Light-emitting device

Abstract

To provide a semiconductor device capable of suppressing influence of variation in characteristics of a transistor.SOLUTION: 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), wherein the first switch selects conduction or non-conduction between the first wiring and a first electrode of the first capacitive element, and, A first electrode of the first capacitor is electrically connected to a first electrode of the second capacitor, a second electrode of the first capacitor is electrically connected to a gate of the transistor, a second electrode of the second capacitor is connected to one of a source and a drain of the transistor, the second switch selects conduction or non-conduction between the second wiring and the gate of the transistor, and the third switch selects conduction or non-conduction between the first electrode of the first capacitor and the 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, and a driving method thereof. The present invention relates to a semiconductor device, such as a transistor, or a manufacturing method thereof. Examples of light-emitting devices include semiconductor devices having active elements such as 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 provides 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 method for driving them. [Background technology]

[0002] Display devices using light-emitting elements have high visibility and are ideal for thinning, but they also have no limitations on the viewing angle. Since there is no display, it is used as an alternative to CRT (cathode ray tube) or LCD display devices. Active matrix display devices using light-emitting elements are attracting attention. The specific configurations proposed vary depending on the 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 (driving transistor) controls the current value supplied to the light emitting element. It is installed in the base.

[0003] For example, by making all the transistors provided 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 using only n-channel transistors. The present invention describes a display device in which: [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-195810 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. The current value of the transistor drain current can be corrected in anticipation of the variation in the value voltage. Proposing a pixel configuration that can achieve this is an important issue in improving the quality of semiconductor devices.

[0006] In view of the above-described problems, one embodiment of the present invention provides a semiconductor device that can suppress the influence of variations in transistor characteristics. It is another 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, a light emitting device, and a semiconductor device in which the influence of deterioration of transistor characteristics is suppressed. An object of the present invention is to provide an optical device or a display device. is a semiconductor device that can suppress variations in brightness due to variations in threshold voltage of transistors. It is another object of the present invention to provide a light-emitting device or a display device. The aspect is a semiconductor device in which the variation in brightness due to the variation in the mobility of the transistor is suppressed. Another object of the present invention is to provide a light-emitting device, a display device, or a semiconductor device. One embodiment of the present invention relates to a semiconductor device, a light-emitting device, and a semiconductor device that operate normally even when a transistor is a normally-off type. Another object of the present invention is to provide a device or a display device. ,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 displays high quality images. Another object of one embodiment of the present invention is to provide a display device that displays images with less unevenness. One of the objects of the present invention is to provide a semiconductor device, a light emitting device, or a display device. One embodiment of the present invention is a semiconductor device that can realize a desired circuit with a small number of transistors. It is another object of the present invention 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 is to provide a semiconductor device, a light-emitting device, or a display device in which the influence of deterioration of the Another embodiment of the present invention is a semiconductor device manufactured with a small number of steps. One of the objects is 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 present invention to solve all of these problems. The above will be made clear from the description, drawings, claims, etc. It is possible to extract other issues from the description of the aspects and claims. [Means for solving the problem]

[0008] One embodiment of the semiconductor device of the present invention is a semiconductor device including 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 first wiring and a pair of electrodes of the first capacitor. The first pair of capacitance elements has a function of selecting conduction 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 second 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 one of 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-conduction between one of the pair of electrodes and one of the source and drain of the transistor The FET has a function of selecting whether to conduct or not conduct.

[0009] In the semiconductor device having the above configuration, the transistor (hereinafter referred to as the driving transistor) is designed to take into account variations in threshold voltage. The voltage applied between the source and gate of a transistor (sometimes called a 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 capacitance 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 whether to establish electrical continuity between the first capacitive element and one of the pair of electrodes. One of the pair of 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 load and the 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. The transistor is connected to one of the pair of electrodes of the first capacitor and the source and drain of the transistor. The second terminal has a function of selecting electrical continuity or non-conduction between the first terminal and the second terminal.

[0011] In the semiconductor device having the above configuration, the transistor (hereinafter referred to as the driving transistor) is designed to take into account variations in threshold voltage. The voltage applied between the source and gate of a transistor (sometimes called a 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 formed by passing current between the anode and cathode of the light-emitting element. The light is emitted with a brightness proportional to the current value.

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

[0014] (Type A) In the semiconductor device according to the above aspect of the present invention, the source of the transistor (drive transistor) 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 (for example, The driving circuit is configured to adjust the potential of the first wiring to that of the cathode of the light-emitting element. The potential of the first wiring is controlled so that there is a period in which the potential is equal to or less than the potential of the first wiring.

[0015] (Type B) In the semiconductor device according to the above aspect of the present invention, the source of the transistor (drive transistor) 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 (for example, 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 in 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 in question must 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 including an oxide semiconductor in a channel formation region. Alternatively, the channel forming region may be made of single crystal silicon. Alternatively, a transistor having a channel forming region made of polycrystalline silicon may be used. Alternatively, a transistor having a non-transistor in the channel forming region can be used. The transistors may be made of amorphous silicon.

[0018] That is, transistors with various structures can be used. There is no limitation on the type of transistor used. Transistors with gates, or amorphous silicon, polycrystalline silicon, microcrystalline (microcrystalline) Non-crystalline silicon (also called crystalline, nanocrystalline, or semi-amorphous) 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 O, etc.), or a thin film of these compound semiconductors or oxide semiconductors 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. These compound semiconductors or oxide semiconductors can be used as the channel of a transistor. It can be used not only for the wiring part but also for other purposes. The compound semiconductor or oxide semiconductor is used for wiring, a resistor element, a pixel electrode, a light-transmitting electrode, etc. These can be formed as films or layers at the same time as the transistors. Therefore, costs can be reduced.

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

[0021] An example of a transistor is a multi-gate transistor having two or more gate electrodes. When a multi-gate structure is used, the channel forming regions are connected in series. Therefore, multiple transistors are connected in series. The gate structure reduces the off-state current and improves the breakdown voltage of the transistor (improving reliability). 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 flat. 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. can be done.

[0022] An example of a transistor is a structure in which gate electrodes are arranged above and below a channel. The structure in which gate electrodes are arranged above and below the channel can be applied to the transistor. 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. The 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] An example of a transistor is a transistor in which a gate electrode is disposed on a channel forming region. a structure in which the gate electrode is located under the channel forming region; a staggered structure; an inverted staggered structure; Tag structure, structure in which the channel formation region is divided into multiple regions, channel formation regions connected in parallel or a transistor having a structure in which channel formation regions are connected in series. can be done.

[0024] As an example of a transistor, a structure provided with an LDD region can be applied. By providing this, 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 changes, 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, an upper limit and a lower limit can be defined. When a numerical range is stated, such as by narrowing the range arbitrarily, or By excluding one point within the scope, the invention can be defined by excluding part of the scope. These can be used to, 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 using first to fifth transistors in a circuit is shown below. In that case, the circuit does not have a sixth transistor. Alternatively, the circuit may be defined as an invention that does not have a capacitance element. Furthermore, it is possible to specify that the circuit has a specific 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 defined 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 used. It is possible to define the invention as not being

[0027] As another example, for a certain value, for example, "a certain voltage is 3V or more and 10V or less." In that case, for example, if a certain voltage is -2V, It is possible to define the invention as follows: It is possible to define the invention as excluding cases where a certain voltage is 13V or higher. For example, the invention may be defined as a voltage between 5V and 8V. For example, the invention can be defined as having a voltage of approximately 9V. For example, the invention is defined as a voltage between 3V and 10V, excluding the case where the voltage is 9V. It is also possible.

[0028] As another specific example, regarding a certain value, for example, "a certain voltage is preferably 10V" may be used. In that case, for example, if a certain voltage is between -2V and 1V, Or, for example, the invention can be defined as follows: It is possible to define the invention as excluding cases where the voltage is 13V or higher.

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

[0030] As another 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 define the invention as excluding the case where a conductive film is provided between the first and second electrodes. [Effects of the Invention]

[0031] In one embodiment of the present invention, a voltage applied between the source and gate of a driving transistor is This reduces the influence of variations in transistor characteristics. It is possible to provide a semiconductor device, a light-emitting device, or a display device that can be used in the present invention. Semiconductor device, light-emitting device, or display device in which the influence of deterioration of transistor characteristics is suppressed Alternatively, the brightness variation due to the variation in the 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 semiconductor device can suppress variations in brightness due to variations in transistor mobility. Alternatively, one embodiment of the present invention can provide a light-emitting device, a display device, or a semiconductor device. A semiconductor device, a light-emitting device, or a semiconductor device that operates normally even if the transistor is a normally-off type In another embodiment of the present invention, a display device can be provided. A semiconductor device, a light-emitting device, and a semiconductor device that can obtain the threshold voltage of a transistor even if the transistor is an OFF type. It is possible to provide a semiconductor device or a display device that displays a high quality image. It is possible to provide a light emitting device or a display device. 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. Alternatively, a device that can realize a desired circuit with a small number of wires can be provided. 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 Alternatively, a semiconductor device, a light emitting device, or a display device can be provided that is manufactured with a small number of steps. It can be provided. [Brief explanation of the drawings]

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

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

[0034] Note that the content (or even a part of the content) described in one embodiment may be used in conjunction with that embodiment. Other content (or even part of content) described in the context, and / or one or more other The contents (or a part of the contents) described in the embodiments may be applied, combined, or replaced. You can make changes etc.

[0035] The configuration of a drawing (or a part thereof) described in one embodiment may be different from that of another drawing. The configuration of the part, the configuration of another figure (or part) described in the embodiment, and / or The combination of 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 diagrams showing ideal examples. The shape is not limited to the shape shown in the figure. For example, variations in shape and errors due to manufacturing techniques may occur. It is possible to include variations in shape due to the

[0037] 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) , wiring, electrodes, terminals, conductive films, layers, display elements, light-emitting elements, loads, etc.) Therefore, the present invention is not limited to predetermined connection relationships, for example, connection relationships shown in drawings or text, and may be applied to any connection relationship shown in drawings or text. This also includes connections other than those shown in the text.

[0038] An example of an electrical connection between X and Y is The elements to be considered (e.g., switches, transistors, capacitance elements, inductors, resistance elements, One or more devices (such as diodes, display elements, light-emitting elements, and loads) can be connected between X and Y. It is possible. The switch has a function to control on / off. A switch can be in a conducting state (ON state) or a non-conducting state (OFF state), allowing current to flow. The switch has the function of controlling whether or not the current flows. It has the function to switch between them.

[0039] An example of a functional connection between X and Y is a function that allows the functional connection between X and Y. 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 (voltage power supply circuits (voltage boost circuits, voltage drop circuits, etc.), level shifter circuits that change the signal potential level, etc.) , voltage source, current source, switching circuit, amplifier circuit (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 circuits (e.g., memory circuits, control circuits, 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 X is transmitted to Y.

[0040] 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, it includes cases where it is explicitly stated that they are electrically connected. If it is simply connected, and only if it is explicitly stated, it is the same as .

[0041] In addition, the circuit diagram shows independent components as if they are electrically connected to each other. Even if the components are different, 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 functions as both the wiring and the electrode. 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.), passive elements (capacitance elements, resistance elements, etc.) ) and the like, a person skilled in the art can easily identify the terminals to which they are connected without specifying the terminals. It may be possible to configure one aspect of the invention. In some cases, it may be 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 Therefore, it is not necessary to limit it to the active element (transistor, diode, etc.), Only some terminals of passive elements (capacitance elements, resistance elements, etc.) are connected to 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 can identify the invention by at least specifying the connection destination of a certain circuit, Or, for a circuit, it may be possible to at least identify its function. In some cases, a person skilled in the art can identify the invention by identifying the function. , 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 where 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 then Purchase a semiconductor device, deposit a light-emitting element on the semiconductor device, and complete the light-emitting device. This is sometimes the case.

[0045] In such a case, the inventor may claim patent infringement against either Company A or Company B. Therefore, if you assert a patent infringement claim against Company A or Company B, It can be determined that one aspect of the invention that can be achieved is clear and described in the present specification, etc. For example, in the case of a transmission / reception system, one aspect of the invention is constituted by only the transmitter. The receiver alone can constitute one aspect of the invention, and the one aspect of the invention is , can be considered to be clear and described in the present specification etc. As another example, 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 configured by only a light-emitting device having a TFT and a light-emitting element. These aspects of the invention are clear and can be understood as follows: It can be judged that it 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 will be explained. Let me give you an example.

[0047] A semiconductor device according to one embodiment of the present invention includes, for example, a transistor and a With the gate potential 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 configuration compensates for variations 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 the capacitor 102. 103. The capacitor 103 has a function of controlling electrical continuity between the capacitor 103 and one electrode (terminal) of the capacitor 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 transistor 102. 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 the 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 The names are interchangeable 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 higher 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 interchanged 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 the drain, respectively. In this case, for example, one of the source and the drain may be connected to the first terminal, The other of the source and drain is referred to as a second terminal, a second electrode, or a first region. This may be referred to as the second area.

[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 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. (DMD) using MEMS (microelectromechanical systems) technology The switch can be made up of a logic circuit combining transistors. When a transistor is used as a switch, the polarity of the transistor is 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] Note that examples of transistors with low off-state current include transistors having an LDD region and multi-layer transistors. a transistor having a double-gate structure or a transistor including an oxide semiconductor in a channel formation region; Also, when combining transistors to operate as a switch, A complementary switch may be formed using 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 work properly.

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

[0054] An example of a transistor is a transistor in which gates are arranged above and below a channel forming 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 in which gates are arranged above and below, a depletion layer is easily formed, and S It is possible to improve the value.

[0055] As an example of a transistor, a source voltage is applied to a channel formation region (or a part thereof). A transistor with a structure in which the electrode and drain electrodes overlap can be used. By using a structure in which 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 part of the channel formation region. This can be done.

