Display device

Abstract

To provide a display device with pixels including memory therein.SOLUTION: The pixel is provided with at least a display element, a capacitive element, an inverter, and a switch. The switch is controlled using a signal held by the capacitive element and a signal outputted from the inverter, thereby supplying voltage to the display element. The inverter and the switch can be composed of transistors having same polarity. A semiconductor layer composing the pixel may be formed of a material with light transmissivity. A gate electrode, a drain electrode and a capacitance electrode may be formed of a conductive layer with light transmissivity. Formation of pixels using light transmissive materials can provide a transmission type display device while having pixels in which memory is 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 configured with 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, particularly to a channel type Semiconductor device having a circuit configured with thin film transistors using an oxide semiconductor film in a composition region - Patents.com 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 a channel layer are widely used. Thin film transistors using amorphous silicon have low field effect mobility, but This has the advantage of being able to accommodate larger area glass substrates.

[0003] Recently, thin film transistors have been fabricated using metal oxides that exhibit semiconducting properties, and electronic devices have been developed. For example, among metal oxides, the technology for applying it to electronic devices and optical devices is attracting attention. It is known that tungsten, tin oxide, indium oxide, zinc oxide, etc. exhibit semiconductor properties. A thin film transistor is formed using a transparent semiconductor layer made of such a metal oxide as a channel forming region. 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 a gate The source electrode, source electrode, and drain electrode are also formed from a transparent conductive film. Therefore, techniques for improving the aperture ratio are being studied (see, for example, Patent Document 2).

[0005] By improving the aperture ratio, light utilization efficiency improves, 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 an improvement in aperture ratio.

[0006] In addition, as a metal auxiliary wiring for the transparent electrode of the electro-optical element, The metal auxiliary wiring and the transparent electrode are overlapped to provide electrical continuity with each other. 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 the storage capacitance electrode (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), Transparent electrodes such as zinc oxide, ZnO, SnO2, and Al, Ag, Cr, Ni, Mo, Metal electrodes such as Au, Ti, Ta, etc., or metal electrodes of alloys containing these can be used. By stacking two or more layers of films made of these materials, contact resistance can be reduced and interface strength can be improved. It is known that this can improve the quality of the image (see, for example, Patent Document 5).

[0009] In addition, the source electrode, drain electrode and The materials for the gate electrode and auxiliary capacitance electrode are indium (In), aluminum (Al), and gold ( Metals such as Au, silver (Ag), indium oxide (In2O3), and tin oxide (SnO2) , zinc oxide (ZnO), cadmium oxide (CdO), cadmium indium oxide (CdI n2O4), cadmium tin oxide (Cd2SnO4), zinc tin oxide (Zn2SnO4) The gate electrode, the source electrode, and the drain electrode may be made of an oxide material such as It is known that the pole materials may all be the same or may be different (see, for example, patent document 1). 6, 7).

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

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-103957 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-81362 [Patent Document 3] Japanese Patent Application Publication No. 2-82221 [Patent Document 4] Japanese Patent Application Publication No. 2-310536 [Patent Document 5] Japanese Patent Application Laid-Open No. 2008-243928 [Patent Document 6] Japanese Patent Application Laid-Open No. 2007-109918 [Patent Document 7] Japanese Patent Application Laid-Open No. 2007-115807 [Patent Document 8] Japanese Patent Application Laid-Open No. 2001-264814 [Patent Document 9] Japanese Patent Application Laid-Open No. 2003-076343 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 with memory. Another object of one embodiment of the present invention is to improve the aperture ratio of a pixel.

[0013] It should be noted that the description of multiple 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 display device including a first circuit having a function of controlling input of a video signal and a video 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. This makes it possible to provide a pixel equipped with a memory. The first to third circuits are made of a light-transmitting material, and the pixel electrodes are It may be placed above.

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

[0016] In the above embodiment, first to third wirings may be provided. The first wiring is electrically connected to the first capacitance element via 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 the control terminal of the second switch. the second capacitance element is electrically connected to the control terminal of the third switch, and the second capacitance element is electrically connected to the control terminal of the third switch. 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 and second capacitance elements, and an inverter The first to third pixel electrodes can be made of 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 is not limited to a specific type as long as it can control the current. An example of a switch is a transistor (e.g., a bipolar transistor, M OS transistors, etc.), diodes (e.g., PN diodes, PIN diodes, short Matthieu diode, MIM (Metal Insulator Metal) diode MIS (Metal Insulator Semiconductor) diode diode-connected transistors, or 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 a mechanically movable electrode, and the movement of the electrode 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 as a simple switch, the polarity (conductivity type) of the transistor is not particularly limited. However, if you want to reduce the off-state current, you should use a transistor with a polarity that reduces the off-state current. An example of a transistor with low off-state current is a transistor having a high resistance region. 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 operates when the source potential is close to the potential of the low-potential power supply (Vss, GND, 0V, etc.). In this case, it is desirable to use an N-channel transistor as the switch. The transistor operates with the source potential close to the potential of the high-potential power supply (Vdd, etc.). In this case, it is desirable 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 source can be increased. This is because a more accurate operation can be achieved by using a transistor as a source. Since follower operation is rare, the output voltage is 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 type transistor and a CM type transistor. When it is made into an OS type switch, the P-channel transistor and the N-channel transistor If either one 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 of the signal for turning the switch on or off can be reduced. Therefore, the power consumption can be reduced.

[0022] When a transistor is used 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 refers to a semiconductor element (transistor, diode, silicon, etc.). However, it refers to a device that has a circuit containing semiconductors. Any device that can be manufactured using semiconductor materials or any device that has semiconductor materials may be called a semiconductor device. In this specification, a display device refers to a device having a display element.

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

[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. It is possible to combine the above devices 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 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 a substrate (e.g., a glass substrate, a plastic substrate, a single crystal substrate, an SOI substrate, etc.) This allows for cost reduction by reducing the number of components, or for the circuit section to be formed. This reduces the number of connection points with the product, thereby improving reliability.

[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 achieve a given function is formed on a certain substrate. Another part of the circuitry required to achieve a given function is formed on a different substrate. For example, some of the circuits required to realize a specific 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 circuit required for the semiconductor device is formed is called COG ( By using the IC chip on glass, the IC is connected to the glass substrate. It is possible to place the chip on the board. Alternatively, the IC chip can be mounted on the board using TAB (Tape Auto) technology. omated Bonding), COF(Chip On Film), SMT(Su Surface 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 cases where the device is directly connected. , 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 connections shown in the drawings or text. This also includes connections other than those mentioned above.

[0030] An example of an electrical connection between X and Y is The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more electrodes (e.g., diodes) can be connected between X and Y.

[0031] An example of a functional connection between X and Y is a function that allows the functional connection between X and Y. Circuits (e.g., logic circuits (inverters, NAND circuits, NOR circuits, etc.), signal conversion 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, voltage source , current sources, switching circuits, amplifier circuits (circuits that can increase the signal amplitude or current amount, etc., operational amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits One or more circuits (e.g., circuits, control circuits) 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] When explicitly stating 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 other connection between X and Y) and When X and Y are connected functionally via a circuit) 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 only that it is

[0033] In this specification, anything explicitly stated as singular is singular. However, even in this case, multiple instances are possible. It is preferable that numbers be plural. But it can also be singular.

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

[0035] Note that technical terms are often used to describe specific embodiments or examples. However, one aspect of the present invention should not be construed as being limited by technical terms.

[0036] In addition, undefined terms (including technical terms such as technical or academic terms) are usually It can be used as a 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] The terms "first," "second," "third," etc. refer to various elements, members, areas, layers, regions, etc. Therefore, the terms "first," "second," "third," etc. are used to distinguish between elements, members, etc. The order and number of regions, layers, areas, etc. are not limited. "The" can be replaced with "the second" or "the third", etc.

[0038] Also, "up," "upward," "downward," "downward," "sideways," "right," "left," Spatial arrangement such as "diagonally," "in the back," "in front," "inside," "outside," or "inside" The phrase "show" simply illustrates the relationship of one element or feature to another element or feature by means of a diagram. However, it is not limited to this usage and is also used to indicate these spatial arrangements. The phrase may include directions in addition to those depicted on the diagram. For example, Y above X is clearly When 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 Y is below X. Thus, the phrase "on" includes the direction of "on" as well as the direction of "under." However, the device in the figure can be rotated in various directions. Therefore, the word "on" can be used to refer to the directions "above" and "below," as well as "sideways." "," "to the right," "to the left," "diagonally," "to the back," "to the front," "inside," "outside," or can include other directions such as "inside"; in other words, interpret it appropriately depending on the situation. It is possible.

[0039] Note that we cannot explicitly say that Y is formed on X, or that Y is formed on X. When describing it, it is not limited to forming Y on X in direct contact with it. This also includes cases where X and Y are not connected, that is, where another object is present between X and Y. Here, X and Y represent the object (e.g., device, element, circuit, wiring, electrode, terminal, conductive film, layer, etc.).

[0040] Therefore, for example, it is not possible to explicitly state that layer Y is formed on (or on) layer X. In the cases described, it means that layer Y is formed directly on layer X, and that layer Y is formed on layer X. Another layer (such as layer Z) is formed directly in contact with it, and layer Y is formed directly on top of it. The other layer (for example, 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. It is not limited to Y being directly on top of X, and there may be 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 Y is formed directly on layer X. When another layer (such as layer Z) is formed and layer Y is formed directly on top of it, The other layer (for example, 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 of "Y below X" or "Y below X." [Effects of the Invention]

[0044] By forming a light-transmitting transistor or a light-transmitting capacitor, a transistor can be formed in a pixel. Even when arranging transistors and capacitors, 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 can be realized while having memory in the pixel. It becomes possible to do this.

