used interchangeably with the embodiment. Another content (which may be a part of the content) described in the form of, and / or one or Selection, combination, etc. of the contents (or even a part of the contents) described in multiple separate embodiments The contents described in the embodiment are as follows: In each embodiment, the contents described in one or more of the drawings referred to, This refers to the content expressed in the call and sentence.

[0051] In addition, a drawing (or a part of a drawing) referred to in one embodiment may be a different part of the drawing. Another figure (or a part of it) referred to in the embodiment, and / or one or more The drawings may be combined with those referred to in multiple separate embodiments (or even a part of them). Thus, it is possible to draw a figure depicting another configuration example. Also, for a figure or a described passage referred to in a certain embodiment it is possible to configure another aspect based on a part of the figure or the described passage. Therefore, in a case where a figure or a passage describing a certain part is provided, another aspect represented by a part of the figure or the passage is also disclosed.

[0052] Therefore, for example, in a drawing (cross-sectional view, plan view, circuit diagram, block diagram, flowchart, process diagram, perspective view, elevation view, layout diagram, timing chart, structure diagram, schematic diagram, graph, table, optical path diagram, vector diagram, state diagram , pattern diagram, waveform diagram, photograph, chemical formula, etc.) or passage in which one or more active elements (transistors, diodes, etc.), wirings, passive elements (capacitive elements, resistive elements, etc.), conductive layers, insulating layers, semiconductor layers, organic materials, inorganic materials, components, substrates, modules, devices, solids, liquids, gases, operation methods, manufacturing methods, etc. are described, it is assumed that it is possible to extract a part thereof to configure an aspect of the invention. (cross-sectional view, plan view, circuit diagram, block diagram, flowchart, process diagram, perspective view, elevation view, layout diagram, timing chart, structure diagram, schematic diagram, graph, table, optical path diagram, vector diagram, state diagram , pattern diagram, waveform diagram, photograph, chemical formula, etc.) or passage in which one or more active elements (transistors, diodes, etc.), wirings, passive elements (capacitive elements, resistive elements, etc.), conductive layers, insulating layers, semiconductor layers, organic materials, inorganic materials, components, substrates, modules, devices, solids, liquids, gases, operation methods, manufacturing methods, etc. are described, it is assumed that it is possible to extract a part thereof to configure an aspect of the invention. , pattern diagram, waveform diagram, photograph, chemical formula, etc.) or passage in which one or more active elements (transistors, diodes, etc.), wirings, passive elements (capacitive elements, resistive elements, etc.), conductive layers, insulating layers, semiconductor layers, organic materials, inorganic materials, components, substrates, modules, devices, solids, liquids, gases, operation methods, manufacturing methods, etc. are described, it is assumed that it is possible to extract a part thereof to configure an aspect of the invention.

[0053] As an example, from a circuit diagram composed of N (N is an integer) circuit elements (transistors, capacitive elements, etc.), it is possible to extract M (M is an integer and M < N) circuit elements (transistors, capacitive elements, etc. ) to configure an aspect of the invention. As another example, from a cross-sectional view composed of N ( N is an integer) layers, it is possible to extract M (M is an integer and M < N) layers to configure an aspect of the invention. As another example, from a flowchart composed of N ( N is an integer) elements, it is possible to extract M (M is an integer and M < N) elements to configure an aspect of the invention.

[0054] In addition, in the drawings or text described in one embodiment, at least one When a specific example is described, it is easy for a person skilled in the art to derive a generic concept of the specific example. It is understood that, therefore, in the drawings or text describing one embodiment, When at least one specific example is described, the generic concept of that specific example is disclosed in this specification. It is possible to constitute one aspect of the invention as described above.

[0055] In addition, at least the contents shown in the drawings (or even a part of the drawings) are disclosed as one embodiment of the invention. It is possible that the above-mentioned embodiment constitutes one aspect of the invention. If the contents are shown in the diagram, even if they are not stated in words, This can be one embodiment of the invention disclosed in this specification. From the drawings, one embodiment of the invention disclosed in this specification can be constructed.

[0056] In addition, active elements (transistors, diodes, etc.), passive elements (capacitive elements, resistive elements, etc.), etc. A person skilled in the art can easily understand the invention without specifying the connection destination of all the terminals of the In particular, when multiple terminals are expected to be connected to each other, Therefore, it is not necessary to limit the connection of the terminal to a specific point. Some terminals of passive elements (capacitive elements, resistive elements, etc.) It is possible to constitute an embodiment of the invention by specifying the connection destination only for the In some cases, this is possible.

[0057] In addition, if a certain circuit is connected to at least one circuit, a person skilled in the art can easily implement the invention. In some cases, it may be possible to identify aspects, and aspects of the invention disclosed herein are such Alternatively, if at least the function of a circuit is specified, a person skilled in the art can easily understand the circuit. In some cases, it may be possible to identify aspects of the invention disclosed herein. The present invention encompasses such cases.

[0058] (Embodiment 1) In this embodiment, a display device will be described.

[0059] A configuration example of a display device (which can also be called a semiconductor device) shown in this embodiment will be described with reference to FIG. The display device has a plurality of pixels. Figure 1 shows the cross-sectional structure of one pixel.

[0060] A circuit 102, a circuit 103, and a circuit 104 are provided above a substrate 101. An insulating layer 105 is provided above the circuits 102 to 104. A conductive layer 106 is provided. Above the substrate 108 (below when viewed in the direction of FIG. 1), A conductive layer 109 is provided between the conductive layer 106 and the conductive layer 109. A medium 107 is provided between the conductive layer 106 and the conductive layer 109. A display element is formed using the medium 107, the conductive layer 106, and the conductive layer 109. The conductive layer 106 can be formed of the circuit 102, the circuit 103, and The conductive layer 106 may be connected to the circuit 102, Regarding the circuit 103 and / or the circuit 104, the whole or a large part thereof However, the present embodiment is not limited thereto.

[0061] In the configuration example of FIG. 1, it is possible to omit either the substrate 108 or the conductive layer 109. It is possible to eliminate any one of the circuits 102, 103, and 104. It is possible.

[0062] Here, the circuit 102, for example, inputs a signal (for example, an image signal) into a pixel. Therefore, the circuit 102 has a function of controlling whether or not the selection transistor Alternatively, it may have a switching transistor.

[0063] Here, the circuit 103 has a function of holding a signal, for example. The circuit 103 has a memory function, for example, a DRAM, an SRAM, etc. , non-volatile memory, etc. Furthermore, the circuit 103 may also include a refresh circuit. It is possible to refresh the data in the DRAM by using the refresh circuit. Therefore, the circuit 103 includes an inverter, a clocked inverter, a capacitance element, an analog It is possible to have a log switch, etc.

[0064] Here, the circuit 104 has a function of controlling the polarity of the voltage supplied to the medium 107, for example. Therefore, depending on the type of the medium 107, the circuit 104 may not be provided. Thus, the circuit 104 may include an inverter, a source follower, an analog switch, etc. In this way, by arranging memory inside the pixel, the frequency of rewriting the signal can be reduced. Since the power consumption can be reduced, the power consumption can be reduced. Not limited to these.

[0065] When the circuits 102 to 104 have the above functions, the circuit 102, the circuit 103, and / or The transistors or wirings included in the circuit 104 are formed using a light-transmitting material. For example, for a transistor, the gate electrode, the semiconductor layer, A part or the whole of the source electrode or the drain electrode is made of a material having light transmitting properties. Therefore, even if a transistor or wiring is arranged, the light Similarly, source signal lines, gate signal lines, capacitance lines, power supply lines, etc. The wiring can also be made of a material having light transmitting properties. The pixel area where the pixels are arranged can transmit light over most of its area. do.

[0066] In addition, the wiring such as the source signal line, the gate signal line, the capacitance wiring, the power supply line, etc. The entire structure may be made of a material having light-transmitting properties, but is not limited thereto. It is possible to configure the insulating film by using a material having high electrical conductivity without using light-transmitting properties. For example, the light-transmitting layer and the light-transmitting layer may be formed of a non-transparent material. In these cases, the area through which light passes is narrow. Therefore, the aperture ratio is reduced, but the high conductivity reduces signal distortion and voltage drop. reduction becomes possible.

[0067] In particular, circuits for driving pixels, such as a gate driver, a source driver, a common electrode (Counter electrode) In a driving circuit or the like, a layer that does not have light-transmitting properties is provided, and wiring and / or It is possible to configure a transistor. Gate driver, source driver, common electrode (Counter electrode) In driving circuits, etc., there is no need to transmit light. Therefore, the electrical conductivity is high. By using thin wiring and electrodes to configure wiring and transistors, signal distortion is reduced. , it is possible to reduce the voltage drop.

[0068] Note that the conductive layer 106 or the conductive layer 109 is formed using a light-transmitting material. Here, as shown in FIG. 1, a circuit 102 and a circuit 103 are provided under a conductive layer 106. In this case, the circuit 102, the circuit 103, or the circuit 104 can be arranged. 3. Alternatively, the circuit 104 can be formed using a light-transmitting material. Therefore, the aperture ratio can be improved. Alternatively, a transmissive display device can be constructed. In other words, it is possible to configure a transmissive display device while arranging memory within the pixel. can.

[0069] Note that the conductive layer 106 and / or the conductive layer 109 may have a light-transmitting property. It is possible for a portion of the conductive layer 106 to have a material that is not conductive, i.e., a material that has a high electrical conductivity. By using a material with high electrical conductivity, light can be reflected from that portion. Therefore, it is possible to configure a semi-transmissive display device.

[0070] Note that the conductive layer 106 is provided under the circuit 102, the circuit 103, or the circuit 104. At least one of the circuit 102 and the conductive layer 106 may be disposed below the conductive layer 106. It is sufficient that a part of the circuit 103 or the circuit 104 is provided.

[0071] The conductive layer 106 can function as a pixel electrode. The layer 109 may function as a common electrode.

[0072] However, the conductive layer 109 is not limited to being formed on the substrate 108. It is also possible to make

[0073] Examples of the medium 107 include liquid crystal, organic EL, inorganic EL, electrophoretic material, and electronic liquid powder. The medium 107 may contain a toner, etc. The optical properties are controlled by the voltage or current supplied to the light emitting diode.

[0074] FIG. 1 shows an example in which a circuit 102, a circuit 103, and a circuit 104 are provided in one pixel. However, the present embodiment is not limited to this. It is also possible to provide less circuitry.

[0075] It is preferable that the substrate 101 or the substrate 108 is an insulating substrate. Examples of these include glass substrates, plastic substrates, flexible substrates, and PET (polyethylene terephthalate). (ethylene terephthalate) substrate, stainless steel foil substrate, SOI substrate, silicon Examples of substrates include substrates made of metals, sapphire substrates, ceramic substrates, quartz substrates, and sapphire substrates. Alternatively, a conductive substrate made of a conductor such as stainless steel and the like, the surface of which is covered with an insulating material, may be used. By using glass or plastic as the substrate, light can be transmitted. Alternatively, the substrates 101 and 108 may be plastic substrates or flexible substrates. By using a plate, it is possible to bend the board, making it less likely to break. become.

[0076] In addition, the substrate 101 or the substrate 108 has a single insulating layer or multiple insulating layers formed on the surface. The insulating layer prevents impurities contained in the substrate from diffusing. It is possible to reduce

[0077] (Embodiment 2) In this embodiment, a display device will be described.

[0078] 2 to 14, the display device (which can also be called a semiconductor device) shown in this embodiment mode will be described. A configuration example of a display device is described below. The display device has a plurality of pixels. The cross-sectional structure of the element is shown.

[0079] As shown in FIG. 2, above the substrate 101, conductive layers 201a and 201b are disposed. An insulating layer 202 is disposed above the conductive layers 201a and 201b. A semiconductor layer 203 is disposed on the insulating layer 202. Conductive layer 204a, conductive layer 204b and conductive layer 204c are disposed. a, the insulating layer 205 is disposed above the conductive layer 204b, the conductive layer 204c, or the semiconductor layer 203. A conductive layer 206 is disposed on the insulating layer 205. 4b is connected to the conductive layer 206 through a contact hole formed in the insulating layer 205. The upper side of the semiconductor layer 203 and the lower sides of the conductive layers 204a and 204b are in contact with each other and connected to each other. It has been done.

[0080] The conductive layer 201a and the conductive layer 201b are films (single layers) formed through the same film formation process. In this case, the insulating layer 11 can be formed by etching the insulating layer 11 or the insulating layer 12. , conductive layer 201a and conductive layer 201b have substantially the same material. a, the conductive layer 204b and the conductive layer 204c are films (single layer or It is possible to form the insulating layer by etching the insulating layer (or the laminated layer). Conductive layer 204a, conductive layer 204b, and conductive layer 204c have substantially the same material.

[0081] The conductive layer 201a can function as a gate electrode of the transistor 207. Alternatively, the conductive layer 201a can function as a gate signal line. The conductive layer 201b can function as a capacitor electrode of the capacitor elements 208 and 209. Alternatively, the conductive layer 201b can function as a storage capacitance line. do.

[0082] The insulating layer 202 can function as a gate insulating layer of the transistor 207. Alternatively, the insulating layer 202 may function as an insulating layer for the capacitors 208 and 209. It is possible.

[0083] The conductive layers 204a and 204b serve as a source electrode and a drain electrode of the transistor 207. Alternatively, the conductive layers 204a and 204b may function as a source signal It is possible for the signal line to function as a line or a video signal line.

[0084] The conductive layer 204c can function as a capacitor electrode of the capacitor 208. Alternatively, the conductive layer 204c can function as a storage capacitor line.

[0085] The semiconductor layer 203 can function as an active layer of a transistor 207. Alternatively, the semiconductor layer 203 may function as a channel layer of the transistor 207. Alternatively, the semiconductor layer 203 may function as a high resistance region of the transistor 207. Alternatively, the semiconductor layer 203 may function as an impurity for the transistor 207. It is possible for the object region to function as an object region.

[0086] The conductive layer 206 can function as a pixel electrode. 6 can function as a capacitor electrode of the capacitor element 209.

[0087] The conductive layer 206 may correspond to the conductive layer 106 shown in FIG. Layer 205 may correspond to insulating layer 105 shown in FIG.

[0088] In this manner, the transistor 207, the capacitor element 208, and the like are disposed below the conductive layer 206. Since the transistor 207, the capacitor 208, and the like have a light-transmitting property, It is possible to increase the display area or to configure a transmissive display device. Then, a selection transistor 207 and capacitor elements 208 and 209 are used. , memory, DRAM, SRAM, analog switch, inverter, clocked inverter It is possible to configure the above.

[0089] Since the conductive layer 201a is present under the semiconductor layer 203, the transistor 207 The transistor 207 can be a bottom-gate transistor. The transistor 207 can be said to be an inverted staggered transistor. Since there is no channel protection film on the semiconductor layer 203, a channel etch type transistor Alternatively, the transistor 207 can be said to be a thin film transistor. I can say that.

[0090] The configuration of the transistors and the capacitors is not limited to that shown in FIG. 2. It is possible to apply.

[0091] For example, a transistor in which an electrode is provided on the opposite side of the channel to the gate electrode is FIG. 3 shows a structure in which the conductive layer 206a is disposed between the semiconductor layer 203 and the insulating layer 206. 2 shows an example of a pixel configuration in which the conductive layer 206a is provided above the transistor 207. The conductive layer 206a can function as a back gate. By supplying a potential different from that of the transistor 207, the operation of the transistor 207 can be stabilized. Alternatively, the conductive layer 206a can be supplied with the same potential as the conductive layer 201a. , the channel of transistor 207 is essentially doubled, resulting in substantially higher mobility. It is possible.

[0092] The conductive layers 206a and 206 are films (single layer or multilayer) formed through the same film formation process. In this case, the conductive layer 20 can be formed by performing an etching process on the conductive layer 20. 6a and the conductive layer 206 are of generally the same material.

[0093] As shown in FIG. 3, the capacitor 208 is disposed between the conductive layer 204c and the conductive layer 201c. In addition, a semiconductor layer 203a may be provided. Here, the semiconductor layers 203 and 203a are Etching is performed on a film (single layer or multilayer) formed through the same film formation process. In this case, the semiconductor layer 203 and the semiconductor layer 203a can be formed of substantially the same material. It has the same materials.

[0094] In addition, the transistors in the peripheral circuit section (for example, the circuit section that drives the pixels) and the transistors in the pixel section As an example, in the pixel section, as shown in FIG. As shown in FIG. 1, the transistor 207 does not have a conductive layer 206a. In the circuit, as shown in FIG. 3, a conductive layer 206a is provided in a transistor 207. In the circuit for driving the pixel portion, the transistor 207 It is very important to control the threshold voltage. Even if the transistor 207 is in a normally-on state, it may still be possible to operate the device. Furthermore, in the pixel area, the aperture ratio is reduced by not providing the conductive layer 206a. Therefore, the transistor 207 in the pixel portion is provided with the conductive layer 206a. The transistor 207 in the circuit for driving the pixel portion is provided with a conductive layer 206a. By adopting this configuration, the display device can be operated appropriately and the aperture ratio of the pixel portion can be increased. It is possible.

[0095] However, this embodiment is not limited to FIG. 3. An example of this is shown in Figure 4.

[0096] Between the insulating layer 205 and the conductive layer 206, the conductive layer 406a and the insulating layer 405 are disposed. Layer 406 a may function as a backgate of transistor 207 . In this way, by using a layer other than the conductive layer 206, a transistor is formed under the conductive layer 206. Therefore, in the pixel, By using the transistor 207 having this structure, the aperture ratio can be improved.

