Light-emitting device

Abstract

To provide a semiconductor device, a light-emitting device, and a display device, capable of suppressing an influence of variations of a characteristic of a transistor.SOLUTION: A circuit 100 of a semiconductor device, includes: a transistor 101; a first wiring 21; a second wiring 22; a first switch 11; a second switch 12; a third switch 13; a first capacitive element 102; and a second capacitive element 103. The first switch selects a conduction and a non-conduction between the first wiring and a first electrode of the first capacitive element. The first electrode of the first capacitive element is electrically connected to the first electrode of the second capacitive element. The second electrode of the first capacitive element is electrically connected to a gate of the transistor. The second electrode of the second capacitive element is connected to one of a source and a drain of the transistor. The second switch selects the conduction and the non-conduction between the second wiring 22 and the gate of the transistor. The third switch selects the conduction and the non-conduction between the first electrode of the first capacitive element and one of the source and the drain of the transistor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a semiconductor device, a light-emitting device, or a display device, or a driving method thereof. The present invention relates to a semiconductor device, such as a transistor, or a manufacturing method thereof. Examples of the light-emitting device include an electroluminescent device. Examples of such light-emitting devices include light-emitting devices having light-emitting elements such as luminescence elements (hereinafter referred to as EL elements). The display device may be, for example, a display device having a light-emitting element such as an EL element or a display element. In particular, the present invention relates to a semiconductor device in which the influence of variations in transistor characteristics is reduced. The present invention relates to a semiconductor device, a light emitting device, a display device, or a driving method thereof. [Background technology]

[0002] Display devices using light-emitting elements have high visibility and are ideal for making them thin, but they also have no limitations on the viewing angle. Since there is no CRT (cathode ray tube) or LCD display, Active matrix display devices using light-emitting elements are attracting attention. The specific configurations proposed vary by manufacturer, but usually include at least a light emitting element and A transistor (switching transistor) that controls the input of a video signal to the pixel; A transistor (drive transistor) that controls the current value supplied to the light emitting element is provided for each pixel. It is provided in the base.

[0003] For example, by making all the transistors in a pixel have the same conductivity type, In the manufacturing process of the semiconductor film, a step of adding an impurity element that gives a certain conductivity to the semiconductor film is performed. In the following Patent Document 1, a pixel can be formed by using only n-channel transistors. A display device in which the [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-195810 A Summary of the Invention [Problem to be solved by the invention]

[0005] In semiconductor devices such as light-emitting devices and display devices, the drain current of a transistor Since the voltage is supplied to the element, if there is variation in the transistor characteristics between pixels, The luminance of the display element such as the light-emitting element is also affected by the variation. This allows the drain current of the transistor to be corrected in anticipation of variations in the value voltage. Proposal of a pixel configuration that can achieve this is an important issue in improving the quality of semiconductor devices.

[0006] In view of the above problems, one embodiment of the present invention provides a semiconductor device that can suppress the influence of variations in transistor characteristics. It is an object of the present invention to provide a semiconductor device, a light-emitting device, or a display device that can achieve the above object. One embodiment of the present invention is a semiconductor device and a light emitting device in which the influence of deterioration of transistor characteristics is suppressed. It is an object of the present invention to provide an optical device or a display device. A semiconductor device in which luminance variations caused by variations in threshold voltage of transistors are suppressed Another object of the present invention is to provide a light-emitting device or a display device. The embodiment is a semiconductor device in which the variation in luminance due to the variation in mobility of a transistor is suppressed. Another object of the present invention is to provide a light-emitting device, a display device, or a light-emitting device. One embodiment of the present invention relates to a semiconductor device, a light-emitting device, and a semiconductor device that operate normally even if a transistor is a normally-off type. Another object of the present invention is to provide a display device or a display apparatus. ,Even if the transistor is normally off, the threshold voltage of the transistor can be obtained. It is an object of the present invention to provide a semiconductor device, a light-emitting device, or a display device. One embodiment of the present invention provides a semiconductor device, a light-emitting device, or a display device that provides high-quality display. Another object of one embodiment of the present invention is to provide a display device that displays images with less unevenness. It is an object of the present invention to provide a semiconductor device, a light-emitting device, or a display device. One embodiment of the present invention is a semiconductor device in which a desired circuit can be realized with a small number of transistors. Another object of the present invention is to provide a light-emitting device or a display device. The present invention relates to a semiconductor device, a light-emitting device, or a semiconductor device that can realize a desired circuit with a small number of wirings. Another object of the present invention is to provide a display device. The object of the present invention is to provide a semiconductor device, a light-emitting device, or a display device in which the influence of deterioration of the semiconductor device, the light-emitting device, or the display device can be suppressed. Another embodiment of the present invention is a semiconductor device and a semiconductor device manufactured in a small number of steps. It is an object of the present invention to provide an optical device or a display device.

[0007] The description of these problems does not preclude the existence of other problems. It is not necessary for the embodiment to solve all of these problems. The above will become apparent from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the description of the aspects, claims, etc. [Means for solving the problem]

[0008] One embodiment of the semiconductor device of the present invention includes a transistor, a first wiring, a second wiring, and a first a switch, a second switch, a third switch, a first capacitance element, and a second capacitance element The first switch includes at least a pair of electrodes of a first wiring and a first capacitor. The first pair of capacitance elements has a function of selecting electrical continuity or non-conduction between the first pair of capacitance elements and one of the first pair of capacitance elements. One of the electrodes of the first capacitor is electrically connected to one of the pair of electrodes of the second capacitor. The other of the pair of electrodes of the first capacitor is electrically connected to the gate of the transistor. The other of the pair of electrodes of the second capacitor is connected to the source and drain of the transistor. The second switch is electrically connected to the second wiring and the gate of the transistor. The third switch has a function of selecting conduction or non-conduction between the first capacitance element Conduction or non-conductance between one of the pair of electrodes and one of the source and drain of the transistor The switch has a function of selecting whether the switch is conductive or non-conductive.

[0009] In the semiconductor device having the above configuration, the transistor (hereinafter, the driving The voltage applied between the source and gate of a transistor (sometimes called a gate-type transistor) can be adjusted. In this way, the drain current of the transistor can be corrected.

[0010] One embodiment of the semiconductor device of the present invention includes a transistor, a load, a first wiring, and a second wiring. , a first switch, a second switch, a third switch, a first capacitive element, and a second The first switch is connected to the first wiring and one of the first capacitance elements. The first capacitive element has a function of selecting electrical continuity or non-continuity between the first capacitive element and one of the pair of electrodes. One of a pair of electrodes of the first capacitor is electrically connected to one of a pair of electrodes of the second capacitor. The other of the pair of electrodes of the first capacitor is electrically connected to the gate of the transistor. The other of the pair of electrodes of the second capacitor is connected to a load and The second switch is electrically connected to one of the source and drain of the second wiring. The third switch has a function of selecting whether to conduct or not conduct between the gate of the transistor and the second switch. The transistor is connected to one of a pair of electrodes of the first capacitor and the source and drain of the transistor. The switch has a function of selecting electrical continuity or non-conduction between the first and second terminals.

[0011] In the semiconductor device having the above configuration, the transistor (hereinafter, the driving The voltage applied between the source and gate of a transistor (sometimes called a gate-type transistor) can be adjusted. In this way, the drain current of the transistor can be corrected. The drain current can be supplied to a load.

[0012] The load can be any element or circuit. For example, the load can be a light-emitting element such as an EL element. A light-emitting element such as an EL element can be a light-emitting element that is electrically connected between the anode and cathode of the light-emitting element. The light emitted is proportional to the current value of the current.

[0013] When using a light-emitting element as a load, for example, the following (Type A) or (Type B ) configuration.

[0014] (Type A) In the semiconductor device according to the above aspect of the present invention, One of the source and drain may be electrically connected to the anode of the light emitting element. In this case, the transistor is an n-channel transistor. The semiconductor device according to one aspect of the present invention includes a means for controlling the potential of the first wiring (e.g., The driving circuit is configured to adjust the potential of the first wiring to the potential of the cathode of the light emitting element. The potential of the first wiring is controlled so that there is a period during which the potential is equal to or lower than the potential of the first wiring.

[0015] (Type B) In the semiconductor device according to the above aspect of the present invention, One of the source and drain may be electrically connected to the cathode of the light-emitting element. In this case, the transistor is a p-channel transistor. The semiconductor device according to one aspect of the present invention includes a means for controlling the potential of the first wiring (e.g., The driving circuit is configured to adjust the potential of the first wiring to that of the anode of the light-emitting element. The potential of the first wiring is controlled so that there is a period during which the potential is equal to or higher than the potential of the first wiring.

[0016] Each of the first switch to the third switch can be configured using a transistor. The transistor can be of the same conductivity type as the driving transistor. can be done.

[0017] The semiconductor device according to one embodiment of the present invention includes a transistor having an oxide semiconductor in a channel formation region. Alternatively, the channel forming region may be made of single crystal silicon. Alternatively, the transistor may be made of polycrystalline silicon. Alternatively, a transistor having a non-transistor in the channel forming region can be used. The transistors may be formed using amorphous silicon.

[0018] That is, transistors having various structures can be used. There is no limitation on the type of transistor used. An example of a transistor is a single crystal silicon A transistor with a gate, or a transistor made of amorphous silicon, polycrystalline silicon, or microcrystalline silicon (micro (also called crystalline, nanocrystalline, or semi-amorphous) silicon. A thin film transistor (TFT) having a single crystal semiconductor film or the like can be used.

[0019] An example of a transistor is a compound semiconductor (e.g., SiGe, GaAs, etc.). , or oxide semiconductors (e.g., ZnO, InGaZnO, indium zinc oxide, ITO (indium tin oxide), SnO, TiO, AlZnSnO(AZTO), InSnZn or a thin film of a compound semiconductor or oxide semiconductor. This allows the manufacturing temperature to be lowered. This makes it possible to fabricate transistors at room temperature, for example. A transistor is formed directly on a low-profile substrate, such as a plastic substrate or a film substrate. In addition, these compound semiconductors or oxide semiconductors can be used as the channel of a transistor. They can be used not only for the control part but also for other purposes. For example, The compound semiconductor or oxide semiconductor is used for wiring, resistor elements, pixel electrodes, light-transmitting electrodes, etc. They can be formed as a film or a layer at the same time as the transistor. This allows costs to be reduced.

[0020] An example of a transistor is a transistor having an organic semiconductor or a carbon nanotube. A resistor such as a resistor 14 can be used.

[0021] An example of a transistor is a multi-gate transistor having two or more gate electrodes. In the case of a multi-gate structure, the channel formation regions are connected in series. Therefore, multiple transistors are connected in series. The off-state current can be reduced and the breakdown voltage of the transistor can be improved (reliability can be improved). Alternatively, a multi-gate structure can be used to separate the drain and source when operating in the saturation region. Even if the voltage between the drain and source changes, the current between the drain and source does not change much, and the slope is A voltage-current characteristic with a flat slope can be obtained. 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, it is possible to realize a differential circuit or a current mirror circuit with good characteristics. is possible.

[0022] An example of a transistor is a structure in which gate electrodes are arranged above and below a channel. A transistor having a structure in which gate electrodes are arranged above and below the channel can be applied. By doing so, the circuit configuration becomes like multiple transistors connected in parallel. As a result, the channel area increases, and the current value can be increased. A structure in which gate electrodes are arranged above and below makes it easier for a depletion layer to form. , the S value can be improved.

[0023] As an example of a transistor, a gate electrode is disposed on a channel formation region. a structure in which the gate electrode is disposed under the channel forming region; a forward staggered structure; Tag structure, structure in which the channel formation region is divided into multiple regions, channel formation regions connected in parallel The present invention uses transistors having a structure in which the channel formation regions are connected in series, or a structure in which the channel formation regions are connected in series. can be done.

[0024] As an example of a transistor, a structure in which an LDD region is provided can be applied. By providing a gate, the off-state current can be reduced or the withstand voltage of the transistor can be improved (reliability can be improved). Alternatively, by providing an LDD region, when operating in the saturation region, Even if the voltage between the drain and source is changed, the drain current does not change much and the slope is flat. A stable voltage-current characteristic can be obtained.

[0025] In addition, regarding the contents not specified in the drawings or text in the specification, Or, for a certain value, it is possible to configure an invention that specifies the upper and lower limits. When a numerical range is stated, such as by narrowing the range arbitrarily, or By excluding one point in the scope, the invention can be defined by excluding a part of the scope. These can, for example, define that prior art does not fall within the technical scope of the present invention. This can be done.

[0026] As a specific example, a circuit diagram in which first to fifth transistors are used in a circuit is shown below. In that case, the circuit does not have a sixth transistor. Alternatively, the circuit does not have a capacitance element. Furthermore, it is possible to specify that the circuit has a certain connection structure. The invention can be configured by specifying that the sixth transistor is not included. The circuit does not have a capacitive element having a specific connection structure. For example, the gate of the third transistor is connected to the gate of the third transistor. Alternatively, the invention may be specified as not having a sixth transistor. For example, a capacitor element having a first electrode connected to the gate of a third transistor may be provided. It is possible to define the invention as not being

[0027] As another specific example, for a certain value, for example, "a certain voltage is 3 V or more and 10 V or less. In that case, for example, if a certain voltage is -2V or more and 1V or less, excluding the case where the voltage is less than 1V. It is possible to stipulate that the invention does not apply when a certain voltage is 13V or more. For example, the invention may be stipulated that the voltage is between 5V and 8V. For example, the voltage may be set to about 9V. For example, the invention is defined as a voltage between 3V and 10V, but excluding the case of 9V. It is also possible.

[0028] As another specific example, for a certain value, for example, "It is preferable that a certain voltage is 10 V" In that case, for example, if a certain voltage is between -2V and 1V, Or, for example, the invention can be defined as except when a certain voltage is: It is possible to define the invention as except when the voltage is 13V or higher.

[0029] As another specific example, when describing the properties of a certain substance, for example, "a certain film is an insulating film," In that case, the insulating film is, for example, an organic insulating film. Alternatively, for example, the insulating film may be an inorganic insulating film. It is possible to define the invention as "except in the case where

[0030] As another specific example, regarding a certain laminated structure, for example, "a certain film is provided between A and B" In that case, for example, if the film is a laminated film of four or more layers, Or, for example, A and its membrane and It is possible to specify the invention as excluding the case where a conductive film is provided between the Effect of the Invention

[0031] In one embodiment of the present invention, a voltage Vcc is applied between the source and gate of a driving transistor in accordance with a threshold voltage of the driving transistor. This allows the voltage at which the transistors are turned on to be determined, thereby reducing the effect of variations in the transistor characteristics. It is possible to provide a semiconductor device, a light-emitting device, or a display device in which the Semiconductor device, light-emitting device, or display device in which the influence of deterioration of transistor characteristics is suppressed Alternatively, the variation in luminance due to the variation in threshold voltage of the transistor can be reduced. It is possible to provide a semiconductor device, a light-emitting device, or a display device in which adhesion is suppressed. Alternatively, the variation in brightness due to the variation in the mobility of the transistors is suppressed. Alternatively, one embodiment of the present invention can provide a light-emitting device, a display device, or a semiconductor device comprising: A semiconductor device, a light-emitting device, and a semiconductor device that operate normally even if the transistor is a normally-off type According to another embodiment of the present invention, a display device can be provided. A semiconductor device and a light-emitting device capable of obtaining a threshold voltage of a transistor even if the transistor is an OFF type. A semiconductor device or a display device that displays a high quality image can be provided. It is possible to provide a light-emitting device or a display device that can display images with less unevenness. It is possible to provide a semiconductor device, a light-emitting device, or a display device having a small number of A semiconductor device, a light-emitting device, or a display device that can realize a desired circuit with a certain number of transistors. It is possible to provide a device that can realize a desired circuit with a small number of wirings. It is possible to provide a semiconductor device, a light-emitting device, or a display device. It is possible to provide a semiconductor device, a light-emitting device, or a display device in which the influence of deterioration of the semiconductor device can be suppressed. Alternatively, a semiconductor device, a light emitting device, or a display device that can be manufactured with a small number of steps can be provided. It can be provided. [Brief description of the drawings]

[0032] [Figure 1] 1 illustrates a structure of a semiconductor device. [Diagram 2] 1 illustrates a structure of a semiconductor device. [Diagram 3] 1 illustrates a structure of a semiconductor device. [Figure 4] 1 illustrates a structure of a semiconductor device. [Diagram 5] 1A to 1C are timing charts and diagrams showing the operation of a semiconductor device. [Figure 6] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 7] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 8] 1 illustrates a structure of a semiconductor device. [Figure 9] 1 illustrates a structure of a semiconductor device. [Figure 10]1 illustrates a structure of a semiconductor device. [Figure 11] 1 illustrates a structure of a semiconductor device. [Figure 12] 1 illustrates a structure of a semiconductor device. [Figure 13] 1 illustrates a structure of a semiconductor device. [Figure 14] 1 illustrates a structure of a semiconductor device. [Figure 15] 1 illustrates a structure of a semiconductor device. [Figure 16] 1 illustrates a structure of a semiconductor device. [Figure 17] 1A to 1C are timing charts and diagrams showing the operation of a semiconductor device. [Figure 18] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 19] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 20] 1A to 1C are timing charts and diagrams showing the operation of a semiconductor device. [Figure 21] 1 illustrates a structure of a semiconductor device. [Figure 22] 1 illustrates a structure of a semiconductor device. [Figure 23] 1 illustrates a structure of a semiconductor device. [Figure 24] 1 illustrates a structure of a semiconductor device. [Diagram 25] 1 illustrates a structure of a semiconductor device. [Figure 26] 1 illustrates a structure of a semiconductor device. [Figure 27] 1 illustrates a structure of a semiconductor device. [Figure 28] 1 illustrates a structure of a semiconductor device. [Figure 29] 1 illustrates a structure of a semiconductor device. [Diagram 30] 1 illustrates a structure of a semiconductor device. [Diagram 31] 1 illustrates a structure of a semiconductor device. [Diagram 32] 1 illustrates a structure of a semiconductor device. [Diagram 33] 1 illustrates a structure of a semiconductor device. [Diagram 34] 1 illustrates a structure of a semiconductor device. [Diagram 35]1A to 1C are diagrams showing the operation of a semiconductor device. [Diagram 36] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 37] 1 illustrates a structure of a semiconductor device. [Figure 38] 1 illustrates a structure of a semiconductor device. [Figure 39] 1 illustrates a structure of a semiconductor device. [Diagram 40] 1 illustrates a structure of a semiconductor device. [Diagram 41] 1 illustrates a structure of a semiconductor device. [Diagram 42] 1 illustrates a structure of a semiconductor device. [Diagram 43] 1 illustrates a structure of a semiconductor device. [Diagram 44] 1 illustrates a structure of a semiconductor device. [Diagram 45] 1 illustrates a structure of a semiconductor device. [Diagram 46] 1 illustrates a structure of a semiconductor device. [Figure 47] 1 illustrates a structure of a semiconductor device. [Figure 48] 1 illustrates a structure of a semiconductor device. [Figure 49] 1 illustrates a structure of a semiconductor device. [Figure 50] 1 illustrates a structure of a semiconductor device. [Figure 51] 1 illustrates a structure of a semiconductor device. [Figure 52] 1 illustrates a structure of a semiconductor device. [Figure 53] 1 illustrates a structure of a semiconductor device. [Figure 54] 1 illustrates a structure of a semiconductor device. [Figure 55] 1 illustrates a structure of a semiconductor device. [Figure 56] 1 illustrates a structure of a semiconductor device. [Figure 57] 1 illustrates a structure of a semiconductor device. [Figure 58] 1 illustrates a structure of a semiconductor device. [Figure 59] 1 illustrates a structure of a semiconductor device. [Figure 60] 1 illustrates a structure of a semiconductor device. [Figure 61] 1 illustrates a structure of a semiconductor device. [Figure 62] 1 illustrates a structure of a semiconductor device. [Figure 63] 1 illustrates a structure of a semiconductor device. [Figure 64] 1 illustrates a structure of a semiconductor device. [Figure 65] 1 illustrates a structure of a semiconductor device. [Figure 66] 1 illustrates a structure of a semiconductor device. [Figure 67] 1 illustrates a structure of a semiconductor device. [Figure 68] 1 illustrates a structure of a semiconductor device. [Figure 69] 1 illustrates a structure of a semiconductor device. [Figure 70] 1 illustrates a structure of a semiconductor device. [Figure 71] 1 illustrates a structure of a semiconductor device. [Figure 72] 1A to 1C are diagrams showing the operation of a semiconductor device. [Figure 73] 1 illustrates a structure of a semiconductor device. [Figure 74] 1 illustrates a structure of a semiconductor device. [Figure 75] 1 illustrates a structure of a semiconductor device. [Figure 76] 1 illustrates a structure of a semiconductor device. [Figure 77] 1 illustrates a structure of a semiconductor device. [Figure 78] 1 illustrates a structure of a semiconductor device. [Figure 79] 1 illustrates a structure of a semiconductor device. [Figure 80] 1 illustrates a structure of a semiconductor device. [Figure 81] 1 illustrates a structure of a semiconductor device. [Figure 82] 1 illustrates a structure of a semiconductor device. [Figure 83] 1 illustrates a structure of a semiconductor device. [Figure 84] 1 illustrates a structure of a semiconductor device. [Figure 85] Electronic devices illustration. [Figure 86] 1 illustrates a structure of a semiconductor device. [Figure 87] 1 illustrates a structure of a semiconductor device. [Figure 88] 1A and 1B are a diagram illustrating a configuration of a semiconductor device and a timing chart. [Figure 89] FIG. 13 is a diagram showing the results of a simulation. [Figure 90] FIG. 13 is a diagram showing the results of a simulation. [Figure 91] Electronic devices illustration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following description, and the embodiments and aspects of the present invention may be modified without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that various modifications may be made to the details. The present invention should not be construed as being limited to the description of the following embodiment. In the configurations described below, the same parts or parts having similar functions are denoted by the same reference numerals. These are commonly used in different drawings, and repeated explanations will be omitted.

[0034] In addition, the contents (or even a part of the contents) described in one embodiment may be used in the embodiment. Another subject matter (or even a part of it) described in the context and / or one or more other embodiments The contents (or a part of the contents) described in the embodiment may be applied, combined, or replaced. You can change it, etc.

[0035] In addition, the configuration of a figure (or a part thereof) described in one embodiment may be different from that of another figure. The configuration of the part, the configuration of another figure (or part) described in the embodiment, and / or The present invention is combined with the configuration of the figure (or a part thereof) described in one or more other embodiments. It can be adjusted.

[0036] In the drawings, the size, thickness, or area may be exaggerated for clarity. Therefore, one aspect of the embodiment of the present invention is not necessarily limited to that scale. The drawings are merely schematic illustrations of ideal examples. The shape is not limited to the shape shown in the figure. For example, there may be variations in shape due to manufacturing techniques, errors, etc. It is possible to include variations in shape due to the above.

[0037] In addition, when it is explicitly stated that X and Y are connected, it means that X and Y are electrically connected. When X and Y are functionally connected, when X and Y are directly connected, Here, X and Y are objects (e.g., devices, elements, circuits, etc.). , wiring, electrodes, terminals, conductive films, layers, display elements, light-emitting elements, loads, etc.) Therefore, the present invention is not limited to a specific connection relationship, for example, a connection relationship shown in a drawing or a sentence, and may be modified in any manner without departing from the spirit or scope of the present invention. This also includes connections other than those shown in the text.

[0038] An example of a case where X and Y are electrically connected is The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more elements (such as an electrode, a display element, a light-emitting element, or a load) can be connected between X and Y. It is possible. The switch has a function that allows it to be turned on and off. A switch can be in a conductive state (on state) or a non-conductive state (off state) and can either pass current or not. The switch has the function of controlling whether or not current flows. It has the function of switching between these modes.

[0039] An example of a case where X and Y are functionally connected is a case where a functional connection between X and Y is possible. Circuits that perform the above functions (for example, logic circuits (inverters, NAND circuits, NOR circuits, etc.), signal conversion conversion circuits (DA conversion circuits, AD conversion circuits, gamma correction circuits, etc.), potential level conversion circuits ( power supply circuits (voltage boost circuits, voltage drop circuits, etc.), level shifter circuits that change the potential level of signals, etc.) , voltage sources, current sources, switching circuits, amplifier circuits (which can increase the signal amplitude or current amount, etc.) circuits, operational amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation One or more devices (such as a memory circuit, a control circuit, etc.) can be connected between X and Y. For example, even if another circuit is inserted between X and Y, the signal output from X X and Y are said to be functionally connected if

[0040] In addition, when it is explicitly stated that X and Y are connected, it means that X and Y are electrically connected. When X and Y are functionally connected, when X and Y are directly connected, In other words, the case where it is explicitly stated that they are electrically connected is also included. The cases are simply connected, and are the same as those only explicitly stated. .

[0041] In addition, the circuit diagram shows independent components as if they are electrically connected to each other. Even if the components are the same, one component may have the functions of multiple components. For example, when a part of the wiring also functions as an electrode, one conductive film has the function of the wiring and Therefore, the electrical connection in this specification In this case, even when one conductive film has the functions of multiple components, Include in the category.

[0042] In addition, there are active elements (transistors, diodes, etc.) and passive elements (capacitive elements, resistive elements, etc.) ) and the like, a person skilled in the art can easily determine the connection destination of all the terminals. It may be possible to configure one aspect of the invention. That is, it is possible to transmit a signal without specifying a connection destination. There are cases where it is possible to determine that one aspect of the invention is clear and described in the present specification, etc. In particular, when there are multiple possible connections to a terminal, it is necessary to specify the connection destination of the terminal as a specific There is no need to limit the location. Therefore, active elements (transistors, diodes, etc.) Only some terminals of passive elements (capacitive elements, resistive elements, etc.) are connected to In some cases, it may be possible to configure one aspect of the invention by specifying the above.

[0043] In addition, if a person skilled in the art identifies at least the connection destination of a certain circuit, he / she can identify the invention. It may be possible to determine the circuitry at least by specifying its function. In some cases, a person skilled in the art may be able to identify the invention. When it is possible to determine that one aspect of the invention is clear and described in the present specification, etc. Therefore, even if you do not specify the function of a circuit, if you specify the connection destination, It is disclosed as one aspect of the invention and can constitute one aspect of the invention. Alternatively, even if the connection destination of a certain circuit is not specified, if the function is specified, it can be considered as an invention. What is disclosed as an embodiment can constitute an embodiment of the invention.

[0044] It should be noted that one aspect of the embodiment of the present invention can be implemented by various people. However, the implementation may involve multiple people. For example, a transmission and reception system In the case of the above, Company A manufactures and sells transmitters, and Company B manufactures and sells receivers. As another example, in the case of a light-emitting device having a TFT and a light-emitting element, Company A manufactures and sells semiconductor devices with TFTs formed on them. Company B Purchase a semiconductor device, deposit light-emitting elements on the semiconductor device, and complete the light-emitting device. This may be the case.

[0045] In such a case, the inventor must be able to assert patent infringement against either Company A or Company B. Therefore, if you assert a patent infringement claim against Company A or Company B, It is possible to determine that one aspect of the invention is clear and described in the present specification, etc. For example, in the case of a transmission / reception system, the transmitter alone constitutes one aspect of the invention. The receiver alone can constitute one aspect of the invention, and the one aspect of the invention is It can be determined that the above is clear and described in the present specification. In the case of a light-emitting device having a TFT and a light-emitting element, a semiconductor device in which the TFT is formed One embodiment of the present invention can be constructed only by a light-emitting device having a TFT and a light-emitting element. These aspects of the invention are clearly defined and are set forth in the present specification. It can be judged that the information is stated in the above.

[0046] (Embodiment 1) One embodiment of the present invention can be used not only for a pixel having a light-emitting element but also for various circuits. For example, it can be used as an analog circuit or as a circuit that functions as a current source. Therefore, in this embodiment, the basic principle of the circuit disclosed in the present invention is Let me give you an example.

[0047] A semiconductor device according to one embodiment of the present invention includes, for example, a transistor and With the gate potential held fixed, the charge held between the gate and source is discharged. A semiconductor device according to one embodiment of the present invention has at least the above structure and a function. This structure compensates for the variation in drain current caused by factors such as the threshold voltage and mobility of transistors. It can be corrected.

[0048] A circuit 100 illustrated in FIG. 1A is a semiconductor device according to one embodiment of the present invention. , switch 11, switch 12, switch 13, transistor 101, capacitance element 102, The capacitor 103 is included. Note that in FIG. 1A, the transistor 101 is an n-channel transistor. A certain case is shown as an example.

