A rapid silicon carbide single crystal growth apparatus with reduced inclusions

Abstract

The application provides a rapid silicon carbide single crystal growth device for reducing carbonization of inclusions, comprising: a crucible, a crucible cover is arranged at the top of the crucible, and a silicon carbide seed crystal is fixed at the bottom of the crucible cover; a barrier layer is arranged in the crucible, the barrier layer and the inner wall of the crucible form a plurality of containing spaces for containing silicon carbide powder; the containing spaces are arranged at intervals; the barrier layer is used for filtering solid graphite particles in gaseous components generated after pyrolysis of the silicon carbide powder; and the surface area of the barrier layer is greater than the bottom area of the crucible, so that the problem of low production efficiency caused by low silicon carbide crystal generation rate of the current silicon carbide single crystal growth device is solved.

Description

Technical Field

[0001] This application relates to the field of crystal growth technology, and in particular to a rapid silicon carbide single crystal growth apparatus for reducing inclusions. Background Technology

[0002] In the PVT (Polymer Transformation) method for single crystal growth, feedstock decomposition is a critical step. The decomposition of feedstock in PVT single crystal growth exhibits non-stoichiometric characteristics, with the gaseous components rich in silicon and containing residual solid graphite. Since this residual solid graphite can potentially enter the crystal under the influence of the component composition, it becomes a significant source of inclusions, severely impacting the quality and performance of the single crystal. Therefore, in actual production, it is urgent to take effective measures to reduce the entry of residual solid graphite from the feedstock into the growth chamber and crystal to improve the quality and stability of single crystal growth.

[0003] To address these issues, the common practice is to coat the raw material surface with porous graphite or high-temperature and corrosion-resistant metal / non-metal carbides. Porous graphite, due to its structural characteristics, can effectively block solid graphite; high-temperature and corrosion-resistant metal / non-metal carbides, utilizing their physicochemical properties, remain stable at high temperatures, filtering out solid graphite and preventing it from entering the crystal growth region, thus reducing the interference of solid graphite on crystal growth to some extent.

[0004] However, covering porous graphite or high-temperature and corrosion-resistant metal / non-metal carbides can reduce the transport efficiency of raw materials, thereby decreasing the crystal growth rate and affecting production efficiency. More seriously, raw materials may accumulate under the barrier layer, which not only further reduces the growth rate but may also affect the composition ratio, leading to defects inside the crystal and reducing the quality and performance of the single crystal. Utility Model Content

[0005] This application provides a rapid silicon carbide single crystal growth apparatus that reduces inclusions, in order to solve the technical problem of low silicon carbide crystal growth rate and low production efficiency caused by existing silicon carbide single crystal growth apparatuses.

[0006] This application provides a rapid silicon carbide single crystal growth apparatus for reducing inclusions, comprising:

[0007] A crucible, with a lid on top; the bottom of the lid is used to fix a silicon carbide seed crystal.

[0008] A barrier layer is disposed inside the crucible, and the barrier layer and the inner wall of the crucible form a plurality of receiving spaces for containing silicon carbide powder; the plurality of receiving spaces are spaced apart; the barrier layer is used to filter solid graphite particles in the gaseous components generated after the pyrolysis of the silicon carbide powder; the surface area of ​​the barrier layer is larger than the bottom area of ​​the crucible.

[0009] In some embodiments, the barrier layer is provided with a plurality of pores, which are used to filter solid graphite particles in the gaseous components generated after the pyrolysis of the silicon carbide powder.

[0010] In some embodiments, the barrier layer includes:

[0011] A first barrier layer is formed between the first barrier layer and the side wall and bottom surface of the crucible to create a plurality of first receiving spaces for containing silicon carbide powder; gaps exist between the first receiving spaces.

[0012] In some embodiments, the first accommodating space gradually increases in cross-sectional area from the bottom toward the crucible lid.

[0013] In some embodiments, the barrier layer includes:

[0014] A second barrier layer is formed between the second barrier layer and the bottom surface of the crucible, forming a plurality of second receiving spaces for containing silicon carbide powder; the second receiving spaces are spaced apart.

[0015] In some embodiments, the cross-sectional area of ​​the second accommodating space gradually increases from the bottom toward the crucible lid.

[0016] In some embodiments, the second barrier layer is provided with a plurality of protrusions, and there are gaps between adjacent protrusions; a third receiving space for receiving silicon carbide powder is formed between the second barrier layer, the protrusions, and the bottom surface of the crucible.

