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

Abstract

The present invention is a base substrate used for a single crystal diamond laminated substrate, the base substrate comprising an initial substrate of any one of a single crystal Si {111} substrate, a single crystal alpha-Al2O3 {0001} substrate, and the like, and an intermediate layer on the initial substrate, the outermost surface of the initial substrate being oriented {111} at the crystal axis lt, and the outermost surface of the initial substrate being oriented {111} at the crystal axis lt with respect to the cubic crystal plane; -1 to 12 gt; the direction has an off angle, or the orientation of the hexagonal crystal plane {0001} is at the crystal axis lt; 10 <-10 > gt; or lt; 11 to 20 gt; the direction has an off angle. As a result, a high-quality single crystal diamond layer is provided which can be applied to an electronic / magnetic device, has a large area (large diameter), has high crystallinity, and has few abnormally grown particles such as protrusions and goldenrain 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 manufacturing 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, enabling operation at high voltages. Furthermore, diamond has the highest thermal conductivity of any known material, making it excellent at dissipating heat. Furthermore, its extremely high carrier mobility and saturation drift velocity make it suitable for high-speed devices.

[0004] Therefore, even compared with semiconductors such as silicon carbide and gallium nitride, diamond has the highest Johnson figure of merit, which indicates its performance as a high-frequency, 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 large-area, high-quality diamond substrate.

[0010] Currently, single-crystal diamond used in diamond semiconductor production is almost exclusively type Ib diamond, synthesized using the high-pressure, high-temperature method (HPHT). This type Ib diamond contains a high concentration of nitrogen impurities and is only available in sizes up to approximately 8 mm square, making it impractical. A tiling method has also been proposed, where multiple HPHT substrates (diamond substrates synthesized using the HPHT method) are joined side by side (Non-Patent Document 1). However, this presents the problem of imperfections at the joints.

[0011] In contrast, vapor phase synthesis (Chemical Vapor Deposition: CVD) can produce high-purity polycrystalline diamond with a large area of ​​approximately 6 inches (150 mm) in diameter. However, single crystal formation suitable for electronic devices is generally difficult. This is because it is difficult to find a suitable material combination with a small difference in lattice constant and linear expansion coefficient between diamond and the substrate used to form the diamond. For example, the lattice constant difference between diamond and single-crystal Si is 34.3%, making heteroepitaxial growth of diamond on the substrate surface extremely difficult.

[0012] The present invention has been developed to address the aforementioned issues, and its purpose is to provide a substrate and a method for manufacturing the same, capable of forming a high-quality single-crystal diamond layer suitable for use in electronic and magnetic devices. This high-quality single-crystal diamond layer has a large area (large diameter), high crystallinity, few hillocks, abnormally grown particles, dislocation defects, and the like, and exhibits high purity and low stress. Furthermore, the present invention provides a single-crystal diamond laminate substrate and a method for manufacturing a single-crystal diamond self-supporting structure substrate having such a single-crystal diamond layer.

[0013] (2) Technical solution

[0014] In order to achieve the above object, the present invention provides a base substrate, characterized in that, in a base substrate for a single crystal diamond laminated substrate, it has:

[0015] an initial substrate, which 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

[0016] The intermediate layer on the initial substrate is composed of a single layer or a stacked film comprising at least any one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film.

[0017] 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 <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0018] If it is such a base substrate, the initial substrate and its deviation angle and the intermediate layer form an appropriate combination, so that a base substrate that can form a high-quality single-crystal diamond layer can be made. The high-quality single-crystal diamond layer is suitable for electronic and magnetic devices, has a large diameter, high crystallinity and few hillocks, abnormal growth particles, dislocation defects, etc., high purity and low stress.

[0019] In this case, 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°. Furthermore, 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°.

[0020] By setting the range to this, the quality improvement effect due to the off angle can be maximized.

[0021] In addition, the outermost surface of the intermediate layer may have an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or an offset angle in the crystal axis <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0022] By setting the off angle in this manner, a base substrate capable of obtaining a high-quality single-crystal diamond layer having high crystallinity and few abnormal growths such as protrusions and lobes, and dislocation defects can be more efficiently manufactured.

[0023] In this case, the off 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°. Furthermore, the off 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°.

[0024] By setting the range to this, the quality improvement effect due to the off angle can be maximized.

[0025] Furthermore, the present invention provides a single crystal diamond laminated substrate characterized in that it has a single crystal diamond layer on the intermediate layer of any of the above-described base substrates.

[0026] Such a single crystal diamond laminated substrate can be made 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, and few protrusions, abnormal growth particles, dislocation defects, etc., and has high purity and low stress.

[0027] In this case, in the single crystal diamond multilayer substrate of the present invention, it is preferred that the single crystal diamond layer be a {111} crystal or a {001} crystal.

[0028] The single crystal diamond multilayer substrate of the present invention can be manufactured by providing the single crystal diamond layer having the above-mentioned plane orientation on the above-mentioned base substrate.

[0029] Furthermore, 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 laminated substrate, characterized in that it comprises:

[0030] a step of preparing an initial substrate, 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

[0031] forming an intermediate layer on the initial substrate, the intermediate layer being composed of a single layer or a stacked layer of at least one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film;

[0032] Wherein, as the initial substrate, 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 off-angle, or the crystal axis <10-10> or <0001> Any of the initial substrates with an offset angle in the orientation.

[0033] If such a method for manufacturing a base substrate is used, by forming an appropriate combination of the initial substrate, its deviation angle, and the intermediate layer, a base substrate capable of forming a high-quality single-crystal diamond layer can be manufactured. The high-quality single-crystal diamond layer is suitable for electronic and magnetic devices, has a large diameter, high crystallinity, and few protrusions, abnormally grown particles, dislocation defects, etc., and has high purity and low stress.

[0034] In this case, 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°. Furthermore, 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°.

[0035] By using an initial substrate having an off angle within such a range, the quality improvement effect due to the off angle can be maximized.

[0036] In addition, the outermost surface of the intermediate layer may 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}, or an off angle in the crystal axis <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0037] By setting the off angle in this manner, a base substrate capable of obtaining a high-quality single-crystal diamond layer having high crystallinity and few abnormal growths such as protrusions and lobes, and dislocation defects can be more efficiently manufactured.

[0038] In this case, the intermediate layer may be formed by setting the off angle of the outermost surface of the intermediate layer in the range of +8.0 to +24.0° or -8.0 to -24.0°. Furthermore, the off angle of the outermost surface of the intermediate layer may be set in the range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

[0039] By setting the range to this, the quality improvement effect due to the off angle can be maximized.

