Substrate substrate, single crystal diamond laminated substrate, and method for producing same

Abstract

The present invention is a method for manufacturing a substrate for use in a single crystal diamond laminated substrate, the method comprising: a step for preparing an initial substrate; and a step for forming, on the initial substrate, an intermediate layer comprising a single-layer film or a laminated film comprising at least a single-crystal Ir film or a single-crystal MgO film. The single-crystal Ir film or the single-crystal MgO film constituting the intermediate layer is formed using an atomization CVD method. As a result, it is possible to provide a method for producing a base substrate with which it is possible to form a film of a high-quality single-crystal diamond layer that can be applied to an electronic / magnetic device, has a large area (large diameter), has high crystallinity, has few abnormally grown particles such as protrusions and golelreuteria crystals, dislocation defects, and the like, and has high purity and low stress.

Description

Technical Field

[0001] The present invention relates to a base substrate and a single crystal diamond laminated substrate and methods for producing the same. Background Art

[0002] Diamond has a wide band gap of 5.47 eV at room temperature and is known as a wide band gap semiconductor.

[0003] Among semiconductors, diamond has a very high dielectric breakdown field strength of 10 MV / cm, which allows it to operate at high voltages. In addition, since it has the highest thermal conductivity of any known material, it also has excellent heat dissipation properties. Furthermore, since its carrier mobility and saturation drift velocity are very large, it is suitable for high-speed devices.

[0004] Therefore, even compared with semiconductors such as silicon carbide and gallium nitride, diamond has the highest value of Johnson performance index, which indicates its performance as a high-frequency and high-power device, and can be said to be the ultimate semiconductor.

[0005] Prior art literature

[0006] Non-patent literature

[0007] Non-patent literature 1: H. Yamada, Appl. Phys. Lett. 104, 102110 (2014). Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] As described above, diamond is expected to be put into practical use as a semiconductor material or a material for electronic and magnetic devices, and it is desired to provide a diamond substrate having a large area and high quality.

[0010] Currently, single crystal diamonds used to make diamond semiconductors are almost all type Ib diamonds synthesized by high-temperature high-pressure method (HPHT). This type Ib diamond contains a lot of nitrogen impurities, and the maximum size available is only about 8 mm square, which is low in practicality. In addition, a mosaic method (non-patent document 1) of connecting multiple HPHT substrates (diamond substrates synthesized by HPHT method) side by side has been proposed, but there is a problem of incompleteness at the joints.

[0011] In this regard, in the gas phase synthesis (chemical vapor deposition, Chemical Vapor Deposition: CVD) method, if it is polycrystalline diamond, a large area of ​​diamond with a diameter of about 6 inches (150mm) can be obtained with high purity, but it is generally difficult to make it single crystal for electronic devices. This is because, as a substrate for forming diamond, it is impossible to achieve a suitable combination of materials with a small difference in lattice constant and linear expansion coefficient with diamond. For example, the difference in lattice constant between diamond and single crystal Si is 34.3%, so it is very difficult to make diamond heteroepitaxially grow on the surface of the substrate.

[0012] The present invention is completed to solve the above-mentioned problems, and its purpose is to provide a substrate and a manufacturing method thereof, wherein the substrate can form a high-quality single-crystal diamond layer, the high-quality single-crystal diamond layer can be applied to electronic and magnetic devices, has a large area (large diameter), high crystallinity, few hillocks, abnormal growth particles, dislocation defects, etc., high purity and low stress. In addition, the present invention also aims to provide a single-crystal diamond laminate substrate having such a single-crystal diamond layer and a manufacturing method of a single-crystal diamond self-supporting structure substrate.

[0013] (II) Technical solution

[0014] In order to solve the above-mentioned purpose, the present invention provides a method for manufacturing a base substrate, which is a method for manufacturing a base substrate for a single-crystal diamond stacked substrate, characterized in that it has: a process of preparing an initial substrate; and a process of forming an intermediate layer composed of a single-layer film or a stacked film containing at least a single-crystal Ir film or a single-crystal MgO film on the initial substrate, and it uses an atomized CVD method to form the single-crystal Ir film or the single-crystal MgO film constituting the intermediate layer.

[0015] According to such a method for manufacturing a base substrate, since a single crystal Ir film or a single crystal MgO film constituting an intermediate layer is formed by atomized CVD, a single crystal Ir film or a single crystal MgO film can be formed with a large diameter and at a low cost. In addition, the uniformity of the film thickness of the intermediate layer can be improved. Therefore, a base substrate can be manufactured on which a high-quality single crystal diamond layer suitable for electronic and magnetic devices can be formed, which has a large diameter, high crystallinity, few protrusions, abnormal growth particles, dislocation defects, etc., high purity, and low stress.

[0016] At this time, it is preferred that the initial substrate be any one of a single crystal Si substrate, a single crystal α-Al 2 O 3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

[0017] The lattice mismatch between the material of these initial substrates and the material of the intermediate layer is small, which makes it easy for the intermediate layer to be epitaxially grown. In addition, large diameters greater than 6 inches (150 mm) in diameter can also be obtained and their price is also relatively cheap.

[0018] In addition, the intermediate layer can be a stacked film further including at least any one of a single crystal yttria-stabilized zirconia film, a single crystal SrTiO 3 film, and a single crystal Ru film.

[0019] By forming such a laminated film, the intermediate layer can be appropriately designed so as to more appropriately play the role of alleviating the lattice mismatch between the initial substrate and the diamond layer.

[0020] In addition, the initial substrate can be set to any one of a Si{111} substrate, an α-Al2O3{0001} substrate, a Fe{111} substrate, a Ni{111} substrate, and a Cu{111} substrate, and the intermediate layer can be set to include at least an Ir{111} film or a MgO{111} film.

[0021] Furthermore, the intermediate layer may further include at least one of a yttria-stabilized zirconia {111} film, a SrTiO 3 {111} film, and a Ru {0001} film.

[0022] By using such an initial substrate and an intermediate layer, a base substrate on which a single crystal diamond {111} layer can be formed can be manufactured.

[0023] At this time, the outermost surface of the initial substrate can be set to have an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}.

[0024] By setting the off angle in this way, a base substrate capable of obtaining a high-quality single-crystal diamond {111} layer having high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be more efficiently manufactured.

[0025] At this time, the off angle of the outermost surface of the initial substrate can be set to a range of +8.0 to +24.0° or -8.0 to -24.0°. The off angle of the outermost surface of the initial substrate can be set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0026] By setting the range to this level, the quality improvement effect brought about by the off angle can be maximized.

[0027] In addition, at this time, the outermost surface of the intermediate layer can be set to have an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}.

[0028] By setting the off angle in this way, a base substrate capable of obtaining a high-quality single-crystal diamond {111} layer having high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be more efficiently manufactured.

[0029] At this time, the deviation angle of the outermost surface of the intermediate layer can be set to a range of +8.0 to +24.0° or -8.0 to -24.0°. Further, the deviation angle of the outermost surface of the intermediate layer can be set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0030] By setting the range to this level, the quality improvement effect brought about by the off angle can be maximized.

[0031] In addition, in the manufacturing method of the base substrate of the present invention, the initial substrate can be set to any one of a Si{001} substrate, an α-Al2O3{11-20} substrate, a Fe{001} substrate, a Ni{001} substrate, and a Cu{001} substrate, and the intermediate layer can be set to include at least an Ir{001} film or a MgO{001} film.

[0032] In addition, the intermediate layer may further include at least one of a yttria-stabilized zirconia {001} film, a SrTiO 3 {001} film, and a Ru {11-20} film.

[0033] By using such an initial substrate and an intermediate layer, a base substrate on which a single crystal diamond {001} layer can be formed can be manufactured.

[0034] At this time, the outermost surface of the initial substrate can be set to be oriented at the crystal axis {001} relative to the cubic crystal plane. <110> The direction sets the deviation angle, or the hexagonal plane orientation {11-20} is in the crystal axis <10-10> or <0001> The direction sets the deviation angle.

[0035] By setting the off angle in this way, a base substrate capable of obtaining a high-quality single-crystal diamond {001} layer having high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be more efficiently manufactured.

[0036] At this time, the off angle of the outermost surface of the initial substrate can be set to a range of +8.0 to +24.0° or -8.0 to -24.0°. Further, the off angle of the outermost surface of the initial substrate can be set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0037] By setting the range to this level, the quality improvement effect brought about by the off angle can be maximized.

[0038] In addition, at this time, the outermost surface of the intermediate layer can be set to be oriented at the crystal axis {001} with respect to the cubic crystal plane. <110> The direction sets the deviation angle, or relative to the hexagonal plane orientation {11-20} in <10-10> or <0001> The direction sets the deviation angle.

[0039] By setting the off angle in this way, a base substrate capable of obtaining a high-quality single-crystal diamond {001} layer having high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be more efficiently manufactured.

[0040] At this time, the deviation angle of the outermost surface of the intermediate layer can be set to a range of +8.0 to +24.0° or -8.0 to -24.0°. Further, the deviation angle of the outermost surface of the intermediate layer can be set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0041] By setting such a range, the high quality effect brought about by the deviation angle can be maximized.