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

[0046] [Figure 1] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 2] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 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. [Figure 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] 4A to 4E are circuit diagrams illustrating examples of the configuration of a display device. [Figure 22] 4A to 4D are circuit diagrams illustrating examples of the configuration of a display device. [Figure 23] FIG. 10 is a circuit diagram illustrating an example of the operation of a display device. [Figure 24] FIG. 10 is a circuit diagram illustrating an example of the operation of a display device. [Figure 25] FIG. 10 is a circuit diagram illustrating an example of the operation of a display device. [Figure 26] FIG. 10 is a circuit diagram illustrating an example of the operation of a display device. [Figure 27] FIG. 10 is a circuit diagram illustrating an example of the operation of a display device. [Figure 28] 4A to 4D are circuit diagrams illustrating examples of the configuration of a display device. [Figure 29]FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Figure 30] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Figure 31] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Figure 32] FIG. 1 is a plan view illustrating a configuration example of a display device. [Figure 33] FIG. 1 is a plan view illustrating a configuration example of a display device. [Figure 34] 1A is a plan view illustrating an example of the configuration of a display device, and B and C are cross-sectional views of the same. [Figure 35] 1 is a cross-sectional view illustrating a configuration example of a display device. [Figure 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 illustrating 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. [Figure 40] 1A to 1H are diagrams illustrating examples of the configuration of electronic devices. [Figure 41] 10A to 10D are diagrams illustrating configuration examples of electronic devices. 10E to 10H are diagrams illustrating application examples of display devices. [Figure 42] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. [Figure 43] FIG. 1 is a circuit diagram illustrating a configuration example of a display device. DETAILED DESCRIPTION OF THE INVENTION

[0047] The following describes embodiments of the present invention. The aspects of the invention described in this specification include, for example, the following: The following problems can be solved. Note that listing multiple problems does not prevent the existence of other problems. Furthermore, 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. Improved wiring resistance, reduced contact resistance, and reduced voltage drop reducing power consumption; improving display quality; and reducing the off-state current of transistors. Examples include reducing the

[0049] Furthermore, the present invention can be implemented in many different ways. It will be understood by those skilled in the art that various changes in form and detail may be made therein 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 embodiments. In the configurations described below, the same parts or parts having similar functions may be 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] Furthermore, the content (or even a part of the content) described in one embodiment may be used in conjunction with that embodiment. Another content (or part of the content) stated in the form of Selection, combination, or the like of the contents (or even a part of the contents) described in a plurality of different embodiments The contents described in the embodiment are as follows: In each embodiment, the contents described in one or more of the referenced drawings, This refers to the content expressed in the call and sentence.

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

[0052] Therefore, for example, in drawings (cross-sectional views, plan views, circuit diagrams, block diagrams, flowcharts, process diagrams, perspective views, elevation views, layout diagrams, timing charts, structure diagrams, schematic diagrams, graphs, tables, optical path diagrams, vector diagrams, state diagrams , waveform diagrams, photographs, chemical formulas, etc.) or texts 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 constitute an aspect of the invention .

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

[0054] In addition, in the drawings or texts described in one embodiment, at least one component 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, in a drawing 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. This can constitute one aspect of the invention.

[0055] Furthermore, at least the contents shown in the drawings (or even a part of the drawings) are disclosed as one aspect of the invention. This is shown and can constitute one aspect of the invention. If the content is described in the diagram, even if it is not stated in words, This can constitute one embodiment of the invention disclosed in this specification. From the attached drawings, one embodiment of the invention disclosed in this specification can be constructed.

[0056] Also, active elements (transistors, diodes, etc.), passive elements (capacitance elements, resistance elements, etc.), etc. A person skilled in the art would be able to identify the invention without specifying the connection destinations of all the terminals of the device. In particular, when multiple terminals are expected to be connected to one another, Therefore, it is not necessary to limit the connection of the terminal to a specific location. Some terminals of passive elements (capacitor, resistor, etc.) By specifying the destination of connection only, it is possible to constitute an embodiment of the invention. It may be possible.

[0057] Furthermore, if a circuit is connected to at least one circuit, a person skilled in the art can easily implement the invention. It may be possible to identify aspects, and aspects of the invention disclosed herein may be such Alternatively, if at least the function of a circuit is specified, a person skilled in the art can easily understand it. 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 structural 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] Above the substrate 101, a circuit 102, a circuit 103, and a circuit 104 are provided. An insulating layer 105 is provided above the circuits 102 to 104. Above the insulating layer 105, 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. The medium 107, the conductive layer 106, and the conductive layer 109 are used to form a display element. The conductive layer 106 can be formed by 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 to this.

[0061] In the configuration example of FIG. 1, either the substrate 108 or the conductive layer 109 may be omitted. It is possible to omit any 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 the pixel. Therefore, the circuit 102 has a function of controlling whether or not a selection transistor is used. 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. The memory may be, for example, a DRAM or an SRAM. , nonvolatile memory, etc. Furthermore, the circuit 103 may also include a refresh circuit. The refresh circuit allows the data in the DRAM to be refreshed. 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, for example, a function of controlling the polarity of the voltage supplied to the medium 107. Therefore, depending on the type of 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 in the pixel, the frequency of signal rewriting can be reduced. However, in this embodiment, 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 made of a light-transmitting material. For example, for a transistor, the gate electrode, the semiconductor layer, and the 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 optical Similarly, source signal lines, gate signal lines, capacitance lines, power supply lines, etc. The wiring can also be made of a light-transmitting material. The pixel area where the pixels are arranged can transmit light over most of the area. do.

[0066] In addition, some or all of the wiring such as the source signal line, gate signal line, capacitance wiring, and power supply line may be The entire structure may be made of a light-transmitting material, but is not limited to this. It is possible to configure the substrate using a material that has high conductivity and does not require light transmission. For example, the light-transmitting layer and the light-transmitting layer may be formed of a transparent material. In these cases, the area through which light is transmitted is narrow. Therefore, the aperture ratio decreases, but the high conductivity reduces signal distortion and voltage drop. reduction becomes possible.

[0067] In particular, circuits for driving pixels, such as gate drivers, source drivers, and common electrodes (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 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, the circuit 102, the circuit 103, and the circuit 104 are formed under the conductive layer 106. 3 or circuit 104. In this case, circuit 102, circuit 10 3, or the circuit 104 can be formed using a light-transmitting material. Therefore, the aperture ratio can be improved. Alternatively, a transmission type 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 to have a material that is not conductive, i.e., a material that has high conductivity. By using a material with high 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 if a part of the circuit 103 or the circuit 104 is arranged.

[0071] The conductive layer 106 can function as a pixel electrode. 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 do this.

[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 conductive layer 106 and the conductive layer 109 The optical properties are controlled by the voltage or current supplied to the light source.

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

[0075] It is desirable 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 include substrates, ceramic substrates, quartz substrates, sapphire substrates, etc. It is also possible to use a conductive substrate made of a conductor such as stainless steel, the surface of which is covered with an insulating material. 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, the substrate can be bent and is 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. ) will be described. The display device has a plurality of pixels. The cross-sectional structure of the element is shown.

[0079] As shown in FIG. 2, conductive layers 201a and 201b are disposed above a substrate 101. An insulating layer 202 is disposed above the conductive layers 201a and 201b. The semiconductor layer 203 is disposed on the insulating layer 202. Conductive layer 204a, conductive layer 204b, and conductive layer 204c are arranged. a, the conductive layer 204b, the conductive layer 204c, or the semiconductor layer 203, an insulating layer 205 A conductive layer 206 is disposed above 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 film can be formed by etching the insulating film (or laminated film). , 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 film by etching the insulating film (or laminated film). 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 capacitor 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 can 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 of 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 can 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 208, and the like are arranged below the conductive layer 206. The transistor 207, the capacitor 208, and the like have a light-transmitting property; It is possible to increase the display rate or to configure a transmissive display device. Then, a transistor 207 and capacitors 208 and 209 are used to form a selection transistor. , memory, DRAM, SRAM, analog switch, inverter, clocked inverter It is possible to configure the following.

[0089] Note that the transistor 207 has a conductive layer 201a below the semiconductor layer 203. It can be said that the transistor 207 is a bottom-gate transistor. It can be said that the transistor 207 is 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 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 gate electrode with respect to the channel portion is 3, the conductive layer 206a is formed on the semiconductor layer 203 and the insulating layer 204. 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, thereby substantially increasing mobility. It is possible.

[0092] The conductive layers 206a and 206 are films (single layer or laminated layer) formed through the same film formation process. In this case, the conductive layer 20 6a and the conductive layer 206 have generally the same material.

[0093] As shown in FIG. 3, the capacitor element 208 is formed between the conductive layer 204c and the conductive layer 201c. It is also possible to provide a semiconductor layer 203a. Here, the semiconductor layers 203 and 203a are Etching a film (single layer or laminate) formed through the same film formation process In this case, the semiconductor layer 203 and the semiconductor layer 203a can be formed by the same method. 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 the 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 However, in the pixel section, if the threshold voltage is Even if the transistor 207 is in a normally-on state, it may still be possible to operate it. Furthermore, in the pixel portion, 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] The conductive layer 406a and the insulating layer 405 are disposed between the insulating layer 205 and the conductive layer 206. Layer 406 a can function as the back gate 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 combining the conductive layer 406b and the conductive layer 206. Alternatively, the capacitor 408a can be formed by using the conductive layer 406b and the conductive layer 406c. It is possible to construct 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 film can be formed by etching the insulating film (or laminated film). 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 generally the same material. is an etching process for a film (single layer or laminate) 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, this embodiment is not limited to this. It is possible to arrange a channel protection film. For example, in transistor 2 in Figure 2, 5 shows the case where a channel protection film 503 is arranged in the case of FIG. 3 and FIG. 4. In this case, 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 O3 to be reduced, thereby reducing 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 there is no need to consider the selection ratio at the time of deposition, materials can be freely selected.

