Carbon-carbon crucible for single crystal furnace and single crystal furnace

Abstract

The utility model provides a carbon-carbon crucible for a single crystal furnace and the single crystal furnace, the carbon-carbon crucible comprises a body, a groove hole is formed in the bottom of the body, and a plug connected with the groove hole in an embedded mode is further arranged on the groove hole. According to the carbon-carbon crucible for the single crystal furnace, a non-integrated structure is adopted, the stress generated when the bottom is heated and expanded can be reduced, a heat dissipation and flow division mode is expanded, bottom stress concentration is reduced, overflowing silicon liquid is prevented from flowing out of the crucible bottom, and the safety and reliability of the carbon-carbon crucible are improved; and the bottom structure is optimized, so that the service life of the carbon-carbon crucible can be further prolonged.

Description

Technical Field

[0001] The present application belongs to the technical field of single crystal silicon rod growth and manufacturing, and in particular relates to a carbon-carbon crucible for a single crystal furnace and a single crystal furnace. Background Art

[0002] When pulling single crystals, a carbon-carbon crucible must be installed outside the quartz crucible. Carbon-carbon crucibles are characterized by high temperature resistance and high strength, and are mainly used to protect the quartz crucible and keep it warm. Existing carbon-carbon crucibles are all one-piece structures. Since the quartz crucible expands when heated, the carbon-carbon crucible cannot dissipate heat when heated, and the carbon-carbon crucible is very prone to deformation. Moreover, the carbon-carbon crucible is affected by the high temperature at the bottom of the quartz crucible, which makes the bottom temperature of the carbon-carbon crucible also very high, which is very prone to stress concentration and cracks. Once cracks appear at the bottom of the carbon-carbon crucible, heat loss will occur, and not only will high-temperature silicon liquid flow out from the cracks, but the quartz crucible will also explode due to the uneven insulation of the carbon-carbon crucible, causing a huge production safety hazard. At the same time, the quartz crucible that matches it is unevenly stressed during use, which affects the service life of the quartz crucible. Summary of the Invention

[0003] The present application provides a carbon-carbon crucible for a single crystal furnace and a single crystal furnace, which solves the technical problem that the existing carbon-carbon crucible has an unreasonable structural design, which leads to stress concentration and cracks.

[0004] To solve at least one of the above technical problems, the technical solution adopted in this application is:

[0005] A carbon-carbon crucible for a single crystal furnace comprises a body, a slot is formed at the bottom of the body, and a plug is provided on the slot for being engaged with the slot.

[0006] Furthermore, the slot is located at the bottom center of the body and is adapted to the outer wall of the plug;

[0007] The height of the plug is not greater than the height of the slot, and the upper end surface of the plug is flush with the upper end surface of the slot.

[0008] Furthermore, the inner wall of the slot is constructed as a stepped table, and the table located on the outermost layer has the largest diameter; wherein the outermost table is constructed on one side of the bottom of the inner layer of the body or one side of the bottom of the outer layer of the body.

[0009] Furthermore, based on the end with the largest diameter of the outermost layer, the diameter of the table gradually decreases along the height direction of the slot.

[0010] Furthermore, the wall surface of the table at the outermost end is constructed as a truncated cone structure, the generatrix angle of which is 0-10°, and the small diameter ends thereof are inclined toward the center line of the slot;

[0011] Alternatively, the wall surface of the table surface at the outermost end is constructed as a straight wall structure.

[0012] Furthermore, a plurality of concave annular grooves are provided at intervals in the middle section of the slotted hole.

[0013] Furthermore, a top supporting ring is also configured at the bottom of the main body. The top supporting ring is protruded from the outer wall surface of the bottom of the main body and is configured as a whole with the main body.

[0014] Furthermore, the top supporting ring is cocentrically arranged with the slot hole, and the diameter of the top supporting ring is larger than the maximum diameter of the slot hole.

[0015] Furthermore, the inner wall of the top supporting ring is flush with the inner wall of the main body.

[0016] A single crystal furnace is equipped with the carbon-carbon crucible as described above.

