Graphite chuck and Czochralski single crystal furnace
By designing radial flow channels on the graphite clamp to divide and converge the argon gas flow, the problem of silicon liquid volatile deposition was solved, improving crystal quality and equipment efficiency while reducing modification costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SICHUAN GOKIN SOLAR TECHNOLOGY CO LTD
- Filing Date
- 2025-05-28
- Publication Date
- 2026-05-01
AI Technical Summary
In the Czochralski process of growing single crystal silicon, the graphite chuck design causes silicon liquid volatiles to deposit on the surface of the seed crystal, resulting in crystal defects. Existing technologies cannot accurately cover the surface of the seed crystal, increasing equipment complexity or energy consumption.
Design a graphite chuck comprising a cylindrical part and an inverted truncated cone part, with multiple radial guide grooves on the outer peripheral wall to divide and converge the argon gas flow, improve the concentration and utilization of the gas flow, enhance heat dissipation capacity, and prevent the gas flow from escaping.
It improves the argon flow rate and utilization rate, reduces the amount of volatiles adhering to the seed crystal surface by 50%-70%, increases the crystal qualification rate by more than 15%, extends the chuck life, and reduces equipment modification costs.
Smart Images
Figure CN224186326U_ABST
Abstract
Description
Graphite chuck and Czochralski single crystal furnace Technical Field
[0001] This application relates to the field of Czochralski single crystal technology, and more particularly to a graphite chuck and a Czochralski single crystal furnace. Background Technology
[0002] In the Czochralski process for growing single-crystal silicon, graphite chucks are used to hold the seed crystal and immerse it in molten silicon. At high temperatures, silicon volatiles (such as SiO gas) easily deposit on the seed crystal surface, leading to crystal defects (such as dislocations and impurity inclusions) and affecting silicon rod yield. Traditional graphite chucks are mostly designed with smooth planes, relying solely on the natural flow of argon gas to flush the seed crystal. However, uneven airflow distribution limits the effectiveness in removing volatiles. While existing technologies improve airflow by adjusting the argon gas flow rate or adding external flow guiding devices, these solutions may increase equipment complexity or energy consumption and are difficult to precisely cover the seed crystal surface. Summary of the Invention
[0003] In view of the above problems, this application provides a graphite chuck and a Czochralski single crystal furnace to solve the problems of complex equipment and difficulty in accurately covering the surface of seed crystals in related technologies.
[0004] To achieve the above objectives, the embodiments of this application provide the following technical solutions:
[0005] This application provides a graphite chuck, comprising: a chuck body, the chuck body including a cylindrical member and an inverted frustum-shaped conical member connected to each other, the cylindrical member being configured to connect a counterweight, and the inverted frustum-shaped conical member being configured to hold a seed crystal; along the axial direction of the cylindrical member, the cylindrical member has a first end face and a second end face opposite to each other, and the inverted frustum-shaped conical member has a large bottom face and a small bottom face opposite to each other, the large bottom face being connected to the first end face and completely overlapping the first end face; the outer peripheral wall of the chuck body is provided with a plurality of guide grooves spaced apart along the circumference of the chuck body, the plurality of guide grooves extending from the small bottom face to the second end face, and the plurality of guide grooves being radially distributed in the direction from the small bottom face to the second end face.
[0006] In one embodiment of this application, the plurality of guide grooves are distributed at equal intervals along the circumferential direction of the clamp body.
[0007] In one embodiment of this application, the cross-sectional shape of the guide groove on the radial section of the cylindrical member is V-shaped, arc-shaped, or rectangular; the inclination angle of the inner wall of the V-shaped guide groove is 10°-90°.
[0008] In one embodiment of this application, the depth of the guide channel is 0.5mm-5mm; and / or, the width of the guide channel is 1mm-8mm.
[0009] In one embodiment of this application, the cylindrical component has a connecting hole configured to connect with the hammer head of the weight; the frustum-shaped component has a clamping hole configured to hold the seed crystal; the central axes of the connecting hole and the clamping hole coincide.
