Base material, preparation method thereof and semiconductor growth equipment

Abstract

The embodiment of the invention provides a base material, a preparation method thereof and semiconductor growth equipment, and relates to the technical field of semiconductor preparation. The base material comprises a substrate, a first material layer and a second material layer, and part of materials in the first material layer permeate into the substrate. The material of the first material layer comprises TaxCy, or comprises Ta and TaxCy. Wherein x + y = 1, 0lt; xlt; 1, 0lt; yt; Yt; 1. The first material layer comprises a plurality of first crystal grain layers, the first crystal grain layers comprise a plurality of first crystal grains, the plurality of first crystal grain layers comprise at least one pair of adjacent first crystal grain layers, and the crystal boundary of the first crystal grain of one of the pair of adjacent first crystal grain layers does not coincide with the crystal boundary of the first crystal grain of the other of the pair of adjacent first crystal grain layers in the direction perpendicular to the substrate. The base material is used for solving the problem that the crystal growth quality of a semiconductor material is affected due to damage of the base material in the preparation process of the semiconductor material. The base material is applied to semiconductor growth equipment so as to improve the quality of a semiconductor material.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor manufacturing, and particularly to a substrate, a preparation method thereof, and a semiconductor growth device. Background Art

[0002] The third-generation semiconductor materials (e.g., silicon carbide (SiC)) have excellent physical properties such as a large bandgap, high resistivity and thermal conductivity, and a high breakdown field strength, and thus have become the preferred semiconductor materials for preparing high-frequency microwave devices (e.g., gallium nitride (GaN)-based high-frequency microwave devices). With the continuous development of the fifth-generation mobile communication technology (5G) and high-power devices such as new energy vehicles, the demand for silicon carbide single crystal substrates is increasing in quantity, and the quality requirements are also continuously improving.

[0003] Currently, the preparation method of the industrialized silicon carbide single crystal substrate is to use the physical vapor transport (PVT) method to grow the silicon carbide single crystal substrate on a substrate (e.g., a graphite substrate). During the process of preparing the silicon carbide single crystal substrate by using the physical vapor transport method, since the temperature of the crystal growth environment is as high as over 2000 °C, and there are fluctuations in the flow fields of carbon (C) and silicon (Si) atmospheres in the crystal growth environment, it is easy to cause the substrate for crystal growth to be eroded, resulting in a change in the temperature field for crystal growth and affecting the growth quality of the crystal. Summary of the Invention

[0004] Embodiments of the present application provide a substrate, a preparation method thereof, and a semiconductor growth device, which are used to improve the problem that the crystal growth quality of semiconductor materials is affected due to damage to the substrate during the preparation process of semiconductor materials, and to improve the quality of semiconductor materials.

[0005] To achieve the above object, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, a substrate for growing semiconductor materials is provided. The substrate includes a base, a first material layer, and a second material layer. Part of the material in the first material layer penetrates into the base. The material of the first material layer includes Ta x C y , or includes Ta and Ta x C y . Wherein, x + y = 1, 0 < x < 1, 0 < y < 1. The first material layer includes a plurality of first grain layers, each first grain layer includes a plurality of first grains, and the plurality of first grain layers include at least a pair of adjacent first grain layers. Along the direction perpendicular to the base, the grain boundaries of the first grains in one of the pair of adjacent first grain layers do not coincide with the grain boundaries of the first grains in the other.

[0007] In the substrate provided in the embodiment of the present application, part of the material in the first material layer penetrates into the base, so that the contact area between the first material layer and the base is larger, and the bonding force between the first material layer and the base is stronger. In this way, the first material layer and the second material layer located on the side of the first material layer away from the base are not easily separated from the base, and the first material layer and the second material layer can better protect the base.

[0008] In an embodiment of the present application, the first material layer includes multiple first grain layers, the first grain layer includes multiple first grains, the multiple first grain layers include at least one pair of adjacent first grain layers, and along a direction perpendicular to the substrate, the grain boundary of the first grain of one of a pair of adjacent first grain layers does not overlap with the grain boundary of the first grain of the other one.

[0009] In this way, when cracks appear in the first material layer, the cracks can be contained in a single first grain layer to prevent the cracks from penetrating the first material layer and extending into the substrate, thereby further improving the protection capability of the first material layer to the substrate. Of course, by such an arrangement, the first material layer can also prevent the cracks from further extending to the substrate when penetrating cracks appear in the second material layer.

[0010] Thus, in the substrate provided by the embodiment of the present application, the first material layer and the second material layer can better protect the substrate. When the physical vapor transport method is used to grow semiconductor materials using the substrate provided by the embodiment of the present application, the temperature resistance and chemical corrosion resistance of the substrate can be better, which is beneficial to ensure the growth temperature field of the semiconductor material, improve the stability of the growth environment of the semiconductor material, and thus improve the quality of the semiconductor material. Of course, the temperature resistance and chemical corrosion resistance of the substrate provided by the embodiment of the present application are better, and the service life of the substrate can also be extended, which is beneficial to reduce the preparation cost of the semiconductor material.

[0011] In some embodiments, the first grains grow anisotropically.

[0012] In some embodiments, the thickness of the first material layer ranges from 1 micrometer to 500 micrometers.

[0013] In some embodiments, the size of the first grains ranges from 5 micrometers to 30 micrometers.

[0014] In some embodiments, the second material layer includes multiple second grain layers, each second grain layer includes second grains, the second grain layer includes multiple second grains, and the multiple second grain layers include at least one pair of adjacent second grain layers. Along the direction perpendicular to the substrate, the grain boundaries of the second grains of one of a pair of adjacent second grain layers do not overlap with the grain boundaries of the second grains of the other one.

[0015] In the substrate provided by the embodiments of the present application, the second material layer includes a plurality of second grain layers, each second grain layer includes second grains, the plurality of second grain layers includes at least a pair of adjacent second grain layers, and along the direction perpendicular to the substrate, the grain boundaries of the second grains in one of the pair of adjacent second grain layers do not coincide with the grain boundaries of the second grains in the other. In this way, even when cracks appear in the second material layer, the cracks can be contained within a single second grain layer, preventing the cracks from penetrating through the second material layer and extending into the first material layer and the substrate, thereby improving the protection ability of the second material layer to the substrate.

[0016] In some embodiments, the second grains grow along the

[220] direction and the

[200] direction.

[0017] In this way, the second material layer can have a relatively high density, it is less likely to have through-cracks, the second material layer can better protect the substrate, such that during the preparation of semiconductor materials, the substrate is not easily damaged by high temperature or chemical atmosphere erosion, thereby improving the temperature resistance and chemical erosion resistance of the substrate, extending the service life of the substrate, and further improving the stability of the semiconductor material growth environment and the quality of the semiconductor materials.

[0018] In some embodiments, the thickness range of the second material layer is 1 micron to 1000 microns.

[0019] In some embodiments, the size range of the second grains is 10 microns to 40 microns.

[0020] In a second aspect, a method for preparing a substrate for semiconductor material growth is provided. The preparation method includes: forming a first material layer on a substrate, the surface of the first material layer being combined with the surface of the substrate; the material of the first material layer includes Ta x C y , or Ta and Ta x C y ; where x + y = 1, 0 < x < 1, 0 < y < 1. The first material layer includes a plurality of first grain layers, each first grain layer includes a plurality of first grains, the plurality of first grain layers includes at least a pair of adjacent first grain layers, and along the direction perpendicular to the substrate, the grain boundaries of the first grains in one of the pair of adjacent first grain layers do not coincide with the grain boundaries of the first grains in the other. A second material layer is formed on the side of the first material layer away from the substrate, and the material of the second material layer includes TaC or Ta.

