Crucible for silicon carbide crystal growth and crystal growth device

Abstract

The utility model provides a crucible for silicon carbide crystal growth and a crystal growth device, and relates to the technical field of semiconductors. The crucible for silicon carbide crystal growth comprises a crucible body and a heat conduction piece. The crucible body is provided with a containing cavity. The heat conduction piece comprises a heat conduction plate and a heat conduction column, the heat conduction plate is provided with a runner for atmosphere to pass through, and the heat conduction column is convexly arranged on the heat conduction plate. The heat conduction piece is installed in the containing cavity, the outer periphery of the heat conduction plate abuts against the side wall of the containing cavity, the heat conduction column extends downwards, and a powder area is formed between the heat conduction plate and the bottom wall of the containing cavity. The powder area is used for containing silicon carbide powder. By arranging the heat conduction piece, the problem that silicon carbide powder in the powder area is heated unevenly can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a crucible and a crystal growth device for silicon carbide crystal growth. Background Art

[0002] In the physical vapor transport (PVT) process, the crucible used to grow crystals is usually heated by a graphite heater. However, because the heater is placed on the outer edge of the crucible, the powder temperature in the central area inside the crucible is lower. The problem caused by this phenomenon is that the vapor generated in the external high temperature environment recrystallizes on the surface of the central area, forming a reverse transport process. The reverse transport not only disrupts the airflow stability in the growth area, but also hinders the escape of internal gas from the central area, which has a negative impact on the quality of the crystal. In addition, the powder in the central area fails to reach the temperature required for its volatilization, resulting in a decrease in volatilization efficiency, which in turn causes inefficient powder utilization.

[0003] Currently, to address the problem of uneven heating inside the crucible, the conventional practice is to add several heat-conducting columns to the bottom of the crucible to conduct the heat from the bottom upward. However, in actual operation, the bottom of the crucible is actually supported by a tray, and the heater is located at the outer edge of the crucible's side wall. The resulting heat transfer is radiative heating from the outside to the inside. This results in the temperature of the bottom wall of the crucible being lower than that of the side wall. Therefore, simply adding heat-conducting columns to the bottom of the crucible is not very effective in improving the temperature uniformity of the powder throughout the crucible.

[0004] In view of this, optimizing the uniform heating of the powder inside the crucible and ensuring that it maintains appropriate temperature conditions throughout the entire process has become an urgent problem to be solved in this field. Utility Model Content

[0005] The purpose of the present application is to provide a crucible and a crystal growth device for silicon carbide crystal growth, so as to improve the technical problem in the prior art that the powder inside the crucible cannot be heated uniformly.

[0006] In a first aspect, the utility model provides a crucible for growing silicon carbide crystals, comprising a crucible body and a heat conducting member;

[0007] The crucible body has a receiving cavity;

[0008] The heat conducting member includes a heat conducting plate and a heat conducting column. The heat conducting plate is provided with a flow channel for the passage of the atmosphere. The heat conducting column is protruded from the heat conducting plate.

[0009] The heat conducting member is installed in the accommodating cavity, and the outer periphery of the heat conducting plate abuts against the side wall of the accommodating cavity. The heat conducting column extends downward, and a powder area is formed between the heat conducting plate and the bottom wall of the accommodating cavity. The powder area is used to place silicon carbide powder.

[0010] In an optional embodiment, the bottom end of the heat-conducting column abuts against the bottom wall of the accommodating cavity.

[0011] In an optional embodiment, a flange is provided on the periphery of the heat conducting plate, and the flange abuts against the side wall of the accommodating cavity.

[0012] In an optional embodiment, the flange is provided on the outer peripheral edge of the top wall of the heat conducting plate, and the flange extends upward, and the outer side wall of the flange abuts against the inner side wall of the accommodating cavity.

[0013] In an optional embodiment, the flange is provided on the outer peripheral edge of the bottom wall of the heat conducting plate, and the flange extends downward, and the outer side wall of the flange abuts against the inner side wall of the accommodating cavity.

