Semiconductor equipment

Abstract

To provide a semiconductor device having good electrical characteristics. [Solution] A transistor having a gate electrode, a source electrode, and a drain electrode, A first insulator on the transistor, a second insulator on the first insulator, and on the second insulator A third insulator, a first electrode in contact with the upper surface of the source electrode, and a drain electrode in contact with the upper surface The second electrode and the second insulator have a first opening that overlaps with the source electrode and a drain The third insulator has a second opening that overlaps with the electrode, and the first opening and the second opening The first electrode is in contact with the side surface of the second insulator and the upper surface of the first insulator inside the opening, and the first electrode is in contact with the second One electrode is positioned through an opening, and the second electrode is positioned through a second opening.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a transistor, a semiconductor device, and electronic equipment. One aspect of the present invention relates to a method for manufacturing a semiconductor device. Another aspect of the present invention relates to a semiconductor wafer , and regarding modules.

[0002] In this specification, a semiconductor device refers to a device that can function by utilizing semiconductor properties. This refers to semiconductor devices in general, including semiconductor elements such as transistors, semiconductor circuits, computing devices, and memory devices. A device is one form of a semiconductor device. Display devices (liquid crystal display devices, light-emitting display devices, etc.), projection Devices, lighting devices, electro-optical devices, energy storage devices, memory devices, semiconductor circuits, imaging devices, electronic equipment Some devices, such as those mentioned above, can be said to possess semiconductor devices.

[0003] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. One aspect of the present invention relates to a product, method, or method of manufacture. Another aspect of the present invention is , process, machine, manufacture, or composition of matter This concerns (—). [Background technology]

[0004] In recent years, the development of semiconductor devices has progressed significantly, with particularly notable advancements in LSIs, CPUs, and memory. It is being developed. The CPU is a semiconductor integrated circuit (at least) separated from the semiconductor wafer. A collection of semiconductor elements having transistors and memory, and electrodes that serve as connection terminals. It is the body.

[0005] Semiconductor circuits (IC chips) such as LSIs, CPUs, and memory are mounted on circuit boards, for example. It is mounted on a printed circuit board and used as one of the components in various electronic devices.

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

[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 Initiative] [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 aims to provide a semiconductor device with good reliability. Alternatively, one aspect of the present invention aims to provide a semiconductor device with a large on-current. This may be one of the topics. Alternatively, one aspect of the present invention relates to a semiconductor with less variation in transistor characteristics. One objective of the present invention is to provide a body device. Alternatively, one aspect of the present invention relates to miniaturization or high concentration. One of the objectives is to provide a semiconductor device that can be integrated. Alternatively, one aspect of the present invention is One of the objectives is to provide a semiconductor device with low power consumption. Or, one aspect of the present invention One of its objectives is to provide a method for manufacturing semiconductor devices with high productivity.

[0011] 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]

[0012] One aspect of the present invention comprises a gate electrode, a gate insulating film, a source electrode, and a drain electrode. A transistor having a first insulator on the transistor and a second insulator on the first insulator The edge body, the third insulator on the second insulator, the first electrode in contact with the upper surface of the source electrode, and It has a second electrode in contact with the upper surface of the rain electrode, and the second insulator overlaps with the source electrode. The third insulator has a first opening and a second opening that overlaps with the drain electrode, and the first The opening, the side of the second insulator inside the second opening, and the top surface of the first insulator The first electrode is in contact with the first opening, and the second electrode is positioned through the second opening. It is a semiconductor device arranged in a continuous manner.

[0013] Furthermore, in the above, the first insulator has a first groove that overlaps the first opening and a second opening It is preferable to have a second groove portion that overlaps the opening portion.

[0014] Furthermore, in the above, the side surface of the first electrode is in the first opening and the first groove. The second electrode is in contact with the third insulator, and the side surface of the second electrode is in contact with the second opening and the second groove. It may also be in contact with a third insulator.

[0015] Furthermore, in the above, the fourth insulator provided in contact with the side surface of the first electrode and the second electrode It has a fifth insulator provided in contact with the side surface of the pole, and the side surface of the fourth insulator is the first open In the opening and the first groove, the third insulator is in contact with the side surface of the fifth insulator, which is the second It is preferable that the opening and the second groove are in contact with the third insulator.

[0016] Furthermore, in the above, it is preferable that the second insulator contains aluminum oxide. Furthermore, in the above, the first insulator includes silicon oxide, and the third insulator is silicon It is preferable that it contains a nitride. Furthermore, in the above, the transistor is an oxide semiconductor layer The oxide semiconductor layer is made of one or more selected from In, Ga, or Zn. It is preferable to have multiple of them.

[0017] Furthermore, in the above, a gate insulating film, a source electrode, and a drain are placed on the oxide semiconductor layer. An in electrode is provided, and a gate electrode is provided on the gate insulating film, and the first insulator is a so An opening is formed superimposed in the region between the gate electrode and the drain electrode, and the gate insulating film It is preferable that the gate electrode is positioned within the opening.

[0018] Furthermore, in the above, the sixth covering the oxide semiconductor layer, source electrode, and drain electrode The insulator has a sixth insulator superimposed on the region between the source electrode and the drain electrode, and Preferably, an opening is formed, and the first insulator is provided on top of the sixth insulator. Furthermore, in the above, it is preferable that the sixth insulator includes silicon nitride.

[0019] Furthermore, in the above, the first insulator and the second insulator are formed in an island shape. Preferably, the third insulator covers the first insulator and the second insulator.

[0020] Furthermore, in the above, the second insulator is the gate electrode, source electrode, and drain electrode. In a region that does not overlap with the third, there is a third opening, and the third insulator is inside the third opening. The side surface of the insulator and the upper surface of the first insulator may be in contact with each other.

[0021] Another aspect of the present invention is a transistor having a source electrode and a drain electrode. And, above the source electrode and drain electrode, a first insulator is formed, and on the first insulator A second insulator containing aluminum oxide is deposited on the second insulator, and the source electrode and heavy A first opening is formed that overlaps with the drain electrode, and a second opening is formed that overlaps with the drain electrode, and the first insulation A third insulator is formed on the body and the second insulator, and a first opening is formed on the third insulator. A fourth insulator is formed to be embedded in the area overlapping with the part and the second opening, and the first The insulator, the third insulator, and the fourth insulator have a third opening that reaches the source electrode, and A fourth opening is formed that reaches the drain electrode, and the third opening is, in a top view, the first The fourth opening is located inside the opening of the first opening, and in a top view, the fourth opening is located inside the second opening. The semiconductor forms the first electrode in the third opening and the second electrode in the fourth opening. This describes the method for manufacturing the body device.

[0022] Furthermore, in the above, the first insulator and the fourth insulator contain silicon oxide. The third insulator preferably contains silicon nitride.

[0023] Furthermore, in the above, the formation of the third and fourth openings is carried out by a gas containing fluorine. It is preferable to carry out the process using the dry etching method employed.

[0024] Another aspect of the present invention involves forming a second insulator on a first insulator, and the second insulator An oxidation having one or more selected from In, Ga, or Zn on its surface. A semiconductor layer is formed, and an oxide semiconductor layer is produced by a dry etching method using a gas containing CH4. The conductive layer is processed into an island shape, and the second is created by a dry etching method using a halogen-containing gas. A method for manufacturing a semiconductor device, which involves processing an insulator into an island shape and exposing the upper surface of the first insulator. ru.

[0025] Furthermore, in the above, the first insulator contains hafnium oxide, and the second insulator contains shi It is preferable that it contains lycon oxide.

[0026] Furthermore, in the above, after processing the second insulator into an island shape, the first insulator and the second insulator A third insulator is formed by covering the body and the oxide semiconductor layer, and the third insulator is silicon It is preferable that the product contains a nitride.

[0027] Furthermore, in the above, a hard mask containing tungsten is formed on the oxide semiconductor layer. Furthermore, it is preferable to process the oxide semiconductor layer into an island shape using the hard mask. [Effects of the Invention]

[0028] 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 with good reliability can be provided. Alternatively, according to one aspect of the present invention, a semiconductor device with a large on-current can be provided. Alternatively, according to one aspect of the present invention, a semiconductor device with less variation in transistor characteristics is provided. This is possible. Alternatively, according to one aspect of the present invention, a semiconductor that can be miniaturized or highly integrated can be produced. An apparatus can be provided. Or, according to one aspect of the present invention, a low-power semiconductor device can be provided. This can provide a semiconductor device with good productivity. Alternatively, according to one aspect of the present invention, a semiconductor device can be manufactured. We can provide a manufacturing method.

[0029] 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]

[0030] [Figure 1] Figure 1A is a top view of a semiconductor device according to one embodiment of the present invention. Figures 1B to 1D are cross-sectional views of a semiconductor device according to one embodiment of the present invention. [Figure 2] Figures 2A to 2D are cross-sectional views of a semiconductor device according to one embodiment of the present invention. [Figure 3] Figure 3 is a cross-sectional view of a semiconductor device according to one aspect of the present invention. [Figure 4] Figure 4A illustrates the classification of IGZO crystal structures. Figure 4B illustrates the XRD spectrum of a CAAC-IGZO film. Figure 4C illustrates the micro-electron diffraction pattern of a CAAC-IGZO film. [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 to 5D 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 to 6D 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 to 7D 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 to 8D 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 to 9D 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 to 10D 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 to 11D 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 to 12D 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 to 13D 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 to 14D 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 showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 15B to 15D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 16] Figure 16A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 16B to 16D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 17] Figure 17A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 17B to 17D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 18] Figure 18A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 18B to 18D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 19] Figure 19A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 19B to 19D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 20] Figure 20A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 20B to 20D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 21] Figure 21A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 21B to 21D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 22] Figure 22A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 22B to 22D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 23] Figure 23A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 23B to 23D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 24] Figure 24A is a top view showing a method for manufacturing a semiconductor device according to one aspect of the present invention. Figures 24B to 24D are cross-sectional views showing a method for manufacturing a semiconductor device according to one aspect of the present invention. [Figure 25] Figure 25 is a schematic diagram showing a model of the dry etching process of In-Ga-Zn oxide. [Figure 26] Figure 26 is a top view illustrating a microwave processing apparatus according to one aspect of the present invention. [Figure 27] Figure 27 is a cross-sectional view illustrating a microwave processing apparatus according to one aspect of the present invention. [Figure 28] Figure 28 is a cross-sectional view illustrating a microwave processing apparatus according to one aspect of the present invention. [Figure 29] Figure 29 is a cross-sectional view illustrating a microwave processing apparatus according to one aspect of the present invention. [Figure 30] Figure 30A is a top view of a semiconductor device according to one embodiment of the present invention. Figure 30B is a cross-sectional view of a semiconductor device according to one embodiment of the present invention. [Figure 31] Figure 31A is a top view of a semiconductor device according to one embodiment of the present invention. Figure 31B is a cross-sectional view of a semiconductor device according to one embodiment of the present invention. [Figure 32] Figure 32A is a top view of a semiconductor device according to one embodiment of the present invention. Figure 32B is a cross-sectional view of a semiconductor device according to one embodiment of the present invention. [Figure 33]Figure 33A is a top view of a semiconductor device according to one embodiment of the present invention. Figures 33B and 33C are cross-sectional views of a semiconductor device according to one embodiment of the present invention. [Figure 34] Figure 34 is a cross-sectional view showing the configuration of a storage device according to one aspect of the present invention. [Figure 35] Figure 35 is a cross-sectional view showing the configuration of a storage device according to one aspect of the present invention. [Figure 36] Figure 36 is a cross-sectional view of a semiconductor device according to one aspect of the present invention. [Figure 37] Figures 37A and 37B are cross-sectional views of a semiconductor device according to one aspect of the present invention. [Figure 38] Figure 38 is a cross-sectional view of a semiconductor device according to one aspect of the present invention. [Figure 39] Figure 39A is a block diagram showing an example of the configuration of a storage device according to one aspect of the present invention. Figure 39B is a schematic diagram showing an example of the configuration of a storage device according to one aspect of the present invention. [Figure 40] Figures 40A to 40H are circuit diagrams showing an example of the configuration of a storage device according to one aspect of the present invention. [Figure 41] Figure 41A is a block diagram of a semiconductor device according to one aspect of the present invention. Figure 41B is a schematic diagram of a semiconductor device according to one aspect of the present invention. [Figure 42] Figures 42A and 42B illustrate an example of an electronic component according to one aspect of the present invention. [Figure 43] Figures 43A to 43E are schematic diagrams of a storage device according to one aspect of the present invention. [Figure 44] Figures 44A to 44H show an electronic device according to one aspect of the present invention. [Modes for carrying out the invention]

[0031] 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.

[0032] 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, layers or resist masks are removed through processes such as etching. While some figures may decrease without being shown in the diagram, this is sometimes omitted to facilitate understanding. Furthermore, in drawings, the same reference numeral is used for identical parts or parts having similar functions, but different numerals are used for different parts. It is used in common across different surfaces, and explanations of its repetition may be omitted. Also, similar functions may be indicated. In such cases, the hatch pattern may be the same, and no specific designation may be assigned.

[0033] Furthermore, the understanding of the invention is particularly important in top views (also called "plan views") or perspective views. For ease of understanding, descriptions of some components may be omitted. Also, some hidden lines, etc. The description may be omitted in some cases.

[0034] 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.

[0035] 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.

[0036] Furthermore, in this specification, etc., if it is explicitly stated that X and Y are connected, The cases are when X and Y are electrically connected and when X and Y are functionally connected. The cases disclosed in this specification, etc., include the case where X and Y are directly connected. Therefore, it is not 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, as disclosed in the diagram or text, are also included. Let's assume that X and Y are the objects (for example, devices, elements, circuits, wiring, electrodes, terminals, etc.). Assume it is a conductive film, layer, etc.

[0037] Furthermore, in this specification, the term "transistor" includes a gate, a drain, and a source. It is an element having at least three terminals. And, drain (drain terminal, drain Between the drain region (or drain electrode) and the source (source terminal, source region, or source electrode) It has a region where channels are formed (hereinafter also called the channel-forming region), This design allows current to flow between the source and drain through a flannel-formed region. In this specification, the channel-forming region refers to the region through which electric current primarily flows.

[0038] Furthermore, if a transistor with a different polarity than that described in the specification or drawings is used, In circuit operation, when the direction of current changes, the source and drain of each The functions may be interchangeable. For this reason, in this specification, etc., source and drain The terms "n" and "n" can sometimes be substituted depending on the context.

[0039] Note that channel length refers to, for example, the length of the semiconductor (or transistor) in a top view of a transistor. When the inverter is ON, the part of the semiconductor through which current flows and the gate electrode overlap each other. In the region or channel-forming region, the source (source region or source electrode) and This refers to the distance between the drain (drain region or drain electrode) and the other terminal. In a zista, the channel length is not necessarily the same across all regions. That is, one The channel length of the transistor may not be fixed to a single value. Therefore, this specification So, the channel length is any one value, maximum value, minimum value, or This will be the average value.

[0040] Channel width refers to, for example, the top view of a transistor in a semiconductor (or transistor) The region where the gate electrode and the part of the semiconductor through which current flows when the gate electrode is ON overlap each other. Channels in a region or channel-forming region, perpendicular to the channel length direction. This refers to the length of the formation region. Note that in a single transistor, the channel width encompasses the entire region. They do not necessarily take the same value. In other words, the channel width of a single transistor is a single value. It may not be fixed. Therefore, in this specification, the channel width is defined as the channel formation region. This is one of the values, the maximum value, the minimum value, or the average value.

[0041] In this specification, depending on the transistor structure, channel formation may actually occur. The channel width in the region (hereinafter also referred to as the "effective channel width") and the transition The channel width shown in the top view of the stylus (hereinafter also referred to as the "apparent channel width") is as follows. ) and may differ. For example, when the gate electrode covers the side of the semiconductor, the effective ch When the channel width becomes larger than the apparent channel width, and its effect can no longer be ignored. For example, in a transistor that is very small and whose gate electrode covers the side of the semiconductor, the semiconductor In some cases, the proportion of channel-forming regions formed on the sides may increase. In such cases, the apparent The effective channel width will be larger than the channel width shown above.

[0042] 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.

[0043] 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.

[0044] 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... In some cases, the defect level density of a semiconductor may increase, or its crystallinity may decrease. Yes, there are. When the semiconductor is an oxide semiconductor, examples of impurities that alter the properties of the semiconductor include: For example, Group 1 elements, Group 2 elements, Group 13 elements, Group 14 elements, Group 15 elements, oxides, etc. Other components besides the main component of conductors include transition metals, such as hydrogen, lithium, sodium, and silicon. These include ions, boron, phosphorus, carbon, and nitrogen. Note that water can also function as an impurity. Furthermore, for example, the inclusion of impurities can cause oxygen vacancies (V) in oxide semiconductors. O :oxygen A vacancy (also called a vacancy) may form.

[0045] In this specification, an oxidized nitride is defined as a compound whose composition contains more oxygen than nitrogen. It is present in large quantities. For example, silicon oxidnitride, in its composition, has more oxygen than nitrogen. The content is high. Also, nitride oxides, in terms of their composition, have a higher nitrogen content than oxygen. For example, silicon nitride has a nitrogen content that is higher than oxygen content in its composition. many.

[0046] 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.

[0047] 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" means that two straight lines are positioned at an angle of -30 degrees or more and 30 degrees or less. It refers to a state or position. Also, "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 in which the temperature is between 85 and 95 degrees. Therefore, it also includes cases between 85 and 95 degrees. "Perpendicular" refers to a state where two straight lines are positioned at an angle between 60 degrees and 120 degrees.

[0048] 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 . ) For example, when a metal oxide is used in the semiconductor layer of a transistor, The metal oxide in question is sometimes referred to as an oxide semiconductor. Therefore, it is sometimes described as an OS transistor. In such cases, it can be rephrased as a transistor having a metal oxide or oxide semiconductor. It is possible.

[0049] Furthermore, in this specification, normally off means not applying a potential to the gate, or When the gate is given a ground potential, the amount of drain flowing through the transistor per 1 μm of channel width is The current is 1 × 10 at room temperature. -20 A or less, 1 × 10 at 85℃ -18 Below A , or 1 × 10 at 125℃ -16 This means being less than or equal to A.

[0050] (Embodiment 1) In this embodiment, Figures 1 to 33 illustrate an example of a semiconductor device according to one aspect of the present invention. This document describes the method for producing the same.

[0051] One aspect of the present invention is a semiconductor comprising, for example, a plurality of transistors having oxide semiconductor layers. A device can be provided. A transistor using an oxide semiconductor layer is an oxide semiconductor. If impurities and oxygen vacancies are present in the region where channels are formed within the layer, the electrical properties will change. This can easily lead to poor reliability. Also, hydrogen near the oxygen deficiency can cause hydrogen to enter the oxygen deficiency. A defect (hereinafter referred to as V) O It is sometimes called H. It forms a ) and generates electrons that become carriers. This can occur. Therefore, oxygen vacancies may form in the region where channels are formed in the oxide semiconductor layer. If present, the transistor exhibits normally-on characteristics (no voltage is applied to the gate electrode). This is because a channel exists and current flows through the transistor. In the region where channels are formed in the ion semiconductor layer, impurities, oxygen vacancies, and V O H is It is preferable that the channels in the oxide semiconductor layer are reduced as much as possible. In other words, the channels in the oxide semiconductor layer are The formed region has a reduced carrier concentration and is type i (true) or substantially type i. It is preferable.

[0052] In contrast, near the oxide semiconductor layer, oxygen that is desorbed by heating (hereinafter referred to as excess oxygen and (It may be called this.) By providing an insulator containing and heat-treating it, oxide semi-oxides are obtained from the insulator. To supply oxygen to the conductive layer, oxygen deficiency, and V O H can be reduced.

[0053] However, the channel formation region of the oxide semiconductor layer and its vicinity (for example, channel formation) If an excess amount of oxygen is supplied to the interface between the region and the gate insulating film, the electrical properties will change. Deterioration of performance (e.g., excessive normally-off of transistors), or deterioration of reliability. This may occur. Also, if an excessive amount of oxygen is supplied to the source or drain region... This can cause a decrease in the transistor's on-current or a decrease in its field-effect mobility. Furthermore, variations in the supplied oxygen within the substrate surface affect the transistor's electrical characteristics. There is a risk of gender variability.

[0054] Therefore, in the oxide semiconductor layer, there is a region that functions as a channel formation region, and It is preferable that sufficient oxygen is supplied in the vicinity of it, but conversely, if an excessive amount of oxygen is supplied... It is preferable to prevent this from happening.

[0055] Therefore, in the semiconductor device shown in this embodiment, an insulating material containing oxygen that is desorbed by heating is used. When diffusing oxygen from the edge material into the oxide semiconductor layer, at the same time, oxygen is released outward from the insulator. The configuration is designed to allow diffusion. This will allow the oxide to escape from the insulator containing oxygen that is released by heating. In the semiconductor layer, the region that functions as a channel-forming region, and its vicinity, sufficient oxygen is provided. It is possible to supply oxygen while ensuring that an excessive amount is not supplied.

[0056] <Example of semiconductor device configuration> An example of the configuration of a semiconductor device having a transistor 200 will be explained using Figures 1A to 1D. Figure 1A is a top view of the semiconductor device. Figures 1B to 1D are also shown. This is a cross-sectional view of the device. Here, Figure 1B is a cross-section of the area indicated by the dashed line A1-A2 in Figure 1A. This is a top view and also a cross-sectional view of transistor 200 in the channel length direction. Figure 1C is also a top view. Figure 1A is a cross-sectional view of the area indicated by the dashed line A3-A4, showing the channel of transistor 200. This is also a cross-sectional view in the width direction. Furthermore, Figure 1D shows the area indicated by the dashed line A5-A6 in Figure 1A. This is a cross-sectional view, and also a cross-sectional view of transistor 200 in the channel width direction. Note that Figure 1A In the top view, some elements have been omitted for clarity.

[0057] 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, and insulator 282 on insulator 280 (insulator 282a, and insulator 282 b) an insulator 283 on the insulator 282, an insulator 286 on the insulator 283, and a sealing portion 2 It has an insulator 274 on 65, insulator 212, insulator 214, insulator 280, insulation Body 282, insulator 283, insulator 286, and insulator 274 function as interlayer films. The insulator 280 is an insulator containing oxygen that is released by the heating described above, and transistor 20 Oxygen can be supplied to the oxide semiconductor layer of 0. The sealing portion 265 has multiple traps The inverter 200, insulator 216, insulator 280, and insulator 282 are surrounded by a structure. It is being sealed. In the sealing portion 265, the insulator 283 is in contact with the upper surface of the insulator 214.

[0058] [Aperture area 400] A semiconductor device according to one aspect of the present invention is electrically connected to the conductor 242a of the transistor 200. The conductor 240a functions as a plug, and the conductor 242b of the transistor 200 and the electric It has a conductive 240b that is electrically connected and functions as a plug. Here, as a plug In the vicinity of the conductor 240a which functions, the insulators 280 and 282 have an opening region 40 0a is provided, and similarly, near the conductor 240b, insulators 280 and 282 An opening region 400b is provided therein. As shown in Figure 1B and other figures, the opening region 400a is a conductor It overlaps with 242a, and the opening region 400b overlaps with the conductor 242b. Also, as a plug, An insulator 241a is provided in contact with the side surface of the conductive material 240a, and similarly, the conductive material 240 An insulator 241b is provided in contact with the side surface of b. Also, an insulator 286 and a conductor 240 A conductor 246a is provided on a, which is electrically connected to the conductor 240a and functions as wiring. Similarly, on the insulator 286 and the conductor 240b, there are electrically connected conductors 240b. Next, a conductor 246b that functions as wiring is provided. Also, on the upper surface of the conductor 242a An insulator 271a is provided in contact with the conductor 242b, and an insulator 271b is provided in contact with the upper surface of the conductor 242b. Also, conductor 242a, conductor 242b, insulator 271a, and insulator 271 An insulator 272 is provided so as to cover b.

[0059] In the following, conductors 242a and 242b will be collectively referred to as conductor 242. There are cases where conductor 240a and conductor 240b are collectively referred to as conductor 240. There is also the case where the opening region 400a and the opening region 400b are collectively referred to as the opening region 400. There are cases where insulators 241a and 241b are collectively referred to as insulator 241. Yes, there are cases where conductors 246a and 246b are collectively referred to as conductor 246. Furthermore, insulators 271a and 271b are sometimes collectively referred to as insulator 271.

[0060] Insulator 212, insulator 214, insulator 271, insulator 272, insulator 282, and insulating At least one of the edge members 283 is protected from impurities such as water and hydrogen entering from the substrate side or from the transition As a barrier insulating film that suppresses diffusion from above to transistor 200, It is preferable that it be able to do so. Therefore, insulator 212, insulator 214, insulator 271, insulation At least one of body 272, insulator 282, and insulator 283 contains hydrogen atoms, hydrogen molecules, Water molecules, nitrogen atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), copper atoms, etc. Using an insulating material that has the function of suppressing the diffusion of impurities (i.e., the above impurities do not easily permeate) It is preferable to use oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable to use an insulating material that has a function to suppress diffusion (i.e., one that is less permeable to the above-mentioned oxygen). It's nice.

[0061] In this specification, a barrier insulating film refers to an insulating film that has barrier properties. In this specification, barrier properties refer to the function of suppressing the diffusion of the corresponding substance (low permeability). It also refers to the act of capturing and fixing a corresponding substance (gettering). This refers to the function of (also known as) insulator 212, insulator 272, and insulator 28 As for point 3, it is preferable to use an insulating film that has a higher function of suppressing hydrogen diffusion. For example, as insulators 214, 271, and 282, hydrogen is captured and It is preferable to use an insulating film that has a high ability to fix hydrogen.

[0062] Here, Figure 2A shows an enlarged cross-sectional view of the vicinity of the conductor 240, as shown in Figure 1B, etc. Also, Figure 2 Figure 2B shows an enlarged cross-sectional view of the configuration shown in A, before the conductor 240 is formed. Figures 2A and 2B are drawings corresponding to both conductor 240a and conductor 240b. It is.

[0063] As shown in Figure 2B, the insulator 282 has an opening in the opening region 400. In the opening region 400, the insulator 280 overlaps the opening of the insulator 282, and the groove portion It may have. The depth of the groove in the insulator 280 is such that the upper surface of the insulator 272 is exposed at most. It is sufficient to reduce it to a thickness of approximately 1 / 4 to 1 / 2 of the maximum film thickness of the insulator 280. That's all you need to do.

[0064] Such an opening region 400 is formed, and the insulator 280 is exposed through the opening in the insulator 282. By performing a heat treatment in this state, oxygen is introduced into the oxide semiconductor layer of transistor 200. While supplying oxygen, a portion of the oxygen contained in the insulator 280 is diffused outward from the opening region 400. This allows for the removal of oxide semi-oxides from the insulator 280 containing oxygen that is released by heating. In the conductive layer, the region that functions as a channel-forming region, and its vicinity, are supplied with sufficient oxygen. It is possible to supply oxygen while ensuring that an excessive amount is not supplied.

[0065] At this time, the hydrogen contained in the insulator 280 combines with oxygen and, through the opening region 400 It can be released to the outside. Hydrogen combined with oxygen is released as water. Therefore, The hydrogen contained in the insulator 280 is reduced, and the hydrogen contained in the insulator 280 is reduced in transistor 2 This can reduce the amount of 00 that gets mixed into the oxide semiconductor layer.

