Device and method for diameter expansion growth of silicon carbide crystal

Abstract

The present invention relates to the field of the preparation of silicon carbide crystals, and in particular to a device and method for the diameter expansion growth of a silicon carbide crystal. The device comprises a graphite diameter expansion device comprising a porous graphite diameter expansion ring. The porous graphite diameter expansion ring serves as a gas channel and is used for releasing an accumulated growth atmosphere during the diameter expansion growth of the silicon carbide crystal. The porous graphite diameter expansion ring not only ensures the smoothness of gas exhaust, but also solves the problem of polycrystalline silicon carbide growing on an edge of a silicon carbide seed crystal hindering the diameter expansion of the silicon carbide crystal. In addition, in the axial direction of the graphite diameter expansion device and in a direction away from the silicon carbide seed crystal, the porosity of the porous graphite diameter expansion ring gradually decreases, so that the growth atmosphere in a graphite crucible is controlled to ensure that the growth atmosphere can be discharged in time when the growth atmosphere is excessive in the early stage, and the discharge amount is reduced when the growth atmosphere in the later growth stage is insufficient, thus increasing the growth rate of the silicon carbide crystal. In addition, hard graphite felt is arranged around the diameter expansion device to serve as a heat insulation material, so that a rational temperature gradient of silicon carbide crystal growth is maintained.

Description

Silicon carbide crystal diameter expansion growth device and silicon carbide crystal diameter expansion growth method Technical Field

[0001] The present invention relates to the field of silicon carbide crystal preparation, and in particular to a silicon carbide crystal diameter expansion growth device and a silicon carbide crystal diameter expansion growth method. Background Art

[0002] Over the past few decades, the application of semiconductor materials in electronic and optoelectronic devices has achieved tremendous success. Silicon carbide (SiC), a wide-bandgap semiconductor material, has garnered significant attention due to its exceptional physical and chemical properties, including a high melting point, high hardness, excellent thermal conductivity, and superior electrical performance. In particular, SiC's exceptional performance in extreme environments, such as high temperature, high pressure, high frequency, and radiation resistance, holds broad application prospects in power electronics, optoelectronics, aerospace, and military applications.

[0003] However, due to the complexity of the growth process of silicon carbide single crystals, achieving high-quality, large-size silicon carbide single crystal growth has always been the goal of scientific researchers. Conducting research on the growth and diameter expansion of silicon carbide single crystals has important scientific significance and practical application value.

[0004] At present, during the expansion growth process of silicon carbide crystals, too much growth atmosphere will accumulate at the angle between the edge of the silicon carbide crystal and the inner wall of the expansion graphite device. After the growth atmosphere is oversaturated, polycrystalline silicon carbide is easily precipitated, thereby deteriorating the crystal quality and hindering the further expansion growth of the silicon carbide crystal, resulting in expansion failure.

[0005] Summary of the Invention

[0006] In order to solve the above technical problems, the present invention provides a silicon carbide crystal diameter expansion growth device and a silicon carbide crystal diameter expansion growth method.

[0007] To achieve the above-mentioned object, the present invention provides a silicon carbide crystal diameter expansion growth device, comprising:

[0008] Graphite crucible, hard graphite ring, graphite expansion device, graphite support;

[0009] The graphite crucible is used to hold silicon carbide raw materials, and the graphite crucible has a graphite crucible cover plate;

[0010] The hard graphite ring is fixed to the inner wall of the graphite crucible;

[0011] The graphite expansion device is arranged above the hard graphite ring;

[0012] A silicon carbide seed crystal is fixed on one side of the graphite holder, the graphite holder is arranged above the graphite expansion device, and the silicon carbide seed crystal faces the inside of the graphite crucible;

[0013] The graphite expansion device includes a porous graphite expansion ring and a hard graphite expansion ring, which are spaced apart and coaxially stacked in sequence, and the cross-sectional diameter of the graphite expansion device gradually increases in the direction away from the silicon carbide seed crystal.

[0014] Optionally, the porous graphite expansion ring has a curved slope structure.

[0015] Optionally, the porosity of the porous graphite expansion ring decreases successively along the axial direction of the graphite expansion device and in a direction away from the silicon carbide seed crystal, or the porosity of the porous graphite expansion ring is the same.

