Method for manufacturing semiconductor devices

Abstract

To provide a semiconductor device with excellent electric characteristics, a manufacturing method for the same, a module, and an electronic appliance.SOLUTION: A transistor 200 includes: an insulator 216 on an insulator 214; conductors 205a and 205b disposed so as to be embedded in the insulator; an insulator 222 on the insulator and the conductor 205; an insulator 224 thereon; an oxide 230a thereon; an oxide 230b thereon; oxides 243a and 243b thereon; conductors 242a and 242b on the respective oxides; an oxide 230c on the oxide 230b; an insulator 250 thereon; conductors 260a and 260b positioned on the insulator and overlapping with the oxide 230c; an insulator 272 in contact with a part of an upper surface of the insulator 224, side surfaces of the oxides 230a, 230b, 243a, and 243b and the conductors 242a and 242b, and upper surfaces of the conductors; an insulator 273 thereon; an insulator 280 thereon; and an insulator 282 thereon.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to a semiconductor device and a method for manufacturing the semiconductor device. Or, one aspect of the present invention relates to a semiconductor wafer, a module, and an electronic device. Note that in this specification and the like, the semiconductor device generally refers to any device that can function by utilizing semiconductor characteristics. Semiconductor devices include semiconductor elements such as transistors, semiconductor circuits, arithmetic units, and storage devices.

[0002] Display devices (such as liquid crystal display devices and light-emitting display devices), projection devices, lighting devices, electro-optical devices, power storage devices, storage devices, semiconductor circuits, imaging devices, and electronic devices may be said to have semiconductor devices. Among them, semiconductor circuits (IC chips) such as LSIs, CPUs, and memories are mounted on a circuit board, for example, a printed wiring board, and are used as one of the components of various electronic devices. Note that one aspect of the present invention is not limited to the above technical field. One aspect of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Or, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter).

[0003]

[0004]

Background Art

[0004] In recent years, the development of semiconductor devices has advanced, and LSIs, CPUs, and memories are mainly used. A CPU is an aggregate of semiconductor elements having a semiconductor integrated circuit (at least transistors and memories) separated from a semiconductor wafer and having electrodes as connection terminals formed thereon.

[0005]

[0006] ​​ Furthermore, a transistor is constructed using a semiconductor thin film formed on a substrate having an insulating surface. The technology is attracting attention. This transistor is used in integrated circuits (ICs) and image display devices (simply display). It is widely applied to electronic devices (also referred to as devices). Applicable to transistors. Silicon-based semiconductor materials are widely known as capable semiconductor thin films, but other materials include Oxide semiconductors are attracting attention.

[0007] Furthermore, transistors using oxide semiconductors have extremely low leakage current in the non-conductive state. It is known to be small. For example, the leakage current of a transistor using an oxide semiconductor is Low-power CPUs and other devices that take advantage of this characteristic have been disclosed (see Patent Document 1). ). Also, for example, the characteristic of low leakage current in transistors using oxide semiconductors. Applications of this technology include the disclosure of memory devices that can retain memory contents over long periods of time. (See Patent Document 2.)

[0008] Furthermore, in recent years, with the miniaturization and weight reduction of electronic devices, the need for even higher density integrated circuits has increased. Demand is increasing. Furthermore, there is a need for improved productivity in semiconductor devices, including integrated circuits. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2012-257187 [Patent Document 2] Japanese Patent Publication No. 2011-151383 [Overview of the project] [Problems that the invention aims to solve]

[0010] One aspect of the present invention aims to provide a semiconductor device having good electrical characteristics. Alternatively, one aspect of the present invention provides a semiconductor device having normally-off electrical characteristics. One of the challenges is to achieve this. Alternatively, one aspect of the present invention provides a semiconductor device with good reliability. One of the objectives is to provide a semiconductor with a high on-current. Alternatively, one aspect of the present invention is a semiconductor with a high on-current. One of the objectives is to provide an apparatus. Alternatively, one aspect of the present invention provides a high frequency characteristic. One objective is to provide a semiconductor device having a micro One of the objectives is to provide a semiconductor device that can be miniaturized or highly integrated. One aspect of the invention aims to provide a highly productive semiconductor device.

[0011] One aspect of the present invention provides a semiconductor device capable of retaining data over a long period of time. This is one of the challenges. One aspect of the present invention provides a semiconductor device with a high information writing speed. One of the challenges is to provide a semiconductor device with a high degree of design freedom. This is one of the challenges. One aspect of the present invention is a semiconductor device that can reduce power consumption. One of the objectives of this invention is to provide a novel semiconductor device. This will be one of the challenges.

[0012] Furthermore, the description of these problems does not preclude the existence of other problems. One approach does not require that all of these issues be resolved. The title will become clear from the description in the specification, drawings, claims, etc. It is possible to extract other issues from the descriptions in the drawings, claims, etc. [Means for solving the problem]

[0013] One aspect of the present invention comprises a first conductor, first and second insulators, and first and second acids In a method for manufacturing a semiconductor device having an oxide, a first oxide is formed on a substrate, and the first A first insulator is formed on the oxide, and an opening is formed in the first insulator that reaches the first oxide. The first oxide film is formed so as to be in contact with the first oxide and the first insulator at the opening. A film is formed, and a first insulating film is formed on the first oxide film using the PEALD method, and the first insulating film A first conductive film is formed on top, and a part of the first oxide film, a part of the first insulating film, and the first Remove a portion of the conductive film until the upper surface of the first insulator is exposed, and then remove the second oxide and the second insulator. The edge body and the first conductor are formed, and the deposition of the first insulating film is performed by heating the substrate to 300°C or higher. The process involves introducing a first gas containing silicon into the chamber, and the oxygen radical A semiconductor comprising the step of introducing a second gas into a chamber that contains but does not contain hydrogen atoms, This describes the method for manufacturing the body device.

[0014] Furthermore, in the process of introducing the second gas, the first oxide, the first oxide film, and the first It is preferable to irradiate the insulator with microwaves.

[0015] Another aspect of the present invention comprises a first conductor, first and second insulators, and a first and A method for manufacturing a semiconductor device having a first oxide and a second oxide, wherein the first oxide is formed on a substrate. A first insulator is formed on the first oxide, and the first oxide is deposited on the first insulator. An opening is formed, and in the opening, the first oxide and the first insulator are in contact with each other. An oxide film is formed, and on the first oxide film, the second is applied using the Thermal ALD method. A first insulating film is formed, a first conductive film is formed on the first insulating film, and a part of the first oxide film, A portion of the first insulating film and a portion of the first conductive film are exposed until the upper surface of the first insulator is exposed. Remove to form a second oxide, a second insulator, and a first conductor, and the first insulating film The film deposition is carried out while heating the substrate to over 350°C, and a first gas containing silicon is introduced into the chamber. - A process of introducing into and a part that includes at least one of ozone and oxygen and does not contain hydrogen atoms. This is a method for manufacturing a semiconductor device, comprising the steps of introducing two gases into a chamber.

[0016] Furthermore, in the above, before forming the first insulating film, the first oxide, the first oxide film, It is preferable to irradiate the first insulator with microwaves. Furthermore, in the above, Before forming the insulating film 1, oxygen is added to the first oxide, the first oxide film, and the first insulator. It is preferable to perform the plasma treatment in an atmosphere containing [the specified element].

[0017] Furthermore, in the above, after the formation of the second oxide, the second insulator, and the first conductor, Furthermore, a third is placed on top of the first insulator, the second oxide, the second insulator, and the first conductor. An insulator is formed, and a silicon nitride film is formed on the third insulator using the PEALD method. Preferably, in the above, before forming the silicon nitride film, the first oxide, It is preferable to irradiate the second oxide and the first insulator with microwaves. [Effects of the Invention]

[0018] According to one aspect of the present invention, a semiconductor device having good electrical characteristics can be provided. Alternatively, according to one aspect of the present invention, a semiconductor device having normally-off electrical characteristics is provided. This is possible. Alternatively, according to one aspect of the present invention, a reliable semiconductor device can be provided. This is possible. Alternatively, according to one aspect of the present invention, a semiconductor device with a large on-current is provided. This is possible. Alternatively, according to one aspect of the present invention, a semiconductor device having high frequency characteristics can be provided. It can be provided. Alternatively, according to one aspect of the present invention, a semiconductor capable of miniaturization or high integration can be provided. A conductive device can be provided. Alternatively, according to one aspect of the present invention, a highly productive semiconductor can be provided. We can provide the device.

[0019] Alternatively, a semiconductor device capable of retaining data over a long period of time can be provided. Alternatively, it is possible to provide a semiconductor device with a high data writing speed. Or, designing it yourself It is possible to provide semiconductor devices with high flexibility, or to reduce power consumption. We can provide semiconductor devices. Or, we can provide novel semiconductor devices. .

[0020] Furthermore, the description of these effects does not preclude the existence of other effects. One embodiment does not need to have all of these effects. Other effects are described in the specification. This will become clear from the description in the drawings, claims, etc., and the specification, drawings, claims From descriptions such as these, it is possible to extract other effects. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1A is a top view of a semiconductor device according to one aspect of the present invention. Figures 1B and 1C are cross-sectional views of a semiconductor device according to one aspect of the present invention. [Figure 2] Figure 2 is a cross-sectional view showing a model of a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 3]Figure 3 is a cross-sectional view showing a model of a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 4] Figures 4A and 4B are cross-sectional views of a semiconductor device according to one aspect of the present invention. [Figure 5] Figure 5A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 5B and 5C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 6] Figure 6A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 6B and 6C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 7] Figure 7A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 7B and 7C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 8] Figure 8A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 8B and 8C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 9] Figure 9A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 9B and 9C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 10] Figure 10A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 10B and 10C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 11] Figure 11A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 11B and 11C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 12] Figure 12A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 12B and 12C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 13]Figure 13A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 13B and 13C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 14] Figure 14A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 14B and 14C are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 15] Figure 15A is a top view illustrating a film deposition apparatus according to one aspect of the present invention. Figure 15B is a cross-sectional view illustrating a film deposition apparatus according to one aspect of the present invention. [Figure 16] Figures 16A to 16C are cross-sectional views illustrating a film deposition apparatus according to one aspect of the present invention. [Figure 17] Figures 17A and 17B illustrate a film formation method according to one aspect of the present invention. [Figure 18] Figure 18 is a cross-sectional view showing the configuration of a storage device according to one aspect of the present invention. [Figure 19] Figure 19 is a cross-sectional view showing the configuration of a storage device according to one aspect of the present invention. [Figure 20] Figure 20A is a block diagram showing an example of the configuration of a storage device according to one aspect of the present invention. Figure 20B is a schematic diagram showing an example of the configuration of a storage device according to one aspect of the present invention. [Figure 21] Figures 21A to 21H are circuit diagrams showing an example of the configuration of a storage device according to one aspect of the present invention. [Figure 22] Figures 22A and 22B are schematic diagrams of a semiconductor device according to one aspect of the present invention. [Figure 23] Figures 23A and 23E are schematic diagrams of a storage device according to one embodiment of the present invention. [Figure 24] Figures 24A to 24F show an electronic device according to one aspect of the present invention. [Figure 25] Figures 25A and 25B are graphs showing the carrier concentrations of the oxides in the examples. [Figure 26] Figures 26A and 26B are graphs showing the hydrogen concentration of the oxides in the examples. [Modes for carrying out the invention]

[0022] The embodiments will be described below with reference to the drawings. However, many embodiments are described. It can be implemented in different ways, without deviating from its purpose and scope. It will be readily apparent to those skilled in the art that the form and details can be varied in various ways. Therefore, the present invention shall not be construed as being limited to the contents described in the following embodiments.

[0023] Furthermore, in the drawings, the size, layer thickness, or area may be exaggerated for clarity. This may be the case. Therefore, it is not necessarily limited to that scale. Note that the drawing is an ideal This is a schematic example and is not limited to the shapes or values ​​shown in the diagram. For example, In the actual manufacturing process, processes such as etching can cause layers and resist masks to be altered as intended. Although there may be some reduction in volume, this is sometimes not reflected in the diagram for the sake of ease of understanding. In drawings, the same reference numeral is used for identical parts or parts having similar functions across different drawings. It is used in common, and explanations of its repetition may be omitted. Also, in cases where similar functions are referred to... In some cases, the hatch patterns are the same, and no specific designation is assigned.

[0024] Furthermore, especially in top views (also called "plan views") and perspective views, the invention is made easily understandable. Therefore, the description of some components may be omitted. Also, some hidden lines and other elements may be omitted. It may be omitted.

[0025] Furthermore, the ordinal numbers used in this specification, etc., as "1st," "2nd," etc., are used for convenience only. It does not indicate the order of processes or stacking order. Therefore, for example, "the first" should be written as "the second". This can be explained by appropriately replacing it with "of" or "the third of," etc. The ordinal numbers described herein do not correspond to the ordinal numbers used to specify one aspect of the present invention. There are cases where this is the case.

[0026] Furthermore, in this specification, phrases indicating placement such as "above" and "below" refer to the relative positions of the components. The positional relationships are used for convenience in explaining them by referring to the diagram. Also, the positions of the components are shown. The relationships change as appropriate depending on the direction in which each component is described. Therefore, in the specification... The terms explained are not limited to those used in the text; they can be appropriately rephrased depending on the context.

[0027] For example, in this specification, it is explicitly stated that X and Y are connected. In this case, X and Y are electrically connected, and X and Y are functionally connected. The cases disclosed in this specification, etc., include cases where X and Y are directly connected. Therefore, it is limited to predetermined connection relationships, for example, connection relationships shown in a diagram or text. Furthermore, connections other than those shown in the diagram or text are also disclosed in the diagram or text. It shall be considered as such.

[0028] Here, X and Y are objects (e.g., devices, elements, circuits, wiring, electrodes, terminals, conductive films, etc.) Let's assume it is a layer, etc.

[0029] Furthermore, the source and drain functions may differ when using transistors with different polarities, or when the circuit The direction of the current may change during operation, which can cause the current to switch positions. In detailed documents, the terms "source" and "drain" may be used interchangeably. ru.

[0030] In this specification, depending on the transistor structure, channel formation may actually occur. Channel width in the channel formation region (hereinafter also referred to as "effective channel width") (hereinafter referred to as "apparent channel") and the channel width shown in the top view of the transistor (hereinafter referred to as "apparent channel") The "gate width" (also called the "gate width") may differ from the "gate width" (or "gate width") of the semiconductor. For example, when the gate covers the side of the semiconductor. The effective channel width becomes larger than the apparent channel width, and this effect cannot be ignored. In some cases, it may disappear. For example, in transistors that are very small and whose gates cover the side of the semiconductor, In some cases, the proportion of channel formation regions formed on the side surface of the semiconductor can become large. Therefore, the effective channel width becomes larger than the apparent channel width.

[0031] In such cases, it can be difficult to estimate the effective channel width through actual measurements. For example, in order to estimate the effective channel width from the design value, the shape of the semiconductor is known. A certain assumption is necessary. Therefore, if the shape of the semiconductor is not precisely known, the effective It is difficult to accurately measure channel width.

[0032] In this specification, when simply referred to as "channel width," it refers to the apparent channel width. There is. Or, in this specification, when simply referred to as channel width, it means effective channel It can refer to width. Note that it can also refer to channel length, channel width, effective channel width, or apparent width. Channel width and other parameters can be determined by analyzing cross-sectional TEM images, etc. can.

[0033] Furthermore, semiconductor impurities refer to components other than the main components that make up the semiconductor, for example, concentrated Elements with a concentration of less than 0.1 atomic percent are considered impurities. The presence of impurities can, for example, lead to... High Density of States (DOS) of semiconductors and low crystallinity In some cases, such as the following may occur. If the semiconductor is an oxide semiconductor, the properties of the semiconductor may change. Examples of impurities that can be altered include Group 1 elements, Group 2 elements, Group 13 elements, and Group 14 elements. These include elements, Group 15 elements, and transition metals other than the main components of oxide semiconductors, for example, Examples include hydrogen, lithium, sodium, silicon, boron, phosphorus, carbon, and nitrogen. In the case of semiconductors, water can also function as an impurity. Also, in the case of oxide semiconductors, for example... In some cases, the presence of impurities can lead to the formation of oxygen vacancies. Also, if the semiconductor is silicon... In this case, impurities that alter the properties of semiconductors include, for example, Group 1 elements other than oxygen and hydrogen. These include Group 2 elements, Group 13 elements, Group 15 elements, and so on.

[0034] In this specification, silicon oxidnitride is defined as having a composition that contains more oxygen than nitrogen. It has a high content of [something]. Also, silicon nitride oxide, in terms of its composition, has more oxygen than [something]. It has a high nitrogen content.

[0035] Furthermore, in this specification, the term "insulator" shall be replaced with "insulating film" or "insulating layer." It is possible to replace the term "conductor" with "conductive film" or "conductive layer." This is possible. Also, the term "semiconductor" can be replaced with "semiconductor film" or "semiconductor layer." can.

[0036] Furthermore, in this specification, "parallel" means that two straight lines have an angle of -10 degrees or more and 10 degrees or less. This refers to a state where objects are arranged in degrees. Therefore, it also includes cases where the angle is between -5 degrees and 5 degrees. Furthermore, "approximately parallel" refers to a state where two straight lines are positioned at an angle of -30 degrees or more and 30 degrees or less. This refers to a straight line. Furthermore, "perpendicular" means that two straight lines are positioned at an angle of 80 degrees or more and 100 degrees or less. This refers to a state where something is perpendicular. Therefore, it also includes cases where the angle is between 85 degrees and 95 degrees. "A straight line" refers to a state in which two straight lines are positioned at an angle between 60 degrees and 120 degrees.

[0037] In this specification, a barrier film is defined as a film that suppresses the permeation of impurities such as water and hydrogen, as well as oxygen. A membrane that has a controlling function, and if the barrier membrane is conductive, it is called a conductive barrier. It is sometimes called the diaphragm.

[0038] In this specification, metal oxide refers to metal in a broad sense. It is an oxide. Metal oxides are oxide insulators and oxide conductors (including transparent oxide conductors). ), oxide semiconductor (also called Oxide Semiconductor or simply OS) They are classified into categories such as the following. For example, when a metal oxide is used in the semiconductor layer of a transistor, the gold Oxides are sometimes referred to as oxide semiconductors. That is, OS FETs or OS transistors. When referring to a transistor, it means a transistor having an oxide or oxide semiconductor. It can be rephrased.

[0039] Furthermore, in this specification, normally off means not applying a potential to the gate, or The current flowing through the transistor per 1 μm of channel width when the gate is given a ground potential. However, at room temperature, 1 × 10 -20 A or less, 1 × 10 at 85℃ -18 A or less, or 1 × 10 at 125℃ -16 This means being less than or equal to A.

[0040] (Embodiment 1) The following describes an example of a semiconductor device having a transistor 200 according to one aspect of the present invention, and I will now explain how to make bison.

[0041] <Example of semiconductor device configuration> Figures 1A, 1B, and 1C show a transistor 200 according to one aspect of the present invention, and These are top and cross-sectional views of the area around transistor 200.

[0042] Figure 1A is a top view of a semiconductor device having transistor 200. Also, Figure 1B, Figure 1C is a cross-sectional view of the semiconductor device. Here, Figure 1B is a cross-sectional view of Figure 1A along line A1-A2 This is a cross-sectional view of the area indicated by the dashed line, and is a cross-sectional view of transistor 200 in the channel length direction. There is also Figure 1C, which is a cross-sectional view of the area shown by the dashed line A3-A4 in Figure 1A. This is also a cross-sectional view of the Rangista 200 in the channel width direction. Note that in the top view of Figure 1A, the figure Some elements have been omitted for clarity.

[0043] A semiconductor device according to one aspect of the present invention comprises an insulator 212 on a substrate (not shown) and an insulator 212 The insulator 214 above, the transistor 200 on the insulator 214, and the transistor 200 above Insulator 280, insulator 282 on insulator 280, insulator 283 on insulator 282, It has an insulator 274 on an insulator 283 and an insulator 281 on an insulator 274. 212, insulator 214, insulator 280, insulator 282, insulator 283, insulator 274, o The insulator 281 functions as an interlayer film. It is also electrically connected to the transistor 200. It has a conductor 240 (conductor 240a and conductor 240b) that functions as a plug. In addition, an insulator 241 (insulator 2) is placed in contact with the side surface of the conductor 240 which functions as a plug. 41a and insulator 241b) are provided. Also, on the insulator 281 and conductor 2 Above 40 is a conductor 246 (conductor) which is electrically connected to the conductor 240 and functions as wiring. 246a and conductor 246b are provided.

[0044] Also, insulator 272, insulator 273, insulator 280, insulator 282, insulator 283, An insulator 241a is provided in contact with the inner wall of the opening of the edge 274 and the insulator 281, A first conductive material of the conductive material 240a is provided in contact with the side surface, and further inside is a conductive material 240a A second conductor is provided. In addition, insulators 272, 273, 280, and The edge body 282, insulator 283, insulator 274, and insulator 281 are in contact with the inner wall of the opening and An edge body 241b is provided, and a first conductor of the conductor 240b is provided in contact with its side surface. Further inside, a second conductor, conductor 240b, is provided. Here, conductor 240 The height of the top surface and the height of the top surface of the insulator 281 can be made to be approximately the same. So, in a configuration in which the first conductor and the second conductor of the conductor 240 are stacked... As shown, the present invention is not limited thereto. For example, the conductor 240 is single The structure may be configured as a layer, or as a laminated structure of three or more layers. In some cases, ordinal numbers are assigned to distinguish them based on their formation order.

[0045] [Transistor 200] As shown in Figure 1, the transistor 200 has an insulator 216 on an insulator 214 and an insulator Conductors 205 (conductors 205a and 2) are arranged to be embedded in 216. 05b) and the insulator 222 on the insulator 216 and the conductor 205, and on the insulator 222 The insulator 224, the oxide 230a on the insulator 224, and the oxide 23 on the oxide 230a 0b, oxide 243a on oxide 230b and oxide 243b, on oxide 243a Conductor 242a, conductor 242b on oxide 243b, and oxide on oxide 230b 230c, an insulator 250 on the oxide 230c, and an oxide 23 located on the insulator 250. The conductor 260 (conductor 260a and conductor 260b) overlapping with 0c, and the insulator 224 Part of the top surface, side of oxide 230a, side of oxide 230b, side of oxide 243a, Side view of oxide 243b, side view of conductor 242a, top view of conductor 242a, conductor 242b The side surface and the insulator 272 that is in contact with the upper surface of the conductor 242b, and the insulator on the insulator 272 It has 273 and, also, oxide 230c is on the side of oxide 243a, oxide 243b It is in contact with the side surface of the conductor 242a and the side surface of the conductor 242b, respectively. 60 has a conductor 260a and a conductor 260b, with the bottom and side of the conductor 260b The conductor 260a is positioned to enclose the conductor 260. Here, as shown in Figure 1B, the conductor 260 The upper surface is positioned to substantially coincide with the upper surface of the insulator 250 and the upper surface of the oxide 230c. Furthermore, the insulator 282 consists of the conductor 260, oxide 230c, insulator 250, and insulator 28 It touches the top surface of each of the zeros.

[0046] Also, insulators 212, 214, 222, 272, 273, The edge 282, insulator 283, and insulator 281 are hydrogen (e.g., hydrogen atoms, hydrogen molecules). It is preferable that the insulator 21 has the function of suppressing the diffusion of at least one of the following. 2, Insulator 214, Insulator 222, Insulator 272, Insulator 273, Insulator 282, Insulator 283 and insulator 281 contain oxygen (e.g., at least one oxygen atom, oxygen molecule, etc.) It is preferable that the insulator 212 has a function to suppress the diffusion of ). For example, insulator 214 , insulator 222, insulator 272, insulator 273, insulator 282, insulator 283, and insulator Each edge 281 has greater permeability to oxygen and hydrogen, or to one or both, than the insulator 224. A lower value is preferable. Insulator 212, Insulator 214, Insulator 222, Insulator 272, Insulator Body 273, insulator 282, insulator 283, and insulator 281 are each insulator 250 It is preferable that the permeability of one or both oxygen and hydrogen is lower than that of the insulator 212. Insulator 214, Insulator 222, Insulator 272, Insulator 273, Insulator 282, Insulator 28 3. The insulator 281 is more oxygen and hydrogen than the insulator 280, either one or both. It is preferable that the permeability of the material is low.

[0047] As shown in Figure 1B, the insulator 272 is located on the top and side surfaces of the conductor 242a, and on the conductor 242b The top and sides of oxide 243a, the sides of oxide 243b, the sides of oxide 230a, It is preferable that it is in contact with the side surface of oxide 230b and the upper surface of insulator 224. It is preferable that the insulator 273 is provided in contact with the body 272. 272, and insulator 273, insulator 280, insulator 224 and oxide 23 It is separated from 0.

[0048] Furthermore, oxide 230 consists of oxide 230a on the insulator 224 and oxide 230a on the oxide 230a. Material 230b and a component placed on the oxide 230b, with at least a portion of it on the upper surface of the oxide 230b It is preferable to have the oxide 230c in contact with the material.

[0049] Furthermore, in transistor 200, in the channel formation region and its vicinity, oxide 23 This describes a configuration in which three layers are stacked: 0a, oxide 230b, and oxide 230c. However, the present invention is not limited thereto. For example, a single layer of oxide 230b, oxide 23 A two-layer structure of 0b and oxide 230a, a two-layer structure of oxide 230b and oxide 230c, or A configuration with four or more layers is also possible. For example, a two-layer structure of oxide 230c may be used. Furthermore, a configuration with a four-layer stacked structure may be used. Also, in transistor 200, the conductor Although 260 is shown as a two-layer laminated structure, the present invention is not limited thereto. For example, the conductor 260 may have a single-layer structure or a multilayer structure of three or more layers. .

[0050] Here, conductor 260 functions as the gate of the transistor, and conductor 242a and Conductors 242b function as either source or drain electrodes. In the 200, the conductor 260, which functions as a gate, is formed by an insulator 280 and the like. It is formed self-aligningly to fill the opening. This allows for the region between conductors 242a and 242b without the need for alignment of conductor 260. The conductive material 260 can be reliably positioned there.

[0051] Furthermore, transistor 200 is made of oxide 230 (oxide 230a) which includes a channel formation region. Metal oxides (oxide 230b and oxide 230c) function as oxide semiconductors. It is preferable to use an oxide semiconductor (hereinafter also referred to as an oxide semiconductor). For example, as an oxide semiconductor A functional metal oxide has an energy gap of 2 eV or more, preferably 2.5 eV or more. It is preferable to use a material. Thus, using a metal oxide with a large energy gap By doing so, the leakage current (off-current) of transistor 200 in the non-conductive state is extremely low. It can be made smaller. By using such transistors, low-power semiconductors can be produced. We can provide the equipment.