[0040] In addition, the present invention also 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 one of the above-mentioned substrate substrate manufacturing methods; a process of performing bias treatment on 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.

[0041] The single crystal diamond laminated substrate manufactured in this way can be made into a single crystal diamond laminated substrate with a high-quality single crystal diamond layer, which is suitable for electronic and magnetic devices, has a large diameter, high crystallinity, and few protrusions, abnormal growth particles, dislocation defects, etc., and has high purity and low stress.

[0042] In this case, in the single crystal diamond multilayer substrate of the present invention, it is preferred that the single crystal diamond layer be a {111} crystal or a {001} crystal.

[0043] The single-crystal diamond multi-layer substrate of the present invention can be manufactured by providing the single-crystal diamond layer having the above-mentioned plane orientation on the above-mentioned base substrate.

[0044] In addition, the present invention also 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 stacked substrate manufactured by any of the above-mentioned methods for manufacturing a single crystal diamond stacked substrate to manufacture a single crystal diamond self-supporting structure substrate.

[0045] In this way, a single-crystal diamond free-standing structure substrate composed only of a single-crystal diamond layer can be manufactured.

[0046] Furthermore, an additional single-crystal diamond layer can be further formed on the single-crystal diamond free-standing structure substrate obtained by the above-mentioned method for manufacturing a single-crystal diamond free-standing structure substrate.

[0047] This allows further film formation to be performed on the substrate consisting solely of the diamond layer by an additive method, thereby further increasing the film thickness.

[0048] (3) Beneficial effects

[0049] According to the base substrate and its manufacturing method of the present invention, an initial substrate, its off-angle, and an intermediate layer are appropriately combined to form a diamond layer, thereby producing a laminated substrate having a high-quality single-crystal diamond layer suitable for electronic and magnetic devices. This high-quality single-crystal diamond layer has a large diameter, high crystallinity, few protrusions, abnormally grown particles, dislocation defects, and the like, and exhibits high purity and low stress. Furthermore, according to the present invention, a single-crystal diamond self-supporting structure substrate can be produced in which only the single-crystal diamond layer is separated from such a single-crystal diamond laminated substrate. Furthermore, a single-crystal diamond self-supporting structure substrate can be produced in which an additional single-crystal diamond layer is formed on a single-crystal diamond self-supporting structure substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 FIG. 1 is a schematic diagram showing an example of the base substrate of the present invention.

[0051] Figure 2 Schematic diagram showing an example of the single-crystal diamond laminated substrate of the present invention.

[0052] Figure 3 FIG1 is a schematic diagram showing an example of a single crystal diamond self-supporting structure substrate according to the present invention.

[0053] Figure 4 FIG1 is a schematic diagram showing another example of the single crystal diamond self-supporting structure substrate of the present invention.

[0054] Figure 5 1 is a flowchart showing an example of a method for manufacturing a base substrate of the present invention.

[0055] Figure 6 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 according to the present invention.

[0056] Figure 7 This is the result of the extreme point method of X-ray diffraction measurement in Example 1.

[0057] Figure 8 These are the results of the out-of-plane method of X-ray diffraction measurement in Example 1.

[0058] Figure 9 These are the results of the extreme point method of X-ray diffraction measurement in Comparative Example 1.

[0059] Figure 10 These are the results of the out-of-plane X-ray diffraction measurement in Comparative Example 1. DETAILED DESCRIPTION

[0060] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0061] As mentioned above, a large-diameter, low-cost, high-quality single-crystal diamond laminate substrate has been sought. Therefore, the inventors of the present application have conducted extensive research to address this technical problem. As a result, they have discovered optimal materials for single-crystal diamond laminate substrates, as well as for selecting optimal materials for the initial substrate and intermediate layer used in the production of single-crystal diamond laminate substrates, and methods for forming these materials, thereby completing the present invention.

[0062] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. Similar components will be denoted by the same reference numerals and described below.

[0063] First, refer to Figure 1 and Figure 2 The base substrate and the single-crystal diamond laminated substrate of the present invention will be described.

[0064] like Figure 1As shown, the base substrate 20 for a single-crystal diamond laminate 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 initial substrate 11 is selected from any 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. Furthermore, the intermediate layer 21 on the initial substrate 11 comprises a single layer or a laminated film comprising at least one of a single-crystal Ir film, a single-crystal MgO film, a single-crystal yttria-stabilized zirconia film, a single-crystal SrTiO3 film, and a single-crystal Ru film. For the base substrate 20 of the present invention, further, the outermost surface of the initial substrate 11 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 off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0065] In addition, if Figure 2 As shown, the single crystal diamond laminated substrate 30 of the present invention is Figure 1 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.

[0066] As described above, the initial substrate 11 can be any 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 lattice mismatch between these initial substrates 11 (bulk substrates) and the material of the intermediate layer 21 is small, thus facilitating epitaxial growth of the intermediate layer 21 during its formation. Furthermore, a large diameter exceeding 6 inches (150 mm) can be achieved, and the cost can be relatively low.

[0067] At this time, if it is desired to obtain {111} crystals and {001} crystals as the single crystal diamond layer 31 to be formed, the starting substrate 11 corresponding thereto can be selected.

[0068] Furthermore, the above-mentioned provisions are set for the deviation angle of the outermost surface of the initial substrate 11. That is, the outermost surface of the initial substrate 11 may have a deviation angle in the direction of the crystal axis <-1-12> relative to the cubic crystal plane orientation {111} of the single crystal Si{111} substrate, etc., and may also have a deviation angle in the direction of the crystal axis <10-10> or <11-20> relative to the hexagonal crystal plane orientation {0001} of the single crystal α-Al2O3{0001} substrate, etc. In addition, the outermost surface of the initial substrate 11 may also have a deviation angle in the direction of the crystal axis <10-10> or <11-20> relative to the cubic crystal plane orientation {001} of the single crystal Si{001} substrate, etc. <110> The direction has an off-angle, and can also be oriented in the crystal axis <10-10> or <10-10> relative to the hexagonal plane orientation {11-20} of the single crystal α-Al2O3 {11-20} substrate. <0001> The direction has a deviation angle.

[0069] By setting such off angle regulations, a high-quality intermediate layer with high crystallinity, few protrusions, abnormal growth, and dislocation defects can be obtained as the intermediate layer formed on the outermost surface of the initial substrate 11 .

[0070] When setting an off angle on the outermost surface of the initial substrate 11, the off angle is preferably set in the range of +8.0 to +24.0° or -8.0 to -24.0°. If the off angle is greater than +8.0° or -8.0°, the effect of setting the off angle can be fully achieved, while if it is less than +24.0° or -24.0°, the high quality effect can be fully achieved.

