Semiconductor device

Abstract

To provide a semiconductor device or the like including a unipolar logic circuit.SOLUTION: In a logic circuit including transistors having the same conductivity type, a reduction in output voltage is prevented by using at least three transistors and a capacitor. By using an oxide semiconductor for a semiconductor layer of a transistor, a logic circuit with high output voltage and high withstand voltage is achieved. With the use of the logic circuit, a semiconductor device with high output voltage and high withstand voltage is achieved.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] One embodiment of the invention disclosed in this specification relates to an object, a method, or a manufacturing method. Alternatively, one aspect of the invention disclosed in the present specification etc. is a process, a machine, a manufacture In particular, this specification One embodiment of the invention disclosed in the document relates to a semiconductor device and an electronic device including the semiconductor device. This is what is done.

[0002] In this specification and the like, a semiconductor device is a device that can function by utilizing semiconductor characteristics. This refers to display devices (liquid crystal display devices, light emitting display devices, etc.), lighting devices, electro-optical devices, Power storage devices, memory devices, semiconductor circuits, imaging devices, electronic devices, etc. have semiconductor devices. There are cases where this happens. [Background technology]

[0003] Recently, oxide semiconductors (OS) have been used in the semiconductor layer where the channel is formed. Transistors using an OS transistor (hereinafter also referred to as OS transistors) are attracting attention. Oxide semiconductors can be formed into films by sputtering or the like, so for example, It can be used for the semiconductor layer of a transistor that constitutes a large display device. A transistor is a type of transistor that uses amorphous silicon in the semiconductor layer where the channel is formed. It is possible to improve and use some of the production equipment, which has the advantage of reducing capital investment. There are also some.

[0004] In addition, OS transistors are known to have extremely low leakage current when they are off. For example, low leakage current is achieved by utilizing the extremely low leakage current characteristics of OS transistors. A CPU with low power consumption has been disclosed (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-257187 Summary of the Invention [Problem to be solved by the invention]

[0006] However, it is known that it is difficult to realize p-channel OS transistors. Therefore, to construct a logic circuit using only OS transistors, It is necessary to construct a logic circuit (a logic circuit made up of transistors of the same conductivity type).

[0007] Even if a p-channel transistor could be realized, it would be difficult to fabricate a p-channel transistor on the same substrate. When a n-channel transistor and an n-channel transistor are separately manufactured, the number of manufacturing steps increases, and the This increases the manufacturing cost and reduces productivity. It is preferable that the transistors are of the same conductivity type. In a unipolar logic circuit consisting of transistors, the output voltage is the threshold voltage (Vt The problem is that the power consumption decreases by an amount equivalent to "power consumption".

[0008] An object of one embodiment of the present invention is to provide a semiconductor device or the like with high productivity. Another object of the present invention is to provide a semiconductor device or the like with low power consumption. Another object of the present invention is to provide a semiconductor device or the like having excellent characteristics. The object of the present invention is to provide a semiconductor device including a unipolar logic circuit in which the output voltage is unlikely to decrease. Another object of the present invention is to provide a novel semiconductor device or the like.

[0009] 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 descriptions in the patent, claims, etc. [Means for solving the problem]

[0010] In a logic circuit composed of transistors of the same conductivity type, at least three transistors A drop in output voltage is prevented by using a capacitor and a capacitor element. By using a compound semiconductor, a logic circuit with a large output voltage and high voltage resistance can be realized. By using a logic circuit, a semiconductor device with a large output voltage and high withstand voltage can be realized.

[0011] One embodiment of the present invention is a semiconductor device including first to third transistors and a capacitor. The transistor has a first gate and a second gate, and is connected to one of the source and drain of the first transistor. The other of the source and drain of the first transistor is electrically connected to the first wiring. the first gate of the first transistor is electrically connected to the fourth gate of the first transistor; The second transistor is electrically connected to the wiring, and one of the source and drain of the second transistor is connected to the first transistor. the other of the source or drain of the first transistor, and the other of the source or drain of the second transistor. The other of the source or drain of the third transistor is electrically connected to the second wiring. One of the drains is electrically connected to the third wiring and serves as the source or drain of the third transistor. The other end of the third transistor is electrically connected to one electrode of the capacitance element, and the gate of the third transistor is connected to the third The other electrode of the capacitance element is electrically connected to the source or drain of the first transistor. The semiconductor device is characterized in that the other of the two terminals is electrically connected to the other terminal.

[0012] Alternatively, one embodiment of the present invention is a semiconductor device including first to third transistors and a capacitor, the first transistor and the third transistor each have a first gate and a second gate; One of the source and the drain of the first transistor is electrically connected to the first wiring. The other of the source and drain of the transistor is electrically connected to the first gate of the first transistor. The second gate of the first transistor is electrically connected to the fourth wiring, and the second gate of the second transistor is electrically connected to the fourth wiring. The source or drain of the first transistor is electrically connected to the other of the source or drain of the second transistor. The other of the source and drain of the second transistor is electrically connected to the second wiring. The third transistor has a source or a drain electrically connected to the third wiring. The other of the source and the drain of the third transistor is electrically connected to one electrode of the capacitor. The first gate of the third transistor is electrically connected to the third wiring. The second gate of the third transistor is electrically connected to the other of the source and drain of the third transistor. The other electrode of the capacitor is electrically connected to the other of the source and drain of the first transistor. The semiconductor device is characterized in that it is connected to

[0013] Alternatively, one embodiment of the present invention is a semiconductor device including first to fourth transistors and a capacitor, The transistor has a first gate and a second gate, and the source or drain of the first transistor One of the inputs is electrically connected to the first wiring, and the other of the inputs is connected to the source or drain of the first transistor. The other is electrically connected to the first gate of the first transistor and the second gate of the first transistor. The second transistor is electrically connected to the second wiring, and one of the source and drain of the second transistor is connected to the first wiring. the other of the source and drain of the first transistor, The other of the source and the drain is electrically connected to a third wiring. Alternatively, one of the drains is electrically connected to the fourth wiring, and the source or The other of the drains is electrically connected to one electrode of the capacitance element, and the gate of the third transistor The other electrode of the capacitor is electrically connected to the source or is electrically connected to the other of the drains, and is connected to one of the source or drain of the fourth transistor. is electrically connected to the other of the source and drain of the third transistor, and The other of the source and drain of the fourth transistor is electrically connected to the second wiring. the gate is electrically connected to the gate of the second transistor. is.

[0014] Either the first gate or the second gate of the first transistor functions as a gate. The first gate or the second gate of the third transistor can function as a gate electrode, and the other gate can function as a back gate. One of the second gates can function as a gate and the other as a back gate. do.

[0015] In addition, at least one of the first transistor and the second transistor has a channel formed therein. The transistor preferably includes an oxide semiconductor in a semiconductor layer. [Effects of the Invention]

[0016] It is possible to provide a semiconductor device with high productivity. It is possible to provide a semiconductor device or the like having good reliability. Alternatively, a semiconductor device including a unipolar logic circuit in which the output voltage is unlikely to decrease can be used. Alternatively, a novel semiconductor device or the like can be provided.

[0017] The description of these effects does not preclude the existence of other effects. An embodiment does not necessarily have all of these effects. Effects other than these may be included in the description, This becomes clear from the description, drawings, claims, etc. From any description, it is possible to extract effects other than these. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a circuit diagram illustrating a semiconductor device. [Figure 2] FIG. 1 is a circuit diagram illustrating a semiconductor device. [Figure 3] 1 is a timing chart illustrating an operation of a semiconductor device. [Figure 4] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 5] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 6] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 7] FIG. 1 is a circuit diagram illustrating a semiconductor device. [Figure 8] 1 is a timing chart illustrating an operation of a semiconductor device. [Figure 9] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 10] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 11] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 12] FIG. 1 is a circuit diagram illustrating a semiconductor device. [Figure 13] 1 is a timing chart illustrating an operation of a semiconductor device. [Figure 14] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 15] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 16] FIG. 1 is a circuit diagram illustrating an operation of a semiconductor device. [Figure 17] 1A and 1B illustrate an example of a transistor. [Figure 18] 1A and 1B illustrate an example of a transistor. [Figure 19] 1A and 1B illustrate an example of a transistor. [Figure 20] 1A and 1B illustrate an example of a transistor. [Figure 21] 1A and 1B illustrate an example of a transistor. [Figure 22] 1A and 1B illustrate an example of a transistor. [Figure 23] 1A and 1B illustrate an example of a transistor. [Figure 24] 1A and 1B illustrate an example of a transistor. [Figure 25] 1A and 1B illustrate an example of a transistor. [Figure 26] 1A and 1B illustrate an example of a transistor. [Figure 27] 1A and 1B illustrate an example of a transistor. [Figure 28] FIG. 2 is a diagram illustrating an energy band structure. [Figure 29] 1A and 1B illustrate an example of a display device. [Figure 30] 1A and 1B illustrate an example of a display device. [Figure 31] FIG. 2 illustrates an example of the configuration of a driver circuit. [Figure 32]1A and 1B illustrate an example of a display device. [Figure 33] 1A and 1B illustrate an example of a display device. [Figure 34] FIG. 2 is a diagram illustrating an example of a display module. [Figure 35] FIG. 1 is a block diagram illustrating an example of a semiconductor device. [Figure 36] 1A and 1B are a flowchart and a schematic perspective view illustrating an example of a manufacturing process for an electronic component. [Figure 37] 1A to 1C illustrate examples of electronic devices. [Figure 38] 1A to 1C illustrate examples of electronic devices. [Figure 39] 1A to 1C illustrate examples of electronic devices. [Figure 40] A circuit model for verifying the operation of semiconductor devices. [Figure 41] 10A to 10C are diagrams showing verification results of the operation of a semiconductor device. DETAILED DESCRIPTION OF THE INVENTION

[0019] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description. The present invention is not limited to the above embodiments, and various changes and modifications may be made in the form and details thereof without departing from the spirit and scope of the present invention. It will be readily understood by those skilled in the art that the present invention can be achieved by the following embodiments. It should not be construed as being limited to the contents of the description. The same reference numerals are used in different drawings to denote the same parts or parts having similar functions. The repeated explanation may be omitted.

[0020] In addition, the position, size, range, etc. of each component shown in the drawings are for the purpose of facilitating understanding of the invention. Therefore, the actual location, size, range, etc. may not be shown. The present invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings, etc.

[0021] In addition, in the drawings, in order to facilitate understanding of the invention, the illustration of some components may be omitted. In addition, some hidden lines may be omitted.

[0022] In this specification, ordinal numbers such as "first" and "second" are used to avoid confusion of components. The numbers are used to indicate the order or priority of the processes or stacking steps. In addition, even if a term is not accompanied by an ordinal number in this specification, etc., it is used to avoid confusion of the constituent elements. In order to clarify the scope of the invention, ordinal numbers may be used in the claims. Even if a term has an ordinal number in the first place, it may be given a different ordinal number in the claims. In addition, even if a term is given an ordinal number in this specification, etc., it may be used in the patent. Ordinal numbers may be omitted in claims, etc.

[0023] In addition, the terms "electrode" and "wiring" used in this specification and the like do not limit the functionality of these components. For example, an "electrode" may be used as part of a "wiring." Furthermore, the terms "electrode" and "wiring" are used interchangeably to refer to the plural "electrodes" and "wirings." This also includes cases where the "line" is formed as a single unit.

[0024] In this specification, the terms "above" and "below" refer to the positional relationship of components directly above or below each other. For example, "electrode on insulating layer A" is not limited to being below and in direct contact with the insulating layer A. If the expression is "B", electrode B does not need to be formed directly on insulating layer A, The inclusion of other components between the edge layer A and the electrode B is not excluded.

[0025] The source and drain functions may also be different when using transistors with different polarities or when using circuits When the direction of the current changes during circuit operation, they are interchanged depending on the operating conditions. Therefore, it is difficult to determine which is the source and which is the drain. In this specification, the terms source and drain may be used interchangeably. Let's say.

[0026] In addition, when it is explicitly stated in this specification that X and Y are connected, is when X and Y are electrically connected and when X and Y are functionally connected. and the case where X and Y are directly connected are considered to be disclosed in this specification and the like. Therefore, the present invention is not limited to predetermined connection relationships, for example, connection relationships shown in drawings or text. Connections other than those shown in the drawings or text are also considered to be described in the drawings or text. do.

[0027] In addition, in this specification, "electrically connected" means "something that has some kind of electrical effect." This includes cases where the device is connected via a " is not subject to any particular restrictions as long as it enables the transmission and reception of electrical signals between connected objects. Therefore, even when it is expressed as "electrically connecting," in an actual circuit, In some cases, there are no physical connections and only wires running.

[0028] Note that the channel length is, for example, the length of a semiconductor (or transistor) in a top view of a transistor. When the transistor is in the on state, the gate electrode overlaps with the semiconductor (the part where current flows). In the region where a channel is formed (also called a "channel forming region") , source (source region or source electrode) and drain (drain region or drain electrode) ) in one transistor. The channel length of a transistor is not necessarily the same value. Therefore, in this specification, the channel length is the area where the channel is formed. The value is any one of the values, the maximum value, the minimum value, or the average value.

[0029] The channel width is the width of the semiconductor (or transistor) when it is in the on state. The region where the current flows and the gate electrode overlap, or the region where the channel is formed. The length of the part where the source and drain face each other in the region. In a transistor, the channel width does not necessarily have the same value in all regions. The channel width of each transistor may not be determined to be a single value. In the document, the channel width is defined as any one value, maximum value, or The minimum or average value.

[0030] Depending on the structure of the transistor, the channel in the region where the channel is actually formed may be The effective channel width (also called the "effective channel width") and the The channel width (also called "apparent channel width") may differ from the When the gate electrode covers the side surface of the semiconductor layer, the effective channel width is For example, when the gate voltage is too high and the In a transistor in which the electrodes cover the side of the semiconductor, the portion of the channel region formed on the side of the semiconductor In this case, the effective channel width may be larger than the apparent channel width. The width of the rule becomes larger.

[0031] In such a case, it may be difficult to estimate the effective channel width through actual measurements. For example, to estimate the effective channel width from the design value, the shape of the semiconductor must be known. Therefore, if the shape of the semiconductor is not known exactly, it is difficult to estimate the effective chip size. Channel width is difficult to measure accurately.

[0032] Therefore, in this specification, the apparent channel width is referred to as the "surrounding channel width (SCW)". In addition, in this specification, So, when we simply write "channel width," it means the enclosed channel width or the apparent channel width. In this specification, when simply referred to as a channel width, it may refer to the actual It may refer to the effective channel width. The width, apparent channel width, and enclosed channel width can be determined by analyzing cross-sectional TEM images. The value can be determined by, for example,

[0033] The field effect mobility of the transistor and the current value per channel width are calculated. In this case, the effective channel width is calculated using the enclosed channel width. The value may differ from that calculated using the channel width.

[0034] In addition, unless otherwise specified, the transistors shown in this specification and the like are enhancement transistors. The transistor is a normally-off type field effect transistor.

[0035] The impurities in a semiconductor refer to, for example, substances other than the main components that make up the semiconductor. For example, the concentration Elements with a concentration of less than 0.1 atomic percent can be considered impurities. The conductor's DOS (Density of State) increases and the carrier mobility The semiconductor may become an oxide semiconductor, and the crystallinity may decrease. In the case of a semiconductor, impurities that change the properties of the semiconductor include, for example, elements of Group 1 and Group 2. elements, group 13 elements, group 14 elements, group 15 elements, and elements other than the main components of oxide semiconductors Transition metals, especially hydrogen (which is also contained in water), lithium, sodium, Silicon, boron, phosphorus, carbon, nitrogen, etc. In the case of oxide semiconductors, for example, hydrogen The inclusion of impurities can cause oxygen vacancies. In this case, impurities that change the properties of semiconductors include, for example, oxygen and Group 1 elements excluding hydrogen. , Group 2 elements, Group 13 elements, Group 15 elements, etc.

[0036] In this specification, "parallel" means that two straight lines are at an angle of -10° or more and 10° or less. Therefore, it includes the case where the angle is between -5° and 5°. "Parallel" refers to a state in which two lines are arranged at an angle of between -30° and 30°. Also, "perpendicular" and "orthogonal" mean that two straight lines are arranged at an angle of 80° or more and 100° or less. Therefore, it also includes the case where the angle is between 85° and 95°. "Straight" refers to two straight lines that form an angle of 60° or more and 120° or less.

[0037] In this specification, the terms "identical," "same," and "equal" are used to refer to counting values ​​and measurement values. " or "uniform" (including their synonyms) unless expressly stated otherwise. The calculations are subject to a margin of error of plus or minus 20%.

[0038] In addition, in this specification, when an etching process is performed after a photolithography process, In this case, unless otherwise specified, the resist mask formed in the photolithography process is It shall be removed after the etching process is completed.

[0039] In this specification, a high power supply potential VDD (hereinafter simply referred to as "VDD" or "H potential") ) indicates a power supply potential that is higher than the low power supply potential VSS. The potential VSS (hereinafter simply referred to as "VSS" or "L potential") is the high power supply potential VDD. It also refers to the power supply potential that is lower than the ground potential. For example, if VDD is at ground potential, VSS is at a potential lower than ground potential. When VSS is at ground potential, VDD is at a potential higher than ground potential.

[0040] Generally, "voltage" refers to the difference between a certain potential and a reference potential (for example, ground potential (GND potential) or In many cases, it refers to the potential difference between the source and the source potential. Therefore, the potential applied to wiring etc. may change depending on the reference potential. In some cases, the terms "voltage" and "potential" can be used interchangeably. Unless otherwise specified, VSS is the reference potential.

[0041] The words "film" and "layer" may be used interchangeably depending on the situation. For example, the term "conductive layer" can be replaced with "conductive film." ". Alternatively, for example, the term "insulating film" may be used. It may be possible to change the term to "insulating layer."

[0042] In addition, in this specification, when the crystal is a trigonal or rhombohedral crystal, it is expressed as a hexagonal crystal system. .

[0043] (Embodiment 1) A semiconductor device 100 of one embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a circuit diagram illustrating the configuration of the body device 100.

[0044] <Configuration Example of Semiconductor Device 100> The semiconductor device 100 includes transistors 111 to 113 and a capacitor 11 The transistors 111 to 113 have a source, a drain, and The transistor 111 is an n-channel transistor having a gate. In addition to the transistor 112 and / or the transistor 113, the transistor 112 and / or the transistor 113 also have a back gate. A back gate can also be provided.

[0045] The gate and back gate are arranged to sandwich the channel forming region of the semiconductor layer. Therefore, the back gate can function in the same way as a gate. The potential may be the same as the gate, or may be the ground potential (GND potential) or any other potential. In addition, by changing the potential of the back gate independently of the gate, The threshold voltage of the transistor can be changed. One of the gates is called the "first gate" and the other is called the "second gate."

[0046] In the semiconductor device 100, one of the source and drain of the transistor 111 is connected to a wiring 121. and the other of the source and drain is electrically connected to node 131. In addition, one of the first gate and the second gate of the transistor 111 is connected to the node 131. The other of the first gate and the second gate is electrically connected to the wiring 124. In addition, one of the source and drain of the transistor 112 is connected to the node 131. The other of the source and drain is electrically connected to the wiring 122. The gate of the transistor 112 is electrically connected to the terminal 102. One of the source and drain of the transistor 113 is electrically connected to the wiring 123. The other of the source and drain is electrically connected to node 132. The gate of the transistor 113 is electrically connected to either the source or the drain of the transistor 113. One electrode of the capacitor 117 is electrically connected to the node 131. The other electrode is electrically connected to node 132. Node 131 is also connected to terminal 105. The terminal 105 is electrically connected to a capacitor element, a gate of a transistor, etc. It is assumed that the input impedance is high.

[0047] In addition, as in the semiconductor device 100a shown in the circuit diagram of FIG. 2A, The back gate is connected to the source or drain of the transistor 113. One of them may be electrically connected.

[0048] In addition, as in the semiconductor device 100b shown in the circuit diagram of FIG. 2B, The back gate is electrically connected to the gate of the transistor 112. That's fine.

[0049] In addition, as in the semiconductor device 100c shown in the circuit diagram of FIG. 2C, The back gate is connected to the source or drain of the transistor 112. It may be electrically connected to the other.

[0050] In addition, as in the semiconductor device 100d shown in the circuit diagram of FIG. 2D, The port is not connected to either the source or the drain of the transistor 113 but is connected to the wiring 125. The transistor 113 may be turned on or off depending on the potential supplied to the wiring 125. Since the state of the node 132 can be controlled, the node 132 can be set to any potential.