[0017] The carbon-carbon crucible for a single crystal furnace designed in this application utilizes a non-integrated structure, which can reduce the stress caused by thermal expansion at the bottom, expand the heat dissipation diversion method, reduce stress concentration at the bottom, prevent overflow of silicon liquid from the bottom of the crucible, and improve the safety and reliability of the carbon-carbon crucible. The optimized bottom structure can further increase the service life of the carbon-carbon crucible. Furthermore, the flat bottom of the carbon-carbon crucible can fit tightly with the bottom of the quartz crucible inside it, ensuring uniform stress on the bottom of the quartz crucible, which can also increase the service life of the quartz crucible. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a cross-sectional view of a carbon-carbon crucible in this application;

[0019] Figure 2 It is a bottom view of the carbon-carbon crucible in this application;

[0020] Figure 3 This is a schematic structural diagram of the slot in Example 1 of the present application;

[0021] Figure 4 This is a schematic diagram of the structure of the slot in the second embodiment of the present application;

[0022] Figure 5 This is a schematic diagram of the structure of the slot in Example 3 of the present application;

[0023] Figure 6 This is a schematic structural diagram of the slot in the fourth embodiment of the present application;

[0024] Figure 7 This is a schematic structural diagram of the slot in the fifth embodiment of the present application;

[0025] Figure 8 This is a schematic diagram of the structure of the slot in Example 6 of the present application;

[0026] Figure 9 This is a schematic structural diagram of the slot in Example 7 of the present application;

[0027] Figure 10 This is a schematic diagram of the structure of the slot in Example 8 of the present application.

[0028] In the picture:

[0029] 10, body 20, top ring 30, slot

[0030] 40. Blockage DETAILED DESCRIPTION

[0031] The present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] This embodiment provides a carbon-carbon crucible for a single crystal furnace, such as Figure 1 As shown, the main body 10 includes a support ring 20 at the bottom of the main body 10, a slot 30 provided on the support ring 20, and a plug 40 that is engaged with the slot 30. The support ring 20 and the slot 30 are annular structures arranged concentrically, and the support ring 20 is integrally arranged with the main body 10 and located at the bottom center of the main body 10. The support ring 20 can be used to improve the stability of the horizontal placement of the carbon-carbon crucible, and at the same time, it can also improve its coordination with the carbon-carbon crucible support shaft (omitted in the figure). The arrangement of the slot 30 and the plug 40, while ensuring the insulation and support of the quartz crucible, can not only effectively reduce the stress concentration in the support ring 20 when the carbon-carbon crucible expands due to heat, but also further expand the heat dissipation diversion method to reduce the bottom stress; the plug 40 can directly prevent the overflow of silicon liquid from directly flowing out of the slot 30 in the bottom of the crucible, thereby improving the safety and reliability of the carbon-carbon crucible.

[0033] like Figure 2 As shown, the top support ring 20 is constructed at the bottom of the main body 10 and protrudes from the outer wall surface of the bottom of the main body 10, that is, the lower bottom surface of the top support ring 20 is protruding from the lower bottom surface of the bottom of the main body 10. Preferably, the bottom height difference H1 is 5-10mm. The inner wall surface of the top support ring 20 is integrally configured with the inner wall of the main body 10, and its lower end surface is constructed as a smooth and flush surface. The structure of the top support ring 20 makes the bottom of the carbon-carbon crucible flat, which can fit tightly with the bottom of the quartz crucible placed inside the carbon-carbon crucible, and makes the bottom of the quartz crucible bear force evenly, and also improves the service life of the quartz crucible. In this way, the stability of the quartz crucible and the carbon-carbon crucible can be guaranteed, and the stability of the carbon-carbon crucible placed on the support shaft can be improved. At the same time, the strength of the bottom of the carbon-carbon crucible can be improved, especially the strength of its cooperation with the support shaft.

[0034] Furthermore, the top support ring 20 and the slot hole 30 are both arranged concentrically with the main body 10, and the diameter of the top support ring 10 is larger than the maximum diameter of the slot hole 30. This not only facilitates the processing of the top support ring 20 and the slot hole 30, but also is beneficial to the strength of the overall structure of the carbon-carbon crucible; it can also improve the convenience and safety of carbon-carbon crucible production.