[0052] For example, as oxide 230, In-M-Zn oxide (where element M is aluminum, galvanic acid) Umium, yttrium, tin, copper, vanadium, beryllium, boron, titanium, iron, nickel Germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium One or more types selected from luminous, tantalum, tungsten, or magnesium. It is preferable to use metal oxides such as ) . In particular, element M can be aluminum, gallium, yttrium It is preferable to use um or tin. Also, as oxide 230, In-M oxide and In-Z n oxide or M-Zn oxide may also be used.

[0053] Oxide 230 consists of oxide 230a, oxide 230b on oxide 230a, and oxide 2 It has oxide 230c on 30b, and oxide 230a below oxide 230b. Therefore, impurities are transferred from the structure formed below oxide 230a to oxide 230b. Diffusion can be suppressed. Also, by having oxide 230c on oxide 230b , diffusion of impurities from structures formed above oxide 230c to oxide 230b It can be suppressed.

[0054] Furthermore, oxide 230 has a layered structure due to oxides with different atomic ratios of each metal atom. It is preferable that the metal oxide used in oxide 230a contains constituent elements The atomic ratio of element M in the oxide is the element of the constituent elements in the metal oxide used in oxide 230b. It is preferable that the ratio is greater than the atomic ratio of element M. Also, the metal oxide used in oxide 230a In this case, the atomic ratio of element M to In is in the metal oxide used in oxide 230b. Furthermore, it is preferable that the atomic ratio of element M to In is greater than that of In. Also, in oxide 230b In the metal oxide used, the atomic ratio of In to element M is used in oxide 230a. It is preferable that the atomic ratio of In to element M in the metal oxide is greater than that of In. Oxide 230c is a metal oxide that can be used in place of oxide 230a or oxide 230b. The object can be used.

[0055] Specifically, for oxide 230a, In:Ga:Zn = 1:3:4 [atomic ratio], Alternatively, a metal oxide in an atomic ratio of 1:1:0.5 may be used. Also, oxide 230b and Then, gold in an atomic ratio of In:Ga:Zn = 4:2:3 or 1:1:1. A group oxide can be used. Also, for oxide 230c, In:Ga:Zn = 1:3:4 [Atomic ratio], Ga:Zn=2:1 [Atomic ratio], or Ga:Zn=2:5 [Atomic ratio] You can use the metal oxide of ]. Also, a specific example of when oxide 230c is used in a layered structure and For example, In:Ga:Zn=4:2:3 [atomic ratio] and In:Ga:Zn=1:3:4 Layered structures with [atomic ratio] Ga:Zn=2:1 [atomic ratio] and In:Ga:Zn=4 Stacked structure with :2:3 [atomic ratio], Ga:Zn=2:5 [atomic ratio], and In:Ga: Layered structure of Zn=4:2:3 [atomic ratio], gallium oxide, and In:Ga:Zn=4: Examples include layered structures with an atomic ratio of 2:3.

[0056] Furthermore, it is preferable that the oxide 230b is crystalline. For example, CAAC, which will be described later. -OS(c-axis aligned crystalline oxide sem It is preferable to use an iconductor. Oxides have few impurities or defects (such as oxygen vacancies), are highly crystalline, and have a dense structure. Therefore, the oxygen is drawn from oxide 230b by the source electrode or drain electrode. This suppresses the removal of oxygen from oxide 230b. As a result, even after heat treatment, oxygen can be removed from oxide 230b. Because the risk of being pulled out is reduced, transistor 200 is less likely to be affected by high temperatures during the manufacturing process. It is stable against the temperature (the so-called thermal budget).

[0057] Furthermore, the energy at the lower end of the conduction band of oxide 230a and oxide 230c is that of oxide 23 It is preferable that the energy is higher than the energy at the lower end of the conduction band at 0b. In other words, oxidation The electron affinity of material 230a and oxide 230c is smaller than the electron affinity of oxide 230b. It is preferable.

[0058] Here, the electron affinity or energy level Ec at the bottom of the conduction band is the same as the vacuum level and the valence band. The ionization potential Ip is the difference between the end energy Ev and the energy gap Eg. The ionization potential Ip can be determined, for example, by ultraviolet photoelectron spectroscopy. (UPS:Ultraviolet Photoelectron Spectrosc The energy gap Eg can be measured using a spectroscopic instrument. It can be measured using an ellipsometer.

[0059] Furthermore, at the joint of oxide 230a, oxide 230b, and oxide 230c, The energy levels at the lower end of the guide band change smoothly. In other words, oxide 230a, oxide The energy levels at the lower end of the conduction band at the junction of 230b and oxide 230c are continuous. It can also be said that it undergoes a gradual change or continuous bonding. In order to do this, oxide 2 At the interface between 30a and oxide 230b, and at the interface between oxide 230b and oxide 230c It is desirable to lower the defect level density of the mixed layer that is formed.

[0060] Furthermore, the primary carrier pathway is oxide 230b. Oxide 230a, oxide 230 By configuring c as described above, the interface between oxide 230a and oxide 230b, and the oxide The defect level density at the interface between 230b and oxide 230c can be reduced. Therefore, the influence of interfacial scattering on carrier conduction is reduced, and transistor 200 has high o This allows for obtaining high current and high frequency characteristics.

[0061] Transistors using oxide semiconductors have a high concentration of donor regions in the channel formation area of ​​the oxide semiconductor. As the degree increases, the carrier concentration becomes extremely large in response to the increase in gate voltage, and normally It becomes more prone to ion characteristics. The donor in oxide semiconductors is mainly oxygen in oxide semiconductors. Missing (V) O (Also called an oxygen vacancy) is formed when hydrogen is captured. In the following, hydrogen trapped in an oxygen deficiency is referred to as V. O It is sometimes referred to as H.

[0062] Furthermore, V is a physical quantity related to the donor concentration in oxide semiconductors. O To quantitatively evaluate H This is difficult. Therefore, oxide semiconductors are evaluated by carrier concentration rather than donor concentration. This may occur. Therefore, in this specification, the donor concentration is used as a parameter for oxide semiconductors. In some cases, carrier concentrations are used that assume a state where no electric field is applied, rather than degrees. Therefore, the term "carrier concentration" as used in this specification can be rephrased as "donor concentration." There are cases where this is the case.

[0063] Furthermore, hydrogen in oxide semiconductors reacts with oxygen bonded to metal atoms to form water, and oxygen This can lead to the formation of defects. This increases the amount of oxygen vacancies in the oxide semiconductor, and V O There is a risk of an increase in H. Also, hydrogen in oxide semiconductors is affected by heat, electric fields, etc. Because it is easily moved by tracing, when an oxide semiconductor contains a lot of hydrogen, it becomes a transistor. This could also lead to a deterioration in its reliability.

[0064] Thus, the hydrogen concentration (H concentration) in oxide semiconductors increases. As a result, transistors tend to exhibit normally-on characteristics, resulting in good electrical properties and reliability. It becomes impossible to construct a semiconductor device having the above characteristics.

[0065] Furthermore, as shown in Figure 1, in transistor 200, an insulator 2 is in contact with the oxide 230. 50 is formed. Here, the insulator 250 is a silicon-containing insulator such as silicon oxide. It is preferable to use a hydrogen such as SiH4 when forming such an insulator 250. Silicon is often used as a raw material gas. When such a raw material gas is deposited, it decomposes. This generates a large amount of highly reactive hydrogen (e.g., hydrogen radicals), and oxide 23 0 to V O H may be formed. Also, a large amount of hydrogen is incorporated into the formed insulator 250. In rare cases, due to heat treatment during the manufacturing process of transistor 200, the hydrogen may diffuse into oxide 230. In some cases, this can occur. Thus, water in the oxide semiconductor can be affected by the gate insulating film deposition process. There is a risk that the elementary concentration may increase.

[0066] In contrast, the transistor 200 shown in this embodiment has ALD (Atomic A gate insulating film (insulator 250) was deposited using the Layer Deposition method. This aims to reduce the hydrogen concentration in the channel formation region of the oxide semiconductor.

[0067] In the ALD method, the first raw material gas for the reaction (hereinafter referred to as the precursor) is the precursor, metal. It can also be called a precursor.) and a second raw material gas (hereinafter referred to as a reactant. The following are introduced alternately into the chamber: (These can also be called the reagent or nonmetallic precursor.) The film is formed by repeatedly introducing the raw material gas. By forming a film, it is possible to deposit atoms layer by layer by utilizing the self-regulating properties inherent in atoms. Therefore, by depositing films using the ALD method, it is possible to deposit extremely thin films and create structures with high aspect ratios. Film deposition, film deposition with few defects such as pinholes, film deposition with excellent coverage, and film deposition at low temperatures. It is possible to do things like this.

[0068] The ALD method uses energy such as heat to react with a precursor and a reactant. It is a film formation method carried out by applying. Among the ALD methods, those that perform the process by introducing plasma-excited reactants into the chamber are sometimes called PEALD (Plasma Enhanced ALD) methods. Also, the ALD method that performs the reaction of the precursor and the reactant only with thermal energy is sometimes called the thermal ALD method with respect to the PEALD method. By introducing it into the chamber, the process is sometimes called PEALD (Plasma Enhanced d ALD) method. Also, for the PEALD method, the ALD method that performs the reaction of the precursor and the reactant only with thermal energy is sometimes called the thermal ALD method.

[0069] Hereinafter, using FIGS. 2 and 3, the mechanism for reducing the hydrogen concentration in the channel formation region of the oxide semiconductor will be described by forming an insulator 250, which is an oxide containing silicon, on the oxide 230 using the ALD method. By forming an insulator 250, which is an oxide containing silicon, on the oxide 230 using the ALD method, the hydrogen concentration in the channel formation region of the oxide semiconductor is reduced.

[0070] First, as shown in FIG. 2, as the first source gas, the precursor 10 is introduced into the chamber. The introduced precursor 10 reacts with one of the amino groups and the OH groups on the surface of the oxide 230 and adsorbs on the surface of the oxide 230. When the precursor 10 adsorbs on the surface of the oxide 230, the self-termination mechanism of the surface chemical reaction acts, and no more precursor 10 adsorbs on the layer of the precursor 10 on the surface of the oxide 230.

[0071] Also, the by-product (HNR 3 R 4 ) desorbed from the precursor 10 in the above reaction contains hydrogen atoms. However, in the introduction step of the precursor 10, since the reaction proceeds by thermal energy, the by-product is not decomposed into highly reactive hydrogen radicals or the like. Therefore, in the introduction step of the precursor 10, a large amount of hydrogen radicals or the like does not generate in the chamber.

[0072] Note that R 1 forming the precursor 10, R 2 forming the precursor 10, R​​​​​​​​3 , and R 4 This represents a functional group, for example For example, hydrogen or hydrocarbon groups such as alkyl groups may be used. 1 , R 2 , R 3 , and R 4 These may each have a different structure, or two or more may have the same structure. Furthermore, the precursor 10 shown in Figure 2 is an aminosilane in which Si is bonded to two N atoms. Although it is a compound, it is not limited to this. In precursor 10, bonding to Si. N can be one or three or more. For example, if Precursor 10 is 2DEAS( Bis(diethylamino)silane), BEMAS(Bis(ethyl) methylamino)silane), BTBAS(Bis(tert-butyl amino)silane), 3DMAS(Tris(dimethylamino)s ilane), 4DMAS(Tetrakis(dimethylamino)sila You may also use ne), etc. Note that precursor 10 is limited to aminosilane compounds. Rather, within the range in which a surface chemical reaction with a self-stopping mechanism can occur, containing silicon You can select the appropriate compound.

[0073] During ALD film deposition, the temperature of the substrate on which the transistor 200 is formed is controlled by the self-conducting surface chemical reaction. Keep the substrate temperature within the appropriate range (also known as the ALD Window) for the stopping mechanism to function. The ALD Window is determined by the temperature characteristics, vapor pressure, decomposition temperature, etc. of the precursor 10. The temperature is determined to be between 100°C and 500°C, preferably between 200°C and 400°C.

[0074] Furthermore, when introducing raw material gases, inert gases such as nitrogen (N2) and argon (Ar) are used as carriers. It may be introduced into the chamber together with the source gas as a gas. Therefore, even if the raw material gas has low volatility or low vapor pressure, the raw material gas can get trapped inside the piping and into the vacuum chamber. This suppresses adsorption inside the lubricant, making it possible to introduce the raw material gas into the chamber. Furthermore, it is possible to improve the uniformity of the formed film. Note that the carrier gas is the raw material gas Instead of introducing the solution only at the time of application, it may be possible to continuously introduce it throughout the ALD film deposition process.

[0075] Next, the excess precursor 10 and by-products in the chamber are discharged from the chamber. (Also called purging.) Purge can be performed while introducing carrier gas, or Vacuum evacuation may be performed without introducing a gas.

[0076] Next, as shown in Figure 2, the reactant 20 is introduced into the chamber as the second raw material gas. The introduced reactant 20 acts as an oxidizing agent, so the surface of the oxide 230 The silicon bonded to it is oxidized. At this time, the reactant 20 is oxidized by the Si-H bond or The Si-N bond is cleaved, but the Si-O bond is not. Here, as a byproduct, CO 2, H2O, NO x These are generated.

[0077] Furthermore, as shown in Figure 2, the reactant 20 is not only silicon on the oxide 230 surface. Furthermore, oxide 230 is also oxidized, V O This can cause H to be removed. As a result, oxide 230 Oxygen deficiency inside V O This is supplemented with oxygen, which helps to reduce the hydrogen concentration in oxide 230. Also, the chamber has an oxidizing atmosphere due to reactant 20, so acid The hydrogen released from compound 230 is released as the byproduct H2O. Note that in Figure 2... As reactant 20, oxygen radical O * This indicates that reactant 20 is It is not limited to that.

[0078] When depositing insulator 250 using the PEALD method, oxygen radicals are used as reactant 20. It can be used as is. Oxygen radicals can be obtained by plasma-forming oxygen gas (O2). Oh, in oxygen plasma, oxygen is present in molecules (e.g., O2 or O3), radicals, and It is present in the form of ions or other states. For example, in oxygen gas, RF (Radio Frequency) By applying high-frequency waves such as (ency) or microwaves, oxygen plasma containing oxygen radicals is produced. It is possible to generate M.

[0079] Furthermore, the second raw material gas containing reactant 20 contains hydrogen atoms or a fraction having hydrogen atoms. It is preferable that the plasma does not contain hydrogen atoms or molecules containing hydrogen atoms. When exposed, a large amount of highly reactive hydrogen radicals are generated, creating a reducing atmosphere inside the chamber. When the chamber becomes a reducing atmosphere, oxygen is extracted from oxide 230 and V O H is formed. Therefore, reactant 20 containing oxygen radicals is formed inside the chamber. It is preferable that the atmosphere is oxidizing.

[0080] When depositing insulator 250 using the PEALD method, the reactant 20 has high reactivity, The substrate temperature should be higher than 200°C, preferably 300°C or higher, and more preferably 350°C or higher. This reduces the carrier concentration in oxide 230. By forming the insulator 250 at a certain temperature, the increase in the hydrogen concentration contained in the oxide 230 is suppressed. It is possible.

[0081] Furthermore, the oxide 230 may be irradiated with high-frequency waves such as RF or microwaves. This will allow, As shown in Figure 2, V in oxide 230 O H can be removed from H. Since the chamber is an oxidizing atmosphere, the reactant 20 causes oxygen deficiency in the oxide 230. V O It can compensate for that.

[0082] Furthermore, when depositing insulator 250 using the thermal ALD method, oz is used as the reactant 20. Ozone gas (O3) can be used. Ozone gas (O3) is made from oxygen gas (O2). It can be generated by an ozone generator. At this time, the reactant 20 contains ozone gas. It may contain oxygen (O3) and oxygen gas (O2). Also, similar to the PEALD method, The second source gas containing actant 20 contains hydrogen atoms or molecules containing hydrogen atoms, etc. It is preferable that it does not occur.

[0083] When depositing insulator 250 using the thermal ALD method, compared to the PEALD method, the reactant Since the reactivity of T20 is low, the substrate temperature should be raised to above 300°C, preferably above 350°C. This reduces the carrier concentration in oxide 230. Also, the above substrate temperature By forming an insulator 250 at a certain temperature, the increase in hydrogen concentration contained in the oxide 230 is suppressed. It is possible.

[0084] Next, a purge is performed to remove any excess reactant 20, CO2, and H2 from the chamber. O, NO x By-products such as these are discharged from the chamber. Purge does not involve introducing a carrier gas. You can proceed in this manner, or you can perform vacuum evacuation without introducing a carrier gas. As shown in Figure 2, a single layer of silicon oxide is formed on the surface of oxide 230. can.

[0085] In a similar manner, with purging in between, the precursor 10 and the reactant 20 are introduced. By performing this process, it is possible to deposit an additional layer of silicon oxide. As shown above, the introduction of precursor 10 and reactant 20 is performed with a purge in between. By repeating the cycle, a single layer of silicon oxide can be deposited one layer at a time. By repeating this cycle multiple times until the film reaches the desired thickness, as shown in Figure 2, An insulator 250 can be formed on the oxide 230.

[0086] The thickness of the insulator 250, which functions as a gate insulating film, of the miniaturized transistor 200. It becomes extremely thin (for example, between 5 nm and 30 nm) and has small variations. It is necessary to do so. In contrast, the film thickness of the insulator 250 repeats the above cycle. Because it can be adjusted by the number of times, precise film thickness adjustment is possible. Therefore, miniaturization The required gate insulator precision for the transistor 200 can be achieved. As shown in Figure 1, the insulator 250 is located at the bottom surface of the opening formed by the insulator 280, etc. The bottom and sides of the opening need to be coated with a film that provides good coverage. As shown in 2, since a single layer of silicon oxide can be deposited one layer at a time, insulation The body 250 can be formed with good coverage over the opening.

[0087] For example, using the PECVD (Plasma Enhanced CVD) method, insulator 2 When depositing a film of 50, silicon hydride such as SiH4 is decomposed in the plasma, and a large amount Hydrogen radicals are generated. The reduction reaction of hydrogen radicals removes oxygen from oxide 230. Pulled out V O When H is formed, the hydrogen concentration in oxide 230 increases. However, As shown in this embodiment, when the insulator 250 is formed using the ALD method, the precursor Almost no hydrogen radicals are generated when introducing 10 or when introducing reactant 20. By using the ALD method to deposit a gate insulating film, the hydrogen concentration in the oxide semiconductor can be increased. This can suppress the increase in carrier concentration in oxide semiconductors. .0 × 10 16 / cm 3 The following is preferably 1.0 × 10 13 / cm 3 It can be made less than It is possible. Transistors using such oxide semiconductors can be made to have normally-off characteristics. This allows for the construction of a semiconductor device with good electrical characteristics and reliability.

[0088] Furthermore, before introducing the precursor 10, as shown in Figure 3, the electromagnetic waves 30 are directed to the oxide 230. Irradiation may be performed. Here, the electromagnetic wave 30 may be a microwave or a high frequency such as RF. It is sufficient if it is there. The irradiated electromagnetic wave 30 penetrates into the oxide 230, and V in the oxide 230 O H is cleaved, hydrogen H is removed from oxide 230, and oxygen deficiency V is created. O remains in oxide 230 In other words, in oxide 230, V OH→H↑+V O This reaction occurs, leading to oxidation. The hydrogen concentration in substance 230 will be reduced. Some of the hydrogen H generated at this time will become oxygen It may combine with other atoms to form H2O and be removed from oxide 230. Also, some of the hydrogen H These may be captured (also called gettering) by the conductor 242.

[0089] Next, as shown in Figure 3, the precursor 10 is introduced in the same manner as above, and then the Perform the update.

[0090] Next, as shown in Figure 3, the reactant 20 is introduced in the same manner as described above. Here, Reactant 20 (e.g., oxygen radical) causes oxygen vacancies in oxide 230 V O to compensate Therefore, the hydrogen concentration in oxide 230 can be reduced by the method shown in Figure 3. and, V O This can also reduce oxygen deficiencies that are the source of H formation.

[0091] Furthermore, when introducing reactant 20 using the PEALD method, oxygen gas (O2) and This refers to the application of high-frequency waves such as microwaves or RF to plasmaize ozone gas (O3). The waves may also be irradiated onto the oxide 230. This will produce the same effect as the irradiation of electromagnetic waves 30 shown in Figure 3. Since the effect can be obtained, when introducing reactant 20, V should be used in parallel. O The removal of H is Yes, it is possible. Furthermore, in the process of introducing the reactant 20 shown in Figure 2, electromagnetic waves The oxide 230 may be irradiated with 30 (microwaves or high-frequency waves such as RF).

[0092] The insulator 250 is formed on the oxide 230 using the same method as shown in Figure 2. It is possible.

[0093] As described above, V that functions as a donor in the oxide semiconductor O H can be reduced so that the carrier concentration in the oxide semiconductor can be 1.0×10 16 / cm 3 or less, preferably 1.0×10 13 / cm 3 or less. A transistor using such an oxide semiconductor can have normally-off characteristics and can constitute a semiconductor device having good electrical characteristics and reliability.

[0094] In FIG. 3, the removal of oxygen deficiency V O was performed simultaneously with the introduction of the reactant 20, but the present embodiment is not limited to this. When irradiating the electromagnetic wave 30 shown in FIG. 3, oxygen gas may be plasmaized by the electromagnetic wave 30 to form oxygen radicals. That is, plasma treatment may be performed in an atmosphere containing oxygen simultaneously with the irradiation of the electromagnetic wave 30. The oxygen deficiency V in the oxide 230 formed by the irradiation of the electromagnetic wave 30 can be O compensated by the formed oxygen radicals. Thereby, while irradiating the electromagnetic wave 30, V H and the oxygen deficiency V O in the oxide 230 can be reduced. O

[0095] It is preferable to use a device having a power source for generating high-density plasma using, for example, microwaves for the plasmaization of oxygen. Alternatively, it may have a power source for applying RF to the substrate side[[ID=四十九]] . By using high-density plasma, high-density oxygen radicals can be generated, and by applying RF to the substrate side, the oxygen radicals generated by the high-density plasma can be efficiently ​​​​​It can be introduced into the oxide 230.

[0096] In the processes shown in FIGS. 2 and 3, the introduction of the precursor 10 was performed prior to the introduction of the reactant 20, but the present embodiment is not limited to this. For example, the introduction of the reactant 20 may be performed before the introduction of the precursor 10 shown in FIGS. 2 and 3. Moreover, for example, before the introduction of the precursor 10, the introduction and purge of the reactant 20 may be repeated a plurality of times. By adopting such a configuration, more oxygen can be supplied to the oxide 230 that becomes the base of the insulator 250. The semiconductor device formed by using such a method has good characteristics and can obtain high reliability.

[0097] Also, in the processes shown in FIGS. 2 and 3, the configuration in which the introduction of the precursor 10 and the introduction of the reactant 20 are repeated one by one is shown, but the present embodiment is not limited to this. For example, in the cycles shown in FIGS. 2 and 3, the introduction and purge of the reactant 20 may be repeated a plurality of times. Also, when the introduction and purge of the reactant 20 are repeated a plurality of times, it is not always necessary to repeat the introduction of the same type of reactant 20.

[0098] In this way, by repeating the introduction and purge of the reactant 20 in the chamber a plurality of times in a short time, extra hydrogen atoms, carbon atoms, chlorine atoms, etc. can be more reliably removed from the precursor adsorbed on the surface of the oxide 230 and excluded outside the chamber. In this manner, the hydrogen concentration in the oxide 230 can be reduced by preventing hydrogen atoms from being incorporated into the oxide 230 and the insulator 250 during film formation.

[0099] ​​​​​​​​​​​​​ Furthermore, as shown in Figure 1B, oxide 230b and the source electrode or drain electrode Functional conductor 242 (conductor 242a and conductor 242b), and oxide 243 between them. (Oxide 243a and oxide 243b) may be arranged. Conductor 242 and oxide 2 Since the conductor 242 does not come into contact with 30, the conductor 242 absorbs the oxygen from the oxide 230. This can be suppressed. In other words, by preventing oxidation of the conductor 242, the conductivity of the conductor 242 can be suppressed. The decrease can be suppressed. Therefore, oxide 243 suppresses the oxidation of conductor 242. It is preferable that it has a function.

[0100] Therefore, it is preferable that oxide 243 has the function of suppressing oxygen permeation. Oxygen permeability between the conductor 242, which functions as an electrode or drain electrode, and the oxide 230b. By arranging oxide 243 which has a suppressive function, the conductor 242 and oxide 230b This is preferable because the electrical resistance between them is reduced. This can improve the electrical characteristics of transistor 200 and the reliability of transistor 200.

[0101] As oxide 243, a metal oxide containing element M may be used. In particular, element M is A Luminium, gallium, yttrium, or tin may be used. Oxide 243 is an oxide. It is preferable that the concentration of element M is higher than that of substance 230b. Also, as oxide 243, Gallium may be used. Alternatively, metal acids such as In-M-Zn oxide may be used as oxide 243. A compound may also be used. Specifically, in the metal oxide used in oxide 243, with respect to In The atomic ratio of element M in oxide 230b is the element relative to In in the metal oxide used in oxide 230b. It is preferably larger than the atomic ratio of element M. Further, the film thickness of the oxide 243 is preferably 0.5 nm or more and 5 nm or less, more preferably 1 nm or more and 3 nm or less. Further, the oxide 243 preferably has crystallinity. When the oxide 243 has crystallinity, the release of oxygen in the oxide 230 can be suitably suppressed. For example, if the oxide 243 has a crystal structure such as a hexagonal crystal, the release of oxygen in the oxide 230 may be suppressed. In addition, the film thickness of the oxide 243 is preferably 0.5 nm or more and 5 nm or less, more preferably 1 nm or more and 3 nm or less. Further, the oxide 243 preferably has crystallinity. When the oxide 243 has crystallinity, the release of oxygen in the oxide 230 can be suitably suppressed. For example, if the oxide 243 has a crystal structure such as a hexagonal crystal, the release of oxygen in the oxide 230 may be suppressed. In addition, the oxide 243 does not necessarily have to be provided. For example, even if the conductor 242 is in contact with the oxide 230b, if the oxidation of the conductor 242 is suppressed and the conductivity is sufficiently high, the oxide 243 may not be provided, and the conductors 242a and 242b may be provided in contact with the oxide 230b.