[0010] In one embodiment of this application, the clamping hole includes a first clamping hole, an intermediate transition hole, and a second clamping hole that are sequentially arranged and connected along its central axis. The first clamping hole is connected to the connecting hole, and the second clamping hole extends through to the small bottom surface. The diameter of the first clamping hole is larger than the diameter of the second clamping hole. The intermediate transition hole is shaped like an inverted frustum.
[0011] In one embodiment of this application, a first arc-shaped transition portion is provided at the junction of the edge of the second clamping hole and the small bottom surface; and / or, a second arc-shaped transition portion is provided at the junction of the first clamping hole and the intermediate transition hole; and / or, a third arc-shaped transition portion is provided at the junction of the second clamping hole and the intermediate transition hole.
[0012] In one embodiment of this application, the first opening of the connecting hole is close to the second end face, and a positioning chamfer is provided at the connection between the first opening and the second end face.
[0013] In one embodiment of this application, the connecting hole includes a first opening and a second opening opposite to each other along its central axis. The first opening is close to the second end face. A limiting surface is provided at the first opening, and the limiting surface is configured to abut against a flange provided on the outer peripheral wall of the hammer head. An anti-retraction groove is provided at the second opening, and the anti-retraction groove is configured to accommodate a spring pin provided on the outer peripheral wall of the hammer head.
[0014] This application also provides a Czochralski single crystal furnace, which includes the graphite chuck described above.
[0015] The graphite chuck provided in this application has the following technical effects:
[0016] Multiple guide channels divide the argon gas flow into several parts, which reduces the resistance to the argon gas flow and makes the airflow smoother, allowing more argon gas to pass through quickly, thereby increasing the argon gas volume.
[0017] Meanwhile, the radial distribution of multiple guide grooves allows the argon gas flow to converge before reaching the seed crystal surface, improving the concentration of the gas flow and thus increasing the argon gas flow rate; it also prevents the gas flow from escaping and improves the utilization rate of argon gas.
[0018] Multiple flow channels can also enhance the heat dissipation capacity of the chuck body, thereby extending the service life of the chuck body.
[0019] Furthermore, there is no need to modify the external argon gas supply system, reducing equipment modification costs. Attached Figure Description
[0020] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 is a three-dimensional structural schematic diagram of the graphite chuck provided in an embodiment of this application;
[0022] Figure 2 is a three-dimensional structural schematic diagram of the graphite chuck provided in the embodiment of this application;
[0023] Figure 3 is a top view of the graphite chuck provided in an embodiment of this application;
[0024] Figure 4 is a bottom view of the graphite chuck provided in an embodiment of this application;
[0025] Figure 5 is a schematic diagram of the internal structure of the graphite chuck provided in the embodiment of this application.
[0026] Figure label:
[0027] 100 - Cylindrical part;
[0028] 101 - Second end face; 102 - Connecting hole; 103 - Positioning chamfer; 104 - Limiting surface; 105 - Anti-retraction groove;
[0029] 200-Inverted frustum-shaped part;
[0030] 201 - Small bottom surface; 202 - Clamping hole;
[0031] 2021 - First clamping hole; 2022 - Intermediate transition hole; 2023 - Second clamping hole; 2024 - Second arc-shaped transition section; 2025 - First arc-shaped transition section;
[0032] 300-Guide channel. Detailed Implementation
[0033] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0034] Referring to Figures 1 and 2, the graphite chuck provided in this embodiment includes: a chuck body.
[0035] The chuck body includes a cylindrical part 100 and an inverted frustum-shaped part 200 connected to each other.
[0036] Along the axial direction of the cylindrical member 100, the cylindrical member 100 has a first end face and a second end face 101 opposite to each other, and the inverted truncated cone member 200 has a large base face and a small base face 201 opposite to each other. The diameter of the large base face is the same as the diameter of the cylindrical member 100, and the large base face is connected to the first end face and completely coincides with the first end face.
[0037] In the crystal growth process (Czochralski method), a counterweight is used as a counterweight device to adjust and control the crystal growth process.