[0051] By providing a back gate in addition to the gate, the carriers flow The flow area becomes larger in the film thickness direction, and the amount of carrier movement increases. As a result, the on-state current of the transistor increases and the field-effect mobility also increases. Therefore, a transistor having a back gate needs to have a transistor with a required on-state current. In addition, the semiconductor layer is covered with the gate and back gate. This reduces the influence of the external electric field on the channel formation region, improving the reliability of the semiconductor device. The back gate will be explained in detail later.

[0052] In addition, a semiconductor layer in which the channels of the transistors 111 to 113 are formed is used. There is no particular limitation on the semiconductor material used. 3 is a transistor in which the semiconductor layer in which the channel is formed is an oxide semiconductor (hereinafter referred to as "O It is preferable to use an oxide semiconductor. Since the value is 2 eV or more, transistors using oxide semiconductors in the semiconductor layer where the channel is formed In addition, the OS transistor can reduce the off-state current. The voltage resistance between the drain and the source is high. By using an OS transistor, the output voltage is high. In particular, at least the transistor 111 and It is preferable that one or both of the transistors 111 and 112 be OS transistors.

[0053] The capacitance of the capacitor 117 is larger than the capacitance generated between the gate and source of the transistor 113. It is preferable that the capacitance generated between the gate and source of the transistor 113 is large. It is preferable that the capacitance be larger than the capacitance occurring between the gate and source of the transistor 111 .

[0054] <Operation Example of Semiconductor Device 100> The semiconductor device 100 can function as an inverter circuit. When a high potential is input to terminal 02, a low potential is output from terminal 105, and when a low potential is input to terminal 102, When this signal is input, an H potential can be output from the terminal 105.

[0055] An example of the operation of the semiconductor device 100 will be described with reference to the timing chart of FIG. 3 and the circuits of FIGS. 4 to 6. In this embodiment, transistors 111 to 114 are The threshold voltages of the transistors 113 are all the same. Also, Vth is greater than 0 volts and (VD In addition, the H potential (VDD) is supplied to the wiring 121, and the H potential (VDD) is supplied to the wiring 1 The L potential (VSS) is supplied to the terminal 22. For example, when a high potential is input to the terminal 102, the wiring 1 An L potential is input to 24.

[0056] Note that an inverted signal of the signal input to the terminal 102 may be input to the wiring 121. In this case, the wiring 121 is not provided, and one of the source and drain of the transistor 111 is connected to the wiring 1. 24 (see FIG. 1(B)).

[0057] As an initial state, the state of the semiconductor device 100 immediately before time T1 is shown in FIG. 4(A). ), the transistors 111 to 113 are in an off state, and the node 13 The potential of the terminal 102 is the H potential, and the potential of the node 132 is H-Vth. L potential is input.

[0058] [Period 151: H potential input period] At time T1, an H potential is input to the terminal 102, an L potential is input to the wiring 124, and An L potential is input to the line 123. Then, the transistor 112 is turned on. When the resistor 112 is turned on, the potential of the node 131 becomes the L potential, and the When the potential of the node 131 becomes the L potential, the The potential of the node 132 connected to the transistor 131 is L-Vth (see FIG. 4B). The timing for inputting the H potential to the terminal 102 is preferably after inputting the L potential to the wiring 123. It's nice.

[0059] [Period 152: L potential input period] At time T2, an L potential is input to the terminal 102, and an H potential is supplied to the wiring 124. As a result, the transistor 112 is turned off and the transistor 111 is turned on. Then, the potential of the node 131 becomes H-Vth. The potential of the node 132 that receives the voltage Vth is H-2×Vth (see FIG. 5A).

[0060] At time T3, an H potential is supplied to the wiring 123. Then, the transistor 113 is turned on. At this time, the potential of the node 132 is The potential difference between H-2×Vth and H-Vth is Vth. The potential of the node 131 connected via the capacitance element 117 also rises by Vth. The potential of the terminal 105 is changed to the H potential (see FIG. 5B). The first gate, the second gate, the source, and the The drain potential becomes the H potential, so that the transistor 111 is turned off.

[0061] Also, as shown at time T4 in FIG. 6, when the potential of the node 132 becomes H-Vth, The resistor 113 is turned off.

[0062] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0063] (Embodiment 2) In this embodiment, a semiconductor device 110 having a different configuration from the semiconductor device 100 will be described. 7A is a circuit diagram illustrating the configuration of a semiconductor device 110. FIG. In order to avoid repetition of the description, the present embodiment will mainly focus on the parts that are different from the semiconductor device 100. The parts not explained in this embodiment are the same as those in other embodiments or in this embodiment. The technical common sense of the contractor should be taken into consideration.

[0064] <Configuration Example of Semiconductor Device 110> The semiconductor device 110 has the same structure as the transistor 113 included in the semiconductor device 100 shown in FIG. a back gate is provided at the source or drain of the transistor 113. The other end of the connector is electrically connected to the other end of the connector.

[0065] Note that an inverted signal of the signal input to the terminal 102 may be input to the wiring 121. In this case, the wiring 121 is not provided, and one of the source and drain of the transistor 111 is connected to the wiring 1. 24 (see FIG. 7(B)).

[0066] Also, as shown in the circuit diagram of the semiconductor device 110a in FIG. 7(C), A back gate is provided to the transistor 112, and the back gate is connected to the gate of the transistor 112. The device may be electrically connected to the

[0067] Also, as shown in the circuit diagram of the semiconductor device 110b in FIG. 7(D), The transistor 112 is provided with a back gate, and the back gate is connected to the source of the transistor 112. The source and drain may be electrically connected to each other.

[0068] The semiconductor device 110, the semiconductor device 110a, and the semiconductor device 110b are also However, the semiconductor device 110, the semiconductor device 110a, and In the semiconductor device 110b, when an L potential is supplied to the wiring 123 in the period 151, The potential of the node 132 becomes Vth.

[0069] <Operation Example of Semiconductor Device 110> An example of the operation of the semiconductor device 110 will be described with reference to the timing chart of FIG. 8 and the circuits of FIGS. 9 to 11. The semiconductor device 110 operates in substantially the same manner as the semiconductor device 100. Here, the differences from the operation of the semiconductor device 100 will be described.

[0070] In this embodiment, the threshold voltages of the transistors 111 to 113 are (also referred to as "Vth") are all the same. The line 124 is connected to the terminal 10. The inverted signal of the signal input to input terminal 2 is input.

[0071] Note that an inverted signal of the signal input to the terminal 102 may be input to the wiring 121. In this case, the wiring 121 is not provided, and one of the source and drain of the transistor 111 is connected to the wiring 1. 24 (see FIG. 7(B)).

[0072] As an initial state, the state of the semiconductor device 110 immediately before time T1 is shown in FIG. 9(A). ), the transistors 111 to 113 are in an off state, and the node 13 The potential of the terminal 10 is H+Vth, and the potential of the node 132 is H-Vth. An L potential is input to 2.

[0073] [Period 151: H potential input period] At time T1, an H potential is input to the terminal 102, an L potential is input to the wiring 124, and An L potential is input to the line 123. Then, the transistor 112 is turned on. When the resistor 112 is turned on, the node 131 is at the L potential. When the potential of the node 131 becomes the L potential, the The potential of the node 132 connected to the transistor 131 is L-Vth (see FIG. 9B).

[0074] [Period 152: L potential input period] At time T2, an L potential is input to the terminal 102, and an H potential is supplied to the wiring 124. As a result, the transistor 112 is turned off and the transistor 111 is turned on. Then, the potential of the node 131 rises from the L potential to H-Vth. The potential of the node 132 connected to the capacitor 117 also tends to rise. When the potential of the node 132 exceeds the Vth of the transistor 113, the transistor 113 is turned on. Therefore, the potential of the node 132 becomes Vth (see FIG. 10A). When the potential of the node 132 reaches Vth, the transistor 113 is turned off.

[0075] At time T3, an H potential is supplied to the wiring 123. Then, the transistor 113 is turned on. At this time, the potential of the node 132 is The potential difference between Vth and H-Vth is H-2×Vth. The potential of node 131 connected via capacitor 117 also rises by H-2×Vth. Therefore, the potential of the node 131 momentarily becomes 2×H−3×Vth (see FIG. 10(B)). ).

[0076] Also, when the potential of the node 131 exceeds H+Vth, the charge of the node 131 is transferred to the wiring 121. As a result, the potential at node 131 drops.

[0077] Then, as shown at time T4 in FIG. 11, when the potential of the node 131 becomes H+Vth, The transistor 111 is turned off. When the potential of the node 132 becomes H-Vth, In this way, the transistor 113 is turned off. Positions can be provided.

[0078] In the operation example of the semiconductor device 110 shown in this embodiment, VDD-2×Vth is Vth In other words, Vth should be less than one-third of VDD. It is essential to do so.

[0079] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0080] (Embodiment 3) In this embodiment, a semiconductor device 120 having a different configuration from the semiconductor device 100 is described as follows. 12A is a circuit diagram illustrating the configuration of a semiconductor device 120. In order to avoid repetition of the description, the present embodiment will mainly focus on the differences from the semiconductor device 100. The parts not explained in this embodiment are the same as those in other embodiments or This can be understood by taking into consideration the common technical knowledge held by a person skilled in the art.

[0081] <Configuration Example of Semiconductor Device 120> The semiconductor device 120 is the same as the semiconductor device 100 shown in FIG. 1A except that a transistor 114 is added. The transistor 114 included in the semiconductor device 120 has a source or drain. One of the inputs is electrically connected to the node 132, and the other of the source and drain is connected to the wiring 12. 2. The gate of the transistor 114 is electrically connected to the terminal 102. are actively connected.

[0082] In addition, as in the semiconductor device 120a shown in the circuit diagram of FIG. 12B, The other of the source and the drain may be electrically connected to the wiring 126. 4 is connected to a wiring different from the wiring 122, A potential different from that of the wiring 122 can be supplied to the other of the source or drain of the capacitor 114. Cut.

[0083] In addition, as in the semiconductor device 120b shown in the circuit diagram of FIG. 12C, A back gate is provided and electrically connected to the gate of the transistor 112. Alternatively, a back gate may be provided to the transistor 114, and the back gate may be connected to the transistor 114. It may be electrically connected to the gate of the transistor 114 .

[0084] In addition, as in a semiconductor device 120c shown in the circuit diagram of FIG. 12(D), A back gate is provided, and the back gate is connected to the source or drain of the transistor 112. Alternatively, the transistor 114 may be provided with a back gate, The back gate is electrically connected to the other of the source and the drain of the transistor 114. That's fine.

[0085] <Operation Example of Semiconductor Device 120> An example of the operation of the semiconductor device 120 will be described with reference to the timing chart of FIG. 13 and FIGS. 14 to 16. The semiconductor device 120 operates in substantially the same manner as the semiconductor device 100. Here, the differences from the operation of the semiconductor device 100 will be described.

[0086] In this embodiment, the threshold voltages ( The voltages Vth and Vth are all the same. The line 121 is connected to the terminal 102, and the L potential (VSS) is supplied to the line 122. Alternatively, the inverse of the input signal may be input.

[0087] As an initial state, the state of the semiconductor device 120 immediately before time T1 is shown in FIG. In (A), the transistors 111 to 114 are in an off state, and the node The potential of the terminal 131 is H+Vth, and the potential of the node 132 is H-Vth. An L potential is input to 102.

[0088] [Period 151: H potential input period] At time T1, an H potential is input to the terminal 102, an L potential is input to the wiring 124, and An L potential is input to the line 123. Then, the transistors 112 and 114 When the transistor 112 and the transistor 114 are turned on, The nodes 131 and 132 are at the L potential. Also, the L potential is output from the terminal 105. (See FIG. 14(B)).

[0089] [Period 152: L potential input period] At time T2, the terminal 102 is at L potential, the wire 124 is at H potential, and the wire 123 is at 2×Vth In this embodiment, a potential of 2×Vth or more is supplied to the wiring 123. Then, the transistor 112 and the transistor 114 are turned off, and The potential of the node 131 becomes H-Vth, and the potential of the node 132 becomes Vth (see FIG. 15(A)). )reference.).

[0090] At time T3, the potential of the wiring 123 is set to H potential. Then, the potential of the node 132 is V At this time, the potential of the node 132 rises from Vth to H-Vth. The potential difference increases by H-2×Vth. The potential of the connected node 131 also rises by H-2×Vth. The potential of the transistor instantaneously becomes 2×H−3×Vth (see FIG. 15(B)).

[0091] However, when the potential of the node 131 exceeds H+Vth, the charge of the node 131 is transferred to the wiring 121 , the potential at node 131 drops.

[0092] Then, as shown at time T4 in FIG. 16, when the potential of the node 131 becomes H+Vth, The transistor 111 is turned off. In addition, the potential of the node 132 is H-Vth. In this way, the terminal 105 is supplied with the H potential. The above potentials can be supplied.

[0093] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0094] (Fourth embodiment) In this embodiment mode, a transistor that can be used in the semiconductor device shown in the above embodiment mode will be described. An example of the structure of the data will be described.

[0095] <Example of transistor structure> The semiconductor device of one embodiment of the present invention includes a bottom-gate transistor and a top-gate transistor. The present invention can be implemented using various types of transistors, such as a transistor having a MOSFET, ... and a transistor having a MOSFET. The semiconductor layer material and transistor structure can be easily replaced to suit the production line. It is possible.

[0096] [Bottom-gate transistor] FIG. 17(A1) shows a channel protection transistor, which is a type of bottom gate transistor. 2 is a cross-sectional view of a transistor 410. The transistor 410 is formed on a substrate 271 with an insulating layer 272 interposed therebetween. The semiconductor layer 242 is formed on the electrode 246 via the insulating layer 226. The electrode 246 can function as a gate electrode. The insulating layer 226 can function as a gate insulating layer. It can function.

[0097] The insulating layer 225 is provided on the channel formation region of the semiconductor layer 242. Electrodes 244a and 244b are provided on the insulating layer 226 in contact with a portion of the insulating layer 226. A portion of electrode 244 a and a portion of electrode 244 b are formed on insulating layer 225 .

[0098] The insulating layer 225 can function as a channel protection layer. By providing the electrode 244a and the electrode 244b, the exposure of the semiconductor layer 242 that occurs when the electrode 244a and the electrode 244b are formed can be prevented. Therefore, when the electrodes 244a and 244b are formed, the semiconductor layer This prevents the channel formation region 242 from being etched. According to this, a transistor with good electrical characteristics can be realized.

[0099] The transistor 410 is also provided with an insulating layer 225 on the electrodes 244a and 244b. The insulating layer 228 has a layer 229 on it.

[0100] When an oxide semiconductor is used for the semiconductor layer 242, the electrodes 244a and 244b At least the portion in contact with the semiconductor layer 242 is provided with oxygen by removing oxygen from a portion of the semiconductor layer 242. It is preferable to use a material that can generate oxygen vacancies. The carrier concentration in the region where the defect occurs increases, and the region becomes n-type, and the n-type region (n + layer) and Therefore, the region can function as a source region or a drain region. Examples of materials that can remove oxygen from an oxide semiconductor and cause oxygen vacancies include , tungsten, titanium, etc.

[0101] The source and drain regions are formed in the semiconductor layer 242, forming an electrode 244a In addition, the contact resistance between the electrode 244b and the semiconductor layer 242 can be reduced. The electrical characteristics of the transistor, such as the effective mobility and threshold voltage, can be improved. can.

[0102] When a semiconductor such as silicon is used for the semiconductor layer 242, the semiconductor layer 242 and the electrode 244a and between the semiconductor layer 242 and the electrode 244b, as an n-type semiconductor or a p-type semiconductor. It is preferable to provide a layer that functions as an n-type semiconductor or a p-type semiconductor. It can function as a source or drain region of a transistor.

[0103] The insulating layer 229 has a function of preventing or reducing the diffusion of impurities into the transistor from the outside. It is preferable to form the insulating layer 229 using a material having the above properties. You can also do this.

[0104] When an oxide semiconductor is used for the semiconductor layer 242, the insulating layer 229 is formed before or after the insulating layer 229 is formed. Alternatively, heat treatment may be performed before or after the formation of the insulating layer 229. The oxygen contained in the insulating layer 229 and other insulating layers is diffused into the semiconductor layer 242, Alternatively, the insulating layer 229 can be formed by heating. By doing so, oxygen vacancies in the semiconductor layer 242 can be compensated for.

[0105] The transistor 411 shown in FIG. 17A2 has a gate electrode formed on the insulating layer 229 and functioning as a back gate. The transistor 410 differs from the transistor 410 in that it has an electrode 223 that can be connected to the electrode 246. It can be formed using the same materials and methods as those described above.

[0106] [About the back gate] Here, we will explain the gate and back gate of a transistor. The back gate is formed of a conductive layer, and the channel forming region of the semiconductor layer is sandwiched between the gate and back gate. Therefore, the back gate can function similarly to a gate. The potential of the back gate may be the same as that of the gate electrode, or may be set to the GND potential or any other potential. The potential of the back gate may be changed independently of the gate. This allows the threshold voltage of the transistor to be changed.

[0107] Both electrode 246 and electrode 223 can function as gates. The insulating layer 226, the insulating layer 228, and the insulating layer 229 each function as a gate insulating layer. The electrode 223 may be provided between the insulating layer 228 and the insulating layer 229. good.

[0108] In addition, either the electrode 246 or the electrode 223 may be referred to as a "gate" or a "gate electrode." In this case, the other is called the "back gate" or "back gate electrode." In 411, when the electrode 223 is called a "gate electrode," the electrode 246 is called a "back gate." When the electrode 223 is used as a "gate electrode," the transistor 4 11 can be considered as a type of top-gate transistor. Either the electrode 221 or the electrode 223 is referred to as the "first gate" or the "first gate electrode", and the other The second gate electrode is sometimes called the "second gate" or "second gate electrode."

[0109] By providing the electrode 246 and the electrode 223 with the semiconductor layer 242 interposed therebetween, the electrode 24 6 and the electrode 223 are set to the same potential, the region where carriers flow in the semiconductor layer 242 The area becomes larger in the film thickness direction, so the amount of carrier movement increases. As the on-current of the transistor 411 increases, the field effect mobility also increases.

[0110] Therefore, the transistor 411 is a transistor having a large on-state current relative to its area. That is, the area occupied by the transistor 411 is determined based on the required on-current. According to one embodiment of the present invention, the area occupied by a transistor can be reduced. Therefore, according to one embodiment of the present invention, a highly integrated semiconductor device can be realized. It is possible.

[0111] In addition, since the gate and back gate are made of conductive layers, the electric current generated outside the transistor is The function of preventing magnetic fields from acting on the semiconductor layer where the channel is formed (especially against static electricity) The back gate is formed larger than the semiconductor layer, By covering the semiconductor layer with a gate, the electric field shielding function can be improved.

[0112] The electrode 246 (gate) and the electrode 223 (back gate) are each externally Therefore, the load generated on the insulating layer 272 side or above the electrode 223 is blocked. Charges such as electrons do not affect the channel forming region of the semiconductor layer 242. As a result, stress Test (e.g., applying a negative charge to the gate - GBT (Gate Bias-Temperature Degradation due to stress tests is suppressed. This reduces the change in the gate voltage (rising voltage) at which the on-current begins to flow. This effect can be achieved whether the electrode 246 and the electrode 223 are at the same potential or different potentials. This occurs in the case of electric potential.

[0113] The GBT stress test is a type of accelerated test that measures the temperature and humidity of the battery during long-term use. It is possible to evaluate the change in characteristics (aging) of a resistor in a short time. The amount of change in the threshold voltage of a transistor before and after testing is an important factor for examining reliability. The smaller the threshold voltage fluctuation, the more reliable the transistor. can.

[0114] In addition, the electrode 246 and the electrode 223 are provided, and the electrode 246 and the electrode 223 are set to the same potential. This reduces the amount of variation in threshold voltage. At the same time, the variations in electrical characteristics are reduced.

[0115] Also, a transistor with a back gate applies a positive charge to the gate. The variation in threshold voltage before and after the back-gate test was also smaller than that of a transistor without a back gate. small.

[0116] In addition, by forming the back gate using a conductive film having a light-shielding property, the semiconductor This prevents light from entering the conductor layer. This can prevent deterioration of electrical characteristics such as a shift in the threshold voltage of the transistor.

[0117] According to one embodiment of the present invention, a highly reliable transistor can be provided. A highly reliable semiconductor device can be realized.