[0102] In addition, the oxide 243 does not necessarily have to be provided. For example, even if the conductor 242 is in contact with the oxide 230b, if the oxidation of the conductor 242 is suppressed and the conductivity is sufficiently high, the oxide 243 may not be provided, and the conductors 242a and 242b may be provided in contact with the oxide 230b. 42, and the conductors 242a and 242b may be provided in contact with the oxide 230b without providing the oxide 243. It is also possible. In one aspect of the present invention, the transistor 200 has a structure in which the insulator 282 and the insulator 250 are in direct contact as shown in FIGS. 1B and 1C. By adopting such a structure, it becomes difficult for oxygen contained in the insulator 280 to be absorbed by the conductor 260. Therefore, the oxygen contained in the insulator 280 can be efficiently supplied to the oxide 230a and the oxide 230b through the oxide 230c, so that the oxygen deficiency in the oxide 230a and the oxide 230b can be reduced, and the electrical characteristics and reliability of the transistor 200 can be improved.

[0103] In one aspect of the present invention, the transistor 200 has a structure in which the insulator 282 and the insulator 250 are in direct contact as shown in FIGS. 1B and 1C. By adopting such a structure, it becomes difficult for oxygen contained in the insulator 280 to be absorbed by the conductor 260. Therefore, the oxygen contained in the insulator 280 can be efficiently supplied to the oxide 230a and the oxide 230b through the oxide 230c, so that the oxygen deficiency in the oxide 230a and the oxide 230b can be reduced, and the electrical characteristics and reliability of the transistor 200 can be improved. By adopting such a structure, it becomes difficult for oxygen contained in the insulator 280 to be absorbed by the conductor 260. Therefore, the oxygen contained in the insulator 280 can be efficiently supplied to the oxide 230a and the oxide 230b through the oxide 230c, so that the oxygen deficiency in the oxide 230a and the oxide 230b can be reduced, and the electrical characteristics and reliability of the transistor 200 can be improved. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used. In addition, impurities such as hydrogen contained in the insulator 280 can be prevented from mixing into the insulator 250, so that the adverse effects on the electrical characteristics and reliability of the transistor 200 can be suppressed. As the insulator 282, silicon nitride, silicon oxynitride, aluminum oxide, or hafnium oxide can be used.

[0104] Insulators 272 and 273 suppress the permeation of impurities such as hydrogen and water, as well as oxygen. It is preferable that it has the function of doing so.

[0105] Figure 4A is an enlarged view of the cross-section of the area indicated by the dashed line A5-A6 in Figure 1A, and tiger This is also a cross-sectional view of the source or drain region of the inverter 200 in the channel width direction. As shown in 4A, the top surface of conductor 242b, the side surface of conductor 242b, and the side of oxide 243b. The surface, the side of oxide 230a, and the side of oxide 230b are insulator 272, and insulating Since the structure is covered by body 273, the sides and top of the conductor 242b are covered. The diffusion of impurities such as hydrogen and water, as well as oxygen, into the conductor 242b from the planar direction is suppressed. Yes, it is possible. Also, the lower surface of the conductor 242b is in contact with the oxide 243b, and oxidation The oxygen in substance 230b is blocked by oxide 243b and therefore diffuses to conductor 242b. This suppresses the spread of oxygen from the surroundings to the conductor 242b. Since dispersion can be suppressed, oxidation of the conductor 242b can be suppressed. The same effect is observed with respect to the conductor 242a. Also, the side surface of oxide 230a and the acid Hydrogen, water, and other impurities enter oxide 230a and oxide 230b from the lateral direction of oxide 230b. The diffusion of pure substances can be suppressed. Examples of insulators 272 include aluminum oxide. Hafnium oxide, gallium oxide, indium gallium zinc oxide, silicon oxide film, nitrogen A silicon oxide film or a silicon nitride film can be used. Also, the insulator 273 and For example, aluminum oxide or hafnium oxide can be used.

[0106] Figure 4B is an enlarged view of the right half of transistor 200 in Figure 1B. Conductor 242b The left side (the area enclosed by the dotted line in Figure 4B) is in contact with oxide 230c, and insulator 2 This suppresses the diffusion of impurities such as hydrogen and water from 50, as well as oxygen, into the conductor 242b. It is possible. Also, the right side of the conductor 242b is in contact with the insulator 272, and insulation The diffusion of impurities such as hydrogen and water from body 280, as well as oxygen, into conductor 242b is suppressed. This is possible. Furthermore, the conductor 242a also exhibits a similar effect.

[0107] As described above, the permeability of impurities such as hydrogen and water, as well as oxygen, around the conductor 242 is suppressed. The structure is enclosed by a functional insulator 272, oxide 230c, and oxide 243b. This suppresses oxidation of the conductor 242, improving the electrical characteristics of the transistor 200 and the transistor This can improve the reliability of the Zista 200.

[0108] Furthermore, as shown in Figure 1C, the oxide 230a and In the region where the oxide 230b and the conductor 260 do not overlap, the height of the bottom surface of the conductor 260 It is preferable that the element is positioned lower than the height of the bottom surface of oxide 230b. , the bottom surface of the conductor 260 in the region where the oxide 230b and the conductor 260 do not overlap. The difference between the height and the height of the bottom surface of oxide 230b is preferably 0 nm or more and 100 nm or less. The wavelength is 3 nm to 50 nm, more preferably 5 nm to 20 nm.

[0109] Thus, the conductor 260, which functions as a gate, is the oxide 230 in the channel formation region. The sides and top surface of b are covered with oxide 230c and insulator 250. This makes it easier to apply the electric field of the conductor 260 to the entire oxide 230b in the channel formation region. Therefore, the on-current of transistor 200 can be increased, improving the frequency characteristics. ru.

[0110] Based on the above, a semiconductor device having normally-off electrical characteristics can be provided. Alternatively, it suppresses fluctuations in electrical characteristics, provides stable electrical characteristics, and improves reliability. A semiconductor device can be provided that has a transistor with a large on-current. A conductive device can be provided. Or, a device having a transistor with high frequency characteristics can be provided. A semiconductor device can be provided that has a transistor with a small off-current. We can provide semiconductor devices.

[0111] The following describes the detailed configuration of a semiconductor device having a transistor 200 according to one aspect of the present invention. I will explain this.

[0112] The conductor 205 is arranged to overlap with the oxide 230 and the conductor 260. It is preferable that the conductor 205 is embedded in the insulator 216. A portion of 05 may be embedded in the insulator 214.

[0113] Here, when the conductor 260 functions as the first gate (also called the top gate) Furthermore, conductor 205 functions as a second gate (also called a bottom gate). There are cases where this is the case. In that case, the potential applied to the conductor 205 is the same as the potential applied to the conductor 260. By changing it independently without linking it, the Vth of transistor 200 can be controlled. This can be done. In particular, by applying a negative potential to the conductor 205, the transistor 200 By making Vth greater than 0V, it becomes possible to reduce the off-current. Therefore, conductor Applying a negative potential to 205 results in a higher rate of electricity being applied to the conductor 260 compared to not applying a potential. The drain current can be reduced when the voltage is 0V.

[0114] Furthermore, as shown in Figure 1A, the conductor 205 is made of the conductor 242a of oxide 230 and conductor It is preferable to provide a larger area than the area that does not overlap with the electric body 242b. In particular, as shown in Figure 1C Thus, the conductor 205 extends beyond the edge that intersects the channel width direction of the oxide 230. In the region as well, elongation is preferable. That is, in the channel width direction of the oxide 230. On the outer side of the side, the conductor 205 and the conductor 260 are superimposed with an insulator in between. It is preferable that the conductor 205 be made larger. Alternatively, by making the conductor 20 5. In the plasma processing of the fabrication process after formation, local charging (char In some cases, it may be possible to alleviate the effects of (called "ji-up"). However, one aspect of the present invention is not limited to this. No. Conductor 205 is located at least between conductor 242a and conductor 242b. It should be superimposed with oxide 230.

[0115] Having the above configuration, the electric field of the conductor 260 which functions as the first gate, The electric field of the conductor 205, which functions as a second gate, electrifies the channel formation region. It can be surrounded by air. In this specification, the first gate and the second gate The structure of the transistor, in which the channel formation region is electrically surrounded by an electric field, is called a surro This is called an underdated channel (S-channel) structure.

[0116] Furthermore, the conductive material 205a suppresses the permeation of impurities such as water or hydrogen and oxygen. A body material is preferred. For example, titanium, titanium nitride, tantalum, or tantalum nitride can be used. This is possible. Also, the conductor 205b is mainly composed of tungsten, copper, or aluminum. It is preferable to use a conductive material such as the above. Note that although the conductive material 205 is shown as two layers, 3 A multilayer structure with more than one layer is also acceptable.

[0117] Here, an oxide semiconductor, an insulator or conductor located beneath the oxide semiconductor, and an acid An insulator or conductor located on the upper layer of a semiconductor is separated by a different film without exposure to the atmosphere. By continuously depositing seeds into a film, the concentration of impurities (especially hydrogen and water) is reduced, resulting in a substantially high-purity product. This is preferable because it allows for the formation of highly intrinsic oxide semiconductor films.

[0118] For example, using a film deposition apparatus having six processing chambers, an insulator 216 and a conductive An insulating film, an oxide 230a, and an insulating film, which will be an insulator 222 and an insulating film 224, will be placed on the body 205. An oxide film that becomes oxide 230b, an oxide film that becomes oxide 243, and a conductor 2 The conductive films that result in a 42 ratio should be deposited sequentially in a continuous manner.

[0119] Insulator 212, Insulator 214, Insulator 272, Insulator 273, Insulator 282, Insulator 2 83 and the insulator 281 are protected from impurities such as water or hydrogen from the substrate side or from above. It is preferable that it functions as a barrier insulating film to suppress contamination of transistor 200. Therefore, insulator 212, insulator 214, insulator 272, insulator 273, insulator 2 82. Insulators 283 and 281 contain hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, and nitrogen It suppresses the diffusion of impurities such as elementary molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms. It is preferable to use an insulating material that has the function of (making it difficult for the above-mentioned impurities to permeate). Alternatively, it may have a function that inhibits the diffusion of oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable to use an insulating material that has properties (that makes it difficult for the above-mentioned oxygen to permeate).

[0120] For example, silicon nitride may be used as the insulator 212, insulator 283, and insulator 281. Using this, insulators 214, 272, 273, and 283 are oxidized. It is preferable to use aluminum or similar materials. This prevents impurities such as water or hydrogen from being absorbed. The material diffuses from the substrate side to the transistor 200 side via the edge 212 and the insulator 214. This can be suppressed. Alternatively, oxygen contained in the insulator 224, etc., insulator 212 , and diffusion to the substrate side via the insulator 214 can be suppressed. Or an insulator 280 in which impurities such as hydrogen are located above the insulator 273, and This suppresses diffusion from the conductor 246 and other materials to the transistor 200 side via the insulator 273. This can be done. In this way, transistor 200 can be treated with impurities such as water or hydrogen, and Insulators 212, 214, and 272, which have the function of suppressing the diffusion of oxygen, The structure shall consist of a body 273, an insulator 282, an insulator 283, and an insulator 281 surrounding it. It is preferable.

[0121] Furthermore, it is preferable to lower the resistivity of insulators 212, 283, and 281. There are cases where this is difficult. For example, the resistivity of insulators 212, 283, and 281. Approximately 1 × 10 13By setting it to Ωcm, processing using plasma, etc. in semiconductor device manufacturing processes. In this, insulator 212, insulator 283, and insulator 281 are conductor 205, conductor It may be possible to mitigate the charge-up of 242 or conductor 260. Insulator The resistivity of insulators 212, 283, and 281 is preferably 1 × 10⁻⁶. 10 Ωc m or more 1×10 15 The density should be less than or equal to Ωcm.

[0122] Furthermore, insulators 216, 280, and 274 have a dielectric constant greater than insulator 214. A low rate is preferable. By using a material with a low dielectric constant as the interlayer film, parasitic activity between wiring is reduced. The capacity can be reduced. For example, insulator 216, insulator 280, and insulator 27 4. Silicon oxide, silicon oxide nitride, silicon nitride, silicon nitride, fluorine silicon oxide with added carbon, silicon oxide with added carbon and nitrogen Silicon, or silicon oxide with voids, can be used as appropriate.

[0123] Insulators 222 and 224 function as gate insulators.

[0124] Here, the insulator 224 in contact with the oxide 230 is preferably such that oxygen is removed by heating. In this specification, oxygen released by heating may be referred to as excess oxygen. For example, The edge body 224 may be made of silicon oxide or silicon oxide nitride, etc., as appropriate. By providing an insulating material in contact with the oxide 230, oxygen deficiency in the oxide 230 is reduced. This can improve the reliability of transistor 200.

[0125] Specifically, as the insulator 224, an oxide material is used from which some oxygen is desorbed by heating. It is preferable to do so. Oxides that desorb oxygen upon heating are defined as those analyzed by thermal desorption gas analysis (TDS( In thermal desorption spectroscopy analysis, oxygen The amount of molecular elimination is 1.0 × 10⁻⁶ 18 molecular / cm² 3 The above is preferably 1.0 × 10 19 molecular / cm² 3 More preferably 2.0 × 10 19 mole cules / cm 3 Above, or 3.0 × 10 20 molecular / cm² 3 That's all. It is an oxide film. The surface temperature of the film during the above TDS analysis was 100°C or higher. A temperature of 700°C or less, or a range of 100°C to 400°C, is preferred.

[0126] Insulator 222 prevents impurities such as water or hydrogen from entering the transistor 200 from the substrate side. It is preferable that it functions as a barrier insulating film that suppresses this. For example, insulator 222 is It is preferable that the hydrogen permeability is lower than that of insulator 224. Insulator 222 and insulator 27 By surrounding the insulator 224 and oxide 230, etc., water or This can prevent impurities such as hydrogen from entering transistor 200.

[0127] Furthermore, the insulator 222 contains oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable that the material has a function to suppress diffusion (i.e., the oxygen does not easily permeate it). For example, insulation It is preferable that body 222 has lower oxygen permeability than insulator 224. By having the function of suppressing the diffusion of impurities, the oxygen contained in oxide 230 becomes insulator 2 This is preferable because it reduces diffusion below 22. Also, the conductor 205 is an insulator. This can suppress the reaction of body 224 with oxygen present in oxide 230.

[0128] The insulator 222 is made of either or both aluminum and hafnium, which are insulating materials. It is preferable to use an insulator containing an oxide. Aluminum and / or hafnium. Insulators containing oxides include aluminum oxide, hafnium oxide, aluminum and ha It is preferable to use an oxide containing hafnium (such as hafnium aluminate). When an insulator 222 is formed using the same material, the insulator 222 is acid from the oxide 230. The emission of elemental particles and the introduction of impurities such as hydrogen from the peripheral area of ​​transistor 200 into oxide 230. It functions as an inhibitory layer.

[0129] Alternatively, these insulators may be, for example, aluminum oxide, bismuth oxide, germanium oxide. Umium, niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, Zirconium oxide may be added. Alternatively, these insulators may be subjected to nitriding treatment. Silicon oxide, silicon oxide nitride, or silicon nitride may be laminated as the insulator. .

[0130] Furthermore, the insulator 222 may be, for example, aluminum oxide, hafnium oxide, tantalum oxide, Zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrT) Includes so-called high-k materials such as iO3 or (Ba,Sr)TiO3 (BST). The insulating material may be used in a single layer or multilayer configuration. As transistors become smaller and more highly integrated... However, thinning the gate insulator can sometimes lead to problems such as leakage current. By using a high-k material as an insulator that functions as an insulator, the physical film thickness can be maintained. This makes it possible to reduce the gate potential during transistor operation.

[0131] The insulators 222 and 224 may have a laminated structure of two or more layers. In that case, it is not limited to laminated structures made of the same material, but also applies to laminated structures made of different materials. good.

[0132] On oxide 230b, oxide 243 is provided, and on oxide 243, a source electrode, and conductor 242 (conductor 242a, and conductor 242) which function as drain electrodes b) is provided. The thickness of the conductive material 242 is, for example, 1 nm or more and 50 nm or less, preferably The range should be between 2nm and 25nm.

[0133] Examples of conductive materials 242 include aluminum, chromium, copper, silver, gold, platinum, tantalum, and nickel. Titanium, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, Magnesium, zirconium, beryllium, indium, ruthenium, iridium, strontium Metal elements selected from rontium and lanthanum, or alloys containing the aforementioned metal elements. Alternatively, it is preferable to use an alloy or the like that which combines the above-mentioned metal elements. For example, tan nitride Tal, titanium nitride, tungsten nitride, nitrides containing titanium and aluminum, tantalum and Aluminum nitrides, ruthenium oxide, ruthenium nitride, strontium and ruthenium It is preferable to use oxides containing um, oxides containing lanthanum and nickel, etc. tantalum nitride, titanium nitride, nitrides containing titanium and aluminum, tantalum and aluminum Nitrides containing lum, ruthenium oxide, ruthenium nitride, and strontium and ruthenium Oxides containing lanthanum and nickel are conductive materials that are resistant to oxidation, or oxygen It is preferable because it is a material that maintains its conductivity even after absorbing moisture.

[0134] Insulator 250 functions as a gate insulator. Insulator 250 is on top of oxide 230c It is preferable to arrange them in contact with the surface. The insulator 250 is silicon oxide, silicon oxide and nitride. silicon nitride oxide, silicon nitride, silicon oxide with added fluorine, carbon-added acid Using silicon oxide, silicon oxide with added carbon and nitrogen, and silicon oxide with voids This is possible. In particular, silicon oxide and silicon oxide-nitride are stable to heat. It is preferable.

[0135] Similar to insulator 224, insulator 250 uses an insulator that releases oxygen upon heating. It is preferable to form an insulator that releases oxygen upon heating, as insulator 250. By providing it in contact with the upper surface of oxide 230c, the channel formation region of oxide 230b is formed It can effectively supply oxygen. Also, similar to insulator 224, insulator 250 It is preferable that the concentration of impurities such as water or hydrogen is reduced. The film thickness of the insulator 250 is It is preferable that the wavelength be between 1 nm and 20 nm.

[0136] Furthermore, a metal oxide may be provided between the insulator 250 and the conductor 260. It is preferable to suppress oxygen diffusion from the insulator 250 to the conductor 260. By providing a metal oxide that suppresses diffusion, the diffusion of oxygen from the insulator 250 to the conductor 260 is suppressed. This is suppressed. In other words, the decrease in the amount of oxygen supplied to oxide 230 can be suppressed. Furthermore, the oxidation of the conductor 260 by oxygen in the insulator 250 can be suppressed.

[0137] Furthermore, the metal oxide may function as part of the gate insulator. Therefore, when silicon oxide or silicon oxide nitride is used for the insulator 250, the metal acid For the oxide, it is preferable to use a metal oxide, which is a high-k material with a high dielectric constant. The insulator is made of a laminated structure of insulator 250 and the metal oxide, making it safe against heat. A laminated structure with constant dielectric constant and high dielectric constant can be achieved. Therefore, the physical properties of the gate insulator This makes it possible to reduce the gate potential applied during transistor operation while maintaining the film thickness. Furthermore, it becomes possible to thin the equivalent oxide film thickness (EOT) of the insulator that functions as a gate insulator. ru.

[0138] Specifically, hafnium, aluminum, gallium, yttrium, zirconium, t Magnesium, titanium, tantalum, nickel, germanium, or magnesium, etc. A metal oxide containing one or more selected types can be used. In particular, A An insulator containing an oxide of either luminium or hafnium, or both. Aluminum, hafnium oxide, aluminum and hafnium oxides (hafnium oxide) It is preferable to use materials such as luminescent coatings.

[0139] Alternatively, the metal oxide may function as part of the gate. It is preferable to provide an oxygen-containing conductive material on the channel-forming region side. By providing this on the channel-forming region side, oxygen released from the conductive material can form channels. It will become easier to supply the region.

[0140] In particular, it is contained in the metal oxide in which the channel is formed, as a conductor that functions as a gate. It is preferable to use a conductive material containing a metal element and oxygen. Conductive materials containing elements and nitrogen may be used. In addition, indium tin oxide and tung oxide may be used. Indium oxide containing tungsten, indium zinc oxide containing tungsten oxide, and tungsten oxide. Indium oxide containing tungsten, indium tin oxide containing titanium oxide, indium zinc oxide Indium tin oxide with added silicon may also be used. Um gallium zinc oxide may also be used. By using such a material, the channel shape In some cases, hydrogen contained in the metal oxide that is formed can be captured. Alternatively, the outside In some cases, it is possible to capture hydrogen that has been introduced from insulators and other materials.

[0141] Although the conductor 260 is shown as a two-layer structure in Figure 1, it may also be a single-layer structure or a three-layer structure or more. The above layered structure is also acceptable.

[0142] Conductor 260a contains hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules. Conductive material that has the function of suppressing the diffusion of impurities such as N2O, NO, NO2, and copper atoms. It is preferable to use a material with low oxygen content. Alternatively, a small amount of oxygen (for example, oxygen atoms, oxygen molecules, etc.) It is preferable to use a conductive material that has the function of suppressing the diffusion of at least (1).

[0143] Furthermore, because the conductor 260a has the function of suppressing oxygen diffusion, the insulator 250 The oxygen contained in the material suppresses the oxidation of the conductor 260b, which reduces its conductivity. Yes, it is possible. Examples of conductive materials that have the function of suppressing oxygen diffusion include tantalum and nitrogen. It is preferable to use tantalum oxide, ruthenium oxide, or similar materials.

[0144] Furthermore, the conductor 260b is a conductive material mainly composed of tungsten, copper, or aluminum. It is preferable to use a conductive material. Also, since the conductor 260 also functions as wiring, It is preferable to use a highly conductive material. For example, tungsten, copper, or aluminum. A conductive material mainly composed of um can be used. In addition, the conductor 260b has a laminated structure. This may also be the case, for example, a laminated structure of titanium, titanium nitride and the above-mentioned conductive material. .

[0145] Insulator 280 may be, for example, silicon oxide, silicon oxide nitride, or nitrogen. Silicon oxide, fluorine-added silicon oxide, carbon-added silicon oxide, carbon The material may include silicon oxide with added nitrogen, or silicon oxide with voids. Preferred. In particular, silicon oxide and silicon oxide nitride are preferred because they are thermally stable. In particular, materials such as silicon oxide, silicon oxide-nitride, and silicon oxide with vacancies are This is preferable because it allows for the easy formation of regions containing oxygen that is released by heating.

[0146] It is preferable that the concentration of impurities such as water or hydrogen in the insulator 280 is reduced. Furthermore, the upper surface of the insulator 280 may be flattened.

[0147] Insulator 282 or insulator 283 may contain impurities such as water or hydrogen from above. It is preferable that it functions as a barrier insulating film to suppress mixing with 80. Also, as an insulator 282 or insulator 283 can function as a barrier insulating film that suppresses oxygen permeation. Preferred. Examples of insulators 282 and 283 include aluminum oxide, nitride, etc. An insulator such as silicon or silicon nitride can be used. For example, insulator 282 As such, aluminum oxide, which has high blocking properties against oxygen, is used as the insulator 283. Therefore, silicon nitride, which has high blocking properties against hydrogen, can be used.

[0148] Furthermore, it is preferable to provide an insulator 274 that functions as an interlayer film on top of the insulator 282. i. Insulator 274, like insulator 224, has an impurity concentration of water or hydrogen in the film. It is preferable that this is reduced.

[0149] Conductors 240a and 240b are primarily composed of tungsten, copper, or aluminum. It is preferable to use conductive materials as components. Also, conductor 240a and conductor 24 0b may be a layered structure.

[0150] Furthermore, when the conductor 240 is made into a laminated structure, the insulator 281, insulator 274, insulator 28 2. The conductor in contact with insulators 280, 273, and 272 is in contact with water or water It is preferable to use a conductive material that has the function of suppressing the permeation of impurities such as elements. For example, tantalum, tantalum nitride, titanium, titanium nitride, ruthenium, or ruthenium oxide. It is preferable to use such a function. In addition, a function that suppresses the permeation of impurities such as water or hydrogen is also used. The conductive material may be used in a single layer or in a multilayer structure. By using this conductive material, The oxygen added to the insulator 280 is absorbed by the conductors 240a and 240b. This can be prevented. Also, impurities such as water or hydrogen can enter from above the insulator 281, preventing conductivity. This suppresses the mixing of material into the oxide 230 through the body 240a and the conductor 240b. Cut.

[0151] Examples of insulators 241a and 241b include silicon nitride and aluminum oxide. An insulator such as um or silicon nitride may be used. Insulator 241a and insulation Since body 241b is provided in contact with insulators 272 and 273, insulator 28 Impurities such as water or hydrogen enter from 0 through conductors 240a and 240b. It is possible to suppress the mixing of oxide 230. In particular, silicon nitride is effective against hydrogen. It is suitable because it has high blocking properties. Also, the oxygen contained in the insulator 280 is conductor 24 This prevents absorption by 0a and conductor 240b.

[0152] Furthermore, the upper surfaces of the conductor 240a and the upper surfaces of the conductor 240b function as wiring. Conductors 246 (conductors 246a and conductors 246b) may be arranged. 46 uses a conductive material whose main component is tungsten, copper, or aluminum. This is preferable. Furthermore, the conductor may also have a laminated structure, for example, titanium, titanium nitride. The above conductive material may be laminated with the conductive material. The conductive material has an opening provided in the insulator. It may be formed to be embedded in something.

[0153] <Component materials for semiconductor devices> The following describes the constituent materials that can be used in semiconductor devices.

[0154] <Circuit board> Examples of substrates for forming the transistor 200 include an insulating substrate, a semiconductor substrate, and A conductive substrate can be used. Examples of insulating substrates include glass substrates, quartz substrates, and Fire substrate, stabilized zirconia substrate (such as yttria-stabilized zirconia substrate), resin substrate There are plates and the like. Also, semiconductor substrates are made of materials such as silicon and germanium. Semiconductor substrates, or silicon carbide, silicon germanium, gallium arsenide, phosphate Examples include compound semiconductor substrates composed of zinc, zinc oxide, and gallium oxide. Furthermore, as mentioned above... A semiconductor substrate having an insulating region inside the semiconductor substrate, for example, SOI (Silicon Examples include on-insulator substrates. Conductive substrates include graphite substrates and metal substrates. These include alloy substrates, conductive resin substrates, etc. Alternatively, substrates containing metal nitrides, metal acids There are substrates containing monoxides, etc. Furthermore, there are substrates on which a conductor or semiconductor is provided on an insulating substrate. A substrate, a semiconductor substrate provided with a conductor or insulator, a conductive substrate provided with a semiconductor or insulator There are substrates with edges provided. Alternatively, substrates on which elements are provided can be used. It is also possible to provide elements on the substrate such as capacitive elements, resistive elements, switching elements, and light-emitting elements. These include children, memory elements, etc.