[0100] In the configuration examples shown in FIGS. 2 to 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 below the conductive layers 204a and 204b. In this case, it is possible to omit the channel protective film 503. If a 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 A resist mask is formed and the layers are etched simultaneously. The mask is then ashed 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 204b are 4b and the underside of the electrode 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 contacts the lower sides of the conductive layers 204a and 204b. A cross-sectional view of the transistor 207 in this case is shown in FIG. 7. Similarly, in FIG. Transistor 207 when the upper side of 03 contacts the lower side 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 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 above-mentioned portion, it is desirable that the semiconductor layer 203 is sufficiently N-type or P-type. In other words, it is desirable that these contact portions are ohmic contacts. .

[0103] 2 to 10, there is no insulating layer between the conductive layers 204a and 204b and the semiconductor layer 203. The present embodiment is not limited to this example. 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 over an insulating layer 1105. The connection is made via the contact holes.

[0104] In this case, the conductive layer in the same layer as the conductive layers 204a and 204b is used to form the channel It is possible to provide an electrode on the opposite side of the gate electrode for the portion. 2. The conductive layer 204e is provided on the opposite side of the gate electrode with respect to the channel portion. In this way, since it is provided in the same layer as the conductive layer 204a, Even when 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 film can be formed by etching the insulating film (or laminated film). The conductive layers 204a, 204b, and 204e generally have the same material.

[0106] 3 to 10, the same transistor 207 as in FIGS. 11 and 12 is used. It can be used.

[0107] When connecting conductive layers arranged via an insulating layer, contacts must be placed on 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 connected. 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 and process steps 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 a higher resistance or a larger layout area. As shown in 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 201a. In this case, the contact resistance may become high. This can reduce the possibility of the layout area becoming larger.

[0108] FIG. 14 shows an example of the contact structure when 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 the conductive layer 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 the conductive layer 406b, 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 will become 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 inverse staggered transistors, but also includes planar transistors. It is also possible to configure it using

[0110] The semiconductor layer 203 shown in FIGS. 2 to 12 is made of a semiconductor film having a single layer structure or a stacked layer structure. The film forming the semiconductor layer can be formed using indium tin oxide (InTeO). 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) Indium Zinc Oxide (Indium Zinc Oxide) containing zinc oxide can also 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. Films made of these materials can be formed by sputtering. do.

[0111] 1 to 14, for example, the conductive layers 201a, 201b, 204a to 204b, 04e, 206, 206a, 406a, 406b, etc. are conductive films of 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 TSO), organic indium, organic tin, zinc oxide (ZnO), and other transparent materials. Indium zinc oxide (Indium Zinc Oxide) containing zinc oxide can also be used. nc Oxide (IZO), zinc oxide doped with gallium (Ga), 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 FIGS. 1 to 14 is formed using a conductive film having a stacked structure, In this case, it is desirable to make the light transmittance of the laminated structure sufficiently high.

[0112] In addition, some or all of the wiring such as the source signal line, gate signal line, capacitance wiring, and power supply line may be All of the components can be made of 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 chromium (Cr), or alloy materials whose main components are these metallic materials, or The nitride containing these metal materials can be used to form a single layer or a multilayer.

[0113] In addition, when ITO is used as one conductive layer and aluminum is used as another, If they are connected, a chemical reaction may occur. To avoid this, it is desirable to use a high melting point material between them. Examples of high melting point materials include molybdenum, titanium, tungsten, tantalum, and chromium. Then, a conductive layer is formed on the film using a high-melting-point material by using a material with high conductivity. It is preferable to use a multilayer film of the material having high 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 silicon dioxide, and the third layer is made of silicon dioxide. The first layer is aluminum and the third layer is molybdenum, or the first layer is molybdenum and the second layer is molybdenum. The first layer is made of aluminum containing a small amount of neodymium, and the third layer is made of molybdenum. By adopting such a 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 can be a single layer or a laminate of a tantalum oxide film or a tantalum oxide film. The film thickness can be formed to 50 nm or more and 250 nm or less using a sputtering method or the like. For example, a silicon oxide film is formed as an insulating layer by sputtering or CVD to a thickness of 100 nm. 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 nitride oxide, DLC (diamond-like carbon) Carbon-containing films such as epoxy, polyimide, polyamide, polyvinylphenol, 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 FIGS. 1 to 14 may be a color filter and / or a black matrix. A 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 adjusted. Since no adjustment margin is required, the panel can be manufactured more easily.

[0116] The semiconductor layer shown in FIGS. 2 to 14, for example, the semiconductor layer 203, may be made of, for example, In, M, or An oxide semiconductor containing Ga, Fe, Ni, or Zn can be used. It represents one or more metal elements selected from Mn, Co, etc. 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 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 used. Insulating nitrides such as silicon nitride and aluminum nitride, or silicon oxynitride Insulating oxides such as aluminum oxynitride 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. This makes it possible to

[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 the 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 cases, 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, etc. Even if stress is applied, fluctuations in the threshold voltage can be prevented.

[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 system, In-Al-Zn-O system, Sn-Ga-Zn-O system, 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 doing so, 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 and aluminum nitride, or silicon oxynitride; Examples include insulating oxynitrides such as aluminum oxynitride.

[0119] As an example, an oxide semiconductor target containing In, Ga, and Zn (In2O3:Ga 2O3:ZnO=1:1:1) can be used to form semiconductor films. 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 atmosphere, oxygen atmosphere, or The atmosphere can be a mixture of argon and oxygen. The thickness of the semiconductor film is 5 nm to 200 nm. It is sufficient to set it to about nm.

[0120] The sputtering method mentioned above includes RF sputtering, which uses a high frequency power supply for the sputtering power supply, and D C sputtering method, pulse DC sputtering method that applies a DC bias in a pulsed manner, etc. The RF sputtering method is mainly used to form insulating films, while the DC sputtering method is mainly used to form insulating films. It is used when forming a metal film.

[0121] Alternatively, a multi-target sputtering device capable of installing multiple targets of different materials may be used. In sputtering equipment, different films can be stacked 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. Alternatively, a chemical reaction may be caused between the target material and the sputtering gas components during film formation. Reactive sputtering, which forms compounds from these, and vias, which apply 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) The transistor 207 may be formed of a silicon layer (crystalline silicon layer or single crystal silicon layer) as a channel layer. 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 to 600°C, typically 200 to 400°C. 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 optical annealing) This is important in that it can release the strain that inhibits the movement of carriers in the island-shaped semiconductor layer 203. The timing of the heat treatment is not particularly limited as long as it is performed after the semiconductor layer 203 is formed. Not determined.

[0124] For 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 of this embodiment stores information in pixels. It has a memory function.

[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, a circuit 1502 for driving or controlling the pixel portion 1501 and a 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 have a function of a gate line driver circuit, a gate It is possible for the circuit to have the function of a gate driver or a scan driver. The circuit 1503 is connected to the source or drain of the transistor disposed in the pixel portion 1501. Alternatively, the circuit 1503 may have a function of controlling the potential of the pixel portion. 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 functions called a controller, pulse generator, etc. It is possible.

[0128] Next, an example of a pixel arranged in the pixel section 1501 is shown in Fig. 16. Fig. 16 shows a circuit for one pixel. The pixel includes a circuit 102, a circuit 103, a circuit 104, a capacitor 1612, and a and a display element 1613 having a pixel electrode. , 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 , may have a function to put the output into 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 to the output terminal of the inverter 1603. , is connected to the switch 1602. The output terminal of the inverter 1603 is connected to the capacitor element 16 04. The wiring 1608 and the wiring 1609 are connected to the switches 1606 and 1609. 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 capacitor element 1604. The switch 1607 is connected to the input signal of the inverter 1603 or the capacitor 160 The signal held in the display element 16 controls the on / off state (conduction and non-conduction). 13 is connected between the node between the switch 1607 and the switch 1606 and the wiring 1615. The capacitor 1612 is connected to the node between the switch 1607 and the switch 1606. , or is connected between the pixel electrode of the display element 1613 and the wiring 1614 .

[0131] In the configuration example of FIG. 16, the capacitor 1612 can be omitted. The capacitance 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 can correspond to a counter electrode or a common electrode. 615. Alternatively, the display element 1613 may have the medium 107. Alternatively, the conductive layer 106 may function as a pixel electrode, and may be formed on the display element 1. The pixel electrode 613 can be made to correspond to the pixel electrode.

[0133] The wiring 1610 and the wiring 1611 may be 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 1611. By connecting to the wire 1609 and the wiring 1614, it is possible to form it as one wiring. The wiring 1614 is connected to the wiring 1608, the wiring 1609, the wiring 1610, or By connecting to the wiring 1611, it is possible to form it as one wiring.

[0134] The switch 1602 is configured to transmit a signal supplied to the wiring 1601 to the pixel (or the capacitor 160 5, 1604, inverter 1603) Therefore, the switch 1602 is used for 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 it from a non-transparent, highly conductive material, it is possible to reduce signal delay. The wiring 1601 may be formed by combining a layer made of a highly conductive material and a layer made of a light-transmitting material. It is possible to form the layer by laminating the layer formed by the method described above.