[0066] Furthermore, as shown in Figure 1A, the opening region 400a and the opening region 400b are respectively guided It is positioned on the electrode 242a and the conductor 242b, and is the gate of transistor 200 They are arranged in approximately line symmetry with respect to the axis of symmetry. Therefore, the oxide of transistor 200 Approximately equal amounts of oxygen can be supplied to the semiconductor layer from the source and drain sides. As a result, in the channel formation region of transistor 200, the source side and the drain side This can prevent large imbalances in the amount of oxygen deficiency.

[0067] As shown in Figure 2B and other figures, the insulator 283 is inside the opening region 400, and the insulator 282 It is in contact with the side surface, the side surface of the insulator 280, and the top surface of the insulator 280. Also, as shown in Figure 2B... Before the conductor 240 was formed, the insulator 283 was formed within the opening region 400. In some cases, a portion of the insulator 274 may be formed to fill the recess. (See Figure 2B) As shown, the upper surface of insulator 274 and the upper surface of insulator 283 may roughly coincide. .

[0068] As shown in Figure 2A, the conductor 240 is positioned to penetrate the opening region 400. In contrast, the conductor 240 is positioned through the opening of the insulator 282, and further insulator 2 It is provided penetrating the bottom of the groove 80. As shown in Figure 2A, the width of the opening region 400 is If the width is not sufficiently large compared to the width of the conductor 240, an opening is formed to embed the conductor 240. In this process, the insulator 274 is almost completely removed. In this case, in the opening region 400, The side surface of insulator 241 will be in contact with insulator 283.

[0069] In this way, the opening region 400 and the conductor 240 which functions as a plug are, when viewed from above By stacking and forming them, the occupied area of ​​the transistor 200 is not greatly increased. A region 400 can be provided. This allows multiple transistors 200 to be arranged at high density. Even with the established design, the placement of transistor 200 will be changed to create surplus space. An opening region 400 can be provided without this. By adopting this configuration, miniaturization Alternatively, it is possible to provide a semiconductor device that can be highly integrated.

[0070] Furthermore, in the above configuration, the insulator 241 is provided in contact with the side surface of the conductor 240. As shown above, the present invention is not limited thereto. For example, as shown in Figure 2C, The insulator 241 may not be provided on the side surface of the electric body 240. In this case, the insulator 280 It is preferable that the excess amount of oxygen or other impurities such as hydrogen contained in the product be sufficiently reduced. Here, the side surface of the conductor 240 is the opening region 400 (the opening of the insulator 282, and This can also be described as the groove portion of the insulator 280.) It is in contact with the insulator 283. By using this configuration, most of the side surface of the conductor 240 is covered with the insulator 283, and insulation Because the excess amount of oxygen or other impurities such as hydrogen in the body has been sufficiently reduced, oxygen This can also suppress the incorporation of impurities such as hydrogen into the conductor 240.

[0071] Furthermore, in the above configuration, the insulator 283 is provided in contact with the side surface of the insulator 241. As shown above, the present invention is not limited thereto. For example, as shown in Figure 2D, The insulator 274 remains within the mouth region 400, and the insulator 274 is in contact with the side surface of the insulator 241. In some cases, the width of the opening area 400 (the width of the opening of the insulator 282, and the insulator This can also be rephrased as the width of the 280 grooves.) This width is significantly larger than the width of the conductor 240. By providing an opening region 400 as shown above, sufficient space is available for the opening into which the conductor 240 is embedded. You can leave a margin.

[0072] Furthermore, in Figure 1A, the shapes of the opening region 400a and the opening region 400b in a top view. The shape is generally square, but the present invention is not limited to this. For example, an opening region The shapes of region 400a and the opening region 400b in top view are rectangular, elliptical, circular, and diamond. The shape may be a combination of these shapes. Also, the opening region 400a and the opening The size of region 400b is set appropriately according to the design of the semiconductor device including transistor 200. It can be determined.

[0073] [Transistor 200] As shown in Figures 1A to 1D, the transistor 200 is located on the insulator 214. 6 and a conductor 205 (conductor 205a, conductor) arranged to be embedded in the insulator 216. The insulating material 205b and the conductor 205c, and the insulating material on the insulator 216 and the insulating material on the conductor 205 Edge body 222, insulator 224 on insulator 222, oxide 230a on insulator 224, Oxide 230b on oxide 230a and oxide 243(oxide 243 a) and oxide 243b), conductor 242a on oxide 243a, and conductor 242a The upper insulator 271a, the conductor 242b on the oxide 243b, and the insulating on the conductor 242b Body 271b, insulator 250a on oxide 230b, and insulator 250 on insulator 250a b and a conductor 260 (conductor) located on the insulator 250b and overlapping with a portion of the oxide 230b. 260a, and conductor 260b), insulator 224, oxide 230 (oxide 230a, and oxide 230b), oxide 243, conductor 242 (conductor 242a, and conductor 242b), positioned to cover the insulator 271 (insulators 271a and 271b). It has an insulator 272, which is made of an insulator 27 2 has a region that is in contact with a part of the upper surface of the insulator 222. Also, the upper surface of the conductor 260 is It is positioned so as to be approximately in line with the top surface of the insulator 250 and the top surface of the insulator 280. Body 282 is in contact with the upper surfaces of the conductor 260, the insulator 250, and the insulator 280, respectively. ru.

[0074] In the following, oxides 230a and 230b will be collectively referred to as oxide 230. There are cases where insulator 250a and insulator 250b are collectively referred to as insulator 250. There is.

[0075] The insulator 280 and the insulator 272 are provided with openings that reach the oxide 230b. An insulator 250 and a conductor 260 are placed within the opening. In the channel length direction of TA200, insulator 271a, conductor 242a and oxide 24 3a, insulator 271b, conductor 242b and oxide 243b, and conductor 260 , and an insulator 250 is provided. The insulator 250 is located on the side of the conductor 260, and It is in contact with the bottom surface of the conductor 260.

[0076] Conductor 260 functions as the first gate (also called the top gate) electrode, and conductor 2 05 functions as a second gate (also called a back gate) electrode. Also, insulator 25 0 acts as the first gate insulating film, and insulators 222 and 224 act as the second gate insulating film. It functions as a gate insulating film. Also, the conductor 242a is either a source electrode or a drain electrode. It functions as one of the two electrodes, and the conductor 242b functions as the other of the source electrode or drain electrode. It is possible. Also, at least a portion of the region of the oxide 230 that overlaps with the conductor 260 is a channel. It functions as a formation region.

[0077] Transistor 200 includes an oxide 230 (oxide 230a, and A metal oxide (hereinafter also called an oxide semiconductor) that functions as a semiconductor (230b) is added to the oxide. It is preferable to use .

[0078] Furthermore, metal oxides that function as semiconductors have a band gap of 2 eV or more, preferably It is preferable to use gold with a band gap of 2.5 eV or higher. By using a specific oxide, the off-current of the transistor can be reduced.

[0079] For example, In-M-Zn, which has indium, element M, and zinc as oxide 230. Oxides (elements M include aluminum, gallium, yttrium, tin, copper, vanadium, and beryllium) Rium, boron, titanium, iron, nickel, germanium, zirconium, molybdenum, ra Tantalum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium It is preferable to use one or more metal oxides selected from among others. For 230, In-Ga oxide, In-Zn oxide, or indium oxide may be used. .

[0080] Here, the atomic ratio of In to element M in the metal oxide used for oxide 230b However, the atomic ratio of In to element M in the metal oxide used in oxide 230a is larger It is preferable.

[0081] In this way, by placing oxide 230a below oxide 230b, oxide 230a Spread of impurities and oxygen to oxide 230b from structures formed below It can suppress dispersion.

[0082] Furthermore, oxides 230a and 230b have a common element other than oxygen (main component By (using this method), the defect level density at the interface between oxide 230a and oxide 230b is reduced. This can be done. The defect level density at the interface between oxide 230a and oxide 230b can be reduced. Because this can be achieved, the influence of interfacial scattering on carrier conduction is small, resulting in a high on-current. You can obtain this.

[0083] Furthermore, it is preferable that oxide 230b has crystalline properties. In particular, CAAC-OS(c-axis aligned crystalline oxi It is preferable to use a semiconductor.

[0084] CAAC-OS has a highly crystalline, dense structure, and is free from impurities or defects (for example) Oxygen deficiency (V O It is a metal oxide with few (etc.). In particular, after the formation of the metal oxide, Heat treatment at a temperature that does not cause polycrystalline formation of the metal oxide (for example, between 400°C and 600°C). By doing this, CAAC-OS can be made to have a more crystalline and dense structure. In this way, by increasing the density of CAAC-OS, impurities in the CAAC-OS can be reduced. The diffusion of substances or oxygen can be further reduced.

[0085] On the other hand, CAAC-OS is difficult to identify clear grain boundaries, so it is difficult to identify grain boundaries. It can be said that a decrease in electron mobility due to CAAC-OS is less likely to occur. Metal oxides have stable physical properties. Therefore, metal oxides having CAAC-OS are resistant to heat and have high reliability.

[0086] In addition, oxides having crystallinity such as CAAC-OS have few impurities or defects (such as oxygen deficiencies) and have a highly crystalline and dense structure. Therefore, it is possible to suppress the extraction of oxygen from the oxide 230b by the source electrode or the drain electrode. As a result, even when heat treatment is performed, the extraction of oxygen from the oxide 230b can be reduced. Therefore, the transistor 200 is stable against high temperatures (so-called thermal budget) in the manufacturing process.

[0087] Next, an enlarged view of the vicinity of the channel formation region in FIG. 1B is shown in FIG. 3. As shown in FIG. 3, the oxide 230b has a region 230 bc that functions as the channel formation region of the transistor 200, and regions 230ba and 230bb that are provided so as to sandwich the region 230bc and function as a source region or a drain region. The region 230bc has at least a part that overlaps with the conductor 260. In other words, the region 230bc is provided in the region between the conductor 242 a and the conductor 242b. The region 230ba is provided so as to overlap with the conductor 242a, and the region 230bb is provided so as to overlap with the conductor 242b.

[0088] The region 230bc that functions as the channel formation region has fewer oxygen deficiencies or lower impurity concentrations than the regions 230ba and 230 bb, and therefore is a high-resistance region with a low carrier concentration. In addition, the regions And region 230bb has a high oxygen deficiency or a high concentration of impurities such as hydrogen, nitrogen, or metal elements, which increases the carrier concentration and reduces the resistance. That is, regions 230ba and region 230bb have a higher carrier concentration and are lower-resistance regions compared to region 230bc. That is, regions 230ba and region 230bb have a higher carrier concentration and

[0089] Here, the carrier concentration of region 230bc that functions as the channel formation region is preferably 18 cm -3 or less, more preferably 17 cm -3 less than, even more preferably less than, even more preferably 16 cm -3 less than, even more preferably 13 cm -3 less than, even more preferably 12 cm -3 less than, even more preferably Although there is no particular limitation on the lower limit value of the carrier concentration of region 230bc that functions as the channel formation region, for example, it can be -9 cm -3 or less.

[0090] In this embodiment, as described above, sufficient oxygen can be supplied to region 230bc and its vicinity from the insulator 280 containing oxygen that desorbs upon heating, and an excessive amount of oxygen can be prevented from being supplied. Also, at this time, the mixing of hydrogen into region 230bc can be suppressed. As a result, oxygen deficiency and VH in region 230bc can be removed O to make region 230bc an i-type or substantially i-type region. Therefore, the variation in the electrical characteristics of transistor 200 can be suppressed, and the reliability can be improved. Also, within the plane of the substrate This helps to suppress variations in the electrical characteristics of transistor 200.

[0091] By using the above configuration, it is possible to provide a semiconductor device with good electrical characteristics. Yes, it is possible. Furthermore, it is possible to provide reliable semiconductor devices. Also, transistors... This makes it possible to provide semiconductor devices with less variation in characteristics.

[0092] Furthermore, between region 230bc and region 230ba or region 230bb, the carrier concentration However, the carrier concentrations in regions 230ba and 230bb are equivalent to or lower than those in regions 230bb. Even if a region is formed with a carrier concentration equivalent to or higher than that of region 230bc Good. In other words, the region in question is between region 230bc and region 230ba or region 230bb. It functions as a junction region. This junction region has hydrogen concentrations in region 230ba and region 23 A hydrogen concentration equivalent to or lower than 0 bb, and equivalent to a hydrogen concentration in the 230 bc region. Or it may be higher than that. Also, the junction region has an oxygen deficiency, region 230b The oxygen deficiency in region a and region 230bb is equivalent to or less than that of region 230bc. This can be equivalent to, or even worse than, oxygen deficiency.

[0093] In Figure 3, regions 230ba, 230bb, and 230bc are oxide 2. An example of formation in 30b is shown, but the present invention is not limited thereto. For example, each of the above regions may be formed not only on oxide 230b but also on oxide 230a. .

[0094] Furthermore, in oxide 230, it can sometimes be difficult to clearly detect the boundaries of each region. The concentrations of metallic elements detected in each region, as well as impurity elements such as hydrogen and nitrogen, are not limited to stepwise changes for each region, and may continuously change within each region. That is, the closer the region is to the channel formation region, the lower the concentrations of metallic elements and impurity elements such as hydrogen and nitrogen may be.

[0095] Also, as shown in FIG. 3, in a cross-sectional view in the channel length direction of the transistor, a groove is formed in a region overlapping with the insulator 250 of the oxide 2 30b, and a part of the insulator 250 may be embedded in the groove. At this time, the insulator 250 is formed in contact with the side walls and the bottom surface of the groove . In this case, it is preferable that the film thickness of the insulator 250 is about the same as the depth of the groove. With such a configuration, even if a damaged region is formed on the surface of the oxide 230b corresponding to the bottom of the opening when forming an opening for embedding the conductor 260 or the like , the damaged region can be removed. Thereby, deterioration of the electrical characteristics of the transistor 200 due to the damaged region can be suppressed.

[0096] In FIG. 3 and the like, the side surface of the opening for embedding the conductor 260 or the like is substantially perpendicular to the surface to be formed of the oxide 230b, including the groove of the oxide 230b, but the present embodiment is not limited to this. For example, the bottom of the opening may have a gentle curved surface and may have a U-shaped shape. Further, for example, the side surface of the opening may be inclined with respect to the surface to be formed of the oxide 230b.

[0097] Also, as shown in FIG. 1C, in a cross-sectional view in the channel width direction of the transistor 200, a curved surface may be provided between the side surface of the oxide 230b and the upper surface of the oxide 230b. That is, The edges of the side surface and the edges of the top surface may be curved (also known as rounded).

[0098] The radius of curvature on the above curved surface is greater than 0 nm, and the oxide 2 in the region overlapping with conductor 242 The thickness of 30b is smaller than the thickness of 30b, or it is smaller than half the length of the region that does not have the curved surface. This is preferable. Specifically, the radius of curvature of the curved surface is greater than 0 nm and less than or equal to 20 nm. Preferably, the wavelength is 1 nm to 15 nm, and more preferably 2 nm to 10 nm. By adopting this shape, the insulator 250 and conductor 260 can be connected to the oxide 230b. This can improve the coverage.

[0099] It is preferable that the oxide 230 has a laminated structure of multiple oxide layers with different chemical compositions. Specifically, in the metal oxide used in oxide 230a, the main component is the metal element. The atomic ratio of element M is the main component of the metal oxide used in oxide 230b. It is preferable that the atomic ratio of element M to the group elements is greater. Also, in oxide 230a In the metal oxide used, the atomic ratio of element M to In is used in oxide 230b. It is preferable that the atomic ratio of element M to In in the metal oxide is greater than that of In. In the metal oxide used in oxide 230b, the atomic ratio of In to element M is, The ratio of the number of atoms of In to element M in the metal oxide used in 230a is greater than the atomic ratio of In in the element M. preferable.

[0100] Here, at the junction of oxide 230a and oxide 230b, the lower end of the conduction band is gently curved. It changes. In other words, the lower end of the conduction band at the junction of oxide 230a and oxide 230b is It can also be said that it changes continuously or joins continuously. In order to do this, acid Lowering the defect level density of the mixed layer formed at the interface between the oxide 230a and the oxide 230b good.

[0101] Specifically, oxide 230a and oxide 230b share a common element as their main component, in addition to oxygen. By having this, a mixed layer with a low defect level density can be formed. For example, oxide 2 If 30b is In-M-Zn oxide, then oxide 230a is In-M-Zn oxide, Even when using M-Zn oxide, oxide of element M, In-Zn oxide, indium oxide, etc. good.

[0102] Specifically, for oxide 230a, In:M:Zn = 1:3:4 [atomic ratio] or This refers to the composition in its vicinity, or In:M:Zn=1:1:0.5 [atomic ratio] or its vicinity. A metal oxide with a similar composition can be used. Also, as oxide 230b, In:M:Zn = A composition of 1:1:1 [atomic ratio] or close to it, or In:M:Zn=4:2:3 [ Atomic ratios, or compositions in their vicinity, or In:M:Zn=5:1:3 [atomic ratio] Alternatively, a metal oxide with a composition in the vicinity of the desired atom may be used. Note that the nearby composition refers to the composition of the desired atom. The numerical ratio is within a range of ±30%. Furthermore, it is preferable to use gallium as element M.

[0103] Furthermore, when depositing metal oxides by sputtering, the above atomic ratio is used for the deposition of the film. Not limited to the atomic ratio of the metal oxides, the sputtering target used for depositing metal oxide films The atomic ratio of the set may also be acceptable.

[0104] By configuring oxide 230a and oxide 230b as described above, oxide 230a and acid The defect level density at the interface with compound 230b can be reduced. Therefore, the interface dispersion The influence of disturbances on carrier conduction is reduced, and transistor 200 has a large on current. Higher frequency characteristics can be obtained.

[0105] In transistor 200, oxide 230 is oxide 230a and oxide 23 Although the present invention shows a configuration in which two layers of 0b are stacked, the present invention is not limited to this. For example, the configuration may consist of a single layer of oxide 230b or a laminated structure of three or more layers. Furthermore, oxide 230a and oxide 230b may each have a layered structure. Furthermore, when the oxide 230 is made into a laminated structure of three or more layers, the insulating material is the same as that of the insulator 250. A portion of the laminated structure of the oxide 230 is formed in the openings formed in the body 280 and the insulator 272. It may be formed.

[0106] Insulator 212, insulator 214, insulator 271, insulator 272, insulator 282, and insulating The edge element 283 has the function of suppressing the diffusion of impurities such as water and hydrogen, as well as oxygen. It is preferable to use an insulator, such as aluminum oxide, magnesium oxide, or magnesium oxide. Phenium, gallium oxide, indium gallium zinc oxide, silicon nitride, or nitride acid Silicone can be used. For example, insulator 212, insulator 272, and insulating It is preferable to use silicon nitride or the like as the edge element 283, as it has higher hydrogen barrier properties. Furthermore, for example, insulators 214, 271, and 282 capture hydrogen. And using aluminum oxide or magnesium oxide, which have a high ability to fix hydrogen. It is preferable that this is done so that impurities such as water and hydrogen do not enter the insulator 212 and the insulator 2 Through 14, diffusion from the substrate side to the transistor 200 side can be suppressed. Alternatively, an interlayer insulating film in which impurities such as water and hydrogen are located outside the insulator 283. Therefore, diffusion towards transistor 200 can be suppressed. Alternatively, insulator 2 Oxygen contained in 24, etc., diffuses to the substrate side via insulators 212 and 214. This can be suppressed. Alternatively, oxygen contained in insulator 280, etc., insulator 2 This can suppress diffusion upwards from transistor 200 via components such as 82. In this way, transistor 200 suppresses the diffusion of impurities such as water and hydrogen, as well as oxygen. Insulators 212, 214, 271, 272, and 28 have the function of 2. It is preferable to have a structure in which the structure is surrounded by an insulator 283.

[0107] Here, insulator 212, insulator 214, insulator 271, insulator 272, insulator 282, And as the insulator 283, an oxide having an amorphous structure may be used. In particular, As the edge body 214, insulator 271, and insulator 282, an amorphous oxide is used. It is preferable to use a material. For example, AlO x (x is any number greater than 0), or Mg O y It is preferable to use a metal oxide such as (where y is any number greater than 0). In metal oxides having an amorphous structure, oxygen atoms have dangling bonds. The dangling bond may have the property of capturing or fixing hydrogen. A metal oxide having such an amorphous structure is used as a component of transistor 200. or by providing it around transistor 200, hydrogen contained in transistor 200 Alternatively, it can capture or fix hydrogen present around transistor 200. In particular, capturing or fixing hydrogen contained in the channel formation region of transistor 200 Preferably, a metal oxide having an amorphous structure is used as a component of the transistor 200. By using it, or by placing it around transistor 200, it has good characteristics and reliability. High transistors (200) and semiconductor devices can be fabricated.

[0108] Also, insulator 212, insulator 214, insulator 271, insulator 272, insulator 282, The insulator 283 may be an oxide having an amorphous structure, but may also be partially polycrystalline. A structural region may be formed. Also, insulator 212, insulator 214, insulator 271 Insulators 272, 282, and 283 are amorphous layers and multi-layered It may also be a multilayer structure in which layers of crystalline structures are stacked. For example, layers of amorphous structures A layered structure with a polycrystalline layer formed on top is also acceptable.

[0109] Insulator 212, Insulator 214, Insulator 216, Insulator 271, Insulator 272, Insulator 2 The deposition of films 80, insulator 282, insulator 283, and insulator 286 is, for example, by sputtering. It can be done using the sputtering method. The sputtering method does not require the use of hydrogen as the deposition gas. Insulator 212, Insulator 214, Insulator 216, Insulator 271, Insulator 272, Insulator 2 The hydrogen concentration of insulators 282, 283, and 286 can be reduced. It is possible. Furthermore, the film deposition method is not limited to sputtering; chemical vapor deposition (C) is also an option. VD (Chemical Vapor Deposition) method, molecular beam epitaxy (MBE: Molecular Beam Epitaxy) method, pulsed laser deposition (P LD:Pulsed Laser Deposition) method, atomic layer deposition (ALD:A Methods such as tomic layer deposition may be used as appropriate.

[0110] Furthermore, it is preferable to lower the resistivity of insulators 212 and 283. For example, the resistivity of insulator 212 and insulator 283 is approximately 1 × 10⁻⁶. 13 Ωcm By doing so, in the process of using plasma in the semiconductor device manufacturing process, the insulator 212, and And the insulator 283 is connected to the conductor 205, conductor 242, conductor 260, or conductor 246 Charge-up can sometimes be mitigated. Insulator 212 and Insulator 283 The resistivity is preferably 1 × 10⁻⁶ 10 Ωcm or more, 1 × 10 15 The density should be less than or equal to Ωcm.

[0111] Furthermore, insulators 216, 274, 280, and 286 are insulator 2 A dielectric constant lower than 14 is preferable. By using a material with a low dielectric constant as the interlayer film, wiring The parasitic capacitance that occurs between them can be reduced. For example, insulator 216, insulator 274, Silicon oxide, silicon oxide-nitride, and fluorine are added as the edge body 280 and the insulator 286. Silicon oxide, silicon oxide with added carbon, silicon oxide with added carbon and nitrogen Alternatively, a suitable material such as silicon oxide with voids can be used.

[0112] The conductor 205 is positioned to overlap with the oxide 230 and the conductor 260. Therefore, it is preferable that the conductor 205 be embedded in an opening formed in the insulator 216. In addition, a portion of the conductor 205 may be embedded in the insulator 214.

[0113] The conductor 205 comprises conductor 205a, conductor 205b, and conductor 205c. The conductor 205a is provided in contact with the bottom surface and side wall of the opening. The conductor 205b is It is provided so as to be embedded in a recess formed in the conductor 205a. Here, the conductor 20 The upper surface of 5b is lower than the upper surface of the conductor 205a and the upper surface of the insulator 216. Conductor 2 05c is provided in contact with the upper surface of the conductor 205b and the side surface of the conductor 205a. Thus, the height of the top surface of the conductor 205c is the height of the top of the conductor 205a and the insulator 21 It is approximately the same as the height of the top surface of 6. In other words, conductor 205b is conductor 205a and conductor It will be enclosed in 205c.

[0114] Here, conductors 205a and 205c are hydrogen atoms, hydrogen molecules, water molecules, and nitrogen atoms. Expansion of impurities such as atoms, nitrogen molecules, nitrogen oxide molecules (N2O, NO, NO2, etc.), and copper atoms. It is preferable to use a conductive material that has the function of suppressing dispersion. Alternatively, oxygen (for example, Using a conductive material that has the function of suppressing the diffusion of at least one of the following: oxygen atoms, oxygen molecules, etc. It is preferable that they be present.

[0115] Conductive material having the function of reducing hydrogen diffusion in conductor 205a and conductor 205c By using this material, impurities such as hydrogen contained in the conductor 205b are removed from the insulator 224, etc. This prevents diffusion into oxide 230. Also, conductor 205a and By using a conductive material that has the function of suppressing oxygen diffusion in the conductor 205c, This can suppress the oxidation of the conductor 205b, which reduces its conductivity. Examples of conductive materials that have a suppressive function include titanium, titanium nitride, tantalum, and nitrogen. It is preferable to use tantalum oxide, ruthenium oxide, etc. The conductive material 205a can be a single layer or a multilayer of the above conductive material. For example, a conductor For 205a, titanium nitride can be used.

[0116] Furthermore, the conductor 205b is a conductive material mainly composed of tungsten, copper, or aluminum. It is preferable to use a material with properties. For example, tungsten can be used for the conductor 205b. stomach.

[0117] Conductor 205 may function as a second gate electrode. In that case, conductor 20 The potential applied to 5 is changed independently of the potential applied to the conductor 260, without being linked to it. This allows us to control the threshold voltage (Vth) of transistor 200. In particular, By applying a negative potential to the conductor 205, the Vth of transistor 200 can be increased. Therefore, it becomes possible to reduce the off-current. Thus, a negative potential is applied to the conductor 205. When applied, the voltage applied to the conductor 260 is greater than when not applied. The inductive current can be reduced.

[0118] Furthermore, the electrical resistivity of the conductor 205 is set considering the potential applied to the conductor 205. The thickness of the conductor 205 is measured and set to match the electrical resistivity. Also, the insulator 21 The film thickness of 6 will be approximately the same as that of conductor 205. Here, within the limits allowed by the design of conductor 205 It is preferable to reduce the film thickness of the conductor 205 and the insulator 216. By making it thinner, the absolute amount of impurities such as hydrogen contained in the insulator 216 is reduced. This allows for the reduction of the diffusion of the impurity into the oxide 230.

[0119] 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 As such, the conductor 205 is at the channel width direction edges of oxide 230a and oxide 230b It is preferable that the region outside the part is also stretched. In other words, the oxide 230 On the outer side of the channel width direction, the conductor 205 and the conductor 260 are insulated. It is preferable that they are superimposed via a body. With this configuration, the first gate electrode and The electric field of conductor 260, which functions as a second gate electrode, and the electric field of conductor 205, which functions as a second gate electrode. The field allows the channel-forming region of oxide 230 to be electrically surrounded. In this model, the channel formation region is formed by the electric fields of the first gate and the second gate. The structure of transistors that are surrounded by air is called a surrounded channel (Sc This is called a hannel structure.