[0014] In an optional embodiment, the thickness of the flange gradually decreases in a direction away from the heat conducting plate.

[0015] In an optional embodiment, a heat-conducting baffle is provided in the radial direction of the heat-conducting column, and the heat-conducting baffle extends from one end of the heat-conducting column to abut against the side wall of the accommodating cavity.

[0016] In an optional embodiment, a heat-conducting boss is protruding from the inner side wall of the accommodating cavity, and the heat-conducting boss abuts against the heat-conducting column.

[0017] In an optional embodiment, the heat conducting member is made of graphite, and pores are formed on the heat conducting member, and the pores form flow channels.

[0018] In a second aspect, the present invention provides a crystal growth device, comprising a body and a crucible for growing silicon carbide crystals according to any one of the aforementioned embodiments;

[0019] A carrying platform is provided in the machine body, and a graphite heater is provided on the outer periphery of the carrying platform;

[0020] The crucible body is carried on the carrying platform.

[0021] The beneficial effects of the crucible for silicon carbide crystal growth and the crystal growth device provided by the embodiments of the present invention include:

[0022] The present application sets the heat-conducting member as a heat-conducting plate and a heat-conducting column protruding from the heat-conducting plate. When the heat-conducting member is installed in the accommodating cavity, the heat-conducting plate abuts against the side wall of the accommodating cavity, so that the heat of the side wall of the crucible body can be transferred to the heat-conducting column located in the powder area through the heat-conducting plate. The heat-conducting column can be used to heat the powder near the center area of ​​the powder area, thereby improving the problem of uneven temperature of the powder in the powder area. The flow channel for the atmosphere to pass through the heat-conducting plate can also evenly flow the atmosphere, allowing the atmosphere to be transmitted upward relatively evenly. Secondly, the setting of the heat-conducting column can prevent the central area of ​​the powder area from being filled with powder, thereby avoiding the recrystallization of powder in the central area of ​​the powder area due to reverse transmission. Thereby improving the utilization rate of the powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 A schematic structural diagram of a crystal growth device provided in an embodiment of the present invention;

[0025] Figure 2 A schematic structural diagram of a crucible for growing silicon carbide crystals provided in an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of the structure of a crucible for growing silicon carbide crystals provided in an embodiment of the present invention, provided with a flange;

[0027] Figure 4 A schematic diagram of another structure of a crucible for silicon carbide crystal growth provided by an embodiment of the present invention, wherein the crucible is provided with a flange;

[0028] Figure 5 A schematic structural diagram of a silicon carbide crystal growth crucible provided in an embodiment of the present invention and provided with a heat-conducting baffle;

[0029] Figure 6 This is a schematic structural diagram of a silicon carbide crystal growth crucible provided in an embodiment of the present invention, in which a heat-conducting boss is provided.

[0030] Icons: 100-crucible for silicon carbide crystal growth; 110-crucible body; 111-accommodating chamber; 113-powder area; 130-heat conducting part; 131-heat conducting plate; 133-heat conducting column; 135-flow channel; 137-flange; 139-heat conducting partition; 141-heat conducting boss; 300-crystal growth device; 310-machine body; 311-carrying platform; 313-graphite heater. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0032] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention.

[0033] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0035] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0036] See also Figure 1 , this embodiment provides a crystal growth apparatus 300 , which is used to produce crystal ingots through a physical vapor transport (PVT) process.

[0037] In this embodiment, the crystal growth apparatus 300 includes a body 310 and a silicon carbide crystal growth crucible 100. A support platform 311 is provided within the body 310, and a graphite heater 313 is disposed on the outer periphery of the support platform 311. The silicon carbide crystal growth crucible 100 is supported on the support platform 311. During the crystal growth process, the graphite heater 313 converts electrical energy into thermal energy, heating the silicon carbide crystal growth crucible 100 and causing the silicon carbide powder in the crucible 100 to sublime. The sublimated silicon carbide atmosphere flows upward and redeposits on the seed crystal to form a single crystal silicon ingot.

