Graphite susceptor with embedded silicon carbide coating and preparation method and application thereof

Abstract

The present invention relates to a graphite base with an embedded silicon carbide coating, and a preparation method and application thereof. The preparation method of the graphite base with an embedded silicon carbide coating comprises the following steps: placing SiO powder and a graphite base in a reaction vessel, wherein the graphite base is located on the volatilization path of the SiO powder; vacuumizing the reaction vessel and heating it to 1100°C-1800°C, then introducing an inert gas with a flow rate of 100sccm-1000sccm into the reaction vessel and keeping it warm, wherein the SiO powder volatilizes to form SiO gas to react with the graphite base, and silicon carbide is formed inside and on the surface of the graphite base; and controlling the temperature of the reaction vessel between 1100°C-1500°C, introducing a diluent gas, a silicon source and a reducing gas into the reaction vessel, and performing a chemical vapor deposition reaction on the surface of the graphite base, thereby obtaining a graphite base with an embedded silicon carbide coating. The graphite base with an embedded silicon carbide coating obtained by the preparation method has excellent thermal shock resistance.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a graphite base with an embedded silicon carbide coating, and a preparation method and application thereof. Background Art

[0002] With the rapid development of the light-emitting diode (LED) industry, the demand for LED epitaxial wafers has continued to increase. LED epitaxial wafers refer to single crystal thin films grown on substrate substrates. The quality of the silicon carbide coated graphite base that supports the substrate substrate directly affects the quality of LED epitaxial wafers. However, the traditional silicon carbide coated graphite base has insufficient thermal shock resistance. After experiencing multiple high-temperature and low-temperature cycles, the silicon carbide coating is prone to peeling. Therefore, it is urgent to develop a preparation method that can improve the thermal shock resistance of the silicon carbide coated graphite base. Summary of the invention

[0003] Based on this, it is necessary to provide a graphite base with an embedded silicon carbide coating and a preparation method and application thereof to address the above problems. The graphite base with an embedded silicon carbide coating prepared by the preparation method has excellent thermal shock resistance.

[0004] The present invention discloses a method for preparing a graphite base with an embedded silicon carbide coating, comprising the following steps:

[0005] Placing SiO powder and a graphite base in a reaction container, wherein the graphite base is located on the volatilization path of the SiO powder;

[0006] The reaction container is evacuated and heated to 1100° C.-1800° C., and then an inert gas with a flow rate of 100 sccm-1000 sccm is introduced into the reaction container and kept warm, so that the SiO gas formed by the volatilization of the SiO powder reacts with the graphite base to form silicon carbide inside and on the surface of the graphite base; and

[0007] The temperature of the reaction container is controlled between 1100° C. and 1500° C., and a dilution gas, a silicon source, and a reducing gas are introduced into the reaction container to perform a chemical vapor deposition reaction on the surface of the graphite base to obtain a graphite base with an embedded silicon carbide coating, wherein the embedded silicon carbide coating includes an embedded part and a surface part, and the SiC grains in the surface part are pyramid-like.

[0008] In one embodiment, in the step of reacting SiO gas formed by volatilization of the SiO powder with the graphite susceptor, CO gas is generated, and the CO gas reduces the concentration of the SiO gas in the reaction container.

[0009] In one embodiment, the mass ratio of the SiO powder to the graphite base is 1:2-1:20.

[0010] In one embodiment, the insulation time is 1 h-10 h.

[0011] In one embodiment, the molar ratio of the silicon source to the reducing gas is 0.05-0.3.

[0012] In one embodiment, in the step of introducing a dilution gas, a silicon source, and a reducing gas:

[0013] The diluent gas includes at least one of argon or helium;

[0014] And / or, the flow rate of the dilution gas is 500 sccm-2000 sccm;

[0015] And / or, the silicon source includes at least one of chlorosilane or silicon tetrachloride;

[0016] And / or, the flow rate of the silicon source is 200 sccm-600 sccm;

[0017] And / or, the reducing gas is hydrogen;

[0018] And / or, the flow rate of the reducing gas is 1000 sccm-10000 sccm.