[0049] Specifically, in FIG. 1A, the switch 11 is connected to a wiring 21 and one electrode of a capacitor 102. 103. The switch 12 is connected to the wiring 22, the other electrode (terminal) of the capacitor 102, and the transistor The switch 13 has a function of controlling the conduction state between the gate of the transistor 101 and the One of the source and drain of the transistor 101, or the other electrode (terminal) of the capacitor element 103 ) and one electrode (terminal) of the capacitor 102 or one electrode (terminal) of the capacitor 103. The other of the source and drain of the transistor 101 has a function of controlling the conduction state of the transistor 101. is connected to the wiring 23. The other electrode (terminal) of the capacitor 103 is connected to a wiring 24 .

[0050] The source (source terminal, source region or source electrode) and drain of a transistor The drain terminal, drain region or drain electrode determines the polarity and so The name is changed depending on the potential applied to the source and drain. In an n-channel transistor, the one to which the lower potential is applied is the source or drain. The side to which a high potential is applied is called the drain. In a transistor, the one to which the lower potential is applied is called the drain, The side to which the higher potential is applied is called the source. For convenience, in this specification, the terms source and drain are used. The connection relationship of transistors may be explained assuming that the In reality, the names of source and drain are interchangeable according to the above potential relationship. The part that functions as a source and the part that functions as a drain are called the source and drain. In that case, for example, one of the source and the drain may be connected to the first terminal, The other of the source and drain is referred to as a second terminal, a second electrode, or a first region. This may be referred to as the second area.

[0051] The switch has a function of switching between a conductive state and a non-conductive state between terminals. It is an element that has the function of controlling whether or not a current flows. has the function of selecting and switching the path through which the current flows. For example, Select whether to allow current to flow through path 1 or path 2. For example, an electrical switch or a mechanical switch can be used. Specifically, transistors, diodes, and digital micromirror devices can be used. Using MEMS (Micro-Electro-Mechanical System) technology such as the Dynamic Multimedia Display (DMD) The switch can be made of a logic circuit combining transistors. When a transistor is used as a switch, the polarity of the transistor is not particularly limited. However, it is preferable to use a transistor with a small off-state current. It is desirable to use different polarities of the transistors depending on the potential.

[0052] As a transistor with a small off-state current, a transistor having an LDD region, A transistor having a double-gate structure or a transistor including an oxide semiconductor in a channel formation region In addition, when transistors are combined to operate as a switch, A complementary switch may be used that uses both n-channel and p-channel types. By using a switch, even if the potential input to the switch changes relatively to the output potential, , can be made to operate properly.

[0053] When using a transistor as a switch, the switch is connected to the input terminal (source or One of the drain terminals), the output terminal (the other of the source or drain), and the terminal that controls conduction On the other hand, when a diode is used as a switch, A switch may not have a terminal that controls conduction. Using a diode as a switch reduces the amount of wiring required to control the terminal. It is possible.

[0054] As an example of a transistor, gates are arranged above and below a channel formation region. By arranging gates above and below the semiconductor film, This results in a circuit configuration in which multiple transistors are connected in parallel. Since the formation region is increased, the current value can be increased. By using a structure with gates arranged above and below, a depletion layer is easily formed, so S It is possible to improve the value.

[0055] As an example of a transistor, a source electrode is provided in a channel formation region (or a part thereof). A transistor with a structure in which the gate electrode and drain electrode overlap can be used. By making the source electrode and drain electrode overlap the semiconductor region (or a part of it), This prevents the operation from becoming unstable due to charge accumulation in a part of the channel formation region. This can be done.

[0056] The capacitor 102 or the capacitor 103 may be, for example, a wiring, a semiconductor film, an electrode, or the like. The insulating film or organic film may be sandwiched between the insulating film and the organic film.

[0057] The circuit 100 shown in FIG. 1A includes a load 104 as shown in FIG. 1B. In the circuit 100 shown in FIG. 1B, the load 104 is a source A connection is made between one of the source and drain electrodes, or the other electrode of the capacitor 103 and the wiring 24. This is being continued.

[0058] In this specification, the load may be, for example, a load having a rectifying property or a load having a capacitive property. There are circuits having resistance, circuits having switches, pixel circuits, and current source circuits. For example, a rectifying current-voltage characteristic has a resistance value that varies depending on the bias direction applied. It has electrical properties that allow current to flow almost exclusively in one direction. Specifically, the load 104 may be a display element (such as a liquid crystal element or an EL element), a light emitting element (EL (electroluminescence) element, etc.), or the like. Lectroluminescence (EL) elements (including organic and inorganic EL elements, organic EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc.), transistors (transistors that emit light in response to current), electron emitters, or display elements or light-emitting Examples include parts of elements (for example, pixel electrodes, anodes, and cathodes).

[0059] FIG. 1C shows a configuration of the circuit 100 when a light-emitting element 104a is used as the load 104. In FIG. 1C, the anode of the light-emitting element 104a is connected to the source of the transistor 101. or one of the drain electrodes or the other electrode of the capacitor 103. 1 shows an example in which the cathode of terminal 104a is connected to wiring 24.

[0060] FIG. 1D shows a circuit 100 in which a light-emitting element 104b is used as the load 104. In FIG. 1D, the cathode of the light-emitting element 104b is connected to the It is connected to one of the source and drain electrodes, or the other electrode of the capacitor 103. The case where the anode of the light emitting element 104b is connected to the wiring 24 is shown as an example. Note that FIG. 1D illustrates an example in which the transistor 101 is a p-channel transistor. is doing.

[0061] Further, a semiconductor device according to one embodiment of the present invention may include, for example, the semiconductor device shown in FIG. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 is provided. , and may further include.

[0062] The semiconductor device shown in FIG. 2A to FIG. 2D includes a circuit 1 shown in FIG. In addition to the above, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 and a 2 and a circuit 202 having a function of supplying a constant voltage or signal to the wiring 23. a circuit 203 having a function of supplying a constant voltage or signal to the wiring 24; and a circuit 204.

[0063] Specifically, the circuit 201 has a function of supplying a potential Vi1 or a potential Vsig to the wiring 21. An example of the circuit 201 is a source driver (a signal line driver circuit). Therefore, the wiring 21 has a function capable of transmitting the potential Vi1 and / or the potential Vsig. Alternatively, the wiring 21 may be a video signal line. Alternatively, the wiring 21 functions as an initialization wiring. do.

[0064] The potential Vi1 is a potential for initializing the potential of each node in the circuit 100. The potential Vi1 is, for example, a potential for supplying a charge to the capacitive element 102. The potential Vi1 is, for example, a potential for turning on the transistor 101. It is preferable that the potential Vi1 is a constant potential. The pattern is not limited to this, and may vary like a pulse signal.

[0065] As an example, before the potential Vsig is supplied to the circuit 100, the potential Vi1 is The signal is supplied to the line 100.

[0066] The potential Vsig is a potential for controlling the magnitude of the drain current of the transistor 101. In the case of the semiconductor device shown in FIG. 2B, the drain current is supplied to the load 104. In the case of the semiconductor device shown in FIG. 2C, the drain current is supplied to the light emitting element 104a. In the case of the semiconductor device shown in FIG. 2D, the drain current is supplied to the light emitting element 104. For example, to keep the drain current of the transistor 101 constant, In addition, for example, the drain current of the transistor 101 is set to a constant value. If the potential Vsig is not set to a constant value, the potential Vsig is changed over time. The signal Vsig is a video signal and / or an analog signal. In one embodiment, the potential Vsig may be a constant potential, but is not limited to this.

[0067] The circuit 202 has a function of supplying a potential Vi2 to the wiring 22. As an example of the potential, there is a power supply circuit. Therefore, the wiring 22 can transmit the potential Vi2. The wiring 22 has a function of being able to supply the power. The potential of the wiring 22 is kept constant. However, one aspect of the embodiment of the present invention is not limited to this, and a variable signal such as a pulse signal may be used. You may move it.

[0068] The potential Vi2 is set to the potential of each node in the circuit 100 (particularly the gate of the transistor 101). In the case of FIG. 2C, the potential Vi2 is the same as the potential of the wiring 24. It is preferable that the current flowing through the light emitting element 104a is equal to or lower than the current flowing through the light emitting element 104a. In the case of FIG. 2D, the potential Vi2 is the potential of the wiring 24. It is preferable that the light emitting element 104b has a light emitting capacity equal to or higher than the light emitting capacity. However, the potential Vi2 is not limited to these. It is preferable that the potential Vi2 is a constant potential. The pattern is not limited to this, and may vary like a pulse signal.

[0069] Note that the wiring 22 can be connected to another wiring or a wiring included in another circuit 100. This makes it possible to reduce the number of wirings.

[0070] The circuit 203 also supplies a power supply potential (high power supply potential or low power supply potential) to the wiring 23. The circuit 203 has a function of supplying a potential VDD or a potential VSS. The circuit 203 has a function of supplying a signal to the power supply circuit 23. Therefore, the wiring 23 is a power supply potential or a signal It has the function of being able to convey or supply. The line 23 has the function of being able to supply current to the transistor 101. Or The wiring 23 has a function of supplying a current to the load 104. The wiring 23 functions as a power supply line. Alternatively, the wiring 23 functions as a current supply line. It is preferable that the potential of the wiring 23 is constant. One aspect of the present embodiment is not limited to this, and may vary like a pulse signal. For example, the potential of the wiring 23 is determined by applying not only a forward bias voltage but also a reverse bias voltage to the load 104. The potential may be such that

[0071] The circuit 204 also supplies a power supply potential (low power supply potential or high power supply potential) to the wiring 24. The circuit 204 has a function of supplying a potential Vcat. An example of the circuit 204 is a power supply circuit. Therefore, the wiring 24 has a function of transmitting or supplying a power supply potential. Alternatively, the wiring 24 can supply a current to the load 104. Alternatively, the wiring 24 has a function of supplying a current to the transistor 101. Alternatively, the wiring 24 functions as a common line. In this case, the wiring 24 functions as a cathode wiring. Alternatively, the wiring 24 functions as an anode wiring. It is preferable that the potential of the wiring 24 is constant. However, one aspect of the embodiment of the present invention is not limited to this, and may fluctuate like a pulse signal. For example, the potential of the wiring 24 is applied to the load 104 not only with a forward bias voltage but also with a reverse bias voltage. It may be a potential that applies pressure.

[0072] The drain current of the transistor 101 is For example, if the potential VDD is higher than the potential Vcat, the direction is determined. When the potential of the wiring 23 is the potential VSS, which is lower than the potential Vcat, a current flows to the wiring 23. Current flows from line 24 to wiring 23 .

[0073] 2A to 2D, the semiconductor device includes a circuit 201 in addition to the circuit 100. 202, 203, and 204 are shown as an example. A semiconductor device according to an embodiment of the present invention does not necessarily include the circuit 201, the circuit 202, the circuit 203, and It is not necessary to include all of the circuits 204, but only one or more of them may be included. stomach.

[0074] In addition, the transistor 101 has at least a function as a current source, for example. Therefore, for example, the transistor 101 has both ends (the source and It has the function of supplying a roughly constant current even if the magnitude of the voltage applied between the drain and the For example, even if the potential of the load 104 changes, the transistor 101 does not change. The function of the resistor 104 is to supply a constant current to the resistor 104. The wiring 101 has a function of supplying a substantially constant current even if the potential of the wiring 23 changes.

[0075] However, one aspect of the embodiment of the present invention is not limited to this. The transistor 101 is a current source. For example, the transistor 101 may not function as a switch. It is possible for the function to be

[0076] A voltage source is a power source other than a current source. A voltage source generates a current that flows through a circuit connected to it. Even if the current flowing through the circuit changes, the circuit has the function of supplying a constant voltage. A current source also has the function of supplying voltage and current, but it supplies a constant current regardless of changes in the The difference between them is whether they have the function of supplying current or not. Even if the voltage across the two terminals changes, the voltage source has the function of supplying a constant current. Even if the voltage is high, the device has the function of supplying a constant voltage.

[0077] Note that FIG. 1 is an example of a circuit configuration, and therefore, additional transistors may be provided. Conversely, at each node in FIG. 1, it is possible to add transistors, switches, etc. It is also possible to eliminate the need for switches, passive elements, etc. The node to which each terminal of the transistor is connected, or / and the load At the node where each terminal is connected, no more transistors are directly connected. Therefore, for example, the load 104 and the transistor 101 At a node where the capacitance element 103 and the switch 13 are connected, The only transistor connected to the node is transistor 101. It is possible to have a configuration in which they are not directly connected.

[0078] Therefore, if no additional transistors are required, the circuit can be constructed with a small number of transistors. It becomes possible.

[0079] The circuit 100 shown in FIG. 1 and FIG. 2 includes a switch 11, a switch 12, a switch 13, and a A transistor can be used for the above.

[0080] In the circuit 100 shown in FIG. 1(A) to FIG. 1(D), a transistor is used as the switch 11. A transistor 11t is used as the switch 12, a transistor 12t is used as the switch 13, and The configuration of the circuit 100 in the case where the capacitor 13t is used is shown in FIG. In FIG. 3(A) to FIG. 3(C), a transistor 11t, a transistor 12t, and a transistor As an example, the case where all the transistors 13t are n-channel type is shown. Now, transistor 11t, transistor 12t, and transistor 13t are all p-channel. The transistor 11t, transistor 12t, By making the transistors 13t and 13i all transistors of the same polarity, However, one aspect of the embodiment of the present invention is not limited to this. It is also possible to use transistors of different polarities.

[0081] Note that in each of FIGS. 3A to 3D, the gate of the transistor 11t is connected to the wiring 31. In response to the potential supplied to the wiring 31, the transistor 11t is turned on or off. The transistor 12t has a gate connected to the wiring 32. Depending on the potential applied to line 32, transistor 12t is either conductive or non-conductive. The gate of the transistor 13t is connected to the wiring 33. Depending on the potential, the transistor 13t is in a conductive state or a non-conductive state. It is preferable that the potentials of the lines 31 to 33 are pulsed and not constant. One aspect of the embodiment is not limited to this. Alternatively, the wirings 31 to 33 are gate It functions as a signal line (gate line), selection signal line, or scan line. There are.

[0082] At least two of the wirings 31 to 33 are connected to each other. Alternatively, at least one of the wirings 31 to 33 may be connected to another circuit 1. 00 can be connected to at least one of the wirings 31 to 33.

[0083] In addition, the semiconductor device according to one embodiment of the present invention includes the circuit 10 shown in FIG. 0, a circuit having a function of supplying various constant voltages and signals to the circuit 100, It is acceptable to have one.

[0084] The semiconductor device shown in FIG. 4A to FIG. 4D includes a circuit 1 shown in FIG. In addition to the above, a circuit 205 having a function of supplying a constant voltage or signal to the wiring 31 and a 2 and a circuit 206 having a function of supplying a constant voltage or signal to the wiring 33. The circuit 205, the circuit 206, and the circuit 207 each have a function of supplying the An example of 207 is a gate driver (scanning line driving circuit).

[0085] In addition, the circuit 201, the circuit 202, the circuit 203, the circuit 204, the circuit 205, the circuit 206, The paths 207 may be one and the same circuit or may be separate circuits.

[0086] 4A to 4D, the semiconductor device includes a circuit 205 in addition to the circuit 100. 205, the circuit 206, and the circuit 207 are shown as an example, but one embodiment of the present invention is The semiconductor device according to the present invention does not necessarily have to include all of the circuits 205, 206, and 207. However, it is not necessary, and it is also possible to have only one or more of them.

[0087] In addition, in the circuit 100 shown in FIG. When the transistor 13t is an n-channel type and the transistor 12t is a p-channel type, The configuration of the circuit 100 in this case is shown in FIG. 37(A). The transistor 101, the transistor 11t, and the transistor 13t are p-channel The configuration of the circuit 100 in the case where the transistor 12t is an n-channel type is shown in FIG. In this way, transistors of various polarities can be used.

[0088] In addition, a semiconductor device according to one embodiment of the present invention includes the circuit shown in FIG. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0089] The semiconductor device shown in FIG. 37(C) and FIG. 37(D) is In addition to the circuit 100, a circuit 205 having a function of supplying a constant voltage or signal to the wiring 31 is provided. 206 having a function of supplying a constant voltage or signal to the wiring 32; and a circuit 207 having a function of supplying a signal.

[0090] 37C and 37D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 05, circuit 206, and circuit 207 are shown as an example, The semiconductor device according to the embodiment does not necessarily include all of the circuits 205, 206, and 207. It is not necessary for the device to have all of these features, but it may have only one or more of them.

[0091] Note that the transistor 101 often operates in the saturation region when a current flows. 3, 4, and 37, the channel length or gate length of the transistor 101 is The length of the transistor 11t, the transistor 12t, and / or the transistor 13t may be increased by It is desirable to make the channel length or gate length longer than the saturation region. The characteristics in the range become flat, and the kink effect can be reduced. More preferably, the resistance is 10 times or more. The channel length or gate length of 1 is 10 μm or more, more preferably 20 μm or more. Alternatively, the channel width or gate width of the transistor 101 is By making the transistor 12t and / or the transistor 13t longer, The transistor 101 can pass a large amount of current even in the saturated region. It is desirable that the capacitance is 5 times or more, and more preferably 10 times or more. The width of the channel or gate is 20 μm or more, and more preferably 30 μm or more. However, one aspect of an embodiment of the present invention is not limited to these.

[0092] Next, the operation of the semiconductor device of one embodiment of the present invention will be described with reference to the circuit 100 illustrated in FIG. We will explain about this.

[0093] The operation of the circuit 100 shown in FIG. 1C is mainly divided into a first operation, a second operation, a third operation, and a fourth operation. However, it is not limited to these, and new actions may be added. It is also possible to add or delete some of the operations.

[0094] In the circuit 100 shown in FIG. The operation of the line 21, the gate-source voltage of the transistor 101 (Vgs101 An example of a timing chart showing the above is shown in FIG.

[0095] First, the first operation performed in the period T11 will be described. As shown in (A), the switches 11, 12, and 13 are in a conductive state. In addition, a potential Vi1 is supplied to the wiring 21. Therefore, in the period T11, as shown in FIG. As shown, a voltage Vi2-Vi1 is supplied to the capacitance element 102, and the anode of the light emitting element 104a The gate voltage of the transistor 101 (Vgs101) is That is, the transistor 101 and the capacitor 102 are This means that it has been initialized.

[0096] In the circuit 100 illustrated in FIG. 1C, the potential Vi2 is connected to the potential Vi1 by the transistor 10. It is desirable that the potential is higher than the potential obtained by adding the threshold voltage Vth of the first potential to the potential Vi2. The potential Vi1 is preferably a potential at which the transistor 101 is turned on. In addition, the potential Vi1 is set to the threshold voltage Vthe of the light emitting element 104a (when the light emitting element 104a emits light). It is desirable that the potential obtained by adding the potential V (the voltage to be applied to the power supply) is lower than the potential Vcat. For example, It is desirable that i1 is equal to or lower than the potential Vcat. When i1 is lower than the potential Vcat, the light emitting element 104a is in a reverse bias state. Therefore, it is possible to reduce the deterioration of the light emitting element 104a or to repair a short-circuited portion. In addition, the potential obtained by subtracting the threshold voltage Vthe of the light emitting element 104a from the potential Vi2 is expressed as follows: It is preferable that the threshold voltage Vthe is lower than the potential Vcat. Assume that

[0097] The second operation performed in the period T12 will be described. In the period T12, As shown in FIG. 1, switch 11 is in a non-conducting state, and switches 12 and 13 are in a conducting state. When the switch 11 is turned off, the charge stored in the capacitance element 102 is The charge is discharged through transistor 101, causing the potential at the source of transistor 101 to rise. When the transistor 101 is turned off, the discharge of charge from the capacitor 102 stops. Finally, the threshold voltage Vth of the transistor 101 is held in the capacitance element 102. Therefore, in the period T12, as shown in FIG. 5C, the threshold voltage Vth The anode of the light emitting element 104a is held at a potential Vi2-Vth, and the transistor 1 The gate-source voltage (Vgs101) of transistor 01 is the threshold voltage Vth. The threshold voltage Vth of the resistor 101 can be obtained.

[0098] It should be noted that it takes until Vgs101 becomes equal to the threshold voltage Vth of the transistor 101. , it may take a very long time. Therefore, Vgs101 is the threshold voltage In many cases, the transistor is operated without lowering Vth completely. The period T12 may end when the voltage Vth is slightly higher than the threshold voltage Vth. In other words, when the period T12 ends, Vgs101 is It can also be said that it is a voltage of a certain magnitude.

[0099] In the second operation, the threshold voltage Vth of the transistor 101 is positive or negative. This is because the transistor 101 is in the off state. This is because the source potential of the transistor 101 can rise until the transistor When the source potential of transistor 101 is higher than the gate potential of transistor 101, Then, the transistor 101 finally turns off and Vgs101 becomes Vth. Therefore, the transistor 101 is an enhancement type (normal Whether it is a depletion type (normally on type) or a non-depletion type (normally on type), it will operate normally. It is possible.

[0100] When the potential of the anode of the light emitting element 104a becomes high, a current flows to the light emitting element 104a. To this end, it is desirable to prevent current from flowing through the light emitting element 104a. In order to prevent this, it is preferable to set the potential Vi2 to a low value. The method is not limited to this. In addition, a switch may be provided in series with the light emitting element 104a. By turning it off, it is possible to prevent current from flowing through the light emitting element 104a. If present, the potential Vi2 may be a high value.

[0101] The third operation performed in the period T13 will be described. In the period T13, As shown in FIG. 1, the switches 11 and 13 are in a conducting state, and the switch 12 is in a non-conducting state. For example, a potential Vi1 is supplied to the wiring 21. As shown in FIG. 6A, the capacitance element 102 has a threshold voltage Vth (or a threshold voltage Vdc depending on Vth). The anode of the light-emitting element 104a is held at a potential Vi1, and the transistor The potential of the gate of the transistor 101 is the potential Vi1+Vth (or a voltage of a magnitude according to Vth). ), and the gate-source voltage (Vgs101) of the transistor 101 is the threshold voltage Vt h (or a voltage according to Vth). The potential of the node or the potential of the source of the transistor 101 can be initialized.

[0102] It is not necessary to perform the third operation. After the second operation, the fourth operation described below may be performed. The operation may be performed.

[0103] The potential of the wiring 21 during the period T13 is not limited to the potential Vi1, but may be a potential of another magnitude. However, the wiring 21 in the period T13 may be set to a potential (for example, potential Vi3). By setting the potential of the input terminal V1 to the potential Vi1, the configuration of the circuit 201 can be simplified. Alternatively, when a plurality of circuits 100 are connected to the wiring 21, the power of the wiring 21 may be By setting the potential at the potential Vi1, a certain circuit 100 is operated in the period T11, and another In the circuit 100, the period T13 can be operated, so that the operating period can be efficiently used. It can be used.

[0104] The fourth operation performed in the period T14 will be described. In the period T14, As shown in FIG. 1, switch 11 is in a conducting state, and switches 12 and 13 are in a non-conducting state. In addition, the potential Vsig is supplied to the wiring 21. Therefore, in the period T14, As shown in FIG. 1B, the capacitance element 102 is supplied with a threshold voltage Vth (or a voltage corresponding to Vth). The voltage Vsig-Vi1-Vα is held in the capacitance element 103, and light is emitted. The anode of the element 104a is at a potential Vi1+Vα, and the gate of the transistor 101 is at a potential The potential Vsig+Vth is reached, and the gate-source voltage of the transistor 101 (Vgs10 1) is the voltage Vsig+Vth-Vi1-Vα. Therefore, the potential Vsig is Alternatively, the voltage of the capacitor 102 and the voltage of the capacitor 103 can be input to the capacitor 103. The sum of this voltage and the gate-source voltage of the transistor 101 can be set to be equal to the gate-source voltage of the transistor 101.

[0105] In the fourth operation, the potential Vα is set to 0.5V when the anode of the light emitting element 104a is in an electrically floating state (floating state). The potential Vα is a potential that changes when the transistor 101 If the capacitance of the light emitting element 104a is off, the capacitance of the capacitance element 102 and the capacitance element 103 are The value is determined according to the ratio of the capacitances of 3. However, depending on the level of the potential Vsig, Since the transistor 101 is turned on, the anode of the light emitting element 104a is turned on through the transistor 101. Therefore, the potential Vα is determined only by the ratio of the capacitances. In addition, the value also changes depending on the charge flowing into the anode of the light emitting element 104a.

[0106] Here, the gate-source voltage Vgs is set to the ideal value, that is, the voltage Vsig+Vth-Vi To approach 1, it is preferable to design the potential Vα to be small. Specifically, The capacitance of the light emitting element 104a is much larger than the capacitance of the capacitance elements 102 and 103. If the capacitance is sufficiently large, the gate-source voltage Vgs can be brought closer to the ideal value.

[0107] Therefore, the capacitance value of the capacitive element 103 is equal to the parasitic capacitance of the load 104 (light emitting element 104a). It is preferable that the capacitance value is smaller than the capacitance value, preferably 1 / 2 or less, more preferably 1 / 5. Alternatively, the area of ​​the electrode of the capacitor 103 is preferably equal to or less than the area of ​​the load 104 (light-emitting element 1). It is preferable that the area of ​​the electrode is smaller than that of the electrode of 04a), preferably less than 1 / 2 the area of ​​the electrode of 04a, more preferably less than 1 / 2 the area of ​​the electrode of 04a. However, one aspect of the embodiment of the present invention is not limited to these. Not done.

[0108] In addition, in order to make the gate-source voltage (Vgs101) closer to the ideal value, the light-emitting element 10 It is desirable to reduce the amount of charge Q flowing into the anode 4a. In order to reduce Q, it is better to make the period T14 as short as possible. If the potential Vsig is supplied to the wiring 21 during the period T13, the switching When the switch 11 is turned on, the potential of the gate of the transistor 101 is set to a potential Vsig This allows the charge amount to be reduced by shortening the period T14. This is desirable for reducing Q.

[0109] Therefore, the length of the period T14 is the same as that of the periods T11, T12, and / or T13. It is preferable that the length is smaller than the length, preferably 2 / 3 times or less, more preferably 1 / 2 times The following are preferable. However, one aspect of the embodiment of the present invention is not limited thereto.

[0110] As described above, it is desirable that the charge amount Q is small. However, the mobility of the transistor 101 is small. When the variation in mobility is large, the charge Q can be expected to suppress the variation in mobility. The reason for this will be explained below.

[0111] In period T14, the charge Q flows from the drain to the source of the transistor 101. Therefore, the charge amount Q is larger as the mobility of the transistor 101 is higher. When the charge amount Q becomes large, the transistor The gate-source voltage (Vgs101) of the transistor 101 becomes smaller. That is, the charge The larger the mobility of the transistor 101, the more the amount of charge Q supplied to the light emitting element 104a. The current value is corrected to be smaller. Also, the smaller the mobility of the transistor 101, the However, a correction is made so that the current value supplied to the light emitting element 104a does not become too small. Therefore, the charge amount Q can suppress the variation in mobility.

[0112] The capacitance of the capacitor 102 is smaller than the capacitance of the parasitic capacitance of the gate of the transistor 101. It is preferable that the thickness is large, preferably at least twice as large, and more preferably at least five times as large. Alternatively, the area of ​​the electrode of the capacitor 102 is larger than the area of ​​the channel of the transistor 101. It is preferable that the difference is larger, preferably at least twice as large, and more preferably at least five times as large. Alternatively, the area of ​​the electrode of the capacitor 102 is larger than the area of ​​the gate electrode of the transistor 101. It is preferable that the difference is larger than the above, preferably at least two times, and more preferably at least five times. Thus, the potential Vsig is input, and the capacitance element 102 and the gate capacitance of the transistor Therefore, when the voltage is capacitively divided, the decrease in the voltage of the capacitive element 102 can be reduced. However, one aspect of an embodiment of the present invention is not limited to this.

[0113] The capacitance of the capacitor 102 is approximately the same as the capacitance of the capacitor 103. The capacitance of the capacitor 102 is preferably equal to or larger than that of the capacitor 103. It is preferable that the difference from the capacitance value is within ±20%, and more preferably within ±10%. Alternatively, the area of ​​the electrode of the capacitor 102 is approximately the same as the area of ​​the electrode of the capacitor 103. It is desirable to have a size of 100 or more. However, one aspect of the embodiment of the present invention is that , but is not limited to this.