[0155] <insulator> Insulators include insulating oxides, nitrides, oxidized nitrides, nitride oxides, and metal oxides. Examples include metal oxides, metal nitrides, and metal nitride oxides.

[0156] For example, as transistors become smaller and more integrated, the gate insulator can be made thinner. This can lead to problems such as leakage current. By using high-k materials, the physical film thickness is maintained while lowering the voltage during transistor operation. This becomes possible. On the other hand, for the insulator that functions as an interlayer film, a material with a low dielectric constant is used. This reduces parasitic capacitance between wires. Therefore, it is possible to reduce the parasitic capacitance that occurs between wires. Then, you should select the materials.

[0157] Furthermore, insulators with high dielectric constants include gallium oxide, hafnium oxide, and zirconium oxide. Oxides containing aluminum, aluminum, and hafnium, aluminum and hafnium Oxidized nitrides, silicon and hafnium oxides, silicon and hafnium Examples include oxide nitrides containing um, or nitrides containing silicon and hafnium.

[0158] Furthermore, examples of insulators with low dielectric constant include silicon oxide, silicon oxide nitride, and silicon nitride oxide. Silicon oxide with added fluorine, silicon oxide with added carbon, carbon and nitrogen Examples include silicon oxide with added material, silicon oxide with voids, or resins.

[0159] Furthermore, transistors using oxide semiconductors suppress the permeation of impurities such as hydrogen and oxygen. By surrounding the transistor with an insulator that has a controlling function, the electrical characteristics of the transistor are stabilized. This is possible. As an insulator that has the function of suppressing the permeation of impurities such as hydrogen and oxygen, For example, boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum, silicon Phosphorus, chlorine, argon, gallium, germanium, yttrium, zirconium, or Insulators containing tan, neodymium, hafnium, or tantalum are used in single-layer or multi-layer configurations. It would be good to have one. Specifically, an insulating material that has the function of suppressing the permeation of impurities such as hydrogen and oxygen. As a supporting material, aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, Yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, or metal oxides such as tantalum oxide, aluminum nitride, titanium aluminum nitride, nitrile Metal nitrides such as titanium dioxide, silicon nitride, or silicon nitride can be used. .

[0160] Furthermore, the insulator that functions as a gate insulator has regions containing oxygen that is released by heating. It is preferable that the insulator has a region containing oxygen that is desorbed by heating. By creating a structure in which silicon oxide or silicon oxide nitride is in contact with oxide 230, This can compensate for the oxygen deficiency present in 230.

[0161] <Conductive material> Examples of conductive materials include aluminum, chromium, copper, silver, gold, platinum, tantalum, nickel, and crystalline silver. Tun, molybdenum, tungsten, hafnium, vanadium, niobium, manganese, magnesium Zium, zirconium, beryllium, indium, ruthenium, iridium, strontium A metallic element selected from um, lanthanum, etc., or an alloy containing the aforementioned metallic elements. It is preferable to use an alloy or the like that which combines the above-mentioned metal elements. For example, tantalum nitride Titanium nitride, tungsten nitride, nitrides containing titanium and aluminum, tantalum and aluminum Luminium-containing nitrides, ruthenium oxide, ruthenium nitride, strontium and ruthenium It is preferable to use oxides containing lanthanum, oxides containing lanthanum and nickel, etc. Tantalum nitride, titanium nitride, titanium and aluminum nitrides, tantalum and aluminum Nitrides containing ruthenium, ruthenium oxide, ruthenium nitride, and strontium and ruthenium Oxides, including lanthanum and nickel oxides, are conductive materials that are resistant to oxidation, or oxygen It is preferable because it is a material that maintains its conductivity even after absorption. Furthermore, it contains impurity elements such as phosphorus. Highly electrically conductive semiconductors, such as polycrystalline silicon, and nickel silicides. Any silicide can be used.

[0162] Furthermore, multiple conductive layers formed from the above materials may be stacked and used. For example, as described above. A laminated structure may be formed by combining a material containing a metallic element with a conductive material containing oxygen. Furthermore, a laminate combining the aforementioned metal element-containing material and a nitrogen-containing conductive material is also used. It may also be used as a structure. Furthermore, a material containing the aforementioned metal element, a conductive material containing oxygen, and nitrogen A laminated structure combining conductive materials containing elements may also be used.

[0163] Furthermore, when using oxide in the channel formation region of a transistor, as the gate A functional conductor combines a material containing the aforementioned metal element with a conductive material containing oxygen. It is preferable to use a combined laminated structure. In this case, an oxygen-containing conductive material is channeled. It is preferable to place it on the channel formation region side. The oxygen-containing conductive material should be placed on the channel formation region side. This makes it easier for oxygen released from the conductive material to be supplied to the channel-forming region.

[0164] In particular, it is contained in the metal oxide in which the channel is formed, as a conductor that functions as a gate. It is preferable to use a conductive material containing a metal element and oxygen. Conductive materials containing elements and nitrogen may be used. For example, titanium nitride, tantalum nitride, etc. A conductive material containing nitrogen may also be used. In addition, indium tin oxide and tungsten oxide may be used. Indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, titanium oxide Indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, indium zinc oxide, Indium tin oxide with added silicon may also be used. Zinc oxide may be used. By using such a material, channels can be formed. In some cases, hydrogen contained in the metal oxide can be captured. Alternatively, the outer insulator In some cases, hydrogen introduced from sources such as these can be captured.

[0165] <Metal oxides> It is preferable to use a metal oxide that functions as an oxide semiconductor as oxide 230. The following describes metal oxides applicable to the oxide 230 according to the present invention.

[0166] The metal oxide preferably contains at least indium or zinc. In particular, indium Preferably, it contains aluminum and zinc. In addition, aluminum and gallium It is preferable that it contains yttrium or tin, as well as boron, titanium, and iron. Nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium , one of the following selected from hafnium, tantalum, tungsten, or magnesium, It may include multiple species.

[0167] Here, the metal oxide is In-M-Zn oxide, which has indium, element M, and zinc. Let's consider the case where it is a substance. Note that element M is aluminum, gallium, yttrium, and This is tin, etc. Other elements that can be applied to element M include boron, titanium, iron, and nitrile. Germanium, Zirconium, Molybdenum, Lanthanum, Cerium, Neodymium, Ha Examples include fluorium, tantalum, tungsten, and magnesium. However, as element M, In some cases, it is acceptable to combine multiple of the aforementioned elements.

[0168] In this specification, metal oxides containing nitrogen are also referred to as metal oxides (metal oxides). They are sometimes collectively referred to as metal oxynitrides (metal oxides). Also, metal oxides containing nitrogen are sometimes called metal oxynitrides (metal oxides). It may also be called tal oxynitride.

[0169] [Structure of metal oxides] Oxide semiconductors (metal oxides) include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. It can be divided into conductors and conductors. Examples of non-single-crystal oxide semiconductors include CAAC-OS, multi-phase Amorphous oxide semiconductor, nc-OS, pseudo-amorphous oxide semiconductor (a-like OS: amor (Phosphor-like oxide semiconductor), and amorphous oxide Examples include semiconductors.

[0170] CAAC-OS has c-axis orientation and multiple nanocrystals are linked in the ab-plane direction. It has a crystalline structure that is linked and distorted. Note that distortion refers to the linkage between multiple nanocrystals. Within a region, between a region with a aligned grid arrangement and another region with a aligned grid arrangement, the grid arrangement This refers to the point where the orientation has changed.

[0171] Nanocrystals are based on a hexagonal shape, but they are not necessarily regular hexagons; they can also be non-regular hexagonal. There are also cases where the distortion has a grid arrangement such as pentagons and heptagons. Furthermore, in CAAC-OS, even near strain, clear grain boundaries (grain bows) are present. It is difficult to confirm (also called unduli). In other words, due to the distortion of the lattice arrangement, the crystal It can be seen that grain boundary formation is suppressed. This is because CAAC-OS is in the ab-plane direction. In this case, the arrangement of oxygen atoms is not dense, and the substitution of metal elements reduces the interatomic bond distance. This is because the distortion can be tolerated due to changes in other factors.

[0172] Furthermore, CAAC-OS consists of a layer containing indium and oxygen (hereinafter referred to as the In layer), and A layered crystal in which layers containing element M, zinc, and oxygen (hereinafter referred to as (M,Zn) layers) are stacked. It tends to have a structure (also called a layered structure). Note that indium and element M are relative to each other. It is interchangeable, and if element M in the (M,Zn) layer is replaced with indium, then (In,M,Zn It can also be represented as a layer. Furthermore, if the indium in the In layer is replaced by element M, (In, It can also be represented as layer M.

[0173] CAAC-OS is a highly crystalline metal oxide. On the other hand, CAAC-OS has a clear bond. Because it is difficult to confirm grain boundaries, a decrease in electron mobility caused by grain boundaries is less likely to occur. It can be said that... Also, the crystallinity of metal oxides decreases due to the inclusion of impurities and the formation of defects. Because this can occur, CAAC-OS may contain impurities or defects (oxygen deficiency (V) O :oxygen v It can also be said that it is a metal oxide with low acancy (also called acancy). Therefore, CAAC- Metal oxides containing OS have stable physical properties. Therefore, CAAC-OS is Metal oxides are heat-resistant and highly reliable.

[0174] nc-OS is used in minute regions (for example, regions between 1 nm and 10 nm, especially regions larger than 1 nm). It has periodicity in the atomic arrangement in the region of 3 nm or less. Also, nc-OS has different na No regularity is observed in the crystal orientation between the crystals. Therefore, no orientation is observed throughout the entire film. Therefore, depending on the analytical method, nc-OS may be a-like OS or amorphous oxide semiconductor. It can sometimes be indistinguishable from the body.

[0175] Furthermore, indium is a type of metal oxide containing indium, gallium, and zinc. Um-gallium-zinc oxide (hereinafter referred to as IGZO) is stable when formed into the nanocrystals described above. It may take on a structure. In particular, IGZO tends to have difficulty growing crystals in the atmosphere. Smaller crystals (for example) are preferable to larger crystals (here, crystals of a few millimeters or a few centimeters). In some cases, using the aforementioned nanocrystal structure may result in greater structural stability.

[0176] a-like OS is a metallic acid having a structure between nc-OS and amorphous oxide semiconductors. It is a monster. a-like OS has porous or low-density regions. That is, a-li ke OS has lower crystallinity compared to nc-OS and CAAC-OS.

[0177] Oxide semiconductors (metal oxides) can take on diverse structures, each possessing different properties. An oxide semiconductor according to one aspect of the present invention is an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, and a-li It may have two or more of the following: ke OS, nc-OS, and CAAC-OS.

[0178] Furthermore, in a semiconductor device according to one aspect of the present invention, the structure of the oxide semiconductor (metal oxide) There are no particular limitations, but it is preferable that it be crystalline. For example, if oxide 230 is CA The AC-OS structure allows for a hexagonal crystal structure of oxide 243. By using the above crystal structure for 0 and oxide 243, a semiconductor device with high reliability can be obtained. It is possible to also roughly analyze oxides 230a, 230c, and 243. The same composition can be achieved.

[0179] [impurities] Here, we will explain the effects of various impurities in metal oxides.

[0180] Furthermore, if the metal oxide contains alkali metals or alkaline earth metals, it can form defect levels. This can result in the generation of carriers. Therefore, alkali metals or alkaline earth metals Transistors that use metal oxides containing the group in the channel formation region are normally-on This is a common characteristic. Therefore, the concentration of alkali metals or alkaline earth metals in metal oxides It is preferable to reduce the degree. Specifically, alkali metals or alkalis in metal oxides. Concentration of earth metals (Secondary Ion Mass Spectrometry (SIMS)) The concentration obtained by ss Spectrometry is 1 × 10⁻⁶ 18 atom / cm 3 The following is preferably 2 × 10 16 atoms / cm 3 Do the following:

[0181] Furthermore, the hydrogen contained in metal oxides reacts with the oxygen bonded to the metal atoms to form water. This can sometimes form an oxygen deficiency. When hydrogen enters this oxygen deficiency, the carrier electrons... In some cases, a child may be produced. Also, some of the hydrogen combines with the metal atom and oxygen, resulting in a crystal. It can generate electrons, which are carriers. Therefore, using a metal oxide containing hydrogen... Transistors tend to exhibit normally-on characteristics.

[0182] Therefore, it is preferable that the hydrogen content in the metal oxide be reduced as much as possible. Specifically In metal oxides, the hydrogen concentration obtained by SIMS is 1 × 10⁻⁶. 20 atoms / cm 3 Less than 1 × 10 19 atoms / cm 3 Less than 5x1 0 18 atoms / cm 3 Less than 1 × 10 18 atoms / cm 3 less than Therefore, metal oxides with sufficiently reduced impurities are used in the channel formation region of the transistor. This allows for the provision of stable electrical characteristics.

[0183] For the metal oxide used in the semiconductor of a transistor, it is preferable to use a thin film with high crystalline properties. It seems that using this thin film can improve the stability or reliability of transistors. Yes, it is possible. Examples of such thin films include thin films of single-crystal metal oxides or thin films of polycrystalline metal oxides. These include thin films of single-crystal metal oxides or thin films of polycrystalline metal oxides. Forming on a substrate requires a high-temperature or laser heating process. Therefore, the manufacturing process This would increase costs and also decrease throughput.

[0184] <Method for fabricating semiconductor devices> Next, regarding the semiconductor device having the transistor 200 according to the present invention, as shown in Figure 1, The manufacturing method will be explained using Figures 5 to 14. In Figures 5 to 14, A in each figure is A top view is shown. In each figure, B corresponds to the area indicated by the dashed line A1-A2 in A. This is a cross-sectional view, and also a cross-sectional view of transistor 200 in the channel length direction. Also, C in each figure This is a cross-sectional view corresponding to the area shown by the dashed line A3-A4 in A, and transistor 200 This is also a cross-sectional view in the channel width direction. Note that in the top view A of each figure, for clarity of the figure Some elements have been omitted.

[0185] First, a substrate (not shown) is prepared, and an insulator 212 is deposited on the substrate. The 12 film deposition methods include sputtering and chemical vapor deposition (CVD). Deposition method, Molecular beam epitaxy (MBE) EAM Epitaxy, Pulsed Laser Deposition (PLD) This can be done using methods such as the Deposition method or the ALD method.

[0186] Furthermore, the CVD method is a type of plasma CVD (PECVD) that utilizes plasma. Enhanced CVD (Enhanced CVD), Thermal CVD (TCVD: Thermal CCVD) which utilizes heat. It can be classified into methods such as the VD method and the photoCVD method which utilizes light. Depending on the source gas used, the process can be metal CVD (MCVD) or organometallic CVD. It can be divided into (MOCVD: Metal Organic CVD) methods.

[0187] Plasma CVD can produce high-quality films at relatively low temperatures. Thermal CVD, on the other hand, is a method that can produce high-quality films at low temperatures. A film deposition method that does not use Zuma, thus minimizing plasma damage to the workpiece. For example, wiring, electrodes, and elements (transistors, capacitive elements, etc.) included in semiconductor devices. ) and others can be charged up by receiving an electric charge from the plasma. In cases where the accumulated charge destroys the wiring, electrodes, and elements contained in the semiconductor device. On the other hand, in the case of thermal CVD methods that do not use plasma, such plasma damage occurs. Therefore, the yield of semiconductor devices can be increased. Also, in the thermal CVD method, Because plasma damage does not occur within the film, a film with fewer defects can be obtained.

[0188] Furthermore, the ALD method utilizes the self-regulating properties of atoms to deposit atoms layer by layer. This allows for the deposition of extremely thin films, enabling film deposition on structures with high aspect ratios, and pinholes. It enables film formation with fewer defects such as blemishes, allows for film formation with excellent coverage, and enables film formation at low temperatures. It has effects such as [mention specific effects]. In addition, the ALD method is a film deposition method that utilizes plasma, called PEA This also includes the LD (Plasma Enhanced ALD) method, which utilizes plasma. This allows for film deposition at lower temperatures, which is preferable in some cases. Casa contains impurities such as carbon. Therefore, a membrane is created by the ALD method. Compared to films formed by other film deposition methods, these films may contain more impurities such as carbon. Furthermore, the quantitative determination of impurities is performed using X-ray photoelectron spectroscopy (XPS). This can be done using tron ​​spectroscopy.

[0189] CVD and ALD are film deposition methods in which particles emitted from a target or other source are deposited. Unlike other methods, this is a film-forming method in which a film is formed by a reaction on the surface of the object being treated. This film-forming method is less affected by the shape of the workpiece and has good step-level coverage. Furthermore, the ALD method has excellent step coverage and excellent thickness uniformity, thus aspect ratio This method is suitable for coating the surface of high-aperture openings, etc. However, the ALD method is relatively suitable for film formation. Because of its slow rate, it should be used in combination with other film deposition methods that have a faster deposition rate, such as CVD. In some cases, this may be preferable.

[0190] The CVD and ALD methods control the composition of the resulting film by adjusting the flow rate ratio of the source gases. This is possible. For example, in the CVD method and ALD method, the flow rate ratio of the raw material gas can be adjusted as needed. A film with the following composition can be formed. Furthermore, for example, in the CVD method and ALD method, film formation can be performed. By changing the flow rate ratio of the raw material gas while simultaneously depositing a film with a continuously changing composition. This is possible. When forming a film while changing the flow rate ratio of the raw material gas, multiple deposition chambers can be used. Compared to the method of film deposition using a conveyor belt, it eliminates the time required for transport and pressure adjustment, thus reducing the time required for film deposition. The interval can be shortened. Therefore, the productivity of semiconductor devices can be increased. There is.

[0191] In this embodiment, silicon nitride is deposited as the insulator 212 by the CVD method. Thus, as the insulator 212, an insulator that is impermeable to copper, such as silicon nitride, is used. By doing so, a diffusive metal such as copper is used in the conductor layer (not shown) below the insulator 212. Even if present, it is possible to suppress the diffusion of the metal to the upper layer through the insulator 212. Furthermore, by using an insulator that is resistant to the permeability of impurities such as water or hydrogen, such as silicon nitride... This suppresses the diffusion of impurities such as water or hydrogen from the layer below the insulator 212. Cut.

[0192] Next, an insulator 214 is deposited on the insulator 212. The insulator 214 is deposited by sputtering. This can be performed using methods such as the blotting method, CVD method, MBE method, PLD method, or ALD method. In this embodiment, aluminum oxide is used as the insulator 214.

[0193] Next, an insulator 216 is deposited on the insulator 214. The insulator 216 is deposited by sputtering. This can be performed using methods such as the blotting method, CVD method, MBE method, PLD method, or ALD method.

[0194] Next, an opening is formed in the insulator 216 that reaches the insulator 214. An opening is, for example, a groove or This also includes slits, etc. Furthermore, the term "opening" can sometimes refer to the area where an opening has been formed. The opening can be formed using wet etching, but dry etching is preferable. This is preferable for microfabrication. In addition, the insulator 214 forms grooves by etching the insulator 216. It is preferable to select an insulator that functions as an etching stopper film during the etching process. When a silicon oxide film is used for the insulator 216 that forms the groove, the insulator 214 is silicon nitride Cone film, aluminum oxide film, and hafnium oxide film are suitable options.

[0195] After the opening is formed, a conductive film that will become the conductor 205a is formed. The conductive film allows oxygen to permeate. It is desirable to include a conductor that has a suppressive function. For example, tantalum nitride, tan nitride Tungsten, titanium nitride, etc. can be used. Alternatively, tantalum, tungsten, titanium The film will be a laminate of aluminum, copper, molybdenum, and a molybdenum-tungsten alloy. This can be done. The conductive film that will become the conductive material 205a can be deposited by sputtering, CVD, or MBE. This can be done using methods such as the PLD method or ALD method.

[0196] In this embodiment, the conductive film that becomes the conductor 205a has a multilayer structure. First, sputtering A tantalum nitride film is formed by a tangent molding process, and titanium nitride is then laminated on top of the tantalum nitride film. By using such a metal nitride as the lower layer of the conductor 205b, the conductor 20 described later Even if a diffusible metal such as copper is used as the conductive film for 5b, if the metal is conductor 205 This can prevent diffusion from a to the outside.

[0197] Next, a conductive film that will become the conductor 205b is formed. The formation of this conductive film is done by plating, spalling, etc. This can be done using methods such as Taring, CVD, MBE, PLD, or ALD. In this embodiment, the conductive film that becomes the conductor 205b is a low-resistance conductive material such as copper. A thin film is formed.

[0198] Next, CMP treatment (Chemical Mechanical Polishing) By doing so, a conductive film that becomes conductor 205a and a conductive film that becomes conductor 205b are obtained. The part is removed, exposing the insulator 216. As a result, the conductor 205a and the conductor are only present in the opening. The conductive material 205b remains. This makes it possible to form a conductive material 205 with a flat upper surface. It is possible. However, in some cases, a portion of the insulator 216 may be removed by the CMP treatment (Figure 5). reference).

[0199] In the above, the conductor 205 was formed to be embedded in the opening of the insulator 216. However, this embodiment is not limited to this. For example, a conductor 20 on an insulator 214 Form 5, deposit an insulator 216 on the conductor 205, and perform CMP treatment on the insulator 216. This means that a portion of the insulator 216 can be removed, exposing the surface of the conductor 205.

[0200] Next, an insulator 222 is formed on the insulator 216 and the conductor 205. As such, an insulating film containing an oxide of aluminum and / or hafnium is formed. It is desirable to do so. Furthermore, an insulator containing an oxide of either aluminum or hafnium or both. Examples include aluminum oxide, hafnium oxide, and aluminum and hafnium oxides. It is preferable to use materials such as aluminum and hafnium aluminate. Insulators containing oxides of one or both of the elements provide a barrier against oxygen, hydrogen, and water. It has. The insulator 222 has barrier properties against hydrogen and water, so the transient Hydrogen and water contained in the structure surrounding Ta 200 are transmitted through the insulator 222. Diffusion into the transistor 200 is suppressed, and the formation of oxygen vacancies in the oxide 230 is inhibited. It can be suppressed.

[0201] The insulator 222 is deposited by sputtering, CVD, MBE, PLD, or A This can be done using methods such as the LD method.

[0202] Next, an insulating film 224A is deposited on the insulator 222. The deposition of the insulating film 224A is performed by spa This can be done using methods such as Taring, CVD, MBE, PLD, or ALD. Cut.

[0203] Next, it is preferable to perform a heat treatment. The heat treatment should be performed at a temperature of 250°C to 650°C. The process is carried out at a temperature of 300°C to 500°C, more preferably 320°C to 450°C. That's fine. Note that the heat treatment should be performed in a nitrogen or inert gas atmosphere, or with an oxidizing gas at 10 pp. The process should be carried out in an atmosphere containing m or more, 1% or more, or 10% or more. Furthermore, the heat treatment should be performed under reduced pressure. It may be done. Alternatively, the heat treatment may be performed after heat treatment in a nitrogen or inert gas atmosphere. To compensate for the removed oxygen, it contains an oxidizing gas at a concentration of 10 ppm or more, 1% or more, or 10% or more. Heat treatment may be performed in a suitable atmosphere.

[0204] In this embodiment, after processing at a temperature of 400°C for 1 hour in a nitrogen atmosphere, The material is then treated in an oxygen atmosphere at a temperature of 400°C for 1 hour. This heat treatment improves insulation. Impurities such as water and hydrogen contained in membrane 224A can be removed.

[0205] Furthermore, the heat treatment may be performed after the film formation of the insulator 222. This heat treatment is as described above. Heat treatment conditions can be used.

[0206] Here, in order to form an excess oxygen region in the insulating film 224A, an oxygen-containing plastic is used under reduced pressure. Zuma treatment may be performed. Oxygen-containing plasma treatment can be performed, for example, using microwaves at high density. It is preferable to use a device that has a power supply for generating plasma. Alternatively, RF can be used on the substrate side. It may have a power supply that applies high-frequency waves such as the above. By using high-density plasma, high density It can generate oxygen radicals, and by applying RF to the substrate side, a high-density plasma can be created. The oxygen radicals generated by this process can be efficiently guided into the insulating film 224A. This device is used to perform plasma treatment with an inert gas, and then replenishes the desorbed oxygen. For this purpose, plasma treatment containing oxygen may be performed. The conditions for the plasma treatment may be selected as appropriate. By selecting this method, it is possible to remove impurities such as water and hydrogen contained in the insulating film 224A. In that case, heat treatment is not necessary.

[0207] Here, aluminum oxide is applied to the insulating film 224A, for example, by sputtering. A film may be formed, and CMP may be performed on the aluminum oxide until the insulating film 224A is reached. Performing this CMP will planarize and smooth the surface of the insulating film 224A. This can be done by placing the aluminum oxide on the insulating film 224A and performing CMP. This makes it easier to detect the endpoint of the CMP. Also, the CMP affects a part of the insulating film 224A. The film may be polished, causing the thickness of the insulating film 224A to become thinner, but when the insulating film 224A is formed... The film thickness can be adjusted accordingly. By planarizing and smoothing the surface of the insulating film 224A, later This prevents deterioration of the coverage rate of the oxide film being deposited, thereby preventing a decrease in the yield of semiconductor devices. In some cases, aluminum oxide may be applied to the insulating film 224A by sputtering. This is preferable because it allows oxygen to be added to the insulating film 224A by forming the film.

[0208] Next, oxide films 230A and 230B are sequentially deposited on insulating film 224A (see Figure 5). (Illuminate). Furthermore, it is preferable to continuously deposit the above oxide film without exposing it to the atmospheric environment. By forming the film without opening it to the air, the oxide film 230A and oxide film 230B are protected from the atmospheric environment. This prevents impurities or moisture from adhering to oxide film 230A and oxide film 230B. The vicinity of the interface can be kept clean.

[0209] The oxide films 230A and 230B were deposited by sputtering, CVD, and MBE. This can be done using methods such as the PLD method or the ALD method.

[0210] For example, oxide film 230A and oxide film 230B are deposited by sputtering. In this case, oxygen or a mixture of oxygen and a noble gas is used as the sputtering gas. By increasing the proportion of oxygen in the puttering gas, excess oxygen in the formed oxide film... This can increase the amount. Also, when the above oxide film is deposited by sputtering: The above-mentioned In-M-Zn oxide target can be used.