[0035] Furthermore, the slot 30 is located at the bottom center of the body 10 and is aligned with the outer wall of the plug 40. The height of the plug 40 is no greater than the height of the slot 30. That is, the height of the plug 40 can be less than or equal to the height of the slot 30, but cannot be greater than the height of the slot 30. If the plug 40 were higher than the height of the slot 30, it would not only hinder the stability of the quartz crucible placed inside the carbon-carbon crucible, but would also affect the temperature gradient of the silicon liquid in the quartz crucible, directly affecting product quality. It would also affect the stability of the carbon-carbon crucible placed on the support shaft.

[0036] When the height of the plug 40 is less than or equal to the height of the slot 30, at least the upper end surface of the plug 40 is ensured to be flush with the upper end surface of the slot 30. The purpose is to first seal the hole on the upper end surface of the slot 30 to improve the sealing performance of the slot 30. At the same time, it can also prevent the silicon liquid from overflowing and accumulating at the slot 30.

[0037] Preferably, the height of the plug 40 is the same as the height of the slot 30, which not only can better seal the slot 30, but also can improve the flatness of the upper and lower end surfaces of the slot 30, improve the stability and consistency of the overall combination of the main body 10, and also ensure its stability in cooperation with the quartz crucible and the supporting shaft.

[0038] like Figure 3-10 As shown, the inner wall of the slot 30 is constructed as a stepped table, which can be two or more layers, and the table located in the outermost layer has the largest diameter, wherein the outermost table is constructed on the side of the bottom of the outer layer of the body 10, as described in 3-6; or, the outermost table is constructed on the side of the bottom of the inner layer of the body 10, as described in Figure 7-10 That is, whether the platform with the largest diameter is constructed above or below the bottom, it can be used to improve the airtightness and strength of the plug 40. Moreover, the platform with a stepped structure can further improve the strength of the plug 40 and enhance the tightness and safety of the fit between the slot 30 and the plug 40.

[0039] like Figure 3 and Figure 7 As shown, in this embodiment, except for the outermost mesa structure with the largest diameter in the slot 30, the other parts are cylindrical surfaces of straight wall structure, wherein, Figure 3 The table with the largest diameter is placed on the outer side of the bottom. Figure 7The table with the largest diameter is arranged on one side of the bottom inner layer. The design of this type of slot 30 is not only simple in structure but also easy to process, and can be convenient for disassembly and maintenance while ensuring that it is closely matched with the plug 40.

[0040] like Figure 4 As shown, it is Figure 3 The biggest difference is that, apart from the bottom-level table structure, the upper portion is a truncated cone-shaped structure with an inclined wall structure, with its small-diameter end integrally connected to the bottom-level table, and its large-diameter end facing upward and positioned close to the upper end surface of the body 10. The busbar angle θ is 0-10°, and the small-diameter ends are inclined toward the centerline of the slot 30. This structural arrangement is more conducive to the tight fit between the plug 40 and the slot 30, making the plug less likely to wobble. It also expands the heat dissipation diversion method, reduces stress concentration at the bottom, prevents overflowing silicone liquid from flowing out of the bottom of the crucible, and improves the safety and reliability of the fit between the slot 30 and the plug 40.

[0041] like Figure 5 As shown, three sets of stepped terraces are arranged from bottom to top along the height of the slot 30, with the terraces gradually decreasing in diameter. The topmost terrace has a straight wall structure. This multi-step structure facilitates the contact area between the slot 30 and the plug 40, improving the safety and reliability of the fit. It also reduces stress caused by thermal expansion at the bottom, expands the heat dissipation distribution method, and reduces stress concentration at the bottom.