[0056] The capacitor 102 or the capacitor 103 may be formed of, 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 connected to the source of the transistor 101. The capacitor 103 is connected to one of the source and drain electrodes or the other electrode of the capacitor 103 and the wiring 24. It continues.

[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 with resistance, circuits with switches, pixel circuits, current source circuits, and the like. 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 (liquid crystal element, EL element, etc.), a light emitting element (EL (electroluminescence) Electroluminescence) elements (EL elements including organic and inorganic materials, 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-emitting devices, or display devices and light-emitting devices 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, The cathode of the terminal 104a is connected to the wiring 24 as an example.

[0060] 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 shows 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 be, for example, a semiconductor device having any of the structures 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 provided. , and may further have.

[0062] The semiconductor device shown in FIGS. 2A to 2D includes the circuit 1 shown in FIGS. 00, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21, and a 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 the potential Vi1 or the potential Vsig to the wiring 21. An example of the circuit 201 is a source driver (signal line driver circuit). Therefore, the wiring 21 has a function 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 capacitor 102. The potential Vi1 is, for example, a potential for turning on the transistor 101. It is desirable 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, The level of the Vsig is constant. 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 also has a function of supplying a potential Vi2 to the wiring 22. Therefore, the wiring 22 can transmit the potential Vi2. The wiring 22 has a function of being able to supply or supplying 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 also be used. It may be moved.

[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 above. In the case of FIG. 2(D), the potential Vi2 is the potential of the wiring 24. It is preferable that the light emitting element 104b has a voltage equal to or higher than the voltage. However, the potential Vi2 is not limited to these. It is desirable 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 wires.

[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 203. Therefore, the wiring 23 is connected to the power supply potential or the signal It has the function of being able to convey or provide. 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 desirable 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 such that not only a forward bias voltage but also a reverse bias voltage is applied to the load 104. It may be a potential that can be obtained by

[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 current to the load 104. Alternatively, the wiring 24 can supply 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 desirable 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 vary like a pulse signal. For example, the potential of the wiring 24 is applied to the load 104 not only as a forward bias voltage but also as a reverse bias voltage. It may also be a potential that applies pressure.

[0072] The potential difference between the potential VDD and the potential Vcat causes the drain current of the transistor 101 to 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 and is lower than the potential Vcat, a current flows to the wiring 23. A current flows from the wire 24 to the wiring 23 .

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

[0074] The transistor 101 has at least a function as a current source, for example. Therefore, for example, the transistor 101 has a Even if the magnitude of the voltage applied between the drain and the capacitor changes, the capacitor has the function of supplying a roughly constant current. Alternatively, for example, the transistor 101 does not change the potential of the load 104. It has the function of supplying a substantially constant current to the load 104. The wiring 101 has a function of supplying a substantially constant current even when the potential of the wiring 23 changes.

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

[0076] A voltage source is another power source that is different from 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 voltage source 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 is whether the current source has the function of supplying current. , has the function of supplying a constant current even if the voltage at both ends changes, and the voltage source Even if the voltage is high, it has the function of supplying a constant voltage.

[0077] Note that FIG. 1 and the like are merely examples of circuit configurations, and therefore, additional transistors may be provided. Conversely, at each node such as in FIG. 1, it is possible to add transistors, switches, etc. It is also possible to eliminate the need for switches and passive elements. The node to which each terminal of the transistor is connected, or / and the node to which the load is connected. At the node where each terminal is connected, no more directly connected transistors are set. Therefore, for example, the load 104 and the transistor 101 At the node where the capacitor 103 and the switch 13 are connected, The only transistor connected is the transistor 101, and the other transistors are connected to that node. 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. This becomes possible.

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

[0080] In the circuit 100 shown in FIGS. 1A to 1D, a transistor is used as the switch 11. a transistor 11t as the switch 12, a transistor 12t as the switch 13, and The configuration of the circuit 100 when using the capacitor 13t is shown in FIGS. 3(A) to 3(D). 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. In this case, transistors 11t, 12t, and 13t are all p-channel transistors. The transistor 11t, the transistor 12t, and transistor 13t are 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] 3A to 3D, the gate of the transistor 11t is connected to the wiring 31. The transistor 11t is connected to the line 31. The gate of the transistor 12t is 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 conducting or non-conducting state. The potentials of the lines 31 to 33 are preferably pulsed and not constant. Alternatively, the wirings 31 to 33 may be gate wirings. 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. 00 can be connected to at least one of the wirings 31 to 33.

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

[0084] The semiconductor device shown in FIGS. 4A to 4D includes the circuit 1 shown in FIGS. 00, a circuit 205 having a function of supplying a constant voltage or signal to the wiring 31, 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] Note that 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. 206 and 207 is 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. It is not necessary 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 transistors. The configuration of the circuit 100 when the transistor 12t is an n-channel type is shown in FIG. In this way, transistors of various polarities can be used.

[0088] Furthermore, a semiconductor device according to one embodiment of the present invention includes a circuit 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

[0089] The semiconductor device shown in FIGS. 37(C) and 37(D) is the same as that shown in FIGS. 37(A) and 37(B). In addition to the circuit 100, a circuit 205 having a function of supplying a constant voltage or signal to the wiring 31 is , a circuit 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 constant voltage or signal to the wiring 33. 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. 205, 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 to have all of them, and it may have only one or more of them.

[0091] Note that the transistor 101 often operates in a saturation region when a current flows. 3, 4, and 37, the channel length or gate length of the transistor 101 The length of the transistor 11t, the transistor 12t, and / or the transistor 13t may be It is desirable to make it longer than the channel length or gate length. The characteristics in the low frequency range become flat, and the kink effect can be reduced. It is desirable that the resistance be 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 may be set to the widths of the transistors 11t, ... By making it longer than the transistor 12t and / or the transistor 13t, 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 using the circuit 100 illustrated in FIG. We will explain about this.

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

[0094] In the circuit 100 shown in FIG. 1C, the switches 11, 12, and 13 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. 5(A).

[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 conducting state. In addition, a potential Vi1 is supplied to the wiring 21. Therefore, in the period T11, As shown, a voltage Vi2-Vi1 is supplied to the capacitance element 102, and the voltage Vout of the light emitting element 104a is The gate voltage of the transistor 101 (Vgs101) is , the voltage Vi2-Vi1. That is, when the transistor 101 and the capacitor 102 are It will be initialized.

[0096] In the circuit 100 shown 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 V1 to the potential Vi2. The potential Vi1 is preferably a potential that turns on the transistor 101. In addition, the potential Vi1 is applied with 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 voltage (starting voltage) is lower than the potential Vcat. It is desirable that i1 be 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 repair the short-circuited portion. Furthermore, the potential obtained by subtracting the threshold voltage Vthe of the light emitting element 104a from the potential Vi2 is It is desirable that the potential be lower than Vcat. Assume that

[0097] The second operation performed in the period T12 will be described. As shown in FIG. 1, the switch 11 is in a non-conducting state, and the switches 12 and 13 are in a conducting state. When the switch 11 is turned off, the charge stored in the capacitor element 102 is The charge is released through the transistor 101, causing the potential at the source of the 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 voltage is not lowered completely to Vth before operation. The period T12 may end when the voltage Vth is slightly higher than the minimum voltage Vth. That is, at the end of the period T12, Vgs101 is It can also be said that the voltage is of a certain magnitude.

[0099] In the second operation, whether 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 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 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 achieve this, 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. By turning it off, it is possible to prevent current from flowing through the light emitting element 104a. If so, the potential Vi2 may be a high value.

[0101] The third operation performed in the period T13 will be described. 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, the potential Vi1 is supplied to the wiring 21. As shown in FIG. 6A, the capacitance element 102 has a threshold voltage Vth (or a capacitance 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 equal to the threshold voltage Vt h (or a voltage of a magnitude 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 described above. After the second operation, the fourth operation described below may be performed. It may also be configured to perform an operation.

[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 potential 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, one circuit 100 operates in the period T11, and another In the circuit 100, the operation can be performed during the period T13, so that the operation 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, 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, As shown in B), the threshold voltage Vth (or a voltage corresponding to Vth) is applied to the capacitance element 102. The voltage Vsig-Vi1-Vα is held in the capacitor element 103, and light is emitted. The anode of the element 104a is at a potential Vi1+Vα, and the gate potential of the transistor 101 is The potential Vsig+Vth is the gate-source voltage of the transistor 101 (Vgs10 1) is the voltage Vsig+Vth-Vi1-Vα. Alternatively, the voltage of the capacitor 102 and the voltage of the capacitor 103 can be input. The sum of the voltages can be set to the gate-source voltage of the transistor 101.

[0105] In the fourth operation, the potential Vα is set to a value that is lower than the value when the anode of the light emitting element 104a is in an electrically floating state (floating). 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 capacitance 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. The capacitance of the light emitting element 104a is sufficiently larger than the capacitance of the capacitor 102 and the capacitor 103. If the value 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 desirable that it be 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 desirable that the area of ​​the electrode is smaller than that of the electrode of 04a), preferably 1 / 2 or less, more preferably However, one aspect of the embodiment of the present invention is not limited to these. It will not be done.

[0108] In addition, 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 in the period T13, the switching When the switch 11 is turned on, the potential of the gate of the transistor 101 is set to the potential Vsig This allows the voltage to quickly approach +Vth. Therefore, the period T14 can be shortened, and the charge amount 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 desirable that it be smaller than the length, preferably 2 / 3 times or less, more preferably 1 / 2 times The following are preferred: However, one aspect of an embodiment of the present invention is not limited to these.

[0110] As mentioned above, it is desirable that the charge quantity Q is small. If the variation in mobility is large, the charge amount Q can be expected to have the effect of suppressing the variation in mobility. The reason for this will be explained below.

[0111] The charge Q flows from the drain to the source of the transistor 101 during the period T14. Therefore, the charge amount Q increases as the mobility of the transistor 101 increases. When the charge amount Q increases, the transistor The gate-source voltage (Vgs101) of the transistor 101 becomes smaller. The larger the mobility of the transistor 101, the more the amount of electrons supplied to the light emitting element 104a. The current value is corrected to be smaller, and the smaller the mobility of the transistor 101, the However, 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 greater than the capacitance of the parasitic capacitance of the gate of the transistor 101. It is also desirable that the value be 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 channel of the transistor 101. It is desirable that the size is larger, preferably at least two times larger, and more preferably at least five times larger. 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 desirable that the difference is larger than the above, preferably at least two times, and more preferably at least five times. As a result, the potential Vsig is input, and the capacitance of the capacitor 102 and the gate capacitance of the transistor When the voltage is divided by the capacitance, the decrease in the voltage of the capacitor 102 can be reduced. However, one aspect of the embodiment of the present invention is not limited to this.

[0113] The capacitance value of the capacitor 102 is approximately the same as the capacitance value 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 ±20% or less, and more preferably ±10% or less. 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 that the size of the same 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 capacitor 102. The voltage Vsig-Vi1-Vα is held in the capacitor 103, and the a The node is at a potential Vel, and the potential of the gate of the transistor 101 is at a potential Vsig+Vth. -Vi1-Vα+Vel, and the gate-source voltage of the transistor 101 (Vgs10 1) is the voltage Vsig+Vth-Vi1-Vα. 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 brightness corresponding to the potential Vsig. The child 104a can be made to emit light.

[0115] The potential Vel is set when a current is passed through the transistor 101 to the light-emitting element 104a. Specifically, it is a potential 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, and the threshold voltage Vth of the transistor 101 is taken into consideration. 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 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 above change can be prevented. Therefore, it is possible to prevent the change from affecting the value of the current supplied to the light emitting element 104a. Display unevenness can be reduced, and high-quality display can be achieved.

[0117] Similarly, the gate-source voltage (Vgs101) of the transistor 101 is set to the voltage Vsig+ Vth-Vi1-Vα can be set to a value 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 be deteriorated and the light emitting element may be damaged. Even if the voltage-current characteristics of the light emitting element 104a change and Vel changes, the change is not This prevents the current value supplied to a from being affected. , a high-quality display can be achieved.

[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, , the transistor 101 can be turned off.

[0119] In the semiconductor device of 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 capacitor 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 voltage 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 the 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 includes the above-described It is sufficient if the structures shown in FIGS. 7(A) to 7(E) can be obtained 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 can be adjusted so that the structures shown in FIGS. 7A to 7E can be realized. The number of wirings to be used can be changed as appropriate.

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

[0122] The semiconductor device shown in FIG. 8A is a circuit diagram of the circuit 100 shown in FIG. Specifically, one of the capacitors 105 is The electrode is connected to the other electrode of the capacitor 103 and the source or drain of the transistor 101. 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, scanning line, gate line, transistor gate This allows the number of wires to be reduced. This can be done.

[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. 8A. 8B shows an example in which the circuit 100 is connected to the line 24. In FIG. 8B shows an example in which a light emitting diode is used instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wires 26 to be reduced.

[0125] The semiconductor device shown in FIG. 8C is a circuit in which the wiring 26 is arranged in the circuit 100 shown in FIG. 8A. 8C, the circuit 100 is connected to the load 104. 8C shows an example in which a light emitting diode is used instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wires 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. 8A. 8(D) shows an example in which the circuit 100 is connected to the line 22. 8D shows an example in which a light emitting diode is used instead of the load 104. The light emitting element 104a or the light emitting element 104b may be used. This allows the number of wires 26 to be reduced.

