Semiconductor equipment

Abstract

To provide a transistor having excellent electric characteristics, small current at non-conduction, and large current at conduction, and a semiconductor device including this transistor, having a high degree of integration, and being tough.SOLUTION: A transistor includes an insulator 102, semiconductors 106a and 106b, conductors 116a and 116b including a region in contact with the semiconductor 106b, a semiconductor 106c existing on the conductor 102 and on the semiconductor 106b and including a region in contact with an upper surface and a side surface of the semiconductor 106b and a side surface of the semiconductor 106a, an insulator 112 on the insulator 102, the semiconductor 106c, and the conductors 116 and 116b, a conductor 104 existing on the insulator 112 and including a region overlapping with the semiconductors 106a to 106c, and an insulator 108 on the insulator 102, the conductor 116a, the conductor 116b, and the conductor 104. The semiconductor 106b includes 124a and 124b in regions overlapping with the conductors 116a and 116b, respectively.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a product, a method, or a method of manufacturing; or to a process, a machine relating to manufactures or compositions of matter. In particular, The present invention relates to, for example, semiconductors, semiconductor devices, display devices, light-emitting devices, lighting devices, energy storage devices, and Related to memory devices or processors. Or semiconductors, semiconductor devices, display devices, light-emitting devices, This relates to a method for manufacturing lighting devices, energy storage devices, memory devices, or processors. Or, semiconductor devices. A method for driving a device, display device, light-emitting device, lighting device, energy storage device, memory device, or processor. To relate to.

[0002] In this specification, a semiconductor device refers to a device that can function by utilizing semiconductor properties. This refers to the general category of display devices, light-emitting devices, lighting devices, electro-optical devices, semiconductor circuits, and electronic equipment. It may have a semiconductor device. [Background technology]

[0003] The technology of constructing transistors using semiconductors on substrates with insulating surfaces is attracting attention. These transistors are widely used in semiconductor devices such as integrated circuits and display devices. Silicon is known as a semiconductor that can be applied to transistors.

[0004] The silicon used in transistor semiconductors comes in amorphous and polycrystalline forms, depending on the application. Recon and single-crystal silicon are used depending on the situation. For example, they are used to make up large display devices. When applied to transistors, amorphous silicon, for which film deposition technology on large-area substrates has been established. It is preferable to use this. On the other hand, a high-performance machine that forms the drive circuit and the pixel circuit on the same substrate When applied to transistors that constitute a display device, transistors with high field-effect mobility are desirable. Polycrystalline silicon capable of fabricating transistors is preferred. Furthermore, it is suitable for constructing integrated circuits and the like. When applied to transistors, single-crystal silicon with even higher field-effect mobility is used. It is preferable to use it. Polycrystalline silicon is subjected to high-temperature heat treatment, or A method of forming it by laser light treatment is known.

[0005] Furthermore, oxide semiconductors have been attracting attention in recent years. Oxide semiconductors are produced using methods such as sputtering. Because it can be used to form thin films, it can be used in the semiconductors of transistors that make up large display devices. This is possible. Also, transistors using oxide semiconductors have high field-effect mobility. Therefore, it is possible to realize a high-performance display device in which the drive circuit and the pixel circuit are formed on the same substrate. Furthermore, some of the production equipment for transistors using amorphous silicon will be modified and utilized. Because this is possible, there is also the advantage of being able to reduce capital investment.

[0006] By the way, transistors using oxide semiconductors exhibit extremely high leakage current in the non-conductive state. It is known that it is small. For example, the leakage characteristics of a transistor using an oxide semiconductor. Low-power CPUs and the like that utilize this technology have been disclosed (see Patent Document 1). When applying transistors using oxide semiconductors to integrated circuits such as CPUs, It is preferable to reduce the size of the components and increase their integration.

[0007] As semiconductor devices become more highly integrated, the formation process is affected by the overlapping of wiring, electrodes, and other components. In some cases, the effect of parasitic capacitance can become significant. Patent Document 2 describes a method from a conductive electrode to a semiconductor By allowing electrons to flow throughout the body, it exhibits excellent electrical properties even when an offset region is present. It is disclosed that a transistor can be obtained. By using the technology disclosed in Patent Document 2 This reduces parasitic capacitance that is formed due to the overlapping of wiring and electrodes. can.

[0008] Furthermore, by constructing a well-type potential with an active layer made of semiconductors, a high electric field effect can be achieved. It has been disclosed that a transistor with mobility can be obtained (see Patent Document 3). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2012-257187 [Patent Document 2] Japanese Patent Publication No. 2011-22507 [Patent Document 3] Japanese Patent Publication No. 2012-59860 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] One of the objectives is to provide a transistor with excellent electrical characteristics. Alternatively, a non-conductive transistor. One of the objectives is to provide a transistor with a small current during conduction. One of the objectives is to provide a transistor with a large value. Alternatively, to provide a transistor with One of the objectives is to provide a semiconductor device that enables the following: or to provide a semiconductor device with a high degree of integration. One of the objectives is to provide a robust semiconductor device. Alternatively, one of the objectives is to provide a novel semiconductor device.

[0011] Furthermore, the description of these problems does not preclude the existence of other problems. The approach does not need to solve all of these problems. This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings It is possible to extract other issues from the descriptions in the surfaces, claims, etc. [Means for solving the problem]

[0012] (1) One aspect of the present invention relates to a semiconductor having an insulator, a first conductor, and a second conductor. A conductive device wherein the upper surface of the semiconductor has a region in contact with an insulator, and the side surface of the semiconductor is an insulating material. Having a region that is in contact with the body, the first conductor and the semiconductor are connected via an insulator. It has a first region that overlaps with the semiconductor, and the first region has a region that faces the top surface of the semiconductor and a side surface of the semiconductor. The second conductor has a region facing the semiconductor and a second region in contact with the semiconductor, and the first region The first region and the second region are semiconductor devices that do not overlap with each other.

[0013] (2) One aspect of the present invention comprises a semiconductor, an insulator, a first conductor, a second conductor, and a third conductive A semiconductor device having a body and a semiconductor, wherein the upper surface of the semiconductor has a region in contact with an insulator, and the semiconductor The side of the body has a region that is in contact with the insulator, and the first conductor is connected to the first conductor via the insulator. The semiconductor and the material have a first region that overlaps with each other, and the first region is the region facing the upper surface of the semiconductor. The second conductor has a region facing the side surface of the semiconductor, and the second conductor has a second region in contact with the semiconductor. The third conductor has a third region in contact with the semiconductor, and the second region and the third region The two regions have overlapping areas, and the first region and the second region do not overlap. It is a body device.

[0014] (3) One aspect of the present invention comprises a semiconductor, a first insulator, a second insulator, a first conductor, and a second A semiconductor device having a conductor and a semiconductor, wherein the semiconductor has a region in contact with a first insulator and a second The first conductor has a first region which does not overlap with the first conductor and the second conductor. It has a second region in which the first conductor and the semiconductor overlap each other via an insulator, and the second conductor The current has a third region in contact with the semiconductor, and the second insulator has a region in contact with the first region. It is a semiconductor device.

[0015] (4) One aspect of the present invention is the second insulator having a higher dielectric constant than the first insulator (3) It is a semiconductor device.

[0016] (5) One aspect of the present invention is a first conductor on a semiconductor and a second conductor on a semiconductor. The semicircular region described in any one of (1) to (4) has a region in which the distance between them is 30 nm or less. It is a conductive device.

[0017] (6) One aspect of the present invention is a semiconductor having a first layer and a second layer, wherein the electron affinity of the first layer and , the electron affinity of the second layer and the half described in any one of (1) to (5) which differs in size It is a conductive device.

[0018] (7) One aspect of the present invention is a semiconductor having indium and oxygen, any of (1) to (6) This is a semiconductor device as described in item 1.

[0019] (8) One aspect of the present invention is a display device, a battery or a sensor, and any of (1) to (7) The electronic device has the semiconductor device described in (1). [Effects of the Invention]

[0020] It is possible to provide transistors with excellent electrical characteristics, or transistors with low current when not conducting. A transistor can be provided that has a large current when conducting. It may be provided. Or, it may be possible to provide a semiconductor device having said transistor. Yes, it is possible. Or, it is possible to provide a highly integrated semiconductor device. Or, a robust semiconductor We can provide a device, or we can provide a novel semiconductor device.

[0021] Furthermore, the description of these effects does not preclude the existence of other effects. The embodiment does not need to have all of these effects. Other effects are described in the specification. This will become clear from the descriptions in the drawings and claims, and the specification, drawings, and claims will be clear from the description, drawings, and claims. It is possible to extract other effects from any of these descriptions. [Brief explanation of the drawing]

[0022] [Figure 1] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 2] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 3] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 4] A figure showing the calculation results of the electrical characteristics of a transistor according to one aspect of the present invention. [Figure 5] A figure showing the calculation results of the electrical characteristics of a transistor according to one aspect of the present invention. [Figure 6]A figure showing the calculation results of the electrical characteristics of a transistor according to one aspect of the present invention. [Figure 7] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 8] A cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 9] A cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 10] A cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 11] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 12] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 13] A cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 14] A cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 15] A top view and a cross-sectional view showing a transistor according to one aspect of the present invention. [Figure 16] A cross-sectional view of a semiconductor device according to one aspect of the present invention. [Figure 17] Circuit diagram of a semiconductor device according to one aspect of the present invention. [Figure 18] A circuit diagram of a storage device according to one aspect of the present invention. [Figure 19] A block diagram of an RF tag according to one aspect of the present invention. [Figure 20] A figure showing an example of the use of an RF tag according to one aspect of the present invention. [Figure 21] A block diagram showing a CPU according to one aspect of the present invention. [Figure 22] A circuit diagram of a memory element according to one aspect of the present invention. [Figure 23] A top view and circuit diagram of a display device according to one aspect of the present invention. [Figure 24] A diagram illustrating a display module according to one aspect of the present invention. [Figure 25] A diagram showing an electronic device according to one aspect of the present invention. [Figure 26]A diagram showing an electronic device according to one aspect of the present invention. [Figure 27] High-resolution TEM image with Cs correction in cross-section of CAAC-OS, and schematic cross-sectional diagram of CAAC-OS. [Figure 28] High-resolution TEM image with Cs correction in the plane of CAAC-OS. [Figure 29] A diagram illustrating the XRD structural analysis of CAAC-OS and single-crystal oxide semiconductors. [Figure 30] A figure showing the electron diffraction pattern of CAAC-OS. [Figure 31] A diagram showing the changes in the crystalline structure of In-Ga-Zn oxide due to electron irradiation. [Figure 32] A cross-sectional view showing the stacking of semiconductors, and a diagram showing the band structure. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is described below. It is not limited to the above, and its form and details can be easily changed in various ways, as can be easily seen by those skilled in the art. It is understood that the present invention is to be interpreted as being limited to the embodiments described below. No. Furthermore, when explaining the structure of the invention using drawings, the same reference numerals may refer to different things. It is used consistently across drawings. Furthermore, when referring to similar items, the hatch pattern is the same. Furthermore, sometimes no symbol is assigned.

[0024] Note that in the diagram, the size, thickness of the film (layer), or area has been exaggerated for clarity. They may exist.

[0025] Furthermore, voltage is defined by a certain potential and a reference potential (e.g., ground potential (GND) or source potential). It often refers to the potential difference between two points. Therefore, it is possible to rephrase voltage as potential. .

[0026] The ordinal numbers "1st" and "2nd" are used for convenience only and do not necessarily indicate the order of processes or layering. It does not indicate order. Therefore, for example, "the first" could be "the second" or "the third." It can be explained by substituting it as appropriate. Also, the ordinal numbers and The ordinal numbers used to specify one aspect of the present invention may not always coincide.

[0027] Furthermore, even when the term "semiconductor" is used, if, for example, its conductivity is sufficiently low, it can be referred to as an "insulator." They may have the following characteristics. Also, the boundary between "semiconductors" and "insulators" is ambiguous, and strictly speaking... In some cases, it may be impossible to distinguish between them. Therefore, the term "semiconductor" as used in this specification is used interchangeably with "insulator". In some cases, it can be rephrased. Similarly, the term "insulator" as used herein may be interpreted as "semiconductor." In some cases, this can be rephrased as "...".

[0028] Furthermore, even when the term "semiconductor" is used, if, for example, its conductivity is sufficiently high, it can be referred to as a "conductor." They may have certain characteristics. Also, the boundary between "semiconductors" and "conductors" is ambiguous, and strictly speaking... In some cases, it may be impossible to distinguish between them. Therefore, the term "semiconductor" as used in this specification is used interchangeably with "conductor". In some cases, it can be rephrased. Similarly, the term "conductor" as used herein means "semiconductor." In some cases, this can be rephrased as "...".

[0029] Furthermore, semiconductor impurities refer to components other than the main components that make up the semiconductor, for example, concentration. Elements present in less than 0.1 atomic percent are considered impurities. The presence of impurities can, for example, affect semiconductors. The formation of Density of State (DOS) in the body, and carrier mobility In some cases, the quality may decrease, or the crystallinity may decrease. In the case of semiconductors, impurities that alter the properties of semiconductors include, for example, Group 1 elements and Group 2 elements. These include elements, Group 14 elements, Group 15 elements, and transition metals other than the main component, and in particular, for example, Hydrogen (also found in water), lithium, sodium, silicon, boron, phosphorus, carbon, nitrogen These are some examples. In the case of oxide semiconductors, for example, the inclusion of impurities such as hydrogen can form oxygen vacancies. This can occur. Also, if the semiconductor is silicon, impurities can change the properties of the semiconductor. In terms of substances, for example, Group 1 elements (excluding oxygen and hydrogen), Group 2 elements, Group 13 elements, and Group 15 elements. There are group elements, etc.

[0030] In the embodiments described below, the case where the semiconductor is an oxide semiconductor will be explained. However, it is not limited to this. For example, as semiconductors, polycrystalline structures, single-crystal structures, etc. Silicon, germanium, etc. may be used. Alternatively, strained silicon or other materials may be used. A semiconductor that can be used may be used. Alternatively, gallium arsenide, which is applicable to HEMTs, may be used as the semiconductor. Aluminum gallium arsenide, indium gallium arsenide, gallium nitride, indium phosphide Silicon germanium and other materials may also be used. By using these semiconductors, high-speed operation is possible. This can be made into a transistor suitable for doing so.

[0031] In this specification, when it is stated that A has a region of concentration B, for example, A If the total concentration in the depth direction of a region is B, then the concentration in the depth direction of a certain region of A If the average value of degrees is B, then the median concentration in the depth direction in a certain region of A is B. In total, if the maximum concentration in the depth direction in a certain region of A is B, then in a certain region of A If the minimum value of the concentration in the depth direction is B, then the concentration in the depth direction converges in a certain region of A. If the value is B, then the concentration in the region where a reliable value of A itself can be obtained through measurement is B. This includes cases such as

[0032] Furthermore, in this specification, A has an area of ​​size B, length B, thickness B, width B, or distance B. When describing something as "doing," for example, the overall size, length, thickness, and width of a certain area of ​​A, Or, if distance B, then size, length, thickness, width, or distance in a region of A. If the average value is B, then the size, length, thickness, width, or distance of a region A is If the median is B, then the maximum size, length, thickness, width, or distance in a region of A. When the maximum value is B, the minimum size, length, thickness, width, or distance in a region of A. If the value is B, it represents the converged size, length, thickness, width, or distance of a region A. If B is the case, then the size, length, and thickness in the region where a reliable value of A itself can be obtained through measurement. This includes cases where the width, length, or distance is B.

[0033] <Relationship between transistor structure and electrical characteristics> The relationship between transistor structure and electrical characteristics is shown in Figures 1 to 6, based on calculations. We will explain using this method.

[0034] Figure 1(A) is an example of a top view of a transistor structure A according to one aspect of the present invention. Figure 1(B) shows an example of a cross-sectional view corresponding to the dashed lines A1-A2 and A3-A4 in A). As shown in Figure 1(A). Note that in Figure 1(A), some parts such as insulators have been omitted for the sake of clarity. show.

[0035] The transistor structure A shown in Figure 1(B) consists of an insulator 102 and a semiconductor 10 on the insulator 102. 6a, semiconductor 106b on semiconductor 106a, and a semiconductor having a region in contact with semiconductor 106b. Semiconductor 116a and conductor 116b, and on conductor 116a, on conductor 116b and semiconductor Located on body 106b, the top and side surfaces of semiconductor 106b, and the side surfaces of semiconductor 106a A semiconductor 106c having a region in contact with the insulator 102 and an insulating layer on the semiconductor 106c. Body 112 and semiconductor 106a, semiconductor 106b and semiconductor 10 located on the insulator 112 A conductor 104 having a region that overlaps with 6c, and on the insulator 102, on the conductor 116a, The device has an insulator 108 on the conductor 116b, on the semiconductor 106c, and on the conductor 104. Furthermore, semiconductor 106b is located in the region where it overlaps with conductor 116a and conductor 116b. They have regions 124a and 124b, respectively. Insulators and conductors are also called semiconductor layers, insulating layers, and conductive layers, respectively.

[0036] In transistor structure A, the insulator 102 functions as a base insulator. The insulator 112 functions as a gate insulator. The conductor 104 also functions as a gate electrode. It has the function of being a source electrode and It functions as a drain electrode. In addition, regions 124a and 124b are sources. It functions as both a region and a drain region. In addition, a portion of semiconductor 106b is a channel. It has the function of a formation region. In addition, semiconductor 106a and semiconductor 106c are semiconductors The channel-forming region contained in 106b is separated from the insulators 102 and 112. It has a function.

[0037] Furthermore, in transistor structure A, the width of the conductor 104 in the A1-A2 cross section is Lg, The region or gap between region 124a and region 124b is called L. Also, the A1-A2 section. The region or gap between the conductor 104 and region 124a is called Loff1, and the conductor 10 The region or gap between 4 and region 124b is called Loff2. Also, in the A3-A4 section... The width of semiconductor 106b in the A3-A4 cross section is called W. The height from the bottom surface to the bottom surface of semiconductor 106b is called h. In semiconductor 106b, the conductor If we define the channel-forming region as only the region that overlaps with 104, then Loff1 and Loff 2 represents the offset region.

[0038] Furthermore, Figure 2(A) is an example of a top view of a transistor structure B according to one embodiment of the present invention. Figure 2(A) shows an example of a cross-sectional view corresponding to the dashed lines B1-B2 and B3-B4. This is shown in 2(B). Note that in Figure 2(A), some parts such as insulators are omitted for ease of understanding. This is an abbreviated version.

[0039] The transistor structure B consists of an insulator 102, a semiconductor 106a on the insulator 102, and a semiconductor 1 A semiconductor 106b on 06a and a conductor 116a having a region in contact with the semiconductor 106b The conductor 116b and the conductor 116a, the conductor 116b and the semiconductor 106b The semiconductor 106b has a region that is in contact with the upper surface and side surface of semiconductor 106b, as well as the side surface of semiconductor 106a. The semiconductor 106c, on the insulator 102, on the semiconductor 106c, on the conductor 116a and the conductor An insulator 112 on the electric body 116b, and semiconductors 106a and 10 on the insulator 112. A conductor 104 having regions that overlap with 6b and semiconductor 106c, and an insulator 102 The device has an insulator 108 on the conductor 116a, on the conductor 116b, and on the conductor 104. Furthermore, semiconductor 106b is located in a region that overlaps with conductor 116a and conductor 116b. These regions have regions 124a and 124b, respectively.