[0021] In some embodiments, forming the first material layer on the substrate includes soaking the substrate in a solution containing tantalum elements; drying the soaked substrate; and calcining the dried substrate.

[0022] In some embodiments, the calcining of the dried substrate includes: placing the dried substrate in a vacuum furnace; heating the vacuum furnace multiple times, and calcining the substrate for a first preset time after each heating; cooling the vacuum furnace to a preset temperature multiple times, and maintaining the temperature for a second preset time after each cooling; and reducing the temperature of the vacuum furnace from the preset temperature to room temperature at a preset cooling rate.

[0023] In some embodiments, forming the second material layer on the side of the first material layer away from the substrate includes: preparing a slurry containing TaC or Ta, and coating the slurry on the first material layer; drying the slurry coated on the first material layer; and sintering the dried slurry.

[0024] In some embodiments, the sintering of the dried slurry includes: placing a substrate with the first material layer and the dried slurry in a heating furnace; increasing the pressure and temperature in the heating furnace multiple times, and sintering the dried slurry for a third preset time after each pressure and temperature increase; within the preset time, reducing the pressure in the heating furnace to normal pressure and reducing the temperature in the heating furnace to normal temperature.

[0025] In a third aspect, a semiconductor growth device is provided, which includes a furnace body and a substrate as described in any of the above embodiments, wherein the substrate is placed inside the furnace body.

[0026] Among them, the technical effects brought about by any design method in the second aspect and the third aspect can refer to the technical effects brought about by different design methods in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present application, the following is a brief introduction to the drawings required for use in some embodiments of the present application. Obviously, the drawings described below are only drawings of some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams, and are not intended to limit the actual size of the product involved in the embodiments of the present application, the actual process of the method, the actual timing of the signal, etc.

[0028] Figure 1 A schematic structural diagram of a graphite substrate coated with a TaC coating provided for related technology;

[0029] Figure 2 A schematic diagram of the structure of a substrate provided in an embodiment of the present application;

[0030] Figure 3A for Figure 2 A magnified view of area Q;

[0031] Figure 3B A microscopic enlarged image of the second material layer provided in an embodiment of the present application;

[0032] Figure 4 A flow chart of a method for preparing a substrate provided in an embodiment of the present application;

[0033] Figure 5 A flow chart of another method for preparing a substrate provided in an embodiment of the present application;

[0034] Figure 6 A flow chart of another method for preparing a substrate provided in an embodiment of the present application;

[0035] Figure 7 A flow chart of another method for preparing a substrate provided in an embodiment of the present application;

[0036] Figure 8 A flow chart of another method for preparing a substrate provided in an embodiment of the present application;

[0037] Fig. 9 A flow chart of another method for preparing a substrate provided in an embodiment of the present application;

[0038] Fig. 10A A diagram showing the energy spectrum test results of the substrate and the first material layer provided in the embodiment of the present application;

[0039] Fig. 10B A distribution diagram of C elements in the substrate and the first material layer provided in an embodiment of the present application;

[0040] Fig. 10C A distribution diagram of the Ta element in the substrate and the first material layer provided in an embodiment of the present application;

[0041] Fig.11 The SEM test result diagram of the substrate and the first material layer provided in the embodiment of the present application;

[0042] Fig. 12A It is the composition analysis diagram of Ta element and C element at position A1;

[0043] Fig. 12B It is the composition analysis diagram of Ta element and C element at position A2;

[0044] Fig.13 This is a SEM test result diagram of the substrate after multiple uses provided in the embodiments of the present application;

[0045] Fig.14 A SEM test result diagram of another substrate and a first material layer provided in an embodiment of the present application;

[0046] Fig.15 A SEM test result diagram of another substrate and a first material layer provided in an embodiment of the present application;

[0047] Fig.16 This is a SEM test result diagram of the comparative substrate provided in Comparative Example 1 of the present application;

[0048] Fig.17 This is a SEM test result diagram of the comparative substrate provided in Comparative Example 2 of the present application;

[0049] Fig.18 A schematic diagram of the structure of a semiconductor growth device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The technical solution in the embodiment of the present application will be described below in conjunction with the accompanying drawings in the embodiment of the present application. In the description of the present application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship, for example, A / B can represent A or B.

[0051] The "and / or" in this application is only a way to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural.

[0052] In the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, a and b, a and c, b and c, or a, b and c, where a, b, and c can be single or multiple.

[0053] In order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with substantially the same functions and effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference.

[0054] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0055] At present, the preparation method of industrialized silicon carbide single crystal substrates is to use physical vapor transport method to grow silicon carbide single crystal substrates on graphite substrates. However, in the process of preparing silicon carbide single crystal substrates by physical vapor transport method, since the temperature of the crystal growth environment reaches above 2000 °C, and there are flow field changes of carbon and silicon atmospheres in the crystal growth environment, it is easy to cause the graphite substrate used for crystal growth to be eroded, resulting in changes in the temperature field for crystal growth and affecting the growth quality of the crystal.

[0056] To solve the above problems, as Figure 1 shown, the related art uses chemical vapor deposition (CVD) method to deposit a TaC coating 02 on the surface of the graphite substrate 01, and uses the TaC coating 02 to protect the graphite substrate 01. However, since the arrangement of TaC grains 021 in different grain layers of the TaC coating 02 formed by the CVD method is exactly the same, once cracks occur in the TaC coating 02, the cracks are through cracks and will directly extend to the graphite substrate 01, resulting in a decrease in the protection ability of the TaC coating 02 to the graphite substrate 01.

[0057] At the same time, the bonding force between the TaC coating 02 prepared by the CVD method and the graphite substrate 01 is poor, and it is easy to delaminate or even generate gaps between the TaC coating 02 and the graphite substrate 01, resulting in a further decrease in the protection ability of the TaC coating 02 to the graphite substrate 01, thereby resulting in poor temperature resistance and chemical erosion resistance of the graphite substrate 01 coated with the TaC coating 02.

[0058] Based on this, as Figure 2 shown, an embodiment of the present application provides a substrate 100 for semiconductor material growth. The substrate 100 includes a substrate 10, a first material layer 20, and a second material layer 30. Part of the material in the first material layer 20 penetrates into the substrate 10. The second material layer 30 is located on the side of the first material layer 20 away from the substrate 10.

[0059] Among them, the material of the first material layer 20 includes Ta x C y , or Ta and Ta x C y , where x + y = 10 < x < 1, 0 < y < 1. The material of the second material layer 30 includes TaC or Ta.

[0060] As Figure 3AAs shown, the first material layer 20 includes a plurality of first grain layers 21, the first grain layer 21 includes a plurality of first grains 211, the plurality of first grain layers 21 include at least one pair of adjacent first grain layers 21, along a direction perpendicular to the substrate 10, a grain boundary 211a of a first grain 211 of a pair of adjacent first grain layers 21 does not overlap with a grain boundary 211b of the first grain 211 of the other pair of adjacent first grain layers 21.

[0061] In the embodiment of the present application, there is no limitation on the number of the first crystal grain layers 21 in the first material layer 20 and the number can be designed according to the actual situation.

[0062] It can be understood that when the material of the first material layer 20 is Ta x C y In the case of the first crystal grain 211 in the first material layer 20, that is, Ta x C y The material of the first material layer 20 is Ta and Ta x C y In the case of x C y Grain.

[0063] In some examples, the material of the first material layer 20 is Ta and Ta x C y In the case of Ta grains, Ta x C y The grains are close to the second material layer 30 .

[0064] In some examples, the material of the substrate 10 may include graphite, or a carbon-carbon composite material, etc.