[0016] Optionally, the thickness of the porous graphite expansion ring is the same or the thickness of the porous graphite expansion ring decreases successively along the axial direction of the graphite expansion device and in a direction away from the silicon carbide seed crystal.

[0017] Optionally, the porosity of the porous graphite expansion ring is in the range of 20%-60%, and the porous graphite expansion ring is plated with a tantalum carbide coating.

[0018] Optionally, the porous graphite expansion ring and the hard graphite expansion ring are tightly connected, the thickness of the porous graphite expansion ring ranges from 0 mm to 2 mm, and the thickness of the hard graphite expansion ring ranges from 5 mm to 15 mm.

[0019] Optionally, the graphite hard felt is filled in the gap between the crucible and the graphite expansion device.

[0020] An embodiment of the present invention further provides a method for growing a silicon carbide crystal by expanding its diameter, using any one of the above-mentioned devices for growing a silicon carbide crystal by expanding its diameter, comprising:

[0021] Filling silicon carbide raw material into the graphite crucible of the silicon carbide crystal diameter expansion growth device;

[0022] The graphite holder with the silicon carbide seed crystal fixed thereon is placed on the graphite expansion device, and the graphite crucible cover is closed;

[0023] The graphite crucible is heated to sublime the silicon carbide raw material. The growth atmosphere generated in the silicon carbide crystal expansion and growth device causes the silicon carbide crystal to grow from the surface of the silicon carbide seed crystal along the axial direction of the graphite expansion device. The porous graphite expansion ring exhausts the gas in time when the growth atmosphere is excessive in the early stage, and reduces the exhaust volume when the growth atmosphere is insufficient in the later stage of growth, thereby finally obtaining a silicon carbide crystal.

[0024] Optionally, the radial temperature gradient range of the growth of silicon carbide crystals in the center of the graphite crucible is 0.5° C. / mm to 2° C. / mm.

[0025] Optionally, the temperature range for the growth of the silicon carbide crystal is 2100° C. to 2300° C., the pressure range for the growth of the silicon carbide crystal is 2 mbar to 10 mbar, and the time range for the growth of the silicon carbide crystal is 100 h to 200 h.

[0026] In summary, the advantages and beneficial effects of the present invention are:

[0027] The present invention provides a silicon carbide crystal expansion growth device and a silicon carbide crystal expansion growth method. The device comprises a graphite expansion device having a porous graphite expansion ring and a hard graphite expansion ring. The porous graphite expansion ring serves as an airway for releasing accumulated growth atmosphere during the silicon carbide crystal expansion growth process. The porous graphite expansion ring ensures unobstructed exhaust and solves the problem of polycrystals growing at the edge of the silicon carbide seed crystal hindering the expansion of the silicon carbide crystal. Furthermore, the porosity of the porous graphite expansion ring gradually decreases along the axial direction of the graphite expansion device and in a direction away from the silicon carbide seed crystal, thereby controlling the growth atmosphere in the graphite crucible, ensuring that excess growth atmosphere can be promptly discharged in the early stage and reducing the discharge amount when insufficient growth atmosphere is in the later stage of growth, thereby improving the growth rate of the silicon carbide crystal.

[0028] At the same time, graphite hard felt is arranged around the expansion device as a heat-insulating material to maintain a reasonable temperature gradient for the growth of silicon carbide crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG1 is a schematic cross-sectional view of a silicon carbide crystal diameter expansion growth device according to an embodiment of the present invention;

[0030] FIG2 is a schematic diagram of a thermal field simulation of a silicon carbide crystal diameter expansion growth method according to an embodiment of the present invention.

[0031] Icons: graphite crucible 1; graphite crucible cover 2; graphite support 3; graphite hard felt 4; hard graphite ring 5; silicon carbide source powder 6; silicon carbide seed crystal 7; porous graphite expansion ring 8; hard graphite expansion ring 9. DETAILED DESCRIPTION

[0032] To facilitate understanding by those skilled in the art, the present invention will be further described in detail below with reference to specific embodiments.