[0019] In one embodiment, in the step of performing chemical vapor deposition reaction, the reaction temperature is 1100° C.-1500° C., and the reaction time is 1 h-10 h.

[0020] A graphite base with an embedded silicon carbide coating is prepared by the above-mentioned preparation method of a graphite base with an embedded silicon carbide coating, comprising a graphite base and an embedded silicon carbide coating, wherein the embedded silicon carbide coating comprises an embedded part and a surface part, and SiC grains in the surface part are pyramid-like.

[0021] In one embodiment, the embedded silicon carbide coating has an embedded depth greater than or equal to 200 μm.

[0022] An application of the graphite base with embedded silicon carbide coating as described above in the preparation of light emitting diode epitaxial wafers.

[0023] In the preparation method of the graphite susceptor with embedded silicon carbide coating provided by the present invention, firstly, the temperature of the reaction container is heated to 1100° C.-1800° C., so that SiO powder is volatilized to become SiO gas and enters into the inside of the graphite susceptor, reacts with C on the surface and inside of the graphite susceptor to form SiC, and the SiC is embedded into the inside of the graphite susceptor; secondly, the temperature of the reaction container is controlled to be between 1100° C.-1500° C., and a dilution gas, a silicon source and a reducing gas are introduced into the reaction container to carry out a chemical vapor deposition reaction on the surface of the graphite susceptor, and silicon carbide is continuously grown on the basis of silicon carbide on the surface of the graphite susceptor, so that, on the one hand, the silicon carbide on the surface layer is integrated with the silicon carbide inside the graphite susceptor, and the bonding force between the embedded silicon carbide coating and the graphite susceptor is improved to a certain extent; on the other hand, the silicon carbide formed by the chemical vapor deposition reaction has good uniformity and high density, and can prevent high-temperature gas from entering the inside of the graphite susceptor, so that the prepared graphite susceptor with embedded silicon carbide coating has excellent thermal shock resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a scanning electron microscope image of the graphite base surface after heat preservation in Example 1;

[0026] Figure 2 This is a scanning electron microscope image of the cross section of the graphite base after heat preservation in Example 1;

[0027] Figure 3 This is a scanning electron microscope image of the surface of the graphite base with an embedded silicon carbide coating prepared in Example 1;

[0028] Figure 4 This is a scanning electron microscope image of a cross section of a graphite base with an embedded silicon carbide coating prepared in Example 1. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of the present invention, the present invention will be described in more detail below. However, it should be understood that the present invention can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the technical field of the terminology of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific implementation methods or embodiments and are not intended to limit the present invention.

[0031] The present invention provides a method for preparing a graphite base with an embedded silicon carbide coating, comprising the following steps:

[0032] S10, placing SiO powder and a graphite base in a reaction container, wherein the graphite base is located on a volatilization path of the SiO powder;

[0033] S20, evacuating the reaction container and heating it to 1100° C.-1800° C., then introducing an inert gas at a flow rate of 100 sccm-1000 sccm into the reaction container and keeping the temperature, wherein SiO gas formed by volatilization of SiO powder reacts with the graphite base to form silicon carbide inside and on the surface of the graphite base; and

[0034] S30, controlling the temperature of the reaction container between 1100°C and 1500°C, introducing a dilution gas, a silicon source and a reducing gas into the reaction container to perform a chemical vapor deposition reaction on the surface of the graphite base, and obtaining a graphite base with an embedded silicon carbide coating, wherein the embedded silicon carbide coating includes an embedded portion and a surface portion, and SiC grains in the surface portion are pyramid-like in shape.

[0035] In the method for preparing a graphite base with an embedded silicon carbide coating provided by the present invention, each step cooperates with each other to ensure that the prepared graphite base with an embedded silicon carbide coating has excellent thermal shock resistance.