[0120] In this specification, etc., an S-channel transistor refers to a pair of gates. The electric fields of one and the other electrodes electrically surround the channel formation region. This represents the structure of the sta. Furthermore, the S-channel structure disclosed in this specification is a Fin-type structure. It differs from conventional and planar structures. By adopting an S-channel structure, short channels A transistor that is less susceptible to the Nell effect, or in other words, a transistor that is less prone to short-channel effects. It is possible.

[0121] Furthermore, as shown in Figure 1C, the conductor 205 is extended to function as wiring. However, this is not limited to the case where a conductor that functions as wiring is placed beneath the conductor 205. It is also possible to configure it in such a way. Furthermore, the conductor 205 is not necessarily provided one per transistor. There is no need to do so. For example, you can configure it so that the conductor 205 is shared by multiple transistors. stomach.

[0122] In transistor 200, the conductor 205 consists of conductor 205a, conductor 205b, The present invention is not limited to the above, but also to the configuration in which conductive material 205c is laminated. No. For example, the conductor 205 is provided as a single layer, two layers, or a laminated structure of four or more layers. It may also be configured as follows: For example, the conductor 205 may be made into two layers: conductor 205a and conductor 205b. It can also be used as a structure.

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

[0124] The insulator 222 suppresses the diffusion of hydrogen (for example, at least one such as a hydrogen atom or hydrogen molecule). It is preferable that it has a function to control oxygen. Also, the insulator 222 is oxygen (for example, oxygen atoms, It is preferable that the function suppresses the diffusion of at least one of the following: oxygen molecules. For example, Insulator 222 suppresses the diffusion of hydrogen and / or oxygen more effectively than insulator 224. It is preferable that it has a function.

[0125] 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. Suitable insulators include aluminum oxide and hafni oxide. Using oxides containing um, aluminum, and hafnium (hafnium aluminate), etc. It is preferable that such a material is used to form the insulator 222. 2 is the release of oxygen from the oxide 230 to the substrate side, and from the peripheral area of ​​the transistor 200. It functions as a layer that suppresses the diffusion of impurities such as hydrogen into the oxide 230. Therefore, insulator 2 By providing 22, the diffusion of impurities such as hydrogen into the inside of transistor 200 is suppressed. This can control and suppress the generation of oxygen vacancies in the oxide 230. Also, the conductor 205 This can suppress the reaction of the insulator 224 or oxide 230 with oxygen. .

[0126] Alternatively, the above insulator may contain, for example, aluminum oxide, bismuth oxide, or germanium oxide. Niobium oxide, silicon oxide, titanium oxide, tungsten oxide, yttrium oxide, oxide Zirconium may be added. Alternatively, these insulators may be nitrided. Also, Insulator 222 is made of silicon oxide, silicon oxide nitride, or silicon nitride. They may be used in stacked form.

[0127] Furthermore, the insulator 222 may be, for example, aluminum oxide, hafnium oxide, tantalum oxide, Zirconium oxide, lead zirconate titanate (PZT), strontium titanate (SrT) (Io3), (Ba,Sr)TiO3 (BST), and other so-called high-k materials are included in the aqueous solution. The edge material may be used in a single layer or in a stacked configuration. As transistors become smaller and more integrated... 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 a body, the physical film thickness is maintained while... This makes it possible to reduce the gate potential during transistor operation.

[0128] The insulator 224 in contact with the oxide 230 is, for example, silicon oxide, silicon oxide nitride, etc. Appropriate use is required. The insulator 224 is processed into an island shape so as to be superimposed on the oxide 230a. It is preferable that the insulator 272 is on the side surface of the insulator 224 and the insulator This configuration will result in contact with the upper surface of 222. By using this configuration, the volume of the insulator 224 will be It can be made significantly smaller, and the insulator 224 and insulator 280 can be separated by the insulator 272. Therefore, the oxygen contained in the insulator 280 diffuses into the insulator 224, and in the insulator 224 It can prevent an excess of oxygen.

[0129] 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. In addition, in Figure 1B and other figures, the insulator 224 is superimposed with the oxide 230a to form an island shape. The present invention is not limited to the configuration described herein. The insulator 224 contains If the amount of oxygen being introduced can be properly adjusted, then, similar to insulator 222, insulator 224 can be patterned It's also acceptable to use a configuration that doesn't involve any processing.

[0130] Oxide 243a and oxide 243b are provided on oxide 230b. 43a and oxide 243b are provided separated by the conductor 260.

[0131] Oxide 243 (oxide 243a and oxide 243b) is a material that suppresses oxygen permeation. It is preferable that it has the ability. Conductor 242 that functions as a source electrode or drain electrode By placing oxide 243, which has the function of suppressing oxygen permeation, between oxide 230b and oxide 230b This is preferable because it reduces the electrical resistance between the conductor 242 and the oxide 230b. By using such a configuration, the electrical characteristics of transistor 200 and the characteristics of transistor 200 Reliability can be improved. Note that the electrical resistance between the conductor 242 and the oxide 230b is... If the amount can be sufficiently reduced, a configuration without oxide 243 may be used.

[0132] As oxide 243, a metal oxide having element M may be used. In particular, as Aluminum, gallium, yttrium, or tin may be used. Oxide 243 is It is preferable that the concentration of element M is higher than that of oxide 230b. Also, as oxide 243 Gallium oxide may also be used. In addition, as oxide 243, In-M-Zn oxide, etc. Metal oxides may be used. Specifically, in the metal oxide used for oxide 243, I The atomic ratio of element M to n is, in the metal oxide used in oxide 230b, relative to In. It is preferable that the atomic ratio of element M is greater than that of the element M. Also, the film thickness of oxide 243 is 0.5 Preferably, it is between 5 nm and 1 nm, more preferably between 1 nm and 3 nm, and even more preferably between 5 nm and 3 nm. The size is between 1 nm and 2 nm. Furthermore, it is preferable that oxide 243 is crystalline. When the oxide 243 is crystalline, the release of oxygen in the oxide 230 can be suitably suppressed. Yes, it is possible. For example, if oxide 243 has a hexagonal crystal structure, then oxide 230 In some cases, it may be possible to suppress the release of oxygen inside.

[0133] The conductor 242a is provided in contact with the upper surface of the oxide 243a, and the conductor 242b is an oxide It is preferable that the conductors 242a and 242 are provided in contact with the upper surface of 243b. b functions as either the source electrode or the drain electrode of transistor 200, respectively.

[0134] Examples of conductors 242 (conductors 242a and 242b) include tantalum. Nitrides containing titanium, nitrides containing molybdenum, nitrides containing tungsten Materials, nitrides containing tantalum and aluminum, nitrides containing titanium and aluminum It is preferable to use such materials. In one embodiment of the present invention, a nitride containing tantalum is particularly Preferred. Also, for example, ruthenium oxide, ruthenium nitride, strontium and ruthenium Oxides containing lanthanum, oxides containing lanthanum and nickel, etc., may also be used. These materials Because it is a conductive material that is resistant to oxidation, or a material that maintains its conductivity even when it absorbs oxygen. ,preferable.

[0135] Furthermore, hydrogen contained in oxide 230b, etc., in conductor 242a or conductor 242b Diffusion may occur. In particular, conductors 242a and 242b contain nitrogen containing tantalum. By using the ion, the hydrogen contained in oxide 230b, etc., becomes conductor 242a or conductive It readily diffuses into body 242b, and the diffused hydrogen has conductor 242a or conductor 242b It can combine with nitrogen. In other words, hydrogen contained in oxides such as 230b is a conductor. It may be absorbed by 242a or conductor 242b.

[0136] Furthermore, a curved surface is not formed between the side surface of the conductor 242 and the top surface of the conductor 242. This is preferable. By using a conductor 242 in which the curved surface is not formed, the cross section in the channel width direction The cross-sectional area of ​​the conductor 242 on the surface can be increased. This allows the conductor 24 By increasing the conductivity of 2, the on-current of transistor 200 can be increased.

[0137] The insulator 271a is provided in contact with the upper surface of the conductor 242a, and the insulator 271b is It is provided in contact with the upper surface of the conductor 242b. Also, the upper surface of the insulator 271a is an insulator. It is preferable that the side surface of the insulator 271a is in contact with the insulator 250, while the insulator 272 is in contact with the insulator 250. The upper surface of the edge 271b is in contact with the insulator 272, and the side surface of the insulator 271b is in contact with the insulator 250. It is preferable that the insulator 271 functions as at least a barrier insulating film against oxygen. It is preferable that the insulator 271 has the function of suppressing the diffusion of oxygen. This is preferable. For example, the insulator 271 has a function that suppresses oxygen diffusion more than the insulator 280. It is preferable to have the following. As the insulator 271, for example, silicon such as silicon nitride. A nitride containing [the specified element] can be used. In addition, the insulator 271 has the function of capturing impurities such as hydrogen. It is preferable that the insulator 271 has an amorphous structure. If an insulator such as a metal oxide, for example, aluminum oxide or magnesium oxide is used... Good. In particular, as the insulator 271, aluminum oxide having an amorphous structure, or By using amorphous aluminum oxide, hydrogen can be captured or solidified more effectively. This is preferable because it may be possible to attach it. This results in a reliable train with good characteristics. ZISTA 200 and semiconductor devices can be manufactured.

[0138] Insulator 272 consists of insulator 224, oxide 230a, oxide 230b, oxide 243, and conductive It is provided so as to cover the electrical body 242 and the insulator 271. The insulator 272 is made of water It is preferable that the insulator 272 has a function to suppress the diffusion of nitrogen. In that case, the insulator 272 is nitrogen It is preferable to include an insulator such as silicon dioxide. Alternatively, hydrogen may be captured as insulator 272. The configuration may have the function of fixing capture and hydrogen. In that case, as the insulator 272 This refers to metal oxides having an amorphous structure, such as aluminum oxide or magnesium oxide. It is preferable that the material contains an insulator such as cium.

[0139] Furthermore, the insulator 272 may have a laminated structure. For example, the insulator 272 may be made of aluminum oxide A laminated structure of aluminum and silicon nitride formed on the aluminum oxide may also be used. By using such a layered structure, a single layer of aluminum oxide or a single layer of silicon nitride can be created. This is preferable because it can enhance the barrier properties.

[0140] By providing the insulators 271 and 272 described above, a barrier property against oxygen is achieved. The conductor 242 can be wrapped in an insulator having the following properties: In other words, the insulator 224 and This prevents the oxygen contained in the insulator 280 from diffusing into the conductor 242. Therefore, the oxygen contained in insulators 224 and 280 directly affects the conductor 242. This can suppress the increase in resistivity and reduction in on-current that can occur due to oxidation.

[0141] Insulator 250 functions as a gate insulator. Insulator 250 is on top of oxide 230b It is preferable to arrange them in contact with the surface. The insulator 250 is silicon oxide, silicon oxide and nitride. silicon nitride, silicon nitride, fluorinated silicon oxide, porous silicon oxide Silicon can be used. In particular, silicon oxide and silicon oxide nitride are heat It is preferable because it is stable against. Furthermore, as the insulator 250, the carbon content in the film is low. It is preferable to do so.

[0142] However, one aspect of the present invention is not limited thereto, and the insulator 250 has carbon in its film. It is also possible. For example, the carbon concentration of the insulator 250 is preferably determined by SIMS analysis, 1 x 10 18 atoms / cm 3 The above 5 x 10 20 atoms / cm 3 The following are more preferable ku is 5 x 10 18 atoms / cm 3 The above 1 x 10 20 atoms / cm 3 The following is Furthermore, the carbon concentration in the film of insulator 250 can be measured by SIMS analysis, etc. ru.

[0143] Insulator 250, like insulator 224, has a concentration of impurities such as water and hydrogen in it. It is preferable that the amount is reduced. The film thickness of the insulator 250 is 1 nm or more and 20 nm or less. It is preferable to do so.

[0144] Furthermore, as shown in Figures 1B and 1C, when the insulator 250 has a two-layer laminated structure, The lower insulator 250a is formed using an insulator that is easily permeable to oxygen, and the upper insulator 25 It is preferable to form 0b using an insulator that has the function of suppressing oxygen diffusion. By using such a configuration, the oxygen contained in the insulator 250a diffuses into the conductor 260. This can suppress the decrease in the amount of oxygen supplied to oxide 230. This is possible. In addition, it suppresses the oxidation of the conductor 260 by oxygen contained in the insulator 250a. This is possible. For example, the insulator 250a can be used in place of the insulator 250 described above. The insulator 250b is made of either aluminum or hafnium. It is preferable to use an insulator containing an oxide of aluminum oxide. Oxides containing nium, aluminum, and hafnium (hafnium aluminate), etc. It is preferable to use it. Also, the film thickness of the insulator 250b should be 0.5 nm or more and 3.0 nm or less. Preferably, the wavelength is between 1.0 nm and 1.5 nm.

[0145] Furthermore, when silicon oxide or silicon oxide nitride is used as the lower layer of the insulator 250, The upper layer of insulator 250 may be made of an insulating material that is a high-k material with a high dielectric constant. i. By making the gate insulator a laminated structure of insulator 250a and insulator 250b, heat In contrast, a stable and highly dielectric laminated structure can be created. Therefore, gate insulation It is possible to reduce the gate potential applied during transistor operation while maintaining the physical thickness of the material. This is the result. In addition, the equivalent oxide film thickness (EOT) of the insulator that functions as a gate insulator can be thinned. It becomes possible.

[0146] Furthermore, a metal oxide may be provided between the insulator 250 and the conductor 260. The material preferably suppresses the diffusion of oxygen 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 reduced. Dispersion 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.

[0147] Furthermore, even if the above metal oxide is configured to function as part of the first gate electrode, Good. For example, a metal oxide that can be used as oxide 230 is the same as the above metal oxide. It can be used in this way. In that case, the conductive material 260a is deposited by sputtering. Therefore, the electrical resistance of the above metal oxide can be reduced to make it a conductor. This is called OC( This can be called an Oxide Conductor electrode.

[0148] Having the above metal oxide, the influence of the electric field from the conductor 260 is not weakened. The on-current of the transistor 200 can be improved. Also, the insulator 250 and the above metal The physical thickness of the group oxide maintains the distance between the conductor 260 and the oxide 230. This makes it possible to suppress the leakage current between the conductor 260 and the oxide 230. Also, By providing a laminated structure of the insulator 250 and the metal oxide, the conductor 260 and the oxide The physical distance between object 230 and the conductor 260, and the electric field strength from the conductor 260 to the oxide 230. This can be easily adjusted as needed.

[0149] Conductor 260 functions as the first gate electrode of transistor 200. Conductor 26 0 comprises a conductor 260a and a conductor 260b disposed on top of the conductor 260a. Preferably, the conductor 260a encloses the bottom and sides of the conductor 260b. It is preferable to arrange them in this manner. Also, as shown in Figures 1B and 1C, the conductor 260 The top surface of the conductor is approximately the same as the top surface of the insulator 250. Note that in Figures 1B and 1C, Although the conductive body 260 is shown as a two-layer structure of conductive material 260a and conductive material 260b, a single-layer structure is also shown. It can be a simple structure, or a laminated structure of three or more layers.

[0150] Conductor 260a contains hydrogen atoms, hydrogen molecules, water molecules, nitrogen atoms, nitrogen molecules, and nitrogen oxide molecules. It is preferable to use a conductive material that has the function of suppressing the diffusion of impurities such as copper atoms. Alternatively, a device that inhibits the diffusion of oxygen (for example, at least one such as an oxygen atom or oxygen molecule). It is preferable to use a conductive material that has conductivity.

[0151] 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 titanium and nitride. Titanium, tantalum, tantalum nitride, ruthenium, ruthenium oxide, etc. are preferred. It's nice.

[0152] Furthermore, since the conductor 260 also functions as wiring, a highly conductive material should be used. This is preferable. For example, the conductor 260b is mainly composed of tungsten, copper, or aluminum. A conductive material can be used. Furthermore, the conductor 260b may also be in a laminated structure. For example, a laminated structure of titanium or titanium nitride and the above-mentioned conductive material may be used.

[0153] Furthermore, in transistor 200, the conductor 260 is formed on an insulator 280 or the like. The conductor 260 is formed in a self-aligning manner to fill the opening. Therefore, the conductor 260 is positioned in the region between the conductor 242a and the conductor 242b. It can be positioned reliably without any problems.

[0154] Furthermore, as shown in Figure 1C, in the channel width direction of transistor 200, insulator 2 When the bottom surface of 22 is used as a reference, the conductor 260 and the oxide 230b overlap. The height of the bottom surface of the region that does not undergo this process is preferably lower than the height of the bottom surface of oxide 230b. The conductor 260, which functions as a electrode, transmits oxide 230b via an insulator 250, etc. By configuring the channel formation region to cover the sides and top surface, the electric field of the conductor 260 is oxidized. This makes it easier to apply the effect to the entire channel formation region of component 230b. Therefore, transistor 200 The on-current can be increased and the frequency characteristics can be improved. Based on the bottom surface of the insulator 222 When considered as a standard, the oxides 230a and 230b and the conductor 260 do not overlap. The difference between the height of the bottom surface of the conductor 260 and the height of the bottom surface of the oxide 230b in region i is, 0 nm to 100 nm, preferably 3 nm to 50 nm, more preferably 5 The range should be between 20 nm and 20 nm.

[0155] The insulator 280 is provided on the insulator 272, and the insulator 250 and the conductor 260 are provided. An opening is formed in the area that is to be cut. Also, the upper surface of the insulator 280 is flattened. That's good too.

[0156] The insulator 280, which functions as an interlayer film, preferably has a low dielectric constant. By using the material as an interlayer film, parasitic capacitance occurring between wiring can be reduced. Insulator 28 It is preferable that 0 be provided using a material similar to that of the insulator 216, for example. In particular, oxide Silicon oxide and silicon nitride are preferred because they are thermally stable. In particular, silicon oxide Materials such as silicon oxidnitride and silicon oxide with voids release oxygen upon heating. This is preferable because it allows for the easy formation of a region containing [the specified element].

[0157] It is preferable that the concentration of impurities such as water and hydrogen in the insulator 280 is reduced. For example, insulator 280 is an acid containing silicon such as silicon oxide and silicon oxide nitride. You can use monsters as appropriate.

[0158] The insulator 282 suppresses the diffusion of impurities such as water and hydrogen from above into the insulator 280. It is preferable that it functions as a barrier insulating film and has the function of capturing impurities such as hydrogen. It is preferable to do so. Furthermore, the insulator 282 is a barrier insulating film that suppresses oxygen permeation. It is preferable that it functions. The insulator 282 is a metal oxide having an amorphous structure. For example, an insulator such as aluminum oxide can be used. Insulator 212 and Insulator 283 Within the region sandwiched between them, it has the function of capturing impurities such as hydrogen in contact with the insulator 280. By providing the insulator 282, impurities such as hydrogen contained in the insulator 280 are captured. This allows the amount of hydrogen within that region to be kept constant. In particular, as an insulator 282 aluminum oxide having an amorphous structure, or aluminum oxide having an amorphous structure Using nium is preferable because it can sometimes capture or fix hydrogen more effectively. This results in a transistor 200 with good characteristics and high reliability, and semiconductor equipment A structure can be created.

[0159] Insulator 282a and insulator 282b on insulator 282a are subjected to an oxygen-containing atmosphere. By forming a film using the puttering method, oxygen can be added to the insulator 280. Insulator 282a has a lower oxygen addition amount to insulator 280 than insulator 282b. Preferably, the RF power during film formation of insulator 282a is used, and the R during film formation of insulator 282b is used. It should be less than F power. This will result in an excess amount of oxygen being added to the insulator 280. This can be suppressed. In addition, in the insulator 282, insulator 282a and insulator 28 In some cases, it can be difficult to clearly detect the boundary of 2b.

[0160] In the above example, the insulator 282 has a laminated structure of insulator 282a and insulator 282b. The above has been shown, but the present invention is not limited thereto. Acid added to insulator 280 If the elemental quantity can be adjusted appropriately, then either insulator 282a or insulator 282b It may also be possible to configure it to include a bun.

[0161] The insulator 283 suppresses the diffusion of impurities such as water and hydrogen from above into the insulator 280. It functions as a barrier insulating film. Insulator 283 is placed on top of insulator 282. The edge material 283 is silicon nitride or silicon nitride oxide, or other silicon-containing nitride It is preferable to use a material. For example, an insulator 283 that is deposited by sputtering. Silicon nitride can be used. By depositing insulator 283 using the sputtering method, density can be increased. It is possible to form a silicon nitride film with high rigidity and resistance to the formation of porosity, etc. Also, an insulator As 283, on top of silicon nitride film deposited by sputtering, further ALD method The deposited silicon nitride films may be stacked. With such a structure, sputtering Even if defects such as voids occur in silicon nitride deposited by the AL method, the coating remains good. The voids are filled with silicon nitride film deposited by method D, thereby improving sealing performance. This is preferable because it allows for this.

[0162] The insulator 286 is provided on the insulator 283 and on the insulator 274. The region of insulator 286 that overlaps with conductor 246 has a higher upper surface height than other regions of insulator 286. This can happen.

[0163] The conductive material 240a is embedded in the insulator 280, insulator 283, and insulator 286. An insulator 241a is provided in contact with the inner wall of the opening into which it is fitted, and the side surface of the insulator 241a is in contact with A first conductive element of the conductive material 240a is provided, and further inside, a second conductive element of the conductive material 240a is provided. An electric element is provided. Also formed on insulators 280, 283, and 286. An insulator 241b is provided in contact with the inner wall of the opening into which the conductor 240b is embedded. The first conductor of the conductor 240b is provided in contact with the side surface of the insulator 241b, and further inside A second conductor, conductor 240b, is provided. Here, conductor 240a, conductor 2 40b, insulator 241a, and insulator 241b are configured so that they do not come into contact with insulator 282. This is preferable. Also, the height of the upper surface of the conductor 240 and the region overlapping with the conductor 246 are considered to be an insulating material. The height of the top surface of the edge 286 can be made to be approximately the same.

[0164] Furthermore, in the above, the first conductor and the second conductor of the conductor 240 The present invention describes a configuration in which layers are stacked, but is not limited thereto. For example, The conductor 240 may be provided as a single layer or as a laminated structure of three or more layers. When a layered structure is present, ordinal numbers may be assigned to distinguish it based on the order of formation.

[0165] Conductors 240a and 240b are primarily composed of tungsten, copper, or aluminum. It is preferable to use conductive materials as components. For example, conductor 240a and conductor 2 As the second conductor of 40b, a conductor mainly composed of tungsten, copper, or aluminum. Use an electrically conductive material.

[0166] Furthermore, the first conductor has a function of suppressing the permeation of impurities such as water and hydrogen. It is preferable to use materials such as tantalum, tantalum nitride, titanium, and titanium nitride. It is preferable to use ruthenium, ruthenium oxide, etc. Also, impurities such as water and hydrogen are not used. Conductive materials that have the function of suppressing transmission may be used in single layers or in multilayers. Impurities such as water and hydrogen contained in the layer above the edge 283, conductor 240a and conductor 2 This can suppress contamination of oxide 230 through 40b.

[0167] Note that in Figure 1A, the conductors 240a and 240b are circular in shape when viewed from above. However, this is not the only example. For example, conductor 240a and conductor 240b However, in a top view, approximately circular shapes such as ellipses, polygonal shapes such as quadrilaterals, and polygonal shapes such as quadrilaterals The corners may be rounded or otherwise shaped.

[0168] Examples of insulators 241a and 241b include silicon nitride and aluminum oxide. Insulators such as silicon nitride can be used. Also, the insulator 241 can be made into a laminated structure. This may also be done. For example, a silicon nitride layer may be provided in contact with the conductor 240, and the silicon nitride layer A configuration in which an aluminum oxide layer is provided on the outside of the insulator 241a and insulator 2 41b consists of insulators 286, 283, 280, 272 and 27 Since it is provided in contact with 1, impurities such as water and hydrogen contained in the insulator 280 become conductive This suppresses the mixing of material into the oxide 230 through the body 240a and the conductor 240b. It can. In particular, silicon nitride is suitable because it has high barrier properties against hydrogen. Also, an insulator To prevent the oxygen contained in 280 from being absorbed by conductors 240a and 240b. It is possible.

[0169] 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. The conductor may also be in a laminated structure, for example, titanium or titanium nitride. The tan and the conductive material may be laminated. The conductor is provided on the insulator. It may be formed to be embedded in the opening.

[0170] <Component materials for semiconductor devices> The following describes the constituent materials that can be used in semiconductor devices.

[0171] <<Substrate>> 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. This may also be done. The elements provided on the substrate may include capacitive elements, resistive elements, switching elements, and light-emitting elements. These include children, memory elements, etc.

[0172] <<Insulator>> Insulators include insulating oxides, nitrides, oxidized nitrides, nitride oxides, and metal oxides. Examples include metal oxides, metal nitrides, and metal nitride oxides.

[0173] 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.

[0174] 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.

[0175] Furthermore, as insulators with low dielectric constant, silicon oxide, silicon oxide nitride, and fluorine are used. Silicon oxide with added carbon, silicon oxide with added carbon and nitrogen Examples include silicon oxide with voids, or resins.

[0176] Furthermore, transistors using metal oxides suppress the permeation of impurities such as hydrogen and oxygen. By surrounding it with an insulator that has the function of stabilizing the electrical characteristics of the transistor. 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, lanthanum An insulator containing fluorine, neodymium, hafnium, or tantalum is used in a single layer or in a multilayer structure. That's all that's needed. Specifically, an insulating material that has the function of suppressing the permeation of impurities such as hydrogen and oxygen. As a body, aluminum oxide, magnesium oxide, gallium oxide, germanium oxide, acid Yttrium oxide, zirconium oxide, lanthanum oxide, neodymium oxide, hafnium oxide, acid Metal oxides such as tantalum oxide, aluminum nitride, silicon nitride, silicon nitride, etc. Metal nitrides can be used.

[0177] 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.

[0178] <<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, titanium and aluminum nitrides, tantalum and aluminum Nitrides containing ruthenium, ruthenium oxide, ruthenium nitride, strontium and ruthenium It is preferable to use oxides containing lanthanum and nickel. Tantalum, titanium nitride, titanium and aluminum nitrides, tantalum and aluminum Includes nitrides, ruthenium oxide, ruthenium nitride, strontium and ruthenium oxides Oxides containing lanthanum and nickel are conductive materials that are resistant to oxidation, or that absorb oxygen. It is preferable because it is a material that maintains conductivity even after being subjected to certain conditions. Furthermore, it does not contain impurity elements such as phosphorus. Highly electrically conductive semiconductors such as polycrystalline silicon and nickel silicides. Silicide may also be used.

[0179] 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.

[0180] Furthermore, when an oxide is used in the channel formation region of a transistor, the gate electrode and A conductor that functions as such includes a material containing the aforementioned metal element and a conductive material containing oxygen. It is preferable to use a combined laminated structure. In this case, an oxygen-containing conductive material is used. It is preferable to place it on the channel formation region side. A conductive material containing oxygen 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.