[0071] Furthermore, when setting an off angle on the outermost surface of the initial substrate 11, the off angle is 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°. Within this off angle range, the effect of setting the off angle is more stable, and the effect of high quality can be fully achieved.

[0072] The surface of the initial substrate 11 on which the intermediate layer is to be formed is preferably polished to Ra ≤ 0.5 nm. This allows the formation of a smooth intermediate layer with few defects.

[0073] As described above, the intermediate layer 21 is composed of a single layer film or a stacked film including at least any one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO 3 film, and a single crystal Ru film.

[0074] As described above, the intermediate layer 21 of the base substrate 20 of the present invention can achieve excellent quality not only when formed as a single layer of the aforementioned material, but also when formed as a stacked structure. Such a stacked film can be designed to more effectively mitigate the lattice mismatch between the initial substrate 11 and the single-crystal diamond layer 31. For example, the sequence from the surface side can be: Ir film / MgO film → initial substrate 11 side. Similarly, by forming a stacked structure with an Ir film / YSZ film, an Ir film / SrTiO3 film, or the like, the lattice mismatch can be more effectively mitigated.

[0075] The thickness of the intermediate layer 21 is preferably at least 5 nm and no more than 50 μm. If the thickness of the intermediate layer 21 is at least 5 nm, 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, it is a very sufficient thickness for the intermediate layer 21. In addition, if the thickness is 50 μm or less, the film formation time will not be prolonged and the surface roughness can be kept low. Therefore, polishing is not required, and the film can be formed at a low cost.

[0076] The outermost surface of the intermediate layer 21 may have an offset angle. The outermost surface of the intermediate layer 21 may have an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, and may have an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}. In addition, the outermost surface of the intermediate layer 21 may have an offset angle in the crystal axis <-1-12> 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> By setting the off angle of the outermost surface of the intermediate layer 21 in this manner, a high-quality single-crystal diamond layer with high crystallinity and few protrusions, abnormal growth, and dislocation defects can be obtained as diamond formed on this surface.

[0077] The off angle of the outermost surface of the intermediate layer 21 is preferably set to a range of +8.0° to +24.0° or -8.0° to -24.0°. If the off angle is greater than +8.0° or -8.0°, the effect of setting the off angle is fully achieved, while if it is less than +24.0° or -24.0°, the high-quality effect is fully achieved. Furthermore, within this range, the deviation from the crystal plane of the outermost surface is not excessive, making it easier to achieve the desired application.

[0078] More preferably, the off 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°. Within this off angle range, the effect of setting the off angle is more stable, and the high-quality effect can be fully achieved.

[0079] The following, Figure 1 、 Figure 2 The manufacturing method of the base substrate and the single crystal diamond laminated substrate shown in FIG. Figure 5 The manufacturing method of the base substrate of the present invention will be described. Figure 6 The method for producing the single-crystal diamond multilayer substrate of the present invention will be described.

[0080] In addition, the present invention can produce Figure 3 The single crystal diamond self-supporting structure substrate 35 is composed of the single crystal diamond layer 31 shown, and Figure 4 The single crystal diamond layer 31 and the additional single crystal diamond layer 41 constitute the single crystal diamond self-supporting structure substrate 40, referring to Figure 6 This production method will be described.

[0081] (Preparation process: Figure 5 Step S11)

[0082] First, an initial substrate 11 is prepared (step S11). The initial substrate 11 can be any 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 (bulk substrate). The lattice mismatch between the material of the initial substrate 11 and the material of the intermediate layer 21 is small, making epitaxial growth of the intermediate layer 21 easy. Furthermore, large diameters greater than 6 inches (150 mm) can be obtained, and the cost is relatively low.

[0083] Here, as the initial substrate 11, the outermost surface of the initial substrate has an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or has an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or has an off angle in the crystal axis <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> By using such an initial substrate 11, as the intermediate layer 21 formed on the surface, a high-quality intermediate layer 21 with high crystallinity and few protrusions, abnormal growth, dislocation defects, etc. can be obtained more effectively.

[0084] 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 offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or to have an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}. On the other hand, when it is desired to obtain a {001} crystal plane orientation as the single crystal diamond layer, the outermost surface of the initial substrate 11 can be set to have an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {001}. <110> The direction is set to an angle of deviation, or relative to the hexagonal plane orientation {11-20} in <10-10> or <0001> Direction sets the deviation angle.

[0085] The surface of the initial substrate 11 on which the intermediate layer 21 is to be formed is preferably polished to Ra ≤ 0.5 nm. This allows the formation of a smooth intermediate layer 21 with few defects.

[0086] The off angle of the outermost surface of the initial substrate 11 is preferably set within the range of +8.0° to +24.0° or -8.0° to -24.0°. If the off angle is greater than +8.0° or -8.0°, the effect of setting the off angle is fully achieved, while if it is less than +24.0° or -24.0°, the high-quality effect is fully achieved. Furthermore, within the above range, the deviation from the crystal plane of the outermost surface is not excessive, making it easier to achieve the desired application.

[0087] Furthermore, it is more preferable to set the off angle of the outermost surface of the initial substrate 11 to a range greater than +15.0° and less than +24.0°, or greater than -15.0° and less than -24.0°. Within this off angle range, the effect of setting the off angle can be more stable, and the high-quality effect can be fully achieved.

[0088] (Intermediate layer forming process: Figure 5 Step S12)

[0089] In step S11, after the initial substrate 11 is prepared, an intermediate layer 21 is formed on the initial substrate 11. The intermediate layer 21 is formed as a single layer or a stacked layer including at least one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film (step S12).

[0090] The outermost surface of the intermediate layer 21 may have an offset angle. The outermost surface of the intermediate layer 21 may have an offset angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, and may have an offset angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}. In addition, the outermost surface of the intermediate layer 21 may also have an offset angle in the crystal axis <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> By setting the off angle of the outermost surface of the intermediate layer 21 in this manner, a high-quality single-crystal diamond layer with high crystallinity and few protrusions, abnormal growth, and dislocation defects can be obtained as diamond formed on this surface.

[0091] When it is desired to obtain a {111} crystal orientation for the single crystal diamond layer 31, at least the outermost surface of the intermediate layer 21 is oriented in the {111} crystal orientation if the intermediate layer 21 is a cubic crystal, and at least the outermost surface of the intermediate layer 21 is oriented in the {0001} crystal orientation if the intermediate layer 21 is a hexagonal crystal. On the other hand, when it is desired to obtain a {001} crystal orientation for the single crystal diamond layer 31, at least the outermost surface of the intermediate layer 21 is oriented in the {001} crystal orientation if the intermediate layer 21 is a cubic crystal, and at least the outermost surface of the intermediate layer 21 is oriented in the {11-20} crystal orientation if the intermediate layer 21 is a hexagonal crystal.