[0137] A signal input to the pixel via the switch 1602 is held in the capacitor 1605. The capacitor 1605 has a function of holding a signal. Furthermore, the capacitance element 1605 decreases over time. 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 is inverted and output through the The signal output from the inverter 1603 is held in a capacitor 1604. Since the signal held by the capacitance element 1604 may attenuate over time, It can be said that it is a DRAM.

[0139] Since the inverter 1603 is provided, the signal held in the capacitor element 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, for example, This does not apply when the device is in an impedance state.

[0140] The switch 1606 connects 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. Whether the potential of the capacitor 1612 or the display element 1613 is supplied or not is controlled. It has the function of

[0141] In this way, 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). Therefore, in this 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 into 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, and gradation can be expressed, and the image 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. 17A, If the switch 1602 is turned on, the capacitance element 1 An H signal is input to 605. A capacitor 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 maintained as is. The L signal is stored in the capacitor 1604. The control terminal of the switch 1603 stores the H signal. When an H signal is supplied to the device, it is turned on, and when an L signal is supplied, it is turned off. If this is the case, switch 1606 is turned off and switch 1607 is turned on. As a result, the potential V1 of the wiring 1609 is supplied to the pixel electrode of the display element 1613. If a potential Vcom is applied to the wiring 1615, the display element 1613 will At this time, the voltage difference between V1 and 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, it is in a black state). ), the display element 1613 displays white. If the display is normally white (when no voltage is supplied, 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 If 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, 17B and 17C are alternately repeated to drive the display element 1613 by AC driving. This can be done.

[0145] At this time, even if the signal is not re-input from the wiring 1601, the capacitor 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 capacitor elements 1604 and 1605, , 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 illustrate the operation when an H signal is input from the wiring 1601. 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, assume that an L signal is supplied from wiring 1601. If 602 is on, an L signal is input to the capacitance element 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 maintained as is. The L signal is stored in the capacitor 1605. is turned on and the switch 1607 is turned off. When the potential Vcom is applied to the wiring 1615, the potential V3 of the wiring 1608 is supplied. 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 in a normally white state (when a voltage is applied), the display element 1613 displays black. When the light is not supplied, the display element 1613 displays white. This 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 shown in FIG. 18B and FIG. 18C are repeated alternately every 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 wire 1601 to 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 609 (the difference between V1 and V2) can be reduced. 5, that is, the potential of the opposing electrode or common electrode, is changed, and common inversion is performed. It's called driving.

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

[0153] First, as shown in FIG. 19A, assume that an H signal is supplied from wiring 1601. If the capacitor 1602 is turned 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 maintained as is. The L signal is stored in the capacitor 1604. The H signal is stored in the capacitor 1605. Therefore, the switch 1606 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 (no voltage is applied), When the display element 1613 is in the black state, the display element 1613 displays white. On the other hand, if the display element 1613 is normally white (when no voltage is supplied, the display element is white), If the display element 1613 is in the black 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 wiring 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 If 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. , a negative voltage is applied to the display element 1613. After that, in each period, 19B and 19C are alternately repeated, the display element 1613 can be AC ​​driven. Then, it becomes necessary to refresh the signals of the capacitor elements 1604 and 1605. When the signal needs to be rewritten, go back to Figure 19A and rewrite the 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 show the operation when an H signal is input from the wiring 1601. 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, assume that an L signal is supplied from wiring 1601. If 602 is on, an L signal is input to the capacitance element 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 maintained as is. The L signal is stored in the capacitor 1605. Therefore, the switch 1606 is turned on. Therefore, the pixel electrode of the display element 1613 is connected to the line 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, it is in black state). If the display element 1613 is black, the display element 1613 will display black. If the display is in a white state (when no voltage is supplied), the display element 1 613 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 Furthermore, the potentials of the wiring 1608, the wiring 1614, and the wiring 1615 are changed from V1 to V6. As a result, even if the potential of the wiring 1614 changes, the display element Almost no voltage is applied to 1613. After that, at each cycle, 20C are alternately repeated. Then, the signals of the capacitor elements 1604 and 1605 are When it becomes necessary to refresh or rewrite a signal 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 display can be performed 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] (Fourth embodiment) 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. The transistor 2101 and the N-channel transistor 2102 are connected to the wiring 2104 and the wiring 2103. This CMOS configuration is achieved by supplying a low voltage to the wiring 2103. and a function of supplying a high voltage to the wiring 2104. By using the S configuration, it is possible to reduce the through current, thereby reducing 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 pulsed signal can also be applied.

[0166] In addition to the case where a polycrystalline silicon semiconductor is used as the semiconductor layer, an oxide semiconductor may also be used. When using an active layer, 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 various p-type dopants and However, in this embodiment, a P-type zinc oxide film can be obtained 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 shown in FIG. 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 can 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-on) The transistor is turned on and current flows even when the voltage between the gate and source is 0V or less. It is possible to make it ... 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. transistor 2101c, transistor 2101d, transistor 2102a and transistor The potential of the gate of the transistor 2101d is set to the value of the bootstrap transistor 2102b. As a result, the potential of the wiring 2104b is increased to a level The inverter 1603 in FIG. 21D can be output as is. a and wiring 2103b have a function of supplying a low voltage, and wiring 2104a and The wiring 2104b has a function of supplying a high voltage. 2103b may be connected to form a single wiring. 104b may be connected to one wiring. 102a, 2102b, and 2101d have the same polarity, which reduces the number of process steps. This makes it possible to:

[0170] In addition, in Figures 21B to 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 type, 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 in the same manner as the switch 1602. It can be achieved.

[0172] FIG. 22A shows an example of the configuration of the switch 1602 with 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 that the gates of the channel transistors 2201 are supplied with signals that are inverted from each other. As a result, the P-channel transistor 2202 and the N-channel transistor By using this CMOS configuration, the MOSFETs 2201 and 2202 can be turned on and off simultaneously. Therefore, the gate of the P-channel transistor 2202 and the N-channel transistor 2201 This allows the amplitude of the voltage supplied to the port to be reduced, thereby reducing power consumption. This makes it possible to:

[0173] In FIG. 22B, a P-channel transistor is not used, but an N-channel transistor 2201 FIG. 22C shows an example of the configuration of a switch 1602 using an N-channel multi-gate structure. 2 shows an example of the configuration of the 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. An example of the configuration of the switch 1602 when the transistor 2201 is a P-channel type is shown in FIG. The switch 1602 is configured using a P-channel transistor 2201p. .

[0175] Next, using the circuits shown in FIGS. 21A to 21E and 22A to 22D, An example of the circuit disclosed in 20C is shown in FIG. 23. The switches 1602, 1606, and 1607 are configured with the circuit shown in FIG. 22B, and the inverter 1603 The circuit in Figure 23 is composed of the circuit in Figure 21C. Therefore, the circuit in Figure 23 is composed of Therefore, the number of process steps can be reduced. Of course, this 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 can be formed of a light-transmitting material. This allows the aperture ratio to be increased. However, the present embodiment is not limited to this. For example, the wiring 2301 is made of a non-transparent material with 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 multilayer state using layers formed of a light-transmitting material. It is possible.

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

[0179] In FIG. 23, both the capacitor 1605 and the capacitor 1604 are 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] 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 a current will continue to flow. In other words, there is a possibility that a through current will flow through the inverter 1603. In this case, the inverter 1603 may consume excess power.

[0183] Therefore, it is possible to reduce the through current by devising a driving method. 27 shows a driving method for reducing the through current of the inverter 1603. As a result, 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 through current can be reduced. In this 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 1604 At this time, the transistor 2101b also turns on, but due to the difference in 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 is larger than that of the star 2101b.

[0185] Next, as shown in FIG. 25, the potential of the wiring 2104 is lowered to a potential V8. 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 as 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 either before or after the potential of the wiring 2104 is changed. Or, both can be done 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, it 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 the case where an H signal is input from the wiring 1601, but when an L signal is input, The same applies to the case where the 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 is turned on, there is no problem in 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 the H level. It can be said that the device 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. If the inverter 1603 does not need to output a signal, the potential of the wiring 2104 is set to 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 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 placed. 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 The circuit diagram of the inverter 1603 when configured with .O2 is shown in FIG. 28B. An example of the configuration when 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 wiring 2104, it is possible to reduce the through current. In the same way as changing the potential, the potential of the gate of the transistor 2802 may be controlled.

[0193] In this case, too, the potential of the wiring 2104 is changed as shown in FIGS. However, even if the potential of the wiring 2104 is kept constant, the transistor This is not a problem as 2802 can reduce the through current.

[0194] 28A to 28C, a transistor is connected 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 transistor 03 and the circuit shown in FIG. Further, a transistor 2803 is connected in series with an N-channel transistor 2102. 28C. As in FIG. 28C, the inverter 1603 is connected to the transistor The position of the P-channel transistor 2101 and the wiring 21 are changed. It can be placed between 03.

[0195] The wiring 2801 connected to the gates of the transistors 2802 and 2803 is This allows the transistor 1602a to be connected to the wiring 2301. The transistors 2802 and 2803 can be turned on only when is turned 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 enter a high impedance state, so you can 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 the circuit in FIG. 16 to which switches 2901 and 2902 have been added.

[0199] The switch 2902 controls the connection or disconnection 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 gradation.

[0200] On the other hand, the switch 2901 is connected to the display element 161. 3. When the switch 2902 is turned on, When or after a signal is being supplied from 1601 to the display element 1613, switch 2 When the display element 1613 is turned off and an analog signal is held in the display element 1613, the wiring 1 If the potential of the wiring 608 or the wiring 1609 is supplied to the display element 1613, The signal value held in 613 will change. 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. This makes it possible to improve the quality and reduce the power consumption at the same time. Not limited to these.