[0181] In particular, as a conductor that functions as a gate electrode, it is included in the metal oxide in which the channel is formed. It is preferable to use a conductive material containing metallic elements and oxygen. Conductive materials containing group elements and nitrogen may be used. For example, titanium nitride or tungsten nitride. Conductive materials containing nitrogen, such as tungsten, may also be used. In addition, indium tin oxide and tungsten oxide may be used. Indium oxide containing tungsten, indium zinc oxide containing tungsten oxide, oxide Titanium-containing indium oxide, titanium oxide-containing indium tin oxide, indium zinc Indium tin oxide with added oxides or silicon may also be used. Zium gallium zinc oxide may also be used. By using such a material, the channel In some cases, hydrogen contained in the formed metal oxide can be captured. Alternatively, outward In some cases, it is possible to capture hydrogen that has entered from insulators and other materials.

[0182] <<Metal Oxides>> As oxide 230, a metal oxide (oxide semiconductor) that functions as a semiconductor is used. This is preferable. Below, metals applicable to oxides 230 and 243 according to the present invention Let's discuss oxides.

[0183] 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, tin, etc. Also, boron, titanium, iron, nitrile Germanium, Zirconium, Molybdenum, Lanthanum, Cerium, Neodymium, Ha One of the following materials is selected from tungsten, tantalum, magnesium, cobalt, etc. It may include multiple species.

[0184] 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 Let M be tin. Other elements that can be used for element M include boron, titanium, iron, and nickel. Germanium, Zirconium, Molybdenum, Lanthanum, Cerium, Neodymium, Hafnium Examples include um, tantalum, tungsten, magnesium, and cobalt. However, element M and Furthermore, it is sometimes acceptable to combine multiple of the aforementioned elements.

[0185] 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.

[0186] <Classification of crystal structures> First, we will explain the classification of crystal structures in oxide semiconductors using Figure 4A. Figure 4A shows an oxide semiconductor, typically IGZO (containing In, Ga, and Zn, and a metallic acid). This is a diagram illustrating the classification of the crystal structures of ionized compounds.

[0187] As shown in Figure 4A, oxide semiconductors can be broadly classified into "Amorphous" It is divided into "Crystalline (crystalline)" and "Crystal (crystal)". They are classified as such. Also, among "Amorphous," there are completely amorp It includes hous. Also, within "Crystalline" there is CAAC(c-ax is-aligned crystalline), nc(nanocrystalli ne), and CAC (cloud-aligned composite) are included. excluding single crystal and poly crystal l). Note that the classification of "Crystalline" includes single crystal, Polycrystalline and completely amorphous materials are excluded. Furthermore, within "Crystal," there are single crystals and poly crystals. It contains crystal.

[0188] The structures within the thick border shown in Figure 4A are "Amorphous" and "Cry It is an intermediate state between "stal (crystal)" and a new boundary region (New crystal This structure belongs to the line phase. In other words, this structure is energetically in It is completely different from a stable "Amorphous" or "Crystal." This can be rephrased as having different structures.

[0189] The crystal structure of the film or substrate can be determined by X-ray diffraction (XRD). It can be evaluated using the ion spectrum. Here, "Crystalline GIXD (Grazing-Incidence) of CAAC-IGZO film, which is classified as " The XRD spectrum obtained by the XRD measurement is shown in Figure 4B. Note that the GIXD method is used for thin films. This method is also called the Seemann-Bohlin method. Hereafter, the GIXD measurement shown in Figure 4B will be used. The resulting XRD spectrum will simply be referred to as the XRD spectrum. Note that the CAA shown in Figure 4B The composition of the C-IGZO film is approximately In:Ga:Zn = 4:2:3 [atomic ratio]. The thickness of the CAAC-IGZO film shown in Figure 4B is 500 nm.

[0190] As shown in Figure 4B, the XRD spectrum of the CAAC-IGZO film clearly shows crystallinity. The peak shown is detected. Specifically, in the XRD spectrum of the CAAC-IGZO film, A peak indicating c-axis orientation is detected near 2θ = 31°. Furthermore, as shown in Figure 4B, The peaks near 2θ = 31° are asymmetrical with respect to the angle at which the peak intensity was detected.

[0191] Furthermore, the crystal structure of the film or substrate is determined by nano-beam diffraction (NBED). Diffraction patterns observed by electron diffraction (extremely small) It can be evaluated by (also called electron diffraction pattern). The folding pattern is shown in Figure 4C. Figure 4C shows an NBED with an electron beam incident parallel to the substrate. This is the diffraction pattern observed by the CAAC-IGZO film shown in Figure 4C. The composition is approximately In:Ga:Zn=4:2:3 [atomic ratio]. Furthermore, micro-electron diffraction... Next, electron diffraction is performed with a probe diameter of 1 nm.

[0192] As shown in Figure 4C, the diffraction pattern of the CAAC-IGZO film shows multiple c-axis orientations. Spots of this nature are observed.

[0193] <<Oxide semiconductor structure>> Note that oxide semiconductors may be classified differently from those shown in Figure 4A when considering their crystal structure. Yes, there are. For example, oxide semiconductors include single-crystal oxide semiconductors and other non-single-crystal oxide semiconductors. It can be divided into two parts. Examples of non-single-crystal oxide semiconductors include the aforementioned CAAC-OS. And there is nc-OS. In addition, non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors and pseudo-non-crystalline oxide semiconductors. crystalline oxide semiconductor (a-like OS: amorphous-like oxide) This includes semiconductors, amorphous oxide semiconductors, and so on.

[0194] Here, we will provide details on the CAAC-OS, nc-OS, and a-like OS mentioned above. Then, I will give an explanation.

[0195] [CAAC-OS] CAAC-OS has multiple crystalline regions, and the c-axis of these crystalline regions is oriented in a specific direction. It is an oriented oxide semiconductor. The specific direction refers to the thickness direction of the CAAC-OS film. , in the direction normal to the surface on which the CAAC-OS film is formed, or in the direction normal to the surface of the CAAC-OS film Yes, there is. Furthermore, a crystalline region is a region in which the atomic arrangement has periodicity. Note that the atomic arrangement is categorized If considered as a child arrangement, a crystalline region is also a region with a aligned lattice arrangement. Furthermore, CAAC- OS has a region in which multiple crystal regions are connected in the ab-plane direction, and this region is strained It may have strain. Note that strain refers to the lattice arrangement in a region where multiple crystal regions are connected. The orientation of the grid arrangement changes between a region with aligned grids and another region with aligned grids. This refers to the location. In other words, CAAC-OS is c-axis oriented and has a clear orientation in the ab-plane direction. It is an oxide semiconductor that does not exist.

[0196] Each of the above multiple crystalline regions is composed of one or more minute crystals (with a maximum diameter of 10 It is composed of crystals smaller than nm. Furthermore, the maximum diameter of the crystalline region is less than 10 nm. If this occurs, the size of the crystalline region may be around several tens of nanometers.

[0197] Also, In-M-Zn oxide (element M is aluminum, gallium, yttrium, sulfite) In one or more types selected from materials such as titanium, CAAC-OS is an indicator. A layer containing um (In) and oxygen (hereinafter referred to as the In layer), and element M, zinc (Zn), and acid A layered crystalline structure (also called a layered structure) is formed by stacking layers containing an element (hereinafter referred to as (M,Zn) layer). It tends to have (u). Furthermore, indium and element M are mutually substitutable. Therefore The (M,Zn) layer may contain indium. Also, the In layer contains element M. This may occur. Furthermore, the In layer may also contain Zn. This layered structure is, for example, In high-resolution TEM images, it is observed as a grid pattern.

[0198] For example, when structural analysis of a CAAC-OS film is performed using an XRD device, the θ / 2θ scale is obtained. Out-of-plane XRD measurements using the CANR showed two peaks indicating c-axis orientation. It is detected at θ=31° or nearby. Note that the position of the peak indicating c-axis orientation (value of 2θ) ) may vary depending on the type and composition of the metal elements that make up CAAC-OS.

[0199] Furthermore, for example, in the electron diffraction pattern of a CAAC-OS film, multiple bright spots (spots) (T) is observed. Note that one spot and another spot are separated by the incident electron beam that has passed through the sample. With the spot (also called the direct spot) as the center of symmetry, observations are made at point-symmetric positions. It can be done.

[0200] When the crystal region is observed from the specific direction described above, the lattice arrangement within that crystal region is a hexagonal lattice. While this is the basic principle, the unit cell is not necessarily a regular hexagon and may be a non-regular hexagon. Also, The above distortion may have a grid arrangement such as a pentagon or heptagon. -In OS, clear grain boundaries were confirmed even near the strain. This is not possible. In other words, the formation of grain boundaries is suppressed by the distortion of the lattice arrangement. This indicates that CAAC-OS has a dense arrangement of oxygen atoms in the ab-plane direction. This is because, or because the bond distance between atoms changes due to the substitution of metal atoms. This is thought to be because it allows for some distortion.

[0201] Furthermore, a crystal structure in which clear grain boundaries can be observed is known as a polycrystalline structure. It is called al). The grain boundaries become recombination centers, where carriers are trapped, and transistors are formed. This is likely to cause a decrease in on-current and a decrease in field-effect mobility. Therefore, CAAC-OS, which does not exhibit visible grain boundaries, has a crystal structure suitable for the semiconductor layer of transistors. It is one of the crystalline oxides that possesses [a certain characteristic]. Note that CAAC-OS requires Zn to be present. A configuration such as the above is preferred. For example, In-Zn oxide and In-Ga-Zn oxide are In It is preferable because it can suppress the generation of grain boundaries more effectively than oxides.

[0202] CAAC-OS is an oxide semiconductor with high crystallinity and no clearly defined grain boundaries. Therefore, CAAC-OS is less prone to a decrease in electron mobility caused by grain boundaries. Furthermore, the crystallinity of oxide semiconductors decreases due to the inclusion of impurities or the generation of defects. Because this can occur, CAAC-OS is an oxide with few impurities or defects (such as oxygen deficiencies). It can also be called a semiconductor. Therefore, oxide semiconductors containing CAAC-OS have stable physical properties. Therefore, oxide semiconductors containing CAAC-OS are heat-resistant and highly reliable. CAAC-OS can withstand high temperatures (so-called thermal budget) in the manufacturing process. It is stable. Therefore, when using CAAC-OS in OS transistors, the manufacturing process is stable. This will broaden the scope of possibilities.

[0203] [nc-OS] 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. In other words, nc-OS is micro It has small crystals. The size of these minute crystals is, for example, between 1 nm and 10 nm. In particular, because they are between 1 nm and 3 nm in size, these minute crystals are also called nanocrystals. Furthermore, nc-OS shows no regularity in crystal orientation between different nanocrystals. Therefore, the entire film... No orientation is observed. Therefore, nc-OS is a-like depending on the analytical method. It may be indistinguishable from OS or amorphous oxide semiconductors. For example, in an nc-OS film... In contrast, when structural analysis is performed using an XRD device, out-of- In plane XRD measurements, no peaks indicating crystallinity were detected. Furthermore, the nc-OS film... In contrast, electron beams with probe diameters larger than those of nanocrystals (e.g., 50 nm or more) are used. When linear diffraction (also called limited-field electron diffraction) is performed, diffraction patterns such as halo patterns are observed. On the other hand, for the nc-OS film, the size is close to or smaller than that of the nanocrystals. Electron diffraction (nanobi) is a method that uses electron beams with a probe diameter (e.g., 1 nm to 30 nm). Also called electron diffraction. When this is performed, a ring-shaped region is formed around the direct spot. In some cases, an electron diffraction pattern may be obtained in which multiple spots are observed within the same area.

[0204] [a-like OS] a-like OS is an oxide having a structure between nc-OS and amorphous oxide semiconductors. It is a semiconductor. an a-like OS has porous or low-density regions. That is, a-like OS has lower crystallinity compared to nc-OS and CAAC-OS. Also, it has a-like properties. OS has a higher hydrogen concentration in the membrane compared to nc-OS and CAAC-OS.

[0205] <<Oxide Semiconductor Composition>> Next, we will explain the details of CAC-OS mentioned above. Note that CAC-OS is a material composition. Regarding achievement.

[0206] [CAC-OS] CAC-OS refers to, for example, metal oxides in which the elements constituting the metal oxide are between 0.5 nm and 10 nm. Below, preferably, a structure of material that is unevenly distributed with a size of 1 nm to 3 nm or near that size. It is formed. Furthermore, in the following, in metal oxides, one or more metal elements are unevenly distributed. The region containing the metal element is 0.5 nm to 10 nm, preferably 1 nm to 3 nm. A mixture of particles smaller than or near a m in size is also called a mosaic or patchy appearance. .

[0207] Furthermore, CAC-OS is a material that separates into a first region and a second region. It forms a zigzag shape, and the first region is distributed within the film (also called a cloud-like structure). In other words, CAC-OS is a structure in which the first region and the second region are mixed. It is a composite metal oxide having the following properties.

[0208] Here, I for the metal elements constituting CAC-OS in In-Ga-Zn oxide The atomic ratios of n, Ga, and Zn are given as [In], [Ga], and [Zn] respectively. To be expressed. For example, in CAC-OS in In-Ga-Zn oxide, the first region This is the region where [In] is greater than the [In] in the composition of the CAC-OS film. The second region is the region where [Ga] is greater than the [Ga] in the composition of the CAC-OS film. That is. Or, for example, in the first region, [In] is greater than [In] in the second region. It is also a region where the [Ga] is large, and the [Ga] is smaller than the [Ga] in the second region. Furthermore, in the second region, [Ga] is greater than [Ga] in the first region, and [I n] is a region where n is smaller than [In] in the first region.

[0209] Specifically, the first region mentioned above mainly consists of indium oxide, indium zinc oxide, etc. This is a region of minutes. Furthermore, the second region mentioned above is gallium oxide, gallium zinc oxide, etc. This is the region in which In is the main component. In other words, the first region described above can be said to be the region in which In is the main component. It can be replaced. Furthermore, the second region described above can be rephrased as the region with Ga as the main component. It is possible.

[0210] Note that a clear boundary may not be observed between the first region and the second region described above. .

[0211] For example, in CAC-OS in In-Ga-Zn oxide, the energy-dispersive X-ray segment Optical method (EDX:Energy Dispersive X-ray spectrosc) EDX mapping obtained using opy revealed the region with In as its main component (the first region) It has a structure in which a region (the second region) and a region mainly composed of Ga are unevenly distributed and mixed. This can be confirmed.

[0212] When CAC-OS is used in a transistor, the conductivity is due to the first region and the second region The insulating properties due to the region work complementarily to enable the switching function (On The function to turn off CAC-OS can be added to it. In other words, CAC-OS and The material has both conductive and insulating properties in parts, and the entire material Then it has the function of a semiconductor. By separating the conductive function and the insulating function, This allows for the maximum enhancement of both functions. Therefore, CAC-OS is used in transistors. This results in a high on-current (I on ), high field-effect mobility (μ), and good switching This enables smooth operation.

[0213] Oxide semiconductors can take on diverse structures, each possessing different properties. One embodiment of the present invention Oxide semiconductors include amorphous oxide semiconductors, polycrystalline oxide semiconductors, a-like OS, and C It may have two or more of the following: AC-OS, nc-OS, and CAAC-OS.

[0214] <Transistors containing oxide semiconductors> Next, we will explain the case where the above oxide semiconductor is used in a transistor.

[0215] By using the above oxide semiconductor in a transistor, a transistor with high field-effect mobility is obtained. This can be achieved. Furthermore, highly reliable transistors can be realized.

[0216] A low-carrier-concentration oxide semiconductor is used in the channel formation region of the transistor. This is preferable. For example, the carrier concentration in the channel formation region of the oxide semiconductor is 1 × 10⁻⁶. 17 c m -3 The following is preferably 1 × 10 15 cm -3 More preferably 1 × 10 13 cm -3 More preferably 1 × 10 11 cm -3 More preferably 1 × 10 10 c m -3 It is less than 1 × 10 -9 cm -3 That concludes the explanation. Note that the carriers in oxide semiconductor films... When lowering the concentration, the impurity concentration in the oxide semiconductor film is reduced, and the defect level density is lowered. It is sufficient to lower the value. In this specification, etc., a low impurity concentration and a low defect level density are used. This is referred to as high-purity intrinsic or substantially high-purity intrinsic. Furthermore, oxide semiconductors with low carrier concentrations are... These are sometimes referred to as high-purity intrinsic or substantially high-purity intrinsic oxide semiconductors.

[0217] Furthermore, oxide semiconductor films that are high-purity intrinsic or substantially high-purity intrinsic have a low defect level density. Therefore, the trap level density may also be low.

[0218] Furthermore, the time required for charges trapped in the trap levels of an oxide semiconductor to disappear is... It can behave for a long time, almost like a fixed charge. Therefore, the trap level density is high. Transistors in which a channel formation region is formed in an oxide semiconductor have unstable electrical properties. There are cases where this occurs.

[0219] Therefore, in order to stabilize the electrical characteristics of a transistor, the impurity concentration in the oxide semiconductor is Reducing it is effective. Furthermore, in order to reduce the impurity concentration in oxide semiconductors, It is also preferable to reduce the concentration of impurities in the adjacent membrane. Examples of impurities include hydrogen, nitrogen, and Examples include potassium metals, alkaline earth metals, iron, nickel, and silicon.

[0220] <Impurities> Here, we will explain the effects of various impurities in oxide semiconductors.

[0221] In oxide semiconductors, if silicon or carbon, which are among the Group 14 elements, Defect levels are formed in oxide semiconductors. Therefore, channel formation regions in oxide semiconductors The concentration of silicon or carbon in the region, and, for example, the insulator and the channel shape of the oxide semiconductor. Concentration of silicon or carbon at the interface with the formation region and near the interface (by secondary ion mass spectrometry) SIMS (Secondary Ion Mass Spectrometry) The resulting concentration is 2 × 10 18 atoms / cm 3 The following is preferably 2 × 10 17 at oms / cm 3 The following applies:

[0222] Furthermore, if alkali metals or alkaline earth metals are present in the oxide semiconductor, defect levels are formed. This can result in the generation of carriers. Therefore, alkali metals or alkaline earth metals may be present. Transistors using oxide semiconductors tend to exhibit normally-on characteristics. Therefore, alkali metals or a in the channel formation region of oxide semiconductors obtained by SIMS The concentration of rutile earth metals is 1 × 10⁻⁶ 18 atoms / cm 3 The following is preferably 2 × 10 1 6 atoms / cm 3 Do the following:

[0223] Furthermore, in oxide semiconductors, when nitrogen is present, electrons, which are carriers, are generated. As the nitrogen concentration increases, it becomes easier to convert to n-type semiconductors. As a result, oxide semiconductors containing nitrogen become semiconductors. The transistor used tends to exhibit normally-on characteristics. Alternatively, oxide semiconductors Furthermore, when nitrogen is present, trap levels may be formed. As a result, transistor The electrical properties of the oxide semiconductor obtained by SIMS may become unstable. The nitrogen concentration in the channel formation region is 5 × 10 19 atoms / cm 3 Less than, preferably 5 x 10 18 atoms / cm 3 More preferably 1 × 10 18 atoms / cm3 More preferably 5 × 10 17 atoms / cm 3 Do the following:

[0224] Furthermore, the hydrogen contained in oxide semiconductors reacts with the oxygen bonded to the metal atoms to form water. Therefore, an oxygen deficiency may form. 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 that act as carriers. Therefore, an oxide semiconductor containing hydrogen is used. Transistors that have been modified tend to exhibit normally-on characteristics. For this reason, the channels of oxide semiconductors It is preferable that the amount of hydrogen in the hydrogen-forming region be reduced as much as possible. Specifically, In the channel formation region of an oxide semiconductor, the hydrogen concentration obtained by SIMS is 1 × 1 0 20 atoms / cm 3 Less than 5 × 10 19 atoms / cm 3 Less than, Preferably 1 × 10 19 atoms / cm 3 Less than 5 × 10 18 ato ms / cm 3 Less than 1 × 10 18 atoms / cm 3 Make it less than.

[0225] Using an oxide semiconductor with sufficiently reduced impurities in the channel formation region of a transistor. This allows for the provision of stable electrical characteristics.

[0226] <<Other Semiconductor Materials>> The semiconductor materials that can be used for oxide 230 are not limited to the metal oxides mentioned above. As monster 230, semiconductor materials with a band gap (not zero-gap semiconductors) Conductive materials may be used. For example, semiconductors of elemental silicon, gallium arsenide, etc. Which compound semiconductors, layered materials that function as semiconductors (also known as atomic layer materials, two-dimensional materials, etc.) It is preferable to use materials such as (u) as semiconductor materials. In particular, layered materials that function as semiconductors It is preferable to use this as a semiconductor material.

[0227] Here, in this specification, etc., "layered material" is a general term for a group of materials having a layered crystalline structure. Yes, it exists. Layered crystalline structures are formed by layers created by covalent or ionic bonds. They are stacked via weaker bonds than covalent or ionic bonds, such as Ruars forces. It is a structure. Layered materials have high electrical conductivity within a unit layer, that is, two-dimensional electrical conductivity. It has high properties. It functions as a semiconductor and is a material with high two-dimensional electrical conductivity in the channel formation region. By using this, it is possible to provide a transistor with a large on-current.

[0228] Examples of layered materials include graphene, silicene, and chalcogenides. It is a compound containing chalcogens. Furthermore, chalcogens are a general term for elements belonging to Group 16. It contains oxygen, sulfur, selenium, tellurium, polonium, and livermorium. Examples of chalcogenides include transition metal chalcogenides and group 13 chalcogenides. .

[0229] For example, a transition metal chalcogenide that functions as a semiconductor can be used as oxide 230. Preferably, a transition metal chalcogenide applicable as oxide 230 is specified. These include molybdenum sulfide (typically MoS2) and molybdenum selenide (typically MoS2) e2), molybdenum tellurium (typically MoTe2), tungsten sulfide (typically W S2), tungsten selenide (typically WSe2), tungsten tellurium (typically (WTe2), hafnium sulfide (typically HfS2), hafnium selenide (typically (HfSe2), zirconium sulfide (typically ZrS2), zirconium selenide (alternative) Examples include ZrSe2).

[0230] <Method for fabricating semiconductor devices> Next, Figure 5 shows a method for manufacturing a semiconductor device, which is one embodiment of the present invention, as shown in Figures 1A to 1D. This will be explained using Figures A through 24D.

[0231] In Figures 5A to 24D, A in each figure indicates a top view. Also, B in each figure indicates A in each figure. This is a cross-sectional view corresponding to the area indicated by the dashed line A1-A2 shown, and is of transistor 200. This is also a cross-sectional view in the direction of the channel length. Furthermore, C in each figure corresponds to the dashed line A3-A4 in A of each figure. This is a cross-sectional view corresponding to the part indicated, and is also a cross-sectional view of transistor 200 in the channel width direction. Yes. Also, D in each figure is a cross-sectional view corresponding to the area indicated by the dashed line A5-A6 in A of each figure. This is also a cross-sectional view of transistor 200 in the channel width direction. Note that the top surface of A in each figure Some elements have been omitted from the diagram for clarity.

[0232] In the following, insulating materials for forming an insulator and conductive materials for forming a conductor are used. Materials, or oxide materials for forming oxides, are produced by sputtering, CVD, MBE, etc. The film can be deposited using appropriate methods such as the PLD method and ALD method.

[0233] Furthermore, the sputtering method uses a high-frequency power supply for sputtering, which is called RF sputtering. Ring method, DC sputtering method using a DC power supply, and pulsed application of electricity to the electrodes There is a pulsed DC sputtering method that changes the pressure. RF sputtering is mainly used for insulating films. It is used when depositing thin films, and DC sputtering is mainly used when depositing metallic conductive films. It can be used. Also, pulsed DC sputtering is mainly used for oxides, nitrides, carbides, etc. It is used when depositing compounds into films using the reactive sputtering method.

[0234] 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.

[0235] 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.

[0236] Furthermore, in the ALD method, the reaction between the precursor and reactant is carried out using only thermal energy. Thermal ALD (Thermal Altode Discharge) method, using plasma-excited reactants. Methods such as EALD (Plasma Enhanced Alopecia) can be used.

[0237] 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, enables film formation with excellent coverage, and enables film formation at low temperatures. What are the effects? In the PEALD method, by using plasma, film deposition at lower temperatures is possible. This can be beneficial in some cases. Furthermore, the precursor used in the ALD method contains impurities such as carbon. Some contain [this]. Therefore, films formed by the ALD method are different from films formed by other film formation methods. Compared to a standard film, it may contain more impurities such as carbon. Note that the quantitative determination of impurities is done using X. X-ray Photoelectron Spectros (XPS) This can be done using `copy`.

[0238] 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.

[0239] 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, the time required for transport or pressure adjustment is eliminated, thus reducing the time spent on film deposition. This can shorten the time required. Therefore, it can increase the productivity of semiconductor devices. There are cases where this is the case.

[0240] First, a substrate (not shown) is prepared, and an insulator 212 is deposited on the substrate (Figure 5A). (See Figure 5D.) The insulator 212 is preferably deposited using the sputtering method. It is possible to use a sputtering method that does not require the use of hydrogen as the film-forming gas, insulator 21 The hydrogen concentration in 2 can be reduced. However, the deposition of the insulator 212 is done by sputtering. This method is not limited to the GRAV method; CVD, MBE, PLD, ALD, etc., may be used as appropriate. That's fine.

[0241] In this embodiment, the insulator 212 is used as the silicon target in an atmosphere containing nitrogen gas. Using this method, silicon nitride is deposited by pulsed DC sputtering. By using the ring method, particle generation due to arcing on the target surface is suppressed. This allows for a more uniform film thickness distribution. Furthermore, by using a pulsed voltage... By doing so, the rise and fall times of the discharge can be made steeper than with high-frequency voltage. This allows for more efficient power supply to the electrodes, improving the sputtering rate and film quality. It is possible.

[0242] By using an insulator that is resistant to the permeability of impurities such as water and hydrogen, such as silicon nitride, This can suppress the diffusion of impurities such as water and hydrogen contained in the layer below the insulator 212. Furthermore, as the insulator 212, an insulator that is impermeable to copper, such as silicon nitride, may be used. Therefore, a diffusive metal such as copper is used in the conductor layer below the insulator 212 (not shown). Even if present, it is possible to suppress the upward diffusion of the metal through the insulator 212.

[0243] Next, an insulator 214 is deposited on the insulator 212 (see Figures 5A to 5D). Insulator The deposition of film 214 is preferably carried out using the sputtering method. Hydrogen is used as the deposition gas. By using the sputtering method, which is not strictly necessary, the hydrogen concentration in the insulator 214 can be reduced. This is possible. However, the deposition of the insulator 214 is not limited to the sputtering method. CVD, MBE, PLD, ALD, etc. may be used as appropriate.

[0244] In this embodiment, the insulator 214 is an aluminum target in an atmosphere containing oxygen gas. Using a tweezers, aluminum oxide is deposited using the pulsed DC sputtering method. By using the sputtering method, the film thickness distribution can be made more uniform, and the sputtering rate and film The quality can be improved. Here, RF (Radio Frequency) power is applied to the substrate. A force may be applied. Depending on the magnitude of the RF power applied to the substrate, the layer below the insulator 214 may be affected. The amount of oxygen injected can be controlled. The RF power is 0 W / cm². 2 That's all for now. 1. 86W / cm 2 The following applies: In other words, the RF power during the formation of the insulator 214 causes the traction The amount of oxygen injected can be varied to suit the characteristics of the transistor. It can inject an amount of oxygen suitable for improving the reliability of the device. Also, the RF frequency is 10M A frequency of Hz or higher is preferable. A typical example is 13.56 MHz. The higher the RF frequency, the better the base This can reduce the damage inflicted on the board.