[0033] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] The present invention provides a silicon carbide crystal diameter expansion growth device, as shown in FIG1 , comprising:

[0035] Graphite crucible 1, hard graphite ring 5, graphite expansion device 10, graphite support 3;

[0036] The graphite crucible 1 is used to hold silicon carbide raw materials, and the graphite crucible 1 has a graphite crucible cover plate 2;

[0037] The hard graphite ring 5 is fixed to the inner wall of the graphite crucible 1;

[0038] The graphite expansion device 10 is arranged above the hard graphite ring 5;

[0039] A silicon carbide seed crystal 7 is fixed on one side of the graphite holder 3. The graphite holder 3 is arranged above the graphite expansion device 10, and the silicon carbide seed crystal 7 faces the inside of the graphite crucible 1.

[0040] The graphite expansion device 10 includes a porous graphite expansion ring 8 and a hard graphite expansion ring 9, which are spaced apart and coaxially stacked in sequence, and the cross-sectional diameter of the graphite expansion device gradually increases in the direction away from the silicon carbide seed crystal.

[0041] Specifically, in the embodiment of the present invention, the porous graphite expansion ring 8 has a bent slope structure.

[0042] The porous graphite expanding ring 8 is configured to have a curved slope structure to facilitate stacking of the porous graphite expanding ring 8 and the hard graphite expanding ring 9, thereby avoiding misalignment between the porous graphite expanding ring 8 and the hard graphite expanding ring 9, which may cause collapse of the graphite expanding device 10.

[0043] The porous graphite expansion ring 8 acts as an airway to release excess growth atmosphere generated during the silicon carbide crystal growth process, ensuring smooth exhaust and improving the growth quality of the silicon carbide crystal. At the same time, it prevents excessive growth atmosphere from accumulating at the angle between the edge of the growing silicon carbide crystal and the inner wall of the silicon carbide crystal expansion growth device, which could lead to the precipitation of polycrystalline silicon carbide. This solves the problem of polycrystalline growth at the edge hindering the expansion growth of the silicon carbide crystal, further improving the quality of silicon carbide crystal growth.

[0044] On the one hand, the porous graphite expansion ring 8 releases excessive growth atmosphere, ensuring the growth conditions of silicon carbide crystals. On the other hand, when releasing excessive growth atmosphere, it does not take away too much heat at the same time, avoiding a large degree of supercooling in the airway, which leads to the deposition and crystallization of silicon carbide atmosphere in the airway, channel blockage, and loss of exhaust function.

[0045] In an embodiment of the present invention, the thickness of the porous graphite expansion ring 8 is the same, and the porosity of the porous graphite expansion ring 8 decreases successively along the axial direction of the graphite expansion device 10 and away from the silicon carbide seed crystal 7, ensuring that the excess growth atmosphere is discharged in time in the early stage of silicon carbide crystal growth, and reducing the discharge amount when the growth atmosphere is insufficient in the later stage of silicon carbide crystal growth, thereby improving the growth rate of silicon carbide crystal.

[0046] In the embodiment of the present invention, the porosity of the porous graphite expansion ring 8 is in the range of 20%-60%.

[0047] In other embodiments, the porosity of the porous graphite expansion rings is the same, and the width of the porous graphite expansion rings decreases in sequence along the axial direction of the graphite expansion device and in a direction away from the silicon carbide seed crystal.

[0048] The porosity and width of the porous graphite expansion ring are used to adjust the exhaust volume during crystal growth, either individually or in combination, so that the growth atmosphere in the graphite crucible satisfies crystal growth.

[0049] In an embodiment of the present invention, the porous graphite expansion ring 8 is coated with a tantalum carbide coating. Since the entire porous graphite expansion ring 8 is coated with a tantalum carbide coating, tantalum carbide will also penetrate into the interior of the porous graphite expansion ring 8 to form a tantalum carbide coating, thereby preventing the released growth atmosphere from corroding the graphite components in the silicon carbide crystal expansion growth device, thereby improving the service life of the graphite components.

[0050] In an embodiment of the present invention, the porous graphite expanding ring 8 and the hard graphite expanding ring 9 are spaced apart and coaxially stacked in sequence, and the hard graphite expanding ring 9 has a structure that matches the porous graphite expanding ring 8, so that the hard graphite expanding ring 9 and the porous graphite expanding ring 8 are tightly connected.