[0211] In particular, during the deposition of oxide film 230A, some of the oxygen contained in the sputtering gas becomes the insulating film. It may be supplied to 224A. Therefore, the sputtering gas for oxide film 230A The oxygen content should be 70% or more, preferably 80% or more, and more preferably 100%. That's all you need to do.

[0212] Furthermore, when forming oxide film 230B by sputtering, the sputtering gas contains When the oxygen content is set to 1% or more and 30% or less, preferably 5% or more and 20% or less, the film is formed. Oxygen-deficient oxide semiconductors are formed. The transistor used in this region provides relatively high field-effect mobility. Also, when the substrate is heated... By performing film formation while simultaneously depositing the oxide film, the crystallinity of the oxide film can be improved. However, one aspect of the present invention is not limited thereto. The oxide film 230B is formed by a sputtering method. In this case, the proportion of oxygen in the sputtering gas is preferably between 30% and 100%. Alternatively, if the film is deposited with an oxygen content of 70% to 100%, an oxygen-rich oxide semiconductor is formed. Transistors using oxygen-rich oxide semiconductors in the channel formation region are relatively high Reliability can be obtained.

[0213] In this embodiment, the oxide film 230A is formed by sputtering, using the In:Ga: Zn = 1:1:0.5 [atomic ratio] (2:2:1 [atomic ratio]), or 1:3:4 [ The film is deposited using a target with an atomic ratio. In addition, as oxide film 230B, sputtering According to the method, In:Ga:Zn = 4:2:4.1 [atomic ratio], or 1:1:1 [ The film is deposited using a target with an atomic ratio. Note that each oxide film is determined by the deposition conditions and atomic ratio. By appropriately selecting the ratio, the oxide 230 can be formed to match the desired properties.

[0214] Next, heat treatment may be performed. The heat treatment can be carried out using the heat treatment conditions described above. The heat treatment removes the water, hydrogen, and other impurities from the oxide film 230A and oxide film 230B. It is possible to remove pure substances, etc. In this embodiment, at a temperature of 400°C in a nitrogen atmosphere After a 1-hour treatment, the sample is continuously treated in an oxygen atmosphere at a temperature of 400°C for another 1 hour. cormorant.

[0215] Next, an oxide film 243A is deposited on the oxide film 230B (see Figure 5). Thin film deposition is performed using sputtering, CVD, MBE, PLD, or ALD methods. It can be done. Oxide film 243A has an atomic ratio of Ga to In, compared to oxide film 230B. It is preferable that the atomic ratio of Ga to In is greater than that of In. In this embodiment, oxide film 2 As 43A, the atom ratio In:Ga:Zn=1:3:4 was obtained by sputtering. The film is deposited using the target.

[0216] Next, a conductive film 242A is deposited on the oxide film 243A (see Figure 5). Thin film deposition is performed using sputtering, CVD, MBE, PLD, or ALD methods. This can be done (see Figure 5).

[0217] Next, using lithography, oxide film 230A, oxide film 230B, and oxide film 243A were obtained. , and the conductive film 242A is processed into an island shape to form oxide 230a, oxide 230b, oxide layer Form layers 243B and 242B (see Figure 6). Furthermore, this process is performed using a dryer. The etching method and the wet etching method can be used. The process is suitable for microfabrication. Although not shown in the diagram, in this process, the insulating film 224A The film thickness may be thinner in areas that do not overlap with oxide 230a.

[0218] In lithography, the resist is first exposed through a mask. Next, exposure... The selected area is removed or left intact using a developer to form a resist mask. Next, By etching through the resist mask, conductors, semiconductors, or insulators, etc. It can be processed into the desired shape. For example, KrF excimer laser light, ArF excimer Using malea light, EUV (Extreme Ultraviolet) light, etc., A resist mask can be formed by exposing the resist. Also, between the substrate and the projection lens Alternatively, an immersion technique may be used, in which a liquid (e.g., water) is filled into the container and exposed to light. Alternatively, electron beams or ion beams may be used. If used, a mask is not required. Note that to remove the resist mask, an ashing process is necessary. Which dry etching process, which wet etching process, dry etching process After processing, wet etching is performed, or dry etching is performed after wet etching. It can perform a processing step.

[0219] Alternatively, a hard mask made of an insulator or conductor may be used instead of a resist mask. When using a hard mask, an insulating film or conductive material that will serve as the hard mask material will be placed on the conductive film 242A. Forming a film, forming a resist mask on it, and etching the hard mask material. This allows for the formation of a hard mask of the desired shape. Etching of conductive film 242A, etc. This can be done after removing the resist mask, or it can be done with the resist mask still in place. That is also good. In the latter case, the resist mask may disappear during etching. Conductive film 24 After etching 2A, the hard mask may be removed by etching. If the material used for the mask does not affect subsequent processes, or can be used in subsequent processes, then it is not necessarily necessary to use a hard mask. There is no need to remove Domask.

[0220] As a dry etching apparatus, a capacitively coupled plasma (CCP) system with parallel plate electrodes is used. (Capacitively Coupled Plasma) Etching apparatus is used. Capacitively coupled plasma etching apparatus having parallel plate electrodes can be used. Alternatively, a high-frequency power supply may be applied to one electrode of the type electrode. Or, one of the parallel plate type electrodes. Alternatively, a configuration in which multiple different high-frequency power supplies are applied to the electrodes may be used. Or a parallel plate type electrode Alternatively, a configuration in which a high-frequency power supply of the same frequency is applied to each of them may be used. Alternatively, a configuration in which high-frequency power supplies of different frequencies are applied may be used. Or, a high-density plasma source may be used. A dry etching apparatus can be used. Dry etching with a high-density plasma source. The device is, for example, an inductively coupled plasma (ICP) device. Etching equipment such as an ed Plasma etching device can be used.

[0221] Here, oxide 230a, oxide 230b, oxide layer 243B, and conductive layer 242 B is formed such that at least a portion of it overlaps with the conductor 205. Also, oxide 230a, The sides of oxide 230b, oxide layer 243B, and conductive layer 242B are insulator 222 It is preferable that it be approximately perpendicular to the top surface. Oxide 230a, Oxide 230b, Oxide The sides of layer 243B and the conductive layer 242B are approximately perpendicular to the upper surface of the insulator 222. This allows for miniaturization and high density when multiple transistors 200 are installed. Alternatively, oxide 230a, oxide 230b, oxide layer 243B, and conductive layer 242 The configuration may be such that the angle between B and the upper surface of the insulator 222 is low. In that case, the oxide Sides of 230a, oxide 230b, oxide layer 243B, and conductive layer 242B and insulator The angle formed by the top surface of 222 is preferably 60° or more and less than 70°. By adopting such a shape, In subsequent processes, the coating properties of the insulator 272 and other materials are improved, reducing defects such as porosity. It is possible.

[0222] Furthermore, there is a curved surface between the side surface of the conductive layer 242B and the upper surface of the conductive layer 242B. In other words, the edges of the sides and the edges of the top surface are preferably curved (hereinafter referred to as rounded). (Also known as) The curved surface, for example, at the edge of the conductive layer 242B, has a radius of curvature of 3 nm. The wavelength should be 10 nm or less, preferably 5 nm to 6 nm. The edges should not have sharp corners. This improves the film's coverage in subsequent film formation processes.

[0223] Next, insulating film 224A, oxide 230a, oxide 230b, oxide layer 243B, and conductive An insulating film 272A is deposited on the electrochemical layer 242B (see Figure 7).

[0224] The insulating film 272A is deposited by sputtering, CVD, MBE, PLD, or A This can be done using methods such as the LD method. The insulating film 272A has a function to suppress oxygen permeation. It is preferable to use an insulating film having a certain property. For example, by sputtering or ALD. Then, aluminum oxide, silicon nitride, silicon oxide, or gallium oxide is deposited as a film. That's good too.

[0225] Next, insulating film 273A is deposited on insulating film 272A (see Figure 7). Insulating film 273A The film deposition is carried out using methods such as sputtering, CVD, MBE, PLD, or ALD. This can be done by, for example, by the ALD method, aluminum oxide can be deposited into a film. In this embodiment, aluminum oxide is deposited by the ALD method. It is also possible to have a configuration in which the edge film 273A is not formed.

[0226] Next, an insulating film that will become an insulator 280 is deposited on the insulating film 273A. The deposition of the insulating film is carried out by sputtering, CVD, MBE, PLD, or ALD. This can be done using methods such as sputtering. For example, as the insulator 280, the sputtering method can be used. A silicon oxide film is formed, and then silicon oxide is applied to it using the PEALD method or thermal ALD method. A recon film should be formed. Here, the insulator 280 is prepared using the PEALD method or thermal ALD. By forming a film using this method, as shown in Figures 2 and 3, the water in the insulator 280 The elementary concentration can be reduced.

[0227] Next, the insulating film that will become the insulator 280 is subjected to CMP treatment to form an insulator 280 with a flat top surface. To accomplish (see Figure 8).

[0228] Next, a portion of the insulator 280, a portion of the insulating film 273A, a portion of the insulating film 272A, and an oxide layer. Parts of 243B and the conductive layer 242B are processed to form an opening that reaches the oxide 230b. The opening is formed so as to overlap with the conductor 205. By means, oxide 243a, oxide 243b, conductor 242a, conductor 242b, insulator Forms 272, an insulator 273, and an insulator 224 (see Figure 8).

[0229] Also, a portion of the insulator 280, a portion of the insulating film 273A, a portion of the insulating film 272A, and the oxide layer The processing of parts of 243B and the conductive layer 242B may be carried out under different conditions. For example, a portion of the insulator 280 is processed by a dry etching method, and a portion of the insulating film 273A is processed. The material is processed by a wet etching method, and a portion of the insulating film 272A, the oxide layer 243B, and the conductive film are removed. A portion of the electrolytic layer 242B may be processed by dry etching.

[0230] Conventional processes such as dry etching can cause oxidation in etching gases, etc. The impurities caused by these impurities adhere to the surface or interior of oxide 230a and oxide 230b, and It can diffuse. Impurities include, for example, fluorine or chlorine.

[0231] To remove the above-mentioned impurities, washing is performed. The washing method involves using a washing solution, etc. These include wet cleaning, plasma treatment using plasma, or cleaning by heat treatment. The above cleaning methods may be combined as appropriate.

[0232] For wet cleaning, use oxalic acid, phosphoric acid, ammonia water, or hydrofluoric acid, etc. Washing may be performed using an aqueous solution diluted with carbonated water or distilled water. Alternatively, distilled water or Ultrasonic cleaning using carbonated water may also be performed.

[0233] Heat treatment may be performed after the etching or cleaning described above. For example, the heat treatment may be performed after the etching or cleaning described above. The heat treatment should be carried out at a temperature between 100°C and 400°C. Note that the heat treatment should be performed using nitrogen gas or an inert gas. A gaseous atmosphere, or containing oxidizing gases at concentrations of 10 ppm or more, 1% or more, or 10% or more. The process is carried out in an atmosphere. For example, the heat treatment may be carried out in an oxygen atmosphere. This results in oxide 23 Oxygen is supplied to 0a and oxide 230b, and oxygen deficiency V O This can help reduce the problem. Furthermore, the heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out using nitrogen gas or an inert gas. After heat treatment in an atmosphere of oxidizing gas, 10 pp of oxidizing gas is added to replenish the desorbed oxygen. The procedure may be carried out in an atmosphere containing m or more, 1% or more, or 10% or more.

[0234] Next, heat treatment may be performed, and this heat treatment shall be carried out under reduced pressure and exposed to the atmosphere. Alternatively, the oxide film 230C may be formed continuously (see Figure 9). Furthermore, this heat treatment is performed as follows: It is preferable to carry out this process in an oxygen-containing atmosphere. By performing this treatment, oxide 2 Removes moisture and hydrogen adsorbed on the surface of 30b, and further removes oxide 230a and The water and hydrogen concentrations in oxide 230b can be reduced. Heat treatment temperature The temperature is preferably between 100°C and 400°C, and more preferably between 150°C and 350°C. In this embodiment, the heat treatment is performed at a temperature of 200°C under reduced pressure.

[0235] Here, the oxide film 230C is at least a portion of the side surface of oxide 230a, and oxide 230b Part of the side and part of the top surface, part of the side of oxide 243, part of the side of conductor 242 so as to be in contact with the side surface of insulator 272, the side surface of insulator 273, and the side surface of insulator 280. It is preferable that it be provided. Conductor 242 is an oxide 243, insulator 272, oxide film 23 Being surrounded by 0C suppresses the decrease in conductivity due to oxidation of conductor 242 in subsequent processes. It can be controlled.

[0236] The deposition of oxide film 230C is performed by sputtering, CVD, MBE, PLD, or A This can be done using methods such as LD. The oxide film 230C is composed of atoms of Ga relative to In. The numerical ratio is preferably greater than the atomic ratio of Ga to In in the oxide film 230B. In terms of application methods, the oxide film 230C is produced by sputtering, with In:Ga:Zn= The film is deposited using a target with an atomic ratio of 1:3:4.

[0237] Furthermore, the oxide film 230C may be layered. For example, by sputtering, The film is deposited using a target with an atomic ratio of n:Ga:Zn=4:2:4.1, and then continuously... The film may also be deposited using a target with an atomic ratio of In:Ga:Zn = 1:3:4.

[0238] During the deposition of oxide film 230C, some of the oxygen contained in the sputtering gas becomes oxide 230 a and oxide 230b may be supplied. Alternatively, during the formation of oxide film 230C, In some cases, some of the oxygen contained in the sputtering gas may be supplied to the insulator 280. Therefore, the proportion of oxygen in the sputtering gas of oxide film 230C is preferably 70% or more. It should be 80% or more, more preferably 100%.

[0239] Next, heat treatment may be performed. Furthermore, this heat treatment may be carried out under reduced pressure and exposed to the atmosphere. Without interruption, irradiation with electromagnetic waves 290 or deposition of insulating film 250A may be carried out continuously. By performing this heat treatment, moisture adsorbed on the surface of the oxide film 230C and other surfaces is removed. It removes hydrogen, and further removes moisture from oxide 230a, oxide 230b, and oxide film 230C. The concentration and hydrogen concentration can be reduced. The heat treatment temperature is 100°C to 400°C. A temperature of ℃ or lower is preferred. In this embodiment, the heat treatment temperature is set to 200℃.

[0240] Next, as shown in Figure 3, electromagnetic wave 290 is transmitted to oxide 230C, insulator 280, acid The oxide 230b and oxide 230a may also be irradiated (see Figure 10). Here, electromagnetic waves For 290, microwaves or high-frequency waves such as RF can be used. The irradiated electromagnetic waves 290 is immersed in oxide 230C, insulator 280, oxide 230b, and oxide 230a. Through these, V O H is removed. Some of the hydrogen produced at this time combines with oxygen. It may be removed as H2O from oxide 230 and insulator 280. Also, Some of the hydrogen may be gettered by the conductor 242. In this way, electromagnetic waves 29 By irradiating with 0, oxide 230C, insulator 280, oxide 230b, and oxide 2 The hydrogen concentration in 30a can be reduced.

[0241] Furthermore, when irradiated with electromagnetic wave 290, the oxygen gas is turned into plasma by electromagnetic wave 290, and acid Elementary radicals may be formed. That is, oxide 230C, insulator 280, oxide 230b Plasma treatment may be performed in an atmosphere containing oxygen for oxide 230a. Oxide 230C and insulator 28 formed by irradiation with electromagnetic waves 290 by oxygen radicals. Oxygen-deficient V in oxide 230b and oxide 230a O It can compensate for that. This allows for irradiation with electromagnetic waves 290 while simultaneously treating oxide 230C, insulator 280, and oxide. V in 230b and oxide 230a O H, and oxygen-deficient V O It can reduce ru.

[0242] Next, an insulating film 250A is deposited on the oxide 230C (see Figure 11). At this time, electromagnetic To continuously deposit an insulating film 250A without exposure to the atmosphere after irradiation with wave 290. This is preferable. As shown with reference to Figures 2 and 3, the insulating film 250A is made by the PEALD method. Alternatively, it is preferable to deposit the film using an ALD method such as thermal ALD. Insulating film 2 For 50A, it is preferable to deposit a film of silicon oxide or silicon oxide nitride. When depositing insulating film 250A using the ALD method, it is preferable to set the substrate temperature higher than 200°C. By heating to 300°C or higher, more preferably 350°C or higher, the insulating film 250A, insulator The hydrogen concentration in 280 and oxide 230 can be reduced. Also, the thermal When depositing insulating film 250A using the ALD method, the substrate temperature is preferably higher than 300°C. Alternatively, by heating to 350°C or higher, insulating film 250A, insulator 280, and oxide 230 It can reduce excessive hydrogen concentration.

[0243] Here, as an example of a device capable of forming films using the ALD method, we have the film deposition apparatus 4000. The configuration will be explained using Figures 15A and 15B. Figure 15A shows a multi-chamber. Figure 15B is a schematic diagram of the Type 4000 film deposition apparatus, and is used in the film deposition apparatus 4000. This is a cross-sectional view of a functional ALD device.

[0244] <Example of a film deposition apparatus configuration> The film deposition apparatus 4000 consists of an loading / unloading room 4002, a loading / unloading room 4004, and a transport room 4006. And, deposition chamber 4008, deposition chamber 4009, deposition chamber 4010, transport arm 4014, It has loading / unloading room 4002, loading / unloading room 4004, and film deposition room 4008 to 4010 is independently connected to the transport chamber 4006. This allows the film deposition chamber 40 Continuous film deposition can be performed without exposure to air in 08 to 4010, and impurities are present in the film. This prevents contamination. Furthermore, contamination of the substrate-film interface and the interfaces between each film is prevented. This reduces the amount of material present, resulting in a cleaner interface.

[0245] Furthermore, loading / unloading room 4002, loading / unloading room 4004, transporting room 4006, and film deposition room 400 8 to 4010 use an inert gas (nitrogen gas) with a controlled dew point to prevent moisture from adhering to the surface. It is preferable to fill the container with (etc.) and to maintain reduced pressure.

[0246] Furthermore, ALD equipment can be used in deposition chambers 4008 to 4010. Even if a film deposition apparatus other than the ALD apparatus is used in any of the film chambers 4008 to 4010, Good. Examples of film deposition apparatus that can be used in film deposition chambers 4008 to 4010 include, Puttering equipment, Plasma CVD (PECVD: Plasma Enhanced C VD) equipment, thermal CVD (TCVD) equipment, optical CVD (Phot o CVD equipment, metal CVD (MCVD: Metal CVD) equipment, metal organic CVD (MOCVD: Metal Organic CVD) equipment, etc. There is also a film deposition chamber 4 One or more of 008 to 4010 may be provided with a device having a function other than the film deposition device As such a device, for example, a heating device (typically, a vacuum heating device), a plasma generation device (typically, a microwave plasma generation device), etc. can be mentioned

[0247] For example, when the film deposition chamber 4008 is a sputtering device, the film deposition chamber 4009 is an ALD device , and the film deposition chamber 4010 is a metal CVD device, a metal oxide can be formed in the film deposition chamber 4008, and the film deposition chamber 4 An insulating film that functions as a gate insulating film in 009, and a conductive film that functions as a gate electrode can be formed in the film deposition chamber 4010 At this time, the metal oxide, the insulating film thereon, and the conductive film thereon can be continuously formed without exposing them to the atmosphere

[0248] Also, the film deposition device 4000 has a configuration including a loading / unloading chamber 4002, a loading / unloading chamber 4004, and a film deposition chamber 400 8 to 4010, but the present invention is not limited to this. The film deposition The film deposition chamber of the device 4000 may have a configuration of four or more. Also, the film deposition chamber of the film deposition device 4000 May have a configuration of two or one. Also, the film deposition device 4000 may be a single wafer type Or a batch type for depositing films on a plurality of substrates at once

[0249] <ALD device> Next, the configuration of the ALD device that can be used in the film deposition device 4000 will be described using FIG. 15B The ALD device includes a film deposition chamber (chamber 4020) and a raw material supply unit 4021 (Raw material supply units 4021a and 4021b), raw material supply unit 4031, and introduction amount controller A high-speed valve 4022a, 4022b and a raw material inlet 4023 (raw material inlet 4023a , and 4023b), raw material inlet 4033, raw material outlet 4024, and exhaust device 402 It has 5. Raw material inlets 4023a, 4023b, installed inside chamber 4020, 4033 and 4033 are supplied via supply pipes and valves to the raw material supply sections 4021a, 4021b, and 40 Each of the 31s is connected, and the raw material outlet 4024 is connected to the discharge pipe, valve and pressure regulator. It is connected to the exhaust system 4025 via [a certain method].

[0250] Furthermore, as shown in Figure 15B, the plasma generator 4028 is connected to the chamber 4020. This allows for film deposition using the PEALD method in addition to the thermal ALD method. The rasma generator 4028 uses an inductively coupled coil 4029 connected to a high-frequency power supply. Plasma (Inductively Coupled Plasma: ICP) type plastic It is preferable to use a zuma generator. The high-frequency power supply should be between 10 kHz and 100 MHz. More preferably 1 MHz to 60 MHz, and more preferably 10 MHz to 60 MHz. It can output power with a specific frequency. For example, 13.56MHz, 60MHz It can output power with a frequency. In ICP-type plasma generators, the substrate or Plasma can also be generated from a distance. This reduces plasma damage to the substrate.

[0251] The PEALD method allows for film deposition even at low temperatures without reducing the deposition rate, thus reducing the deposition efficiency. It is best used with a single-wafer film deposition apparatus.

[0252] Inside the chamber is a substrate holder 4026, and a substrate 40 30 is placed. The substrate holder 4026 has a mechanism to which a constant potential or high frequency is applied. A substrate holder 4026 may be floating. It may also be grounded. In addition, a heater 4027 is provided on the outer wall of the chamber. The temperature of the inside of the chamber 4020, the substrate holder 4026, and the surface of the substrate 4030, etc. It can be controlled. Heater 4027 raises the temperature of the substrate 4030 surface to 100°C or higher. It is preferable that the temperature can be controlled to 0°C or below, preferably between 200°C and 400°C, and the heater It is preferable that the temperature of the 4027 itself can be set to between 100°C and 500°C.

[0253] In the raw material supply sections 4021a, 4021b, and 4031, vaporizers and heating means are used. This forms a raw material gas from solid or liquid raw materials. Alternatively, the raw material supply unit 4021a, 4021b and 4031 may be configured to supply a gaseous raw material gas.

[0254] Furthermore, Figure 15B shows two raw material supply units 4021 and one raw material supply unit 4031. While an example is shown, this embodiment is not limited thereto. One raw material supply unit 4021 is provided, Or, three or more may be provided. Also, two or more raw material supply units 4031 may be provided. Also, high The rapid valves 4022a and 4022b can be precisely controlled in time, and the raw material supply unit 402 Controlling the supply of raw material gas from 1a and raw material gas supplied from raw material supply unit 4021b. It is structured in a way that allows for control.

[0255] In the film deposition apparatus shown in Figure 15B, the substrate 4030 is loaded onto the substrate holder 4026, and After sealing the bar 4020, the heater 4027 is used to heat the substrate 4030 to a desired temperature (e.g., For example, the temperature should be between 100°C and 500°C, preferably between 200°C and 400°C, and the raw materials should be supplied. The supply of raw material gas from the supply unit 4021a, exhaust by the exhaust device 4025, and raw material The supply of raw material gas from the supply unit 4031 and exhaust gas from the exhaust device 4025 are alternated. By returning the material, a thin film is formed on the substrate surface. Furthermore, in the formation of the thin film, a raw material supply section is also used. The raw material gas supplied from 4021b and exhaust gas from exhaust device 4025 may be used. The temperature of heater 4027 depends on the type of film being formed, the source gas, the desired film quality, the substrate, and the location of the film. The appropriate value should be determined according to the heat resistance of the film or element being used. For example, heater 4027 The film may be deposited by setting the temperature to 200°C or more and 300°C or more and 300°C or more and 500°C The film may be formed using the following settings.

[0256] By depositing the film while heating the substrate 4030 using the heater 4027, the necessary processes in subsequent steps are achieved. The heating treatment of the substrate 4030 can be omitted. That is, a heater 4027 is provided. By using the chamber 4020 or the film deposition apparatus 4000, the film on the substrate 4030 can be deposited. This method can perform both the molding process and the heat treatment of the substrate 4030.

[0257] In the film deposition apparatus shown in Figure 15B, the raw materials used in the raw material supply units 4021 and 4031 (volatile By appropriately selecting (such as bio-active organometallic compounds), the silica oxide shown in Figures 2 and 3 can be obtained. It is possible to form films such as condensate. When forming a silicon oxide film, the first raw material supply unit 40 Silicone-containing precursors are supplied from 21. Silicone-containing precursors include: The aforementioned precursor can be used. In addition, the raw material supply unit 4031 can supply reactor A reactant is supplied, for example, containing at least one of ozone and oxygen. An oxidizing agent can be used. Furthermore, it is preferable that the oxidizing agent does not contain hydrogen.

[0258] Figure 16 illustrates different configurations of ALD equipment that can be used with the film deposition apparatus 4000. To clarify, the configuration and functions of the ALD device shown in Figure 15B are described in detail. Explanations may be omitted in some cases.

[0259] Figure 16A is a schematic diagram showing one embodiment of the PEALD apparatus. The PEALD apparatus 4100 is, A reaction chamber 4120 and a plasma generation chamber 4111 are provided above the reaction chamber 4120. Reaction chamber 4120 can be called a chamber. Alternatively, reaction chamber 4120 and plasma generation... The reaction chamber 4111 can be collectively referred to as the chamber. The reaction chamber 4120 is the raw material inlet. The plasma generation chamber 4111 has a raw material inlet 413 It has 3. In addition, the plasma generator 4128 generates high-frequency waves such as RF and microwaves. The gas introduced into the plasma generation chamber 4111 is applied to the plasma, and plasma is introduced into the plasma generation chamber 4111. 4131 can be generated. When generating plasma 4131 using microwaves. Typically, microwaves with a frequency of 2.45 GHz are used. The plasma generated using this method is called ECR (Electron Cyclotron Resonance). It is sometimes called plasma (nance). Also, the reaction chamber 4120 is connected to the substrate holder 4126 It has a substrate 4130 placed on it. Raw material gas introduced from raw material inlet 4123 The material is decomposed by heat from a heater in the reaction chamber 4120 and piled up on the substrate 4130. The raw material gas introduced from the raw material inlet 4133 is used in the plasma generator 412. As a result of step 8, the source gas becomes a plasma. The source gas, now in a plasma state, reaches the surface of the substrate 4130. Before reaching the substrate 4130, it recombines with electrons and other molecules, becoming a radical state and reaching the substrate 4130. Thus, an ALD apparatus that uses radicals to deposit films is called a radical ALD (Radic ALD). It is sometimes called an al-Enhanced ALD device. Also, the PEALD device 410. In version 0, the plasma generation chamber 4111 is shown to be located above the reaction chamber 4120, This embodiment is not limited thereto. Plasma generation chamber 4111 is located on the side of reaction chamber 4120. They may be installed adjacent to each other.