[0245] As an insulator 214, it has an amorphous structure with high functionality for capturing and fixing hydrogen. It is preferable to use a metal oxide having such properties, for example, aluminum oxide. This provides an insulating Hydrogen contained in the surrounding material 216, etc., is captured or fixed, and the hydrogen diffuses into the oxide 230. This can prevent this. In particular, as the insulator 214, aluminum oxide having an amorphous structure is used. By using aluminum or amorphous aluminum oxide, water can be filtered more effectively. It is preferable because it can capture or fix the element. This gives it good properties and reliability. Highly reliable transistors 200 and semiconductor devices can be fabricated.

[0246] Next, an insulator 216 is deposited on the insulator 214 (see Figures 5A to 5D). Insulator The deposition of film 216 is preferably carried out using the sputtering method. Hydrogen is used as the deposition gas. By using the sputtering method, which is not strictly necessary, the hydrogen concentration in the insulator 216 can be reduced. This is possible. However, the deposition of the insulator 216 is not limited to the sputtering method. CVD, MBE, PLD, ALD, etc. may be used as appropriate.

[0247] In this embodiment, the insulator 216 is used as the silicon target in an atmosphere containing oxygen gas. Using this method, silicon oxide is deposited by pulsed DC sputtering. By using the ring method, the film thickness distribution can be made more uniform, improving the sputtering rate and film quality. It is possible.

[0248] Insulators 212, 214, and 216 are continuously used without exposure to the atmosphere. It is preferable to deposit the film in this manner. For example, a multi-chamber type film deposition apparatus may be used. This reduces the amount of hydrogen in the film of insulators 212, 214, and 216. This method allows for the formation of a film, and furthermore, it reduces the incorporation of hydrogen into the film between each film formation step. .

[0249] Next, an opening is formed in the insulator 216 that reaches the insulator 214 (see Figures 5A to 5D). An opening includes, for example, grooves and slits. Also, the region in which an opening is formed. This may be referred to as an opening. The opening may be formed using wet etching, Dry etching is preferable for microfabrication. Dry etching is described below. A dry etching apparatus can be used. Also, the insulator 214 is made of insulator 216 Select an insulator that functions as an etching stopper film when etching to form grooves. Preferably, the insulator 216 forming the groove is silicon oxide or silicon oxidnitride. When CON is used, the insulator 214 is silicon nitride, aluminum oxide, hafnium oxide. It is preferable to use this. Furthermore, a recess is formed in the insulator 214 superimposed on the opening of the insulator 216. There are cases where this occurs.

[0250] After the opening is formed, a conductive film 205A is deposited (see Figures 5A to 5D). Conductive film 20 5A preferably contains a conductor that has the function of suppressing oxygen permeation. For example, nitride Tantalum, tungsten nitride, titanium nitride, etc. can be used. Alternatively, oxygen permeability A conductor having a function to suppress overheating, and tantalum, tungsten, titanium, molybdenum, and It can be a multilayer film of aluminum, copper, and molybdenum tungsten alloy. Conductive film 2 The 05A film is deposited using sputtering, CVD, MBE, PLD, ALD, etc. It can be done by doing so.

[0251] In this embodiment, titanium nitride is deposited as the conductive film 205A. By using a material in the lower layer of the conductor 205b, the conductor 20 is made possible by the insulator 216, etc. This can suppress the oxidation of 5b. Furthermore, the diffusion of copper and other materials as the conductor 205b can be suppressed. Even when using a metal that is prone to diffusing, it is possible to prevent the metal from diffusing out of the conductor 205a. Cut.

[0252] Next, the conductive film 205B is deposited (see Figures 5A to 5D). These are tantalum, tungsten, titanium, molybdenum, aluminum, copper, and molybdenum tan. Gusten alloys and the like can be used. The conductive film can be formed by plating, sputtering, etc. This can be carried out using methods such as CVD, MBE, PLD, and ALD. In terms of form, tungsten is deposited as the conductive film 205B.

[0253] Next, a CMP treatment is performed to remove a portion of conductive film 205A and conductive film 205B. , the insulator 216 is exposed (see Figures 6A to 6D). As a result, conductive material is present only at the opening. Body 205a and conductor 205b remain. Note that the insulator 21 Part of 6 may be removed.

[0254] Next, etching is performed to remove the upper part of the conductor 205b (see Figures 7A to 7D). . ) As a result, the upper surface of the conductor 205b is connected to the upper surface of the conductor 205a and the insulator 216 It will be lower than the top surface. For etching the conductor 205b, dry etching or wet etching is used. While etching can be used, dry etching is preferable for microfabrication. .

[0255] Next, a conductive film 205C is applied to the insulator 216, the conductor 205a, and the conductor 205b. A film is formed (see Figures 8A to 8D). Conductive film 205C is formed in the same way as conductive film 205A. It is desirable to include a conductor that has the function of suppressing oxygen permeation.

[0256] In this embodiment, titanium nitride is deposited as the conductive film 205C. By using the material on top of the conductor 205b, the conductor 20 is made possible by the insulator 222, etc. This can suppress the oxidation of 5b. Furthermore, the diffusion of copper and other materials as the conductor 205b can be suppressed. Even when using a metal that is prone to diffusing, it is possible to prevent the metal from diffusing out of the conductor 205c. Cut.

[0257] Next, a CMP treatment is performed to remove a portion of the conductive film 205C and expose the insulator 216. (See Figures 9A to 9D.) As a result, the conductor 205a and the conductor are located only in the opening. 205b and the conductor 205c remain. As a result, the top surface of the conductor 205 is flat. Furthermore, the conductor 205b can form conductor 205a and conductor 20 The structure is enclosed in 5c. Therefore, impurities such as hydrogen are removed from the conductor 205b. To prevent diffusion outside of 205a and conductor 205c, and to prevent diffusing outside of conductor 205a and conductive This prevents oxygen from entering from outside body 205c and oxidizing the conductor 205b. Note that the CMP process may remove a portion of the insulator 216.

[0258] Next, an insulator 222 is formed on the insulator 216 and the conductor 205 (Figures 10A to 10A). See Figure 10D.) As insulator 222, one or both aluminum and hafnium. It is preferable to form an insulator containing one of the oxides. Note that one of aluminum and hafnium Alternatively, as an insulator containing both oxides, aluminum oxide, hafnium oxide, aluminum It is preferable to use oxides containing um and hafnium (such as hafnium aluminate). Insulators containing oxides of aluminum and / or hafnium are suitable for oxygen, It has barrier properties against hydrogen and water. The insulator 222 has barrier properties against hydrogen and water. By having properties, hydrogen contained in the structure provided around transistor 200, The diffusion of priming fluid into the inside of the transistor 200 through the insulator 222 is suppressed. This can suppress the formation of oxygen vacancies in oxide 230.

[0259] The insulator 222 was deposited using sputtering, CVD, MBE, PLD, and ALD methods. This can be done using methods such as the above. In this embodiment, the ALD method is used for the insulator 222. Then, a hafnium oxide film is deposited.

[0260] Next, it is preferable to perform a heat treatment. The heat treatment is preferably performed at a temperature of 250°C to 650°C. It is preferable to carry it out at a temperature of 300°C to 500°C, and more preferably at 320°C to 450°C. The heat treatment is performed in an atmosphere of nitrogen gas or an inert gas, or with an oxidizing gas for 10 minutes. The procedure should be carried out in an atmosphere containing ppm or more, 1% or more, or 10% or more. For example, nitrogen gas and oxygen. When performing heat treatment in a gas mixture atmosphere, it is sufficient to use about 20% oxygen gas. The heat treatment may be carried out under reduced pressure. Alternatively, the heat treatment may be carried out under nitrogen gas or an inert gas. After heat treatment in an atmosphere, an oxidizing gas of 10 ppm or more is added to replenish the desorbed oxygen. Heat treatment may be carried out in an atmosphere containing % or more, or 10% or more.

[0261] Furthermore, it is preferable that the gas used in the above heat treatment is highly purified. For example, The amount of moisture contained in the gas used in the heat treatment described above is 1 ppb or less, preferably 0.1 ppb or less. More preferably, the level should be 0.05 ppb or less. Heat treatment using highly purified gas. By performing this process, it is possible to prevent moisture and other substances from being absorbed into the insulator 222, etc., as much as possible. can.

[0262] In this embodiment, as a heat treatment, after the film formation of the insulator 222, nitrogen gas and oxygen gas are used. The treatment is performed at a temperature of 400°C for 1 hour with a flow rate ratio of 4 slm: 1 slm. This method allows for the removal of impurities such as water and hydrogen contained in the insulator 222. Furthermore, when using an oxide containing hafnium as the insulator 222, the heat treatment will In some cases, a portion of the insulator 222 may crystallize. Also, the heat treatment of the insulator 224 This can also be done at other times, such as after film deposition.

[0263] Next, an insulator 224 is deposited on the insulator 222 (see Figures 10A to 10D). The edge material 224 is deposited using sputtering, CVD, MBE, PLD, ALD, etc. This can be done using the sputtering method. In this embodiment, the insulator 224 is made of sputtering material. A silicon oxide film is deposited using this method. Sputtering does not require the use of hydrogen as the deposition gas. By using this method, the hydrogen concentration in the insulator 224 can be reduced. The insulator 224 is Since it comes into contact with oxide 230a in a later process, the hydrogen concentration is reduced in this way. It is suitable.

[0264] Next, oxide film 230A and oxide film 230B are deposited sequentially on the insulator 224 (Figure 10). See Figures A through 10D. Note that oxide films 230A and 230B are exposed to the atmospheric environment. It is preferable to deposit the film continuously without exposure to the atmosphere. By depositing the film without exposure to the atmosphere, the oxide film 23 This prevents impurities or moisture from the atmospheric environment from adhering to 0A and the oxide film 230B. This allows the vicinity of the interface between oxide film 230A and oxide film 230B to be kept clean.

[0265] The oxide films 230A and 230B were deposited by sputtering, CVD, and MBE. This can be done using methods such as the PLD method and the ALD method.

[0266] 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 targets can be used.

[0267] In particular, during the deposition of oxide film 230A, some of the oxygen contained in the sputtering gas acts as an insulator. It may be supplied to 224. Therefore, the oxygen contained in the sputtering gas The percentage should be 70% or more, preferably 80% or more, and more preferably 100%.

[0268] Furthermore, when forming oxide film 230B by sputtering, the sputtering gas contains The proportion of oxygen is greater than 30% and less than or equal to 100%, preferably between 70% and 100%. When a film is formed using this method, an oxygen-rich oxide semiconductor is created. The transistors used in the channel formation region offer relatively high reliability. However, this generation One aspect of the invention is not limited to this. When the oxide film 230B is formed by sputtering, The oxygen content in the sputtering gas should be 1% to 30%, preferably 5% or more. When the film is deposited with an oxygen content of 0% or less, an oxygen-deficient oxide semiconductor is formed. Transistors using a monocrystalline semiconductor in the channel formation region can achieve relatively high field-effect mobility. Furthermore, by performing film deposition while heating the substrate, the crystallinity of the oxide film can be improved. It can be done.

[0269] In this embodiment, the oxide film 230A is formed by sputtering, using the In:Ga: The film is deposited using an oxide target with a Zn = 1:3:4 [atomic ratio]. Also, oxide film 23 As 0B, by sputtering, In:Ga:Zn=4:2:4.1 [atomic ratio] The film is deposited using the oxide target of ]. Note that each oxide film is formed under different deposition conditions and atomic ratios. By selecting appropriately, the desired properties for oxide 230a and oxide 230b can be determined. It is good to form it.

[0270] Next, an oxide film 243A is deposited on the oxide film 230B (see Figures 10A to 10D). The 243A oxide film was deposited using sputtering, CVD, MBE, PLD, and ALD methods. This can be done using methods such as the following. The oxide film 243A has an atomic ratio of Ga to In, which is acid It is preferable that the atomic ratio of Ga to In in the film 230B is greater than that of In. This is an oxide film 243A, produced by sputtering, with an In:Ga:Zn ratio of 1:3:4. The film is deposited using an oxide target with an atomic ratio of [number of atoms].

[0271] Note that the insulator 222, insulator 224, oxide film 230A, oxide film 230B, and oxide film It is preferable to deposit 243A by sputtering without exposing it to the atmosphere. For example, a multi-chamber type film deposition apparatus can be used. This allows for the deposition of insulator 222, The edge body 224, oxide film 230A, oxide film 230B, and oxide film 243A, the hydrogen in the film It reduces the amount of hydrogen present during film formation, and further reduces the amount of hydrogen mixed into the film between each film formation step. can.

[0272] Next, it is preferable to perform a heat treatment. The heat treatment is performed on oxide film 230A and oxide film 230B. The process should be carried out within a temperature range in which the oxide film 243A does not undergo polycrystallization, which is between 250°C and 650°C. The following steps should preferably be performed at a temperature of 400°C to 600°C. Note that the heat treatment is performed using nitrogen gas. Alternatively, an inert gas atmosphere, or an oxidizing gas at 10 ppm or more, 1% or more, The process should be carried out in an atmosphere containing 10% or more of the substance. For example, heat treatment should be performed in a mixed atmosphere of nitrogen and oxygen gas. In this case, the oxygen gas concentration should be around 20%. This supplies oxygen to oxide 230. Therefore, oxygen deficiency (V O ) can be reduced. Also, the heat treatment can be performed under reduced pressure. Good. Alternatively, the heat treatment can be performed in a nitrogen gas 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.

[0273] Furthermore, it is preferable that the gas used in the above heat treatment is highly purified. For example, The amount of moisture contained in the gas used in the heat treatment described above is 1 ppb or less, preferably 0.1 ppb or less. More preferably, the level should be 0.05 ppb or less. Heat treatment using highly purified gas. By performing this process, moisture, etc., is removed from oxide film 230A, oxide film 230B, and oxide film 243A. This can prevent it from being absorbed as much as possible.

[0274] In this embodiment, the heat treatment is performed at a temperature of 400°C for 1 hour in a nitrogen atmosphere. After this, the process is carried out continuously in an oxygen atmosphere at a temperature of 400°C for 1 hour. According to the principle, water, hydrogen, etc. in oxide film 230A, oxide film 230B, and oxide film 243A This allows for the removal of impurities, etc. Furthermore, this heat treatment results in the oxide film 230B This improves the crystallinity and creates a denser, more compact structure. The diffusion of oxygen or impurities within the film 230B can be reduced.

[0275] In this way, oxide film 230A, oxide film 230B, and oxide film 243A are subjected to oxygenation treatment. By doing this, oxygen vacancies in oxide film 230A, oxide film 230B, and oxide film 243A are eliminated. , repaired by supplied oxygen, in other words, "V O This prompts the reaction "+O→null". It can be advanced. Furthermore, oxide film 230A, oxide film 230B, and oxide film 243 The oxygen supplied reacts with the hydrogen remaining in A, removing the hydrogen as H2O. This allows (dehydration) the hydrogen remaining in oxide 230 to become oxygen. Recombining into the missing part V O This can suppress the formation of H.

[0276] Next, a conductive film 242A is deposited on the oxide film 243A (see Figures 10A to 10D). The conductive film 242A was deposited using sputtering, CVD, MBE, PLD, and ALD methods. This can be done using methods such as the following. For example, the conductive film 242A can be produced using the sputtering method. Then, a tantalum nitride film should be formed. Note that a heat treatment should be performed before forming the conductive film 242A. This may be done under reduced pressure, without exposure to air, and continuously to form a conductive film 2 42A may be formed as a film. By performing such a treatment, the surface of the oxide film 243A It removes moisture and hydrogen adsorbed on it, and further, oxide film 230A, oxide film 230B, Furthermore, the water concentration and hydrogen concentration in the oxide film 243A can be reduced. The temperature is preferably between 100°C and 400°C. In this embodiment, the heat treatment temperature is set to 2 Let's set the temperature to 0°C.

[0277] Next, an insulating film 271A is deposited on the conductive film 242A (see Figures 10A to 10D). The insulating film 271A is deposited by sputtering, CVD, MBE, PLD, or A This can be done using methods such as the LD method. The insulating film 271A has a function to suppress oxygen permeation. It is preferable to use an insulating film having sputtering. For example, as insulating film 271A, sputtering The aluminum oxide film can be deposited according to the method.

[0278] In this embodiment, as the insulating film 271A, an aluminium is used in an atmosphere containing oxygen gas. Using a GET, aluminum oxide is deposited by pulsed DC sputtering. The RF power applied to the board is 0.62 W / cm². 2 The following applies: Preferably, 0 W / cm² 2 That's all. 0.31 W / cm² 2 The following applies: By reducing the RF power, the amount injected into the conductive film 242A is reduced. This suppresses the amount of oxygen released and prevents oxidation of the conductive film 242A.

[0279] Furthermore, the conductive film 242A and the insulating film 271A are not exposed to the atmosphere, and sputtering is performed. It is preferable to deposit the film using the densification method. For example, if a multi-chamber type film deposition apparatus is used... Good. This reduces the amount of hydrogen in the conductive film 242A and the insulating film 271A during film formation. Furthermore, it is possible to reduce the incorporation of hydrogen into the film between each film formation process.

[0280] Next, a hard mask layer 275A is deposited on the insulating film 271A. (Figures 11A to 11) (See D.) The hard mask layer 275A was deposited using sputtering, CVD, or MBE. This can be done using methods such as the PLD method or ALD method. The hard mask layer 275A is This film functions as a hard mask for forming oxide 230b and other materials in a later process. For the hard mask layer 275A, a metallic material or an inorganic insulating material may be used. For example, as the hard mask layer 275A, tungsten is formed by the sputtering method. A film can be formed. Furthermore, after forming the insulating film 271A, a hard mask can be applied without exposure to the atmosphere. The configuration may also involve continuously depositing layers 275A.

[0281] Next, an organic coating film 276A is formed on the hard mask layer 275A. (Figures 11A to 11A) See 11D.) The organic coating film 276A adheres to the hard mask and resist mask described later. It may have a function to improve performance. The formation of the organic coating film 276A may be, for example, spin This can be done using a coating method or the like. As the organic coating film 276A, a non-photosensitive organic resin is used. You can use it. For example, as the organic coating film 276A, SOG (Spin On Glas s) A film or an SOC (Spin On Carbon) film can be deposited. Also, for example... For example, as the organic coating film 276A, a laminated film is formed by depositing an SOC film and an SOG film on top of it. It may be used. The organic coating film 276A may be provided as needed, and the resist described later If the mask alone is sufficient, the configuration may be configured without the organic coating film 276A.

[0282] Next, a resist mask 277 is formed on the organic coating film 276A using lithography. This is achieved. (See Figures 11A to 11D.) As for the resist mask 277, photoresist A photosensitive organic resin, also known as a photoresist, can be used. For example, a positive-type photoresist or A negative type photoresist can be used. The photoresist mask 277 is a photoresist. DIST can be deposited with a uniform thickness by using methods such as spin coating. It is possible.

[0283] In lithography, first, the photoresist is exposed through a mask. Next, exposure The treated area is removed or left intact using a developer to form a resist mask 277. For example, KrF excimer laser light, ArF excimer laser light, EUV (Extreme By exposing the resist using ultraviolet light, etc., the resist mask 2 Form 77. Alternatively, fill the space between the substrate and the projection lens with a liquid (e.g., water) to create a dewdrop. Photoluminescence or immersion technology may be used. Alternatively, instead of the aforementioned light, an electron beam or ions may be used. A beam may be used. Note that when using an electron beam or ion beam, a mask is required. This becomes unnecessary.

[0284] Next, using the resist mask 277, the conductive film 242A, insulating film 271A, and hard mass are used. The 275A layer and the 276A organic coating film are processed into island-like structures, forming the conductive layer 242B and the insulating layer 27 1B, a hard mask 275 and an organic coating film 276 are formed (see Figures 12A to 12D). Light. ).

[0285] This process can be carried out using either a dry etching method or a wet etching method. Dry etching is suitable for microfabrication, therefore, the dry etching method is used. Preferably, the etching gas is one or more of fluorine, chlorine, and bromine. A halogen-containing etching gas can be used. Oxygen, nitrogen, helium, argon, or hydrogen gas can be added to the gas as appropriate. It can be added. Also, the etching conditions are the target to be etched (conductive film 242A, Cut as appropriate according to the insulating film 271A, hard mask layer 275A, and organic coating film 276A. It can be replaced.

[0286] 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 voltage 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 voltages are applied to the electrodes may be used. Or a parallel plate type electrode Alternatively, a configuration in which the same high-frequency voltage is applied to each of them is also possible. Alternatively, a configuration in which high-frequency voltages 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.

[0287] Next, using the hard mask 275, oxide film 230A, oxide film 230B, and oxide film 243A is processed into island-like structures to form oxide 230a, oxide 230b, and oxide layer 243B. It forms (see Figures 13A to 13D).

[0288] This process can be carried out using either a dry etching method or a wet etching method. Dry etching is suitable for microfabrication, therefore, the dry etching method is used. This is preferable. The etching gas includes hydrocarbons such as methane (CH4) gas. It is preferable to use an etching gas. Hydrocarbons used as etching gases include... Tan (CH4), Ethane (C2H6), Propane (C3H8), Butane (C4H10 ), Ethylene (C2H4), propylene (C3H6), acetylene (C2H2), and pro One or more pins (C3H4) can be used. Note that etchants containing hydrocarbons may also be used. Add oxygen, nitrogen, helium, argon, or hydrogen gas as needed to the gas. It can be added. Also, in the etching process, the above dry etching process Placement can be used.

[0289] In this embodiment, an example is given for the case where methane (CH4) is used as the etching gas. The oxide films 230A, 230B, and 243A are shown to be In, Ga, Alternatively, when using an oxide having one or more selected from Zn, methane Etching can be performed relatively easily by using (CH4) gas.

[0290] Here, using a mixed gas of CH4 gas and Ar gas, the In-Ga-Zn oxide is used. An example of a model for etching oxide film 230B will be explained using Figure 25. Figure 2 In section 5, In, Ga, and Zn are grouped together as metal atoms M. e It is represented as follows.

[0291] Ar gas is ionized in the plasma to generate Ar ions, as shown in Figure 25. Ar ions are accelerated by the bias voltage applied to the electrode on the substrate side, and the oxide film 23 It collides with the surface of 0B. Here, the oxygen atom in oxide film 230B is a metal atom M e Lighter than Therefore, it is relatively easily removed by collisions with Ar ions. When the oxygen atom is removed, The metal atom M adjacent to the oxygen atom e The bond with the oxygen atom was broken, and the oxygen atom in question was present. Oxygen deficiency V is formed in the ito. O In this way, oxygen atoms are removed from the oxide film 230B.

[0292] Also, CH4 gas is decomposed in the plasma to generate CH3 radicals 295. Here, the metal atom M whose bond with an oxygen atom has been broken e has high reactivity. Therefore, As shown in FIG. 25, the generated CH3 radicals 295 can coordinate with the metal atom M e relatively easily.

[0293] The desorption of oxygen atoms further proceeds around the metal atom M coordinated with the CH3 radical 295 e The bond between the metal atom M coordinated with the CH3 radical 295 e and the oxygen atom adjacent to the metal atom M e is broken, and further CH3 radicals coordinate with the metal atom M. By repeating this cycle, as shown in FIG. 25, the metal atom M e sublimes as a metal complex 296. In this way, by forming the metal complex 296, the metal atom M is removed from the oxide film 230B. e e

[0294] Here, as the metal complex 296, for example, In(CH3)3, Ga(CH3)3, Zn(CH3)2, etc. are formed. All of these metal complexes have a boiling point of 70°C or lower and relatively high volatility. Therefore, even when the substrate temperature is relatively low, the reaction of the model shown in FIG. 25 can proceed. In this way, by using a mixed gas of CH4 gas and Ar gas, the processing of In-Ga-Zn oxide, which is a difficult-to-etch material, can be easily performed.

[0295] ​​​​​​​​​ In addition, the etching model of oxide film 230B was described above, but oxide film 23 0A and oxide film 243A can also be etched according to a similar model.

[0296] As described above, when dry etching is performed using CH4 gas, etc., organic coating By-products may be formed from the sides of the film 276 and the resist mask 277. Therefore, during the etching process shown in Figure 12, or at the beginning of the etching process shown in Figure 13 In this stage, the organic coating film 276 and the resist mask 277 are removed, and the hard mask 275 It is preferable to perform the etching process using a mask.

[0297] Furthermore, during the dry etching process using CH4 gas, the organic coating film 276 and The resist mask 277 may disappear. Therefore, below the resist mask 277, It is preferable to provide a hard mask 275 that does not disappear during the etching process.

[0298] Furthermore, the hard mask 275 contains tungsten, and the insulator 224 contains silicon oxide. If present, methane (CH4) gas is used to form oxide film 230A, oxide film 230B, and acid It is preferable to etch the film 243A. By etching in this way The etching selectivity ratios of oxide film 230A, oxide film 230B, and oxide film 243A are set by The domask 275 and insulator 224 can be made significantly larger. Therefore, this work At this stage, with the insulator 224 remaining flat, oxide film 230A, oxide film 230B, and The oxide film 243A can be formed in an island-like manner. This allows the insulator 224, which will be described later, to In the process of forming island-like structures, the regions that do not overlap with the oxide 230a of the insulator 224 are cleaned. This allows for removal and prevents the insulator 222 from being over-etched.

[0299] Furthermore, the resist mask 277 and the organic coating film 276 remain after the process shown in Figure 13. If this occurs, perform dry etching such as ashing, or wet etching. U, perform wet etching after dry etching, or wet etching The material can be removed by performing a dry etching treatment after the initial polishing process.

[0300] Next, an etching process is performed to superimpose the insulator 224 with the oxide 230a in an island-like manner. The process is carried out (see Figures 14A to 14D). The etching process is performed by dry etching or Wet etching can be used. Dry etching is used for fine processing. Because it is suitable for the process, it is preferable to use the dry etching method. For example, a halogen-based etching gas containing one or more of fluorine, chlorine, and bromine is used. It is possible to use halogen-containing etching gases with oxygen gas, nitrogen gas, and helium. Mugas, argon gas, or hydrogen gas can be added as appropriate. The above-mentioned dry etching apparatus can be used for the etching process.

[0301] Here, during the processing of the insulator 224, the insulator 222 is not over-etched. This is preferable. Therefore, etching is performed under conditions where the etching selectivity ratio for the insulator 222 is large. It is preferable that the insulator 224 contains silicon oxide and a gas containing fluorine When etching, it is preferable that the insulator 222 contains hafnium oxide. By etching, the sides of the insulator 224 and the surface of the insulator 222 will be etched in the process described later. An insulator 272 can be provided in contact with the surface. In other words, the insulator 224 can be placed in contact with the insulator 272 This allows the insulator 280 to be separated. With this configuration, the insulator From 280 through the insulator 224, an excess amount of oxygen or impurities such as hydrogen can be introduced, which can then be converted into oxides. This prevents contamination of 230.