[0097] Note that the capacitor 408 is formed using a conductive film in the same layer as the conductive layer 406a. The capacitor 408 is formed using the conductive layer 406b and the conductive layer 201c. Alternatively, the capacitor 409 can be formed by using the conductive layer 406b and the conductive layer 206. Alternatively, the capacitor 408a can be formed by using the conductive layer 406b and a conductive It is possible to construct the layer 204 using the layer 204d.

[0098] The conductive layer 201a and the conductive layer 201c are films (single layers) formed through the same film formation process. In this case, the insulating layer 11 can be formed by etching the insulating layer 11 or the insulating layer 12. The conductive layers 201a and 201c are made of substantially the same material. 204b and 204d are films (single layer or laminate) formed through the same film formation process. In this case, the conductive layer 204a and the conductive Layer 204b and conductive layer 204d have approximately the same material. performs etching on a film (single layer or multilayer) formed through the same film formation process. In this case, the conductive layer 406a and the conductive layer 406b can be formed by It has the same material.

[0099] 2, 3, and 4, the transistor 207 is provided on the semiconductor layer 203 as follows: An example in which no channel protection film is provided will be shown. However, the present embodiment is not limited to this. It is possible to provide a channel protection film. For example, in the transistor 2 in FIG. 5 shows the case where a channel protection film 503 is arranged on the substrate 507. Similarly, in the cases of FIGS. In addition, a channel protection film can be disposed to form a transistor. In the transistor 207, the channel protection film 503 is disposed, so that the semiconductor layer 2 This allows the thickness of the MOSFET to be thin, which makes it possible to reduce the off-state current. Or, reduce the S value (subthreshold swing value). Alternatively, etching of the semiconductor layer 203 and the conductive layers 204a and 204b is possible. Since it is not necessary to take into consideration the selection ratio at the time of deposition, it is possible to freely select materials.

[0100] In the configuration example shown in FIG. 2 to FIG. 5, a semiconductor layer 203 is disposed under conductive layers 204a and 204b. The present embodiment is not limited to these configurations, and may be configured as shown in FIG. Alternatively, the semiconductor layer 203 may be disposed over the entire area under the conductive layers 204a and 204b. In this case, it is possible not to provide the channel protection film 503. If the mask is not provided, it is called a multi-tone mask (also called a half-tone mask or gray-tone mask). ) can be used to reduce the number of masks (reticles). For example, The films constituting the semiconductor layer 203, the conductive layer 204a, and the conductive layer 204b are The layers are deposited successively. A resist mask is formed and the layers are etched simultaneously. The mask is then ashed or the like to etch only the conductive layer 204a and the conductive layer 204b. A single exposure mask is used to expose the channel portion of the semiconductor layer 203, etc. In addition, a resist mask for etching the conductive layer 204a and the conductive layer 204b is formed. It is possible to achieve this.

[0101] 2 to 6 show examples of pixel configurations, in which the upper side of the semiconductor layer 203 and the conductive layers 204a and 20 4b and the underside of the insulating layer 4b are in contact with each other and electrically connected. The embodiment is not limited to this. A conductive layer may also be provided. Hereinafter, such a configuration example will be described with reference to FIGS. Explain.

[0102] In FIG. 2, the upper side of the semiconductor layer 203 is in contact with the lower sides of the conductive layers 204a and 204b. A cross-sectional view of a transistor 207 in this case is shown in FIG. Transistor 207 when the upper side of .03 contacts the lower sides of conductive layers 204a and 204b. 8 shows a cross-sectional view of the semiconductor layer 203 and the conductive layer 20 A cross-sectional view of transistor 207 when the undersides of 4a and 204b are in contact is shown in FIG. Similarly, in FIG. 6, the channel protection film 503 is not disposed, and the upper side of the semiconductor layer 203 is 2 is a cross-sectional view of a transistor 207 when the lower sides of the conductive layers 204a and 204b are in contact with each other. 10. In FIG. 10, the conductive layer 206 and the semiconductor layer 203 are in contact with each other. In the portion, it is desirable that the semiconductor layer 203 is sufficiently N-type or P-type. In other words, it is preferable that these contact portions are ohmic contacts. .

[0103] 2 to 10, there is no insulation between the conductive layers 204a and 204b and the semiconductor layer 203. A configuration example in which no edge layer is provided is shown. Of course, the present embodiment is not limited to this. An insulating layer may be provided between the conductive layers 204a and 204b and the semiconductor layer 203. As an example, a cross-sectional view of the case where an insulating layer 1105 is provided in FIG. The conductive layers 204a and 204b and the semiconductor layer 203 are provided on an insulating layer 1105. The connection is made via a contact hole.

[0104] In this case, the conductive layers 204a and 204b are formed in the same layer as the conductive layers 204a and 204b. It is possible to provide an electrode on the opposite side of the gate electrode to the portion of the semiconductor substrate. 2. The conductive layer 204e is provided on the opposite side of the channel portion to the gate electrode. In this way, since it is provided in the same layer as the conductive layer 204a, Even if such a transistor structure is used, it is possible to prevent the aperture ratio from decreasing.

[0105] The conductive layers 204a, 204b, and 204e are films (single layers) formed through the same film formation process. In this case, the insulating layer 11 can be formed by etching the insulating layer 11 or the insulating layer 12. , conductive layer 204a, conductive layer 204b, and conductive layer 204e have substantially the same material.

[0106] In addition, in the case of the pixels in FIG. 3 to FIG. 10, the transistor 207 similar to that in FIG. 11 and FIG. 12 is used. It can be used.

[0107] When connecting the conductive layers of each layer arranged via an insulating layer, it is necessary to apply a contact to the insulating layer. An example of the contact structure in this case is shown in Figure 13. In the case of the connector structure 1301, the conductive layer 201b, the conductive layer 204b, and the conductive layer 206 are electrically Contact holes are formed in the insulating layer 205 and the insulating layer 202 to effectively connect the These contact holes are formed at the same time. In this case, the number of masks (reticles) However, the number of steps in the process can be reduced. When it is desired to connect the two, the connection must be made via the conductive layer 206. On the other hand, the contact structure may require higher resistance or larger layout area. As shown in FIG. 1302, a contact hole is opened in the insulating layer 202, and the conductive layer 204a and the conductive layer It is also possible to directly connect to 201a. In this case, the contact resistance may become high. It is possible to reduce the possibility of the layout area increasing.

[0108] FIG. 14 shows an example of a contact structure in which conductive layers 406a and 406b are present. In the case of the contact structure 1401, the insulating layers 405, 205, and 202 are simultaneously provided with contact holes. The holes are opened to connect the conductive layers 201a, 204b, 406a, and 206. Therefore, the number of masks (reticles) and the number of process steps can be reduced. When connecting 6a to the conductive layer 204b or the conductive layer 201a, the connection is made via the conductive layer 206. Since it is necessary to connect the On the other hand, as in the contact structure 1402, the insulating layer 205 and the insulating layer 2 Contact holes are opened in 02, and the conductive layer 406b is connected to the conductive layer 204d and the conductive layer 201c. In this case, the contact resistance may be high, or Alternatively, it is possible to reduce the possibility that the layout area becomes large.

[0109] 2 to 12 show examples of bottom gate transistors. The form of the transistor is not limited to this. It may also be configured using a top-gate transistor. Similarly, the present invention is not limited to inverted staggered transistors, but may be applied to planar transistors. It is also possible to configure it using

[0110] The semiconductor layer 203 shown in FIGS. 2 to 12 is a semiconductor film having a single layer structure or a stacked structure. The semiconductor layer can be formed of an indium tin oxide (InTTO). Tin Oxide (ITO), Indium Tin Oxide with Silicon Oxide (ITSO), Formed from a light-transmitting material such as organic indium, organic tin, or zinc oxide (ZnO) In addition, indium zinc oxide (InZO) containing zinc oxide can be used. ide:IZO), zinc oxide doped with gallium (Ga), tin oxide (SnO2 ), indium oxide with tungsten oxide, indium zinc oxide with tungsten oxide oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, etc. The film made of these materials can be formed by a sputtering method. do.

[0111] In addition, the conductive layers shown in FIGS. 1 to 14, for example, the conductive layers 201a, 201b, 204a to 204b, 04e, 206, 206a, 406a, 406b, etc. are conductive films having a single layer structure or a laminated structure. The conductive layers can be formed from indium tin oxide (In Indium Tin Oxide (ITO), silicon oxide-containing indium tin oxide (I The material used is a transparent material such as TSO, organic indium, organic tin, or zinc oxide (ZnO). In addition, indium zinc oxide (InZO) containing zinc oxide can be used. ZnO (Insulated Zinc Oxide), gallium (Ga) doped material, tin oxide (SnO2), indium oxide with tungsten oxide, indium oxide with tungsten oxide Indium zinc oxide, indium oxide with titanium oxide, indium tin oxide with titanium oxide The film made of these materials may be formed by sputtering. However, when the conductive layer shown in FIG. 1 to FIG. 14 is formed using a conductive film having a laminated structure, In this case, it is desirable to make the light transmittance in the laminate structure sufficiently high.

[0112] In addition, the wiring such as the source signal line, the gate signal line, the capacitance wiring, the power supply line, etc. It is possible to configure the entire structure using a material with high electrical conductivity. For example, a light-transmitting layer and a light-transmitting layer may be used. In this case, the wiring material may be, for example, For example, aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), Molybdenum (Mo), Nickel (Ni), Platinum (Pt), Copper (Cu), Gold (Au), Silver ( Ag), manganese (Mn), neodymium (Nd), niobium (Nb), cerium (Ce), Metallic materials such as Cr (chromium), or alloy materials whose main components are these metallic materials, or The nitride containing these metallic materials can be used to form a single layer or a multilayer structure.

[0113] In addition, when ITO is used as one conductive layer and aluminum is used as another conductive layer, If they are connected, a chemical reaction may occur. To avoid this, it is advisable to use a high melting point material between them. For example, Examples of high melting point materials include molybdenum, titanium, tungsten, tantalum, and chromium. Then, a conductive layer is formed on the film using the high melting point material by using a material with high conductivity. It is preferable to form a multi-layer film of the material having high electrical conductivity. For example, when forming a conductive film in a laminated structure, the first layer is made of molybdenum, the second layer is made of The first layer is aluminum and the third layer is molybdenum, or the first layer is molybdenum and the second layer is The first layer is made of aluminum containing a small amount of neodymium, and the third layer is made of molybdenum. With this configuration, hillocks can be prevented.

[0114] The insulating layers shown in FIGS. 1 to 14, for example, the insulating layers 105, 202, 205, 405, 110 5, etc. are silicon oxide film, silicon oxynitride film, silicon nitride film, silicon nitride oxide film, Aluminum oxide film, aluminum nitride film, aluminum oxynitride film, aluminum oxynitride film The insulating layer may be a single layer or a multilayer of a tantalum oxide film or a tantalum oxide film. The film thickness can be set to 50 nm or more and 250 nm or less by using a sputtering method or the like. For example, a silicon oxide film is formed as an insulating layer with a thickness of 100 nm by sputtering or CVD. Alternatively, an aluminum oxide film can be formed to a thickness of 100 nm by sputtering. Alternatively, it can be formed of silicon oxide, silicon nitride, silicon oxynitride, Insulating films containing oxygen or nitrogen, such as silicon oxynitride, DLC (Diamond-Like Carbon) Carbon-containing films such as ethylene glycol, epoxy, polyimide, polyamide, polyvinylphenol, From organic materials such as benzocyclobutene and acrylic, or siloxane materials such as siloxane resin The film may have a single layer or a laminate structure.

[0115] The insulating layer shown in FIG. 1 to FIG. 14 may be a color filter and / or a black matrix. The color filter is provided on the substrate 101 side. This eliminates the need to provide a color filter on the opposing substrate, and the positions of the two substrates can be changed. Since no adjustment margin is required, the panel can be manufactured more easily.

[0116] The semiconductor layer shown in FIG. 2 to FIG. 14, for example, the semiconductor layer 203, may be, for example, In, M, or In the present invention, an oxide semiconductor containing Ga, Fe, Ni, or Zn can be used. It represents one or more metal elements selected from Mn, Co, etc. Also, M represents When Ga is used, the semiconductor film made of this material is called an In-Ga-Zn-O system non-single crystal film. In addition to the metal element contained as M in the above oxide semiconductor, impurities Contains Fe, Ni or other transition metal elements, or oxides of said transition metals. The semiconductor layer 203 may contain insulating impurities. Insulating oxides such as silicon oxide, germanium oxide, and aluminum oxide are typical examples. Insulating nitrides such as silicon nitride and aluminum nitride, or silicon oxynitride Insulating oxides and nitrides such as aluminum oxide nitride are used. The insulating nitride is added at a concentration that does not impair the electrical conductivity of the oxide semiconductor. By adding insulating impurities to the oxide semiconductor, crystallization of the oxide semiconductor can be suppressed. By suppressing the crystallization of the oxide semiconductor, the characteristics of the thin film transistor can be stabilized. It becomes possible to do so.

[0117] By including impurities such as silicon oxide in the In-Ga-Zn-O oxide semiconductor, Even when heat treatment is performed at 300° C. to 600° C., the oxide semiconductor is not crystallized or microcrystalline grains are generated. The In-Ga-Zn-O based oxide semiconductor layer is used as a channel formation region. In the manufacturing process of thin-film transistors, heat treatment is performed to improve the S value and field effect mobility. However, even in such a case, the thin film transistor is normally on. In addition, it is possible to prevent the thin film transistor from being subjected to thermal stress, bias stress, or the like. Even if a stress is applied, the threshold voltage can be prevented from fluctuating.

[0118] In addition to the above, In is also used as an oxide semiconductor for the channel formation region of a thin-film transistor. -Sn-Zn-O, In-Al-Zn-O, Sn-Ga-Zn-O, Al-Ga- Zn-O series, Sn-Al-Zn-O series, In-Zn-O series, Sn-Zn-O series, Al-Z nO-based, In-O-based, Sn-O-based, and Zn-O-based oxide semiconductors can be used. That is, impurities that suppress crystallization and maintain the amorphous state are added to these oxide semiconductors. By adding impurities, the characteristics of the thin film transistor can be stabilized. Insulating oxides such as silicon oxide, germanium oxide, and aluminum oxide; insulating nitrides such as silicon nitride, aluminum nitride, etc., or silicon oxynitride; Examples of the insulating oxynitrides include aluminum oxynitride.

[0119] As an example, an oxide semiconductor target containing In, Ga, and Zn (In2O3:Ga A semiconductor film can be formed by sputtering using ZnO (ZnO = 1:1:1). The sputtering conditions are, for example, a distance between the substrate 101 and the target of 30 mm to 50 mm. 0mm, pressure 0.1Pa~2.0Pa, DC power output 0.25kW~5.0 kW (when using an 8-inch diameter target), atmosphere is argon, oxygen, or The atmosphere may be a mixture of argon and oxygen. The thickness of the semiconductor film is 5 nm to 200 nm. It is sufficient to set the distance to about nm.

[0120] The sputtering method is RF sputtering, which uses a high-frequency power source for the sputtering power supply, or D The C sputtering method and the pulse DC sputtering method, which apply a DC bias in a pulsed manner, can be used. The RF sputtering method is mainly used to deposit insulating films, while the DC sputtering method is mainly used to deposit insulating films. It is used when forming a metal film.

[0121] Also, a multi-target sputtering device capable of mounting multiple targets of different materials may be used. In sputtering equipment, different films can be laminated in the same chamber, or It is also possible to simultaneously sputter multiple types of materials to form a single film. - A method using a magnetron sputtering device equipped with a magnetic field generating mechanism inside (magnetron sputtering method) and ECR sputtering method using plasma generated by microwaves. Also, a chemical reaction between the target material and the sputtering gas components may be performed during the film formation. The reactive sputtering method, which forms a compound from these, and the via method, which applies a voltage to the substrate during film formation, A sputtering method or the like may also be used.

[0122] The semiconductor material used for the channel layer of the transistor 207 is an oxide semiconductor. For example, the silicon layer (amorphous silicon layer, microcrystalline silicon layer, polycrystalline silicon layer, etc.) A crystalline silicon layer or a single crystal silicon layer may be used as the channel layer of the transistor 207. Alternatively, a light-transmitting organic semiconductor material may be used as the channel layer of the transistor 207. Alternatively, a carbon nanotube or a compound semiconductor such as gallium arsenide or indium phosphide may be used. stomach.

[0123] After the semiconductor layer 203 is formed, the semiconductor layer 203 is heated at 100° C. in a nitrogen atmosphere or in an air atmosphere. It is preferable to carry out heat treatment at a temperature of 200° C. to 600° C., typically 200° C. to 400° C. For example, Heat treatment can be performed at 350°C for 1 hour in a nitrogen atmosphere. The conductor layer 203 is rearranged at the atomic level. This heat treatment (including photo-annealing, etc.) This is important in that it can release the distortion that inhibits the movement of carriers in the island-shaped semiconductor layer 203. The timing of the above heat treatment is not particularly limited as long as it is performed after the semiconductor layer 203 is formed. Not determined.

[0124] As an example, a semiconductor device or a display device can be manufactured using the above materials. It is possible.