[0065] In the substrate 100 provided in the embodiment of the present application, part of the material in the first material layer 20 penetrates into the base 10, so that the contact area between the first material layer 20 and the base 10 is large, and the bonding force between the first material layer 20 and the base 10 is strong. In this way, the first material layer 20 and the second material layer 30 located on the side of the first material layer 20 away from the base 10 are not easily separated from the base 10, and the first material layer 20 and the second material layer 30 can better protect the base 10.

[0066] In the embodiment of the present application, the first material layer 20 includes a plurality of first crystal grain layers 21, the first crystal grain layer 21 includes a plurality of first crystal grains 211, and the plurality of first crystal grain layers 21 include at least one pair of adjacent first crystal grain layers 21, and along the direction perpendicular to the substrate 10, the grain boundary 211a of the first crystal grain 211 of one of the pair of adjacent first crystal grain layers 21 does not overlap with the grain boundary 211b of the first crystal grain 211 of the other. In this way, when cracks appear in the first material layer 20, the cracks can be contained in a single first crystal grain layer 21, and the cracks are prevented from penetrating the first material layer 20 and extending into the substrate 10, thereby further improving the protection capability of the first material layer 20 to the substrate. Of course, by such a configuration, the first material layer 20 can also prevent the cracks from further extending to the substrate 10 when penetrating cracks appear in the second material layer 30.

[0067] Therefore, in the substrate 100 provided in the embodiment of the present application, the first material layer 20 and the second material layer 30 can better protect the base 10. When the physical vapor transport method is used to grow semiconductor materials using the substrate 100 provided in the embodiment of the present application, the temperature resistance and chemical corrosion resistance of the substrate 100 can be better, which is conducive to ensuring the growth temperature field of the semiconductor material, improving the stability of the growth environment of the semiconductor material, and further improving the quality of the semiconductor material.

[0068] Of course, the substrate 100 provided in the embodiment of the present application has good temperature resistance and chemical corrosion resistance, and can also extend the service life of the substrate 100, thereby helping to reduce the preparation cost of semiconductor materials.

[0069] It is understandable that the material of the substrate 10 includes graphite and the material of the first material layer 20 includes Ta. x C y When the material of the second material layer 30 includes TaC or Ta, the first material layer 20 is located between the second material layer 30 and the substrate 10. The first material layer 20 can also alleviate the thermal expansion coefficient mismatch between the substrate 10 and the second material layer 30, adjust the stress in the substrate 100, and improve the problem of cracks in the second material layer caused by the thermal expansion coefficient mismatch, so that the second material layer 30 can better protect the substrate 10.

[0070] In some examples, the size of the first grain 211 may range from 5 μm to 30 μm. For example, the size of the first grain 211 may be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm.

[0071] In this way, the size of the first crystal grain 211 is small, the specific surface area of ​​the first material layer 20 is large, and the stress of the first material layer 20 can be small, so that the stress between the substrate 10 and the second material layer 30 can be better adjusted, and the problem of cracks in the second material layer due to the mismatch of thermal expansion coefficients between the substrate and the second material layer can be improved. At the same time, the stress of the first material layer 20 is small, and cracks can be prevented from being generated in the first material layer 20, thereby improving the yield of the first material layer 20.

[0072] In some embodiments, the first crystal grains 211 may grow anisotropically. In this case, the plurality of first crystal grains 211 in the first material layer 20 may grow along a plurality of crystal directions. By setting in this way, the first material layer 20 may have a higher density, and through cracks are less likely to appear in the first material layer 20. The first material layer 20 may better protect the substrate 10, thereby further improving the temperature resistance and chemical corrosion resistance of the substrate 100.

[0073] In some embodiments, the content of the C element in a portion of the first material layer 20 close to the substrate 10 is greater than the content of the C element in a portion of the first material layer 20 far from the substrate 10 .

[0074] In this way, the portion of the first material layer 20 close to the substrate 10 has a higher content of C element, and the performance of the portion of the first material layer 20 close to the substrate 10 is similar to that of the substrate 10. The first material layer 20 and the substrate 10 can be tightly connected, which is beneficial to improve the bonding force between the first material layer 20 and the substrate 10, so that the first material layer 20 can better protect the substrate 10.

[0075] In some embodiments, the first material layer 20 has a thickness ranging from 10 micrometers to 500 micrometers.

[0076] For example, the thickness of the first material layer 20 may be 10 micrometers, 20 micrometers, 50 micrometers, 100 micrometers, 200 micrometers, 300 micrometers, 400 micrometers, 500 micrometers, etc.

[0077] In this way, on the one hand, the thickness of the first material layer 20 will not be too small, and the first material layer 20 can better connect the substrate 10 and the second material layer 30, so that the first material layer 20 and the second material layer 30 can better protect the substrate 10, and the first material layer 20 can also better relieve the stress between the substrate 10 and the second material layer 30, and improve the problem of cracks in the second material layer. On the other hand, the thickness of the first material layer 20 will not be too large, so that the thickness of the substrate 100 will not be too large, which is conducive to reducing the preparation cost of the substrate 100.

[0078] In some embodiments, Figure 3A and Figure 3BAs shown, the second material layer 30 includes a plurality of second grain layers 31, the second grain layer 31 includes a plurality of second grains 311, the plurality of second grain layers 31 include at least one pair of adjacent second grain layers 31, along a direction perpendicular to the substrate 10, the grain boundary 311a of the second grain 311 of one of a pair of adjacent second grain layers 31 does not overlap with the grain boundary 311b of the second grain 311 of the other pair of adjacent second grain layers 31.

[0079] It can be understood that when the material of the second material layer 30 is TaC, the second grains 311 in the second material layer 30 are TaC grains. When the material of the second material layer 30 is Ta, the second grains 311 in the second material layer 30 are Ta grains.

[0080] In the embodiment of the present application, there is no limitation on the number of the second crystal grain layers 31 included in the second material layer 30 , and the number can be designed according to actual conditions.

[0081] Exemplarily, the second crystal grains 311 in the first material layer 20 may be arranged in a stacked staggered manner.

[0082] In the substrate 100 provided in the embodiment of the present application, the second material layer 30 includes a plurality of second crystal grain layers 31, each of which includes a second crystal grain 311, and the plurality of second crystal grain layers 31 include at least one pair of adjacent second crystal grain layers 31, and along the direction perpendicular to the substrate 10, the grain boundary 311a of the second crystal grain 311 of one of the pair of adjacent second crystal grain layers 31 does not overlap with the grain boundary 311b of the second crystal grain 311 of the other pair of adjacent second crystal grain layers 31. In this way, even if cracks appear in the second material layer 30, the cracks can be contained in a single second crystal grain layer 31, and the cracks are prevented from penetrating the second material layer 30 and extending into the first material layer 20 and the substrate 10, thereby improving the protection capability of the second material layer 30 to the substrate.

[0083] During the preparation process of semiconductor materials, when the semiconductor materials are grown using the substrate 100 provided in the embodiment of the present application, the substrate 100 is not easily damaged by high temperature or chemical atmosphere erosion, which is beneficial to improving the stability of the crystal growth environment of the semiconductor materials and improving the quality of the semiconductor materials.

[0084] In some examples, the size of the second grain 311 may be 10 micrometers to 40 micrometers. For example, the size of the second grain 311 may be 10 micrometers, 15 micrometers, 20 micrometers, 30 micrometers, or 40 micrometers.

[0085] In this way, the size of the second grains 311 is smaller, the specific surface area of ​​the second material layer 30 is larger, and the stress of the second material layer 30 can be smaller, so that cracks are not easily generated in the second material layer 30, thereby improving the yield of the second material layer 30.

[0086] In some embodiments, the second grains 311 may grow in an orientation along the

[200] direction and the

[220] direction.