[0042] like Figure 6 As shown, a table with the largest diameter is provided on the bottom surface of the slotted hole 30. Two sets of spaced-apart concave annular grooves are also provided in the middle section of the slotted hole 30. The wall of the table at the outermost end, i.e., the uppermost end of the slotted hole 30, is constructed as a truncated cone, with a generatrix angle θ of 0-10°, and its smaller diameter ends are inclined toward the centerline of the slotted hole 30. This multi-structure arrangement enhances the strength of the connection with the plug 40, expanding the heat dissipation contact area while also reducing the concentration of thermal stress and minimizing stress accumulation at the bottom of the body 10. This ensures a secure seal while also improving the overall strength of the carbon-carbon crucible.

[0043] like Figure 8 As shown, it is Figure 4The biggest difference is that the table with the largest diameter is constructed on the bottom side of the inner layer of the main body 10. Specifically, the section directly connected to the table with the largest diameter is a truncated cone-shaped structure with an inclined wall structure, and its small diameter end is integrally connected to the table with the largest diameter, and its large diameter end is arranged downward and close to the lower end face of the main body 10. Among them, the busbar angle θ is 0-10°, and its small diameter end is inclined toward the center line of the slot 30. The setting of this structure can also promote the close fit between the plug 40 and the slot 30 and prevent the plug from shaking; at the same time, it can also expand the heat dissipation diversion mode, reduce the stress concentration at the bottom, avoid the overflow of silicon liquid from flowing out of the bottom of the crucible, and improve the safety and reliability of the fit between the slot 30 and the plug 40; and it does not affect the flatness of the lower bottom surface of the outer layer of the carbon-carbon crucible.

[0044] like Figure 9 As shown, it is Figure 5 The most significant difference is that the largest-diameter terrace is located on the inner bottom side of the body 10. Specifically, two sets of stepped terraces are arranged from top to bottom along the height of the slot 30, with the terraces gradually decreasing in diameter. The lowest terrace has a straight wall structure. This multi-step structure also facilitates the mating of the slot 30 and the plug 40, increasing the contact area. This not only improves the safety and reliability of the mating, but also reduces the stress caused by thermal expansion at the bottom, expands the heat dissipation method, and reduces stress concentration at the bottom.

[0045] like Figure 10 As shown, it is Figure 6 The most significant difference is that the largest-diameter table is located on the inner bottom side of the body 10. Two sets of spaced-apart concave annular grooves are provided at the lower section of the slot 30. The wall section near the largest-diameter table is constructed as a straight-cylindrical table structure. The wall at the outermost end, or the lowest end of the slot 30, is constructed as a truncated cone with a generatrix angle θ of 0-10°, and its smaller-diameter end is inclined toward the centerline of the slot 30. This multi-structure arrangement improves the strength of the plug 40 while not expanding the heat dissipation contact area. It also reduces the concentration of thermal stress, minimizing stress accumulation at the bottom of the body 10. While ensuring a secure seal, it also improves the overall strength of the carbon-carbon crucible.

[0046] In the above-described embodiments, the diameter D1 of the bottom of the body is set to 50-400 mm, the diameter D2 of the largest diameter table in the slot 30 is 10-400 mm, and the thickness H2 is 5-8 mm; the diameter D3 of the smallest diameter table is 5-350 mm; and the overall height H3 of the slot 30 is 30-35 mm. In other embodiments, the diameter D1 of the bottom of the body can be set to 180-250 mm, D2 to 120-130 mm, and D3 to 110-120 mm. When the slot 30 is configured as a multi-step structure with two or more layers, the diameter and thickness of the other tables between the largest diameter table and the smallest diameter table can be set according to actual needs. This structure can reduce the stress caused by thermal expansion of the body 10, reduce the magnitude of stress concentration, and improve the strength of the bottom fit.

[0047] Those skilled in the art should know that when the diameter of the bottom of the body is set to different values, the sizes of D1, D2, H2, and H3 can be adjusted according to the corresponding proportions mentioned above, or according to actual needs, which is not specifically limited here.