[0201] Another example of the configuration is when the number of gradations that can be displayed per pixel, i.e., 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 achieve multiple gradations using area gradation. 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 sub-pixel. You are supposed to input it.

[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 video 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] 30 and 31 show an example in which two sub-pixels are provided in one pixel, 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 aperture ratio, the number of bits can be easily increased.

[0205] In addition, wiring 2103, 1610, 1611, 1614, 1609, 1608, 2104, etc. This allows the number of wirings to be reduced. It is possible to reduce it.

[0206] As another example of the configuration, a part of the circuit 104 is changed as shown in FIG. Alternatively, a switch 4206 is provided in series with the switch 1607. 42 shows the 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 applied to the switch 1606 or the switch 1609. Regardless of whether 607 is on or off, it can be prevented from being supplied to the display element 1613. .

[0207] As yet another modification, 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 1608b are connected between the display element 1613 and the wiring 1609b. The switches 4307a and 4307b are connected in series. As long as the connection is made in a different configuration, it is possible to connect the two. Switch 4307a and switch 4307b are alternately turned on and off. When 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 may be provided. is.

[0209] (Sixth embodiment) 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. 2 are used as 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 connected to each other. By using this contact structure, the pixel The aperture ratio can be improved. Alternatively, the contact resistance can be reduced, and the This allows for a reduction in pressure drop, or a reduction in layout area. This allows more circuits to be arranged. However, this 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 connected to the drain of the transistor 1602a. 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. The source electrode is connected to the gate electrode.

[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 the 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 wiring. It is possible to form the substrate using a material that does not require special care. An example of this is shown in Figure 33.

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

[0215] 34A to 34C, the transistor 1602a, the wiring 1601, and the wiring 2 A partial configuration example of 103 will be described. FIG. 34A is a plan view of this configuration example. FIG. 34B is a 34B is a diagram showing an example of a cross-sectional structure taken along the cutting line AB in FIG. 34A, and FIG. 34C is a diagram showing a cross-sectional structure taken along the cutting line AB in FIG. FIG. 10 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 non-light-transmitting material with 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 non-transparent material with high conductivity. 1aa is made of a light-transmitting material. In this case, a multi-tone mask (halftone mask) can be formed. A mask (also called a tone mask or gray-tone mask) is used to reduce the number of masks (reticles). 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 layer can be obtained with a single mask. 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) so as to have a region where the conductive layer 201ba is not present; 4bb, it is also possible to arrange the conductive layer 204ba so that there is an area below the conductive layer 204bb where the conductive layer 204ba is not present. be.

[0218] 34B and 34C, the light-transmitting layers (conductive layers 201aa, 204aa, 2 On the conductive layers 201ab, 204ab, etc., a non-transparent layer is formed. , 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 non-light-transmitting layer. Conductive layers are formed in this manner, and 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 using conductive layers 201ca and 201cb. The source electrode (201cb) has a light-transmitting property, and the conductive layer (201cb) has a non-light-transmitting property and a high conductivity. The conductive layer 204ca is made up of 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 high conductivity. The source electrode is formed using conductive layers 204da and 204db. The conductive layer 204a has a light-transmitting property, and the conductive layer 204db has a light-non-transmitting property and has high conductivity. The electrodes are formed using conductive layers 201da and 201db. The conductive layer 201db has a non-transparent property and a high conductivity. The conductive layer 204ea is transparent. The conductive layer 204eb is non-light-transmitting and has high conductivity.

[0221] Similarly, as shown in FIG. 34C, a light-transmitting layer is disposed below a non-light-transmitting layer. Conductive layers are formed so as to have regions where no conductive material is present, and these layers are used to form transistors and capacitors. Using such a layer structure, it is possible to construct a quantum element as shown in Figure 2. FIG. 36 shows an example of a cross-sectional view of a transistor and a capacitor formed in this manner.

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

[0223] It should be noted that elements having such layers can also be used in other transistor structures and capacitor element structures. For example, the same formation is possible in the cases shown in FIGS.

[0224] The transistors and capacitors shown in FIGS. 35 and 34 are used in the circuit that drives the pixel. In such circuits, it is not necessary to have light-transmitting properties, and This is because it is desirable to form wiring in a layer with a low dielectric constant. This is not limited to this.

[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 this 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. 37A1. Also, FIG. 37B is a plan view of the thin film transistor 420. 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. A plan view is shown.

[0227] The thin film transistor 410 is a type of bottom gate structure called a 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, the thin film transistor 420 disposed in the driving circuit of the semiconductor device is The configuration of register 410 will 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 third insulating layer 414, a fourth insulating layer 415, a fourth insulating layer 416, a fourth insulating layer 417, a fourth insulating layer 418, a fourth insulating layer 419, a fourth insulating layer 420, a fourth insulating layer 421, a fourth insulating layer 422, a fourth insulating layer 423, a 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 formed. 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. Furthermore, 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 high-resistance source region 414a and the high-resistance drain region 414b are formed in a thin film. This region has a higher resistance than 414b (I-type region).

[0230] The thin film transistor 410 has a source electrode layer 415a and a 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 make up logic gates and thin film transistors that make up 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 one high-resistance drain region 414b, which is required to withstand voltage, is set to the width of the other high-resistance drain region 414b. 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 overlap width with 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 explanation has been given using a transistor, a multi-gate transistor having multiple channel forming regions may be used as needed. A thin film transistor having the same structure can also be formed.

[0233] In addition, a conductive layer 417 is provided above and overlapping the channel formation region 413. 7 is electrically connected to the gate electrode layer 411 and set to the same potential. By applying a gate voltage 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, can be 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 stacked together.

[0235] The protective insulating layer 403 is formed on the first gate insulating layer 402 provided below the protective insulating layer 403. It is preferable that the insulating film is in contact with the insulating film that serves as the base. , 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 a silicon nitride film. It is effective to

[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 third insulating layer 424, a fourth insulating layer 425, a fourth insulating layer 426, a fourth insulating layer 427, a fourth insulating layer 428, a fourth insulating layer 429 ...30, a fourth insulating layer 431, a The first gate insulating layer 402a, the second gate insulating layer 402b, and the oxide layer including the channel forming region The oxide semiconductor layer 422, the oxide insulating layer 426 which functions as a channel protection layer, and the source electrode layer 4 25a and the 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 addition, in order to form the oxide semiconductor layer 422, at least a material constituting the oxide semiconductor layer 422 is After the semiconductor film is formed, heat treatment (dehydration or dehydrogenation) is performed to reduce impurities such as moisture. Heat treatment for dehydration or dehydrogenation is carried out, followed by slow cooling. Then, an 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 disposed in the pixel is formed by the oxide semiconductor layer 422. The oxide insulating layer 426 is in contact with the gate electrode layer 421 and overlaps with the oxide insulating layer 426 serving as 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] 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 light-transmitting conductive film is also used for a gate electrode layer 421 of the thin film transistor 420.

[0242] In addition, the pixel in which the thin film transistor 420 is disposed is provided with 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 can be realized. The layer 402a, the second gate insulating layer 402b, and the oxide insulating layer 426 are also irradiated with visible light. It is preferable to use a light-transmitting film.

[0243] In this specification, a film that is transparent to visible light is a film that has a visible light transmittance of 75 to 100 %, and if the film is conductive, it is also called a transparent conductive film. electrode layer, source electrode layer, drain electrode layer, pixel electrode layer, or other electrode layer, 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 transmittance of visible light is 50 to 75%.

[0244] 38A to 38F and 39A to 39E, thin film transistors on the same substrate will be described below. The steps for 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, 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, if capacitance is required not only in the pixel section but also in the drive circuit, A capacitance wiring layer is also formed on the driver circuit. The resist mask is formed by the inkjet method. If the resist mask is formed by the inkjet method, a photomask is not required. Therefore, the manufacturing cost can be reduced.

[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 underlayer 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 in the pixel portion and the like are transparent to visible light. For example, a film made of an In-Sn-Zn-O based material, 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 film 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 used for the gate electrode layers 411 and 421 is a sputtering method or a vacuum deposition method ( The coating is formed by a method such as electron beam evaporation, arc discharge ion plating, or spraying. In addition, when using a sputtering method, a target containing 2% by weight or more and 10% by weight or less of SiO2 is used. The transparent conductive film contains SiOx (X>0) which 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 formed by depositing a silicon oxide layer using a plasma CVD method or a sputtering method. 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 can be formed using SiH4, oxygen, and nitrogen as the deposition gas. 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 or more and 200 nm or less 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 gate insulating layer is formed as a two-layer structure with the first gate insulating layer 40. As 2a, a silicon nitride film or a silicon nitride oxide film having a thickness of 100 nm is used. The second gate insulating layer 402b is a silicon oxide film with 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. The oxide semiconductor film 430 has an amorphous crystal structure.

[0253] In this embodiment, after the oxide semiconductor film 430 is formed, heating is performed for dehydration or dehydrogenation. After this heat treatment, the oxide semiconductor film 430 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 reducing the thickness of the oxide semiconductor film 430, the oxide semiconductor film 430 can be crystallized by heat treatment after the formation of the oxide semiconductor film 430. This can suppress the above.