[0040] In transistor structure B, the insulator 102 functions as a base insulator. The insulator 112 functions as a gate insulator. The conductor 104 also functions as a gate electrode. It has the function of being a source electrode and It functions as a drain electrode. In addition, regions 124a and 124b are sources. It functions as both a region and a drain region. In addition, a portion of semiconductor 106b is a channel. It has the function of a formation region. In addition, semiconductor 106a and semiconductor 106c are semiconductors The channel-forming region contained in 106b is separated from the insulators 102 and 112. It has a function.

[0041] Furthermore, in transistor structure B, the width of the conductor 104 in the B1-B2 cross section is Lg, The distance between region 124a and region 124b is called L. Also, the conductor in the B1-B2 cross section. The region or gap between 104 and region 124a is called Loff1, and the conductor 104 and region 1 The region or gap between 24b and 24b is called Loff2. Also, in the B3-B4 section... The width of semiconductor 106b is called W. Also, the bottom surface of conductor 104 in the B3-B4 cross section The height from the semiconductor 106b to the bottom surface is called h. In semiconductor 106b, the conductor 104 If we define the channel-forming region as only the regions that overlap with each other, then Loff1 and Loff2 are This becomes a fset region.

[0042] Therefore, transistor structure B has a different shape from transistor structure A insulator 112. .

[0043] Furthermore, Figure 3(A) is an example of a top view of a transistor structure C according to one embodiment of the present invention. Figure 3(A) shows an example of a cross-sectional view corresponding to the dashed lines C1-C2 and C3-C4. This is shown in 3(B). Note that in Figure 3(A), some parts such as the insulator have been omitted for ease of understanding. This is an abbreviated version.

[0044] The transistor structure C consists of an insulator 102, a semiconductor 106a on the insulator 102, and a semiconductor 1 A semiconductor 106b on 06a and a conductor 116a having a region in contact with the semiconductor 106b The conductor 116b and the conductor 116a, the conductor 116b and the semiconductor 106b The semiconductor 106b has a region that is in contact with the upper surface and side surface of semiconductor 106b, as well as the side surface of semiconductor 106a. The semiconductor 106c, on the insulator 102, on the semiconductor 106c, on the conductor 116a and the conductor An insulator 112 on the electric body 116b, and semiconductors 106a and 10 on the insulator 112. 6b has regions that overlap with semiconductor 106c, conductor 116a, and conductor 116b. The conductor 104, on the insulator 102, on the conductor 116a, on the conductor 116b and the conductor It has an insulator 108 on 104 and, . The semiconductor 106b has a conductor 116a and Regions 124a and 124b are located in the region overlapping with the conductor 116b.

[0045] In the transistor structure C, the insulator 102 functions as a base insulator. The insulator 112 functions as a gate insulator. The conductor 104 also functions as a gate electrode. It has the function of being a source electrode and It functions as a drain electrode. In addition, regions 124a and 124b are sources. It functions as both a region and a drain region. In addition, a portion of semiconductor 106b is a channel. It has the function of a formation region. In addition, semiconductor 106a and semiconductor 106c are semiconductors The channel-forming region contained in 106b is separated from the insulators 102 and 112. It has a function.

[0046] Furthermore, in the transistor structure C, region 124a and region 124 in the C1-C2 cross section The distance between b is called L. Also, the conductor 104 and region 124a in the C1-C2 cross section The overlapping regions or their widths are called Lov1, and the conductor 104 and region 124b overlap each other. The region or its width is called Lov2. Also, the semiconductor 106b in the C3-C4 cross section The width is referred to as W. Also, from the bottom surface of the conductor 104 in the C3-C4 cross section, semiconductor 106b The height to the bottom surface is called h. In semiconductor 106b, region 124a and region 124b If the region overlapping with the conductor 104 between them is considered the channel-forming region, then Lov1 and Lov2 This is the overlapping region.

[0047] Therefore, transistor structure C is a combination of transistor structure A and transistor structure B, The shape of the conductor 104 is different. Specifically, transistor structure A and transistor structure B has a region in which conductors 116a and 116b and conductor 104 overlap each other. Although it is not a structure, the transistor structure C has conductive materials 116a and 116b and conductive materials The structure has regions that overlap with body 104.

[0048] Here, structures having an offset region (transistor structure A and transistor structure B) This is because the on-current (Ion and It is also indicated.) is presumed to become smaller. This is because the offset region of the transistor This is due to resistance. On the other hand, a structure with an overlapping region has an offset region. Parasitic capacitance is larger than that of structures with a region. Note that on current refers to the gate of a transistor. When a voltage exceeding the threshold voltage is applied to the electrode, the current flowing between the source and drain is... cormorant.

[0049] Next, regarding the transistor structures A, B, and C described above... The change in electrical characteristics due to the difference in L is then evaluated by calculation. Note that the calculation will use syn We will use the Sentaurus from psys and employ a three-dimensional structure.

[0050] The conditions used in the calculations are shown in the table below.

[0051] [Table 1]

[0052] Note that Eg is the energy gap, Nc is the effective density of states in the conduction band, and Nv is the effective density of states in the valence band. This shows the density of states.

[0053] Furthermore, with h set to 20nm and W set to 40nm, transistor structure A and transistor structure B So, Lg is set to 60nm, and in the transistor structure C, Lov is set to 20nm. And set L to 60nm, 80nm, 100nm, 120nm, 140nm or 260nm The electrical characteristics are then calculated. In addition, in transistor structure A and transistor structure B Loff1 and Loff2 are the values ​​obtained by subtracting Lg from L and dividing by 2. In terms of wavelengths, these are 0nm, 10nm, 20nm, 30nm, 40nm, or 100nm. The lengths of semiconductors 106a and 106b in the L direction are 120 nm in L. This is the added value.

[0054] The calculated gate voltage (also denoted as Vg) - drain current (also denoted as Id) The characteristics are shown in Figure 4. In Figure 4, the dotted line represents transistor structure A, and the dashed line represents the transistor structure A. The solid line shows transistor structure B, and the solid line shows transistor structure C. Also, the Vg-Id characteristics shown in Figure 4. Therefore, the on-current and subthreshold swing value (also referred to as the S value) in each L are obtained. The following is derived and shown in Figure 5. Note that the on-current is calculated by multiplying the drain voltage (also denoted as Vd) by 1. Let V be the threshold voltage (also written as Vth), and the gate voltage be the voltage obtained by adding 1.5V to the threshold voltage. This shows the drain current when the gate voltage is 2.7V. The stroke swing value is the value when the drain voltage is 1V or 0.1V. show.

[0055] Figure 6 shows the relationship between the on-current of transistor structure C and transistor structures A and C. This shows the ratio of the on-currents of transistor structure B. As L increases, the on-current compared to transistor structure C increases. The gap is widening.

[0056] On the other hand, in transistor structure A, even if L is 140 nm, the 8 in transistor structure C It was shown that an on-current of approximately 0% can be obtained. Furthermore, even when L is 120 nm, the transistor It was shown that an on-current of approximately 90% of that of the DISTA structure C could be obtained. Also, L was 100 nm. Even so, it was shown that an on-current of approximately 98% of that of the transistor structure C could be obtained. Transistor structure A has a higher on-current than transistor structure C when L is 80 nm or less. It was shown that the value increases. Therefore, if the offset region is less than or equal to a certain size For example, there is almost no difference in on-current between transistor structure A and transistor structure C. It was found that, in transistor structure A, Loff1 and Loff2 When the wavelength is 40 nm or less, preferably 30 nm or less, and more preferably 20 nm or less, This demonstrates that transistors with high on-current and low parasitic capacitance can be realized.

[0057] Furthermore, in transistor structure B, even if L is 120 nm, the 8 in transistor structure C It was shown that an on-current of approximately 0% can be obtained. Furthermore, even when L is 100 nm, the transistor... It was shown that an on-current of approximately 90% of that of the zista structure C can be obtained. Also, when L is 80 nm It was shown that even with this, an on-current of about 95% of the transistor structure C can be obtained. So, if the offset region is below a certain size, the transistor structure B and the transistor It was found that there was almost no difference in on-current compared to the sta structure C. Specifically, In the zista structure C, Loff1 and Loff2 are 30 nm or less, preferably 20 nm. When the wavelength is less than or equal to m, and more preferably less than or equal to 10 nm, the on-current is high and the parasitic capacitance is low. This shows that transistors can be realized.

[0058] In transistor structures A and B, as well as in transistor structure C, The reason why virtually no difference in on-current was obtained is due to the fluting by the gate electrode (conductor 104). The contribution of the fringe field is suggested. That is, carriers are also present in the offset region due to the fringe field. This may have induced a reaction that did not result in significant resistance.

[0059] The presence of a fringe field contribution is evident when comparing transistor structure A and transistor structure B. This can be understood by doing so. Transistor structure A is different from transistor structure B in that the insulator 112 is It differs in that it does not have a facet region. Also, insulator 108 is higher than insulator 112. It has relative permittivity. Therefore, the induction of carriers into the offset region by the fringe field is The increase likely suppressed the decrease in on-current. It can be seen that the fringe field contributes to the on-current of a transistor with a certain frequency range.

[0060] Furthermore, the contribution of the fringe field increases as the thickness of the conductor 104 increases. Therefore, the conductor 10 The thicker 4 is, the better. For example, the thickness of the conductor 104 should be 20 nm or more, preferably 30 nm. The wavelength should be m or greater, more preferably 50 nm or greater, and more preferably 100 nm or greater.

[0061] Furthermore, in transistor structure A, the contribution of the fringe field is due to the semiconductor 106c and the insulating The higher the relative permittivity of material 108, the higher it becomes. Therefore, semiconductor 106c and insulator 108 A higher relative permittivity is preferable. For example, a relative permittivity of semiconductor 10⁶c of 10⁶c is preferable. The value should be 15 or more, more preferably 20 or more, and more preferably 25 or more. For example, the relative permittivity of the insulator 108 is 5 or more, preferably 10 or more, and more preferably 1 It should be 5 or more, more preferably 20 or more.

[0062] Furthermore, in transistor structure B, the contribution of the fringe field is due to semiconductor 106c and insulator 1 The relative permittivity of semiconductor 12 and insulator 108 increases as their relative permittivity increases. Therefore, semiconductor 106c, insulator It is preferable that the relative permittivity of the edge body 112 and the insulator 108 is high. For example, the dielectric constant of the insulator 112 The relative permittivity is 3 or more, preferably 4 or more, more preferably 6 or more, and more preferably 10 or more. The above is sufficient. Also, for example, the relative permittivity of semiconductor 106c should be 10 or more, preferably 15 More preferably, it should be 20 or more, and more preferably 25 or more. Also, for example The dielectric constant of the insulator 108 is 5 or more, preferably 10 or more, and more preferably 15 or more. More preferably, it should be 20 or more.

[0063] Furthermore, transistor structures A and B are affected by the electric field of the conductor 104. The semiconductor 106b can be electrically surrounded (by the electric field generated from the conductor, the semiconductor The structure of a transistor that electrically surrounds the body is called a surrounded channel. This is called an s-channel structure. Therefore, the entire (bulk) semiconductor 106b contains A channel may be formed. In an s-channel structure, the source of the transistor - It is possible to pass a large current between the drains and increase the current during conduction (on-current). ru.

[0064] Due to the s-channel structure, the contribution of the fringe field is also extended to the side of semiconductor 106b. Therefore, the s-channel structure extends to the offset region due to the fringe electric field. This structure is clearly suitable for reducing resistance.

[0065] <Transistor Structure 1> Figure 7(A) is an example of a top view of a transistor according to one embodiment of the present invention. An example of a cross-sectional view corresponding to the dashed lines D1-D2 and D3-D4 is shown in Figure 7(B). Note that in Figure 7(A), some parts, such as the insulator, are omitted for ease of understanding.

[0066] The transistors shown in Figures 7(A) and 7(B) have a conductor 413 on the substrate 400 and a base An insulator 402 having protrusions on the plate 400 and on the conductor 413, and on the protrusions of the insulator 402 semiconductor 406a, semiconductor 406b on semiconductor 406a, and semiconductor on semiconductor 406b 406c, an insulator 412 on the semiconductor 406c, a conductor 404 on the insulator 412, and It has an insulator 408 on the edge 402, on the semiconductor 406b, and on the conductor 404. Here, conductor 413 is used as part of the transistor, but it is not limited to this. For example, the conductor 413 may be a component independent of the transistor.

[0067] Furthermore, semiconductor 406b functions as a channel formation region for the transistor. Conductor 404 is the first gate electrode of the transistor (also called the front gate electrode). It functions as such. Also, the conductor 413 is the second gate electrode (battery) of the transistor. It also functions as a gate electrode. In addition, the insulator 408 serves as a barrier layer. It has the function of blocking oxygen and / or hydrogen. The insulator 408 has the function of blocking oxygen and / or hydrogen. It has the ability. Or, the insulator 408 is, for example, semiconductor 406a or / and semiconductor 4 It has a higher ability to block oxygen and / or hydrogen than O6c.

[0068] The transistor is connected to the conductor 424a via the conductors 426a and 426b, etc. It is also acceptable for each to be electrically connected to the conductor 424b. And the conductor 426b is an insulator 408, an insulator 418 on the insulator 408, and an insulator 4 The insulator 428 on 18 and the openings provided therein, respectively, are the sources of the transistors. It is electrically connected to the region and the drain region. Also, conductor 424a and conductor 424 b, for example, functions as wiring in a semiconductor device.

[0069] Furthermore, in the D3-D4 cross section, semiconductor 406c has at least the upper surface of semiconductor 406b It has a region that is in contact with the side surface. Furthermore, the conductor 404 has a semiconductor in the D3-D4 cross section. The body 406c and the insulator 412 face the top and side surfaces of the semiconductor 406b. The conductor 413 faces the lower surface of the semiconductor 406b via the insulator 402. 402 does not need to have a protrusion. Furthermore, it does not need to have semiconductor 406c. Furthermore, it is not necessary to have an insulator 408.

[0070] In Figure 7(B), the transistor has a portion that is in contact with the conductor 426a and a portion that is in contact with the semiconductor 406b. Even if the region between the conductor 404 and the overlapping portion has high resistance, the fringe of the conductor 404 Because the resistance in that region is reduced by the electric field, a decrease in the transistor's on-current is less likely to occur. It has a complex structure. For details on the fringe field, please refer to the explanations in Figures 1 to 6.

[0071] However, the region in question may be a region with lower resistance than the other regions. For example, inert elements such as noble gases, elements with high bonding energy with oxygen, and elements with high bonding energy with oxygen. A region containing highly reactive elements or elements that react with oxygen to form stable oxides. It is also acceptable if the region contains, for example, helium, boron, carbon, nitrogen, neon, and magnesium. Zium, aluminum, silicon, phosphorus, argon, calcium, titanium, vanadium, Chromium, manganese, iron, cobalt, germanium, krypton, strontium, yt Rium, zirconium, niobium, molybdenum, xenon, lanthanum, cerium, neodymium , a region comprising one or more selected from hafnium, tantalum, or tungsten That is also acceptable. For example, if the region contains the above-mentioned elements in 5 × 10 19 atoms / cm 3 That's all good Mashiku is 1 x 10 20 atoms / cm 3 More preferably 2 × 10 20 Atom s / cm 3 The above is more comfortable 5x10 20 atoms / cm 3 The region including the above That is also acceptable. In this specification, the aforementioned elements may also be referred to as impurities.

[0072] In the following, semiconductors 406a, 406b, and 406c are referred to as oxide semiconductors. The following will explain the case where semiconductor 406a, semiconductor 406b, and semiconductor 406c The semiconductor may be one other than an oxide semiconductor.

[0073] Note that insulator 402 is an insulator containing excess oxygen.

[0074] For example, an insulator containing excess oxygen is an insulator that has the function of releasing oxygen through heat treatment. For example, silicon oxide containing excess oxygen releases oxygen through heat treatment, etc. It is silicon oxide that can do so. Therefore, in the insulator 402, oxygen can move through the film is an insulator. That is, the insulator 402 may be an insulator having oxygen permeability. For example, the insulator 402 may be an insulator having higher oxygen permeability than the semiconductor 406a.

[0075] An insulator containing excess oxygen may have a function of reducing oxygen deficiency in the semiconductor 406b. In the semiconductor 406b, oxygen deficiency forms DOS and becomes a hole trap or the like. Also when hydrogen enters the site of oxygen deficiency, electrons as carriers may be generated. Therefore, by reducing oxygen deficiency in the semiconductor 406b, stable electrical characteristics can be imparted to the transistor.

[0076] Here, an insulator that releases oxygen by heat treatment releases 1 × 10 or more, 1 × 10 18 atoms / cm 3 or more, 1 × 10 19 atoms / cm 3 or more, or 1 × 10 20 atoms / cm 3 or more of oxygen (in terms of the number of oxygen atoms) within the surface temperature range of 100°C or higher and 70

[0077] Here, the method for measuring the amount of oxygen released using TDS analysis will be described below.

[0078] The total amount of gas released when the measurement sample is subjected to TDS analysis is proportional to the integral value of the ionic strength of the released gas. And by comparison with a standard sample, the total amount of gas released can be calculated.

[0079] For example, the TDS analysis results of a silicon substrate containing hydrogen with a predetermined density as a standard sample, and From the TDS analysis results of the measured sample, the amount of oxygen molecules released from the measured sample (N O2 ) is the formula shown below This can be determined by the following: Here, the gas detected with a mass-to-charge ratio of 32 obtained by TDS analysis Assume that all of these originate from oxygen molecules. The mass-to-charge ratio of CH3OH is 32, but the existence of We will not consider this here as it has a low probability. Also, the isotope of the oxygen atom with mass number 17 Regarding oxygen atoms and oxygen molecules containing oxygen atoms with a mass number of 18, the abundance in nature The rate is so small that it will not be considered.

[0080] N O2 =N H2 / S H2 ×S O2 ×α

[0081] N H2 This value represents the density of hydrogen molecules detached from the standard sample. H2 The standard test This is the integral value of the ionic intensity when the material is analyzed by TDS. Here, the reference value of the standard sample is N H2 / S H2 Let's assume that. S O2 This is the integral value of the ionic intensity when the sample is subjected to TDS analysis. Yes, it exists. α is a coefficient that affects the ionic strength in TDS analysis. For details of the formula shown above, see below. For further information, please refer to Japanese Patent Publication No. 6-275697. The amount of oxygen released is determined by the Electronics Science Using the EMD-WA1000S / W temperature-controlled desorption analyzer manufactured by Gaku Corporation, the standard sample was: For example, 1 x 10 16 atoms / cm 2 Measurements are taken using a silicon substrate containing hydrogen atoms. .

[0082] Furthermore, in TDS analysis, some oxygen is detected as oxygen atoms. Oxygen molecules and oxygen atoms The ratio of these can be calculated from the ionization rate of oxygen molecules. Note that α above represents the oxygen component. Because it includes the ionization rate of the oxygen atom, by evaluating the amount of oxygen molecule released, the amount of oxygen atom released can be determined. Even if it's there, it can still be estimated.