[0127] The load 104, the light emitting element 104a or the light emitting element 104b is connected to the capacitive element 105. By adding this to the circuit 100, the third and fourth operations described in this embodiment can be performed. Therefore, the charge fluctuation at either the source or the drain of the transistor 101 is suppressed. Therefore, the voltage Vα 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, by appropriately adjusting the capacitance value of the capacitor 105, the amount of charge in the period T14 can be The amount of change in potential due to Q can be adjusted. This reduces the variation in mobility. , can be done 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 desirable that the ratio be smaller than the above, preferably 1 / 2 or less, and more preferably 1 / 3 or less. Alternatively, the capacitance value of the capacitive element 105 is set to be equal to the capacitance of the load 104 (light emitting element 104a). It is desirable that the value be smaller than this, preferably 1 / 2 or less, more preferably 1 / 3 or less. This allows for 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) are The total area is preferably larger than the area of ​​the electrode of the capacitor 103, and more preferably at least twice as large. , and more preferably, 5 times or more. The total capacitance value of the capacitor 103 is larger than the total capacitance value of the capacitor 103. It is preferable that the ratio is 2 times or more, and more preferably 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, a larger 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] 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 desirable that it is smaller than the product, preferably 1 / 2 times or less, more preferably 1 / 3 times or less 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 3, preferably 1 / 2 or less, more preferably 1 / It is preferable to set it to 3 times or less. This allows for optimal operation within the same layout area. However, one aspect of the embodiment of the present invention is not limited to this.

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

[0133] The semiconductor device shown in FIGS. 9A to 9D includes the circuit 1 shown in FIGS. 00, a circuit 201 having a function of supplying a constant voltage or signal to the wiring 21, and a 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 potential. Alternatively, the wiring 26 may be used as a capacitance wiring. It is desirable that the potential of the wiring 26 is constant. However, one aspect of the embodiment of the present invention is not limited to this, and may vary like a pulse signal. .

[0134] In addition, the circuit 100 shown in any one of FIGS. 1(B) to 1(D) and FIGS. 8(B) to 8(D) may be The color filter may be used as a pixel of a display device. Then, pixels corresponding to a plurality of hues are displayed. 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 element 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 the pixel corresponding to (B). The transistor 101(R), the transistor 101(G) included in the circuit 100(G), and the circuit At least one of the transistors 100(B) and 101(B) has the channel The ratio of channel width to channel length may be different from the others. a load 104(R) included in the circuit 100(G), a load 104(G) included 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 is preferably 1.2 times or more than that of the transistor 101 corresponding to the first color. More preferably, it is 1.5 times or more. The ratio of the channel width to the channel length of the transistor 101 is 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 circuit diagram in which 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 The transistor 101(R) included in the circuit 100(R) and the transistor 101(G) included in the circuit 100(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 other circuits. 100(R) has a load 104(R), the circuit 100(G) has a load 104(G), The currents supplied to the loads 104(B) of the circuit 100(B) are set to different values. It can be determined.

[0137] In addition, in the case of FIG. 10B, the capacitor 105(R) included 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 the capacitance value 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 size is 1.5 times or more, more preferably 2 times or more, than that of the child 105. However, one aspect of the embodiment of the present invention is not limited to this.

[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 addition, in FIG. 10B, the circuit 100 shown in FIG. 8A is used as a pixel of a display device. 8B to 8D. It may also 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 11A, the transistor 101, the capacitor 102, and the capacitor 103 are included. FIG. 11(A) shows an example in which the transistor 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 the 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 source and the drain of the transistor 101. One of the source and drain electrodes or the other electrode of the capacitor 103 and one of the electrodes of the capacitor 102 are connected to each other. The capacitor 103 has a function of controlling conduction between the first electrode and the second electrode of the capacitor 103. The switch 14 is connected to either the source or the drain of the transistor 101 or the capacitance element The transistor 103 has a function of controlling the conduction state 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 and 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. 11(A) has a load 104 as shown in FIG. 11(B). In the circuit 100 shown in FIG. 11B, the load 104 may be a transistor 101. between one of the source or drain of the capacitor 103 and the wiring 24, or between the other electrode of the capacitor 103 and the wiring 24 is connected to.

[0143] FIG. 11C shows the 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 source 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. The case where the cathode of 104a is connected to the wiring 24 is shown as an example.

[0144] 11D shows the circuit 10 when a light emitting element 104b is used as the load 104. 11D shows the structure of the light-emitting element 104b. 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. 1, the anode of the light emitting element 104b is connected to the wiring 24. Note that FIG. 11D shows an example in which the transistor 101 is a p-channel transistor. This shows that.

[0145] Further, 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

[0146] The semiconductor device shown in FIGS. 12A to 12D is a semiconductor device shown in FIGS. 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. 22, 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 driving 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 also has a function of supplying a potential Vi2 to the wiring 22. Therefore, the wiring 22 can transmit the potential Vi2. The wiring 22 has a function of being able to supply or supplying 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 also be used. It may be moved.

[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 current to the load 104. Alternatively, the wiring 23 may function as a power supply line. Alternatively, the wiring 23 functions as a current supply line. The potential of 23 is preferably a constant potential, but one aspect of the present invention is that For example, the potential of the wiring 23 is not limited to a constant value, but may fluctuate like a pulse signal. 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 current to the load 104. Alternatively, the wiring 24 can supply 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 desirable 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 vary like a pulse signal. For example, the potential of the wiring 24 is applied to the load 104 not only as a forward bias voltage but also as a reverse bias voltage. It may also be a potential that applies pressure.

[0151] The circuit 224 also has a function of supplying a potential Vi1 to the wiring 25. Therefore, the wiring 25 can transmit the potential Vi1. The wiring 25 has a function to be able to supply or to provide the same. 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 also be used. It may be moved.

[0152] 12A to 12D, the semiconductor device includes a circuit 2 in addition to the circuit 100. 20, a case where the circuit 221, the circuit 222, the circuit 223, and the circuit 224 are included as an example. 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 have all of the circuits 222, 223, and 224, and any one of them may be used. It may have only one or more.

[0153] 11 and 12, the circuit 100 includes, for example, a switch 11 and a switch 12. 2. Transistors can be used for the switches 13 and 14.

[0154] In the circuit 100 shown in FIGS. 11A to 11D, a transistor is used as the switch 11. transistor 11t as switch 12, transistor 12t as switch 13 13t and a transistor 14t 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 example shows a case where all the transistors 11t are n-channel. The transistors 12t, 13t, and 14t are all transistors of the same polarity. By using a MOSFET as a transistor, these transistors can be manufactured with fewer steps. One aspect of the embodiment is not limited to this, and transistors of different polarities may also 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 capacitor 14t is connected to the wiring 34. In accordance with the potential supplied to the wiring 34, The transistor 14t is turned on or off. The potential of 34 is preferably pulsed and not constant, but in one embodiment of the present invention. Alternatively, the wirings 31 to 34 may be gate signal lines, selection signal lines, or the like. It functions as a signal line or a scanning 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. 00 can be connected to at least one of the wirings 31 to 34.

[0157] Further, 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 FIGS. 14A to 14D is a semiconductor device shown in FIGS. In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is , 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. The semiconductor device according to one embodiment of the present invention does not necessarily include the circuits 230, 231, 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 okay to have it.

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

[0162] Furthermore, 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

[0163] The semiconductor device shown in FIG. 38(C) and FIG. 38(D) is the same as that shown in FIG. 38(A) and FIG. 38(B). In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is , 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.

[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. The semiconductor device according to one embodiment of the present invention does not necessarily include the circuits 230, 231, 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 a 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 that the length of the transistor 14t is longer than that of the transistor 14t. Preferably, it is 10 times or more. The channel length or gate length 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 Preferably, it is 5 times or more, more preferably 10 times or more. The channel width or gate width of the transistor 101 is preferably 20 μm or more. More preferably, the thickness is 30 μm or more. However, one aspect of the embodiment of the present invention is to Not limited.

[0166] The semiconductor devices shown in FIGS. 13(A) to 13(D) and FIGS. 38(A) and 38(B) In this device, the gates of the transistors 12t and 13t are both connected to the same wiring. 15(A) to 15(D) show the configurations of the casing ... In the semiconductor device shown in FIG. 1D, the gates of the transistors 12t and 13t are 10. The case where the potential is connected to the wiring 32 is shown as an example. As a result, the transistor 12t and the transistor 13t are in a conductive state or a non-conductive state.

[0167] Further, 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 FIGS. 16A to 16D is a semiconductor device shown in FIGS. In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is , 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, circuit 231, and 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 to have all of them, and it may have only one or more of them.

[0170] In addition, in the circuit 100 shown in FIG. 16C, the transistor 101 and the transistor 11 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, the transistor 101, the transistor 11t, and the 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 channel type is shown in FIG.

[0171] Furthermore, a semiconductor device according to one embodiment of the present invention includes a circuit 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

[0172] The semiconductor device shown in FIG. 42(C) and FIG. 42(D) is the same as that shown in FIG. 42(A) and FIG. 42(B). In addition to the circuit 100, a circuit 230 having a function of supplying a constant voltage or signal to the wiring 31 is , 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, circuit 231, and 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 to have all of them, and it may have only one or more of them.

[0174] In the semiconductor device shown in FIGS. 13A to 13D, the adjacent circuits 100 The gate of one transistor may be connected to the gate of another transistor. For example, the gates of 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 included in the circuit 100(i, j+1) in the j+1th row is connected to the 10 shows an example in which the first wiring 31(j) is connected.

[0175] In the semiconductor device shown in FIGS. 15A to 15D, the adjacent circuits 100 The gate of one transistor may be connected to the gate of another transistor. For example, the gates of 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 included in the circuit 100(i, j+1) in the j+1th row is connected to the 10 shows an example in which the first wiring 31(j) is connected.

[0176] 39 and 40, the gate of the transistor 11t in the circuit 100 on the jth row and the gate of the transistor 14t included 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 configurations 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 how 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 row wiring 31(j) and the j+1-th row wiring 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 using the circuit 100 shown in FIG. 11C as an example. This article explains:

[0179] The operation of the circuit 100 shown in FIG. 11C mainly includes 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 actions or delete some actions.

[0180] In FIG. 11C, a switch 14 is added to the circuit of 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. 11(C), the switch 11, the switch 12, the switch 13, 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 7(A), the switch 11 is in a non-conducting state, the switches 12, 13, and The switch 14 is in a conducting state. Therefore, in the period T11, as shown in FIG. 17(B), The voltage Vi2-Vi1 is supplied to the capacitance element 102, and the anode of the light emitting element 104a is at 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] The switch 11 is in a conductive state when the potential of the wiring 21 does not have an adverse effect. In this case, the switch 14 may be in a non-conducting state.

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

[0185] The second operation performed in the period T12 will be described. In the period T12, ), the switches 11 and 14 are in a non-conducting state, the switches 12 and Switch 13 is in a conducting state. Switch 11 and switch 14 are in a non-conducting state. The charge stored in the capacitor 102 is released 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 capacitor 102 stops. Finally, 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, the threshold voltage Vth is held in the capacitor 102, and the anode of the light emitting element 104a is at a potential The gate-source voltage (Vgs101) of the transistor 101 is Vi2-Vth. That is, 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 voltage is not lowered completely to Vth before operation. The period T12 may end when the voltage Vth is slightly higher than the minimum voltage Vth. That is, at the end of the period T12, Vgs101 is It can also be said that the voltage is of a certain magnitude.

[0187] In the second operation, whether 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 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 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 achieve this, it is desirable to prevent current from flowing through the light emitting element 104a. However, in one embodiment of the present invention, the potential Vi2 is preferably set to a low value so that the The embodiment is not limited to this. By turning off the light emitting element 104a, it is possible to prevent current from flowing to 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, ), the switches 11 and 14 are in a conducting state, the switches 12 and 13 are in a conducting state, and the switches 11 and 14 are in a conducting state. 13 is in a non-conductive state. The potential Vsig is supplied to the wiring 21. At T13, as shown in FIG. 18A, the capacitance element 102 is applied 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 The potential of the gate becomes the potential Vsig+Vth, and the gate-source voltage of the transistor 101 (V gs101) is the voltage Vsig+Vth-Vi1. 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, the switch 14 may be placed in a non-conducting state.

[0191] The fourth operation performed in the period T14 will be described. In the period T14, ), the switches 11, 12, 13, and 14 are non-conductive. Therefore, in the period T14, as shown in FIG. 18B, 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 current can be passed through the light emitting element 104a, and the light emitting element 104b emits light with 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 fluctuations 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 influence of the current value supplied to the element 104a. This can reduce noise and provide a high-quality display.

[0193] Similarly, the gate-source voltage (Vgs101) of the transistor 101 is set to the 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 value of the current supplied to the light emitting element 104a. Alternatively, it is possible to prevent the light emitting element 104a from deteriorating and causing the light emitting element 10 Even if the voltage-current characteristics of the light emitting element 104a change and Vel changes, the change is not applied to the light emitting element 104a. Therefore, it is possible to reduce display unevenness and improve 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 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-light emitting 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 this from happening.

[0195] In the semiconductor device of 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 capacitor 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 voltage 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 value of the capacitive element 103 is the capacitance value of the parasitic capacitance of the load 104 (light emitting element 104a). It is desirable that it is smaller than, preferably 1 / 2 times or less, more preferably 1 / 5 times or less. Alternatively, the area of ​​the electrode of the capacitor element 103 is preferably the same as that of the load 104 (light-emitting element 104a ) is preferably smaller than the area of ​​the electrode, preferably 1 / 2 or less, more preferably Preferably, 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 greater than the capacitance of the parasitic capacitance of the gate of the transistor 101. It is also desirable that the value be 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 channel of the transistor 101. It is desirable that the size is larger, preferably at least two times larger, and more preferably at least five times larger. 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 desirable that the difference is larger than the above, preferably at least two times, and more preferably at least five times. As a result, the potential Vsig is input, and the capacitance of the capacitor 102 and the gate capacitance of the transistor When the voltage is divided by the capacitance, the decrease in the voltage of the capacitor 102 can be reduced. However, one aspect of the embodiment of the present invention is not limited to this.

[0198] The capacitance value of the capacitor 102 is approximately the same as the capacitance value 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 ±20% or less, and more preferably ±10% or less. 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 that the size of the same However, one aspect of the embodiment of the present invention is that , but is not limited to this.