[0042] In addition, the present invention provides a method for manufacturing a single crystal diamond stacked substrate, characterized in that it includes: a process of preparing a substrate substrate manufactured by any of the above-mentioned substrate substrate manufacturing methods; a process of biasing the surface of the intermediate layer of the substrate substrate to form diamond cores; and a process of growing the diamond cores formed on the intermediate layer to perform epitaxial growth to form a single crystal diamond layer.

[0043] According to such a manufacturing method, a single crystal diamond laminated substrate having a high-quality single crystal diamond layer suitable for electronic and magnetic devices can be manufactured. The high-quality single crystal diamond layer has a large diameter, high crystallinity, few abnormal growth particles such as protrusions and crystalline particles, dislocation defects, etc., high purity and low stress.

[0044] In the method for producing a single crystal diamond multilayer substrate of the present invention, the single crystal diamond layer is made of a {111} crystal.

[0045] Furthermore, the single crystal diamond layer may be set to be a {001} crystal.

[0046] In the method for producing a single crystal diamond laminated substrate of the present invention, a single crystal diamond layer having these plane orientations can be formed.

[0047] In addition, the present invention provides a method for manufacturing a single crystal diamond self-supporting structure substrate, characterized in that only the single crystal diamond layer is taken out from a single crystal diamond laminated substrate manufactured by any of the above-mentioned methods for manufacturing a single crystal diamond laminated substrate to manufacture a single crystal diamond self-supporting structure substrate.

[0048] In this way, a single crystal diamond self-supporting structure substrate consisting only of a single crystal diamond layer can be manufactured.

[0049] Furthermore, an additional single crystal diamond layer can be further formed on the single crystal diamond self-supporting structure substrate obtained by the above-mentioned method for manufacturing a single crystal diamond self-supporting structure substrate.

[0050] This allows further film formation to be performed on the substrate consisting only of the diamond layer by an additional method, thereby further increasing the film thickness.

[0051] In addition, the present invention provides a base substrate, characterized in that, in the base substrate for a single crystal diamond stacked substrate, it has: an initial substrate and an intermediate layer on the initial substrate composed of a single layer film or a stacked film containing at least a single crystal Ir film or a single crystal MgO film, and the thickness uniformity of the intermediate layer is within ±10% in the entire surface.

[0052] Thus, in the base substrate of the present invention, the uniformity of the film thickness of the intermediate layer can be within ±10% in the entire surface. Therefore, a base substrate can be manufactured that can form a high-quality single-crystal diamond layer suitable for electronic and magnetic devices, with a large diameter, high crystallinity, few protrusions, abnormal growth particles, dislocation defects, etc., high purity, and low stress.

[0053] At this time, the initial substrate may be any one of a single crystal Si substrate, a single crystal α-Al 2 O 3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

[0054] The lattice mismatch between the material of the initial substrate and the material of the intermediate layer is small, and epitaxial growth of the intermediate layer 21 can be easily performed. In addition, large diameters greater than 6 inches (150 mm) can be obtained and the price is relatively low.

[0055] In addition, the intermediate layer may be a stacked film further including at least any one of a single crystal yttria-stabilized zirconia film, a single crystal SrTiO 3 film, and a single crystal Ru film.

[0056] By forming such a laminated film, the intermediate layer can be appropriately designed so as to more appropriately play the role of alleviating the lattice mismatch between the initial substrate and the diamond layer.

[0057] In addition, a base substrate can be manufactured, wherein the initial substrate is any one of a single crystal Si{111} substrate, a single crystal Si{001} substrate, a single crystal α-Al2O3{0001} substrate, a single crystal α-Al2O3{11-20} substrate, a single crystal Fe{111} substrate, a single crystal Fe{001} substrate, a single crystal Ni{111} substrate, a single crystal Ni{001} substrate, a single crystal Cu{111} substrate, and a single crystal Cu{001} substrate,

[0058] The outermost surface of the initial substrate has an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or has an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or has an offset angle in the crystal axis <001> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

[0059] If such a base substrate is used, by forming an appropriate combination of the initial substrate and its deviation angle and the intermediate layer, a base substrate that can form a high-quality single-crystal diamond layer can be manufactured. This high-quality single-crystal diamond layer is more suitable for electronic and magnetic devices, has a large diameter, high crystallinity, fewer protrusions, abnormal growth particles, dislocation defects, etc., higher purity and lower stress.

[0060] In addition, the base substrate can be manufactured such that the deviation angle of the outermost surface of the initial substrate is in the range of +8.0 to +24.0° or -8.0 to -24.0°. In addition, the base substrate can be manufactured such that the deviation angle of the outermost surface of the initial substrate is greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0061] By setting such a range, the high quality effect brought about by the deviation angle can be maximized.

[0062] In addition, the following substrate can be manufactured: the outermost surface of the intermediate layer has an offset angle in the direction of the crystal axis <-1-12> relative to the cubic crystal plane orientation {111}, or has an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the hexagonal crystal plane orientation {0001}, or has an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the cubic crystal plane orientation {001}. <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

[0063] By setting the off angle in this way, a base substrate from which a high-quality single-crystal diamond layer can be obtained can be more efficiently manufactured. The high-quality single-crystal diamond layer has high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects.

[0064] The base substrate can be manufactured such that the deviation angle of the outermost surface of the intermediate layer is in the range of +8.0 to +24.0° or -8.0 to -24.0°. Further, the base substrate can be manufactured such that the deviation angle of the outermost surface of the intermediate layer is greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0065] By setting such a range, the high quality effect brought about by the deviation angle can be maximized.

[0066] Furthermore, the present invention provides a single crystal diamond laminated substrate, characterized in that a single crystal diamond layer is provided on the intermediate layer of any of the above-mentioned base substrates.

[0067] Such a single crystal diamond laminated substrate has a single crystal diamond layer formed on an intermediate layer having a film thickness uniformity within ±10% over the entire surface, and can therefore be manufactured into a single crystal diamond laminated substrate having a high-quality single crystal diamond layer, which is suitable for electronic and magnetic devices, has a large diameter, high crystallinity, few protrusions, abnormally grown particles, dislocation defects, etc., and has high purity and low stress.

[0068] (III) Beneficial effects

[0069] According to the manufacturing method of the base substrate of the present invention, since the single crystal Ir film or single crystal MgO film constituting the intermediate layer is formed by atomized CVD, the single crystal Ir film or single crystal MgO film can be formed with a large diameter and at a low cost. The uniformity of the film thickness of the intermediate layer can be improved, and in particular, the film thickness uniformity can be made within ±10% in the entire surface. Therefore, a base substrate on which a high-quality single crystal diamond layer can be formed can be manufactured. The high-quality single crystal diamond layer is suitable for electronic and magnetic devices, has a large diameter, high crystallinity, and has few abnormal growth particles such as protrusions and crystalline, dislocation defects, etc., high purity, and low stress. In addition, by forming a single crystal diamond layer on the base substrate, a single crystal diamond stacked substrate having a single crystal diamond layer having the above-mentioned characteristics can be manufactured. Furthermore, according to the present invention, a single crystal diamond self-supporting structure substrate can be manufactured by separating only the single crystal diamond stack from such a single crystal diamond stack substrate, or a single crystal diamond self-supporting structure substrate can be manufactured by further forming an additional single crystal diamond layer on the single crystal diamond self-supporting structure substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1It is a flowchart which shows an example of the manufacturing method of the base substrate of this invention.

[0071] Figure 2 It is a flowchart showing an example of the process of the method for manufacturing a single crystal diamond laminated substrate and the process of the method for manufacturing a single crystal self-supporting structure substrate of the present invention.

[0072] Figure 3 FIG. 1 is a schematic diagram showing an example of the base substrate of the present invention.

[0073] Figure 4 FIG. 1 is a schematic diagram showing an example of the single crystal diamond laminated substrate of the present invention.

[0074] Figure 5 FIG. 1 is a schematic diagram showing another example of the base substrate of the present invention.

[0075] Figure 6 FIG. 1 is a schematic diagram showing another example of the single crystal diamond laminated substrate of the present invention.

[0076] Figure 7 FIG. 1 is a schematic diagram showing an example of a single crystal diamond self-supporting structure substrate according to the present invention.

[0077] Figure 8 FIG. 1 is a schematic diagram showing another example of the single crystal diamond self-supporting structure substrate of the present invention. DETAILED DESCRIPTION

[0078] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0079] As mentioned above, in the past, it was sought to obtain a large-caliber, low-cost, high-quality single-crystal diamond laminated substrate. Therefore, in order to solve such a technical problem, the inventor of the present application repeatedly conducted in-depth research. As a result, it was found that the method most suitable for forming an intermediate layer in a single-crystal diamond laminated substrate and a base substrate for manufacturing a single-crystal diamond laminated substrate is an atomized CVD method, and then the present invention was completed.