[0017] In some embodiments, the barrier layer includes:

[0018] The third barrier layer forms several fourth containment spaces between the side walls of the crucible for containing silicon carbide powder; the cross-sectional area of ​​the third barrier layer gradually decreases in the same vertical direction from the bottom of the crucible towards the crucible lid.

[0019] In some embodiments, the barrier layer is composed of a plurality of filter blocks;

[0020] The filter block is provided with a first connecting hole and a second connecting hole; the first connecting hole is provided along the width direction of the filter block; the second connecting hole is provided along the length direction of the filter block.

[0021] The filter blocks are connected by bolts passing through the first or second connecting hole.

[0022] In some embodiments, the diameter of the hole is any value in the range of 10 to 12 mm; the spacing between adjacent holes is any value in the range of 20 to 30 mm.

[0023] This application provides a rapid silicon carbide single crystal growth apparatus with reduced inclusions, comprising: a crucible with a crucible lid at the top; the bottom of the crucible lid is used to fix a silicon carbide seed crystal; a barrier layer disposed inside the crucible, the barrier layer and the inner wall of the crucible forming a plurality of receiving spaces for containing silicon carbide powder; the plurality of receiving spaces are spaced apart; the barrier layer is used to filter solid graphite particles in the gaseous components generated after the pyrolysis of the silicon carbide powder; the surface area of ​​the barrier layer is larger than the bottom area of ​​the crucible, so as to improve the generation rate of silicon carbide crystals through the silicon carbide single crystal growth apparatus provided in this application, thereby improving the production efficiency of silicon carbide crystals. Attached Figure Description

[0024] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a first structural schematic diagram of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application;

[0026] Figure 2 This is a schematic diagram of the second structure of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0027] Figure 3 This is a schematic diagram of the third structure of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application;

[0028] Figure 4 This is a schematic diagram of the fourth structure of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0029] Figure 5 This is a fifth structural schematic diagram of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application;

[0030] Figure 6 This is a sixth structural schematic diagram of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application;

[0031] Figure 7 This is a schematic diagram of the structure of the filter block in this application;

[0032] Figure 8 This is a schematic diagram of a current rapid silicon carbide single crystal growth device that reduces inclusions.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1-Crucible; 11-Crucible lid; 12-Silicon carbide seed crystal; 13-Silicon carbide powder; 2-Blocking layer; 21-Void; 22-First blocking layer; 23-Second blocking layer; 231-Protrusion; 24-Third blocking layer; 25-Filter block; 251-First connecting hole; 252-Second connecting hole. Detailed Implementation

[0035] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0036] In some technologies, the silicon carbide crystal growth rate under silicon carbide single crystal growth equipment is low, resulting in low production efficiency. To solve this technical problem, this application provides a rapid silicon carbide single crystal growth apparatus that reduces inclusions. The structure of each part of the rapid silicon carbide single crystal growth apparatus that reduces inclusions is described below:

[0037] For example, currently, a common method is to coat the surface of the raw material with porous graphite or high-temperature and corrosion-resistant metal / non-metal carbides. Porous graphite, due to its structural characteristics, can provide some barrier effect against solid graphite; high-temperature and corrosion-resistant metal / non-metal carbides, utilizing their physicochemical properties, remain stable at high temperatures, filtering the solid graphite and preventing it from entering the crystal growth region, thus reducing the interference of solid graphite on crystal growth to a certain extent. A schematic diagram of a current rapid silicon carbide single crystal growth device for reducing inclusions is shown below. Figure 8 As shown, the interference of solid graphite on crystal growth is reduced by covering the crucible with porous graphite or high-temperature and corrosion-resistant metal / non-metal carbides.

[0038] However, covering porous graphite or high-temperature and corrosion-resistant metal / non-metal carbides can reduce the transport efficiency of raw materials, thereby decreasing the crystal growth rate and affecting production efficiency. More seriously, raw materials may accumulate under the barrier layer, which not only further reduces the growth rate but may also affect the composition ratio, leading to defects inside the crystal and reducing the quality and performance of the single crystal.

[0039] This application provides a rapid silicon carbide single crystal growth apparatus for reducing inclusions, comprising:

[0040] Crucible 1, with a crucible lid 11 on top; the bottom of the crucible lid 11 is used to fix the silicon carbide seed crystal 12.