[0036] In step S10, in order to ensure excellent bonding between the silicon carbide coating and the graphite base, in one embodiment, before placing the SiO powder and the graphite base in a reaction vessel, the graphite base is pretreated. Preferably, the pretreatment step includes: first polishing the graphite base, then ultrasonically cleaning the graphite base, and finally drying; preferably, the roughness of the graphite base is polished to less than 1.6 μm.

[0037] In one embodiment, the graphite base is ultrasonically cleaned using water, and the ultrasonic cleaning time is 10 min-20 min, including but not limited to 10 min, 12.5 min, 15 min, 17.5 min or 20 min.

[0038] In one embodiment, the mass ratio of the SiO powder to the graphite base is 1:2-1:20, including but not limited to 1:2, 1:4, 1:6, 1:8, 1:10, 1:12, 1:14, 1:16, 1:18 or 1:20.

[0039] Using SiO powder as a raw material can accurately control the raw material composition of the chemical vapor reaction, thereby increasing the embedding depth of the embedded silicon carbide coating in the graphite base. In one embodiment, the purity of the SiO powder is greater than or equal to 99.99%.

[0040] In step S20, the temperature of the reaction container is heated to 1100°C-1800°C, including but not limited to 1100°C, 1200°C, 1300°C, 1400°C, 1500°C, 1600°C, 1700°C or 1800°C, so that the SiO powder is volatilized into SiO gas and enters the interior of the graphite base, reacts with the surface and internal C of the graphite base to form SiC, thereby embedding the SiC into the interior of the graphite base.

[0041] In one embodiment, in the step of reacting SiO gas formed by volatilization of SiO powder with the graphite base, CO gas is also generated. The CO gas reduces the concentration of SiO gas in the reaction container, promotes the volatilization of SiO powder, and prevents the deposition rate of SiC from being too fast, promotes the SiO gas to enter the interior of the graphite base, thereby embedding SiC into the interior of the graphite base.

[0042] It should be noted that under normal pressure (100 kPa), SiO powder exists in solid form from room temperature to 1700°C. The lower the pressure, the lower the volatilization temperature of SiO powder. In a vacuum environment, when the temperature reaches 1100°C-1200°C, SiO powder will begin to volatilize; and in a vacuum environment, there is no oxygen, and SiO will not react to form silicon dioxide.

[0043] In one embodiment, in the vacuum treatment step, the absolute pressure of the reaction container is less than or equal to 10Pa, including but not limited to 0Pa, 1Pa, 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa or 10Pa.

[0044] In one embodiment, in the heating step, the heating rate is 5°C / min-10°C / min, including but not limited to 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min or 10°C / min.

[0045] In one embodiment, the insulation time is 1 h-10 h, including but not limited to 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0046] The introduction of inert gas can firstly dilute SiO gas and promote the volatilization of SiO powder; secondly, it can provide an inert environment, discharge residual oxygen and other gases in the reaction container, and prevent oxidation and other side reactions; thirdly, it can adjust the pressure of the reaction container, thereby controlling the nucleation rate of SiC, and then controlling the deposition rate of SiC. In the step of introducing inert gas into the reaction container, the flow rate of the inert gas is 100sccm-1000sccm, including but not limited to 100sccm, 200sccm, 300sccm, 400sccm, 500sccm, 600sccm, 700sccm, 800sccm, 900sccm or 1000sccm; the inert gas includes at least one of argon and helium.

[0047] In step S30, the temperature of the reaction container is controlled between 1100°C and 1500°C, and a dilution gas, a silicon source and a reducing gas are introduced into the reaction container to carry out a chemical vapor deposition reaction on the surface of the graphite base, and silicon carbide continues to grow on the basis of the silicon carbide on the surface of the graphite base. Thus, on the one hand, the silicon carbide on the surface is integrated with the silicon carbide inside the graphite base, and the bonding force between the embedded silicon carbide coating and the graphite base is improved to a certain extent. On the other hand, the silicon carbide formed by the chemical vapor deposition reaction has good uniformity and high density, which prevents high-temperature gas from entering the interior of the graphite base, and finally the obtained graphite base with an embedded silicon carbide coating has excellent thermal shock resistance.