[0038] The cylindrical part 100 is used to connect with the counterweight, and the inverted frustum-shaped part 200 is used to clamp the seed crystal and immerse it in the molten silicon. The volatiles of the molten silicon are easy to deposit on the surface of the seed crystal, so it is necessary to use argon gas to flush the surface of the seed crystal to reduce the adhesion of volatiles on the surface of the seed crystal, thereby improving the crystal quality.
[0039] The outer peripheral wall of the chuck body is provided with a plurality of guide grooves 300 distributed circumferentially along the chuck body. The plurality of guide grooves 300 extend from the bottom surface 201 to the second end surface 101, and are radially distributed in the direction from the bottom surface 201 to the second end surface 101.
[0040] Argon gas flows in the guide groove 300, and the direction of argon gas flow is from the second end face 101 toward the small bottom face 201.
[0041] Multiple guide channels 300 divide the argon gas flow into several parts, reducing the resistance to the argon gas flow and making the flow smoother, allowing more argon gas to pass through quickly, thereby increasing the argon gas volume. At the same time, the radial distribution of the multiple guide channels 300 allows the argon gas flow to converge before reaching the seed crystal surface, improving the concentration of the gas flow and thus increasing the argon gas flow rate; it also prevents gas flow from escaping, improving the utilization rate of argon gas.
[0042] Furthermore, there is no need to modify the external argon gas supply system, reducing equipment modification costs.
[0043] It should be noted that the multiple flow channels 300 can also enhance the heat dissipation capacity of the chuck body, thereby extending the service life of the chuck body.
[0044] It should be noted that, through multiple experimental tests, the chuck body provided in this application can reduce the amount of volatiles adhering to the surface of the seed crystal by 50%-70% and increase the crystal qualification rate by more than 15%.
[0045] Referring to Figures 3 and 4, in this embodiment of the application, a plurality of guide grooves 300 are distributed at equal intervals along the circumferential direction of the clamp body.
[0046] The uniform distribution of multiple flow channels 300 can ensure the stability of argon gas flow and also ensure that the argon gas flow uniformly removes volatiles adhering to different areas of the seed crystal surface, thereby improving crystal quality.
[0047] Referring again to Figures 3 and 4, in the embodiments of this application, the cross-sectional shape of the guide groove 300 on the radial section of the cylindrical member 100 includes, but is not limited to, V-shape, arc shape or rectangle.
[0048] The above-mentioned flow channel 300 has a simple shape and is easy to manufacture.
[0049] When the cross-sectional shape of the flow channel 300 is V-shaped, the inclination angle of the inner wall of the flow channel 300 is 10°-90° to guide the airflow to converge towards the surface of the seed crystal.
[0050] In this embodiment of the application, the depth of the guide groove 300 is 0.5mm-5mm.
[0051] The above data are the optimal range determined after parameter optimization based on crystal material, chuck body size and process objectives, and verified through multiple experiments. When the groove depth is less than 0.5mm, the flow guiding effect is poor. When the groove depth is greater than 5mm, volatiles are easily accumulated in the flow guiding groove 300, requiring frequent cleaning, and the airflow resistance increases, which can easily cause eddies.
[0052] In this embodiment of the application, the width of the guide groove 300 is 1mm-8mm.
[0053] The above data are the optimal range determined after parameter optimization based on crystal material, chuck body size and process objectives, and verified through multiple experiments. When the groove width is less than 1mm, a "gas knife" effect may be formed, which can easily scratch the crystal surface. When the groove width is greater than 8mm, the airflow velocity at the edge of the guide groove 300 is too low, and the airflow velocity inside the groove is uneven.
[0054] Referring to Figure 5, in this embodiment of the application, the cylindrical member 100 is provided with a connecting hole 102, which is used to connect with the hammer head of the hammer; the inverted cone member 200 is provided with a clamping hole 202, and the seed crystal is disposed in the clamping hole 202, so that the clamping hole 202 is used to clamp the seed crystal.
[0055] The central axes of the connecting hole 102 and the clamping hole 202 coincide, making the weight, the chuck body and the seed crystal coaxial, preventing eccentricity from causing crystal growth defects.