[0083] Note N O2 This is the amount of oxygen molecules released. The amount released when converted to oxygen atoms is the amount of oxygen molecules. This will be twice the amount released.

[0084] Alternatively, insulators that release oxygen through heat treatment may contain peroxide radicals. Specifically, the spin density caused by peroxide radicals is 5 × 10⁻⁶ 17 spins / cm 3 This means the above. Furthermore, for insulators containing peroxide radicals, the g value in ESR is 2. It may also have asymmetrical signals in the vicinity of 01.

[0085] Alternatively, an insulator containing excess oxygen is silicon oxide (SiO₂) with excess oxygen. X (X>2) It may be present. Silicon oxide (SiO₂) with excess oxygen. X (X>2)) represents the number of silicon atoms It contains more than twice the amount of oxygen atoms per unit volume. The number of electrons and oxygen atoms can be determined by Rutherford backscattering (RBS). These are values ​​measured by scalar-scattering spectrometry.

[0086] Figure 7(B) shows that the electric field of the conductor 404 electrically surrounds the semiconductor 406b. It is a possible s-channel structure. Therefore, between the source and drain of the transistor... It can handle large currents and increase the current during conduction (on-current).

[0087] Because it provides a high on-current, the s-channel structure is used in miniaturized transistors. It can be said to be a suitable structure. Because the transistor can be miniaturized, it is a semiconductor having the transistor. The device can be made into a highly integrated, high-density semiconductor device. For example, The lunger has a channel length of preferably 40 nm or less, more preferably 30 nm or less. More preferably, the region has a range of 20 nm or less, and the transistor has a preferred channel width. The region is 40 nm or less, more preferably 30 nm or less, and more preferably 20 nm or less. It has.

[0088] Note that channel length refers to, for example, the length of the semiconductor (or transistor) in a top view of a transistor. When the zista is in the ON state, the part of the semiconductor through which current flows and the gate electrode overlap each other. In the region where the channel is formed, the source (source region or source power) This refers to the distance between the electrode and the drain (drain region or drain electrode). In transistors, the channel length is not necessarily the same across all regions. That is, The channel length of a transistor may not be fixed to a single value. Therefore, this specification In the book, the channel length is any one value, the maximum value, in the region where the channel is formed. Use the minimum or average value.

[0089] Channel width refers to, for example, the state when the semiconductor (or transistor) is ON in the top view. A region or channel where the part of the semiconductor through which current flows and the gate electrode overlap each other. This refers to the length of the portion where the source and drain face each other in the region where the filter is formed. Note that the channel width in a single transistor is not necessarily the same across all regions. No. In other words, the channel width of a single transistor may not be fixed to a single value. Therefore, in this specification, the channel width is any one of the regions in which the channel is formed. This value is the maximum, minimum, or average value.

[0090] Furthermore, depending on the transistor structure, the channel may actually be formed in the region where the channel is formed. The channel width (hereinafter referred to as the effective channel width) and the top view of the transistor are shown. The channel width (hereinafter referred to as the apparent channel width) may differ from the actual channel width. For example, In transistors with a three-dimensional structure, the effective channel width is shown in the top view of the transistor. The apparent channel width shown in [the relevant section] becomes larger, and its effect can no longer be ignored. In some cases, such as in transistors with a fine and three-dimensional structure, the upper surface of the semiconductor may be The ratio of channel regions formed on the side surface of the semiconductor to the ratio of channel regions formed In some cases, the apparent channel width shown in the top view may become larger. However, the effective channel width actually formed is larger.

[0091] By the way, in transistors with a three-dimensional structure, the effective channel width is measured Estimation can be difficult in some cases. For example, estimating the effective channel width from the design value. In order to do this, it is necessary to assume that the shape of the semiconductor is known. If this information is not precisely known, it is difficult to accurately measure the effective channel width.

[0092] Therefore, in this specification, in the top view of a transistor, the semiconductor and the gate electrode are relative to each other. The length of the portion where the source and the drain face each other in the overlapping region, which is apparently the channel width, may be referred to as the "surrounded channel width (SCW: Surrounded Channe l Width)". Also, in this specification, when simply described as the channel width it may refer to the surrounded channel width or the apparent channel width. Or in this specification, when simply described as the channel width, it may refer to the effective channel width occasionally. Note that the channel length, channel width, effective channel width, apparent channel width, surrounded channel width, etc. can be determined by obtaining a cross-sectional TEM image, etc. and analyzing the image etc.

[0093] In addition, when calculating the field-effect mobility of a transistor, the current value per channel width, etc., the surrounded channel width may be used for calculation. In that case, it may take a different value from the case where the effective channel width is used for calculation.

[0094] Also, a voltage lower or higher than the source electrode voltage may be applied to the conductor 413 to vary the threshold voltage of the transistor in the positive or negative direction. For example, by varying the threshold voltage of the transistor in the positive direction, normally-off can be realized, where the transistor is in a non-conducting state (off state) even when the gate voltage is 0V. Note that the voltage applied to the conductor 413 may be variable or fixed. When making the voltage applied to the conductor 413 variable, a circuit for controlling the voltage may be electrically connected to the conductor 413 .

[0095] Next, semiconductors applicable to semiconductor 406a, semiconductor 406b, semiconductor 406c, etc. will be described. Hereinafter.

[0096] Semiconductor 406b is, for example, an oxide semiconductor containing indium. When semiconductor 406b contains indium, for example, the carrier mobility (electron mobility) increases. Also, it is preferable that semiconductor 406b contains element M. Element M is preferably aluminum, gallium, yttrium, tin, or the like. Elements applicable to other element M include boron, silicon, titanium, iron, nickel, germanium, yttrium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, etc. However, there may be cases where a plurality of the aforementioned elements are combined as element M. Element M is, for example, an element with a high binding energy with oxygen. For example, it is an element with a higher binding energy with oxygen than indium. Or, element M is, for example, an element having a function of increasing the energy gap of an oxide semiconductor. Also, it is preferable that semiconductor 406b contains zinc. The oxide semiconductor may be more likely to crystallize when it contains zinc. However, semiconductor 406b is not limited to an oxide semiconductor containing indium. Semiconductor 406b may be, for example, an oxide semiconductor that does not contain indium and contains zinc, such as zinc tin oxide, gallium tin oxide, an oxide semiconductor containing gallium, an oxide semiconductor containing tin, etc. Element M is, for example, an element with a high binding energy with oxygen. For example, it is an element with a higher binding energy with oxygen than indium. Or, element M is, for example, an element having a function of increasing the energy gap of an oxide semiconductor. Also, it is preferable that semiconductor 406b contains zinc. The oxide semiconductor may be more likely to crystallize when it contains zinc. However, semiconductor 406b is not limited to an oxide semiconductor containing indium. Semiconductor 406b may be, for example, an oxide semiconductor that does not contain indium and contains zinc, such as zinc tin oxide, gallium tin oxide, an oxide semiconductor containing gallium, an oxide semiconductor containing tin, etc. However, semiconductor 406b is not limited to an oxide semiconductor containing indium. Semiconductor 406b may be, for example, an oxide semiconductor that does not contain indium and contains zinc, such as zinc tin oxide, gallium tin oxide, an oxide semiconductor containing gallium, an oxide semiconductor containing tin, etc.

[0097] However, semiconductor 406b is not limited to an oxide semiconductor containing indium. Semiconductor 40 6b may be, for example, an oxide semiconductor that does not contain indium and contains zinc, such as zinc tin oxide, gallium tin oxide, an oxide semiconductor containing gallium, an oxide semiconductor containing tin, etc. Also, semiconductor 406b may be an oxide semiconductor containing gallium, an oxide semiconductor containing tin, etc. It doesn't matter.

[0098] Semiconductor 406b uses, for example, an oxide with a large energy gap. Semiconductor 406 The energy gap of b is, for example, 2.5 eV to 4.2 eV, preferably 2.8 eV. The voltage should be between eV and 3.8eV, and more preferably between 3eV and 3.5eV.

[0099] For example, semiconductors 406a and 406c contain oxygen other than that which constitutes semiconductor 406b. It is an oxide semiconductor composed of one or more elements, or two or more elements. Semiconductor 406 From among the elements other than oxygen that make up b, one or more, or two or more, semiconductor 406a and Since semiconductor 406c is formed, the interface between semiconductor 406a and semiconductor 406b, and the semiconductor At the interface between the conductor 406b and the semiconductor 406c, interface states are less likely to form.

[0100] Semiconductors 406a, 406b, and 406c contain at least indium. This is preferable. Furthermore, when semiconductor 406a is In-M-Zn oxide, the sum of In and M is When set to 100 atomic%, preferably In is less than 50 atomic and M is 50 Atomic% or more, more preferably less than 25 atomic% of In and 75 atomic% of M. The mic% must be 1% or higher. Also, when semiconductor 406b is In-M-Zn oxide, In and When the sum of M is 100 atomic%, preferably In is 25 atomic%, M is less than 75 atomic%, more preferably In is 34 atomic or more, and M is 6 It shall be less than 6 atomic%. Also, when semiconductor 406c is In-M-Zn oxide, When the sum of n and M is 100 atomic%, preferably In is 50 atomic. Less than %, M is 50 atomic% or more, and more preferably In is less than 25 atomic%. The M component is set to 75 atomic% or higher. Note that semiconductor 406c is the same type as semiconductor 406a. An oxide may be used.

[0101] The semiconductor 406b uses an oxide having a larger electron affinity than the semiconductor 406a and the semiconductor 406c. For example, as the semiconductor 406b, an oxide having an electron affinity larger by 0.07 eV or more and 1.3 eV or less, preferably 0.1 eV or more and 0.7 eV or less, more preferably 0.15 eV or more and 0.4 eV or less than those of the semiconductor 406a and the semiconductor 406c is used. Note that the electron affinity is the difference between the vacuum level and the energy of the lower end of the conduction band. For example, as the semiconductor 406b, an oxide having an electron affinity larger by 0.07 eV or more and 1.3 eV or less, preferably 0.1 eV or more and 0.7 eV or less, more preferably 0.15 eV or more and 0.4 eV or less than those of the semiconductor 406a and the semiconductor 406c is used. Note that the electron affinity is the difference between the vacuum level and the energy of the lower end of the conduction band. For example, as the semiconductor 406b, an oxide having an electron affinity larger by 0.07 eV or more and 1.3 eV or less, preferably 0.1 eV or more and 0.7 eV or less, more preferably 0.15 eV or more and 0.4 eV or less than those of the semiconductor 406a and the semiconductor 406c is used. Note that the electron affinity is the difference between the vacuum level and the energy of the lower end of the conduction band. Note that the electron affinity is the difference between the vacuum level and the energy of the lower end of the conduction band.

[0102] Note that indium gallium oxide has a small electron affinity and high oxygen blocking property. Therefore, it is preferable that the semiconductor 406c contains indium gallium oxide. The gallium atom ratio [Ga / (In + Ga)] is, for example, 70% or more, preferably 80% or more, more preferably 90% or more. Note that indium gallium oxide has a small electron affinity and high oxygen blocking property. Therefore, it is preferable that the semiconductor 406c contains indium gallium oxide. The gallium atom ratio [Ga / (In + Ga)] is, for example, 70% or more, preferably 80% or more, more preferably 90% or more. The gallium atom ratio [Ga / (In + Ga)] is, for example, 70% or more, preferably 80% or more, more preferably 90% or more.

[0103] At this time, when a gate voltage is applied, a channel is formed in the semiconductor 406b having a large electron affinity among the semiconductors 406a, 406b, and 406c. At this time, when a gate voltage is applied, a channel is formed in the semiconductor 406b having a large electron affinity among the semiconductors 406a, 406b, and 406c.

[0104] Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. The mixed region has a low interface level density. Therefore, the laminate of the semiconductors 406a, 406b, and 406c has a band structure in which the energy changes continuously (also referred to as a continuous junction) in the vicinity of each interface. Note that FIG. 32(A) shows the semiconductors 406a, 406b, Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. The mixed region has a low interface level density. Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. The mixed region has a low interface level density. Therefore, the laminate of the semiconductors 406a, 406b, and 406c has a band structure in which the energy changes continuously (also referred to as a continuous junction) in the vicinity of each interface. Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. The mixed region has a low interface level density. Therefore, the laminate of the semiconductors 406a, 406b, and 406c has a band structure in which the energy changes continuously (also referred to as a continuous junction) in the vicinity of each interface. Here, there may be a mixed region between the semiconductor 406a and the semiconductor 406b. Also, there may be a mixed region between the semiconductor 406b and the semiconductor 406c. The mixed region has a low interface level density. Therefore, the laminate of the semiconductors 406a, 406b, and 406c has a band structure in which the energy changes continuously (also referred to as a continuous junction) in the vicinity of each interface. Note that FIG. 32(A) shows the semiconductors 406a, 406b, This is a cross-sectional view of semiconductor 406c stacked in this order. Figure 32(B) is a cross-sectional view of Figure 32(A). This is the energy (Ec) at the lower end of the conduction band corresponding to the dashed line P1-P2 of semiconductor 40 This shows the case where the electron affinity of semiconductor 406c is greater than that of 6a. Also, Figure 32(C) shows the semiconductor This shows the case where the electron affinity of semiconductor 406c is smaller than that of material 406a.

[0105] At this time, the electrons are not in semiconductor 406a and semiconductor 406c, but in semiconductor 406b. It mainly moves through the middle. As mentioned above, at the interface between semiconductor 406a and semiconductor 406b The interface state density at the interface between semiconductor 406b and semiconductor 406c By lowering the value, the movement of electrons in semiconductor 406b is less inhibited, and The on-current of the inverter can be increased.

[0106] The on-current of a transistor can be increased as the factors that hinder electron movement are reduced. Yes, it is possible. For example, if there are no factors hindering electron movement, it is estimated that electrons will move efficiently. Electron movement is inhibited, for example, when the physical irregularities of the channel-forming region are large. It will be done.

[0107] To increase the on-current of the transistor, for example, the top or bottom surface of semiconductor 406b (The surface to be formed, in this case semiconductor 406a) within a 1 μm × 1 μm area, the mean square of the squares Root Mean Square (RMS) roughness is less than 1 nm, preferably 0.6 It should be less than nm, more preferably less than 0.5 nm, and more preferably less than 0.4 nm. Furthermore, the average surface roughness (also called Ra) in a 1 μm × 1 μm area is less than 1 nm. Preferably less than 0.6 nm, more preferably less than 0.5 nm, and more preferably 0.4 nm. It should be less than m. Also, the maximum height difference (also called PV) within a 1 μm × 1 μm area. .) is less than 10 nm, preferably less than 9 nm, more preferably less than 8 nm, The minimum is less than 7 nm. RMS roughness, Ra, and PV are measured by SII Nanotech. Measurements are taken using a scanning probe microscope system SPA-500 manufactured by Knology Co., Ltd. It is possible.

[0108] In oxide semiconductors, oxygen vacancies can degrade the electrical properties of transistors. Therefore, reducing oxygen deficiencies in the channel formation region is important for transistor safety. This is important for providing consistent electrical characteristics. On the other hand, the source region of the transistor and When an oxide semiconductor is used in the drain region, oxygen vacancies cause the oxide semiconductor to have low resistance. This can be done. Therefore, to increase the on-current of the transistor, an oxygen deficiency is created. There are times when it is better to do so.

[0109] For example, an oxide semiconductor has an oxygen vacancy (V O Also written as: ) If present, oxygen deficiency site Hydrogen can enter and form a donor level. Below, water is used at oxygen-deficient sites. The state in which the element is incorporated is V O It is sometimes written as H. Note that in oxygen-deficient sites, hydrogen It is more stable when oxygen is introduced than when other substances are introduced. Therefore, by supplying oxygen to oxide semiconductors... , V O H can be reduced.

[0110] Furthermore, if the transistor has an s-channel structure, the entire semiconductor 406b is A channel is formed. Therefore, the thicker the semiconductor 406b, the larger the channel region becomes. In other words, the thicker the semiconductor 406b, the higher the on-current of the transistor can be. For example, 20 nm or more, preferably 40 nm or more, more preferably 60 nm or more Preferably, the semiconductor 406b has a region with a thickness of 100 nm or more. However, The productivity of semiconductor devices may decrease, for example, 300 nm or less, preferably 2 A semiconductor 406b having a region with a thickness of 00 nm or less, more preferably 150 nm or less, and That's all you need to do.

[0111] Furthermore, in order to increase the on-current of the transistor, the thickness of the semiconductor 406c should be as small as possible. Preferably, less than 10 nm, preferably 5 nm or less, and even more preferably 3 nm or less. The semiconductor 406c may have a region of the above. On the other hand, the semiconductor 406c has channel formation To the semiconductor 406b, elements other than oxygen that constitute the adjacent insulator (hydrogen, silicon, etc.) It has a function to block (and) from entering. Therefore, semiconductor 406c has a certain It is preferable that it has a thickness of a certain degree. For example, 0.3 nm or more, preferably 1 nm or more. More preferably, the semiconductor 406c has a region with a thickness of 2 nm or more. The semiconductor 406c suppresses the outward diffusion of oxygen released from the insulator 402, etc. It is preferable that it has the property of blocking oxygen.

[0112] Furthermore, in order to increase reliability, semiconductor 406a should be thick and semiconductor 406c should be thin. Preferred. For example, 10 nm or more, preferably 20 nm or more, and more preferably 40 nm. More preferably, the semiconductor 406a has a region with a thickness of 60 nm or more. By increasing the thickness of semiconductor 406a, the interface between the adjacent insulator and semiconductor 406a The distance to the semiconductor 406b where the channel is formed can be increased. However, the semiconductor The productivity of the device may decrease, for example, 200 nm or less, preferably 120 nm. The semiconductor 406a has a region with a thickness of m or less, more preferably 80 nm or less. stomach.

[0113] For example, between semiconductor 406b and semiconductor 406a, for example, secondary ion mass spectrometry (S In IMS (Secondary Ion Mass Spectrometry) , 1 x 10 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 Not yet Full, more preferably 2 × 10 18 atoms / cm 3 Regions where the silicon concentration is less than It has. Also, between semiconductor 406b and semiconductor 406c, in SIMS, 1 × 10 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 Less than, further Preferably 2 × 10 18 atoms / cm 3 It has a region where the silicon concentration is less than [a certain level].

[0114] Furthermore, in order to reduce the hydrogen concentration of semiconductor 406b, semiconductor 406a and semiconductor 406 It is preferable to reduce the hydrogen concentration of c. Semiconductors 406a and 406c are SIMS In 2 × 10 20 atoms / cm 3 The following is preferably 5 × 10 19 atom / cm3 More preferably 1 × 10 19 atoms / cm 3 More preferably, 5 ×10 18 atoms / cm 3 It has a region with the following hydrogen concentrations. Also, semiconductor 406 To reduce the nitrogen concentration of b, reduce the nitrogen concentrations of semiconductors 406a and 406c. This is preferable. Semiconductors 406a and 406c are 5 × 10 in SIMS. 19 atoms / cm 3 Less than 5 × 10 18 atoms / cm 3 The following are better Mashiku is 1 x 10 18 atoms / cm 3 More preferably 5 × 10 17 Atom s / cm 3 It has a region with the following nitrogen concentrations.