[0125] (Embodiment 3) In this embodiment, a display device will be described. The display device according to this embodiment receives a video signal. A first circuit having a function of controlling the input of a video signal and a second circuit having a function of holding a video signal. A third circuit having a function of controlling the polarity of a voltage supplied to a display element such as a liquid crystal element. The display device according to the present embodiment stores information in pixels. It has a memory function that

[0126] FIG. 15 shows a circuit diagram (block diagram) of the entire display device (which can also be called a semiconductor device). In the pixel section 1501, a plurality of pixels are arranged in a matrix. Around the pixel portion 1501, there are a circuit 1502 for driving or controlling the pixel portion 1501 and The display device further includes a circuit 1502 and a circuit 1503. 3. The circuit 1504 supplies a signal to the

[0127] The circuit 1502 controls the potential of the gate of the transistor arranged in the pixel portion 1501. Therefore, the circuit 1502 can function as a gate line driver circuit, a gate It is possible for the circuit to have the function of a light driver or a scan driver. The circuit 1503 is a transistor arranged in the pixel portion 1501. Alternatively, the circuit 1503 may have a function of controlling the potential of the input terminal. 1501 can have a function of supplying a video signal. 03 is a circuit called a source line driver circuit, source driver, or data driver. The circuit 1503 can be realized by using only analog switches. The circuits 1502 and 1503 are provided with a clock signal, a start pulse, and Various signals are input, such as a latch signal, a video signal, and a counter voltage inversion signal. A signal such as the following is supplied from the circuit 1504 to the circuits 1502 and 1503. The circuit 1504 may have a function called a controller, a pulse generator, etc. It is possible.

[0128] Next, an example of a pixel arranged in the pixel portion 1501 is shown in FIG. 16. FIG. 16 shows a circuit diagram of one pixel. The pixel includes a circuit 102, a circuit 103, a circuit 104, a capacitor 1612, and A display element 1613 having a pixel electrode is also provided. , but not limited to these.

[0129] The circuit 102 includes a switch 1602. The circuit 103 includes an inverter 1603, a capacitor, and a The circuit 104 has switches 1606 and 1607. Here, the inverter 1603 may have a function of inverting a signal, or , the output may be made to have a high impedance state (floating state). .

[0130] The switch 1602 is connected to the wiring 1601. The capacitor 1605 is connected to the wiring 1601. The capacitor 1604 is connected between the wiring 1610 and the switch 1602. The input terminal of the inverter 1603 is connected between the output terminal of the inverter 1603 and the , connected to the switch 1602. The output terminal of the inverter 1603 is connected to the capacitance element 16 04. The wiring 1608 and the wiring 1609 are connected to the switches 1606 and 160 7. The switch 1606 receives the output signal of the inverter 1603, or Alternatively, the on / off (conduction / non-conduction) is controlled by a signal held in the capacitance element 1604. The switch 1607 is connected to the input signal of the inverter 1603 or the capacitance element 160 The on / off (conducting / non-conducting) state is controlled by the signal held in the display element 16. 13 is connected between a node between the switch 1607 and the switch 1606 and a wiring 1615. The capacitor 1612 is connected to the node between the switch 1607 and the switch 1606. , or between a pixel electrode of the display element 1613 and a wiring 1614 .

[0131] In the configuration example of FIG. 16, the capacitor 1612 can be omitted. The quantity element 1604 may be omitted.

[0132] When the circuit diagram shown in FIG. 16 is compared with the cross-sectional view shown in FIG. 1, for example, the conductive layer 10 The conductive layer 109 may correspond to a counter electrode or a common electrode. 615. Alternatively, the display element 1613 may correspond to the medium 107. Alternatively, the conductive layer 106 may function as a pixel electrode. The pixel electrode 613 can correspond to the pixel electrode.

[0133] In addition, the wiring 1610 and the wiring 1611 are connected to each other to form one wiring. It is possible to connect the wiring 1610 and / or the wiring 1611 to the wiring 1608 and the wiring 1609. By connecting the line 1609 and the wiring 1614, it is possible to form them into one wiring. The wiring 1614 is the wiring 1608, the wiring 1609, the wiring 1610, or By connecting to the wiring 1611, it is possible to form them as one wiring.

[0134] The switch 1602 is a switch that switches a signal supplied to the wiring 1601 to a pixel (or a capacitor 160 5, 1604, inverter 1603) Thus, the switch 1602 serves as a switching or selecting It is possible to say that it has a function.

[0135] The wiring 1601 is electrically connected to the circuit 1503 shown in FIG. A video signal can be supplied from the line 1503 to the wiring 1601. The line 1601 may be called a source line, a source signal line, a data line, a data signal line, etc. It is Noh.

[0136] The wiring 1601 is formed of a light-transmitting material to increase the aperture ratio. However, the present embodiment is not limited to this. For example, the wiring 1601 can be By forming the board from a material that is non-transparent and has high electrical conductivity, it is possible to reduce signal delay. In addition, the wiring 1601 may be formed by a layer of a material having high conductivity and a layer of a material having light transmitting properties. It is possible to form the layer by laminating a layer formed by

[0137] A signal input to the pixel via the switch 1602 is held in a capacitor 1605. The capacitance element 1605 has a function of holding a signal. Moreover, the capacitance element 1605 can be considered as a memory. It is possible that the signal being held may decay, making it a DRAM. .

[0138] The inverter 1603 receives a signal held in the capacitor 1605 or a signal held in the switch 1602. The signal supplied from the wiring 1601 through the The signal output from the inverter 1603 is held in a capacitance element 1604. Since the signal held by the capacitance element 1604 may attenuate over time, It is possible to say that it is a DRAM.

[0139] Since the inverter 1603 is provided, the signal held in the capacitor 1605 is usually The signal held in the capacitor 1604 is an inverted signal. When one is an H signal (high level signal), the other is an L signal (low level signal). However, if the inverter 1603 does not output a signal, e.g. This does not apply when the impedance state is set.

[0140] The switch 1606 supplies the potential of the wiring 1608 to the capacitor 1612 or the display element 16 Similarly, the switch 1607 has a function of controlling whether or not the signal is supplied to the wiring 16. 9 is supplied to the capacitor element 1612 or the display element 1613. It has the function of

[0141] In this manner, the signal held in the capacitor 1605 and the signal held in the capacitor 1604 In many cases, the switches 1606 and 1607 are inverted to each other. Often, one is in the on state (conducting state) and the other is in the off state (non-conducting state). In that case, the display element 1613 is connected to either the wiring 1609 or the wiring 1608. At this time, the potential of the wiring 1609 and the potential of the wiring 1608 are If the potentials are different, the potentials supplied to the display element 1613 are also different. 13 can be controlled to different states (e.g., transparent and non-transparent, luminous and non-luminous, bright and dark, scattering and transparent), etc. Therefore, the display state can be changed, gradation can be expressed, and images can be displayed. It becomes possible to display.

[0142] Next, an example of the operation of the circuit shown in FIG. 16 will be described. First, as shown in FIG. If the switch 1602 is on, the capacitance element 1 An H signal is input to 605. A capacitance element 1604 is connected to the inverter 1603 as follows: An L signal is input.

[0143] Next, as shown in FIG. 17B, the switch 1602 is turned off. Then, the capacitance element 1604 The signal stored in 1605 is held as is. The L signal is stored in the capacitance element 1604. The control terminal of the switch 1603 is held at 0 V, and the capacitance element 1605 is held at 0 V. When an H signal is supplied to the element, it is in the ON state, and when an L signal is supplied, it is in the OFF state. If this is the case, then switch 1606 is turned off and switch 1607 is turned on. Thus, the pixel electrode of the display element 1613 is supplied with the potential V1 of the wiring 1609. If a potential Vcom is applied to the wiring 1615, the display element 1613 will At this time, the voltage V1 is higher than the potential Vco If it is greater than m, a positive voltage is applied to the display element 1613. The display element 1613 is normally black (when no voltage is supplied, the display element is in a black state). ), the display element 1613 displays white. If the display is normally white (when no voltage is applied, the display is in a white state), Child 1613 will display black.

[0144] Next, when it is necessary to drive the display element 1613 by AC, that is, for example, the display element 1 When 613 is a liquid crystal element, it is necessary to apply a negative voltage to the display element 1613. At that time, as shown in FIG. 17C, the potential of the wiring 1609 is changed from V1 to V2. At this time, the potential V2 is lower than the potential Vcom. In other words, V1-Vcom and Vcom-V2 are roughly the same size. As a result, a negative voltage is applied to the display element 1613. After that, By alternately repeating FIG. 17B and FIG. 17C, the display element 1613 is AC-driven. This can be done.

[0145] At this time, even if the signal is not re-input from the wiring 1601, the capacitance elements 1605 and 1604 Since the signal is maintained, the display element can be displayed by alternating between FIG. 17B and FIG. 17C. Therefore, it is possible to reduce power consumption. When it becomes necessary to refresh the signals of the capacitance elements 1604 and 1605, 17A, or when it becomes necessary to rewrite the signal, return to FIG. 17A and reconnect the wiring 16 Input the signal from 01.

[0146] 17A to 17C, the operation when an H signal is input from the wiring 1601 will be described. However, when an L signal is input, the same operation is performed. An example of this is shown in Figures 18A to 18C. vinegar.

[0147] First, as shown in FIG. 18A, it is assumed that an L signal is supplied from a wiring 1601. If the capacitor 1602 is on, an L signal is input to the capacitor 1605. An H signal is input to 04 via an inverter 1603.

[0148] Next, as shown in FIG. 18B, the switch 1602 is turned off. Then, the capacitance element 1604 The signal stored in 1605 is held as is. The L signal is stored in the capacitor 1605. is turned on and the switch 1607 is turned off. A potential V3 of the wiring 1608 is supplied to the wiring 1608. If this is the case, the difference between V3 and Vcom is applied to the display element 1613. At this time, if the potential V3 and the potential Vcom are approximately the same potential, the display element 161 3, almost no voltage is applied. If it is black (when no voltage is supplied, it is in a black state), the display element 1613 On the other hand, when the display element 1613 is normally white (when no voltage is applied), the display element 1613 displays black. When the light is not supplied, the display element 1613 displays white. It becomes.

[0149] Next, when it is necessary to drive the display element 1613 by AC, that is, for example, the display element 1 When 613 is a liquid crystal element, as shown in FIG. 18C, the potential of the wiring 1609 is set to V1 However, the potential of the wiring 1608 is not changed. Even if the potential of 609 changes, almost no voltage is applied to the display element 1613. After that, the patterns of FIG. 18B and FIG. 18C are repeated alternately for each certain period. , when it becomes necessary to refresh the signals of the capacitive elements 1604 and 1605, or When it becomes necessary to rewrite the signal, return to FIG. 18A and reconnect the wiring 1601 to the Input the signal.

[0150] In this way, whether an H signal or an L signal is input from the wiring 1601, the It is possible to display the image while performing flow driving or inversion driving.

[0151] In the driving methods shown in FIGS. 17A to 17C and 18A to 18C, the display element When the polarity of 1613 is reversed, that is, when AC driving is performed, the wiring 1615 However, by changing the potential of the wiring 1615, The amplitude of the potential of the wiring 161 can be reduced. 5, i.e., the potential of the opposing electrode or common electrode, is changed, which is called common inversion. It's called driving.

[0152] Therefore, the operation method when performing common inversion driving is shown in FIG. 19A to FIG. 19C and FIG. 20. A to C are shown.

[0153] First, as shown in FIG. 19A, it is assumed that an H signal is supplied from a wiring 1601. If the capacitor 1602 is on, an H signal is input to the capacitor 1605. An L signal is input to 04 via an inverter 1603.

[0154] Next, as shown in FIG. 19B, the switch 1602 is turned off. Then, the capacitance element 1604 The signal stored in 1605 is held as is. The L signal is stored in the capacitance element 1604. The H signal is stored in the capacitor 1605. The switch 1607 is turned on and the pixel electrode of the display element 1613 is turned off. A potential V5 is applied to the wiring 1609. A potential V6 is applied to the wiring 1615. If this is the case, the voltage applied to the display element 1613 is the difference between V5 and V6. At this time, if the potential V5 is greater than the potential V6, a positive polarity If the display element 1613 is normally black (when no voltage is applied), When the light is turned on, the display element 1613 displays white. On the other hand, if the display element 1613 is normally white (when no voltage is applied, the display element is white), If the display element 1613 is in the ON state, the display element 1613 will display black.

[0155] Note that the potential supplied to the wiring 1614 is not limited to a specific value. It is desirable to change the potential of the wiring 1614 with the same amplitude as the potential supplied to the line 1615. Therefore, for example, the same potential as that of the wiring 1615 is supplied to the wiring 1614. However, the present embodiment is not limited to this.

[0156] Next, when it is necessary to drive the display element 1613 by AC, that is, for example, the display element 1 When 613 is a liquid crystal element, it is necessary to apply a negative voltage to the display element 1613. At that time, as shown in FIG. 19C, the potential of the wiring 1609 is changed from V5 to V6. Then, the potentials of the wiring 1608, the wiring 1615, and the wiring 1614 are changed from V6 to V5. At this time, the potential V6 is lower than the potential V5. Then, a negative voltage is applied to the display element 1613. 19B and 19C are alternately repeated to drive the display element 1613 with an AC current. Then, it becomes necessary to refresh the signals of the capacitance elements 1604 and 1605. When you need to rewrite the signal, go back to Figure 19A and rewrite the distribution. A signal is input from line 1601 .

[0157] At this time, the potential of the wiring 1615 is also changed, so the change amount (amplitude) of the potential of the wiring 1609 Therefore, it is possible to reduce power consumption.

[0158] 19A to 19C, the operation when an H signal is input from the wiring 1601 will be described. However, when an L signal is input, the same operation is performed. An example of this is shown in Figures 20A to 20C. vinegar.

[0159] First, as shown in FIG. 20A, it is assumed that an L signal is supplied from a wiring 1601. If the capacitor 1602 is on, an L signal is input to the capacitor 1605. An H signal is input to 04 via an inverter 1603.

[0160] Next, as shown in FIG. 20B, the switch 1602 is turned off. Then, the capacitance element 1604 The signal stored in 1605 is held as is. The L signal is stored in the capacitor 1605. Therefore, the switch 1606 is turned on. The switch 1607 is turned on and the switch 1608 is turned off. The potential V6 of the line 1608 is supplied. The potential V6 is applied to the wiring 1615. If this is the case, then almost no voltage is applied to the display element 1613. The display element 1613 is normally black (when no voltage is supplied, the display element is in a black state). If so, the display element 1613 will display black. If the display is in a mary white state (when no voltage is applied, the display is in a white state), 613 will display white.

[0161] Next, when it is necessary to drive the display element 1613 by AC, that is, for example, the display element 1 When 613 is a liquid crystal element, as shown in FIG. 20C, the potential of the wiring 1609 is set to V5 to V6. Furthermore, the potentials of the wiring 1608, the wiring 1614, and the wiring 1615 are changed to As a result, even if the potential of the wiring 1614 changes, the display element Almost no voltage is applied to 1613. After that, in each period, 20C are alternately repeated. Then, the signals of the capacitance elements 1604 and 1605 When it becomes necessary to refresh the signal or when it becomes necessary to rewrite the signal Returning to FIG. 20A, a signal is input again from the wiring 1601.

[0162] In this way, whether an H signal or an L signal is input from the wiring 1601, the The image can be displayed while performing current driving or inversion driving. Furthermore, the inversion drive can be performed without inputting the video signal again. This allows for a reduction in power consumption.

[0163] (Embodiment 4) In this embodiment mode, a circuit included in a display device (semiconductor device) will be described with reference to drawings. do.

[0164] 21A to 21E show specific examples of the inverter 1603 shown in FIG. 16 etc. 1A shows an example in which the inverter 1603 is configured as a CMOS. A resistor 2101 and an N-channel transistor 2102 are connected to a wiring 2104 and a wiring 2103. In this CMOS configuration, a low voltage is supplied to the wiring 2103. and a function of supplying a high voltage to the wiring 2104. By using the S configuration, the shoot-through current can be reduced, resulting in lower power consumption. .

[0165] Note that a voltage that does not change over time is supplied to the wiring 2103 or the wiring 2104. However, the present invention is not limited to this, and a pulse-like signal can also be applied.

[0166] In addition, not only polycrystalline silicon semiconductors are used as the semiconductor layer, but also oxide semiconductors can be used. When using an ac transistor, it is possible to form a P-channel transistor. The dopant that becomes the septum (e.g., N, B, Cu, Li, Na, K, Rb, P, As, Substitutional doping with a variety of P-type dopants and dopants (and their mixtures) has been used to A P-type zinc oxide film can be realized by using a doping method. is not limited to this.

[0167] In FIG. 21B, a resistor element 2101a is used instead of the P-channel transistor 2101. The inverter 1603 is connected to the resistor element 2101a. The same semiconductor layer as that of the transistor 2102 can be used. Therefore, for example, the resistor element 2101a can be formed using an oxide semiconductor. In this case, the N-channel transistor 2102 has a channel layer The oxide semiconductor layer used and the oxide semiconductor layer used as the resistor element 2101a , it is possible for the layers to be composed of layers that exist in the same layer.

[0168] In FIG. 21C, instead of the P-channel transistor 2101, a transistor 2101b The inverter 1603 shown in FIG. The transistor 2101b is a depletion type (normally-off). Even if the voltage between the gate and source is 0V or less, the transistor turns on and current flows. It is possible to make it possible to make the N-channel transistor 2102 and the Since the polarity of the first electrode 2101b is the same as that of the first electrode 2101a, the number of process steps can be reduced.

[0169] FIG. 21D shows an example of an inverter 1603 having a bootstrap function. A transistor 2101c, a transistor 2101d, a transistor 2102a, and a transistor The potential of the gate of the transistor 2101d is set to the bootstrap potential. As a result, the potential of the wiring 2104b is increased to a sufficiently high level by the wrapping operation. In addition, the inverter 1603 in FIG. a and the wiring 2103b have a function of supplying a low voltage, and the wiring 2104a and The wiring 2104b has a function of supplying a high voltage. 2103b may be connected together to form a single wiring. 104b may be connected to one wiring. Since 102a, 2102b, and 2101d are of the same polarity, the process steps can be reduced. This makes it possible.