[0260] Figure 16B is a schematic diagram showing one embodiment of the PEALD apparatus. The PEALD apparatus 4200 is, It has a chamber 4220. The chamber 4220 has an electrode 4213 and a raw material discharge port 4 224, has a substrate holder 4226 on which a substrate 4230 is placed. Electrode 4213 This includes a raw material inlet 4223 and a shutter that supplies the introduced raw material gas into the chamber 4220. It has a power head 4214. Also, the electrode 4213 is connected to a capacitor 4217. A power supply 4215 capable of applying high frequency is connected to the board holder 4226. A mechanism for applying electric potential or high frequency may be provided. Alternatively, the substrate holder 4 226 may be floating or grounded. Electrode 4213, and base The plate holder 4226 has an upper electrode for generating plasma 4231 and a lower electrode, respectively. It functions as an electrode. The raw material gas introduced from the raw material inlet 4223 is fed into chamber 422 It is decomposed by heat from the heater located at 0 and deposited on the substrate 4230. Alternatively, The raw material gas introduced from the material inlet 4223 is supplied to the electrode 4213 and the substrate holder 4226. A plasma state is created between the plasma 4231 and the substrate. The potential difference (also called the ion sheath) that occurs between 4230 causes the ion to be incident on the substrate 4230.

[0261] Figure 16C is a schematic diagram showing a different embodiment of the PEALD apparatus from Figure 16B. The LD apparatus 4300 has a chamber 4320. The chamber 4320 contains electrodes 4 It has a 313, a raw material discharge port 4324, and a substrate holder 4326, on which a substrate 4330 is placed. The electrode 4313 is connected to the raw material inlet 4323 and the introduced raw material gas is connected to the chamber 43. It has a shower head 4314 that supplies water into 20. Also, the electrode 4313 has a A power supply 4315 capable of applying high frequency is connected via the denser 4317. (Board holder) 4326 may be provided with a mechanism to which a constant potential or high frequency is applied. Alternatively, the substrate holder 4326 may be floating or grounded. The pole 4313 and the substrate holder 4326 are for generating plasma 4331, respectively. It functions as an upper electrode and a lower electrode. The PEALD device 4300 has electrode 4313 and Between the board holders 4326, a power supply 432 can apply high frequency via a capacitor 4322. It differs from the PEALD device 4200 in that it has a connected mesh 4319. By providing the mesh 4319, the plasma 4231 can be separated from the substrate 4130. The raw material gas introduced from the raw material inlet 4323 is supplied to the chamber 4320. It is decomposed by heat from the source and deposited on the substrate 4330. Alternatively, the raw material inlet 4323 The raw material gas introduced from is plasma-like between electrode 4313 and substrate holder 4326. It becomes a plasma state. The raw material gas, which has become a plasma state, has its charge removed by mesh 4319. Radicals and other electrically neutral substances reach the substrate 4130. Therefore, ion incidence This allows for film deposition with suppressed damage caused by plasma.

[0262] <Film deposition sequence> Figure 17A shows the film deposition sequence using the ALD apparatus shown in Figure 15B. First, Chan The circuit board 4030 is set in the circuit board holder 4026 inside the bar 4020 (S101). Next, The temperature of heater 4027 is controlled (S102). Next, the temperature of substrate 4030 is controlled within the substrate surface. The substrate 4030 is held on the substrate holder 4026 so that it is uniform (S103). Next, The precursor and reactant are alternately introduced into chamber 4020, with purging in between. Then, a film is deposited on the substrate 4030 (S104). Also, between S103 and S104, The inside of the 4020 can be treated to create an oxygen atmosphere. Set the circuit board 4030, After holding, the inside of the chamber 4020 is made into an oxygen atmosphere, so the substrate 4030 and In some cases, oxygen can be added to the film formed on the substrate 4030. Also, the substrate 40 before film formation Hydrogen can be desorbed from the film provided on substrate 403 and substrate 403. Hydrogen in the 0 or film reacts with oxygen added to the substrate 4030 or film, and water It may detach from the substrate 4030 or the film as (H2O).

[0263] Figure 17B shows a specific example of the above film deposition sequence. S101 to S103 above Therefore, the circuit board 4030 is set in the circuit board holder 4026, and the temperature of the heater 4027 is adjusted. The substrate 4030 is then held in place.

[0264] Next, the precursor and reactant are introduced alternately to deposit a film on the substrate 4030. (S104). The introduction of the precursor and reactant is performed in pulses. Figure 17B shows the introduction of the precursor and reactant, respectively, as ON. The period during which the system is not implemented is indicated by OFF. The precursor and reactant are During periods when neither system is in place, the inside of chamber 4020 is purged. Chamber 4 The pulse time for introducing the precursor to O20 is 0.1 seconds or more and 1 second or less, preferably 0. It is preferable to set the time between 0.5 seconds and 1 second. Also, during the period when the precursor is not introduced, In other words, the time for purging the chamber 4020 is preferably between 0.05 seconds and 30 seconds. The interval shall be between 1 second and 20 seconds. A pulse is used to introduce the reactant into chamber 4020. The duration is preferably 0.1 seconds or more and 30 seconds or less, more preferably 0.3 seconds or more and 15 seconds or less. It is also important to note that during periods when the reactant is not introduced, i.e., inside chamber 4020, The loading time shall be between 0.05 seconds and 30 seconds, preferably between 1 second and 20 seconds.

[0265] The film deposition process involves introducing a precursor, evacuating the precursor, introducing a reactant, and then... By repeating the exhaust process, which is considered one cycle, a film with the desired thickness can be produced. It is formed.

[0266] Furthermore, between S103 and S104, a process is performed to create an oxygen atmosphere inside chamber 4020. If done so, a reactant may be introduced into chamber 4020. As a reactant, Selected from ozone (O3), oxygen (O2), and water (H2O) to function as oxidizing agents. It is preferable to introduce one or more of these. In this embodiment, as the reactant, Oxygen (O3) and oxygen (O2) are used. In this case, the reactant is shown in S104. Similar to the method described above, it is preferable to introduce the substance in a pulsed manner, but the present invention is not limited thereto. The reactant may be introduced continuously. During the period when the reactant is not introduced, Purge the contents of chamber 4020. Pulse to introduce reactant into chamber 4020. The duration is preferably 0.1 seconds or more and 30 seconds or less, more preferably 0.3 seconds or more and 15 seconds or less. It is also important to note that during periods when the reactant is not introduced, i.e., inside chamber 4020, The duration of the process shall be between 1 second and 30 seconds, preferably between 1 second and 20 seconds. By introducing a reactant such as an oxidizing agent into bar 4020, substrate 4030, or substrate The film placed on 4030 is exposed to reactants such as oxidizing agents.

[0267] Note that if temperature control of the heater 4027 is not required after setting the circuit board 4030 (S101), The combination may be omitted. Also, after holding the substrate 4030 (S103), the chamber 4020 If it is not necessary to create an oxygen atmosphere inside, this step can be omitted.

[0268] By depositing the insulating film 250A using the ALD apparatus described above, the results shown in Figures 2 and 3 are obtained. The insulating film 250A can be deposited using the model shown. This allows the insulating film 25 The hydrogen concentrations of 0A, insulator 280, and oxide 230 can be reduced. The carrier concentration in oxide 230 is 1.0 × 10⁻⁶. 16 / cm 3 The following is preferably 1.0 ×10 13 / cm 3 It can be reduced to less than this. Transition using such oxide 230 The sta can be made normally off, and has good electrical characteristics and reliability. A conductive device can be constructed.

[0269] Next, conductive films 260Aa and 260Ab are deposited. The conductive film 260Ab is deposited by sputtering, CVD, MBE, PLD, or A This can be done using methods such as LD. For example, the CVD method is preferred. In the application method, a conductive film 260Aa was deposited using the ALD method, and the conductive film was then processed using the CVD method. Deposit 260Ab (see Figure 12).

[0270] Next, by CMP treatment, an oxide film 230C, an insulating film 250A, and a conductive film 260Aa are formed. By polishing the conductive film 260Ab until the insulator 280 is exposed, the oxide 230 c. Form an insulator 250 and a conductor 260 (conductor 260a and conductor 260b) (See Figure 13).

[0271] Next, heat treatment may be performed. In this embodiment, heat treatment is performed at a temperature of 400°C in a nitrogen atmosphere. The process is carried out for 1 hour. This heat treatment reduces the moisture content in the insulators 250 and 280. The temperature and hydrogen concentration can be reduced.

[0272] Next, on the conductor 260, on the oxide 230c, on the insulator 250, and on the insulator 280 , an insulator 282 is formed. The insulator 282 is deposited by sputtering, CVD, MB This can be done using methods such as the E method, PLD method, or ALD method (see Figure 14). Insulator As an insulating film that becomes 282, for example, aluminum oxide can be used by sputtering. It is preferable to form a film. Using the sputtering method, insulator 282 in an oxygen-containing atmosphere By performing this film formation, oxygen can be added to the insulator 280 while the film is being formed. In this case, it is preferable to deposit the insulator 280 while heating the substrate. Also, the conductor 2 By forming an insulator 282 in contact with the upper surface of 60, insulation is maintained during the subsequent heat treatment. This is preferable because it can suppress the absorption of oxygen from body 280 into conductor 260. It's nice.

[0273] Next, an insulator 283 is deposited on the insulator 282 (see Figure 14). Insulator 283 is also an insulator. Similar to the edge material 250, it is preferable to deposit the film using the PEALD method. The insulator 283 is Therefore, it is preferable to form a film of silicon nitride or silicon nitride oxide. The film deposition can be carried out in the same manner as shown in Figures 2 and 3, but as reactant 20 Nitrogen radicals are used. Nitrogen radicals are obtained by plasma-forming nitrogen gas. Oh, nitrogen plasma contains nitrogen in the form of molecules, radicals, or ions. For example, by applying high-frequency waves such as RF or microwaves to nitrogen gas, nitrogen radicals can be produced. A nitrogen plasma containing can be generated. At this time, the reactant 20 contains hydrogen. It is preferable that there be none.

[0274] Next, heat treatment may be performed. In this embodiment, heat treatment is performed at a temperature of 400°C in a nitrogen atmosphere. The process is carried out for 1 hour. This heat treatment causes the acid added by the film formation of the insulator 282 to be removed. The element is diffused into the insulator 280, and further, through the oxide 230c, the oxide 230a, and It can be supplied to oxide 230b. Note that this heat treatment is performed after film formation of insulator 283. This procedure is not limited to this; it may also be performed after the deposition of the insulator 282.

[0275] Here, as shown in Figure 3, electromagnetic waves 292 are transmitted to oxide 230, insulator 250, and insulator. The edge body 280, insulator 282, and insulator 283 may also be irradiated (see Figure 14). For electromagnetic wave 292, microwaves or high-frequency waves such as RF may be used. The electromagnetic wave 292 penetrates into the oxide 230, insulator 250 and insulator 280, and V in the ra O H is removed. Some of the hydrogen produced at this time combines with oxygen to form H2O. Furthermore, some of the hydrogen may be removed from the oxide 230 and the insulator 280. In some cases, the conductor 242 may getter. Also, when irradiated with electromagnetic waves 292, The oxygen gas may be turned into a plasma by magnetic wave 292, forming oxygen radicals. In other words, Oxide 230, insulator 250, insulator 280, insulator 282 and insulator 283a contain oxygen Plasma treatment may be performed in an atmosphere having the above characteristics. In this way, oxide 230, insulating The hydrogen concentration in body 250 and insulator 280 can be reduced.

[0276] Furthermore, irradiation with electromagnetic waves 292 is not limited to after the deposition of the insulator 283. For example, This can be done immediately after the formation of the conductor 260, or after the deposition of the insulator 282. For example, the process of introducing the reactant for the deposition of the insulating film 283, as shown in Figures 2 and 3. You can go that way.

[0277] Next, an insulator 274 may be deposited on the insulator 283. The deposition of the insulator 274 is performed by spa This can be done using methods such as tarring, CVD, MBE, PLD, or ALD. can.

[0278] Next, an insulator 281 may be deposited on the insulator 274. The deposition of the insulator 281 is performed by spa This can be done using methods such as tarring, CVD, MBE, PLD, or ALD. Yes, it is possible. As the insulator 281, for example, silicon nitride can be formed by sputtering. It is preferable to form a film.

[0279] Next, insulator 272, insulator 273, insulator 280, insulator 282, insulator 283, insulator The edge 274 and the insulator 281 have openings that reach the conductors 242a and 242b. To form the opening. The opening can be formed using lithography.

[0280] Next, an insulating film to become an insulator 241 is formed, and the insulating film is anisotropically etched to form an insulator. Form 241. The insulating film is deposited by sputtering, CVD, MBE, PL This can be done using the D method or the ALD method, etc. It is preferable to use an insulating film that has the function of suppressing oxygen permeation. For example, the above Similar to the deposition of insulator 283, it is preferable to deposit silicon nitride using the PEALD method. Yes, silicon nitride is preferable because it has high hydrogen blocking properties.

[0281] Furthermore, as an anisotropic etching of the insulating film that becomes the insulator 241, for example, dry etching Methods such as the G method can be used. By providing an insulator 241 on the side wall of the opening, oxygen from the outside can be blocked. This suppresses the transmission of the current and prevents oxidation of the conductors 240a and 240b that are to be formed next. This can be done. Also, impurities such as water and hydrogen can be removed from conductors 240a and 240b. It can prevent it from spreading to the outside.

[0282] Next, conductive films that will become conductor 240a and conductor 240b are deposited. Conductive 240a The conductive film that forms the conductor 240b has the function of suppressing the permeation of impurities such as water and hydrogen. It is desirable to have a laminated structure that includes a conductive material. For example, tantalum nitride, titanium nitride, etc. It can be made into a laminate of materials such as tungsten, molybdenum, and copper. Conductor 24 The deposition of conductive films with a conductivity of 0 can be done by sputtering, CVD, MBE, PLD, or AL. This can be done using methods such as the D method.

[0283] Next, by performing CMP treatment, the conductive films that become conductor 240a and conductor 240b are formed. A portion is removed to expose the insulator 281. As a result, the conductive film remains only in the aforementioned opening. This makes it possible to form conductors 240a and 240b with flat upper surfaces. (See Figure 1). Note that this CMP treatment may remove a portion of the insulator 281. .

[0284] Next, a conductive film that will become conductor 246 is formed. The formation of the conductive film that will become conductor 246 is performed by This can be done using methods such as puttering, CVD, MBE, PLD, or ALD. can.

[0285] Next, a conductive film to become conductor 246 is processed by lithography, resulting in conductor 240a. The conductor 246a that is in contact with the upper surface and the conductor 246b that is in contact with the upper surface of the conductor 240b form To accomplish (see Figure 1).

[0286] Based on the above, a semiconductor device having the transistor 200 shown in Figure 1 can be fabricated. As shown in Figures 5 to 14, the method for manufacturing the semiconductor device shown in this embodiment is used. Thus, transistor 200 can be manufactured.

[0287] According to one aspect of the present invention, a semiconductor device having good electrical characteristics can be provided. Alternatively, according to one aspect of the present invention, a semiconductor device having normally-off electrical characteristics is provided. This is possible. Alternatively, according to one aspect of the present invention, a reliable semiconductor device can be provided. It is possible to provide a semiconductor device with a large on-current according to one aspect of the present invention. To be able to. Or, according to one aspect of the present invention, to provide a semiconductor device having high frequency characteristics. This is possible. Alternatively, according to one aspect of the present invention, a semiconductor device that can be miniaturized or highly integrated is possible. This can provide a semiconductor device with low off-current. Alternatively, according to one aspect of the present invention, a semiconductor device with low off-current. This can provide a semiconductor with reduced power consumption according to one aspect of the present invention. An apparatus can be provided. Alternatively, according to one aspect of the present invention, a highly productive semiconductor device can be provided. We can provide this.

[0288] The configurations, methods, etc., described above in this embodiment are not shown in other embodiments and other examples. It can be used in appropriate combination with the composition, structure, method, etc.

[0289] (Embodiment 2) In this embodiment, one form of a semiconductor device will be described with reference to Figures 18 and 19.

[0290] [Storage device 1] Figure 18 shows an example of a semiconductor device (memory device) using a capacitive element, which is one aspect of the present invention. As shown, in one aspect of the present invention, a semiconductor device is provided in which transistor 200 is above transistor 300. The capacitive element 100 is provided above the transistors 300 and 200. It is provided. Note that the transistor 200 is the transistor described in the previous embodiment. The Sta200 can be used.

[0291] Transistor 200 is a transistor in which a channel is formed in a semiconductor layer having an oxide semiconductor. It is a transistor. Transistor 200 is used in memory devices because it has a low off-current. This makes it possible to retain memory content for a long period of time. In other words, refresh Because it does not require any operation, or because the refresh operation is performed very infrequently, the memory Power consumption can be significantly reduced.

[0292] In the semiconductor device shown in Figure 18, wiring 1001 is connected to the source and electrical source of transistor 300. The wiring 1002 is electrically connected to the drain of transistor 300. Furthermore, wiring 1003 is electrically connected to either the source or the drain of transistor 200. The wiring 1004 is then electrically connected to the first gate of transistor 200, and the wiring 1 006 is electrically connected to the second gate of transistor 200. And, The gate of transistor 300, and the other of the source and drain of transistor 200, The wiring 1005 is electrically connected to one of the electrodes of the capacitance element 100, and the wiring 1005 is connected to the electrode of the capacitance element 100. It is electrically connected to the other side.

[0293] Furthermore, the memory device shown in Figure 18, when arranged in a matrix, allows the memory cell array to function as a memory cell array. It can be configured.

[0294] <Transistor 300> The transistor 300 is provided on the substrate 311 and has a conductor 316 that functions as a gate. , an insulator 315 that functions as a gate insulator, and a semiconductor region 31 which is part of the substrate 311 3, and a low-resistance region 314a that functions as a source region or drain region, and low It has a resistive region 314b. Transistor 300 is either a p-channel or n-channel type. Any type is acceptable.

[0295] Here, the transistor 300 shown in Figure 18 is in the semiconductor region 313 where the channel is formed. A portion of the substrate 311 has a convex shape. In addition, the side and top surfaces of the semiconductor region 313 are made of an insulating material. The conductor 316 is provided so as to cover the edge 315. Materials that adjust the work function may be used. Such a transistor 300 is on a semiconductor substrate. It is also called a FIN-type transistor because it utilizes a protruding part. Furthermore, it may have an insulator that functions as a mask for forming the protrusion. This example shows a case where a protrusion is formed by processing a part of a semiconductor substrate, but when processing an SOI substrate... A semiconductor film having a convex shape may be formed.

[0296] Note that the transistor 300 shown in Figure 18 is just one example, and its structure is not limited to that example. A suitable transistor should be used depending on the configuration and driving method.

[0297] <Capacitive element 100> The capacitive element 100 is located above the transistor 200. The capacitive element 100 is the first A conductor 110 that functions as an electrode, a conductor 120 that functions as a second electrode, and It has an insulator 130 that functions as a dielectric.

[0298] Furthermore, for example, the conductor 112 provided on the conductor 240 and the conductor 110 are formed simultaneously. This is possible. Furthermore, the conductor 112 is connected to the capacitive element 100, the transistor 200, and It functions as a plug or wire that electrically connects to transistor 300.

[0299] In Figure 18, the conductors 112 and 110 are shown as single-layer structures, but this configuration is not limited to this example. It is not specified, and may be a laminated structure of two or more layers. For example, a conductor with barrier properties and a highly conductive material A conductor with barrier properties and a conductor with high conductivity are bonded to each other. A highly conductive material may be formed.

[0300] Furthermore, the insulator 130 may be, for example, silicon oxide, silicon oxide nitride, or silicon oxide nitride. Silicon nitride, aluminum oxide, aluminum oxide nitride, aluminum oxide nitride, nitrile Aluminum oxide, hafnium oxide, hafnium oxide nitride, hafnium oxide nitride, hafnium nitride It can be made using materials such as nium, and can be constructed in layers or as a single layer.

[0301] For example, the insulator 130 may contain a material with high dielectric strength, such as silicon oxynitride, and a high dielectric strength material. It is preferable to use a laminated structure with a high-k material. With this configuration, the capacity element Child 100 has a high dielectric constant (high-k) insulator, which ensures sufficient capacitance. By having an insulator with high dielectric strength, the dielectric strength is improved, and the electrostatic discharge of the capacitive element 100 is reduced. It can suppress damage.

[0302] Furthermore, as an insulator of high-dielectric constant (high-k) materials (materials with a high relative permittivity), Having gallium, hafnium oxide, zirconium oxide, aluminum and hafnium Oxides, aluminum and hafnium-containing oxides and nitrides, silicon and hafnium Oxides having silicon and hafnium, or silicon and ha Examples include nitrides containing humium.

[0303] On the other hand, materials with high dielectric strength (materials with low dielectric constant) include silicon oxide and nitrogen oxide. Silicon oxide, silicon nitride, silicon nitride, silicon oxide with added fluorine, carbon Silicon oxide with added carbon and nitrogen, silicon oxide with voids It may be made of concrete or resin.

[0304] <Wiring layer> Between each structure, there is a wiring layer containing interlayer membranes, wiring, and plugs. This is also possible. Furthermore, multiple wiring layers can be provided depending on the design. Here, the plug In the case of a conductor that functions as wiring, where multiple structures are grouped together and assigned the same code, There is a possibility of this occurring. Furthermore, in this specification, etc., the wiring and the plug that electrically connects to the wiring are integrated. It may also be an object. That is, when a part of the conductor functions as wiring, and the conductor Some parts may function as plugs.

[0305] For example, on transistor 300, there are insulators 320, 322, and an insulator as interlayer films. The edge body 324 and the insulator 326 are arranged in order in stacked layers. Also, the insulator 320, Insulators 322, 324, and 326 contain capacitive elements 100 or transients Conductors 328 and 330, etc., which are electrically connected to the sta 200, are embedded within. Furthermore, conductors 328 and 330 function as plugs or wiring.

[0306] Furthermore, the insulator, which functions as an interlayer film, acts as a planarizing film that covers the uneven shape beneath it. It may function. For example, the upper surface of the insulator 322 may be chemically and mechanically polished to improve flatness. The surface may be flattened by a flattening treatment such as the CMP method.

[0307] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, as shown in Figure 18. Insulators 350, 352, and 354 are arranged in a stacked manner. Furthermore, a conductor 356 is formed on insulators 350, 352, and 354. Conductor 356 functions as a plug or wiring.

[0308] Similarly, insulators 210, 212, 214, and 216 are conductive Body 218 and the conductor (conductor 205) that constitutes the transistor 200 are embedded. It is present. Furthermore, the conductor 218 is electrically connected to the capacitive element 100 or the transistor 300. It functions as a connecting plug or wiring. Furthermore, the conductor 120 and the insulator An insulator 150 is provided above 130.

[0309] Here, similar to the insulator 241 shown in the above embodiment, a conductor 2 that functions as a plug An insulator 217 is provided in contact with the side surface of 18. The insulator 217 is in contact with the insulator 210, insulator 212, insulator 214, and insulator 216 are provided in contact with the inner wall of the opening formed therein. In other words, insulator 217 is connected to conductor 218, insulator 210, insulator 212, insulator It is provided between 214 and the insulator 216. Note that the conductor 205 is conductor 2 Since it can be formed in parallel with 18, the insulator 217 is in contact with the side surface of the conductor 205. It may also be formed.

[0310] Examples of insulators 217 include silicon nitride, aluminum oxide, or silicon nitride oxide. An insulator such as Ricon can be used. Insulator 217 is insulator 212, insulator 214, Since it is installed in contact with the insulator 222, water can enter from the insulator 210 or insulator 216, etc. Alternatively, it suppresses the incorporation of impurities such as hydrogen into the oxide 230 through the conductor 218. This is possible. In particular, silicon nitride is preferred because it has high blocking properties for hydrogen. Furthermore, oxygen contained in the insulator 210 or insulator 216 is absorbed by the conductor 218. This can prevent it.

[0311] The insulator 217 can be formed in the same manner as the insulator 241. For example, PEA A silicon nitride film is deposited using the LD method, and the conductive material 356 is reached using anisotropic etching. You just need to form an opening.

[0312] Insulators that can be used as interlayer films include insulating oxides, nitrides, and acids. Examples include nitrides, nitride oxides, metal oxides, metal oxide nitrides, and metal nitride oxides.

[0313] For example, by using a material with a low dielectric constant for the insulator that functions as an interlayer film, wiring The parasitic capacitance that occurs between them can be reduced. Therefore, depending on the function of the insulator, the material You should choose this option.

[0314] For example, insulators 150, 210, 352, and 354 have a ratio It is preferable to have an insulator with a low dielectric constant. For example, the insulator may be silicon nitride. , nitride silicon, fluorine-added silicon oxide, carbon-added silicon oxide, carbon and silicon oxide with nitrogen added, silicon oxide having voids, or resins, etc. This is preferable. Alternatively, the insulator may be silicon oxide, silicon oxide nitride, or silicon oxide nitride Cone, silicon nitride, silicon oxide with added fluorine, silicon oxide with added carbon, carbon Lamination of silicon oxide with added elements and nitrogen or porous silicon oxide with resin It is preferable that it has a structure. Silicon oxide and silicon oxide-nitride are thermally stable. Therefore, by combining it with resin, a thermally stable laminated structure with a low dielectric constant is achieved. This can be done. Examples of resins include polyester, polyolefin, and polyamide (nylon Examples include ramid, polyimide, polycarbonate, or acrylic.

[0315] Furthermore, transistors using oxide semiconductors suppress the permeation of impurities such as hydrogen and oxygen. By surrounding the transistor with an insulator that has a controlling function, the electrical characteristics of the transistor are stabilized. Therefore, hydrogen, etc. can be present in insulators 214, 212, and 350, etc. An insulator that has the function of suppressing the permeation of impurities and oxygen should be used.