[0051] During the growth of silicon carbide crystals, the porous graphite expansion ring 8 is used to release excess growth atmosphere. The porous graphite expansion ring 8 and the hard graphite expansion ring 9 are spaced apart, and appropriate porosity and corresponding porosity distribution are selected accordingly, so that the growth atmosphere is released without excessive release, thereby avoiding the problem of insufficient growth atmosphere affecting the growth rate.

[0052] In the embodiment of the present invention, the porous graphite expansion ring 8 and the hard graphite expansion ring 9 are evenly spaced apart.

[0053] In other embodiments, the porous graphite expansion ring and the hard graphite expansion ring are unevenly spaced apart or are spaced apart according to actual silicon carbide crystal growth conditions.

[0054] In an embodiment of the present invention, the porous graphite expansion ring 8 and the hard graphite expansion ring 9 are connected by splicing. In other embodiments, the porous graphite expansion ring and the hard graphite expansion ring are connected by other suitable methods.

[0055] In an embodiment of the present invention, the cross-sectional diameter of the graphite expansion device 10 gradually increases in the direction away from the silicon carbide seed crystal 7, so that the graphite expansion device 10 is trumpet-shaped. The trumpet-shaped channel is the expansion channel, which guides the silicon carbide seed crystal 7 to expand and grow.

[0056] In an embodiment of the present invention, the thickness of the porous graphite expansion ring ranges from 0 mm to 2 mm, and the thickness of the hard graphite expansion ring ranges from 5 mm to 15 mm.

[0057] In an embodiment of the present invention, the silicon carbide crystal expansion growth device also includes a graphite hard felt 4, which fills the gap between the graphite crucible 1 and the graphite expansion device 10. The graphite hard felt 4 is used to maintain the radial temperature gradient between the graphite expansion device 10 and the silicon carbide crystal growth center.

[0058] In an embodiment of the present invention, the graphite hard felt 4 is a thermal insulation material, which is used to maintain the temperature of the graphite expansion device 10, so that the temperature of the graphite expansion device 10 and the growth temperature of the center of the expansion channel form a reasonable radial temperature gradient, thereby realizing radial temperature adjustment and ensuring the growth temperature gradient. The thermal insulation material is adjusted according to the actual needs of the expansion growth of the silicon carbide crystal.

[0059] In an embodiment of the present invention, the temperature of the graphite expansion device 10 is higher than the growth temperature of the center of the expansion channel, and the temperature gradient between the temperature of the graphite expansion device 10 and the growth temperature of the center of the expansion channel is in the range of 0.5°C / mm to 2°C / mm.

[0060] The present invention also provides a method for growing a silicon carbide crystal by expanding its diameter, which uses the above-mentioned silicon carbide crystal growth device by expanding its diameter, comprising:

[0061] Step S10, filling silicon carbide raw material into the graphite crucible of the silicon carbide crystal diameter expansion growth device;

[0062] Step S20, placing the graphite holder with the silicon carbide seed crystal fixed thereon on the graphite expansion device, and closing the graphite crucible cover;

[0063] Step S30, heating the graphite crucible to allow the silicon carbide raw material to sublime, generating a growth atmosphere in the silicon carbide crystal expansion and growth device, and growing silicon carbide crystals from the surface of the silicon carbide seed crystal along the axial direction of the graphite expansion device, wherein the porous graphite expansion ring exhausts the gas in time when the growth atmosphere is excessive in the early stage, and reduces the exhaust volume when the growth atmosphere is insufficient in the later stage of growth, thereby finally obtaining silicon carbide crystals.

[0064] Specifically, step S10 is performed to fill the silicon carbide raw material 6 into the graphite crucible 1 of the silicon carbide crystal diameter expansion growth device.

[0065] In the embodiment of the present invention, the silicon carbide raw material 6 is silicon carbide powder, and the powder has a small particle size, which is convenient for sublimation in the subsequent heating process.

[0066] Step S20 is executed to place the graphite holder 3 with the silicon carbide seed crystal 7 fixed thereon on the graphite expansion device 10 , and close the graphite crucible cover 2 .

[0067] In the embodiment of the present invention, the silicon carbide seed crystal 7 is adhered to the surface of the graphite holder 3 .