[0170] In addition, in FIG. 21B to FIG. 21D, when the transistor is an N-channel type, However, the present invention is not limited to this. A P-channel type can also be formed in the same manner. As an example, when the transistors 2101b and 2102 in FIG. 21C are P-channel types, An example of this case is shown in FIG. An inverter is configured using a transistor 2102p.

[0171] Next, specific examples of the switches 1602, 1606, 1607, etc. shown in FIG. 16 etc. will be described. The switches 1602, 1606, and 1607 are analog switches or transfer switches. 22A to 22D show examples of the configuration of the switch 1602. The other switches 1606, 1607, etc. are configured similarly to the switch 1602. It can be achieved.

[0172] FIG. 22A shows an example of the configuration of the switch 1602 using a CMOS configuration. , a P-channel transistor 2202 and an N-channel transistor 2201 are connected in parallel. The gate of the P-channel transistor 2202 and the gate of the N-channel transistor 2203 are connected to each other. It is desirable to supply mutually inverted signals to the gates of the two channel transistors 2201. As a result, the P-channel transistor 2202 and the N-channel transistor The CMOS configuration allows the MOSFETs 2201 and 2202 to be turned on and off simultaneously. Therefore, the gates of the P-channel transistor 2202 and the N-channel transistor 2201 are This allows the amplitude of the voltage supplied to the port to be reduced, thereby reducing power consumption. This makes it possible.

[0173] In FIG. 22B, a P-channel transistor is not used, and an N-channel transistor 2201 FIG. 22C shows an example of the configuration of a switch 1602 using an N-channel multi-gate structure. 22 shows an example of the configuration of a switch 1602 provided with a loop-type transistor 2201.

[0174] In the configuration examples of FIGS. 22B and 22C, the transistor 2201 is an N-channel type. The configuration of the switch 1602 is not limited to this. For example, a P-channel transistor As an example, the N-channel transistor in FIG. 22B can be used to configure a switch in the same manner. FIG. 22D shows an example of the configuration of the switch 1602 when the transistor 2201 is a P-channel type. The switch 1602 is configured using a P-channel transistor 2201p. .

[0175] Next, using the circuits shown in FIGS. 21A to 21E and FIGS. 22A to 22D, An example of the circuit disclosed in 20C is shown in FIG. The switches 1602, 1606, and 1607 are configured with the circuit shown in FIG. 22B. The circuit in Figure 23 is therefore composed of transistors of the same polarity. Therefore, the number of process steps can be reduced. Of course, the present embodiment is not limited to this, and other configurations may also be applied. It is possible.

[0176] In the circuit of FIG. 23, the gate of the transistor 1602 a is connected to a wiring 2301 . The wiring 2301 can be connected to the circuit 1502 in FIG. Therefore, a selection signal can be supplied from the circuit 1502 to the wiring 2301. Therefore, the wiring 2301 is also called a gate line, a gate signal line, a scan line, a scan signal line, etc. It is possible to be called.

[0177] Note that the wiring 2301 is formed of a light-transmitting material. This can increase the aperture ratio. However, the present embodiment is not limited to this. For example, the wiring 2301 is made of a material that is non-transparent and has high conductivity, so that the signal It is possible to reduce the delay. Note that the wiring 2301 is made of a material with high conductivity. In this case, wiring is formed in a multi-layer state using layers formed of a light-transmitting material. It is possible.

[0178] In FIG. 23, a liquid crystal element 1613 a is used as the display element 1613 . The switch 1602, the switch 1606, and the switch 1607 are transistors. A transistor 1602a, a transistor 1606a, and a transistor 1607a are arranged.

[0179] In FIG. 23, the capacitor 1605 and the capacitor 1604 are both connected to the wiring 1610. In other words, the wiring 1611 is omitted and is integrated into the wiring 1610. This can be done.

[0180] Although the capacitor 1612 is omitted in FIG. 23, it may be provided.

[0181] Note that the wiring 2103 may be connected to the wiring 1610 and integrated into one wiring.

[0182] In FIG. 23, the configuration of FIG. 21C is used as the inverter 1603. In this case, Depending on the signal input to the inverter 1603, the transistors 2101b and 2102 There is a possibility that the current will continue to flow. In other words, there is a possibility that a shoot-through current will flow through the inverter 1603. In that case, there is a risk that the inverter 1603 will consume excess power.

[0183] Therefore, it is possible to reduce the shoot-through current by devising a driving method. FIG. 27 shows a driving method for reducing the through current of the inverter 1603. As an example, the potential of the wiring 2104 is not kept at a high potential, but is increased. When it is no longer necessary to continue, the potential is lowered. The transistor 2101b is turned off, and the flow of a shoot-through current can be reduced. In that case, the output may go into a high impedance state.

[0184] First, as shown in FIG. 24, an H signal is input from a wiring 1601 through a transistor 1602a. At this time, the potential V7 of the wiring 2104 becomes higher than the potential of the wiring 2103. Then, the N-channel transistor 2102 is turned on, and the capacitor element 1604 At this time, the transistor 2101b is also turned on, but due to the difference in the on-resistance Therefore, the L signal is output. At that time, the through current continues to flow. The ratio W / L of the channel width W to the channel length L of the transistor 2102 is It is desirable that the W / L of the stalk 2101b be larger than that of the stalk 2101b.

[0185] Next, as shown in FIG. 25, the potential of the wiring 2104 is lowered to a potential V8. Here, V7> V8, which is approximately equal to the potential of the wiring 2103. Since 101b is turned off, the flow of through current can be reduced. The signal held by element 1604 remains an L signal.

[0186] At this time, the transistor 1602a is also turned off, but the transistor 1602 The timing when a is turned off can be before or after the potential of the wiring 2104 is changed. Or, both may be performed at the same time.

[0187] At this time, the potential V8 of the wiring 2104 may be approximately the same as the potential of the wiring 2103. The potential V8 is higher than the potential of the wiring 2103 by the threshold voltage of the transistor 2101b. It is sufficient if the potential is lower than the increased potential. More preferably, the potential is equal to the potential of the wiring 2103. As a result, the number of potentials required can be reduced, and the device can be made smaller. This becomes possible.

[0188] 24 and 25 show a case where an H signal is input from the wiring 1601, but The same applies when the above is done, and such cases are shown in Fig. 26 and Fig. 27. First, as shown in Fig. 26, An L signal is input from the wiring 1601 through the transistor 1602a. The potential V7 of the wiring 2104 is higher than the potential of the wiring 2103. Since the channel transistor 2102 is off, the transistor 2101b is on, An H signal is output to the capacitor 1604. At this time, the N-channel transistor 2102 Since the line 2104 is off, no through current flows. The potential is lower than the potential V7 by the threshold voltage of the transistor 2101b. If the voltage is such that the transistor 1606a turns on, there is no problem with the operation.

[0189] Next, as shown in FIG. 27, the potential of the wiring 2104 is lowered to a potential V8. Here, V7> As a result, the transistor 2101b is turned off. At this time, the signal held by the inverter 1603 remains at H level. It can be said that the input is in a low impedance state.

[0190] In this way, the inverter 1603 outputs a signal only when it needs to, i.e. Only when it is necessary to rewrite the signal of the capacitor 1604, the potential of the wiring 2104 is increased. When the inverter 1603 does not need to output a signal, the potential of the wiring 2104 is By lowering the voltage, the through current in the inverter 1603 can be reduced. Therefore, power consumption can be reduced.

[0191] In addition, in Figs. 24 to 27, the inverter 1603 is driven by devising a driving method. However, the present embodiment is not limited to this. By partially modifying the circuit configuration of 03, it is possible to reduce the shoot-through current. An example of this case is shown in Figs. 28A to 28D.

[0192] In FIG. 28A, a transistor 2104 is connected between the wiring 2104 and the output terminal of the inverter 1603. The configuration of the inverter 1603 when a switch 2802a connected in series with 101b is arranged. The switch 2802a is connected to the transistor 2101b and the inverter 160. 3, or between the wiring 2104 and the transistor 2101b. Therefore, in comparison with FIG. 28A, switch 2802a may be connected to transistor 28 FIG. 28B shows a circuit diagram of the inverter 1603 when configured with the inverter 1602. An example of the configuration in which the connection location of the transistor 2802 is changed is shown in FIG. By using such a circuit configuration, the potential of the gate of the transistor 2802 is controlled to turn it on and off. By controlling the current passing through the wiring 2104, it is possible to reduce the through current. In the same manner as changing the potential, the potential of the gate of the transistor 2802 may be controlled.

[0193] In this case, the potential of the wiring 2104 is changed as shown in FIG. 24 to FIG. 27. However, even if the potential of the wiring 2104 is kept constant, This is not a problem because 2802 can reduce the shoot-through current.

[0194] 28A to 28C, a transistor is provided between the wiring 2104 and the output terminal of the inverter 1603. However, the present invention is not limited to this, and the output terminal of the inverter 1603 and the wiring 21 It is also possible to place a transistor between the MOSFET and the MOSFET 03. Further, a transistor 2803 is connected in series with an N-channel transistor 2102. 28C. In addition, as in FIG. 28C, the transistor The position of the P-channel transistor 2101 and the wiring 21 It can be placed between 03.

[0195] The wiring 2801 connected to the gates of the transistors 2802 and 2803 is In this way, the transistor 1602a This allows transistors 2802 and 2803 to be turned on only when is on. Therefore, when the operation of the inverter 1603 is not required, the through current can be reduced. Furthermore, by connecting to the wiring 2301, the wiring is shorter than when a separate wiring is provided. The number of lines can be reduced, but the present embodiment is not limited to this.

[0196] The inverter 1603 in FIG. 28D is configured to control transistors 2802 and 2803. This allows you to control whether to output a signal or put it into a high impedance state, It can also be called a drive inverter.

[0197] (Embodiment 5) In this embodiment mode, a circuit included in a display device (semiconductor device) will be described with reference to drawings. do.

[0198] FIG. 29 shows an example of a circuit configuration in which a part of the circuit shown in FIG. 16 is modified. The circuit in FIG. 29 has the following configuration: This corresponds to a circuit in which switches 2901 and 2902 are added to the circuit in FIG.

[0199] The switch 2902 controls the electrical connection between the display element 1613 and the wiring 1601. Therefore, by turning on the switch 2902, the wiring 1601 The signal supplied to the display element 1613 can be directly supplied to the display element 1613. In many cases, the signal supplied to the wiring 1601 is a digital signal. In the case of a log signal, it is possible to directly input an analog signal to the display element 1613. This makes it possible to display in analog gradations.

[0200] On the other hand, the switch 2901 is connected to the display element 161. The switch 2902 is turned on so that the power is not supplied to the wiring 3. When a signal is being supplied from 1601 to the display element 1613, or after that, switch 2 When the switch 902 is turned off and an analog signal is held in the display element 1613, the wiring 1 When the potential of the wiring 1608 or the wiring 1609 is supplied to the display element 1613, The signal value held in 613 will change. To prevent this, Then, the switch 2901 is turned on and off. Then, a signal is input via the switch 1602. When the potential of the wiring 1608 or the wiring 1609 is increased, the switch 2901 is turned on. is supplied to the display element 1613. It is possible to improve the quality and reduce the power consumption at the same time. The present invention is not limited to these.

[0201] Another example of the configuration is when the number of gradations that can be displayed by one pixel, that is, the number of bits, is increased. 30 and 31. In FIG. 16, the number of bits of the video signal held in the pixel is 1 bit. Therefore, two gradations are displayed. In this case, a plurality of sub-pixels are provided in one pixel. By controlling the display area, it is possible to realize multiple gradations using the area gradation method. It becomes like this.

[0202] In FIG. 30, a wiring 2301 is used to input a video signal to two sub-pixels at the same time. In order to input signals at the same time, a wiring 1601a is provided in addition to the wiring 1601. A signal supplied to either the wiring 1601 or the wiring 1601a is transmitted to each subpixel. The user is then prompted to enter the information.

[0203] On the other hand, in FIG. 31, a wiring 2301 and a wiring 2301a are used to sequentially transmit images to two sub-pixels. The circuit diagram for inputting a signal is shown. A video signal is input to one of the sub-pixels from a wiring 2301. The image signals are input to the other sub-pixel through the wiring 2301a. Therefore, signals can be input sequentially from the wiring 1601 to each sub-pixel.

[0204] Although an example in which two sub-pixels are provided in one pixel is shown in FIG. 30 and FIG. 31, The number of bits is not limited to two. It is possible to increase the number of bits. If the capacitor and the capacitor element are made of a light-transmitting material, the number of bits can be increased. Since this does not affect the decrease in the aperture ratio, the number of bits can be easily increased.

[0205] In addition, wiring 2103, 1610, 1611, 1614, 1609, 1608, 2104, etc. It is possible to share and consolidate the wiring between multiple sub-pixels. This reduces the number of wirings. It is possible to reduce it.

[0206] As another example of the configuration, a case where a part of the circuit 104 is changed is shown in FIG. A switch 4206 is connected in series with the switch 1607. FIG. 42 shows a case where both the switch 4206 and the switch 4207 are provided. By controlling the on / off of the switch 4206 and / or the switch 4207, Therefore, the potential of the wiring 1608 or the wiring 1609 is changed by the switch 1606 or the switch 1 Regardless of whether 607 is on or off, the light is not supplied to the display element 1613. .

[0207] As yet another modified example, a case where a part of the circuit 104 is changed is shown in FIG. This corresponds to the switch 1607 and the wiring 1609 in FIG. 16 being divided into two. A voltage for a positive electrode is supplied to the wire 1609a, and a voltage for a negative electrode is supplied to the wire 1609b. The wiring 1608 is connected to a voltage source that prevents a voltage from being supplied to the display element 1613. For example, a voltage approximately equal to that of the wiring 1615 is supplied to the display element 1613. A switch 1607 and a switch 4307a are connected in series between the switch 1607 and the switch 4307a. Similarly, a switch 1607b and a switch 1609b are connected between the display element 1613 and the wiring 1609b. The switches 4307a and 4307b are connected in series. As long as the two are connected in the same way, they can be connected in different configurations. Switch 4307a and switch 4307b are alternately turned on and off. When switch 4307a is on, switch 4307b is off and switch 4307a is When it is off, the switch 4307b is turned on. As a result, inversion driving can be performed. Cut.

[0208] Although FIG. 43 shows a configuration in which the capacitor 1612 is not provided, it is possible to provide the capacitor. It is.

[0209] (Embodiment 6) In this embodiment mode, a circuit included in a display device (semiconductor device) will be described with reference to drawings. do.

[0210] 32 is a plan view showing an example of the layout of the circuit shown in FIG. The transistor 207 and the capacitor 208 shown in FIG. The contact structure is the contact structure 130 shown in FIG. 2, a contact hole is opened in the insulating layer 202, and the conductive layer 204a and the conductive layer 201 are By using this contact structure, the pixel The aperture ratio of the semiconductor device can be improved. Alternatively, the contact resistance can be reduced, and the The voltage drop can be reduced. Or, the layout area can be reduced. This allows more circuits to be arranged. However, the present embodiment is not limited to this. Various transistor structures, contact structures, capacitor element structures, etc. can be used. It is Noh.

[0211] As shown in FIG. 32, the contact hole 3201b is The source electrode of the N-channel transistor 2102 is connected to the gate electrode of the N-channel transistor 2103. Similarly, the contact hole 3201a is connected to the drain electrode of the transistor 2101b. (source electrode) and the gate electrode are connected.

[0212] Furthermore, the contact hole 3202 is connected to the drain electrode (source electrode) (or the drain electrode (source electrode) of the transistor 1606a) and a pixel electrode It is connected to 3203.

[0213] As shown in FIG. 32, a transistor, a capacitor, a wiring, and the like are formed using a light-transmitting material. As a result, the aperture ratio can be increased. One embodiment of the present invention is not limited to this. For example, the wiring may be a light-transmitting It is possible to form the electrode using a material that does not require a special coating, as shown in Figure 33.

[0214] In FIG. 33, the wiring 1601, the wiring 2301, and the wiring 2104 are made of a material having high electrical conductivity. Therefore, they are not transparent. Therefore, by using a material with high electrical conductivity, the signal wave This makes it possible to reduce the distortion of the shape.

[0215] 34A to 34C, the transistor 1602a, the wiring 1601, and the wiring 2 A configuration example of a part of 103 will be described. FIG. 34A is a plan view of this configuration example. FIG. 34B is a FIG. 34C is a diagram showing an example of a cross-sectional structure taken along the cutting line AB in FIG. 34A. FIG. 13 is a diagram showing another example of a cross-sectional structure.

[0216] In FIG. 34B, the wiring 1601 is a laminate of the conductive layer 204ab and the conductive layer 204aa. Here, the conductive layer 204ab is made of a material that is non-transparent and has high conductivity. The conductive layer 204aa is made of a light-transmitting material. 103 is a laminate of a conductive layer 201ab and a conductive layer 201aa. The conductive layer 201ab is made of a material that is non-transparent and has high electrical conductivity. 1aa is made of a light-transmitting material. In this case, a multi-tone mask (halftone mask) can be used. Using a tone mask or gray-tone mask, the number of masks (reticles) is reduced. For example, the conductive layer 201aa and the conductive layer 201ab may be formed continuously. At the same time, these layers are etched and the resist is ashed, etc., By etching only the conductive layer 201ab, a light-transmitting It is possible to form a pattern having areas that are light-transmitting and areas that are non-light-transmitting.