[0114] The fifth operation performed in the period T15 will be described. In the period T15, As shown in FIG. 1, the switches 11, 12, and 13 are in a non-conducting state. During the period T15, as shown in FIG. 6C, the threshold voltage Vth is held in the capacitance element 102. The voltage Vsig-Vi1-Vα is held in the capacitance element 103, and the a The node is at potential Vel, and the potential of the gate of the transistor 101 is at potential Vsig+Vth. -Vi1-Vα+Vel, and the gate-source voltage of the transistor 101 (Vgs10 1) is the voltage Vsig+Vth-Vi1-Vα. Therefore, A current of a certain magnitude can be passed through the light emitting element 104a, and the light emitting element can emit light with a luminance according to the potential Vsig. The child 104a can be made to emit light.

[0115] The potential Vel is set when a current is applied to the light-emitting element 104a via the transistor 101. Specifically, the potential is between the potential VDD and the potential Vcat.

[0116] In the fifth operation, the gate-source voltage (Vgs101) of the transistor 101 is set to The voltage Vsig is Vsig+Vth-Vi1-Vα, taking into account the threshold voltage Vth of the transistor 101. Therefore, with the above configuration, the threshold voltage of the transistor 101 can be set to a value. It is possible to prevent the variation in Vth from affecting the current value supplied to the light emitting element 104a. Or, even if the transistor 101 deteriorates and the threshold voltage Vth changes, the above change can be prevented. This can prevent the change in the current supplied to the light emitting element 104a from being influenced by the change in the current. It is possible to reduce display unevenness and provide a high-quality display.

[0117] Similarly, the gate-source voltage (Vgs101) of the transistor 101 is set to a voltage Vsig+ Vth-Vi1-Vα can be set to a value that is independent of Vel. Therefore, the variation in the voltage-current characteristics of the light emitting element 104a affects the current supplied to the light emitting element 104a. Alternatively, the light emitting element 104a may deteriorate and the light emitting element may become Even if the voltage-current characteristic of the light emitting element 104a changes and Vel changes, the change is not This prevents the current value supplied to a from being affected. Therefore, display unevenness can be reduced. , a high-quality display can be obtained.

[0118] During a part of the fifth operation, the transistor 101 is forcibly turned off. In this way, it is possible to create a situation in which the light emitting element 104a does not emit light. For example, by turning on the switch 12, , transistor 101 can be turned off.

[0119] In the semiconductor device according to one embodiment of the present invention, in the second operation, The gate of the transistor 101 is kept at a potential Vi2. Even if the threshold voltage Vth has a negative value, the transistor 101 In this case, the potential of the source is stored in the capacitance element 102 until it becomes higher than the potential Vi2 of the gate. Therefore, in the semiconductor device according to one embodiment of the present invention, Even if the transistor 101 is normally on, in the fifth operation, The gate-source of the transistor 101 is set to a value that takes into account the threshold voltage Vth of the transistor 101. The voltage (Vgs101) can be set.

[0120] Note that schematic diagrams of the circuit 100 in the periods T11 to T15 are shown in FIGS. In the semiconductor device according to one embodiment of the present invention, the circuit 100 has the above-described It is sufficient to have the structure shown in FIG. 7(A) to FIG. 7(E) between the two. The semiconductor device according to one embodiment of the present invention is not limited to the circuit 100 having the configuration shown in FIGS. In the semiconductor device according to one embodiment of the present invention, the circuit 100 is The arrangement and number of switches and the supply of various potentials are determined so that the structures shown in FIGS. The number of wirings for performing the above-mentioned processing can be changed as appropriate.

[0121] In addition, in the semiconductor device of one embodiment of the present invention, in the circuit 100 illustrated in FIG. The semiconductor device may further include a capacitance element 105 connected to the load 104. In the semiconductor device according to the embodiment, a light-emitting element 104a and a A connected capacitor 105 may be further included. The semiconductor device is a light-emitting element 104b connected to the circuit 100 shown in FIG. A capacitor 105 may further be included.

[0122] The semiconductor device shown in FIG. 8A is a circuit 100 shown in FIG. Specifically, one of the capacitors 105 is The other electrode of the capacitor 103 and the source or drain of the transistor 101 are The other electrode of the capacitor 105 is connected to a wiring 26. 8A shows an example in which the circuit 100 has a load 104. However, in FIG. 8A, the load 104 is replaced by a light emitting element 104a or a light emitting element 104b. b may also be used.

[0123] The wiring 26 can be connected to various wirings. For example, the wiring 22, the wiring 23, wiring 24, or wiring of another circuit 100, a scanning line, a gate line, a transistor gate This can reduce the number of wires. It is possible to do this.

[0124] The semiconductor device shown in FIG. 8B is a circuit in which the wiring 26 is disposed in the circuit 100 shown in FIG. 8B, the circuit 100 is connected to the load 104. 8B, a light emitting diode is provided instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wirings 26 to be reduced.

[0125] The semiconductor device shown in FIG. 8C is a circuit in which the wiring 26 is disposed in the circuit 100 shown in FIG. 8C, the circuit 100 is connected to the load 104. 8C shows an example in which a light emitting diode is provided instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wirings 26 to be reduced.

[0126] The semiconductor device shown in FIG. 8D is a circuit in which the wiring 26 is disposed in the circuit 100 shown in FIG. 8D, the circuit 100 is connected to the load 104. 8D, a light emitting diode is provided instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wirings 26 to be reduced.

[0127] A capacitive element 105 is connected to the load 104, the light emitting element 104a, or the light emitting element 104b. By adding the circuit 100, the third and fourth operations described in this embodiment can be performed. In this way, the charge fluctuation at either the source or drain of the transistor 101 is suppressed. Therefore, the gate-source voltage Vg can be reduced. s can be made closer to the ideal value, i.e., voltage Vsig+Vth-Vi1, and load 1 04. The current supplied to the light emitting element 104a or the light emitting element 104b is accurately controlled by adjusting the voltage Vsig. can be made closer to the value reflected in

[0128] Alternatively, the capacitance value of the capacitance element 105 may be appropriately adjusted to adjust the amount of charge in the period T14. The amount of change in potential due to Q can be adjusted. This reduces the variation in mobility. , can be carried out more appropriately.

[0129] The area of ​​the electrodes of the capacitor 105 is larger than the area of ​​the electrodes of the load 104 (light-emitting element 104a). It is preferable that the value is smaller than the above, and more preferable that the value is 1 / 2 or less, and more preferable that the value is 1 / 3 or less. Alternatively, the capacitance value of the capacitive element 105 is set to be equal to or smaller than the capacitance of the load 104 (light emitting element 104a). It is preferable that the value is smaller than the value, preferably 1 / 2 times or less, and more preferably 1 / 3 times or less. This allows optimal operation within the same layout area. However, one aspect of an embodiment of the present invention is not limited to this.

[0130] The area of ​​the electrode of the capacitor 105 and the area of ​​the electrode of the load 104 (light-emitting element 104a) The total is preferably larger than the area of ​​the electrode of the capacitor 103, and more preferably, is at least twice as large. More preferably, it is 5 times or more. The sum of the capacitance values ​​of the capacitance elements 103 and 4 (light emitting elements 104a) is greater than the capacitance value of the capacitance element 103. It is preferable that the ratio is 2 times or more, and more preferable that the ratio is 5 times or more. The voltage is transferred between the capacitive element 103, the capacitive element 105, and the load 104 (light emitting element 104a). When the capacitance is divided, more voltage can be applied to the capacitive element 103. However, one aspect of the embodiment of the present invention is not limited to this.

[0131] Note that the area of ​​the electrode of the capacitor 105 is the same as that of the electrode of the capacitor 102 or the capacitor 103. It is preferable that the product is smaller than the above, and more preferable that the product is smaller than 1 / 2, and more preferable that the product is smaller than 1 / 3. Alternatively, the capacitance of the capacitor 105 is preferably set to be equal to or smaller than that of the capacitor 102 or the capacitor 10. It is desirable that the capacitance value be smaller than that of 3, preferably 1 / 2 or less, and more preferably 1 / It is preferable to set the ratio to 3 or less. This allows optimal operation within the same layout area. However, one aspect of the embodiment of the present invention is not limited thereto.

[0132] In addition, the semiconductor device according to one embodiment of the present invention includes the circuit 10 shown in FIG. 0, a circuit having a function of supplying various constant voltages and signals to the circuit 100, It is acceptable to have one.

[0133] The semiconductor device shown in FIG. 9A to FIG. 9D includes a circuit 1 shown in FIG. In addition to the above, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 and a 2 and a circuit 202 having a function of supplying a constant voltage or signal to the wiring 23. a circuit 203 having a function of supplying a constant voltage or signal to the wiring 24; 9A includes a wiring 26 and a circuit 204. The circuit 208 has a function of supplying a constant voltage or signal. Examples of the circuit 208 include: Therefore, the wiring 26 has a function of transmitting a predetermined electric potential. Alternatively, the wiring 26 may be used as a capacitance wiring. It is desirable that the potential of the wiring 26 be a constant potential. However, one aspect of the embodiment of the present invention is not limited to this, and may fluctuate like a pulse signal. .

[0134] In addition, any one of the circuits 100 shown in FIG. 1B to FIG. 1D and FIG. 8B to FIG. The pixels may be used as pixels of a display device. When the pixel is provided in a display device, the transistor 101 of the pixel is The ratio of the channel width to the channel length of the pixel may be different. The capacitance value of the transistor 105 may also differ depending on the corresponding hue.

[0135] FIG. 10A shows a case where the circuit 100 shown in FIG. 1B is used as a pixel of a display device. In FIG. 10A, the circuit 100 (R) corresponds to a pixel corresponding to red (R). , the circuit 100(G) corresponds to a pixel corresponding to green (G), and the circuit 100(B) corresponds to a pixel corresponding to blue (B). In one embodiment of the present invention, the transistor included in the circuit 100(R) corresponds to a pixel corresponding to the pixel in FIG. A transistor 101(R) included in the circuit 100(G), and a transistor 101(G) included in the circuit At least one of the transistors 101(B) of the transistor 100(B) is The ratio of channel width to channel length may be different from the others. A load 104(R) in the circuit 100(G), a load 104(G) in the circuit 100( The current supplied to each of the loads 104(B) in the load 104(B) can be set to a different value. As an example, the channel width and channel width of the transistor 101 corresponding to the second color can be The length ratio of the transistor 101 corresponding to the first color is preferably 1.2 times or more, and more preferably 1.2 times or more. More preferably, it is 1.5 times or more. The ratio of the channel width to the channel length of the transistor 101 is set to be equal to or larger than that of the transistor 101 corresponding to the first color. It is preferable that the ratio is more than 1, preferably 1.5 times or more, and more preferably 2 times or more. However, one aspect of the embodiment of the present invention is not limited to this.

[0136] FIG. 10B shows a case where the circuit 100 shown in FIG. 8A is used as a pixel of a display device. In the case of FIG. 10B, as in the case of FIG. 10A, the circuit 100 (R) and a transistor 101(R) in the circuit 100(G). 01(G) and at least one of the transistor 101(B) included in the circuit 100(B). However, the ratio of the channel width to the channel length may be different from the others. 100(R) has a load 104(R), the circuit 100(G) has a load 104(G), The current supplied to each of the loads 104(B) in the circuit 100(B) is set to a different value. It can be determined.

[0137] In the case of FIG. 10B, the capacitor 105(R) in the circuit 100(R) and the The capacitor 105(G) in the circuit 100(G) and the capacitor 105 in the circuit 100(B) At least one of (B) and (C) may have a different capacitance value from the others. The capacitance value of the capacitive element 105 corresponding to the second color is equal to that of the capacitive element 105 corresponding to the first color. It is preferable that the ratio is 1.2 times or more, and more preferably 1.5 times or more. The capacitance value of the capacitive element 105 corresponding to the third color is equal to that of the capacitive element 105 corresponding to the first color. It is preferable that the thickness of the electrode 105 is 1.5 times or more, and more preferably 2 times or more. However, one aspect of the embodiment of the present invention is not limited thereto.

[0138] In addition, in FIG. 10(A) and FIG. 10(B), the circuit 100(R) has a load 104(R). , the circuit 100(G) has a load 104(G), and the circuit 100(B) has a load 104(B). 10(A) or 10(B), the case where the load Instead of 104(R), load 104(G), or load 104(B), Alternatively, the light emitting element 104a or the light emitting element 104b may be used.

[0139] In FIG. 10B, the circuit 100 shown in FIG. 8A is used as a pixel of a display device. 8B to 8D are shown as an example. The pixel may be used as a pixel of a display device.

[0140] Next, a circuit 100 illustrated in FIG. 11A is a semiconductor device according to one embodiment of the present invention. The circuit 100 includes a switch 11, a switch 12, a switch 13, a switch 14, a transistor 101, a capacitor 102, and a capacitor 103. FIG. 11(A) shows an example in which the MOSFET 101 is an n-channel type. A) with a switch 14 added. The above can also be applied to FIG. 11(A) and the like.

[0141] Specifically, in FIG. 11A, the switch 11 is connected to a wiring 21 and one of the terminals of the capacitor 102. The switch has a function of controlling the conduction state between the first electrode and the second electrode of the capacitor 103. The transistor 12 is connected to the wiring 22 and the other electrode of the capacitor 102 or the gate electrode of the transistor 101. The switch 13 controls the conduction state between the transistor 101 and the One of the source or drain electrodes or the other electrode of the capacitor 103 and one of the capacitors 102 or one electrode of the capacitor 103. The switch 14 is connected to either the source or drain of the transistor 101 or the capacitance element The transistor 103 has a function of controlling the electrical continuity between the other electrode and the wiring 25. The other of the source and drain of the transistor 101 is connected to the wiring 23. One of the source or drain of the capacitor 101 and the other electrode of the capacitor 103 are connected to a wiring 24. It has been done.

[0142] The circuit 100 shown in FIG. 11A has a load 104 as shown in FIG. In the circuit 100 shown in FIG. between the wiring 24 and one of the source or drain of the capacitor 103 or the other electrode of the capacitor 103 is connected to

[0143] FIG. 11C shows a configuration of the circuit 100 when a light emitting element 104a is used as the load 104. In FIG. 11C, the anode of the light-emitting element 104a is connected to the sole of the transistor 101. The light emitting element is connected to one of the source and drain electrodes of the capacitor 103 and the other electrode of the capacitor 103. A case where the cathode of 104a is connected to the wiring 24 is shown as an example.

[0144] FIG. 11D shows a circuit 10 in which a light-emitting element 104b is used as the load 104. In FIG. 11D, the cathode of the light-emitting element 104b is connected to the transistor 10 1 or the other electrode of the capacitor 103. In this example, the anode of the light emitting element 104b is connected to the wiring 24. Note that in FIG. 11D, the transistor 101 is a p-channel transistor. This is shown.

[0145] In addition, a semiconductor device according to one embodiment of the present invention may include the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0146] The semiconductor device shown in FIG. 12A to FIG. 12D is In addition to the circuit 100, a circuit 220 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 221 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 23 and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24. and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25. and

[0147] Specifically, the circuit 220 has a function of supplying a potential Vsig to the wiring 21. An example of the wiring 21 is a source driver (signal line driver circuit). has a function capable of transmitting or supplying the potential Vsig. Alternatively, the wiring 21 functions as a video signal line.

[0148] The circuit 221 has a function of supplying a potential Vi2 to the wiring 22. As an example of the potential, there is a power supply circuit. Therefore, the wiring 22 can transmit the potential Vi2. The wiring 22 has a function of being able to supply the power. The potential of the wiring 22 is kept constant. However, one aspect of the embodiment of the present invention is not limited to this, and a variable signal such as a pulse signal may be used. You may move it.

[0149] The circuit 222 also supplies a power supply potential (high power supply potential or low power supply potential) to the wiring 23. The circuit 222 has a function of supplying a potential VDD or a potential VSS. Therefore, the wiring 23 has a function of transmitting the power supply potential, Alternatively, the wiring 23 may be connected to the transistor 101. Alternatively, the wiring 23 has a function of supplying a current to the load 104. Alternatively, the wiring 23 has a function of supplying a current. Alternatively, the wiring 23 functions as a current supply line. It is desirable for the potential of 23 to be a constant potential, but one aspect of the embodiment of the present invention is that this For example, the potential of the wiring 23 is changed by the load 1. 04 may be a potential that applies not only a forward bias voltage but also a reverse bias voltage. .

[0150] The circuit 223 also supplies a power supply potential (low power supply potential or high power supply potential) to the wiring 24. The circuit 223 has a function of supplying a potential Vcat. An example of the circuit 223 is a power supply circuit. Therefore, the wiring 24 has a function of transmitting or supplying a power supply potential. Alternatively, the wiring 24 can supply a current to the load 104. Alternatively, the wiring 24 has a function of supplying a current to the transistor 101. Alternatively, the wiring 24 functions as a common line. In this case, the wiring 24 functions as a cathode wiring. Alternatively, the wiring 24 functions as an anode wiring. It is preferable that the potential of the wiring 24 is constant. However, one aspect of the embodiment of the present invention is not limited to this, and may fluctuate like a pulse signal. For example, the potential of the wiring 24 is applied to the load 104 not only with a forward bias voltage but also with a reverse bias voltage. It may be a potential that applies pressure.

[0151] The circuit 224 has a function of supplying a potential Vi1 to the wiring 25. As an example of the potential, there is a power supply circuit. Therefore, the wiring 25 can transmit the potential Vi1. The wiring 25 has a function of being able to supply the power. The potential of the wiring 25 is kept constant. However, one aspect of the embodiment of the present invention is not limited to this, and a variable signal such as a pulse signal may be used. You may move it.

[0152] 12A to 12D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 20, a circuit 221, a circuit 222, a circuit 223, and a circuit 224. However, a semiconductor device according to one embodiment of the present invention does not necessarily include the circuits 220, 221, It is not necessary to include all of the circuits 222, 223, and 224, and any one of them may be included. It may have only one or more.

[0153] In addition, the circuit 100 shown in FIG. 11 and FIG. 12 includes, as an example, a switch 11 and a switch 1 2. Transistors can be used for the switches 13 and 14.

[0154] In the circuit 100 shown in FIG. 11(A) to FIG. 11(D), a transistor is used as the switch 11. A transistor 11t is used as the switch 12, a transistor 12t is used as the switch 13, A configuration of the circuit 100 when a transistor 13t is used as the switch 14 and a transistor 14t is used as the switch 14. are shown in Fig. 13(A) to Fig. 13(D). Note that in Fig. 13(A) to Fig. 13(D), Transistor 11t, transistor 12t, transistor 13t, and transistor 14 The case where all the transistors 11t and 11t are n-channel type is shown as an example. The transistors 12t, 13t, and 14t are all transistors of the same polarity. By using a MOS transistor as a gate, these transistors can be manufactured with fewer steps. One aspect of the embodiment is not limited to this, and transistors of different polarities may be used. It is Noh.

[0155] 13A to 13D, the gate of the transistor 11t is connected to the wiring 3. 1. The transistor 11t is turned on in response to the potential supplied to the wiring 31. The transistor 12t is in a non-conducting state or a non-conducting state. The transistor 12t is turned on or off depending on the potential supplied to the wiring 32. The gate of the transistor 13t is connected to the wiring 33. Depending on the potential applied, the transistor 13t is in a conductive state or a non-conductive state. The gate of the transistor 14t is connected to the wiring 34. In accordance with the potential supplied to the wiring 34, The transistor 14t is in a conductive state or a non-conductive state. The potential of 34 is preferably pulsed and not constant, but in accordance with one embodiment of the present invention. Alternatively, the wirings 31 to 34 may be gate signal lines, selection signal lines, etc. It functions as a signal line or a scan line.

[0156] At least two of the wirings 31 to 34 are connected to each other. Alternatively, at least one of the wirings 31 to 34 may be connected to another circuit 1. 00 can be connected to at least one of the wirings 31 to 34.

[0157] In addition, a semiconductor device according to one embodiment of the present invention includes the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0158] The semiconductor device shown in FIG. 14A to FIG. 14D is In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is 2, a circuit 231 having a function of supplying a constant voltage or signal to the wiring 32, and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 33 and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 34. and a circuit 233 having the same. An example of 233 is a gate driver (scanning line driving circuit).

[0159] 14A to 14D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 30, a circuit 231, a circuit 232, and a circuit 233 are shown as an example. In the semiconductor device according to one embodiment of the present invention, the circuit 230, the circuit 231, the circuit 232, It is not necessary to have all of the circuits 233, but only one or more of them. is also good.

[0160] In addition, the circuit 220, the circuit 221, the circuit 222, the circuit 223, the circuit 224, the circuit 230, The circuit 231, the circuit 232, and the circuit 233 may be one and the same circuit, or may be separate circuits. It's fine.

[0161] In addition, in the circuit 100 shown in FIG. 14t is an n-channel type, transistors 11t, 12t, and 1 The configuration of the circuit 100 when 3t is a p-channel type is shown in FIG. In the circuit 100 shown in FIG. 1D, the transistor 101 and the transistor 14t are p-channel. transistor 11t, transistor 12t, and transistor 13t are n-channel type; The configuration of the circuit 100 in the case of a panel type is shown in FIG.

[0162] In addition, a semiconductor device according to one embodiment of the present invention includes a circuit shown in FIG. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0163] The semiconductor device shown in FIG. 38(C) and FIG. 38(D) is In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is 2, a circuit 231 having a function of supplying a constant voltage or signal to the wiring 32, and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 33 and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 34. and a circuit 233 having a

[0164] 38C and 38D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 30, a circuit 231, a circuit 232, and a circuit 233 are shown as an example. In the semiconductor device according to one embodiment of the present invention, the circuit 230, the circuit 231, the circuit 232, It is not necessary to have all of the circuits 233, but only one or more of them. is also good.

[0165] Note that the transistor 101 often operates in the saturation region when a current flows. 13, 14, and 38, the channel length or gate length of the transistor 101 is The length of the gate is determined by the transistor 11t, the transistor 12t, the transistor 13t, and / or It is desirable to make the length longer than the transistor 14t. Preferably, it is 5 times or more longer, and more preferably, It is preferable that the difference is 10 times or more. The length of the channel or gate is 10 μm or more, and more preferably 20 μm or more. By increasing the gate length or the gate length, the characteristics in the saturation region become flat, and the kink effect is reduced. Alternatively, the channel width or gate width of the transistor 101 can be reduced. , transistor 11t, transistor 12t, transistor 13t, and / or transistor By making the transistor 101 longer than the transistor 14t, the transistor 101 can be Preferably, the current can be increased by 5 times or more, and more preferably by 10 times or more. It is preferable that the channel width or gate width of the transistor 101 is 20 μm or more. More preferably, the thickness is 30 μm or more. However, in one aspect of the embodiment of the present invention, Not limited.

[0166] The semiconductor devices shown in FIGS. 13(A) to 13(D) and FIGS. 38(A) and 38(B) In the device, the gates of the transistors 12t and 13t are both connected to a single wiring. 15(A) to 15(D) show the configuration of the casing 13(A) to 13(D). In the semiconductor device shown in FIG. 1D, the gates of the transistors 12t and 13t are In the example shown, the potential is connected to the wiring 32. As a result, the transistor 12t and the transistor 13t are in a conductive state or a non-conductive state.

[0167] In addition, a semiconductor device according to one embodiment of the present invention includes the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0168] The semiconductor device shown in FIG. 16A to FIG. 16D is In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is 2, a circuit 231 having a function of supplying a constant voltage or signal to the wiring 32, and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 34 and a circuit 233 having a function of supplying a signal.

[0169] 16A to 16D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 30, a circuit 231, and a circuit 233 are shown as an example. The semiconductor device according to the embodiment does not necessarily include all of the circuits 230, 231, and 233. It is not necessary for the device to have all of these features, but it may have only one or more of them.

[0170] In addition, in the circuit 100 shown in FIG. t and transistor 14t are n-channel type, transistor 12t and transistor 1 The configuration of the circuit 100 when 3t is a p-channel type is shown in FIG. In the circuit 100 shown in FIG. 1D, a transistor 101, a transistor 11t, and a transistor The transistor 14t is a p-channel type, and the transistors 12t and 13t are n-channel. The configuration of the circuit 100 in the case of a panel type is shown in FIG.

[0171] In addition, a semiconductor device according to one embodiment of the present invention includes a circuit shown in FIG. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0172] The semiconductor device shown in FIG. 42(C) and FIG. 42(D) is In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is 2, a circuit 231 having a function of supplying a constant voltage or signal to the wiring 32, and a circuit 232 having a function of supplying a constant voltage or signal to the wiring 34 and a circuit 233 having a function of supplying a signal. 1. An example of the circuit 233 is a gate driver (scanning line driving circuit).

[0173] 42C and 42D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 30, a circuit 231, and a circuit 233 are shown as an example. The semiconductor device according to the embodiment does not necessarily include all of the circuits 230, 231, and 233. It is not necessary for the device to have all of these features, but it may have only one or more of them.

[0174] In the semiconductor device shown in FIG. 13A to FIG. 13D, The gate of one transistor may be connected to the gate of another transistor. For example, the gates of the transistors 11t and 14t may be connected together. 9, the gate of the transistor 11t included in the circuit 100(i, j) in the i-th column and the j-th row, The gate of the transistor 14t in the circuit 100(i, j+1) in the jth row is connected to the 13 shows an example in which the second wiring 31(j) is connected to the first wiring 31(j).

[0175] In the semiconductor device shown in FIG. 15A to FIG. 15D, The gate of one transistor may be connected to the gate of another transistor. For example, the gates of the transistors 11t and 14t may be connected together. 0, the gate of the transistor 11t included in the circuit 100(i, j) in the i-th column and the j-th row, The gate of the transistor 14t in the circuit 100(i, j+1) in the jth row is connected to the 13 shows an example in which the second wiring 31(j) is connected to the first wiring 31(j).

[0176] 39 and 40, the gate of the transistor 11t in the j-th row circuit 100 is and the gate of the transistor 14t in the circuit 100 in the j+1th row are connected to the wiring 3 in the jth row. 1(j) is shown as an example. However, one aspect of the present invention is that The present invention is not limited to the configuration, and examples thereof include those shown in FIGS. 14(A) to 14(D), 38(C) and 38(D). In the semiconductor device shown in FIG. 1D, the circuit 230 is connected to the wiring 31(j) in the jth row and the wiring 31(j) in the j+1th row. A potential may be supplied to the wiring 34(j+1).

[0177] FIG. 41 shows a state in which a potential is supplied from the circuit 230 to the wiring 31 and the wiring 34. Specifically, in FIG. 41, the j-th output terminal out(j) of the circuit 230 is The potential is applied to the j-th line 31(j) and the j+1-th line 34(j+1). That is, for example, between the scanning line driving circuit and the pixel area, wiring of different rows is This is equivalent to connecting.

[0178] Next, the operation of one mode of the semiconductor device of the present invention will be described with reference to the circuit 100 shown in FIG. This article explains:

[0179] The operation of the circuit 100 shown in FIG. 11C is mainly divided into a first operation, a second operation, a third operation, and a fourth operation. However, one aspect of the embodiment of the present invention is not limited to this. It is also possible to add new operations or delete some operations.

[0180] In FIG. 11C, a switch 14 is added to the circuit in FIG. 1C. Therefore, it is possible to delete the third operation (period T13) shown in FIG. 6(A).

[0181] In the circuit 100 shown in FIG. The operation of the switch 14, the potential of the wiring 21, and the gate-source voltage of the transistor 101 An example of a timing chart showing the voltage (Vgs101) is shown in FIG.

[0182] First, the first operation performed in the period T11 will be described. As shown in FIG. 7(A), the switch 11 is in a non-conducting state, the switches 12, 13, and The switch 14 is in a conductive state. Therefore, in the period T11, as shown in FIG. The capacitance element 102 is supplied with a voltage Vi2-Vi1, and the anode of the light-emitting element 104a is supplied with a potential V i1, and the gate-source voltage (Vgs101) of the transistor 101 becomes voltage Vi2 That is, the transistor 101 and the capacitor element 102 are initialized. This will be the case.

[0183] In addition, the switch 11 is in a conductive state when the potential of the wiring 21 does not have an adverse effect. In that case, the switch 14 may be in a non-conducting state.

[0184] The switch 13 may be in a non-conducting state.

[0185] The second operation performed in the period T12 will be described. In the period T12, As shown in FIG. 1, the switches 11 and 14 are in a non-conducting state, the switches 12 and Switch 13 is in a conductive state. Switch 11 and switch 14 are in a non-conductive state. The charge stored in the capacitance element 102 is discharged through the transistor 101. The potential of the source of the transistor 101 rises. Then, when the transistor 101 is turned off, The discharge of charge from the capacitance element 102 stops. Eventually, the threshold voltage of the transistor 101 Vth is held in the capacitor 102. Therefore, in the period T12, as shown in FIG. As shown in FIG. 1, the threshold voltage Vth is held in the capacitance element 102, and the anode of the light emitting element 104a is at potential Vi2-Vth, and the gate-source voltage (Vgs101) of the transistor 101 is In other words, the threshold voltage Vth of the transistor 101 is obtained. This can be done.