[0048] It should be noted that the pyramid-like shape represents a quadrangular pyramid shape or a triangular pyramid shape.

[0049] In one embodiment, the dilution gas includes at least one of argon or helium, and the flow rate of the dilution gas is 500 sccm-2000 sccm, including but not limited to 500 sccm, 750 sccm, 1000 sccm, 1250 sccm, 1500 sccm, 1750 sccm or 2000 sccm.

[0050] In one embodiment, the silicon source includes at least one of chlorosilane and silicon tetrachloride, and the flow rate of the silicon source is 200 sccm-600 sccm, including but not limited to 200 sccm, 300 sccm, 400 sccm, 500 sccm or 600 sccm.

[0051] In one embodiment, the reducing gas is hydrogen, and the flow rate of the reducing gas is 1000sccm-10000sccm, including but not limited to 1000sccm, 2000sccm, 3000sccm, 4000sccm, 5000sccm, 6000sccm, 7000sccm, 8000sccm, 9000sccm or 10000sccm.

[0052] In one embodiment, the molar ratio of the silicon source to the reducing gas is 0.05-0.3, including but not limited to 0.05, 0.1, 0.15, 0.2, 0.25 or 0.3.

[0053] In one embodiment, in the step of performing a chemical vapor deposition reaction, the reaction temperature is 1100°C-1500°C, including but not limited to 1100°C, 1200°C, 1300°C, 1400°C or 1500°C, and the reaction time is 1h-10h, including but not limited to 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h.

[0054] The present invention also provides a graphite base with an embedded silicon carbide coating, which is prepared by the above-mentioned preparation method of a graphite base with an embedded silicon carbide coating, comprising a graphite base and an embedded silicon carbide coating, wherein the embedded silicon carbide coating comprises an embedded portion and a surface portion, and the SiC grains in the surface portion are pyramid-like. The pyramid-like SiC grains in the surface portion can improve the corrosion resistance of the embedded silicon carbide coating.

[0055] In one embodiment, the embedded silicon carbide coating has an embedded depth greater than or equal to 200 μm.

[0056] In some embodiments, the thickness of the surface layer portion is greater than or equal to 100 μm.

[0057] The graphite base with embedded silicon carbide coating provided by the present invention has excellent thermal shock resistance, and after experiencing multiple high-temperature and low-temperature cycles, the embedded silicon carbide coating still does not peel off.

[0058] The present invention also provides a use of the graphite base with embedded silicon carbide coating as described above in the preparation of light emitting diode epitaxial wafers.

[0059] Hereinafter, the graphite base with embedded silicon carbide coating and its preparation method and application will be further described through the following specific embodiments.

[0060] Example 1

[0061] The graphite base was polished with sandpaper, ultrasonically cleaned with pure water for 20 minutes, and then dried in an oven at 120° C. for 2 hours to obtain a pretreated graphite base.

[0062] A 600 g, 10 mm thick pre-treated graphite base was placed in a vacuum furnace, along with 100 g of SiO powder.

[0063] The vacuum furnace was evacuated, and then the temperature was raised to 1300°C at a rate of 5°C / min. After the temperature stabilized, 1000sccm of argon was introduced and the temperature was kept for 1 hour to form silicon carbide inside and on the surface of the graphite base. The scanning electron microscope image of the surface of the graphite base after the temperature was kept is shown in Figure 2. Figure 1 As shown in the figure, the scanning electron microscope image of the cross section of the graphite base after insulation is as follows Figure 2 As shown, comprehensive Figure 1 and Figure 2 It can be seen that there are a small amount of SiC particles on the graphite base, and a large amount of SiC is generated inside the graphite, with an embedded depth of about 700 μm.