[0199] 19A to 19D are schematic diagrams of the circuit 100 in the periods T11 to T14. 19(D) and 19(D), respectively. It is sufficient if the structures shown in FIGS. 19(A) to 19(D) can be taken in each period. Therefore, a semiconductor device according to one embodiment of the present invention includes a circuit having the configuration shown in FIGS. The semiconductor device according to one embodiment of the present invention is not limited to the circuit 100. In this case, the arrangement and number of switches are determined so that the structures shown in FIGS. 19(A) to 19(D) can be realized. 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 switches 11 and 12 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 inverter 101 is shown below. 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. This timing chart differs from the timing chart shown in FIG.

[0203] The sixth operation performed in the period T16 will be described. In the period T16, ), 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 to a value that is lower than the value at which the anode of the light-emitting element 104a is electrically floating (floating state). The potential Vα is a potential that 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 value of the transistor Since the transistor 101 is turned on, a current flows through the transistor 101 to the anode of the light emitting element 104a. Therefore, the potential Vα is not determined only by the ratio of the capacitances. The value also changes depending on the charge flowing into the anode of the optical element 104a.

[0205] The charge amount Q is expected to have the effect of suppressing the variation in mobility. The reason for this is explained below. and explain.

[0206] The charge Q flows from the drain to the source of the transistor 101 during the period T16. Therefore, the charge amount Q increases as the mobility of the transistor 101 increases. When the charge amount Q increases, the transistor The gate-source voltage (Vgs101) of the transistor 101 becomes smaller. The larger the mobility of the transistor 101, the more the amount of electrons supplied to the light emitting element 104a. The current value is corrected to be smaller, and the smaller the mobility of the transistor 101, the However, 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. The gate-source voltage can be set to a value that takes into account the threshold voltage Vth and mobility.

[0208] 8, the semiconductor device according to one embodiment of the present invention includes the circuit 1 shown in FIG. 00 may further include a capacitive element 105 connected to a load 104. Similarly, 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. It may further include a capacitor 105 connected to 104b.

[0209] The semiconductor device shown in FIG. 21A is the same as the circuit 100 shown in FIG. 11B except that the load 10 4. Specifically, one of the capacitors 105 One 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 the wiring 26. 21A shows an example in which the circuit 100 includes a load 104. 21A, the load 104 is replaced by 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, scanning lines, gate lines, This allows the number of wires to be reduced. can be reduced.

[0211] The semiconductor device shown in FIG. 21B is different from the circuit 100 shown in FIG. 21A in that the wiring 26 21B shows an example in which the circuit 100 is connected to the wiring 24. 21B 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.

[0212] The semiconductor device shown in FIG. 21C is the same as the circuit 100 shown in FIG. 21A except that the wiring 26 21C shows an example in which the circuit 100 is connected to the wiring 23. 21(C) 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.

[0213] The semiconductor device shown in FIG. 21D is the same as the circuit 100 shown in FIG. 21A except that the wiring 26 21D shows 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 the same as the 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 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 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 controlled by the voltage Vsi This allows us to get closer to a value that accurately reflects g.

[0216] Alternatively, the capacitance value of the capacitor 105 may be adjusted appropriately to adjust the charge amount during the period T16. The amount of change in potential due to Q can be adjusted. This reduces the variation in mobility. , can be done 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 desirable that the ratio be smaller than the above, preferably 1 / 2 or less, and more preferably 1 / 3 or less. Alternatively, the capacitance value of the capacitive element 105 is set to be equal to the capacitance of the load 104 (light emitting element 104a). It is desirable that the value be smaller than this, preferably 1 / 2 or less, more preferably 1 / 3 or less. This allows for 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) are The total area is preferably larger than the area of ​​the electrode of the capacitor 103, and more preferably at least twice as large. , and more preferably, 5 times or more. The total capacitance value of the capacitor 103 is larger than the total capacitance value of the capacitor 103. It is preferable that the ratio is 2 times or more, and more preferably 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, a larger 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] 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 desirable that it is smaller than the product, preferably 1 / 2 times or less, more preferably 1 / 3 times or less 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 3, preferably 1 / 2 or less, more preferably 1 / It is preferable to set it to 3 times or less. This allows for optimal operation within the same layout area. However, one aspect of the embodiment of the present invention is not limited to this.

[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, scanning line, gate line, transistor gate This allows the number of wires to be reduced. This can be done.

[0221] Further, 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

[0222] The semiconductor device shown in FIGS. 22A to 22D is a semiconductor device shown in FIGS. 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. 22, 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, the circuit 100 shown in FIG. 22A has a constant voltage or The circuit 225 has a function of supplying a signal.

[0223] 11(B) to 11(D) and 21(B) to 21(D). 100 may be used as a pixel of a display device. When a pixel is provided in a display device, the transistors of the pixel are switched according to the corresponding color. The ratio of the channel width to the channel length of the pixel 101 may be different. The capacitance value of the capacitor 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. 23(A), the circuit 100(R) is connected to the image 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, The transistor 101(R) included in the circuit 100(G) and the transistor 101(G) included in the circuit 100(G) At least one of the transistors 101(B) of the circuit 100(B) is The ratio of channel width to channel length may be different from the others. ) has a load 104(R), a circuit 100(G) has a load 104(G), a circuit 100 (B) has a load 104 (B) and the current supplied to each of the loads 104 (B) is set to a different value. can be done.

[0225] 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. 23(B), as in the case of FIG. 23(A), the circuit 10 100(R) and the transistor 101(R) included in the circuit 100(G). 101(G) and at least one of the transistors 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. The load 104(R) of the circuit 100(R) and the load 104(G) of 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 addition, in the case of FIG. 23B, the capacitor 105(R) included 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 addition, in FIG. 23(B), the circuit 100 shown in FIG. 21(A) is used as a pixel of a display device. 21(B) to 21(E) are used as an example. 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. , a current is supplied to the load 104 without performing an operation to correct the variation in the threshold voltage. It is also possible to operate them together.

[0230] This embodiment describes an example of the basic principle. Part or all of the above may be freely combined with part or all of 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 Embodiment Mode 1. 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] 24A to 24D show examples of the circuit 100. The circuit 100 shown in FIG. 24(D) is a switchable circuit for the circuit 100 shown in FIG. 1(A) to FIG. 1(D). The switch 914 corresponds to a configuration in which a The conduction state between the other of the source or drain of the transistor 101 and the wiring 23 is controlled. Alternatively, it has a function of controlling the conduction state 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 the function of preventing current from flowing to the load 104.

[0233] Further, 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

[0234] The semiconductor device shown in FIGS. 25A to 25D 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 24. and a circuit 204 having a

[0235] The circuit 100 shown in FIGS. 24 and 25 includes switches 11, 12, and 13. 3. A transistor can be used for the switch 914.

[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 can be connected to a circuit 9206 that has the 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 one of 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 is connected to the other circuit 100. It is possible to connect them.

[0238] The circuit 100 shown in FIGS. 24 and 25 operates in the same manner as the circuit 100 shown in FIGS. However, as an example, in the circuit 100 shown in FIG. 24 and FIG. 25, During periods T11 to T13 and T15 shown in FIG. 6, the switch 914 is turned on. It is preferable that the switch 914 is in a non-conducting state during the period T14. 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 this.

[0239] Alternatively, the switch 914 may be set to a non-conductive 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-conductive 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-conductive state during part of the period T15. This prevents current from flowing to the light emitting element 104a and other elements, thereby providing a non-light emitting period. Yes, it is possible.

[0242] The circuit 100 shown in FIG. 24B and FIG. 25B is the same as that shown in FIG. 8, FIG. 9, and FIG. 10B. Similarly, a capacitive element 105 connected to the load 104 may be further included. The circuit 100 shown in FIG. 24C and FIG. 25C includes a capacitor connected to the light-emitting element 104a. It may further include an element 105. 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 capacitor 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] 24B to 24D and the circuit 100 shown in FIGS. 25B to 25 10D, in which the capacitor 105 is added to the circuit 100. The pixels corresponding to the respective hues may be set on the display device. When the pixel is turned on, the channel of the transistor 101 of the pixel is turned on according to the corresponding color. The ratio of the channel width to the channel length may be different.

[0244] It is also possible to provide the switch 914 in 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 examples of the circuit 100 shown in FIG. 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 transistor 104 has a function of controlling electrical continuity between one electrode of the transistor 104 and the other electrode of the capacitor 103. If switch 913 is in a conducting state, then switch 914 turns on transistor 101. one of the source and 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 electrode and the other electrode.

[0245] Further, 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 further provided. It may have.

[0246] The semiconductor device shown in FIGS. 27A to 27D is a semiconductor device shown in FIGS. 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 24. and a circuit 204 having a

[0247] 26 and 27, the circuit 100 includes the switches 11, 12, and 1 3. A transistor can be used for the switch 914.

[0248] The circuit 100 shown in FIGS. 26 and 27 is the same as the circuit shown in FIG. 1, FIG. 2, FIG. 24, or FIG. 25. It can perform the same operations as 100.

[0249] The circuit 100 shown in FIG. 26B and FIG. 27B is the same as that shown in FIG. 8, FIG. 9, and FIG. 10B. Similarly, a capacitive element 105 connected to the load 104 may be further included. The circuit 100 shown in FIG. 26C and FIG. 27C includes a capacitor connected to the light-emitting element 104a. It may further include an element 105. 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 between one electrode of the capacitor 105 and the transistor 101. The other potential of the capacitor element 105 is controlled by the control circuit 104. The poles are connected to the separately provided wiring 26, wiring 24, wiring 23, or wiring 22.

[0250] 26B to 26D and the circuit 100 shown in FIGS. 27B to 27C. 10D, in which the capacitor 105 is added to the circuit 100. The pixels corresponding to the respective hues may be set on the display device. When the pixel is turned on, the channel of the transistor 101 of the pixel is turned on according to the corresponding color. The ratio of the channel width to the channel length may be different.

[0251] The switch 914 may be provided in a location other than that shown in FIGS. 24, 25, 26, and 27. For example, configuration examples of the circuit 100 are shown in FIGS. The circuit 100 shown in FIGS. 28A to 28D is similar to the circuit shown in FIGS. 9. Each of these 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 capacitor element 10 3. Furthermore, the switch 13 has a function of controlling the conduction 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 103. 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] Further, 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 FIGS. 29A to 29D is a semiconductor device shown in FIGS. 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 24. and a circuit 204 having a

[0254] The circuit 100 shown in FIGS. 28 and 29 includes the switches 11, 12, and 1 3. A transistor can be used for the switch 914.

[0255] The circuit 100 shown in FIGS. 28 and 29 is similar to that shown in FIGS. 1, 2, 24, 25, 26 and 27. However, as an example, the circuit 100 shown in FIG. In the circuit 100 shown in FIG. 29, the periods T11 to T13 and the period T1 shown in FIG. In period T15, switch 914 is in a conducting state, and in period T14, switch 914 is in a non-conducting state. Therefore, during the period T14, the transistor 1 It is possible to prevent electric charges from leaking to the light emitting element 104a etc. via the light emitting element 104b. However, one aspect of an embodiment of the present invention is not limited to this.

[0256] Alternatively, the switch 914 may be in a non-conductive 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-conductive state during part of the period T15. This prevents current from flowing to the light emitting element 104a and other elements, thereby providing a non-light emitting period. Yes, it is possible.

[0258] It is also possible to set the switch 914 in a non-conductive state during the period T12. At T12, the switch 914 is turned off, and the light-emitting element Therefore, the anode of the element 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 is the same as that shown in FIG. 8, FIG. 9, FIG. 10B, etc. Similarly, the amplifier may further include a capacitive element 105 connected to the load 104. 28(C) and 29(C) is connected to the light-emitting element 104a. It may further include a capacitor 105. Similarly, in FIG. 28(D) and FIG. 29(D), 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 capacitor element 105 is connected to the source or drain of the capacitor element 105. The electrode is connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring 22. .

[0260] 28B to 28D and the circuit 100 shown in FIGS. 10D, in which the capacitor 105 is added to the circuit 100. The pixels corresponding to the respective hues may be set on the display device. When the pixel is turned on, the channel of the transistor 101 of the pixel is turned on according to the corresponding color. The ratio of the channel width to the channel length may be different.

[0261] It is also possible to provide the switch 914 in a location other than that shown in FIGS. For example, configuration examples of the circuit 100 are shown in FIGS. 30A to 30D. The circuit 100 shown in FIGS. 30A to 30D is a circuit 100 shown in FIGS. 1A to 1D. 30(A) corresponds to a configuration in which a switch 914 is added to the above. The switch 914 is connected to either the source or drain of the transistor 101 and the capacitor The other electrode of the element 103 has a function of controlling the conduction state 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. 30(C), 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 conduction 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 It has the function of controlling the conduction state between the cathode of the transistor 104b and the cathode of the transistor 104c.

[0262] Further, 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 FIGS. 31A to 31D is a semiconductor device shown in FIGS. 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 24. and a circuit 204 having a

[0264] The circuit 100 shown in FIGS. 30 and 31 includes the switches 11, 12, and 1 3. A transistor can be used for the switch 914.

[0265] The circuit 100 shown in FIGS. 30 and 31 is similar to that shown in FIGS. 1, 2, 24, 25, 26, 27, It can perform the same operation as the circuit 100 shown in Figures 28 and 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 conducting 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 to the state shown in FIG. 1, 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 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-conductive 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. It can also be a value.

[0267] Alternatively, the switch 914 may be in a non-conductive 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. It can also be a value.

[0268] Alternatively, the switch 914 is kept in a non-conductive state during part of the period T15. This prevents current from flowing to the light emitting element 104a and other elements, thereby providing a non-light emitting period. Yes, it is possible.