[0302] Furthermore, as described above, the insulator 224 is kept flat, that is, the film thickness of the insulator 224 It is preferable to perform this etching process when the variation within the substrate surface is small. Therefore, the variation in the time until the insulator 224 is removed within the substrate surface becomes smaller, This prevents the edge 222 from being over-etched and a portion of the insulator 222 from disappearing. This prevents a portion of the insulator 224 from remaining on the insulator 222.

[0303] Furthermore, the hard mask 275 may be removed during the etching process (Figure 14A). (See Figure 14D.) The hard mask 275 can be removed by dry etching or wet etching. A post-etching method can be used. However, the material of the hard mask 275 may cast shadows on subsequent processes. If there is no resonance, or if it can be used in a later process, it is not always necessary to remove the hard mask 275. There's no need for it.

[0304] Furthermore, in the hard mask removal process, the insulating layer 271B is removed from the conductive layer 242B. As it functions as a screen, the conductive layer 242B is on the side, as shown in Figures 14B and 14C. There is no curved surface between the surface and the top surface. As a result, the conductive material 242a and conductive material shown in Figure 1B The end of body 242b where the side and top surfaces meet is angular. The side and top surfaces of the conductor 242 meet Because the end is angular, the cross-section of the conductor 242 is different compared to when the end has a curved surface. The product becomes larger. As a result, the resistance of conductor 242 is reduced, so transistor 20 The ON current of 0 can be increased.

[0305] Furthermore, if the insulating layer 271B functions as a mask for the conductive layer 242B, the insulator 224 Before processing into an island shape, the hard mask 275 may be removed. The removal of 75 may be carried out in parallel with the processing of the insulator 224 into island shapes.

[0306] Furthermore, the etching process shown in Figures 12 to 14 may be carried out continuously without exposure to the outside air. For example, the etching process may be carried out continuously in the same chamber, or The process may also be carried out using a chamber-type etching apparatus, without exposure to the outside air.

[0307] Furthermore, in the etching process shown in Figures 12 to 14, the insulator 224 and oxide 230 a, oxide 230b, oxide layer 243B, conductive layer 242B, and insulating layer 271B are small At the very least, it is formed so that a portion overlaps with the conductor 205. Also, the insulator 224 and oxide 23 Sides of 0a, oxide 230b, oxide layer 243B, conductive layer 242B, and insulating layer 271B The surface is preferably approximately perpendicular to the upper surface of the insulator 222. Insulator 224, oxidation Material 230a, oxide 230b, oxide layer 243B, conductive layer 242B, and insulating layer 271 The side of B is approximately perpendicular to the top surface of the insulator 222, which allows multiple transistors 2 When 00 is provided, it becomes possible to reduce the area and increase the density. Alternatively, insulator 224, oxide 2 30a, oxide 230b, oxide layer 243B, conductive layer 242B, and insulating layer 271B The angle between the side surface and the top surface of the insulator 222 may be set to a low angle. In that case, Insulator 224, oxide 230a, oxide 230b, oxide layer 243B, conductive layer 242B, The angle between the side surface of the insulating layer 271B and the top surface of the insulator 222 is 60 degrees or more and less than 70 degrees. This is preferable. By having this shape, in subsequent processes, the insulator 272 and the like The coating properties are improved, and defects such as porosity can be reduced.

[0308] Furthermore, the by-products generated in the etching process shown in Figures 12 to 14 are insulator 224, Oxide 230a, oxide 230b, oxide layer 243B, conductive layer 242B, and insulating layer 2 It may be formed in layers on the side surface of 71B. In this case, the layered by-product is an insulator. 224, oxide 230a, oxide 230b, oxide 243, conductor 242, and insulator This will be formed between 271 and the insulator 272. If the process is carried out in this manner to manufacture transistor 200, the reliability of transistor 200 will be poor. This can lead to deformation. Therefore, it is preferable to remove the layered by-product.

[0309] Next, insulator 222, insulator 224, oxide 230a, oxide 230b, oxide layer 24 An insulator 272 is formed on 3B, the conductive layer 242B, and the insulating layer 271B (Figure 15). (See A to Figure 15D.) The insulator 272 was deposited by sputtering, CVD, and MBE. This can be done using methods such as the PLD method and the ALD method. In this embodiment, the insulator 27 2. Using an aluminum target in an atmosphere containing oxygen gas, pulse DC spall Aluminum oxide is deposited using the tarning method. Also, as insulator 272, sputtering Silicon nitride may be deposited by law. Also, the insulator 272 is a part of the upper surface of the insulator 222. It is closely related to.

[0310] The insulator 272 may also have a laminated structure. For example, by sputtering, Aluminum oxide is deposited into a film, and then nitride is formed on the aluminum oxide by sputtering. A film of ricon may be formed. By making the insulator 272 such a multilayer structure, water, hydrogen, This may improve the ability to suppress the diffusion of certain impurities and oxygen.

[0311] In this way, oxide 230a, oxide 230b, oxide layer 243B, and conductive layer 242B is an insulator 272 and an insulating layer 271B, which have the function of suppressing the diffusion of oxygen. It can be covered with this. This allows for subsequent processes to remove oxide 230a, oxide 230b, and acid This reduces the diffusion of oxygen into the ionized layer 243B and the conductive layer 242B.

[0312] Next, an insulating film that will become an insulator 280 is formed on the insulator 272. This can be done using methods such as sputtering, CVD, MBE, PLD, and ALD. Yes, it is possible. For example, a silicon oxide film can be formed as the insulating film using the sputtering method. The insulating film, which will become the insulator 280, is deposited by sputtering in an oxygen-containing atmosphere. By doing so, an insulator 280 containing excess oxygen can be formed. Also, water is used as the film-forming gas. By using a sputtering method that does not require the use of a particle, the hydrogen concentration in the insulator 280 can be reduced. It can be reduced. Furthermore, a heat treatment may be performed before the deposition of the insulating film. Heat treatment This process may be carried out under reduced pressure, and the insulating film may be deposited continuously without exposure to the atmosphere. By performing such a process, moisture and water adsorbed on the surface of the insulator 272 can be removed. The element is removed, and further oxide 230a, oxide 230b, oxide layer 243B, and insulator The water and hydrogen concentrations in 224 can be reduced. The heat treatment described above The following heat treatment conditions can be used.

[0313] Next, the insulating film that will become the insulator 280 is subjected to CMP treatment, and the insulator 280 has a flat top surface. This forms (see Figures 15A to 15D). Furthermore, on the insulator 280, for example, spats... A silicon nitride film is formed by the taring method, and the silicon nitride is deposited until it reaches the insulator 280. CMP processing may also be performed.

[0314] Next, a portion of the insulator 280, a portion of the insulator 272, a portion of the insulating layer 271B, and the conductive layer 24 Part of 2B and part of the oxide layer 243B are processed to create an opening that reaches the oxide 230b. The opening is formed. It is preferable that the opening be formed so as to overlap with the conductor 205. Through the formation of insulator 271a, insulator 271b, conductor 242a, conductor 242b, Oxide 243a and oxide 243b are formed (see Figures 16A to 16D).

[0315] When forming the above-mentioned opening, the upper part of oxide 230b may be removed. By removing a portion of 0b, grooves are formed in the oxide 230b. Therefore, the groove may be formed in the above-mentioned opening formation step, or the opening formation step and They may be formed using different processes.

[0316] Also, a portion of the insulator 280, a portion of the insulator 272, a portion of the insulating layer 271B, and the conductive layer 24 Processing of part of 2B and the oxide layer 243B is done by dry etching or wet etching. The etching method can be used. Dry etching is suitable for microfabrication. Furthermore, the processing may be carried out under different conditions. For example, the insulator 280 Part of the insulator 272 and part of the insulating layer 271B were processed using the dry etching method. The material was processed by a wet etching method, and a portion of the conductive layer 242B and a portion of the oxide layer 243B were removed. The part may be processed by dry etching. Also, a part of the conductive layer 242B and the oxide layer 2 Some of the processing for 43B may be carried out under different conditions.

[0317] Here, the side surface of oxide 230a, the top and side surfaces of oxide 230b, and the side of conductor 242. Adhesion of impurities to surfaces, the sides of the insulator 280, etc., or diffusion of such impurities into these surfaces. This may occur. A process to remove such impurities may be performed. Also, the above-mentioned In some cases, etching can create damaged areas on the oxide 230b surface. The region may be removed. The impurities include insulator 280, insulator 272, and insulating layer 27. A portion of 1B, the conductive layer 242B, and components contained in the insulator 222 form the above-mentioned opening. The components contained in the materials used in the equipment used, the gas used for etching, and These impurities can be caused by components contained in the liquid, for example, Examples include hafnium, aluminum, silicon, tantalum, fluorine, and chlorine.

[0318] In particular, impurities such as aluminum or silicon are CAAC-O230b oxide. It inhibits S formation. Therefore, it inhibits CAAC-OS formation of aluminum or silicon. It is preferable that harmful impurity elements are reduced or removed. For example, oxide 230 b, and its vicinity, should have a concentration of aluminum atoms of 5.0 atomic percent or less. Preferably, 2.0 atomic% or less, more preferably 1.5 atomic% or less, and 1.0 atomic% or less. More preferably, and even more preferably less than 0.3 atomic percent.

[0319] Furthermore, impurities such as aluminum or silicon can inhibit the formation of CAAC-OS. , pseudo-amorphous oxide semiconductor (a-like OS: amorphous-like ox The region of the metal oxide that has become an ide semiconductor is considered a non-CAAC region. It may be called that. In the non-CAAC region, the density of the crystal structure is reduced, so V O H It forms in large quantities, making it easier for transistors to become normally-on. Therefore, oxide 230 It is preferable that the non-CAAC region of b is reduced or eliminated.

[0320] In contrast, it is preferable that oxide 230b has a layered CAAC structure. It is preferable that the CAAC structure extends to the lower end of the drain of oxide 230b. In transistor 200, the conductor 242a or conductor 242b, and its vicinity. This functions as a drain. In other words, near the lower end of the conductor 242a (conductor 242b) Preferably, oxide 230b has a CAAC structure. In this way, drain pressure Even at the drain end, which significantly affects the CA, the damaged area of ​​oxide 230b is removed, Having an AC structure further suppresses fluctuations in the electrical characteristics of transistor 200. Yes, it is possible. Furthermore, it can improve the reliability of transistor 200.

[0321] To remove the above-mentioned impurities, a cleaning process is performed. The cleaning method involves using a cleaning solution, etc. These include wet cleaning, plasma treatment using plasma, and cleaning by heat treatment. The cleaning process may be combined as appropriate. Note that this cleaning process will deepen the grooves. This can happen.

[0322] For wet cleaning, use ammonia water, oxalic acid, phosphoric acid, hydrofluoric acid, etc., with carbonated water. Alternatively, the cleaning process may be carried out using an aqueous solution diluted with pure water, pure water, carbonated water, etc. Ultrasonic cleaning may be performed using these aqueous solutions, pure water, or carbonated water. Alternatively, These cleaning methods may be combined as appropriate.

[0323] In this specification, etc., an aqueous solution obtained by diluting commercially available hydrofluoric acid with pure water is referred to as diluted hydrofluoric acid. It is called an acid, and a solution obtained by diluting commercially available ammonia water with pure water is sometimes called diluted ammonia water. Yes. Furthermore, the concentration and temperature of the aqueous solution depend on the impurities to be removed and the semiconductor device being cleaned. The composition should be adjusted as appropriate. The ammonia concentration of the diluted ammonia solution should be 0.0 The concentration should be between 1% and 5%, preferably between 0.1% and 0.5%. The hydrogen fluoride concentration of the hydrochloric acid is 0.01 ppm to 100 ppm, preferably 0.1 ppm. It should be between 10 ppm and above.

[0324] For ultrasonic cleaning, a frequency of 200 kHz or higher, preferably 900 kHz or higher, is used. It is preferable to have this. By using this frequency, damage to oxides such as 230b is reduced. It can be reduced.

[0325] Also, the above cleaning process may be performed multiple times, and the cleaning liquid may be changed for each cleaning process. For example as the first cleaning process, a process using diluted hydrofluoric acid or diluted aqueous ammonia may be performed, and as the second cleaning process, a process using pure water or carbonated water may be performed.

[0326] In this embodiment, as the above cleaning process, wet cleaning is performed using diluted hydrofluoric acid and then wet cleaning is performed using pure water or carbonated water. By performing this cleaning process impurities adhering to the surface or diffused inside the oxide 230a, oxide 230b, etc. can be removed Furthermore, the crystallinity of the oxide 230b can be enhanced.

[0327] If the above-mentioned removal of impurities is not performed before forming the insulating film 250A described later, the impurities may remain between the oxide 230a, oxide 230b, conductor 242, insulator 280, etc. and the insulator 250a.

[0328] Heat treatment may be performed after the above etching or after the above cleaning. The heat treatment may be performed at 100 °C or higher and 450°C or lower, preferably 350°C or higher and 400°C or lower. Note that the heat treatment is performed in an atmosphere of nitrogen gas or an inert gas, or an atmosphere containing 10 ppm or more, 1% or more, or 10% or more of an oxidizing gas. For example, the heat treatment is preferably performed in an oxygen atmosphere. Thereby, oxygen can be supplied to the oxide 230a and the oxide 230b to reduce the oxygen deficiency V O Moreover, by performing such heat treatment, the crystallinity of the oxide 23 0b can be improved. Also, the heat treatment may be performed under reduced pressure. Also Alternatively, the material may be heat-treated in an oxygen atmosphere, followed by continuous heat-treatment in a nitrogen atmosphere without exposure to the atmosphere. You may do so.

[0329] Next, an insulating film 250A, which will become the insulator 250a, is deposited (see Figures 17A to 17D). A heat treatment may be performed before the deposition of the insulating film 250A, and this heat treatment may be performed under reduced pressure. The insulating film 250A may be deposited continuously without exposure to air. This process is preferably carried out in an oxygen-containing atmosphere. By performing such a treatment, oxidation The moisture and hydrogen adsorbed on the surface of material 230b are removed, and further oxide 230a, Furthermore, the water and hydrogen concentrations in oxide 230b can be reduced. Heat treatment The temperature is preferably between 100°C and 400°C.

[0330] Insulating film 250A can be produced using methods such as sputtering, CVD, MBE, PLD, and ALD. It can be formed using [a specific method]. In addition, the insulating film 250A has reduced or removed hydrogen atoms. It is preferable to deposit the film using a film deposition method that utilizes a gas. This allows the water in the insulating film 250A to be deposited. The elemental concentration can be reduced. The insulating film 250A comes into contact with the oxide 230b in a later process. Since it becomes an insulator 250a, it is preferable that the hydrogen concentration is reduced in this way.

[0331] Furthermore, it is preferable to deposit the insulating film 250A using the ALD method. The thickness of the insulator 250, which functions as a gate insulating film of the inverter 200, is extremely thin (e.g. For example, a range of 5nm to 30nm, and it is necessary to minimize the variation. In contrast, the ALD method alternately introduces a precursor and a reactant (oxidizing agent). This is a film deposition method, and the film thickness can be adjusted by repeating this cycle. Therefore, precise film thickness adjustment is possible. Thus, miniaturized transistor 200 is required. This enables the achievement of gate insulating film accuracy. Also, as shown in Figures 17B and 17C. As shown, the insulating film 250A is located on the bottom and side surfaces of the opening formed by the insulator 280, etc. Therefore, it is necessary to form a film with good coverage. On the bottom and side surfaces of the opening, the atomic layer is one Since it can be deposited layer by layer, the insulating film 250A can be applied to the opening with good coverage. It can be used to form a thin film.

[0332] Furthermore, for example, when depositing an insulating film 250A using the PECVD method, hydrogen-containing The membrane gas is decomposed in the plasma, generating a large amount of hydrogen radicals. Reduction of hydrogen radicals. The reaction removes oxygen from oxide 230b and V O When H is formed, oxide 2 The hydrogen concentration in 30b increases. However, the insulating film 250A is deposited using the ALD method. This suppresses the generation of hydrogen radicals both when introducing the precursor and when introducing the reactant. Therefore, by forming an insulating film 250A using the ALD method, the oxide can be formed. This prevents the hydrogen concentration in 230b from becoming too high.

[0333] Next, microwave treatment may be performed in an oxygen-containing atmosphere (see Figures 17A to 17D). ). Here, microwave processing refers to, for example, generating a high-density plasma using microwaves. This refers to processing using a device that has a power supply. The dotted lines shown in Figures 17B to 17D are This refers to radio waves such as Kuro waves, RF, oxygen plasma, or oxygen radicals. Microwave The process involves a power supply that generates a high-density plasma using microwaves, for example, a micro It is preferable to use a wave processing device. Furthermore, the microwave processing device applies RF to the substrate side. It may have a power supply. By using high-density plasma, high-density oxygen radicals are generated. It is possible to generate by applying RF to the substrate side. The oxygen ions can be efficiently guided into oxide 230b. The wave treatment is preferably performed under reduced pressure, with a pressure of 60 Pa or higher, preferably 133 Pa. More preferably 200 Pa or more, and even more preferably 400 Pa or more and 700 Pa or less. This should be done. Also, the oxygen flow rate ratio (O2 / O2+Ar) should be 50% or less, preferably 10%. The process should be carried out at a concentration of 30% or less. Furthermore, the processing temperature should be 750°C or lower, preferably 500°C or lower. For example, it should be done at around 400°C. Also, after oxygen plasma treatment, expose to the outside air. Heat treatment may be performed continuously without interruption.

[0334] As shown in Figures 17B to 17D, microwave processing is performed in an oxygen-containing atmosphere. Using microwaves or high-frequency waves such as RF, oxygen gas is turned into plasma, and the oxygen plasma It is possible to apply the agent to the region between the conductors 242a and 242b of oxide 230b. It is possible to irradiate region 230bc with microwaves or high-frequency waves such as RF at this time. Yes, it is possible. In other words, in the region 230bc shown in Figure 3, microwaves or high-frequency waves such as RF, acid It is possible to apply elementary plasma, etc. Through the action of plasma, microwaves, etc., V in region 230bc O By cleaving H, hydrogen H can be removed from region 230bc. Furthermore, in region 230bc, "V OH → H + V O The reaction " occurred in area 230 The hydrogen concentration in bc can be reduced. Therefore, the oxygen deficiency in region 230bc, and V O This can reduce H and lower the carrier concentration. Furthermore, it forms in region 230bc. In the oxygen vacancies created, oxygen radicals generated by the oxygen plasma, or contained in the insulator 250, are added. By supplying oxygen, the oxygen deficiency in region 230bc is further reduced, and the carrier The concentration can be reduced.

[0335] On the other hand, in regions 230ba and 230bb shown in Figure 3, there are conductors 242a and A conductor 242b is provided. As shown in Figures 17B to 17D, the conductor 242a And conductor 242b is affected by microwaves, or high-frequency waves such as RF, oxygen plasma, etc. Because it is shielded, these effects do not extend to regions 230ba and 230bb. As a result, microwave processing is performed in regions 230ba and 230bb, V O H This prevents a decrease in carrier concentration because it does not result in a reduction or an oversupply of oxygen. Cut.

[0336] In this way, oxygen vacancies are selectively created in the oxide semiconductor region 230bc, and V O H By removing it, region 230bc can be made type i or substantially type i. Furthermore, Excessive flow in areas 230ba and 230bb, which function as drain areas or drain areas. This suppresses the supply of oxygen and maintains n-type formation. This suppresses fluctuations in the electrical characteristics of transistor 200, preventing variations in the electrical characteristics of transistor 200 within the substrate surface. It can suppress the growth.

[0337] Therefore, it is possible to provide a semiconductor device with less variation in transistor characteristics. Furthermore, it is possible to provide semiconductor devices with good reliability. In addition, it has good electrical characteristics. We can provide semiconductor devices.

[0338] In microwave processing, the electromagnetic interaction between microwaves and molecules in oxide 230b is In some cases, thermal energy is directly transferred to oxide 230b. Furthermore, oxide 230b may be heated. Such heat treatment is microwave annealing. It is sometimes called "oil." By performing microwave processing in an oxygen-containing atmosphere, oxygen annealing occurs. In some cases, an effect equivalent to that can be obtained. Also, if oxide 230b contains hydrogen, The thermal energy is transferred to the hydrogen in oxide 230b, and the activated hydrogen then turns into oxide It is possible that it will be released from 230b.

[0339] Next, an insulating film 250B, which will become the insulator 250b, is deposited (see Figures 18A to 18D). The 250B insulating film is deposited using sputtering, CVD, MBE, PLD, and ALD. The film can be formed using methods such as [method name]. The insulating film 250B has a function that suppresses the diffusion of oxygen. It is preferable to form it using an insulator. With this configuration, the insulator 2 This can suppress the diffusion of oxygen contained in 50a into the conductor 260. In other words, This can suppress the decrease in the amount of oxygen supplied to the oxide 230. Also, the insulator 250a The oxidation of the conductor 260 by the contained oxygen can be suppressed. For example, insulating film 250 A is provided using a material that can be used for the insulator 250 described above, and the insulating film 250B is It can be provided using the same material as the insulator 222.

[0340] Specifically, the insulating film 250B is made of hafnium, aluminum, gallium, and yttrium. Umium, Zirconium, Tungsten, Titanium, Tantalum, Nickel, Germanium, Magnesium Metal oxides or oxides containing one or more metals selected from nesium, etc. Any metal oxide that can be used as 230 can be used. In particular, aluminum It is preferable to use an insulator containing an oxide of one or both of hafnium.

[0341] In this embodiment, silicon oxide nitride is used as the insulating film 250A by CVD, and insulation Hafnium oxide is deposited as film 250B using the thermal ALD method.

[0342] Microwave treatment may be performed after the deposition of the insulating film 250B. This microwave treatment is performed before The microwave treatment conditions described above, which are performed after the deposition of the insulating film 250A, may also be used. The microwave treatment performed after deposition of 50A is omitted, and the microwave treatment is performed after deposition of insulating film 250B. You may proceed with the processing.

[0343] Furthermore, after the deposition of insulating film 250A and after the deposition of insulating film 250B, the microwaves After processing, heat treatment may be performed while maintaining a reduced pressure state. In insulating film 250A, insulating film 250B, oxide 230b, and oxide 230a It can efficiently remove hydrogen. Also, some of the hydrogen is absorbed by conductor 242 (conductor 2 It may be gettered by 42a and conductor 242b), or by microwave. Even if the step of performing heat treatment while maintaining a reduced pressure state after processing is repeated multiple times Good. By repeatedly performing the heat treatment, the insulating film 250A, the oxide 230b, and the acid Hydrogen in compound 230a can be removed even more efficiently. The heat treatment temperature is as follows: It is preferable to use a temperature of 300°C to 500°C. Furthermore, the above microwave treatment, i.e. Microwave annealing may also serve as the heat treatment. By microwave annealing, oxide 2 If 30b, etc., is sufficiently heated, this heat treatment may not be necessary.

[0344] Furthermore, microwave treatment is performed to modify the film quality of insulating film 250A and insulating film 250B. This suppresses the diffusion of hydrogen, water, impurities, etc. Therefore, the conductor 260 and Through subsequent processes such as deposition of a conductive film or post-treatment such as heat treatment, the insulator 250 is used This suppresses the diffusion of hydrogen, water, impurities, etc., into oxide 230b, oxide 230a, etc. It is possible.

[0345] Next, a conductive film to become conductor 260a and a conductive film to become conductor 260b are deposited in sequence. The deposition of the conductive film that will become the conductive body 260a and the conductive film that will become the conductive body 260b is performed by sputtering. This can be carried out using methods such as CVD, MBE, PLD, and ALD. In terms of form, titanium nitride is deposited as a conductive film to become conductor 260a using the ALD method, and conductor 2 Tungsten is deposited as the conductive film 60b using the CVD method.

[0346] Next, CMP treatment is performed to create insulating film 250A, insulating film 250B, and conductive material 260a. Polish the conductive film and the conductive film that will become the conductor 260b until the insulator 280 is exposed. By doing so, the insulator 250a, insulator 250b, conductor 260a, and conductor 260b Formed (see Figures 19A to 19D). As a result, the insulator 250 is formed of oxide 230 The opening that reaches b and the inner walls (side walls and bottom surface) of the groove of oxide 230b are arranged to cover them. It is placed there. Also, the conductors 260a and 260b are connected via the insulator 250, It is positioned to fill the opening and the groove mentioned above.

[0347] Next, a heat treatment may be performed under the same conditions as the heat treatment described above. In this embodiment, nitrogen The process is carried out at a temperature of 400°C for 1 hour in a plain atmosphere. This heat treatment causes the insulator 250 Furthermore, the moisture and hydrogen concentrations in the insulator 280 can be reduced. After heat treatment, the insulator 282 may be deposited continuously without exposure to the atmosphere.

[0348] Next, on the insulator 250, on the conductor 260, and on the insulator 280, insulator 282a Insulator 282b is formed continuously (see Figures 20A to 20D). Insulator 282 The deposition of film a and insulator 282b was carried out by sputtering, CVD, MBE, and PLD methods. This can be done using methods such as ALD. The film is preferably formed using the sputtering method. Hydrogen does not necessarily have to be used as the deposition gas. By using the sputtering method, the hydrogen concentration in insulator 282a and insulator 282b is reduced. The degree can be reduced.

[0349] In this embodiment, the insulator 282a and the insulator 282b are an atmosphere containing oxygen gas. Using an aluminum target in an atmospheric environment, aluminum oxide is produced by pulsed DC sputtering. A film is formed. At this time, oxygen can be added to the insulator 280. Also, pulse D By using the C sputtering method, the film thickness distribution can be made more uniform, and the sputtering rate and The film quality can be improved. Furthermore, the RF power applied to the substrate is 1.86 W / cm². 2 below Preferably, 0 W / cm². 2 More than 0.31W / cm 2 The following applies: Reduce RF power This reduces the amount of oxygen injected into the insulator 280. Therefore, the insulator 282a reduces the RF power applied to the substrate to 0 W / cm². 2 It is formed as a film and an insulator 282b applies an RF power of 0.31 W / cm² to the substrate. 2 It is used to form a film.

[0350] Next, a portion of the insulator 282a and a portion of the insulator 282b are processed to create an opening region 400. a and opening region 400b are formed (see Figures 21A to 21D). Opening region 400 a overlaps with at least a portion of the conductor 242a, and the aperture region 400b overlaps with at least the conductor 2 It overlaps with a portion of 42b. It also overlaps with the opening of the insulator 282 in the opening region 400, Grooves may be formed on the edge 280. Part of the insulator 282a, part of the insulator 282b The processing of the insulator 280 may be done using wet etching, but dry etching may be used. Using a cutting tool is preferable for microfabrication. Also, the depth of the groove in the insulator 280 is deep At most, it is sufficient to expose the upper surface of the insulator 272, for example, the maximum film thickness of the insulator 280. It should be between 1 / 4 and 1 / 2 of the thickness.

[0351] Next, insulators 282a, 282b, 280, 272, and 222 , and process the insulator 216 until it reaches the upper surface of the insulator 214 (Figures 22A to 22A). See D.) The process may use wet etching, but dry etching may be used. Having it present is preferable for microfabrication.

