Composite cone for single crystal production

Abstract

The invention discloses a composite cone for single crystal production. The composite cone comprises a high-strength composite layer cone at the bottom, the embedding part is arranged at the edge of the high-strength composite layer cone body, and the bulge is arranged on the surface of the edge part of the high-strength composite layer cone body; the ceramic quartz upper cover is arranged above the high-strength composite layer cone and is matched with the high-strength composite layer in shape; the lifting assembly penetrates through the high-strength composite layer cone and the ceramic quartz upper cover and then protrudes out of the upper portion of the ceramic quartz upper cover, and the lifting assembly is used for reducing stress concentration of the bottom of the ceramic quartz upper cover. Compared with the prior art, the composite cone can bear a large range of cold and hot temperature switching, then provides higher strength and better brittleness resistance, can provide better integrity and supporting performance through the composite cone at the bottom, and can prevent the cone from directly falling into molten silicon to pollute a silicon material even if the cone is broken under the extremely small probability.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal production equipment, and in particular to a composite cone used for single crystal production. Background Art

[0002] At present, the production method of single crystal silicon rods is RCZ (repeated feeding and pulling method), which is a cyclic feeding method. After the materials are loaded in the crucible, the materials are melted at high temperature. The feeder needs to feed the crucible in the furnace 40-50 times. Since the single crystal preparation has high requirements for oxygen content, carbon content, minority carrier life, and resistivity, high-purity and pollution-free materials are required for auxiliary feeding, so the feeder cone is made of high-purity quartz. Although it can meet the quality requirements, due to the limitations of the high-purity quartz material itself, it is brittle and easy to crack.

[0003] During the charging process of the RCZ circulation section, the vertebrae are repeatedly switched from high temperature 1500℃ to low temperature 16℃, and this needs to be completed in a short time. During this process, the vertebrae expand and contract due to heat and cold, and the stress of hot and cold shock is released, which makes it very easy to burst. In addition, during the charging process, the material blocks need to be dropped from a high place for charging, and the gravity directly impacts the vertebrae. Due to the high brittleness of quartz, it is easy to crack under high temperature due to impact cracks. At the same time, all the molten silicon in the crucible needs to be completely handled, and the cost loss can be as high as 100,000 yuan, which is 50 times the cost of the vertebrae. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems and provide a composite cone for single crystal production.

[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0006] A composite cone for single crystal production, comprising a high-strength composite layer cone at the bottom;

[0007] The engaging portion is arranged at the edge of the high-strength composite layer vertebral body, and the protrusion is arranged on the surface of the edge of the high-strength composite layer vertebral body;

[0008] A ceramic quartz upper cover is arranged above the high-strength composite layer cone and is adapted to the shape of the high-strength composite layer;

[0009] The lifting component passes through the high-strength composite layer cone and the ceramic quartz upper cover and protrudes above the ceramic quartz upper cover. The lifting component is used to reduce the stress concentration at the bottom of the ceramic quartz upper cover.

[0010] As a further description of the above technical solution, reinforcing ribs are distributed inside the ceramic quartz upper cover.

[0011] As a further description of the above technical solution, the reinforcing ribs are mesh reinforcing ribs, and the shape of the mesh reinforcing ribs is compatible with the shape of the ceramic quartz upper cover.

[0012] As a further description of the above technical solution, the mesh reinforcement ribs include a plurality of longitudinal reinforcement ribs arranged along the busbars of the ceramic quartz upper cover and a plurality of annular reinforcement ribs arranged along the length direction of the longitudinal reinforcement ribs.

[0013] As a further description of the above technical solution, the material of the reinforcing rib is tungsten wire, molybdenum wire or any other metal material.

[0014] As a further description of the above technical solution, the lifting assembly includes a base, and a pull rod is integrally formed at the upper end of the base, and the pull rod passes through the through hole in the center of the ceramic quartz upper cover and the high-strength composite layer vertebral body.

[0015] As a further description of the above technical solution, the material of the lifting component is ceramic quartz.

[0016] As a further description of the above technical solution, the ceramic quartz upper cover is a cone, and the edge of the ceramic quartz upper cover is subjected to arc transition treatment.

[0017] As a further description of the above technical solution, the high-strength composite layer vertebral body is a carbon-carbon composite layer vertebral body.

[0018] As a further description of the above technical solution, the ceramic quartz upper cover is formed by an ingot casting process.

[0019] The beneficial effects of the present invention are as follows:

[0020] The present invention provides better temperature resistance and stability by setting a double-layer composite cone, which can withstand a wide range of hot and cold temperature switching, and secondly provides higher strength and better brittleness resistance to avoid large external force impact. The composite cone at the bottom can provide better integrity and support. Even if the cone breaks under a very small probability, it can avoid falling directly into the molten silicon after breaking and contaminating the silicon material. Finally, the composite cone at the bottom can effectively reduce the situation of cone rupture caused by stress concentration.