[0118] Figure 17(B1) shows a channel protection transistor, which is one of the bottom gate transistors. 4 shows a cross-sectional view of transistor 420. Transistor 420 has a similar structure to transistor 410. The structure is different in that an insulating layer 225 covers the semiconductor layer 242. 25, the semiconductor layer 242 that is generated when the electrode 244a and the electrode 244b are formed Therefore, when the electrodes 244a and 244b are formed, the semiconductor This can prevent the layer 242 from becoming thin.

[0119] In addition, a portion of the insulating layer 225 overlapping the semiconductor layer 242 is selectively removed to form an opening. In this case, the semiconductor layer 242 and the electrode 244a are electrically connected to each other. In another opening formed by selectively removing a part of the insulating layer 225 overlapping the semiconductor layer The insulating layer 229 overlaps with the channel forming region and is electrically connected to the electrode 244b. This region can function as a channel protection layer.

[0120] The transistor 421 illustrated in FIG. 17B2 has a gate electrode formed on the insulating layer 229 and functioning as a back gate. The transistor 420 differs from the transistor 420 in that it has an electrode 223 that can be connected.

[0121] Also, the transistors 420 and 421 are the same as the transistors 410 and 421. The distance between the electrode 244a and the electrode 246 and the distance between the electrode 244b and the electrode 246 are larger than the distance between the electrode 244a and the electrode 246 and the electrode 244b. Therefore, the distance between the electrodes 244a and 246 is increased. In addition, the parasitic capacitance generated between the electrode 244b and the electrode 246 can be reduced. According to one embodiment of the present invention, a transistor with favorable electrical characteristics can be realized. Cut.

[0122] The transistor 425 shown in FIG. 17C1 is a bottom-gate transistor. The transistor 425 is a channel-etched transistor having an insulating layer 225. Instead, the electrode 244a and the electrode 244b are formed in contact with the semiconductor layer 242. Therefore, the part of the semiconductor layer 242 that is exposed when the electrodes 244a and 244b are formed is etched. On the other hand, since the insulating layer 229 is not provided, productivity of the transistor can be improved. It can be done.

[0123] The transistor 426 shown in FIG. 17C2 has a gate electrode formed on the insulating layer 229 and functioning as a back gate. The transistor 425 differs from the transistor 425 in that it has an electrode 223 that can be connected.

[0124] [Top-gate transistor] FIG. 18A1 shows a cross-sectional view of a transistor 430, which is a type of top-gate transistor. The transistor 430 is formed by a semiconductor layer 272 on a substrate 271 via an insulating layer 272. 42, and an electrode contacting a part of the semiconductor layer 242 is provided on the semiconductor layer 242 and the insulating layer 272. and an electrode 244b in contact with a part of the semiconductor layer 242. , electrode 244a, and electrode 244b, and an insulating layer 226 is formed on the insulating layer 226. It has 46.

[0125] The transistor 430 is connected between the electrode 246 and the electrode 244a, and between the electrode 246 and the electrode 244b do not overlap, the parasitic capacitance generated between the electrode 246 and the electrode 244a, and Furthermore, the parasitic capacitance occurring between the electrode 246 and the electrode 244b can be reduced. After the electrode 246 is formed, the impurity 255 is introduced into the semiconductor using the electrode 246 as a mask. By introducing the impurities into the semiconductor layer 242, the impurities are self-aligned in the semiconductor layer 242. A pure region can be formed (see FIG. 18(A3)). A transistor with good electrical characteristics can be realized.

[0126] The introduction of the impurity 255 can be performed using an ion implantation device, an ion doping device, or a plasma treatment device. This can be done using a processing device.

[0127] The impurity 255 may be, for example, at least one of a group 13 element or a group 15 element. When an oxide semiconductor is used for the semiconductor layer 242, In this case, the impurity 255 is at least one element selected from the group consisting of rare gases, hydrogen, and nitrogen. It is also possible to use

[0128] The transistor 431 shown in FIG. 18A2 has an electrode 223 and an insulating layer 227. The transistor 431 is formed on the insulating layer 272. The electrode 223 has an insulating layer 227 formed on the electrode 223. The electrode 223 has a Therefore, the insulating layer 227 can function as a gate insulating layer. The insulating layer 227 can function as the insulating layer 226. It can be achieved.

[0129] Like the transistor 411, the transistor 431 has a large on-state current relative to its area. That is, for the required on-current, the transistor 4 According to one aspect of the present invention, the area occupied by the transistor 31 can be reduced. Therefore, according to one aspect of the present invention, a highly integrated semiconductor device can be manufactured. A body device can be realized.

[0130] The transistor 440 illustrated in FIG. 18B1 is a top-gate transistor. The transistor 440 is formed by forming the electrodes 244a and 244b on a semiconductor substrate. The transistor 430 differs from the transistor 430 in that the layer 242 is formed. The transistor 441 has an electrode 223 and an insulating layer 227. 40. In the transistor 440 and the transistor 441, the semiconductor layer 242 A part of the semiconductor layer 242 is formed on the electrode 244a, and another part of the semiconductor layer 242 is formed on the electrode 244b. will be done.

[0131] Like the transistor 411, the transistor 441 has a large on-state current relative to its area. That is, for the required on-current, the transistor 4 According to one aspect of the present invention, the area occupied by the transistor 41 can be reduced. Therefore, according to one aspect of the present invention, a highly integrated semiconductor device can be manufactured. A body device can be realized.

[0132] The transistor 442 illustrated in FIG. 19A1 is a top-gate transistor. The transistor 442 has an electrode 244a and an electrode 244b on the insulating layer 229. The electrodes 244a and 244b are formed on the insulating layers 228 and 229. The opening is electrically connected to the semiconductor layer 242 .

[0133] Also, a part of the insulating layer 226 that does not overlap with the electrode 246 is removed. A portion of the insulating layer 226 of the electrode 442 extends beyond the end of the electrode 246 .

[0134] The electrode 246 and the insulating layer 226 are used as a mask to introduce impurities 255 into the semiconductor layer 242. By this, an impurity region is formed in the semiconductor layer 242 in a self-aligned manner. This can be done (see FIG. 19(A3)).

[0135] At this time, the impurity 255 is not introduced into the region of the semiconductor layer 242 that overlaps with the electrode 246, and the electrode Impurities 255 are introduced into the region that does not overlap with the insulating layer 246. The impurity concentration in the region where the impurity 255 is introduced through the insulating layer 226 is The electrode 246 in the semiconductor layer 242 is lower than the region where the impurity 255 is introduced. An LDD (Lightly Doped Drain) region is formed in the adjacent region.

[0136] The transistor 443 shown in FIG. 19A2 has an electrode 223 below the semiconductor layer 242. The electrode 223 is connected to the semiconductor layer 221 via an insulating layer 272. 242. The electrode 223 can function as a back gate electrode.

[0137] In addition, the transistor 444 shown in FIG. 19B1 and the transistor shown in FIG. 19B2 Like the area 445, the insulating layer 226 may be entirely removed in areas that do not overlap with the electrode 246. In addition, the transistor 446 shown in FIG. 19(C1) and the transistor shown in FIG. 19(C2) As in the case of the insulating layer 226, the insulating layer 226 may be left without being removed except for the opening.

[0138] The transistors 444 to 447 are also formed by forming the electrode 246. As a result, the semiconductor layer 242 is doped with impurities 255 using the mask. An impurity region can be formed in a self-aligned manner.

[0139] [s-channel transistor] FIG. 20 illustrates an example of a transistor structure in which an oxide semiconductor is used as the semiconductor layer 242. In FIG. FIG. 20A is a top view of the transistor 451. FIG. 20B is a top view of the transistor 451 shown in FIG. This is a cross-sectional view of the portion L1-L2 indicated by the dashed line (cross-sectional view in the channel length direction). 20(C) is a cross-sectional view of the portion W1-W2 indicated by the dashed line in FIG. 20(A) (in the channel width direction). (cross-sectional view).

[0140] The transistor 451 includes a semiconductor layer 242, an insulating layer 226, an insulating layer 272, an insulating layer 282, and an insulating layer 290. The edge layer 274 includes an electrode 224, an electrode 243, an electrode 244a, and an electrode 244b. Electrode 243 can function as a gate. Electrode 224 can function as a back gate. The insulating layer 226, the insulating layer 272, the insulating layer 282, and the insulating layer 274 serve as gate insulating layers. The electrode 244a can function as either a source electrode or a drain electrode. The electrode 244b can function as the other of the source electrode or the drain electrode.

[0141] An insulating layer 275 is provided on the substrate 271, and the electrode 224 and the insulating layer 27 are provided on the insulating layer 275. 3 is provided. In addition, an insulating layer 274 is provided on the electrode 224 and the insulating layer 273. Furthermore, an insulating layer 282 is provided on the insulating layer 274, and an insulating layer 27 is provided on the insulating layer 282. 2 is provided.

[0142] The semiconductor layer 242a is provided on the protrusion formed on the insulating layer 272, and the semiconductor layer 242a A semiconductor layer 242b is provided on the semiconductor layer 242b. An electrode 244a, The semiconductor layer 242b has a region overlapping with the electrode 244a. , can function as one of the source and drain of the transistor 451. The region overlapping with the electrode 244b of the transistor 451 is the other of the source and drain of the transistor 451. It can function as such.

[0143] In addition, a semiconductor layer 242c is provided in contact with a part of the semiconductor layer 242b. An insulating layer 226 is provided on the conductor layer 242c, and an electrode 243 is provided on the insulating layer 226. are.

[0144] The transistor 451 is formed on the upper surface and side surface of the semiconductor layer 242b in the region W1-W2. The side surface of the semiconductor layer 242a is covered with the semiconductor layer 242c. By providing the semiconductor layer 242b above the protrusions provided on the layer 272, the side of the semiconductor layer 242b The surface can be covered with the electrode 243. That is, the transistor 451 can The semiconductor layer 242b can be electrically surrounded by the field. In this way, the electric field of the conductive film electrically surrounds the semiconductor layer where the channel is formed. The structure of the transistor is a surrounded channel (s-channel) structure. A transistor with an s-channel structure is called an "s-channel It is also called an "s-channel transistor" or "s-channel transistor."

[0145] In the s-channel structure, a channel is formed in the entire (bulk) semiconductor layer 242b. In the s-channel structure, the drain current of the transistor can be increased. Furthermore, the electric field of the electrode 243 can As a result, the entire channel formation region formed in the semiconductor layer 242b can be depleted. Therefore, in the s-channel structure, the off-state current of the transistor can be further reduced. It is possible.

[0146] In addition, by increasing the height of the protrusions of the insulating layer 272 and reducing the channel width, the s-channel The effect of increasing the on-current and reducing the off-current due to the n-type structure can be further enhanced. Furthermore, when processing the semiconductor layer 242b, the exposed semiconductor layer 242a may be removed. In this case, the side surfaces of the semiconductor layer 242a and the semiconductor layer 242b may be aligned.

[0147] In addition, the insulating layer 228 is provided over the transistor 451, and the insulating layer 229 is provided over the insulating layer 228. On the insulating layer 229, an electrode 225a, an electrode 225b, and an electrode 225c are provided. The electrode 225a is provided on the insulating layer 229 and the insulating layer 228. The opening is electrically connected to the electrode 244a via a contact plug. 225b is an opening provided in the insulating layer 229 and the insulating layer 228, and is a contact plug. The electrode 225c is electrically connected to the electrode 244b via the insulating layer 229 and An opening provided in the insulating layer 228 is electrically connected to the electrode 244c via a contact plug. is connected.

[0148] The insulating layer 282 may be made of hafnium oxide, aluminum oxide, tantalum oxide, or aluminum. By forming the insulating layer 282 from silicate or the like, it is possible to make the insulating layer 282 function as a charge trapping layer. By injecting electrons into the insulating layer 282, the threshold voltage of the transistor can be changed. Electrons can be injected into the insulating layer 282 by using, for example, the tunnel effect. By applying a positive voltage to the electrode 224, tunnel electrons are injected into the insulating layer 282. You can enter.

[0149] <Energy band structure of semiconductor layer 242 (1)> Here, the semiconductor layer 242a, the semiconductor layer 242b, and the semiconductor layer 242c are stacked. The function and effect of the semiconductor layer 242 formed will be explained using the energy The band structure diagram will be explained below. Figure 28(A) shows the band structure of the D1-D2 dashed line in Figure 20(B). In other words, Figure 28(A) shows the energy band structure of the region indicated by 4 shows the energy band structure of the channel formation region of the transistor 451.

[0150] In Figure 28(A), Ec382, Ec383a, Ec383b, Ec383c, Ec386 are the insulating layer 272, the semiconductor layer 242a, the semiconductor layer 242b, and the semiconductor layer 242c, respectively. , indicates the energy of the conduction band minimum of the insulating layer 226.

[0151] Here, the electron affinity is the energy difference between the vacuum level and the top of the valence band (the "ionization potential"). It is the value obtained by subtracting the band gap from the Using a spectroscopic ellipsometer (HORIBA JOBIN YVON UT-300) The energy difference between the vacuum level and the top of the valence band can be measured by ultraviolet photoelectron spectroscopy ( UPS:Ultraviolet Photoelectron Spectrosco Measurement can be performed using a PHI VersaProbe device.

[0152] The In-Ga was formed using a target with an atomic ratio of In:Ga:Zn=1:3:2. The band gap of α-Zn oxide is approximately 3.5 eV and the electron affinity is approximately 4.5 eV. In addition, the In-Ga was formed using a target with an atomic ratio of In:Ga:Zn=1:3:4. The band gap of Zn-oxide is about 3.4 eV and the electron affinity is about 4.5 eV. , In-Ga- formed using a target with an atomic ratio of In:Ga:Zn=1:3:6 The band gap of ZnO is about 3.3 eV and the electron affinity is about 4.5 eV. In-Ga-Z formed using a target with an atomic ratio of In:Ga:Zn=1:6:2 The band gap of n-oxide is about 3.9 eV and the electron affinity is about 4.3 eV. In-Ga-Zn formed using a target with a molecular ratio of In:Ga:Zn=1:6:8 The band gap of the oxide is about 3.5 eV and the electron affinity is about 4.4 eV. In-Ga-Zn formed using a target with a numerical ratio of In:Ga:Zn=1:6:10 The band gap of the oxide is about 3.5 eV and the electron affinity is about 4.5 eV. In-Ga-Zn oxide formed using a target with a numerical ratio of In:Ga:Zn=1:1:1 The band gap of the oxide is about 3.2 eV, and the electron affinity is about 4.7 eV. In-Ga-Zn oxide formed using a target with a ratio of In:Ga:Zn=3:1:2 The band gap of the material is approximately 2.8 eV and the electron affinity is approximately 5.0 eV.

[0153] Since the insulating layer 272 and the insulating layer 226 are insulators, Ec382 and Ec386 are It is closer to the vacuum level than 3a, Ec383b, and Ec383c (it has a smaller electron affinity). ).

[0154] Also, Ec383a is closer to the vacuum level than Ec383b. is 0.07 eV or more and 1.3 eV or less than Ec383b, preferably 0.1 eV or more and 0.07 eV or less than Ec383b. 0.7 eV or less, more preferably 0.15 eV to 0.4 eV, close to the vacuum level. preferable.

[0155] Also, Ec383c is closer to the vacuum level than Ec383b. is 0.07 eV or more and 1.3 eV or less than Ec383b, preferably 0.1 eV or more and 0.07 eV or less than Ec383b. 0.7 eV or less, more preferably 0.15 eV to 0.4 eV, close to the vacuum level. preferable.

[0156] Here, between the semiconductor layer 242a and the semiconductor layer 242b, there is a semiconductor layer 242a and a semiconductor layer 242b. In some cases, the semiconductor layer 242b and the semiconductor layer 242c are mixed. There may be a mixed region of the semiconductor layer 242b and the semiconductor layer 242c between them. The interface state density is low in the overlap region. The stack of the semiconductor layer 242c and the semiconductor layer 242d has a structure in which energy is continuously distributed near the interfaces of the semiconductor layer 242c and the semiconductor layer 242d. This results in a band structure that changes (also called a continuous junction).

[0157] At this time, the electrons are not in the semiconductor layer 242a and the semiconductor layer 242c, but in the semiconductor layer 2 Therefore, the electrons move mainly through the semiconductor layer 242a and the semiconductor layer 242b. Interface state density at the interface, the interface between the semiconductor layer 242b and the semiconductor layer 242c By lowering the level density, the movement of electrons in the semiconductor layer 242b is inhibited. Therefore, the on-state current of the transistor 451 can be increased.

[0158] In addition, the interface between the semiconductor layer 242a and the insulating layer 272, and the interface between the semiconductor layer 242c and the insulating layer 226 Although trap levels 390 due to impurities and defects can be formed near the interface, The presence of the conductor layer 242a and the semiconductor layer 242c allows the semiconductor layer 242b and the This allows the rapping level to be kept away.

[0159] When the transistor 451 has an s-channel structure, the region W1-W2 Therefore, a channel is formed in the entire semiconductor layer 242b. The thicker the semiconductor layer 242b, the larger the channel region. For example, the on-current of the capacitor 451 can be increased by 10 nm or more, preferably 40 nm or more. A region having a thickness of 100 nm or more, more preferably 60 nm or more, and even more preferably 100 nm or more. However, the semiconductor device having the transistor 451 may be a semiconductor layer 242b. Therefore, for example, it is preferable that the thickness is 300 nm or less, preferably 200 nm or less. The semiconductor layer 242b may have a thickness of 150 nm or less. As the channel formation region shrinks, the thinner the semiconductor layer 242b, the more the transistor Therefore, the thickness of the semiconductor layer 242b is preferably less than 10 nm. may be.

[0160] In order to increase the on-state current of the transistor 451, the thickness of the semiconductor layer 242c is small. For example, it is less than 10 nm, preferably 5 nm or less, and more preferably 3 The semiconductor layer 242c may have a region of 100 nm or less. The semiconductor layer 242b in which the channel is formed is doped with elements other than oxygen (water) that constitute the adjacent insulator. It has the function of blocking the penetration of elements such as silicon and silicon dioxide. It is preferable that 242c has a certain thickness. For example, it is preferable that it is 0.3 nm or more. a semiconductor layer 242c having a region with a thickness of at least 1 nm, more preferably at least 2 nm; Just do that.

[0161] In order to increase reliability, the semiconductor layer 242a is thick and the semiconductor layer 242c is thin. For example, it is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 40 If the semiconductor layer 242a has a region with a thickness of 60 nm or more, more preferably 60 nm or more, By increasing the thickness of the semiconductor layer 242a, the adjacent insulator and the semiconductor layer 242a The distance from the interface with the semiconductor layer 242b where the channel is formed can be increased. However, productivity of a semiconductor device including the transistor 451 may decrease. For example, the thickness is 200 nm or less, preferably 120 nm or less, and more preferably 80 nm or less. The semiconductor layer 242a may have the above-mentioned region.

[0162] Note that silicon in an oxide semiconductor may become a carrier trap or a carrier generation source. Therefore, the lower the silicon concentration of the semiconductor layer 242b, the more preferable. Between the layer 242b and the semiconductor layer 242a, for example, secondary ion mass spectroscopy (SIMS: 1×10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than, more Preferably 2 x 10 18 atoms / cm 3 It has a region where the silicon concentration is less than In addition, a 1×10 19 a toms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than, even more preferred Kuha 2 x 10 18 atoms / cm 3 The silicon concentration is less than 1000 .mu.m.

[0163] In order to reduce the hydrogen concentration in the semiconductor layer 242b, the semiconductor layer 242a and the semiconductor layer It is preferable to reduce the hydrogen concentration in the semiconductor layer 242a and the semiconductor layer 242c. , SIMS, 2 × 10 20 atoms / cm 3 Less than or equal to 5 x 10 19 a toms / cm 3 Less than or equal to 1×10 19 atoms / cm 3 Below are some more good ones: Preferably 5 x 10 18 atoms / cm 3 The hydrogen concentration range is as follows: In order to reduce the nitrogen concentration in the conductor layer 242b, the semiconductor layer 242a and the semiconductor layer 242c It is preferable to reduce the nitrogen concentration in the semiconductor layer 242a and the semiconductor layer 242c. In S, 5 x 10 19 atoms / cm 3 Less than 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 More preferably, 5×10 17 atoms / cm 3 The nitrogen concentration ranges as follows:

[0164] Note that when copper is mixed into an oxide semiconductor, electron traps may be generated. The flip-flop may cause the threshold voltage of the transistor to shift in the positive direction. The copper concentration on the surface or inside of the semiconductor layer 242b is preferably as low as possible. Layer 242b has a copper concentration of 1×10 19 atoms / cm 3 Below, 5 x 10 18 atoms / cm 3 or less, or 1 x 10 18 atoms / cm 3 It is preferable to have the following region: stomach.