[0352] Next, a heat treatment is preferable. The heat treatment is preferably performed at a temperature of 250°C to 650°C. Alternatively, the process should be carried out at a temperature between 400°C and 600°C. Furthermore, this heat treatment is performed on oxide film 243A. It is preferable that the heat treatment temperature is lower than the heat treatment temperature performed after film formation. Note that the heat treatment also uses nitrogen gas. Alternatively, the process is carried out in an inert gas atmosphere. By performing this heat treatment, the contents of the insulator 280 are Oxygen and hydrogen bound to that oxygen are released to the outside through the opening region 400. Yes, it is possible. At the same time, insulator 282a, insulator 282b, insulator 280, insulator 272, insulation The insulating material is insulated from the side surface of the insulating material 280 formed by processing the body 222 and the insulating material 216. The oxygen contained in body 280, and the hydrogen bonded with that oxygen, can be released to the outside. Furthermore, hydrogen that combines with oxygen is released as water. Therefore, the hydrogen contained in insulator 280 This reduces unwanted oxygen and hydrogen. The heat treatment is performed in the opening region 400. This is done after the formation of insulator 282a, insulator 282b, insulator 280, insulator 27 2. This may be performed after processing the insulators 222 and 216.

[0353] In this way, the oxygen-containing insulator 280 that is desorbed by heating is released from region 230bc To supply sufficient oxygen to the area and its vicinity, and to prevent the supply of excessive amounts of oxygen. This can be done. In addition, at this time, it is possible to suppress the mixing of hydrogen into region 230bc. This allows for oxygen deficiency in region 230bc, and V O Remove H, and region 230b c can be of type i or substantially of type i. Therefore, the electrical characteristics of transistor 200 This can suppress fluctuations in performance and improve reliability. Furthermore, it allows for the use of two transistors within the substrate surface. This can suppress variations in the electrical characteristics of 00.

[0354] Next, an insulator 283 is formed on top of the insulators 214 and 282b (Figure 23A). (See Figure 23D.) The insulator 283 is located in the opening region 400a and the opening region 400b. It is preferable that it be in contact with the insulator 280. The insulator 283 is formed by sputtering. This can be done using methods such as CVD, MBE, PLD, or ALD. Insulator The deposition of film 283 is preferably carried out using the sputtering method. Hydrogen is used as the deposition gas. By using the sputtering method, which is not strictly necessary, the hydrogen concentration in the insulator 283 can be reduced. This can be done. In addition, the insulator 283 may have a multilayer structure. For example, sputtering method A silicon nitride film is formed using [a specific method], and silicon nitride is then applied to the silicon nitride using the ALD method. A film may be formed using this method.

[0355] Here, the insulator 283 is formed in an island shape, consisting of insulator 216, insulator 222, and insulator 2 72, is provided covering insulator 280, insulator 282a, and insulator 282b. By encasing the transistor 200 with the highly barrier-oriented insulators 283 and 214, This prevents moisture and hydrogen from entering from the outside.

[0356] In the above, the transistor 200 is enclosed by the insulator 283 and the insulator 214. The present invention is not limited to the configuration described above. For example, Figures 22A to 22A In the process shown in 22D, the insulator 214 is also processed into an island shape, exposing the upper surface of the insulator 212. Alternatively, the transistor 200 may be enclosed by insulators 283 and 212. In this case, the upper surface of the insulator 283 is in contact with the upper surface of the insulator 212 in the sealing portion 265.

[0357] Next, an insulating film, which will become an insulating film 274, is formed on the insulating film 283 (Figures 24A to 24). (See D.) The insulating film that will become the insulator 274 is deposited by sputtering, CVD, or MBE. This can be done using methods such as the PLD method or the ALD method. In this embodiment, insulation Silicon oxide is deposited as the insulating film for body 274 by the CVD method.

[0358] Next, the insulator 274 is polished by CMP until the insulator 283 is exposed. This is embedded within the sealing portion 265, the opening region 400a, and the opening region 400b. In this manner, an insulator 274 is formed. (See Figures 23A to 23D.) Here, the insulator The top surface of 274 is flattened, and the height of the top surface of insulator 274 and the top surface of insulator 283 The heights are roughly the same. The CMP process removes a portion of the upper surface of the insulator 283. In some cases, the insulator 28 is located within the opening region 400a and the opening region 400b. In some cases, an insulator 274 may be formed to fill the recess formed in 3.

[0359] Next, an insulator 286 is deposited on the insulator 274 and the insulator 283 (Figure 24A). (See Figure 24D.) The insulator 286 was deposited by sputtering, CVD, or MBE. This can be done using methods such as the PLD method or the ALD method. In this embodiment, the insulator As 286, silicon oxide is deposited using the sputtering method.

[0360] Next, an opening that penetrates the opening region 400a and reaches the conductor 242a, and the opening region 400 An opening is formed that penetrates b and reaches the conductor 242b (see Figures 24A to 24D). . ) Here, the opening that reaches the conductor 242a is, in a top view, the opening region 400a The opening located inside the opening of the insulator 282 and reaching the conductor 242b is, when viewed from above, Therefore, it is preferable that it be located inside the opening of the insulator 282 in the opening region 400b.

[0361] The formation of the openings reaching the conductor 242 is done by forming a mask using lithography, and Edge 286, insulator 274, insulator 283, insulator 280, insulator 272, and insulator 271 can be removed by anisotropic etching. The opening that reaches the conductor 242 is Due to its high aspect ratio shape, it is preferable to use a dry etching method. The above-mentioned dry etching apparatus can be used for the etching process.

[0362] In this case, if the aperture region 400 and the conductor 240 are not superimposed, the conductor 242 is reached. To form the opening, a thick interlayer insulating film is used, consisting of insulator 286, insulator 283, and The edge 282 and the insulator 280 need to be opened. Insulator 286 and insulator 2 80 is silicon oxide, insulator 283 is silicon nitride, and insulator 282 is aluminum It mainly consists of fluorine oxide. Therefore, using an etching gas containing fluorine, the above opening is When formed in a single unit, the insulators 286, 280, and 283 can be formed relatively easily. While it is possible to form an opening, it becomes difficult to form an opening in the insulator 282.

[0363] When removing the insulator 282 using an etching gas containing fluorine, the insulator 282 is Since it is preferable that the kinetic energy of the irradiated ions is large, a high-power bias is applied to the substrate. The process involves applying the material and performing dry etching. At this time, the opening that reaches the conductor 242 is opened. If the pattern is formed using only a resist mask, the resist will be formed during the dry etching process. There is a risk of the mask being destroyed. Therefore, in addition to the resist mask, tungsten or similar material may be used. It is necessary to form a hard mask. Also, an etching gas containing fluorine is used. When removing the insulator 282, the cross-sectional shape of the opening of the insulator 282 is the same as the opening of the insulator 280. The cross-sectional shape may be significantly tapered compared to the mouth's cross-sectional shape.

[0364] However, in this embodiment, in the process shown in Figures 21A to 21D, the opening region Since the insulator 282 in region 400 has been removed, the formation of an opening that reaches the conductor 242 Therefore, it is not necessary to remove the insulator 282. Thus, in this embodiment, Since it is not necessary to remove the insulator 282 under harsh conditions, the opening that reaches the conductor 242 is It can be formed more easily and in a shape that is closer to vertical. Thus, the form of this embodiment By using the method shown, semiconductor devices can be manufactured with high productivity.

[0365] Furthermore, when aluminum oxide is used for insulators 271 and 272, the conductor In forming the 242 openings, these also need to be etched. However, Compared to the edge body 282, the insulators 271 and 272 have a thinner film thickness, so dry edge The insulators 271 and 272 can be easily removed using the ching method.

[0366] Next, an insulating film to become the insulator 241 is formed, and the insulating film is anisotropically etched, An insulator 241 is formed in the opening that reaches the conductor 242. The insulating film that becomes the insulator 241 The film deposition is carried out using sputtering, CVD, MBE, PLD, or ALD methods. This can be done. The insulating film that becomes the insulator 241 has a function that suppresses oxygen permeation. It is preferable to use an insulating film having the following properties. For example, using the ALD method, aluminum oxide It is preferable to deposit a film of [unspecified material]. Alternatively, silicon nitride can be deposited using the PEALD method. This is preferable. Silicon nitride is preferred because it has high barrier properties against hydrogen.

[0367] 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 passed through the conductors 240a and 240b. This prevents substances from contaminating oxide 230.

[0368] Next, the conductors 240a and 240b are placed in the opening that reaches the conductor 242. A conductive film is formed. The conductive films that will become conductor 240a and conductor 240b are made of water, hydrogen, etc. It is desirable to have a laminated structure that includes a conductor that has the function of suppressing the transmission of impurities. For example, tantalum nitride, titanium nitride, etc., and tungsten, molybdenum, copper, etc. It can be laminated. The conductive film that will become the conductor 240 can be deposited by sputtering, CV This can be performed using methods such as the D method, MBE method, PLD method, or ALD method.

[0369] Next, by performing CMP treatment, the conductive films that become conductor 240a and conductor 240b are formed. A portion is removed, exposing the upper surface of the insulator 286. As a result, an opening reaches the conductor 242. The conductive film remains only on the portion, resulting in a flat upper surface for the conductor 240a and conductor 240 b can be formed (see Figures 1A to 1D). In this way, the opening region 400 When an insulator 241 and a conductor 240 are formed on the inside, the insulator 241 and the conductor 240 This structure does not come into contact with the insulator 282. Furthermore, the CMP treatment results in the insulator 286 A portion of the top surface may be removed.

[0370] In this way, the opening region 400 and the conductor 240 which functions as a plug are, when viewed from above By stacking and forming them, the occupied area of ​​the transistor 200 is not greatly increased. A region 400 can be provided. This allows multiple transistors 200 to be arranged at high density. Even with the established design, the placement of transistor 200 will be changed to create surplus space. An opening region 400 can be provided without this. By adopting this configuration, miniaturization Alternatively, it is possible to provide a semiconductor device that can be highly integrated.

[0371] 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.

[0372] 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 of the conductor 240b, and the conductor 246b that is in contact with the upper surface of the conductor 240b Formed. Although not shown in the diagram, at this time, the conductor 246a and conductor 246b and the insulator 28 A portion of the insulator 286 in the region that does not overlap with 6 may be removed.

[0373] Furthermore, a dicing line (scribe line, division line, or A cutting line (sometimes called a cutting line) may be provided. The substrate on which the semiconductor device is formed is dicing Because it is separated at the grind, the group of transistors surrounded by the sealing portion 265 is one chip and It will then be removed.

[0374] Based on the above, a semiconductor device having the transistor 200 shown in Figures 1A to 1D is fabricated. This is possible. As shown in Figures 1A to 1D and 5A to 24D, in this embodiment By using the semiconductor device fabrication method shown, transistor 200 can be manufactured with high productivity. It is possible.

[0375] <Microwave Processing Equipment> The following describes a microwave processing apparatus that can be used in the above-mentioned semiconductor device fabrication method. I will explain.

[0376] First, Figure 2 shows the configuration of a manufacturing equipment that minimizes the inclusion of impurities during the manufacturing of semiconductor devices and other equipment. 6. This will be explained using Figures 27 and 28.

[0377] Figure 26 schematically shows a top view of the single-wafer multi-chamber manufacturing apparatus 2700. The manufacturing apparatus 2700 includes a cassette port 2761 for housing the substrate and a substrate alignment An alignment port 2762 for performing an atmospheric substrate supply chamber 2701 and an atmospheric substrate From the board supply room 2701, the substrate is transported to the atmospheric substrate transport room 2702, and the substrate is brought in. Furthermore, a load lock chamber that switches the pressure inside the room from atmospheric pressure to reduced pressure, or from reduced pressure to atmospheric pressure. 2703a, and the removal of the substrate, and the room pressure from reduced pressure to atmospheric pressure, or from atmospheric pressure Unload lock chamber 2703b for switching to reduced pressure, and transport chamber 2 for transporting substrates in vacuum. 704, chamber 2706a, chamber 2706b, chamber 2706c It has a chamber 2706d and

[0378] Furthermore, the atmospheric substrate transport chamber 2702 is connected to the load lock chamber 2703a and the unload lock chamber. It is connected to the loading lock chamber 2703b, and the load lock chamber 2703a and the unload lock chamber 270 3b is connected to transport chamber 2704, and transport chamber 2704 is connected to chamber 2706a, It connects to bar 2706b, chamber 2706c, and chamber 2706d.

[0379] Furthermore, gate valves GV are provided at the connection points of each chamber, and the atmospheric substrate supply chamber 270 Except for chamber 1 and the atmospheric substrate transport chamber 2702, each chamber can be independently maintained in a vacuum state. Furthermore, a transport robot 2763a is provided in the atmospheric substrate transport chamber 2702, and transport A transport robot 2763b is installed in the transport room 2704. The transport robot 2763b can transport the substrates within the manufacturing apparatus 2700. ru.

[0380] The back pressure (total pressure) in the transport chamber 2704 and each chamber is, for example, 1 × 10⁻⁶ -4 Pa or less Preferably 3 × 10 -5 Pa or less, more preferably 1 × 10⁻⁶ -5 It should be Pa or less. Furthermore, the mass-to-charge ratio (m / z) of the transport chamber 2704 and each chamber is 18 for gas molecules. The partial pressure of an atom is, for example, 3 × 10⁻¹⁰ -5 Pa or less, preferably 1 × 10⁻⁶ -5 Pa and below, More preferably 3 × 10 -6 The Pa level should be less than or equal to the Pa level. Also, the transport chamber 2704 and each chamber. The partial pressure of a gas molecule (atom) with a m / z of 28 is, for example, 3 × 10⁻¹⁰ -5 Pa or below preferred Or 1 x 10 -5 Pa or less, more preferably 3 × 10 -6 It shall be less than Pa. The partial pressure of gas molecules (atoms) in supply chamber 2704 and each chamber with a m / z of 44 is, for example, ba, 3 x 10 -5 Pa or less, preferably 1 × 10⁻⁶ -5 Pa or less, more preferably 3 × 1 0 -6 It should be Pa or less.

[0381] The total pressure and partial pressure in the transport chamber 2704 and each chamber were measured using a mass spectrometer. It can be measured. For example, with a quadrupole mass spectrometer (Q-mas) manufactured by ULVAC, Inc. Also called s.) You can use Qulee CGM-051.

[0382] Furthermore, the transport chamber 2704 and each chamber are constructed to minimize external or internal leaks. It is desirable to make it a set. For example, the leak rate of the transport chamber 2704 and each chamber is , 3 x 10 -6 Pa·m 3 / s or less, preferably 1 × 10 -6 Pa·m 3 Set to / s or less. Also, for example, the leak rate of a gas molecule (atom) with m / z 18 is 1 × 10⁻⁶. -7 P a·m 3 / s or less, preferably 3 × 10 -8 Pa·m 3 It should be less than or equal to / s. Also, for example, The leak rate of a gas molecule (atom) with m / z 28 is 1 × 10⁻⁶ -5 Pa·m 3 / s or less Preferably 1 × 10 -6 Pa·m 3 It should be less than or equal to / s. Also, for example, if m / z is 44 The leak rate of gas molecules (atoms) is 3 × 10 -6 Pa·m 3 / s or less, preferably 1× 10 -6 Pa·m 3 Set to / s or less.

[0383] Regarding the leak rate, the total pressure and partial pressure were measured using the aforementioned mass spectrometer. Then we can derive it. The leak rate depends on external leaks and internal leaks. The problem is the inflow of gas from outside the vacuum system due to a tiny hole or a faulty seal. Internal leaks are caused by leaks from partitions such as valves within a vacuum system or by the release of gas from internal components. This is caused by [something]. In order to keep the leak rate below the above-mentioned value, external leaks and internal leaks are [something]. We need to take measures from both sides.

[0384] For example, the opening and closing parts of the conveying chamber 2704 and each chamber are sealed with metal gaskets. It is good to do so. Metal gaskets are made of iron fluoride, aluminum oxide, or chromium oxide. It is preferable to use a metal gasket that is coated. Metal gaskets have better adhesion than O-rings. External leakage can be reduced. Also, by using iron fluoride, aluminum oxide, chromium oxide, etc. By using a metal passivation coating, impurities released from the metal gasket are contained. This suppresses the release of gases and reduces internal leakage.

[0385] Furthermore, as a component of the manufacturing apparatus 2700, aluminum with low emission gas containing impurities is used. It uses nium, chromium, titanium, zirconium, nickel, or vanadium. Also, the previous A metal with low emission gases containing the aforementioned impurities is coated onto an alloy containing iron, chromium, nickel, etc. It may also be used in reverse. Alloys containing iron, chromium, and nickel are rigid and heat resistant. Furthermore, it is suitable for processing. Here, in order to reduce the surface area, the surface irregularities of the material are polished. By reducing these factors, the amount of emitted gas can be reduced.

[0386] Alternatively, the components of the aforementioned manufacturing apparatus 2700 may be made of iron fluoride, aluminum oxide, chromium oxide, etc. Any covering will do.

[0387] The components of the manufacturing apparatus 2700 are preferably made of metal as much as possible, such as quartz. When installing viewing windows or similar devices, the surface should be treated with iron fluoride to suppress the release of gases. It is best to coat it thinly with aluminum oxide, chromium oxide, or similar materials.

[0388] The adsorbed material present in the transport chamber 2704 and each chamber is adsorbed to the inner walls, etc. This does not affect the pressure in the transport chamber 2704 and each chamber, however, the pressure in the transport chamber 2704 and each chamber This causes gas release when exhausting the chamber. Therefore, the leak rate and exhaust speed are related. Although there is no direct connection, a pump with high exhaust capacity is used to transport chamber 2704 and each chamber. It is important to remove as much of the adsorbed material as possible and to evacuate the system beforehand. To promote the desorption of adsorbed material, the transport chamber 2704 and each chamber may be baked. Baking can increase the desorption rate of adsorbed substances by about 10 times. The process should be carried out at a temperature between 100°C and 450°C. At this time, an inert gas is introduced into the transport chamber 2704. Furthermore, when adsorbed substances are removed while being introduced into each chamber, they are difficult to remove by exhaust alone. The desorption rate of water and other substances can be further increased. By heating it to a temperature similar to that of King, the desorption rate of adsorbed substances can be further increased. It is preferable to use a noble gas as the inert gas in this case.

[0389] Alternatively, by introducing an inert gas such as a heated noble gas or oxygen into the transport chamber 27 The pressure in 04 and each chamber is increased, and after a certain period of time, the transfer chamber 2704 and each It is preferable to perform a process to exhaust the chamber. By introducing heated gas into the conveying chamber 2704 And adsorbed material can be removed from each chamber, transport chamber 2704 and each chamber This process can reduce impurities present in the bar. Note that this process should be repeated between 2 and 30 times. It is more effective to repeat the procedure, preferably between 5 and 15 times. Specifically, warm An inert gas whose temperature is between 40°C and 400°C, preferably between 50°C and 200°C. By introducing oxygen, etc., the pressure inside the transport chamber 2704 and each chamber can be raised to 0.1 Pa or less. Above 10 kPa or less, preferably 1 Pa or more and 1 kPa or less, more preferably 5 Pa or more and 1 The pressure should be 00 Pa or less, and the period for maintaining the pressure should be 1 minute or more and 300 minutes or less, preferably 5 minutes or more and 120 minutes or less. It should be less than a minute. After that, transport chamber 2704 and each chamber should be kept for 5 minutes to 300 minutes. Preferably, exhaust the system for a period of 10 minutes to 120 minutes.

[0390] Next, the cross-sectional model of chambers 2706b and 2706c is shown in Figure 27. I will explain using a diagram.

[0391] Chambers 2706b and 2706c are, for example, used to apply microwaves to the workpiece. This is a chamber capable of performing processing. Note that chamber 2706b and chamber The only difference between this and the 2706c is the atmosphere used during microwave processing. Other configurations Since these points are common to all, they will be explained together below.

[0392] Chambers 2706b and 2706c are connected to slot antenna board 2808. It has a dielectric plate 2809, a substrate holder 2812, and an exhaust port 2819. Outside chambers 2706b and 2706c, etc., there is a gas supply source 2801 and Valve 2802, high-frequency generator 2803, waveguide 2804, and mode converter 2805 And gas tube 2806, waveguide 2807, matching box 2815, and high-frequency power supply. A 2816, a vacuum pump 2817, and a valve 2818 are provided.

[0393] The high-frequency generator 2803 is connected to the mode converter 2805 via the waveguide 2804. The mode converter 2805 is connected to the slot antenna plate 2808 via the waveguide 2807. It continues. The slot antenna plate 2808 is positioned in contact with the dielectric plate 2809. Furthermore, the gas supply source 2801 is connected to the mode converter 2805 via the valve 2802. And the gas passes through the mode converter 2805, waveguide 2807 and dielectric plate 2809. Gas is supplied to chambers 2706b and 2706c via tube 2806. Furthermore, the vacuum pump 2817 is connected to the valve 2818 and exhaust port 2819. It has the function of exhausting gases, etc., from chamber 2706b and chamber 2706c. Furthermore, the high-frequency power supply 2816 is connected to the board holder 2812 via the matching box 2815. Connecting.

[0394] The substrate holder 2812 has the function of holding the substrate 2811. For example, substrate 2811 It has the function of electrostatically or mechanically chucking. Also, high-frequency power supply 2816 or It functions as an electrode to which power is supplied. It also has a heating mechanism 2813 inside. It has a function to heat the substrate 2811.

[0395] Vacuum pump 2817 can be used in various ways, such as dry pumps and mechanical booster pumps. Ion pumps, titanium sublimation pumps, cryopumps, or turbomolecular pumps These can be used. In addition, a cryotrap can be used in addition to the vacuum pump 2817. It is acceptable. Using a cryopump and cryotrap allows for efficient water exhaust. This is particularly preferable.

[0396] Furthermore, the heating mechanism 2813 may be a heating mechanism that uses, for example, a resistance heating element. Alternatively, by heat conduction or thermal radiation from a medium such as a heated gas, It may also be used as a heating mechanism. For example, GRTA (Gas Rapid Thermature) (Lamp Annealing) or LRTA (Lamp Rapid Thermal A RTA (Rapid Thermal Annealing) such as annealing This can be used. GRTA performs heat treatment using high-temperature gas. An inert gas is used.

[0397] Furthermore, the gas supply source 2801 is connected to the purifier via a mass flow controller. It is acceptable to use a gas with a dew point of -80°C or lower, preferably -100°C or lower. It is preferable to use oxygen gas, nitrogen gas, and noble gases (such as argon gas). Use it.

[0398] Examples of dielectric plates 2809 include silicon oxide (quartz) and aluminum oxide (aluminum oxide). Mina or yttrium oxide (yttria) can be used. Also, dielectric plate 28 Another protective layer may be formed on the surface of 09. The protective layer may be magnesium oxide. Zium, titanium dioxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, Dielectric plate: Silicon oxide, aluminum oxide, or yttrium oxide can be used. 2809 will be exposed to the particularly high-density region of the high-density plasma 2810, which will be described later. Therefore, damage can be mitigated by providing a protective layer. As a result, particles during processing This can suppress increases in the number of cases, etc.

[0399] The high-frequency generator 2803 can handle frequencies such as 0.3 GHz to 3.0 GHz, and 0.7 GHz. Generates microwaves between z and 1.1 GHz, or between 2.2 GHz and 2.8 GHz. It has the function of causing the microwaves generated by the high-frequency generator 2803 to be transmitted to the waveguide 2804. This is transmitted to the mode converter 2805 via [a certain method]. In the mode converter 2805, the TE mode is [a certain method]. The transmitted microwaves are converted to TEM mode. Then, the microwaves are transmitted through waveguide 280. It is transmitted to the slot antenna board 2808 via 7. The slot antenna board 2808 has multiple A slot hole is provided, and microwaves pass through the slot hole and the dielectric plate 2809. Then, an electric field is generated below the dielectric plate 2809, and the high-density plasma 2810 It can be generated. The high-density plasma 2810 is supplied from the gas supply source 2801. Depending on the type of gas, ions and radicals exist. For example, oxygen radicals exist. ru.

[0400] At this time, the substrate 2811 is exposed to ions and radicals generated in the high-density plasma 2810. This allows for modification of films on substrate 2811. Furthermore, the high-frequency power supply 2816 It may be preferable to apply a bias to the substrate 2811 side using the high-frequency power supply 28 16 includes, for example, RF (Radio Frequency) with frequencies such as 13.56MHz and 27.12MHz. A high frequency power supply can be used. By applying a bias to the circuit board, Ions in the density plasma 2810 can be efficiently delivered deep into openings such as films on the substrate 2811. It can be achieved.

[0401] For example, in chamber 2706b or chamber 2706c, gas supply source 2801 or By introducing oxygen, oxygen radical treatment using high-density plasma 2810 can be performed. can.

[0402] Next, the cross-sectional model of chambers 2706a and 2706d is shown in Figure 28. I will explain using a diagram.

[0403] Chambers 2706a and 2706d are, for example, used to expose the workpiece to electromagnetic waves. This is a chamber capable of firing. Note that chamber 2706a and chamber 2 The only difference between the 706d and this model is the type of electromagnetic wave they use. Other components are the same. Since there is a lot of information, the following explanation will be summarized.

[0404] Chambers 2706a and 2706d are one or more lamps 2820 It also includes a substrate holder 2825, a gas inlet 2823, and an exhaust port 2830. Outside of chambers 2706a and 2706d, etc., there is a gas supply source 2821 Valve 2822, vacuum pump 2828, and valve 2829 are provided.

[0405] The gas supply source 2821 is connected to the gas inlet 2823 via a valve 2822. The vacuum pump 2828 is connected to the exhaust port 2830 via valve 2829. 2820 is positioned opposite the board holder 2825. The board holder 2825 is It has the function of holding the substrate 2824. The substrate holder 2825 also has a heating mechanism inside. It has a component 2826 and a function to heat the substrate 2824.

[0406] Lamp 2820, for example, has a function that emits electromagnetic waves such as visible light or ultraviolet light. Any light source with the necessary properties can be used. For example, wavelengths between 10 nm and 2500 nm, and between 500 nm. It emits electromagnetic waves with a peak above 2000 nm or below, or between 40 nm and 340 nm. A light source with the necessary functionality should be used.

[0407] For example, lamp 2820 could be a halogen lamp, a metal halide lamp, or a xenon lamp. Arc lamps, carbon arc lamps, high-pressure sodium lamps, or high-pressure mercury lamps, etc. You can use this light source.

[0408] For example, some or all of the electromagnetic waves emitted from lamp 2820 are transmitted to substrate 2824 By being absorbed, the film on the substrate 2824 can be modified. For example, the birth of defects It is possible to create or reduce impurities, or remove them. Note that while heating the substrate 2824 This process allows for efficient generation or reduction of defects, or removal of impurities.

[0409] Alternatively, for example, electromagnetic waves emitted from lamp 2820 may affect the substrate holder 2825 The circuit board 2824 may be heated by adding heat to the inside of the circuit board holder 2825. It is not necessary to have a thermal mechanism 2826.

[0410] For vacuum pump 2828, refer to the description for vacuum pump 2817. Also, heating machine Structure 2826 refers to the description of the heating mechanism 2813. Also, gas supply source 2821 See the description for gas source 2801.