[0269] The circuit 100 shown in FIG. 30(B) and FIG. 31(B) is the same as that shown in FIG. 8, FIG. 9, FIG. 21 and 22, a capacitance element 105 connected to a load 104 is further included. Similarly, the circuit 100 shown in FIG. 30(C) and FIG. 31(C) may be used in conjunction with the light-emitting element 10. 30(D) and 30(E), a capacitor element 105 may be further provided. 31(D) 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 capacitor 105 is connected to a separately provided wiring 26, wiring 24, wiring 23, or wiring It is connected to line 22.

[0270] 30(B) to 30(D) and the circuit 100 shown in FIGS. 10D, in which the capacitor 105 is added to the circuit 100. The pixels corresponding to the respective hues may be set on the display device. When the pixel is turned on, the channel of the transistor 101 of the pixel is turned on according to the corresponding color. The ratio of the channel width to the channel length 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 other drawings other than FIG. 1, the same as in FIGS. 24 to 31, 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 FIGS. 24 to 31. An example of such a circuit is shown in Figure 87.

[0272] Next, in the circuits of Figures 1 and 11, etc., what is the difference between the driving methods shown in Figures 5 and 17, etc.? An example of a case where a different driving method is used is shown below. It is preferable to connect the wiring 23 between pixels in the row direction rather than between pixels in the column direction. Therefore, in Figs. 34(A) to 34(D), the circuit 10 shown in Figs. 1(A) to 1(D) is 34(A) to 34(D) show examples of arrangement of 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 below 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 capacitor 102, and the gate source of the transistor 101 When the voltage between the switches (Vgs101) becomes voltage Vi2-Vi1, the wiring 21 and the switch 14 The potential Vi1 is not supplied via the line 21 but is supplied via the line 23. 5, 17, and the like can be applied to one embodiment of the semiconductor device of the present invention. is.

[0274] The operation of the circuit 100 shown in FIG. 34C mainly includes a first operation, a second operation, a third operation, and a fourth operation. It can be divided into four movements, the fourth movement and the fifth movement. However, it is not limited to these, and new movements 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, 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 gate-source of the transistor 101 is The voltage (Vgs101) is the voltage Vi2-Vi1. This means that the capacitor 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. The potential of the source of the transistor 101 rises. When the transistor 102 is in the ON state, the charge discharge from the capacitor element 102 stops. Therefore, in the period T12, the threshold voltage Vth of the capacitor 102 is held at 1. The threshold voltage Vth is maintained 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. Therefore, the period of the second operation can be secured longer. Since the threshold voltage of the resistor 101 can be obtained, a clear display with little display unevenness can be obtained. It is possible to provide instructions.

[0278] The third operation performed in the period T13 will be described. In the period T13, ), 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, the 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, or 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 during the period T14 will be described. During 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 the threshold voltage Vth, and the capacitance element 103 holds the 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 Vsig+Vth, and the potential between the gate and source of transistor 101 The voltage (Vgs101) is 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. During 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 corresponding to the potential Vsig is applied to the light emitting element 104 a, causing the light emitting element 104a to emit light with a luminance corresponding to the potential Vsig. can.

[0281] The potential Vel is set when a current is passed through the transistor 101 to the light-emitting element 104a. Specifically, it is a potential 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, and the threshold voltage Vth of the transistor 101 is taken into consideration. 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 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 above change can be prevented. Therefore, it is possible to prevent the change from affecting the value of the current supplied to the light emitting element 104a. Display unevenness can be reduced, and high-quality display can be achieved.

[0283] Note that, even during a part of the period T15, the light emission is performed by controlling the potential of the wiring 23. A non-light emitting period can be provided 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. can be done.

[0284] Although the switch 14 is not provided in FIGS. 34 and 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 FIGS. 34 and 35, the present invention is not limited to this. Similar to Figures 24 to 87, a switch 914 may be provided.

[0286] In addition, in FIG. 34 and FIG. 35, the operation was performed by changing the potential of the wiring 23, but it is also possible to use multiple wirings. 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. 1(A) to FIG. 1(D) or The switch 814 and the switch 15 are added to the circuit 100 shown in FIGS. 34 to 36, and the wiring These correspond to a configuration in which wiring 23a and wiring 23b are provided instead of 23. 32(A) to 32(D), the switch 814 is a The transistor 23a has a function of controlling the conduction state between the other of the source and the drain and the wiring 23a. The switch 15 is connected to the other of the source and 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 the wiring 21 in parallel without intersecting it.

[0288] Further, 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

[0289] The semiconductor device shown in FIGS. 33A to 33D is a semiconductor device shown in FIGS. 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; a circuit 203a having a function of supplying a 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. The circuit 203b also 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 may function as an initialization wiring. It is desirable that the potential of the wiring 23a be a constant potential. 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 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 present invention is not limited to this. For example, the potential of the wiring 23b may be changed by 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 electrode.

[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 202. 2. It is not necessary to have all of the circuits 203a, 203b, and 204. It may have only one or more.

[0293] The circuit 100 shown in FIGS. 32 and 33 includes the switches 11, 12, and 13. 3. Transistors can be used for the switches 814 and 15.

[0294] The circuit 100 shown in FIGS. 32 and 33 operates in the same manner as the circuit 100 shown in FIGS. 34 to 36. However, in the circuit 100 shown in FIGS. 32 and 33, during the period T11, During the period T12, the switch 814 is in a conducting state and the switch 815 is in a non-conducting 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. 32(B) and FIG. 33(B) is the same as that shown in FIG. 8, FIG. 9, FIG. 21, and FIG. 22. Similarly, the capacitor 105 connected to the load 104 may be further included. 32(C) and 33(C) is connected to the light-emitting element 104a. It may further include a capacitor 105. Similarly, in FIG. 32(D) and FIG. 33(D), 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 capacitor 105 is connected to one of the source and 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] 32B to 32D and the circuit 100 shown in FIGS. 10D, in which the capacitor 105 is added to the circuit 100. The pixels corresponding to the respective hues may be set on the display device. When the pixel is turned on, the channel of the transistor 101 of the pixel is turned on according to the corresponding color. The ratio of the channel width to the channel length may be different.

[0297] Although the switch 14 is not provided in FIGS. 32 and 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 FIGS. 32 and 33, the present invention is not limited to this. Similar to Figures 24 to 87, a switch 914 may be provided.

[0299] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[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, connect one wire to another, and This section describes the structure of the stopper 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. 1(C) In the circuit 100 shown in FIG. 43A, the switch 14 is connected to the capacitor 102. Controlling the conduction state between one electrode of the capacitor 103 and the wiring 25 or between one electrode of the capacitor 103 and the wiring 25 It has the function of

[0302] The operation is the same as that shown in FIGS. 17 to 20. However, in FIG. 18(A), the fourth operation In the example shown in FIG. 43(A), the switch 14 is in a conducting 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. It is also possible to use the switch 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, as shown in FIG. ), the case where a switch 914 is provided as in FIG. 30 is shown in FIG. 43(F).

[0304] 8, 9, 21, 22, etc., the circuit 100 shown in FIG. 43(A) may be configured as follows: It is possible to add a capacitor 105. For 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 the wiring 26 .

[0305] The wiring 26 can be connected to various wirings, as in FIGS. 8 and 21. 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 the wiring of the other circuit 100 It can be connected to a variety of wiring.

[0306] The wiring 25 can be connected to various wirings. For example, 43A, the wiring 25 is connected to the wiring 24. An example of a device connected to the following is shown below.

[0307] The circuit 100 shown in FIG. 43E is similar to the circuit 100 shown in FIG. 43D except that a capacitive element One electrode of the capacitor element 105 is connected to the capacitor element 105. The other electrode of the capacitor 105 is connected to the wiring 26. It has been done.

[0308] 44 includes a circuit 100 shown in FIG. 43 and a wiring 21 connected to the circuit 100. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 225 includes a plurality of circuits.

[0309] 43 and 44 show the configuration of the circuit 100 when the light emitting element 104a is used. However, a semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIGS. In the configuration, the light emitting element 104a is not provided, or the load 104 is provided instead of the light emitting element 104a. Alternatively, it may have a configuration including a 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. 45(A) can be implemented as In the circuit 100, the wiring 25 is connected to the wiring 24.

[0311] 8, 9, 21, 22, etc. for the circuit 100 shown in FIG. 45(A). Similarly, it is possible to add a capacitor 105 or connect a wiring. The circuit 100 shown in FIG. 45B is the circuit 100 shown in FIG. 45A with 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. It is also possible to connect both the wiring 26 and the wiring 25 to the wiring 24.

[0312] The semiconductor device shown in FIGS. 45(C) and 45(D) is similar to the semiconductor device shown in FIGS. 45(A) and 45(B). 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 shown. 20, a circuit 221 having a function of supplying a constant voltage or signal to the wiring 22, a constant voltage to the wiring 23, a circuit 222 having a function of supplying a voltage or signal; a function of supplying a constant voltage or signal to the wiring 24; a circuit 223 having a function of supplying a constant voltage or signal to the wiring 26; Each of the circuits has a plurality of circuits.

[0313] Although FIG. 45 shows the configuration of the circuit 100 when 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 the circuit 100 shown in FIG. 4a, or a load 104 or a light-emitting element 104a 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 FIGS. 11, 32, 34, 43, 45, etc., or Alternatively, the switch 14 may be added to the circuits shown in Figs. 24, 26, 28, 30, 32, 34, etc. For example, the circuit 100 shown in FIG. 46A can be implemented as a circuit shown in FIG. 28(C) or the circuit 100 shown in FIG. 28(C). In the circuit 100 shown in FIG. 46(A), the switch 14 is added. The transistor 101 is connected to the other end of the capacitor 103 via a transistor 914. The light emitting element 104a has a function of controlling the conduction state between the light emitting element 104a and the other electrode or the anode of the light emitting element 104a.

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

[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 that shown in FIG. 46(A). 43(A), the switch 14 is provided as a capacitance element. The conduction 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 not only one switch equivalent to the switch 14 but also multiple switches. For example, the circuit 100 shown in FIG. 46(D) includes a capacitor element 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 one electrode of the capacitor 102 and one electrode of the capacitor 103; The switch 14b has a function of controlling the conduction state between the electrode and the wiring 25. In other words, the configuration of the circuit 100 shown in FIG. It can be said that switch 14 has been added in two places.

[0318] 47, in addition to the circuit 100 shown in FIG. 46, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

[0319] 46 and 47 show the configuration of the circuit 100 when the light emitting element 104a is used. However, a semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIGS. In the configuration, the light emitting element 104a is not provided, or the load 104 is provided instead of the light emitting element 104a. Alternatively, it may have a configuration including a 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 FIGS. 46 and 87. Various configurations can be used. In this case, the driving method is as 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 the circuit 100 shown in FIG. 46(A) except that the position of the switch 14 is different. In the circuit 100 shown in FIG. 8(A), the switch 14 is connected to the source or drain of the transistor 101. It has the function of controlling the conduction state 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. 48(B) can be implemented as a 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 FIGS. 48(C) and 48(D) is similar to the semiconductor device shown in FIGS. 48(A) and 48(B). 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 shown. 20, a circuit 221 having a function of supplying a constant voltage or signal to the wiring 22, a constant voltage to the wiring 23, a circuit 222 having a function of supplying a voltage or signal; a function of supplying a constant voltage or signal to the wiring 24; a circuit 223 having a function of supplying a constant voltage or signal to the wiring 25; Each of the circuits has a plurality of circuits.

[0323] Although FIG. 48 shows the configuration of the circuit 100 when 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 the circuit 100 shown in FIG. 4a, or a load 104 or a light-emitting element 104a instead of the light-emitting element 104a. b) may be included.

[0324] The circuit 100 shown in FIG. 49A is different from the case where the switch 14 and the switch 914 are provided. 11C. In this example, a switch 914 is added to the circuit 100 shown in FIG. 11C. 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 the 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] In this case, the driving method is the same as that shown in FIGS. 5, 6, 17, 18, 20, 35, and 36. An example of the 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 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 capacitor element 101 and the capacitor 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, it may be in a conducting state. 4 may be in a non-conducting state.

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

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

[0330] The second operation performed during the period T12 will be described. During the period T12, the switch 1 1, switch 14 and switch 914 are in a non-conductive state, and switch 12 and switch 13 are in a conductive state When the switches 11, 914, and 14 are in a non-conducting state, The charge stored in the capacitor element 102 is released through the transistor 101. The potential of the source of transistor 101 rises. Then, when 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 capacitance element 102 The value voltage Vth is maintained, 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 (or V That is, the threshold voltage Vth of the transistor 101 (or a voltage of a magnitude according to Vth) can be obtained.

[0331] In the second operation, whether 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 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 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. It is desirable to prevent current from flowing through the light emitting element 104a. For this purpose, it is preferable to set the potential Vi2 to a low value. By setting the state, it is possible to prevent current from flowing to 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 during the period T13 will be described. During the period T13, the switch 1 Switch 1 and switch 14 are in a conducting state, and switch 12, switch 13, and switch 914 are in a non-conducting state. 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 The gate-source voltage of transistor 101 (Vgs101) is Vsig+Vth-Vi1. Therefore, the potential Vsig can be input to the capacitor 103. The sum of the voltage of the capacitance element 102 and the voltage of the capacitance element 103 is It is possible to make it the inter-substrate 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 during the period T14 will be described. During the period T14, the switch 1 1, switch 12, switch 13, and switch 14 are in a non-conducting state, and switch 91 Therefore, during the period T14, the threshold voltage Vth is held in the capacitor 102. The voltage Vsig-Vi1 is held in the capacitor 103, and the anode of the light emitting element 104a The potential of the gate of the transistor 101 is Vsig+Vth+Ve The gate-source voltage of transistor 101 (Vgs101) is Vsig+ Therefore, a current having a magnitude corresponding 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 corresponding 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 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-light emitting 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, by turning off the switch 914, 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] The sixth operation performed during the period T16 will be described. During 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 to a value that is lower than the value at which the anode of the light-emitting element 104a is electrically floating (floating state). The potential Vα is a potential that 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 value of the transistor Since the transistor 101 is turned on, a current flows through the transistor 101 to the anode of the light emitting element 104a. Therefore, the potential Vα is not determined only by the ratio of the capacitances. The value also changes depending on the charge flowing into the anode of the optical element 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. When configured in this way, the gates of the transistors can be connected together, as in Figure 15. is.