[0041] A barrier layer 2 is disposed within the crucible 1, forming several accommodating spaces with the inner wall of the crucible 1 for containing silicon carbide powder 13. These accommodating spaces are spaced apart. The barrier layer 2 is any one or more of a porous graphite layer, a porous graphite layer coated with an inert metal, a porous inert metal layer, or a porous non-metallic carbide layer. To facilitate atmosphere transport, several pores 21 can also be provided in the barrier layer 2. These pores 21 are configured to filter solid graphite particles from the gaseous components generated after the pyrolysis of the silicon carbide powder 13. The diameter of each pore 21 is any value within the range of 10 to 12 mm, and the spacing between adjacent pores 21 is any value within the range of 20 to 30 mm. In this application, the surface area of ​​the barrier layer is larger than the bottom area of ​​the crucible. That is, compared with the current rapid silicon carbide single crystal growth device that reduces inclusions, the barrier layer 2 structure provided in this application has a larger area, which increases the transmission area between the gaseous components generated by the pyrolysis of silicon carbide powder 13 and the barrier layer 2. While ensuring the filtering and blocking effect of solid graphite, the growth rate of the silicon carbide seed crystal 12 is increased.

[0042] In this process, heating the crucible 1 causes the silicon carbide powder 13 to decompose and generate gaseous components; the barrier layer 2 filters the solid graphite particles in the gaseous components, allowing the silicon carbide seed crystal 12 to grow. The gaseous components include silicon vapor, carbon particles, carbon monoxide, carbon dioxide, silicon dioxide, etc.

[0043] This application provides a rapid silicon carbide single crystal growth apparatus that reduces inclusions. By optimizing the design of the barrier layer 2 structure, the transmission area between the gaseous components generated by the decomposition of silicon carbide powder 13 and the barrier layer 2 is increased. Under the premise of ensuring the filtering and blocking effect of solid graphite, the growth rate of the silicon carbide seed crystal 12 is improved.

[0044] like Figure 1 The diagram shown is a first structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0045] In this embodiment, the barrier layer 2 includes:

[0046] A first barrier layer 22 is formed between the first barrier layer 22 and the side wall and bottom surface of the crucible 1 to form a plurality of first receiving spaces for accommodating silicon carbide powder 13; there are gaps between the first receiving spaces.

[0047] Specifically, multiple first accommodating spaces can be provided within the crucible 1. In this embodiment, the first barrier layer 22 has four surfaces. The first barrier layer 22, together with the sidewall and bottom surface of the crucible 1, forms a first accommodating space for accommodating silicon carbide powder 13. The first accommodating spaces are spaced apart, allowing the gaseous components generated from the decomposition of the silicon carbide powder 13 to be filtered through the first barrier layer 22, thus enabling the growth of the silicon carbide seed crystal 12. Because the contact area between the silicon carbide powder 13 and the barrier layer 2 is increased, and there are gaps between the first accommodating spaces, the transport area between the gaseous components generated from the decomposition of the silicon carbide powder 13 and the barrier layer 2 is improved, thereby increasing the growth rate of the silicon carbide seed crystal 12.

[0048] like Figure 2 The diagram shown is a second structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0049] In this embodiment, the cross-sectional area of ​​the first accommodating space gradually increases from the bottom toward the crucible lid 11.

[0050] Specifically, by setting the first barrier layer 22 located away from the side wall of the crucible 1 as an inclined surface, the contact area between the silicon carbide powder 13 and the barrier layer 2 is further increased. The inclined surface can prevent the silicon carbide powder 13 from accumulating at the barrier layer 2, thereby further improving the growth rate of the silicon carbide seed crystal 12 and avoiding the generation of defects after the silicon carbide seed crystal 12 grows.

[0051] like Figure 3 The diagram shown is a third structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0052] In this embodiment, the barrier layer 2 includes:

[0053] The second barrier layer 23 forms a plurality of second receiving spaces for accommodating silicon carbide powder 13 between the second barrier layer 23 and the bottom surface of the crucible 1; the second receiving spaces are spaced apart.

[0054] Specifically, multiple second containment spaces can be provided within the crucible 1. In this embodiment, the second barrier layer 23 has five surfaces. The second barrier layer 23 and the bottom surface of the crucible 1 together form a second containment space for containing silicon carbide powder 13. The second containment spaces are spaced apart, i.e., have gaps, allowing the gaseous components generated by the decomposition of silicon carbide powder 13 to be filtered through the second barrier layer 23, thus enabling the growth of the silicon carbide seed crystal 12. Because the contact area between the silicon carbide powder 13 and the barrier layer 2 is increased, and there are gaps between the second containment spaces, the transmission area of ​​the gaseous components generated by the decomposition of silicon carbide powder 13 to the barrier layer 2 is further improved compared to the first containment space, thereby increasing the growth rate of the silicon carbide seed crystal 12.