[0254] Note that before the oxide semiconductor film 430 was formed by a sputtering method, argon gas was introduced. Reverse sputtering is performed to generate plasma, and the film is attached to the surface of the second gate insulating layer 402b. It is preferable to remove the dust that is present on the target. In an argon atmosphere, a voltage is applied to the substrate side using an RF power supply to form plasma near the substrate. It is a method of modifying the surface by forming a gas. Note that nitrogen, helium, oxygen, etc. can be used instead of argon. The sputtering process can also be carried out 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. An oxide semiconductor film 43 was formed by sputtering using a Zn-O-based oxide semiconductor target. The oxide semiconductor film 430 is formed under a rare gas (typically, argon) atmosphere. , under an oxygen atmosphere, or under an atmosphere of a rare gas (typically argon) and oxygen. When the sputtering method is used, the SiO2 layer can be formed by 2 wt. The oxide semiconductor film 430 is crystallized by deposition using a target containing 10 wt % or less of the above. 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 subjected to a second photolithography process to form an island-shaped oxide semiconductor film. In addition, a resist mask for forming an island-shaped oxide semiconductor layer is applied to the substrate. If the resist mask is formed by the ink jet 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 strain 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 apparatus, and the oxide semiconductor layer is After the heat treatment in a nitrogen atmosphere, the oxide semiconductor layer is cooled to a predetermined temperature or lower. This prevents the oxide semiconductor layer from coming into contact with the air, preventing water and hydrogen from re-entering the oxide semiconductor layer. Semiconductor layers 431 and 432 are obtained (see FIG. 38B). In this embodiment, , heating at a temperature T in a nitrogen atmosphere to dehydrate or dehydrogenate the oxide semiconductor layer; After the treatment, the temperature is raised to a temperature that will prevent water from entering again (specifically, 10 The substrate is slowly cooled in the same furnace (until the temperature drops to 0°C or more). The heat treatment can also 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 nitrogen introduced into the heat treatment device does not contain water, hydrogen, etc. The purity of rare gases such as helium, neon, and argon must be 6N (99.9999%) or higher. Preferably, the impurity concentration is 7N (99.99999%) or more (i.e., 1 ppm or less, preferably It is preferable to keep the concentration below 0.1 ppm.

[0259] Depending on the conditions of the first heat treatment or the material of the oxide semiconductor layer, the oxide semiconductor layer In some cases, the film crystallizes to form 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 removed from the mold and subjected to a photolithography process.

[0261] Before the oxide semiconductor film 430 is formed, an inert gas atmosphere (nitrogen, helium, or neodymium) is used. Heat treatment (400°C or higher but below the distortion point of the substrate) in an oxygen atmosphere (e.g., argon) ) to remove impurities such as hydrogen and water contained in the layer, thereby forming a gate insulating layer. .

[0262] Next, a metal oxide film 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 A resist mask 433b is formed, and selective etching is performed to form a metal electrode layer 434, and forming a metal electrode layer 435 (see FIG. 38C).

[0263] The material of the metal conductive film is an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W. Alternatively, alloys containing the above elements or alloys of combinations of the above elements may be used. 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 three-layer laminate structure, or an aluminum layer on a molybdenum layer and the aluminum It is preferable to use a three-layer laminate structure in which a molybdenum layer is laminated on a metal conductive film. The 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 step is carried out. 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, only a part of the oxide semiconductor layer 431 is etched. The oxide semiconductor layer 437 is then formed by etching, and has a groove (depression). 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 materials are used, the manufacturing cost can be reduced.

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

[0267] In the fifth photolithography step, the metal electrode layer 435 overlapping with the oxide semiconductor layer 432 is 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 adjusted appropriately so that this does not occur.

[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) of the oxide semiconductor layer 437. 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 and is formed by an oxide film deposition method such as a sputtering method. The insulating film 439 can be formed by using an appropriate method that prevents impurities such as water and hydrogen from being 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 between room temperature and 300°C. In this embodiment, the temperature is set to 100° C. The film is formed under a rare gas (typically argon) atmosphere, an oxygen atmosphere, or a rare gas (typically The target can be oxygen (argon) and oxygen atmosphere. A silicon nitride target or a silicon target can be used. Silicon oxide was deposited by sputtering using a silicon target under oxygen and nitrogen atmosphere. The oxide semiconductor layer 432 and the oxide semiconductor layer 437 can be formed in contact with the oxide semiconductor layer 432 and the oxide semiconductor layer 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 2 For example, the temperature is increased by heating in a nitrogen atmosphere. The second heat treatment is carried out 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] 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 heat treatment in step 2.

[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 silicon dioxide, and the second heat treatment is performed in 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 The 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 subjected to the second heat treatment to make the entire film oxygen-excessive, so that the entire film becomes highly resistive. An oxide semiconductor layer 422 that has been converted to i-type oxide is formed.

[0274] After the second heat treatment, the oxide semiconductor layer 422 is exposed in a nitrogen or inert gas atmosphere. 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 performed in an oxygen gas, N2O gas atmosphere, or in an ultra-dry atmosphere. Dry air (dew point below -40°C, preferably below -60°C) is used.

[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 can be improved. Specifically, by forming the high-resistance drain region 414b, the drain voltage 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 formed in a structure in which the efficiency can be changed stepwise. 15b is connected to a wiring that supplies 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, preventing a local high electric field from being applied. The breakdown voltage of the resistor 410 can be improved.

[0276] 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, 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 oxide semiconductor layer 422 is covered with a channel formation region 26. Note that, as in this embodiment, the second gate insulating layer 402b is formed of an oxide film. 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 reduction). When 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, the second gate insulating layer 402b can be prevented 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 A resist mask is formed by a process, and the light-transmitting conductive film is etched using this resist mask. 39C, the source electrode layer 425a and the drain electrode layer 42 After the etching step, the resist mask is removed.

[0279] The methods for forming a transparent conductive film include sputtering and vacuum deposition (electron beam deposition, etc.). The conductive film can be formed by arc discharge ion plating or spraying. 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 such as Sn-O, Zn-O, and Zn-O 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 contains SiOx (X>0) which inhibits crystallization, and is then processed in a later process. It is preferable to suppress crystallization during the heat treatment for dehydration or dehydrogenation. It's 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 mask, no photomask is required, which reduces manufacturing costs. Cut.

[0281] Next, as shown in FIG. 39D, oxide insulating layers 416, 426, source electrode layer 425a, A protective insulating layer 403 is formed over the R A silicon nitride film is formed as the protective insulating layer 403 by RF sputtering. The PET 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 Using inorganic insulating films that block this, silicon nitride films, aluminum nitride films, and nitride oxide films are used. 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 formed on the first gate insulating film 401. 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 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. Providing a silicon nitride film so as to surround the display device improves the reliability of the display device.

[0283] Next, a planarization insulating layer 404 is formed over the protective insulating layer 403. For example, heat-resistant materials such as polyimide, acrylic, benzocyclobutene, polyamide, and epoxy are used. In addition to the above organic materials, low dielectric constant materials (lo wk materials), siloxane resin, PSG (phosphorus glass), BPSG (boron phosphorus glass) ) can be used. It is possible to laminate a plurality of insulating films made of these materials. In this way, the planarization insulating layer 404 may be formed.

[0284] Siloxane-based resin is a Si-OS compound formed using siloxane-based materials as starting materials. The siloxane resin corresponds to a resin containing an i bond. Alternatively, an organic group having a fluoro group may be used. That's fine.

[0285] The method for forming the planarization insulating layer 404 is not particularly limited, and may be a sputtering method, a SO 4 method, or the like, depending on the material. G method, spin coating, dip coating, spray coating, droplet ejection method (inkjet method, screen Printing machines, such as offset printing, doctor knives, roll coaters, curtain coaters, 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, 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, reducing manufacturing costs. 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, Al-Zn-O-based non-single crystal containing nitrogen is used. films, i.e., Al-Zn-ON based non-single crystal films, Zn-O based non-single crystal films containing nitrogen, and nitrogen It is also possible to use an Sn-Zn-O based non-single crystal film containing Al-Zn-O based non-single crystal film. The composition ratio (atomic %) of zinc in the single crystal film is 47 atomic % or less, and the composition ratio 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. The composition ratio (atomic percentage) of nitrogen in the crystal film is larger than that of the original. However, since ITO etching is particularly prone to leaving residues, Indium oxide zinc oxide alloy (In2O3-ZnO) was used to improve the workability of the alloy. It's okay to be there.

[0288] The composition ratio of the light-transmitting conductive film is expressed in atomic percent, and is measured by an electron probe microanalyzer. (EPMA:Electron Probe X-ray MicroAnalyzer ) will be evaluated by analysis.

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

[0290] Through the above process, nine exposure masks are used to form thin film transistors on the same substrate 400. A driver circuit including the thin film transistor 410 and a pixel portion including the 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-etched thin film transistor. This is a channel protective thin film transistor including an oxide semiconductor layer 422 that is entirely i-type.

[0291] In addition, the first gate insulating layer 402a and the second gate insulating layer 402b are used as dielectrics, and the 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 the individual pixels to form a pixel portion. and a driver circuit having a thin film transistor 410 is arranged around the pixel portion. This can be one of the substrates for manufacturing an active matrix display device. For 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 to check 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 conductive layer 417 has a potential that is equal to that of the gate electrode. This layer may be the same as or different from layer 411 and serves as a second gate electrode layer. The potential of the conductive layer 417 can be set to GND, 0 V, or in a floating state. It's okay to have it.

[0294] In addition, a resist mask for forming the conductive layer 417 and the pixel electrode layer 427 is formed by inkjet printing. If the resist mask is formed by the ink-jet method, the photomask Since no additional materials are 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 Sa 5007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature Degree, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient , vibration, smell or infrared measuring function), microphone 5008, etc. It can have.