[0087] In this way, the density of the second material layer 30 can be relatively high, through-cracks are less likely to appear in the second material layer 30, and the second material layer 30 can better protect the substrate 10. During the preparation process of the semiconductor material, the substrate 10 is not easily damaged by high temperature or chemical atmosphere erosion, thereby improving the temperature resistance and chemical erosion resistance of the substrate 100, extending the service life of the substrate 100, and further improving the stability of the semiconductor material growth environment and the quality of the semiconductor material.

[0088] In some embodiments, the thickness range of the second material layer 30 is 10 microns to 1000 microns. For example, the thickness of the second material layer 30 can be 10 microns, 20 microns, 50 microns, 100 microns, 200 microns, 300 microns, 400 microns, 500 microns, 600 microns, 800 microns, or 1000 microns, etc.

[0089] In this way, the thickness of the second material layer 30 will not be too small, so that the second material layer 30 can better protect the substrate 10. At the same time, the thickness of the second material layer 30 will not be too large, so that the preparation cost of the second material layer 30 can be reduced, and further the thickness of the substrate 100 can be smaller and the preparation cost of the substrate 100 can be lower.

[0090] The embodiments of the present application provide a method for preparing a substrate 100 for semiconductor material growth. Refer to Figure 2 to Figure 4 , the preparation method includes:

[0091] S100. Form a first material layer 20 on the substrate 10, and part of the material in the first material layer 20 penetrates into the substrate 10. The material of the first material layer 20 includes Ta x C y , or Ta and Ta x C y ; where x + y = 1, 0 < x < 1, 0 < y < 1. The first material layer 20 includes a plurality of first grain layers 21, the first grain layer 21 includes a plurality of first grains 211, the plurality of first grain layers 21 includes at least a pair of adjacent first grain layers 21, and along the direction perpendicular to the substrate 10, the grain boundary 211a of the first grains 211 in one of the pair of adjacent first grain layers 21 does not coincide with the grain boundary 211b of the first grains 211 in the other.

[0092] S200. Form a second material layer 30 on the side of the first material layer 20 away from the substrate 10, and the material of the second material layer 30 includes TaC or Ta.

[0093] The technical effect that can be achieved by the preparation method provided in the embodiment of the present application is the same as the beneficial effect that can be achieved by the substrate 100 provided in the embodiment of the present application, and will not be repeated here.

[0094] Combine the following Figure 5 The preparation method provided in the above examples of the present application is described in detail.

[0095] like Figure 5 As shown, in some embodiments, step S100 includes steps S110 to S130.

[0096] S110, immersing the substrate 10 in a solution containing tantalum element.

[0097] In some examples, the solution containing tantalum element may be a tantalum pentachloride solution, a fluorotantalate (H2TaF7) solution, a tantalum ethoxide solution, or a tantalum pentoxide (Ta2O5) solution, etc.

[0098] Exemplarily, the solvent of the tantalum pentachloride solution may be an alcohol solvent, for example, the solvent of the tantalum pentachloride solution may include at least one of ethanol, ethylene glycol, propanol, propylene glycol, butanol, and butanediol.

[0099] In some examples, the concentration of tantalum pentachloride may be 5% to 95%. For example, the concentration of tantalum pentachloride may be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, etc.

[0100] S120, drying the soaked substrate 10.

[0101] For example, the soaked substrate 10 may be dried at a temperature of 60° C. to 80° C. for 5 to 7 hours.

[0102] S130, calcining the dried substrate 10.

[0103] Taking tantalum pentachloride as an example, during the calcination process, Ta x C y The formation process of tantalum pentachloride is explained as Ta(OC4H9)5 in the solution. After calcination, Ta(OC4H9)5 is first converted into TaO. TaO is unstable and will be converted into Ta2O5 during the calcination process. Ta2O5 reacts with the substrate 10 to form Ta x C y and CO.

[0104] In some examples, the dried substrate 10 may be calcined in an inert gas environment, wherein the inert gas may be argon.

[0105] In the method for preparing the substrate 100 provided in the embodiment of the present application, the first material layer 20 is prepared by using the substrate 10 and a solution containing a tantalum element, so that the tantalum element can react with the substrate 10, thereby converting a portion of the substrate 10 into Ta. x C y . The converted Ta x C y Penetrating into the substrate 10 can make the contact area between the first material layer 20 and the substrate 10 larger. Therefore, the first material layer 20 formed by the preparation method provided in the embodiment of the present application can have a stronger bonding force with the substrate 10, and the first material layer 20 is not easy to separate from the substrate 10, so that the bonding force between the first material layer 20 (or the first material layer 20 and the second material layer 30) and the substrate 10 can be stronger (for example, the interface bonding strength between the first material layer 20 (or the first material layer 20 and the second material layer 30) and the substrate 10 can reach 2 megapascals (MPa) to 20 MPa), and the first material layer 20 is less likely to separate from the substrate 10, thereby improving the protective ability of the first material layer 20 to the substrate 10, and improving the temperature resistance and chemical corrosion resistance of the substrate 100.

[0106] In some embodiments, Figure 6 As shown, while the substrate 10 is immersed in a solution containing tantalum element, the preparation method further includes step S140.

[0107] S140, placing the solution containing tantalum element in which the substrate 10 is immersed in a pressure chamber for gas pressurization treatment.

[0108] For example, a solution containing tantalum element in which the substrate 10 is immersed can be placed in a container, and then the container is placed in a pressure chamber for gas pressurization treatment.

[0109] Exemplarily, during the gas pressurization process, the gas pressure may be 1 MPa to 2 MPa. For example, the gas pressure may be 1 MPa, 1.5 MPa, or 2 MPa. The embodiment of the present application may appropriately adjust the pressurization time according to the desired pressurization effect and gas pressure. Exemplarily, the pressurization time may be 0.5 hour to 1 hour.

[0110] Exemplarily, the gas pressurization rate may be 0.05 MPa / min to 0.2 MPa / min. For example, the gas pressurization rate may be 0.05 MPa / min, 0.1 MPa / min, 0.2 MPa / min, etc.

[0111] In the embodiment of the present application, the solution containing tantalum element immersed in the substrate 10 is subjected to gas pressurization treatment, which can improve the infiltration rate and infiltration uniformity of the solution containing tantalum element, so that the solution containing tantalum element can better penetrate into the substrate 10. After the immersed substrate 10 is dried and calcined, the formed Ta x C y It can penetrate more into the substrate 10, further increase the contact area between the first material layer 20 and the substrate 10, further improve the bonding force between the substrate 10 and the first material layer 20, increase the thickness of the first material layer 20, and improve the protection ability of the first material layer 20 to the substrate 10.

[0112] In some embodiments, the material of the substrate 10 includes graphite, and the porosity of the substrate 10 may be 3% to 65%.

[0113] For example, the porosity of substrate 10 may be 3%, 10%, 15%, 20%, 30%, 40%, 45%, 50%, 60%, 65%, etc.

[0114] It is understandable that graphite is a material with a certain porosity. Therefore, when the substrate 10 is immersed in a solution containing tantalum, the solution containing tantalum will slowly penetrate into the interior of the substrate 10 through the gaps in the substrate 10 and wrap the graphite particles in the substrate 10.