[0165] The above-mentioned three-layer structure is an example. For example, a semiconductor layer without the semiconductor layer 242a or the semiconductor layer 242c Alternatively, a two-layer structure may be used. 242c, a semiconductor layer 242a, a semiconductor layer 242b, and a semiconductor layer 242c are provided above or below the semiconductor layer 242a, a semiconductor layer 242b, and a semiconductor layer 242c. Alternatively, a four-layer structure may be used, which includes any one of the semiconductors exemplified above. Above layer 242a, below semiconductor layer 242a, above semiconductor layer 242c, below semiconductor layer 242c The semiconductor layer 242a, the semiconductor layer 242b, and the semiconductor layer 242c are disposed in two or more locations. It may also be an n-layer structure (n is an integer of 5 or more) having one of the semiconductors exemplified above. do not have.

[0166] In particular, the transistor 451 described in this embodiment has a semiconductor The upper surface and side surfaces of the layer 242b are in contact with the semiconductor layer 242c, and the lower surface of the semiconductor layer 242b is in contact with the semiconductor layer In this way, the semiconductor layer 242b is formed in contact with the semiconductor layer 242a. By covering the semiconductor layer 242c, the influence of the trap level can be further reduced. This can be done.

[0167] The band gaps of the semiconductor layer 242a and the semiconductor layer 242c are It is preferable that the band gap is wider than that of b.

[0168] According to one embodiment of the present invention, a transistor with little variation in electrical characteristics can be provided. Therefore, a semiconductor device with little variation in electrical characteristics can be realized. According to one embodiment, a highly reliable transistor can be realized. Therefore, a semiconductor device with good performance can be realized.

[0169] In addition, the band gap of oxide semiconductors is 2 eV or more, so the semiconductor in which the channel is formed A transistor that uses an oxide semiconductor for its body layer can have an extremely small off-state current. Specifically, when the voltage between the source and drain is 3.5V and the temperature is 25°C, The off-state current per 1 μm of panel width is 1×10 -20 Less than A, 1 x 10 -22 Below A or is 1 x 10 -24 That is, the on / off ratio can be increased by 20 orders of magnitude to 150 In addition, the OS transistor can achieve a dielectric strength between the source and drain of By using OS transistors, we can provide semiconductor devices with high output voltage and high breakdown voltage. It is possible.

[0170] According to one embodiment of the present invention, a transistor with low power consumption can be provided. As a result, a semiconductor device with low power consumption can be realized.

[0171] Depending on the purpose, the electrode 224 that can function as a back gate may not be provided. FIG. 21A is a top view of the transistor 451a. FIG. 21(C) is a cross-sectional view of the portion L1-L2 indicated by the dashed line in FIG. 21(A). The transistor 451a is a cross-sectional view of a portion W1-W2 indicated by a dashed line. The electrode 224, the insulating layer 273, the insulating layer 274, and the insulating layer 282 are omitted from the electrode 451. By eliminating the need for electrodes and insulating layers, the productivity of transistors can be improved. Therefore, the productivity of the semiconductor device can be improved.

[0172] Another example of an s-channel transistor is shown in FIG. 22. FIG. 22(A) shows a transistor. 22(B) and 22(C) are top views of the star 452. 10 is a cross-sectional view of a portion L1-L2 and a portion W1-W2 indicated by a chain line.

[0173] The transistor 452 has the same configuration as the transistor 451, but the electrodes 244a and The difference is that the electrodes 244a and 244b are in contact with the side surfaces of the semiconductor layers 242a and 242b. In addition, the insulating layer 228 covering the transistor 452 may be formed using the same insulating layer as the transistor 451. An insulating layer having a flat surface may be used. A pole 225b and an electrode 225c may be provided.

[0174] Another example of an s-channel transistor is shown in FIG. 23. FIG. 23(A) shows a transistor. 23(B) is a top view of the part L indicated by the dashed line in FIG. 1-L2 and a cross-sectional view of the portion W1-W2. As in the case of 51, the semiconductor layer 242a and the semiconductor layer 242b are formed on the protrusions provided on the insulating layer 272. In addition, an electrode 244a and an electrode 244b are provided on the semiconductor layer 242b. A region of the semiconductor layer 242b overlapping with the electrode 244a is provided as the transistor 453. The semiconductor layer 242b overlaps with the electrode 244b. The other region can function as the source or drain of the transistor 453. The region 269 of the semiconductor layer 242b sandwiched between the electrodes 244a and 244b is a channel. It can function as a hole-forming region.

[0175] The transistor 453 is formed by removing a part of the insulating layer 228 to form an opening in the region overlapping the region 269. A semiconductor layer 242c is provided along the side and bottom surfaces of the opening. An insulating layer is formed in the opening via the semiconductor layer 242c and along the side and bottom surfaces of the opening. In addition, the semiconductor layer 242c and the insulating layer 226 are formed in the opening. An electrode 243 is provided through the opening and along the side and bottom surfaces of the opening.

[0176] The opening is formed between the semiconductor layer 242a and the semiconductor layer 24 in the cross section in the channel width direction. Therefore, in the region 269, the semiconductor layer 242a and The side surfaces of the semiconductor layer 242b are covered with the semiconductor layer 242c.

[0177] In addition, an insulating layer 229 is provided on the insulating layer 228, and an insulating layer 277 is provided on the insulating layer 229. In addition, electrodes 225a, 225b, and 225c are provided on the insulating layer 277. The electrode 225a is provided with an insulating layer 277, an insulating layer 229, and an insulating layer 228. In the opening formed by removing a part of the electrode 244a, an electrical connection is established between the electrode 244a and the contact plug. The electrode 225b is electrically connected to the insulating layer 277, the insulating layer 229, and the insulating In the opening formed by removing a portion of the layer 228, an electrode 244 is formed via a contact plug. b. The electrode 225c is electrically connected to the insulating layer 277 and the insulating layer 229. In the opening formed by removing a part of the is connected to.

[0178] Depending on the purpose, the electrode 224 that can function as a back gate may not be provided. FIG. 24A is a top view of the transistor 453a. 1 is a cross-sectional view of a portion L1-L2 and a portion W1-W2 indicated by a dashed line in FIG. 453a is a circuit diagram of the transistor 453, which is connected to the electrode 224, the insulating layer 274, and the insulating layer 282. By not providing these electrodes and insulating layers, the productivity of the transistor is improved. Therefore, the productivity of the semiconductor device can be improved.

[0179] Another example of an s-channel transistor is shown in FIG. 25. FIG. 25(A) shows a transistor. 25(B) is a top view of the part L1 indicated by the dashed line in FIG. 25(C) is a cross-sectional view of the area W1-W2 indicated by the dashed line in FIG. 2 is a cross-sectional view of FIG.

[0180] The transistor 454 is a type of bottom-gate transistor having a back gate electrode. In the transistor 454, the electrode 243 is formed over the insulating layer 274. An insulating layer 226 is provided to cover the electrode 243. The semiconductor layer 242 included in the transistor 454 is a semiconductor It has a stack of a conductor layer 242a and a semiconductor layer 242b.

[0181] In addition, an electrode 244a and an electrode 244b are formed on the insulating layer 226 in contact with a part of the semiconductor layer 242. In addition, an electrode 244a and an electrode 244b are formed in contact with a part of the semiconductor layer 242. An insulating layer 228 is formed on the insulating layer 44b. An insulating layer 229 is formed on the insulating layer 228. An electrode 224 is formed on the insulating layer 229 in a region overlapping with the semiconductor layer 242. It is being done.

[0182] The electrode 224 provided on the insulating layer 229 is connected to the insulating layer 229, the insulating layer 228, and the insulating layer 229. The openings 247a and 247b in the electrode 226 are electrically connected to the electrode 243. Therefore, the same potential is supplied to the electrode 224 and the electrode 243. It is not necessary to provide either the opening 247a or the opening 247b. It is not necessary to provide both the opening 247a and the opening 247b. If no electrode is provided, different potentials can be applied to the electrode 224 and the electrode 243 .

[0183] <Energy band structure of semiconductor layer 242 (2)> FIG. 28(B) shows the energy band structure of the portion indicated by the dashed line D3-D4 in FIG. 25(B). FIG. 28B shows the energy band of the channel formation region of the transistor 454. The structure is shown.

[0184] In FIG. 28B, Ec384 indicates the energy of the bottom of the conduction band of the insulating layer 228. By forming the semiconductor layer 242 into two layers, the semiconductor layer 242a and the semiconductor layer 242b, a transistor In addition, since the semiconductor layer 242c is not provided, the trap level 390, but the semiconductor layer 242 is more susceptible to the influence of the electric field 390 than when the semiconductor layer 242 has a single layer structure. Effective mobility can be achieved.

[0185] Depending on the purpose, the electrode 224 that can function as a back gate may not be provided. FIG. 26(A) is a top view of the transistor 454a. is a cross-sectional view of the portion L1-L2 and the portion W1-W2 shown by the dashed line in FIG. 26(A). The transistor 454a is connected to the electrode 224, the opening 247a, and the By omitting these electrodes and openings, Therefore, the productivity of the semiconductor device can be improved. do.

[0186] FIG. 27 shows an example of a transistor having an s-channel structure. The transistor 448 has almost the same configuration as the transistor 447 described above. The transistor 448 is a type of top-gate transistor having a back gate. FIG. 27(A) is a top view of the transistor 448. FIG. 27(B) is a top view of the transistor 448. 27(A) is a cross-sectional view of the portion L1-L2 indicated by the dashed line. 1 is a cross-sectional view of the portion W1-W2 indicated by the arrow.

[0187] FIG. 27 shows a semiconductor layer 242 constituting a transistor 448, which is formed by using an inorganic semiconductor layer such as silicon. 27 shows an example of a configuration in which an electrode 224 is provided on a substrate 271. An insulating layer 272 is provided on the electrode 224. A semiconductor layer 242 is formed on the protrusion.

[0188] The semiconductor layer 242 includes a semiconductor layer 242i, two semiconductor layers 242t, and two semiconductor layers 242i. The semiconductor layer 242i is disposed between two semiconductor layers 242t. In addition, the semiconductor layer 242i and the two semiconductor layers 242t are disposed between the two semiconductor layers 242u. An electrode 243 is provided in a region overlapping with the semiconductor layer 242i.

[0189] When the transistor 448 is in an on state, a channel is formed in the semiconductor layer 242i. The semiconductor layer 242i functions as a channel formation region. The semiconductor layer 242u functions as a high concentration impurity region (LDD). In addition, one or both of the two semiconductor layers 242t t may not be provided. In addition, one of the two semiconductor layers 242u functions as a source region, and the other semiconductor layer 242u functions as a drain region.

[0190] The electrode 244a provided on the insulating layer 229 is connected to the insulating layer 226, the insulating layer 228, and the insulating layer 229. An opening 247c is provided in the layer 229, and the opening 247c is electrically connected to one of the semiconductor layers 242u. The electrode 244b provided on the insulating layer 229 is connected to the insulating layer 226 and the insulating layer 229. 28 and the other side of the semiconductor layer 242u in the opening 247d provided in the insulating layer 229. and is electrically connected.

[0191] The electrode 243 provided on the insulating layer 226 is connected to the insulating layer 226 and the insulating layer 272. The electrode 224 is electrically connected to the opening 247a and the opening 247b. Therefore, the same potential is supplied to the electrode 243 and the electrode 224. It is not necessary to provide either the opening 247a or the opening 247b. In the case where both the openings 247a and 247b are not provided, In this case, different potentials can be applied to the electrodes 243 and 224 .

[0192] <Film formation method> The conductive layers, insulating layers, and semiconductor layers such as electrodes shown in this specification are formed by chemical vapor deposition (CVD). Vapor Deposition (Vapor Deposition), evaporation, or sputtering Generally, the CVD method is a plasma CVD method that uses plasma. (PECVD: Plasma Enhanced CVD) method, thermal CVD ( Thermal CVD (TCVD) methods are also available. Atmospheric Pressure CVD (APCVD) method Furthermore, depending on the source gas used, there are metal CVD (MCVD) method, metal organic CVD (MOCVD) method, etc. can.

[0193] Generally, the evaporation method includes resistance heating evaporation, electron beam evaporation, MBE (Molecular Beam Evaporation), Beam Epitaxy) method, PLD (Pulsed Laser Deposit) ion) method, IAD (Ion beam Assisted Deposition) method , ALD (Atomic Layer Deposition) method, etc.

[0194] The plasma CVD method can produce high-quality films at relatively low temperatures. When using a deposition method that does not use plasma during deposition, damage to the surface to be deposited may occur. Moreover, a film with few defects can be obtained.

[0195] Generally, the sputtering method is classified into DC sputtering method, magnetron sputtering method, sputtering, RF sputtering, ion beam sputtering, ECR (Electro Cyclotron Resonance (Cyclotron Resonance) sputtering method, facing target sputtering They can be classified into methods such as the tarring method.

[0196] In the facing target sputtering method, the plasma is confined between the targets. It is possible to reduce plasma damage to the substrate. Also, depending on the tilt of the target, This allows the incident angle of sputtering particles onto the substrate to be shallow, improving step coverage. It can be done.

[0197] The CVD and ALD methods are film formation methods in which particles emitted from a target or the like are deposited. Unlike the conventional method, this is a film formation method in which a film is formed by a reaction on the surface of the object to be treated. Therefore, this is a film formation method that is less affected by the shape of the workpiece and has good step coverage. In particular, the ALD method has excellent step coverage and thickness uniformity, making it suitable for aspect ratio However, the ALD method is relatively Because the deposition rate is slow, it is used in combination with other deposition methods such as CVD, which has a faster deposition rate. In some cases, this is preferable.

[0198] In the CVD and ALD methods, the composition of the resulting film can be controlled by the flow rate ratio of the source gases. For example, in the CVD and ALD methods, the flow rate ratio of the source gases can be adjusted to any desired value. In addition, for example, in the CVD method and the ALD method, it is possible to form a film having a composition. By changing the flow rate ratio of the source gases while When forming a film while changing the flow rate ratio of the source gases, multiple film forming chambers can be used. Compared to forming a film by hand, the time required for film formation is shortened by the time required for transport and pressure adjustment. Therefore, the productivity of transistors and semiconductor devices can be improved. There are cases where this happens.

[0199] <About the constituent materials of transistors, etc.> 〔substrate〕 There is no particular limitation on the material used for the substrate 271. Depending on the purpose, the material may be transparent or non-transparent, or may be heat-treated. The material should be selected taking into consideration the heat resistance required to withstand the heat. Glass substrates such as glass and aluminoborosilicate glass, ceramic substrates, quartz substrates, and surface treatment substrates. The substrate 271 may be a semiconductor substrate, a flexible substrate, or the like. (Flexible substrate), laminated film, base film, etc. may also be used.

[0200] The semiconductor substrate may be a single semiconductor made of silicon or germanium, for example. Conductor substrate, or silicon carbide, silicon germanium, gallium arsenide, indium phosphide Compound semiconductor substrates made of silicon, zinc oxide, or gallium oxide are also available. The semiconductor substrate may be a single-crystal semiconductor or a polycrystalline semiconductor.

[0201] Examples of materials for flexible substrates, laminating films, and base films include polyethylene. polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether Polypropylene (PES), Polytetrafluoroethylene (PTFE), Polypropylene, Poly Ester, polyvinyl fluoride, polyvinyl chloride, polyolefin, polyamide (nylon , aramid, etc.), polyimide, polycarbonate, aramid, epoxy resin, acrylic A cellulose-based resin or the like can be used.

[0202] The flexible substrate used for the substrate 271 is preferably one having a lower linear expansion coefficient, since deformation due to the environment is suppressed. The flexible substrate used for the substrate 271 has a linear expansion coefficient of, for example, 1×10 -3 / K or less, 5 x10 -5 / K or less, or 1×10 -5 / K or less. Since ramid has a low linear expansion coefficient, it is suitable for a flexible substrate.

[0203] [Insulating layer] Insulating layer 272, insulating layer 273, insulating layer 274, insulating layer 275, insulating layer 282, insulating layer 22 8, the insulating layer 226, the insulating layer 229, and the insulating layer 277 are made of aluminum nitride, aluminum oxide, or the like. Aluminum, aluminum oxide nitride, aluminum oxide nitride, magnesium oxide, silicon nitride Silicon oxide, silicon oxide nitride, silicon oxynitride, gallium oxide, germanium oxide tungsten oxide, yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide The materials selected from aluminum, tantalum oxide, aluminum silicate, etc. are used in a single layer or In addition, oxide materials, nitride materials, oxynitride materials, and oxynitride materials are also used. That is, a material in which a plurality of materials are mixed may be used.

[0204] In this specification, the term "nitride oxide" refers to a compound containing more nitrogen than oxygen. Also, oxynitrides refer to compounds that contain more oxygen than nitrogen. The content of Measurements can be made using techniques such as kScattering Spectrometry. .

[0205] In particular, the insulating layer 275 and the insulating layer 229 are formed using an insulating material that is difficult for impurities to penetrate. For example, boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum, aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium, A single layer of insulating material containing zirconium, lanthanum, neodymium, hafnium or tantalum For example, oxide films can be used as insulating materials that are difficult for impurities to penetrate. Aluminum, Aluminum Nitride, Aluminum Oxide Nitride, Aluminum Oxide Nitride, Oxide Gallium, germanium oxide, yttrium oxide, zirconium oxide, lanthanum oxide, acid Examples of the oxide include neodymium oxide, hafnium oxide, tantalum oxide, and silicon nitride. The insulating layer 273 or the insulating layer 229 may be made of indium tin zinc oxide (I n-Sn-Zn oxide) may also be used.

[0206] By using an insulating material that is difficult for impurities to penetrate for the insulating layer 275, impurities from the substrate 271 side can be prevented. The diffusion of impurities can be suppressed, and the reliability of the transistor can be improved. By using an insulating material that is difficult for objects to penetrate, the diffusion of impurities from the insulating layer 229 side is suppressed. This can improve the reliability of the transistor.

[0207] Insulating layer 272, insulating layer 273, insulating layer 274, insulating layer 282, insulating layer 228, insulating layer 22 6, the insulating layer 229, and the insulating layer 277 are formed of a plurality of insulating layers made of these materials. The insulating layer 272, the insulating layer 273, the insulating layer 274, the insulating layer 282, and the insulating layer 283 may be laminated. The methods for forming the edge layer 228, the insulating layer 226, the insulating layer 229, and the insulating layer 277 are not particularly limited. Sputtering, CVD, MBE, PLD, ALD, spin coating Various forming methods can be used.

[0208] For example, when forming an aluminum oxide film using thermal CVD, the solvent and aluminum The raw material gas is a vaporized liquid containing a precursor compound (e.g., TMA), and H2O is used as an oxidizer. The chemical formula of trimethylaluminum is Al(CH3)3. Other liquid materials include tris(dimethylamido)aluminum and triisobutene. Aluminum tris(2,2,6,6-tetramethyl-3,5-heptyl) Tandione, etc.

[0209] In addition, when an oxide semiconductor is used for the semiconductor layer 242, the hydrogen concentration in the semiconductor layer 242 is In order to prevent this increase, it is preferable to reduce the hydrogen concentration in the insulating layer. It is preferable to reduce the hydrogen concentration in the insulating layer in contact with 2. Specifically, The concentration was 2×10 20 atoms / cm 3 Less than or equal to 5 x 10 19 atoms / cm 3 Less than or equal to 1×10 19 atoms / cm 3 Below, More preferably 5×10 18 atoms / cm 3 In addition, the semiconductor layer 242 In order to prevent an increase in the nitrogen concentration, it is preferable to reduce the nitrogen concentration in the insulating layer. It is preferable to reduce the nitrogen concentration in the insulating layer in contact with the conductor layer 242. The nitrogen concentration in the layer was measured by SIMS at 5×10 19 atoms / cm 3Less than, preferably is 5 x 10 18 atoms / cm 3 Less than or equal to 1×10 18 atoms / cm 3 Less than 5 × 10, more preferably 17 atoms / cm 3 The following applies.

[0210] The concentration measured by SIMS analysis may vary by ±40%. There is.