[0343] Furthermore, the wiring 22 and the wiring 25 can be connected to various other wirings. For example, The circuit 100 shown in FIG. 49B differs from the circuit 100 shown in FIG. 49A in that the wiring 25 is connected to the 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 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] 49(C) is an example of a case where the capacitance element 105 is provided in a different arrangement from that of FIG. 49(C). The circuit 100 shown in FIG. 49D is obtained by adding a capacitor 105 to the circuit 100 shown in FIG. 49A. 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 the 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 signal; a function of supplying a constant voltage or 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 225 includes a plurality of circuits.

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

[0348] 49(C) and 49(D), the same applies to 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] Although FIG. 49 shows a case where one capacitance element 105 is added, One embodiment is not limited to this. It is possible to add many capacitance elements. For example, the circuit 100 shown in FIG. 49A. The circuit 100 shown in FIG. 49A is provided with a capacitor 105a and a capacitor 105b. 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 capacitor element 105b is connected to the anode of the light emitting element 104a. The other electrode of element 105 b is connected to wiring 27 .

[0350] The wiring 25 can be connected to other wirings, for example, as shown in FIG. The circuit 100 shown in FIG. 50(C) is the circuit 100 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. 50D. 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. 51A except that 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 signal; a function of supplying a constant voltage or 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 having a function of supplying a constant voltage or a signal to the wiring 27; Each of the circuits has a

[0354] An example of the circuit 226 is a power supply circuit. , or has the ability to convey or provide; or The wiring 27 functions as a capacitance wiring. The potential of the wiring 27 is a constant potential. However, one aspect of the embodiment of the present invention is not limited to this, and a pulse signal may be used. 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 the circuit 100.

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

[0356] In the various circuits described above, the wiring 22 can be connected to other wirings. As a result, it is possible to reduce the number of wirings. 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 different from the circuit 100 shown in FIG. 11C in that the wiring 22 is provided. 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. 1C. A configuration in which the line 22 is connected to the wiring 21 is shown.

[0358] Also, it is possible to add a capacitance element 105 as in the case of FIGS. 8, 9, 21, 22, etc. For example, the circuit 100 shown in FIG. 53(C) 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 etc., 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 signal; a function of supplying a constant voltage or 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 signal.

[0361] 53 and 54 show the configuration of the circuit 100 when the light emitting element 104a is used. However, a semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIGS. In the configuration, the light emitting element 104a is not provided, or the load 104 is provided instead of the light emitting element 104a. Alternatively, it may have a configuration including a 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 certain 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. 11C in that the wiring 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. 1A, a wiring 22 is connected to a wiring 21.

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

[0364] It is also possible to apply this to the case where the position of the switch 14 is changed, as shown in FIG. The circuit 100 shown in FIG. 43(E) is different from the circuit 100 shown in FIG. 43(E) in that the wiring 22 is connected to the wiring 21. The connected configuration is shown.

[0365] 56, in addition to the circuit 100 shown in FIG. 55, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 when the light emitting element 104a is used. However, a semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIGS. In the configuration, the light emitting element 104a is not provided, or the load 104 is provided instead of the light emitting element 104a. Alternatively, it may have a configuration including a light emitting element 104b.

[0367] The circuit 100 shown in FIG. 57A is similar to the circuit 100 shown in FIG. 46A in that 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. 28C in that 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 FIGS. 8, 9, 21, 22, etc. For example, the circuit 100 shown in FIG. 57C is similar to the circuit 100 shown in FIG. , corresponds to a configuration in which a switch 914 is added.

[0370] The circuit 100 shown in FIG. 57(D) is similar to the circuit 100 shown in FIG. 53(D) except that 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, in addition to the circuit 100 shown in FIG. 57, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

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

[0373] The circuit 100 shown in FIG. 59A is similar to the circuit 100 shown in FIG. 57A in that the arrangement The configuration when the line 25 is connected to the wiring 24 is shown.

[0374] The circuit 100 shown in FIG. 59B is similar to the circuit 100 shown in FIG. 57C in that The configuration when the line 25 is connected to the wiring 24 is shown.

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

[0376] 60, in addition to the circuit 100 shown in FIG. 59, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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, a semiconductor device according to one embodiment of the present invention includes the circuit 100 shown in FIGS. In the configuration, the light emitting element 104a is not provided, or the load 104 is provided instead of the light emitting element 104a. Alternatively, it may have a configuration including a light emitting element 104b.

[0378] The wiring 22 can be connected to wiring other than the wiring 21. For example, the wiring 22 can 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] The circuit 100 shown in FIG. 61B is different from the circuit 100 shown in FIG. 1C in that the wiring 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. 21A except that The diagram shows a configuration in which the line 22 is connected to the wiring 24 .

[0381] The circuit 100 shown in FIG. 61D is the same as the circuit 100 shown in FIG. 43A except that The diagram shows a configuration in which the line 22 is connected to the wiring 24 .

[0382] 62, in addition to the circuit 100 shown in FIG. 61, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

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

[0384] Also, it is possible to add a capacitance element 105 as in the case of FIGS. 8, 9, 21, 22, etc. For example, the circuit 100 shown in FIG. 63(A) is similar to the circuit 100 shown in FIG. 61(B). 8A. In the circuit 100 shown in FIG. 8A, the capacitor 105 is added. 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 similar to the circuit 100 shown in FIG. 46A in that This corresponds to a configuration in which the line 22 is connected to the wiring 24.

[0386] The circuit 100 shown in FIG. 63C is similar to the circuit 100 shown in FIG. 28C in that 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 the same as the circuit 100 shown in FIG. 63(C). 100, a capacitance element 105 is added as in FIGS. 8, 9, 21, 22, etc. Equivalent.

[0388] 64, in addition to the circuit 100 shown in FIG. 63, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

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

[0390] The circuit 100 shown in FIG. 65(A) is similar to the circuit 100 shown in FIG. 61(D) except that a switch In the circuit 100 shown in FIG. 65(A), the switch 914 is connected to one of the source and drain of the transistor 101 and the other electrode of the capacitor 103. It also has the function of controlling the conduction state between the anode of the light emitting element 104a and the cathode of the light emitting element 104b.

[0391] The circuit 100 shown in FIG. 65B is similar to the circuit 100 shown in FIG. 61A in that 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. 61C. 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. 61(D). 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 wiring 21 connected to the circuit 100. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

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

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

[0397] The circuit 100 shown in FIG. 67B is the same as the circuit 100 shown in FIG. 65D. 8, 9, 21, 22, etc., corresponds to a configuration in which a capacitive element 105 is added.

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

[0399] 68, in addition to the circuit 100 shown in FIG. 67, a constant voltage is applied to the wiring 21. a circuit 220 having a function of supplying a voltage or signal; a function of supplying a constant voltage or 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 signal.

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

[0401] In the circuit 100 shown in FIG. 32, as in the previous figures, the switch 14 32, a switch 914, a capacitor element 105, etc. can be added. In the circuit 100, various wires are connected to other various wires to reduce the number of wires. For example, the circuit 100 shown in FIG. 69(A) to FIG. 69(D) can be implemented as 1, a switch 14 is added to the circuit 100 shown in FIGS. 32(A) to 32(D). These correspond to the above configurations, respectively.

[0402] Further, 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 FIGS. 70(A) to 70(D) is a semiconductor device shown in FIGS. 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; a circuit 222a having a function of supplying a voltage or a signal to a wiring 23b; 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. Has.

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

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

[0406] The circuit 100 shown in FIG. 73(B) is similar to the circuit 100 shown in FIG. 69(C) except that a switch The switch 914 corresponds to a configuration in which the switch 914 is added to the transistor 101. One of the source and drain electrodes of the capacitor 103 and the anode of the light-emitting element 104a It has the function of controlling the conduction state between the

[0407] Furthermore, 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 further provided. It may have.

[0408] The semiconductor device shown in FIG. 73(C) and FIG. 73(D) is the same as that shown in FIG. 73(A) and FIG. 73(B). 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; a circuit 222a having a function of supplying a voltage or a signal to a wiring 23b; 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. Has.

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

[0410] In the circuit 100 shown in FIG. 34, as in the previous figures, the switch 14 34, a switch 914, a capacitor element 105, etc. can be added. In the circuit 100, various wires are 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 the semiconductor device of one embodiment of the present invention will be described below using the circuit 100 in FIG. 71C as an example. An example will be described.

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

[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 conducting state, and the potential Vi1 is supplied to the wiring 23. During 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) is the voltage Vi2-Vi1.

[0414] Although FIG. 72(A) shows an example in which the switch 11 is in a non-conducting state, The switch 11 may be in a conducting state. Also, in FIG. 72(A), the switch 14 is in a non-conducting state. Although the case where the switch 14 is in a conducting state is shown as an example, the switch 14 may be in a conducting 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 voltage Vi2-Vi3. Also, the switch 13 may be in a conducting state.

[0415] The second operation performed during the period T12 will be described. During the period T12, ), the switches 11 and 14 are in a non-conducting state, the switches 12 and The wiring 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 eventually the threshold voltage Vth of the transistor 101 becomes Therefore, during the period T12, the threshold voltage Vth is held in the capacitive element 102. The anode of the light emitting element 104a is maintained 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 during the period T13 will be described. During the period T13, ), the switches 11 and 14 are in a conducting state, the switches 12 and 13 are in a conducting state, and the switches 11 and 14 are in a conducting state. The wiring 21 is supplied with a potential Vsig, and the wiring 23 is supplied with a potential Vsig. The potential VDD is supplied to the line 25, and the potential Vi3 is supplied to the line 25. Therefore, in the period T13, The capacitive element 102 holds the threshold voltage Vth, and the capacitive element 103 holds the voltage Vsig-Vi3. The anode of the light emitting element 104a is held at a potential Vi3, and the gate of the transistor 101 The potential of the gate 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.

[0417] The fourth operation performed during the period T14 will be described. During the period T14, ), 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 the threshold voltage Vth, and the capacitive element 103 holds the voltage Vsig-Vi3. The anode of the light emitting element 104a is held at a potential Vel, and the gate of the transistor 101 The potential of the gate of the transistor 101 becomes Vsig+Vth-Vi3+Vel. The source voltage (Vgs101) is Vsig+Vth-Vi3.

[0418] The potential Vel is set when a current is passed through the transistor 101 to the light-emitting element 104a. 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 is Vsig+Vth-Vi3, and the threshold voltage Vth of the transistor 101 is taken into consideration. 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 affected. Alternatively, even if the transistor 101 deteriorates and the threshold voltage Vth changes, the above change does not occur. Therefore, it is possible to prevent the influence of the current value supplied to the optical element 104a. This reduces noise and allows for high-quality display.

[0420] In the semiconductor device of 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 capacitor 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 voltage 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. , wiring 24, wiring 25, wiring 26, wiring 27, or wiring of another circuit 100, scanning line, This shows the case where the device is connected to a gate line, a wiring connected to the gate of a transistor, etc. This reduces the number of wires. 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, change, add, modify, delete, adapt, supersede or subsede Therefore, a part or all of the present embodiment may be used in conjunction with other embodiments. It may be freely combined with, applied to, or substituted for any or all of the above. can.

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

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

[0424] In FIG. 74(B), the circuit 100(i, j) in the i-th column and the j-th row and the 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 are connected to one wiring. They share 23.

[0425] In FIG. 74(C), the circuit 100(i, j) in the i-th column and the j-th row and the 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 are connected to one wiring. 23. In addition, the circuit 100(i, j) in the i-th column and j-th row and the circuit 100(i, j) in the i-th column and 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. These wirings 23 are connected to each other.

[0426] In FIG. 74(D), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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 the same wiring 23. are arranged side by side with the wiring 21.

[0427] In FIG. 74(E), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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 the same wiring 23. are arranged so as to intersect with the wiring 21.

[0428] In FIG. 74(F), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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. 75(A), the circuit 100(i, j) in the i-th column and the j-th row and the 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) in the i+1th column and the j+1th row i+1, j+1) share one wire 21, one wire 22, and one wire 23.

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

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

[0432] In FIG. 75(D), the circuit 100(i, j) in the i-th column and the j-th row and the 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), the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21 and one wiring 23. The circuit 100(i+1, j) in the i+1th column and the circuit 100(i+1, j+1) in 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 are connected to one wiring 22 and one wiring 2 3. In addition, the circuit 100(i, j+1) in the i-th column and the circuit 100(i, j+1) in the j+1-th row share the same circuit. The circuit 100(i+1, j+1) in the first row shares one wiring 22 and one wiring 23. These wires 23 are connected to each other.

[0434] In FIG. 76(A), the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21 and one wiring 22. The circuit 100(i+1, j) in the i+1th column and the circuit 100(i+1, j+1) in the j+1th row share one wiring 21 and one wiring 22. In addition, the circuit 100 (i , j), the circuit 100(i, j+1) in the i-th column and j+1-th row, and the 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. 76(B), the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21 and one wiring 23. The circuit 100(i+1, j) in the i+1th column and the circuit 100(i+1, j+1) in the j+1th row The circuit 100 (i , j), the circuit 100(i, j+1) in the i-th column and j+1-th row, and the 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. 76(C), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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), the circuit 100(i, j) in the i-th column and the j-th row and the 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 j-th row, and the circuit 100(i, j) in the i-th column and j+1-th row 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 arranged so as to intersect with the wiring 21. The wiring 23 is arranged so as to intersect with the wiring 21. It is arranged alongside line 21.