[0115] In the embodiment of the present application, the porosity of the substrate 10 is 3% to 65%. In this way, the porosity of the substrate 10 is not too small, which is conducive to the solution containing tantalum element to penetrate into the substrate 10 and convert the graphite particles in the substrate 10 into Ta. x C y The crystal grains are formed by the substrate 10 and the first material layer 20, thereby improving the bonding force between the substrate 10 and the first material layer 20. At the same time, the porosity of the substrate 10 is not too large, thereby ensuring the density of the substrate 10 and the density of the first material layer 20. When the substrate 100 provided by the preparation method of the embodiment of the present application is used to prepare the semiconductor material, the substrate 100 is not easily corroded, and the erosion weight loss rate of the substrate 100 can be small, thereby facilitating the stability of the growth environment of the semiconductor material and improving the growth quality of the semiconductor material.

[0116] In some embodiments, Figure 7 As shown, the above step S130 may include steps S131 to S134.

[0117] S131, placing the dried substrate 10 in a vacuum furnace.

[0118] S132, heating the vacuum furnace multiple times, and calcining the substrate 10 for a first preset time after each heating.

[0119] It can be understood that, in step S132, when the temperature in the vacuum furnace is different, the first preset time length can be the same or different.

[0120] In some examples, step S132 may include: heating to 250°C to 350°C, calcining for 4 to 6 hours, then heating to 850°C to 950°C, calcining for 2.5 to 3.5 hours, and finally heating to 1200°C to 1300°C, calcining for 3 to 5 hours. At this time, the vacuum furnace is heated three times, and the heating trend is relatively gentle, which is conducive to controlling the grain size in the first material layer 20.

[0121] When the solution containing tantalum element is tantalum pentachloride solution, calcining at a temperature of 250℃~350℃ for 4 hours to 6 hours can convert Ta(OC4H9)5 on the substrate 10 into TaO. TaO is unstable. Calcination at a temperature of 850℃~950℃ for 2.5 hours to 3.5 hours can convert TaO into Ta2O5. Calcination at a temperature of 1200℃~1300℃ for 3 hours to 5 hours can make Ta2O5 react with the substrate 10 to generate Ta x C y and CO.

[0122] In other examples, step S132 may include: heating to 600°C to 800°C, calcining for 6 hours to 8 hours, and then heating to 1200°C to 1300°C, calcining for 4 hours to 6 hours. At this time, the vacuum furnace is heated twice, and the heating process is relatively simple, which is conducive to simplifying the calcination process and improving the preparation efficiency.

[0123] S133, cooling the vacuum furnace to a preset temperature in multiple times, and maintaining the temperature for a second preset time after each cooling.

[0124] It is also understandable that, in step S133, when the temperature in the vacuum furnace is different, the second preset time length may be the same or different.

[0125] In some examples, the step S133 may include: cooling to 900° C. to 1100° C., maintaining for 0.5 to 2 hours, and then cooling to 750° C. to 850° C., maintaining for 0.5 to 1 hour.

[0126] S134, reducing the temperature of the vacuum furnace from a preset temperature to room temperature at a preset cooling rate.

[0127] In some examples, the preset temperature may be 750° C. to 850° C., and the preset cooling rate may be 15° C. / hour to 25° C. / hour.

[0128] It is understandable that the heating and cooling mentioned in the above embodiments of the present application are all achieved within a period of time. For example, the above heating and cooling process can be achieved within 0.5h to 2.5h.

[0129] like Figure 8 As shown, in some embodiments, step S200 includes steps S210 to S230.

[0130] S210 , preparing a slurry containing TaC or Ta, and coating the slurry on the first material layer 20 .

[0131] It can be understood that TaC or Ta mentioned here refers to TaC powder or Ta powder.

[0132] In some examples, in addition to TaC or Ta, the slurry may further include a solvent, a co-solvent, a defoamer, a thickener, a linear saturated aliphatic hydrocarbon, and carbon powder, wherein the carbon powder serves as a flux and provides a carbon source.

[0133] The solvent may include at least one of ethanol, propanol, n-butanol, acetone and butanone. The cosolvent may include at least one of tetrahydrofuran, chloroform and glycerol. The defoamer may include BYK defoamer, and the thickener may include cellulose ether.

[0134] In some examples, by weight, in the slurry, TaC powder or Ta powder may account for 25 to 40 parts, the solvent may account for 20 to 35 parts, the defoamer may account for 1 to 3 parts, the thickener may account for 2 to 5 parts, the straight-chain saturated fatty hydrocarbon may account for 5 to 15 parts, and the carbon powder may account for 1 to 3 parts.

[0135] By adjusting the proportion of each component in the slurry, the fluidity and viscosity of the slurry can be adjusted, so that the slurry can be better coated on the first material layer 20.

[0136] In some examples, the various components of the slurry may be mixed and stirred for 2 to 3 hours before the slurry is coated on the first material layer 20. For example, the slurry may be mixed and stirred for 2 hours, 2.5 hours, or 3 hours.

[0137] For example, the slurry may be sprayed onto the first material layer 20 using a spray machine.

[0138] S220 , drying the slurry coated on the first material layer 20 .

[0139] In some examples, the slurry coated on the first material layer 20 may be dried at a temperature of 180° C. to 220° C. for 8 to 12 hours.

[0140] S230, sintering the dried slurry.

[0141] In the preparation method of the substrate 100 provided in the embodiment of the present application, a slurry containing TaC and Ta is coated on the first material layer 20, and the slurry is dried and sintered to obtain the second material layer 30. In this way, multiple layers of second grain layers 31 can be formed in the second material layer 30, and the multiple second grain layers 31 can include at least one pair of adjacent second grain layers 31, and in the direction perpendicular to the substrate 10, the grain boundary of the second grain of one of the pair of adjacent second grain layers 31 does not overlap with the grain boundary of the second grain of the other. Even if cracks appear in the second material layer 30, the cracks can be contained in a single second grain layer 31 to prevent the cracks from penetrating the second material layer 30 and extending into the substrate 10, thereby improving the protection capability of the second material layer 30 to the substrate 10 and improving the temperature resistance and chemical corrosion resistance of the substrate 100.

[0142] Compared with the preparation method provided by the related art, the preparation method provided by the embodiment of the present application adopts a simpler preparation process, which is beneficial to improving the preparation efficiency of the substrate 100.

[0143] In some embodiments, Fig. 9 As shown, step S230 may include steps S231 to S233.

[0144] S231, placing the substrate 10 with the first material layer 20 and the dried slurry in a heating furnace.

[0145] S232, increasing the pressure and temperature in the heating furnace for multiple times, and sintering the dried slurry for a third preset time after each increase in pressure and temperature.

[0146] It can be understood that, in step S232, under different pressures and temperatures, the third preset time length may be the same or different.

[0147] In some examples, step S232 may include: sintering for 3 to 5 hours at a pressure of 700 mbar to 900 mbar and a temperature of 500°C to 700°C; increasing the pressure to 1000 mbar to 1100 mbar and the temperature to 1600°C to 1800°C, and sintering for 8 to 10 hours; increasing the pressure to 145 kPa to 155 kPa and the temperature to 2200°C to 2400°C, and sintering for 14 to 16 hours.

[0148] In other examples, step S232 may include: sintering for 11 to 13 hours at a pressure of 900 mbar to 1000 mbar and a temperature of 1100°C to 1300°C; increasing the pressure to 130 kPa to 150 kPa and the temperature to 2200°C to 2500°C, and sintering for 18 to 22 hours.

[0149] S233. Within a preset time, the pressure in the heating furnace is reduced to normal pressure, and the temperature in the heating furnace is reduced to normal temperature.

[0150] In some other embodiments, in some embodiments, step S200 includes: forming a second material layer on a side of the first material layer away from the substrate by using a chemical vapor deposition process.

[0151] To better illustrate the beneficial effects that can be achieved by the substrate prepared by the preparation method provided in the embodiments of the present application, the present application provides 8 embodiments and 2 comparative examples. Among them, the substrate is a graphite substrate as an example, and the solution containing tantalum element is a tantalum pentachloride n-butanol solution as an example.