[0064] The vacuum furnace was evacuated to 10Pa, the temperature was controlled at 1300°C, and argon, hydrogen and methyltrichlorosilane (MTS) were introduced into the vacuum furnace and kept warm for 3 hours. A chemical vapor deposition reaction was carried out on the surface of the graphite base, wherein the flow rate of argon was 1000sccm, the flow rate of hydrogen was 5000sccm, the flow rate of methyltrichlorosilane was 500sccm, and the molar ratio of methyltrichlorosilane to hydrogen was 0.1.

[0065] Stop introducing hydrogen and methyltrichlorosilane into the vacuum furnace, keep the argon gas constant, stop heating, and when the vacuum furnace cools down to room temperature, introduce air into the vacuum furnace until the pressure inside the vacuum furnace reaches atmospheric pressure, and then obtain a graphite base with an embedded silicon carbide coating. The scanning electron microscope image of the surface of the graphite base with an embedded silicon carbide coating is as follows: Figure 3 As shown, from Figure 3 It can be seen that the SiC grains in the embedded silicon carbide coating are pyramid-like; the scanning electron microscope image of the cross section of the graphite base with embedded silicon carbide coating is as follows: Figure 4 As shown, from Figure 4 It can be seen that the embedded silicon carbide coating is deeply embedded in the graphite base.

[0066] Comparative Example 1

[0067] The graphite base was polished with sandpaper, ultrasonically cleaned with pure water for 20 minutes, and then dried in an oven at 120° C. for 2 hours to obtain a pretreated graphite base.

[0068] 600 g of pretreated graphite base was placed in a vacuum furnace, which was evacuated to 10 Pa, and then heated to 1300°C at a rate of 5°C / min. After the temperature stabilized, argon, hydrogen and methyltrichlorosilane (MTS) were introduced into the vacuum furnace and kept warm for 3 hours. Chemical vapor deposition reaction was carried out on the surface of the graphite base, wherein the flow rate of argon was 1000 sccm, the flow rate of hydrogen was 5000 sccm, the flow rate of methyltrichlorosilane was 500 sccm, and the molar ratio of methyltrichlorosilane to hydrogen was 0.1.

[0069] Stop introducing hydrogen and methyltrichlorosilane into the vacuum furnace, keep the argon gas unchanged, stop heating, and when the vacuum furnace cools down to room temperature, introduce air into the vacuum furnace until the pressure in the vacuum furnace reaches atmospheric pressure, thereby obtaining a graphite base with a silicon carbide coating.

[0070] Comparative Example 2

[0071] The graphite base was polished with sandpaper, ultrasonically cleaned with pure water for 20 minutes, and then dried in an oven at 120° C. for 2 hours to obtain a pretreated graphite base.

[0072] 600 g of the pretreated graphite base was placed in a vacuum furnace, and 100 g of SiO powder was also placed in the furnace.

[0073] The vacuum furnace was evacuated, and then the temperature was raised to 1000°C at a rate of 5°C / min. After the temperature stabilized, 1000sccm of argon gas was introduced and kept at this temperature for 1 hour.

[0074] The vacuum furnace was evacuated to 10Pa, and argon, hydrogen and methyltrichlorosilane (MTS) were introduced into the vacuum furnace. The temperature was controlled to 1000°C and kept warm for 3 hours. A chemical vapor deposition reaction was carried out on the surface of the graphite base, wherein the flow rate of argon was 1000sccm, the flow rate of hydrogen was 5000sccm, the flow rate of methyltrichlorosilane was 500sccm, and the molar ratio of methyltrichlorosilane to hydrogen was 0.1.

[0075] Stop introducing hydrogen and methyltrichlorosilane into the vacuum furnace, keep argon unchanged, stop heating, and when the vacuum furnace cools down to room temperature, introduce air into the vacuum furnace until the pressure inside the vacuum furnace reaches atmospheric pressure. At this time, no embedded silicon carbide coating is formed on the surface of the graphite base.