[0211] When an oxide semiconductor is used for the semiconductor layer 242, oxygen is released from the insulating layer by heating. In particular, the insulating layer in contact with the semiconductor layer 242 is preferably formed using an insulating layer that is exposed to light. For example, the insulating layer may be formed by heating the surface of the insulating layer. Heat treatment at a surface temperature of 100°C to 700°C, preferably 100°C to 500°C. Thermal Desorption Spectroscopy (TDS) In the electron spectroscopy, the amount of oxygen released, converted to oxygen atoms, was 1.0 × 10 18 a toms / cm 3 or more, preferably 1.0 × 10 19 atoms / cm 3 More than, more preferred Or 1.0 x 10 20 atoms / cm 3 It is preferable to use an insulating layer having the above properties. In the specification, the oxygen released by heating is also called "excess oxygen." An insulating layer from which more oxygen is released is also called an "insulating layer containing excess oxygen."

[0212] Alternatively, an insulating layer containing excess oxygen can be formed by adding oxygen to an insulating layer. The process of adding oxygen can be carried out by heat treatment under an oxygen atmosphere, ion implantation equipment, ion doping equipment, etc. This can be done using a doping device or a plasma treatment device. As a gas, 16 O2 or 18 Oxygen gas such as O2, nitrous oxide gas or ozone In this specification, the process of adding oxygen is referred to as "oxygen doping." Also called "processing."

[0213] In addition, by forming an insulating layer by a sputtering method in an atmosphere containing oxygen, Oxygen can be introduced into

[0214] Generally, a capacitance element has a structure in which a dielectric is sandwiched between two opposing electrodes. The thinner the thickness (the shorter the distance between the two opposing electrodes), and the higher the dielectric constant of the dielectric However, the thinner the dielectric, the larger the capacitance value. The current that flows unintentionally between the two electrodes due to the tunnel effect, etc. (hereinafter referred to as "leak") The capacitance element's breakdown voltage is likely to decrease. do.

[0215] The overlapping portion of the gate electrode, gate insulating layer, and semiconductor layer of the transistor acts as a capacitance element. (Hereinafter, this function is also referred to as "gate capacitance"). A channel is formed in the region where the gate electrode overlaps. The formation region functions as two electrodes of the capacitor element. It is preferable that the gate capacitance has a large value, but increasing the capacitance value If the gate insulating layer is made thinner to reduce the gate capacitance, problems such as an increase in leakage current and a decrease in dielectric strength will occur. This can easily cause problems.

[0216] Therefore, hafnium silicate (HfSi x O y (x>0, y>0) Nitrogen-doped hafnium silicate (HfSi x O y N z (x>0, y>0, z>0 )), nitrogen-doped hafnium aluminate (HfAl x O y N z (x>0, y>0 , z>0)), hafnium oxide, or yttrium oxide. This makes it possible to ensure a sufficient capacitance value of the capacitance element even if the dielectric is made thick.

[0217] For example, if a high-k material with a large dielectric constant is used as the dielectric, the dielectric Since the capacitance value is equivalent to that when silicon oxide is used as the dielectric, the capacitance element can be This reduces the leakage current that occurs between the two electrodes formed. It may also have a laminated structure of the insulating material and other insulating materials.

[0218] The insulating layer 228 has a flat surface. In addition to insulating materials, polyimide, acrylic resin, benzocyclobutene resin, polyamide Organic materials having heat resistance, such as amides and epoxy resins, can be used. In addition to the electrical materials, low-k materials, siloxane resins, PSG (Lingala It is possible to use boron nitride (BPSG) and phosphate boron phosphate glass (BPSG). A plurality of insulating layers may be stacked.

[0219] The siloxane resin is a Si—O— compound formed using a siloxane material as a starting material. It corresponds to a resin containing Si bonds. Siloxane resins contain organic groups (e.g., alkane) as substituents. Alternatively, an alkyl group or an aryl group, or a fluoro group may be used. It's okay to be there.

[0220] The method for forming the insulating layer 228 is not particularly limited, and may be a sputtering method, an SOG method, or the like, depending on the material. , spin coating, dip coating, spray coating, droplet ejection method (inkjet method, etc.), printing For example, a printing method (screen printing, offset printing, etc.) may be used.

[0221] Further, the sample surface may be subjected to CMP treatment. This reduces the unevenness of the surface, thereby improving the coverage of the insulating layer and conductive layer that will be formed later.

[0222] [Semiconductor layer] The semiconductor layer 242 may be formed of a material such as a single crystal semiconductor, a polycrystalline semiconductor, a microcrystalline semiconductor, or an amorphous semiconductor. Examples of semiconductor materials that can be used include silicon and germanium. Silicon germanium, silicon carbide, gallium arsenide, and oxide can also be used. Compound semiconductors such as nitride semiconductors and nitride semiconductors, as well as organic semiconductors can be used. .

[0223] In addition, when an organic semiconductor is used as the semiconductor layer 242, a low molecular weight organic material having an aromatic ring is used. and π-electron conjugated conductive polymers can be used. For example, rubrene, tetracene, etc. , pentacene, perylenediimide, tetracyanoquinodimethane, polythiophene, polya Cetylene, polyparaphenylene vinylene, etc. can be used.

[0224] As mentioned above, the band gap of the oxide semiconductor is 2 eV or more. By using an oxide semiconductor for 42, it is possible to realize a transistor with extremely low off-state current. In addition, OS transistors have a high withstand voltage between the source and drain. It is possible to provide a highly reliable transistor. It is also possible to provide a semiconductor device with high reliability. Therefore, a semiconductor device with a high breakdown voltage can be provided.

[0225] In this embodiment, the case where an oxide semiconductor is used for the semiconductor layer 242 will be described. The oxide semiconductor used for the semiconductor layer 242 is, for example, an oxide semiconductor containing indium (In). For example, when an oxide semiconductor contains indium, carrier transport is facilitated. In addition, the oxide semiconductor preferably contains an element M.

[0226] The element M is preferably aluminum, gallium, yttrium, tin, or the like. Other elements that can be used for element M include boron, silicon, titanium, iron, nickel, Germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium , tantalum, tungsten, magnesium, etc. However, as the element M, In some cases, it is acceptable to combine multiple elements. For example, the element M has a bond energy with oxygen of The element M is an element with a high energy gap. For example, the element M increases the energy gap of an oxide semiconductor. The oxide semiconductor preferably contains zinc. The body may be more prone to crystallization when it contains zinc.

[0227] However, the oxide semiconductor used for the semiconductor layer 242 is not limited to an oxide containing indium. Examples of oxide semiconductors include zinc tin oxide, gallium tin oxide, and gallium oxide. oxides containing zinc, oxides containing gallium, oxides containing tin, and oxides not containing indium It may be a semiconductor or the like.

[0228] For example, the semiconductor layer 242 may be formed by thermal CVD using InGaZnO X (X>0) Deposit a film In the case of trimethylindium (In(CH3)3), trimethylgallium (Ga(C H3)3), and dimethylzinc (Zn(CH3)2). The combination is not limited to the above, and triethylgallium (Ga(C2H5)) may be used instead of trimethylgallium. 3) can also be used, and diethyl zinc (Zn(C2H5)2) can be used instead of dimethyl zinc. It can also be used.

[0229] For example, the semiconductor layer 242 may be formed by an ALD method using InGaZnO X (X>0) Deposit a film In this case, In(CH3)3 gas and O3 gas are introduced repeatedly to form an InO2 layer. Then, Ga(CH3)3 gas and O3 gas are introduced repeatedly to form a GaO layer. Then, Zn(CH3)2 gas and O3 gas are introduced repeatedly to form a ZnO layer. The order of these layers is not limited to this example. Two-layer and mixed compound layers such as InZnO2 layer, GaInO layer, ZnInO layer, GaZnO layer Alternatively, instead of O3 gas, H may be formed by bubbling water with an inert gas such as Ar. Although O gas may be used, it is preferable to use O gas that does not contain H. Instead of CH3)3 gas, In(C2H5)3 gas or tris(acetylacetonato)in Tris(acetylacetonato)indium may be used. Also, instead of Ga(CH3)3 gas, Ga(C2H5)3 gas or Tris(acetylacetonato)gallium may also be used. Gallium (Ga) is also called Ga(acac)3. It is also used in gases such as Zn(CH3)2 and zinc acetate. Lead may also be used. The gas species are not limited to these.

[0230] When forming oxide semiconductor films by sputtering, indium is used to reduce the number of particles. It is preferable to use a target containing M. Also, an oxide target having a high atomic ratio of element M is preferable. When using a target containing indium, the conductivity of the target may be reduced. When using a target, the conductivity of the target can be increased, making DC discharge and AC discharge easier. Therefore, it becomes easier to handle large-area substrates, which increases the productivity of semiconductor devices. It is possible.

[0231] As mentioned above, when forming an oxide semiconductor film by sputtering, the target element For example, the molecular ratio of In:M:Zn is 3:1:1, 3:1:2, 3:1:4, 1:1:0. .5, 1:1:1, 1:1:2, 1:4:4, 5:1:7, 4:2:4.1, 5:1:6 , and their neighboring areas.

[0232] When an oxide semiconductor is formed by sputtering, the atomic ratio of the target is deviated. In particular, zinc may be deposited as an oxide semiconductor with a target atomic ratio of 0.1 to 0.2. The atomic ratio of the deposited film may be smaller than that of the target. The ratio of the number of atoms of zinc to be used may be between 40 atomic % and 90 atomic %. be.

[0233] The semiconductor layer 242a, the semiconductor layer 242b, and the semiconductor layer 242c are made of In or Ga. It is preferable to form the insulating layer using a material containing one or both of these elements. Typically, the insulating layer is made of In-Ga oxide. (oxide containing In and Ga), In-Zn oxide (oxide containing In and Zn), In-M -Zn oxide (oxide containing In, element M, and Zn. Element M is Al, Ti, Ga, Y , Zr, La, Ce, Nd or Hf, and more oxygen than In. It is a metallic element that has a strong bonding force with metals.

[0234] The semiconductor layer 242a and the semiconductor layer 242c are formed by the same metal element as that of the semiconductor layer 242b. In other words, it is preferable that the material contains one or more kinds of the same metal element. When the material is used, the interface between the semiconductor layer 242a and the semiconductor layer 242b and the semiconductor layer This can make it difficult for interface states to occur at the interface between the semiconductor layer 242c and the semiconductor layer 242b. This makes it difficult for carriers to be scattered or captured at the interface, and improves the field-effect mobility of the transistor. It is also possible to reduce the variation in the threshold voltage of the transistor. Therefore, it is possible to realize a semiconductor device with good electrical characteristics. This becomes:

[0235] The semiconductor layer 242b is an In-M-Zn oxide, and the semiconductor layer 242a and the semiconductor When the layer 242c is also an In-M-Zn oxide, the semiconductor layer 242a and the semiconductor layer 242 c is In:M:Zn=x1:y1:z1 [atomic ratio], and the semiconductor layer 242b is In:M:Z If n=x2:y2:z2 [atomic ratio], then y1 / x1 is greater than y2 / x2. The semiconductor layer 242a, the semiconductor layer 242c, and the semiconductor layer 242b can be selected so that Preferably, the semiconductor is arranged so that y1 / x1 is 1.5 times or more larger than y2 / x2. The semiconductor layer 242a, the semiconductor layer 242c, and the semiconductor layer 242b are preferably selected. The semiconductor layer 242a and the semiconductor layer 242b are formed such that y1 / x1 is at least twice as large as y2 / x2. More preferably, y1 / x1 is selected to be greater than y2 / x2 or more. Select layer 242b. When y1 is equal to or greater than x1, the transistor has stable electrical characteristics. However, if y1 is three times or more than x1, the field effect of the transistor Since the mobility is reduced, it is preferable that y1 is less than three times x1. By configuring the semiconductor layer 242a and the semiconductor layer 242c as described above, The layer 242c can be a layer in which oxygen vacancies are less likely to occur than in the semiconductor layer 242b.

[0236] When the semiconductor layer 242a and the semiconductor layer 242c are made of In-M-Zn oxide, I When the sum of n and element M is 100 atomic %, the atomic ratio of In to element M is: Preferably, In is less than 50 atomic % and the element M is 50 atomic % or more, and more preferably Preferably, In is less than 25 atomic % and the element M is 75 atomic % or more. When the semiconductor layer 242b is an In-M-Zn oxide, the sum of In and element M is 100 The atomic ratio of In to element M in atomic % is preferably 25 atoms. ic% or more, element M is less than 75 atomic %, and more preferably In is 34 atomic % or more. c% or more, and element M is less than 66 atomic %.

[0237] For example, the semiconductor layer 242a containing In or Ga and the semiconductor layer 242b containing In or Ga 242c as In:Ga:Zn=1:3:2, 1:3:4, 1:3:6, 1:4:5, Formed using targets with atomic ratios of 1:6:4, 1:9:6, or nearby The target used was an In-Ga-Zn oxide or an In:Ga=1:9 atomic ratio target. In-Ga oxide formed by the above method, gallium oxide, etc. can be used. Layer 242b: In:Ga:Zn=3:1:2, 1:1:1, 5:5:6, 5:1:7 , or 4:2:4.1 or a target with an atomic ratio close to these. The semiconductor layer 242a and the semiconductor layer 242b may be made of n-Ga-Zn oxide. The atomic ratios of the semiconductor layer 242b and the semiconductor layer 242c are each calculated by multiplying the atomic ratios by the above-mentioned plus or minus factor as an error. Includes a minus 20% fluctuation.

[0238] The low impurity concentration and low defect level density (low oxygen vacancies) are called high purity intrinsic or In order to provide stable electrical characteristics to OS transistors, The impurities and oxygen vacancies in the oxide semiconductor layer are reduced to make the semiconductor layer 242 highly intrinsic. It is preferable that the oxide semiconductor layer be an oxide semiconductor layer that can be regarded as intrinsic or substantially intrinsic. The channel forming region in the semiconductor layer 242 is an oxide semiconductor that can be regarded as intrinsic or substantially intrinsic. It is preferable that the body layer be made of a material other than the polymer.

[0239] In particular, impurities and oxygen vacancies in the semiconductor layer 242b are reduced to make it highly purified and intrinsic. It is preferable that the oxide semiconductor layer 242b be an oxide semiconductor layer that can be regarded as intrinsic or substantially intrinsic. In addition, at least the channel forming region in the semiconductor layer 242b is considered to be intrinsic or substantially intrinsic. It is preferable to use a semiconductor layer in which the

[0240] Note that an oxide semiconductor layer that can be considered substantially intrinsic is an oxide semiconductor layer having a carrier density of , 8×10 11 / cm 3 Less than 1 x 10 11 / cm 3 less than, more preferably 1×10 10 / cm 3 Less than 1 x 10 -9 / cm 3 The oxide semiconductor layer having the above structure is cormorant.

[0241] When an oxide semiconductor layer is used as the semiconductor layer 242, CAAC-OS (C Axis Aligned Crystalline Oxide Semiconductor CAAC-OS is an oxide film having multiple crystal parts aligned along the c-axis. It is one of the compound semiconductors.

[0242] In addition, the oxide semiconductor layer used for the semiconductor layer 242 has a region that is not CAAC. It is preferable that the thickness is less than 20% of the total body layer.

[0243] The CAAC-OS has a dielectric anisotropy. The dielectric constant in the c-axis direction is larger than that in the b-axis direction. The transistor with the gate electrode aligned along the c-axis using CAAC-OS has Because of its large dielectric constant, the electric field generated from the gate electrode easily reaches the entire CAAC-OS. This makes it possible to reduce the subthreshold swing value (S value). Transistors using CAAC-OS layers are less likely to experience an increase in S value due to miniaturization.

[0244] In addition, the CAAC-OS has a small dielectric constant in the a-axis and b-axis directions, so the source and drain Therefore, the influence of the electric field generated between the gates is reduced. , etc. are unlikely to occur, and the reliability of the transistor can be improved.

[0245] Here, the channel length modulation effect is the effect of increasing the drain voltage when the drain voltage is higher than the threshold voltage. This refers to the phenomenon in which the depletion layer expands from the inside, shortening the effective channel length. The channel effect is a phenomenon in which a decrease in the threshold voltage and other electrical characteristics occur due to a shortened channel length. The smaller the transistor, the greater the deterioration of electrical characteristics due to these phenomena. It is easy to occur.

[0246] After the oxide semiconductor layer is formed, oxygen doping treatment may be performed. In order to further reduce impurities such as moisture or hydrogen contained in the oxide semiconductor layer and to highly purify the oxide semiconductor layer, It is preferable to carry out a heat treatment.

[0247] For example, under a reduced pressure atmosphere, under an inert atmosphere such as nitrogen or a rare gas, under an oxidizing atmosphere, or under an ultra-dry atmosphere. Dry air (measured using a CRDS (cavity ring-down laser spectroscopy) dew point meter) The moisture content when the air is cooled is 20 ppm or less (-55°C in terms of dew point), preferably 1 ppm or less. Preferably, the oxide semiconductor layer is subjected to heat treatment in an air atmosphere of 10 ppb or less. An oxidizing atmosphere is an atmosphere containing 10 ppm or more of oxidizing gases such as oxygen, ozone, or nitrogen dioxide. An inert atmosphere is an atmosphere in which the above-mentioned oxidizing gases are less than 10 ppm. It also refers to an atmosphere filled with nitrogen or a rare gas.

[0248] Furthermore, by performing a heat treatment, the impurities are released and the oxygen contained in the insulating layer 226 is also removed. The oxygen vacancies in the oxide semiconductor layer can be reduced by diffusing the oxygen vacancies in the oxide semiconductor layer. After the heat treatment in an inert atmosphere, an oxidizing gas is added to replace the desorbed oxygen. The heat treatment may be carried out in an atmosphere containing 10 ppm or more, 1% or more, or 10% or more. The heat treatment may be performed at any time after the oxide semiconductor layer is formed.

[0249] There is no particular limitation on the heating device used for the heat treatment. For example, an electric furnace or an LR furnace may be used. TA (Lamp Rapid Thermal Anneal) equipment, GRTA (Gas Rapid Thermal Anneal (RTA) equipment The LRTA device uses a halogen lamp, Metal halide lamps, xenon arc lamps, carbon arc lamps, high-pressure sodium The light (electromagnetic waves) emitted from lamps such as lamps and high-pressure mercury lamps The GRTA device is a device that uses high-temperature gas to perform heat treatment.

[0250] The heat treatment is carried out at a temperature of 250°C or higher and 650°C or lower, preferably 300°C or higher and 500°C or lower. The treatment time should be within 24 hours. Heat treatment for more than 24 hours will result in a decrease in productivity. Therefore, it is not desirable.

[0251] 〔electrode〕 Electrode 243, electrode 224, electrode 244a, electrode 244b, electrode 225a, and electrode 22 The conductive material for forming 5b may be aluminum, chromium, iron, copper, silver, gold, or white. Gold, tantalum, nickel, cobalt, titanium, molybdenum, tungsten, hafnium, Selected from vanadium, niobium, manganese, magnesium, zirconium, beryllium, etc. Materials containing one or more of the above metal elements can be used. Highly conductive semiconductors, such as polycrystalline silicon, and nickel silicide, Any silicide may be used. A plurality of conductive layers made of these materials may be stacked. Good too.

[0252] In addition, the electrodes 243, 224, 244a, 244b, 225a, and The conductive material for forming the electrode 225b is indium tin oxide (ITO). Tin Oxide), Indium Oxide with Tungsten Oxide, Tungsten Oxide Indium zinc oxide containing titanium oxide, indium oxide containing titanium oxide Indium tin oxide, indium zinc oxide, indium gallium zinc oxide, silicon Conductive materials containing oxygen, such as doped indium tin oxide, titanium nitride, tantalum nitride, etc. Any conductive material containing nitrogen can be used. Also, the above-mentioned materials containing metal elements can be used. A laminated structure in which a conductive material containing oxygen is combined with the above-mentioned It is also possible to use a laminated structure that combines a material containing a metal element with a conductive material containing nitrogen. In addition, the materials containing the above-mentioned metal elements, conductive materials containing oxygen, and conductive materials containing nitrogen are The method for forming the conductive material is not particularly limited. Various methods for forming the film, such as vapor deposition, CVD, and sputtering, can be used.

[0253] [Contact plug] The contact plug may be made of a material with high embedding properties, such as tungsten or polysilicon. A conductive material can be used. The side and bottom surfaces of the material can be covered with a titanium layer, a nitride layer, or the like. It may be covered with a barrier layer (diffusion prevention layer) made of a titanium layer or a laminate of these. The barrier layer may also be referred to as a contact plug.