[0217] However, the present embodiment is not limited to this. b, the conductive layer 201b is disposed so as to have a region where the conductive layer 201ba is not present. 4bb, there may be an area where the conductive layer 204ba is not present. be.

[0218] In addition, in FIG. 34B and FIG. 34C, the light-transmitting layers (conductive layers 201aa, 204aa, 2 On the conductive layers 201ab, 204ab, etc. , 201bb, 204bb, etc.), but this embodiment is not limited to this. For example, it is possible to form the layers in the reverse order. It is also possible to form a layer structure in which a layer is sandwiched between layers having no light transmitting properties.

[0219] As shown in FIG. 34B, a light-transmitting layer is disposed below a light-non-transmitting layer. Conductive layers are formed in such a manner that transistors and capacitor elements are formed using these layers. Using such a layer structure, it is possible to fabricate transistors and FIG. 35 shows an example of a cross-sectional view of a capacitor element.

[0220] The gate electrode is formed by using conductive layers 201ca and 201cb. The source electrode (201cb) is light-transmitting and has high conductivity. The drain electrode is formed using conductive layers 204ca and 204cb. The drain electrode has a light-transmitting property, and the conductive layer 204cb has a light-non-transmitting property and has high conductivity. The source electrode is formed using conductive layers 204da and 204db. The conductive layer 204db is light-non-transmitting and has high conductivity. The electrodes are formed using conductive layers 201da and 201db. The conductive layer 201db has a non-light-transmitting property and a high conductivity. The conductive layer 204ea is transparent. The conductive layer 204eb has non-light-transmitting properties and high conductivity.

[0221] Similarly, as shown in FIG. 34C, a layer having light-transmitting properties is disposed below a layer having no light-transmitting properties. Conductive layers are formed so as to have regions that are not conductive, and these layers are used to form transistors and capacitors. Using such a layer structure, it is possible to construct a quantum well as shown in FIG. FIG. 36 shows an example of a cross-sectional view in which a transistor and a capacitor are formed.

[0222] The gate electrode is formed using a conductive layer 201eb. The conductive layer 201eb has a non-light-transmitting property. The source electrode (drain electrode) is formed using the conductive layer 204fb. The conductive layer 204fb is opaque and has high conductivity. The conductive layer 204gb is non-translucent and The electrode of the capacitor element is formed using the conductive layer 201fb. The conductive layer 204hb is opaque and has high conductivity. The conductive layer 204hb is non-light-transmitting and has high conductivity.

[0223] In addition, elements having such layers can also be used in other transistor structures and capacitor structures. For example, the same formation is possible in the cases shown in FIG. 3 to FIG.

[0224] The transistors and capacitor elements shown in FIG. 35 and FIG. 34 are included in a circuit for driving a pixel. In such circuits, it is not necessary to have light transmission properties, and the This is because it is desirable to form wiring in a layer with a low dielectric constant. This is not limited to the above.

[0225] (Embodiment 7) One mode of a manufacturing method of a display device (semiconductor device) will be described with reference to FIGS. 37A1 to 39. In this embodiment, a method for manufacturing two thin film transistors having different structures on the same substrate is described. An example of the above will be described.

[0226] FIG. 37A1 is a plan view of one thin film transistor 410, and FIG. 37A2 is a plan view of the other thin film transistor 410. FIG. 37B is a plan view of the thin film transistor 420. Also, FIG. 37B shows the line C1-C in FIG. 37A2 and a cross-sectional view taken along line D1-D2 in FIG. 37A2. 37A1 and 37A2 are cross-sectional views taken along line C3-C4 and D3-D4, respectively, of FIG. The surface view is shown.

[0227] The thin film transistor 410 is one of the bottom gate structures called channel etch type. The thin film transistor 420 is called a channel protection type (also called a channel stop type). This is one of the bottom gate structures. Thin film transistor 410 and thin film transistor 420 The thin film transistor 410 is also called an inverted staggered thin film transistor. On the other hand, the thin film transistor 420 is disposed in the pixel. First, a thin-film transistor disposed in a driving circuit of a semiconductor device is a thin-film transistor 420. The configuration of register 410 will now be described.

[0228] The thin film transistor 410 includes a gate electrode layer 411, a first insulating layer 412, a second insulating layer 413, a first insulating layer 414, a second insulating layer 415, a first insulating layer 416, a second insulating layer 417, a first insulating layer 418, a second insulating layer 419, a first insulating layer 420, a second insulating layer 421, a first insulating layer 422, a second insulating layer 423, a first insulating layer 424, a second insulating layer 425, a first insulating layer 426, a second insulating layer 427, a first insulating layer 428, a second insulating layer 429, a first insulating layer 430, a second insulating layer 431, a first insulating layer 432, a second insulating layer 433, a first insulating layer 434, a second insulating layer 435, a first insulating layer 436, a second insulating layer 437, a first insulating The first gate insulating layer 402a, the second gate insulating layer 402b, and at least the channel forming region 413, an oxide having a high resistivity source region 414a, and a high resistivity drain region 414b. The semiconductor layer 412, the source electrode layer 415a, and the drain electrode layer 415b are included. An oxide insulating layer 416 covering the thin film transistor 410 and in contact with the channel formation region 413 is It is provided.

[0229] A high resistance source region 414a is formed in a self-aligned manner in contact with the lower surface of the source electrode layer 415a. In addition, the high-resistance drain region 414b is in contact with the lower surface of the drain electrode layer 415b. The channel formation region 413 is formed in a self-aligned manner. The thickness of the high-resistance source region 414a and the high-resistance drain region 414b are thin. This region has a higher resistance than 414b (I-type region).

[0230] In addition, the thin film transistor 410 includes a source electrode layer 415a and The drain electrode layer 415b is preferably made of a metal material.

[0231] In addition, in a liquid crystal display device, when a pixel portion and a driver circuit are formed on the same substrate, In this paper, thin-film transistors that compose logic gates and thin-film transistors that compose analog circuits are used. A transistor is a transistor in which only positive or only negative polarity is applied between the source and drain electrodes. Logic gates include inverter circuits, NAND circuits, NOR circuits, latch circuits, etc. Analog circuits include sense amplifiers, constant voltage generators, and VCOs. Therefore, the width of the high-resistance drain region 414b, which is required to withstand a certain voltage, is set to be smaller than that of the other The width of the high-resistance source region 414a may be designed to be wider than that of the high-resistance source region 414b. 4a and the high-resistance drain region 414b, even if the width of the overlapping portion of the gate electrode layer 411 is increased, good.

[0232] The thin film transistor 410 disposed in the driving circuit is a thin film transistor with a single gate structure. Although the above description is based on a transistor, a multi-gate transistor having multiple channel formation regions may be used as necessary. A thin film transistor having the above structure can also be formed.

[0233] In addition, a conductive layer 417 is provided so as to overlap the channel formation region 413. 7 is electrically connected to the gate electrode layer 411 and set to the same potential. A gate voltage is applied from above and below the oxide semiconductor layer 412 disposed between the conductive layers 417. In addition, the gate electrode layer 411 and the conductive layer 417 can be set to different potentials, for example, a fixed potential. When setting it to GND or 0V, the electrical characteristics of the TFT, such as the threshold voltage, are controlled. can be done.

[0234] In addition, a protective insulating layer 403 and a planarizing insulating layer 404 are provided between the conductive layer 417 and the oxide insulating layer 416. 04 and stack them together.

[0235] The protective insulating layer 403 is formed by insulating a first gate insulating layer 402 provided below the protective insulating layer 403. It is preferable that the insulating film be in contact with the substrate. , hydrogen ions, OH - In particular, the protective insulating layer 4 The first gate insulating layer 402a in contact with the gate insulating film 403 or the insulating film serving as the base is made of silicon nitride. It is valid if

[0236] Next, the structure of the channel protective thin film transistor 420 disposed in the pixel will be described.

[0237] The thin film transistor 420 includes a gate electrode layer 421, a first insulating layer 422, a second insulating layer 423, a first insulating layer 424, a second insulating layer 425, a first insulating layer 426, a second insulating layer 427, a first insulating layer 428, a second insulating layer 429, a first insulating layer 430, a second insulating layer 431, a first insulating layer 432, a second insulating layer 433, a The first gate insulating layer 402a, the second gate insulating layer 402b, and the oxide layer including the channel forming region The semiconductor layer 422, the oxide insulating layer 426 functioning as a channel protection layer, and the source electrode layer 4 25a, and a drain electrode layer 425b. The oxide insulating layer 426 is in contact with the source electrode layer 425a and the drain electrode layer 425b. A protective insulating layer 403 and a planarizing insulating layer 404 are laminated. A pixel electrode layer 427 in contact with the drain electrode layer 425b is provided on the thin film transistor 420. It is electrically connected to the transistor 420 .

[0238] In order to form the oxide semiconductor layer 422, at least a component constituting the oxide semiconductor layer 422 is Heat treatment (dehydration or dehydrogenation) to reduce impurities such as moisture after the formation of the semiconductor film. Heat treatment for dehydration or dehydrogenation is performed, followed by slow cooling. Then, the oxide insulating layer 426 is formed in contact with the oxide semiconductor layer 422, and the like. Reducing the carrier concentration of 422 improves the electrical characteristics of the thin film transistor 420. This leads to improved reliability.

[0239] The channel formation region of the thin film transistor 420 arranged in the pixel is the oxide semiconductor layer 422. Among these, the oxide insulating layer 426 is in contact with the gate electrode layer 421 and overlaps the oxide insulating layer 426 which is a channel protective layer. The thin film transistor 420 is protected by the oxide insulating layer 426. Therefore, in the etching process for forming the source electrode layer 425a and the drain electrode layer 425b, This can prevent the compound semiconductor layer 422 from being etched.

[0240] In addition, the thin film transistor 420 is a light-transmitting thin film transistor having a high aperture ratio. In order to realize a display device that can transmit light, the source electrode layer 425a and the drain electrode layer 425b are A conductive film having optical properties is used.

[0241] A gate electrode layer 421 of the thin film transistor 420 is also formed using a light-transmitting conductive film.

[0242] In addition, in the pixel where the thin film transistor 420 is arranged, a pixel electrode layer 427 or other The electrode layer (capacitor electrode layer, etc.) and other wiring layers (capacitor wiring layer, etc.) are transparent to visible light. By using a conductive film having the first gate insulating film, a display device having a high aperture ratio is realized. Layer 402a, second gate insulating layer 402b, and oxide insulating layer 426 are also photosensitive to visible light. It is preferable to use a light-transmitting film.

[0243] In this specification, a film that is transparent to visible light has a visible light transmittance of 75 to 100 %, and if the film is conductive, it is also called a transparent conductive film. An electrode layer, a source electrode layer, a drain electrode layer, a pixel electrode layer, or other electrode layers, etc. As the metal oxide applied to the wiring layer, a conductive film that is semitransparent to visible light may be used. Translucent to visible light means that the visible light transmittance is 50 to 75%.

[0244] Hereinafter, referring to Figs. 38A to 38F and Figs. 39A to 39E, a thin-film transistor formed on the same substrate will be described. The steps of fabricating the thin film transistor 410 and the thin film transistor 420 will be described. The cross-sectional structure shown corresponds to the cross-sectional structure of FIG. 37B.

[0245] First, as shown in FIG. 38A, a light-transmitting conductive film is formed on a substrate 400 having an insulating surface. After that, the gate electrode layers 411 and 421 are formed by a first photolithography process. In addition, the first photolithography process is performed on the light-transmitting conductive film. In addition, when capacitance is required not only in the pixel section but also in the drive circuit, A capacitance wiring layer is also formed on the driving circuit. The resist mask is formed by the inkjet method. If the resist mask is formed by the inkjet method, no photomask is required. This reduces manufacturing costs.

[0246] There is no significant limitation on the substrate that can be used as the substrate 400 having an insulating surface. However, at least The substrate must have sufficient heat resistance to withstand subsequent heat treatment. 400 is a substrate made of an insulating material such as a glass substrate, a ceramic substrate, a quartz substrate, or a sapphire substrate. A plate can be used.

[0247] In addition, an insulating film serving as a base film may be provided between the substrate 400 and the gate electrode layers 411 and 421. The undercoat film has a function of preventing the diffusion of impurity elements from the substrate 400. a silicon oxide film, a silicon nitride oxide film, or a silicon oxynitride film; It can be formed by a laminated structure of a plurality of films.

[0248] The materials of the gate electrode layers 411 and 421 and the capacitor wirings of the pixel portion and the like are transparent to visible light. For example, a film made of an In-Sn-Zn-O system, In- Al-Zn-O system, Sn-Ga-Zn-O system, Al-Ga-Zn-O system, Sn-Al-Z nO series, In-Zn-O series, Sn-Zn-O series, Al-Zn-O series, In-O series, Sn The gate electrode layers 411 and 421 can be formed of a metal oxide such as Zn-O or Zn-O. The thickness of the capacitance wiring of the pixel portion or the like is appropriately selected within the range of 50 nm to 300 nm. The metal oxide film forming method for the gate electrode layers 411 and 421 is a sputtering method or a vacuum deposition method ( The deposition method includes deposition by electron beam, deposition by arc discharge, deposition by ion plating, and deposition by spraying. In addition, when using a sputtering method, a target containing SiO2 in an amount of 2% by weight or more and 10% by weight or less is used. The transparent conductive film is formed using a SiOx (X>0) that inhibits crystallization. However, it will crystallize during the heat treatment for dehydration or dehydrogenation in the subsequent process. It is preferable to suppress

[0249] Next, a gate insulating layer is formed on the gate electrode layers 411 and 421 .

[0250] The gate insulating layer is a silicon oxide layer formed by plasma CVD or sputtering. A silicon nitride layer, a silicon oxynitride layer, or a silicon nitride oxide layer is formed as a single layer or a stacked layer. For example, a plasma deposition can be performed using SiH4, oxygen, and nitrogen as deposition gases. A silicon oxynitride layer may be formed by a chemical vapor deposition (CVD) method.

[0251] In this embodiment, as shown in FIG. 38A, a first gate electrode having a film thickness of 50 nm to 200 nm is formed. a first gate insulating layer 402a and a second gate insulating layer 402b having a thickness of 50 nm to 300 nm. The first gate insulating layer 40 is formed into a two-layer structure. A silicon nitride film or a silicon nitride oxide film having a thickness of 100 nm is used as 2a. The second gate insulating layer 402b is a silicon oxide film having a thickness of 100 nm.

[0252] An oxide semiconductor film 43 having a thickness of 2 nm to 200 nm is formed on the second gate insulating layer 402b. 0 is formed. The crystal structure of the oxide semiconductor film 430 is amorphous.

[0253] In this embodiment, after the oxide semiconductor film 430 is formed, heating is performed for dehydration or dehydrogenation. The oxide semiconductor film 430 after the heat treatment is maintained in an amorphous state. In order to achieve this, the oxide semiconductor film 430 is preferably thin, ie, 50 nm or less. By making the oxide semiconductor film 430 thin, the oxide semiconductor film 430 can be crystallized by heat treatment after the formation of the oxide semiconductor film 430. The above-mentioned problems can be suppressed.

[0254] Note that before the oxide semiconductor film 430 is formed by a sputtering method, argon gas is introduced. Reverse sputtering is performed to generate plasma, and the second gate insulating layer 402b is adhered to the surface of the second gate insulating layer 402b. It is preferable to remove the dust that is in the target. In an argon atmosphere, a voltage is applied to the substrate side using an RF power source to form plasma near the substrate. In addition, nitrogen, helium, oxygen, etc. can be used instead of argon. It is also possible to carry out the sputtering process in an atmosphere.

[0255] The oxide semiconductor film 430 is an In-Ga-Zn-O based non-single crystal film, an In-Sn-Zn-O based , In-Al-Zn-O system, Sn-Ga-Zn-O system, Al-Ga-Zn-O system, Sn- Al-Zn-O series, In-Zn-O series, Sn-Zn-O series, Al-Zn-O series, In-O In this embodiment, an In-Ga-based, Sn-O-based, or Zn-O-based oxide semiconductor film is used. Using a Zn-O-based oxide semiconductor target, an oxide semiconductor film 43 was formed by sputtering. The oxide semiconductor film 430 is formed under a rare gas (typically, argon) atmosphere. , in an oxygen atmosphere, or in an atmosphere of rare gas (typically argon) and oxygen. When the sputtering method is used, the SiO2 film is formed at 2% by weight. The oxide semiconductor film 430 is crystallized by depositing the oxide semiconductor film 430 using a target containing 10% by weight or less of the oxide semiconductor film 430. The SiOx (X>0) is included to inhibit the dehydration or dehydrogenation in the subsequent process. It is preferable to suppress crystallization during the heat treatment.

[0256] Next, the oxide semiconductor film 430 is processed into an island-shaped oxide semiconductor film by a second photolithography process. In addition, a resist mask for forming an island-shaped oxide semiconductor layer is applied to the ink. If the resist mask is formed by the inkjet method, the photomask Since no disks are used, manufacturing costs can be reduced.

[0257] Next, the oxide semiconductor layer is dehydrated or dehydrogenated. The temperature of the heat treatment in step 1 is 350° C. or higher and lower than the distortion point of the substrate, preferably 400° C. or higher. Here, the substrate is placed in an electric furnace, which is a type of heat treatment device, and the oxide semiconductor layer is After the heat treatment is performed in a nitrogen atmosphere, the oxide semiconductor layer is cooled to a predetermined temperature or lower. This prevents water and hydrogen from re-entering the oxide semiconductor layer, and the oxide Semiconductor layers 431 and 432 are obtained (see FIG. 38B). In this embodiment, , heating at a temperature T in a nitrogen atmosphere for dehydrating or dehydrogenating the oxide semiconductor layer; After the treatment, the temperature is lowered to a temperature that will not allow water to enter again (specifically, 10°C from temperature T). The substrate is then cooled slowly in the same furnace until the temperature drops to 0°C or more. Alternatively, the heat treatment can be carried out in an atmosphere of sodium, neon, argon, or the like.