[0115] Furthermore, the presence of copper in oxide semiconductors can sometimes generate electron traps. The voltage may cause the transistor's threshold voltage to fluctuate in the positive direction. Therefore, A lower copper concentration on or inside the semiconductor 406b is preferable. For example, semiconductor 4 06b has a copper concentration of 1 × 10⁻⁶ 19 atoms / cm 3 Below, 5 x 10 18 ate / c m 3 The following, or 1 × 10 18 atoms / cm 3 It is preferable to have the following regions: Furthermore, a lower copper concentration on or inside the semiconductor 406a is preferable. For example, The conductor 406a has a copper concentration of 1 × 10⁻⁶ 19 atoms / cm 3 Below, 5 x 10 18 Atom s / cm 3 The following, or 1 × 10 18 atoms / cm 3 It is preferable to have the following regions: Furthermore, a lower copper concentration on or inside the semiconductor 406c is preferable. For example, semiconductor 406c has a copper concentration of 1 × 10⁻⁶ 19 atoms / cm 3 Below, 5 x 10 18 a toms / cm 3 The following, or 1 × 10 18 atoms / cm 3 The region has the following: And that is preferable.

[0116] The three-layer structure described above is just one example. For example, a two-layer structure without semiconductor 406a or semiconductor 406c. The structure itself is also acceptable. Alternatively, it can be above or below semiconductor 406a, or on semiconductor 406c. Examples of semiconductors 406a, 406b, and 406c are shown above or below. It may also be a four-layer structure having any one of the semiconductors. Alternatively, on top of semiconductor 406a, At two or more locations below semiconductor 406a, above semiconductor 406c, or below semiconductor 406c any of the semiconductors exemplified as semiconductor 406a, semiconductor 406b, and semiconductor 406c It may also be an n-layer structure (where n is an integer greater than or equal to 5) with one layer.

[0117] The structure of oxide semiconductors will be described below.

[0118] In this specification, "parallel" means that two straight lines are positioned at an angle of -10° or more and 10° or less. This refers to a state where the temperature is in a certain condition. Therefore, it also includes cases where the temperature is between -5° and 5°. A "row" refers to a state where two straight lines are positioned at an angle of -30° or more and 30° or less. Furthermore, "perpendicular" refers to a state in which two straight lines are positioned at an angle of 80° to 100°. Therefore, it also includes cases where the angle is between 85° and 95°. Also, "approximately perpendicular" means two This refers to a state in which two straight lines are arranged at an angle between 60° and 120°.

[0119] Furthermore, in this specification, if a crystal is trigonal or rhombohedral, it will be represented as a hexagonal crystal system. .

[0120] <Oxide semiconductor structure> The structure of oxide semiconductors will be described below.

[0121] Oxide semiconductors are divided into single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. As a non-single-crystal oxide semiconductor, CAAC-OS (C Axis Aligned) is used. Crystalline Oxide Semiconductor, Polycrystalline Oxide Semiconductor Conductor, nc-OS (nanocrystalline Oxide Semiconductor) ctor), pseudo-amorphous oxide semiconductor (a-like OS: amorphous li Examples include amorphous oxide semiconductors (such as ke Oxide Semiconductors).

[0122] From another perspective, oxide semiconductors include amorphous oxide semiconductors and other crystalline oxide semiconductors. They can be divided into conductors and crystalline oxide semiconductors. Examples of crystalline oxide semiconductors include single-crystal oxide semiconductors and CAAC-O Examples include S, polycrystalline oxide semiconductors, and nc-OS.

[0123] Generally, an amorphous structure is defined as a structure that is not fixed in a metastable state and is isotropic. It is known that it does not have a heterogeneous structure. Also, the bond angles are flexible and short distance It can also be described as a structure that possesses order but lacks long-range order.

[0124] Conversely, in the case of oxide semiconductors, which are inherently stable, a completely amorphous (complete) semiconductor is possible. It cannot be called an oxide semiconductor (ely amorphous). Furthermore, it is not isotropic. For example, an oxide semiconductor (having a periodic structure in a minute region) is made of a completely amorphous oxide It cannot be called a semiconductor. However, a-like OS exhibits periodicity in a minute region. Although it has a structure, it is porous and has an unstable structure. Therefore, in terms of physical properties, it is amorphous oxidation. It can be said to be similar to a semiconductor.

[0125] <caac-os> First, let me explain CAAC-OS.

[0126] CAAC-OS is an oxide semiconductor having multiple c-axis oriented crystalline portions (also called pellets). It is a type of conductor.

[0127] Transmission Electron Microscope (TEM) A composite analysis image of the bright-field image and diffraction pattern of CAAC-OS (high-frequency analysis) is obtained using the scope. Also called a resolving TEM image.) When observing this image, multiple pellets can be identified. In high-resolution TEM images, the boundaries between pellets, i.e., grain boundaries, are visible. It cannot be clearly confirmed that CAAC-OS occurs at the grain boundaries. This means that a decrease in electron mobility due to this is less likely to occur.

[0128] The following describes CAAC-OS as observed by TEM. Figure 27(A) shows, This shows a high-resolution TEM image of a cross-section of CAAC-OS observed from a direction approximately parallel to the sample surface. For observing high-resolution TEM images, spherical aberration correction is necessary. The Corrector function was used. High-resolution TEM images using spherical aberration correction were obtained. This is specifically called a Cs-corrected high-resolution TEM image. Acquisition of Cs-corrected high-resolution TEM images is, for example, done in Japan. This is performed using an atomic-resolution analytical electron microscope, such as the JEM-ARM200F, manufactured by this electronics company. It is possible.

[0129] Figure 27(B) shows a magnified Cs-corrected high-resolution TEM image of region (1) in Figure 27(A). Figure 27(B) shows that the metal atoms in the pellet are arranged in layers. The arrangement of metal atoms in each layer is such that the surface forming the CAAC-OS film (also called the surface to be formed) Alternatively, it reflects the irregularities of the upper surface and is parallel to the surface or upper surface of the CAAC-OS that is formed.

[0130] As shown in Figure 27(B), CAAC-OS has a characteristic atomic arrangement. Figure 27(C) The characteristic atomic arrangement is shown with auxiliary lines. Figures 27(B) and 27(C) Therefore, the size of each pellet is approximately 1 nm to 3 nm, and the pellets are It can be seen that the size of the gap caused by the tilt is about 0.8 nm. Therefore, Lett can also be called a nanocrystal (nc). AC-OS, CANC (C-Axis Aligned nanocrystals) It can also be called an oxide semiconductor having [a certain characteristic].

[0131] Here, based on the Cs-corrected high-resolution TEM image, the pellets of CAAC-OS on substrate 5120 are... The arrangement of the To 5100 can be schematically represented as a structure resembling stacked bricks or blocks. (See Figure 27(D).) The tilt between the pellets observed in Figure 27(C) The area where the condensation is occurring corresponds to region 5161 shown in Figure 27(D).

[0132] Furthermore, Figure 28(A) shows the Cs in the plane of CAAC-OS observed from a direction approximately perpendicular to the sample surface. Corrected high-resolution TEM images are shown. Regions (1), (2), and (3) in Figure 28(A). Magnified Cs-corrected high-resolution TEM images are shown in Figures 28(B), 28(C), and 28(C), respectively. As shown in 28(D). From Figures 28(B), 28(C), and 28(D), the pellets are It can be confirmed that metal atoms are arranged in a triangular, square, or hexagonal shape. However, However, no regularity is observed in the arrangement of metal atoms between different pellets.

[0133] Next, the CA was analyzed by X-ray diffraction (XRD). Let's discuss AC-OS. For example, CAAC-OS, which has an InGaZnO4 crystal. In contrast, when structural analysis is performed using the out-of-plane method, as shown in Figure 29(A)... In some cases, a peak may appear at a diffraction angle (2θ) near 31°. This peak is in InGaZ Since it is attributed to the (009) plane of the nO4 crystal, the CAAC-OS crystal is c-axis oriented. It can be confirmed that the c-axis is oriented in a direction substantially perpendicular to the surface to be formed or the upper surface.

[0134] In addition, in the structural analysis using the out-of-plane method of CAAC-OS, 2θ is 31°. In addition to the nearby peak, a peak may also appear when 2θ is near 36°. The adjacent peak indicates that some of the crystals in CAAC-OS do not have c-axis orientation. This indicates that the more preferable CAAC-OS is the structural solution by the out-of-plane method. Analysis revealed a peak around 31° for 2θ, but no peak around 36° for 2θ.

[0135] On the other hand, for CAAC-OS, X-rays are incident from a direction approximately perpendicular to the c-axis in an in-plan configuration. Structural analysis using the e method reveals a peak near 2θ = 56°. This peak corresponds to In It is attributed to the (110) plane of the GaZnO4 crystal. In the case of CAAC-OS, 2θ is 56 The sample is fixed in the vicinity of °, and the analysis is performed while rotating the sample around the normal vector of the sample surface as the axis (φ axis). Even after performing a φ scan, no clear peak appears, as shown in Figure 29(B). Furthermore, if it is a single-crystal oxide semiconductor of InGaZnO4, then fixing 2θ to around 56°, φs If this occurs, the pi is assigned to a crystal plane equivalent to the (110) plane, as shown in Figure 29(C). Six lines are observed. Therefore, structural analysis using XRD indicates that CAAC-OS is It can be confirmed that the orientation of the a-axis and b-axis is irregular.

[0136] Next, we will explain CAAC-OS analyzed by electron diffraction. For example, InGaZ For CAAC-OS having nO4 crystals, a probe with a diameter of 300 nm is placed parallel to the sample surface. When an electron beam is incident, a diffraction pattern like the one shown in Figure 30(A) (limited field transmission electron diffraction) is observed. Sometimes a pattern (also called a diffraction pattern) may appear. This diffraction pattern is indicative of InGaZnO4. The spot originates from the (009) plane of the crystal. Therefore, electron diffraction also reveals... The pellets contained in CAAC-OS have c-axis orientation, and the c-axis is approximately aligned with the surface to be formed or the upper surface. It can be seen that it is oriented in a vertical direction. On the other hand, for the same sample, the probe is oriented perpendicular to the sample surface. Figure 30(B) shows the diffraction pattern when an electron beam with a diameter of 300 nm is incident on the surface. Figure 30 (B) shows a ring-shaped diffraction pattern. Therefore, electron diffraction also shows that It can be seen that the a-axis and b-axis of the pellets contained in CAAC-OS do not have any orientation. Note that the first ring in Figure 30(B) is the (010) plane of the InGaZnO4 crystal. This is thought to be caused by the (100) surface, etc. Also, the second ring in Figure 30(B) is (110) This is thought to be caused by the surface, etc.

[0137] As mentioned above, CAAC-OS is a highly crystalline oxide semiconductor. Crystallinity can decrease due to the inclusion of impurities or the formation of defects, so the opposite perspective is needed. CAAC-OS can also be described as an oxide semiconductor with few impurities or defects (such as oxygen vacancies).

[0138] Impurities are elements other than the main components of oxide semiconductors, such as hydrogen, carbon, silicon, and transition metals. There are elements, for example. For instance, oxygen is more abundant than the metallic elements that make up oxide semiconductors such as silicon. Elements with strong bonding forces can alter the atomic arrangement of oxide semiconductors by removing oxygen from them. It disrupts the crystallinity and causes a decrease in its properties. Also, heavy metals such as iron and nickel, argon, and nickel... Because carbon oxides and other elements have a large atomic radius (or molecular radius), they affect the atomic arrangement of oxide semiconductors. This disrupts the crystallinity and reduces its properties.

[0139] When oxide semiconductors contain impurities or defects, their properties may change due to light, heat, etc. For example, impurities contained in oxide semiconductors can act as carrier traps, or carriers It can become a source of emissions. Furthermore, oxygen vacancies in oxide semiconductors can act as carrier traps. In some cases, it may act as a carrier source by capturing hydrogen.

[0140] CAAC-OS, with its low impurity and oxygen vacancies, is an oxide semiconductor with a low carrier density. Specifically, the carrier density is set to 8 × 10⁻⁶. 11 / cm 3 Less than 1 × 10 11 / cm 3 Less than 1 × 10 10 / cm 3 It is less than 1 × 10 -9 / cm 3 The above can be achieved. This is called an intrinsic oxide semiconductor. CAAC-OS has a low impurity concentration and a low defect level density. In other words, it can be said to be an oxide semiconductor with stable properties.

[0141] <nc-os> Next, I will explain nc-OS.

[0142] nc-OS is a region in which the crystalline part can be confirmed in high-resolution TEM images, and is clearly It has regions where the crystalline portion cannot be confirmed. The crystalline portion contained in nc-OS is They are often between 1 nm and 10 nm in size, or between 1 nm and 3 nm. Oxide semiconductors with a crystal size greater than 10 nm and less than or equal to 100 nm are subjected to microcrystalline oxidation. It is sometimes called a solid semiconductor. nc-OS, for example, in high-resolution TEM images, shows grain boundaries. It may not be possible to confirm this clearly. Furthermore, nanocrystals are the pellets in CAAC-OS. They may share the same origin. Therefore, in the following, the crystalline portion of nc-OS will be referred to as a pellet. There are cases where this happens.

[0143] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially between 1 nm and 3 nm). The atomic arrangement has periodicity in the region of less than nm. In addition, nc-OS has different pellets. No regularity in crystal orientation is observed between the layers. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analysis method, nc-OS can be classified as a-like OS or amorphous oxide semiconductor. In some cases, it may be difficult to distinguish between them. For example, with nc-OS, X has a larger diameter than the pellet. When using lines, out-of-plane analysis detects peaks that indicate crystal planes. It is not released. Also, for nc-OS, a probe diameter larger than the pellet (e.g., 50n) is required. When electron diffraction is performed using an electron beam (of m or greater), a diffraction pattern similar to a halo pattern can be observed. It is measured. On the other hand, compared to nc-OS, the size is close to or smaller than the pellet size. When nanobeam electron diffraction is performed using an electron beam of a certain diameter, spots can be observed. When nanobeam electron diffraction is performed on c-OS, a high-brightness ring-shaped pattern is observed. A region may be observed. Furthermore, multiple spots may be observed within a ring-shaped region. There are cases where this is the case.

[0144] Thus, since there is no regularity in the crystal orientation between pellets (nanocrystals), nc- The OS has RANC (Random Aligned nanocrystals) Oxide semiconductors, or NANCs (Non-Aligned nanocrystals) It can also be called an oxide semiconductor having ).

[0145] nc-OS is an oxide semiconductor with higher orderliness than amorphous oxide semiconductors. Therefore, nc-OS has a lower defect level density than a-like OS and amorphous oxide semiconductors. However, nc-OS does not show any regularity in crystal orientation between different pellets. nc-OS has a higher defect level density compared to CAAC-OS.

[0146] <a-like OS> a-like OS is an oxide semiconductor having a structure between nc-OS and amorphous oxide semiconductors. It is a conductor.

[0147] a-like OS exhibits porosity (also called voids) in high-resolution TEM images. In some cases, the crystalline region can be clearly identified in high-resolution TEM images. It has a region where the crystalline part cannot be identified, and a region where the crystalline part cannot be identified.

[0148] Because it has porosity, a-like OS has an unstable structure. Below, a-like To demonstrate that the OS has a less stable structure compared to CAAC-OS and nc-OS. This shows the structural changes caused by electron irradiation.

[0149] The samples to be irradiated with electrons are a-like OS (referred to as sample A) and nc-OS ( Prepare Sample B (referred to as Sample B) and CAAC-OS (referred to as Sample C). The sample is also an In-Ga-Zn oxide.

[0150] First, high-resolution cross-sectional TEM images are obtained for each sample. It can be seen that all of them have crystalline parts.

[0151] The determination of which part should be considered a single crystal can be made as follows. For example, The unit cell of an InGaZnO4 crystal has three In-O layers and a Ga-Zn-O layer. It is known to have a structure in which 6 layers, totaling 9 layers, are stacked in layers along the c-axis. The spacing between adjacent layers is approximately the same as the spacing between grid planes (also called the d value) of the (009) plane. Yes, and its value has been determined to be 0.29 nm from crystal structure analysis. Therefore, the lattice fringes Areas with a spacing of 0.28 nm or more and 0.30 nm or less are considered to be the crystalline regions of InGaZnO4. This can be done. Note that the lattice patterns correspond to the ab-plane of the InGaZnO4 crystal.

[0152] Figure 31 shows an example of investigating the average size of the crystalline regions (22 to 45 locations) in each sample. However, the length of the lattice fringes mentioned above is used as the size of the crystal portion. From Figure 31, a-lik It can be seen that the crystalline portion of eOS increases in proportion to the cumulative amount of electron irradiation. As shown in (1) in Figure 31, the initial TEM observation is approximately 1.2 nm. The crystal part (also referred to as the initial nucleus) with a size of, at an electron cumulative irradiation dose of 4.2×10 8 e - / nm 2 it can be seen that it has grown to a size of about 2.6 nm. On the other hand, nc-OS and CAAC-OS show no change in the size of the crystal part from the start of electron irradiation until the electron cumulative irradiation dose reaches 4.2×10 8 e - / nm 2 . Specifically, as shown in (2) and (3) of FIG. 31, regardless of the electron cumulative irradiation dose, the sizes of the crystal parts of nc-OS and CAAC-OS are about 1.4 nm and about 2.1 nm respectively, as can be seen .

[0153] Thus, a-like OS may show growth of the crystal part upon electron irradiation. On the other hand, it can be seen that nc-OS and CAAC-OS show almost no growth of the crystal part due to electron irradiation. That is, it can be seen that a-like OS has an unstable structure compared to nc-OS and CAAC-O S.

[0154] Also, because it has voids, a-like OS has a lower density structure compared to nc-OS and CAAC-OS. Specifically, the density of a-like OS is 78.6% or more and less than 92.3% of the density of a single crystal with the same composition. Also, the densities of nc-OS and CAAC -OS are 92.3% or more and less than 100% of the density of a single crystal with the same composition. An oxide semiconductor with a density less than 78% of that of a single crystal is difficult to form a film itself.

[0155] For example, in an oxide semiconductor satisfying In:Ga:Zn = 1:1:1 [atomic ratio], rhombic The density of a single crystal InGaZnO4 having a hexahedral crystal structure is 6.357 g / cm 3 and becomes. Therefore, in an oxide semiconductor satisfying, for example, In:Ga:Zn = 1:1:1 [atomic ratio], the density of the a-like OS is 5.0 g / cm 3 or more and less than 5.9 g / cm 3 and becomes. Also, in an oxide semiconductor satisfying, for example, In:Ga:Zn = 1:1:1 [atomic ratio], the density of the nc-OS and the density of the CAAC-OS are 5.9 g / cm 3 or more and less than 6.3 g / cm 3 and becomes.

[0156] Note that there may be cases where single crystals of the same composition do not exist. In that case, by combining single crystals with different compositions in any ratio, it is possible to estimate the density corresponding to the single crystal in the desired composition. The density corresponding to the single crystal of the desired composition may be estimated using a weighted average with respect to the ratio of combining single crystals with different compositions. However, it is preferable to estimate the density by combining as few types of single crystals as possible.