[0080] The present invention is a method for manufacturing a substrate, which is a method for manufacturing a substrate for a single-crystal diamond laminated substrate, characterized in that it comprises: a process of preparing an initial substrate; and a process of forming an intermediate layer composed of a single-layer film or a laminated film containing at least a single-crystal Ir film or a single-crystal MgO film on the initial substrate, and using an atomized CVD method to form the single-crystal Ir film or the single-crystal MgO film constituting the intermediate layer.

[0081] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. In the following, similar components are described with the same reference numerals.

[0082] First, refer to Figure 3 and Figure 4 The base substrate and the single crystal diamond laminated substrate of the present invention will be described.

[0083] like Figure 3 As shown, the base substrate 20 for a single crystal diamond laminated substrate of the present invention comprises an initial substrate 11 and an intermediate layer 21 on the initial substrate 11. In the present invention, the intermediate layer 21 is configured to be composed of a single layer film or a laminated film including at least a single crystal Ir film or a single crystal MgO film. Further, in the present invention, the film thickness uniformity of the intermediate layer 21 can be set to within ±10% in the entire surface. Such film thickness uniformity of the intermediate layer 21 is easily achieved by adopting the atomized CVD method described later.

[0084] The film thickness uniformity (film thickness distribution) of the intermediate layer of the present invention can be calculated by measuring 9 or more points on the entire surface of the intermediate layer and by: film thickness uniformity [±%] = (maximum film thickness - minimum film thickness) / ((average film thickness) × 2) × 100. The film thickness can be measured using a step-type film thickness meter, an optical interference film thickness meter, etc., and the measuring method is not particularly limited as long as the film thickness at each location can be measured.

[0085] In addition, if Figure 4 As shown, the single crystal diamond laminated substrate 30 of the present invention is Figure 3 The illustrated base substrate 20 has a single crystal diamond layer 31 on the intermediate layer 21. The intermediate layer 21 has the function of alleviating the lattice mismatch between the initial substrate 11 and the single crystal diamond layer 31.

[0086] In the base substrate 20 of the present invention, the intermediate layer 21 may be a single crystal Ir film or a single crystal MgO film, but a stacked film of these films is more preferred. Figure 5 As shown, the intermediate layer 21 on the initial substrate 11 is preferably a laminated film composed of a single crystal MgO film 22 and a single crystal Ir film 23. The intermediate layer 21 of the base substrate 20 of the present invention can also be made into a laminated film that further includes at least one of a single crystal yttria-stabilized zirconia (YSZ) film, a single crystal SrTiO3 film, and a single crystal Ru film in addition to at least one of a single crystal Ir film and a single crystal MgO film. Such a laminated film can be designed in a manner that more appropriately has the effect of alleviating the lattice mismatch between the initial substrate 11 and the single crystal diamond layer 31. As Figure 5 As shown in FIG. 1 , when the intermediate layer 21 on the initial substrate 11 is a laminated film composed of a single crystal MgO film 22 and a single crystal Ir film 23, it is inevitable that when manufacturing the single crystal diamond laminated substrate 30, as shown in FIG. Figure 6 As shown, the intermediate layer 21 is a stacked film composed of a single crystal MgO film 22 and a single crystal Ir film 23 .

[0087] In addition, in the present invention, it is preferred that the initial substrate 11 is set to any one of a single crystal Si substrate, a single crystal α-Al2O3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate. The lattice mismatch between these initial substrates 11 (block substrates) and the material of the intermediate layer 21 is small, so when the intermediate layer 21 is formed, the epitaxial growth of the intermediate layer 21 can be easily performed. In addition, a large diameter greater than 6 inches (150 mm) in diameter can be obtained, and its price is also relatively cheap.

[0088] The following, Figure 3~Figure 6 The following describes a method for manufacturing a base substrate and a single crystal diamond laminate substrate shown in FIG. Figure 1 The method for manufacturing the base substrate of the present invention is described below. Figure 2 The method for manufacturing the single crystal diamond laminated substrate of the present invention is described. Figure 7 The single crystal diamond self-supporting structure substrate 35 composed of the single crystal diamond layer 31 shown in FIG. Figure 8 The single crystal diamond self-supporting structure substrate composed of the single crystal diamond layer 31 and the additional single crystal diamond layer 41 is shown, but its manufacturing method will also refer to Figure 2 Provide explanation.

[0089] (Preparation process: Figure 1 Step S11)

[0090] First, prepare the initial substrate 11 (step S11). The initial substrate 11 is preferably any one of a single crystal Si substrate, a single crystal α-Al2O3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate (block substrate). The lattice mismatch between the material of the initial substrate 11 listed above and the material of the intermediate layer 21 is small, and the epitaxial growth of the intermediate layer 21 can be easily performed. In addition, a large diameter greater than 6 inches (150 mm) in diameter can be obtained, and its price is also relatively cheap.

[0091] When the initial substrate 11 is set as the above substrate, if the plane orientation setting regulations are combined, it can be made into any one of Si{111} substrate, α-Al2O3{0001} substrate, Fe{111} substrate, Ni{111} substrate, and Cu{111} substrate. In addition, the initial substrate 11 can also be any one of Si{001} substrate, α-Al2O3{11-20} substrate, Fe{001} substrate, Ni{001} substrate, and Cu{001} substrate.

[0092] The surface of the initial substrate 11 on which the intermediate layer 21 is to be formed is preferably polished to achieve Ra≤0.5 nm. This allows the intermediate layer 21 to be smooth and with few defects.

[0093] When it is desired to obtain a {111} crystal plane orientation as the single crystal diamond layer 31, the outermost surface of the initial substrate 11 can be set to have an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or to have an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}. By setting the off angle on the outermost surface of the initial substrate 11 in this way, as the intermediate layer 21 formed on the surface, a high-quality intermediate layer 21 with high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be obtained more effectively.

[0094] The off angle of the outermost surface of the initial substrate 11 is preferably set to a range of +8.0 to +24.0° or -8.0 to -24.0°. If the off angle is above +8.0 and -8.0°, the effect of setting the off angle can be fully obtained, and if it is below +24.0 and -24.0, the high quality effect can be fully obtained. In addition, if it is within the above range, the deviation from the {111} crystal plane of the outermost surface will not be too large, so it is easy to achieve the application of the composite purpose.

[0095] Furthermore, it is more preferable to set the deviation angle to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0° on the outermost surface of the initial substrate 11. If it is within the above deviation angle range, it is more stable, and the effect of setting the deviation angle can be fully obtained, and the high quality effect can be fully obtained.

[0096] On the other hand, when it is desired to obtain a {001} crystal plane orientation as a single crystal diamond layer, the outermost surface of the initial substrate 11 may be oriented at the crystal axis {001} relative to the cubic crystal plane orientation. <110> The direction sets the deviation angle, or the hexagonal plane orientation {11-20} is in <10-10> or <0001> By setting the deviation angle on the outermost surface of the initial substrate 11, a high-quality intermediate layer 21 with high crystallinity and few abnormal growths such as protrusions and crystalline particles and dislocation defects can be obtained more effectively as the intermediate layer 21 formed on the surface.

[0097] It is preferred that the deviation angle of the outermost surface of the initial substrate 11 at this time is set to a range of +8.0 to +24.0° or -8.0 to -24.0°. If the deviation angle is above +8.0 and -8.0°, the effect of setting the deviation angle can be fully obtained, and if it is below +24.0 and -24.0, the high quality effect can be fully obtained. In addition, if it is within the above range, the deviation from the {111} crystal plane of the outermost surface will not be too large, so it is easy to achieve the application of the composite purpose.

[0098] Furthermore, the deviation angle when setting the deviation angle on the outermost surface of the initial substrate 11 is more preferably set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°. If it is within the above deviation angle range, it is more stable, and the effect of setting the deviation angle can be fully obtained, and the high quality effect can be fully obtained.

[0099] (Middle layer forming process: Figure 1 Step S12)

[0100] After the initial substrate 11 is prepared in step S11, an intermediate layer 21 composed of a single layer film or a stacked film including at least a single crystal Ir film or a single crystal MgO film is then formed on the initial substrate 11 (step S12). Among them, the single crystal Ir film or the single crystal MgO film constituting the intermediate layer 21 is formed by atomized CVD method, which is a feature of the present invention.

[0101] In addition, the intermediate layer 21 can be a stacked film further including at least any one of a single crystal yttria-stabilized zirconia (YSZ) film, a single crystal SrTiO 3 film, and a single crystal Ru film.

[0102] When it is desired to obtain a {111} crystal orientation as the single crystal diamond layer 31, in the case of a cubic crystal, at least the outermost surface of the intermediate layer 21 is also set to a {111} crystal orientation, and in the case of a hexagonal crystal, at least the outermost surface of the intermediate layer 21 is also set to a {0001}. In this case, the intermediate layer 21 can be set to include at least an Ir{111} film or a MgO{111} film. In addition, the intermediate layer 21 can be set to further include at least any one of a yttria-stabilized zirconia {111} film, a SrTiO3{111} film, and a Ru{0001} film.