[0152] Example 1

[0153] Embodiment 1 of the present application provides a substrate and a preparation method thereof. The preparation method comprises:

[0154] The tantalum pentachloride n-butanol solution soaked with the graphite substrate is placed in a container, wherein the concentration of tantalum pentachloride in the tantalum pentachloride n-butanol solution is 70%, and the porosity of the graphite substrate is 45%.

[0155] The container is placed in a pressure chamber for pressurization treatment. The gas pressurization rate is 0.1MPa / min. After the pressure in the pressure chamber reaches 1MPa, it is maintained for 1h (hour) and then the pressure is released.

[0156] The soaked graphite substrate was transferred to a vacuum furnace and dried at 60°C for 7 h.

[0157] Argon gas was introduced into the vacuum furnace to maintain the pressure in the vacuum furnace at 900 mbar.

[0158] Calcination is carried out, and the calcination process includes a step-by-step heating process and a step-by-step cooling process. Among them, the step-by-step heating process includes: it takes 1 hour to increase the temperature to 300°C and calcine for 5 hours; then it takes 2 hours to increase the temperature to 900°C and calcine for 3 hours; finally, it takes 1 hour to increase the temperature to 1250°C and calcine for 4 hours. The staged cooling process includes: it takes 1 hour to reduce the temperature to 1000°C, maintain for 1 hour, then it takes 1 hour to reduce the temperature to 800°C, maintain for 1 hour, and finally reduce the temperature to room temperature at a rate of 20°C / h to obtain a graphite substrate with a first material layer. At this time, the first material layer, i.e., Ta x C y layer.

[0159] 4N grade TaC is dissolved in an organic solvent to prepare a TaC-containing slurry, which includes: 32.7 parts of TaC powder, 25 parts of ethanol, 20 parts of tetrahydrofuran, 1.5 parts of BYK defoamer, 3.5 parts of cellulose ether, 10 parts of straight-chain saturated aliphatic hydrocarbon, and 1.3 parts of carbon powder.

[0160] After the slurry containing the above components was mixed and stirred for 2.5 hours, the slurry was sprayed onto the surface of the graphite substrate with the first material layer using a sprayer.

[0161] The sprayed graphite substrate was placed in a heating furnace, the temperature was raised to 200°C in an air environment, and dried for 10 hours.

[0162] Argon gas was introduced into the heating furnace, and the sintering was carried out at a pressure of 800 mbar and a temperature of 600°C for 4 hours, and then the pressure was increased to 1000 mbar, the temperature was increased to 1700°C, and the sintering was carried out for 9 hours, and finally the pressure was increased to 150 kPa, the temperature was increased to 2300°C, and the sintering was carried out for 15 hours, and finally the temperature was reduced to room temperature and the pressure was reduced to normal pressure in 20 hours, and the second material layer was obtained, thereby obtaining the substrate F1. At this time, the second material layer is also the TaC layer.

[0163] Fig. 10A : is an energy dispersive spectrometer (EDS) test result diagram of the graphite substrate 10a and the first material layer 20a. Fig. 10B is a distribution diagram of C element in the graphite substrate 10a and the first material layer 20a, Fig. 10C Graph 1 is a distribution diagram of Ta element in the graphite substrate 10a and the first material layer 20a.

[0164] like Fig. 10A As shown, the first material layer 20a formed in Example 1 of the present application is not only located on the surface of the graphite substrate 10a, but also penetrates into the graphite substrate 10a. The contact area between the first material layer 20a and the graphite substrate 10a is large, so that the bonding force between the first material layer 20a and the graphite substrate 10a is strong.

[0165] By observation Fig. 10B It can be seen that in the first material layer 20a formed in Example 1 of the present application, the closer to the graphite substrate 10a, the more C elements there are. Fig. 10C It can be seen that in the first material layer 20 a formed in Example 1 of the present application, the farther away from the graphite substrate 10 a , the more Ta elements there are.

[0166] Fig.11 This is a morphology diagram obtained by observing the graphite substrate 10a with the first material layer 20a provided in Example 1 of the present application using a scanning electron microscope (SEM). Fig. 12A for Fig.11 Composition analysis diagram of Ta element and C element at position A1 in the figure. Fig. 12B for Fig.11 Composition analysis diagram of Ta element and C element at position A2 in the figure.

[0167] like Fig.11 As shown, position A2 is closer to the graphite substrate 10a than position A1. Fig. 12A As shown, the ratio of Ta content to C content at position A1 is 1.1:1. Fig. 12B As shown, the ratio of the Ta content to the C content at position A2 is 0.78: 1. It can be seen that in the portion of the first material layer 20a far from the graphite substrate, the ratio of the Ta content to the C content is close to 1:1, while the portion of the first material layer 20a close to the graphite substrate is in a carbon-rich environment, so the ratio of the Ta content to the C content inside is less than 1.

[0168] The substrate F1 provided in Example 1 of the present application was subjected to SEM testing after multiple uses, and the results are as follows: Fig.13 After testing, it is known that even if cracks appear in the substrate F1 provided in Example 1 of the present application after repeated use, the crack width can be controlled within 1 micron, and no through cracks will be formed in the substrate F1. The substrate F1 can still be used to produce high-quality semiconductor materials after repeated use.

[0169] Example 2

[0170] Embodiment 2 of the present application provides a substrate and a preparation method thereof. The preparation method comprises:

[0171] The tantalum pentachloride n-butanol solution soaked with the graphite substrate is placed in a container, wherein the concentration of tantalum pentachloride in the tantalum pentachloride n-butanol solution is 70%, and the porosity of the graphite substrate is 45%.

[0172] The container is placed in a pressure chamber for pressurization treatment. The gas pressurization rate is 0.2MPa / min. After the pressure in the pressure chamber reaches 1MPa, it is maintained for 1 hour and then the pressure is released.

[0173] The soaked graphite substrate was transferred to a vacuum furnace and dried at 80°C for 5 h.

[0174] Argon gas was introduced into the vacuum furnace to maintain the pressure in the vacuum furnace at 800 mbar.

[0175] Calcination is carried out, and the calcination process includes a step-by-step heating process and a step-by-step cooling process. Among them, the step-by-step heating process includes: it takes 1 hour to raise the temperature to 250°C and calcine for 6 hours; then it takes 2 hours to raise the temperature to 850°C and calcine for 3.5 hours; finally, it takes 1 hour to raise the temperature to 1200°C and calcine for 5 hours. The staged cooling process includes: it takes 1 hour to reduce the temperature to 900°C, maintain it for 2 hours, then it takes 1 hour to reduce the temperature to 9750°C, maintain it for 1 hour, and finally cool it to room temperature at a rate of 15°C / h to obtain a graphite substrate with a first material layer. At this time, the first material layer, i.e., Ta x C y layer.

[0176] 4N grade TaC is dissolved in an organic solvent to prepare a TaC-containing slurry, which includes: 25 parts of TaC powder, 20 parts of ethanol, 25 parts of tetrahydrofuran, 3 parts of BYK defoamer, 2 parts of cellulose ether, 15 parts of straight-chain saturated aliphatic hydrocarbon, and 3 parts of carbon powder.

[0177] After the slurry containing the above components was mixed and stirred for 2.5 hours, the slurry was sprayed onto the surface of the graphite substrate with the first material layer using a sprayer.

[0178] The sprayed graphite substrate was placed in a heating furnace, the temperature was raised to 180°C in an air environment, and dried for 12 hours.