[0411] The microwave processing apparatus that can be used in this embodiment is not limited to the above. Figure 29 shows The microwave processing apparatus 2900 shown can be used. Quartz tube 2901, gas supply source 2801, valve 2802, high-frequency generator 2803, wave guide Pipe 2804, gas pipe 2806, vacuum pump 2817, valve 2818, and exhaust port 28 It has 19. In addition, the microwave processing apparatus 2900 has multiple substrates inside the quartz tube 2901. A substrate holder 2 that holds 2811 (2811_1 to 2811_n, where n is an integer of 2 or greater). It has 902. In addition, the microwave processing apparatus 2900 has heating on the outside of the quartz tube 2901. It may have means 2903.

[0412] The microwaves generated by the high-frequency generator 2803 are transmitted through the waveguide 2804 to the quartz tube 2 The light is directed onto the substrate located inside 901. The vacuum pump 2817 is directed via valve 2818. It is connected to the exhaust port 2819, and the pressure inside the quartz tube 2901 can be adjusted. Furthermore, the gas supply source 2801 is connected to the gas pipe 2806 via the valve 2802. Furthermore, the desired gas can be introduced into the quartz tube 2901. This allows the substrate 2811 inside the quartz tube 2901 to be heated to a desired temperature. The heating means 2903 may heat the gas supplied from the gas supply source 2801. The microwave processing device 2900 heats and microwaves the substrate 2811. The processes can be performed simultaneously. In addition, after heating the substrate 2811, microwave processing is performed. This can be done. In addition, after microwave treatment of the substrate 2811, heat treatment can be performed. It is possible to do so.

[0413] Substrates 2811_1 to 2811_n all form a semiconductor device or memory device. It can be a processing board, or some of the boards can be dummy boards. For example, board 2811_1 , and substrate 2811_n is used as a dummy substrate, and substrates 2811_2 to substrate 2811_n- 1 may be used as the processing substrate. Also, substrates 2811_1, 2811_2, and 2811 _n-1 and substrate 2811_n are used as dummy substrates, and substrates 2811_3 to substrate 281 1_n-2 may be used as the processing substrate. By using a dummy substrate, microwave processing and During the heat treatment process, multiple substrates are treated uniformly, reducing variations between substrates. Therefore, it is preferable. For example, the processing unit closest to the high-frequency generator 2803 and waveguide 2804. By placing a dummy substrate on the board, direct exposure of the processing substrate to microwaves is suppressed. This is preferable because it allows for this.

[0414] By using the above manufacturing equipment, it is possible to suppress the contamination of the workpiece with impurities while modifying the film. This will become possible.

[0415] <Modified examples of semiconductor devices> In the following, an example of a semiconductor device, which is one aspect of the present invention, will be shown using Figures 30 to 33. I will explain.

[0416] <Example 1 of a semiconductor device> Below, an example of a semiconductor device according to one aspect of the present invention will be described using Figure 30. .

[0417] Figure 30A shows a top view of the semiconductor device. Figure 30B shows the A3-A4 shown in Figure 30A. This is a cross-sectional view corresponding to the area indicated by the dashed line in Figure 30A. The cross-sectional view corresponding to the indicated part can be found by referring to transistor 200 shown in Figure 1B. Note that in the top view of Figure 30A, some elements have been omitted for clarity.

[0418] Note that in the semiconductor device shown in Figure 30, the semiconductor device shown in <Example of semiconductor device configuration> is a semiconductor device. Structures that have the same function as the structures that constitute the same part shall be denoted with the same reference numeral. The constituent materials of the semiconductor device are those described in detail in <Examples of Semiconductor Device Configurations>. It is possible.

[0419] The semiconductor device shown in Figure 30 is a modified version of the semiconductor device shown in Figure 1. In a conductive device, the transistor 200 has n oxides 230 (oxide 230_1 to The configuration having oxide 230_n (where n is a natural number) differs from the semiconductor device in Figure 1. Each of the oxides 230_1 to 230_n has a channel-forming region.

[0420] The semiconductor device shown in Figure 30 has an insulator 250 on the top and side surfaces of multiple channel formation regions. A conductor 260 is provided via a conductor 246 (conductor 246a, and The conductor 246b) is stretched in the A3-A4 direction, and through the conductor 240, oxide 2 It is electrically connected to 30_1 or oxide 230_n. Also, similar to the semiconductor device shown in Figure 1. Furthermore, the conductor 240a penetrates the opening region 400a, and the conductor 240b penetrates the opening region 400b. It is installed by going all the way through.

[0421] In other words, in the semiconductor device shown in Figure 30, transistor 200 is one gate electrode It has multiple channel formation regions. The transistor 200 shown in Figure 30 has multiple Having a channel formation region allows for obtaining a large on-current. The channel-forming region is covered by a gate electrode, i.e., an s-channel structure. Therefore, a large on-current can be obtained in each channel formation region. Alternatively, in the channel width direction of transistor 200, with reference to the bottom surface of insulator 222 At that time, the bottom surface of the region of the conductor 260 where the conductor 260 and the oxide 230b do not overlap. Since the height is lower than the height of the interface between the top surface of oxide 230b and insulator 250, A large on-current can be obtained in the channel formation region.

[0422] For other configurations, refer to the semiconductor device configuration shown in Figure 1.

[0423] <Modified example of a semiconductor device 2> In the following section, an example of a semiconductor device according to one aspect of the present invention will be described using Figure 31. .

[0424] Figure 31A shows a top view of the semiconductor device. Figure 31B shows the A3-A4 shown in Figure 31A. This is a cross-sectional view corresponding to the area indicated by the dashed line in Figure 31A. Note that the dashed line A1-A2 is shown in Figure 31A. The cross-sectional view corresponding to the indicated part can be found by referring to transistor 200 shown in Figure 1B. Note that some elements have been omitted in the top view of Figure 31A for clarity.

[0425] Note that in the semiconductor device shown in Figure 31, the semiconductor device shown in <Example of semiconductor device configuration> is a semiconductor device. Structures that have the same function as the structures that constitute the same part shall be denoted with the same reference numeral. The constituent materials of the semiconductor device are those described in detail in <Examples of Semiconductor Device Configurations>. It is possible.

[0426] The semiconductor device shown in Figure 31 is a modified example of the semiconductor device shown in Figure 30. In a semiconductor device, transistor 200 is made up of n oxides 230 (oxide 230_1 The ultimate oxide 230_n (where n is a natural number) is also present. Furthermore, each oxide 230_1 to oxide 23 Each of 0_n has a channel-forming region.

[0427] The semiconductor device shown in Figure 31 has an insulator 250 on the upper and side surfaces of multiple channel formation regions. A conductor 260 is provided via a conductor 246 (conductor 246a, and The conductor 246b) is stretched in the A3-A4 direction, and through the conductor 240, oxide 2 It is electrically connected to 30_1 or oxide 230_n. Also, similar to the semiconductor device shown in Figure 1. Furthermore, the conductor 240a penetrates the opening region 400a, and the conductor 240b penetrates the opening region 400b. It is installed by going all the way through.

[0428] The semiconductor device shown in Figure 31 has multiple channel formation regions in the transistor 200. Adjacent to the oxide 230_1 located at the end of transistor 200, at least oxide A transistor 200D with 230D is positioned. Similarly, the terminals of transistor 200 A transistor 200D is placed adjacent to the oxide 230_n which is positioned as shown.

[0429] In other words, the semiconductor device shown in Figure 31 has multiple channel formation regions of transistor 200 The configuration includes having transistors 200D at one end or both ends in the parallel direction. This differs from the semiconductor device shown in Figure 30.

[0430] Here, transistor 200D has gate wiring, source wiring, or drain wiring. It is not necessary to electrically connect to one or all of them. In other words, transistor 200D In some cases, transistors are installed in a non-functional state. Therefore, The ZISTA200D is sometimes referred to as a dummy transistor (sacrificial transistor).

[0431] Also, the shortest distance between oxide 230_D and oxide 230_1, and the distance between oxide 230_1 and oxide The shortest distance to substance 230_2 is preferably approximately equal. Similarly, oxide 230_ The shortest distance between D and oxide 230_n, and the shortest distance between oxide 230_n-1 and oxide 230_n. For short distances, it is preferable that they be approximately equal. Note that if n is 1, one of the oxides 2 The shortest distance between 30_D and oxide 230_1, and the other distance between oxide 230_D and oxide 230_ The shortest distance to 1 is preferably approximately equal.

[0432] Furthermore, the shortest distance between conductor 242a and conductor 242b in oxide 230_D is, The shortest distance between conductor 242a and conductor 242b in compound 230_1 is approximately equal to It may be small or large. Similarly, conductor 242a and conductivity in oxide 230_D The shortest distance to body 242b is between conductor 242a and conductor 242b in oxide 230_n. The shortest distance to [location] may be approximately equal to, or greater than, that distance.

[0433] When multiple oxides 230 are formed in parallel, the oxides 230 located at the ends are affected during processing. This makes it more prone to variations in shape. Also, some of the insulator 280 and the oxide 230 The layered structure on the channel-forming region is removed to create an opening, exposing a portion of the upper surface of the oxide 230. In the process, the edge shape of the area to be removed (also called the opening), or the relationship between the oxide 230 and the opening Due to factors such as the distance from the edges, variations occur in the exposed surface area of ​​oxide 230. There are cases where this occurs.

[0434] Therefore, as shown in Figure 31, by providing transistor 200D, transistor 2 If a shape defect occurs in the oxide 230_D that 00D possesses, or if a defect occurs on the oxide 230_D Even if a shape defect occurs in the opening, acid will form in the region sandwiched between transistors 200D. The shape of the monster 230 becomes homogeneous.

[0435] Therefore, by placing transistor 200D adjacent to transistor 200, When a number of transistors 200 are provided, the characteristics of the multiple transistors 200 vary. This can reduce sticking.

[0436] Furthermore, if multiple oxides 230 are provided at equal intervals in a certain area, the wiring layout will be changed. This makes circuit design easier.

[0437] Furthermore, in the semiconductor device shown in Figure 31, transistor 200 has one gate electrode. In contrast, it has multiple channel formation regions. The transistor 200 shown in Figure 31 has multiple channels By having a channel formation region, a large on-current can be obtained. Also, each channel The channel-forming region becomes a structure covered by a gate electrode, i.e., an s-channel structure. Therefore, a large on-current can be obtained in each channel formation region. Alternatively, in the channel width direction of transistor 200, the bottom surface of insulator 222 is used as a reference. At that time, the height of the bottom surface of the region where the conductor 260 and the oxide 230b do not overlap. Since the height is lower than the height of the interface between the top surface of oxide 230b and insulator 250, A large on-current can be obtained in the channel formation region.

[0438] For other configurations, refer to the semiconductor device configuration shown in Figure 1.

[0439] <Modified example of semiconductor device 3> In the following section, an example of a semiconductor device according to one aspect of the present invention will be described using Figure 32. .

[0440] Figure 32A shows a top view of the semiconductor device. Figure 32B shows the A3-A4 shown in Figure 32A. This is a cross-sectional view corresponding to the area indicated by the dashed line in Figure 32A. Note that the dashed line A1-A2 is shown in Figure 32A. The cross-sectional view corresponding to the indicated part can be found by referring to transistor 200 shown in Figure 1B. Note that some elements have been omitted in the top view of Figure 32A for clarity.

[0441] Furthermore, in the semiconductor device shown in Figure 32, the semiconductor device shown in <Example of semiconductor device configuration> is a semiconductor device. Structures that have the same function as the structures that constitute the same part shall be denoted with the same reference numeral. The constituent materials of the semiconductor device are those described in detail in <Examples of Semiconductor Device Configurations>. It is possible.

[0442] The semiconductor device described in this section is a modified version of the semiconductor device shown in Figure 31. The transistor 200 is an oxide 230 having n channel formation regions (note that n The individual channel formation regions are channel formation region 235_1 to channel formation region 235_n The semiconductor device shown in Figure 31 differs in that it has multiple (where n is a natural number). A conductor 260 is provided on the upper and side surfaces of the channel-forming region via an insulator 250. Yes, they are.

[0443] Furthermore, the conductor 242 (conductor 242a and conductor 242b) is in the A3-A4 direction. It is stretched and, via the conductor 240 (conductor 240a and conductor 240b), conducts It is electrically connected to body 246 (conductors 246a and 246b). Also shown in Figure 1. Similar to semiconductor devices, the conductor 240a penetrates the aperture region 400a, and the conductor 240b It is installed by penetrating the opening region 400b.

[0444] Here, Figure 32 shows the case where n=2 for the sake of simplicity. Therefore, the transition Sta 200 consists of two channel-forming regions (channel-forming region 235_1 and channel-forming region 235_1 and channel-forming region 235_1). It has an oxide 230 having a constituent region 235_2).

[0445] In oxide 230, the source region and the drain region are made of conductor 242a, or conductor It is electrically connected to the electric body 242b. Therefore, for example, conductor 242a and conductor 24 6a means that multiple connections are made by electrically connecting via at least one conductor 240a. In the channel formation region (channel formation region 235_1 to channel formation region 235_n), Pressure can be applied.

[0446] In other words, for a transistor 200 having n channel formation regions 235, it is not necessarily It is not necessary to provide n conductors 240. A transistor having n channel-forming regions 235 For Zistar, it is preferable that the value be 1 or more, preferably 1 or more and less than n.

[0447] Furthermore, as transistors become smaller, the conductor that functions as wiring to the transistor is electrically... The size of the plug that connects via gas also needs to be miniaturized. The reduced contact area between the body and the conductive material that functions as wiring increases the wiring resistance. There is a tendency.

[0448] In the semiconductor device described in this section, a transistor having n channel formation regions To provide a number of plugs less than n for 200, conductor 2 functions as a plug. Each of the 40 sizes is made larger than, for example, the conductor 240 shown in the semiconductor device in Figure 31. Because this is possible, power consumption can be reduced.

[0449] Furthermore, the semiconductor device shown in Figure 32 has multiple channel formation regions connected to the transistor 200. And adjacent to the oxide 230_1 located at the end of transistor 200, at least A transistor 200D having oxide 230D is arranged. Similarly, transistor 200 The transistor 200D is placed adjacent to the oxide 230_n located at the end of the electrode.

[0450] Therefore, the semiconductor device shown in Figure 32 has multiple channel formation regions on the upper and side surfaces, which are insulated. A conductor 260 is provided via body 250. Also, conductor 246a and conductor 246b is stretched in the A3-A4 direction and is electrically connected to oxide 230_n.

[0451] Furthermore, the semiconductor device shown in Figure 32 has multiple channel formation regions connected to the transistor 200. Adjacent to the channel formation region 235_1 located at the end of transistor 200, A transistor 200D having at least oxide 230D is arranged. Similarly, Adjacent to the channel formation region 235_n located at the end of transistor 200, transistor 2 Place 00D.

[0452] In other words, one end of the direction in which the multiple channel formation regions of transistor 200 are arranged in parallel, or A 200D transistor is placed at both ends.

[0453] Here, transistor 200D has gate wiring, source wiring, or drain wiring. It is not necessary to electrically connect to one or all of them. In other words, transistor 200D In some cases, transistors are installed in a non-functional state. Therefore, The ZISTA200D is sometimes referred to as a dummy transistor (sacrificial transistor).

[0454] Also, the shortest distance between oxide 230_D and oxide 230_1, and the distance between oxide 230_1 and oxide The shortest distance to substance 230_2 is preferably approximately equal. Similarly, oxide 230_ The shortest distance between D and oxide 230_n, and the shortest distance between oxide 230_n-1 and oxide 230_n. For short distances, it is preferable that they be approximately equal. Note that if n is 1, one of the oxides 2 The shortest distance between 30_D and oxide 230_1, and the other distance between oxide 230_D and oxide 230_ The shortest distance to 1 is preferably approximately equal.

[0455] Furthermore, the shortest distance between conductor 242a and conductor 242b in oxide 230_D is, The shortest distance between conductor 242a and conductor 242b in compound 230_1 is approximately equal to It may be small or large. Similarly, conductor 242a and conductivity in oxide 230_D The shortest distance to body 242b is between conductor 242a and conductor 242b in oxide 230_n. The shortest distance to [location] may be approximately equal to, or greater than, that distance.

[0456] Furthermore, the shortest distance between conductor 242a and conductor 242b in oxide 230_D, and the acid The difference between the shortest distance between conductor 242a and conductor 242b in oxide 230_1 is, The shortest distance between conductor 242a and conductor 242b in 230_1, and the oxide 230_2 The difference between the shortest distance between conductor 242a and conductor 242b may be greater than the difference between the two. .

[0457] When multiple channel formation regions 235 are formed in parallel, channel formation located at the end Region 235 is prone to shape variations due to processing. Also, a part of the insulator 280, The stacked structure on the channel-forming region of oxide 230 is removed and an opening is provided, and the oxide 230 In the process of exposing a portion of the upper surface, the shape of the end of the area to be removed (also called an opening), or Due to the influence of the distance between the oxide 230 and the edge of the opening, the exposed upper surface of the oxide 230 There may be variations in area.

[0458] Therefore, as shown in Figure 32, by providing transistor 200D, transistor 2 If a shape defect occurs in the oxide 230_D that 00D possesses, or if a defect occurs on the oxide 230_D Even if a shape defect occurs in the opening, acid will form in the region sandwiched between transistors 200D. The shape of the monster 230 becomes homogeneous.

[0459] Therefore, by placing transistor 200D adjacent to transistor 200, When a number of transistors 200 are provided, the characteristics of the multiple transistors 200 vary. This can reduce sticking.

[0460] Furthermore, in the semiconductor device shown in Figure 32, transistor 200 has one gate electrode. In contrast, it has multiple channel formation regions. The transistor 200 shown in Figure 32 has multiple channels By having a channel formation region, a large on-current can be obtained. Also, each channel The channel-forming region becomes a structure covered by a gate electrode, i.e., an s-channel structure. Therefore, a large on-current can be obtained in each channel formation region. Alternatively, in the channel width direction of transistor 200, the bottom surface of insulator 222 is used as a reference. At that time, the height of the bottom surface of the region where the conductor 260 and the oxide 230b do not overlap. Since the height is lower than the height of the interface between the top surface of oxide 230b and insulator 250, A large on-current can be obtained in the channel formation region.

[0461] For other configurations, refer to the semiconductor device configuration shown in Figure 1.

[0462] <Modification 4 of semiconductor device> In the following section, an example of a semiconductor device, which is one aspect of the present invention, will be described using Figure 33. .

[0463] Figure 33A shows a top view of the semiconductor device 500. The x-axis in Figure 33A represents transistor 2 The y-axis is taken parallel to the channel length direction, and the x-axis is taken perpendicular to the x-axis. Also, see Figure 3. 3B is a cross-sectional view corresponding to the area shown by the dashed line A1-A2 in Figure 33A, and tra This is also a cross-sectional view of the channel length direction of the radiator 200. Figure 33C is shown in Figure 33A as A3- This is a cross-sectional view corresponding to the area indicated by the dashed line on A4, and is also a cross-sectional view of the opening region 400c. Note that some elements have been omitted in the top view of Figure 33A for clarity.

[0464] Furthermore, in the semiconductor device shown in Figure 33, the semiconductor device shown in <Example of semiconductor device configuration> is a semiconductor device. Structures that have the same function as the structures that constitute the same part shall be denoted with the same reference numeral. The constituent materials of the semiconductor device are those described in detail in <Examples of Semiconductor Device Configurations>. It is possible.

[0465] The semiconductor device 500 shown in Figure 33 is a modified example of the semiconductor device shown in Figure 1. The semiconductor device 500 shown has insulators 282 and 280, transistor 20 The fact that the aperture region 400c is formed in a region that does not overlap with 0 is the same as the semiconductor device shown in Figure 1. different.

[0466] The semiconductor device 500 has multiple transistors 200 arranged in a matrix, multiple It has an opening region 400a, a plurality of opening regions 400b, and a plurality of opening regions 400c. Furthermore, multiple conductors 260 that function as gate electrodes of transistor 200, It is provided extending in the axial direction. Opening regions 400a and 400b are shown in Figure 1. Similar to the semiconductor device shown, it is placed on oxide 230, but the aperture region 400c is It is formed in a region that does not overlap with the oxide 230 and the conductor 260. Also, multiple Rangitator 200, multiple conductors 260, multiple aperture regions 400a, multiple aperture regions 40 A sealing portion 265 is formed to surround 0b and multiple opening regions 400c. Furthermore, transistor 200, conductor 260, aperture region 400a, aperture region 400b, and The number, arrangement, and size of the opening regions 400c are not limited to the structure shown in Figure 33. The settings should be adjusted as appropriate to match the design of the semiconductor device 500.

[0467] As shown in Figure 2B, the opening region 400a and the opening region 400b are connected to the conductor 240a It is positioned overlapping with the conductor 240b. In contrast, as shown in Figure 2C, the aperture region In region 400c, the conductors 240 are not arranged in overlapping positions, but the rest of the structure is in the opening region 4 It is the same as 00a and the opening region 400b. Therefore, the details of the opening region 400c are as described above. The description of the opening region 400 in Figure 2B can be taken into consideration.

[0468] By providing an aperture region 400c that does not overlap with transistor 200 and performing heat treatment, While supplying oxygen to the oxide 230 of transistor 200, the acid contained in the insulator 280 A portion of the element can be diffused outward more. This allows transistor 200 Even when the arrangement density is small, that is, when the arrangement of transistors 200 is sparse, This can prevent an excessive amount of oxygen from being supplied to the 200.

[0469] Furthermore, in Figure 33A, the shape of the opening region 400c in a top view is approximately rectangular. However, the present invention is not limited thereto. For example, when viewed from above in the opening region 400c The shapes can be rectangles, ovals, circles, rhombuses, or combinations thereof. Good. Also, the area of ​​the aperture region 400c and the spacing between the transistors are half of the area including the transistor 200. It can be set appropriately according to the design of the conductive device. For example, the density of transistor 200 In areas with a small degree of saturation, the area of ​​the 400c aperture can be increased, or the arrangement of the 400c aperture can be adjusted. The spacing can be narrowed. Also, for example, in regions where the density of transistors 200 is high, This can be achieved by reducing the area of ​​the 400c opening region or by widening the spacing between the opening regions.

[0470] According to one aspect of the present invention, a semiconductor device having good electrical characteristics can be provided. Furthermore, according to one aspect of the present invention, a semiconductor device with good reliability can be provided. According to one aspect of the present invention, a semiconductor device with a large on-current can be provided. According to one aspect of the present invention, a semiconductor device with less variation in transistor characteristics is provided. This is possible. Furthermore, according to one aspect of the present invention, a semiconductor device that can be miniaturized or highly integrated is provided. It can be provided. Furthermore, according to one aspect of the present invention, a low-power semiconductor device can be provided. This is possible. Furthermore, according to one aspect of the present invention, a method for manufacturing semiconductor devices with high productivity is provided. It is possible.

[0471] The configurations and methods described in this embodiment are similar to those described in other configurations and methods of this embodiment. Alternatively, it can be used in appropriate combination with the configurations, methods, etc., shown in other embodiments.

[0472] (Embodiment 2) In this embodiment, one form of a semiconductor device will be described with reference to Figures 34 to 38.

[0473] [Storage device 1] An example of a semiconductor device (memory device) according to one aspect of the present invention is shown in Figure 34. In this semiconductor device, transistor 200 is located above transistor 300, and a capacitive element 100 is located above transistors 300 and 200. As transistor 200, the transistor 200 described in the previous embodiment is used. It is possible.

[0474] 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.

[0475] In the semiconductor device shown in Figure 34, 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.

[0476] Furthermore, the memory device shown in Figure 34, when arranged in a matrix, allows the memory cell array to function as a matrix. It can be configured.

[0477] <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.

[0478] Here, the transistor 300 shown in Figure 34 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 conductive material 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.

[0479] Note that the transistor 300 shown in Figure 34 is just one example, and its structure is not limited to that example. A suitable transistor should be used depending on the configuration or driving method.

[0480] <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. Here, the insulator 130 is in the form described above. It is preferable to use an insulator that can be used as the insulator 286 shown in the diagram.

[0481] Furthermore, the conductor 112 and the conductor 110 can be formed simultaneously. 12 is electrically connected to the capacitive element 100, transistor 200, or transistor 300. It functions as a connecting plug or wiring. Also, conductor 112 and conductor 11 0 corresponds to the conductor 246 shown in the previous embodiment.

[0482] In Figure 34, the conductors 112 and 110 are shown as having a single-layer structure, but this configuration is not limited to this. 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.

[0483] 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.

[0484] 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.

[0485] 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.

[0486] 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.

[0487] <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.

[0488] 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.

[0489] 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.

[0490] A wiring layer may be provided on the insulator 326 and the conductor 330. For example, as shown in Figure 34. 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.

[0491] 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.

[0492] 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.

[0493] Examples of insulators 217 include silicon nitride, aluminum oxide, or silicon nitride oxide. An insulator such as Ricon can be used. Insulator 217 is an insulator, insulator 210, insulator 212, Since it is provided in contact with the edge 214 and the insulator 222, the insulator 210 or the insulator 2 Impurities such as water or hydrogen from 16 etc. are mixed into the oxide 230 through the conductor 218. This can suppress the growth of hydrogen. In particular, silicon nitride is preferred because it has high barrier properties against hydrogen. It is suitable. Also, oxygen contained in the insulator 210 or insulator 216 is absorbed by the conductor 218. This can prevent it from happening.

[0494] 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.

[0495] 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.

[0496] 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.

[0497] 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 have fluorine added. Silicon oxide, silicon oxide with added carbon, silicon oxide with added carbon and nitrogen, It is preferable to have a porous silicon oxide or resin, or the insulator This involves adding silicon oxide, silicon oxide nitride, silicon oxide nitride, silicon nitride, and fluorine. Silicon oxide, silicon oxide with added carbon, silicon oxide with added carbon and nitrogen It is preferable to have a laminated structure of silicon oxide having pores or cavities and a resin. Because silicon and silicon oxide-nitride are thermally stable, they can be combined with resins. This allows for a thermally stable laminated structure with a low dielectric constant. Examples of resins include: Polyester, polyolefin, polyamide (nylon, aramid, etc.), polyimide, Materials include polycarbonate or acrylic.

[0498] 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 characteristi...

Claims

1. A transistor having an electrode, a gate insulating film, a source electrode, and a drain electrode, The first insulator on the transistor, The second insulator on the first insulator, The third insulator on the second insulator, A first electrode in contact with the upper surface of the source electrode, It has a second electrode that is in contact with the upper surface of the drain electrode, The second insulator has a first opening that overlaps with the source electrode and a second opening that overlaps with the drain electrode, The third insulator is in contact with the side surface of the second insulator and the upper surface of the first insulator inside the first opening and the second opening. The first electrode is positioned through the first opening, The semiconductor device wherein the second electrode is positioned through the second opening.

2. In claim 1, A semiconductor device wherein the first insulator has a first groove that overlaps the first opening and a second groove that overlaps the second opening.

3. In claim 1 or claim 2, The side surface of the first electrode is in contact with the third insulator at the first opening and the first groove. A semiconductor device wherein the side surface of the second electrode is in contact with the third insulator at the second opening and the second groove.

4. In any one of claims 1 to 3, The second insulator is a semiconductor device containing aluminum oxide.

5. In any one of claims 1 to 4, The first insulator comprises silicon oxide, The semiconductor device comprises a silicon nitride as the third insulator.

6. In any one of claims 1 to 5, The transistor has an oxide semiconductor layer, The aforementioned oxide semiconductor layer has one or more selected from In, Ga, or Zn, wherein the semiconductor device is a semiconductor device.

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