[0103] On the other hand, if it is desired to obtain a {001} crystal orientation as the single crystal diamond layer 31, in the case of a cubic crystal, at least the outermost surface of the intermediate layer 21 is also set to a {001} crystal orientation, and in the case of a hexagonal crystal, at least the outermost surface of the intermediate layer 21 is also set to a {11-20} crystal orientation. In this case, the intermediate layer can be set to include at least an Ir{001} film or a MgO{001} film. In addition, the intermediate layer 21 can also be set to further include at least any one of a yttria-stabilized zirconia {001} film, a SrTiO3{001} film, and a Ru{11-20} film.

[0104] In the present invention, the single crystal Ir film or single crystal MgO film constituting the intermediate layer 21 is formed by the atomized CVD method as described above. If the atomized CVD method is used for at least one layer constituting the intermediate layer 21, the effect of the present invention can be obtained. For the formation of other layers constituting the intermediate layer 21, in addition to the atomized CVD method, sputtering, electron beam evaporation, atomic layer deposition, molecular beam epitaxy, pulsed laser deposition, etc. can be used. For the single crystal Ir film, single crystal MgO film, single crystal yttria-stabilized zirconia (YSZ) film, single crystal SrTiO3 film, single crystal Ru film, etc., which are metals and metal oxides and can constitute the intermediate film, it is preferred to use the atomized CVD method that can be formed with a large diameter and low cost.

[0105] The film-forming apparatus based on the atomization CVD method is composed of an atomization section that utilizes ultrasonic vibration to atomize a raw material solution containing atoms of the material to be film-formed to generate mist, a carrier gas supply section that supplies a carrier gas for transporting the mist, a chamber in which a substrate is set and the film is formed, and an exhaust system that discharges unnecessary raw materials.

[0106] In the chamber, the substrate is heated on a heating stage and rotated as needed to form a highly crystalline and uniform film. By controlling the flow of the raw material gas, a highly crystalline and uniform film can also be formed.

[0107] Alternatively, the film may be formed by placing a substrate on a heating stage provided in an open system and supplying mist from a spray nozzle to the surface of the substrate to cause a thermal reaction.

[0108] The material contained in the raw material solution is not particularly limited as long as it contains at least metal atoms to be formed into a film and can be atomized, and may be an inorganic material or an organic material.

[0109] The raw material solution is not particularly limited as long as it can atomize the above-mentioned metal atoms. As the raw material solution, a solution obtained by dissolving or dispersing the metal in an organic solvent or water in the form of a complex or a salt can be appropriately used. As the form of the complex, for example, acetylacetone complex, carbonyl complex, ammine complex (Ammine), hydrazide complex (hydride) etc. can be listed. As the form of the salt, for example, metal chloride salts, metal bromide salts, metal iodide salts etc. can be listed. In addition, a solution obtained by dissolving the above-mentioned metal in hydrobromic acid, hydrochloric acid, hydrogen iodide etc. can also be used as an aqueous solution of the salt.

[0110] In addition, additives such as hydrohalic acid or oxidizing agent may be mixed in the raw material solution. Examples of the hydrohalic acid include hydrobromic acid, hydrochloric acid, and hydroiodic acid, among which hydrobromic acid and hydroiodic acid are preferred. Examples of the oxidizing agent include peroxides such as hydrogen peroxide, sodium peroxide, barium peroxide, and benzoyl peroxide; and organic peroxides such as hypochlorous acid, perchloric acid, nitric acid, ozone water, peracetic acid, and nitrobenzene.

[0111] As the raw material solution for forming MgO, an aqueous solution of magnesium chloride may be used.

[0112] In order to obtain an oxide composed of multiple metal elements, a plurality of raw material solutions may be mixed and atomized, or separate raw material solutions for each element may be atomized separately.

[0113] The film is preferably formed while heating the substrate at a temperature within a range of 200 to 1000°C.

[0114] As described above, the intermediate layer 21 can achieve good quality not only when it is a single layer of the material, but also when it is a stacked structure. For example, it can be set to be →Ir film / MgO film→initial substrate 11 side from the surface side of the base substrate 20. Similarly, it can also be more effectively played a role in alleviating lattice mismatch by forming a stacked structure with Ir film / YSZ film, Ir film / SrTiO3 film, etc. Figure 5 As described above, the single crystal MgO film 22 and the single crystal Ir film 23 are stacked on the initial substrate 11. In this case, the sequence from the surface side of the base substrate 20 is →Ir film / MgO film →initial substrate 11 side.

[0115] The thickness of the intermediate layer 21 is preferably 5 nm or more and 50 μm or less. If the thickness of the intermediate layer 21 is 5 nm or more, it will not be removed in the subsequent diamond formation process. In addition, if the thickness of the intermediate layer 21 is 50 μm or less, the thickness of the intermediate layer 21 is sufficient. In addition, if the thickness is 50 μm or less, the film-making time will not be prolonged, and the surface roughness can be ensured to be low. Therefore, polishing is not necessary, and film-making can be performed at low cost.

[0116] The outermost surface of the intermediate layer 21 may be provided with an off angle in the direction of the crystal axis <-1-12> with respect to the cubic crystal plane orientation {111}, or with an off angle in the direction of the crystal axis <10-10> or <11-20> with respect to the hexagonal crystal plane orientation {0001}. Thus, as the single crystal diamond layer 31 formed on the surface, a high-quality single crystal diamond {111} layer with high crystallinity and few abnormal growths such as protrusions and precipitates, and dislocation defects can be obtained more effectively.

[0117] It is preferred that the deviation angle of the outermost surface of the intermediate layer 21 at this time is set to a range of +8.0 to +24.0° or -8.0 to -24.0°. If the deviation angle is above +8.0 and -8.0°, the effect of setting the deviation angle can be fully obtained, and if it is below +24.0 and -24.0, the high quality effect can be fully obtained. In addition, if it is within the above range, the deviation from the {111} crystal plane of the outermost surface will not be too large, so it is easy to achieve the application of the composite purpose.

[0118] More preferably, the deviation angle of the outermost surface of the intermediate layer 21 is greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°. If it is within the above deviation angle range, it is more stable, and the effect of setting the deviation angle can be fully obtained, and the high quality effect can be fully obtained.

[0119] With respect to the crystal plane orientation {001}, in a cubic crystal, the crystal axis <110> direction, or in the hexagonal plane orientation {11-20} in <10-10> or <0001> By setting the off angle in the direction, a high-quality single-crystal diamond {001} layer with high crystallinity and few abnormal growths such as protrusions and crystalline aggregates, and dislocation defects can be obtained as diamond formed on the surface.

[0120] It is preferred that the deviation angle of the outermost surface of the intermediate layer 21 at this time is set to a range of +8.0 to +24.0° or -8.0 to -24.0°. If the deviation angle is above +8.0 and -8.0°, the effect of setting the deviation angle can be fully obtained, and if it is below +24.0 and -24.0, the high quality effect can be fully obtained. In addition, if it is within the above range, the deviation from the {001} crystal plane of the outermost surface will not be too large, so it is easy to achieve the application of the composite purpose.

[0121] It is more preferable that the deviation angle of the outermost surface of the intermediate layer 21 is set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°. If it is within the above deviation angle range, it is more stable, and the effect of setting the deviation angle can be fully obtained, and the high quality effect can be fully obtained.

[0122] Through the above Figure 1 The steps S11 and S12 can manufacture the base substrate 20 of the present invention (see Figure 3 , Figure 5 ).

[0123] The present invention further provides a method for manufacturing a single crystal diamond laminated substrate 30, characterized in that it includes: a step of preparing a base substrate 20 manufactured by the method for manufacturing a base substrate 20 in the above manner; a step of performing a bias treatment on the surface of the intermediate layer 21 of the base substrate 20 for forming diamond cores; and a step of growing the diamond cores formed on the intermediate layer 21 to perform epitaxial growth to form a single crystal diamond layer 31. This will be described in more detail below.

[0124] Figure 2 S11, S12 and Figure 1 S11 and S12 are the same process. Through the processes S11 and 12, the base substrate 20 can be manufactured. Figure 2 As shown, by performing the subsequent steps S13 and S14, a single crystal diamond laminated substrate 30 is manufactured.

[0125] (Bias treatment process: Figure 2 S13)

[0126] The surface of the intermediate layer 21 of the base substrate 20 is subjected to bias treatment to form a diamond core (step S13). The base substrate 20 with the intermediate layer 21 formed thereon is placed in a reduced pressure chamber, and after the pressure is reduced by a vacuum pump, a diamond core with the outermost surface of the intermediate layer 21 and the crystal orientation aligned is formed by direct current discharge. The discharge gas is preferably methane diluted with hydrogen.

[0127] (Single crystal diamond layer process: Figure 2 S14)

[0128] Next, the diamond nuclei formed on the intermediate layer 21 are grown to perform epitaxial growth, and a single crystal diamond layer 31 is formed (step S14). That is, a single crystal layer is formed on the bias-treated base substrate 20. This step can be performed by microwave plasma CVD, DC plasma CVD, hot filament CVD, arc discharge CVD, etc., which are vapor phase synthesis (CVD) methods.