[0092] The off angle of the outermost surface of the intermediate layer 21 is preferably within the range of +8.0° to +24.0° or -8.0° to -24.0°. If the off angle is greater than +8.0° or -8.0°, the effect of setting the off angle is fully achieved, while if it is less than +24.0° or -24.0°, the high-quality effect is fully achieved. Furthermore, within this range, the deviation from the crystal plane of the outermost surface is not excessive, making it easier to achieve the desired application.

[0093] More preferably, the off 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°. Within this off angle range, the effect of setting the off angle is more stable, and the high-quality effect can be fully achieved.

[0094] The intermediate layer 21 can be formed by sputtering, electron beam evaporation, atomic layer deposition, molecular beam epitaxy, pulsed laser deposition, etc. Furthermore, the single crystal Ir film, single crystal MgO film, single crystal yttria-stabilized zirconia (YSZ) film, single crystal SrTiO3 film, and single crystal Ru film used in the present invention as metals and metal oxides can be formed using atomized CVD, which can be formed with a large aperture and at low cost.

[0095] The film-forming apparatus based on the atomization CVD method consists of an atomization section that uses 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.

[0096] In the chamber, the substrate is heated on a heating stage and rotated as needed to form a highly crystalline and uniform film. Highly crystalline and uniform films can also be formed by controlling the flow of raw material gases.

[0097] 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 substrate surface to cause a thermal reaction.

[0098] The material contained in the raw material solution is not particularly limited as long as it contains at least metal atoms of the desired film and can be atomized, and may be an inorganic material or an organic material.

[0099] 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 salt can be appropriately used. As the form of the complex, for example, acetylacetone complex, carbonyl complex, ammonia complex (Ammine), hydrazide complex (hydride) etc. can be listed. As the form of the salt, for example, metal chloride, metal bromide, metal iodide 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.

[0100] In addition, additives such as hydrohalic acids and oxidizing agents may be mixed into the raw material solution. Examples of hydrohalic acids include hydrobromic acid, hydrochloric acid, and hydroiodic acid, with hydrobromic acid and hydroiodic acid being preferred. Examples of oxidizing agents 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.

[0101] As the raw material solution for forming MgO, an aqueous solution of magnesium chloride may be used.

[0102] 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.

[0103] The film is preferably formed while heating the substrate to a temperature within a range of 200 to 1000°C.

[0104] As described above, the intermediate layer 21 can achieve excellent quality not only when composed of a single layer of the aforementioned materials, but also when formed into a stacked structure. For example, it can be arranged in the following order from the surface side: → Ir film / MgO film → initial substrate 11 side. Similarly, a stacked structure such as Ir film / YSZ film, Ir film / SrTiO3 film, etc. can be formed to more effectively mitigate lattice mismatch.

[0105] 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 very sufficient. In addition, if the thickness is 50 μm or less, the film forming time will not be prolonged and the surface roughness can be kept low. Therefore, polishing is not required, and the film can be formed at a low cost.

[0106] As described above, the outermost surface of the intermediate layer 21 can be provided with an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or with an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}. This allows for a high-quality single-crystal diamond {111} layer to be formed on this surface, with high crystallinity and minimal protrusions, abnormal growth, dislocation defects, and the like, to be more efficiently obtained.

[0107] The off angle of the outermost surface of the intermediate layer 21 is preferably set within the range of +8.0° to +24.0° or -8.0° to -24.0°. If the off angle is +8.0° or above or -8.0°, the effect of setting the off angle is fully achieved, while if it is +24.0° or below or -24.0°, the high-quality effect is fully achieved. Furthermore, within this range, the deviation from the {111} crystal plane of the outermost surface is not excessive, making it easier to achieve the desired application.

[0108] More preferably, the off 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°. Within this off angle range, the effect of setting the off angle is more stable, and the high-quality effect can be fully achieved.

[0109] As for the outermost surface of the intermediate layer 21, as described above, by <110> Direction setting deviation angle, 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 protrusions, abnormal growth, dislocation defects, etc. can be obtained as the diamond formed on the surface.

[0110] The off angle of the outermost surface of the intermediate layer 21 is preferably set within the range of +8.0° to +24.0° or -8.0° to -24.0°. If the off angle is +8.0° or -8.0° or greater, the effect of setting the off angle is fully achieved, while if it is +24.0° or -24.0° or less, the high-quality effect is fully achieved. Furthermore, within this range, the deviation from the {001} crystal plane of the outermost surface is not excessive, making it easier to achieve the desired application.

[0111] More preferably, the off 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°. Within this off angle range, the effect of setting the off angle is more stable, and the high-quality effect can be fully achieved.

[0112] Through the above Figure 5 The steps S11 and S12 can manufacture the base substrate 20 of the present invention (see Figure 1 ).

[0113] Furthermore, the present invention provides a method for manufacturing a single-crystal diamond laminated substrate 30, characterized by comprising: preparing a base substrate 20 manufactured by the above-described method for manufacturing a base substrate 20; subjecting the surface of the intermediate layer 21 of the base substrate 20 to a bias treatment for forming diamond nuclei; and causing the diamond nuclei formed on the intermediate layer 21 to grow epitaxially to form a single-crystal diamond layer 31. This process is described in more detail below.

[0114] Figure 6 S11, S12 and Figure 5 The steps S11 and S12 are the same step. Through the steps S11 and S12, the base substrate 20 can be manufactured. Figure 6 In the subsequent steps S13 and S14 shown, the single crystal diamond laminated substrate 30 is manufactured.

[0115] (Bias treatment process: Figure 6 S13)

[0116] The surface of the intermediate layer 21 of the base substrate 20 is biased to form diamond nuclei (step S13). The base substrate 20, with the intermediate layer 21 formed thereon, is placed in a reduced pressure chamber. After the pressure is reduced using a vacuum pump, a DC discharge is performed to form diamond nuclei with the outermost surface of the intermediate layer 21 aligned with the crystal orientation. The discharge gas is preferably methane diluted with hydrogen.

[0117] (Single crystal diamond layer process: Figure 6 S14)

[0118] Next, the diamond nuclei formed on the intermediate layer 21 are grown to perform epitaxial growth, forming a single-crystal diamond layer 31 (step S14). Specifically, a single-crystal layer is formed on the bias-treated base substrate 20. This step can be performed using a vapor phase CVD method such as microwave plasma CVD, DC plasma CVD, hot-filament CVD, or arc discharge CVD.