[0021] In order to more clearly illustrate the structural features and functions of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a stereoscopic view of the composite vertebral body of the present invention;

[0023] Figure 2 is a front view of the composite vertebral body of the present invention;

[0024] Figure 3 is a top view of the composite vertebral body of the present invention;

[0025] Figure 4 yes Figure 3 Sectional view of AA in the middle;

[0026] Figure 5 It is a three-dimensional diagram of a composite pyramidal quartz upper cover in another embodiment of the present invention.

[0027] Figure numerals: 100, high-strength composite layer vertebral body; 200, interlocking portion; 300, ceramic quartz upper cover; 400, mesh reinforcement ribs; 410, longitudinal reinforcement ribs; 420, annular reinforcement ribs; 500, lifting assembly; 510, bottom support; 520, pull rod; 600, through hole. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] The embodiment of the present application provides a composite cone for single crystal production, which is used to solve the problem in the prior art that the material block is dropped from a high place for loading, and the gravity directly impacts the cone. Because the quartz is highly brittle, the cone will be broken. When the cone is broken, it will cause molten silicon pollution, reduce carbon content, minority carrier life and resistance quality, and under the measure of seed crystal bonding, the high temperature time of the crucible is increased, and the crucible reacts with molten silicon to produce more oxygen atoms, resulting in an increase in oxygen atoms in the molten silicon, an increase in the oxygen content of the crystal rod, and easy formation of oxygen precipitation, dislocation and other defects in the crystal. At the same time, if the bonding cannot be proposed, all the molten silicon in the crucible will need to be fully processed, and the cost loss will be greatly increased. The loss of a single furnace will be as high as 100,000 yuan, which is 50 times the cost of the cone. At the same time, when the cone is lifted in and out of the barrel, the gravity applied by the material block and the upward pulling force of the crystal will cause the force point of the cone to be concentrated, increasing its risk of failure.

[0030] The technical concept of this application is to provide better temperature resistance and stability by setting a double-layer composite cone, which can withstand a wide range of hot and cold temperature switching (16°C-1450°C), and secondly provide higher strength and better brittleness resistance to avoid large external impacts (can withstand 10kg external force and the risk of falling at 2m). Secondly, the composite cone at the bottom can provide better integrity and support. Even if the cone breaks with a very small probability, it can avoid falling directly into the molten silicon after cracking and contaminating the silicon material. Finally, the composite cone at the bottom can effectively reduce the situation of cone rupture caused by stress concentration.

[0031] like Figure 1-Figure 5As shown, in one embodiment, a composite cone for single crystal production includes a high-strength composite layer cone 100 at the bottom;

[0032] A fitting portion 200 is provided at the edge of the high-strength composite layer cone 100. In some embodiments, the fitting portion 200 is an annular protruding structure. By providing the fitting portion 200, the high-strength composite layer cone 100 can be closely matched with the ceramic quartz upper cover 300 above, thereby improving the stability of the connection between the two.

[0033] A ceramic quartz upper cover 300 is provided at the upper end of the high-strength composite layer vertebral body 100. The ceramic quartz upper cover 300 is adapted to the high-strength composite layer vertebral body 100, and the structure of the two cooperates to form a complete vertebral body.

[0034] A through hole 600 is opened at the center of the high-strength composite layer cone 100 and the ceramic quartz upper cover 300. The lifting component 500 passes through the through hole 600 and the upper end of the lifting component 500 protrudes from the upper end of the ceramic quartz upper cover 300. By pulling the lifting component 500, the entire composite cone can be moved up and down in the barrel.

[0035] In the present application, compared with the existing quartz material, the ceramic quartz top cover 300 is a high-purity, impurity-free and pollution-free material, which will not affect the quality of the silicon material and can meet the production requirements of the crystal rod. At the same time, compared with the existing high-purity quartz, the strength of ceramic quartz is 8-10 times that of high-purity quartz. Under the existing loading process, 10kg of material falls from a height of 2m without causing hidden cracks or other damage to the ceramic quartz top cover 300. At the same time, the ceramic quartz top cover 300 has a conical shape, and its edges and corners are treated with arc transitions, so that the silicon material can slide freely along the surface of the ceramic quartz top cover 300 under the action of gravity.