[0179] Argon gas was introduced into the heating furnace, and the sintering was carried out for 3 hours at a pressure of 700 mbar and a temperature of 700°C, and then the pressure was increased to 1000 mbar, the temperature was increased to 1800°C, and the sintering was carried out for 8 hours, and finally the pressure was increased to 145 kPa, the temperature was increased to 2400°C, and the sintering was carried out for 16 hours, and finally the temperature was reduced to room temperature and the pressure was reduced to normal pressure in 25 hours, and the second material layer was obtained, thereby obtaining the substrate F2. At this time, the second material layer is also the TaC layer.

[0180] Example 3

[0181] The tantalum pentachloride n-butanol solution soaked with the graphite substrate is placed in a container, wherein the concentration of tantalum pentachloride in the tantalum pentachloride n-butanol solution is 70%, and the porosity of the graphite substrate is 45%.

[0182] The container is placed in a pressure chamber for pressurization treatment. The gas pressurization rate is 0.05MPa / min. When the pressure in the pressure chamber reaches 2MPa, it is maintained for 0.5h and then the pressure is released.

[0183] The soaked graphite substrate was transferred to a vacuum furnace and dried at 60°C for 7 h.

[0184] Argon gas was introduced into the vacuum furnace to maintain the pressure in the furnace at 1000 mbar.

[0185] Calcination is carried out, and the calcination process includes a step-by-step heating process and a step-by-step cooling process. Among them, the step-by-step heating process includes: it takes 1 hour to increase the temperature to 350°C and calcine for 4 hours; then it takes 2 hours to increase the temperature to 950°C and calcine for 2.5 hours; finally, it takes 1 hour to increase the temperature to 1300°C and calcine for 3 hours. The staged cooling process includes: it takes 1 hour to reduce the temperature to 1100°C, maintain it for 0.5 hours, then it takes 1 hour to reduce the temperature to 850°C, maintain it for 0.5 hours, and finally reduce the temperature to room temperature at a rate of 25°C / h to obtain a graphite substrate with a first material layer. At this time, the first material layer, i.e., Ta x C y layer.

[0186] 4N grade TaC is dissolved in an organic solvent to prepare a slurry containing TaC. The slurry may include: 40 parts of TaC powder, 35 parts of ethanol, 15 parts of tetrahydrofuran, 1 part of BYK defoamer, 5 parts of cellulose ether, 5 parts of straight-chain saturated aliphatic hydrocarbon, and 1 part of carbon powder.

[0187] After the slurry containing the above components was mixed and stirred for 2.5 hours, the slurry was sprayed onto the surface of the graphite substrate with the first material layer using a sprayer.

[0188] The sprayed graphite substrate was placed in a heating furnace, the temperature was raised to 220°C in an air environment, and dried for 8 hours.

[0189] Argon gas was introduced into the heating furnace, and the sintering was carried out at a pressure of 900 mbar and a temperature of 500°C for 5 hours, and then the pressure was increased to 1100 mbar, the temperature was increased to 1600°C, and the sintering was carried out for 10 hours. Finally, the pressure was increased to 155 kPa, the temperature was increased to 2200°C, and the sintering was carried out for 14 hours. Finally, it took 15 hours to reduce the temperature to room temperature and the pressure to normal pressure, and thus the second material layer was obtained, thereby obtaining the substrate F3. At this time, the second material layer is also the TaC layer.

[0190] Example 4

[0191] Embodiment 4 of the present application provides a substrate and a preparation method thereof. The difference between the preparation method provided in Embodiment 4 and the preparation method provided in Embodiment 1 is that the preparation method provided in Embodiment 4 does not perform gas pressurization treatment, and only immerses the graphite substrate in a tantalum pentachloride solution at room temperature and pressure for 1 hour. The preparation method provided in Embodiment 4 can be used to prepare a substrate F4.

[0192] Except for the above differences, the preparation method provided in Example 4 is the same as the preparation method provided in Example 1, so the second material layer in the substrate F4 is also the TaC layer, and the first material layer is also the Ta x C y layer.

[0193] Example 5

[0194] Example 5 of the present application provides a substrate and a preparation method thereof. The difference between the preparation method provided in Example 5 and the preparation method provided in Example 1 is that the staged temperature increase process during the calcination process of Example 5 is: the pressure in the vacuum furnace is maintained at 900 mbar, calcined at a temperature of 700°C for 7 hours, and then calcined at a temperature of 1200°C for 5 hours. The preparation method provided in Example 5 can be used to prepare the substrate F5.

[0195] It can be understood that the second material layer in the substrate F5 is also a TaC layer, and the first material layer is also a Ta x C y layer.

[0196] Example 6

[0197] Example 6 of the present application provides a substrate and a preparation method thereof. The difference between the preparation method provided in Example 6 and the preparation method provided in Example 1 is that the process of sintering the dried graphite substrate in Example 6 includes: sintering for 12 hours at a pressure of 1000 mbar and a temperature of 1200°C, then increasing the pressure to 140 kPa, increasing the temperature to 2300°C, sintering for 20 hours, and finally reducing the temperature to room temperature and the pressure to normal pressure for 20 hours. Substrate F6 can be prepared using the preparation method provided in Example 6.

[0198] It can be understood that the second material layer in the substrate F6 is also a TaC layer, and the first material layer is also a Ta x C y layer.

[0199] Embodiment 7:

[0200] Embodiment 7 of the present application provides a substrate and a preparation method thereof. The difference between the preparation method provided in Embodiment 6 and Embodiment 3 is that the porosity of the graphite substrate used in Embodiment 7 is 14%. The preparation method provided in Embodiment 7 can be used to prepare a substrate F7.

[0201] It can be understood that the second material layer in the substrate F7 is also a TaC layer, and the first material layer is also a Ta x C y layer.

[0202] Fig.14 This is a SEM test result diagram of the graphite substrate 10b with the first material layer 20b provided in Example 3. Fig.15 This is a SEM test result diagram of the graphite substrate 10c with the first material layer 20c provided in Example 7. Fig.14As shown, the portion of the first material layer 20b provided in Example 3 that penetrates into the graphite substrate 10b has a large difference in depth at different locations. Fig.15 As shown, the penetration depth of the portion of the first material layer 20c provided in Example 7 that penetrates into the graphite substrate 10c has a small difference at different positions.

[0203] It can be seen that the thickness of the first material layer is related to the porosity of the substrate. The greater the porosity of the substrate, the deeper the penetration depth of the first material layer into the substrate and the greater the thickness of the first material layer.

[0204] Example 8

[0205] Example 8 provides a substrate and a preparation method thereof. Compared with the preparation method provided in Example 1, the preparation method provided in Example 8 is different from the preparation method provided in Example 1 in that Example 8 forms a second material layer on the first material layer by a CVD method.

[0206] Wherein, forming the second material layer on the first material layer by CVD method may include, for example, placing the graphite substrate with the first material layer into a chemical vapor deposition furnace. Evacuate to a pressure less than 50Pa, then raise the temperature to 1200°C, introduce a mixed gas consisting of ethane, TaCl5, hydrogen (H2) and carrier gas argon, and enter the chemical vapor deposition furnace at a stable flow rate. The furnace pressure is maintained at 5000Pa. First, the molar ratio of TaCl5 and ethane gas is controlled to 1.2:1 to form a transition layer with a thickness of 50μm. Then, the molar ratio of TaCl5 and ethane gas is controlled to 3:1 to form a second material layer with a thickness of 60μm.

[0207] The substrate F8 can be prepared by the preparation method provided in Example 8. In the substrate F8, the first material layer is also Ta x C y layer, and the second material layer is also the TaC layer.