[0055] like Figure 4 The diagram shown is a fourth structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0056] In this embodiment, the cross-sectional area of ​​the second accommodating space gradually increases from the bottom toward the crucible lid 11.

[0057] Specifically, by setting the sidewall of the second barrier layer 23 as an inclined surface, the contact area between the silicon carbide powder 13 and the barrier layer 2 is further increased. The inclined surface can prevent the silicon carbide powder 13 from accumulating at the barrier layer 2, thereby further improving the growth rate of the silicon carbide seed crystal 12 and avoiding the generation of defects after the silicon carbide seed crystal 12 grows.

[0058] like Figure 5 The diagram shown is a fifth structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0059] In this embodiment, the second barrier layer 23 is provided with a plurality of protrusions 231, and there is a gap between adjacent protrusions 231; a third receiving space for receiving silicon carbide powder 13 is formed between the second barrier layer 23, the protrusions 231 and the bottom surface of the crucible 1.

[0060] Specifically, multiple third containment spaces can be provided within the crucible 1. In this embodiment, the second barrier layer 23 has several protrusions 231, which, together with the bottom surface of the crucible 1, form third containment spaces for containing silicon carbide powder 13. These third containment spaces are spaced apart, allowing gaseous components generated from the decomposition of silicon carbide powder 13 to be filtered through the second barrier layer 23, thus enabling the growth of the silicon carbide seed crystal 12. Because the contact area between the silicon carbide powder 13 and the barrier layer 2 is increased, and the gaps between the second containment spaces further enhance the transport area between the gaseous components generated from the decomposition of silicon carbide powder 13 and the barrier layer 2, thereby increasing the growth rate of the silicon carbide seed crystal 12.

[0061] like Figure 6 The diagram shown is a sixth structural schematic of the rapid silicon carbide single crystal growth apparatus for reducing inclusions in this application.

[0062] In this embodiment, the barrier layer 2 includes:

[0063] The third barrier layer 24 forms several fourth accommodating spaces for accommodating silicon carbide powder 13 between the side walls of the crucible 1; the cross-sectional area of ​​the third barrier layer 24 located in the same vertical direction gradually decreases from the bottom of the crucible 1 toward the crucible cover 11.

[0064] Specifically, multiple fourth accommodating spaces can be provided within the crucible 1. In this embodiment, the third barrier layer 24 is disposed on the side wall of the crucible 1 in a suspended manner. The third barrier layer 24 and the side wall of the crucible 1 together form a fourth accommodating space for accommodating silicon carbide powder 13. The fourth accommodating spaces are spaced apart, i.e., have gaps. The cross-sectional area of ​​the third barrier layer 24 located in the same vertical direction gradually decreases, thereby preventing the gaseous components generated by the decomposition of silicon carbide powder 13 from being blocked by the upper third barrier layer 24. This allows the gaseous components generated by the decomposition of silicon carbide powder 13 to be filtered through the third barrier layer 24, thus enabling the growth of the silicon carbide seed crystal 12. Because the contact area between the silicon carbide powder 13 and the barrier layer 2 is increased, and there are gaps between the second accommodating spaces, the transport area between the gaseous components generated by the decomposition of silicon carbide powder 13 and the barrier layer 2 is improved, thereby increasing the growth rate of the silicon carbide seed crystal 12.

[0065] like Figure 7 The diagram shown is a schematic representation of the structure of the filter block in this application.

[0066] In this embodiment, the barrier layer 2 is composed of a plurality of filter blocks 25; each filter block 25 is provided with a first connecting hole 251 and a second connecting hole 252; the first connecting hole 251 is provided along the width direction of the filter block 25; the second connecting hole 252 is provided along the length direction of the filter block 25; wherein, the plurality of filter blocks 25 are connected to each other by bolts passing through the first connecting hole 251 or the second connecting hole 252.