[0038] Please refer to Figures 2 to 6 In this embodiment, the crucible 100 for silicon carbide crystal growth includes a crucible body 110 and a heat-conducting member 130. The crucible body 110 has a receiving cavity 111. The heat-conducting member 130 includes a heat-conducting plate 131 and a heat-conducting column 133. The heat-conducting plate 131 is provided with a flow channel 135 for the passage of atmosphere. The heat-conducting column 133 is protruded from the heat-conducting plate 131. The heat-conducting member 130 is installed in the receiving cavity 111, and the outer peripheral edge of the heat-conducting plate 131 abuts against the side wall of the receiving cavity 111. The heat-conducting column 133 extends downward, and a powder area 113 is formed between the heat-conducting plate 131 and the bottom wall of the receiving cavity 111. The powder area 113 is used to place silicon carbide powder.

[0039] In this embodiment, the heat conducting member 130 is configured as a heat conducting plate 131 and a heat conducting column 133 protruding from the heat conducting plate 131. When the heat conducting member 130 is installed in the accommodating chamber 111, the heat conducting plate 131 abuts against the side wall of the accommodating chamber 111. In this way, the heat from the side wall of the crucible body 110 can be transferred to the heat conducting column 133 located in the powder area 113 through the heat conducting plate 131. The heat conducting column 133 can be used to heat the powder near the center area of ​​the powder area 113, thereby improving the problem of uneven temperature of the powder in the powder area 113. The flow channel 135 for the atmosphere to pass through the heat conducting plate 131 can also evenly flow the atmosphere and allow the atmosphere to be transmitted upward relatively evenly. Secondly, the provision of the heat conducting column 133 can prevent the central area of ​​the powder area 113 from being filled with powder, thereby avoiding the recrystallization of powder in the central area of ​​the powder area 113 due to reverse transmission, thereby improving the utilization rate of the powder.

[0040] In this embodiment, the crucible body 110 is made of graphite. The crucible body 110 includes a lower body and an upper cover, and the upper cover is detachably mounted on the lower body, and the two enclose a receiving chamber 111. Generally, the inner side of the upper cover will be attached to the seed crystal during crystal growth. The receiving chamber 111 is generally divided into three areas from bottom to top, namely the powder area 113, the sublimation area and the growth area. Silicon carbide powder is filled in the powder area 113, which is the area below the heat conducting plate 131 in this embodiment. The atmosphere after the silicon carbide powder is sublimated flows upward into the sublimation area through the flow channel 135 above the heat conducting plate 131, and then deposited on the outer periphery of the seed crystal in the growth area to form a crystal ingot.

[0041] In this embodiment, the heat conductor 130 is made of graphite. The heat conducting plate 131 is a circular graphite plate with pores formed thereon. The pores form a flow channel 135, and the sublimation of the silicon carbide atmosphere can pass through the heat conducting plate 131 through the pores. The heat conducting column 133 is cylindrical and made of graphite. The heat conducting column 133 and the heat conducting plate 131 are integrally formed. Before crystal growth, the upper cover of the crucible body 110 is opened, the silicon carbide powder is filled in the powder area 113, and then the heat conducting member 130 is installed in the accommodating cavity 111 and the heat conducting column 133 is inserted into the powder. The heat conducting plate 131 and the heat conducting column 133 are both made of graphite because graphite has high thermal conductivity. In some embodiments, in order to enable the lower end of the heat conducting column 133 to be better inserted into the silicon carbide powder, the lower end of the heat conducting column 133 can be set to a pointed shape.

[0042] In this embodiment, the bottom end of the heat conducting pillar 133 abuts against the bottom wall of the accommodating cavity 111 .

[0043] In this embodiment, the bottom ends of the heat-conducting pillars 133 abut against the bottom wall of the accommodating cavity 111. Thus, the sidewalls of the crucible body 110 can transfer heat to the heat-conducting pillars 133 via the heat-conducting plates 131, and the bottom wall of the crucible body 110 can also transfer heat upward to the heat-conducting pillars 133. Of course, if the temperature of the heat-conducting pillars 133 is high and the temperature of the bottom wall of the crucible body 110 is low, the heat-conducting pillars 133 can also transfer heat to the bottom wall of the crucible body 110.