[0297] FIG. 40A shows a mobile computer, which includes the above-mentioned components, as well as 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. 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. are included. In addition to the above, it is equipped with an antenna 5014 and a shutter button 5015. , an 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, and the like. FIG. 40G shows a television receiver, which includes a tuner, an image processor, etc. in addition to the components described above. 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, which in addition to the above-mentioned components, has a support base 5018, etc. 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, reader / writer 5021, etc. In addition to the above, there are transmitters, receivers, and one-segment units for mobile phones and mobile terminals. tuners for minute reception 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. Functions, touch panel function, calendar, date or time display function, various software Functions that control 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 programs or data recorded on recording media 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 By displaying text information or images that take parallax into account on multiple displays, It can have the function of displaying a stereoscopic image. The device has the functions of taking still images, taking videos, and automatically or Manual correction function, function to save captured images to a recording medium (external or built-in to the camera) 40A to 40C, and the like. The functions that the electronic devices shown in FIGS. 40H and 41A to 41D can have are not limited to these. The function 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 example of a building 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 example of a building 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 Figures 41E and 41F, a display device (semiconductor device) is installed on the wall and the unit bath. However, the building of this embodiment is not limited to this example, and various parts of the building may be used. A semiconductor device can be incorporated into the

[0305] Next, a configuration example of a moving object incorporating a display device (semiconductor device) 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 the body 502 of the automobile. 9, and provides on-demand information on the operation of the vehicle or information input from inside and outside the vehicle. The semiconductor device may also 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. The ceiling 503 above the seats of the passenger airplane A display panel 5031 is attached to the display panel 5030 via a hinge portion 5032. 5031 has the function of displaying information when operated by passengers. The figure shows the state of the display panel 5031 when in use. The extension and contraction of the hinge part 5032 allows passengers to It will be possible to watch Nel 5031 footage.

[0308] In addition, in Figures 41G and 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 motor vehicles (cars, buses, trucks, etc.). It can be applied to various moving objects such as railway vehicles, 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 about these.

[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 include a display medium whose brightness, reflectance, transmittance, etc. change. The display element provided in 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 depending on the 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 is a device having an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. An 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), formed by matter, formed by inorganic matter, formed by organic matter Those made of inorganic materials, those made of polymeric materials, and those made of low molecular weight materials. There are those that contain materials, or those that contain high molecular weight materials 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 devices include Spindt type and carbon nanotube (CNT) MIM (Metal-Insulator-Metal) MIS (Metal-Insulator-Semiconductor) type, a stack of metal-insulator-semiconductor semiconductor type, MOS type, silicon type, thin film diode type, diamond Thin film types such as metal-insulator-semiconductor-metal type, HEED type, EL type, porous silicon However, there are other types of electron-emitting devices, including surface conduction (SCE) types. A variety of different types can be used.

[0313] In this specification, the term "liquid crystal display device" refers to a display device having a liquid crystal element. They are classified into direct view type, projection type, etc. depending on the image display method. Liquid crystal elements can be classified as transmissive, reflective, or semi-transmissive depending on whether they transmit or reflect light. 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 by a pair of electrodes and a liquid crystal layer. The optical modulation effect is achieved by applying an electric field (horizontal, vertical or diagonal) to the liquid crystal. 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, lyotropic liquid crystals Tropic liquid crystal, low molecular weight liquid crystal, polymer liquid crystal, polymer dispersed liquid crystal (PDLC), ferroelectric liquid crystal , antiferroelectric liquid crystal, main chain liquid crystal, side chain 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 Birefringence ence) 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-mentioned configuration examples, and various configuration examples are possible. A liquid crystal display device can be applied.

[0316] An example of electronic paper is one that is displayed by molecules (optical anisotropy, dye molecule orientation, etc.). ), particle-based displays (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. These are indicated by molecular light absorption, or by spontaneous emission caused by electron-hole combinations. Specifically, an example of electronic paper is a micro Capsule electrophoresis, horizontally moving electrophoresis, vertically moving electrophoresis, spherical twist ball, Magnetic twist ball, cylindrical twist ball method, charged toner, electronic liquid powder, magnetophoretic type, Magnetic heat sensitive, electrowetting, light scattering (transparent / opaque), cholesteric liquid Crystalline / photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic color Liquid crystal dispersion type, movable film, color development and decolorization by leuco dye, photochromic, electro There are various types of materials, such as thermochromic, electrodeposition, and flexible organic electroluminescence. The electronic paper is not limited to the above, and various types can be used. By using capsule-type electrophoresis, the drawbacks of the electrophoretic method, such as aggregation of electrophoretic particles, It can solve the problem of precipitation. Electronic liquid powder has fast response, high reflectivity, wide viewing angle, and low power consumption. It has advantages in terms of power consumption and memory capacity.

[0317] An example of a plasma display is a substrate with electrodes formed on its surface, and a display panel with the electrodes and minute A substrate having grooves formed on its surface and a phosphor layer formed in the grooves is placed opposite the substrate at a narrow interval, and a rare gas is then applied to the substrate. Other examples of plasma displays include: Some have a structure in which a 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] There are also display devices that require lighting devices. For example, liquid crystal display devices, grating laser devices, etc. Display devices using light valves (GLVs), 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] Furthermore, examples of the display device include 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 formed on the same substrate as the plurality of 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. The circuit is placed on a substrate where there is a chip on glass (COG) Examples of such IC chips include IC chips that are 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. This can improve reliability by reducing the number of connections to circuit components. In addition, circuits with high drive voltages or high drive frequencies consume a lot of power. Therefore, it is recommended 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 made up of IC chips, resistors, capacitors, inductors, transistors, etc. It may also include a flexible printed circuit (FPC) attached to the display. The device is connected via a flexible printed circuit (FPC) and contains IC chips, resistors, etc. A printed wiring board (P) on which resistors, capacitors, inductors, transistors, etc. are mounted. 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, an optical 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 this case, in the case of a color display device having R (red), G (green), and B (blue) color elements, The minimum unit of an image is composed of three pixels: an R pixel, a G pixel, and a B pixel. However, the number of color elements is not limited to three, and more than three colors may be used, or colors other than RGB may be used. Colors may also be used. For example, adding white makes it possible to use RGBW (W is white). Or, for example, yellow, cyan, magenta, emerald green, vermilion, etc., can be added to RGB. It is possible to add one or more colors, or colors similar to at least one of the RGB colors. can be added to RGB. For example, R, G, B1, B2. 1 and B2 are both blue, but have slightly different wavelengths. It is also possible to use G and B. By using these color elements, the image becomes more realistic. 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 this case, there are multiple areas for controlling brightness for each color element, and the gradation is In this case, one area for controlling brightness is considered to be one pixel. In other words, one color element is made up of multiple pixels. Even if there are multiple areas that control brightness within one color element, they can be grouped together and used 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 varied. In the various brightness control areas, the signal supplied to each is slightly different. In other words, for one color element, multiple regions may be used to widen the viewing angle. The potentials of the pixel electrodes of the respective regions may be different. The voltage applied to the 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] When explicitly stating one pixel (three colors), the three pixels of R, G, and B are considered to be one pixel. When explicitly describing one pixel (one color), for one color element, When there are multiple regions, they can be collectively regarded as one pixel.

[0325] The plurality of pixels can be arranged (distributed) in a matrix form, 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. For example, full color with three color elements (e.g. RGB) In the 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 herein can be used with transistors of various structures. In other words, there are no particular restrictions on the configuration of the transistor. In this embodiment, a display device having pixels with a high aperture ratio can be manufactured. Some examples of the configuration of the transistor will be described.

[0327] Examples of transistors include amorphous silicon, polycrystalline silicon, and microcrystalline silicon. Non-single crystals such as silicon (also called single crystal, 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 increase the size of the manufacturing equipment. Therefore, it is possible to manufacture a large number of display devices at the same time. Since the manufacturing temperature is low, it is possible to manufacture 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, part of the film that forms the transistor is exposed to light. Therefore, the aperture ratio can be improved.

[0328] When producing polycrystalline silicon, a catalyst (nickel, etc.) is used to This will further improve the performance and make it possible to manufacture transistors with good 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 circuit, gamma correction circuit, DA conversion circuit, etc.) are integrated on the board. It can be formed.

[0329] When manufacturing microcrystalline silicon, a catalyst (nickel, etc.) is used to This further improves the performance and makes it possible to manufacture transistors with good 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 The driver circuit (scanning line driving circuit) can be formed integrally on the substrate. Therefore, if laser irradiation is not performed, 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 a catalyst (nickel, etc.). It is possible to produce polycrystalline or microcrystalline silicon without using a silicon nitride.

[0330] It should be noted that improving the crystallinity of silicon to polycrystalline or microcrystalline is not possible for the entire panel. It is desirable, but not limited to, that only a partial area of ​​the panel is covered with silicon. The crystallinity of the film may be improved by selectively irradiating the laser beam. 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 part of the circuit (for example, an analog switch). As a result, the crystallization of silicon is improved only in the areas where high-speed circuit operation 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. 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, manufacturing costs can be reduced.

[0331] Examples of transistors 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, 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. These compound semiconductors or oxide semiconductors can be used in 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 a transistor, This can reduce costs.

[0332] 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, manufacturing at low vacuum, or manufacturing at large scale. It can be manufactured on a mold substrate. Therefore, it can be manufactured without using a mask (reticle). This allows for easy changes to the transistor layout. 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 required area, it is possible to apply the film only to the required area by etching after forming the film on the entire surface. This method wastes less material and is less costly than the chipping method.

[0333] Examples of transistors include transistors with organic semiconductors and carbon nanotubes. These can be used to form transistors on a flexible substrate. A semiconductor device using such a substrate can be made resistant to shock. do.