[0186] It should be noted that it takes until Vgs101 becomes equal to the threshold voltage Vth of the transistor 101. , it may take a very long time. Therefore, Vgs101 is the threshold voltage In many cases, the transistor is operated without lowering Vth completely. The period T12 may end when the voltage Vth is slightly higher than the threshold voltage Vth. In other words, when the period T12 ends, Vgs101 is It can also be said that it is a voltage of a certain magnitude.

[0187] In the second operation, the threshold voltage Vth of the transistor 101 is positive or negative. This is because the transistor 101 is in the off state. This is because the source potential of the transistor 101 can rise until the transistor When the source potential of transistor 101 is higher than the gate potential of transistor 101, Then, the transistor 101 finally turns off and Vgs101 becomes Vth. Therefore, the transistor 101 is an enhancement type (normal Whether it is a depletion type (normally on type) or a non-depletion type (normally on type), it will operate normally. It is possible.

[0188] When the potential of the anode of the light emitting element 104a becomes high, a current flows to the light emitting element 104a. To this end, it is desirable to prevent current from flowing through the light emitting element 104a. In order to prevent this, it is preferable to set the potential Vi2 to a low value. The embodiment is not limited to this. In addition, a switch may be provided in series with the light emitting element 104a. By turning off the light emitting element 104a, it is possible to prevent current from flowing through the light emitting element 104a. In this case, the potential Vi2 may be a high value.

[0189] The third operation performed in the period T13 will be described. In the period T13, As shown in FIG. 1, the switches 11 and 14 are in a conducting state, the switches 12 and 13 is in a non-conductive state. In addition, the potential Vsig is supplied to the wiring 21. At T13, as shown in FIG. 18A, the capacitance element 102 is charged with a threshold voltage Vth (or Vt h), and the voltage Vsig-Vi1 is held in the capacitive element 103. The anode of the light emitting element 104a is held at a potential Vi1, and the gate of the transistor 101 is held at a potential Vi2. The potential of the gate of the transistor 101 becomes the potential Vsig+Vth, and the gate-source voltage of the transistor 101 (V gs101) is the voltage Vsig+Vth-Vi1. Therefore, the potential Vsig is The voltage of the capacitor 102 and the voltage of the capacitor 103 can be input to the capacitor 103. The sum of the voltages can be set to the gate-source voltage of transistor 101. .

[0190] At this time, it is also possible to put the switch 14 into a non-conducting state.

[0191] The fourth operation performed in the period T14 will be described. In the period T14, As shown in FIG. 1, the switches 11, 12, 13, and 14 are non-conductive. Therefore, in the period T14, as shown in FIG. The threshold voltage Vth is held, the voltage Vsig-Vi1 is held in the capacitive element 103, and the light emitting element The anode of the transistor 104a is at potential Vel, and the gate of the transistor 101 is at potential V sig+Vth+Vel, and the gate-source voltage of the transistor 101 (Vgs10 1) is the voltage Vsig+Vth-Vi1. Therefore, the magnitude according to the potential Vsig The light emitting element 104a can emit a current of 100 mA at a luminance corresponding to the potential Vsig. 4a can be made to emit light.

[0192] In the fourth operation, the gate-source voltage (Vgs101) of the transistor 101 is set to V sig+Vth-Vi1, which is set to a value taking into account the threshold voltage Vth of the transistor 101 Therefore, with the above configuration, the threshold voltage Vth of the transistor 101 can be increased. This can prevent the fluctuation from affecting the value of the current supplied to the light emitting element 104a. Alternatively, even if the transistor 101 deteriorates and the threshold voltage Vth changes, the change does not affect the light-emitting element. Therefore, it is possible to prevent the current value supplied to the element 104a from being affected. This can reduce noise and provide a high-quality display.

[0193] Similarly, the gate-source voltage (Vgs101) of the transistor 101 is set to a voltage Vsig+ Vth-Vi1, which can be set to a value independent of Vel. The variation in the voltage-current characteristics of the light emitting element 104a affects the current value supplied to the light emitting element 104a. Alternatively, it is possible to prevent the light emitting element 104a from deteriorating and causing a deterioration of the light emitting element 10 Even if the voltage-current characteristic of 4a changes and Vel changes, the change is not provided to the light emitting element 104a. This prevents the current value from being affected. This reduces display unevenness and improves quality. It can give a good display.

[0194] During a part of the fourth operation, the transistor 101 is forcibly turned off. In addition, by preventing a current from flowing through the light emitting element 104a, the light emitting element 104a does not emit light. In other words, it is possible to provide a non-emission period. For example, by turning on switch 12, transistor 101 is turned off. Alternatively, by turning on the switch 14, a current is supplied to the light emitting element 104a. It is possible to prevent the flow of

[0195] In the semiconductor device according to one embodiment of the present invention, in the second operation, The gate of the transistor 101 is kept at a potential Vi2. Even if the threshold voltage Vth has a negative value, the transistor 101 In this case, the potential of the source is stored in the capacitance element 102 until it becomes higher than the potential Vi2 of the gate. Therefore, in the semiconductor device according to one embodiment of the present invention, Even if the transistor 101 is normally on, in the fourth operation, The gate-source of the transistor 101 is set to a value that takes into account the threshold voltage Vth of the transistor 101. The voltage (Vgs101) can be set.

[0196] The capacitance of the capacitive element 103 is the capacitance of the parasitic capacitance of the load 104 (light emitting element 104a). It is preferable that it is smaller than 1 / 2 times, and more preferable that it is smaller than 1 / 5 times. Alternatively, the area of ​​the electrode of the capacitor element 103 is preferably set to be smaller than that of the load 104 (light-emitting element 104a ) is preferably smaller than the area of ​​the electrode, more preferably 1 / 2 or less, and even more preferably It is preferable that the ratio is 1 / 5 or less. However, one aspect of the embodiment of the present invention is not limited to this. stomach.

[0197] The capacitance of the capacitor 102 is smaller than the capacitance of the parasitic capacitance of the gate of the transistor 101. It is preferable that the thickness is large, preferably at least twice as large, and more preferably at least five times as large. Alternatively, the area of ​​the electrode of the capacitor 102 is larger than the area of ​​the channel of the transistor 101. It is preferable that the difference is larger, preferably at least twice as large, and more preferably at least five times as large. Alternatively, the area of ​​the electrode of the capacitor 102 is larger than the area of ​​the gate electrode of the transistor 101. It is preferable that the difference is larger than the above, preferably at least two times, and more preferably at least five times. Thus, the potential Vsig is input, and the capacitance element 102 and the gate capacitance of the transistor Therefore, when the voltage is capacitively divided, the decrease in the voltage of the capacitive element 102 can be reduced. However, one aspect of an embodiment of the present invention is not limited to this.

[0198] The capacitance of the capacitor 102 is approximately the same as the capacitance of the capacitor 103. The capacitance of the capacitor 102 is preferably equal to or larger than that of the capacitor 103. It is preferable that the difference from the capacitance value is within ±20%, and more preferably within ±10%. Alternatively, the area of ​​the electrode of the capacitor 102 is approximately the same as the area of ​​the electrode of the capacitor 103. It is desirable to have a size of 100 or more. However, one aspect of the embodiment of the present invention is that , but is not limited to this.

[0199] 19A to 19C are schematic diagrams of the circuit 100 in the periods T11 to T14. 19(D) shows a semiconductor device according to one embodiment of the present invention. It is sufficient if the structures shown in FIG. 19(A) to FIG. 19(D) can be obtained in each period. A semiconductor device according to one embodiment of the present invention includes a circuit having the configuration shown in FIG. The semiconductor device according to one embodiment of the present invention is not limited to the circuit 100. In order to realize the structures shown in FIG. 19(A) to FIG. 19(D), the arrangement and number of switches are determined. The number of wirings for supplying various potentials can be changed as appropriate.

[0200] After the period T13 in which the third operation is performed, there is a period T14 in which the fourth operation is performed. Before this, a period T16 in which a sixth operation is performed may be provided.

[0201] In the circuit 100 shown in FIG. 11C, when the period T16 is provided, The operation of the switches 12, 13, and 14, the potential of the wiring 21, and the transistor An example of a timing chart showing the gate-source voltage (Vgs101) of the transistor 101 is shown in FIG. This is illustrated in Figure 20(A).

[0202] In the timing chart shown in FIG. 20A, a period T16 is inserted between the periods T13 and T14. 17A in that a timing chart shown in FIG.

[0203] A sixth operation performed in the period T16 will be described. In the period T16, As shown in FIG. 1, the switch 12 is in a conducting state, the switches 11, 13, and Therefore, in the period T16, as shown in FIG. The gate-source voltage (Vgs101) of transistor 101 is Vsig+Vth-Vi1 It becomes -Vα.

[0204] In the sixth operation, the potential Vα is set so that the anode of the light-emitting element 104a is in an electrically floating state (floating state). The potential Vα changes when the transistor 101 is in an off-state. If so, the capacitance of the light-emitting element 104a and the capacitances of the capacitive elements 102 and 103 are However, depending on the level of the potential Vsig, the transistor Since the transistor 101 is turned on, a current is applied to the anode of the light-emitting element 104a through the transistor 101. Therefore, the potential Vα is not determined only by the capacitance ratio. The value also changes depending on the charge flowing into the anode of the photoelement 104a.

[0205] The charge amount Q is expected to have the effect of suppressing the variation in mobility. The reason for this is as follows. I will explain it below.

[0206] In period T16, the charge Q flows from the drain to the source of the transistor 101. Therefore, the charge amount Q is larger as the mobility of the transistor 101 is higher. When the charge amount Q becomes large, the transistor The gate-source voltage (Vgs101) of the transistor 101 becomes smaller. That is, the charge The larger the mobility of the transistor 101, the more the amount of charge Q supplied to the light emitting element 104a. The current value is corrected to be smaller. Also, the smaller the mobility of the transistor 101, the However, a correction is made so that the current value supplied to the light emitting element 104a does not become too small. Therefore, the charge amount Q can suppress the variation in mobility.

[0207] After the period T16, in the period T14, the gate-source voltage (Vgs1 01) is the voltage Vsig+Vth-Vi1-Vα. Therefore, the threshold voltage of the transistor 101 is The gate-source voltage can be set to a value that takes into account the threshold voltage Vth and mobility.

[0208] In addition, in the semiconductor device according to one embodiment of the present invention, similarly to FIG. 8, the circuit 1 shown in FIG. 00, may further include a capacitive element 105 connected to a load 104. In the same manner, in the semiconductor device of one embodiment of the present invention, in the circuit 100 illustrated in FIG. The light emitting element 104a may further include a capacitor element 105 connected to the light emitting element 104a. In the semiconductor device according to one embodiment of the present invention, a light-emitting element is added to the circuit 100 shown in FIG. A capacitor 105 connected to 104b may be further included.

[0209] The semiconductor device shown in FIG. 21A is a circuit 100 shown in FIG. 11B. Specifically, one of the capacitance elements 105 is The other electrode of the capacitor 103 and the source or drain of the transistor 101 are connected to each other. The other electrode of the capacitor 105 is connected to a wiring 26. In addition, FIG. 21A shows an example in which the circuit 100 includes a load 104. 21A, a light emitting element 104a or a light emitting element A child 104b may also be used.

[0210] The wiring 26 can be connected to various wirings. For example, the wiring 22, the wiring 23, wiring 24, wiring 25, or wiring of another circuit 100, a scanning line, a gate line, a transistor This allows the number of wires to be reduced. It is possible to reduce

[0211] The semiconductor device shown in FIG. 21B is the same as the circuit 100 shown in FIG. 21B is an example in which the circuit 100 is connected to the wiring 24. 21B, instead of the load 104, Alternatively, the light emitting element 104a or the light emitting element 104b may be used. By doing so, the number of wirings 26 can be reduced.

[0212] The semiconductor device shown in FIG. 21C is the same as the circuit 100 shown in FIG. 21C is an example in which the circuit 100 is connected to the wiring 23. 21C shows an example in which the load 104 is replaced by the load 104. Alternatively, the light emitting element 104a or the light emitting element 104b may be used. By doing so, the number of wirings 26 can be reduced.

[0213] The semiconductor device shown in FIG. 21D is the same as the circuit 100 shown in FIG. 21D is an example in which the circuit 100 is connected to the wiring 22. 21(D) shows an example in which the load 104 is replaced by Alternatively, the light emitting element 104a or the light emitting element 104b may be used. By doing so, the number of wirings 26 can be reduced.

[0214] The semiconductor device shown in FIG. 21E is a circuit 100 shown in FIG. 21A, except that the wiring 26 21E shows an example in which the circuit 100 is connected to the wiring 25. 21(E) shows an example in which the load 104 is replaced by Alternatively, the light emitting element 104a or the light emitting element 104b may be used. By doing so, the number of wirings 26 can be reduced.

[0215] A capacitive element 1 is connected in parallel to the load 104, the light emitting element 104a or the light emitting element 104b. 05 is added to the circuit 100, the sixth operation and the fourth operation described in the above embodiment can be realized. In operation, the charge fluctuations at either the source or drain of transistor 101 Therefore, the gate-source voltage Vα can be reduced. The voltage Vgs can be made closer to the ideal value, i.e., the voltage Vsig+Vth-Vi1. , the current supplied to the load 104, the light emitting element 104a, or the light emitting element 104b is a voltage Vsi This allows us to get closer to a value that accurately reflects g.

[0216] Alternatively, the capacitance value of the capacitance element 105 may be appropriately adjusted to adjust the amount of charge in the period T16. The amount of change in potential due to Q can be adjusted. This reduces the variation in mobility. , can be carried out more appropriately.

[0217] The area of ​​the electrodes of the capacitor 105 is larger than the area of ​​the electrodes of the load 104 (light-emitting element 104a). It is preferable that the value is smaller than the above, and more preferable that the value is 1 / 2 or less, and more preferable that the value is 1 / 3 or less. Alternatively, the capacitance value of the capacitive element 105 is set to be equal to or smaller than the capacitance of the load 104 (light emitting element 104a). It is preferable that the value is smaller than the value, preferably 1 / 2 times or less, and more preferably 1 / 3 times or less. This allows optimal operation within the same layout area. However, one aspect of an embodiment of the present invention is not limited to this.

[0218] The area of ​​the electrode of the capacitor 105 and the area of ​​the electrode of the load 104 (light-emitting element 104a) The total is preferably larger than the area of ​​the electrode of the capacitor 103, and more preferably, is at least twice as large. More preferably, it is 5 times or more. The sum of the capacitance values ​​of the capacitance elements 103 and 4 (light emitting elements 104a) is greater than the capacitance value of the capacitance element 103. It is preferable that the ratio is 2 times or more, and more preferable that the ratio is 5 times or more. The voltage is transferred between the capacitive element 103, the capacitive element 105, and the load 104 (light emitting element 104a). When the capacitance is divided, more voltage can be applied to the capacitive element 103. However, one aspect of the embodiment of the present invention is not limited to this.

[0219] Note that the area of ​​the electrode of the capacitor 105 is the same as that of the electrode of the capacitor 102 or the capacitor 103. It is preferable that the product is smaller than the above, and more preferable that the product is smaller than 1 / 2, and more preferable that the product is smaller than 1 / 3. Alternatively, the capacitance of the capacitor 105 is preferably set to be equal to or smaller than that of the capacitor 102 or the capacitor 10. It is desirable that the capacitance value be smaller than that of 3, preferably 1 / 2 or less, and more preferably 1 / It is preferable to set the ratio to 3 or less. This allows optimal operation within the same layout area. However, one aspect of the embodiment of the present invention is not limited thereto.

[0220] The wiring 25 can be connected to various wirings. For example, the wiring 22, the wiring 24, wiring 26, or wiring of another circuit 100, a scanning line, a gate line, a transistor gate This can reduce the number of wires. It is possible to do this.

[0221] In addition, a semiconductor device according to one embodiment of the present invention may include a semiconductor device having the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0222] The semiconductor device shown in FIG. 22A to FIG. 22D is In addition to the circuit 100, a circuit 220 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 221 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 23 and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24. and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25. Furthermore, in the circuit 100 shown in FIG. 22A, a constant voltage or The circuit 225 has a function of supplying a signal.

[0223] In addition, any one of the circuits shown in FIG. 11(B) to FIG. 11(D) and FIG. 21(B) to FIG. 21(D) 100 may be used as a pixel of a display device. When the pixel is provided in a display device, the transistor of the pixel is The ratio of the channel width to the channel length of the transistor 101 may be different. The capacitance value of the capacitive element 105 may also differ depending on the corresponding hue.

[0224] FIG. 23A shows a case where the circuit 100 shown in FIG. 11B is used as a pixel of a display device. In FIG. 23A, the circuit 100 (R) is a pixel corresponding to red (R). The circuit 100(G) corresponds to a pixel corresponding to green (G), and the circuit 100(B) corresponds to a pixel corresponding to green (G). This corresponds to a pixel corresponding to blue (B). In one embodiment of the present invention, A transistor 101(R) included in a circuit 100(G) and a transistor 101(G) included in a circuit At least one of the transistors 101(B) of the circuit 100(B) is The channel width to channel length ratio may be different from the others. A load 104(R) in the circuit 100(R), a load 104(G) in the circuit 100(G), (B) to set the current supplied to each of the loads 104(B) to different values. can be done.

[0225] FIG. 23B shows a circuit diagram of a display device in which the circuit 100 shown in FIG. 21A is used as a pixel of the display device. In the case of FIG. 23B, as in the case of FIG. 23A, the circuit 10 0(R) and a transistor 101(R) in the circuit 100(G). At least one of the transistor 101(G) and the transistor 101(B) of the circuit 100(B) However, the ratio of the channel width to the channel length may be different from the others. A load 104(R) in the circuit 100(R) and a load 104(G) in the circuit 100(G) , the current supplied to each of the loads 104(B) of the circuit 100(B) is set to a different value. It can be set.

[0226] In the case of FIG. 23B, the capacitor 105(R) in the circuit 100(R) and the The capacitor 105(G) in the circuit 100(G) and the capacitor 105 in the circuit 100(B) At least one of (B) and (C) may have a different capacitance value from the others.

[0227] In addition, in FIG. 23(A) and FIG. 23(B), the circuit 100(R) has a load 104(R). , the circuit 100(G) has a load 104(G), and the circuit 100(B) has a load 104(B). 23(A) or 23(B), the case where the load Instead of 104(R), load 104(G), or load 104(B), Alternatively, the light emitting element 104a or the light emitting element 104b may be used.

[0228] In FIG. 23B, the circuit 100 shown in FIG. 21A is used as a pixel of a display device. 21B to 21E. may be used as a pixel of a display device.

[0229] In this embodiment, the variation in the threshold voltage of the transistor 101 is corrected. However, one aspect of the embodiment of the present invention is not limited to this. For example, Therefore, a current is supplied to the load 104 without performing any operation to correct the variation in the threshold voltage. It is also possible to operate the device in combination with the other devices.

[0230] This embodiment describes an example of the basic principle. Any part or all of the above may be freely combined with any part or all of the other embodiments. It can be applied or substituted.

[0231] (Embodiment 2) In this embodiment, a configuration example of a circuit 100 which is a semiconductor device according to one embodiment of the present invention will be described. In this embodiment mode, a switch is added to the circuit shown in the first embodiment mode. The following describes the configuration and the case where a part of the driving method is changed. The contents described in 1 can also be applied to this embodiment.

[0232] 24(A) to 24(D) show configuration examples of the circuit 100. The circuit 100 shown in FIG. 24(D) is a circuit 100 shown in FIG. 1(A) to FIG. The switch 914 corresponds to a configuration in which a A transistor 101 is connected to the wiring 23 via a gate for controlling the conduction state between the other of the source and drain of the transistor 101 and the wiring 23. Alternatively, the semiconductor device 10 has a function of controlling the electrical continuity between the wiring 23 and the wiring 24. Alternatively, the switch 914 has a function of preventing current from flowing through the capacitor 103. Alternatively, the switch 914 has a function of preventing current from flowing through the capacitor 102. Alternatively, the switch 914 has a function of preventing current from flowing to the load 104.

[0233] In addition, a semiconductor device according to one embodiment of the present invention may include the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0234] The semiconductor device shown in FIG. 25(A) to FIG. 25(D) is In addition to the circuit 100, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 202 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 203 having a function of supplying a constant voltage or signal to the wiring 23. and a circuit 203 having a function of supplying a constant voltage or a signal to the wiring 24. and a circuit 204 having a

[0235] In addition, the circuit 100 shown in FIG. 24 and FIG. 25 includes a switch 11, a switch 12, a switch 1 3. The switch 914 can be a transistor.

[0236] As an example, when the switch 914 is a transistor 914t as shown in FIG. In this case, the gate of the transistor 914t is connected to the wiring 932, and the wiring 93 2 may be connected to a circuit 9206 having a function of supplying a constant voltage or signal. An example of the circuit 9206 is a gate driver (scanning line driver circuit). .

[0237] At least two of the wirings 31 to 33 and the wiring 932 are Alternatively, at least the wirings 31 to 33 and the wiring 932 may be connected to each other. At least one of the wirings 31 to 33 and the wiring 932 of another circuit 100. It is possible to connect them.

[0238] The circuit 100 shown in FIGS. 24 and 25 operates in a similar manner to the circuit 100 shown in FIGS. However, as an example, in the circuit 100 shown in FIG. During periods T11 to T13 and T15 shown in FIG. In period T14, it is preferable that switch 914 is in a non-conducting state. As a result, in the period T14, the light emitting element 104a However, in one aspect of the embodiment of the present invention, This is not limited to the above.

[0239] Alternatively, the switch 914 may be in a non-conducting state during the period T13. As a result, no current flows through the transistor 101, and the gate and This makes it easier to control the potential at each node in the circuit 100, such as the source.

[0240] Alternatively, the switch 914 may be in a non-conducting state during the period T11. As a result, no current flows through the transistor 101, and the gate and This makes it easier to control the potential at each node in the circuit 100, such as the source.

[0241] Alternatively, the switch 914 is kept in a non-conducting state even during a part of the period T15. This prevents current from flowing to the light emitting element 104a etc., and provides a non-light emitting period. Yes, it is possible.

[0242] Note that the circuit 100 shown in FIG. 24B and FIG. 25B is similar to that shown in FIG. 8, FIG. 9, and FIG. Similarly, the load 104 may further include a capacitive element 105 connected thereto. The circuit 100 shown in FIG. 24C and FIG. 25C includes a capacitor connected to the light-emitting element 104a. The element 105 may be further included. Similarly, the elements shown in FIG. The circuit 100 may further include a capacitor 105 connected to the light-emitting element 104b. Specifically, one electrode of the capacitor 105 is connected to the other electrode of the capacitor 103 and the transistor The other terminal of the capacitance element 105 is connected to either the source or the drain of the transistor 101. The electrodes are connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring 22.

[0243] In addition, the circuit 100 shown in FIG. 24B to FIG. 24D and the circuit 100 shown in FIG. The display device may include a circuit in which the capacitor 105 is added to the circuit 100 shown in FIG. The pixels corresponding to the respective hues may be provided on the display device. When the pixel is turned on, the channel of the transistor 101 in the pixel is changed according to the corresponding color. The ratio of the width to the length of the channel may be different.

[0244] It is also possible to provide the switch 914 at a location other than that shown in FIGS. Specifically, as an example, the conduction state between the wiring 23 and the wiring 24 can be controlled. For example, in FIG. 26(A) to FIG. 26(D), 26A to 26D show configuration examples of the circuit 100 shown in FIG. In the configuration in which a switch 914 is added to the circuit 100 shown in FIGS. The switch 914 corresponds to the source or drain of the transistor 101. The second electrode has a function of controlling electrical continuity between one electrode of the first electrode and the other electrode of the capacitor 103. If switch 13 is in a conducting state, switch 914 is connected to transistor 101. One of the source or drain of the capacitor 102 and one of the electrodes of the capacitor 103 It has the function of controlling the electrical continuity between the two electrodes.

[0245] In addition, a semiconductor device according to one embodiment of the present invention may include the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 is further provided. It may also have.

[0246] The semiconductor device shown in FIG. 27A to FIG. 27D is In addition to the circuit 100, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 202 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 203 having a function of supplying a constant voltage or signal to the wiring 23. and a circuit 203 having a function of supplying a constant voltage or a signal to the wiring 24. and a circuit 204 having a

[0247] In addition, the circuit 100 shown in FIG. 26 and FIG. 27 includes a switch 11, a switch 12, a switch 1 3. The switch 914 can be a transistor.

[0248] The circuit 100 shown in FIG. 26 and FIG. 27 is the same as the circuit shown in FIG. 1, FIG. 2, FIG. 24, or FIG. It can perform the same operations as 100.

[0249] Note that the circuit 100 shown in FIG. 26B and FIG. 27B is similar to that shown in FIG. 8, FIG. 9, and FIG. Similarly, the load 104 may further include a capacitive element 105 connected thereto. The circuit 100 shown in FIG. 26C and FIG. 27C includes a capacitor connected to the light-emitting element 104a. The element 105 may be further included. Similarly, the elements shown in FIG. The circuit 100 may further include a capacitor 105 connected to the light-emitting element 104b. Specifically, one electrode of the capacitor 105 is connected to the other electrode of the capacitor 103. In addition, the switch 914 is connected to one electrode of the capacitor 105 and the transistor 101. The other potential of the capacitance element 105 is controlled to be conductive between the source or drain of the capacitance element 105 and the other potential of the capacitance element 105. The poles are connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring 22.

[0250] In addition, the circuit 100 shown in FIG. 26(B) to FIG. 26(D) and the circuit 100 shown in FIG. 27(B) to FIG. The display device may include a circuit in which the capacitor 105 is added to the circuit 100 shown in FIG. The pixels corresponding to the respective hues may be provided on the display device. When the pixel is turned on, the channel of the transistor 101 in the pixel is changed according to the corresponding color. The ratio of the width to the length of the channel may be different.

[0251] The switch 914 may be provided at a location other than that shown in FIG. 24, FIG. 25, FIG. 26, and FIG. 27. For example, configuration examples of the circuit 100 are shown in FIGS. The circuit 100 shown in FIG. 28(A) to FIG. 28(D) is similar to the circuit 100 shown in FIG. 9 corresponds to a configuration in which a switch 914 is added to the circuit 100 shown in FIG. The switch 914 is connected to one of the source and drain of the transistor 101 and the capacitance element 10 3. Furthermore, the switch 13 has a function of controlling the conductive state between the other electrode of the If the switch 914 is in the ON state, the switch 914 connects one electrode of the capacitor 102 and one electrode of the capacitor 1 The capacitor 103 has a function of controlling electrical continuity between one electrode of the capacitor 103 and the other electrode of the capacitor 103. do.

[0252] In addition, a semiconductor device according to one embodiment of the present invention includes the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0253] The semiconductor device shown in FIG. 29(A) to FIG. 29(D) is In addition to the circuit 100, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 202 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 203 having a function of supplying a constant voltage or signal to the wiring 23. and a circuit 203 having a function of supplying a constant voltage or a signal to the wiring 24. and a circuit 204 having a

[0254] In addition, the circuit 100 shown in FIG. 28 and FIG. 29 includes a switch 11, a switch 12, a switch 1 3. The switch 914 can be a transistor.

[0255] The circuit 100 shown in FIGS. 28 and 29 is similar to that shown in FIGS. However, as an example, the circuit shown in FIG. In the circuit 100 shown in FIG. 29, the periods T11 to T13 and the period T1 In period T15, switch 914 is in a conducting state, and in period T14, switch 914 is in a non-conducting state. As a result, in the period T14, the transistor 1 It is possible to prevent electric charges from leaking to the light emitting element 104a through the light emitting element 01. However, However, one aspect of an embodiment of the present invention is not limited thereto.

[0256] Alternatively, the switch 914 may be in a non-conducting state during the period T11. As a result, no current flows through the transistor 101, making it easier to control the potential.

[0257] Alternatively, the switch 914 is kept in a non-conducting state even during a part of the period T15. This prevents current from flowing to the light emitting element 104a etc., and provides a non-light emitting period. Yes, it is possible.

[0258] In addition, during the period T12, the switch 914 may be in a non-conducting state. At T12, the switch 914 is turned off, so that the light-emitting element Therefore, the anode of the transistor 104a can be maintained at the potential Vi1 without providing the period T13. That is, after the second operation in the period T12 is completed without performing the third operation, The fourth operation at 14 can be performed.