[0439] In FIG. 76(F), the circuit 100(i, j) in the i-th column and the j-th row and the 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. Circuit 100(i, j) in the i-th column and j-th row, and circuit 100(i, j) in the i-th column and j+1-th row 00(i, j+1), circuit 100(i+1, j) in the jth row of the i+1th column, and circuit 100(i+1, j) in the jth row of the i+1th column 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), the circuit 100(i, j) in the i-th column and the j-th row and the circuit 100(i, j) in the i-th column and the j+1-th row are (i, j+1) share one wiring 21 and one wiring 22. The circuit 100(i+1, j) in the i+1th column and the circuit 100(i+1, j+1) in the j+1th row share one wiring 21 and one wiring 22. In addition, the circuit 100 (i , j), the circuit 100(i, j+1) in the i-th column and j+1-th row, and 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 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 added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[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 capacitor element 102, and the like. one electrode of the capacitor element 103, the active layer of the transistor 13t, the transistor 1 The semiconductor film 301 functions as the active layer of the transistor 101. The conductive film 302 functions as the active layer of the capacitor 102. 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, the load 104 may be provided so as to be connected to the conductive film 308. 13C, the light-emitting element 104a is connected to the conductive film 308. 13(D), the light emitting element is connected to the conductive film 308. The cathode of the optical element 104b may be provided.

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

[0447] In FIG. 78, the semiconductor film 320 functions as the active layer of the transistor 11t. The semiconductor film 321 functions as the active layer of the transistor 12t. The semiconductor film 323 functions as the 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. serves 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 functions as a gate electrode and is connected to either the source or the drain of the transistor 11t. 28 is connected to the wiring 22 and either the source or the 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 The conductive film 330 is connected to the conductive film 326 and the wiring 33. The conductive film 331 is connected to the conductive film 325 and one of the source and drain of the transistor 101. On the other hand, 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 and drain is connected to a wiring 25 .

[0450] In the case of FIG. 13B, the 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. 13(D), a light emitting element is provided so as to be connected to the conductive film 331. The cathode of the optical element 104b may be provided.

[0451] An example of a cross-sectional view taken along the dashed line A1-A2 in FIG. 78 is shown in FIG. 80(A). An example of a cross-sectional view taken along the dashed line B1-B2 is shown in FIG. 80(B). In FIG. 80, a substrate 800 An insulating film 801 is formed on the insulating film 801, and wiring 31, a conductive film 324, and a conductive 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 formed 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. are.

[0453] Then, the insulating film 802, the conductive film 327 located thereon, 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 wiring 23 overlapping with the semiconductor film 333 and the shape of the conductive film 331 overlapping 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 the example shown 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. 79, the conductive film 331 is located inside 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 formed so that the portion overlapping with the conductive film 333 is partially surrounded by the conductive film 331. It is located inside 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-state current can be increased while keeping the area of ​​the semiconductor film 333 small.

[0456] Note that a transistor can be formed using various substrates. The substrate is not limited to the above. 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, tungsten foil substrates, flexible substrates, laminated films, fibrous Examples of glass substrates include barium boron nitride (BBO) and glass-based substrates. Examples include silicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of substrates include polyethylene terephthalate (PET) and polyethylene naphthalate. Plastics such as polyethersulfone (PEN) and polyethersulfone (PES) or acrylic Examples of laminating films include flexible synthetic resins such as polyethylene terephthalate (PE), ... 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. By manufacturing transistors, there is little variation in characteristics, size, or shape, It is possible to manufacture transistors with high current capacity and small size. When a circuit is constructed using transistors, it is possible to reduce the power consumption of the circuit or to increase the integration density of the circuit. 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. As the substrate, in addition to the substrate on which the above-mentioned transistor can be formed, a paper substrate, a cellophane substrate, etc. substrate, stone substrate, wood substrate, fabric substrate (natural fibers (silk, cotton, linen), synthetic fibers (nylon, Polyurethane, polyester) or recycled fiber (acetate, cupra, rayon, recycled These substrates include raw polyester, leather substrates, and rubber substrates. This allows for the formation of transistors with good characteristics and low power consumption. This allows for the manufacture of devices that are less likely to break, more heat resistant, lighter in weight, or thinner.

[0458] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[0459] (Sixth embodiment) 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 gate electrode, and conductive films 504 and 505 that are in contact with the semiconductor film 501. The semiconductor film 501 has a first region 506 which functions as a channel forming region. , a second region 507 functioning as a source or a drain, and a second region 508. The second region 507 and the second region 508 sandwich the first region 506 therebetween. In FIG. 81(A), the semiconductor film 501 is divided into a first region 506, a second region 507, and a Between the first and second regions 508, a third region 509 and a third region 508 functioning as an LDD region are provided. 10 is shown as an example.

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

[0462] The transistor shown in FIG. 81B has a first oxide insulating film 520a, 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 using an oxide insulating film from which part of the oxygen is released by heating. 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 containing oxygen that satisfies the stoichiometric composition, or Aluminum oxide (AlO) contains more oxygen than the stoichiometric composition. x , x is 3 / 2 or more). In addition, the aluminum oxynitride should have a stoichiometric composition. Some of the oxygen in aluminum oxide containing oxygen is replaced with nitrogen.

[0465] The transistor is formed by a semiconductor film 521, an insulating film 522 on the semiconductor film 521, and an insulating film 523. The gate electrode 522 is provided at a position overlapping the semiconductor film 521 with the gate electrode 522 sandwiched therebetween. The semiconductor film 521 includes an electrode 523, and conductive films 524 and 525 that are in contact with the semiconductor film 521. The membrane 521 overlaps with the electrode 523, and at least a portion of the membrane functions as a channel forming region. A first region 526 and a second region 528 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 be formed of silicon, germanium, silicon germanium, or the like. 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 electrode 523. The conductive film 524 and the conductive film 525 are partly 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 fluctuations in the on-current of the 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 electrode 523 does not necessarily have to be provided. By providing the conductive film 528, the conductive film 524 and the conductive film 525 are formed in misaligned positions. Even if the conductive film 524 and the conductive film 525 are overlapped with the upper part of the electrode 523, the conductive film 524 and the conductive film 525 are prevented from being electrically connected to the electrode 523. You can do this.

[0469] In the insulating film 520, the first insulating oxide film 520c is formed on the third insulating oxide film 520c located in the lower layer. A second oxide insulating film 520a 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 edge 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. 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 in the first region 526 can be prevented from passing through 520b. 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 etching treatment, exposure of the edge of the semiconductor film 521 to a reduced pressure atmosphere, etc. Oxygen vacancies are easily formed at the ends of the carbon nanotube due to oxygen elimination. When oxygen vacancies are formed at the end of the semiconductor film 521, parasitic chokes are generated. However, with the above-described structure, Preventing oxygen vacancies from being formed at the end of the semiconductor film 521 in the region 526 of the off-state current The flow can be reduced.

[0471] The phrase "a portion of the oxygen is released by heating" refers to the TDS (Thermal Desor Thermal desorption spectroscopy (TDS) 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 converted into oxygen atoms in TDS analysis. .

[0473] The amount of gas desorbed during TDS analysis is proportional to the integral value of the spectrum. The amount of released gas is calculated from 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 the specified atom. is the ratio of the atomic density to the value.

[0474] For example, the TDS analysis results of a silicon wafer containing a predetermined density of hydrogen as a standard sample, and From the results of TDS analysis of the insulating film, the amount of oxygen molecules desorbed from the insulating film (N O2 ) is calculated using the following formula 1. There is 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 , which is assumed to be derived from oxygen molecules. Also, 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 a mass number of 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 converted value 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's say S O2 is the integral value of the spectrum obtained by TDS analysis of the insulating film. , is a coefficient that affects the spectral intensity in TDS analysis. For details of Equation 1, see The amount of oxygen released from the insulating film is measured by the method described in JP-A-6-275697. A thermal desorption analyzer EMD-WA1000S / W manufactured by the Company 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, the amount of oxygen atoms released can be estimated by evaluating the amount of oxygen molecules released. It can also be estimated.

[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 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 means that the number of oxygen atoms per unit volume is more than twice the number of silicon atoms. The number of silicon atoms and oxygen atoms per volume was measured by Rutherford backscattering spectroscopy. value.

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

[0481] The first oxide insulating film 530a is formed using an oxide insulating film from which oxygen is partly released by heating. As the oxide insulating film from which part of the oxygen is released by heating, an oxide having a stoichiometric composition is used. It is preferable to use an insulating film containing more oxygen than silicon. Silicon oxide, silicon oxynitride, silicon nitride oxide, gallium oxide, hafnium oxide For example, yttrium oxide, yttrium oxide, etc. can be used.

[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 containing oxygen that satisfies the stoichiometric composition, or Aluminum oxide (AlO) contains more oxygen than the stoichiometric composition. x , x is 3 / 2 or more). In addition, the aluminum oxynitride should have a stoichiometric composition. Some of the oxygen in aluminum oxide containing oxygen is replaced with 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 provided at a position overlapping the semiconductor film 531 with the insulating film 532 interposed therebetween; The electrode 533 functions as a gate electrode, 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 that functions as a source or drain 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 be formed of silicon, germanium, silicon germanium, or the like. Various semiconductors such as aluminum and oxide semiconductors can be used.

[0485] The transistor has sidewalls 539 having insulating films on the sides of the electrodes 533. An insulating film 540 is provided on the electrode 533. The conductive film 534 and the conductive film 535 are partly in contact with the sidewall 539. The conductive film 535 does 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 film 535 The contact area between the film 535 and the semiconductor film 531 can be prevented from changing. The on-state current of the transistor changes due to the misalignment of the conductive films 534 and 535. movement can be prevented.

[0486] The insulating film 540 located on the electrode 533 does not necessarily have to be 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 overlapped with the upper part of the electrode 533, the conductive film 534 and the conductive film 535 are prevented from being electrically connected to the electrode 533. You can do this.

[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 has a first region 536 formed of the first oxide. The first oxide insulating film 530a is in contact with the second region 537 and the second region 538. The insulating film 530a and the second oxide insulating film 530b are in contact with each other.

[0488] When 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 applied to 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 conductor film 531 into a desired shape, The semiconductor film 531 is exposed to a reduced pressure atmosphere at the end of the semiconductor film 531 due to oxygen desorption. Oxygen vacancies are easily formed. Oxygen vacancies act as carrier transport paths, so When oxygen vacancies form at the edges of film 531, parasitic channels are created, which can cause transistor However, in one embodiment of the present invention, the above structure increases the off-state current of the first region 53. 6, oxygen vacancies are prevented from being formed at the edge of the semiconductor film 531, and the off-current is reduced. It is possible.

[0489] In addition, impurities such as water or hydrogen, which act as electron donors (donors), are reduced, and the acid The oxide semiconductor (purified Oxide) is highly purified by reducing the electron vacancies. An i-type semiconductor is an intrinsic semiconductor or is very close to an i-type semiconductor. 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. The concentration of impurities such as moisture and hydrogen is sufficiently reduced. and a highly purified oxide semiconductor film having reduced oxygen vacancies is used. This allows the off-state current of the transistor to be reduced.

[0490] Specifically, a transistor using a highly purified oxide semiconductor film for a channel formation region is The low flicker current can be proven 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 the 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 flow into or capacitance The off-state current is measured using a circuit that controls the charge flowing out of the capacitor with the transistor. In this measurement, a highly purified oxide semiconductor film was used as a channel type of the transistor. The off-state current of the transistor is calculated from the change in the charge amount per unit time of the capacitor. As a result, when the voltage between the source electrode and the drain electrode of the transistor was 3 V, It was found that an even lower off-state current of several tens of yA / μm can be obtained when A transistor using a highly purified oxide semiconductor film for a channel formation region has an 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. In order to make the oxide semiconductor film i-type (intrinsic), a dehydration process described later is used. Alternatively, dehydrogenation is effective. In addition, gallium (Ga) is included as a stabilizer to reduce fluctuations. It is preferable that the stabilizer contains tin (Sn). It is preferable that hafnium (Hf) is contained as a stabilizer. It is preferable that the material contains aluminum (Al) as a stabilizer. It is preferable that the metal contains zirconium (Zr).

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

[0493] For example, oxide semiconductors include indium oxide, tin oxide, zinc oxide, and oxides of binary metals. In-Zn oxides, Sn-Zn oxides, Al-Zn oxides, Zn-Mg oxides 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, an In-Ga-Zn oxide means an oxide containing In, Ga, and Zn. The ratio of In, Ga, and Zn is not important. In-Ga-Zn oxides have a sufficiently high resistance in the absence of an electric field, and The flow can be made sufficiently small and the mobility is 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 Crystal Preferably, the film is a tetrathylene oxide semiconductor (TTA) 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 nanometers to several tens of nanometers in size. The membrane is a membrane made of a thin film of crystalline matter. The amorphous and crystalline parts in the CAAC-OS film were observed using a tron ​​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 part included in the CAAC-OS film has a c-axis that is the normal vector of the surface on which the CAAC-OS film is formed. The triangle is aligned parallel to the normal vector of the sphere or surface 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 b-axis may be different. In this specification, when simply referring to a vertical axis, it means that the This also 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 becomes amorphous in the heat-treated region.

[0499] The c-axis of the crystalline 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 (on which the film is formed) is The c-axis direction of the crystallographic regions differs depending on the cross-sectional shape of the plane or the surface. The c-axis direction of the crystalline 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. The film is formed by carrying out a crystallization process such as a heat treatment after the film is formed.