[0068] Execute step S30, heat the graphite crucible 1, so that the silicon carbide raw material 6 sublimates, and a growth atmosphere is generated in the silicon carbide crystal expansion growth device. Silicon carbide crystals grow from the surface of the silicon carbide seed crystal 7 along the axial direction of the graphite expansion device 10. The porous graphite expansion ring 8 exhausts the gas in time when the growth atmosphere is excessive in the early stage, and reduces the exhaust volume when the growth atmosphere is insufficient in the later stage of growth, thereby finally obtaining silicon carbide crystals.

[0069] In the embodiment of the present invention, the graphite expansion device 10 is trumpet-shaped, and the trumpet-shaped channel is the expansion channel, which guides the silicon carbide seed crystal 7 to expand and grow.

[0070] During the growth of silicon carbide crystals, the porous graphite expansion ring 8 in the graphite expansion device 10 is used to release the excess growth atmosphere generated during the growth of the silicon carbide crystals, thereby improving the growth quality of the silicon carbide crystals; at the same time, it avoids the accumulation of excessive growth atmosphere at the angle between the edge of the growing silicon carbide crystal and the inner wall of the silicon carbide crystal expansion growth device, resulting in the precipitation of polycrystalline silicon carbide, thereby further improving the quality of silicon carbide crystal growth.

[0071] In an embodiment of the present invention, the porous graphite expansion ring 8 and the hard graphite expansion ring 9 are spaced apart and coaxially stacked in sequence, so that during the growth process of the silicon carbide crystal, excessive growth atmosphere is released through the porous graphite expansion ring 8, but not too much, thereby avoiding the problem of insufficient growth atmosphere affecting the growth rate.

[0072] In an embodiment of the present invention, the porosity of the porous graphite expansion ring 8 decreases successively along the axial direction of the graphite expansion device 10 and away from the silicon carbide seed crystal 7, ensuring that the excess growth atmosphere is discharged in time in the early growth stage of the silicon carbide crystal, and reducing the discharge amount when the growth atmosphere is insufficient in the later growth stage, thereby improving the growth rate of the silicon carbide crystal.

[0073] In the embodiment of the present invention, the porosity of the porous graphite expansion ring 8 is in the range of 20%-60%.

[0074] In an embodiment of the present invention, the silicon carbide crystal expansion growth device also includes a graphite hard felt 4, which fills the gap between the crucible and the graphite expansion device 10. The graphite hard felt 4 is used to maintain the radial temperature gradient between the graphite expansion device 10 and the silicon carbide crystal growth center.

[0075] In an embodiment of the present invention, the graphite hard felt 4 is a thermal insulation material, which is used to maintain the temperature of the graphite expansion device 10, so that the temperature of the graphite expansion device 10 and the growth temperature of the center of the expansion channel form a reasonable radial temperature gradient, thereby realizing radial temperature adjustment and ensuring the growth temperature gradient. The thermal insulation material is adjusted according to the actual needs of the expansion growth of the silicon carbide crystal.

[0076] As shown in FIG2 , by filling the gap between the crucible and the graphite expansion device 10 with graphite hard felt 4 as a heat-insulating material, the thermal field temperature in the graphite crucible 1 has a certain axial gradient, and a reasonable temperature gradient is obtained in the graphite crucible 1, which is beneficial to improving the growth quality of silicon carbide crystals.

[0077] In an embodiment of the present invention, the temperature of the graphite expansion device 10 is higher than the growth temperature of the center of the expansion channel, and the temperature gradient between the temperature of the graphite expansion device 10 and the growth temperature of the center of the expansion channel is in the range of 0.5°C / mm to 2°C / mm.

[0078] The temperature range of the silicon carbide crystal growth is 2100° C. to 2300° C., the pressure range of the silicon carbide crystal growth is 2 mbar to 10 mbar, and the time range of the silicon carbide crystal growth is 100 h to 200 h.

[0079] In an embodiment of the present invention, the silicon carbide crystal is grown in an argon atmosphere, the growth temperature of the silicon carbide crystal is 2300° C., the growth pressure of the silicon carbide crystal is 5.0 mbar, and the growth time of the silicon carbide crystal is 100 h.

[0080] In the embodiment of the present invention, after the reaction is completed, the graphite crucible 1 is cooled at a rate of 5° C. / min, and silicon carbide crystals are obtained after cooling.