[0259] The circuit 100 shown in FIG. 28B and FIG. 29B may be the same as the circuit 100 shown in FIG. 8, FIG. 9, FIG. 10B, etc. Similarly, the device may further include a capacitive element 105 connected to the load 104. In addition, the circuit 100 shown in FIG. 28C and FIG. 29C is connected to the light-emitting element 104a. A capacitor 105 may be further included. Similarly, in FIG. The illustrated circuit 100 further includes a capacitor 105 connected to the light-emitting element 104b. Specifically, one electrode of the capacitor 105 is connected to the other electrode of the capacitor 103. In addition, the switch 914 is connected to one electrode of the capacitor 105 and the transistor 1 The other of the capacitance element 105 is connected to the source or drain of the capacitance element 105. The electrodes are connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring 22. .

[0260] In addition, the circuit 100 shown in FIG. 28(B) to FIG. 28(D) and the circuit 100 shown in FIG. The display device may include a circuit in which the capacitor 105 is added to the circuit 100 shown in FIG. The pixels corresponding to the respective hues may be provided on the display device. When the pixel is turned on, the channel of the transistor 101 in the pixel is changed according to the corresponding color. The ratio of the width to the length of the channel may be different.

[0261] It is also possible to provide the switch 914 at a location other than that shown in FIGS. For example, configuration examples of the circuit 100 are shown in FIG. The circuit 100 shown in FIG. 30(A) to FIG. 30(D) is a circuit 100 shown in FIG. 0 with a switch 914 added. The switch 914 is connected to one of the source and drain of the transistor 101 and the capacitance element The other electrode of the transistor 103 has a function of controlling the electrical connection between the wiring 24. In B), the switch 914 is connected to either the source or drain of the transistor 101. and a function of controlling the conduction state between the other electrode of the capacitor 103 and the load 104. In FIG. 30C, the switch 914 is connected to the source or drain of the transistor 101. Between one electrode of the drain and the other electrode of the capacitor 103 and the anode of the light emitting element 104a In FIG. 30(D), the switch 914 has a function of controlling the conductive state. One of the source and drain electrodes of the transistor 101 and the other electrode of the capacitor element 103, and the light-emitting element The transistor 104b has a function of controlling the electrical continuity between the transistor 104b and the cathode.

[0262] In addition, a semiconductor device according to one embodiment of the present invention includes the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0263] The semiconductor device shown in FIG. 31A to FIG. 31D is In addition to the circuit 100, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 is provided. 2, a circuit 202 having a function of supplying a constant voltage or signal to the wiring 22, and a circuit 203 having a function of supplying a constant voltage or signal to the wiring 23. and a circuit 203 having a function of supplying a constant voltage or a signal to the wiring 24. and a circuit 204 having a

[0264] In addition, the circuit 100 shown in FIG. 30 and FIG. 31 includes a switch 11, a switch 12, a switch 1 3. The switch 914 can be a transistor.

[0265] The circuit 100 shown in FIGS. 30 and 31 is similar to that shown in FIGS. It can perform the same operation as the circuit 100 shown in FIG. 28 and FIG. 29. However, as an example, In the circuit 100 shown in FIGS. 30 and 31, the period T11 and the period T During periods T13 to T15, the switch 914 is in a conductive state, and during period T12, the switch Preferably, switch 914 is in a non-conducting state. As a result, in the period T12, the switch 914 is turned off. By setting the anode of the light emitting element 104a in this state, the anode of the light emitting element 104a is maintained at the potential Vi1 during the period T12. Therefore, the period T13 is not provided, that is, the third operation is not performed, and the period T1 is completed. After the second operation in period T2 is completed, the fourth operation in period T14 can be performed. However, one aspect of the embodiment of the present invention is not limited to this.

[0266] Alternatively, the switch 914 may be in a non-conducting state during the period T11. As a result, no current flows through the light emitting element 104a, etc., and the potential Vi2 of the wiring 22 is high. A value is also acceptable.

[0267] Alternatively, the switch 914 may be in a non-conducting state during the period T12. As a result, no current flows through the light emitting element 104a, etc., and the potential Vi2 of the wiring 22 is high. A value is also acceptable.

[0268] Alternatively, the switch 914 is kept in a non-conducting state even during a part of the period T15. This prevents current from flowing to the light emitting element 104a etc., and provides a non-light emitting period. Yes, it is possible.

[0269] The circuit 100 shown in FIG. 30B and FIG. 31B is similar to the circuit 100 shown in FIG. 21 and 22, the load 104 is connected to the capacitance element 105. Similarly, the circuit 100 shown in FIG. 30C and FIG. 31C may be used as a light-emitting element 10. 30(D) and 30(E), a capacitance element 105 may be further connected to the capacitance element 4a. 31D, the circuit 100 includes a capacitor 105 connected to the light-emitting element 104b. Specifically, one electrode of the capacitor 105 is connected to the The other electrode is connected to either the source or the drain of the transistor 101. The other electrode of the capacitance element 105 is connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring It is connected to line 22.

[0270] In addition, the circuit 100 shown in FIG. 30(B) to FIG. 30(D) and the circuit 100 shown in FIG. The display device may include a circuit in which the capacitor 105 is added to the circuit 100 shown in FIG. The pixels corresponding to the respective hues may be provided on the display device. When the pixel is turned on, the channel of the transistor 101 in the pixel is changed according to the corresponding color. The ratio of the width to the length of the channel may be different.

[0271] 24 to 31, a switch 914 is added to the circuit shown in FIG. 1. However, the circuit in which the switch 914 is added is not limited to the circuit shown in FIG. In the circuits shown in the drawings other than FIG. 1, the switch For example, a circuit in which a switch 914 is added can be used as shown in FIG. In the configuration in which the switch 14 is added, a switch 914 is added as in the case of FIG. 24 to FIG. 31. It is possible to configure a circuit in which this is done. An example of this is shown in Figure 87.

[0272] Next, in the circuits of FIG. 1 and FIG. 11, the driving method shown in FIG. 5 and FIG. 17 is different from the driving method shown in FIG. An example of a case where a different driving method is used will be shown. Note that when such a driving method is used, It is preferable to connect the wiring 23 between pixels in the row direction rather than between pixels in the column direction. Therefore, in FIG. 34(A) to FIG. 34(D), the circuit 10 shown in FIG. 34(A) to 34(D), different wirings 21 1 shows an example in which a plurality of circuits 100 connected to each other are connected to a common wiring 23. In other words, the wiring 23 is provided so as to intersect with the wiring 21.

[0273] An example of the operation of one embodiment of a semiconductor device of the present invention will be described with reference to the circuit 100 shown in FIG. In this operation, the first operation in FIG. 5(B) and FIG. 17(B) is Then, a voltage Vi2-Vi1 is supplied to the capacitance element 102, and the gate source of the transistor 101 When the inter-gate voltage (Vgs101) becomes voltage Vi2-Vi1, the wiring 21 and the switch 14 The potential Vi1 is not supplied via the line 23, but via the line 24. The contents described in FIG. 5, FIG. 17, etc. can be applied to one embodiment of the semiconductor device of the present invention. It is.

[0274] The operation of the circuit 100 shown in FIG. 34C is mainly divided into a first operation, a second operation, a third operation, and a fourth operation. It can be divided into four operations, the fourth operation and the fifth operation. However, it is not limited to these, and new operations It is also possible to add or delete some operations.

[0275] First, the first operation performed in the period T11 will be described. As shown in FIG. 5(A), the switch 11 is in a non-conducting state, and the switches 12 and 13 are in a conducting state. In addition, a potential Vi1 is supplied to the wiring 23. Therefore, in the period T11, The anode of the light emitting element 104a is at a potential Vi1, and the gate-source of the transistor 101 is The voltage (Vgs101) is the voltage Vi2-Vi1. This means that the capacitive element 102 is initialized.

[0276] The second operation performed in the period T12 will be described. In the period T12, ), the switch 11 is in a non-conducting state, and the switches 12 and 13 are in a conducting state. In addition, the potential VDD is supplied to the wiring 23. When the potential VDD is supplied to the wiring 23, As a result, the charge stored in the capacitor 102 is released through the transistor 101. Then, the potential of the source of the transistor 101 rises. Then, the transistor 101 is turned off. When the transistor 101 goes into the ON state, the charge discharge from the capacitor 102 stops. The threshold voltage Vth of 1 is held in the capacitance element 102. Therefore, in the period T12, The threshold voltage Vth is held at 102, and the anode of the light-emitting element 104a is at a potential Vi2-Vth The gate-source voltage (Vgs101) of the transistor 101 is the threshold voltage Vth That is, the threshold voltage Vth of the transistor 101 can be obtained.

[0277] In this way, the first and second operations can be performed without using the wiring 21. The second operation period can be longer. Therefore, the trans- formation can be performed more accurately. Since the threshold voltage of resistor 101 can be obtained, a clear display with little display unevenness can be obtained. It is possible to provide the following:

[0278] The third operation performed in the period T13 will be described. In the period T13, As shown in FIG. 1, the switches 11 and 13 are in a conducting state, and the switch 12 is in a non-conducting state. Any potential may be supplied to the wiring 23, for example, potential VDD or A potential Vi1 is supplied to the wiring 21. A potential Vi3 is supplied to the wiring 21. The potential Vi3 is It may be the same height as the potential Vcat, the same height as the potential Vi2, or the same height as the potential Vi1. Therefore, in the period T13, the threshold voltage Vth is held in the capacitor 102. The anode of the light emitting element 104a is at a potential Vi3, and the gate of the transistor 101 is at a potential becomes the potential Vi3+Vth, and the gate-source voltage of the transistor 101 (Vgs101 ) is the threshold voltage Vth.

[0279] The fourth operation performed in the period T14 will be described. In the period T14, ), the switch 11 is in a conducting state, and the switches 12 and 13 are in a non-conducting state. In addition, the potential Vsig is supplied to the wiring 21. Therefore, in the period T14, The element 102 holds a threshold voltage Vth, and the capacitive element 103 holds a voltage Vsig-Vi3-Vα is maintained, the anode of the light emitting element 104a is at a potential Vi3+Vα, and the transistor 10 The potential of the gate of transistor 101 becomes the potential Vsig+Vth, and The voltage (Vgs101) is equal to the voltage Vsig+Vth-Vi3-Vα.

[0280] The fifth operation performed in the period T15 will be described. In the period T15, As shown, the switches 11, 12, and 13 are in a non-conducting state. In the period T15, the threshold voltage Vth is held in the capacitance element 102, and the voltage V sig-Vi3-Vα is maintained, the anode of the light emitting element 104a is at the potential Vel, and The potential of the gate of the transistor 101 is Vsig+Vth-Vi3-Vα+Vel. The gate-source voltage (Vgs101) of the transistor 101 is Vsig+Vth- Therefore, a current having a magnitude according to the potential Vsig is applied to the light emitting element 104 a, and the light emitting element 104a can emit light with a luminance according to the potential Vsig. can.

[0281] The potential Vel is set when a current is applied to the light-emitting element 104a via the transistor 101. Specifically, the potential is between the potential VDD and the potential Vcat.

[0282] In the fifth operation, the gate-source voltage (Vgs101) of the transistor 101 is set to The voltage Vsig is Vsig+Vth-Vi3-Vα, taking into account the threshold voltage Vth of the transistor 101. Therefore, with the above configuration, the threshold voltage of the transistor 101 can be set to a value. It is possible to prevent the variation in Vth from affecting the current value supplied to the light emitting element 104a. Or, even if the transistor 101 deteriorates and the threshold voltage Vth changes, the above change can be prevented. This can prevent the change in the current supplied to the light emitting element 104a from being influenced by the change in the current. It is possible to reduce display unevenness and provide a high-quality display.

[0283] Note that, even during a part of the period T15, the light emission is performed by controlling the potential of the wiring 23. It is possible to provide a non-light emitting period by preventing current from flowing through the element 104a etc. For example, when the potential of the wiring 23 is equal to the potential of the wiring 24, no current flows. is possible.

[0284] Although the switch 14 is not provided in FIG. 34 and FIG. 35, the present invention is not limited to this. 11 to 23, a switch 14 may be provided.

[0285] Although the switch 914 is not provided in FIG. 34 and FIG. 35, the present invention is not limited to this. Similar to Figures 24-87, a switch 914 may be provided.

[0286] In addition, in FIG. 34 and FIG. 35, the operation is performed by changing the potential of the wiring 23. It is also possible to control the potential by using the above method. An example of this case is shown below. 35, 5, 17, etc. can be applied to one embodiment of the semiconductor device of the present invention. 32A to 32D show examples of the circuit 100. The circuit 100 shown in FIG. 32(A) to FIG. 32(D) may be the same as the circuit 100 shown in FIG. A switch 814 and a switch 15 are added to the circuit 100 shown in FIG. 34 to FIG. These correspond to a configuration in which wiring 23a and wiring 23b are provided instead of 23. In FIG. 32(A) to FIG. 32(D), the switch 814 is a solenoid for the transistor 101. The transistor 23a has a function of controlling the electrical continuity between the other of the source and the drain and the wiring 23a. In addition, the switch 15 is connected to the other of the source or drain of the transistor 101 and the wiring 2. 3b.

[0287] The wiring 23a and / or the wiring 23b may be provided so as to intersect with the wiring 21. However, it is also possible to provide it in parallel with the wiring 21 without intersecting it.

[0288] In addition, a semiconductor device according to one embodiment of the present invention may include a semiconductor device having the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0289] The semiconductor device shown in FIG. 33A to FIG. 33D is In addition to the circuit 100, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21 is provided. A circuit 202 having a function of supplying a constant voltage or signal to the wiring 22 and a circuit 203 having a function of supplying a constant voltage or signal to the wiring 23a A circuit 203a having a function of supplying a constant voltage or a signal to a wiring 23b. a circuit 203b having a function of supplying a constant voltage or signal to the wiring 24; Specifically, the circuit 203a supplies a potential Vi1 to the wiring 23a. In addition, the circuit 203b supplies a power supply potential (high power supply potential or A circuit having a function of supplying a low power supply potential, for example, a potential VDD or a potential VSS. An example of 203a and circuit 203b is a power supply circuit.

[0290] Therefore, the wiring 23a has a function of transmitting or supplying the potential Vi1. Alternatively, the wiring 23a has a function as an initialization wiring. It is preferable that the potential of the wiring 23a is constant. In one embodiment, the signal is not limited to this and may fluctuate like a pulse signal.

[0291] Therefore, the wiring 23b has a function of transmitting or supplying a power supply potential. Alternatively, the wiring 23b has a function of supplying a current to the transistor 101. Alternatively, the wiring 23b has a function of supplying a current to the load 104. Alternatively, the wiring 23b may function as a power supply line. Alternatively, the wiring 23b functions as a current supply line. The potential is preferably a constant potential, but one aspect of the embodiment of the present invention is not limited to this. For example, the potential of the wiring 23b is a potential of the load 104. The potential may be such that not only a forward bias voltage but also a reverse bias voltage is applied to the positive electrode 14 .

[0292] 33A to 33D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 01, a circuit 202, a circuit 203a, a circuit 203b, and a circuit 204. However, a semiconductor device according to one embodiment of the present invention does not necessarily include the circuits 201 and 20 2. It is not necessary to include all of the circuits 203a, 203b, and 204. It may have only one or more.

[0293] In addition, the circuit 100 shown in FIG. 32 and FIG. 33 includes a switch 11, a switch 12, a switch 1 3. Transistors can be used for the switch 814 and the switch 15.

[0294] The circuit 100 shown in FIGS. 32 and 33 operates in the same manner as the circuit 100 shown in FIGS. However, in the circuit 100 shown in FIG. 32 and FIG. 33, During the period T12, the switch 814 is in a conductive state and the switch 15 is in a non-conductive state. In a period T15, the switch 814 is set to a non-conductive state, and the switch 15 is set to a conductive state.

[0295] The circuit 100 shown in FIG. 32B and FIG. 33B is similar to that shown in FIG. Similarly, the load 104 may further include a capacitive element 105 connected thereto. In addition, the circuit 100 shown in FIG. 32C and FIG. 33C is connected to the light-emitting element 104a. A capacitor 105 may be further included. Similarly, in FIG. The illustrated circuit 100 further includes a capacitor 105 connected to the light-emitting element 104b. Specifically, one electrode of the capacitor 105 may be connected to the other electrode of the capacitor 103. The transistor 101 is connected to either the source or the drain of the transistor 101. The other electrode is connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring 22. do.

[0296] In addition, the circuit 100 shown in FIG. 32(B) to FIG. 32(D) and the circuit 100 shown in FIG. The display device may include a circuit in which the capacitor 105 is added to the circuit 100 shown in FIG. The pixels corresponding to the respective hues may be provided on the display device. When the pixel is turned on, the channel of the transistor 101 in the pixel is changed according to the corresponding color. The ratio of the width to the length of the channel may be different.

[0297] Although the switch 14 is not provided in FIG. 32 and FIG. 33, the present invention is not limited to this. 11 to 23, a switch 14 may be provided.

[0298] Although the switch 914 is not provided in FIG. 32 and FIG. 33, the present invention is not limited to this. Similar to Figures 24-87, a switch 914 may be provided.

[0299] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0300] (Embodiment 3) In this embodiment, a configuration example of a circuit 100 which is a semiconductor device according to one embodiment of the present invention will be described. In this embodiment, a switch and a Add wires, change some of the connections, or connect one wire to another to make the wires This paper describes the structure for stopping the laser beam and the case where some of the driving methods are changed. The contents described in the first and second embodiments can also be applied to this embodiment.

[0301] The circuit 100 shown in FIG. 43A is the same as the circuit 100 shown in FIG. 11C except that the switch 14 A configuration in which the position is different, or a configuration in which a switch 14 is added to the circuit 100 shown in FIG. In the circuit 100 shown in FIG. Controlling electrical continuity between one electrode of the capacitor 103 and the wiring 25 It has the function of

[0302] The operation is the same as that in FIG. 17 to FIG. 20. However, in FIG. 18(A), the fourth operation In the example shown in FIG. 43(A), the switch 14 is in a conductive state. In this embodiment, the switch 14 is preferably in a non-conducting state. One aspect of the present invention is not limited to this.

[0303] In FIG. 43A, a switch 914 is provided as in FIGS. 24 to 31. In FIG. 43(A), as in FIG. 32, FIG. 33, etc., It is also possible to provide a switch 814 and a switch 15. It is also possible to control the potential of the wiring 23, such as in FIG. 30, a switch 914 is provided as shown in FIG. 43(F).

[0304] 8, 9, 21, 22, etc., the circuit 100 shown in FIG. 43(A) may be It is possible to add a capacitor 105. As an example, the circuit 10 shown in FIG. 43A. The circuit 100 corresponds to a configuration in which a capacitor 105 is added to the circuit 100 shown in FIG. One electrode of the capacitor 105 is connected to the other electrode of the capacitor 103. The other electrode of the capacitor 105 is connected to a wiring 26 .

[0305] In addition, the wiring 26 can be connected to various wirings, as in FIG. 8, FIG. 21, etc. For example, the circuit 100 shown in FIG. 43C has the same structure as the circuit 100 shown in FIG. In this example, the wiring 26 is connected to the wiring 25. In addition to the line 25, the wiring 24, the wiring 22, the wiring 23, the gate signal line, and wiring of other circuits 100 It is possible to connect to various wiring such as the above.

[0306] The wiring 25 can be connected to various wirings. For example, 43A, the wiring 25 is different from the wiring 24. Here is an example of a 32-bit LSI connected to the

[0307] The circuit 100 shown in FIG. 43E is a circuit 100 shown in FIG. 43D, which is provided with a capacitive element The capacitor element 105 is connected to one of the electrodes of the capacitor element 105. The other electrode of the capacitance element 105 is connected to the wiring 26. It has been done.

[0308] 44 includes a circuit 100 shown in FIG. 43 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 22 a circuit 221 having a function of supplying a constant voltage or signal to the wiring 23; A circuit 223 having a function of supplying a constant voltage or signal to the line 24, and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25 a circuit 224 having a function of supplying a constant voltage or signal to the wiring 26; Each of the circuits includes a plurality of circuits of the circuit 225.

[0309] 43 and 44 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0310] As in FIG. 43(D), the wiring 25 is connected to various wirings in FIG. 11 and the like. For example, the circuit 100 shown in FIG. In the circuit 100 , the wiring 25 is connected to the wiring 24 .

[0311] In addition, the circuit 100 shown in FIG. 45(A) can also be used in conjunction with FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. Similarly, it is possible to add a capacitor 105 or connect a wiring. For example, The circuit 100 shown in FIG. 45B is the circuit 100 shown in FIG. 45A, except that a capacitor 105 One electrode of the capacitor 105 corresponds to the capacitor 10 The other electrode of the capacitor element 105 is connected to the wiring 26. It should be noted that the wiring 25 can also be connected to the wiring 26 instead of the wiring 24. In addition, both the wiring 26 and the wiring 25 can be connected to the wiring 24.

[0312] The semiconductor device shown in FIG. 45(C) and FIG. 45(D) is similar to the semiconductor device shown in FIG. 45(A) and FIG. In addition to the circuit 100 shown in FIG. 1, a circuit 2 having a function of supplying a constant voltage or a signal to the wiring 21 is also provided. 20, a circuit 221 having a function of supplying a constant voltage or signal to wiring 22, A circuit 222 having a function of supplying a voltage or signal, and a function of supplying a constant voltage or signal to the wiring 24 and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26. Each of the first and second circuits has a plurality of circuits.

[0313] In addition, FIG. 45 shows the configuration of the circuit 100 in the case where the light emitting element 104a is used. The semiconductor device according to one embodiment of the present invention includes a light-emitting element 10 in a circuit 100 shown in FIG. 4a is not present, or a load 104 or a light-emitting element 104 is present instead of the light-emitting element 104a. b may be included.

[0314] In the circuit shown in FIG. 1, one or both of the switches 14 and 914 are Additionally, both switches, switch 14 and switch 914, may be provided. That is, the switch 914 is added to the configurations shown in FIG. 11, FIG. 32, FIG. 34, FIG. 43, FIG. 45, etc., or Alternatively, the switch 14 may be added to Figs. 24, 26, 28, 30, 32, 34, etc. For example, the circuit 100 shown in FIG. 46A can be implemented as a 28C. Alternatively, a switch 914 may be added to the circuit 100 shown in FIG. In the circuit 100 shown in FIG. A transistor 914 is connected to one of the source and drain of the transistor 101 and the other of the capacitor element 103. The light emitting element 104a has a function of controlling the electrical continuity between the light emitting element 104a and one of the electrodes or the anode of the light emitting element 104a.

[0315] In FIG. 46(A), similarly to FIG. 44(D) and FIG. 45, the wiring 25 is connected to other wiring For example, in the circuit 100 shown in FIG. An example in which 25 is connected to wiring 24 is shown in FIG.

[0316] The location of the switch 14 is not limited to that shown in FIG. 46(A), and may be other locations, similar to that shown in FIG. The circuit 100 shown in FIG. 46(C) is different from the circuit shown in FIG. 43(A), the switch 14 is provided as a capacitance element. The conductive state between one electrode of the capacitor 102 and one electrode of the capacitor 103 and the wiring 25 is It has the function of controlling

[0317] In addition, it is possible to provide a plurality of switches equivalent to the switch 14, rather than just one. For example, the circuit 100 shown in FIG. 46D includes a capacitor 10 instead of the switch 14. A function for controlling the conduction state between the other electrode of the light emitting element 103 and the anode of the light emitting element 104a and the wiring 24. A switch 14a having a function of switching ON / OFF, one electrode of the capacitor 102 and one electrode of the capacitor 103, The switch 14b has a function of controlling the electrical connection between the electrode and the wiring 25. In other words, the circuit shown in FIG. 46(D) is different in configuration from the circuit 100 shown in FIG. It can be said that switch 14 has been added in two places.

[0318] 47 includes a circuit 100 shown in FIG. 46, and a constant voltage is applied to the wiring 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 22 a circuit 221 having a function of supplying a constant voltage or signal to the wiring 23; A circuit 223 having a function of supplying a constant voltage or signal to the line 24, and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25 Each of the circuits 224 has a function of supplying the following.

[0319] 46 and 47 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIG. 46 and FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0320] The configurations in which the switch 14 and the switch 914 are provided are not limited to those shown in FIG. 46 and FIG. 87 . Various configurations can be used. In this case, the driving method is shown in Figs. 5, 6, 17, 18, This can be done in the same manner as in Figures 20, 35, and 36. The circuit 100 shown in Figure 48(A) is This corresponds to a configuration in which the position of the switch 14 is different from that of the circuit 100 shown in FIG. In the circuit 100 shown in FIG. 8(A), a switch 14 is connected to the source or drain of a transistor 101. The drain electrode 24 has a function of controlling the electrical continuity between one of the drains and the wiring 25.

[0321] Also, in FIG. 48(A), similarly to FIG. 44(D) and FIG. 45, the wiring 25 is connected to another wiring. For example, the circuit 100 shown in FIG. 48B may be the same as the circuit shown in FIG. 1 shows an example in which the wiring 25 is connected to the wiring 24 in the circuit 100.

[0322] The semiconductor device shown in FIG. 48(C) and FIG. 48(D) is In addition to the circuit 100 shown in FIG. 1, a circuit 2 having a function of supplying a constant voltage or a signal to the wiring 21 is also provided. 20, a circuit 221 having a function of supplying a constant voltage or signal to wiring 22, A circuit 222 having a function of supplying a voltage or signal, and a function of supplying a constant voltage or signal to the wiring 24 and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25. Each of the first and second circuits has a plurality of circuits.

[0323] In addition, FIG. 48 shows the configuration of the circuit 100 in the case where the light emitting element 104a is used. The semiconductor device according to one aspect of the present invention includes a light emitting element 10 in a circuit 100 shown in FIG. 4a is not present, or a load 104 or a light-emitting element 104 is present instead of the light-emitting element 104a. b may be included.

[0324] The circuit 100 shown in FIG. 49A is different from the circuit 100 shown in FIG. 11C. In FIG. 11C, a switch 914 is added to the circuit 100. corresponds to a configuration in which a switch 14 is added to the circuit 100 shown in FIG. In the circuit 100 shown in (A), a switch 914 is connected to the source or drain of a transistor 101. Conduction between one electrode of the drain and the other electrode of the capacitor 103 and the anode of the light emitting element 104a It has the function of controlling the state.

[0325] The driving method in this case is the same as that shown in Figs. 5, 6, 17, 18, 20, 35, and 36. An example of a driving method is shown below.

[0326] First, the first operation performed in the period T11 will be described. Switch 11 and switch 914 are in a non-conducting state, and switches 12, 13, and 1 4 is in a conductive state. Therefore, during the period T11, the voltage Vi2-Vi1 is applied to the capacitance element 102. The anode of the light emitting element 104a is at a potential Vi1, and the gate of the transistor 101 is at a potential Vi2. The gate-source voltage (Vgs101) is the voltage Vi2-Vi1. This means that the capacitance element 101 and the capacitance element 102 are initialized.

[0327] Note that the switch 11 is connected to the transistor 101 and the capacitor 102 when the potential of the wiring 21 is If it does not adversely affect the initialization, the switch may be in a conductive state. In that case, switch 1 4 may be in a non-conducting state.

[0328] The switch 13 may be in a non-conducting state.

[0329] The switch 914 may be in a conductive state.

[0330] The second operation performed in the period T12 will be described. In the period T12, the switch 1 1, switch 14 and switch 914 are non-conductive, switch 12 and switch 13 are conductive When the switch 11, the switch 914, and the switch 14 are in a non-conducting state, The charge stored in the capacitance element 102 is discharged through the transistor 101. The potential of the source of the transistor 101 rises. Then, when the transistor 101 is turned off, Finally, the discharge of charge from the capacitor 102 stops. The voltage Vth is held in the capacitance element 102. Therefore, in the period T12, the threshold voltage Vth is held in the capacitance element 102. The value voltage Vth is maintained, the anode of the light emitting element 104a is at a potential Vi2-Vth, and The gate-source voltage (Vgs101) of the transistor 101 is the threshold voltage Vth (or V th) is the threshold voltage Vth (or a voltage whose magnitude corresponds to Vth) can be obtained.

[0331] In the second operation, the threshold voltage Vth of the transistor 101 is positive or negative. This is because the transistor 101 is in the off state. This is because the source potential of the transistor 101 can rise until the transistor When the source potential of transistor 101 is higher than the gate potential of transistor 101, Then, the transistor 101 finally turns off and Vgs101 becomes Vth. Therefore, the transistor 101 is an enhancement type (normal Whether it is a depletion type (normally on type) or a non-depletion type (normally on type), it will operate normally. It is possible.