[0056] Referring again to Figure 5, in this embodiment of the application, the clamping hole 202 includes a first clamping hole 2021, an intermediate transition hole 2022 and a second clamping hole 2023 arranged and connected in sequence along its central axis. The first clamping hole 2021 is connected to the connecting hole 102 and the second clamping hole 2023 extends through to the small bottom surface 201.
[0057] The diameter of the first clamping hole 2021 is larger than the diameter of the second clamping hole 2023, and the intermediate transition hole 2022 is shaped like an inverted frustum to connect the first clamping hole 2021 and the second clamping hole 2023.
[0058] In other words, the diameter of the clamping hole 202 gradually decreases, and the contact surface between the seed crystal and the chuck body forms a gradient transition. When subjected to force, the stress can be evenly distributed, avoiding local stress from exceeding the tensile strength of the seed crystal, thereby reducing the risk of the bar falling off due to seed crystal fracture.
[0059] Referring to Figures 4 and 5, in this embodiment of the application, a first arc-shaped transition portion 2025 is provided at the junction of the edge of the second clamping hole 2023 and the small bottom surface 201 to reduce the sharpness of the edge of the second clamping hole 2023 and prevent the seed crystal surface from being scratched.
[0060] Referring to Figure 5, in this embodiment of the application, a second arc-shaped transition portion 2024 is provided at the junction of the first clamping hole 2021 and the intermediate transition hole 2022, so that the junction of the first clamping hole 2021 and the intermediate transition hole 2022 is smooth and without sharp edges, thus avoiding scratches on the surface of the seed crystal.
[0061] Referring to Figure 5, in this embodiment of the application, a third arc-shaped transition portion is provided at the junction of the second clamping hole 2023 and the intermediate transition hole 2022, so that the junction of the second clamping hole 2023 and the intermediate transition hole 2022 is smooth and without sharp edges, thus avoiding scratches on the surface of the seed crystal.
[0062] Referring to Figure 5, in this embodiment of the application, the connecting hole 102 includes a first opening and a second opening opposite to each other along its central axis. The first opening is close to the second end face 101, and a positioning chamfer 103 is provided at the connection between the first opening and the second end face 101.
[0063] The guide bevel of the positioning chamfer 103 can guide the hammer head of the hammer to quickly align with the connecting hole 102, thereby improving the connection efficiency between the hammer head of the hammer and the cylindrical part 100.
[0064] Referring to Figures 3 and 5, in this embodiment of the application, a limiting surface 104 is provided at the first opening. The limiting surface 104 is an annular limiting surface that surrounds the outer periphery of the first opening. The limiting surface 104 is used to abut against the flange provided on the outer peripheral wall of the hammer head.
[0065] During the process of quickly aligning and connecting the hammer head with the connecting hole 102, the limiting surface 104 abuts against the flange to provide a signal that the connection is complete; at the same time, it prevents the hammer head from continuing to extend downward.
[0066] The second opening is provided with an anti-retraction groove 105, which is used to accommodate the spring pin provided on the outer peripheral wall of the hammer head, so as to limit and fasten the hammer head and prevent the hammer head from coming out of the connecting hole 102.
[0067] This application also provides a Czochralski single crystal furnace, which includes the graphite chuck described above.
[0068] In summary, this application provides a graphite chuck and a Czochralski single crystal furnace. The graphite chuck includes a chuck body, which includes a cylindrical member 100 and an inverted frustum-shaped member 200 connected to each other. Along the axial direction of the cylindrical member 100, the cylindrical member 100 has a first end face and a second end face 101 opposite to each other. The inverted frustum-shaped member 200 has a large bottom face and a small bottom face 201 opposite to each other. The large bottom face is connected to the first end face and completely coincides with the first end face. The cylindrical member 100 is used to connect with a counterweight, and the inverted frustum-shaped member 200 is used to hold a seed crystal. The outer peripheral wall of the chuck body is provided with a plurality of guide grooves 300 distributed circumferentially along the chuck body. The plurality of guide grooves 300 extend from the small bottom face 201 to the second end face 101, and the plurality of guide grooves 300 are radially distributed in the direction from the small bottom face 201 to the second end face 101.