[0119] 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.

[0120] 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 2 ).

[0121] Furthermore, in the above-described method for manufacturing a single-crystal diamond laminated substrate, single-crystal diamond {111} can be obtained by setting the initial substrate 11, the intermediate layer 21, or both thereof to a {111} crystal orientation if cubic, or to a {0001} crystal orientation if hexagonal. For example, single-crystal diamond {111} can be formed when a single-crystal Si {111} substrate or a single-crystal α-Al2O3 {0001} substrate is used as the initial substrate 11.

[0122] On the other hand, in the above-described method for manufacturing a single-crystal diamond laminated substrate, single-crystal diamond {001} can be obtained by setting the initial substrate 11, the intermediate layer 21, or both thereof to a {001} crystal orientation if cubic, or a {11-20} crystal orientation if hexagonal. For example, single-crystal diamond {001} can be formed when a single-crystal Si {001} substrate or a single-crystal α-Al2O3 {11-20} substrate is used as the initial substrate 11.

[0123] 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 3 ). The following is a more detailed description.

[0124] (Single crystal diamond removal process: Figure 6 S15)

[0125] In this process, after the process of forming the single crystal diamond layer 31 (process S14), only the single crystal diamond layer 31 is removed to form 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.

[0126] By making the film self-supporting, there is an advantage in that process measures are facilitated in subsequent additional film formation or device processing.

[0127] Furthermore, when diamond is used in electronic and magnetic devices, a single crystal diamond free-standing structure substrate consisting only of a single crystal diamond layer is sometimes convenient because it is not affected by layers below the intermediate layer.

[0128] (Single crystal diamond additional film forming process: Figure 6 S16)

[0129] 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 can be manufactured (see Figure 4 ). That is, it can Figure 3 The single crystal diamond self-supporting structure substrate 35 shown is formed by an additive process. Since the film is formed from a single material, there is no damage, which is effective for reducing stress. This process also helps to thicken the diamond film.

[0130] The additional single crystal diamond layer 41 formed in this step may be undoped or doped, or a combination thereof.

[0131] Before the additional single crystal diamond layer 41 is additionally formed, if the surface of the single crystal diamond free-standing structure substrate 35 serving as the base is polished, a smooth crystal with few defects can be obtained.

[0132] According to the manufacturing method of the base substrate, single crystal diamond stacked substrate, and single crystal diamond self-supporting structure substrate of the present invention described above, a method for manufacturing a stacked substrate with a high-quality single crystal diamond layer at low cost can be provided. The high-quality single crystal diamond layer is suitable for electronic and magnetic devices and has a large diameter, high crystallinity, few protrusions, abnormal growth particles, dislocation defects, etc., high purity, and low stress.

[0133] Example

[0134] Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples.

[0135] (Example 1)

[0136] 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 (111), and a 16° off angle in the <11-20> direction was prepared as the initial substrate 11 (refer to Figure 1 The initial substrate 11) Figure 5 、 Figure 6 Step S11).

[0137] Then, an Ir film is grown heteroepitaxially on the surface of the initial substrate 11 to form an intermediate layer 21 ( Figure 5 、 Figure 6 Step S12).

[0138] To form the Ir film as the intermediate layer 21, 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. The substrate was heated to 850°C and evacuated with a vacuum pump to confirm that the base pressure reached approximately 8.0 × 10 -5 After the pressure dropped below 14 Pa, argon gas was introduced. The opening of the valve connected to the exhaust system was adjusted to 14 Pa, and the input power was set to 1500 W for 3 minutes to form a film. The resulting film thickness was about 1 μm.

[0139] The crystallinity of the film was measured from the outermost surface using an X-ray diffraction (XRD) apparatus (RIGAKU SmartLab) by the extreme point method and the out-of-plane method. As a result, the extreme point method detected a (111) plane diffraction peak when the (111) plane was oriented in the normal direction of the substrate main surface, but no (111) plane diffraction peak was detected when the (001) plane was oriented in the normal direction of the substrate main surface. The results of the extreme point method are shown in Figure 7 The point arrangement of the (111) diffraction peak when there is no eutectic crystal constituting {111}.

[0140] In addition, in the Out-of-plane method, only the main peak of diffraction intensity at 2θ = 40.7° attributed to Ir (111) and its multiple reflection peaks were observed, confirming that the intermediate layer is a single crystal Ir (111) crystal grown by epitaxial growth. The results of the Out-of-plane method are shown in Figure 8 The half-maximum width of the rocking curve of the Ir(111) peak is 0.13°.

[0141] The base substrate 20 of the present invention is manufactured in the above manner (see Figure 1 ).

[0142] Next, the base substrate 20 is subjected to a pre-treatment (bias treatment) for forming diamond nuclei ( Figure 6 Step S13) wherein the base substrate 20 having the intermediate layer 21 formed thereon is mounted 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 to dilute methane (CH4 / (CH4+H2)=5.0vol.%) at a flow rate of 500sccm. The opening of the valve connected to the exhaust system was adjusted to set the pressure to 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds to perform bias treatment on the surface of the intermediate layer 21 (ie, the surface of the single crystal Ir(111) film).

[0143] Next, a single crystal diamond layer 31 (undoped diamond film) is heteroepitaxially grown by microwave CVD ( Figure 6 Step S14) wherein the bias-treated base substrate 20 is placed in a chamber of a microwave CVD device and evacuated by a vacuum pump until the base pressure reaches approximately 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=4.0 vol.%) was introduced into the processing chamber at a flow rate of 1000 sccm as the raw material gas. The opening of the valve connected to the exhaust system was adjusted to set the pressure to 1.5×10 4 After the film was formed for 150 hours, a direct current was passed. The substrate temperature during the film formation was measured with a high-temperature thermometer and found to be 980°C.

[0144] The single crystal diamond layer 31 obtained is a complete continuous film with no peeling on the entire surface of the 150 mm diameter. The cross-sectional schematic diagram of the single crystal diamond laminate substrate 30 thus manufactured is shown in FIG. Figure 2 shown.

[0145] Next, the α-Al2O3 wafer as the initial substrate 11 is etched with hot phosphoric acid. Furthermore, the Ir film as the intermediate layer 21 is removed by dry etching. Thus, a single crystal diamond {111} self-supporting substrate 35 ( Figure 6 Step S15).

[0146] Finally, a single crystal diamond layer (additional single crystal diamond layer 41) is heteroepitaxially grown again by microwave CVD ( Figure 6 The additional single crystal diamond layer 41 is formed under the same conditions as those for forming the non-doped diamond film.