[0258] In the first heat treatment, nitrogen or a rare gas such as helium, neon, or argon is used. It is preferable that the gas does not contain water, hydrogen, etc. The purity of rare gases such as helium, neon, and argon is 6N (99.9999%) or higher. Preferably, the concentration of impurities is 7N (99.99999%) or more (i.e., 1 ppm or less, It is preferable to keep the concentration of the EDTA concentration at 0.1 ppm or less.

[0259] Depending on the conditions of the first heat treatment or the material of the oxide semiconductor layer, In some cases, the film may crystallize to become a microcrystalline or polycrystalline film.

[0260] In addition, the first heat treatment of the oxide semiconductor layer is performed on the oxide semiconductor layer before it is processed into the island-shaped oxide semiconductor layer. The heat treatment can also be performed on the semiconductor film 430. In that case, after the first heat treatment, The substrate is then taken out and subjected to a photolithography process.

[0261] In addition, before the oxide semiconductor film 430 is formed, an inert gas atmosphere (nitrogen, helium, or neodymium) is used. Heat treatment (400℃ or higher but below the distortion point of the substrate) in an oxygen atmosphere (air, argon, etc.) ) to obtain a gate insulating layer from which impurities such as hydrogen and water contained in the layer have been removed. .

[0262] Next, a metal oxide semiconductor layer was formed over the second gate insulating layer 402b and the oxide semiconductor layers 431 and 432. After the conductive film is formed, a resist mask 433a and A resist mask 433b is formed, and selective etching is performed to form a metal electrode layer 434, And a metal electrode layer 435 is formed (see FIG. 38C).

[0263] The material of the metal conductive film is an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W. or an alloy containing the above elements as components, or an alloy containing a combination of the above elements. The metal conductive film may be a titanium layer, an aluminum layer on the titanium layer, and a titanium layer on the aluminum layer. A laminated three-layer structure, or an aluminum layer on a molybdenum layer and the aluminum It is preferable to form a three-layer laminate structure in which a molybdenum layer is laminated on a metal conductive film. The insulating film may have a single layer structure, a two-layer structure, or a laminated structure of four or more layers.

[0264] Resist masks 433a and 433b for forming metal electrode layers 434 and 435 are formed. The resist masks 433a and 433b may be formed by an ink-jet method. When the film is formed by the photolithography method, no photomask is used, and therefore the manufacturing cost can be reduced.

[0265] Next, the resist masks 433a and 433b are removed, and a fourth photolithography process is performed. A resist mask 436a and a resist mask 436b are formed by this, and selective etching is performed. Then, a source electrode layer 415a and a drain electrode layer 415b are formed (see FIG. 38D). Note that in the fourth photolithography step, the oxide semiconductor layer 431 is only partially etched. The oxide semiconductor layer 437 is formed by etching the oxide semiconductor layer 437. Resist masks 436a and 436b for forming grooves (recesses) are formed on 431 by inkjet printing. If the resist mask is formed by the ink-jet method, the photomask Since no additional heat is used, the manufacturing cost can be reduced.

[0266] Next, the resist masks 436a and 436b are removed, and a fifth photolithography process is performed. A resist mask 438 is formed to cover the oxide semiconductor layer 437, and the oxide semiconductor layer 432 is The top metal electrode layer 435 is removed (see FIG. 38E).

[0267] Note that the metal electrode layer 435 overlapping with the oxide semiconductor layer 432 in the fifth photolithography step In order to remove the oxide semiconductor layer 432, the oxide semiconductor layer 432 is also removed when the metal electrode layer 435 is etched. The materials and etching conditions are appropriately adjusted so that this is not the case.

[0268] After removing the resist mask 438, as shown in FIG. 38F, The oxide insulating film 43 is in contact with the surface and side surfaces of the oxide semiconductor layer 437 and the groove (depression portion) of the oxide semiconductor layer 437. 9. The oxide insulating film 439 serves as a protective insulating film.

[0269] The oxide insulating film 439 has a thickness of at least 1 nm. The insulating film 439 can be formed by using an appropriate method that does not allow impurities such as water and hydrogen to be mixed into the insulating film 439. In this embodiment, the oxide insulating film 439 is formed to a thickness of 30 The substrate temperature during film formation is set to room temperature or higher and 300°C or lower. In this embodiment, the temperature is set to 100° C. The film is heated under a rare gas (typically argon) atmosphere, under oxygen atmosphere, or under a rare gas (typically The method can be carried out under an atmosphere of argon and oxygen. A silicon oxide target or a silicon target can be used. Silicon oxide was deposited by sputtering in oxygen and nitrogen atmosphere using a silicon target. In contact with the low-resistance oxide semiconductor layers 432 and 437, The oxide insulating film 439 is resistant to moisture, hydrogen ions, and OH. - It does not contain impurities such as An inorganic insulating film is used to block the intrusion of A silicon nitride oxide film, an aluminum oxide film, an aluminum oxynitride film, or the like is used.

[0270] Next, a second heat treatment (preferably a second heat treatment) is performed under an inert gas atmosphere or an oxygen gas atmosphere. For example, the heating is performed in a nitrogen atmosphere. The second heat treatment is performed at 250° C. for 1 hour under atmospheric pressure. The grooves of the oxide semiconductor layer 437 and the top and side surfaces of the oxide semiconductor layer 432 are in contact with the oxide insulating film 439. It is heated in this state.

[0271] FIG. 39A shows a state after the second heat treatment. In FIG. 39A, the oxide semiconductor layer 412 The oxide semiconductor layer 437 is the oxide semiconductor layer 437 that has been subjected to the second heat treatment, and the oxide semiconductor layer 422 is the oxide semiconductor layer 437 that has been subjected to the first heat treatment. The oxide semiconductor layer 432 is subjected to the second heat treatment.

[0272] Through the above steps, the oxide semiconductor film 430 after deposition is dehydrated or dehydrogenated. The first heat treatment is for the purpose of oxidizing the fluorine-containing compound, and the second heat treatment is for the purpose of oxidizing the fluorine-containing compound under an inert gas atmosphere or an oxygen gas atmosphere. The heat treatment is carried out.

[0273] Therefore, in the oxide semiconductor layer 412, a region overlapping with the source electrode layer 415a has a high resistance. The source region 414a is formed in a self-aligned manner, and the region overlapping the drain electrode layer 415b is A high-resistance drain region 414b is formed in a self-aligned manner. The entire region is an i-type region, which serves as a channel formation region 413. The layer 432 is heated to a second temperature so that the entire film is made oxygen-excessive, and the entire film is made highly resistive. In this way, an i-type oxide semiconductor layer 422 is formed.

[0274] After the second heat treatment, the oxide semiconductor layer 422 is exposed in an inert gas atmosphere containing nitrogen. When heat treatment is performed under atmospheric pressure or reduced pressure, a high-resistance (i-type) oxide semiconductor layer is formed. Therefore, in the second heat treatment and subsequent steps, the oxide semiconductor layer 422 is Heat treatment with 422 exposed should be done in an oxygen gas, N2O gas atmosphere, or ultra-dry This is done with dry air (dew point below -40°C, preferably below -60°C).

[0275] Note that the oxide semiconductor layer overlapping with the drain electrode layer 415b (and the source electrode layer 415a) In the layer 412, a high-resistance drain region 414b (or a high-resistance source region 414a) is formed. By forming the thin film transistor 410, the reliability of the driving circuit in which the thin film transistor 410 is provided is improved. Specifically, by forming the high-resistance drain region 414b, the drain current can be reduced. The conductive layer 415b extends from the high-resistance drain region 414b to the channel forming region 413. Therefore, the drain electrode layer 4 can be structured so that the efficiency can be changed stepwise. 15b is connected to a wiring for supplying a high power supply potential VDD to operate the thin film transistor 410. In this case, even if a high electric field is applied between the gate electrode layer 411 and the drain electrode layer 415b, The high-resistance drain region 414b acts as a buffer to prevent a local high electric field from being applied. This can improve the breakdown voltage of the resistor 410.

[0276] In addition, the drain electrode layer 415b (or the source electrode layer 415a) of the oxide semiconductor layer 412 A high-resistance drain region 414b (or a high-resistance source region 414a) is formed in the overlapping region. By forming the thin film transistor 410 in the driver circuit, the channel formation The leakage current in the region 413 can be reduced.

[0277] Next, as shown in FIG. 39B, a resist mask is formed by a sixth photolithography process. 440a and a resist mask 440b are formed, and the oxide insulating film 439 is selectively etched. The oxide insulating layer 416 and the oxide insulating layer 426 are formed by etching. The insulating film 26 covers a region of the oxide semiconductor layer 422 that is to form a channel formation region, and serves as a channel protection film. Note that, as in this embodiment, an oxide film is used as the second gate insulating layer 402b. When a oxide insulating layer is used, the second gate insulating layer is formed by etching the oxide insulating layer 439. A part of the edge layer 402b may also be etched, resulting in a thinner film thickness (film loss). In the case where a nitride insulating film having a high selectivity with respect to the oxide insulating film 439 is used as the gate insulating layer 402b, In this case, it is possible to prevent the second gate insulating layer 402b from being thinned by etching.

[0278] After removing the resist masks 440a and 440b, the oxide semiconductor layer 422 and the oxide insulating layer A light-transmitting conductive film is formed on the edge layer 426. Then, a seventh photolithography process is performed. A resist mask is formed by a process, and the light-transmitting conductive film is etched using the resist mask. As shown in FIG. 39C, the source electrode layer 425a and the drain electrode layer 42 After the etching process, the resist mask is removed.

[0279] The method for forming a conductive film with light transmission includes sputtering and vacuum deposition (electron beam deposition, etc.). For the conductive film, a method such as arc discharge ion plating or spraying can be used. The material is a conductive material that is transparent to visible light, such as an In-Sn-Zn-O system. , In-Al-Zn-O system, Sn-Ga-Zn-O system, Al-Ga-Zn-O system, Sn- Al-Zn-O series, In-Zn-O series, Sn-Zn-O series, Al-Zn-O series, In-O Metal oxides of the Sn-O, Sn-O, and Zn-O types can be used. The thickness of the film is appropriately selected within the range of 50 nm to 300 nm. In this case, the film is formed using a target containing 2% by weight or more and 10% by weight or less of SiO2, The transparent conductive film is made to contain SiOx (X>0) which inhibits crystallization, and is then processed in a later step. It is preferable to suppress crystallization during the heat treatment for dehydration or dehydrogenation. It is nice.

[0280] Note that a resist mask for forming the source electrode layer 425a and the drain electrode layer 425b is used. The resist mask may be formed by an inkjet method instead of a photolithography process. When the inkjet method is used to form the film, no photomask is used, reducing manufacturing costs. Cut.

[0281] Next, as shown in FIG. 39D, the oxide insulating layers 416, 426, the source electrode layer 425a, A protective insulating layer 403 is formed over the drain electrode layer 425b. A silicon nitride film is formed as the protective insulating layer 403 by using the RF sputtering method. The TA method is suitable for mass production and is therefore preferred as a method for forming the protective insulating layer 403. 03 is water, hydrogen ions, OH - It does not contain impurities such as The inorganic insulating film used is a silicon nitride film, an aluminum nitride film, or a nitride oxide film. A silicon film, an aluminum oxynitride film, or the like is used. Of course, the protective insulating layer 403 has a light-transmitting property. It is an insulating film.

[0282] The protective insulating layer 403 is also a first gate insulating film provided below the protective insulating layer 403. It is preferable that the insulating film is in contact with the layer 402a or the insulating film serving as the base. Water, hydrogen ions, and OH from near the surface - It blocks the intrusion of impurities such as In particular, the first gate insulating layer 402a in contact with the protective insulating layer 403 or the insulating film serving as the base It is effective to use a silicon nitride film. By providing a silicon nitride film so as to surround the display device, the reliability of the display device is improved.

[0283] Next, a planarization insulating layer 404 is formed over the protective insulating layer 403. For heat resistance, polyimide, acrylic, benzocyclobutene, polyamide, epoxy, etc. In addition to the above organic materials, low dielectric constant materials (lo wk materials), siloxane resin, PSG (phosphorus glass), BPSG (borophosphorus glass) In addition, it is possible to laminate multiple insulating films made of these materials. In this way, the planarization insulating layer 404 may be formed.

[0284] 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.

[0285] The method for forming the planarization insulating layer 404 is not particularly limited. Depending on the material, it may be a sputtering method, a SO G method, spin coating, dip, spray coating, droplet ejection method (inkjet method, screen printing, offset printing, etc.), doctor knife, roll coater, curtain coater, A knife coater or the like can be used.

[0286] Next, an eighth photolithography step is performed to form a resist mask and a planarization insulating layer 4 04, and the protective insulating layer 403 is etched to form a contact that reaches the drain electrode layer 425b. A contact hole 441 is formed. Also, the gate electrode layer 411 and A contact hole reaching the drain electrode layer 425b is also formed. A resist mask for forming contact holes may be formed by an inkjet method. When a resist mask is formed using the inkjet method, no photomask is used, so manufacturing costs are reduced. This can reduce costs.

[0287] Next, after removing the resist mask, a light-transmitting conductive film is formed. The conductive film material is indium oxide (In2O3) or an indium oxide tin oxide alloy. (In2O3-SnO2, abbreviated as ITO) etc. are formed using sputtering or vacuum deposition methods. As another material for the conductive film having light-transmitting properties, a nitrogen-containing Al-Zn-O-based non-single crystal films, i.e. Al-Zn-ON non-single crystal films, Zn-O non-single crystal films containing nitrogen, and nitrogen It is also possible to use a Sn-Zn-O-based non-single crystal film containing Al-Zn-ON. The composition ratio (atomic %) of zinc in the single crystal film is 47 atomic % or less, and the composition ratio (atomic %) of aluminum in the non-single crystal film is 47 atomic % or less. The composition ratio (atomic %) of aluminum in the non-single crystal film is larger than that of the non-single crystal film. This is larger than the composition ratio (atomic percentage) of nitrogen in the crystal film. Etching of such materials is performed with hydrochloric acid. However, since ITO etching is particularly prone to leaving residues, Indium oxide zinc oxide alloy (In2O3-ZnO) was used to improve the machining processability. It's fine if you're there.

[0288] The composition ratio of the light-transmitting conductive film is expressed in atomic percent. (EPMA:Electron Probe X-ray MicroAnalyzer ) will be used for the evaluation.

[0289] Next, a ninth photolithography process is performed to form a resist mask and to form a As shown in FIG. 39E, the pixel electrode layer 427 and the conductive layer 417 are removed. A contact hole is formed in the planarization insulating layer 404 and the protective insulating layer 403. Through 441, the pixel electrode layer 427 is electrically connected to the drain electrode layer 425b.

[0290] Through the above steps, a thin-film transistor was formed on the same substrate 400 using nine exposure masks. A driver circuit including a thin film transistor 410 and a pixel portion including a thin film transistor 420 can be fabricated. The thin film transistor 410 for the driving circuit has a high resistance source region 414a, a high resistance drain region 414b, and a The oxide semiconductor layer 412 includes a drain region 414b and a channel formation region 413. The thin film transistor 420 for the pixel is a channel-etch type thin film transistor. This is a channel-protective thin film transistor including an oxide semiconductor layer 422 which is entirely i-type.

[0291] In addition, the first gate insulating layer 402a and the second gate insulating layer 402b are used as dielectrics to form a capacitance wiring. A capacitor element formed by a layer and a capacitor electrode can also be formed on the same substrate 400. The transistors 420 and the capacitors are arranged in a matrix corresponding to each pixel to form a pixel portion. and arranging a driver circuit having a thin film transistor 410 around the pixel portion. This can be one of the substrates for manufacturing an active matrix type display device. For the sake of convenience, this type of substrate is referred to as an active matrix substrate in this specification.

[0292] The pixel electrode layer 427 is electrically connected to the capacitor electrode layer. The contact hole for connecting to the contact hole 441 is formed at the same time. In addition, the capacitor electrode layer has the same light-transmitting property as the source electrode layer 425a and the drain electrode layer 425b. The materials can be formed in the same process.

[0293] The conductive layer 417 is provided so as to overlap with the channel formation region 413 of the oxide semiconductor layer 412. and a bias-thermal stress test for checking the reliability of the thin film transistor 410. (hereinafter referred to as BT test), the thin film transistor 410 before and after the BT test The amount of change in the threshold voltage can be reduced. This may be the same as or different from layer 411 and serves as a second gate electrode layer. The conductive layer 417 may be set to a potential of GND, 0 V, or in a floating state. It's fine.

[0294] In addition, a resist mask for forming the conductive layer 417 and the pixel electrode layer 427 is formed by ink jet printing. If the resist mask is formed by the ink-jet method, the photomask Since no additional heat is used, the manufacturing cost can be reduced.

[0295] (Embodiment 8) In this embodiment, an example of an electronic device including a display device will be described.

[0296] 40A to 40H and 41A to 41D are diagrams showing electronic devices. The child device includes a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, Operation keys 5005 (including a power switch or an operation switch), a connection terminal 5006, a sensor Sa5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature degree, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient , vibration, odor or infrared measuring functions), microphone 5008, etc. It is possible to have.