[0044] Please refer to Figure 3 and Figure 4 In some embodiments of the present application, a flange 137 is provided on the periphery of the heat conducting plate 131 , and the flange 137 abuts against the side wall of the accommodating cavity 111 .

[0045] In this embodiment, a flange 137 is provided on the outer periphery of the heat conducting plate 131 . The flange 137 can increase the contact area between the heat conducting plate 131 and the side wall of the crucible body 110 , so that more heat of the crucible body 110 can be transferred to the center through the heat conducting plate 131 .

[0046] In some embodiments, please refer to Figure 3 The flange 137 is provided on the outer periphery of the top wall of the heat conducting plate 131 and extends upward, and the outer side wall of the flange 137 abuts against the inner side wall of the accommodating cavity 111. Figure 4 Of course, in other embodiments, the flange 137 is provided on the outer periphery of the bottom wall of the heat conducting plate 131, and the flange 137 extends downward, with the outer sidewall of the flange 137 abutting the inner sidewall of the accommodating cavity 111. Alternatively, flanges 137 may be provided on both the upper and lower outer peripheries of the heat conducting plate 131. The flange 137 may be integrally formed with the heat conducting plate 131 and the heat conducting pillars 133.

[0047] Furthermore, the thickness of the flange 137 gradually decreases in a direction away from the heat conducting plate 131 .

[0048] In this embodiment, the flange 137 is thinned in the direction away from the heat conducting plate 131 , so that the flange 137 can be better inserted into the silicon carbide powder and avoid affecting the uniform distribution of the atmosphere.

[0049] Please refer to Figure 5 In some other embodiments of the present application, a heat-conducting baffle 139 is provided radially of the heat-conducting column 133 , and the heat-conducting baffle 139 extends from one end of the heat-conducting column 133 to abut against the side wall of the accommodating cavity 111 .

[0050] In this embodiment, a heat-conducting baffle 139 is provided in the radial direction of the heat-conducting column 133, and the end of the heat-conducting baffle 139 is abutted against the side wall of the crucible body 110. In this way, the heat of the side wall of the crucible body 110 can also be transferred inward through the heat-conducting baffle 139 to the internal silicon carbide powder and the heat-conducting column 133, thereby achieving uniform heating of the silicon carbide powder.

[0051] It should be noted that the number, cross-sectional area, shape and distribution position of the heat-conducting baffles 139 can be set according to actual needs, and generally uniform distribution is preferred. The heat-conducting baffles 139 are integrally formed with the heat-conducting columns 133 and the heat-conducting plates 131.

[0052] Of course, please refer to Figure 6 In some other embodiments of the present application, a heat-conducting boss 141 may be provided on the inner sidewall of the accommodating cavity 111. The heat-conducting boss 141 extends from the sidewall of the accommodating cavity 111 along the radial direction of the crucible body 110 toward the center of the accommodating cavity 111, so that the end of the heat-conducting boss 141 abuts against the heat-conducting column 133.

[0053] In this embodiment, a heat-conducting boss 141 is provided in the crucible body 110, and the heat-conducting boss 141 is integrally formed with the crucible body 110. The heat-conducting boss 141 can conduct the heat of the side wall of the crucible body 110 inward to the silicon carbide powder and the heat-conducting column 133 in contact with it, thereby achieving uniform heating of the silicon carbide powder.

[0054] Furthermore, in order to avoid the influence of the heat-conducting partition 139 or the heat-conducting boss 141 on the atmosphere transmission path, pores are also provided on the heat-conducting plate 131 and the heat-conducting boss 141 to facilitate the flow of atmosphere, thereby preventing the heat-conducting member 130 from affecting the uniform distribution of the atmosphere.