[0129] The single crystal diamond layer 31 may be composed of individual layers of undoped or doped diamond, or a stacked structure of undoped and doped diamond.

[0130] Through the above steps S11 and S12 followed by steps S13 and S14, the single crystal diamond laminated substrate 30 of the present invention can be manufactured (see Figure 4 , Figure 6 ).

[0131] Furthermore, in the above-mentioned method for manufacturing a single crystal diamond laminated substrate, in either or both of the initial substrate 11 and the intermediate layer 21, by setting the crystal orientation to {111} in the case of a cubic crystal, or by setting the crystal orientation to {0001} in the case of a hexagonal crystal, a single crystal diamond {111} can be obtained.

[0132] On the other hand, in the above-mentioned method for manufacturing a single crystal diamond stacked substrate, in either the initial substrate 11 or the intermediate layer 21, or both, in the case of a cubic crystal, the crystal orientation is set to {001}, and in the case of a hexagonal crystal, the crystal orientation is set to {11-20}, so that a single crystal diamond {001} can be obtained.

[0133] The present invention also provides a method for manufacturing a single crystal diamond self-supporting structure substrate, which manufactures a single crystal diamond self-supporting structure substrate 35 (see Figure 7 ). A more detailed description is given below.

[0134] (Single crystal diamond extraction process: Figure 2 S15)

[0135] In this process, after the process of forming the single crystal diamond layer 30 (process S14), only the single crystal diamond layer 31 is taken out to make a single crystal diamond self-supporting structure substrate 35 (process S15). In order to make such a self-supporting substrate, chemical etching, laser irradiation, polishing, etc. can be used.

[0136] By making the film self-supporting, there is an advantage that process measures can be easily taken in subsequent additional film formation or device processing.

[0137] Furthermore, when diamond is used for electronic and magnetic devices, a single crystal diamond self-supporting structure substrate consisting only of a single crystal diamond layer is sometimes convenient because it is not affected by the intermediate layer or below.

[0138] (Single crystal diamond additional film forming process: Figure 2 S16)

[0139] Furthermore, in the present invention, by further forming an additional single crystal diamond layer 41 on the single crystal diamond self-supporting structure substrate 35 obtained up to step S15 (step S16), a single crystal diamond self-supporting structure substrate 40 (see Figure 8 ). That is, Figure 7The single crystal diamond self-supporting structure substrate 35 shown is formed by an additive method. Since the film is formed of a single material, there is no damage, which is effective for reducing stress. This process is also conducive to thickening the diamond film.

[0140] The additional single crystal diamond layer 41 formed in this step may be undoped or doped, or a combination thereof.

[0141] Before the additional single crystal diamond layer 41 is additionally formed, if the surface of the single crystal diamond self-supporting structure substrate 35 as a substrate is polished, a smooth crystal with few defects can be obtained.

[0142] According to the manufacturing method of the substrate substrate, single crystal diamond stacked substrate, and single crystal diamond self-supporting structure substrate of the present invention described above, it is possible to provide a method for manufacturing a stacked substrate having a high-quality single crystal diamond layer at a low cost. The high-quality single crystal diamond layer is suitable for electronic and magnetic devices, has a large diameter, high crystallinity, and has few abnormal growth particles such as protrusions and crystalline particles, dislocation defects, etc., and has high purity and low stress.

[0143] Example

[0144] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[0145] (Example 1)

[0146] A double-sided polished single crystal α-Al2O3 wafer with a diameter of 150 mm, a thickness of 1000 μm, a crystal plane orientation of {0001}, and an off angle of +16° in the <11-20> direction was prepared as an initial substrate 11 ( Figure 1 , Figure 2 Step S11).

[0147] Next, a MgO film was heteroepitaxially grown on the surface of the initial substrate by atomized CVD method, and the first layer of the intermediate layer 21 was formed under the following conditions ( Figure 5 Single crystal MgO film 22)( Figure 1 , Figure 2 Step S12).

[0148] A "magnesium oxide aqueous solution" is used as the raw material solution of the atomized CVD method. The raw material solution is stored in the mist generation source. Then, the flow control valve is opened to supply the carrier gas from the carrier gas source into the chamber. After the atmosphere in the chamber is fully replaced with the carrier gas, the flow rate of the carrier gas is adjusted to 10,000 sccm and the flow rate of the dilution carrier gas is adjusted to 30,000 sccm. Oxygen is used as the carrier gas.

[0149] Next, the ultrasonic vibrator is vibrated at 2.4 MHz, and the vibration is transmitted to the raw material solution through water, thereby atomizing the raw material solution to generate mist. The mist is introduced into the chamber through a supply pipe using a carrier gas. Under atmospheric pressure, the mist is thermally reacted with the initial substrate installed on a heating plate in the chamber and heated to 800° C., so that the MgO (111) film is heteroepitaxially grown on the surface of the initial substrate 11 until the thickness reaches 1 μm.

[0150] Next, the Ir film ( Figure 5 The single crystal Ir film 23) is heteroepitaxially grown on the single crystal MgO (111) film 22 to form a stacked intermediate layer 21 composed of Ir film / MgO.

[0151] When forming the single crystal Ir film 23, an RF (13.56 MHz) magnetron sputtering method using an Ir target with a diameter of 8 inches (200 mm), a thickness of 5 mm, and a purity of 99.9% or more as a target material was used. The substrate on which the single crystal MgO film 22 had been formed was heated to 900°C, and evacuated with a vacuum pump to confirm that the base pressure became approximately 8.0×10 -5 After the pressure dropped below 13 Pa, argon gas was introduced. After the opening of the valve connected to the exhaust system was adjusted to 13 Pa, the input power was set to 1500 W for 30 minutes to form a film. The obtained film thickness was about 1 μm.

[0152] The film thickness uniformity of the stacked intermediate layer composed of the Ir film / MgO film was evaluated and found to be ±3.8%.

[0153] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the pole method and the out-of-plane method. As a result, there was no crystalline component constituting Ir{111}, and only the main peak of diffraction intensity attributable to Ir(111) and its multiple reflection peaks at 2θ=40.7° were observed, confirming that the surface of the intermediate layer was a single crystal Ir(111) crystal formed by epitaxial growth.

[0154] By the above method, the Figure 5 The substrate 20 is shown.

[0155] Next, the base substrate 20 is subjected to a pretreatment (bias treatment) for forming diamond nuclei ( Figure 2 Step S13) wherein the base substrate 20 having the intermediate layer 21 formed thereon is placed on a flat electrode and the base pressure is confirmed to be approximately 1.3×10 -4Pa, hydrogen was introduced into the processing chamber at a flow rate of 500 sccm to dilute methane (CH4 / (CH4+H2)=5.0 vol.%). The opening of the valve connected to the exhaust system was adjusted to keep the pressure at 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds, thereby performing bias treatment on the surface of the intermediate layer 21 (that is, the surface of the single crystal Ir (111) film 23).

[0156] Next, a single crystal diamond layer 31 (non-doped diamond film) is heteroepitaxially grown by microwave CVD ( Figure 2 Step S14) wherein the bias-treated substrate 20 is mounted in a chamber of a microwave CVD device and evacuated by a vacuum pump until the base pressure becomes approximately 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=5.0 vol.%) was introduced into the processing chamber as a raw material gas at a flow rate of 1000 sccm. The opening of the valve connected to the exhaust system was adjusted so that the pressure was 1.5×10 4 After 100 ℃, direct current was passed to form a film for 100 hours. The substrate temperature during the film formation was measured with a high temperature thermometer and found to be 980°C.

[0157] The obtained single crystal diamond layer 31 is a complete continuous film with no peeling on the entire surface of 150 mm in diameter. The cross-sectional schematic diagram of the multilayer substrate (single crystal diamond laminated substrate 30) is shown in FIG. Figure 6 shown.

[0158] Next, the α-Al2O3 wafer as the initial substrate 11 is etched using hot phosphoric acid. Dry etching is further performed to remove the laminated film of the single crystal MgO film 22 and the single crystal Ir film 22 as the intermediate layer 21. Thus, a single crystal diamond (111) self-supporting substrate 35 ( Figure 2 Step S15).

[0159] Finally, a single crystal diamond layer (additional single crystal diamond layer 41) is heteroepitaxially grown again by microwave CVD ( Figure 2 The additional single crystal diamond layer 41 is formed under the same conditions as those for forming the above-mentioned non-doped diamond film.

[0160] The obtained single crystal diamond layer 41 is also a complete continuous film with no peeling on the entire surface of 150 mm in diameter. The cross-sectional schematic diagram of the single crystal diamond self-supporting structure substrate 40 composed of the single crystal diamond layer 31 and the additional single crystal diamond layer 41 is shown in FIG. Figure 8 shown.

[0161] A 2 mm square sample was cut out from the single crystal diamond self-supporting structure substrate 40 and used as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0162] Regarding the film thickness, a cross section of the sample was observed using a scanning secondary electron microscope (SEM), and the total thickness of the diamond layer was approximately 400 μm.