[0254] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0255] (Embodiment 5) The semiconductor device disclosed in the above embodiment can be used in a driver circuit of a display device. In this embodiment, an example in which the semiconductor device disclosed in the above embodiment is used in a display device will be described. This will be explained using the drawings.

[0256] <Example of a display device> FIG. 29(A) is a block diagram illustrating an example of the configuration of a display device 500. The display device 500 shown includes a drive circuit 511, a drive circuit 521a, a drive circuit 521b, and It has a display area 531. The driving circuit 511, the driving circuit 521a, and the driving circuit The circuit 521b may be collectively referred to as a "drive circuit" or a "peripheral drive circuit."

[0257] The driving circuits 521a and 521b can function as, for example, scanning line driving circuits. The driver circuit 511 can function as, for example, a signal line driver circuit. The display area 531 may be formed by the driving circuit 521b. A circuit of some kind may be provided at a position facing the driving circuit 511 across the substrate.

[0258] In addition, the display device 500 shown in FIG. 29(A) is arranged substantially parallel to each other and is driven by The potential of m wirings 5 ​​is controlled by the circuit 521a and / or the driving circuit 521b. 35, and n lines of electrodes each arranged approximately in parallel and having a potential controlled by a driving circuit 511. The display area 531 has a plurality of wirings 536 arranged in a matrix. It has a pixel 532. The pixel 532 has a pixel circuit 534 and a display element.

[0259] In addition, by making the three pixels 532 function as one pixel, a full color display can be realized. The three pixels 532 can be transparent, each emitting red, green, or blue light. The transmittance, reflectance, or emitted light amount is controlled by the three pixels 532. The colors are not limited to a combination of red, green, and blue, but may also be yellow, cyan, and magenta.

[0260] In addition to the pixels that control red, green, and blue light, a pixel 532 that controls white light is added. In this case, four pixels 532 may be grouped together to function as one pixel. By adding the pixel 532, the brightness of the display area can be increased. The number of pixels 532 that function as a function of the red, green, blue, yellow, cyan, and magenta is increased. By using them together, the reproducible color gamut can be expanded.

[0261] When pixels are arranged in a 1920 x 1080 matrix, it becomes what is known as full high definition (" Also known as "2K resolution," "2K1K," or "2K." The device 500 can be realized. For example, the pixels can be arranged in a matrix of 3840 x 2160. When arranged in a grid, it becomes what is known as ultra high definition ("4K resolution", "4K2K", It is possible to realize a display device 500 capable of displaying at a resolution of 1080p (also called "4K"). For example, if pixels are arranged in a 7680 x 4320 matrix, Super Hi-Vision (also called "8K resolution," "8K4K," or "8K") By increasing the number of pixels, it is possible to realize a display device 500 capable of displaying at a resolution of 1 It is also possible to realize a display device 500 capable of displaying at a resolution of 6K or 32K.

[0262] The wiring 535_i (i is a natural number between 1 and m) in the i-th row is Among the multiple pixels 532 arranged in rows and columns of n (m and n are both natural numbers of 1 or more), i The wiring 536_j in the jth column is electrically connected to the n pixels 532 arranged in the row. (j is a natural number between 1 and n) is the pixel 532 arranged in m rows and n columns, and the pixel 532 arranged in the jth column is the pixel 532 in the mth row and nth column. The pixel 532 is electrically connected to m pixels 532 provided therein.

[0263] [Display element] The display device 500 can take a variety of forms or have a variety of display elements. An example of a display element is an EL (electroluminescence) element (organic EL element, Inorganic EL elements, or EL elements containing organic and inorganic materials), LEDs (white LEDs, red LED, green LED, blue LED, etc.), transistor (transistor that emits light according to the current) Electron emission element, liquid crystal element, electronic ink, electrophoretic element, grating light bar GLV (Glass Liquid Crystal Display), MEMS (Micro-Electro-Mechanical Systems) Display element, Digital Micromirror Device (DMD), DMS (Digital Micromirror Scatter), MIRASOL (registered trademark), IMOD (Interferometric Module) MEMS display elements, shutter-type MEMS display elements, optical interference-type MEMS display elements electrons, electrowetting elements, piezoelectric ceramic displays, carbon nanotubes Display elements using a magnetic field, etc., which use electrical or magnetic effects to improve contrast, brightness, and reflectivity. Some display devices have display media that change their reflectivity, transmittance, etc. A marker may also be used.

[0264] An example of a display device using an EL element is an EL display. An example of a display device using the above is a field emission display (FED) or SED type flat panel display (SED: Surface-conduction El Quantum dot displays An example of such a device is a quantum dot display. An example is a liquid crystal display (transmissive liquid crystal display, semi-transmissive liquid crystal display). , reflective LCD displays, direct-view LCD displays, projection LCD displays, etc. An example of a display device using electronic ink, electronic liquid powder (registered trademark), or electrophoretic elements Examples include electronic paper. The display device is a plasma display panel (PDP). may be.

[0265] When realizing a semi-transmissive or reflective LCD display, the pixel voltage A part or all of the electrodes may be made to function as a reflective electrode. For example, A part or all of the pixel electrodes may be made of aluminum, silver, or the like. Furthermore, in this case, it is also possible to provide a memory circuit such as an SRAM below the reflective electrode. This further reduces power consumption.

[0266] When using an LED, graphene or graphene is placed under the LED electrode or nitride semiconductor. Graphene and graphite can be arranged in layers to form a multilayer film. In this way, by providing graphene or graphite, it is possible to form a nitride layer on the graphene or graphite. Semiconductors, such as n-type GaN semiconductor layers having crystallinity, can be easily formed. Furthermore, a p-type GaN semiconductor layer having crystals is formed on top of that to form an LED. It is possible to combine graphene or graphite with a crystalline n-type GaN semiconductor layer. An AlN layer may be provided between the GaN layer and the LED. However, by providing graphene, the GaN semiconductor of the LED The layer can also be deposited by sputtering.

[0267] 29(B), 29(C), 30(A), and 30(B) show the structure used for pixel 532. 1 shows an example of a circuit configuration that can be implemented.

[0268] [Example of a pixel circuit for a light-emitting display device] The pixel circuit 534 shown in FIG. 29B includes a transistor 461, a capacitor 463, and a transistor 29B. The path 534 is electrically connected to a light emitting element 469 that can function as a display element.

[0269] One of the source electrode and the drain electrode of the transistor 461 is electrically connected to the wiring 536_j. Furthermore, the gate electrode of the transistor 461 is electrically connected to the wiring 535_i. A video signal is supplied from the wiring 536_j.

[0270] The transistor 461 has a function of controlling writing of a video signal to a node 465. .

[0271] One of a pair of electrodes of the capacitor 463 is electrically connected to the node 465, and the other is The source electrode and the drain electrode of the transistor 461 are electrically connected to the The other of the electrodes is electrically connected to node 465 .

[0272] The capacitor 463 functions as a storage capacitor for storing data written to the node 465. It has.

[0273] One of the source electrode and the drain electrode of the transistor 468 is connected to the potential supply line VL_a. The other end is electrically connected to node 467. The gate electrode of 8 is electrically connected to node 465 .

[0274] One of the source electrode and the drain electrode of the transistor 464 is electrically connected to the potential supply line V0. and the other is electrically connected to a node 467. The gate electrode is electrically connected to the wiring 535_i.

[0275] One of the anode and cathode of the light emitting element 469 is electrically connected to the potential supply line VL_b. and the other is electrically connected to node 467.

[0276] The light emitting element 469 may be, for example, an organic electroluminescence element (also called an organic EL element). However, the light-emitting element 469 is not limited to this. For example, an inorganic EL element made of an inorganic material may be used.

[0277] For example, a high power supply potential VDD is applied to one of the potential supply lines VL_a and VL_b. and the other is supplied with a low power supply potential VSS.

[0278] In the display device 500 having the pixel circuit 534 of FIG. 29(B), the driver circuit 521a and / or the driver circuit 521b sequentially selects the pixels 532 in each row, and the transistors 461, Then, the transistor 464 is turned on to write the video signal to the node 465 .

[0279] The pixel 532 in which data is written to the node 465 is connected to the transistor 461 and the transistor The register 464 is turned off, which puts the node 465 into a holding state. A current flows between the source and drain electrodes of the transistor 468 according to the potential of the input data. The amount of current is controlled, and the light emitting element 469 emits light with a brightness according to the amount of current flowing. By performing this step sequentially, an image can be displayed.

[0280] As shown in FIG. 30A, the transistor 461, the transistor 464, and the transistor 465 are connected to each other. A transistor having a back gate may be used as the transistor 468. The transistor 461 and the transistor 464 shown in A) have a back gate and a gate electrode. They are electrically connected. Therefore, the gate and back gate are always at the same potential. The back gate of the transistor 468 is electrically connected to the node 467. The back gate is always at the same potential as the node 467 .

[0281] [An example of a pixel circuit for a liquid crystal display device] The pixel circuit 534 shown in FIG. 29C includes a transistor 461 and a capacitor 463. In addition, the pixel circuit 534 shown in FIG. 29(C) is a liquid crystal element that can function as a display element. 462 is electrically connected to

[0282] The potential of one of the pair of electrodes of the liquid crystal element 462 is set appropriately according to the specifications of the pixel circuit 534. For example, a common potential is applied to one of the pair of electrodes of the liquid crystal element 462. Alternatively, one of the pair of electrodes of the liquid crystal element 462 may be set to the same potential as the capacitance line CL. On the other hand, different potentials may be applied to the pixels 532. The liquid crystal element 462 is electrically connected to the node 466. The alignment state is set by the data.

[0283] As a driving method of the display device including the liquid crystal element 462, for example, TN (Twisted Nematic) Nematic mode, STN (Super Twisted Nematic) mode Mode, VA mode, ASM (Axially Symmetric Aligned Mix cro-cell mode, OCB (Optically Compensated B refrigeration mode, FLC (Ferroelectric Liquid d Crystal) mode, AFLC (AntiFerroelectric Liq. Crystal) mode, MVA mode, PVA (Patterned Ver Artificial Alignment mode, IPS mode, FFS mode, or TBA (Transverse Bend Alignment) mode may also be used. In addition to the above-mentioned driving method, the display device can also be driven by an ECB (Electric Carrier Board) or the like. Ally Controlled Birefringence mode, PDLC (P Polymer Dispersed Liquid Crystal (PNLC) mode (Polymer Network Liquid Crystal) mode, guest However, the liquid crystal element and its driving method are not limited to these. A variety of materials can be used.

[0284] When liquid crystal elements are used as display elements, thermotropic liquid crystals, low molecular weight liquid crystals, polymer liquid crystals, etc. The liquid crystals that can be used include polymer dispersed liquid crystals, ferroelectric liquid crystals, and antiferroelectric liquid crystals. Depending on the conditions, the liquid crystal material can be in a cholesteric phase, a smectic phase, a cubic phase, or a chiral phase. It shows nematic phase, isotropic phase, etc.

[0285] Alternatively, a liquid crystal that exhibits a blue phase without using an alignment film may be used. The blue phase is one of the liquid crystal phases. When the temperature of cholesteric liquid crystal is increased, the cholesteric The blue phase appears just before the transition from the crystalline phase to the isotropic phase. Therefore, a liquid crystal composition containing 5% by weight or more of a chiral agent is used to improve the temperature range. The liquid crystal composition containing the liquid crystal exhibiting the blue phase and the chiral agent has a response speed of It is short (less than 1 msec), has optical isotropy so alignment processing is not required, and is not dependent on viewing angle. In addition, since there is no need to provide an alignment film, rubbing treatment is also unnecessary. This prevents electrostatic damage caused by the soldering process, and prevents the LCD display from being damaged during the manufacturing process. This reduces the number of defects and damages to the device, thereby improving the productivity of liquid crystal display devices. This makes it possible to:

[0286] In addition, a pixel is divided into several regions (subpixels), each of which is oriented in a different direction. It is called multi-domain or multi-domain design, which is designed to defeat molecules. The method can be used.

[0287] The specific resistance of the liquid crystal material is 1×10 9 Ω·cm or more, preferably 1×10 11 Ω·cm or more, and more preferably 1×10 12 Ω·cm or more. The resistivity values ​​in this document are those measured at 20°C.

[0288] In the pixel circuit 534 in the ith row and the jth column, the source electrode and the drain electrode of the transistor 461 One of the electrodes is electrically connected to the wiring 536_j, and the other is electrically connected to the node 466. The gate electrode of the transistor 461 is electrically connected to the wiring 535_i. The line 536_j supplies the video signal. The transistor 461 supplies a It has the function of controlling the writing of video signals.

[0289] One of the pair of electrodes of the capacitor 463 is connected to a wiring to which a specific potential is supplied (hereinafter, referred to as a capacitor line CL ), and the other is electrically connected to a node 466. The value of the potential is set as appropriate according to the specifications of the pixel circuit 534. It functions as a storage capacitor that stores data written in the memory card 466 .

[0290] For example, in a display device 500 having a pixel circuit 534 shown in FIG. 29(C), a driver circuit 521a and / or the pixel circuits 534 in each row are sequentially selected by the driving circuit 521b, and the transistors The starter 461 is turned on to write the video signal to the node 466.

[0291] In the pixel circuit 534 in which the video signal is written to the node 466, the transistor 461 is turned off. By doing this for each row, the display area 531 You can display images.

[0292] In addition, as shown in FIG. 30B, the transistor 461 has a back gate. The transistor 461 shown in FIG. Therefore, the gate and back gate are always at the same potential.

[0293] [Example of peripheral circuit configuration] Next, a configuration example of the driver circuit 511 will be described with reference to FIG. The digital signal processing circuit 510 includes a soft register 512 and a DA conversion output circuit 513 .

[0294] The shift register 512 includes n registers SR (register SR_1 to register SR_n). The shift register 512 receives a start pulse SP, a clock signal CLK, etc. The circuit constituting the shift register 512 is made up of the semiconductor device disclosed in the above embodiment. The position can be used.

[0295] The DA conversion output circuit 513 includes n conversion output circuits CA (conversion output circuits CA_1 to CA_2). The DA conversion output circuit 513 outputs a digital signal including video information. The conversion output circuit CA converts the input digital signal into an analog voltage signal. It has the function of converting it into a number.

[0296] [Peripheral circuit operation example] In this embodiment, the driver circuit 511 is connected to the pixel circuits 534 in the i-th row via the wiring 536_1. The operation of supplying a video signal to j will now be described.

[0297] When the wiring 535_i of the i-th row is selected, a start pulse SP is input to the shift register 512. The outputs of the registers SR_1 to SR_n in the shift register 512 are The output is sent sequentially in synchronization with the clock signal CLK, triggered by the start pulse SP. Therefore, the operating conversion output circuits CA_j are sequentially selected in synchronization with the clock signal CLK. will be done.

[0298] Specifically, when a start pulse SP is input to the shift register 512, the first A column selection signal indicating that the first column has been selected is sent from register SR_1 to the conversion output circuit CA Therefore, the column selection signal that indicates that the j-th column has been selected is input to the conversion output circuit. The path CA_j is input.

[0299] The conversion output circuit CA_j to which the column selection signal is input outputs the data input to the conversion output circuit CA_j. The digital signal is converted into an analog voltage signal (video signal) and output to a wiring 536_j.

[0300] The above operation is repeated until m rows and n columns are reached, at which point writing of the next frame begins. In this way, an image can be displayed in the display area 531.

[0301] 31(B), between the shift register 512 and the DA conversion output circuit 513 The level shifter 514 may be provided in the shifter L corresponding to each column. The j-th column shifter LS_j has a shifter LS_1 to a shifter LS_n. The voltage amplitude of the signal output from the register 512 is increased and input to the conversion output circuit CA_j. By providing the level shifter 514, the operation of the shift register 512 Therefore, the power consumption of the display device 500 can be reduced. Cut.

[0302] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0303] (Embodiment 6) The transistor and the semiconductor device described in the above embodiment are used to Part or all of the operating circuitry is integrated onto the same substrate as the pixel section to form a system-on-panel. A display device in which the transistor described in the above embodiment can be used An example of the configuration will be described with reference to FIGS. 32 and 33.

[0304] <Example of a Liquid Crystal Display Device and an Example of an EL Display Device> As examples of the display device, a display device using a liquid crystal element and a display device using an EL element are described. In FIG. 32A, a pixel portion 400 provided on a first substrate 4001 is A sealant 4005 is provided to surround the second substrate 4006. In FIG. 32(A), the sealing material 4005 on the first substrate 4001 In a region different from the surrounded region, a single crystal semiconductor or a polycrystalline semiconductor is formed on a separately prepared substrate. A signal line driver circuit 4003 and a scanning line driver circuit 4004 made of conductors are mounted. In addition, the signal line driver circuit 4003, the scanning line driver circuit 4004, or the pixel portion 4002 The various signals and potentials are applied to the FPC (Flexible Printed Circuit). It is supplied by FPC4018a and FPC4018b.

[0305] In FIG. 32(B) and FIG. 32(C), the pixel section 40 provided on the first substrate 4001 A sealant 4005 is provided so as to surround the gate electrode 4002 and the scanning line driver circuit 4004. In addition, a second substrate 4006 is provided on the pixel portion 4002 and the scanning line driver circuit 4004. Therefore, the pixel portion 4002 and the scanning line driver circuit 4004 are connected to the first substrate 4001. The display element is sealed by a sealant 4005 and a second substrate 4006 . In FIG. 32(B) and FIG. 32(C), the sealing material 4005 on the first substrate 4001 Therefore, a single crystal semiconductor or a multi-crystal semiconductor is formed on a separately prepared substrate in a region different from the region surrounded by the substrate. A signal line driver circuit 4003 formed of a crystalline semiconductor is mounted. In 32(C), the signal line driver circuit 4003, the scanning line driver circuit 4004, or the pixel Various signals and potentials applied to the unit 4002 are supplied from an FPC 4018 .

[0306] In addition, in FIG. 32(B) and FIG. 32(C), a signal line driver circuit 4003 is separately formed. Although an example in which the scanning line is mounted on the first substrate 4001 is shown, the present invention is not limited to this configuration. The driver circuit may be formed separately and mounted, or may be mounted as part of the signal line driver circuit or the scanning line driver circuit. Alternatively, only a part of the above may be formed separately and mounted.

[0307] The method of connecting the separately formed drive circuit is not particularly limited, and may be a wire bond. ing, COG (Chip On Glass), TCP (Tape Carrier) Package), COF (Chip On Film), etc. can be used. 32(A) is a circuit board on which a signal line driver circuit 4003 and a scanning line driver circuit 4004 are mounted by COG. FIG. 32(B) is an example in which a signal line driver circuit 4003 is mounted by COG. FIG. 32C shows an example in which the signal line driver circuit 4003 is implemented using TCP.

[0308] The display device also includes a panel in which a display element is sealed, and a controller for the panel. This may also include a module in which an IC or the like including the above is mounted.

[0309] The pixel portion and the scanning line driver circuit provided on the first substrate have a plurality of transistors. The transistor described in the above embodiment can be applied to this semiconductor device.

[0310] 33(A) and 33(B) are cross-sections of the region indicated by the chain line N1-N2 in FIG. 32(B). The display device shown in FIGS. 33(A) and 33(B) has an electrode 401. 5, and the electrode 4015 is connected to a terminal of the FPC 4018 and an anisotropic conductive layer 4019. The electrode 4015 is electrically connected to the insulating layer 4112 and the insulating layer 4113. 11, and electrically connected to the wiring 4014 in an opening formed in the insulating layer 4110. are.

[0311] The electrode 4015 is formed from the same conductive layer as the first electrode layer 4030. The source and drain electrodes of the transistor 4010 and the transistor 4011 are the same. The same conductive layer is used.

[0312] The pixel portion 4002 and the scanning line driver circuit 4004 provided on the first substrate 4001 are 33(A) and 33(B), the pixel portion 4002 includes a plurality of transistors. a transistor 4010 included in the scanning line driver circuit 4004; 33A illustrates a transistor 4010 and a transistor 4011. 11, an insulating layer 4112, an insulating layer 4111, and an insulating layer 4110 are provided, and In (B), a partition wall 4510 is formed on the insulating layer 4112.

[0313] The transistor 4010 and the transistor 4011 are provided over an insulating layer 4102. The transistor 4010 and the transistor 4011 are formed by insulating layers 4102. An electrode 4017 is formed thereon, and an insulating layer 4103 is formed on the electrode 4017. . The electrode 4017 can function as a back gate electrode.