[0055] In summary, the present application sets the heat conducting member 130 as a heat conducting plate 131 and a heat conducting column 133 protruding from the heat conducting plate 131. When the heat conducting member 130 is installed in the accommodating chamber 111, the heat conducting plate 131 abuts against the side wall of the accommodating chamber 111, so that the heat of the side wall of the crucible body 110 can be transferred to the heat conducting column 133 located in the powder area 113 through the heat conducting plate 131. The heat conducting column 133 can be used to heat the powder near the center area of ​​the powder area 113, thereby improving the problem of uneven temperature of the powder in the powder area 113. The flow channel 135 for the atmosphere to pass through the heat conducting plate 131 can also evenly flow the atmosphere and allow the atmosphere to be transmitted upward relatively evenly. Secondly, the setting of the heat conducting column 133 can prevent the central area of ​​the powder area 113 from being filled with powder, thereby avoiding the recrystallization of powder in the central area of ​​the powder area 113 due to reverse transmission, thereby improving the utilization rate of the powder.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A crucible for silicon carbide crystal growth, characterized in that: It comprises a crucible body (110) and a heat conducting member (130); The crucible body (110) has a receiving cavity (111); The heat conducting member (130) includes a heat conducting plate (131) and a heat conducting column (133); the heat conducting plate (131) is provided with a flow channel (135) for the passage of atmosphere; and the heat conducting column (133) is protruded from the heat conducting plate (131); The heat conducting member (130) is installed in the accommodating cavity (111), and the outer periphery of the heat conducting plate (131) abuts against the side wall of the accommodating cavity (111). The heat conducting column (133) extends downward, and a powder area (113) is formed between the heat conducting plate (131) and the bottom wall of the accommodating cavity (111). The powder area (113) is used to place silicon carbide powder.

2. The crucible for silicon carbide crystal growth according to claim 1, characterized in that: The bottom end of the heat-conducting column (133) abuts against the bottom wall of the accommodating cavity (111).

3. The crucible for silicon carbide crystal growth according to claim 1, wherein: The outer periphery of the heat conducting plate (131) is provided with a flange (137), and the flange (137) abuts against the side wall of the accommodating cavity (111).

4. The crucible for silicon carbide crystal growth according to claim 3, characterized in that: The flange (137) is arranged on the outer peripheral edge of the top wall of the heat conducting plate (131), and the flange (137) extends upward, and the outer side wall of the flange (137) abuts against the inner side wall of the accommodating cavity (111).

5. The crucible for silicon carbide crystal growth according to claim 3, characterized in that: The flange (137) is arranged on the outer peripheral edge of the bottom wall of the heat conducting plate (131), and the flange (137) extends downward, and the outer side wall of the flange (137) abuts against the inner side wall of the accommodating cavity (111).

6. The crucible for silicon carbide crystal growth according to claim 4 or 5, characterized in that: The thickness of the flange (137) gradually decreases in a direction away from the heat conducting plate (131).

7. The crucible for silicon carbide crystal growth according to claim 1, wherein: A heat-conducting baffle (139) is provided in the radial direction of the heat-conducting column (133), and one end of the heat-conducting baffle (139) away from the heat-conducting column (133) extends to abut against the side wall of the accommodating cavity (111).

8. The crucible for silicon carbide crystal growth according to claim 1, wherein: A heat-conducting boss (141) is convexly provided on the inner side wall of the accommodating cavity (111), and the heat-conducting boss (141) abuts against the heat-conducting column (133).

9. The crucible for silicon carbide crystal growth according to claim 1, wherein: The heat conducting member (130) is made of graphite, and pores are formed on the heat conducting member (130), and the pores form the flow channel (135).

10. A crystal growth device, characterized in that: It comprises a machine body (310) and the crucible for growing silicon carbide crystals as described in any one of claims 1 to 9; A carrying platform (311) is provided in the machine body (310), and a graphite heater (313) is provided on the outer periphery of the carrying platform (311); The crucible body (110) is supported on the supporting platform (311).

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