[0208] Comparative Example 1

[0209] See also Fig.16 Comparative Example 1 provides a substrate and a preparation method thereof. Compared with the preparation method provided in Example 8, the preparation method provided in Comparative Example 1 does not prepare the first material layer, and only prepares the TaC coating 30a on the graphite substrate 10d by CVD. The comparative substrate D1 can be prepared by the preparation method provided in Comparative Example 1. The comparative substrate D1 only includes the TaC coating.

[0210] Comparative Example 2

[0211] See also Fig.17Comparative Example 2 provides a substrate and a preparation method thereof. Compared with the preparation method provided in Example 1, the preparation method provided in Comparative Example 2 no longer prepares the first material layer, but directly forms the second material layer 30b on the graphite substrate 10e. The comparative substrate D2 can be prepared by the preparation method provided in Comparative Example 2. The comparative substrate D1 only includes the second material layer 30b, which is also the TaC layer.

[0212] Fig.16 This is a SEM test result diagram of the comparative substrate D1 provided in Comparative Example 1. Fig.17 This is a SEM test result diagram of the comparative substrate D2 provided in Comparative Example 2.

[0213] By observation Fig.16 The comparative substrate D1 and Fig.17 It can be seen from the comparative substrate D2 that a plurality of second grain layers can be formed in the second material layer prepared by the preparation method of the present application, and the grains are stacked on each other, which is denser than the TaC coating formed by the CVD method, and is less prone to through-cracks.

[0214] The substrates prepared in the above examples (Examples 1 to 8) and comparative examples (Comparative Examples 1 and 2) were tested to obtain the Ta content in the substrates. x C y The thickness of the TaC layer (TaC coating) and Ta x C y The test results are shown in Table 1.

[0215] Table 1

[0216]

[0217] The substrates prepared in the above examples (Examples 1 to 8) and comparative examples (Comparative Examples 1 and 2) were subjected to high temperature etching and thermochemical etching experiments, simulating the growth environment of SiC crystals using the PVT method, and the substrates were placed in an environment with a temperature of 2300°C and etched in a SiC atmosphere, and the experiment lasted for 100 hours. The test results are shown in Table 2 below.

[0218] Table 2

[0219] sample Weight before experiment (g) Weight after the experiment (g) Erosion weight loss rate (%) Substrate F1 46.7103 46.0390 1.43 Substrate F2 47.8269 47.3314 1.04 Substrate F3 47.1923 46.7274 0.98 Substrate F4 46.3194 45.5326 1.70 Substrate F5 47.5247 46.5326 2.09 Substrate F6 47.3215 46.4137 1.91 Substrate F7 45.7621 45.2377 1.15 Substrate F8 47.9024 46.3529 3.23 Comparative substrate D1 46.7247 45.1371 3.40 Comparative substrate D2 46.7372 45.0261 3.66

[0220] Wherein, erosion weight loss rate = [(weight before experiment - weight after experiment) / weight before experiment] × 100%. It can be understood that the "erosion weight loss rate" in the table is the total weight loss rate of the above-mentioned substrate. By comparing the weight loss rates of the substrates provided in Examples 1 to 8 and the erosion weight loss rates of the substrates provided in Comparative Examples 1 and 2, it can be seen that the erosion weight loss rate of the substrates provided in the examples of the present application in the above-mentioned experiments is smaller, and the temperature resistance and chemical corrosion resistance of the substrates provided in the examples of the present application are better.

[0221] In the above embodiments of the present application, the semiconductor material is silicon carbide material as an example for illustration. It is understandable that the substrate can also be used to grow other materials that require high-temperature growth or epitaxy, such as aluminum nitride (AlN) and gallium nitride (GaN).

[0222] like Fig.18 As shown, some embodiments of the present application provide a semiconductor growth device 200 , which includes a chamber 201 and a substrate 100 as described in any of the above embodiments, and the substrate 100 is placed inside the chamber 201 .

[0223] The chamber 201 provides a suitable environment for the growth of semiconductor materials, such as a temperature environment and a gas environment.

[0224] In some examples, the semiconductor growth device 200 may further include a heating device, a heat preservation device, and a gas delivery device connected to the chamber 201 .

[0225] In some examples, the semiconductor growth device 200 can be applied to a variety of semiconductor growth processes, such as an epitaxial growth process, a physical vapor deposition process, a physical vapor transport process, a chemical vapor deposition process, etc.

[0226] The technical effect that can be achieved by the semiconductor growth equipment provided in the embodiment of the present application is the same as the technical effect that can be achieved by the substrate provided in any of the above embodiments of the present application, and will not be repeated here.

[0227] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0228] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A substrate for growing semiconductor materials, It is characterized in that include: substrate; a first material layer, wherein a portion of the material in the first material layer penetrates into the substrate; The material of the first material layer includes Ta x C y , or includes Ta and Ta x C y ; wherein, x + y = 1, 0 < x < 1, 0 < y < 1; the first material layer includes a plurality of first grain layers, the first grain layer includes a plurality of first grains, the plurality of first grain layers includes at least a pair of adjacent first grain layers, along the direction perpendicular to the substrate, the grain boundaries of the first grains of one of a pair of adjacent first grain layers do not coincide with the grain boundaries of the first grains of the other one. The second material layer is located on a side of the first material layer away from the substrate, and the material of the second material layer includes TaC or Ta.

2. The substrate according to claim 1, It is characterized in that The first grains grow anisotropically.

3. The substrate according to claim 1 or 2, It is characterized in that The thickness of the first material layer ranges from 1 micron to 500 microns.

4. The substrate according to any one of claims 1 to 3, It is characterized in that The size of the first crystal grains ranges from 5 micrometers to 30 micrometers.

5. The substrate according to any one of claims 1 to 4, It is characterized in that The second material layer includes multiple second grain layers, the second grain layers include multiple second grains, and the multiple second grain layers include at least one pair of adjacent second grain layers. Along the direction perpendicular to the substrate, the grain boundaries of the second grains in one of a pair of adjacent second grain layers do not overlap with the grain boundaries of the second grains in the other pair of adjacent second grain layers.

6. The substrate according to claim 5, It is characterized in that The second grains grow along the [220] direction and the [200] direction.

7. The substrate according to claim 5 or 6, It is characterized in that The size of the second crystal grains ranges from 10 microns to 40 microns.

8. The substrate according to any one of claims 1 to 7, It is characterized in that The thickness of the second material layer ranges from 1 micrometer to 1000 micrometers.

9. A method for preparing a substrate for growing semiconductor materials, It is characterized in that include: forming a first material layer on a substrate, wherein a portion of the material of the first material layer penetrates into the substrate; The material of the first material layer includes Ta x C y , or Ta and Ta x C y ; wherein, x + y = 1, 0 < x < 1, 0 < y < 1; the first material layer includes a plurality of first grain layers, the first grain layer includes a plurality of first grains, the plurality of first grain layers includes at least a pair of adjacent first grain layers, along the direction perpendicular to the substrate, the grain boundaries of the first grains of one of a pair of adjacent first grain layers do not coincide with the grain boundaries of the first grains of the other A second material layer is formed on a side of the first material layer away from the substrate, and a material of the second material layer includes TaC or Ta.

10. The preparation method according to claim 9, It is characterized in that The step of forming a first material layer on a substrate comprises: The substrate is immersed in a solution containing tantalum element; Drying the soaked substrate; The dried substrate is calcined.

11. The preparation method according to claim 9, It is characterized in that The forming of the second material layer on a side of the first material layer away from the substrate comprises: Preparing a slurry containing TaC or Ta, and coating the slurry on the first material layer; Drying the slurry coated on the first material layer; The dried slurry is sintered.

12. A semiconductor growth device, It is characterized in that include: Chamber, The substrate according to any one of claims 1 to 8, wherein the substrate is placed inside the chamber.

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