[0163] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the extreme point method and the out-of-plane method. As a result, there was no crystalline component constituting diamond {111}, and only a diffraction intensity peak at 2θ = 43.9° belonging to diamond (111) was observed, confirming that the diamond layer was a single crystal diamond (111) crystal formed by epitaxial growth.

[0164] If the single crystal diamond (111) laminated substrate and the self-supporting substrate are applied to electronic and magnetic devices, high-performance devices can be obtained. For example, high-performance electric devices can be obtained.

[0165] Furthermore, since it can be obtained as a large-diameter substrate, the production cost can be kept low.

[0166] (Example 2)

[0167] The initial substrate 11 in Example 1 is made into a single crystal α-Al2O3 wafer with a crystal plane orientation of {0001}, an offset angle of +8° in the <11-20> direction and double-sided polishing. Except for this, the single crystal diamond (111) self-supporting substrate 40 is obtained in the same manner.

[0168] The film thickness uniformity of the stacked intermediate layer composed of the Ir film / MgO film was evaluated and found to be ±4.2%.

[0169] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the extreme point method and the out-of-plane method. As a result, there was no crystalline component constituting diamond {111}, and only a diffraction intensity peak at 2θ = 43.9° belonging to diamond (111) was observed, confirming that the diamond layer was a single crystal diamond (111) crystal formed by epitaxial growth.

[0170] (Example 3)

[0171] The initial substrate 11 in Example 1 is made into a single crystal α-Al2O3 wafer with a crystal plane orientation of {0001}, a deviation angle of +24° in the <11-20> direction and double-sided polishing. Except for this, the single crystal diamond (111) self-supporting substrate 40 is obtained in the same manner.

[0172] The film thickness uniformity of the stacked intermediate layer composed of the Ir film / MgO film was evaluated and found to be ±6.5%.

[0173] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the extreme point method and the out-of-plane method. As a result, there was no crystalline component constituting diamond {111}, and only a diffraction intensity peak at 2θ = 43.9° belonging to diamond (111) was observed, confirming that the diamond layer was a single crystal diamond (111) crystal formed by epitaxial growth.

[0174] (Example 4)

[0175] A double-side polished single-crystal α-Al 2 O 3 wafer having a diameter of 150 mm, a thickness of 1000 μm, and a crystal plane orientation of {0001} was prepared as the initial substrate 11 .

[0176] Next, a MgO film was heteroepitaxially grown on the surface of the initial substrate by atomized CVD method, and the first layer of the intermediate layer 21 ( Figure 5 The single crystal MgO film 22 in the film).

[0177] The raw material solution in the atomized CVD method uses a "magnesium oxide aqueous solution". The raw material solution is stored in the mist generation source. Next, the flow control valve is opened to supply the carrier gas from the gas source into the chamber. After the atmosphere in the chamber is fully replaced with the carrier gas, the flow rate of the carrier gas is adjusted to 10,000 sccm and the flow rate of the dilution carrier gas is adjusted to 30,000 sccm. Oxygen is used as the carrier gas.

[0178] Next, the ultrasonic vibrator is vibrated at 2.4 MHz, and the vibration is transmitted to the raw material solution through water, thereby atomizing the raw material solution to generate mist. The mist is introduced into the chamber through a supply pipe using a carrier gas. Under atmospheric pressure, the mist is thermally reacted with the initial substrate installed on a heating plate in the chamber and heated to 800° C., so that the MgO (111) film is heteroepitaxially grown on the surface of the initial substrate 11 until the thickness reaches 1 μm.

[0179] Next, an Ir film is heteroepitaxially grown on the single crystal MgO (111) film 22 to form a stacked intermediate layer 21 composed of an Ir film / MgO.

[0180] When forming the single crystal Ir film 23, an RF (13.56 MHz) magnetron sputtering method was used, using an Ir target with a diameter of 8 inches (200 mm), a thickness of 5 mm, and a purity of 99.9% or more as a target material. The substrate on which the single crystal MgO film 22 had been formed was heated to 900°C, and evacuated with a vacuum pump to confirm that the base pressure was about 8.0×10-5 After the pressure dropped below 13 Pa, argon gas was introduced. After the opening of the valve connected to the exhaust system was adjusted to 13 Pa, the input power was set to RF 1500 W and film formation was carried out for 30 minutes. The obtained film thickness was about 1 μm.

[0181] The thickness uniformity of the intermediate layer of the Ir film / MgO film stack was evaluated and found to be ±9.5%.

[0182] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the pole method and the Out-of-plane method. As a result, the chrystal component constituting Ir{111} was included, and only the main peak of diffraction intensity attributable to Ir(111) and its multiple reflection peaks at 2θ=40.7° were observed, confirming that the surface of the intermediate layer was a single crystal Ir(111) crystal containing chrystal formed by epitaxial growth.

[0183] By the above method, the Figure 5 The substrate 20 is shown.

[0184] Next, the base substrate 20 is subjected to a pretreatment (bias treatment) for forming diamond nuclei ( Figure 2 Step S13) wherein the base substrate 20 having the intermediate layer 21 formed thereon is placed on a flat electrode and the base pressure is confirmed to be approximately 1.3×10 -4 Pa, hydrogen was introduced into the processing chamber at a flow rate of 500 sccm to dilute methane (CH4 / (CH4+H2)=5.0 vol.%). The opening of the valve connected to the exhaust system was adjusted to keep the pressure at 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds, thereby performing bias treatment on the surface of the intermediate layer 21 (that is, the surface of the single crystal Ir (111) film 23).

[0185] Next, a single crystal diamond layer 31 (non-doped diamond film) is heteroepitaxially grown by microwave CVD ( Figure 2 Step S14) wherein the bias-treated substrate 20 is mounted in a chamber of a microwave CVD device and evacuated by a vacuum pump until the base pressure becomes approximately 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=5.0 vol.%) was introduced into the processing chamber as a raw material gas at a flow rate of 1000 sccm. The opening of the valve connected to the exhaust system was adjusted so that the pressure was 1.5×10 4 After 100 ℃, direct current was passed to form a film for 100 hours. The substrate temperature during the film formation was measured with a high temperature thermometer and found to be 980°C.

[0186] The obtained single crystal diamond layer 31 is a complete continuous film with no peeling on the entire surface of 150 mm in diameter. The cross-sectional schematic diagram of the multilayer substrate (single crystal diamond laminated substrate 30) is shown in FIG. Figure 6 shown.

[0187] Next, the α-Al2O3 wafer as the initial substrate 11 is etched with hot phosphoric acid. Dry etching is further performed to remove the laminated film of the single crystal MgO film 22 and the single crystal Ir film 22 as the intermediate layer 21. Thus, a single crystal diamond (111) self-supporting substrate 35 is obtained.

[0188] Finally, a single crystal diamond layer (additional single crystal diamond layer 41) is heteroepitaxially grown again by microwave CVD. The formation of the additional single crystal diamond layer 41 is performed under the same conditions as those for forming the above-mentioned non-doped diamond film.

[0189] The obtained single crystal diamond layer 41 is also a complete continuous film with no peeling on the entire surface of 150 mm in diameter. The cross-sectional schematic diagram of the single crystal diamond self-supporting structure substrate 40 composed of the single crystal diamond layer 31 and the additional single crystal diamond layer 41 is shown in FIG. Figure 8 shown.

[0190] A 2 mm square sample was cut out from the single crystal diamond self-supporting structure substrate 40 and used as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0191] Regarding the film thickness, a cross section of the sample was observed using a scanning secondary electron microscope (SEM), and the total thickness of the diamond layer was approximately 400 μm.

[0192] The crystallinity was measured from the outermost surface of the film using an X-ray diffraction (XRD) device (RIGAKU SmartLab) by the pole method and the out-of-plane method. As a result, only the diffraction intensity peak at 2θ=43.9° belonging to diamond (111) was observed, including the chrystal component constituting diamond {111}, confirming that the diamond layer was a single crystal diamond (111) crystal containing chrystal formed by epitaxial growth.

[0193] In particular, if the single crystal diamond {111} laminated substrates and self-supporting substrates containing no chalcogenides of Examples 1 to 3 are applied to electronic and magnetic devices, it is considered that performance degradation during use of the devices, such as the generation of leakage current, can be more effectively suppressed.

[0194] (Comparative Example 1)

[0195] The same method as in Example 1 was used except that the MgO (111) film was formed by epitaxially growing the single crystal MgO layer to 1 μm in a vacuum at a substrate temperature of 900° C. using an electron beam evaporation method in Example 1. The thickness uniformity of the stacked intermediate layer composed of the Ir film / MgO film was evaluated, and the thickness uniformity was ±10.8%. In addition, the film formation time of the MgO film was more than 5 times that of Example 1.