[0076] Comparative Example 3

[0077] The graphite base was polished with sandpaper, ultrasonically cleaned with pure water for 20 minutes, and then dried in an oven at 120° C. for 2 hours to obtain a pretreated graphite base.

[0078] 600 g of pretreated graphite base was placed in a vacuum furnace, and 100 g of SiO powder was placed in the vacuum furnace. The vacuum furnace was evacuated and then heated to 1300°C at a rate of 5°C / min. After the temperature stabilized, 1000 sccm of argon was introduced and kept warm for 1 hour to form silicon carbide inside and on the surface of the graphite base.

[0079] The vacuum furnace was evacuated to 10Pa, the temperature was controlled at 1300℃, and after keeping warm for 3 hours, the heating was stopped. When the vacuum furnace was cooled to room temperature, air was introduced into the vacuum furnace until the pressure in the vacuum furnace reached atmospheric pressure. The silicon carbide coating on the surface of the graphite base was relatively loose.

[0080] The thermal shock resistance of the graphite susceptor with embedded silicon carbide coating prepared in Example 1 and the graphite susceptors with silicon carbide coating prepared in Comparative Examples 1 to 3 was tested in the following manner. The test results are shown in Table 1.

[0081] Test Example 1

[0082] Test method: thermal shock test is carried out in a muffle furnace at 400℃. The specific operation steps are to put the test product (graphite base with embedded silicon carbide coating, graphite base with silicon carbide coating) into a 400℃ muffle furnace, let it stand for 1 hour, then take it out and put it into water, and then put it back into the muffle furnace, and repeat it for multiple times until the through cracks stop.

[0083] Table 1

[0084]

[0085] Example 2

[0086] Example 2 was carried out with reference to Example 1, except that the mass ratio of SiO powder to graphite base was 1:2.

[0087] Example 3

[0088] Example 3 was carried out with reference to Example 1, except that the mass ratio of SiO powder to graphite base was 1:10.

[0089] Example 4

[0090] Example 4 was carried out with reference to Example 1, except that the flow rate of hydrogen was 5000 sccm, the flow rate of methyltrichlorosilane was 1000 sccm, and the molar ratio of the silicon source to the reducing gas was 0.2.

[0091] Example 5

[0092] Example 5 was carried out with reference to Example 1, except that the flow rate of hydrogen was 5000 sccm, the flow rate of methyltrichlorosilane was 1500 sccm, and the molar ratio of the silicon source to the reducing gas was 0.3.

[0093] Test Example 2

[0094] Test Example 2 was carried out with reference to Test Example 1 to test the thermal shock resistance of the graphite base with embedded silicon carbide coating prepared in Examples 2 to 5. The test method was as follows. The test results are shown in Table 2.

[0095] Table 2

[0096]

[0097] Example 6

[0098] Example 6 is carried out in accordance with Example 1, except that after the vacuum furnace is evacuated, the temperature is then raised to 1100°C at a rate of 5°C / min. After the temperature stabilizes, 1000sccm of argon gas is introduced and the temperature is maintained for 1 hour to form silicon carbide inside and on the surface of the graphite base.

[0099] Example 7

[0100] Example 7 is carried out in accordance with Example 1, except that after the vacuum furnace is evacuated, the temperature is then raised to 1500°C at a rate of 5°C / min. After the temperature stabilizes, 1000sccm of argon gas is introduced and the temperature is maintained for 1 hour to form silicon carbide inside and on the surface of the graphite base.

[0101] Example 8

[0102] Example 8 is carried out with reference to Example 1, except that after the vacuum furnace is evacuated, the temperature is then raised to 1800°C at a rate of 5°C / min. After the temperature stabilizes, 1000sccm of argon gas is introduced and the temperature is maintained for 1 hour to form silicon carbide inside and on the surface of the graphite base.