[0048] For the multi-step slot 30, the diameter difference between the middle section and the step surface at the end away from the maximum-diameter table is minimal. Even if there is a difference, the plug 40 is also made of carbon-carbon material, making it easy to insert and insert. The structure of each plug 40 is compatible with that of the slot 30, thereby preventing the silicon melt from flowing out of the gap between the quartz crucible and the carbon-carbon crucible, avoiding damage to other thermal components of the single crystal furnace, and preventing safety accidents caused by scalding the single crystal furnace cooling water pipe, thereby improving the safety performance of the single crystal furnace growth process.

[0049] In this embodiment, the fit between the plug 40 and the slot hole 30 can be a threaded fit, that is, the inner wall of the slot hole 30 and the outer wall of the plug 40 are threadedly connected; of course, a rivet-type interference fit can also be used, that is, a rivet interference connection is used at the matching wall surface of the plug 40 and the slot hole 30. This is a commonly used connection structure in this field and the drawings are omitted.

[0050] The utility model also provides a single crystal furnace, which is equipped with the carbon-carbon crucible as described above.

[0051] The carbon-carbon crucible for a single crystal furnace designed in this application utilizes a non-integrated structure, which can reduce the stress caused by thermal expansion at the bottom, expand the heat dissipation diversion method, reduce stress concentration at the bottom, prevent overflow of silicon liquid from the bottom of the crucible, and improve the safety and reliability of the carbon-carbon crucible. The optimized bottom structure can further increase the service life of the carbon-carbon crucible. Furthermore, the flat bottom of the carbon-carbon crucible can fit tightly with the bottom of the quartz crucible inside it, ensuring uniform stress on the bottom of the quartz crucible, which can also increase the service life of the quartz crucible.

[0052] The above embodiments of the present application are described in detail. The contents described are only preferred embodiments of the present application and should not be considered to limit the scope of implementation of the present application. All equivalent changes and improvements made within the scope of the present application should still fall within the scope of the patent coverage of the present application.

Claims

1. A carbon-carbon crucible for a single crystal furnace, characterized in that: The utility model comprises a main body, a slot hole is arranged at the bottom of the main body, and a plug which is engaged with the slot hole is also arranged on the slot hole.

2. A carbon-carbon crucible for a single crystal furnace according to claim 1, characterized in that: The slot is located at the bottom center of the body and is matched with the outer wall of the plug; The height of the plug is not greater than the height of the slot, and the upper end surface of the plug is flush with the upper end surface of the slot.

3. A carbon-carbon crucible for a single crystal furnace according to claim 1 or 2, characterized in that: The inner wall of the slot hole is constructed as a stepped table, and the diameter of the outermost table is the largest; wherein the outermost table is constructed on one side of the bottom of the inner layer of the body or one side of the bottom of the outer layer of the body.

4. The carbon-carbon crucible for a single crystal furnace according to claim 3, characterized in that: Based on the outermost end with the largest diameter, the diameter of the table gradually decreases along the height direction of the slot hole.

5. The carbon-carbon crucible for a single crystal furnace according to claim 4, characterized in that: The wall surface of the table at the outermost end is constructed as a truncated cone structure, the generatrix angle of which is 0-10°, and the small diameter ends thereof are inclined toward the center line of the slot hole; Alternatively, the wall surface of the table surface located at the outermost end is constructed as a straight wall structure.

6. A carbon-carbon crucible for a single crystal furnace according to claim 4 or 5, characterized in that: A plurality of concave annular grooves arranged at intervals are arranged in the middle section of the slot hole.

7. The carbon-carbon crucible for a single crystal furnace according to claim 1, characterized in that: A top supporting ring is also arranged at the bottom of the main body. The top supporting ring is convexly arranged on the outer wall surface of the bottom of the main body and is configured integrally with the main body.

8. The carbon-carbon crucible for a single crystal furnace according to claim 7, characterized in that: The top supporting ring is cocentrically arranged with the slot hole, and the diameter of the top supporting ring is larger than the maximum diameter of the slot hole.

9. The carbon-carbon crucible for a single crystal furnace according to claim 8, characterized in that: The inner wall of the top supporting ring is flush with the inner wall of the main body.

10. A single crystal furnace, characterized in that: A carbon-carbon crucible as described in any one of claims 1 to 9 is provided.

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