[0332] When the potential of the anode of the light emitting element 104a becomes high, a current flows to the light emitting element 104a. In order to prevent a current from flowing through the light emitting element 104a, In order to achieve this, it is preferable to set the potential Vi2 to a low value. By setting the light emitting element 104a in this state, it is possible to prevent current from flowing through the light emitting element 104a. Therefore, the potential Vi2 may be a high value.

[0333] The switch 914 may be in a conductive state.

[0334] The third operation performed in the period T13 will be described. In the period T13, the switch 1 Switch 1 and switch 14 are conductive, and switch 12, switch 13, and switch 914 are non-conductive. In addition, the potential Vsig is supplied to the wiring 21. Therefore, in the period T13, The threshold voltage Vth (or a voltage corresponding to Vth) is held in the capacitance element 102. The capacitance element 103 is held at a voltage Vsig-Vi1, and the anode of the light-emitting element 104a is held at a potential V The potential of the gate of the transistor 101 becomes Vsig+Vth, and the transistor The gate-source voltage of transistor 101 (Vgs101) is Vsig+Vth-Vi1. Therefore, the potential Vsig can be input to the capacitance element 103. The sum of the voltage of the capacitance element 102 and the voltage of the capacitance element 103 is the gate source of the transistor 101. It is possible to make the voltage between the gates equal to the gate voltage.

[0335] At this time, the switch 14 may be placed in a non-conducting state.

[0336] The switch 914 may be in a conductive state.

[0337] The fourth operation performed in the period T14 will be described. In the period T14, the switch 1 1, switch 12, switch 13, and switch 14 are in a non-conducting state, and switch 91 4 is in a conductive state. Therefore, during the period T14, the threshold voltage Vth is held in the capacitance element 102. The voltage Vsig-Vi1 is held in the capacitance element 103, and the anode of the light emitting element 104a The potential of the gate of the transistor 101 is Vsig+Vth+Ve l, and the gate-source voltage of transistor 101 (Vgs101) is Vsig+ Therefore, a current having a magnitude according to the potential Vsig is applied to the light emitting element 10. 4a, causing the light emitting element 104a to emit light with a luminance according to the potential Vsig. can be done.

[0338] During a part of the fourth operation, the transistor 101 is forcibly turned off. In addition, by preventing a current from flowing through the light emitting element 104a, the light emitting element 104a does not emit light. In other words, it is possible to provide a non-emission period. For example, by turning on switch 12, transistor 101 is turned off. Alternatively, by turning on the switch 14, a current is supplied to the light emitting element 104a. Alternatively, the switch 914 can be turned off to prevent the current from flowing. This makes it possible to prevent current from flowing to the light emitting element 104a.

[0339] After the period T13 in which the third operation is performed, there is a period T14 in which the fourth operation is performed. Before this, a period T16 in which a sixth operation is performed may be provided.

[0340] A sixth operation performed in the period T16 will be described. In the period T16, the switch 1 2 is in a conducting state, and switch 11, switch 13, switch 914, and switch 14 are non-conducting. Therefore, in the period T16, the gate-source voltage (Vg s101) becomes the voltage Vsig+Vth-Vi1-Vα.

[0341] In the sixth operation, the potential Vα is set so that the anode of the light-emitting element 104a is in an electrically floating state (floating state). The potential Vα changes when the transistor 101 is in an off-state. If so, the capacitance of the light-emitting element 104a and the capacitances of the capacitive elements 102 and 103 are However, depending on the level of the potential Vsig, the transistor Since the transistor 101 is turned on, a current is applied to the anode of the light-emitting element 104a through the transistor 101. Therefore, the potential Vα is not determined only by the capacitance ratio. The value also changes depending on the charge flowing into the anode of the photoelement 104a.

[0342] The switches 12 and 13 are controlled to be turned on and off at the same timing. Therefore, the switches 12 and 13 are made of transistors of the same polarity. In this configuration, the gates of the transistors can be connected together, as in Figure 15. It is.

[0343] In addition, the wiring 22 and the wiring 25 can be connected to various other wirings. For example, The circuit 100 in FIG. 49B is the same as the circuit 100 in FIG. 49A except that the wiring 25 is connected to wiring 24.

[0344] 8, 9, 21, 22, etc., a capacitance element 105 may be additionally provided. For example, the circuit 100 shown in FIG. 49(C) can be implemented by using the circuit 1 shown in FIG. 00, and a capacitance element 105 is added. The electrode of the capacitor 105 is connected to the other electrode of the capacitor 103. , and is connected to wiring 26.

[0345] As an example of a case where the capacitance element 105 is provided in a layout different from that in FIG. 49(C), The circuit 100 shown in FIG. 49D is obtained by adding a capacitor 105 to the circuit 100 shown in FIG. One electrode of the capacitor element 105 is connected to the positive electrode of the light emitting element 104a. The other electrode of the capacitor 105 is connected to a wiring 26 .

[0346] 50, in addition to the circuit 100 shown in FIG. 49, a constant voltage is applied to the wiring 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 22 a circuit 221 having a function of supplying a constant voltage or signal to the wiring 23; A circuit 223 having a function of supplying a constant voltage or signal to the line 24, and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25 a circuit 224 having a function of supplying a constant voltage or signal to the wiring 26; Each of the circuits includes a plurality of circuits of the circuit 225.

[0347] 49 and 50 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention is similar to the circuit 100 shown in FIG. 49 and FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0348] In addition, in Figs. 49(C) and 49(D), Figs. 8, 21, 43, 45, and 4 Similarly to the wiring 22, wiring 23, wiring 24, wiring 25, wiring 26, etc., the wiring 22, wiring 23, wiring 24, wiring 25, wiring 26, etc. are connected to each other. It is possible to continue.

[0349] In addition, although FIG. 49 shows a case where one capacitance element 105 is added, In one embodiment, the circuit 100 to which the capacitor 105 is added further includes It is possible to add many capacitance elements. For example, the circuit 100 shown in FIG. In addition, a capacitor 105a and a capacitor 105b are added to the circuit 100 shown in FIG. One electrode of the capacitor 105a is connected to the other electrode of the capacitor 103. The other electrode of the capacitor element 105a is connected to the wiring 26. One electrode of the capacitance element 105b is connected to the anode of the light emitting element 104a. The other electrode of the element 105 b is connected to a wiring 27 .

[0350] In addition, the wiring 25 can be connected to other wirings. For example, as shown in FIG. The circuit 100 shown in FIG. 50(C) is a circuit in which the wiring 25 is connected to the wiring 24. This corresponds to the above configuration.

[0351] The circuit 100 shown in FIG. 51C is similar to the circuit 100 shown in FIG. This corresponds to a configuration in which the line 25 is connected to the wiring 24 .

[0352] The circuit 100 shown in FIG. 51D is similar to the circuit 100 shown in FIG. This corresponds to a configuration in which the line 25 is connected to the wiring 24 .

[0353] 52, in addition to the circuit 100 shown in FIG. 51, a constant voltage is applied to the wiring 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 22 a circuit 221 having a function of supplying a constant voltage or signal to the wiring 23; A circuit 223 having a function of supplying a constant voltage or signal to the line 24, and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25 a circuit 224 having a function of supplying a constant voltage or signal to the wiring 26; A plurality of circuits 225 and a plurality of circuits 226 each having a function of supplying a constant voltage or a signal to the wiring 27 Each of the first and second input circuits has a circuit.

[0354] An example of the circuit 226 is a power supply circuit. , has the ability to convey or provide; or The wiring 27 functions as a capacitance wiring. The potential of the wiring 27 is set to a constant potential. However, one aspect of the embodiment of the present invention is not limited thereto, and may be a pulse signal. The wiring 27 may be connected to other wirings. For example, the wiring 25, the wiring 24, the wiring 22, the wiring 26, the wiring 23, the gate signal line, other circuits It is possible to connect to various wirings, such as the wiring of circuit 100.

[0355] 51 and 52 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention is similar to the circuit 100 shown in FIG. 51 and FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0356] In the various circuits described above, the wiring 22 can be connected to other wirings. As a result, the number of wirings can be reduced. For example, the wiring 22 can be Wire 21, wire 23, wire 23a, wire 23b, wire 24, wire 25, wire 26, wire 27 Alternatively, the wiring 22 can be connected to a scanning line, a gate line, a transistor, or the like. It is possible to connect the gate of the transistor to the wiring connected to the gate of the transistor. The circuit 100 shown in FIG. 3A is the same as the circuit 100 shown in FIG. The configuration connected to line 21 is shown.

[0357] Similarly, the circuit 100 shown in FIG. 53B is similar to the circuit 100 shown in FIG. A configuration in which the line 22 is connected to the wiring 21 is shown.

[0358] In addition, it is possible to add a capacitance element 105 in the same manner as in FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. For example, the circuit 100 shown in FIG. 53C is similar to the circuit 100 shown in FIG. 21A. In the circuit 100 shown in FIG. 21A, a capacitor 105 is added. This corresponds to a configuration in which the line 22 is connected to the wiring 21.

[0359] Similarly, in FIG. 43 and the like, the wiring 22 can be connected to the wiring 21. For example, the circuit 100 shown in FIG. 53(D) is the same as the circuit 100 shown in FIG. , the wiring 22 is connected to the wiring 21.

[0360] 54, in addition to the circuit 100 shown in FIG. 53, a constant voltage is applied to the wiring 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0361] 53 and 54 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention is similar to the circuit 100 shown in FIG. 53 and FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0362] When a certain wiring is connected to a first wiring, the second wiring is also connected to the first wiring. For example, the wiring 22 may be connected to a third wiring. When the wiring 25 is connected to another wiring, the wiring 25 can also be connected to another wiring. For example, the circuit 100 shown in FIG. 55A is similar to the circuit 100 shown in FIG. 22 is connected to the wiring 21, and the wiring 25 is connected to the wiring 24, as shown in FIG. In the circuit 100 shown in FIG. 45, the wiring 25 is connected to the wiring 24. In the circuit 100 shown in FIG.

[0363] In addition, it is possible to add a capacitance element 105 in the same manner as in FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. For example, the circuit 100 shown in FIG. 55(B) is similar to the circuit 100 shown in FIG. 45B. This corresponds to a configuration in which the line 22 is connected to the wiring 21.

[0364] This can also be applied when the position of the switch 14 is changed. The circuit 100 shown in FIG. 43E is different from the circuit 100 shown in FIG. The connected configuration is shown.

[0365] 56 includes a circuit 100 shown in FIG. 55 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; Among the circuits 225 having the function of supplying a constant voltage or signal to the line 26, a plurality of circuits are It has.

[0366] 55 and 56 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0367] The circuit 100 shown in FIG. 57A is similar to the circuit 100 shown in FIG. An example in which a line 22 is connected to a wiring 21 is shown.

[0368] The circuit 100 shown in FIG. 57B is similar to the circuit 100 shown in FIG. An example in which a line 22 is connected to a wiring 21 is shown.

[0369] Also, a switch 914 can be added as in FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. For example, the circuit 100 shown in FIG. 57C is similar to the circuit 100 shown in FIG. , this corresponds to a configuration in which a switch 914 is added.

[0370] The circuit 100 shown in FIG. 57(D) is a circuit 100 shown in FIG. 53(D) with a switch 914 is added, or the arrangement of the switch 14 in FIG. 57(C) is changed. This corresponds to the formation of

[0371] 58 includes a circuit 100 shown in FIG. 57 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0372] 57 and 58 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0373] The circuit 100 shown in FIG. 59A is similar to the circuit 100 shown in FIG. The configuration shown is when the line 25 is connected to the wiring 24.

[0374] The circuit 100 shown in FIG. 59B is similar to the circuit 100 shown in FIG. The configuration shown is when the line 25 is connected to the wiring 24.

[0375] The circuit 100 shown in FIG. 59C is similar to the circuit 100 shown in FIG. 57D. The configuration shown is when the line 25 is connected to the wiring 24.

[0376] 60 includes a circuit 100 shown in FIG. 59 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; Among the circuits 225 having the function of supplying a constant voltage or signal to the line 26, a plurality of circuits are It has.

[0377] 59 and 60 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention is similar to the circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0378] The wiring 22 can be connected to a wiring other than the wiring 21. For example, the wiring 22 can also be connected to the wiring 24. For example, the circuit 100 shown in FIG. In the circuit 100 shown in FIG. 11C, the wiring 22 is connected to the wiring 24. .

[0379] In addition, the circuit 100 shown in FIG. 61B is different from the circuit 100 shown in FIG. 22 indicates a configuration connected to wiring 24.

[0380] The circuit 100 shown in FIG. 61C is similar to the circuit 100 shown in FIG. A configuration in which line 22 is connected to wiring 24 is shown.

[0381] The circuit 100 shown in FIG. 61D is similar to the circuit 100 shown in FIG. A configuration in which line 22 is connected to wiring 24 is shown.

[0382] 62 includes a circuit 100 shown in FIG. 61 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0383] 61 and 62 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0384] In addition, it is possible to add a capacitance element 105 in the same manner as in FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. For example, the circuit 100 shown in FIG. 63(A) is similar to the circuit 100 shown in FIG. 8A. In the circuit 100 shown in FIG. 8A, This corresponds to a configuration in which the line 22 is connected to the wiring 24 .

[0385] The circuit 100 shown in FIG. 63B is the same as the circuit 100 shown in FIG. This corresponds to a configuration in which the line 22 is connected to the wiring 24 .

[0386] In addition, the circuit 100 shown in FIG. 63C is the same as the circuit 100 shown in FIG. This corresponds to a configuration in which the line 22 is connected to the wiring 24 .

[0387] The circuit 100 shown in FIG. 63(D) is a circuit diagram of the circuit 100 shown in FIG. 63(C). 100, a capacitance element 105 is added to the capacitance element 105 as in the case of FIG. 8, FIG. 9, FIG. 21, FIG. 22, etc. Equivalent.

[0388] 64 includes a circuit 100 shown in FIG. 63, and a constant voltage is applied to the wiring 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0389] 63 and 64 show the configuration of the circuit 100 when the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0390] The circuit 100 shown in FIG. 65(A) is a circuit 100 shown in FIG. 61(D) including a switch. In the circuit 100 shown in FIG. 65(A), the switch 914 The source or drain of the transistor 101 and the other electrode of the capacitor 103 are connected to each other. It also has a function of controlling the electrical connection between the anode of the light emitting element 104a.

[0391] The circuit 100 shown in FIG. 65B is similar to the circuit 100 shown in FIG. An example in which a line 25 is connected to a wiring 24 is shown.

[0392] The circuit 100 shown in FIG. 65C is similar to the circuit 100 shown in FIG. An example in which a line 25 is connected to a wiring 24 is shown.

[0393] The circuit 100 shown in FIG. 65(D) is similar to the circuit 100 shown in FIG. An example in which a line 25 is connected to a wiring 24 is shown.

[0394] 66 includes a circuit 100 shown in FIG. 65 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0395] 65 and 66 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0396] In addition, the circuit 100 shown in FIG. 67A is the same as the circuit 100 shown in FIG. 8, 9, 21, 22, etc., this corresponds to a configuration in which a capacitive element 105 is added.

[0397] In addition, the circuit 100 shown in FIG. 67B is the same as the circuit 100 shown in FIG. 8, 9, 21, 22, etc., this corresponds to a configuration in which a capacitive element 105 is added.

[0398] In addition, the circuit 100 shown in FIG. 67C is the same as the circuit 100 shown in FIG. 8, 9, 21, 22, etc., this corresponds to a configuration in which a capacitive element 105 is added.

[0399] 68 includes a circuit 100 shown in FIG. 67 and a constant voltage supply 21. A circuit 220 having a function of supplying a voltage or a signal, and a function of supplying a constant voltage or a signal to the wiring 23 a circuit 222 having a function of supplying a constant voltage or signal to the wiring 24; A circuit 224 having a function of supplying a constant voltage or signal to the line 25, and a circuit 225 having a function of supplying a constant voltage or signal to the wiring 26 Each of the circuits 225 has a function of supplying the following.

[0400] 67 and 68 show the configuration of the circuit 100 in the case where the light emitting element 104a is used. However, the semiconductor device according to one embodiment of the present invention includes a circuit 100 shown in FIG. In the configuration, the light emitting element 104a is not included, or the load 104 is included instead of the light emitting element 104a. Alternatively, it may have a configuration including the light emitting element 104b.

[0401] In the circuit 100 shown in FIG. 32, as in the previous drawings, the switch 14 In addition, a switch 914, a capacitor 105, etc. can be added. In the circuit 100, various wires can be connected to other various wires to reduce the number of wires. For example, the circuit 100 shown in FIG. Similar to 1, a switch 14 is added to the circuit 100 shown in FIG. 32(A) to FIG. 32(D). These correspond to the above configurations, respectively.

[0402] In addition, a semiconductor device according to one embodiment of the present invention includes the circuits shown in FIGS. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 may be provided. It may also have.

[0403] The semiconductor device shown in FIG. 70(A) to FIG. 70(D) is In addition to the circuit 100, a circuit 220 having a function of supplying a constant voltage or signal to the wiring 21 is provided. A circuit 221 having a function of supplying a constant voltage or signal to the wiring 22 and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 23a A circuit 222a having a function of supplying a constant voltage or a signal to a wiring 23b. and a circuit 222b having a function of supplying a constant voltage or signal to the wiring 24. 223 and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25. Yes.

[0404] 70A to 70D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 20, the circuit 221, the circuit 222a, the circuit 222b, the circuit 223, and the circuit 224. However, a semiconductor device according to one embodiment of the present invention does not necessarily have to include a circuit 10. In addition to 0, the circuit 220, the circuit 221, the circuit 222a, the circuit 222b, the circuit 223, and It is not necessary to include all of the circuits 224, but only one or more of them may be included. stomach.

[0405] The circuit 100 shown in FIG. 73A is similar to the circuit 100 shown in FIG. 32C, except that a switch 9 is added. The switch 914 corresponds to a configuration in which the source of the transistor 101 is added. One of the source or drain, the other electrode of the capacitor 103, and the anode of the light-emitting element 104a The diode has a function of controlling the conduction state between the diodes.

[0406] The circuit 100 shown in FIG. 73B is a circuit 100 shown in FIG. 69C, which is provided with a switch. The switch 914 corresponds to a configuration in which the solenoid 914 of the transistor 101 is added. One of the source or drain, the other electrode of the capacitor 103, and the anode of the light-emitting element 104a The switch has a function of controlling the electrical continuity between the switch and the power supply.

[0407] In addition, a semiconductor device according to one embodiment of the present invention includes the circuit shown in FIG. In addition to the circuit 100, a circuit having a function of supplying various constant voltages and signals to the circuit 100 is further provided. It may also have.

[0408] The semiconductor device shown in FIG. 73(C) and FIG. 73(D) is In addition to the circuit 100, a circuit 220 having a function of supplying a constant voltage or signal to the wiring 21 is provided. A circuit 221 having a function of supplying a constant voltage or signal to the wiring 22 and a circuit 222 having a function of supplying a constant voltage or signal to the wiring 23a A circuit 222a having a function of supplying a constant voltage or a signal to a wiring 23b. and a circuit 222b having a function of supplying a constant voltage or signal to the wiring 24. 223 and a circuit 224 having a function of supplying a constant voltage or signal to the wiring 25. Yes.

[0409] 73C and 73D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 20, the circuit 221, the circuit 222a, the circuit 222b, the circuit 223, and the circuit 224. However, a semiconductor device according to one embodiment of the present invention does not necessarily have to include a circuit 10. In addition to 0, the circuit 220, the circuit 221, the circuit 222a, the circuit 222b, the circuit 223, and It is not necessary to include all of the circuits 224, but only one or more of them may be included. stomach.

[0410] In the circuit 100 shown in FIG. 34, as in the figures described above, the switch 14 In addition, a switch 914, a capacitor 105, etc. can be added. In the circuit 100, various wires can be connected to other various wires to reduce the number of wires. For example, in FIG. 71(A) to FIG. 71(D), 4(D) show examples of the layout of the circuit 100.

[0411] The operation of a semiconductor device according to one embodiment of the present invention will be described with reference to the circuit 100 in FIG. An example will be described.

[0412] The operation of the circuit 100 shown in FIG. 71C is mainly divided into a first operation, a second operation, a third operation, and a fourth operation. It can be divided into 4 operations. However, it is not limited to these, and new operations may be added, or , it is also possible to delete some of the operations.

[0413] First, the first operation performed in the period T11 will be described. As shown in FIG. 2(A), the switches 11, 13, and 14 are in a non-conducting state. The switch 12 is in a conductive state. In addition, the potential Vi1 is supplied to the wiring 23. Therefore, In the period T11, the anode of the light-emitting element 104a is at a potential Vi1, and the transistor 101 The gate-source voltage (Vgs101) of this transistor is the voltage Vi2-Vi1.

[0414] In addition, FIG. 72(A) shows an example in which the switch 11 is in a non-conducting state. Switch 11 may be in a conducting state. Also, in FIG. 72(A), switch 14 is in a non-conducting state. Although the on state is shown as an example, the switch 14 may be in a conductive state. In this case, the potential Vi3 is supplied to the wiring 25. The node is at potential Vi3, and the gate-source voltage of transistor 101 (Vgs101) becomes a voltage Vi2-Vi3. In addition, the switch 13 may be in a conductive state.

[0415] The second operation performed in the period T12 will be described. In the period T12, As shown in FIG. 1, the switches 11 and 14 are in a non-conducting state, the switches 12 and The line 23 is supplied with a potential VDD or a potential higher than the potential Vi1. When the potential VDD is supplied to the wiring 23, the potential stored in the capacitor 102 is The charge stored in the capacitor is released, and finally the threshold voltage Vth of the transistor 101 becomes equal to the capacitance of the capacitor. Therefore, in the period T12, the threshold voltage Vth is held in the capacitance element 102. The anode of the light-emitting element 104a is held at a potential Vi2-Vth, and the transistor 101 The gate-source voltage (Vgs101) is equal to the threshold voltage Vth.

[0416] The third operation performed in the period T13 will be described. In the period T13, As shown in FIG. 1, the switches 11 and 14 are in a conducting state, the switches 12 and The wiring 21 is supplied with a potential Vsig, and the wiring 23 is supplied with a potential Vsig. A potential VDD is supplied to the line 25, and a potential Vi3 is supplied to the line 25. Therefore, during the period T13, The capacitive element 102 holds a threshold voltage Vth, and the capacitive element 103 holds a voltage Vsig-Vi3. The anode of the light emitting element 104a is held at a potential Vi3, and the gate of the transistor 101 is The potential of the gate of the transistor 101 becomes the potential Vsig+Vth, and the gate-source voltage of the transistor 101 (V gs101) is at a voltage Vsig+Vth-Vi3. Also, the switch 14 is in a non-conducting state. may be also possible.

[0417] The fourth operation performed in the period T14 will be described. As shown in FIG. 1, the switches 11, 12, 13, and 14 are non-conductive. In addition, the potential VDD is supplied to the wiring 23. Therefore, in the period T14, The capacitive element 102 holds a threshold voltage Vth, and the capacitive element 103 holds a voltage Vsig-Vi3. The anode of the light emitting element 104a is held at a potential Vel, and the gate of the transistor 101 is The potential of the gate of the transistor 101 becomes Vsig+Vth-Vi3+Vel. The source voltage (Vgs101) is equal to the voltage Vsig+Vth-Vi3.

[0418] The potential Vel is set when a current is applied to the light-emitting element 104a via the transistor 101. Specifically, it is set to a potential between the potential VDD and the potential Vcat. This will be the case.

[0419] In the fourth operation, the gate-source voltage (Vgs101) of the transistor 101 is set to The voltage Vsig+Vth-Vi3 is set to a value taking into account the threshold voltage Vth of the transistor 101. Therefore, with the above configuration, the threshold voltage Vth of the transistor 101 can be set. This can prevent the variation in the current value supplied to the light emitting element 104a from being influenced by the variation in the current value. Alternatively, the above change does not occur even if the transistor 101 deteriorates and the threshold voltage Vth changes. This prevents the current value supplied to the optical element 104a from being affected. This reduces glare and provides a high-quality display.

[0420] In the semiconductor device according to one embodiment of the present invention, in the second operation, The gate of the transistor 101 is kept at a potential Vi2. Even if the threshold voltage Vth has a negative value, the transistor 101 In this case, the potential of the source is stored in the capacitance element 102 until it becomes higher than the potential Vi2 of the gate. Therefore, in the semiconductor device according to one embodiment of the present invention, Even if the transistor 101 is normally on, in the fourth operation, The gate-source of the transistor 101 is set to a value that takes into account the threshold voltage Vth of the transistor 101. The voltage (Vgs101) can be set.

[0421] In this embodiment, a certain wiring is connected to various other wirings, for example, wiring 21, wiring 22, wiring 23, etc. , wiring 24, wiring 25, wiring 26, wiring 27, or wiring of another circuit 100, a scanning line, This shows the case where the gate line is connected to the wiring connected to the gate of the transistor. This can reduce the number of wirings. Switches and other elements, such as switch 914, switch 814, switch 14, and capacitive element 10 5 and the like are added. In other words, this embodiment is a part of the other embodiments. or the whole of the same, change, add, modify, delete, adapt, supersede or subscrib Therefore, a part or the whole of this embodiment corresponds to another embodiment. The present invention may be freely combined, adapted, or substituted with any or all of the above. can.

[0422] (Embodiment 4) 74 to 76 show examples of layouts of various wirings in a semiconductor device according to one embodiment of the present invention. vinegar.

[0423] In FIG. 74A, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 23. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row share one wiring 21 and one wiring 23.

[0424] In FIG. 74B, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i+1-th column and the j-th row are shared. 00(i+1, j) share one wiring 23. 0(i, j+1) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row They share 23.

[0425] In FIG. 74C, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i+1-th column and the j-th row are shared. 00(i+1, j) share one wiring 23. 0(i, j+1) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row 23. In addition, the circuit 100(i, j) in the i-th column and the j+1-th row The circuit 100(i, j+1) shares one wiring 23. 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are They share the wiring 23. And these wirings 23 are connected to each other.

[0426] In FIG. 74(D), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares one wiring 23. is arranged alongside the wiring 21.

[0427] In FIG. 74(E), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares one wiring 23. are arranged so as to intersect with the wiring 21.

[0428] In FIG. 74(F), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares two wirings 23. The two wirings 23 are arranged to cross each other and are connected to each other.

[0429] In FIG. 75A, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21, one wiring 22, and one wiring 23. In addition, the circuit 100(i+1, j) in the i+1th column and the jth row and the circuit 100( i+1, j+1) share one wiring 21, one wiring 22, and one wiring 23.

[0430] In FIG. 75B, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 22. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row The circuit 100 (i , j) and the circuit 100(i+1, j) in the (i+1)th column and the jth row share one wiring 23. In addition, the circuit 100(i, j+1) in the i-th column and the j+1-th row of the circuit 10 0 (i+1, j+1) share one wiring 23.

[0431] In FIG. 75C, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 23. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row In addition, the circuit 100 (i , j) and the circuit 100(i+1, j) in the (i+1)th column and the jth row share one wiring 22. In addition, the circuit 100(i, j+1) in the i-th column and the j+1-th row of the circuit 10 0 (i+1, j+1) share one wiring 22.

[0432] In FIG. 75(D), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i+1-th column and the j-th row are shared. 00(i+1, j) share one wiring 22 and one wiring 23. The circuit 100(i, j+1) in the first row and the circuit 100(i+1, j+1) in the i+1 column and the j+1 row 1) share one wiring 22 and one wiring 23.

[0433] In FIG. 75(E), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 23. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row In addition, the circuit 100 (i , j) and the circuit 100(i+1, j) in the (i+1)th column and the jth row are connected to one wiring 22 and one wiring 2 3. Also, the circuit 100(i, j+1) in the i-th column and the circuit 100(j+1) in the j+1-th row The circuit 100 (i+1, j+1) in the first row shares one wiring 22 and one wiring 23. These wirings 23 are connected to each other.

[0434] In FIG. 76A, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 22. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row The circuit 100 (i , j), circuit 100(i, j+1) in the i-th column and j-th row, circuit 100(i +1, j), and the circuit 100(i+1, j+1) in the (i+1)th column and the (j+1)th row are connected to one wiring 23 The wiring 23 is arranged in parallel with the wiring 21 and the wiring 22.

[0435] In FIG. 76B, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 23. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row In addition, the circuit 100 (i , j), circuit 100(i, j+1) in the i-th column and j-th row, circuit 100(i +1, j), and the circuit 100(i+1, j+1) in the (i+1)th column and the (j+1)th row are connected to one wiring 22 The wiring 22 is arranged in parallel with the wiring 21 and the wiring 23.