[0147] The obtained single crystal diamond layer is also a complete continuous film with no peeling on the entire surface of the 150 mm 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 4 shown.

[0148] A 2 mm square sample was cut out from the single crystal diamond self-supporting structure substrate 40 as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0149] Regarding the film thickness, observation of a cross section of the sample using a scanning secondary electron microscope (SEM) revealed that the total thickness of the diamond layer was approximately 400 μm.

[0150] The crystallinity of the film was measured using an X-ray diffraction (XRD) instrument (RIGAKU SmartLab) from the outermost surface. The results showed that only the diffraction intensity peak at 2θ = 43.9°, attributed to diamond (111), was observed, confirming that the diamond layer was composed of single-crystal diamond {111} crystals grown epitaxially. There was no eutectic component.

[0151] 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 power devices.

[0152] Furthermore, since it can be obtained as a large-diameter substrate, the production cost can be kept low.

[0153] (Example 2)

[0154] 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 8° in the <11-20> direction was prepared as the initial substrate 11 (refer to Figure 1 The initial substrate 11) Figure 5 、 Figure 6 Step S11).

[0155] Then, an Ir film is grown heteroepitaxially on the surface of the initial substrate 11 to form an intermediate layer 21 ( Figure 5 、 Figure 6 Step S12).

[0156] To form the Ir film as the intermediate layer 21, 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. The substrate was heated to 850°C and evacuated with a vacuum pump to confirm that the base pressure was approximately 8.0×10 -5After the pressure dropped below Pa, argon gas was introduced. The opening of the valve connected to the exhaust system was adjusted to 14 Pa, and the input power was set to 1500 W. Film formation was carried out for 30 minutes. The resulting film thickness was about 1 μm.

[0157] X-ray diffraction (XRD) analysis (RIGAKU SmartLab) was performed using the extreme point and out-of-plane methods to measure the crystallinity of the film from the outermost surface. The results revealed no Ir{111}-containing crystalline components, and only a main peak of diffraction intensity at 2θ = 40.7° attributed to Ir(111) and its multiple reflection peaks were observed, confirming that the intermediate layer was composed of epitaxially grown single-crystal Ir(111). The full width at half maximum of the rocking curve for the Ir(111) peak was 0.12°.

[0158] The base substrate 20 of the present invention is manufactured in the above manner (see Figure 1 ).

[0159] Next, the base substrate 20 is subjected to a pre-treatment (bias treatment) for forming diamond nuclei ( Figure 6 Step S13) wherein the base substrate 20 having the intermediate layer 21 formed thereon is mounted 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 to dilute methane (CH4 / (CH4+H2)=5.0vol.%) at a flow rate of 500sccm. The opening of the valve connected to the exhaust system was adjusted to set the pressure to 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds to perform bias treatment on the surface of the intermediate layer 21 (ie, the surface of the single crystal Ir{111} film).

[0160] Next, a single crystal diamond layer 31 (non-doped diamond film) is heteroepitaxially grown by microwave CVD ( Figure 6 In step S14, the base substrate 20 subjected to the bias treatment is placed in the chamber of the microwave CVD device and evacuated by a vacuum pump until the base pressure is about 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=4.0 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 to set the pressure to 1.5×10 4 After the film was formed, a direct current was passed for 80 hours. The substrate temperature during the film formation was measured with a high temperature thermometer and found to be 980°C.

[0161] The single crystal diamond layer 31 obtained is also a complete continuous film with no peeling on the entire surface of the 150 mm diameter. The cross-sectional schematic diagram of the single crystal diamond laminated substrate 30 thus manufactured is shown in FIG. Figure 2 shown.

[0162] A 2 mm square sample was cut out from the single crystal diamond laminated substrate 30 as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0163] Regarding the film thickness, observation of the sample cross section using a scanning secondary electron microscope (SEM) revealed that the total thickness of the diamond layer was approximately 100 μm. Compared to Example 1, while thinner, the film was continuous and had a smooth surface. The dislocation defect density was also reduced.

[0164] The crystallinity of the film was measured using an X-ray diffraction (XRD) instrument (RIGAKU SmartLab) from the outermost surface. The only diffraction intensity peak at 2θ = 43.9°, attributed to diamond (111), was observed, confirming that the diamond layer was composed of single-crystal diamond {111} crystals grown epitaxially. No crystalline crystalline was observed.

[0165] If this single crystal diamond {111} laminated substrate is applied to electronic and magnetic devices, high-performance devices can be obtained. For example, high-performance electric power devices can be obtained.

[0166] Furthermore, since it can be obtained as a large-diameter substrate, the production cost can be kept low.

[0167] (Example 3)

[0168] 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 24° in the <11-20> direction was prepared as the initial substrate 11 (refer to Figure 1 The initial substrate 11) Figure 5 、 Figure 6 Step S11).

[0169] Then, an Ir film is grown heteroepitaxially on the surface of the initial substrate 11 to form an intermediate layer 21 ( Figure 5 、 Figure 6 Step S12).

[0170] To form the Ir film as the intermediate layer 21, 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. The substrate was heated to 850°C and evacuated with a vacuum pump to confirm that the base pressure reached approximately 8.0×10 -5After the pressure dropped below Pa, argon gas was introduced. The opening of the valve connected to the exhaust system was adjusted to 14 Pa, and the input power was set to 1500 W. Film formation was carried out for 30 minutes. The resulting film thickness was about 1 μm.

[0171] X-ray diffraction (XRD) analysis (RIGAKU SmartLab) was performed using both the extreme point and out-of-plane methods to determine the crystallinity of the film from the outermost surface. The results revealed no Ir{111}-containing crystalline components, and only a main peak of diffraction intensity at 2θ = 88.1° attributable to Ir(222) and its multiple reflection peaks were observed, confirming that the intermediate layer was composed of epitaxially grown single-crystal Ir(111). The full width at half maximum of the rocking curve for the Ir(222) peak was 0.12°.

[0172] The base substrate 20 of the present invention is manufactured in the above manner (see Figure 1 ).

[0173] Next, the base substrate 20 is subjected to a pre-treatment (bias treatment) for forming diamond nuclei ( Figure 6 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 to dilute methane (CH4 / (CH4+H2)=5.0vol.%) at a flow rate of 500sccm. The opening of the valve connected to the exhaust system was adjusted to set the pressure to 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds to perform bias treatment on the surface of the intermediate layer 21 (ie, the surface of the single crystal Ir{111} film).