[0069] Multiple guide channels 300 divide the argon gas flow into several parts, reducing the resistance to the argon gas flow and making the flow smoother. This allows more argon gas to pass through quickly, thereby increasing the argon gas volume. Simultaneously, the radial distribution of the multiple guide channels 300 allows the argon gas flow to converge before reaching the seed crystal surface, improving the concentration of the gas flow and thus increasing the argon gas velocity. It also prevents gas dissipation, improving argon gas utilization. Furthermore, the multiple guide channels 300 enhance the heat dissipation capacity of the chuck body, thereby extending its service life.
[0070] Furthermore, there is no need to modify the external argon gas supply system, reducing equipment modification costs.
[0071] The various embodiments or embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.
[0072] It should be noted that the terms "one embodiment," "embodiment," "exemplary embodiment," "some embodiments," etc., mentioned in the specification indicate that the described embodiment may include a specific feature, structure, or characteristic, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.
[0073] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.
[0074] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).
[0075] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.
[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A graphite chuck, characterized in that, include: The chuck body includes a cylindrical member and an inverted frustum-shaped conical member connected to each other. The cylindrical member is configured to connect a counterweight, and the inverted frustum-shaped conical member is configured to hold a seed crystal. Along the axial direction of the cylindrical member, the cylindrical member has a first end face and a second end face, and the inverted frustum-shaped conical member has a large bottom face and a small bottom face. The large bottom face is connected to the first end face and completely coincides with the first end face. The outer peripheral wall of the chuck body is provided with a plurality of guide grooves distributed circumferentially along the chuck body. The plurality of guide grooves extend from the small bottom face to the second end face, and are radially distributed in the direction from the small bottom face to the second end face.
2. The graphite chuck according to claim 1, characterized in that, The plurality of guide grooves are distributed at equal intervals along the circumference of the clamp body.
3. The graphite chuck according to claim 1, characterized in that, On the radial section of the cylindrical component, the cross-sectional shape of the guide groove is V-shaped, arc-shaped, or rectangular; the inclination angle of the inner wall of the V-shaped guide groove is 10°-90°.
4. The graphite chuck according to claim 1, characterized in that, The depth of the guide channel is 0.5mm-5mm; and / or the width of the guide channel is 1mm-8mm.
5. The graphite chuck according to claim 1, characterized in that, The cylindrical component has a connecting hole configured to connect with the hammer head of the counterweight; the frustum-shaped component has a clamping hole configured to hold the seed crystal; the central axes of the connecting hole and the clamping hole coincide.
6. The graphite chuck according to claim 5, characterized in that, The clamping hole includes a first clamping hole, an intermediate transition hole, and a second clamping hole that are sequentially arranged and connected along its central axis. The first clamping hole is connected to the connecting hole, and the second clamping hole extends through to the small bottom surface. The diameter of the first clamping hole is larger than the diameter of the second clamping hole. The intermediate transition hole is shaped like an inverted frustum.
7. The graphite chuck according to claim 6, characterized in that, A first arc-shaped transition portion is provided at the junction of the edge of the second clamping hole and the small bottom surface; and / or, a second arc-shaped transition portion is provided at the junction of the first clamping hole and the intermediate transition hole; and / or, a third arc-shaped transition portion is provided at the junction of the second clamping hole and the intermediate transition hole.
8. The graphite chuck according to claim 5, characterized in that, The first opening of the connecting hole is close to the second end face, and a positioning chamfer is provided at the connection between the first opening and the second end face.
9. The graphite chuck according to claim 5, characterized in that, The connecting hole includes a first opening and a second opening opposite each other along its central axis. The first opening is close to the second end face. A limiting surface is provided at the first opening. The limiting surface is configured to abut against a flange provided on the outer peripheral wall of the hammer head. An anti-retraction groove is provided at the second opening. The anti-retraction groove is configured to accommodate a spring pin provided on the outer peripheral wall of the hammer head.
10. A Czochralski single crystal furnace, characterized in that, Includes the graphite chuck as described in any one of claims 1-9.