[0196] (Comparative Example 2)

[0197] The same method as in Example 1 was used except that the MgO (111) film was formed by epitaxially growing the single crystal MgO layer to 1 μm in a vacuum at a substrate temperature of 900° C. using an electron beam evaporation method in Example 1. The thickness uniformity of the stacked intermediate layer composed of the Ir film / MgO film was evaluated, and the thickness uniformity was ±13.1%. In addition, the film formation time of the MgO film was more than 5 times that of Example 4.

[0198] If a diamond film is formed on an intermediate layer with poor film thickness uniformity (>±10%) such as in Comparative Examples 1 and 2, a low-quality single-crystal diamond layer with reduced crystallinity, increased protrusions, abnormally grown particles, dislocation defects, or high stress is very likely to be formed. In addition, compared with film formation by atomized CVD, the film formation time is increased, the device cost is increased, and the manufacturing cost of the base substrate and the single-crystal diamond laminated substrate is increased.

[0199] This specification contains the following protocols.

[0200] [1]: A method for manufacturing a substrate, which is a method for manufacturing a substrate for a single-crystal diamond laminate substrate, characterized in that it comprises: a step of preparing an initial substrate; and a step of forming an intermediate layer composed of a single-layer film or a laminated film comprising at least a single-crystal Ir film or a single-crystal MgO film on the initial substrate, wherein the single-crystal Ir film or the single-crystal MgO film constituting the intermediate layer is formed by atomized CVD method.

[0201] [2]: According to the method for manufacturing a base substrate of [1], the initial substrate is set to any one of a single crystal Si substrate, a single crystal α-Al2O3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

[0202] [3]: According to the method for manufacturing a base substrate of [1] or [2] above, the intermediate layer is set to be a stacked film further including at least any one of a single-crystalline yttria-stabilized zirconia film, a single-crystalline SrTiO3 film and a single-crystalline Ru film.

[0203] [4]: According to the manufacturing method of the base substrate described in [1], [2] or [3] above, the initial substrate is set to be any one of a Si{111} substrate, an α-Al2O3{0001} substrate, a Fe{111} substrate, a Ni{111} substrate, and a Cu{111} substrate, and the intermediate layer is set to include at least an Ir{111} film or a MgO{111} film.

[0204] [5]: The method for manufacturing a base substrate according to [4] above, wherein the intermediate layer further comprises at least one of a yttria-stabilized zirconia {111} film, a SrTiO3 {111} film, and a Ru {0001} film.

[0205] [6]: According to the manufacturing method of the substrate substrate described in [4] or [5] above, the outermost surface of the initial substrate is set to have an offset angle in the direction of the crystal axis <-1-12> relative to the cubic crystal plane orientation {111}, or to have an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the hexagonal crystal plane orientation {0001}.

[0206] [7]: According to the method for manufacturing a base substrate of the above-mentioned [6], the deviation angle of the outermost surface of the initial substrate is set to the range of +8.0~+24.0° or -8.0~-24.0°.

[0207] [8]: According to the manufacturing method of the base substrate described in [6] or [7] above, the deviation angle of the outermost surface of the initial substrate is set to a range greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0208] [9]: According to the manufacturing method of the substrate substrate described in [4], [5], [6], [7] or [8] above, the outermost surface of the intermediate layer is set to have an offset angle in the direction of the crystal axis <-1-12> relative to the cubic crystal plane orientation {111}, or to have an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the hexagonal crystal plane orientation {0001}.

[0209]

[10] : According to the method for manufacturing a base substrate of the above-mentioned [9], the off angle of the outermost surface of the intermediate layer is set to the range of +8.0~+24.0° or -8.0~-24.0°.

[0210]

[11] : According to the manufacturing method of the base substrate described in [9] or

[10] above, the deviation angle of the outermost surface of the intermediate layer is set to a range greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0211]

[12] : According to the manufacturing method of the base substrate described in [1], [2] or [3] above, the initial substrate is set to be any one of a Si{001} substrate, an α-Al2O3{11-20} substrate, a Fe{001} substrate, a Ni{001} substrate, and a Cu{001} substrate, and the intermediate layer is set to include at least an Ir{001} film or a MgO{001} film.

[0212]

[13] : According to the method for manufacturing a base substrate of the above-mentioned

[12] , the intermediate layer is set to further include at least any one of a yttria-stabilized zirconia {001} film, a SrTiO3{001} film, and a Ru{11-20} film.

[0213]

[14] : According to the method for manufacturing a base substrate of

[12] or

[13] , the outermost surface of the initial substrate is set to be oriented on the crystal axis with respect to the cubic crystal plane orientation {001} <110> The direction is set at an angle of deviation, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> The direction sets the deviation angle.

[0214]

[15] : According to the method for manufacturing a base substrate of the above-mentioned

[14] , the deviation angle of the outermost surface of the initial substrate is set to the range of +8.0~+24.0° or -8.0~-24.0°.

[0215]

[16] : According to the manufacturing method of the base substrate described in

[14] or

[15] above, the deviation angle of the outermost surface of the initial substrate is set to a range greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0216]

[17] : According to the method for manufacturing a substrate according to

[13] ,

[14] ,

[15] or

[16] , the outermost surface of the intermediate layer is set to be oriented on the crystal axis with respect to the cubic crystal plane {001} <110> The direction sets the deviation angle, or the hexagonal plane orientation {11-20} is in <10-10> or <0001> The direction sets the deviation angle.

[0217]

[18] : According to the manufacturing method of the base substrate of the above-mentioned

[17] , the deviation angle of the outermost surface of the intermediate layer is set to the range of +8.0~+24.0° or -8.0~-24.0°.

[0218]

[19] : According to the manufacturing method of the base substrate described in

[17] or

[18] above, the deviation angle of the outermost surface of the intermediate layer is set to a range greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0219]

[20] : A method for manufacturing a single crystal diamond laminate substrate, characterized in that it comprises:

[0220] A step of preparing a base substrate manufactured by the method for manufacturing a base substrate of [1], [2], [3], [4], [5], [6], [7], [8], [9],

[10] ,

[11] ,

[12] ,

[13] ,

[14] ,

[15] ,

[16] ,

[17] ,

[18] , or

[19] ;

[0221] A step of performing a bias treatment on the surface of the intermediate layer of the base substrate to form diamond cores; and

[0222] A step of growing diamond nuclei formed on the intermediate layer to perform epitaxial growth to form a single crystal diamond layer.

[0223]

[21] : The method for producing a single crystal diamond laminated substrate according to

[20] above, wherein the single crystal diamond layer is a {111} crystal.

[0224]

[22] : The method for producing a single crystal diamond laminated substrate according to

[20] above, wherein the single crystal diamond layer is a {001} crystal.

[0225]

[23] : A method for manufacturing a single crystal diamond self-supporting structure substrate, characterized in that only the single crystal diamond layer is taken out from a single crystal diamond stacked substrate manufactured by the manufacturing method of a single crystal diamond stacked substrate described in

[20] ,

[21] or

[22] to manufacture a single crystal diamond self-supporting structure substrate.

[0226]

[24] : A method for manufacturing a single crystal diamond self-supporting structure substrate, characterized in that an additional single crystal diamond layer is further formed on the single crystal diamond self-supporting structure substrate obtained by the method for manufacturing a single crystal diamond self-supporting structure substrate of the above-mentioned

[23] .

[0227]

[25] : A substrate substrate, in a substrate substrate for a single crystal diamond laminate substrate, comprises: an initial substrate; and an intermediate layer on the initial substrate consisting of a single layer film or a laminated film comprising at least a single crystal Ir film or a single crystal MgO film, wherein the film thickness uniformity of the intermediate layer is within ±10% over the entire surface.

[0228]

[26] : According to the base substrate of

[25] above, the initial substrate is any one of a single crystal Si substrate, a single crystal α-Al2O3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

[0229]

[27] : According to the base substrate of

[25] or

[26] above, the intermediate layer is a stacked film further comprising at least any one of a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film and a single crystal Ru film.

[0230]

[28] : The substrate according to

[25] ,

[26] or

[27] , wherein the initial substrate is any one of a single crystal Si{111} substrate, a single crystal Si{001} substrate, a single crystal α-Al2O3{0001} substrate, a single crystal α-Al2O3{11-20} substrate, a single crystal Fe{111} substrate, a single crystal Fe{001} substrate, a single crystal Ni{111} substrate, a single crystal Ni{001} substrate, a single crystal Cu{111} substrate and a single crystal Cu{001} substrate, and the outermost surface of the initial substrate has an offset angle relative to the cubic crystal plane orientation {111} in the crystal axis <-1-12> direction, or has an offset angle relative to the hexagonal crystal plane orientation {0001} in the crystal axis <10-10> or <11-20> direction, or has an offset angle relative to the cubic crystal plane orientation {001} in the crystal axis <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

[0231]

[29] : According to the base substrate described in

[28] above, the deviation angle of the outermost surface of the initial substrate is in the range of +8.0~+24.0° or -8.0~-24.0°.