[0081] Finally, it should be noted that any modification or equivalent replacement of part or all of the technical features based on the device structure of the present invention and the technical solutions of the embodiments, which does not deviate from the essence of the corresponding technical solutions of the present invention, falls within the patent scope of the device structure of the present invention and the implementation scheme.

Claims

1. A silicon carbide crystal diameter expansion growth device, characterized in that, Comprising: A graphite crucible, a hard graphite ring, a graphite diameter-expanding device, and a graphite support; The graphite crucible is used to hold silicon carbide raw materials, and the graphite crucible has a graphite crucible cover plate; The hard graphite ring is fixed to the inner side wall of the graphite crucible; The graphite diameter-expanding device is arranged above the hard graphite ring; One side of the graphite support is fixed with a silicon carbide seed crystal, the graphite support is arranged above the graphite diameter-expanding device, and the silicon carbide seed crystal faces the inside of the graphite crucible; Among them, the graphite diameter-expanding device includes a porous graphite diameter-expanding ring and a hard graphite diameter-expanding ring, the porous graphite diameter-expanding ring and the hard graphite diameter-expanding ring are stacked at intervals and coaxially in sequence, and the cross-sectional diameter of the graphite diameter-expanding device gradually increases in the direction away from the silicon carbide seed crystal.

2. The silicon carbide crystal diameter expanding growth device according to claim 1, characterized in that, The porous graphite diameter-expanding ring has a bent slope structure.

3. The silicon carbide crystal diameter expanding growth device according to claim 1, characterized in that, The porosity of the porous graphite diameter-expanding ring decreases sequentially along the axis of the graphite diameter-expanding device and in the direction away from the silicon carbide seed crystal, or the porosity of the porous graphite diameter-expanding ring is the same.

4. The silicon carbide crystal diameter expansion growth device according to claim 1, wherein The thickness of the porous graphite diameter-expanding ring is the same, or the thickness of the porous graphite diameter-expanding ring decreases sequentially along the axis of the graphite diameter-expanding device and in the direction away from the silicon carbide seed crystal.

5. The silicon carbide crystal diameter expansion growth device according to claim 1, characterized in that, The porosity of the porous graphite diameter-expanding ring ranges from 20% to 60%, and the porous graphite diameter-expanding ring is coated with a tantalum carbide coating.

6. The silicon carbide crystal diameter expansion growth device according to claim 1, wherein, The porous graphite diameter-expanding ring and the hard graphite diameter-expanding ring are tightly connected, the thickness range of the porous graphite diameter-expanding ring is 0 mm to 2 mm, and the thickness range of the hard graphite diameter-expanding ring is 5 mm to 15 mm.

7. The silicon carbide crystal diameter expansion growth device according to claim 1, wherein Further comprising: Graphite hard felt, and the graphite hard felt is filled in the gap between the crucible and the graphite diameter-expanding device.

8. A method for growing a silicon carbide crystal with an enlarged diameter, which uses a silicon carbide crystal diameter-enlarging growth device as described in any one of claims 1 to 7, characterized in that, Comprising: Filling silicon carbide raw materials into the graphite crucible of the silicon carbide crystal diameter-expanding growth device; Placing the graphite support fixed with a silicon carbide seed crystal on the graphite diameter-expanding device and closing the graphite crucible cover plate; Heating the graphite crucible to sublime the silicon carbide raw materials, and generating a growth atmosphere in the silicon carbide crystal diameter-expanding growth device. The silicon carbide crystal grows along the axis of the graphite diameter-expanding device from the surface of the silicon carbide seed crystal. Among them, the porous graphite diameter-expanding ring exhausts gas in time when the growth atmosphere is excessive in the early stage, and reduces the exhaust gas volume when the growth atmosphere is insufficient in the later stage, and finally obtains a silicon carbide crystal.

9. The method for growing a silicon carbide crystal with an enlarged diameter according to claim 8, wherein, The radial temperature gradient of the silicon carbide crystal growth at the center of the graphite crucible ranges from 0.5 °C / mm to 2 °C / mm.

10. A method for growing a silicon carbide crystal with an enlarged diameter as described in claim 8, characterized in that, The temperature range for the silicon carbide crystal growth is 2100 °C to 2300 °C, the pressure range for the silicon carbide crystal growth is 2 mbar to 10 mbar, and the time range for the silicon carbide crystal growth is 100 h to 200 h.

Images