[0157] As described above, the oxide semiconductor takes various structures and each has various characteristics. Also, the oxide semiconductor may be, for example, a laminated film having two or more of an amorphous oxide semiconductor, a-like OS, nc-OS, CAAC-OS.

[0158] In FIG. 7, as the substrate 400, for example, an insulator substrate, a semiconductor substrate, or a conductor substrate may be used. Examples of the insulator substrate include a glass substrate, a quartz substrate, a sapphire substrate, a stabilized zirconia substrate (such as a yttria-stabilized zirconia substrate), a resin substrate, etc. ​​Furthermore, as semiconductor substrates, for example, single-component semiconductor substrates such as silicon and germanium, Or silicon carbide, silicon germanium, gallium arsenide, indium phosphide, phosphorus oxide Examples include compound semiconductor substrates such as lead and gallium oxide. Furthermore, the inside of the aforementioned semiconductor substrate... A semiconductor substrate having an insulating region, for example, SOI (Silicon On Insulator) Examples include tor substrates. Conductive substrates include graphite substrates, metal substrates, alloy substrates, and conductive substrates. Examples include resin substrates, or substrates containing metal nitrides or metal oxides. There are also substrates in which a conductor or semiconductor is provided on an insulating substrate, and semiconductor substrates A substrate provided with a conductor or an insulator, a substrate provided with a semiconductor or an insulator on a conductive substrate There are boards or similar materials. Alternatively, you may use substrates on which elements are mounted. Examples of elements that can be used include capacitive elements, resistive elements, switch elements, light-emitting elements, and memory elements. be.

[0159] Furthermore, a flexible substrate may be used as the substrate 400. One method for creating a transistor is to fabricate a transistor on a non-flexible substrate, and then... Another method involves peeling off the zista and transferring it to the flexible substrate 400. In that case, It is preferable to provide a release layer between the non-flexible substrate and the transistor. Note that the substrate 400 is Alternatively, a sheet, film, or foil made of woven fibers may be used. Also, the substrate 400 It may also be stretchable. Furthermore, when the bending or pulling of the substrate 400 is stopped, it returns to its original shape. It may have the property of returning to its original shape. Alternatively, it may have the property of not returning to its original shape. Substrate 4 The thickness of 00 is, for example, 5 μm or more and 700 μm or less, preferably 10 μm or more and 500 μm. More preferably, the thickness is 15 μm or more and 300 μm or less. When the substrate 400 is thinned, Semiconductor devices can be made lighter. Also, by making the substrate 400 thinner, glass, etc. Even when used, it may have elasticity, or it may return to its original shape when you stop bending or pulling it. It may have a tendency to return to its original shape. Therefore, if it is dropped or otherwise damaged, the semiconductor device on the substrate 400 may... It can mitigate the impact of shocks and other shocks. In other words, it can provide a robust semiconductor device. ru.

[0160] The flexible substrate 400 can be, for example, metal, alloy, resin, or glass. Alternatively, those fibers can be used. The substrate 400, which is a flexible substrate, undergoes linear expansion. A lower ratio is preferable as it suppresses deformation due to the environment. The substrate 400 is a flexible substrate. For example, the coefficient of thermal expansion is 1 × 10⁻⁶. -3 / K or less, 5×10 -5 / K or less, or 1×1 0 -5 Any material with a K value of 0.5 or less should be used. Examples of resins include polyester and poly Olefins, polyamides (nylon, aramid, etc.), polyimides, polycarbonates, Examples include acrylic. In particular, aramid has a low coefficient of thermal expansion, making it suitable for flexible substrates. 400 is preferred.

[0161] Examples of conductors 413 include boron, nitrogen, oxygen, fluorine, silicon, phosphorus, and aluminum. Nium, titanium, chromium, manganese, cobalt, nickel, copper, zinc, gallium, yt Rium, zirconium, molybdenum, ruthenium, silver, indium, tin, tantalum, and A conductor containing one or more types of tungsten can be used in a single layer or in a multilayer structure. For example, They may be alloys or compounds, including conductors containing aluminum, and conductors containing copper and titanium. Conductors containing copper and manganese, conductors containing indium, tin and oxygen, titanium Conductors containing nitrogen may also be used.

[0162] Examples of insulators 402 include boron, carbon, nitrogen, oxygen, fluorine, magnesium, and Aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium An insulator containing zirconium, lanthanum, neodymium, hafnium, or tantalum, in a single layer Alternatively, it can be used in a laminated configuration. Note that the insulator 402 is silicon nitride, silicon nitride It may contain nitrogen-containing insulators such as nitrates.

[0163] The insulator 402 may also serve to prevent the diffusion of impurities from the substrate 400. If semiconductor 406b is an oxide semiconductor, insulator 402 supplies oxygen to semiconductor 406b. They can take on the role of providing.

[0164] Examples of insulators 412 include boron, carbon, nitrogen, oxygen, fluorine, magnesium, and Aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium An insulator containing zirconium, lanthanum, neodymium, hafnium, or tantalum, in a single layer Alternatively, it can be used in a laminated configuration.

[0165] Examples of conductors 404 include boron, nitrogen, oxygen, fluorine, silicon, phosphorus, and aluminum. Nium, titanium, chromium, manganese, cobalt, nickel, copper, zinc, gallium, yt Rium, zirconium, molybdenum, ruthenium, silver, indium, tin, tantalum, and A conductor containing one or more types of tungsten can be used in a single layer or in a multilayer structure. For example, They may be alloys or compounds, including conductors containing aluminum, and conductors containing copper and titanium. Conductors containing copper and manganese, conductors containing indium, tin and oxygen, titanium Conductors containing nitrogen may also be used.

[0166] Examples of insulators 408 include boron, carbon, nitrogen, oxygen, fluorine, magnesium, and Aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium An insulator containing zirconium, lanthanum, neodymium, hafnium, or tantalum, in a single layer Alternatively, they can be used in a laminated configuration. The insulator 408 is preferably aluminum oxide, or an acid nitride. Silicon oxide, silicon nitride, gallium oxide, yttrium oxide, zirconium oxide, oxide An insulator containing lanthanum, neodymium oxide, hafnium oxide, or tantalum oxide, in a single layer, Alternatively, it can be used in a laminated configuration.

[0167] Examples of insulators 418 include boron, carbon, nitrogen, oxygen, fluorine, magnesium, and Aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium An insulator containing zirconium, lanthanum, neodymium, hafnium, or tantalum, in a single layer Alternatively, they can be used in a laminated configuration. The insulator 418 is preferably silicon oxide or nitrogen oxide. An insulator containing silicon dioxide can be used in a single layer or in a multilayer structure.

[0168] Examples of insulators 428 include boron, carbon, nitrogen, oxygen, fluorine, magnesium, and Aluminum, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium An insulator containing zirconium, lanthanum, neodymium, hafnium, or tantalum, in a single layer Alternatively, they can be used in a laminated configuration. The insulator 428 is preferably silicon oxide or nitrogen oxide. An insulator containing silicon dioxide can be used in a single layer or in a multilayer structure.

[0169] Examples of conductors 426a and 426b include boron, nitrogen, oxygen, fluorine, Silicon, phosphorus, aluminum, titanium, chromium, manganese, cobalt, nickel, copper, Zinc, gallium, yttrium, zirconium, molybdenum, ruthenium, silver, indium Conductors containing one or more of the following: luminous, tin, tantalum, and tungsten, in a single layer or in a multilayer Any material can be used. For example, alloys or compounds may be used, such as conductors containing aluminum or copper. Conductors containing titanium, conductors containing copper and manganese, indium, tin and oxygen Conductors containing titanium and nitrogen may also be used.

[0170] Examples of conductors 424a and 424b include boron, nitrogen, oxygen, fluorine, Silicon, phosphorus, aluminum, titanium, chromium, manganese, cobalt, nickel, copper, Zinc, gallium, yttrium, zirconium, molybdenum, ruthenium, silver, indium Conductors containing one or more of the following: luminous, tin, tantalum, and tungsten, in a single layer or in a multilayer Any material can be used. For example, alloys or compounds may be used, such as conductors containing aluminum or copper. Conductors containing titanium, conductors containing copper and manganese, indium, tin and oxygen Conductors containing titanium and nitrogen may also be used.

[0171] In Figure 7, the conductor 404, which is the first gate electrode of the transistor, and the second gate electrode An example was shown in which the conductor 413, which is a pole, is not electrically connected, but according to one aspect of the present invention... The structure of the lunger is not limited to this. For example, as shown in Figure 8(A), the conductor 40 It is also acceptable for the structure to be such that 4 and the conductor 413 are electrically connected via the conductor 405 or the like. i. By using this configuration, the same potential is supplied to the conductor 404 and the conductor 413. Therefore, the switching characteristics of the transistor can be improved. Alternatively, see Figure 8(B As shown in ( ), the structure may not have a conductor 413.

[0172] Alternatively, in Figure 7, the conductive material electrically connected to the source and drain regions of the transistor is shown. An example is shown in which the electric element 426a and the conductor 426b have regions in contact with the semiconductor 406b. However, the structure of the transistor according to one aspect of the present invention is not limited thereto. For example, Figure 9(A As shown in ), conductors 426a and 426b are semiconductors 406b and 4 It is also acceptable for it to have a region that penetrates 06a and is in contact with the insulator 402. Alternatively, see Figure 9( As shown in B), the semiconductor 406b has a region that penetrates and is in contact with the semiconductor 406a. That's fine.

[0173] Alternatively, in Figure 7, the semiconductor 406c and the insulator 412 overlap with the conductor 404. Although only an example of arrangements with such arrangements has been shown, the structure of the transistor according to one aspect of the present invention is not limited to this. It is not possible. For example, as shown in Figure 10(A), semiconductor 406c and insulator 412 are semiconductor They may be arranged to cover the conductor 406b and semiconductor 406a. Alternatively, as shown in Figure 10( As shown in B), semiconductor 406c is arranged to overlap with semiconductor 406b, and insulator 41 2 may be arranged to cover semiconductors 406c, 406b, and 406a. do not have.

[0174] <Transistor Structure 2> Figure 11(A) is an example of a top view of a transistor according to one embodiment of the present invention. Figure 11(B) shows an example of a cross-sectional view corresponding to the dashed lines E1-E2 and E3-E4. As shown in Figure 11(A). Note that in Figure 11(A), some parts such as insulators have been omitted for ease of understanding. To show.

[0175] The transistors shown in Figures 11(A) and 11(B) are connected to a conductor 413 on the substrate 400. an insulator 402 having protrusions on the substrate 400 and the conductor 413, and the protrusions of the insulator 402 The semiconductor 406a on the lower part, the semiconductor 406b on the semiconductor 406a, and the upper surface of the semiconductor 406b Conductors 416a and 41 have regions that are in contact with the semiconductor 406b and do not come into contact with the side surface of semiconductor 406b. 6b and in a region on semiconductor 406b that does not overlap with conductors 416a and 416b The semiconductor 406c is positioned, the insulator 412 is on the semiconductor 406c, and the conductive material is on the insulator 412. The electric body 404 and the insulator 408 on the insulator 402, semiconductor 406b, and conductor 404. It has, and. Note that here, the conductor 413 is used as part of the transistor, It is not limited to this. For example, if the conductor 413 is a component independent of the transistor That's fine.

[0176] For example, conductors 416a and 416b may be boron, nitrogen, oxygen, and f Electrolyte, silicon, phosphorus, aluminum, titanium, chromium, manganese, cobalt, nickel Copper, zinc, gallium, yttrium, zirconium, molybdenum, ruthenium, silver, A conductor containing one or more of the elements tin, tantalum, and tungsten, in a single layer, or It can be used in a laminated configuration. For example, it may be an alloy or compound, or a conductor containing aluminum. Conductors containing copper and titanium, conductors containing copper and manganese, indium, tin and Conductors containing oxygen, titanium, and nitrogen may also be used.

[0177] The transistor shown in Figure 11 has a different conductor 416a compared to the transistors shown in Figure 7, etc. The differences lie in the presence of the conductive element 416b, but the other components are similar. Therefore, the details of the transistor shown in Figure 11 are the same as those of the transistor shown in Figure 7, etc. The information provided can be taken into consideration.

[0178] The transistor shown in Figure 11 has a different conductor 416a compared to the transistors shown in Figure 7, etc. Furthermore, the presence of the conductor 416b allows for the realization of a transistor with a larger on-current. It is sometimes possible.

[0179] <Transistor Structure 3> Figure 12(A) is an example of a top view of a transistor according to one embodiment of the present invention. Figure 12(B) shows an example of a cross-sectional view corresponding to the dashed lines F1-F2 and F3-F4. As shown in Figure 12(A). Note that in Figure 12(A), some parts such as insulators have been omitted for ease of understanding. To show.

[0180] The transistors shown in Figures 12(A) and 12(B) are connected to a conductor 413 on the substrate 400. an insulator 402 having protrusions on the substrate 400 and the conductor 413, and the protrusions of the insulator 402 The semiconductor 406a on the lower part, the semiconductor 406b on the semiconductor 406a, and the upper surface of the semiconductor 406b and Conductors 416a and 416b having regions in contact with the side surface, and semiconductor 406 Semiconductor 40 is located on b in a region that does not overlap with the conductors 416a and 416b. 6c, an insulator 412 on semiconductor 406c, a conductor 404 on insulator 412, and an insulator It has an insulator 408 on 402, on semiconductor 406b, and on conductor 404. Here, conductor 413 is used as part of the transistor, but it is not limited to this. Alternatively, the conductor 413 may be a component independent of the transistor.

[0181] The transistor shown in Figure 12 has a different conductor 416a compared to the transistor shown in Figure 11. The difference is that the conductor 416b has a region in contact with the side surface of the semiconductor 406b, but otherwise The configuration is similar. Therefore, the details of the transistor shown in Figure 12 are shown in Figure You can refer to the descriptions of transistors shown in section 11, etc.

[0182] The transistor shown in Figure 12 has a different conductor 416 compared to the transistors shown in Figure 11, etc. The on-current is limited to the extent that a and the conductor 416b have a region in contact with the side surface of semiconductor 406b. In some cases, it is possible to create transistors with larger sizes.

[0183] Note that in Figure 12, the conductor 404, which is the first gate electrode of the transistor, and the second gate... An example was shown in which the conductive electrode 413 is not electrically connected, but this relates to one aspect of the present invention. The structure of a transistor is not limited to this. For example, as shown in Figure 13(A), a conductor The structure may also have a region where 404 and the conductor 413 are in contact. By doing so, the same potential is supplied to conductor 404 and conductor 413, so the transient The switching characteristics of the switch can be improved. Alternatively, as shown in Figure 13(B), The structure may not have the conductor 413.

[0184] Alternatively, in Figure 12, the semiconductor 406c and the insulator 412 overlap with the conductor 404. Although an example of placement only in this configuration has been shown, the structure of a transistor according to one aspect of the present invention is not limited to this. It is not done. For example, as shown in Figure 14(A), semiconductor 406c is semiconductor 406b and It may also be arranged so as to cover semiconductor 406a. Alternatively, as shown in Figure 14(B) , semiconductor 406c is arranged to cover semiconductor 406b and semiconductor 406a, and an insulator 412 is conductor 416a, conductor 416b, semiconductor 406c, semiconductor 406b and semiconductor It is also acceptable to position it so as to cover body 406a.

[0185] <Transistor Structure 4> Figure 15(A) is an example of a top view of a transistor according to one embodiment of the present invention. Figure 15(B) shows an example of a cross-sectional view corresponding to the dashed lines G1-G2 and G3-G4. As shown in Figure 15(A). Note that in Figure 15(A), some parts such as insulators have been omitted for ease of understanding. To show.

[0186] The transistors shown in Figures 15(A) and 15(B) are connected to a conductor 413 on the substrate 400. an insulator 402 having protrusions on the substrate 400 and the conductor 413, and the protrusions of the insulator 402 The semiconductor 406a on the lower part, the semiconductor 406b on the semiconductor 406a, and the upper surface of the semiconductor 406b and Conductors 416a and 416b having regions in contact with the side surface, and semiconductor 406 A semiconductor 4 is located on b in a region that does not overlap with the conductor 416a but overlaps with the conductor 416b. 06c, an insulator 412 on semiconductor 406c, a conductor 404 on insulator 412, and insulation It has an insulator 408 on the body 402, on the semiconductor 406b, and on the conductor 404. The transistor shown in Figure 15 has a region where the conductor 404 overlaps with the conductor 416b. Note that, although conductor 413 is treated as part of the transistor here, it is not limited to this. For example, the conductor 413 may be a component independent of the transistor.

[0187] The transistor shown in Figure 15 has a different conductive component compared to the transistor shown in Figure 12, with the conductive component 404 being... It differs in that it has an overlapping region with the electric body 416b, but the other configurations are similar. Therefore, the details of the transistor shown in Figure 15 are the same as those shown in Figure 12, etc. You can refer to the information provided regarding this matter.

[0188] Furthermore, as shown in Figure 15(B), the transistor has a function as a gate electrode. The conductive material 404 and the semiconductor 406b, which functions as a channel-forming region, overlap each other. This region is called the Lov region.

[0189] If the Lov region is too large, the parasitic capacitance increases, affecting the switching characteristics of the transistor. This may reduce the value. Therefore, the size of the Lov region shown in Figure 15(B) is the size of the chat Less than 100% of the size of the flannel formation region, preferably less than 80%, and more preferably 50% It shall be less than. For example, the size of the Lov region shall be less than 50 nm, preferably less than 20 nm. More preferably, the nm size should be less than 10 nm.

[0190] The transistor shown in Figure 15 has a different conductor 404 compared to the transistors shown in Figure 12, etc. Because it has a region that overlaps with the conductor 416b, it enables the realization of a transistor with a large on-current. It may be possible in some cases.

[0191] The transistor structures shown above are just examples, and combinations of these structures are also part of the present invention. It falls under the category of "appearance."

[0192] <Semiconductor device> The following describes a semiconductor device according to one aspect of the present invention.

[0193] The following describes an example of a semiconductor device utilizing a transistor according to one aspect of the present invention. do.

[0194] Figure 16(A) shows a cross-sectional view of a semiconductor device according to one embodiment of the present invention. The semiconductor shown in Figure 16(A) The device has a transistor 2200 using a first semiconductor at the bottom and a second semiconductor at the top. It has a transistor 2100 using a second semiconductor. Figure 16(A) shows a transistor 2100 using a second semiconductor. The example shown uses the transistor exemplified in Figure 11 as transistor 2100. .

[0195] The first semiconductor may be a semiconductor with a different energy gap than the second semiconductor. For example, if the first semiconductor is a semiconductor other than an oxide semiconductor, and the second semiconductor is an oxide semiconductor... As the first semiconductor, silicon, germanium, etc., in polycrystalline and single-crystal structures. You may use any of these. Alternatively, you may use a strained semiconductor such as strained silicon. Alternatively, as the first semiconductor, a high electron mobility transistor (HEMT) is used. Gallium arsenide, arsenide (applicable to ron Mobility Transistor) Luminium gallium, indium gallium arsenide, gallium nitride, indium phosphide, silica Congermanium and other materials may also be used. By using these semiconductors as the first semiconductor, This allows for the creation of a transistor 2200 suitable for high-speed operation. Furthermore, oxide semiconductors... By using a conductor as the second semiconductor, a transistor 2100 with a low off-current is achieved. It is possible.