[0103] Example 9

[0104] Example 9 is carried out with reference to Example 1, except that after the vacuum furnace is evacuated, the temperature is then raised to 1800°C at a rate of 5°C / min. After the temperature stabilizes, 1000sccm of argon gas is introduced and the temperature is maintained for 10 hours to form silicon carbide inside and on the surface of the graphite base.

[0105] Example 10

[0106] Example 10 is carried out with reference to Example 1, except that after the vacuum furnace is evacuated, the temperature is then raised to 1500°C at a rate of 5°C / min. After the temperature stabilizes, 1000sccm of argon gas is introduced and the temperature is maintained for 5 hours to form silicon carbide inside and on the surface of the graphite base.

[0107] Test Example 3

[0108] Test Example 3 was carried out with reference to Test Example 1 to test the thermal shock resistance of the graphite bases with embedded silicon carbide coatings prepared in Examples 6 to 10. The test method was as follows. The test results are shown in Table 3.

[0109] Table 3

[0110]

[0111] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a graphite susceptor with an embedded silicon carbide coating, characterized in that: The following steps are involved: Placing SiO powder and a graphite base in a reaction container, wherein the graphite base is located on the volatilization path of the SiO powder, and the mass ratio of the SiO powder to the graphite base is 1:2-1:6; The reaction container is evacuated and heated to 1300° C.-1800° C., and then an inert gas with a flow rate of 900 sccm-1000 sccm is introduced into the reaction container and kept warm for 5 h-10 h, wherein the SiO gas formed by the volatilization of the SiO powder reacts with the graphite susceptor to form silicon carbide inside and on the surface of the graphite susceptor, and CO gas is generated in the step of reacting the SiO gas formed by the volatilization of the SiO powder with the graphite susceptor, and the CO gas reduces the concentration of the SiO gas in the reaction container; and The temperature of the reaction container is controlled between 1100°C and 1500°C, and a dilution gas, a silicon source and a reducing gas are introduced into the reaction container to perform a chemical vapor deposition reaction on the surface of the graphite base to obtain a graphite base with an embedded silicon carbide coating, wherein in the step of performing the chemical vapor deposition reaction, the reaction temperature is 1300°C to 1500°C, the embedded silicon carbide coating includes an embedded part and a surface part, the embedded depth of the embedded silicon carbide coating is greater than or equal to 700 μm, and the SiC grains in the surface part are pyramid-like.

2. The method for preparing a graphite susceptor with an embedded silicon carbide coating according to claim 1, characterized in that: The molar ratio of the silicon source to the reducing gas is 0.05-0.

3.

3. The method for preparing a graphite susceptor with an embedded silicon carbide coating according to claim 1, characterized in that: In the step of introducing dilution gas, silicon source and reducing gas: The diluent gas includes at least one of argon or helium; And / or, the flow rate of the dilution gas is 500 sccm-2000 sccm; And / or, the silicon source includes at least one of chlorosilane or silicon tetrachloride; And / or, the flow rate of the silicon source is 200 sccm-600 sccm; And / or, the reducing gas is hydrogen; And / or, the flow rate of the reducing gas is 1000 sccm-10000 sccm.

4. The method for preparing a graphite susceptor with an embedded silicon carbide coating according to claim 1, characterized in that: In the step of performing chemical vapor deposition reaction, the reaction time is 1h-10h.

5. A graphite susceptor with an embedded silicon carbide coating, characterized in that: The method for preparing a graphite base with an embedded silicon carbide coating according to any one of claims 1 to 4 is adopted, comprising a graphite base and an embedded silicon carbide coating, wherein the embedded silicon carbide coating comprises an embedded portion and a surface portion, the embedded depth of the embedded silicon carbide coating is greater than or equal to 700 μm, and the SiC grains in the surface portion are pyramid-like in shape.

6. Use of the graphite base with embedded silicon carbide coating as claimed in claim 5 in preparing light emitting diode epitaxial wafers.

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