[0232]

[30] : According to the base substrate of

[28] or

[29] above, the deviation angle of the outermost surface of the initial substrate is greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0233]

[31] : According to the substrate substrate of

[25] ,

[26] ,

[27] ,

[28] ,

[29] or

[30] above, the outermost surface of the intermediate layer has an offset angle in the direction of the crystal axis <-1-12> relative to the cubic crystal plane orientation {111}, or has an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the hexagonal crystal plane orientation {0001}, or has an offset angle in the direction of the crystal axis <10-10> or <11-20> relative to the cubic crystal plane orientation {001}. <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

[0234]

[32] : According to the base substrate of

[31] above, the deviation angle of the outermost surface of the intermediate layer is in the range of +8.0~+24.0° or -8.0~-24.0°.

[0235]

[33] : According to the base substrate of

[31] or

[32] above, the deviation angle of the outermost surface of the intermediate layer is greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0236]

[34] : A single crystal diamond stacked substrate having a single crystal diamond layer on the intermediate layer of the base substrate of

[25] ,

[26] ,

[27] ,

[28] ,

[29] ,

[30] ,

[31] ,

[32] or

[33] .

[0237] The above embodiments are merely examples, and any technical solution having substantially the same structure and achieving the same technical effect as the technical concept described in the claims of the present invention is included in the protection scope of the present invention.

Claims

1. A method for manufacturing a base substrate, which is a method for manufacturing a base substrate for a single crystal diamond laminated substrate, characterized in that: It has: The process of preparing an initial substrate; and forming an intermediate layer composed of a single layer film or a stacked film including at least a single crystal Ir film or a single crystal MgO film on the initial substrate, A single crystal Ir film or a single crystal MgO film constituting the intermediate layer is formed using a mist CVD method.

2. The method for manufacturing a base substrate according to claim 1, characterized in that: The initial substrate is set to be any one of a single crystal Si substrate, a single crystal α-Al 2 O 3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

3. The method for manufacturing a base substrate according to claim 1, characterized in that: The intermediate layer is set to be a stacked film further including at least any one of a single-crystalline yttria-stabilized zirconia film, a single-crystalline SrTiO 3 film, and a single-crystalline Ru film.

4. The method for manufacturing a base substrate according to claim 1, characterized in that: The initial substrate is set to be any one of a Si{111} substrate, an α-Al2O3{0001} substrate, a Fe{111} substrate, a Ni{111} substrate, and a Cu{111} substrate, The intermediate layer is set to include at least an Ir{111} film or a MgO{111} film.

5. The method for manufacturing a base substrate according to claim 4, characterized in that: The intermediate layer is set to further include at least any one of a yttria-stabilized zirconia {111} film, a SrTiO3 {111} film, and a Ru {0001} film.

6. The method for manufacturing a base substrate according to claim 4, characterized in that: The outermost surface of the initial substrate is set to have an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}.

7. The method for manufacturing a base substrate according to claim 6, characterized in that: The off angle of the outermost surface of the initial substrate is set to a range of +8.0 to +24.0° or -8.0 to -24.0°.

8. The method for manufacturing a base substrate according to claim 6, wherein: The off angle of the outermost surface of the initial substrate is set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

9. The method for manufacturing a base substrate according to claim 4, characterized in that: The outermost surface of the intermediate layer is set to have an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or set to have an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}.

10. The method for manufacturing a base substrate according to claim 9, characterized in that: The off angle of the outermost surface of the intermediate layer is set to a range of +8.0 to +24.0° or -8.0 to -24.0°.

11. The method for manufacturing a base substrate according to claim 9, characterized in that: The off angle of the outermost surface of the intermediate layer is set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

12. The method for manufacturing a base substrate according to claim 1, characterized in that: The initial substrate is set to be any one of a Si{001} substrate, an α-Al2O3{11-20} substrate, a Fe{001} substrate, a Ni{001} substrate, and a Cu{001} substrate, The intermediate layer is set to include at least an Ir{001} film or a MgO{001} film.

13. The method for manufacturing a base substrate according to claim 12, characterized in that: The intermediate layer is set to further include at least any one of a yttria-stabilized zirconia {001} film, a SrTiO3 {001} film, and a Ru{11-20} film.

14. The method for manufacturing a base substrate according to claim 12, characterized in that: The outermost surface of the initial substrate is set to be oriented with respect to the cubic crystal plane {001} on the crystal axis <110> The direction is set at an angle of deviation, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> The direction sets the deviation angle.

15. The method for manufacturing a base substrate according to claim 14, characterized in that: The off angle of the outermost surface of the initial substrate is set to a range of +8.0 to +24.0° or -8.0 to -24.0°.

16. The method for manufacturing a base substrate according to claim 14, characterized in that: The off angle of the outermost surface of the initial substrate is set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

17. The method for manufacturing a base substrate according to claim 13, characterized in that: The outermost surface of the intermediate layer is oriented in the direction of the crystal axis {001} with respect to the cubic crystal plane. <110> The direction sets the deviation angle, or the hexagonal plane orientation {11-20} is in <10-10> or <0001> The direction sets the deviation angle.

18. The method for manufacturing a base substrate according to claim 17, characterized in that: The off angle of the outermost surface of the intermediate layer is set to a range of +8.0 to +24.0° or -8.0 to -24.0°.

19. The method for manufacturing a base substrate according to claim 17, characterized in that: The off angle of the outermost surface of the intermediate layer is set to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

20. A method for manufacturing a single crystal diamond laminate substrate, characterized in that: It includes: A step of preparing a base substrate manufactured by the method for manufacturing a base substrate according to any one of claims 1 to 19; A step of performing a bias treatment on the surface of the intermediate layer of the base substrate to form diamond cores; and A step of growing diamond nuclei formed on the intermediate layer to perform epitaxial growth to form a single crystal diamond layer.

21. The method for manufacturing a single crystal diamond laminated substrate according to claim 20, characterized in that: The single crystal diamond layer is set to be a {111} crystal.

22. The method for manufacturing a single crystal diamond laminated substrate according to claim 20, characterized in that: The single crystal diamond layer is set to be a {001} crystal.

23. A method for manufacturing a single crystal diamond self-supporting structure substrate, characterized in that: Only the single crystal diamond layer is taken out from the single crystal diamond multilayer substrate manufactured by the method for manufacturing a single crystal diamond multilayer substrate according to claim 20 to manufacture a single crystal diamond free-standing structure substrate.

24. A method for manufacturing a single crystal diamond self-supporting structure substrate, characterized in that: An additional single crystal diamond layer is further formed on the single crystal diamond self-supporting structure substrate obtained by the method for manufacturing a single crystal diamond self-supporting structure substrate according to claim 23.

25. A substrate, characterized in that: The base substrate for a single crystal diamond laminate substrate has: an initial substrate; and The intermediate layer on the initial substrate is composed of a single layer or a stacked layer of at least a single crystal Ir film or a single crystal MgO film, The thickness uniformity of the intermediate layer is within ±10% in the entire surface.

26. The base substrate according to claim 25, characterized in that The initial substrate is any one of a single crystal Si substrate, a single crystal α-Al2O3 substrate, a single crystal Fe substrate, a single crystal Ni substrate, and a single crystal Cu substrate.

27. The base substrate according to claim 25, characterized in that The intermediate layer is a stacked film further including at least any one of a single crystal yttria-stabilized zirconia film, a single crystal SrTiO 3 film, and a single crystal Ru film.

28. The base substrate according to claim 25, characterized in that The initial substrate is any one of a single crystal Si{111} substrate, a single crystal Si{001} substrate, a single crystal α-Al2O3{0001} substrate, a single crystal α-Al2O3{11-20} substrate, a single crystal Fe{111} substrate, a single crystal Fe{001} substrate, a single crystal Ni{111} substrate, a single crystal Ni{001} substrate, a single crystal Cu{111} substrate, and a single crystal Cu{001} substrate, The outermost surface of the initial substrate has an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or has an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or has an offset angle in the crystal axis <001> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

29. The base substrate according to claim 28, characterized in that The deviation angle of the outermost surface of the initial substrate is in the range of +8.0 to +24.0° or -8.0 to -24.0°.

30. The base substrate according to claim 28, characterized in that The off angle of the outermost surface of the initial substrate is in a range of greater than +15.0° and less than +24.0°, or greater than -15.0° and less than -24.0°.

31. The base substrate according to claim 25, characterized in that The outermost surface of the intermediate layer has an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or has an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or has an offset angle in the crystal axis <001> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an offset angle, or relative to the hexagonal plane orientation {11-20}, the crystal axis <10-10> or <0001> Directions have a deviation angle.

32. The base substrate according to claim 31, characterized in that The deviation angle of the outermost surface of the intermediate layer is in the range of +8.0 to +24.0° or -8.0 to -24.0°.

33. The base substrate according to claim 31, characterized in that The off angle of the outermost surface of the intermediate layer is in the range of greater than +15.0° and less than +24.0°, or greater than -15.0° and less than -24.0°.

34. A single crystal diamond laminate substrate, characterized in that: The base substrate according to any one of claims 25 to 33 has a single crystal diamond layer on the intermediate layer.

Images