[0196] Note that transistor 2200 can be either an n-channel or p-channel type, but the circuit Use the appropriate transistor. Also, transistor 2100 or / and tra As transistor 2200, the transistors mentioned above and the transistor shown in Figure 16(A) are used. There are cases where it is not necessary to use it.

[0197] The semiconductor device shown in Figure 16(A) has a traverse via insulators 2201 and 2207. Transistor 2200 has transistor 2100 on top. Also, transistor 2200 Between the transistor 2100 and multiple conductors 2202 that function as wiring are arranged. Furthermore, multiple conductors 2203 embedded in various insulators separate the upper and lower layers. The wiring and electrodes arranged therein are electrically connected. Furthermore, the semiconductor device is a transient The insulator 2204 on the sta 2100, the conductor 2205 on the insulator 2204, and the transistor The source electrode and drain electrode of the TA2100 are formed in the same single layer (through the same process). It has an electrical unit 2206.

[0198] Insulator 2204 can be, for example, boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum. nium, silicon, phosphorus, chlorine, argon, gallium, germanium, yttrium, di An insulator containing lanthanum, neodymium, hafnium, or tantalum, in a single layer, Alternatively, it can be used in a laminated configuration. Note that the insulator 2204 is silicon nitride, silicon nitride. It may also contain nitrogen-containing insulators such as those mentioned above.

[0199] Alternatively, the insulator 2204 may be made of resin. For example, polyimide, polyamide, etc. A resin containing acrylic, silicone, etc., can be used. By using a resin, the insulator 220 In some cases, it is not necessary to flatten the top surface of 4. Also, the resin forms a thick film in a short time. This allows for increased productivity.

[0200] By using a stacked structure of multiple transistors, multiple circuits can be arranged at high density. It is possible.

[0201] Here, the first semiconductor used in transistor 2200 is a single semiconductor contained in the semiconductor substrate 2211. When crystalline silicon is used, hydrogen in the insulator near the first semiconductor of transistor 2200 A high concentration is preferable. The hydrogen terminates the dangling bonds of the silicon. This improves the reliability of transistor 2200. On the other hand, transistor When an oxide semiconductor is used as the second semiconductor in transistor 2100, the second It is preferable that the hydrogen concentration of the insulator near the semiconductor is low. The hydrogen is present in the oxide semiconductor. This is one of the factors that generate carriers, thus reducing the reliability of transistor 2100. This can be a contributing factor. Therefore, the transistor 2200 using single-crystal silicon, And when stacking transistors 2100 using oxide semiconductors, hydrogen is placed between them. Placing the insulator 2207, which has a blocking function, improves the reliability of both transistors. It is effective for that purpose.

[0202] Examples of insulators 2207 include aluminum oxide, aluminum oxide and nitride, and gallium oxide. M, gallium oxide nitride, yttrium oxide, yttrium oxide nitride, hafnium oxide, acid An insulator containing hafnium nitride, yttria-stabilized zirconia (YSZ), etc., in a single layer Alternatively, they can be used in a laminated configuration.

[0203] Furthermore, the transistor 2100, which uses an oxide semiconductor, is covered by the transistor 2100. It is preferable to form an insulator on top that has the function of blocking hydrogen. An insulator similar to insulator 2207 can be used, and aluminum oxide in particular can be applied. This is preferable. The aluminum oxide film is resistant to both impurities such as hydrogen and water, and oxygen. Therefore, the insulator covering transistor 2100 has a high barrier effect that prevents the film from being permeated. By using an aluminum oxide film as 2208, the acid contained in transistor 2100 This prevents the detachment of oxygen from oxide semiconductors and also prevents the contamination of oxide semiconductors with water and hydrogen. This can prevent that.

[0204] Note that the 2200 transistor is not only a planar type transistor, but also various types It can be made into a transistor. For example, a FIN-type transistor. This is possible. An example of a cross-sectional view in that case is shown in Figure 16(B). Semiconductor substrate 2211 An insulator 2212 is placed on top. The semiconductor substrate 2211 has a thin protrusion at the tip ( It also has a protrusion. The protrusion does not have to have a thin tip; for example, a roughly rectangular parallelepiped. It may be a protrusion, or a protrusion with a thick tip. A gate insulator 2214 is placed there, and a gate electrode 2213 is placed on top of it. The semiconductor substrate 2211 has a source region and a drain region 2215 formed on it. In this example, the semiconductor substrate 2211 is shown having a protrusion, but this is one aspect of the present invention. The semiconductor devices relating to this are not limited to these. For example, by processing an SOI substrate, a convex semi-semiconductor can be formed. It is acceptable to form a conductive region.

[0205] In the above circuit, if the connections of the electrodes of transistor 2100 and transistor 2200 are different By doing so, various circuits can be constructed. Below, one embodiment of the present invention of semiconductor This section describes an example of a circuit configuration that can be realized using a physical device.

[0206] The circuit diagram shown in Figure 17(A) is a p-channel type transistor 2200 and an n-channel type transistor This is a so-called CMO (Continuously Multi-Motorized) configuration, where two Rangitar 2100s are connected in series, with each gate connected. This shows the configuration of the S-inverter.

[0207] Furthermore, the circuit diagram shown in Figure 17(B) is for transistors 2100 and 2200. This shows a configuration where the source and drain are connected. It can function as a so-called CMOS analog switch.

[0208] A transistor according to one aspect of the present invention is used to retain stored data even when power is not supplied. Figure 18 shows an example of a semiconductor device (memory device) that can be stored and has no limit on the number of write cycles. This will be shown.

[0209] The semiconductor device shown in Figure 18(A) consists of a transistor 3200 using a first semiconductor and a second semiconductor It has a semiconductor transistor 3300 and a capacitive element 3400. The transistors mentioned above can be used as the Rangista 3300.

[0210] Transistor 3300 is a transistor that uses an oxide semiconductor. Transistor 33 Due to the low off-current of 00, the memory content stored in a specific node of the semiconductor device over a long period of time It is possible to retain it. In other words, it does not require a refresh operation, or refresh Because the frequency of flash operation can be made extremely low, it is possible to create semiconductor devices with low power consumption. This is the result.

[0211] In Figure 18(A), the first wiring 3001 is electrically connected to the source of transistor 3200. The second wire 3002 is connected and electrically connected to the drain of transistor 3200. Furthermore, the third wire 3003 is electrically connected to one of the source and drain of transistor 3300. The fourth wire 3004 is connected to the gate of transistor 3300 and is electrically connected to the gate of transistor 3300. And the gate of transistor 3200, and the source of transistor 3300, The other end of the drain is electrically connected to one of the electrodes of the capacitive element 3400 and to the fifth wiring 30 05 is electrically connected to the other electrode of the capacitive element 3400.

[0212] The semiconductor device shown in Figure 18(A) is capable of maintaining the gate potential of transistor 3200. Having these characteristics, it is possible to write, hold, and read information as shown below. ru.

[0213] This section will explain how to write and retain information. First, the potential of the fourth wiring 3004 is set to the traction control. The potential is set so that transistor 3300 becomes conductive, and transistor 3300 becomes conductive. This causes the potential of the third wiring 3003 to be the gate of transistor 3200, and the capacitance It is supplied to node FG, which is electrically connected to one of the electrodes of the quantitative element 3400. A predetermined charge is applied (written) to the gate of the transistor 3200. Here, different A charge that gives two potential levels (hereinafter referred to as Low-level charge and High-level charge) .) is assumed to be given. Then, the potential of the fourth wiring 3004 is set to The potential is set so that the zista 3300 becomes non-conductive, thereby making the transistor 3300 non-conductive. As a result, charge is retained at node FG.

[0214] Because the off-current of transistor 3300 is extremely small, the charge at node FG remains constant over a long period of time. It is retained.

[0215] Next, we will explain how to read the information. A predetermined potential (constant potential) is applied to the first wiring 3001. In this state, when an appropriate potential (readout potential) is applied to the fifth wiring 3005, the second wiring 3002 takes on a potential corresponding to the amount of charge held at node FG. This is the transistor. If 3200 is an n-channel type, then a high-level charge will be applied to the gate of transistor 3200. The apparent threshold voltage V when given th_H This is the transistor 3200 Apparent threshold voltage V when a low level charge is applied to the gate th_L Yo This is because it becomes lower. Here, the apparent threshold voltage is defined as the transistor 3200 This refers to the potential of the fifth wiring 3005 necessary to achieve a "conductive state". Then, set the potential of the fifth wiring 3005 to V th_H and V th_L By setting the potential V0 between these points, Therefore, the charge applied to node FG can be determined. For example, in writing, node FG If a high-level charge is applied, the potential of the fifth wiring 3005 will be V0(> V th_H ) In that case, transistor 3200 will be in a "conducting state". On the other hand, node FG If a low-level charge is applied, the potential of the fifth wiring 3005 is V0( <V th_L Even in this state, transistor 3200 remains in a "non-conductive state". By determining the potential of the second wiring 3002, the information held in node FG can be read. It can be released.

[0216] Furthermore, when memory cells are arranged in an array, the information of the desired memory cell is read. The data must be read. In order to avoid reading information from other memory cells, the node Regardless of the charge applied to FG, the potential at which transistor 3200 becomes "non-conductive" , in other words, V th_H A lower potential should be applied to the fifth wiring 3005. Or, no The potential at which transistor 3200 becomes "conductive" regardless of the charge applied to FG. , in other words, V th_L A higher potential should be applied to the fifth wiring 3005.

[0217] The semiconductor device shown in Figure 18(B) is different from the one in Figure 18(A) in that it does not have transistor 3200. This is different from the semiconductor device shown. In this case, it operates similarly to the semiconductor device shown in Figure 18(A). It allows for more efficient information writing and retention.

[0218] The information readout process in the semiconductor device shown in Figure 18(B) will be explained. When terminal 3300 becomes conductive, the floating third wiring 3003 and the capacitive element 3400 The two circuits become conductive, and charge is redistributed between the third wiring 3003 and the capacitive element 3400. As a result, the potential of the third wiring 3003 changes. The amount of change in the potential of the third wiring 3003 is the capacitance. The potential of one electrode of element 3400 (or the charge accumulated in the capacitive element 3400) They take on different values.

[0219] For example, let V be the potential of one electrode of the capacitive element 3400, C be the capacitance of the capacitive element 3400, and the third The capacitance component of wiring 3003 is CB, and the charge of the third wiring 3003 before redistribution is CB If the potential is VB0, then the potential of the third wiring 3003 after the charge has been redistributed is (CB × VB0 + C × V) / (CB + C). Therefore, the state of the memory cell is the capacity element If one of the electrodes of the child 3400 takes on two states, V1 and V0 (V1 > V0), then , the potential of the third wiring 3003 when the potential V1 is maintained (=(CB×VB0+C×V 1) / (CB+C)) is the potential of the third wiring 3003 when the potential V0 is maintained (= It can be seen that this is higher than (CB × VB0 + C × V0) / (CB + C)).

[0220] Then, by comparing the potential of the third wiring 3003 with a predetermined potential, the information is read out. It is possible.

[0221] In this case, the first semiconductor is applied to the drive circuit for driving the memory cell. Using a transistor, a second semiconductor was applied to the transistor 3300. The components should be stacked and arranged on top of the drive circuit.

[0222] The semiconductor device described above is a transistor with extremely low off-current using an oxide semiconductor. By applying this, it becomes possible to retain memory content over a long period of time. In other words, LIFF Refreshing operations may become unnecessary or extremely infrequent. This enables the realization of semiconductor devices with low power consumption. Furthermore, the power supply is Even if there is no such thing (however, it is preferable that the potential is fixed), over a long period of time It is possible to retain the contents of memory.

[0223] Furthermore, since this semiconductor device does not require high voltage for writing information, element degradation does not occur. It is difficult. For example, unlike conventional non-volatile memory, the concentration of electrons on the floating gate Because electrons are not drawn in or out from the floating gate, the insulator does not deteriorate. The problem does not arise. That is, the semiconductor device according to one aspect of the present invention is a non-volatile memory Unlike the previous issue, there is no limit to the number of rewrite cycles, and the reliability of the semiconductor has dramatically improved. It is a device. Furthermore, the writing of information depends on the conductive and non-conductive states of the transistor. This allows for high-speed operation.

[0224] <RFタグ> In the following, we will use Figure 19 to describe the RF tag including the transistor or memory device mentioned above. I will explain.

[0225] An RF tag according to one aspect of the present invention has a memory circuit inside, stores information in the memory circuit, and It uses means of contact, such as wireless communication, to exchange information with the outside world. Therefore, RF tags are used for individual identification of items by reading their unique information. It can be used in systems and other applications. However, high reliability is required for these applications. Sex is required.

[0226] The configuration of an RF tag will be explained using Figure 19. Figure 19 shows an example of the configuration of an RF tag. This is a lock diagram.

[0227] As shown in Figure 19, the RF tag 800 is connected to the communicator 801 (also known as an interrogator, reader / writer, etc.). Antenna 8 receives a radio signal 803 transmitted from antenna 802 connected to ( It has 04. The RF tag 800 also has a rectifier circuit 805, a constant voltage circuit 806, and a demodulation circuit 8 It has a modulation circuit 808, a logic circuit 809, a memory circuit 810, and a ROM 811. Furthermore, the semiconductor of the transistor exhibiting rectification action included in the demodulation circuit 807 has a reverse current For example, an oxide semiconductor can be used to sufficiently suppress the reverse This suppresses the decrease in rectification due to directional current and prevents the output of the demodulation circuit from saturating. In other words, the output of the demodulation circuit can be made nearly linear with respect to the input of the demodulation circuit. Oh, the data transmission method is electromagnetic, where a pair of coils are placed facing each other and communicate through mutual induction. Coupling method, electromagnetic induction method which uses an inductive electromagnetic field for communication, radio wave method which uses radio waves for communication. These can be broadly categorized into three types. The RF tag 800 can be used in any of these methods.

[0228] Next, the configuration of each circuit will be explained. Antenna 804 is connected to the communication device 801. This is for transmitting and receiving wireless signals 803 with Tenor 802. Also, a rectifier circuit 8 05 rectifies the input AC signal generated by receiving a wireless signal with antenna 804. For example, half-wave voltage doubling rectification is performed, and the rectified signal is smoothed by a subsequent capacitive element. This is a circuit for generating the input potential. Note that the input or output side of the rectifier circuit 805 It may have a limiter circuit. A limiter circuit is a circuit that, when the amplitude of the input AC signal is large, When the generated voltage is high, control is implemented to prevent power exceeding a certain level from being input to the subsequent circuit. This is a circuit for that purpose.

[0229] The constant voltage circuit 806 generates a stable power supply voltage from the input potential and supplies it to each circuit. This is a circuit. Note that the constant voltage circuit 806 may also have an internal reset signal generation circuit. The reset signal generation circuit utilizes the stable rise of the power supply voltage to generate the logic circuit 80. This is a circuit for generating a reset signal for number 9.

[0230] The demodulation circuit 807 demodulates the input AC signal by detecting its envelope and generates a demodulated signal. This is a circuit for that purpose. Furthermore, the modulation circuit 808 responds to the data output from the antenna 804. This is a circuit for performing modulation.

[0231] Logic circuit 809 is a circuit for analyzing and processing demodulated signals. Memory circuit 810 is This is a circuit that holds the input information, and includes a row decoder, column decoder, memory area, etc. It has. Furthermore, ROM811 stores unique numbers (IDs), etc., and outputs them according to the processing. This is a circuit for that purpose.

[0232] Furthermore, the circuits described above can be selected or omitted as appropriate.

[0233] Here, the above-mentioned memory device can be used in the memory circuit 810. In one aspect of the present invention Since the memory device can retain information even when the power supply is cut off, it is suitable for RF tags. Furthermore, the memory device according to one aspect of the present invention requires less power (voltage) for writing data compared to conventional non-volatile memories, so it is also possible not to cause a difference in the maximum communication distance between data reading and writing. Moreover, it is possible to suppress malfunction or incorrect writing due to insufficient power during data writing. In addition, the memory device according to one aspect of the present invention can be used as a non-volatile memory, so it can also be applied to ROM811. In that case, it is preferable for the producer to separately prepare a command for writing data to ROM811 and prevent the user from freely rewriting it.

[0234] The producer writes a unique number before shipping and then ships the product. Instead of assigning unique numbers to all the manufactured RF tags, it becomes possible to assign unique numbers only to the good products to be shipped, so that the unique numbers of the products after shipping are not discontinuous and customer management corresponding to the products after shipping becomes easy.

[0235] <Usage examples of RF tags> Hereinafter, usage examples of the RF tag according to one aspect of the present invention will be described with reference to FIG. 20. The applications of RF tags are extensive. For example, banknotes, coins, securities, bearer bonds, certificates (such as driver's licenses and resident cards, see FIG. 20(A)), packaging containers (such as wrapping paper and bottles, see FIG. 20(C)), recording media (such as DVDs and video tapes, see FIG. 20(B)), vehicles (such as bicycles, see FIG. 20(D)), personal items (such as bags and glasses), food products, plants, animals, the human body, clothing, daily necessities, medical products including drugs and medicines, or electronic devices (liquid crystal watches

[0236] Articles such as display devices, EL display devices, television equipment, or mobile phones, or each article It can be used by attaching it to luggage tags (see Figures 20(E) and 20(F)), etc. can.

[0236] An RF tag 4000 according to one aspect of the present invention can be attached to or embedded in the surface of an object. It is fixed to the product. For example, in the case of a book, it is embedded in the paper, and in the case of a package made of organic resin. The RF tag is embedded inside the organic resin and fixed to each article. The 4000 is designed to be small, thin, and lightweight, and even after being fixed to an object, it does not affect the design of the object itself. It does not impair the integrity of banknotes, coins, securities, bearer bonds, or certificates. Authentication functionality can be provided to the same type of object using an RF tag 4000 according to one aspect of the present invention. This authentication function can be used to prevent counterfeiting. It can also be used for packaging containers and recording media. The present invention relates to the body, personal belongings, food products, clothing, household goods, or electronic devices, etc. By attaching RF tags 4000, the efficiency of systems such as inspection systems can be improved. This is possible. Furthermore, even vehicles can be fitted with an RF tag 4000 according to one aspect of the present invention. By attaching it, you can enhance security against theft and other crimes.

[0237] As described above, an RF tag according to one aspect of the present invention can be used for each of the above-mentioned applications. can.

[0238] <cpu> The following describes a CPU that includes semiconductor devices such as the transistors and memory devices mentioned above. I will explain.

[0239] Figure 21 is a block diagram showing an example configuration of a CPU that uses some of the transistors described above. be.