[0297] FIG. 40A shows a mobile computer, which, in addition to the above, includes a switch 5009, an infrared 40B shows a portable image sensor equipped with a recording medium. A playback device (for example, a DVD playback device) that includes a second display unit 500 in addition to the above. 2, a recording medium reading unit 5011, etc. FIG. 40C shows a goggle-type display. In addition to the above, the display includes a second display unit 5002, a support unit 5012, and earphones 50 13, etc. FIG. 40D shows a portable gaming machine, which, in addition to the above, A recording medium reading unit 5011, etc. can be included. FIG. In addition to the above, it also has an antenna 5014 and a shutter button 5015. , image receiving unit 5016, etc. FIG. 40F shows a portable gaming machine. In addition to the above, it may have a second display unit 5002, a recording medium reading unit 5011, etc. FIG. 40G shows a television receiver, which includes a tuner, an image processor, etc. in addition to the above components. FIG. 40H shows a portable television receiver, which, in addition to the above, can also receive signals. The device may have a charger 5017 capable of transmitting and receiving signals, etc.

[0298] FIG. 41A shows a display having a support base 5018 and the like in addition to the above-mentioned components. FIG. 41B shows a camera, which, in addition to the above, has an external connection port 5019, The camera may have a shutter button 5015, an image receiving unit 5016, etc. In addition to the above, a pointing device 5020, an external connection port 5019, a reader / writer 5021, etc. FIG. 41D shows a mobile phone. In addition to the above, there are transmitters, receivers, and one-segment units for mobile phones and mobile terminals. tuners for minute receiving services, etc.

[0299] The electronic devices shown in FIGS. 40A to 40H and 41A to 41D have various functions. For example, various information (still images, videos, text images, etc.) can be displayed on the display unit. Functions, touch panel functions, calendars, functions to display dates or times, etc., various software Functions for controlling processing by software (programs), wireless communication functions, and Ability to connect to various computer networks, wireless communication function to store various data Functions for transmitting or receiving, reading out programs or data recorded on a recording medium The electronic device may have a function of displaying information on a display unit. In the device, one display unit is used mainly to display image information, and another display unit is used mainly to display A function that displays text information or displays images that take parallax into account on multiple displays. It can have a function of displaying a stereoscopic image. The device has the functions of taking still images, taking videos, and automatically or Ability to manually correct images and store captured images on a recording medium (external or built-in to the camera) The camera can have a function of displaying the captured image on the display unit. The functions that the electronic device shown in FIG. 40H and FIG. 41A to FIG. 41D can have are not limited to these. The number of inputs is not limited and can have a variety of functions.

[0300] The electronic device described in this embodiment has a display unit for displaying some information. This is one of its characteristics.

[0301] Next, application examples of the display device (semiconductor device) will be described. First, the display device is used to display a stationary object, such as a building. An example in which a display device (semiconductor device) is applied to an object will be described.

[0302] FIG. 41E is a diagram illustrating an embodiment of a structure in which a display device (semiconductor device) is incorporated. The semiconductor device includes a housing 5022, a display portion 5023, a remote control device 5024 which is an operation portion, and a speaker 5025. The semiconductor device can be mounted on the wall of a room as a wall-mounted display device. This type of display does not require a large installation space, so it can be used with a large screen (40 inches). This is a suitable method for incorporating a semiconductor device having a display unit 5023 (inch or more) into a structure. do.

[0303] FIG. 41F is a diagram illustrating an embodiment of a structure in which a display device (semiconductor device) is incorporated. The semiconductor device includes a display panel 5026. The display panel 5026 is a unit The bather can watch the video on the display panel 5026. It becomes Noh.

[0304] In addition, in FIG. 41E and FIG. 41F, a display device (semiconductor device) is installed on the wall and the unit bath. However, the structure of the present embodiment is not limited to this, and may be used in various places of the structure. A semiconductor device can be incorporated in the

[0305] Next, a configuration example of a moving object in which the display device (semiconductor device) is incorporated will be described.

[0306] FIG. 41G is a diagram illustrating one mode of an automobile provided with a display device (semiconductor device). The semiconductor device has a display panel 5028. The display panel 5028 is mounted on a vehicle body 502 of the automobile. 9, and transmits on demand the operation of the vehicle or information input from inside and outside the vehicle. The semiconductor device may have a navigation function.

[0307] FIG. 41H is a diagram illustrating an embodiment of a passenger airplane provided with a display device (semiconductor device). The semiconductor device has a display panel 5031. A display panel 5031 is attached to the display panel 5030 via a hinge portion 5032. 5031 has a function of displaying information when operated by passengers. The figure shows the state of the display panel 5031 when in use. The expansion and contraction of the hinge part 5032 allows passengers to It will be possible to watch Nell 5031 videos.

[0308] In addition, in Fig. 41G and Fig. 41H, examples of a car and a passenger airplane are shown as moving objects. However, the present embodiment is not limited to these, and may be applied to motorcycles, four-wheeled vehicles (cars, buses, trucks, etc.). It can be applied to various moving objects such as railroad cars, ships, and aircraft. Cut.

[0309] (Embodiment 9) In this embodiment, a semiconductor device and a display device according to the invention disclosed in this specification are We will explain these and other matters.

[0310] In this specification, the term "display device" refers to a device having a display element. The display device to which the invention is applied is a display device that uses electromagnetic effects to improve contrast, Examples of the display medium include those that have a changeable brightness, reflectance, transmittance, etc. The display element of the display device is an EL (electroluminescence) element. (EL elements containing organic and inorganic materials, organic EL elements, inorganic EL elements), LED (white LED ED, red LED, green LED, blue LED, etc.), transistor (lights up according to current transistor), electron emission element, liquid crystal element, electronic ink, electrophoretic element, grating Light valves (GLV), plasma tubes, digital micromirror devices (DMD) ), piezoelectric ceramic elements, carbon nanotubes, etc. An example of a display device is an EL display. Examples include field emission displays (FED) or SED flat panel displays. Spray (SED: Surface-conduction Electron-emissive An example of a display device using a liquid crystal element is a liquid crystal display. Display devices (transmissive liquid crystal display devices, transflective liquid crystal display devices, reflective liquid crystal display devices, direct-view liquid crystal display devices) Display devices using electronic ink or electrophoretic elements. An example of such a device is electronic paper. A device equipped with the element is sometimes called a display device, and sometimes called a light-emitting device. A light-emitting device having a light-emitting element as a display element is a specific example of a display device.

[0311] An example of an EL element includes an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. One example of an EL layer is a device that uses light emission (fluorescence) from singlet excitons. those that utilize emission from triplet excitons (phosphorescence), and those that utilize emission from singlet excitons (fluorescence). ) and those that utilize light emission from triplet excitons (phosphorescence), Those formed by matter, those formed by inorganic matter, those formed by organic matter Those made of inorganic materials, those made of polymeric materials, those made of low molecular weight materials Materials that contain both polymeric and low molecular weight materials, etc. The EL element is not limited to this, and various elements can be used.

[0312] An example of an electron-emitting device is a device that extracts electrons by concentrating a high electric field on a cathode. Specifically, examples of electron-emitting elements include Spindt type and carbon nanotube (CNT) MIM (Metal-Insulator-Metal) MIS (Metal-Insulator-Semiconductor) type, a stack of metal-insulator-semiconductor emissive type, MOS type, silicon type, thin film diode type, diamond Thin film types such as metal-insulator-semiconductor-metal type, HEED type, EL type, and porous silicon However, there are other types of electron emitters, including surface conduction (SCE) types. A variety of different types of filters can be used.

[0313] In this specification, the liquid crystal display device refers to a display device having a liquid crystal element. Depending on the image display method, they are classified as direct-view type, projection type, etc. Also, the illumination light passes through the pixels. Depending on whether they transmit or reflect light, they can be classified as transmissive, reflective, or semi-transmissive. One example is an element that controls the transmission or non-transmission of light by the optical modulation action of liquid crystals. The element can be constructed with a pair of electrodes and a liquid crystal layer. The optical modulation is caused by the electric field applied to the liquid crystal (horizontal electric field, vertical electric field, or diagonal electric field). The liquid crystals used in the liquid crystal element are nematic liquid crystals, Steric Liquid Crystals, Smectic Liquid Crystals, Discotic Liquid Crystals, Thermotropic Liquid Crystals, Rio Tropic liquid crystal, low molecular weight liquid crystal, polymer liquid crystal, polymer dispersed liquid crystal (PDLC), ferroelectric liquid crystal , antiferroelectric liquid crystal, main chain type liquid crystal, side chain type polymer liquid crystal, banana type liquid crystal, and the like.

[0314] The display method of the liquid crystal display device is TN (Twisted Nematic) mode. mode, STN (Super Twisted Nematic) mode, IPS (In-P lane-Switching) mode, FFS(Fringe Field Switching) mode, ching) mode, MVA(Multi-domain Vertical Alig) nment) mode, PVA(Patterned Vertical Alignme) nt) mode, ASV (Advanced Super View) mode, ASM (A xially Symmetric aligned Micro-cell) mode, OCB(Optically Compensated Birefringence) Mode, ECB (Electrically Controlled Birefring induction mode, FLC (Ferroelectric Liquid Crystal al) mode, AFLC (AntiFerroelectric Liquid Cry stal) mode, PDLC (Polymer Dispersed Liquid Crystal Crystal mode, PNLC (Polymer Network Liquid Crystal Crystal Mode, Guest Host Mode, and Blue Phase ) modes, etc.

[0315] Of course, the invention disclosed in this specification is not limited to the above configuration examples, and various configuration examples are possible. A liquid crystal display device can be used.

[0316] One example of electronic paper is one that is displayed by molecules (optical anisotropy, dye molecule orientation, etc.). ), Particle-based display (electrophoresis, particle migration, particle rotation, phase change, etc.), Film Those that are displayed by the movement of one end of the molecule, and those that are displayed by coloring / phase change of the molecule. It is indicated by the light absorption of molecules, or by the spontaneous emission of light caused by the combination of electrons and holes. Specifically, an example of electronic paper is a micro Capsule-type electrophoresis, horizontally moving electrophoresis, vertically moving electrophoresis, spherical twist ball, Magnetic twist ball, cylindrical twist ball method, charged toner, electronic liquid powder, magnetic migration type, Magnetic heat sensitive, electrowetting, light scattering (transparent / opaque), cholesteric liquid Crystal / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic color Liquid crystal dispersion type, movable film, color development and erasure by leuco dye, photochromic, electrochromic There are various types of organic electroluminescence (EL), such as chromic, electro-deposition, and flexible OLED. However, various types of electronic paper can be used. By using capsule-type electrophoresis, the disadvantages of electrophoretic methods such as aggregation of electrophoretic particles, It can solve the precipitation problem. Electronic powder has high response speed, high reflectivity, wide viewing angle, low consumption It has advantages in terms of power consumption, memory properties, etc.

[0317] An example of a plasma display is a substrate with electrodes formed on its surface, and a substrate with electrodes and minute A substrate having grooves on its surface and a phosphor layer formed in the grooves is placed opposite the substrate at a narrow distance. Other examples of plasma displays include Some have a structure in which the plasma tube is sandwiched between film-like electrodes from above and below. A plasma tube is a glass tube that contains discharge gas, RGB phosphors, etc. By applying a voltage between the electrodes, ultraviolet light is generated and the phosphor is illuminated. The invention disclosed in this specification includes the above-mentioned configuration example. The present invention is not limited to the above, and plasma displays of various configurations can be applied.

[0318] In addition, there are display devices that require lighting devices. For example, liquid crystal display devices, grating laser devices, etc. Display devices using light valves (GLVs) and digital micromirror devices (DMDs) These lighting devices include, for example, lighting devices using EL elements. Devices, cold cathode tubes, hot cathode tubes, LEDs, laser light sources, mercury lamps, etc. can be used. .

[0319] Moreover, the display device may be a display device having a plurality of pixels each including a display element. In this case, the display device may include a peripheral driving circuit for driving a plurality of pixels. The peripheral driving circuit of the device may be a circuit formed on the same substrate as the multiple pixels, or may be formed on a separate substrate. Both of these circuits may be provided as peripheral drive circuits. The circuit formed on a separate substrate is connected to the pixel by wire bonding or bumps, etc. A circuit that is placed on a substrate that has a chip on glass (COG) Examples of the IC chip include an IC chip connected by a TAB or the like.

[0320] Part of the circuit is formed on the same substrate as the pixel section, reducing the number of parts and reducing costs. It is possible to improve reliability by reducing the number of connections to the circuit components. In addition, circuits with high drive voltages or high drive frequencies consume a lot of power. Therefore, it is necessary to mount such a circuit on a substrate (such as a single crystal By using this IC chip, This can prevent an increase in power consumption.

[0321] In addition, display devices are equipped with IC chips, resistor elements, capacitor elements, inductors, transistors, etc. The display may also include a flexible printed circuit (FPC) attached to the display. The device is connected via a flexible printed circuit (FPC) and has IC chips, resistors, etc. A printed wiring board (P The display device may include an optical sheet such as a polarizing plate or a retardation plate. The display device may include a lighting device, a housing, an audio input / output device, a light sensor, etc. It may contain.

[0322] In this specification, one pixel refers to one element whose brightness can be controlled. For example, one pixel represents one color element, and the brightness is expressed by one color element. In that case, in the case of a color display device having R (red), G (green), and B (blue) color components, The minimum unit of an image is composed of three pixels: an R pixel, a G pixel, and a B pixel. However, the color elements are not limited to three colors, and three or more colors may be used, or colors other than RGB may be used. Colors may also be used. For example, white may be added to make it RGBW (W is white). Or, for example, yellow, cyan, magenta, emerald green, vermilion, etc., in RGB. It is possible to add one or more colors, or a color similar to at least one of the colors in RGB. can be added to RGB. For example, R, G, B1, B2. 1 and B2 are both blue, but have slightly different wavelengths. Similarly, R1, R2, It is also possible to use G and B as color elements. By using such color elements, the image becomes closer to the real thing. By using such color elements, power consumption can be reduced. This can be done.

[0323] When controlling the brightness of one color element using multiple areas, For example, when performing area gradation or when using sub-pixels In the case of a color element, there are multiple regions for controlling brightness, and the gradation is In this case, one area for controlling the brightness is considered to be one pixel. In other words, one color element is composed of multiple pixels. Even if there are multiple areas that control brightness within one color element, they are grouped together and treated as one color element. In this case, one color element is composed of one pixel. In addition, when controlling the brightness of one color element using multiple regions, Therefore, the size of the area contributing 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 display elements, such as molecules, differs for each pixel electrode. In the case of a multi-color display, the viewing angle can be widened. This can reduce power consumption or extend the life of the display element. This can be done.

[0324] In addition, when it is explicitly stated that one pixel (three colors) is one pixel, the three pixels of R, G, and B are regarded as one pixel. When explicitly stating one pixel (one color), the following is true for one color element: When there are multiple regions, they can be collectively regarded as one pixel.

[0325] The pixels can be arranged (distributed) in a matrix, for example. Arranged in a matrix means that the pixels are arranged in a straight line in the vertical or horizontal direction. It is not limited to being arranged in a row on top. For example, full color with three color elements (e.g. RGB) In a display device, the pixel arrangement is, for example, a stripe arrangement, three color Examples include a delta arrangement made up of element dots and a Bayer arrangement.

[0326] (Embodiment 10) The invention disclosed in this specification can use transistors of various structures. In other words, there is no particular restriction on the configuration of the transistor. In this embodiment, a display device having pixels with a high aperture ratio can be manufactured. Some configuration examples of the transistor will be described.

[0327] Examples of transistors include amorphous silicon, polycrystalline silicon, and microcrystalline (microcrystalline) silicon. Non-single crystals such as silicon (also called amorphous, nanocrystalline, or semi-amorphous) A thin film transistor (TFT) having a semiconductor film can be used. For example, it can be manufactured at a lower temperature than single crystal silicon. Therefore, it is possible to reduce the manufacturing cost or to increase the size of the manufacturing equipment. This allows for manufacturing on a large substrate, making it possible to manufacture a large number of display devices at the same time. Since the manufacturing temperature is low, it is possible to manufacture the device at low cost. Therefore, a transistor can be manufactured over a light-transmitting substrate. Alternatively, light transmission through a display element can be controlled by using a transistor on a light-transmitting substrate. Alternatively, because the transistor is thin, a part of the film that forms the transistor is exposed to light. Therefore, the aperture ratio can be improved.

[0328] In addition, when producing polycrystalline silicon, a catalyst (nickel, etc.) is used to This will further improve the device's properties, making it possible to manufacture transistors with excellent electrical properties. As a result, the gate driver circuit (scanning line driver circuit), the source driver circuit (signal line driver circuit), and signal processing circuits (signal generation circuits, gamma correction circuits, DA conversion circuits, etc.) are integrated on the board. It can be formed.

[0329] In addition, when manufacturing microcrystalline silicon, a catalyst (nickel, etc.) is used to make the crystals This further improves the properties of the resulting transistor, making it possible to manufacture transistors with excellent electrical characteristics. It is also possible to improve the crystallinity by simply applying heat treatment without laser irradiation. As a result, part of the source driver circuit (analog switches, etc.) and the gate driver A driver circuit (scanning line driving circuit) can be formed integrally on the substrate. When laser irradiation is not performed for this purpose, unevenness in the crystallinity of the silicon can be suppressed. Therefore, it is possible to display images with improved quality. However, it is difficult to use the catalyst (nickel, etc.). It is possible to produce polycrystalline or microcrystalline silicon without the use of a SiO 2 .