[0316] Examples of insulators that have the function of suppressing the permeation of impurities such as hydrogen and oxygen include, Boron, carbon, nitrogen, oxygen, fluorine, magnesium, aluminum, silicon, phosphorus, salt Element, argon, gallium, germanium, yttrium, zirconium, lanthanum, neo An insulator containing zym, hafnium, or tantalum may be used in a single layer or in a multilayer configuration. Specifically, as an insulator that has the function of suppressing the permeation of impurities such as hydrogen and oxygen, Aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, yttrium oxide Umium, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, or tan oxide Metal oxides such as tar, silicon nitride, or silicon nitride can be used. .

[0317] Conductors that can be used in wiring and plugs include aluminum, chromium, copper, and silver. Gold, platinum, tantalum, nickel, titanium, molybdenum, tungsten, hafnium, vanilla Dium, niobium, manganese, magnesium, zirconium, beryllium, indium, Materials containing one or more metallic elements selected from thenium and others can be used. Semiconductors with high electrical conductivity, such as polycrystalline silicon containing impurity elements like nitrates, Silicides such as nickel silicide may also be used.

[0318] For example, conductor 328, conductor 330, conductor 356, conductor 218, and conductor 1 12, etc., are metal materials, alloy materials, metal nitride materials, or formed from the above materials. Conductive materials such as metal oxide materials can be used in a single layer or in a laminated form. Heat resistance and It is preferable to use high-melting-point materials such as tungsten or molybdenum that can achieve both conductivity and electrical conductivity. Tungsten is preferable. Alternatively, a low-resistance conductive material such as aluminum or copper may be used. It is preferable to form it with a material. By using a low-resistance conductive material, the wiring resistance can be reduced. It is possible.

[0319] <Wiring or plugs in layers containing oxide semiconductors> Furthermore, when an oxide semiconductor is used for transistor 200, excess near the oxide semiconductor An insulator having an oxygen region may be provided. In that case, the insulator having the excess oxygen region A barrier-type insulator is provided between the insulator having the excess oxygen region and the conductor. It is preferable to provide one.

[0320] For example, in Figure 18, insulators 224 and 280 have excess oxygen, and conductor 2 It is preferable to provide an insulator 241 between 40 and 40. Insulator 241, insulator 222, insulator 2 72, and the insulator 273 are provided in contact with each other, so that the insulator 224 and the transient The STA200 can be constructed to be sealed with a barrier-type insulator. Furthermore, it is preferable that the insulator 241 is in contact with a part of the insulator 280. By extending to the insulator 274, the diffusion of oxygen and impurities can be further suppressed. ru.

[0321] In other words, by providing the insulator 241, the excess insulation of the insulators 224 and 280 is eliminated. This can suppress the absorption of oxygen by the conductor 240. Also, the insulator 241 By having this, the impurity hydrogen diffuses to the transistor 200 via the conductor 240. This can suppress the action.

[0322] Furthermore, the insulator 241 is designed to suppress the diffusion of impurities such as water or hydrogen, and oxygen. It is preferable to use an insulating material that has the function of [doing something]. For example, silicon nitride, silicon nitride oxide, It is preferable to use aluminum oxide or hafnium oxide. In particular, silica nitride N is preferred because it has high blocking properties for hydrogen. In addition, other options include, for example, magnesium oxide. Nesium, gallium oxide, germanium oxide, yttrium oxide, zirconium oxide, acid Metal oxides such as lanthanum oxide, neodymium oxide, or tantalum oxide can be used. ru.

[0323] The above is a description of the example configuration. By using this configuration, a tortoise having an oxide semiconductor can be constructed. In semiconductor devices using transistors, the aim is to suppress fluctuations in electrical characteristics and improve reliability. It can be increased. Alternatively, a transistor having an oxide semiconductor with a large on-current can be used. It can be provided. Or, a transistor having an oxide semiconductor with a low off-current. We can provide it. Or, we can provide a semiconductor device with reduced power consumption. ru.

[0324] [Storage device 2] Figure 19 shows an example of a storage device using a semiconductor device according to one aspect of the present invention. The memory device shown is transistor 200, transistor 300, and shown in Figure 18. In addition to a semiconductor device having a quantitative element 100, it also has a transistor 400.

[0325] Transistor 400 can control the second gate voltage of transistor 200. For example, the first gate and second gate of transistor 400 are connected to the source and diode. Connect the source of transistor 400 to the second gate of transistor 200. The configuration is as follows. When the negative potential of the second gate of transistor 200 is maintained in this configuration, The voltage between the first gate and source of the transistor 400 and the voltage between the second gate and source The voltage becomes 0V. In transistor 400, the second gate voltage and the first gate voltage Because the drain current is very small when the voltage is 0V, transistor 200 and transistor Even without supplying power to transistor 400, the negative potential of the second gate of transistor 200 can be maintained for an extended period. This can be maintained for a period of time. This allows transistors 200 and 400 A storage device having this feature can retain its contents for a long period of time.

[0326] Therefore, in Figure 19, wiring 1001 is electrically connected to the source of transistor 300. Furthermore, wiring 1002 is electrically connected to the drain of transistor 300. Wiring 1003 is electrically connected to either the source or drain of transistor 200. Wire 1004 is electrically connected to the gate of transistor 200, and wire 1006 is connected to the transistor It is electrically connected to the back gate of transistor 200. And transistor 300 The gate, and the other of the source and drain of transistor 200, are of the capacitive element 100. The wiring 1005 is electrically connected to one electrode and to the other electrode of the capacitive element 100. It is connected. Wiring 1007 is electrically connected to the source of transistor 400, and wiring 1008 is electrically connected to the gate of transistor 400, and wiring 1009 is connected to the transistor Electrically connected to the back gate of transistor 400, wiring 1010 is the drain of transistor 400. It is electrically connected to the input. Here, wiring 1006, wiring 1007, wiring 1008, And wiring 1009 is electrically connected.

[0327] Furthermore, the storage device shown in Figure 19 is arranged in a matrix, similar to the storage device shown in Figure 18. This allows for the construction of a memory cell array. Note that one transistor 40 0 can control the second gate voltage of multiple transistors 200. Therefore, it is preferable to use fewer transistors 400 than transistors 200.

[0328] <Transistor 400> Transistor 400 is formed on the same layer as transistor 200 and is manufactured in parallel. It is a transistor that can be manufactured. Transistor 400 is the first gate. Conductive conductors 460 (conductors 460a and 460b), and a second gate The functional conductor 405 (conductor 405a and conductor 405b) and the gate insulating layer An insulator 222 and an insulator 450 that function together, and an oxide 43 having a channel-forming region. 0c and the conductor 442a, oxide 443a, oxide 431a, and which function as a source, Oxide 431b, and conductor 442b, oxide 443b, oxide that functions as a drain. 432a, and oxide 432b, and conductor 440 (conductor 440) which functions as a plug a) and conductor 440b), and an insulator that functions as a barrier insulating film for conductor 440 It has 441 (insulator 441a and insulator 441b).

[0329] In transistor 400, conductor 405 is in the same layer as conductor 205. Material 431a and oxide 432a are in the same layer as oxide 230a, and oxide 431 b, and oxide 432b are in the same layer as oxide 230b. Conductor 442 is conductive Body 242 is in the same layer. Oxide 443 is in the same layer as oxide 243. Oxide 4 30c is the same layer as oxide 230c. Insulator 450 is the same layer as insulator 250. Conductor 460 is in the same layer as conductor 260. Conductor 440 is in the same layer as conductor 24. It is the same layer as 0. Insulator 441 is the same layer as insulator 241.

[0330] Furthermore, structures formed in the same layer can be formed simultaneously. For example, oxide 4 30c can be formed by processing an oxide film that becomes oxide 230c.

[0331] Oxide 430c, which functions as the active layer of transistor 400, is the same as oxide 230, etc. Thus, oxygen deficiency is reduced, and impurities such as hydrogen or water are reduced. The threshold voltage of transistor 400 is set to greater than 0V, reducing the off-current and the second gate The drain current can be made very small when the gate voltage and the first gate voltage are 0V. ru.

[0332] <Dicing line> In the following, by dividing a large-area substrate into semiconductor elements, multiple semiconductor devices are created. Dicing lines (scribe lines, division lines) are provided when extracting chips. This explains the cutting line (which may also be called the cutting line). For example, the method of division is... First, grooves (dicing lines) are formed in the substrate to divide the semiconductor elements, In some cases, the semiconductor device may be cut during grinding, resulting in its division into multiple semiconductor devices.

[0333] Here, for example, as shown in Figure 19, the region where the insulator 272 and the insulator 222 are in contact. It is preferable to design it so that it becomes a dicing line. In other words, multiple transistors A memory cell having 200, and a dicing laser provided on the outer edge of the transistor 400 An opening is provided in the insulator 224 near the region that will be in. Also, the side of the insulator 224 An insulator 272 is provided to cover it.

[0334] In other words, at the opening provided in the insulator 224, the insulator 222 and the insulator 272 They come into contact. For example, in this case, the insulator 222 and the insulator 272 are made of the same material and using the same method. They may be formed by the same material and method. Insulators 222 and 272 are provided by the same material and method. This can improve adhesion. For example, aluminum oxide is preferred. It's nice.

[0335] With this structure, the insulator 222 and the insulator 272, the insulator 224, the transistor It can enclose transistors 200 and 400. Insulator 222, and insulation Body 272 has the function of suppressing the diffusion of oxygen, hydrogen, and water, therefore, in this embodiment By dividing the substrate for each circuit region where the semiconductor element shown is formed, multiple chips can be formed. Even after processing, impurities such as hydrogen or water can enter from the side of the divided substrate, causing problems. This prevents diffusion to transistor 200 and transistor 400.

[0336] Furthermore, due to this structure, excess oxygen in the insulator 224 is transferred to the insulator 272 and the insulator 222 This prevents diffusion to the outside via the insulator 224. Therefore, excess oxygen in the insulator 224 Efficiently forms a channel in transistor 200 or transistor 400. It is supplied to the oxide. With this oxygen, transistor 200 or transistor 400 This can reduce the oxygen vacancy in the oxide where channels are formed. The oxide in which the channel is formed in transistor 200 or transistor 400 This allows for the creation of oxide semiconductors with low defect level density and stable properties. This suppresses fluctuations in the electrical characteristics of the transistor 200 or transistor 400, and also improves reliability. It can improve sexual performance.

[0337] The configurations and methods shown in this embodiment are similar to those shown in other embodiments and other examples. It can be used in appropriate combination with structures, methods, etc.

[0338] (Embodiment 3) In this embodiment, using Figures 20 and 21, we will explain one aspect of the present invention in which an oxide is used to half The transistor used as the conductor (which may be referred to as an OS transistor below), and the capacitance element This section explains the storage device to which the child is applied (hereinafter sometimes referred to as the OS memory device). The OS memory device includes at least a capacitive element and an OS transistor that controls the charging and discharging of the capacitive element. This is a memory device that has a zistor. The off-current of the OS transistor is extremely small, so the OS Memory devices possess excellent retention characteristics and can function as non-volatile memory.

[0339] <Example of a storage device configuration> Figure 20A shows an example of the configuration of the OS memory device. The storage device 1400 is connected to peripheral circuit 141 1, and a memory cell array 1470. Peripheral circuit 1411 is a row circuit 1420, It has a column circuit 1430, an output circuit 1440, and a control logic circuit 1460.

[0340] The column circuit 1430 includes, for example, a column decoder, a precharge circuit, a sense amplifier, and a writing It has a power supply circuit, etc. The precharge circuit has the function of precharging the wiring. The amplification amplifier has the function of amplifying the data signal read from the memory cell. The above wiring is connected to the memory cells of the memory cell array 1470. More details will be provided later. The amplified data signal is output via the output circuit 1440. It is output to the outside of the storage device 1400 as RDATA. Also, the row circuit 1420 is, for example It has a row decoder, a word line driver circuit, etc., and can select the row to access. ru.

[0341] The storage device 1400 receives a low power supply voltage (VSS) from an external source as the power supply voltage, and peripheral circuits 14 The high power supply voltage (VDD) for 11 and the high power supply voltage (VIL) for the memory cell array 1470 are It is supplied. In addition, the storage device 1400 contains control signals (CE, WE, RE) and address signals. The address signal ADDR and the data signal WDATA are input from an external source. The address signal ADDR is the line The WDATA signal is input to the decoder and column decoder, and then input to the writing circuit.

[0342] The control logic circuit 1460 processes external input signals (CE, WE, RE). It then generates control signals for the row decoder and column decoder. CE is the chip enable signal. WE is the write enable signal, and RE is the read enable signal. The signals processed by the control logic circuit 1460 are not limited to these. If necessary, you can input other control signals.

[0343] The memory cell array 1470 consists of multiple memory cells MC arranged in a matrix, and multiple It has the wiring. Note that the wiring connecting the memory cell array 1470 and the row circuit 1420 The number of lines is determined by the configuration of the memory cell MC, the number of memory cell MCs in a single row, and other factors. Also, the number of wires connecting the memory cell array 1470 and the column circuit 1430 is noted. This is determined by factors such as the configuration of the recell MC and the number of memory cell MCs in each row.

[0344] In Figure 20A, the peripheral circuit 1411 and the memory cell array 1470 are on the same plane. Although examples of how to form it have been shown, this embodiment is not limited to this. For example, As shown in Figure 20B, the memory cell array 1470 is superimposed on a portion of the peripheral circuit 1411. It may be provided in such a way. For example, so as to overlap below the memory cell array 1470, A configuration that includes a sense amplifier is also possible.

[0345] Figure 21 illustrates an example of a memory cell configuration that can be applied to the above-mentioned memory cell MC.

[0346] [DOSRAM] Figures 21A to 21C show examples of circuit configurations for DRAM memory cells. And, DRAM using a 1OS transistor 1 capacitance element type memory cell is called DOSRAM. (Dynamic Oxide Semiconductor Random Acce. It is sometimes called ss Memory. As shown in Figure 21A, memory cell 1471 is a tra It has a transistor M1 and a capacitive element CA. Note that the transistor M1 has a gate (flow It has a front gate (sometimes called a back gate) and a back gate.

[0347] The first terminal of transistor M1 is connected to the first terminal of capacitive element CA, and transistor M The second terminal of 1 is connected to wiring BIL, and the gate of transistor M1 is connected to wiring WOL. Next, the back gate of transistor M1 is connected to wiring BGL. Capacitive element C The second terminal of A is connected to wiring CAL.

[0348] Wiring BIL functions as a bit line, and wiring WOL functions as a word line. CAL functions as wiring for applying a predetermined potential to the second terminal of the capacitive element CA. During data writing and reading, a low-level potential is applied to the wiring CAL. It is preferable to do so. Wiring BGL is used to apply potential to the back gate of transistor M1. It functions as wiring. By applying an arbitrary potential to wiring BGL, the transistor The threshold voltage of M1 can be increased or decreased.

[0349] Furthermore, the memory cell MC is not limited to memory cell 1471, and the circuit configuration can be changed. This is possible. For example, a memory cell MC can be a memory cell 1472 as shown in Figure 21B. The back gate of transistor M1 is connected to the WOL wiring instead of the BGL wiring. It is also possible to do so. For example, the memory cell MC is like the memory cell 1473 shown in Figure 21C. In addition, a single-gate transistor, that is, a transistor without a back gate, M It may also be a memory cell composed of 1.

[0350] When the semiconductor device shown in the above embodiment is used as a memory cell 1471, etc., a transistor Transistor 200 is used as M1, and capacitive element 100 is used as capacitive element CA. This can be done. By using an OS transistor as transistor M1, the transistor The leakage current of the M1 can be made very low. In other words, the written data can be transmitted Because it can be retained for a long time by ZISTA M1, the frequency of memory cell refresh is reduced. This can reduce the amount of memory required. Furthermore, it eliminates the need for memory cell refresh operations. It can be done. Also, because the leakage current is very low, memory cell 1471, memory cell 1472, The memory cell 1473 can hold multi-level data or analog data.

[0351] Furthermore, in DOSRAM, as described above, overlaps below the memory cell array 1470 As shown, by using a configuration that includes a sense amplifier, the bit line can be shortened. This reduces the bit line capacitance and thus the memory cell retention capacity.

[0352] [NOSRAM] Figures 21D to 21H show the rotation of a gain cell type memory cell with two transistors and one capacitance element. An example of a circuit configuration is shown. As shown in Figure 21D, the memory cell 1474 is connected to transistor M2 and It has a transistor M3 and a capacitive element CB. Transistor M2 is the front gate It has a gate (sometimes simply called a gate) and a back gate. In this specification, etc., A memory device having a gain cell type memory cell using an OS transistor in the transistor M2. , NOSRAM(Nonvolatile Oxide Semiconductor It is sometimes referred to as RAM.

[0353] The first terminal of transistor M2 is connected to the first terminal of the capacitive element CB, and transistor M The second terminal of 2 is connected to the wiring WBL, and the gate of transistor M2 is connected to the wiring WOL. Next, the back gate of transistor M2 is connected to wiring BGL. Capacitive element C The second terminal of B is connected to wiring CAL. The first terminal of transistor M3 is connected to wiring R. The second terminal of transistor M3 is connected to BL, and the wiring SL is connected to transistor M The gate of 3 is connected to the first terminal of the capacitive element CB.

[0354] Wiring WBL functions as the write bit line, and wiring RBL functions as the read bit line. The wiring WOL functions as a word line. The wiring CAL is the second of the capacitive element CB. It functions as wiring to apply a predetermined potential to the terminal. When writing data, data retention During the process, when reading data, a low-level potential is applied to the wiring CAL. Preferred. Wiring BGL is wiring for applying potential to the back gate of transistor M2. It functions as follows: By applying an arbitrary potential to the wiring BGL, the transistor M2 The threshold voltage can be increased or decreased.

[0355] Furthermore, the memory cell MC is not limited to memory cell 1474, and the circuit configuration can be changed as appropriate. This is possible. For example, the memory cell MC is like the memory cell 1475 shown in Figure 21E. In this configuration, the back gate of transistor M2 is connected to the WOL wiring instead of the BGL wiring. It may also be made into a memory cell MC, as shown in Figure 21F, memory cell 1476 As shown above, a single-gate transistor, that is, a transistor without a back gate A memory cell composed of sta M2 may also be used. Furthermore, for example, the memory cell MC is shown in Figure 2. As shown in memory cell 1477 in 1G, the wiring WBL and wiring RBL are connected to a single wiring BIL. It would also be acceptable to use a structure that summarizes the information in this way.

[0356] When the semiconductor device shown in the above embodiment is used as a memory cell 1474, etc., a transistor Transistor 200 is used as M2, and transistor 300 is used as transistor M3. Capacitive element 100 can be used as the capacitive element CB. Transistor M2 By using an OS transistor, the leakage current of transistor M2 can be made very low. This allows the written data to be retained for a long time by transistor M2. This allows for a reduction in the frequency of memory cell refreshes. Furthermore, it eliminates the need for memory cell refresh operations. Also, the leakage current is very low. Because the temperature is low, the memory cell 1474 can store multi-level data or analog data. The same applies to memory cells 1475 to 1477.

[0357] Note that transistor M3 is a transistor having silicon in the channel formation region (hereinafter (Sometimes called Si transistors) The conductivity type of Si transistor is It may be an n-channel type or a p-channel type. Si transistors are OS transistors In some cases, the field-effect mobility is higher than that of a transistor. Therefore, readout transistor A Si transistor may be used as transistor M3, which functions as a transistor. By using a Si transistor for transistor M3, a transistor can be stacked on top of transistor M3. Since a converter M2 can be provided, the occupied area of ​​the memory cell is reduced, and the storage device is high It is possible to integrate the resources.

[0358] Also, transistor M3 may be an OS transistor. Transistors M2, M3 When OS transistors are used, the memory cell array 1470 uses only n-type transistors. It can be used to construct a circuit.

[0359] Figure 21H also shows an example of a gain cell type memory cell with 3 transistors and 1 capacitance element. The memory cell 1478 shown in Figure 21H consists of transistors M4 to M6 and a capacitive element C. It has C. Capacitive elements CC are provided as appropriate. Memory cell 1478 has wiring BIL, RW Electrically connected to L, WWL, BGL, and GNDL. Wiring GNDL is low level. This is a wiring that provides a potential. Note that memory cell 1478 is replaced with wiring R instead of wiring BIL. BL and WBL may be electrically connected.

[0360] Transistor M4 is an OS transistor with a back gate, and the back gate is It is electrically connected to wiring BGL. Note that the back gate and gate of transistor M4 They may be electrically connected to each other. Alternatively, transistor M4 may have a back gate. It's not necessary.

[0361] Note that transistors M5 and M6 are either n-channel Si transistors or p-channel Si transistors, respectively. A channel-type Si transistor is also acceptable. Alternatively, transistors M4 to M6 can be OS transistors. It can also be a stapler; in this case, the memory cell array 1470 is rotated using only n-type transistors. A path can be constructed.

[0362] When the semiconductor device shown in the above embodiment is used as the memory cell 1478, transistor M Transistor 200 is used as transistor 4, and transistors M5 and M6 are transistor 300. Using this, the capacitive element 100 can be used as the capacitive element CC. Transistor M4 and By using an OS transistor, the leakage current of transistor M4 is reduced to a very low level. It can be done.

[0363] Note that the peripheral circuit 1411 and memory cell array 1470 shown in this embodiment, etc. The configuration is not limited to those described above. These circuits, and the connections to them The arrangement or function of lines, circuit elements, etc., may be changed, deleted, or added as needed. stomach.

[0364] The configurations and methods shown in this embodiment are similar to those shown in other embodiments and other examples. It can be used in appropriate combination with structures, methods, etc.

[0365] (Embodiment 4) In this embodiment, using Figure 22, the semiconductor device of the present invention is mounted on a chip 1200. Here is an example. Chip 1200 has multiple circuits (systems) mounted on it. Uni, the technology of integrating multiple circuits (systems) onto a single chip is called system-on-chip ( It is sometimes referred to as a System on Chip (SoC).

[0366] As shown in Figure 22A, the chip 1200 is a CPU (Central Processor). ing Unit) 1211, GPU (Graphics Processing Un) it)1212, one or more analog arithmetic units 1213, one or more memory controllers Roller 1214, one or more interfaces 1215, one or more networks It has circuits 1216, etc.

[0367] The chip 1200 is provided with bumps (not shown), and as shown in Figure 22B, pre The first side of the Printed Circuit Board (PCB) 1201 It connects to this. In addition, multiple bumps 1202 are provided on the back surface of the first face of PCB1201. It is configured to connect to the motherboard 1203.

[0368] Motherboard 1203 includes memory devices such as DRAM 1221 and flash memory 1222. A place may be provided. For example, the DOSR shown in the previous embodiment may be placed in the DRAM1221. AM can be used. Also, for example, in the flash memory 1222, the above embodiment The NOSRAM shown can be used.

[0369] CPU1211 preferably has multiple CPU cores. Also, GPU1212 It is preferable that it has multiple GPU cores. Also, CPU1211 and GPU1 Each of 212 may have memory to temporarily store data. Or, CP The memory common to both U1211 and GPU1212 is provided on chip 1200. Alternatively, the aforementioned NOSRAM or DOSRAM can be used for this memory. Furthermore, the GPU1212 is suitable for parallel computation of large amounts of data, and is ideal for image processing and multiply-accumulate operations. It can be used. The GPU1212 can be used with an image processing circuit using the oxide semiconductor of the present invention. By providing a multiply-accumulate circuit, image processing and multiply-accumulate operations can be performed with low power consumption. This will become possible.

[0370] Furthermore, because the CPU1211 and GPU1212 are located on the same chip, The wiring between CPU1211 and GPU1212 can be shortened, and CPU1211 or Data transfer to GPU1212, and notes held by CPU1211 and GPU1212. Data transfer between the two, and after calculations on GPU1212, from GPU1212 to CPU12 The transfer of calculation results to 11 can be done at high speed.

[0371] The analog processing unit 1213 includes an A / D (analog / digital) conversion circuit and a D / A (digital / digital) conversion circuit. It has one or both of the digital / analog conversion circuits. Also, analog arithmetic unit 1213 The above-mentioned sum-of-accumulate circuit may be provided.

[0372] The memory controller 1214 is a circuit that functions as a controller for the DRAM 1221. It also has a circuit that functions as an interface for the flash memory 1222.

[0373] Interface 1215 is for display devices, speakers, microphones, cameras, and controllers. It has an interface circuit for connecting to external devices such as a torpedo. A controller is a motor This includes mice, keyboards, game controllers, etc. USB (Universal Serial Bus), HDMI (registered trademark) (H (using igh-Definition Multimedia Interface, etc.) It is possible to be there.

[0374] The network circuit 1216 is a LAN (Local Area Network), etc. It has a network circuit. It may also have a circuit for network security. stomach.

[0375] The above circuit (system) can be formed on chip 1200 using the same manufacturing process. It is possible. Therefore, even if the number of circuits required for chip 1200 increases, the manufacturing process does not need to be increased. This eliminates the need for additional processing, allowing for the low-cost manufacturing of the Chip 1200.

[0376] PCB1201 equipped with chip 1200 having GPU1212, DRAM122 1, and the motherboard 1203 equipped with flash memory 1222, GPU module It can be called Lure 1204.

[0377] The GPU module 1204 has a chip 1200 that uses SoC technology, Its size can be reduced. Also, because it excels at image processing, smart Phones, tablet devices, laptop PCs, portable (take-out) game consoles, etc. It is suitable for use in portable electronic devices. Also, a multiply-accumulate circuit using the GPU1212. This leads to the development of deep neural networks (DNNs) and convolutional neural networks. (CNN), Recurrent Neural Network (RNN), Autoencoder, Deep Boltzmann It can perform calculations such as those for machine learning (DBM) and deep belief networks (DBN). Therefore, the chip 1200 is the AI ​​chip, or the GPU module 1204 is the AI ​​system module. It can be used as a joule.

[0378] The configurations and methods shown in this embodiment are similar to those shown in other embodiments and other examples. It can be used in appropriate combination with structures, methods, etc.