[0174] Next, a single crystal diamond layer 31 (non-doped diamond film) is heteroepitaxially grown by microwave CVD ( Figure 6 In step S14, the base substrate 20 subjected to the bias treatment is placed in the chamber of the microwave CVD device and evacuated by a vacuum pump until the base pressure reaches about 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=4.0 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 to set the pressure to 1.5×10 4 After the evaporation, a direct current was passed for 80 hours to form a film.

[0175] The substrate temperature during film formation was measured with a high-temperature thermometer and found to be 980°C.

[0176] The single crystal diamond layer 31 obtained is also a complete continuous film with no peeling on the entire surface of the 150 mm diameter. The cross-sectional schematic diagram of the single crystal diamond laminated substrate 30 manufactured in this way is as follows Figure 2 shown.

[0177] A 2 mm square sample was cut out from the single crystal diamond laminated substrate 30 as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0178] Regarding the film thickness, observation of the sample cross section using a scanning secondary electron microscope (SEM) revealed that the total thickness of the diamond layer was approximately 100 μm. Although thinner than in Example 1, the film was continuous and had a smooth surface. The dislocation defect density was also reduced.

[0179] The crystallinity of the film was measured using an X-ray diffraction (XRD) instrument (RIGAKU SmartLab) from the outermost surface. The results showed that only the diffraction intensity peak at 2θ = 43.9°, attributed to diamond (111), was observed, confirming that the diamond layer was epitaxially grown single-crystal diamond {111} crystals. There were no crystalline structures.

[0180] If this single crystal diamond {111} laminated substrate is applied to electronic and magnetic devices, high-performance devices can be obtained, for example, high-performance electric power devices.

[0181] Furthermore, since it can be obtained as a large-diameter substrate, the production cost can be kept low.

[0182] In the comparative examples described below, the Figure 1 、 2 The off angle of the initial substrate 11, the crystallinity of the intermediate layer 21, etc. are different from those of the embodiment, but the outline of the cross-sectional structure is the same as Figure 1 、 2 In addition, the Figure 5 、 6 The process is the same except that the deviation angle of the initial substrate prepared is different.

[0183] (Comparative Example)

[0184] A double-sided polished single-crystal α-Al2O3 wafer (with no off angle) with a diameter of 150 mm, a thickness of 1000 μm, and a crystal plane orientation of {0001} was prepared as the initial substrate 11 (equivalent to the substrate of the embodiment). Figure 1 The substrate without deviation angle in the initial substrate 11 (corresponding to the embodiment of Figure 5 、 Figure 6 Step S11).

[0185] Then, an Ir film is grown heteroepitaxially on the surface of the initial substrate 11 to form an Ir film {111} intermediate layer 21 (corresponding to the embodiment of Figure 5 、 Figure 6 Step S12).

[0186] To form the Ir film as the intermediate layer 21, 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. The substrate was heated to 850°C and evacuated with a vacuum pump to confirm that the base pressure was approximately 8.0×10 -5 After the pressure dropped below Pa, argon gas was introduced. The opening of the valve connected to the exhaust system was adjusted to 14 Pa, and the input power was set to 1500 W. Film formation was carried out for 30 minutes. The resulting film thickness was about 1 μm.

[0187] The crystallinity of the film was measured using an X-ray diffraction (XRD) apparatus (RIGAKU SmartLab) using the extreme point method and the out-of-plane method. The results showed that the extreme point method detected a diffraction peak for the {111} plane when the {111} plane was oriented in the normal direction to the substrate main surface, but no diffraction peak for the {001} plane when the {111} plane was oriented in the normal direction to the substrate main surface. The results of the extreme point method are shown in Figure 9 The point arrangement of the {111} diffraction peak when {111} is composed of eutectic crystals.

[0188] In addition, in the Out-of-plane method, only the main peak of diffraction intensity at 2θ = 40.7° attributed to Ir (111) and its multiple reflection peaks were observed, confirming that the intermediate layer is a single crystal Ir {111} crystal grown by epitaxial growth. The results of the Out-of-plane method are shown in Figure 10 The half-maximum width of the rocking curve of the Ir{111} peak is 0.16°.

[0189] The base substrate 20 of the comparative example (equivalent to the base substrate of the embodiment) was manufactured in the above manner. Figure 1 The substrate with the changed off angle in the initial substrate 11).

[0190] Next, the base substrate 2 is subjected to a pretreatment (bias treatment) for forming diamond cores (corresponding to the embodiment). Figure 6 Step S13) wherein the base substrate 20 having the intermediate layer 21 formed thereon is placed on a flat electrode, and it is confirmed that the base pressure is 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 set the pressure to 1.3×10 4 After Pa, a negative voltage was applied to the substrate-side electrode and plasma was irradiated for 90 seconds to perform bias treatment on the surface of the intermediate layer 21 (ie, the surface of the single crystal Ir{111} film).

[0191] Then, a single crystal diamond layer 31 (non-doped diamond film) is heteroepitaxially grown by microwave CVD (corresponding to the embodiment Figure 6 In step S14, the base substrate 20 subjected to the bias treatment is placed in the chamber of the microwave CVD device and evacuated by a vacuum pump until the base pressure reaches about 1.3×10 -4 Pa, hydrogen-diluted methane (CH4 / (CH4+H2)=4.0 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 to set the pressure to 1.5×10 4 After the film was formed, a direct current was passed and the film was formed for 150 hours. The substrate temperature during the film formation was measured with a high temperature thermometer and found to be 980°C.

[0192] The single crystal diamond layer 31 obtained is a complete continuous film with no peeling on the entire surface of the 150 mm diameter. Figure 2 The structure is the same.

[0193] Next, the α-Al2O3 wafer as the initial substrate 11 is etched with hot phosphoric acid. Further, the Ir film as the intermediate layer 21 is removed by dry etching. Thus, a single crystal diamond {111} self-supporting substrate 35 (corresponding to the embodiment) is obtained. Figure 6 Step S15).

[0194] Finally, a single crystal diamond layer (additional single crystal diamond layer 41) is heteroepitaxially grown again by microwave CVD (corresponding to the embodiment Figure 6 The additional single crystal diamond layer 41 is formed under the same conditions as those used to form the non-doped diamond film.

[0195] The obtained single crystal diamond layer is also a complete continuous film with no peeling on the entire surface of the 150 mm diameter. Figure 4 The structure is the same.

[0196] A 2 mm square sample was cut out from the single crystal diamond self-supporting structure substrate 40 as an evaluation sample, and the film thickness and crystallinity were evaluated.

[0197] Regarding the film thickness, observation of a cross section of the sample using a scanning secondary electron microscope (SEM) revealed that the total thickness of the diamond layer was approximately 400 μm.