[0240] The CPU shown in Figure 21 is an ALU1191 (ALU: Arithmet) mounted on board 1190. IC logic unit, arithmetic circuit, ALU controller 1192, instruction Timing decoder 1193, interrupt controller 1194, timing controller 1195, Register 1196, Register Controller 1197, Bus Interface 1 198 (Bus I / F), rewritable ROM1199, and ROM interface It has a ROM I / F (1189). The substrate 1190 is a semiconductor substrate, SOI base A plate, glass substrate, etc. are used. ROM1199 and ROM interface 1189 are It may also be provided on a separate chip. Of course, the CPU shown in Figure 21 is a simplified representation of its configuration. This is just one example; actual CPUs have a wide variety of configurations depending on their application. For example, a configuration including the CPU or arithmetic circuit shown in Figure 21 is considered as one core, and multiple such cores are included Alternatively, the configuration may be such that each core operates in parallel. Furthermore, the CPU performs internal calculations. The number of bits that can be handled by circuits and data buses is, for example, 8 bits, 16 bits, 32 bits, 64 bits. This can be represented as bits, etc.

[0241] Instructions input to the CPU via the bus interface 1198 are instructions The signal is input to decoder 1193, decoded, and then processed by ALU controller 1192, interface Raptor controller 1194, register controller 1197, timing controller It is entered into 1195.

[0242] ALU controller 1192, interrupt controller 1194, register controller R1197 and timing controller 1195 control various commands based on the decoded instructions. To perform the operation. Specifically, the ALU controller 1192 controls the operation of the ALU 1191. It generates a signal for that purpose. Also, the interrupt controller 1194 is the CPU programmer. During execution, interrupt requests from external input / output devices and peripheral circuits are prioritized and masked. The state is judged and processed. The register controller 1197 adds register 1196 It generates a response and reads or writes to register 1196 depending on the CPU state.

[0243] Furthermore, the timing controller 1195 is connected to the ALU 1191 and the ALU controller 119 2. Instruction decoder 1193, interrupt controller 1194, and It generates signals to control the timing of the operation of the register controller 1197. For example, The timing controller 1195 uses the reference clock signal CLK1 to determine the internal clock signal It is equipped with an internal clock generation unit that generates CLK2, and the internal clock signal CLK2 is the above It supplies power to various circuits.

[0244] In the CPU shown in Figure 21, a memory cell is located in register 1196. The transistors and memory devices mentioned above can be used as 1196 memory cells. ru.

[0245] In the CPU shown in Figure 21, the register controller 1197 receives information from the ALU 1191. Following the instructions, select the hold operation in register 1196. That is, register 11 In the memory cell of 96, data is retained by a flip-flop, or capacity Select whether to retain data using an element. Data retention using a flip-flop is If selected, power voltage is supplied to the memory cells in register 1196. If data retention in the capacitive element is selected, data rewriting to the capacitive element will not occur. This process can be performed to stop the supply of power voltage to the memory cells in register 1196. .

[0246] Figure 22 shows an example of a circuit diagram of a memory element 1200 that can be used as register 1196. The memory element 1200 has a circuit 1201 in which the stored data volatilizes when the power is cut off, and Circuit 1202 that prevents data from volatilizing when disconnected, switch 1203, switch 1204 It has a logic element 1206, a capacitive element 1207, and a circuit 1220 having a selection function. Circuit 1202 consists of a capacitive element 1208, a transistor 1209, and a transistor 12 It has 10 and. The memory element 1200 may also have a diode, a resistor, if necessary. It may further include other elements such as inductors.

[0247] Here, the memory device described above can be used in circuit 1202. Memory element 1200 When the power supply voltage to is cut off, the gate of transistor 1209 in circuit 1202 is G The configuration is such that ND (0V) or a potential that turns off transistor 1209 is continuously input. For example, the gate of transistor 1209 is grounded via a load such as a resistor. .

[0248] Switch 1203 uses a single-conductivity (e.g., n-channel) transistor 1213. The switch 1204 is configured to have a conductivity type opposite to that of a single-conductivity type (for example, a p-channel type). An example using transistor 1214 is shown. Here, the first terminal of switch 1203 The child corresponds to one of the source and drain of transistor 1213, and the second of switch 1203. The terminals correspond to the source and drain of transistor 1213, and switch 1203 is The control signal RD input to the gate of transistor 1213 controls the first terminal and the second terminal. Conductivity or non-conductivity between terminals (i.e., the conductive or non-conductive state of transistor 1213) The state is selected. The first terminal of switch 1204 is connected to the source and dot of transistor 1214. Corresponding to one side of the rain, the second terminal of switch 1204 is the source of transistor 1214. Corresponding to the other side of the drain, switch 1204 is input to the gate of transistor 1214. The control signal RD determines whether the first terminal and the second terminal are conductive or non-conductive (i.e., The conduction or non-conduction state of transistor 1214 is selected.

[0249] One of the sources and drains of transistor 1209 is connected to the pair of electrodes of capacitive element 1208. One side of this is electrically connected to the gate of transistor 1210. Here, the connection part Let the minute be node M2. One of the sources and drains of transistor 1210 is at a low power supply potential. It is electrically connected to a wire (e.g., a GND wire) that can supply power, and the other is a switch. The first terminal of 1203 (one of the source and drain of transistor 1213) is electrically connected. The second terminal of switch 1203 (source and drain of transistor 1213) On the other hand, the first terminal of switch 1204 (the source and drain of transistor 1214) is the first terminal of switch 1204. It is electrically connected to the second terminal of switch 1204 (the terminal of transistor 1214). The other end (the drain and the other side) is electrically connected to wiring that can supply the power potential VDD. The second terminal of switch 1203 (the other terminal of the source and drain of transistor 1213) ) and the first terminal of switch 1204 (one of the source and drain of transistor 1214) ) and the input terminal of logic element 1206 and one of the pair of electrodes of capacitive element 1207, These are electrically connected. Here, the connection point is called node M1. A pair of capacitive elements 1207. The other electrode can be configured to receive a constant potential. For example, a low-voltage The system can be configured to receive either a source potential (such as GND) or a high power supply potential (such as VDD) as input. The other of the pair of electrodes of the capacitive element 1207 is a distribution capable of supplying a low power supply potential. It is electrically connected to a wire (for example, a GND wire). This configuration allows for a constant potential to be input. For example, a low power supply potential (such as GND). ) or a configuration in which a high power supply potential (VDD, etc.) is input. Capacitive element 120 The other of the pair of electrodes (8) is connected to a wire capable of supplying a low power potential (e.g., GND). It is electrically connected to a wire.

[0250] Capacitive elements 1207 and 1208 are used to detect parasitic capacitance in transistors and wiring. It was possible to omit it by actively using it.

[0251] The gate of transistor 1209 is input with the control signal WE. Switch 1203 and Switch 1204 is controlled by a control signal RD, which is different from the control signal WE, between the first and second terminals. A conductive or non-conductive state is selected between the terminals of one switch and the second terminal of the other switch. When the terminals of one switch are conductive, the terminals of the other switch, specifically the first and second terminals, are not conductive. This is the result.

[0252] The source and drain of transistor 1209 are connected to the data held in circuit 1201. The corresponding signal is input. In Figure 22, the signal output from circuit 1201 is the transistor An example is shown where the source and drain of switch 1203 are input. The signal output from the second terminal (the other end of the source and drain of transistor 1213) is: The logic element 1206 inverts its logic value, resulting in an inverted signal, which is then transmitted via circuit 1220. This is then input to circuit 1201.

[0253] Note that in Figure 22, the second terminal of switch 1203 (source and terminal of transistor 1213) The signal output from the other side of Rain is routed through logic element 1206 and circuit 1220. An example of input to path 1201 is shown, but it is not limited to this. The second terminal of switch 1203 The signal output from (the other side of the source and drain of transistor 1213) is the inverse of the logic value. It may be input to circuit 1201 without being converted. For example, within circuit 1201, If there is a node that holds a signal that is the inverted logical value of the signal input from the input terminal The second terminal of switch 1203 (the other of the source and drain of transistor 1213) The signal output from this node can be input to the node in question.

[0254] Furthermore, in Figure 22, among the transistors used in the memory element 1200, Transistors other than TA1209 are films or substrates 119 made of semiconductors other than oxide semiconductors. It can be a transistor in which a channel is formed at 0. For example, silicon or s A transistor can be used to form a channel on a recon substrate. Also, memory element 1 All transistors used in the 200 are transistors whose channels are formed from oxide semiconductors. It can also be set to a sta. Alternatively, the memory element 1200 can be other than transistor 1209. The channel may include a transistor formed of an oxide semiconductor, and the remaining transistors The channel is formed in a layer or substrate 1190 made of a semiconductor other than an oxide semiconductor. It can also be represented as a transistor.

[0255] In Figure 22, circuit 1201 can be, for example, a flip-flop circuit. Furthermore, logic elements such as inverters and clocked inverters can be used as logic elements 1206. It is possible.

[0256] In a semiconductor device according to one aspect of the present invention, while the memory element 1200 is not supplied with a power supply voltage, The data stored in circuit 1201 is transferred to the capacitive element 1208 provided in circuit 1202. It can be held by.

[0257] Furthermore, transistors with channels formed in oxide semiconductors exhibit extremely low off-currents. For example, the off-current of a transistor in which a channel is formed in an oxide semiconductor is crystalline. It is significantly smaller than the off-current of a transistor in which a channel is formed in silicon. Therefore, by using the transistor as transistor 1209, the memory element 12 Even when no power supply voltage is supplied to 00, the signal held by the capacitive element 1208 persists for a long period of time. The data is preserved. In this way, the memory element 1200 retains its stored contents (data) even when the power supply voltage is interrupted. It is possible to hold (T).

[0258] Furthermore, by providing switches 1203 and 1204, the pre-charge function is activated. Since it is a memory element characterized by performing an operation, after the power supply voltage is restored, the circuit 1201 This can shorten the time it takes to restore the original data.

[0259] Furthermore, in circuit 1202, the signal held by the capacitive element 1208 is transmitted to the transistor The signal is input to gate 1210. As a result, the power supply voltage to memory element 1200 is restored. After that, the signal held by the capacitive element 1208 is controlled by the state of transistor 1210 ( It can be converted to a conductive or non-conductive state and read from circuit 1202. Therefore, even if the potential corresponding to the signal held in the capacitive element 1208 fluctuates slightly, the original signal remains. It is possible to read the issue number accurately.

[0260] Such memory elements 1200 are stored in registers and cache memory of the processor. By using it in a storage device, it prevents the loss of data in the storage device due to a power supply interruption. This is possible. Furthermore, after the power supply voltage is restored, the system will quickly return to the state it was in before the power supply was interrupted. Therefore, the entire processor, or one of the components of the processor, This allows for power-off even for short periods in multiple logic circuits, thus reducing power consumption. It can be suppressed.

[0261] Although the memory element 1200 was explained as an example of being used in a CPU, the memory element 1200 is a DSP ( Digital Signal Processor), Custom LSI, PLD (Pr LSIs such as grammable logic devices, RF-ID (Radi It can also be applied to frequency identification.

[0262] <Display device> The following describes an example of the configuration of a display device according to one aspect of the present invention.

[0263] [Example Configuration] Figure 23(A) shows a top view of a display device according to one embodiment of the present invention. Also, Figure 23(B) This includes a pixel circuit in which liquid crystal elements are used for the pixels of a display device according to one aspect of the present invention. Figure 23(C) shows an organic EL element in the pixels of a display device according to one embodiment of the present invention. The pixel circuit when used is shown.

[0264] The transistors used for the pixels can be the transistors described above. Here, An example using an n-channel transistor is shown. Note that the transistor used for the pixel is the same as the one used for the pixel. A transistor manufactured through a single process may be used as the driving circuit. By using the aforementioned transistors in the element and drive circuit, a high display quality can be achieved, or / This will result in a more reliable display device.

[0265] Figure 23(A) shows an example of a top view of an active-matrix display device. The circuit board of the display device. On 5000 are the pixel section 5001, the first scan line drive circuit 5002, and the second scan line drive circuit. A path 5003 and a signal line drive circuit 5004 are arranged. The pixel unit 5001 is connected to multiple signal lines. Therefore, it is electrically connected to the signal line drive circuit 5004, and the first scan line is controlled by multiple scan lines. It is electrically connected to the drive circuit 5002 and the second scan line drive circuit 5003. Each region separated by the scan lines and signal lines contains pixels, each with a display element. Furthermore, the substrate 5000 of the display device is FPC (Flexible Printed Circuit). The timing control circuit (controller, control I) is connected via a connection part such as the d Circuit. It is electrically connected to (also called C).

[0266] First scan line drive circuit 5002, second scan line drive circuit 5003 and signal line drive circuit 5 004 is formed on the same substrate 5000 as the pixel section 5001. Therefore, the drive circuit is separate. Compared to manufacturing by hand, the cost of manufacturing the display device can be reduced. If the dynamic circuit is fabricated separately, the number of connections between wires increases. Therefore, on the same 5000 circuit board... By providing a drive circuit, the number of connections between wires can be reduced, improving reliability, or / and yield can be improved.

[0267] [Liquid crystal display device] Furthermore, an example of the pixel circuit configuration is shown in Figure 23(B). Here, the image of a VA-type liquid crystal display device This shows a pixel circuit that can be applied to elements such as elementary components.

[0268] This pixel circuit can be applied to configurations in which a single pixel has multiple pixel electrodes. The elementary electrodes are connected to different transistors, and each transistor can be driven by a different gate signal. It is configured in such a way that the individual pixel electrodes of the multi-domain designed pixels are made possible. The signals applied to it can be controlled independently.

[0269] Gate wiring 5012 of transistor 5016 and gate wiring 50 of transistor 5017 13 is separated so that different gate signals can be applied. On the other hand, data The source or drain electrode 5014, which functions as a line, connects to the transistor 5016. Commonly used in transistor 5017. Transistor 5016 and transistor 50 17 can use the transistors mentioned above as appropriate. This allows for a high display quality. Alternatively, and / or a highly reliable liquid crystal display device can be provided.

[0270] A first pixel electrode electrically connected to transistor 5016, and an electrical connection between transistor 5017 and The shape of the second pixel electrode, which is electrically connected to the first pixel electrode, will be described. The pole shapes are separated by slits. The first pixel electrode has a V-shaped spread. The second pixel electrode is formed to surround the outside of the first pixel electrode.

[0271] The gate electrode of transistor 5016 is electrically connected to the gate wiring 5012, and the transistor The gate electrode of sta 5017 is electrically connected to gate wiring 5013. By applying different gate signals to transistor 5012 and gate wiring 5013, transistor 5016 and the transistor... By varying the operating timing of the 5017 inverter, the orientation of the liquid crystal can be controlled.

[0272] Furthermore, the capacitive wiring 5010, the gate insulator which functions as a dielectric, and the first pixel electrode A capacitive element may be formed by a capacitive electrode electrically connected to a second pixel electrode.

[0273] The multi-domain structure comprises a first liquid crystal element 5018 and a second liquid crystal element 5019 in each pixel. The first liquid crystal element 5018 is composed of a first pixel electrode, a counter electrode, and a liquid crystal layer between them. The second liquid crystal element 5019 is composed of a second pixel electrode, a counter electrode, and a liquid crystal layer between them. ru.

[0274] Furthermore, the display device according to one aspect of the present invention is not limited to the pixel circuit shown in Figure 23(B). For example, a new switch, resistor, capacitive element, or transistor can be added to the pixel circuit shown in Figure 23(B). You may add elements such as switches, sensors, or logic circuits.

[0275] [Organic EL display device] Another example of a pixel circuit configuration is shown in Figure 23(C). Here, a display using an organic EL element is shown. The pixel structure of the device is shown.

[0276] Organic EL elements, when a voltage is applied to the light-emitting element, have a pair of electrical components. Electrons are injected from one pole and holes from the other into a layer containing a luminescent organic compound. An electric current flows. Then, electrons and holes recombine, causing the luminescent organic compound to... An excited state is formed, and light is emitted when that excited state returns to the ground state. This is the mechanism. Therefore, such light-emitting devices are called current-excited light-emitting devices.

[0277] Figure 23(C) shows an example of a pixel circuit. Here, one pixel has an n-channel type An example using two transistors is shown. Note that the n-channel type transistor is as described above. Transistors can be used. Furthermore, the pixel circuit is suitable for digital time-gradation driving. It can be used.

[0278] Applicable pixel circuit configurations and pixel operation when digital time-gradation driving is applied. I will explain.

[0279] Pixel 5020 has a switching transistor 5021, a driving transistor 5022, It has a light-emitting element 5024 and a capacitive element 5023. Switching transistor 502 1 has a gate electrode connected to scan line 5026, and the first electrode (source electrode, drain electrode) One side is connected to signal line 5025, and the second electrode (the other of the source electrode and drain electrode) drives It is connected to the gate electrode of the drive transistor 5022. In this configuration, the gate electrode is connected to the power line 5027 via the capacitive element 5023, and the first electrode is connected to the power supply. The second electrode is connected to the first electrode (pixel electrode) of the light-emitting element 5024, and the second electrode is connected to the first electrode (pixel electrode) of the light-emitting element 5024. The second electrode of the light-emitting element 5024 corresponds to the common electrode 5028. Common electrode 5028 It is electrically connected to a common potential line formed on the same substrate.

[0280] The switching transistor 5021 and the driving transistor 5022 are as described above. A generator can be used. This allows for a display of high quality and / or reliability. It will be a high-performance organic EL display device.

[0281] The potential of the second electrode (common electrode 5028) of the light-emitting element 5024 is set to the low power supply potential. Low power supply potential is a potential lower than the high power supply potential supplied to power line 5027, for example. GND, 0V, etc. can be set as low power supply potentials. Forward direction of light-emitting element 5024 The high and low power supply potentials are set to be above the threshold voltage, and the potential difference between them is used for the light-emitting element. By applying current to sub 5024, the light-emitting element 5024 is made to emit light. The forward voltage of the light-emitting element 5024 refers to the voltage required to achieve the desired brightness, and is less than Both include the forward threshold voltage.

[0282] Furthermore, the capacitive element 5023 is used as a substitute for the gate capacitance of the drive transistor 5022. It may be possible to omit it. Regarding the gate capacitance of the drive transistor 5022, channel A capacitance may be formed between the lubrication region and the gate electrode.

[0283] Next, we will explain the signal input to the drive transistor 5022. Voltage input, voltage drive In this method, the drive transistor 5022 is in one of two states: on or off. The deo signal is input to the drive transistor 5022. To operate 2 in the linear region, a voltage higher than the voltage of power line 5027 is used for the drive transistor. This is applied to the gate electrode of the zista 5022. Additionally, the signal line 5025 is driven by the power line voltage. Apply a voltage greater than or equal to the threshold voltage Vth of transistor 5022.

[0284] When performing analog grayscale driving, the gate electrode of the driving transistor 5022 is connected to the light-emitting element 50 The value obtained by adding the forward voltage of the 24 transistor to the threshold voltage Vth of the drive transistor 5022 is greater than or equal to the forward voltage of the 24 transistor. Apply voltage. Note that the drive transistor 5022 should operate in the saturation region. Enter a number and flow current to the light-emitting element 5024. Also, saturate the drive transistor 5022. To operate in the region, the potential of power line 5027 is set to the gate of drive transistor 5022. The potential is raised higher than the t. By making the video signal analog, the video signal is sent to the light-emitting element 5024. By applying a current corresponding to the number, analog grayscale driving can be performed.

[0285] Furthermore, the display device according to one aspect of the present invention is not limited to the pixel configuration shown in Figure 23(C). For example, the pixel circuit shown in Figure 23(C) includes switches, resistors, capacitives, sensors, and traps. You may add an inverter or logic circuit.