[0334] As the transistor, transistors with various other structures can be used. For example, ,Transistors include 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 as the transistors, This allows a larger current to flow, 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 achieve low power consumption, miniaturization, high-speed operation, and the like.

[0335] An 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, the structure is such that 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 can reduce 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 can be made 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] An example of a transistor is a transistor with a structure in which gate electrodes are arranged above and below the channel. The structure in which gate electrodes are arranged above and below the channel can be applied. 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. The structure in which the gate electrode is placed makes it easier for a depletion layer to form, 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 placed under the channel region, a normal staggered structure, an inverted 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 A transistor having a structure in which regions are connected in series can be used.

[0338] An example of a transistor is a transistor having a source electrode or a gate electrode in the channel region (or a part thereof). A transistor with an overlapping drain electrode can be used. By using a structure in which the source electrode and drain electrode overlap the This can prevent unstable operation caused by charge accumulation in a part 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 or improves the breakdown voltage of the transistor (improving reliability). Alternatively, by providing a high resistance region, the drain Even if the voltage between the gate and source changes, the drain current does not change much, and the voltage-current characteristics 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 (for example, 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 Examples of glass substrates include 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 vinyl chloride are some of the base film materials. Examples include polyester, polyamide, polyimide, inorganic vapor deposition film, and paper. In particular, when a transistor is manufactured using a semiconductor substrate, a single crystal substrate, an SOI substrate, or the like, This reduces variations in characteristics, size, or shape, and increases current capacity and size. It is possible to manufacture transistors with small noise. By configuring the circuit as described above, it is possible to reduce the power consumption of the circuit or to increase the integration density 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, a cellophane substrate, etc. , stone substrate, wood substrate, fabric substrate (natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane) Recycled fiber (acetate, cupro, rayon, recycled polyester) or recycled fiber (acetate, cupro, rayon, recycled 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. This allows for the manufacture of thinner devices, the provision of heat resistance, and the reduction in weight or thickness.

[0342] Here, a transistor is defined as a transistor having at least three terminals including a gate, a drain, and a source. The element has a channel region between a drain region and a source region. A current can 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 or the drain. The region that functions as a source and the region that functions as a drain are called the source and the drain, respectively. In this 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] Also, 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. is referred to as a first terminal, a first electrode, or a first region, and the other of the emitter and the collector is referred to as a second 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." is.

[0344] A gate is a gate electrode and a gate wiring (gate line, gate signal line, scanning line, scanning signal line, etc.) The gate electrode is the entire structure including the channel. The semiconductor that forms the gate region and the conductive film that overlaps it via the gate insulating film. However, part of the gate electrode is a high resistance region or a source region (or drain The gate insulating film may overlap the gate electrode (gate region). 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 to 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 them. For example, a part of the gate wiring that is extended When the gate electrode and the channel region overlap, that area (region, conductive film, wiring, etc.) 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 the function of connecting 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 It can also be called wiring.

[0347] For example, in a multi-gate transistor, one gate electrode and another gate electrode are connected. 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 can 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 made of the same material and is located on the same island (island) as the gate electrode or gate wiring. The parts (regions, conductive films, wiring, etc.) that form the gate electrode and gate wiring As another example, the conductor that connects the gate electrode and the gate wiring may be called a line. A conductive film formed of a material different from that of the gate electrode or gate wiring is also included in the gate It may be called a gate electrode or a gate wiring.

[0348] The gate terminal is a part of the gate electrode (region, conductive film, wiring, etc.), or a part of the 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 this case, 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 formed in the same layer as the gate of the transistor, or wiring formed in the same material as the gate of the transistor It may refer to 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, and the like.

[0350] The source is a combination of a source region, a source electrode, and a source wiring (a source line, a source signal line, a data line, etc.). This refers to the whole or part of the signal lines (also called data signal lines, 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, it refers to a low concentration semiconductor region where the concentration of P-type impurities or N-type impurities is low. If the highly impurity region is a high resistance region, it is not considered to be included in the source region. The source electrode is made of a material different from the source region and is electrically isolated from the source region. However, the source electrode refers to the conductive layer that is connected to the source. The source electrode is sometimes called the source electrode, including the source region. Wiring for connecting between electrodes, wiring for connecting between source electrodes of each pixel, refers to a wiring for connecting the 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 part (region, conductive film, wiring, etc.) is called a source electrode. In other words, the source electrode and the source wiring are clearly separated. For example, there are regions where the source wiring is extended and cannot be distinguished from the other. When 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 also 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 Similarly, the source electrode may 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.) can be called lines. In the strict sense, However, depending on the specifications at the time of manufacture, etc., there are cases where the device does not have the function of connecting to the source electrode. It is made of the same material as the source electrode or source wiring, and is 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 also be called a source electrode. This may also be called a 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 a part (area, conductive film, wiring, etc.) that is being used.

[0355] Note that 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 calling it a "transistor," the source (drain) of the transistor may not be connected to that wiring. In this case, the source wiring, source line, source signal line, data line and 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 the transistor, or Examples include wiring for storage capacitors, power supply lines, and substrates. There are semi-potential supply wirings, etc.

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

[0357] 101 Substrate 102 circuits 103 Circuit 104 circuits 105 Insulating layer 106 Conductive layer 107 Medium 108 PCB 109 Conductive Layer 202 Insulating layer 203 Semiconductor layer 205 Insulation Layer 206 Conductive layer 207 Transistor 208 Capacitor 209 Capacitor 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. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

2. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. In a plan view, the fourth conductive layer has a first region having a first width along the first direction, a second region having a second width along the first direction, and a third region having a third width along the first direction. The second width is greater than the first width and greater than the third width. In a plan view, the first region, the second region, and the third region are arranged in this order in a second direction perpendicular to the first direction. The second region does not overlap with the channel formation region of the second transistor. The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

3. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. In a plan view, the fourth conductive layer has a first region having a first width along the first direction, a second region having a second width along the first direction, and a third region having a third width along the first direction. The second width is greater than the first width and greater than the third width. In a plan view, the first region, the second region, and the third region are arranged in this order in a second direction perpendicular to the first direction. The second region does not overlap with the channel formation region of the second transistor. In a plan view, the fifth conductive layer overlaps with both ends of the second region along the second direction, The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

4. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. The length of the second channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the third channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the second channel-forming region in the channel-length direction is greater than the length of the first channel-forming region in the channel-length direction. The area of ​​the oxide semiconductor layer having the second channel-forming region is larger than the area of ​​the oxide semiconductor layer having the first channel-forming region. The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

5. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. In a plan view, the fourth conductive layer has a first region having a first width along the first direction, a second region having a second width along the first direction, and a third region having a third width along the first direction. The second width is greater than the first width and greater than the third width. In a plan view, the first region, the second region, and the third region are arranged in this order in a second direction perpendicular to the first direction. The second region does not overlap with the channel formation region of the second transistor. The length of the second channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the third channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the second channel-forming region in the channel-length direction is greater than the length of the first channel-forming region in the channel-length direction. The area of ​​the oxide semiconductor layer having the second channel-forming region is larger than the area of ​​the oxide semiconductor layer having the first channel-forming region. The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

6. Having first to third transistors, a capacitive element, a display element, and first to third wiring, One of the sources and drains of the first transistor is electrically connected to the first wiring. The source and drain of the first transistor are electrically connected to the gate of the second transistor and to one electrode of the capacitive element. The source and drain of the second transistor are electrically connected to the pixel electrode of the display element and to the source and drain of the third transistor. The source and drain of the second transistor are electrically connected to the second wiring. The source and drain of the third transistor are electrically connected to the third wiring. The first channel formation region of the first transistor, the second channel formation region of the second transistor, and the third channel formation region of the third transistor are each an oxide semiconductor in a display device, A first conductive layer having a region extending in a first direction in a plan view and functioning as the gate of the first transistor, A second conductive layer having a region extending in the first direction in a plan view and functioning as the second wiring, A third conductive layer having a region extending in the first direction in a plan view and functioning as the third wiring, A fourth conductive layer having the function of one electrode of the capacitive element, A fifth conductive layer having a region located below the fourth conductive layer and functioning as the other electrode of the capacitive element, It has a sixth conductive layer that functions as a pixel electrode of the display element, In a plan view, the fourth conductive layer has a region located between the first conductive layer and the second conductive layer. In a plan view, the second conductive layer has a region located between the second channel-forming region and the third conductive layer. In a plan view, the fourth conductive layer has a first region having a first width along the first direction, a second region having a second width along the first direction, and a third region having a third width along the first direction. The second width is greater than the first width and greater than the third width. In a plan view, the first region, the second region, and the third region are arranged in this order in a second direction perpendicular to the first direction. The second region does not overlap with the channel formation region of the second transistor. In a plan view, the fifth conductive layer overlaps with both ends of the second region along the second direction, The length of the second channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the third channel-forming region in the channel width direction is greater than the length of the first channel-forming region in the channel width direction. The length of the second channel-forming region in the channel-length direction is greater than the length of the first channel-forming region in the channel-length direction. The area of ​​the oxide semiconductor layer having the second channel-forming region is larger than the area of ​​the oxide semiconductor layer having the first channel-forming region. The sixth conductive layer overlaps with each of the first transistor, the second transistor, the third transistor, and the capacitive element. Display device.

7. In any one of claims 1 to 6, The channel length direction of the second channel-forming region is along the direction of the first direction. Display device.

8. In any one of claims 1 to 7, The oxide semiconductor comprises In, Ga, and Zn. Display device.

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