[0314] The transistors 4010 and 4011 are the same as those described in the above embodiment modes. The transistors described in the above embodiments can be used because they have little fluctuation in electrical characteristics. Therefore, the present invention shown in Fig. 33(A) and Fig. 33(B) is The display device according to the embodiment can be made a highly reliable display device.

[0315] 33(A) and 33(B), the transistor 4010 and the transistor The transistor 4011 has a structure similar to that of the transistor 452 described in the above embodiment. The example shows the case where a transistor is used.

[0316] The display devices shown in FIGS. 33A and 33B each include a capacitor 4020. The capacitor 4020 is connected to one of the source electrode and the drain electrode of the transistor 4010. The electrode 4021 has a region where the electrode 4021 overlaps with the insulating layer 4103 interposed therebetween. It is formed from the same conductive layer as electrode 4017.

[0317] In general, the capacitance of a capacitor provided in a display device is determined by the capacitance of the resistor of a transistor arranged in a pixel portion. The capacitance is set to be able to hold charge for a predetermined period, taking into consideration the current flowing through the capacitor. The capacitance may be set in consideration of the off-state current of the transistor and the like.

[0318] For example, by using an OS transistor in a pixel portion of a liquid crystal display device, the capacitance of a capacitor element can be reduced. The volume of the liquid crystal can be reduced to 1 / 3 or even 1 / 5. By using a resistor, the formation of a capacitive element can be omitted.

[0319] The transistor 4010 provided in the pixel portion 4002 is electrically connected to the display element. 3(A) is an example of a liquid crystal display device using a liquid crystal element as a display element. In the figure, a liquid crystal element 4013, which is a display element, has a first electrode layer 4030 and a second electrode layer 4040. 031 and a liquid crystal layer 4008. The liquid crystal layer 4008 is sandwiched between alignment films. The second electrode layer 4031 is provided with an insulating layer 4032 and an insulating layer 4033 which function as a second electrode layer. The first electrode layer 4030 and the second electrode layer 4031 are disposed on the second substrate 4006 side. Overlapping through layer 4008.

[0320] The spacers 4035 are columnar spacers obtained by selectively etching the insulating layer. and the distance (cell gap) between the first electrode layer 4030 and the second electrode layer 4031 is controlled. A spherical spacer may also be used.

[0321] Note that OS transistors are used as the transistors 4010 and 4011. It is preferable that the OS transistor has a low current value in an off state (off-state current value). Therefore, the retention time of the electric signals such as the image signals can be extended. When the power is on, the write interval can be set longer, so the frequency of refresh operations can be reduced. This reduces the power consumption.

[0322] In addition, OS transistors have relatively high field-effect mobility, enabling high-speed operation. Therefore, by using the above transistor in a pixel portion of a display device, a high-quality image can be displayed. In addition, a driver circuit section and a pixel section can be separately formed on the same substrate. This makes it possible to reduce the number of parts in the display device.

[0323] In addition, in display devices, black matrices (light-shielding layers), polarizing members, phase difference members, reflecting members, For example, a polarizing substrate and a positioning member may be provided. Circularly polarized light produced by a retardation substrate may also be used. Either may be used.

[0324] Furthermore, a light-emitting element that utilizes electroluminescence is used as a display element included in the display device. An EL element is a device that is disposed between a pair of electrodes. The EL element has a layer containing a light-emitting compound (also called an "EL layer") between a pair of electrodes. When a potential difference greater than the threshold voltage is generated, holes are injected into the EL layer from the anode side, and the cathode Electrons are injected from the electrode side. The injected electrons and holes recombine in the EL layer, forming a The luminescent material contained therein emits light.

[0325] EL elements are also classified according to whether the light-emitting material is an organic compound or an inorganic compound. Generally, the former is called an organic EL element, and the latter is called an inorganic EL element.

[0326] When a voltage is applied to an organic EL element, electrons are emitted from one electrode and holes are emitted from the other electrode. are injected into the EL layer, and then the carriers (electrons and holes) recombine. By this, the light-emitting organic compound forms an excited state, and the excited state returns to the ground state. Due to this mechanism, such a light-emitting element is called a current-excited light-emitting element. It is called a child.

[0327] In addition to the light-emitting compound, the EL layer may contain a material having a high hole injection property and a material having a high hole transport property. , hole blocking material, material with high electron transporting ability, material with high electron injecting ability, or bipolar The layer may contain a highly functional substance (a substance having high electron-transporting and hole-transporting properties).

[0328] The EL layer can be formed by a variety of methods, including vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating. It can be formed in any way.

[0329] Inorganic EL elements are divided into dispersion-type inorganic EL elements and thin-film-type inorganic EL elements depending on the element structure. Dispersion-type inorganic EL elements have a light-emitting layer in which particles of a light-emitting material are dispersed in a binder. The emission mechanism is a donor-acceptor interaction that utilizes the donor and acceptor levels. Thin-film inorganic EL devices sandwich the light-emitting layer between dielectric layers. Furthermore, this structure is sandwiched between electrodes, and the light emission mechanism utilizes the inner-shell electron transition of metal ions. In this example, the light-emitting element is an organic EL element. do.

[0330] The light emitting element only needs to have at least one of the pair of electrodes transparent in order to extract light. The transistor and the light emitting element are formed on the substrate, and light is emitted from the surface opposite to the substrate. The top emission structure emits light from the top surface, while the bottom emission structure emits light from the substrate side. bottom emission) structure and dual emission (double emission) structure that emits light from both sides ) structure, and any light emitting element with any emission structure can be applied.

[0331] FIG. 33(B) shows a light-emitting display device (also called an "EL display device") that uses light-emitting elements as display elements. The light-emitting element 4513, which is a display element, is provided in the pixel portion 4002. The light-emitting element 4513 is electrically connected to the transistor 4010. The first electrode layer 4030, the light-emitting layer 4511, and the second electrode layer 4031 are laminated together. The light emitting element 4513 may be formed in accordance with the direction of light to be extracted from the light emitting element 4513. The configuration of 513 can be changed as needed.

[0332] The partition wall 4510 is formed using an organic insulating material or an inorganic insulating material, particularly a photosensitive resin. An opening is formed on the first electrode layer 4030 using a material, and the side of the opening has a continuous curved surface. It is preferable to form the inclined surface so as to have a certain slope.

[0333] The light-emitting layer 4511 may be composed of a single layer or a plurality of layers stacked. Either way is fine.

[0334] The second electrode layer is formed to prevent oxygen, hydrogen, moisture, carbon dioxide, and the like from entering the light-emitting element 4513. A protective layer may be formed on the insulating layer 4031 and the partition wall 4510. The protective layer may be formed of silicon nitride. silicon nitride oxide, aluminum oxide, aluminum nitride, aluminum oxynitride, Forming aluminum oxide nitride, DLC (Diamond Like Carbon), etc. In addition, the first substrate 4001, the second substrate 4006, and the sealant 40 The space sealed by 05 is sealed with a filler 4514. A protective film (laminating film) with high airtightness and low outgassing is used to prevent exposure to the outside air. It is preferable to package (enclose) the product in a protective film (film, ultraviolet curing resin film, etc.) or a cover material. It's nice.

[0335] Filler 4514 can be an inert gas such as nitrogen or argon, or an ultraviolet curing resin or Thermosetting resins can be used, such as PVC (polyvinyl chloride), acrylic resins, Polyimide, epoxy resin, silicone resin, PVB (polyvinyl butyral) or Ethylene vinyl acetate (EVA) can also be used. may contain a desiccant.

[0336] The sealing material 4005 is made of glass materials such as glass frit, or ordinary materials such as two-component mixed resin. Resin materials such as heat-curable resin, photo-curable resin, and thermosetting resin can be used. The sealing material 4005 may also contain a desiccant.

[0337] If necessary, a polarizing plate or a circular polarizing plate (including an elliptical polarizing plate) may be provided on the light-emitting surface of the light-emitting element. Optical films such as retardation plates (λ / 4 plates, λ / 2 plates) and color filters may be provided as appropriate. In addition, an anti-reflection film may be provided on the polarizing plate or the circular polarizing plate. Anti-glare treatment can be applied to diffuse reflected light and reduce glare.

[0338] In addition, by using a microcavity structure for the light-emitting element, it is possible to extract light with high color purity. In addition, by combining a microcavity structure with a color filter, This reduces congestion and improves the visibility of the displayed image.

[0339] A first electrode layer and a second electrode layer (a pixel electrode layer, a common electrode layer, a pair of electrodes) that apply a voltage to the display element In the case of a light-emitting diode (also called a counter electrode layer), the direction of the light to be extracted, the location of the electrode layer, and The light transmission property or reflectivity can be selected depending on the pattern structure of the electrode layer.

[0340] The first electrode layer 4030 and the second electrode layer 4031 are made of an indium oxide containing tungsten oxide. oxide, indium zinc oxide with tungsten oxide, indium oxide with titanium oxide Indium tin oxide, indium tin oxide containing titanium oxide, indium zinc oxide A conductive material having light-transmitting properties, such as indium tin oxide doped with silicon oxide, may be used. This can be done.

[0341] The first electrode layer 4030 and the second electrode layer 4031 are made of tungsten (W) and molybdenum. (Mo), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (N b), Tantalum (Ta), Chromium (Cr), Cobalt (Co), Nickel (Ni), Titanium Metals such as titanium (Ti), platinum (Pt), aluminum (Al), copper (Cu), and silver (Ag) or its alloy, or metal nitride thereof. .

[0342] The first electrode layer 4030 and the second electrode layer 4031 are made of a conductive polymer (conductive polymer). The conductive polymer can be formed using a conductive composition containing a conductive polymer. For example, a so-called π-electron conjugated conductive polymer can be used. or its derivatives, polypyrrole or its derivatives, polythiophene or its derivatives or a copolymer consisting of two or more of aniline, pyrrole and thiophene, or Its derivatives are also included.

[0343] In addition, since transistors are easily damaged by static electricity, a protection circuit for protecting the drive circuit is required. It is preferable that the protection circuit is configured using a non-linear element.

[0344] By using the transistor described in the above embodiment, a highly reliable display device can be provided. In addition, by using the transistor described in the above embodiment, high definition and This makes it possible to provide a display device with a large area and good display quality. It is possible to provide a display device in which the above-mentioned problem is reduced.

[0345] <Example of a display module> A display module will be described as an example of a semiconductor device using the above-described transistor. The display module 6000 shown in FIG. Between the two, touch sensor 6004 connected to FPC6003 and FPC6005 a display panel 6006, a backlight unit 6007, a frame 6009, a printer The backlight unit 6007 has a backlight substrate 6010 and a battery 6011. The battery 6011, the touch sensor 6004, etc. may not be provided.

[0346] The semiconductor device of one embodiment of the present invention includes, for example, a touch sensor 6004, a display panel 6006, It can be used for an integrated circuit mounted on a printed circuit board 6010. For example, The display device described above can be used for the panel 6006.

[0347] The upper cover 6001 and the lower cover 6002 are connected to the touch sensor 6004 and the display panel 6006. The shape and dimensions can be changed as needed to suit sizes such as 006.

[0348] The touch sensor 6004 is a resistive or capacitive touch sensor connected to the display panel 6 6006. A touch sensor function can be added to the display panel 6006. For example, it is possible to provide a touch sensor electrode in each pixel of the display panel 6006. It is also possible to add a capacitive touch panel function. By providing an optical sensor in each pixel of the panel 6006 and adding the function of an optical touch sensor, It is also possible to do the following.

[0349] The backlight unit 6007 includes a light source 6008. It may be configured to be provided at the end of the unit 6007 and to use a light diffusion plate. When a light-emitting display device or the like is used for 6006, the backlight unit 6007 is omitted. It is possible.

[0350] The frame 6009 not only protects the display panel 6006 but also protects the printed circuit board 6010 from the side. It also functions as an electromagnetic shield to block the electromagnetic waves generated. 009 may also function as a heat sink.

[0351] The printed circuit board 6010 includes a power supply circuit, a signal circuit for outputting a video signal, and a clock signal. The power supply for the power supply circuit is a battery 6011. If a commercial power source is used as the power source, , the battery 6011 can be omitted.

[0352] In addition, components such as polarizing plates, retardation plates, and prism sheets have been added to the Display Module 6000. It may also be provided as follows.

[0353] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0354] (Embodiment 7) The semiconductor device described in the above embodiment can be used for a lighting device or the like. FIG. 35(A) shows a block diagram of the lighting device 1100. The lighting device 1100 is roller 1101, pre-driver 1102, voltage generating circuit 1103, and light emitting unit 1104 The semiconductor device shown in the above embodiment is used in the pre-driver 1102, for example. It is possible.

[0355] The light emitting unit 1104 has one or more LEDs 1114. In this embodiment, the light emitting element Although an LED is used as an example, other light emitting elements may be used. This is a circuit for generating a voltage to be supplied to the light emitting unit 1104. For example, a switching regulator may be used. This is a circuit for driving the voltage generating circuit 1103. The voltage is controlled by a pre-driver 1102 .

[0356] The controller 1101 includes, for example, a brightness adjustment circuit, a light emitting section short circuit detection circuit, a dimming PWM signal The controller 1101 controls the light emitting unit 1104 to emit light. A signal that determines the brightness is supplied to the pre-driver 1102. In addition, a temperature sensor, a light sensor, and the like are separately provided. The signal that takes into account the information obtained from these detectors is sent to the pre-driving It can also be supplied to the driver 1102.

[0357] Furthermore, the lighting device 1100 can be applied to lighting devices in various fields. Lighting devices for indoor use (LED bulbs and LED fluorescent lamps), outdoor lighting devices, liquid crystal displays (LCDs) backlight devices for vehicles (automobiles, motorcycles, etc.), lighting devices for railway vehicles, For example, vehicle lighting devices include headlights, Lamps (headlights), front combination lamps, daytime running lamps, These include combination lamps, turn signals, and room lamps.

[0358] The semiconductor device described in the above embodiment may be used in a motor driving device that controls the operation of a motor. As an example, the block diagram of the motor driving device 1200 is shown in FIG. The motor driving device 1200 includes a controller 1201, a pre-driver 120, and a 2, a voltage generating circuit 1203, and a motor 1204. The conductor device can be used in the pre-driver 1202, for example.

[0359] The voltage generating circuit 1203 is a circuit for generating a voltage to be supplied to the motor 1204. The voltage generating circuit 1203 may be, for example, a power transistor. 202 is a circuit for driving the voltage generating circuit 1203. The voltage output from 03 is controlled by a pre-driver 1202.

[0360] The controller 1201 transmits a signal that determines the output of the motor 1204 to the pre-driver 1202. The controller 1201 controls the motor based on information obtained from a separately provided detector. The output of the controller 1204 can be determined.

[0361] This embodiment mode can be appropriately combined with other embodiment modes and examples shown in this specification. can.

[0362] (Embodiment 8) In this embodiment, the semiconductor device described in the above embodiment is applied to an electronic component. , and examples of electronic devices equipped with the electronic components will be described with reference to FIGS. 36 and 37. Electronic components are also called semiconductor packages or IC packages. There are multiple standards and names depending on the terminal extraction direction and terminal shape. In the embodiment, an example of an electronic component will be described.

[0363] The electronic component is a semiconductor device according to the above embodiment that is used in an assembly process (post-process). The device is completed by combining components other than the semiconductor device.

[0364] The post-process will be explained using the flowchart shown in Figure 36(A). After the element substrate having the semiconductor device shown in the above embodiment is completed, the back surface ( The back surface (the surface on which semiconductor devices are not formed) is ground (step S1). By thinning the element substrate through grinding, warping of the element substrate can be reduced, and electronic components can be It is possible to reduce the size of the device.

[0365] Next, a "dicing step" is carried out to separate the element substrate into a plurality of chips (step S2). Then, the separated chips are individually picked up and bonded onto the lead frame. The die bonding process is then carried out (step S3). The joining to the frame is done by resin joining, tape joining, etc., depending on the product. In addition, instead of a lead frame, the chip is bonded to an interposer substrate. You may do so.

[0366] Next, the leads of the lead frame and the electrodes on the chip are electrically connected with thin metal wires. The wire bonding process is then carried out to connect the wires to the substrate (step S4). Silver wire or gold wire can be used. Wire bonding is also called ball bonding. Alternatively, wedge bonding can be used.

[0367] The wire-bonded chip is sealed with epoxy resin in the "sealing process (module)". The electronic components are then sealed in a resin (step S5). The circuitry built into the chip and the wires connecting the chip and the leads are mechanically It can protect from external forces and reduce deterioration of characteristics (reduced reliability) due to moisture and dust. It is possible.

[0368] Next, a "lead plating process" is carried out to plate the leads of the lead frame (step The plating process prevents the leads from rusting and makes it easier to mount the leads on a printed circuit board. The soldering can be done more reliably. Then, the leads are cut and shaped. Then, a "forming process" is carried out (step S7).

[0369] Next, a "marking process" is carried out, in which printing (marking) is applied to the surface of the package. (Step S8) Then, the "inspection process" ( After step S9), the electronic component is completed.

[0370] The electronic components described above may be configured to include the transistors described in the above embodiments. This reduces malfunctions in high temperature environments and reduces manufacturing costs. It is possible to realize an electronic component having the semiconductor device. The present invention includes a semiconductor device that reduces malfunctions under high voltage and suppresses manufacturing costs. This is an electronic component that has been miniaturized and has relaxed restrictions on the environment in which it can be used.

[0371] A perspective view of the completed electronic component is shown in FIG. 36(B). As an example of a product, a perspective view of a QFP (Quad Flat Package) is shown below. The electronic component 700 shown in FIG. 36(B) includes leads 705 and a semiconductor device 703. The semiconductor device 703 is the semiconductor device described in the above embodiment mode or the like. It is possible.

[0372] The electronic component 700 shown in FIG. 36(B) is mounted on, for example, a printed circuit board 702. A plurality of such electronic components 700 are combined together, and each is electrically connected to a printed circuit board 702. By connecting the components together, a substrate (mounting substrate 704) on which electronic components are mounted is completed. The mounting board 704 is used in electronic devices and the like.

[0373] Next, referring to FIG. 37, a vehicle (such as a bicycle) driven by power from a fixed power source is provided with a power supply. Regarding application examples in which the above electronic components are applied to drive circuits that drive inverters, motors, etc., and explain.

[0374] FIG. 37(A) shows an electric bicycle 1010 as an application example. The electric bicycle 1011 is powered by passing an electric current through the motor 1011. 010 is a power storage device 1012 for supplying current to a motor 1011, and a motor 37A, the pedal 1011 is connected to a driving circuit 1013. is illustrated, but may not be necessary.

[0375] The driver circuit 1013 is provided with an electronic component including the semiconductor device described in the above embodiment. The mounting board is installed. Therefore, it is possible to make an electric bicycle equipped with miniaturized electronic components. It will also be possible to realize electric bicycles with low power consumption and long range. Furthermore, it is possible to realize an electric bicycle with good reliability.

[0376] FIG. 37(B) shows an electric vehicle 1020 as another application example. 20 obtains power by passing current through the motor 1021. The vehicle 1020 includes a power storage device 1022 for supplying current to a motor 1021, and a motor and a drive circuit 1023 for driving the motor 1021.

[0377] The driver circuit 1023 is provided with an electronic component including the semiconductor device described in the above embodiment. Therefore, it is possible to make an electric vehicle equipped with miniaturized electronic components. It will also be possible to realize electric vehicles that consume less power and have a longer driving range. Furthermore, it is possible to realize an electric vehicle with good reliability.

[0378] Further, electronic components including the semiconductor device described in the above embodiment can be used not only in electric vehicles (EVs). It is used in hybrid vehicles (HEV) and plug-in hybrid vehicles (PHEV), etc. It is also possible.

[0379] As described above, the electronic devices described in this embodiment mode include the semiconductor device according to the above embodiment. The electronic components are mounted on a mounting board. It is possible to realize electronic devices equipped with these components. It is also possible to realize electronic devices with low power consumption. Furthermore, it is possible to realize an electronic device with good reliability.

[0380] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible.

[0381] (Embodiment 9) A semiconductor device according to one embodiment of the present invention can be used in a control circuit of various electronic devices. Specific examples of electronic devices using a semiconductor device according to one embodiment of the present invention are illustrated in FIGS.