[0286] When applying the above-mentioned transistor to the circuit illustrated in Figure 23, the source electrode is on the low-potential side. The structure is such that the first electrode and the drain electrode (second electrode) are electrically connected to the high potential side. This is considered complete. Furthermore, the potential of the first gate electrode is controlled by a control circuit, and the second gate electrode The electrode has a configuration that allows input of potentials lower than the potential applied to the source electrode, as exemplified above. You can just mark it as "completed".

[0287] For example, in this specification, etc., display element, display device having a display element, light-emitting element A light-emitting device, which is a device having a sub-element and a light-emitting element, can be used in various forms or It can have various elements. Display elements, display devices, light-emitting elements, or light-emitting devices are, for example, EL elements (EL elements including organic and inorganic materials, organic EL elements, inorganic EL elements), L LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc.), transistors (for current) Transistors that emit light accordingly, electron emission elements, liquid crystal elements, electronic inks, electrophoretic elements, Grating light bulbs (GLV), plasma display panels (PDP), ME Display elements using MS (Micro-Electro-Mechanical Systems), Digital Micro Chromilar device (DMD), DMS (Digital Microshutter), IMOD (Interference Modulation) element, shutter-type MEMS display element Optical interference type MEMS display elements, electrowetting elements, piezoelectric ceramic elements It has at least one of the following: a spray, a display element using carbon nanotubes, etc. In addition to these, electrical or magnetic effects affect contrast, brightness, reflectance, and transmittance. It may have a display medium in which such elements change. An example of a display device using an EL element is Examples include EL displays. One example of a display device using an electron-emitting element is a fee FED (Floating Emission Display) or SED (Solid Emission Display) type flat panel display (SED) :Surface-conduction Electron-emitter Dis Examples include (play). An example of a display device using liquid crystal elements is a liquid crystal display ( Transmissive liquid crystal displays, semi-transmissive liquid crystal displays, reflective liquid crystal displays, direct-view type Examples include liquid crystal displays (LCDs) and projection liquid crystal displays. Electronic ink, or electrophoresis. Examples of display devices using elements include electronic paper. Semitransmissive liquid crystal displays When realizing a display or reflective liquid crystal display, some or all of the pixel electrodes The solution is to make it function as a reflective electrode. For example, part or all of the pixel electrodes. However, it is sufficient to have aluminum, silver, etc. Furthermore, in that case, below the reflecting electrode It is also possible to incorporate memory circuits such as SRAM. This further reduces power consumption. It can be reduced.

[0288] Furthermore, white light (W) is used for backlighting (organic EL elements, inorganic EL elements, LEDs, fluorescent lamps, etc.). In order to display a display device in full color using a color layer (also called a color filter), .) may be used. The colored layer may be, for example, red (R), green (G), and blue (B). Yellow (Y) and other colors can be used in appropriate combinations. By using a colored layer, Compared to not using a colored layer, the color reproduction can be improved. In this case, the colored layer By arranging regions that have a colored layer and regions that do not have a colored layer, the region that does not have a colored layer White light in the area may be used directly for display. A portion of the area may be placed without a colored layer. This reduces the decrease in brightness caused by the colored layer when displaying bright content, and reduces power consumption by 20%. In some cases, this can be reduced by about 30%. However, this is not possible with self-emissive elements such as organic EL elements and inorganic EL elements. When using elements for full-color display, R, G, B, Y, and W are used, each having its own emitted color. It is also acceptable to emit light from an element. By using an element that emits light, it is possible to achieve better results than when using a colored layer. In some cases, power consumption can be reduced even further.

[0289] <module> In the following section, a display module using a semiconductor device according to one aspect of the present invention is shown in Figure 24. We will use this to provide an explanation.

[0290] The display module 8000 shown in Figure 24 consists of an upper cover 8001 and a lower cover 8002. In between, the touch panel 8004 is connected to the FPC8003, and the FPC8005 is connected to the touch panel 8004. Cell 8006, backlight unit 8007, frame 8009, printed circuit board 801 0, has battery 8011. Note that backlight unit 8007, battery 8 It may not have features such as 011 or the touch panel 8004.

[0291] A semiconductor device according to one aspect of the present invention can be used, for example, as cell 8006.

[0292] The upper cover 8001 and the lower cover 8002 are the touch panel 8004 and cell 80 The shape and dimensions can be appropriately modified to match the size of 06.

[0293] The touch panel 8004 uses a resistive or capacitive touch panel, and cell 8006 It can be used by superimposing it on the other substrate. Also, touch the opposing substrate (encapsulating substrate) of cell 8006. It is also possible to incorporate panel functionality. Alternatively, within each pixel of cell 8006... It is also possible to incorporate an optical sensor and use an optical touch panel. Alternatively, Cell 800 By providing touch sensor electrodes within each of the six pixels, it is also possible to create a capacitive touch panel. It is possible.

[0294] The backlight unit 8007 has a light source 8008. The light source 8008 is used as the backlight. A configuration using a light-diffusing plate, which is provided at the end of unit 8007, may also be used.

[0295] Frame 8009 provides protection for cell 8006, as well as the operation of printed circuit board 8010. It may also function as an electromagnetic shield to block the generated electromagnetic waves. The Mu8009 may also function as a heat sink.

[0296] The printed circuit board 8010 is a power supply circuit and a signal for outputting video and clock signals. It has a power processing circuit. The power supply that provides power to the power supply circuit is an external commercial power supply. Alternatively, a power source provided separately by battery 8011 may be used. In that case, it is not necessary to have battery 8011.

[0297] Furthermore, the display module 8000 includes additional components such as polarizing plates, phase difference plates, and prism sheets. They may also be provided.

[0298] <Electronic equipment> A semiconductor device according to one aspect of the present invention comprises a display device, a personal computer, and a recording medium. Image playback devices (typically DVDs: Digital Versatile Discs) To be used in a device that has a display capable of playing back recording media such as the above and displaying the images thereof. This is possible. In addition, electronic devices that can use a semiconductor device according to one aspect of the present invention This includes mobile phones, game consoles including portable models, mobile data terminals, e-readers, and video cameras. , cameras such as digital still cameras, goggle-type displays (head-mounted displays) (Ray), navigation systems, sound reproduction devices (car audio, digital audio) Players, photocopiers, fax machines, printers, multifunction printers, ATMs Examples include ATMs and vending machines. Specific examples of these electronic devices are shown in Figure 25. vinegar.

[0299] Figure 25(A) shows a portable game console, consisting of a casing 901, casing 902, display unit 903, and display unit. 904, Microphone 905, Speaker 906, Control Keys 907, Stylus 908 It has the following features. The portable game console shown in Figure 25(A) has two display units 903 and a display unit. Although it has part 904, the number of display units that a portable game console has is not limited to this. .

[0300] Figure 25(B) shows a portable data terminal, comprising a first housing 911, a second housing 912, and a first display unit 9 13. It has a second display unit 914, a connection unit 915, an operation key 916, etc. First display unit 913 The first housing 911 is provided, and the second display unit 914 is provided in the second housing 912. Furthermore, the first housing 911 and the second housing 912 are connected by a connecting part 915. The angle between the first housing 911 and the second housing 912 can be changed by the connecting part 915. The video in the first display unit 913 is connected to the first housing 911 and the second housing 9 in the connection unit 915. The configuration may be such that it switches according to the angle between 12 and 12. Also, the first display unit 913 and a display in which at least one of the second display unit 914 is provided with a function as a position input device. A display device may be used. Note that the function as a position input device is provided by the display device. It can be added by providing a control panel. Alternatively, the function as a position input device can be... By installing a photoelectric conversion element, also called a photosensor, in the pixel section of the display device, additional features can be added. It is possible.

[0301] Figure 25(C) shows a notebook personal computer, comprising a casing 921, a display unit 922, and a keyboard. It includes a board 923, a pointing device 924, and the like.

[0302] Figure 25(D) shows an electric refrigerator-freezer, consisting of a casing 931, a refrigerator door 932, and a freezer door 93 It has a third-class rating.

[0303] Figure 25(E) shows a video camera, comprising a first housing 941, a second housing 942, a display unit 943, It has an operation key 944, a lens 945, a connecting part 946, etc. Operation key 944 and lens 945 is provided in the first housing 941, and the display unit 943 is provided in the second housing 942. And the first housing 941 and the second housing 942 are connected by a connecting part 946. The angle between the first housing 941 and the second housing 942 can be changed by the connecting part 946. The video on the display unit 943 is connected to the first housing 941 and the second housing 94 in the connection unit 946. The configuration may also be configured to switch according to the angle between 2 and 3.

[0304] Figure 25(F) is a regular passenger car, consisting of the body 951, wheels 952, dashboard 953, and It has Ito 954, etc.

[0305] <Electronic devices with curved surfaces in their display or light-emitting areas> In the following, an example of an electronic device according to one aspect of the present invention is a curved surface in the display area or light-emitting area. The electronic devices we possess will be explained with reference to Figure 26. As an example, we will explain information devices, particularly portable information devices (portable devices). Examples of information devices that have wireless capabilities include mobile phones (phablets, smartphones) This also includes smartphones, tablet devices (slate PCs), etc.

[0306] Figure 26(A-1) is a perspective view illustrating the external dimensions of the portable device 1300A. 2) is a top view of the portable device 1300A. Figure 26(A-3) is the portable device 1300A. This is a diagram illustrating the usage state.

[0307] Figures 26(B-1) and 26(B-2) are perspective views illustrating the external appearance of the portable device 1300B. This is a diagram.

[0308] Figures 26(C-1) and 26(C-2) are perspective views illustrating the external shape of the portable device 1300C. This is a diagram.

[0309] <Mobile devices> The portable device 1300A can perform functions such as making phone calls, creating and viewing emails, and browsing a notebook or other information. It possesses one or more functions selected from among the functions.

[0310] The portable device 1300A has display units along multiple sides of its casing. For example, The display unit can be provided by arranging a display device with transparency along the inside of the housing. This allows text information and image information to be stored in the first region 1311 and / or the second region. It can be displayed as 1312.

[0311] For example, images used for three operations can be displayed in the first region 1311 (Figure See 26(A-1). Also, as shown by the dashed rectangle in the figure, text information etc. is in the second area. It can be displayed in region 1312 (see Figure 26(A-2)).

[0312] If a second area 1312 is placed on top of the portable device 1300A, the portable device 1300A While still stored in the breast pocket of his clothing, the second area 1312 of the portable device 1300A The displayed text and image information can be easily confirmed by the user (Figure 26 (A-3)). (See reference.) For example, the phone number or name of the caller of an incoming call, etc., on a mobile device 130 It can be observed from above at 0A.

[0313] Furthermore, the portable device 1300A has input devices between the display device and the housing, inside the display device, or on the housing. It may have a sensor, etc. Input devices include, for example, a touch sensor, an optical sensor, an ultrasonic sensor. A sir or similar device can be used. When the input device is placed between the display device and the housing or on the housing. Matrix switch method, resistive film method, ultrasonic surface acoustic wave method, infrared method, electromagnetic induction A touch panel using methods such as capacitive touch or similar technology can be used. Furthermore, the input device can be placed within the display device. When deploying, use in-cell type sensors or on-cell type sensors. That's all you need to do.

[0314] Furthermore, the portable device 1300A is equipped with a vibration sensor and other sensors that detect vibrations detected by the vibration sensor. It has a storage device that stores a program that switches to a mode that rejects incoming calls based on vibration. This allows the user to lightly tap and shake the portable device 1300A over their clothes. By giving it a command, you can switch it to a mode that rejects incoming calls.

[0315] The portable device 1300B has a display unit having a first area 1311 and a second area 1312. It has a housing 1310 that supports the display unit.

[0316] The housing 1310 has multiple bends, and the longest bend of the housing 1310 is the first region It is sandwiched between region 1311 and the second region 1312.

[0317] The portable device 1300B has a second region 1312 provided along the longest bend on its side. It can be used for directing purposes.

[0318] The portable device 1300C has a display unit having a first area 1311 and a second area 1312. It has a housing 1310 that supports the display unit.

[0319] The housing 1310 has multiple bends, and the second longest bend of the housing 1310 is the first It is sandwiched between region 1311 and the second region 1312.

[0320] The portable device 1300C can be used with the second area 1312 facing upwards. [Explanation of Symbols]

[0321] 102 Insulator 104 Conductors 106a Semiconductor 106b Semiconductor 106c semiconductor 108 Insulator 112 Insulator 116a Conductor 116b Conductor 124a area 124b area 400 circuit boards 402 Insulator 404 Conductors 405 Conductor 406a Semiconductor 406b Semiconductor 406c semiconductor 408 Insulator 412 Insulator 413 Conductors 416a Conductor 416b Conductor 418 Insulator 424a Conductor 424b Conductor 426a Conductor 426b Conductor 428 Insulator 800 RF tags 801 Communication device 802 Antenna 803 Wireless signal 804 Antenna 805 Rectifier circuit 806 Constant Voltage Circuit 807 Demodulation Circuit 808 Modulation Circuit 809 Logic Circuits 810 Memory circuit 811 ROM 901 cabinet 902 cabinet 903 Display section 904 Display section 905 Microphone 906 Speakers 907 Operation Keys 908 Stylus 911 cabinet 912 cabinet 913 Display section 914 Display section 915 Connection part 916 Operation Keys 921 cabinet 922 Display section 923 Keyboard 924 Pointing Devices 931 cabinet 932 Refrigerator door 933 Freezer door 941 cabinet 942 cabinets 943 Display section 944 Operation Keys 945 lens 946 Connection part 951 Body 952 wheels 953 Dashboard 954 Light 1189 ROM Interface 1190 circuit board 1191 ALU 1192 ALU Controller 1193 Instruction Decoder 1194 Interrupt Controller 1195 Timing Controller 1196 Register 1197 Register Controller 1198 Bus Interface 1199 ROM 1200 memory elements 1201 Circuit 1202 Circuit 1203 Switch 1204 Switch 1206 Logic Element 1207 Capacitive element 1208 Capacitive element 1209 Transistors 1210 Transistors 1213 Transistors 1214 Transistors 1220 Circuit 1300A Portable Devices 1300B Portable Devices 1300C Portable Devices 1310 cabinet 1311 area 1312 area 2100 transistors 2200 transistors 2201 Insulator 2202 Conductor 2203 Conductor 2204 Insulator 2205 Conductor 2206 Conductor 2207 Insulator 2208 Insulator 2211 Semiconductor substrate 2212 Insulator 2213 Terminal 2214 Gate Insulator 2215 Source area and drain area 3001 Wiring 3002 Wiring 3003 Wiring 3004 Wiring 3005 Wiring 3200 transistors 3300 transistors 3400 Capacitive element 4000 RF tags 5000 circuit boards 5001 pixel section 5002 Scan Line Drive Circuit 5003 Scan Line Drive Circuit 5004 Signal Line Drive Circuit 5010 Capacitor wiring 5012 Gate Wiring 5013 Gate wiring 5014 Drain electrode 5016 Transistor 5017 Transistor 5018 Liquid crystal element 5019 Liquid crystal element 5020 pixels 5021 Switching Transistor 5022 Driver Transistor 5023 Capacitive element 5024 Light-emitting element 5025 Signal Line 5026 scan lines 5027 Power line 5028 Common electrode 5100 pellets 5120 circuit board 5161 area 8000 Display Module 8001 Top cover 8002 Lower cover 8003 FPC 8004 Touch Panel 8005 FPC 8006 cell 8007 Backlight Unit 8008 light source 8009 Frame 8010 Printed Circuit Board 8011 Battery< / cpu>

Claims

1. A first conductive layer having the function of the first gate electrode of a transistor, A first insulating layer having a region located above the first conductive layer, An oxide semiconductor layer having a region located above the first conductive layer via the first insulating layer and having a channel formation region for the transistor, A second conductive layer having a region in contact with the upper surface of the oxide semiconductor layer and functioning as one of the source electrode and drain electrode of the transistor, A third conductive layer having a region in contact with the upper surface of the oxide semiconductor layer and functioning as the other of the source electrode and drain electrode of the transistor, A second insulating layer having a region located above the oxide semiconductor layer, The device comprises a fourth conductive layer having a region that overlaps with the oxide semiconductor layer via the second insulating layer and functioning as the second gate electrode of the transistor, One end of the oxide semiconductor layer in the channel length direction overlaps with the second conductive layer, and the other end of the oxide semiconductor layer in the channel length direction overlaps with the third conductive layer. The oxide semiconductor layer has a first region that overlaps with the second conductive layer and does not overlap with the first conductive layer, the third conductive layer, and the fourth conductive layer; a second region that does not overlap with the first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer; a third region that overlaps with the first conductive layer and does not overlap with the second conductive layer, the third conductive layer, and the fourth conductive layer; and a fourth region that overlaps with the first conductive layer and the fourth conductive layer. In a plan view of the transistor, the first region is connected to the fourth region via the second region and the third region in that order. In a plan view of the transistor, the second conductive layer does not have a region that overlaps with the first conductive layer, nor does it have a region that overlaps with the fourth conductive layer. In a plan view of the transistor, the third conductive layer has a region that overlaps with the fourth conductive layer. A semiconductor device wherein at least a portion of the edge of the second insulating layer overlaps the oxide semiconductor layer.

2. A first conductive layer having the function of the first gate electrode of a transistor, A first insulating layer having a region located above the first conductive layer, An oxide semiconductor layer having a region located above the first conductive layer via the first insulating layer and having a channel formation region for the transistor, A second conductive layer having a region in contact with the upper surface of the oxide semiconductor layer and functioning as one of the source electrode and drain electrode of the transistor, A third conductive layer having a region in contact with the upper surface of the oxide semiconductor layer and functioning as the other of the source electrode and drain electrode of the transistor, A second insulating layer having a region located above the oxide semiconductor layer, The device comprises a fourth conductive layer having a region that overlaps with the oxide semiconductor layer via the second insulating layer and functioning as the second gate electrode of the transistor, One end of the oxide semiconductor layer in the channel length direction overlaps with the second conductive layer, and the other end of the oxide semiconductor layer in the channel length direction overlaps with the third conductive layer. The oxide semiconductor layer has a first region that overlaps with the second conductive layer and does not overlap with the first conductive layer, the third conductive layer, and the fourth conductive layer; a second region that does not overlap with the first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer; a third region that overlaps with the first conductive layer and does not overlap with the second conductive layer, the third conductive layer, and the fourth conductive layer; and a fourth region that overlaps with the first conductive layer and the fourth conductive layer. In a plan view of the transistor, the first region is connected to the fourth region via the second region and the third region in that order. In a plan view of the transistor, the second conductive layer does not have a region that overlaps with the first conductive layer, nor does it have a region that overlaps with the fourth conductive layer. In a plan view of the transistor, the third conductive layer has a region that overlaps with the fourth conductive layer. At least a portion of the edge of the second insulating layer overlaps the oxide semiconductor layer, The width of the second conductive layer in the channel width direction of the transistor is greater than the width of the oxide semiconductor layer in the channel width direction of the transistor. A semiconductor device wherein the width of the third conductive layer in the channel width direction of the transistor is greater than the width of the oxide semiconductor layer in the channel width direction of the transistor.

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