[0067] In this embodiment, the filter block 25 can be configured as a cube. Through the arrangement of the first connecting hole 251 and the second connecting hole 252, the filter block 25 can be connected in the horizontal or vertical direction to form the structure of the barrier layer 2. The manufacturer can combine the filter blocks 25 according to the customer's requirements to form the structure of the barrier layer 2, thereby improving the manufacturer's production efficiency for the rapid silicon carbide single crystal growth device with reduced inclusions. Furthermore, the first connecting hole 251 and the second connecting hole 252 are located at the center of the filter block 25, which does not occupy too much volume of the filter block 25 and will not affect the filtration effect of the barrier layer 2.

[0068] This application provides a rapid silicon carbide single crystal growth apparatus for reducing inclusions, which involves fixing a silicon carbide seed crystal 12 onto a crucible lid 11 and growing the crystal under a vacuum of 10... -2 ~10 -3 Carbonization is performed at 500℃ for 2 hours under the condition of Pa; silicon carbide powder 13 is filled into the containment space, and finally the entire crucible 1 is placed in the center of the growth chamber of the single crystal growth furnace. The growth chamber is then evacuated to a vacuum degree of 10. -5 Pa~10 -2 Pa; The single crystal growth furnace is heated to a temperature of 2273K~2773K inside crucible 1. Inert gas is introduced to adjust the growth pressure to 50-80mbar to carry out the growth of silicon carbide crystals. After the silicon carbide crystal growth is completed, the pressure inside the growth chamber is adjusted to 1000mbar and cooled to room temperature to obtain high-quality silicon carbide single crystals.

[0069] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A rapid silicon carbide single crystal growth apparatus for reducing inclusions, characterized in that, include: A crucible (1) is provided with a crucible lid (11) on the top; the bottom of the crucible lid (11) is used to fix the silicon carbide seed crystal (12). A barrier layer (2) is disposed inside the crucible (1). The barrier layer (2) and the inner wall of the crucible (1) form a plurality of accommodating spaces for accommodating silicon carbide powder (13). The plurality of accommodating spaces are spaced apart. The barrier layer (2) is used to filter solid graphite particles in the gaseous components generated after the pyrolysis of the silicon carbide powder (13). The surface area of ​​the barrier layer (2) is larger than the bottom area of ​​the crucible (1).

2. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 1, characterized in that, The barrier layer (2) is provided with a number of holes (21), which are used to filter solid graphite particles in the gaseous components generated after the silicon carbide powder (13) is pyrolyzed.

3. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 1, characterized in that, The barrier layer (2) includes: A first barrier layer (22) is formed between the first barrier layer (22) and the side wall and bottom surface of the crucible (1) to form a plurality of first receiving spaces for containing silicon carbide powder (13); there are gaps between the first receiving spaces.

4. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 3, characterized in that, The cross-sectional area of ​​the first accommodating space gradually increases from the bottom toward the crucible lid (11).

5. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 1, characterized in that, The barrier layer (2) includes: The second barrier layer (23) forms a plurality of second containment spaces for containing silicon carbide powder (13) between the second barrier layer (23) and the bottom surface of the crucible (1); the second containment spaces have gaps between them.

6. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 5, characterized in that, The cross-sectional area of ​​the second accommodating space gradually increases from the bottom toward the crucible lid (11).

7. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 5, characterized in that, The second barrier layer (23) is provided with a plurality of protrusions (231), and there is a gap between adjacent protrusions (231); a third receiving space for containing silicon carbide powder (13) is formed between the second barrier layer (23), the protrusions (231) and the bottom surface of the crucible (1).

8. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 1, characterized in that, The barrier layer (2) includes: The third barrier layer (24) forms several fourth containment spaces for containing silicon carbide powder (13) between the side walls of the crucible (1); the cross-sectional area of ​​the third barrier layer (24) located in the same vertical direction gradually decreases from the bottom of the crucible (1) toward the crucible cover (11).

9. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 1, characterized in that, The barrier layer (2) is composed of a plurality of filter blocks (25); The filter block (25) is provided with a first connecting hole (251) and a second connecting hole (252); the first connecting hole (251) is provided along the width direction of the filter block (25); the second connecting hole (252) is provided along the length direction of the filter block (25). The filter blocks (25) are connected to each other by bolts passing through the first connecting hole (251) or the second connecting hole (252).

10. The rapid silicon carbide single crystal growth apparatus for reducing inclusions according to claim 2, characterized in that, The diameter of the hole (21) is any value in the range of 10 to 12 mm; the spacing between adjacent holes (21) is any value in the range of 20 to 30 mm.

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