[0436] In FIG. 76C, a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares one wiring 22 and one wiring 23 . The wiring 22 and the wiring 23 are arranged side by side with the wiring 21.

[0437] In FIG. 76(D), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares one wiring 22 and one wiring 23 . The wiring 22 and the wiring 23 are arranged so as to intersect with the wiring 21.

[0438] In FIG. 76(E), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21. Also, the circuit 100 ( i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 21 In addition, the circuit 100(i, j) in the i-th column and the j-th row, and the circuit 10 0(i, j+1), the circuit 100(i+1, j) in the i+1th column and the jth row, and The second circuit 100 (i+1, j+1) shares one wiring 22 and one wiring 23 . The wiring 22 is disposed so as to intersect with the wiring 21. The wiring 23 is disposed so as to intersect with the wiring 21. It is arranged in line with line 21.

[0439] In FIG. 76(F), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100 in the i-th column and the j+1-th row are 0(i, j+1) share one wiring 21. (i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and j+1th row are connected to one wiring 2 1. Also, the circuit 100(i, j) in the i-th column and j-th row and the circuit 1 00(i, j+1), circuit 100(i+1, j) in the jth row of the i+1th column, and The circuit 100 (i+1, j+1) in the 1st row shares one wiring 22 and one wiring 23. The wiring 23 is arranged so as to intersect with the wiring 21. The wiring 22 is It is arranged alongside the wiring 21.

[0440] In FIG. 76(G), a circuit 100(i, j) in the i-th column and the j-th row and a circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) shares one wiring 21 and one wiring 22. The th circuit 100(i+1, j) and the circuit 100(i+1, j+1) in the i+1th column and the j+1th row The circuit 100 (i , j), circuit 100(i, j+1) in the i-th column and j-th row, circuit 100(i +1, j), and the circuit 100(i+1, j+1) in the (i+1)th column and the (j+1)th row are connected to the two wirings 2 The two wirings 23 are arranged to cross each other. It is connected to

[0441] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0442] (Embodiment 5) FIG. 77 shows an example of a top view of the circuit 100 shown in FIG.

[0443] In FIG. 77, the semiconductor film 300 is an active layer of the transistor 11t, a part of the capacitance element 102, one electrode of the capacitor 103, the active layer of the transistor 13t, The active layer of the transistor 4t functions as the active layer of the transistor 101. The conductive film 302 functions as the active layer of the transistor 12t. The conductive film 303 functions as the other electrode of the capacitor 103. 304 functions as the gate of transistor 13t.

[0444] The conductive film 305 is connected to the wiring 22 and one of the source and drain of the transistor 12t. The conductive film 306 is connected to the other of the source and the drain of the transistor 12t. The conductive film 307 is connected to the conductive film 304 and the wiring 33. The conductive film 308 is a conductive film that is connected to the conductive film 303 and the source or drain of the transistor 101. one of the inputs of the transistor 13t, one of the source or drain of the transistor 14t, The conductive film 309 is connected to either the source or the drain of the transistor 1 The other of the source or drain of 4t is connected to a wiring 25.

[0445] In the case of FIG. 13B, a load 104 may be provided so as to be connected to the conductive film 308. In the case of FIG. 13C, the light-emitting element 104a is connected to the conductive film 308. In the case of FIG. 13(D), the emitter is connected to the conductive film 308. It is only necessary to provide a cathode for the optical element 104b.

[0446] Next, a top view of the circuit 100 shown in FIG. 13(A) is shown in FIG. 78 as an example.

[0447] In FIG. 78, the semiconductor film 320 functions as an active layer of the transistor 11t. The semiconductor film 321 functions as an active layer of the transistor 12t. The semiconductor film 323 functions as an active layer of the transistor 13t. The semiconductor film 333 functions as an active layer of the transistor 101.

[0448] The conductive film 324 serves as the other electrode of the capacitor 102 and the gate of the transistor 101. The conductive film 325 functions as the other electrode of the capacitor 103. functions as the gate of transistor 13t.

[0449] The conductive film 327 serves as one electrode of the capacitor 102 and one electrode of the capacitor 103. The conductive film 3 is connected to either the source or the drain of the transistor 11t. 28 is connected to the wiring 22 and one of the source and drain of the transistor 12t. The conductive film 329 is connected to the other of the source and drain of the transistor 12t and the conductive film 3 24. The conductive film 330 is connected to the conductive film 326 and the wiring 33. The conductive film 331 is a conductive film that is connected to the conductive film 325 and one of the source and drain of the transistor 101. One of the source or drain of the transistor 13t and the source of the transistor 14t The conductive film 332 is connected to either the source or drain of the transistor 14t. The other of the source or drain is connected to a wiring 25 .

[0450] In the case of FIG. 13B, a load 104 may be provided so as to be connected to the conductive film 331. 13C, the light-emitting element 104a is connected to the conductive film 331. In the case of FIG. 13(D), a light emitting element is provided so as to be connected to the conductive film 331. It is only necessary to provide a cathode for the optical element 104b.

[0451] FIG. 80(A) shows an example of a cross-sectional view taken along the dashed line A1-A2 in FIG. An example of a cross-sectional view taken along the dashed line B1-B2 is shown in FIG. An insulating film 801 is formed on the insulating film 801. The wiring 31, the conductive film 324, and the conductive A conductive film 325 is formed on the wiring 31, the conductive film 324, and the conductive film 325. An insulating film 802 is formed.

[0452] A conductive film 327 is formed over the insulating film 802 so as to overlap with the conductive film 325 . The portion where the conductive film 325, the insulating film 802, and the conductive film 327 overlap is the capacitor 103. A conductive film 327 is formed over the insulating film 802 in a position overlapping with the conductive film 324. The overlapping portion of the conductive film 324, the insulating film 802, and the conductive film 327 forms a capacitive element. The semiconductor layer 102 is disposed on the insulating film 802 at a position overlapping with the conductive film 324. A film 333 is formed on the semiconductor film 333. The wiring 23 and the conductive film 331 are formed on the semiconductor film 333. is.

[0453] Then, the insulating film 802, the conductive film 327, the semiconductor film 333, the wiring 23, An insulating film 803 is formed to cover the conductive film 331 .

[0454] Next, a top view of the circuit 100 shown in FIG. 13(A) is shown in FIG. 79 as an example. The shape of the portion of the wiring 23 that overlaps with the semiconductor film 333 and the shape of the conductive film 331 that overlaps with the semiconductor film 333 are different. The shape of the part overlapping with the body membrane 333 is different from that shown in the top view of FIG. In FIG. 8, the portion of the wiring 23 that overlaps with the semiconductor film 333 has a U-shape. The portion of the conductive film 331 that overlaps with the semiconductor film 333 is partially surrounded by the wiring 23. In this way, the conductive film 331 is located on the inside of the U-shaped curved portion of the wiring 23. The portion overlapping the semiconductor film 333 has a U-shape. The conductive film 331 is arranged so that the portion overlapping the conductive film 333 is partially surrounded by the conductive film 331. It is located on the inside of the U-shaped curve.

[0455] The conductive film or wiring in contact with the source or drain of the transistor 101 has a U-shape. In this case, even if the area of ​​the semiconductor film 333 is small, a large channel width can be ensured. Therefore, the on-current can be increased while keeping the area of ​​the semiconductor film 333 small.

[0456] Note that transistors can be formed using various substrates. An example of the substrate is a semiconductor substrate (e.g., a single crystal substrate). plate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate, metal substrate Plate, stainless steel substrate, substrate with stainless steel foil, tungsten Substrates, substrates with tungsten foil, flexible substrates, laminated films, fibrous Examples of glass substrates include barium borate. Examples include silicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of the substrate include polyethylene terephthalate (PET) and polyethylene naphthalate. Plastics such as polyethersulfone (PEN) and polyethersulfone (PES), or acrylics Examples of lamination films include synthetic resins with flexibility such as polystyrene. Examples include propylene, polyester, vinyl, polyvinyl fluoride, and vinyl chloride. Examples of the material film include polyester, polyamide, polyimide, and inorganic vapor deposition film. In particular, semiconductor substrates, single crystal substrates, SOI substrates, etc. are used By manufacturing transistors, there is little variation in characteristics, size, or shape, It is possible to manufacture transistors with high current capability and small size. By configuring a circuit using transistors, it is possible to reduce the power consumption of the circuit or to increase the circuit integration density. This can be done.

[0457] Note that a transistor is formed using a certain substrate and then transferred to another substrate. However, the transistor may be disposed on another substrate. In addition to the substrate on which the above-mentioned transistors can be formed, the substrates include paper substrates, cellophane substrates, and the like. substrates made of natural fibers (silk, cotton, hemp), synthetic fibers (nylon, Polyurethane, polyester) or regenerated fiber (acetate, cupra, rayon, regenerated The substrates used are made of synthetic polyester, leather, or rubber. This allows the formation of transistors with good characteristics and low power consumption. It is possible to manufacture devices that are less likely to break, heat resistant, lightweight, or thin.

[0458] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0459] (Embodiment 6) In this embodiment, a transistor used in a semiconductor device according to one embodiment of the present invention will be described. An example of a specific configuration will be described.

[0460] The transistor shown in FIG. 81(A) includes a semiconductor film 501 and an insulating film 50 on the semiconductor film 501. 2, and a gate electrode 503 provided at a position overlapping the semiconductor film 501 with an insulating film 502 interposed therebetween. The semiconductor film 501 includes an electrode 503 that functions as a semiconductor film, and a conductive film 504 and a conductive film 505 that are in contact with the semiconductor film 501. The semiconductor film 501 is divided into a first region 506 which functions as a channel formation region and a second region 507 which functions as a channel formation region. , a second region 507 functioning as a source or drain and a second region 508. The second region 507 and the second region 508 sandwich the first region 506 therebetween. In FIG. 81A, the semiconductor film 501 is divided into a first region 506, a second region 507, and A third region 509 and a third region 508 functioning as an LDD region are disposed between the first region 508 and the second region 509. 10 is shown as an example.

[0461] In FIG. 81A, a transistor having a thin semiconductor film 501 is shown as an example. However, in one embodiment of the present invention, a transistor having a channel formation region in a bulk semiconductor substrate is The thin semiconductor film may be, for example, an amorphous semiconductor or a polycrystalline semiconductor. A conductor, a single crystal semiconductor, or the like can be used. Various semiconductors such as ruthenium, silicon germanium, and oxide semiconductors can be used. Cut.

[0462] The transistor shown in FIG. 81B includes a first oxide insulating film 520a and a second oxide insulating film 52 0b, and the insulating film 520 having the third oxide insulating film 520c.

[0463] The first oxide insulating film 520a and the third oxide insulating film 520c are partially deoxygenated by heating. The oxide insulating film is formed from a material that releases oxygen when heated. It is preferable to use an insulating film containing more oxygen than the oxygen that satisfies the stoichiometric composition. The first oxide insulating film 520a and the third oxide insulating film 520c are made of silicon oxide, Silicon nitride, silicon oxide nitride, gallium oxide, hafnium oxide, yttrium oxide, etc. can be used.

[0464] The second oxide insulating film 520b is formed of an oxide insulating film that prevents oxygen diffusion. Examples of the film 520b include aluminum oxide and aluminum oxynitride. Aluminum oxide is aluminum oxide that contains oxygen and has a stoichiometric composition, or Aluminum oxide (AlO) contains more oxygen than satisfies the stoichiometric composition. x , x is 3 / 2 or more). In addition, the aluminum oxynitride satisfies the stoichiometric composition. In aluminum oxide containing oxygen, some of the oxygen is replaced by nitrogen.

[0465] The transistor is formed by a semiconductor film 521, an insulating film 522 on the semiconductor film 521, and an insulating A gate electrode 522 is provided at a position overlapping with the semiconductor film 521 with the film 522 interposed therebetween. The semiconductor film 521 includes an electrode 523, and a conductive film 524 and a conductive film 525 which are in contact with the semiconductor film 521. The membrane 521 overlaps with the electrode 523, and at least a part of the membrane 521 functions as a channel forming region. A first region 526 and a second region that functions as a source or drain and sandwiches the first region 526. The first region 550 and the second region 551 .

[0466] The semiconductor film 521 is made of, for example, an amorphous semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or the like. The semiconductor film 521 may include silicon, germanium, silicon germanium, etc. Various semiconductors such as aluminum and oxide semiconductors can be used.

[0467] The transistor has a sidewall 527 having an insulating film provided on the side of the electrode 523. An insulating film 528 is provided on the upper portion of the electrode 523. The conductive film 524 and the conductive film 525 are partially in contact with the sidewall 527. The conductive film 525 does not necessarily have to be in contact with the sidewall 527. The conductive films 524 and 525 are formed so as to be in contact with the conductive film 527. Even if the positions of the conductive film 524 and the conductive film 525 are slightly misaligned, the conductive film 524 and the conductive film 525 Therefore, the contact area between the conductive film 5 and the semiconductor film 521 can be prevented from changing. Preventing a change in the on-current of a transistor due to misalignment of the conductive film 525 and the conductive film 24. It is possible.

[0468] The insulating film 528 located on the upper portion of the electrode 523 is not necessarily provided, but the insulating film By providing the conductive film 528, the conductive film 524 and the conductive film 525 are formed in a misaligned position. 23, the conductive film 524 and the conductive film 525 are prevented from being electrically connected to the electrode 523. It is possible to do so.

[0469] In the insulating film 520, the first oxide insulating film 5 is formed on the third oxide insulating film 520c located in the lower layer. A first oxide insulating film 20a and a second oxide insulating film 520b are laminated in this order. An opening 529 is provided in the first oxide insulating film 520a and the second oxide insulating film 520b. In the opening 529, a semiconductor film 521 included in the transistor is provided. The first oxide insulating film 520a is formed on the semiconductor film 521 so as to be in contact with an end portion of the semiconductor film 521. The second oxide insulating film 520b is provided around the first oxide insulating film 521. The third oxide insulating film 520 is provided around the semiconductor film 521 with the third oxide insulating film 520a sandwiched therebetween. The portion c is provided under the semiconductor film 521 .

[0470] When the semiconductor film 521 is an oxide semiconductor, the insulating film 520 having the above structure can be used. As a result, oxygen released from the first oxide insulating film 520a by heating is transferred to the second oxide insulating film 520b. Since the oxygen can be prevented from passing through 520b, the oxygen can be prevented from passing through the first region 526. The semiconductor film 521 is efficiently supplied to the end portion of the semiconductor film 521. The released oxygen is supplied to the lower part of the semiconductor film 521. The transistors in the formation region are formed by etching the semiconductor film 521 into a desired shape. The semiconductor film 521 is then subjected to an etching process, and the end of the semiconductor film 521 is exposed to a reduced pressure atmosphere. Oxygen vacancies are easily formed at the ends of the 1 due to oxygen elimination. If oxygen vacancies are formed at the end of the semiconductor film 521, parasitic chokes will form. However, with the above-mentioned configuration, 5. The formation of oxygen vacancies at the end of the semiconductor film 521 in the region 526 of the off-state current The flow can be reduced.

[0471] In addition, "a portion of oxygen is released by heating" refers to TDS (Thermal Desor Thermal desorption spectroscopy (TDA) analysis was performed to convert the The calculated oxygen release rate is 1.0 x 10 18atoms / cm 3 More than 3.0x, preferably 10 20 atoms / cm 3 This means that the above is the case.

[0472] Below, we will explain how to measure the amount of desorbed oxygen in terms of oxygen atoms using TDS analysis. .

[0473] The amount of gas desorbed during TDS analysis is proportional to the integral value of the spectrum. The amount of gas released is calculated based on the ratio of the integral value of the film spectrum to the reference value of the standard sample. The reference value of the standard sample is the integral of the spectrum of the sample containing a specific atom. is the ratio of the atomic density to the value.

[0474] For example, the results of a TDS analysis of a silicon wafer containing a specific density of hydrogen as a standard sample, From the results of TDS analysis of the insulating film, the amount of desorbed oxygen molecules (N O2 ) is calculated using the following formula 1. There is an example of a compound with a mass number of 32, CH3OH, which may exist in insulating films. Therefore, all of the spectra detected at mass number 32 obtained by TDS analysis are We assume that it is derived from an oxygen molecule. In addition, the mass number of the oxygen atom, which is an isotope of the oxygen atom, is 17. The oxygen molecule, which contains an oxygen atom with mass number 18, also exists in extremely small amounts in nature. Therefore, we assume that it does not exist.

[0475] N O2 =N H2 / S H2 ×S O2 ×α (Formula 1)

[0476] N H2 is the density of hydrogen molecules desorbed from the standard sample. H2 is a standard test The standard value of the standard sample is N H2 / S H2 Let us assume that S O2 is the integral value of the spectrum obtained by TDS analysis of the insulating film. α is is a coefficient that affects the spectral intensity in TDS analysis. For details of Equation 1, see The amount of oxygen desorbed from the insulating film is measured by the method described in Electron Science and Technology Corporation. A thermal desorption analyzer EMD-WA1000S / W manufactured by Epson Corporation was used, and a 1×1 0 16 atoms / cm 2 The measurement is performed using a silicon wafer containing hydrogen atoms.

[0477] In addition, some oxygen is detected as oxygen atoms in TDS analysis. The ratio of the oxygen molecules can be calculated from the ionization rate of the oxygen molecules. Since the ionization rate of oxygen molecules is included in the calculation, the amount of oxygen atoms released can be evaluated. It is possible to estimate even if

[0478] In addition, N O2 is the amount of oxygen molecules released. In the case of an insulating film, when converted to oxygen atoms, The amount of released oxygen is twice the amount of desorbed oxygen molecules.

[0479] In the above-mentioned structure, the insulating film from which oxygen is released by heating is silicon oxide (S iO X (X>2)) or silicon oxide (SiO X (X>2) It contains more than twice as many oxygen atoms as silicon atoms per unit volume. The number of silicon atoms and oxygen atoms per volume were measured by Rutherford backscattering spectrometry. value.

[0480] The transistor shown in FIG. 81C has a first oxide insulating film 530a and a second oxide insulating film 5 It is provided on an insulating film 530 having a thickness of 30b.

[0481] The first oxide insulating film 530a is formed using an oxide insulating film from which oxygen is partially released by heating. The oxide insulating film from which oxygen is partially released by heating is an oxide having a stoichiometric composition. It is preferable to use an insulating film containing more oxygen than silicon. Silicon oxide, silicon oxynitride, silicon nitride oxide, gallium oxide, hafnium oxide Examples of materials that can be used include tungsten oxide, yttrium oxide, and the like.

[0482] The second oxide insulating film 530b is formed of an oxide insulating film that prevents oxygen diffusion. Examples of the film 530b include aluminum oxide and aluminum oxynitride. Aluminum oxide is aluminum oxide that contains oxygen and has a stoichiometric composition, or Aluminum oxide (AlO) contains more oxygen than satisfies the stoichiometric composition. x , x is 3 / 2 or more). In addition, the aluminum oxynitride satisfies the stoichiometric composition. In aluminum oxide containing oxygen, some of the oxygen is replaced by nitrogen.

[0483] The transistor is formed by a semiconductor film 531 located on an insulating film 530 and an insulating film 531 on the semiconductor film 531. A gate insulating film 532 is provided at a position overlapping with the semiconductor film 531 with the insulating film 532 interposed therebetween. The electrode 533 functions as a gate, and the conductive film 534 and the conductive film 535 are connected to the semiconductor film 531. The semiconductor film 531 overlaps with the electrode 533, and at least a part of the semiconductor film 531 has a channel shape. A first region 536 functions as a deposition region, and a first It has a second region 537 and a second region 538 sandwiching the region 536 .

[0484] The semiconductor film 531 is made of, for example, an amorphous semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or the like. The semiconductor film 531 may include silicon, germanium, silicon germanium, etc. Various semiconductors such as aluminum and oxide semiconductors can be used.

[0485] In the transistor, a sidewall 539 having an insulating film is provided on the side of the electrode 533. An insulating film 540 is provided on the upper portion of the electrode 533. The conductive film 534 and the conductive film 535 are partially in contact with the sidewall 539. 4 and the conductive film 535 do not necessarily have to be in contact with the sidewall 539. The conductive film 534 and the conductive film 535 are formed so as to be in contact with the wall 539. Even if the positions of the conductive film 534 and the conductive film 535 are slightly misaligned, the conductive film 534 and the conductive It is possible to prevent the contact area between the film 535 and the semiconductor film 531 from changing. The on-state current of the transistor is changed due to the positional deviation of the conductive film 534 and the conductive film 535. movement can be prevented.

[0486] The insulating film 540 located on the upper portion of the electrode 533 is not necessarily provided. By providing the conductive film 540, the conductive film 534 and the conductive film 535 are formed in misaligned positions. Even if the conductive film 534 and the conductive film 535 are exposed to the upper portion of the electrode 533, the conductive film 534 and the conductive film 535 are prevented from being electrically connected to the electrode 533. It is possible to do so.

[0487] The insulating film 530 is formed by forming a second insulating oxide film 530b around the first insulating oxide film 530a. The semiconductor film 531 is provided with the first oxide in the first region 536. The first oxide insulating film 530a is in contact with the second region 537 and the second region 538. It contacts the insulating film 530a and the second oxide insulating film 530b.

[0488] In the case where the semiconductor film 531 is an oxide semiconductor, the first oxide film is heated. The oxygen released from the second oxide insulating film 530a is prevented from passing through the second oxide insulating film 530b. Therefore, the oxygen is effectively absorbed in the edge of the semiconductor film 531 in the first region 536. Note that a transistor having an oxide semiconductor in a channel formation region is Etching process for etching the conductive film 531 into a desired shape, The edge of the semiconductor film 531 is exposed to a reduced pressure atmosphere, and oxygen is released from the edge of the semiconductor film 531. Oxygen vacancies are easily formed. And since oxygen vacancies act as paths for carriers to move, When oxygen vacancies form at the edge of film 531, a parasitic channel is created, which causes the transistor However, in one embodiment of the present invention, the above-described structure increases the off-state current of the first region 53. Prevents oxygen vacancies from being formed at the edge of the semiconductor film 531 in 6, and reduces the off-current. It is possible.

[0489] In addition, impurities such as moisture and hydrogen, which act as electron donors, are reduced, and the acid The reduced electron vacancies result in a highly purified oxide semiconductor. A de semiconductor is an i-type (intrinsic semiconductor) or is very close to an i-type. Therefore, the transistor including the oxide semiconductor has a characteristic of having an extremely low off-state current. The band gap of the oxide semiconductor is 2 eV or more, preferably 2.5 eV or more. More preferably, the concentration of impurities such as moisture or hydrogen is sufficiently reduced. In addition, an oxide semiconductor film that has been highly purified by reducing oxygen vacancies is used. This allows the off-state current of the transistor to be reduced.

[0490] Specifically, a transistor in which a highly purified oxide semiconductor film is used for a channel formation region can be The low f-current can be verified by various experiments. For example, 6 Even if the device has a channel length of 10 μm, the voltage between the source and drain electrodes ( In the drain voltage range of 1V to 10V, the off-state current is Below the measurement limit of Isa, i.e. 1×10 -13 A characteristic of less than A can be obtained. In this case, the off-state current normalized by the channel width of the transistor is 100 zA / μm or less. In addition, by connecting the capacitance element and the transistor, The off-state current is measured using a circuit that controls the charge flowing out of the capacitance element with the transistor. In the measurement, a highly purified oxide semiconductor film was used as a channel type transistor. The off-state voltage of the transistor is calculated from the change in the charge amount per unit time of the capacitance element. The current was measured when the voltage between the source and drain electrodes of the transistor was 3 V. It was found that an even lower off-current of several tens of yA / μm can be obtained when A transistor in which a highly purified oxide semiconductor film is used for a channel formation region has a low off-state current. , which is significantly lower than that of a transistor using crystalline silicon.

[0491] As the oxide semiconductor, it is preferable to use an oxide containing In or Zn. More preferably, an oxide containing In and Ga or an oxide containing In and Zn is used. In order to make the oxide semiconductor film i-type (intrinsic), a dehydration process described later is used. In addition, dehydrogenation is effective. In addition, gallium (Ga) is included as a stabilizer to reduce the fluctuation. It is preferable that the stabilizer contains tin (Sn). It is preferable that the stabilizer contains hafnium (Hf). It is preferable that the material contains aluminum (Al) as a stabilizer. It is preferable that it contains Zr.

[0492] Other stabilizers include the lanthanides lanthanum (La) and cerium ( Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), hol Ho, Erbium, Thulium, Ytterbium, Ru It may contain one or more of the elements tetraethium (Lu).

[0493] For example, oxide semiconductors include indium oxide, tin oxide, zinc oxide, and oxides of binary metals. In-Zn oxide, Sn-Zn oxide, Al-Zn oxide, Zn-Mg oxide, Oxides, Sn-Mg oxides, In-Mg oxides, In-Ga oxides, ternary metal oxides In-Ga-Zn oxide (also written as IGZO), In-Al-Zn oxide Oxides, In-Sn-Zn oxides, Sn-Ga-Zn oxides, Al-Ga-Zn oxides oxides, Sn-Al-Zn oxides, In-Hf-Zn oxides, In-La-Zn oxides In-Ce-Zn oxides, In-Pr-Zn oxides, In-Nd-Zn oxides , In-Sm-Zn oxide, In-Eu-Zn oxide, In-Gd-Zn oxide, In-Tb-Zn oxide, In-Dy-Zn oxide, In-Ho-Zn oxide, I n-Er-Zn oxide, In-Tm-Zn oxide, In-Yb-Zn oxide, In -Lu-Zn ​​oxides, In-Sn-Ga-Zn oxides, which are oxides of quaternary metals, I n-Hf-Ga-Zn oxide, In-Al-Ga-Zn oxide, In-Sn-Al- Zn-based oxide, In-Sn-Hf-Zn-based oxide, In-Hf-Al-Zn-based oxide are used. The oxide semiconductor may contain silicon.

[0494] For example, In-Ga-Zn oxide means an oxide containing In, Ga, and Zn. The ratio of In, Ga, and Zn is not important. In addition, metal elements other than In, Ga, and Zn In-Ga-Zn oxides have a sufficiently high resistance when no electric field is present, and therefore, The flow can be made sufficiently small and the mobility is also high.

[0495] The oxide semiconductor film may be in a single crystal, polycrystalline (also called polycrystalline), or amorphous state. The oxide semiconductor film is made of CAAC-OS (C Axis Aligned Crystalline Crystalline). Preferably, the film is a Talline Oxide Semiconductor film.

[0496] The CAAC-OS film is neither completely single crystalline nor completely amorphous. is an oxide semiconductor with a crystalline-amorphous mixed phase structure in which the amorphous phase has crystalline parts of several nm to several tens of nm in size. The membrane is a membrane made of a material that is ... The amorphous and crystalline parts in the CAAC-OS film were observed by a phonon microscope. The boundaries between the grains are not clear. Since the CAAC-OS film does not have grain boundaries, electron transfer due to grain boundaries is not observed. Mobility is less likely to decrease.

[0497] The crystal parts in the CAAC-OS film have c-axes that are normal vectors to the surface on which the CAAC-OS film is formed. The triangle is aligned parallel to the normal vector of the ab plane and perpendicular to the ab plane. The metal atoms are arranged in a layered or hexagonal shape when viewed perpendicular to the c-axis. Metal atoms and oxygen atoms are arranged in layers. The crystal parts are aligned along the a-axis and The orientation of the a-axis may be different. In this specification, when it is simply described as vertical, it means 85 This includes the range of -5° to 95°. This also includes the range of 5° or less.

[0498] The ratio of the amorphous portion to the crystalline portion in the CAAC-OS film does not need to be uniform. For example, when crystals are grown from the surface side of the CAAC-OS film, The proportion of crystalline parts is high near the surface where the film is formed, and the proportion of amorphous parts is high near the surface where the film is formed. In addition, by adding impurities to the CAAC-OS film, In some cases, the crystalline portion may become amorphous in the heat treatment region.

[0499] The c-axis of the crystal part in the CAAC-OS film is the normal vector of the surface on which the CAAC-OS film is formed. The CAAC-OS film shape (the shape of the film on which the film is formed) is The orientation of the c-axis between crystallographic regions differs depending on the cross-sectional shape of the surface or the cross-sectional shape of the plane. The c-axis direction of the crystal part is the same as that of the surface on which the CAAC-OS film is formed. The direction is parallel to the normal vector or the surface normal vector. This is formed by subjecting the film to a crystallization treatment such as a heat treatment.

[0500] By using the CAAC-OS film, the electrical characteristics of the transistors can be improved by irradiating them with visible light or ultraviolet light. Since the variation in properties is reduced, a highly reliable transistor can be obtained.