[0500] By using the CAAC-OS film, the electrical characteristics of the transistor can be improved by irradiating it 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 by sputtering a polycrystalline oxide semiconductor target. The sputtering target is used to form a film by sputtering. Upon impact, the crystalline regions contained in the sputtering target cleave from the ab plane, forming a -b Peels off as flat or pellet-shaped sputtered particles with surfaces parallel to the plane In this case, the plate-like sputtered particles may be transferred to the substrate while maintaining their crystalline state. 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 can be reduced. A deposition gas at 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 film is formed at a temperature between 200°C and 500°C. When a plate-shaped sputtering particle reaches the substrate, migration occurs on the substrate, The flat surface of the sputtered particle adheres to the substrate.

[0505] In addition, increasing the oxygen ratio in the deposition gas and optimizing the power reduces plasma damage during deposition. 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 following are the results:

[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. This can be changed as appropriate depending on the kit.

[0508] For example, the oxide semiconductor film may contain 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 sputtering, it is preferable that the atomic ratio of In :Ga:Zn=1:1:1, 4:2:3, 3:1:2, 1:1:2, 2:1:3, or An In-Ga-Zn oxide target with an atomic ratio of 3:1:4 is used. an oxide semiconductor film is formed using an In-Ga-Zn oxide target having In addition, the addition of In, Ga, and Zn makes it easier for polycrystals or CAAC-OS to form. The relative density of the target containing the fluorine-containing compound 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 deposited oxide semiconductor film is dense. 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 molar ratio, 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), 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 to form 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 achieve an improvement in mobility.

[0510] Specifically, the oxide semiconductor film is formed by holding the substrate in a treatment chamber maintained in a reduced pressure state. The remaining moisture in the processing chamber is removed, and the sputtering gas from which hydrogen and moisture have been removed is introduced. During film formation, the substrate temperature is preferably 100°C or higher and 600°C or lower. Preferably, the temperature may be 200° C. or higher and 400° C. or lower. This allows the concentration of impurities contained in the formed oxide semiconductor film to 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 displacement pump. Also, a turbo pump is used as the exhaust means. A cold trap may be added to the process chamber. Then, for example, hydrogen atoms, compounds containing hydrogen atoms such as water (H2O) (more preferably carbon Since the exhaust gas contains oxygen (including compounds containing hydrogen atoms), the oxide semiconductor film formed in the treatment chamber is The concentration of impurities contained in the material can be reduced.

[0511] Note that the oxide semiconductor film formed by sputtering or the like contains moisture or hydrogen ( The water or hydrogen atoms form donor levels. Therefore, in one embodiment of the present invention, To reduce impurities such as water or hydrogen in semiconductor films (dehydration or dehydrogenation) , an oxide semiconductor film is heated under a reduced pressure atmosphere, an inert gas atmosphere such as nitrogen or a rare gas, or an acid atmosphere. 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 carried out in an atmosphere of air, preferably 1 ppm or less, preferably 10 ppb or less. To administer.

[0512] By performing heat treatment on the oxide semiconductor film, moisture or hydrogen in the oxide semiconductor film is released. 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 strain point of the glass substrate.

[0513] Note that the heat treatment causes oxygen to be released from the oxide semiconductor film and oxygen to be left in the oxide semiconductor film. Therefore, in one embodiment of the present invention, a gate electrode in contact with the oxide semiconductor film is 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 that serve 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 i-type. This reduces variations in the electrical characteristics of transistors due to oxygen vacancies, and It is possible to achieve improved characteristics.

[0514] Note that the heat treatment for supplying oxygen to the oxide semiconductor film is performed using nitrogen, ultra-dry air, or dilute In a gas (argon, helium, etc.) atmosphere, preferably at 200°C to 400°C The temperature is, for example, 250°C or higher and 350°C or lower. 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 with 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 5 and a conductive film 606. Furthermore, the transistor has a semiconductor film 604, a conductive film 605, and a The insulating film 607 formed over the conductive film 606 may also be included in the components.

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

[0518] The transistor shown in FIG. 82B is a bottom-gate type 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 protection film formed on the semiconductor film 614 The semiconductor film 614 includes a protective film 618 and conductive films 615 and 616 formed on the semiconductor film 614 . Furthermore, 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 in the components.

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

[0521] By providing the channel protection film 618, the 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 caused by the transistor, thereby improving its reliability. Cut.

[0522] The transistor shown in FIG. 82C is a bottom-gate type with 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 by insulating films formed over the conductive film 625, the conductive film 626, and the semiconductor film 624. A membrane 627 may be included in the components.

[0524] In addition, the transistor shown in FIG. 82C has an insulating layer at the position where it overlaps with the semiconductor film 624. It may further include a back gate electrode formed on the 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 located on the insulating film 643 and overlaps with the semiconductor film 644. The transistor has an insulating film 647 formed on the gate electrode 642 as its constituent element. It may be included.

[0527] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[0528] (Embodiment 7) In this embodiment, a light-emitting device, which is one mode of a semiconductor device of the present invention, is taken as an example. The external appearance will be explained using Figure 83. Figure 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. 83(B) corresponds to 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 sealing material 4020 is provided to surround the pixel portion 4002 and the circuit 4003. A second substrate 4006 is provided on the pixel portion 4002 and 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, and a signal is supplied to the pixel portion 4002. Each of the circuits 4003 and 4004 includes a plurality of transistors. 3(B), a transistor 4008 included in a circuit 4003 and a transistor 4009 included in a pixel portion 4002 are 4009 and a transistor 4010 are shown as examples.

[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 structure of the light emitting element 4011 can be changed as appropriate depending on the direction and polarity of the transistor 4009. It can be done.

[0532] In addition, various signals and voltages given 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 wirings 4014 and 401 5 and is supplied from the 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 wiring 4015 is formed of a conductive film. The gate electrodes of the transistor 4010 and the transistor 4008 are made of the same conductive film. It is 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 can be made of 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 made of a glass plate, a plastic plate, a polyester film, or the like. It is desirable to use a light-transmitting material such as rubber or acrylic film.

[0536] In addition to inert gases such as nitrogen and argon, filler 4007 can also be used, such as ultraviolet curing resin. In this embodiment, the filler 4007 is made of nitrogen. An example using

[0537] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[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 driver circuit 701, and a driver The pixel portion 700 includes a plurality of circuits 100 that function as pixels. The driving circuits 701 and 702 supply various constant voltages and signals to the respective circuits 100. It has the function of supplying a signal.

[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 is provided with a plurality of circuits 100 that function as current sources. The current output from 100 is supplied to the pixels of the pixel section 711 .

[0541] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[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 (typically DVD: Digital Versatile Disc) (Devices having a display that can play back recording media such as DVDs and display the images) In addition, electronic devices in which the semiconductor device according to one embodiment of the present invention can be used are Mobile phones, portable game consoles, personal digital assistants, e-books, video cameras, digital cameras, Cameras such as digital still cameras, goggle-type displays (head-mounted displays) ), navigation systems, sound reproduction devices (car audio, digital audio players) Years, etc.), copiers, fax machines, printers, printer-combined machines, automated teller machines Examples of such electronic devices include ATMs and vending machines. Shown in 91.

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

[0544] FIG. 85(B) shows a display device, which includes a housing 5201, a display unit 5202, a support stand 5203, and the like. 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 portion 5202. This includes all display devices for displaying information, such as for data, TV broadcast reception, and advertising displays.

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

[0546] FIG. 85(D) 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. A 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. 85(E) shows a mobile phone, which includes a housing 5801, a display unit 5802, an audio input unit 5803, It has an audio output unit 5804, operation keys 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, and a 5903, a second display unit 5904, a connection unit 5905, operation keys 5906, etc. Table 1 The display unit 5903 is provided on the first housing 5901, and the second display unit 5904 is provided on the second housing 5902. The first housing 5901 and the second housing 5902 are connected by 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. The first housing 5901 and the second housing 5902 may be switched according to the angle between them. A semiconductor device according to one embodiment of the present invention is an integrated circuit for controlling the driving of a portable information terminal. It can be used for the first display portion 5903 and the second display portion 5904. At least one of the display unit 5903 and the second display unit 5904 has a function as a position input device. It is also possible to use a display device to which the following functions are added: This can be added by providing a touch panel on the display 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 made of a printed material. 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 path, etc. 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 is equipped with a speaker 900532 and a microphone 90 0533, a transmitting / receiving circuit 900534, a signal processing circuit 9 including a CPU and a controller, etc. 00535 is formed. Such a module, input means 900536, 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 formed in the housing 900539.

[0553] The display panel 900501 is a pixel section and a part of a peripheral driving circuit (a driving circuit with an operating frequency of 100 Hz). The driving circuit with low frequency is integrated on the substrate using TFT, and some peripheral driving circuits (multiple (a driving circuit with a high operating frequency among the driving circuits) is formed on an IC chip, and the IC chip may be mounted on the display panel 900501 using COG (Chip On Glass). Alternatively, the IC chip can be bonded using TAB (Tape Automated Bonding) Alternatively, a printed circuit board or the like may be used to connect the glass substrate. It is possible to reduce the power consumption of display devices and extend the usage time of mobile phones on a single charge. It is also possible to reduce the cost of mobile phones.

[0554] This embodiment may be modified, added, revised, deleted, or added to any or all of the other embodiments. This corresponds to application, superordinate conception, or subordinate conception. Part or all of the invention may be freely combined with part or all of the other embodiments. Alternatively, it can be implemented as a replacement.

[0555] In addition, in the figures or text described in a certain embodiment, it is possible to extract a part thereof to constitute 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 constitute an aspect of the invention. Thus, for example, in drawings or text in which one or more active elements (such as transistors, diodes, etc.), wirings, passive elements (such as capacitive elements, resistive elements, etc.), 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 constitute an aspect of the invention. For example, from a circuit diagram composed of N [[ID=...]] devices, operation methods, manufacturing methods, etc. are described, it is assumed that a part thereof can be extracted to constitute an aspect of the invention. For example, from a circuit diagram composed of N (N is an integer) circuit elements (such as transistors, capacitive elements, etc.), it is possible to extract M (M is an integer and M < N) circuit elements (such as transistors, capacitive elements, etc.) to constitute an aspect of the invention. As another example, from a cross-sectional view composed of N (N is an integer) layers, it is possible to extract M (M is an integer and M < N) layers to constitute an aspect of the invention. As yet another example, from a flowchart composed of N (N is an integer) elements, it is possible to extract M (M is an integer and M < N) elements to constitute an aspect of the invention. In addition, when at least one specific example is described in the figures or text described in a certain embodiment, those skilled in the art can easily derive the upper concept of the specific example. Therefore, in the figures or text described in a certain embodiment, when at least one specific example is described, those skilled in the art can easily derive the upper concept of the specific example.

[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, 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. 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. When at least one specific example is described, the generic concept of that specific example is also considered as one aspect of the invention. and can constitute one aspect of the invention.

[0557] At least the contents shown in the drawings (or even a part of the drawings) are disclosed as one aspect of the invention. This is shown and can constitute one aspect of the invention. If the content is shown in the diagram, it is considered to be a part of the It is disclosed as one embodiment of the present invention and can constitute 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, switch 11, switch 12, switch 13, The configuration of the circuit 100 when transistors are used for the switch 914 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. The switch 12 is a transistor 12t, and the switch 13 is a transistor 13t. 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....

Claims

1. A pixel includes first to sixth transistors and a light-emitting element, the second to sixth transistors function as switches in a light-emitting device, 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 the 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 the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor; one of a source and a drain of the sixth transistor is electrically connected to one of a source and a drain of the first transistor; the other of the source and the drain of the sixth transistor is electrically connected to a third wiring; the first transistor has a function of controlling a current flowing between the third wiring and the light-emitting element in accordance with a potential of a video signal input to the pixel; a first conductive film that functions 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 spaced apart from the first semiconductor film; the first semiconductor film has a first region that is located apart from a channel formation region of the first transistor and overlaps with the first conductive film; a channel formation region of the first transistor and the first region are electrically connected 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 sixth transistors and a light-emitting element, the second to sixth transistors function as switches in a light-emitting device, 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 the 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 the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor; one of a source and a drain of the sixth transistor is electrically connected to one of a source and a drain of the first transistor; the other of the source and the drain of the sixth transistor is electrically connected to a third wiring to which a second power supply potential is input; the first transistor has a function of controlling a current flowing between the third wiring and the light-emitting element in accordance with a potential of the video signal input to the pixel; a first conductive film that functions 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 spaced apart from the first semiconductor film; the first semiconductor film has a first region that is located apart from a channel formation region of the first transistor and overlaps with the first conductive film; a channel formation region of the first transistor and the first region are electrically connected 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.

3. A pixel includes first to sixth transistors and a light-emitting element, the second to sixth transistors function as switches in a light-emitting device, 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 the 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 the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor; one of a source and a drain of the sixth transistor is electrically connected to one of a source and a drain of the first transistor; the other of the source and the drain of the sixth transistor is electrically connected to a third wiring; the first transistor has a function of controlling a current flowing between the third wiring and the light-emitting element in accordance with a potential of a video signal input to the pixel; Among the second to sixth transistors, 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 that functions 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 spaced apart from the first semiconductor film; the first semiconductor film has a first region that is located apart from a channel formation region of the first transistor and overlaps with the first conductive film; a channel formation region of the first transistor and the first region are electrically connected 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.

4. A pixel includes first to sixth transistors and a light-emitting element, the second to sixth transistors function as switches in a light-emitting device, 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 the 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 the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor; one of a source and a drain of the sixth transistor is electrically connected to one of a source and a drain of the first transistor; the other of the source and the drain of the sixth transistor is electrically connected to a third wiring to which a second power supply potential is input; the first transistor has a function of controlling a current flowing between the third wiring and the light-emitting element in accordance with a potential of the video signal input to the pixel; Among the second to sixth transistors, 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 that functions 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 spaced apart from the first semiconductor film; the first semiconductor film has a first region that is located apart from a channel formation region of the first transistor and overlaps with the first conductive film; a channel formation region of the first transistor and the first region are electrically connected 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.

Images