[0379] (Embodiment 5) In this embodiment, regarding the application example of a memory device using the semiconductor device shown in the previous embodiment, Let me explain. The semiconductor device shown in the above embodiment is, for example, used in various electronic devices (for example, information Terminals, computers, smartphones, e-readers, digital cameras (including video cameras) This can be applied to storage devices (including recording and playback devices, navigation systems, etc.). Secondly, computers include tablet computers, notebook computers, and This includes not only desktop computers but also large computers such as server systems. Alternatively, the semiconductor device shown in the previous embodiment may be a memory card (for example, S Various types of removable media such as D cards, USB memory sticks, and SSDs (Solid State Drives) This applies to bubble storage devices. Figure 23 schematically shows several configuration examples of removable storage devices. As shown above, for example, the semiconductor device shown in the above embodiment is a packaged memory chip It is processed into plastic and used in various storage devices and removable memory.

[0380] Figure 23A is a schematic diagram of a USB memory device. The USB memory device 1100 consists of a casing 1101 and a key It has a cap 1102, a USB connector 1103 and a circuit board 1104. The circuit board 1104 is , housed in the casing 1101. For example, the circuit board 1104 has a memory chip 1105, Controller chip 1106 is installed. Memory chip 110 on board 1104 The semiconductor device shown in the above embodiment can be incorporated into 5, etc.

[0381] Figure 23B is a schematic diagram of the external appearance of an SD card, and Figure 23C is a schematic diagram of the internal structure of an SD card. This is a diagram of the equation. The SD card 1110 consists of a housing 1111, a connector 1112, and a circuit board 111. It has 3. The circuit board 1113 is housed in the housing 1111. For example, the circuit board 1113 has A memory chip 1114 and a controller chip 1115 are mounted on the circuit board 11. By also providing a memory chip 1114 on the back side of 13, the capacity of the SD card 1110 can be increased. It is possible to do so. Furthermore, a wireless chip with wireless communication functionality may be provided on the circuit board 1113. Yes. This allows the memory chip to be controlled wirelessly between the host device and the SD card 1110. Data can be read and written to p1114. Memory chip 1 on board 1113 The semiconductor device shown in the above embodiment can be incorporated into 114, etc.

[0382] Figure 23D is a schematic diagram of the external appearance of the SSD, and Figure 23E is a schematic diagram of the internal structure of the SSD. The SSD1150 has a housing 1151, a connector 1152, and a circuit board 1153. The circuit board 1153 is housed in the casing 1151. For example, the circuit board 1153 has memory chips. The chip 1154, memory chip 1155, and controller chip 1156 are installed. The memory chip 1155 is the work memory of the controller chip 1156, for example D An OSRAM chip can be used. A memory chip 1154 is also provided on the back side of the circuit board 1153. By doing so, the capacity of the SSD1150 can be increased. (Memory chip on board 1153) The semiconductor device shown in the above embodiment can be incorporated into 1154, etc.

[0383] The configurations and methods shown in this embodiment are similar to those shown in other embodiments and other examples. It can be used in appropriate combination with structures, methods, etc.

[0384] (Embodiment 6) In this embodiment, a specific example of an electronic device applicable to a semiconductor device according to one aspect of the present invention is described. This will be explained using Figure 24.

[0385] More specifically, a semiconductor device according to one aspect of the present invention is a processor such as a CPU or GPU It can be used in a s or chip. Figure 24 shows a CPU and GP according to one aspect of the present invention. This section provides specific examples of electronic devices equipped with processors or chips such as U.

[0386] <Electronic Equipment and Systems> A GPU or chip according to one aspect of the present invention can be mounted in various electronic devices. Examples of electronic devices include, for instance, television equipment, desktop or notebook computers. Personal computers, computer monitors, digital signage (Digi Digital signage (electronic billboards), large game machines such as pachinko machines, and other relatively large devices. In addition to electronic devices with screens, digital cameras, digital video cameras, and digital photo Examples include frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices. Furthermore, by providing an integrated circuit or chip according to one aspect of the present invention in an electronic device, Artificial intelligence can be installed in the sub-devices.

[0387] An electronic device according to one aspect of the present invention may have an antenna. The antenna receives a signal. This allows the display unit to show images, information, etc. Also, the electronic device acts as an antenna. Furthermore, if a secondary battery is present, the antenna may be used for contactless power transmission.

[0388] An electronic device according to one aspect of the present invention includes a sensor (force, displacement, position, velocity, acceleration, angular velocity, rotation). Number, distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, electric current, voltage, power (including functions for measuring radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation) It is acceptable to have it.

[0389] An electronic device according to one aspect of the present invention can have various functions. For example, various information Functions to display (still images, videos, text images, etc.) on the display unit, touch panel function, calendar Functions to display the date or time, and to run various software (programs). Functions include: wireless communication, and reading programs or data recorded on a recording medium. It can have functions, etc. Figure 24 shows an example of an electronic device.

[0390] [mobile phone] Figure 24A illustrates a mobile phone (smartphone), which is a type of information terminal. The information terminal 5500 has a housing 5510 and a display unit 5511, and an input interface - As a face, a touch panel is provided on the display unit 5511, and buttons are located on the housing 5510. It is provided.

[0391] The information terminal 5500 utilizes artificial intelligence by applying a chip according to one embodiment of the present invention. The application can be run. As an application utilizing artificial intelligence. For example, an application that recognizes a conversation and displays the content of that conversation on the display unit 5511. The display unit 5511 recognizes characters, shapes, etc., entered by the user on the touch panel. The application to be displayed on the display unit 5511, and the biometric authentication such as fingerprints and voiceprints are performed. Applications are one example.

[0392] [Information Terminal 1] Figure 24B illustrates the desktop information terminal 5300. The information terminal 5300 consists of the main unit 5301 of the information terminal, the display 5302, and the keyboard 5 It has 303 and

[0393] The desktop information terminal 5300, like the information terminal 5500 described above, is based on the first part of the present invention. By applying a chip of this type, it is possible to run applications that utilize artificial intelligence. Yes, it is possible. Examples of applications that utilize artificial intelligence include design support software. Examples include document editing software and automatic menu generation software. By using the 5300 top-type information terminal, it is possible to develop new artificial intelligence.

[0394] In the above, smartphones and desktop information terminals were used as examples of electronic devices. As shown in Figures 24A and 24B, respectively, for smartphones and desktops It can be applied to information terminals other than information terminals. This includes smartphones and desktop computers. Other types of information terminals include, for example, PDAs (Personal Digital Adapters). Examples include assistants, notebook computers, and workstations.

[0395] [electric appliances] Figure 24C shows an example of an electrical appliance, the electric refrigerator-freezer 5800. The storage unit 5800 includes a casing 5801, a door for the refrigerator compartment 5802, a door for the freezer compartment 5803, and the like.

[0396] By applying a chip according to one aspect of the present invention to an electric refrigerator 5800, artificial intelligence An electric refrigerator-freezer 5800 with the following features can be realized. By utilizing artificial intelligence... The electric refrigerator-freezer 5800 is used to store food items, and the food It has a function that automatically generates menus based on the expiration dates of ingredients, and the menus are stored in the 5800 electric refrigerator / freezer. It can have features such as automatically adjusting the temperature to suit the ingredients being used.

[0397] In this example, we have described electric refrigerators and freezers as electrical appliances, but other electrical appliances and For example, vacuum cleaners, microwave ovens, electric ovens, rice cookers, water heaters, induction cooktops , water dispensers, heating and cooling appliances including air conditioners, washing machines, dryers, etc. Examples include audiovisual equipment.

[0398] [Game console] Figure 24D shows a portable game console, model 5200, which is an example of a game console. It includes a housing 5201, a display unit 5202, buttons 5203, etc.

[0399] By applying a GPU or chip according to one aspect of the present invention to a portable game console 5200, This makes it possible to create a low-power portable game console, the 5200. Furthermore, due to its low power consumption, Because it can reduce heat generation from the circuit, the heat generated by the circuit itself, the surrounding circuits, and This can minimize the impact on the module.

[0400] Furthermore, by applying a GPU or chip according to one aspect of the present invention to the portable game console 5200... This makes it possible to realize the 5200, a portable game console equipped with artificial intelligence.

[0401] Originally, the progression of the game, the behavior of creatures appearing in the game, and the phenomena that occur in the game, etc. The expression is determined by the program of the game, but the handheld game console 520 By applying artificial intelligence to 0, it becomes possible to create expressions that are not limited to game programs. For example, the questions the player asks, the game's progress, the time, and the characters that appear in the game. This allows for expressions that describe a change in a person's words and actions.

[0402] Furthermore, when playing games that require multiple players on the 5200 handheld game console, artificial intelligence is used. This allows for the creation of anthropomorphic game players, thus enabling the opponent to be represented by artificial intelligence. By making it a night game, it's possible to play the game even by yourself.

[0403] Figure 24D shows a portable game console as an example of a game console, but this is one aspect of the present invention. Game consoles to which the GPU or chip is applied are not limited thereto. GPU of one aspect of the present invention Alternatively, game machines to which the chip can be applied include, for example, home console game machines and entertainment facilities. Arcade game machines installed in facilities (game centers, amusement parks, etc.), and sports facilities. Examples include pitching machines for batting practice.

[0404] [Mobile] A GPU or chip according to one aspect of the present invention is used in a mobile vehicle and the area around the driver's seat of the vehicle. It can be applied to this.

[0405] Figure 24E1 shows an example of a mobile vehicle, automobile 5700, and Figure 24E2 shows the interior of the automobile. This is a diagram showing the area around the windshield. In Figure 24E2, it is mounted on the dashboard. In addition to the display panels 5701, 5702, and 5703 that were cut off, the pillar The installed display panel 5704 is illustrated.

[0406] Display panels 5701 to 5703 display the speedometer, tachometer, and It provides various information by displaying mileage, fuel gauge, gear status, air conditioning settings, etc. It is possible to do so. Furthermore, the display items and layout shown on the display panel can be customized by the user. It can be modified as needed to suit your preferences, and the design can be enhanced. The panel 5701 to the display panel 5703 can also be used as a lighting device.

[0407] The display panel 5704 shows the information from an imaging device (not shown) installed in the automobile 5700. By projecting images, it is possible to compensate for the blind spots (visibility obstructed by pillars). In other words, by displaying images from an imaging device installed on the outside of the automobile 5700 This can compensate for blind spots and enhance safety. It also displays images that fill in the gaps in what is not visible. This allows for a more natural and seamless safety check. (Display panel 570) Item 4 can also be used as a lighting device.

[0408] A GPU or chip according to one aspect of the present invention can be applied as a component of artificial intelligence, for example If so, the chip can be used in the autonomous driving system of the automobile 5700. The chip can be used in systems for road guidance, hazard prediction, and other purposes. (Display panel 57) Panels 01 through 5704 are configured to display information such as road guidance and hazard predictions. That's good too.

[0409] In the above, an automobile was described as an example of a moving object, but the moving object is an automobile. It is not limited to these. For example, examples of moving objects include trains, monorails, ships, and aircraft (helicopters). Other examples include unmanned aerial vehicles (drones), airplanes, and rockets, and these can be moved Applying a chip according to one aspect of the present invention to a moving object to provide it with a system utilizing artificial intelligence. It is possible.

[0410] [Broadcasting System] A GPU or chip according to one aspect of the present invention can be applied to a broadcasting system.

[0411] Figure 24F schematically illustrates data transmission in a broadcasting system. Specifically, Figure 24F is the radio waves (broadcast signals) transmitted from broadcasting station 5680 to each household's television receiver. This shows the path to the signal reaching the TV 5600. The TV 5600 is equipped with a receiving device. (Not shown in the diagram) The broadcast signal received by antenna 5650 is transmitted via the receiving device, It is transmitted to TV5600.

[0412] In Figure 24F, antenna 5650 is UHF (Ultra High Frequency) The diagram shows an antenna, but the antenna 5650 is a BS / 110°CS antenna. It can also be used for antennas such as CS antennas.

[0413] Radio waves 5675A and 5675B are broadcast signals for terrestrial broadcasting, and radio tower 5670 is The received radio wave 5675A is amplified and used to transmit radio wave 5675B. In each household, the antenna By receiving radio wave 5675B with Na5650, you can watch terrestrial TV broadcasts with TV5600. It is possible. Furthermore, the broadcasting system is not limited to terrestrial broadcasting as shown in Figure 24F, but also includes artificial satellite broadcasting. This could also include satellite broadcasting using stars, or data broadcasting via fiber optic lines.

[0414] The broadcasting system described above applies a chip according to one aspect of the present invention and utilizes artificial intelligence for broadcasting. It can also be used as a transmission system. Broadcast data is transmitted from broadcast station 5680 to TVs 5600 in each home. At that time, the encoder compresses the broadcast data, and the antenna 5650 receives the broadcast When data is received, the decoder of the receiving device included in the TV5600 processes the broadcast data Data recovery is performed. By using artificial intelligence, for example, the compression method of the encoder is restored. In motion compensation prediction, which is one aspect of the law, the recognition of display patterns contained in the displayed image. It can do this. It can also perform in-frame predictions using artificial intelligence. Also, for example... For example, receiving low-resolution broadcast data and using the high-resolution TV5600 to view the same broadcast data When displaying the data, the decoder performs upconversion and other processes during the restoration of the broadcast data. It can perform image interpolation.

[0415] The broadcasting system using artificial intelligence described above is designed to handle the increasing volume of broadcast data in ultra-high-definition television. It is suitable for revision (UHDTV: 4K, 8K) broadcasting.

[0416] Furthermore, as an application of artificial intelligence on the TV5600 side, for example, the TV5600 can be equipped with artificial intelligence A recording device having the capability may be provided. By having such a configuration, the recording device By having artificial intelligence learn the user's preferences, the system automatically records programs that match the user's taste. It can be drawn.

[0417] The electronic device described in this embodiment, its functions, examples of artificial intelligence applications, and their effects. These can be combined as appropriate with descriptions of other electronic devices.

[0418] The configurations and methods shown in this embodiment are similar to those shown in other embodiments and other examples. It can be used in appropriate combination with structures, methods, etc. [Examples]

[0419] In this example, as shown in Figure 1, oxide 230a, oxide 230b, oxide 230c, and insulating Samples 1A to 1I corresponding to body 250 were prepared, and the carrier concentration of these samples was determined. We will now explain the results of the measurements.

[0420] First, we will explain the method for preparing samples 1A through 1I.

[0421] As samples 1A to 1I, a quartz substrate was prepared, and on the quartz substrate, In-Ga-Z A 5nm thick 1 / 2 oxide film (hereinafter referred to as IGZO film) is made using the DC sputtering method. The film was deposited with this intention. IGZO film deposition uses an In:Ga:Zn=1:3:4 [atomic ratio] ter GET was used (hereinafter, this IGZO film will be referred to as IGZO film (134)). The deposition gas was Using 45 sccm of oxygen gas, the deposition pressure was set to 0.7 Pa (Canon Anelva miniature). Measurements were taken using Gauge MG-2. The deposition power was set to 500W, and the substrate temperature was set to 200°C. The temperature was set to °C, and the target-substrate distance was set to 60 mm. The IGZO film (134) was oxide Compatible with 230a.

[0422] Furthermore, without exposure to the atmosphere, the IGZO film (134) is coated with DC sputtering. The film was deposited using the IGZO method, aiming for a thickness of 35 nm. IGZO film deposition is performed using the In:Ga:Zn= Using a 4:2:4.1 [atomic ratio] target (hereinafter, the IGZO film is referred to as the IGZO film ( (423) is the name given. Oxygen gas at 45 sccm is used as the deposition gas, and the deposition pressure is 0.7 Pa. (Measured using a Canon Anelva miniature gauge MG-2.) The film deposition power was The power was set to 500W, the substrate temperature to 200°C, and the target-substrate distance to 60mm. The IGZO film (423) corresponds to oxide 230b.

[0423] Next, samples 1A to 1I were subjected to a heat treatment at 400°C for 1 hour under a nitrogen atmosphere. Furthermore, the samples were subjected to a heat treatment at 400°C for 1 hour under an oxygen atmosphere.

[0424] Next, in samples 1A to 1I, sputtering was performed on the IGZO film (423). A tantalum nitride film with a thickness of 25 nm was deposited using [a specific method]. Then, the tantalum nitride film was [a specific method]. It was removed by dry etching. In this dry etching process, the etching gas was used as CF4 and Cl2 were used. The deposition and removal of the tantalum nitride film were carried out according to the above embodiment. As shown in Figures 5 and 8, the formation of the conductive layer 242B and the removal of a portion of the conductive layer 242B are performed. It corresponds to the process.

[0425] Next, samples 1A to 1I were washed with an aqueous solution of hydrofluoric acid diluted with pure water. Ta.

[0426] Next, samples 1A to 1I were subjected to a heat treatment at 350°C for 1 hour under a nitrogen atmosphere. Furthermore, the samples were subjected to a heat treatment at 350°C for 1 hour under an oxygen atmosphere.

[0427] Next, in samples 1A to 1I, the IGZO film (423) is placed on the IGZO film (13 4) was deposited using the DC sputtering method with a target thickness of 5 nm. IGZO film (134 The process was carried out under the same conditions as for the IGZO film (134) described above. The IGZO film formed in this process ( 134) corresponds to oxide 230c.

[0428] Next, in samples 1B through 1E, the PEALD method was used to target a film thickness of 10 nm using acid A silicon oxide film was deposited. This silicon oxide film corresponds to insulator 250. PEALD One cycle involves introducing an aminosilane compound gas as a precursor for 0.5 seconds, followed by 18 seconds. Intermittent purging was performed, and oxygen gas was flowed as a reactant for 1.4 seconds to stabilize the flow rate. Next, the RF plasma generator output was set to 2800W and oxygen plasma was irradiated for 18 seconds. Then, a purge was performed for 8 seconds. During PEALD deposition, 550 sccm of nitrogen gas and 50 We continued to introduce argon gas from sccm as the carrier gas during the deposition of PEALD. The plate temperatures were 200°C for sample 1B, 300°C for sample 1C, 350°C for sample 1D, and 300°C for sample 1E. The temperature was set to 400℃.

[0429] Furthermore, in samples 1F to 1I, a film thickness of 10 nm was targeted using the thermal ALD method. A silicon oxide film was formed. This silicon oxide film corresponds to the insulator 250. Thermal One cycle of ALD involves introducing an aminosilane compound gas as a precursor for 0.5 seconds. Then, purge for 18 seconds, and introduce a mixed gas of ozone and oxygen as a reactant for 18 seconds. Then, a purge was performed for 8 seconds. During the deposition of the thermal ALD film, 550 sccm of nitrogen gas and 50 sccm of argon gas was continuously introduced as the carrier gas. The substrate temperature in the film was 200°C for sample 1F, 300°C for sample 1G, and 350°C for sample 1H. The temperature of material 1I was set to 400°C.

[0430] Next, in samples 1B to 1I, a portion of the silicon oxide film is dry-etched. The material was removed by the process, forming an opening that reached the IGZO film. In this dry etching process, CF4 was used as the etching gas.

[0431] Furthermore, Ti-Al, which functions as an electrode, is placed in contact with the IGZO film at the opening. An alloy film was formed.

[0432] Samples 1A to 1I prepared in the manner described above were used with a Hall effect manufactured by Toyo Technica Co., Ltd. The sheet resistance value was measured using the fruit measuring instrument "ResiTest 8400 series". The carrier concentration was then calculated. Carrier concentrations of samples 1A to 1E [1 / cm³] 3 [Figure] In 25A, the carrier concentrations of sample 1A, sample 1F to sample 1I are [1 / cm³]. 3 ] in Figure 25B show.

[0433] As shown in Figure 25A, sample 1 was deposited using the PEALD method and the substrate temperature was raised to 300°C or higher. Samples C, 1D, and 1E had a higher IG than sample 1A, which did not have a silicon oxide film deposited. The carrier concentration of the ZO film is extremely low. Furthermore, as shown in Figure 25B, the film was deposited using the thermal ALD method, with a substrate temperature of 350°C or higher. Samples 1H and 1I also showed more characteristics than sample 1A, which did not have a silicon oxide film deposited. The carrier concentration in the IGZO film decreased significantly.

[0434] Furthermore, the substrate temperature is raised to 350°C or higher, and the film is deposited using the PEALD method or the thermal ALD method. Furthermore, the sheet resistance values ​​of the IGZO films of sample 1D, sample 1E, sample 1H, and sample 1I are as follows: The measurement limit of the metering effect measuring instrument was exceeded. Therefore, for samples 1D, 1E, and 1H , and the carrier concentration of the IGZO film in sample 1I is 1 × 10 13 / cm 3 It is estimated to be less than It is measured.

[0435] Next, samples 2A to 2I are prepared corresponding to samples 1A to 1I, and each sample is... SIMS analysis was performed on the IGZO film. Here, samples 2A to 2I were used instead of a quartz substrate. A silicon group on which a thermal oxide film (Thermal SiOx) with a thickness of 100 nm has been formed. In terms of using a plate and not forming a Ti-Al alloy film that functions as an electrode, Although it differs from Sample 1A to Sample 1I, the other structures are the same as those of Sample 1A to Sample 1I. That is the case.

[0436] Hydrogen concentration of samples 2A to 2E [atoms / cm³] 3 ] is shown in Figure 26A, sample 2A, test Hydrogen concentration of sample 2F to sample 2I [atoms / cm³] 3 Figure 26B shows [this]. Figure 26A and In Figure 26B, the horizontal axis represents the depth of the sample (nm). The analysis direction is the direction from the back surface of the sample toward the front surface. The IGZO film was defined as the quantitative layer for hydrogen. .

[0437] As shown in Figure 26B, samples 2F to 2I, which were deposited by the thermal ALD method, oxidized The hydrogen concentration profile was almost identical for sample 2A, which did not have a silicon film deposited, and for sample 2A. Furthermore, as shown in Figure 26A, in samples 2B to 2E, which were deposited using the PEALD method, the substrate Although the hydrogen concentration was slightly higher in samples 2D and 2E, which were at higher temperatures, silicon oxide was deposited. The hydrogen concentration profile was generally similar to that of sample 2A, which did not contain any hydrogen.

[0438] As described above, while heating the substrate, oxidation is performed using the PEALD method or the Thermal ALD method. By forming a silicon oxide film, the hydrogen concentration in the IGZO film beneath the silicon oxide film is It was shown that the increase can be suppressed and the carrier concentration can be reduced. By using it in a transistor, it is possible to make the transistor normally off, resulting in good performance. A semiconductor device with electrical characteristics and reliability can be constructed. [Explanation of Symbols]

[0439] 10: Precursor, 20: Reactant, 30: Electromagnetic wave, 200: Transistor, 205 : Conductor, 205a: Conductor, 205b: Conductor, 210: Insulator, 212: Insulator, 2 14: Insulator, 216: Insulator, 217: Insulator, 218: Conductor, 222: Insulator, 2 24: Insulator, 224A: Insulator, 230: Oxide, 230a: Oxide, 230A: Oxide Film, 230b: Oxide, 230B: Oxide film, 230c: Oxide, 230C: Oxide film, 24 0: Conductor, 240a: Conductor, 240b: Conductor, 241: Insulator, 241a: Insulator , 241b: insulator, 242: conductor, 242a: conductor, 242A: conductive film, 242b : Conductor, 242B: Conductive layer, 243: Oxide, 243a: Oxide, 243A: Oxide film , 243b: oxide, 243B: oxide layer, 246: conductor, 246a: conductor, 246 b: conductor, 250: insulator, 250A: insulating film, 260: conductor, 260a: conductor 260Aa: conductive film, 260Ab: conductive film, 260b: conductor, 272: insulator, 272 A: insulating film, 273: insulator, 273A: insulating film, 274: insulator, 280: insulator, 2 81: Insulator, 282: Insulator, 283: Insulator, 283a: Insulator, 290: Electromagnetic wave, 292: Electromagnetic waves

Claims

1. A first metal oxide layer having a region that will form the channel of the transistor is formed on the substrate. An insulator is formed above the first metal oxide layer. An opening is formed in the insulator that reaches the first metal oxide layer. In the aforementioned opening, a metal oxide film is formed so as to be in contact with the first metal oxide layer. An insulating film is formed on top of the metal oxide film, A conductive film is formed on top of the insulating film, A method for manufacturing a semiconductor device, comprising removing a portion of the metal oxide film, a portion of the insulating film, and a portion of the conductive film until the upper surface of the insulator is exposed, thereby forming a second metal oxide layer, an insulating layer, and a conductive layer, Before forming the insulating film, the first metal oxide layer, the metal oxide film, and the insulator are irradiated with microwaves. A method for manufacturing a semiconductor device, comprising the steps of: introducing a first gas containing silicon into a chamber while heating the substrate to 300°C or higher using the PEALD method; and introducing a second gas containing oxygen radicals into the chamber while heating the substrate to 300°C or higher.

2. A first metal oxide layer having a region that will form the channel of the transistor is formed on the substrate. An insulator is formed above the first metal oxide layer. An opening is formed in the insulator that reaches the first metal oxide layer. In the aforementioned opening, a metal oxide film is formed so as to be in contact with the first metal oxide layer. An insulating film is formed on top of the metal oxide film, A conductive film is formed on top of the insulating film, A method for manufacturing a semiconductor device, comprising removing a portion of the metal oxide film, a portion of the insulating film, and a portion of the conductive film until the upper surface of the insulator is exposed, thereby forming a second metal oxide layer, an insulating layer, and a conductive layer, Before forming the insulating film, the first metal oxide layer, the metal oxide film, and the insulator are irradiated with microwaves to remove hydrogen from the first metal oxide layer. A method for manufacturing a semiconductor device, comprising the steps of: introducing a first gas containing silicon into a chamber while heating the substrate to 300°C or higher using the PEALD method; and introducing a second gas containing oxygen radicals into the chamber while heating the substrate to 300°C or higher.

3. A first metal oxide layer having a region that will form the channel of the transistor is formed on the substrate. An insulator is formed above the first metal oxide layer. An opening is formed in the insulator that reaches the first metal oxide layer. In the aforementioned opening, a metal oxide film is formed so as to be in contact with the first metal oxide layer. An insulating film is formed on top of the metal oxide film, A conductive film is formed on top of the insulating film, A method for manufacturing a semiconductor device, comprising removing a portion of the metal oxide film, a portion of the insulating film, and a portion of the conductive film until the upper surface of the insulator is exposed, thereby forming a second metal oxide layer, an insulating layer, and a conductive layer, Before forming the insulating film, the first metal oxide layer, the metal oxide film, and the insulator are irradiated with microwaves to release hydrogen trapped in oxygen vacancies within the first metal oxide layer. A method for manufacturing a semiconductor device, comprising the steps of: introducing a first gas containing silicon into a chamber while heating the substrate to 300°C or higher using the PEALD method; and introducing a second gas containing oxygen radicals into the chamber while heating the substrate to 300°C or higher.

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