[0198] The crystallinity of the film was measured using an X-ray diffraction (XRD) instrument (RIGAKU SmartLab) from the outermost surface. A diffraction intensity peak at 2θ = 43.9° attributed to diamond (111) was observed, confirming that the diamond layer was composed of single-crystal diamond {111} crystals grown epitaxially. Luan crystal components were present.

[0199] As described above, the presence of chrysoprase components within the single-crystal diamond crystals in the Comparative Examples reveals that these single-crystal diamond layers exhibit lower quality, exhibiting numerous abnormal growth patterns and dislocation defects, compared to the Examples. It is believed that when the single-crystal diamond {111} laminated substrates and free-standing substrates of the Comparative Examples are used in electronic and magnetic devices, it is difficult to achieve high-performance devices compared to the Examples.

[0200] This specification contains the following protocols.

[0201] [1]: A base substrate for a single crystal diamond laminate substrate having:

[0202] an initial substrate, which 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

[0203] The intermediate layer on the initial substrate is composed of a single layer or a stacked film comprising at least any one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film.

[0204] 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 <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0205] [2]: According to the base substrate described in [1] 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°.

[0206] [3]: According to the base substrate of [1] or [2] 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°.

[0207] [4]: According to the substrate substrate of [1], [2] or [3] above, 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 <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0208] [5]: According to the base substrate of [4] above, the offset 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°.

[0209] [6]: According to the base substrate of [4] or [5] 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°.

[0210] [7]: A single crystal diamond laminate substrate having a single crystal diamond layer on the intermediate layer of the base substrate of [1], [2], [3], [4], [5] or [6].

[0211] [8]: The single crystal diamond laminated substrate according to [7] above, wherein the single crystal diamond layer is a {111} crystal or a {001} crystal.

[0212] [9]: A method for manufacturing a base substrate, which is a method for manufacturing a base substrate for a single-crystal diamond laminated substrate, comprising:

[0213] a step of preparing an initial substrate, 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

[0214] forming an intermediate layer on the initial substrate, the intermediate layer being composed of a single layer or a stacked layer of at least one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film;

[0215] As the initial substrate, the outermost surface of the initial substrate has an off angle in the crystal axis <-1-12> direction relative to the cubic crystal plane orientation {111}, or has an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or has an off angle in the crystal axis <10-10> or <11-20> direction relative to the cubic crystal plane orientation {001}. <110> The direction has an off-angle, or the crystal axis <10-10> or <0001> Any of a substrate having an offset angle in its direction.

[0216]

[10] : According to the manufacturing method of the base substrate of the above-mentioned [9], 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°.

[0217]

[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 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°.

[0218]

[12] : According to the manufacturing method of the base substrate of the above-mentioned [9],

[10] or

[11] , 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 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 off-angle, or the crystal axis <10-10> or <0001> The direction has a deviation angle.

[0219]

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

[12] , 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° to form the intermediate layer.

[0220]

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

[12] or

[13] , 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° to form the intermediate layer.

[0221]

[15] :A method for manufacturing a single crystal diamond laminate substrate, comprising:

[0222] A process for preparing a substrate manufactured by the method for manufacturing a substrate described in [9],

[10] ,

[11] ,

[12] ,

[13] or

[14] above;

[0223] a step of performing a bias treatment on the surface of the intermediate layer of the base substrate to form diamond cores;

[0224] A step of growing diamond nuclei formed on the intermediate layer to perform epitaxial growth to form a single crystal diamond layer.

[0225]

[16] : According to the method for manufacturing a single crystal diamond laminated substrate according to the above

[15] , the single crystal diamond layer is set to be a {111} crystal or a {001} crystal.

[0226]

[17] : A method for manufacturing a single crystal diamond self-supporting structure substrate, which comprises removing only the single crystal diamond layer from a single crystal diamond laminate substrate manufactured by the method for manufacturing a single crystal diamond laminate substrate described in

[15] or

[16] above, to manufacture a single crystal diamond self-supporting structure substrate.

[0227]

[18] : A method for manufacturing a single crystal diamond self-supporting structure substrate, which further forms an additional single crystal diamond layer 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

[17] .

[0228] The above embodiments are merely examples, and all technical solutions having substantially the same structure and achieving the same technical effects as those described in the claims of the present invention are within the scope of protection of the present invention.

Claims

1. A substrate, characterized in that: The base substrate for a single crystal diamond laminate substrate has: an initial substrate, which 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 intermediate layer on the initial substrate is composed of a single layer or a stacked film including at least any one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film. 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.

2. The base substrate according to claim 1, 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°.

3. The base substrate according to claim 1, 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°.

4. The base substrate according to claim 1, 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.

5. The base substrate according to claim 4, 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°.

6. The base substrate according to claim 4, 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°.

7. A single crystal diamond laminate substrate, characterized in that: The base substrate according to any one of claims 1 to 6 has a single crystal diamond layer on the intermediate layer.

8. The single crystal diamond laminated substrate according to claim 7, characterized in that The single crystal diamond layer is a {111} crystal or a {001} crystal.

9. 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: a step of preparing an initial substrate, 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 a step of forming an intermediate layer on the initial substrate, wherein the intermediate layer is composed of a single layer or a stacked layer of at least any one of a single crystal Ir film, a single crystal MgO film, a single crystal yttria-stabilized zirconia film, a single crystal SrTiO3 film, and a single crystal Ru film, As the initial substrate, the outermost surface of the initial substrate 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> Any of the substrates having an offset angle in the direction.

10. The method for manufacturing a base substrate according to claim 9, 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°.

11. The method for manufacturing a base substrate according to claim 9, 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°.

12. The method for manufacturing a base substrate according to claim 9, 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 an off angle in the crystal axis <10-10> or <11-20> direction relative to the hexagonal crystal plane orientation {0001}, or an off angle in the crystal axis <001> 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.

13. The method for manufacturing a base substrate according to claim 12, characterized in that: The intermediate layer is formed by setting the off angle of the outermost surface of the intermediate layer to a range of +8.0 to +24.0° or -8.0 to -24.0°.

14. The method for manufacturing a base substrate according to claim 12, characterized in that: The intermediate layer is formed by setting the off angle of the outermost surface of the intermediate layer to a range of greater than +15.0 and less than +24.0°, or greater than -15.0 and less than -24.0°.

15. 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 9 to 14; 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.

16. The method for manufacturing a single crystal diamond laminated substrate according to claim 15, characterized in that: The single crystal diamond layer is set to be a {111} crystal or a {001} crystal.

17. 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 15 to manufacture a single crystal diamond free-standing structure substrate.

18. 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 producing a single crystal diamond self-supporting structure substrate according to claim 17.

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