[0501] The CAAC-OS film can be formed, for example, by sputtering a polycrystalline oxide semiconductor target. The sputtering target is used to form a film by sputtering. Upon impact, the crystalline regions in the sputtering target cleave from the ab plane, forming a -b: The particles peel off as plate-like or pellet-like sputtered particles with surfaces parallel to the surface. In this case, the plate-like sputtered particles may be crystalline and may be crystalline. By reaching the plate, a CAAC-OS film can be formed.

[0502] In addition, the following conditions are preferably applied to form the CAAC-OS film.

[0503] By reducing the amount of impurities mixed in during film formation, it is possible to prevent the crystal state from being destroyed by impurities. For example, the concentration of impurities (hydrogen, water, carbon dioxide, nitrogen, etc.) present in the processing chamber can be In addition, the impurity concentration in the deposition gas may be reduced. A deposition gas having a temperature of -80°C or lower, preferably -100°C or lower, is used.

[0504] In addition, by increasing the substrate heating temperature during film formation, the migration of sputtered particles after they reach the substrate is reduced. Specifically, the substrate heating temperature is set to 100° C. or higher and 740° C. or lower, preferably The deposition temperature is set to 200°C or higher and 500°C or lower. When a plate-shaped sputtered particle reaches a substrate, migration occurs on the substrate, The flat surface of the sputtered particle adheres to the substrate.

[0505] In addition, by increasing the oxygen ratio in the deposition gas and optimizing the power, plasma damage during deposition is reduced. The oxygen ratio in the deposition gas is preferably 30% by volume or more, and more preferably 100% by volume or more. The product is %.

[0506] As an example of a sputtering target, an In-Ga-Zn-O compound target is The details are shown below.

[0507] InO X powder, GaO Y Powder and ZnO Z The powders are mixed in a specified number of moles and then pressurized. By heat treatment at a temperature between 1000 and 1500℃, polycrystalline In-Ga -Zn-O compound target, where X, Y and Z are any positive numbers. , the predetermined molar ratio is, for example, InO X powder, GaO Y Powder and ZnO Z Powder, 2 :2:1, 8:4:3, 3:1:1, 1:1:1, 4:2:3 or 3:1:2. The type of powder and the molar ratio of the powder to be mixed depend on the sputtering target to be prepared. The setting can be changed as appropriate depending on the kit.

[0508] For example, the oxide semiconductor film may be formed using In (indium), Ga (gallium), and Zn ( It can be formed by sputtering using a target containing In-Ga- When the Zn-based oxide semiconductor film is formed by a sputtering method, the atomic ratio is preferably In :Ga:Zn=1:1:1, 4:2:3, 3:1:2, 1:1:2, 2:1:3, or A target of In-Ga-Zn oxide with the atomic ratio of 3:1:4 is used. The oxide semiconductor film is formed by using an In-Ga-Zn oxide target having the above structure. Polycrystal or CAAC-OS is easily formed. The relative density of the target containing the fluorine is 90% or more and 100% or less, preferably 95% or more and less than 100%. By using a target with a high relative density, the oxide semiconductor film formed is finely divided. A dense film forms.

[0509] When an In-Zn oxide material is used as the oxide semiconductor, The atomic ratio of the metal elements is In:Zn=50:1 to 1:2 (converted to a molar ratio of In2 O3:ZnO=25:1 to 1:4), preferably In:Zn=20:1 to 1:1 (molar number In terms of ratio, In2O3:ZnO=10:1 to 1:2), and more preferably In:Zn = 15:1 to 1.5:1 (converted to mole ratio In2O3:ZnO = 15:2 to 3:4 For example, a target used for forming an oxide semiconductor film made of an In-Zn oxide is When the atomic ratio is In:Zn:O=X:Y:Z, Z>1.5X+Y. The ratio of Zn By keeping the ratio within the above range, it is possible to realize an improvement in mobility.

[0510] Specifically, the oxide semiconductor film is formed by holding the substrate in a treatment chamber that is kept in a reduced pressure state. The residual moisture in the treatment chamber is removed while introducing a sputtering gas from which hydrogen and moisture have been removed. During the film formation, the substrate temperature is preferably set to 100° C. or higher and 600° C. or lower. Preferably, the temperature may be 200° C. or higher and 400° C. or lower. In this way, the impurity concentration in the formed oxide semiconductor film can be reduced. Damage caused by tarring is reduced. To remove residual moisture in the processing chamber, an adsorption type It is preferable to use a vacuum pump. For example, a cryopump, an ion pump, a titanium sa It is preferable to use a blimpation pump. Also, as the exhaust means, a turbo pump is used. A cold trap may be added to the vacuum chamber. The processing chamber is evacuated using a cryopump. Then, for example, hydrogen atoms, water (H2O) and other compounds containing hydrogen atoms (preferably carbon Since the exhaust gas contains fluorine atoms, the oxide semiconductor film formed in the treatment chamber is This can reduce the concentration of impurities contained in the material.

[0511] Note that moisture or hydrogen ( Water or hydrogen can form donor levels and Therefore, in one embodiment of the present invention, To reduce impurities such as moisture or hydrogen in semiconductor films (dehydration or dehydrogenation) For the oxide semiconductor film, a reduced pressure atmosphere, an inert gas atmosphere such as nitrogen or a rare gas, or an oxygen atmosphere is used. Under nitrogen gas atmosphere or ultra-dry air (CRDS (cavity ring-down laser spectroscopy) When measured using a dew point meter, the moisture content is 20 ppm (-55°C in dew point equivalent) or less. The heat treatment is performed in an atmosphere of air, preferably 1 ppm or less, preferably 10 ppb or less. Carry out.

[0512] By performing heat treatment on the oxide semiconductor film, moisture or hydrogen is released from the oxide semiconductor film. Specifically, the substrate temperature is 250° C. or higher and 750° C. or lower, preferably 400° C. or higher. For example, the heat treatment may be performed at 500° C. for 3 to 6 minutes. If the RTA method is used for the heat treatment, dehydration or dehydrogenation can be carried out in a short time. Therefore, processing can be performed at temperatures exceeding the distortion point of the glass substrate.

[0513] Note that the heat treatment causes oxygen to be released from the oxide semiconductor film and the oxygen to be left in the oxide semiconductor film. Therefore, in one embodiment of the present invention, a vacancy may be formed in the gate electrode in contact with the oxide semiconductor film. An insulating film containing oxygen is used as an insulating film such as a gate insulating film. After the insulating film is formed, heat treatment is performed, whereby oxygen is supplied from the insulating film to the oxide semiconductor film. With the above structure, oxygen vacancies serving as donors are reduced, and oxygen atoms contained in the oxide semiconductor film are The stoichiometric composition of the oxide semiconductor can be satisfied. As a result, the oxide semiconductor film is made into an i-type oxide semiconductor film. This reduces the variation in the electrical characteristics of transistors caused by oxygen vacancies, and Improved characteristics can be achieved.

[0514] Note that the heat treatment for supplying oxygen to the oxide semiconductor film is performed using nitrogen, ultra-dry air, or rare earth metal. In a gas (argon, helium, etc.) atmosphere, preferably at 200°C to 400°C The gas has a water content of 20 ppm or less. It is desirable that the concentration is not more than 1 ppm, and more preferably not more than 10 ppb.

[0515] The transistor shown in FIG. 82(A) is a bottom-gate type having a channel-etched structure.

[0516] The transistor shown in FIG. 82(A) has a gate electrode 602 formed on an insulating surface. a gate insulating film 603 on the gate electrode 602; A semiconductor film 604 overlapping the electrode 602 and a conductive film 60 formed on the semiconductor film 604 The transistor further includes a semiconductor film 604, a conductive film 605, and a conductive film 606. An insulating film 607 formed over the conductive film 606 may also be included as a component thereof.

[0517] In addition, the transistor shown in FIG. 82(A) has an insulating layer at a position overlapping with the semiconductor film 604. It may further include a back gate electrode formed on film 607 .

[0518] The transistor shown in FIG. 82B is a bottom-gate type transistor with a channel protection structure.

[0519] The transistor shown in FIG. 82(B) has a gate electrode 612 formed on an insulating surface. a gate insulating film 613 on the gate electrode 612; A semiconductor film 614 overlapping the electrode 612 and a channel holder formed on the semiconductor film 614 The semiconductor film 614 includes a protective film 618 and a conductive film 615 and a conductive film 616 formed on the semiconductor film 614 . Further, the transistor is formed on the channel protective film 618, the conductive film 615, and the conductive film 616. The insulating film 617 formed on the insulating film 617 may be included as a component thereof.

[0520] In addition, the transistor shown in FIG. 82B has an insulating layer at a position overlapping with the semiconductor film 614. It may further include a back gate electrode formed on film 617 .

[0521] By providing the channel protection film 618, a channel forming region of the semiconductor film 614 is formed. Thinning of the film caused by plasma or etching agent during etching in later processes This can prevent damage such as that described above, thereby improving the reliability of the transistor. Cut.

[0522] The transistor shown in FIG. 82C is a bottom-gate type having a bottom-contact structure.

[0523] The transistor shown in FIG. 82(C) has a gate electrode 622 formed on an insulating surface. a gate insulating film 623 on the gate electrode 622; and a conductive film 625 on the gate insulating film 623. The conductive film 626 overlaps with the gate electrode 622 on the gate insulating film 623. In addition, the semiconductor film 624 is formed over the conductive film 625 and the conductive film 626. The transistor is formed of an insulating film formed over a conductive film 625, a conductive film 626, and a semiconductor film 624. A membrane 627 may be included as a component.

[0524] In addition, the transistor shown in FIG. 82C has an insulating layer at a position overlapping with the semiconductor film 624. It may further include a back gate electrode formed on film 627 .

[0525] The transistor shown in FIG. 82(D) is a top-gate type with a bottom-contact structure.

[0526] The transistor shown in FIG. 82(D) is formed by a conductive film 645 formed on an insulating surface, A conductive film 646, a conductive film 645, a semiconductor film 644 formed on the conductive film 646, and a semiconductor film 644, a gate insulating film 643 formed on the conductive film 645 and the conductive film 646, and a gate insulating film The gate electrode 642 is overlapped with the semiconductor film 644 on the insulating film 643. The transistor has an insulating film 647 formed on the gate electrode 642 as a component thereof. It may be included.

[0527] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0528] (Embodiment 7) In this embodiment, a light-emitting device, which is one mode of the semiconductor device of the present invention, is taken as an example. The external appearance will be described with reference to FIG. 83. FIG. 83(A) shows a transistor formed on a first substrate. The transistor and the light emitting element are mounted on a panel sealed with a sealant between a first substrate and a second substrate. FIG. 83(B) is a cross-sectional view taken along line A-A' in FIG. 83(A).

[0529] A pixel portion 4002, a circuit 4003, and a circuit 4004 are provided on a first substrate 4001. A sealant 4020 is provided to surround the pixel portion 4002 and the circuit 4003. A second substrate 4006 is provided on the circuit 4004. The circuit 4003 and the circuit 4004 are disposed between the first substrate 4001 and the second substrate 4006. The filling material 4007 is sealed together with the sealing material 4020 .

[0530] A pixel portion 4002 is provided on the first substrate 4001. A signal is supplied to the pixel portion 4002. Each of the circuits 4003 and 4004 includes a plurality of transistors. In FIG. 3(B), a transistor 4008 included in a circuit 4003 and a 4010 are shown as an example.

[0531] The light emitting element 4011 is connected to the source or drain of the transistor 4009. A part of the wiring 4017 is used as a pixel electrode. In addition to the element electrodes, the light-emitting element 4011 has a counter electrode 4012 and a light-emitting layer 4013. The structure is not limited to that shown in this embodiment. The configuration of the light emitting element 4011 can be changed as appropriate according to the direction and polarity of the transistor 4009. It is possible to do so.

[0532] In addition, various signals and voltages applied to the circuit 4003, the circuit 4004, or the pixel portion 4002 are Although not shown in the cross-sectional view of FIG. 83(B), the lead-out wirings 4014 and 401 5 and is supplied from connection terminal 4016.

[0533] In this embodiment, the connection terminal 4016 is connected to the counter electrode 4012 of the light emitting element 4011. The lead wiring 4014 is formed from the same conductive film as the wiring 4017. The lead wire 4015 is formed of a conductive film. The gate electrodes of the transistors 4010 and 4008 are made of the same conductive film. has been formed.

[0534] The connection terminal 4016 is electrically connected to a terminal of the FPC 4018 via an anisotropic conductive film 4019. are electrically connected.

[0535] The first substrate 4001 and the second substrate 4006 may be made of glass or metal (typically stainless steel). However, the light emitting element 4011 may be made of a material such as stainless steel, ceramics, or plastic. The second substrate 4006 located in the direction of light extraction from the substrate must be transparent. Therefore, the second substrate 4006 is a glass plate, a plastic plate, a polyester film, etc. It is preferable to use a light-transmitting material such as rubber or acrylic film.

[0536] In addition, filler 4007 can be inert gas such as nitrogen or argon, or ultraviolet-curing resin. In this embodiment, the filler 4007 is made of nitrogen. This shows an example using

[0537] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0538] (Embodiment 8) The circuit 100 according to one embodiment of the present invention can be used in a pixel portion of a display device. The circuit 100 according to one embodiment of the present invention can be used as a driver circuit of a display device.

[0539] FIG. 84A is a block diagram of a display device which corresponds to one of the semiconductor devices according to one embodiment of the present invention. The display device shown in FIG. 84(A) includes a pixel portion 700, a driving circuit 701, and a driving The pixel portion 700 includes a plurality of circuits 100 each functioning as a pixel. The driving circuits 701 and 702 supply various constant voltages and signals to the respective circuits 100. It has the function of supplying a number.

[0540] FIG. 84B is a block diagram of a display device which corresponds to one of the semiconductor devices according to one embodiment of the present invention. The display device shown in FIG. 84(B) includes a pixel portion 711 and a driver circuit 710. The driving circuit 710 includes a plurality of circuits 100 each functioning as a current source. The current output from 100 is supplied to a pixel included in a pixel portion 711 .

[0541] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0542] (Embodiment 9) A semiconductor device according to one aspect of the present invention includes a display device, a personal computer, and a recording medium. Image playback devices with advanced functions (typically DVD: Digital Versatile Disc (Devices having a display capable of playing back recording media such as 3D models and displaying the images) In addition, an electronic device in which the semiconductor device according to one embodiment of the present invention can be used can be provided. Mobile phones, handheld game consoles, personal digital assistants, e-books, video cameras, digital cameras, etc. Cameras such as TasStill cameras, goggle-type displays (head-mounted displays) ), navigation systems, audio playback devices (car audio, digital audio players) Years, etc.), copiers, facsimiles, printers, printer-combiners, automated teller machines Examples of electronic devices include ATMs and vending machines. Shown in figure 91.

[0543] FIG. 85A shows a portable game machine, which includes a housing 5001, a housing 5002, a display unit 5003, A display unit 5004, a microphone 5005, a speaker 5006, operation keys 5007, The semiconductor device according to one embodiment of the present invention is a driver for a portable game machine. It can be used for an integrated circuit for controlling the operation of the display unit 5003 or the display unit 5004. The portable game machine shown in FIG. 85(A) has two display units 5003 and 5 004, the number of display units that the portable game machine has is not limited to this.

[0544] FIG. 85B shows a display device, which includes a housing 5201, a display unit 5202, a support stand 5203, etc. A semiconductor device according to one embodiment of the present invention includes an integrated circuit for controlling the driving of a display device, Alternatively, it can be used for the display unit 5202. This includes all display devices used to display information, such as for data, TV broadcast reception, and advertising displays.

[0545] FIG. 85C shows a notebook personal computer, which includes a housing 5401 and a display unit 5402. 5403, a pointing device 5404, etc. The semiconductor device includes an integrated circuit for controlling the operation of a notebook personal computer, Or, it can be used for the display portion 5402 .

[0546] FIG. 85D shows a portable information terminal, which includes a housing 5601, a display unit 5602, and an operation key 5603. The portable information terminal shown in FIG. 85(D) has a modem built in a housing 5601. The semiconductor device according to one embodiment of the present invention may be a semiconductor device for controlling the driving of a portable information terminal. It can be used in an integrated circuit or the display portion 5602.

[0547] FIG. 85E shows a mobile phone. The mobile phone includes a housing 5801, a display unit 5802, an audio input unit 5803, The device has a voice output unit 5804, an operation key 5805, a light receiving unit 5806, etc. By converting the light received in the sensor into an electrical signal, an external image can be captured. The semiconductor device according to one aspect of the present invention is an integrated circuit for controlling the operation of a mobile phone, or a display. It can be used for the display unit 5802.

[0548] FIG. 85(F) shows a portable information terminal, which includes a first housing 5901, a second housing 5902, a first display unit 5903, a second display unit 5904, a connection unit 5905, operation keys 5906, etc. The display unit 5903 is provided in the first housing 5901, and the second display unit 5904 is provided in the second housing 59 The first housing 5901 and the second housing 5902 are connected to each other via a connection portion 59 5905, and the angle between the first housing 5901 and the second housing 5902 is The image on the first display unit 5903 can be changed by the connection unit 5905. It may also be configured to switch according to the angle between the first housing 5901 and the second housing 5902. The semiconductor device according to one embodiment of the present invention is an integrated circuit for controlling the driving of a portable information terminal. The first display portion 5903 and the second display portion 5904 can be used. At least one of the display unit 5903 and the second display unit 5904 has a function as a position input device. A display device with the following function as a position input device may be used. This can be added by providing a touch panel to the display device. Alternatively, it can be used as a position input device. The function of this is to provide a photoelectric conversion element, also called a photosensor, in the pixel portion of the display device. But you can add it.

[0549] Next, with reference to FIG. 91, an example of the configuration of a mobile phone according to the present invention will be described.

[0550] The display panel 900501 is detachably mounted in the housing 900530. The shape and dimensions of the display panel 900501 can be changed as needed. The housing 900530 to which the display panel 900501 is fixed is a printed circuit board. It is fitted into the substrate 900531 and assembled as a module.

[0551] Also, display panels 900501, touch panels, FPCs, printed circuit boards, frames, heat dissipation Plates, optical films, polarizing plates, retardation plates, prism sheets, diffusion plates, backlights, light guide plates , LED, CFL, front light, controller, driver circuit, or signal processing circuit A display module can be formed by providing a display panel 900501. It is also possible to provide the opposing substrate (sealing substrate) with a touch panel function.

[0552] The display panel 900501 is connected to the printed circuit board 900531 via the FPC 900513. The printed circuit board 900531 includes a speaker 900532 and a microphone 90 0533, a transmission / reception circuit 900534, a signal processing circuit 9 including a CPU and a controller, etc. Such a module, an input means 900536, a battery The display panel 900501 is assembled with the battery 900537 and stored in the housing 900539. The pixel portion is arranged so as to be visible through an opening window formed in the housing 900539.

[0553] The display panel 900501 includes a pixel section and a part of a peripheral driving circuit (a driving circuit having a plurality of driving circuits, each of which has a different operating frequency). The driving circuits with low wavelengths are integrated on the substrate using TFTs, and some of the peripheral driving circuits (multiple A driving circuit having a high operating frequency among the driving circuits of the above is formed on an IC chip, and the IC chip may be mounted on the display panel 900501 using COG (Chip On Glass). Or, the IC chip is bonded by TAB (Tape Automated Bonding) Alternatively, a printed circuit board or a printed circuit board may be used to connect the glass substrate. It is expected that the power consumption of the display device will be reduced and the usage time of the mobile phone will be extended on a single charge. In addition, the cost of the mobile phone can be reduced.

[0554] This embodiment may be modified, added, revised, deleted, or altered in whole or in part with respect to other embodiments. This corresponds to an application, a superordinate concept, or a subordinate concept. Part or all of the present invention may be freely combined with part or all of the other embodiments. Alternatively, it may be implemented in place of the above.

[0555] In addition, in the figures or text described in a certain embodiment, it is possible to extract a part thereof to form an aspect of the invention. Therefore, when a figure or text describing a certain part is provided, the content obtained by extracting a part of the figure or text thereof is also disclosed as an aspect of the invention and can form an aspect of the invention. Thus, for example, in a drawing or text in which one or more active elements (such as transistors and diodes), wirings, passive elements (such as capacitive elements and resistive elements), conductive layers, insulating layers, semiconductor layers, organic materials, inorganic materials, components, devices, operation methods, manufacturing methods, etc. are described, it is assumed that a part thereof can be extracted to form an aspect of the invention. For example, from a circuit diagram composed of N (N is an integer) circuit elements (such as transistors and capacitive elements), M (M is an integer and M < N) circuit elements (such as transistors and capacitive elements) can be extracted to form an aspect of the invention. As another example, from a cross-sectional view composed of N (N is an integer) layers, M (M is an integer and M < N) layers can be extracted to form an aspect of the invention. As yet another example, from a flowchart composed of N (N is an integer) elements, M (M is an integer and M < N) elements can be extracted to form an aspect of the invention. In addition, in the figures or text described in a certain embodiment, when at least one specific example is described, it is easily understood by those skilled in the art to derive the upper concept of the specific example. Therefore, in the figures or text described in a certain embodiment, it is possible to extract a part thereof to form an aspect of the invention.

[0556] In addition, in the figures or text described in a certain embodiment, when at least one specific example is described, it is easily understood by those skilled in the art to derive the upper concept of the specific example. Therefore, in the figures or text described in a certain embodiment, it is possible to extract a part thereof to form an aspect of the invention. When at least one specific example is described, the generic concept of the specific example is also considered as one aspect of the invention. and can be construed as one embodiment of the invention.

[0557] At least the contents shown in the drawings (or even a part of the drawings) are disclosed as one embodiment of the invention. It is possible that the above-mentioned embodiment constitutes one aspect of the invention. If the contents are shown in the diagram, they are understood to be accurate even if they are not stated in words. It is disclosed as one embodiment of the present invention and can be construed as one embodiment of the present invention. Similarly, even if a part of the drawings is taken out, it is not disclosed as one embodiment of the invention. and can constitute one aspect of the invention.

[0558] (Embodiment 10) In FIG. 49(A), as an example, a switch 11, a switch 12, a switch 13, The configuration of the circuit 100 when transistors are used for the switch 14 and the switch 914 is shown in FIG. 8(A).

[0559] In the circuit 100 shown in FIG. 88(A), a transistor 11t is used as the switch 11. A transistor 12t is used as the switch 12, and a transistor 13t is used as the switch 13. The switch 14 is made of a transistor 14t, and the switch 914 is made of a transistor The 914t is used.

[0560] In FIG. 88(A), transistors 11t, 12t, and 13 t, transistor 14t, and transistor 914t are all n-channel types. As an example, transistor 11t, transistor 12t, transistor 13t, The transistors 14t and 914t are all transistors of the same polarity. Therefore, these transistors can be manufactured with a small number of steps. One embodiment is not limited to this, and transistors of different polarities can also be used.

[0561] In addition, in FIG. 88A, the gate of the transistor 11t is connected to the wiring 31. The transistor 11t is turned on o...

Claims

1. A pixel includes first to fifth transistors and a light-emitting element, the second transistor to the fifth transistor function as a switch, one of a source and a drain of the second transistor is electrically connected to a first wiring; the other of the source and the drain of the second transistor is electrically connected to one of the source and the drain of the third transistor; the other of the source and the drain of the third transistor is electrically connected to the light emitting element; one of a source and a drain of the fourth transistor is electrically connected to the light emitting element; the other of the source and the drain of the fourth transistor is electrically connected to a second wiring; one of a source and a drain of the fifth transistor is electrically connected to a gate of the first transistor; the first transistor has a function of controlling a current flowing between a third wiring and the light-emitting element in response to a potential of a video signal input to the pixel; a first conductive film having a function as a gate electrode of the first transistor; a first semiconductor film in which a channel formation region of the first transistor, a channel formation region of the second transistor, a channel formation region of the third transistor, and a channel formation region of the fourth transistor are disposed and are continuous with each other; a second semiconductor film in which a channel formation region of the fifth transistor is disposed and which is separated from the first semiconductor film; the first semiconductor film has a first region that is spaced apart from the first channel formation region and overlaps with the first conductive film; the first channel formation region and the first region are electrically connected to each other via a channel formation region of the third transistor; a capacitance element is formed by the first conductive film and the first region; the first region is arranged alongside a channel formation region of the first transistor in a direction intersecting a channel length direction of the first transistor; Light emitting device.

2. A pixel includes first to fifth transistors and a light-emitting element, the second transistor to the fifth transistor function as a switch, One of a source and a drain of the second transistor is electrically connected to a first wiring to which a video signal is input, the other of the source and the drain of the second transistor is electrically connected to one of the source and the drain of the third transistor; the other of the source and the drain of the third transistor is electrically connected to the light emitting element; one of a source and a drain of the fourth transistor is electrically connected to the light emitting element; the other of the source and the drain of the fourth transistor is electrically connected to a second wiring to which a first power supply potential is input; one of a source and a drain of the fifth transistor is electrically connected to a gate of the first transistor; the first transistor has a function of controlling a current flowing between a third wiring to which a second power supply potential is input and the light-emitting element in response to a potential of the video signal input to the pixel; a first conductive film having a function as a gate electrode of the first transistor; a first semiconductor film in which a channel formation region of the first transistor, a channel formation region of the second transistor, a channel formation region of the third transistor, and a channel formation region of the fourth transistor are disposed and are continuous with each other; a second semiconductor film in which a channel formation region of the fifth transistor is disposed and which is separated from the first semiconductor film; the first semiconductor film has a first region that is spaced apart from the first channel formation region and overlaps with the first conductive film; a capacitance element is formed by the first conductive film and the first region; the first region is arranged alongside a channel formation region of the first transistor in a direction intersecting a channel length direction of the first transistor; Light emitting device.

3. A pixel includes first to fifth transistors and a light-emitting element, the second transistor to the fifth transistor function as a switch, one of a source and a drain of the second transistor is electrically connected to a first wiring; the other of the source and the drain of the second transistor is electrically connected to one of the source and the drain of the third transistor; the other of the source and the drain of the third transistor is electrically connected to the light emitting element; one of a source and a drain of the fourth transistor is electrically connected to the light emitting element; the other of the source and the drain of the fourth transistor is electrically connected to a second wiring; one of a source and a drain of the fifth transistor is electrically connected to a gate of the first transistor; the first transistor has a function of controlling a current flowing between a third wiring and the light-emitting element in response to a potential of a video signal input to the pixel; Among the second transistor to the fifth transistor, only the fifth transistor has a source or a drain that is always electrically connected to the gate of the first transistor; a first conductive film having a function as a gate electrode of the first transistor; a first semiconductor film in which a channel formation region of the first transistor, a channel formation region of the second transistor, a channel formation region of the third transistor, and a channel formation region of the fourth transistor are disposed and are continuous with each other; a second semiconductor film in which a channel formation region of the fifth transistor is disposed and which is separated from the first semiconductor film; the first semiconductor film has a first region that is spaced apart from the first channel formation region and overlaps with the first conductive film; a capacitance element is formed by the first conductive film and the first region; the first region is arranged alongside a channel formation region of the first transistor in a direction intersecting a channel length direction of the first transistor; Light emitting device.

4. A pixel includes first to fifth transistors and a light-emitting element, the second transistor to the fifth transistor function as a switch, One of a source and a drain of the second transistor is electrically connected to a first wiring to which a video signal is input, the other of the source and the drain of the second transistor is electrically connected to one of the source and the drain of the third transistor; the other of the source and the drain of the third transistor is electrically connected to the light emitting element; one of a source and a drain of the fourth transistor is electrically connected to the light emitting element; the other of the source and the drain of the fourth transistor is electrically connected to a second wiring to which a first power supply potential is input; one of a source and a drain of the fifth transistor is electrically connected to a gate of the first transistor; the first transistor has a function of controlling a current flowing between a third wiring to which a second power supply potential is input and the light-emitting element in response to a potential of the video signal input to the pixel; Among the second transistor to the fifth transistor, only the fifth transistor has a source or a drain that is always electrically connected to the gate of the first transistor; a first conductive film having a function as a gate electrode of the first transistor; a first semiconductor film in which a channel formation region of the first transistor, a channel formation region of the second transistor, a channel formation region of the third transistor, and a channel formation region of the fourth transistor are disposed and are continuous with each other; a second semiconductor film in which a channel formation region of the fifth transistor is disposed and which is separated from the first semiconductor film; the first semiconductor film has a first region that is spaced apart from the first channel formation region and overlaps with the first conductive film; a capacitance element is formed by the first conductive film and the first region; the first region is arranged alongside a channel formation region of the first transistor in a direction intersecting a channel length direction of the first transistor; Light emitting device.

Images