[0036] Optionally, in some embodiments, the high-strength composite layer cone 100 is a carbon-carbon composite layer cone, and the carbon-carbon composite layer is a composite structure composed of carbon materials, which is mainly composed of carbon fibers and a carbon matrix. The carbon-carbon composite layer is resistant to high temperatures and can withstand temperature switching of 16-1500°C, which can effectively reduce melting during operation, thereby affecting the normal use of the upper ceramic quartz cover 300. At the same time, since the carbon-carbon composite layer is arranged at the bottom of the ceramic quartz cover 300, it can support the ceramic quartz cover 300. Even if the ceramic quartz cover 300 is broken with a very small probability, due to the high-strength support of the carbon-carbon composite layer, the fragments of the ceramic quartz cover 300 will not fall into the barrel below and contaminate the molten material. At the same time, the lifting component 500 in the present application passes through the high-strength composite layer vertebral body and the ceramic quartz upper cover 300 below in sequence. The lifting component 500 first contacts the high-strength composite layer vertebral body, and the stress is first transmitted to the high-strength composite layer vertebral body, and then transmitted to the ceramic quartz layer, which can reduce the stress concentration at the bottom of the ceramic quartz upper cover 300, thereby effectively reducing the risk of cracking the ceramic quartz upper cover 300.

[0037] Optionally, the lifting assembly 500 includes a bottom bracket 510 at the bottom of the high-strength composite layer vertebral body 100, and a pull rod 520 integrally formed with the bottom bracket 510. In some embodiments, the bottom bracket 510 is a structure adapted to the high-strength composite layer vertebral body 100, such as a vertebral body. The pull rod 520 is a cylindrical structure. In some other embodiments, the pull rod 520 may also be other structures, which can be adapted to the shapes of the high-strength composite layer vertebral body 100 and the through hole 600 in the ceramic quartz upper cover 300, and is not limited here.

[0038] Optionally, refer to Figure 5 , there are reinforcing ribs distributed in the ceramic quartz upper cover 300. In some embodiments, the reinforcing ribs are mesh reinforcing ribs 400, and the shape of the mesh reinforcing ribs 400 is adapted to the shape of the ceramic quartz upper cover 300. The mesh reinforcing ribs 400 include a plurality of longitudinal reinforcing ribs 410 arranged along the busbar of the ceramic quartz upper cover 300 and a plurality of annular reinforcing ribs 420 arranged along the length direction of the longitudinal reinforcing ribs 410, wherein the material of the reinforcing ribs is any one of tungsten wire, molybdenum wire or other metal materials. For the material of the reinforcing ribs, it is only necessary to meet the requirements of high temperature resistance and high toughness and tensile strength, and no specific limitation is made here. By setting the reinforcing ribs, the tensile strength and deformation resistance of the ceramic quartz upper cover 300 can be improved. At the same time, after cracking with an extremely low probability, it will not fall directly into the crucible molten silicon, so that the ceramic quartz upper cover 300 can have a higher integrity. During production, the ceramic quartz upper cover 300 is produced by the ingot casting process, and reinforcing ribs can be added during the production process.

[0039] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite cone for single crystal production, characterized in that: It includes a high-strength composite layer cone at the bottom; The engaging portion is arranged at the edge of the high-strength composite layer vertebral body, and the protrusion is arranged on the surface of the edge of the high-strength composite layer vertebral body; A ceramic quartz upper cover is arranged above the high-strength composite layer cone and is adapted to the shape of the high-strength composite layer; The lifting component passes through the high-strength composite layer cone and the ceramic quartz upper cover and protrudes above the ceramic quartz upper cover. The lifting component is used to reduce the stress concentration at the bottom of the ceramic quartz upper cover.

2. The composite cone for single crystal production according to claim 1, characterized in that: Reinforcing ribs are distributed inside the ceramic quartz upper cover.

3. The composite cone for single crystal production according to claim 2, characterized in that: The reinforcing ribs are mesh reinforcing ribs, and the shape of the mesh reinforcing ribs is compatible with the shape of the ceramic quartz upper cover.

4. The composite cone for single crystal production according to claim 3, characterized in that: The mesh reinforcement ribs include a plurality of longitudinal reinforcement ribs arranged along the generatrix of the ceramic quartz upper cover and a plurality of annular reinforcement ribs arranged along the length direction of the longitudinal reinforcement ribs.

5. The composite cone for single crystal production according to claim 3, characterized in that: The reinforcing rib is made of either tungsten wire or molybdenum wire.

6. The composite cone for single crystal production according to claim 1, characterized in that: The lifting assembly comprises a bottom bracket, the upper end of which is integrally formed with a pull rod, and the pull rod passes through a through hole in the center of the ceramic quartz upper cover and the high-strength composite layer vertebral body.

7. The composite cone for single crystal production according to claim 6, characterized in that: The material of the lifting component is ceramic quartz.

8. The composite cone for single crystal production according to claim 1, characterized in that: The ceramic quartz upper cover is a cone, and the edge of the ceramic quartz upper cover is processed with an arc transition.

9. The composite cone for single crystal production according to claim 1, characterized in that: The high-strength composite layer vertebral body is a carbon-carbon composite layer vertebral body.

10. The composite cone for single crystal production according to claim 1, characterized in that: The ceramic quartz upper cover is formed by an ingot casting process.

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