[0382] Examples of electronic devices using a semiconductor device according to one embodiment of the present invention include display devices such as televisions and monitors. , lighting equipment, desktop or notebook personal computers, word processors stored on recording media such as DVD (Digital Versatile Disc) Image playback devices that play still or moving images, portable CD players, radios, tapes Recorders, headphone stereos, stereos, table clocks, wall clocks, cordless telephone handsets , transceivers, mobile phones, car phones, portable game consoles, tablet terminals, pachinko machines large game consoles such as PCs, calculators, personal digital assistants, electronic organizers, e-book readers, electronic translators, High frequency devices such as voice input devices, video cameras, digital still cameras, electric shavers, microwave ovens, etc. Wave heating devices, electric rice cookers, electric washing machines, electric vacuum cleaners, water heaters, electric fans, hair dryers, air Air conditioning equipment such as conditioners, humidifiers, dehumidifiers, dishwashers, dish dryers, and clothes dryers electric refrigerators, electric freezers, electric refrigerator-freezers, DNA storage freezers, pocket refrigerators Examples include electric lights, tools such as chainsaws, smoke detectors, and medical equipment such as dialysis machines. Furthermore, guide lights, traffic lights, conveyor belts, elevators, escalators, and industrial robots , energy storage systems, industrial equipment such as energy storage devices for power leveling and smart grids Examples include:

[0383] In addition, moving objects propelled by electric motors using power from a power storage device are also included in the category of electronic devices. The above-mentioned mobile units include, for example, electric vehicles (EVs), vehicles with internal combustion engines and electric vehicles (EVs), and Hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), These tires and wheels are converted into tracks, and motorized vehicles including electrically assisted bicycles are also available. Bicycles, motorcycles, electric wheelchairs, golf carts, small or large boats, submarines, helicopters Examples include aircraft, rockets, satellites, space probes, planetary probes, and spacecraft. .

[0384] An example of an electronic device is shown in FIG. 38. In FIG. 38, a display device 8000 is an embodiment of the present invention. 8 is an example of an electronic device using the semiconductor device 8004 according to the present invention. 8000 corresponds to a display device for receiving TV broadcasts, and includes a housing 8001, a display unit 8002, and a speaker unit. 8003, a semiconductor device 8004, a power storage device 8005, and the like. The semiconductor device 8004 is provided inside the housing 8001. This allows the driving of cooling devices such as cooling fans inside the display device 8000 and adjustment of light emission brightness. The display device 8000 can be controlled by receiving power from a commercial power source. Alternatively, power stored in the power storage device 8005 can be used.

[0385] The display unit 8002 includes a liquid crystal display device, an emitting device having a light emitting element such as an organic EL element in each pixel, and Device, electrophoretic display device, DMD (Digital Micromirror Device) ce), PDP (Plasma Display Panel), FED (Field A display device such as a Fluorescence Emission Display can be used.

[0386] In addition to TV broadcast reception, display devices are also used for personal computers and advertising displays. , including all display devices for displaying information.

[0387] In FIG. 38, a stationary lighting device 8100 includes a semiconductor device 8 according to one embodiment of the present invention. 8103. Specifically, the lighting device 8100 includes a housing 8101, It includes a light source 8102, a semiconductor device 8103, a power storage device 8105, and the like. The body device 8103 is installed inside a ceiling 8104 where a housing 8101 and a light source 8102 are installed. However, the semiconductor device 8103 may be provided inside the housing 8101. The semiconductor device 8103 controls the luminance of the light source 8102. The lighting device 8100 can also be supplied with power from a commercial power source. Alternatively, power stored in a power storage device can be used.

[0388] In addition, FIG. 38 illustrates a fixed lighting device 8100 provided on a ceiling 8104. However, in the semiconductor device according to one embodiment of the present invention, the sidewall 8405, the floor 8406, and the like are not included in the ceiling 8104. 8406, windows 8407, etc., or It can also be used as a tabletop lighting device.

[0389] The light source 8102 may be an artificial light source that artificially obtains light using electricity. Specifically, incandescent lamps, fluorescent lamps and other discharge lamps, and light-emitting devices such as LEDs and organic EL elements The element is an example of the artificial light source.

[0390] In FIG. 38, an air conditioner having an indoor unit 8200 and an outdoor unit 8204 is 8A and 8B are examples of electronic devices using a semiconductor device 8203 according to one embodiment of the present invention. The internal unit 8200 includes a housing 8201, an air outlet 8202, a semiconductor device 8203, a power storage device 820 38, the semiconductor device 8203 is provided in the indoor unit 8200. However, the semiconductor device 8203 may be provided in the outdoor unit 8204. Alternatively, the semiconductor device 8203 may be provided in both the indoor unit 8200 and the outdoor unit 8204. The semiconductor device 8203 can be used in the compressor of an air conditioner. The air conditioner can also be powered by commercial power. The power supply can be received, and the power stored in the power storage device 8205 can be used. can.

[0391] In Figure 38, a separate type air conditioner consisting of an indoor unit and an outdoor unit is shown. As an example, it is an all-in-one air conditioner that has the functions of both the indoor unit and the outdoor unit in a single housing. The semiconductor device according to one embodiment of the present invention can be used for the conditioner.

[0392] In FIG. 38, an electric refrigerator-freezer 8300 includes a semiconductor device 8304 according to one embodiment of the present invention. Specifically, an electric refrigerator-freezer 8300 includes a housing 8301, Refrigerator door 8302, freezer door 8303, semiconductor device 8304, power storage device 8305, etc. In FIG. 38, a power storage device 8305 is provided in a housing 8301. The motor used in the compressor of the electric refrigerator-freezer 8300 is driven by the body device 8304. The electric refrigerator-freezer 8300 can also be supplied with power from a commercial power source. The power can be received, or power stored in the power storage device 8305 can be used.

[0393] The portable game machine 2900 shown in FIG. 39(A) includes a housing 2901, a housing 2902, a display unit 2903, and a 903, display unit 2904, microphone 2905, speaker 2906, operation switch 29 07, etc. The portable game machine 2900 also has an antenna, a battery, etc., inside the housing 2901. The portable game machine shown in FIG. 39(A) has two display units 29 The number of display units is not limited to this. 903 is provided with a touch screen as an input device, and a stylus 2908 or the like is used. It is more operable.

[0394] The information terminal 2910 shown in FIG. 39(B) includes a housing 2911, a display unit 2912, a microphone 2913, and a microphone unit 2914. 17, speaker unit 2914, camera 2913, external connection unit 2916, and operation switch The display unit 2912 includes a display panel and a touch panel using a flexible substrate. The information terminal 2910 also has an antenna inside the housing 2911, The information terminal 2910 is, for example, a smartphone, a mobile phone, a tablet, or the like. Used as a notebook type information terminal, tablet type personal computer, e-book reader, etc. It is possible.

[0395] A notebook personal computer 2920 shown in FIG. 39(C) includes a housing 2921, a display unit 2922, a keyboard 2923, and a pointing device 2924. The notebook personal computer 2920 has an antenna, a battery, and the like inside the housing 2921. It has a terry, etc.

[0396] The video camera 2940 shown in FIG. 39(D) includes a housing 2941, a housing 2942, a display unit 29 43, an operation switch 2944, a lens 2945, and a connection part 2946. The switch 2944 and the lens 2945 are provided in the housing 2941. 3 is provided in a housing 2942. A video camera 2940 is provided in a housing 2941. The housing 2941 and the housing 2942 are provided with an antenna, a battery, etc. on the side. 2946, and the angle between the housing 2941 and the housing 2942 is 46. ​​The housing 2942 relative to the housing 2941 Depending on the angle, the orientation of the image displayed on the display unit 2943 can be changed, and the image can be displayed / hidden. Switching can be done.

[0397] An example of a bangle-type information terminal is shown in FIG. 39(E). The information terminal 2950 has a housing 2951. The information terminal 2950 has a housing 2951 and a display unit 2952. The display unit 2952 is supported by a curved housing 2951. The display unit 2952 is provided with a display panel using a flexible substrate. It is possible to provide an information terminal 2950 that is flexible, lightweight, and easy to use.

[0398] An example of a wristwatch-type information terminal 2960 is shown in FIG. 39(F). The information terminal 2960 includes a housing 2961, Display unit 2962, band 2963, buckle 2964, operation switch 2965, input / output terminal The information terminal 2960 includes an antenna, a battery, and the like inside the housing 2961. The information terminal 2960 is equipped with a mobile phone, e-mail, document viewing and creation, It can be used for various applications such as music playback, internet communication, and computer games. It can be done.

[0399] The display surface of the display unit 2962 is curved, and display can be performed along the curved display surface. The display unit 2962 is also equipped with a touch sensor, and can be operated by touching the screen with a finger or a stylus. For example, the icon 2967 displayed on the display unit 2962 can be operated by touching the The operation switch 2965 is used to start the application. In addition to settings, you can also turn the power on and off, turn wireless communication on and off, activate silent mode, and It can have various functions such as turning on and off the power saving mode, turning on and off the power saving mode, etc. The operating system installed in the information terminal 2960 controls the operation of the operation switch 29 You can also set up to 65 functions.

[0400] The information terminal 2960 is also capable of performing standardized short-range wireless communication. For example, by communicating with a wireless headset, you can make hands-free calls. The information terminal 2960 is also provided with an input / output terminal 2966, and can be connected to other information terminals. Data can be exchanged directly through the connector. Charging can also be performed via the input / output terminal 2966. It may also be powered by a line.

[0401] 39(G) is an external view showing an example of an automobile. The automobile 2980 includes a body 2981, It has wheels 2982, a dashboard 2983, and lights 2984. The car 2980 is equipped with an antenna, a battery, etc.

[0402] The semiconductor device of one embodiment of the present invention can be used in a display portion, a light-emitting portion, a motor, or the like of the above-described electronic devices. Among the electronic devices mentioned above, the present invention can be used in a control unit of a microwave oven. High frequency heating devices such as microwave ovens and electric rice cookers require high power for a short period of time. Furthermore, it is necessary to control high power stably for a certain period of time. By using this device, power can be controlled stably, resulting in highly reliable electronic equipment. It is possible to realize the device.

[0403] This embodiment mode can be implemented by appropriately combining with the configurations described in other embodiment modes. It is possible. [Example]

[0404] Silvaco's circuit simulator Smartspice version 4.10. 6.R was used to verify the operation of the semiconductor device 100. The circuit model used for the verification is shown in FIG. The circuit simulator does not have a model of a transistor with a back gate. Therefore, the transistor 111 is configured by connecting the transistor 111a and the transistor 111b in parallel. A connected model was used.

[0405] The main setting parameters are Level=36, VTO=0.4197V, and the thickness of the gate insulating layer. length of the transistor 111a=20 nm, L / W of the transistor 111a=0.5 μm / 300 μm, L / W of 111b=0.5 μm / 300 μm, L / W of transistor 112=0.5 μm / 1000 μm, L / W of transistor 113=0.5 μm / 400 μm, capacitance element 11 The capacitance of 7 is 10 pF, VDD=3.3 V, and GND=VSS=0 V.

[0406] In the circuit diagram shown in FIG. 40, VIN indicates a signal supplied to terminal 102. UT indicates a signal supplied to the terminal 105. VINB1 is supplied to the wiring 124. VINB2 indicates a signal supplied to the wiring 123. VF1 indicates a The potential at node 132 is shown.

[0407] The verification results are shown in Figure 41. When VIN becomes the H potential (VDD) during period 151, VO UT becomes low potential (GND=VSS). Also, VIN becomes low potential during period 152. As a result of the verification, it is found that the semiconductor device 100 functions as an inverter circuit. It was confirmed that it can function as a [Explanation of symbols]

[0408] 100 Semiconductor device 102 terminals 105 terminal 110 Semiconductor device 111 Transistor 112 transistors 113 Transistor 114 transistors 117 Capacitor element 120 Semiconductor device 121 Wiring 122 Wiring 123 Wiring 124 Wiring 125 Wiring 126 Wiring 131 nodes 132 nodes 151 period 152 period 223 Electrode 224 electrode 225 Insulating Layer 226 Insulating Layer 227 Insulating Layer 228 Insulating Layer 229 Insulating Layer 242 Semiconductor layer 243 Electrode 246 Electrode 255 Impurities 269 ​​areas 271 Circuit Board 272 Insulating Layer 273 Insulating Layer 274 Insulating Layer 275 Insulating Layer 277 Insulating Layer 282 Insulating Layer 382 Ec 384 Ec 386 Ec 390 trap levels 410 Transistor 411 Transistor 420 transistors 421 Transistor 425 transistor 426 Transistor 430 transistors 431 Transistor 440 transistors 441 Transistor 442 transistors 443 Transistor 444 transistor 445 transistor 446 Transistor 447 Transistor 448 transistors 451 Transistor 452 transistors 453 Transistor 454 transistor 461 Transistor 462 Liquid crystal element 463 Capacitor 464 transistors 465 nodes 466 nodes 467 nodes 468 transistors 469 Light-emitting element 500 display device 511 Drive circuit 512 Shift Register 513 DA conversion output circuit 514 Level Shifter 531 Display area 532 pixels 534 pixel circuit 535 Wiring 536 Wiring 700 Electronic Components 702 Printed Circuit Board 703 Semiconductor Devices 704 Mounting board 705 Lead 1010 Electric Bicycle 1011 Motor 1012 Electricity storage device 1013 Drive circuit 1020 Electric Vehicle 1021 Motor 1022 Electricity storage device 1023 drive circuit 1100 Lighting equipment 1101 Controller 1102 Pre-driver 1103 Voltage Generation Circuit 1104 Light-emitting part 1114 LED 1200 Motor Drive Unit 1201 Controller 1202 Pre-driver 1203 Voltage Generation Circuit 1204 Motor 2900 handheld game console 2901 Case 2902 Case 2903 Display section 2904 Display section 2905 Microphone 2906 Speaker 2907 Operation switch 2908 Stylus 2910 Information terminal 2911 Case 2912 Display section 2913 Camera 2914 Speaker section 2915 Operation switch 2916 External connection part 2917 Mike 2920 Notebook Personal Computer 2921 Case 2922 Display section 2923 keyboard 2924 Pointing Device 2940 video camera 2941 Case 2942 Case 2943 Display section 2944 Operation switch 2945 Lens 2946 Connection 2950 Information terminal 2951 Case 2952 Display section 2960 Information Terminal 2961 Case 2962 Display section 2963 bands 2964 Buckle 2965 Operation switch 2966 Input / output terminal 2967 icons 2980 Automobiles 2981 Body 2982 wheels 2983 Dashboard 2984 Light 4001 board 4002 Pixel section 4003 Signal line driver circuit 4004 Scanning line driver circuit 4005 Sealing material 4006 board 4008 Liquid crystal layer 4010 transistor 4011 transistor 4013 Liquid crystal element 4014 Wiring 4015 Electrode 4017 Electrode 4018 FPC 4019 Anisotropic conductive layer 4020 Capacitor 4021 Electrode 4030 Electrode layer 4031 Electrode layer 4032 Insulation layer 4033 Insulation layer 4035 Spacer 4102 Insulation layer 4103 Insulation layer 4110 Insulation layer 4111 Insulation layer 4112 Insulation layer 4510 Bulkhead 4511 Light-emitting layer 4513 Light-emitting element 4514 Filling material 6000 Display Module 6001 Top cover 6002 Lower cover 6003 FPC 6004 Touch Sensor 6005 FPC 6006 Display Panel 6007 Backlight Unit 6008 Light source 6009 Frame 6010 printed circuit board 6011 Battery 8000 display device 8001 Case 8002 Display section 8003 Speaker section 8004 Semiconductor devices 8005 Electricity storage devices 8100 Lighting equipment 8101 Housing 8102 Light source 8103 Semiconductor devices 8104 Ceiling 8105 Electricity storage devices 8200 indoor unit 8201 Housing 8202 Ventilation outlet 8203 Semiconductor devices 8204 Outdoor unit 8205 Energy storage devices 8300 Electric refrigerator-freezer 8301 Housing 8302 Refrigerator door 8303 Freezer door 8304 Semiconductor devices 8305 Energy storage devices 8405 Side wall 8406 floors 8407 Window 100a Semiconductor device 100b semiconductor device 100c Semiconductor device 100d Semiconductor Devices 110a Semiconductor device 110b semiconductor device 111a transistor 111b transistor 120a Semiconductor device 120b semiconductor device 120c Semiconductor equipment 225a electrode 225b electrode 225c electrode 242a Semiconductor layer 242b Semiconductor layer 242c Semiconductor layer 242i Semiconductor layer 242t Semiconductor layer 242u Semiconductor layer 244a electrode 244b electrode 244c electrode 247a aperture 247b aperture 247c aperture 247d aperture 383a Ec 383b Ec 383c Ec 4018b FPC 451a Transistor 453a Transistor 454a Transistor 521a drive circuit 521b drive circuit 535_i wiring 536_j Wiring

Claims

1. a first transistor, a second transistor, a third transistor, and a capacitance element; the first transistor, the second transistor, and the third transistor are transistors of the same conductivity type, a semiconductor layer in which a channel of the first transistor is formed, a semiconductor layer in which a channel of the second transistor is formed, and a semiconductor layer in which a channel of the third transistor is formed each contain an oxide semiconductor; the oxide semiconductor contains In and Ga; the first transistor has a first gate on one of an upper side and a lower side of a channel formation region; the first transistor has a second gate on the other of the upper side and the lower side of the channel formation region; the second transistor has a gate only above a channel forming region; the third transistor has a gate only above a channel formation region; one of a source and a drain of the first transistor is electrically connected to a first wiring; a first gate of the first transistor electrically connected to the other of the source and the drain of the first transistor; a second gate of the first transistor is electrically connected to a fourth wiring; one of the source and the drain of the second transistor is electrically connected to a second wiring; the other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; one of a pair of electrodes of the capacitance element is electrically connected to the other of the source and the drain of the second transistor; one of the source and the drain of the third transistor is electrically connected to a third wiring; the other of the source and the drain of the third transistor is electrically connected to the other of the pair of electrodes of the capacitor element; a gate of the third transistor electrically connected to a fifth wiring;

2. a first transistor, a second transistor, a third transistor, and a capacitance element; the first transistor, the second transistor, and the third transistor are transistors of the same conductivity type, a semiconductor layer in which a channel of the first transistor is formed, a semiconductor layer in which a channel of the second transistor is formed, and a semiconductor layer in which a channel of the third transistor is formed each contain an oxide semiconductor; the oxide semiconductor contains In and Ga; the first transistor has a first gate on one of an upper side and a lower side of a channel formation region; the first transistor has a second gate on the other of the upper side and the lower side of the channel formation region; the second transistor has a gate above a channel forming region; the second transistor does not have a gate below a channel formation region; the third transistor has a gate above a channel formation region; the third transistor does not have a gate below a channel formation region; one of a source and a drain of the first transistor is electrically connected to a first wiring; a first gate of the first transistor electrically connected to the other of the source and the drain of the first transistor; a second gate of the first transistor is electrically connected to a fourth wiring; one of the source and the drain of the second transistor is electrically connected to a second wiring; the other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; one of a pair of electrodes of the capacitance element is electrically connected to the other of the source and the drain of the second transistor; one of the source and the drain of the third transistor is electrically connected to a third wiring; the other of the source and the drain of the third transistor is electrically connected to the other of the pair of electrodes of the capacitor element; a gate of the third transistor electrically connected to a fifth wiring;

3. a first transistor, a second transistor, a third transistor, and a capacitance element; the first transistor, the second transistor, and the third transistor are transistors of the same conductivity type, a semiconductor layer in which a channel of the first transistor is formed, a semiconductor layer in which a channel of the second transistor is formed, and a semiconductor layer in which a channel of the third transistor is formed each contain an oxide semiconductor; the oxide semiconductor contains In and Ga; the first transistor has a first gate on one of an upper side and a lower side of a channel formation region; the first transistor has a second gate on the other of the upper side and the lower side of the channel formation region; the second transistor has a gate above a channel forming region; the second transistor does not have a back gate; the third transistor has a gate above a channel formation region; the third transistor does not have a back gate; one of a source and a drain of the first transistor is electrically connected to a first wiring; a first gate of the first transistor electrically connected to the other of the source and the drain of the first transistor; a second gate of the first transistor is electrically connected to a fourth wiring; one of the source and the drain of the second transistor is electrically connected to a second wiring; the other of the source and the drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; one of a pair of electrodes of the capacitance element is electrically connected to the other of the source and the drain of the second transistor; one of the source and the drain of the third transistor is electrically connected to a third wiring; the other of the source and the drain of the third transistor is electrically connected to the other of the pair of electrodes of the capacitor element; a gate of the third transistor electrically connected to a fifth wiring;

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