[0330] In addition, the crystallinity of silicon can be improved to polycrystalline or microcrystalline, etc., for the entire panel. It is preferable, but not limited to, that the silicon is formed only in a part of the panel. The crystallinity of the film may be improved by selectively irradiating the laser beam to the film. For example, it is possible to irradiate only the peripheral circuit area, which is an area other than the pixels. , only in the area of ​​the gate driver circuit and the source driver circuit, or only in the area of ​​the source driver circuit The laser light may be irradiated only onto a portion of the circuit (eg, an analog switch). As a result, the crystallization of silicon is improved only in the areas where high-speed circuitry is required. Since there is little need for high-speed operation in the pixel region, the crystallinity does not need to be improved. This allows the pixel circuit to operate without any problems even if the Since the area to be improved is small, the manufacturing process can be shortened. This can improve throughput and reduce manufacturing costs. Since only a small number of units can be manufactured, the manufacturing cost can be reduced.

[0331] Examples of the transistor include ZnO, a-InGaZnO, SiGe, and GaAs. , IZO, ITO, SnO, TiO, AlZnSnO (AZTO) and other compound semiconductors A transistor having an oxide semiconductor or a thin film of such a compound semiconductor or oxide semiconductor This allows the manufacturing temperature to be lowered. Therefore, for example, it is possible to manufacture a transistor at room temperature. A transistor can be formed directly on a substrate, such as a plastic substrate or a film substrate. In addition, these compound semiconductors or oxide semiconductors can be used as the channel region of a transistor. These compounds can be used not only for the purpose of A semiconductor or an oxide semiconductor is used as a wiring, a resistor element, a pixel electrode, a light-transmitting electrode, or the like. Since they can be formed during the manufacturing process of transistors, This can reduce costs.

[0332] Note that an example of a transistor is a transistor formed by an ink-jet method or a printing method. These can be used for manufacturing at room temperature, low vacuum, or large It can be manufactured on a mold substrate. Therefore, it can be manufactured without using a mask (reticle). This makes it possible to easily change the layout of the transistors. It can be manufactured without using resist, which reduces material costs and the number of processes. Or, since it is possible to apply the film only to the necessary parts, it is possible to apply the film to the entire surface and then etch it. This method wastes less material and is less costly than the mixing method.

[0333] An example of a transistor is a transistor having an organic semiconductor or a carbon nanotube. These techniques allow transistors to be formed on flexible substrates. A semiconductor device using such a substrate can be made resistant to shock. do.

[0334] As the transistor, transistors having various other structures can be used. For example, As transistors, MOS transistors, junction transistors, bipolar transistors, A MOS transistor can be used as the transistor. This allows the size of the transistor to be reduced. By using bipolar transistors, This allows a larger current to flow, thereby enabling the circuit to operate at high speed. In addition, MOS transistors and bipolar transistors are mixed and formed on a single substrate. This makes it possible to realize low power consumption, compact size, high speed operation, and the like.

[0335] One example of a transistor is a multi-gate transistor with two or more gate electrodes. In the case of a multi-gate structure, the channel regions are connected in series, Therefore, multiple transistors are connected in series. This makes it possible to reduce the off-state current and improve the breakdown voltage of the transistor (improving reliability). Alternatively, the multi-gate structure reduces the voltage between the drain and source when operating in the saturation region. Even if the voltage changes, the current between the drain and source does not change much, and the slope of the voltage-current characteristic The slope of the voltage-current characteristic is flat. By using this, it is possible to realize an ideal current source circuit or an active load with a very high resistance. As a result, a differential circuit or a current mirror circuit with good characteristics can be realized.

[0336] One example of a transistor is a transistor with a structure in which gate electrodes are arranged above and below the channel. A transistor can be applied. The structure has gate electrodes arranged above and below the channel. This results in a circuit configuration in which multiple transistors are connected in parallel. The channel area increases, so the current value can be increased. By using a structure in which a gate electrode is placed, a depletion layer is easily formed, so the S value (Subthreshold swing value) can be improved.

[0337] An example of a transistor is a structure in which a gate electrode is disposed above a channel region. A structure in which the gate electrode is disposed under the channel region, a positive staggered structure, a reverse staggered structure, a channel A structure in which the channel region is divided into multiple regions, a structure in which the channel regions are connected in parallel, or a structure in which the channel regions are connected in parallel A transistor having a structure in which regions are connected in series can be used.

[0338] As an example of a transistor, a source electrode or A transistor with an overlapping drain electrode can be used. By making the structure such that the source electrode and drain electrode overlap the This can prevent the operation from becoming unstable due to charge accumulating in a portion of the panel region.

[0339] As an example of a transistor, a structure in which a high resistance region is provided can be applied. This reduces the off-state current and improves the breakdown voltage of the transistor (improving reliability). Alternatively, by providing a high resistance region, the drain current can be reduced when the transistor operates in the saturation region. Even if the voltage between the gate and source changes, the drain current does not change much, and the voltage-current characteristic The slope of the characteristic can be made flat.

[0340] A variety of substrates can be used to form transistors. An example of the substrate is a semiconductor substrate (e.g., a single crystal substrate or Silicon substrate, SOI substrate, glass substrate, quartz substrate, plastic substrate, metal substrate, Stainless steel substrate, substrate with stainless steel foil, tungsten substrate, Tungsten foil substrates, flexible substrates, laminated films, fibrous materials An example of a glass substrate is barium borosilicate glass. Examples of flexible substrates include glass, aluminoborosilicate glass, and soda lime glass. Examples include polyethylene terephthalate (PET), polyethylene naphthalate (PEN ), plastics such as polyethersulfone (PES), or acrylic. Examples of laminated films include polypropylene, Polyester, vinyl, polyvinyl fluoride, or polyvinyl chloride are some of the base film materials. Examples include polyester, polyamide, polyimide, inorganic vapor deposition film, and paper. In particular, a transistor is manufactured using a semiconductor substrate, a single crystal substrate, an SOI substrate, or the like. This reduces variation in characteristics, size, or shape, and increases current capacity and size. It is possible to manufacture transistors with small capacitance. By configuring the circuit as above, it is possible to reduce the power consumption of the circuit or to increase the degree of integration of the circuit.

[0341] One substrate is used to form a transistor, and then the transistor is transferred to another substrate and The transistor may be disposed on a substrate of the following type: In addition to the substrate on which the above-mentioned transistors can be formed, a paper substrate and a cellophane substrate are also available. , stone substrate, wood substrate, fabric substrate (natural fibers (silk, cotton, hemp), synthetic fibers (nylon, polyurethane) regenerated fiber (acetate, cupra, rayon, regenerated polyester) or regenerated fiber (acetate, cupra, rayon, regenerated polyester) The substrates include leather substrates, rubber substrates, etc. This allows for the formation of transistors with better characteristics, lower power consumption, and less damage. It is possible to manufacture a device that is lighter, has heat resistance, and is thinner or lighter.

[0342] Here, a transistor is defined as a transistor having at least three terminals including a gate, a drain, and a source. A channel region is provided between the drain region and the source region. A current can flow through the drain region, the channel region, and the source region. Here, the source and drain vary depending on the structure or operating conditions of the transistor. Therefore, it is difficult to determine which is the source and which is the drain. The region that functions as a source and the region that functions as a drain are called the source and drain, respectively. In that case, for example, one of the source and the drain may be connected to the first terminal, The other of the source and drain is referred to as a second terminal, a second electrode, or a first region. This may be referred to as the second area.

[0343] A transistor has at least three terminals including a base, an emitter, and a collector. In this case, the element may be, for example, an element having one of an emitter and a collector. The first terminal, the first electrode, or the first region is referred to as the first terminal, the first electrode, or the first region, and the other of the emitter and the collector is referred to as the second terminal. It may be written as a terminal, a second electrode, or a second region. When a polarized transistor is used, the term "gate" can be replaced with "base." It is.

[0344] A gate is a gate electrode and a gate wiring (gate line, gate signal line, scanning line, scanning signal line, etc.). The term "gate electrode" refers to the entire structure including the channel The semiconductor that forms the gate region and the conductive film that overlaps with the gate insulating film However, a part of the gate electrode is a high resistance region or a source region (or drain The gate insulating film may overlap the gate insulator film. The wiring is a wiring for connecting the gate electrodes of each transistor, a wiring for connecting the gate electrodes of each pixel, Wiring for connecting between gate electrodes, or wiring for connecting a gate electrode and another wiring Say something.

[0345] A portion (region, conductive film) that functions as both a gate electrode and a gate wiring Such a part (region, conductive film, wiring, etc.) is called a gate electrode. In other words, the gate electrode and the gate wiring are clearly There are also areas where it is difficult to distinguish between the two. For example, a part of the gate wiring that is extended When the gate and channel regions overlap, the area (region, conductive film, wiring, etc.) becomes a gate. It functions as a gate wiring, but also as a gate electrode. Such a portion (region, conductive film, wiring, etc.) may be called a gate electrode or a gate wiring. You can also call it that.

[0346] It is made of the same material as the gate electrode and forms the same island as the gate electrode. The part (region, conductive film, wiring, etc.) that is connected to the gate electrode may also be called the gate electrode. It is made of the same material as the wiring and is connected to the gate wiring by forming the same island. The part (region, conductive film, wiring, etc.) that is connected to the gate may also be called the gate wiring. , conductive film, wiring, etc.) do not overlap with the channel region in the strict sense. However, there are cases where the gate electrode does not have a function to connect to another gate electrode. In view of the above, the gate electrode or gate wiring is formed of the same material. The part (area, conductive film, wiring, etc.) that forms the same island as the route wiring and is connected Therefore, such parts (regions, conductive films, wiring, etc.) are also called gate electrodes or gate You can call it wiring.

[0347] 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 film made of the same material. In this case, the part (region, conductive film, wiring, etc.) for connecting the gate electrodes is Alternatively, a multi-gate transistor may be called a single transistor. Since it can be considered as a transistor, it can also be called a gate electrode. The gate electrode or gate wiring is formed of the same material and has the same island (island) as the gate electrode or gate wiring. The parts (regions, conductive films, wiring, etc.) that form the gate electrodes and gate wiring As another example, the conductor that connects the gate electrode and the gate wiring may be called a conductor line. A conductive film formed of a material different from that of the gate electrode or the gate wiring is also called a gate electrode. The gate electrode may be called a gate wiring.

[0348] The gate terminal refers to a part of the gate electrode (a region, a conductive film, a wiring, etc.), or a gate electrode and It refers to a part of an electrically connected part (area, conductive film, wiring, etc.). cormorant.

[0349] A certain wiring may be called a gate wiring, a gate line, a gate signal line, a scanning line, a scanning signal line, or the like. In some cases, the gate of the transistor may not be connected to the wiring. The wiring, gate line, gate signal line, scanning line, or scanning signal line is the same as the gate of a transistor. wiring made of the same material as the gate of a transistor, or wiring made of the same material as the gate of a transistor In some cases, it means wiring formed at the same time as the gate of a transistor. , a storage capacitor wiring, a power supply line, a reference potential supply wiring, etc.

[0350] The source is the source region, the source electrode, and the source wiring (source line, source signal line, data line, etc.). This refers to the whole or a part of the wiring (also called the data signal line, etc.). The base region is a region where P-type impurities (such as boron or gallium) or N-type impurities (such as phosphorus or arsenic) are abundant. Therefore, low concentration impurities such as P-type and N-type impurities are called low concentration impurities. If the highly-doped region is a high-resistance region, it is not considered to be included in the source region. The source electrode is made of a different material from the source region and is electrically isolated from the source region. The source electrode is the conductive layer that is connected to the source. The source electrode is sometimes called the source line, including the source region. Wiring for connecting between the electrodes, wiring for connecting between the source electrodes of each pixel, refers to a wiring for connecting a source electrode to another wiring.

[0351] In addition, there is a portion (region, conductive layer) that functions as a source electrode and a source wiring. Such a portion (region, conductive film, wiring, etc.) is called the source electrode. In other words, the source electrode and the source wiring are clearly defined. For example, there are regions where the source wiring is extended and cannot be distinguished from the other. If the source region overlaps with the source region, the overlapping region (region, conductive film, wiring, etc.) It functions as a source wiring, but also as a source electrode. Such a portion (region, conductive film, wiring, etc.) may be called a source electrode or a source wiring. You can call it a line.

[0352] 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 films, wiring, etc.), parts that connect source electrodes (region, conductive film, wiring, etc.), and the part overlapping with the source region (region The source electrode may also be made of the same material as the source wiring. The area that is connected to the source wiring and forms the same island is also Such parts (areas, conductive films, wiring, etc.) may be called lines. In the strict sense, In some cases, the function of connecting to the source electrode is not provided. However, depending on the specifications at the time of manufacture, The source electrode or source wiring is formed of the same material, and the source electrode or source wiring is formed of the same material. There are connected parts (areas, conductive films, wiring, etc.). The conductive film, wiring, etc. may also be called a source electrode or a source wiring.

[0353] For example, the conductive film in the portion connecting the source electrode and the source wiring is Alternatively, a conductive film formed of a material different from the source wiring may be called a source electrode. This may be called the source wiring.

[0354] 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 an object (such as an area, conductive film, wiring, etc.).

[0355] In addition, 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 this is called, 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 Wiring formed in the same layer as the source (drain) of the transistor. The wiring is made of the same material as the source (drain) of a transistor, or Examples include wiring for storage capacitors, power lines, and substrates. There are semi-potential supply wirings, etc.

[0356] The explanation of the drain is the same as that of the source, and so the explanation thereof will be applied mutatis mutandis. [Explanation of symbols]

[0357] 101 Substrate 102 Circuit 103 Circuit 104 Circuit 105 Insulating layer 106 Conductive Layer 107 Medium 108 Substrate 109 Conductive Layer 202 Insulating layer 203 Semiconductor layer 205 Insulating layer 206 Conductive Layer 207 Transistor 208 Capacitive element 209 Capacitive element 201a, 201aa, 201ab, 201b, 201ba, 201bb, 201c, 2 01ca, 201cb, 201da, 201db, 201eb, 201fb conductive layer 203a Semiconductor layer 204a, 204aa, 204ab, 204b, 204ba, 204bb, 204c, 2 04ca, 204cb, 204d, 204da, 204db, 204e, 204ea, 2 04eb, 204fb, 204gb, 204hb conductive layer 206a Conductive layer

Claims

1. a first gate electrode on a glass substrate; a gate insulating layer on the first gate electrode; an oxide semiconductor layer on the gate insulating layer; a source electrode and a drain electrode having a region in contact with an upper surface of the oxide semiconductor layer; a first insulating layer having a region in contact with an upper surface of the oxide semiconductor layer; a second gate electrode provided on the oxide semiconductor layer and having a region overlapping with the first gate electrode; a second insulating layer on the second gate electrode; a pixel electrode provided on the second insulating layer and directly connected to one of the source electrode and the drain electrode; a capacitance element having an area overlapping the pixel electrode, one electrode of the capacitance element has the same material as the second gate electrode; the other electrode of the capacitance element has the same material as the source electrode and the drain electrode; the pixel electrode has an area overlapping with each of the first gate electrode, the source electrode, the drain electrode, the oxide semiconductor layer, the second gate electrode, and the capacitance element; the first insulating layer has a region in contact with the source electrode and the drain electrode, the first gate electrode is formed of a laminate containing aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium; the second gate electrode is formed of a laminate containing aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium; the oxide semiconductor layer contains indium, gallium, and zinc; each of the source electrode and the drain electrode has a first layer and a second layer in contact with the first layer; the first layer comprises indium and oxygen; The display device, wherein the second layer comprises aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium.

2. a first gate electrode on a glass substrate; a gate insulating layer on the first gate electrode; an oxide semiconductor layer on the gate insulating layer; a source electrode and a drain electrode having a region in contact with an upper surface of the oxide semiconductor layer; a first insulating layer having a region in contact with an upper surface of the oxide semiconductor layer; a second gate electrode provided on the oxide semiconductor layer and having a region overlapping with the first gate electrode; a second insulating layer on the second gate electrode; a pixel electrode provided on the second insulating layer and directly connected to one of the source electrode and the drain electrode; a capacitance element having an area overlapping the pixel electrode, one electrode of the capacitance element has the same material as the first gate electrode; the other electrode of the capacitance element has the same material as the second gate electrode; the pixel electrode has an area overlapping with each of the first gate electrode, the source electrode, the drain electrode, the oxide semiconductor layer, the second gate electrode, and the capacitance element; the first insulating layer has a region in contact with the source electrode and the drain electrode, the first gate electrode is formed of a laminate containing aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium; the second gate electrode is formed of a laminate containing aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium; the oxide semiconductor layer contains indium, gallium, and zinc; each of the source electrode and the drain electrode has a first layer and a second layer in contact with the first layer; the first layer comprises indium and oxygen; The display device, wherein the second layer comprises aluminum, tungsten, titanium, tantalum, copper, silver, manganese, neodymium, niobium, cerium or chromium.

3. In claim 1 or 2, The display device includes an oxide semiconductor layer having microcrystals or polycrystals.

4. In claim 1 or 2, The display device, wherein the gate insulating layer is a stack of a silicon oxide film, a silicon oxynitride film, a silicon nitride film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, an aluminum nitride oxide film, or a tantalum oxide film.

5. In claim 1 or 2, The display device, wherein the first insulating layer is a stack of a silicon oxide film, a silicon oxynitride film, a silicon nitride film, a silicon nitride oxide film, an aluminum oxide film, an aluminum nitride film, an aluminum oxynitride film, an aluminum nitride oxide film, or a tantalum oxide film.

6. In claim 2, The pixel electrodes comprise indium and tin.

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