Monocrystalline silicon leakage-proof crucible

Abstract

The utility model relates to the field of monocrystalline silicon production equipment, and particularly discloses a leakage-proof crucible for monocrystalline silicon. Comprising a crucible upper, a crucible bottom and a connecting part between the crucible upper and the crucible bottom which are integrally formed, the crucible upper is of a structure flared from inside to outside, the crucible bottom is in a circular arc shape, and the wall thickness of the connecting part is larger than that of the crucible upper; the crucible upper and the crucible bottom of the crucible are integrally formed, silicon leakage caused by leakage of a high-temperature molten silicon body can be prevented when the inner quartz crucible is broken, the crucible upper of the crucible is integrally flared from inside to outside, the quartz crucible and the carbon-carbon crucible are conveniently separated, the inner quartz crucible is not prone to being clamped in the outer carbon-carbon crucible, and the service life of the crucible is prolonged. The internal quartz crucible can be easily taken out after crystal pulling is finished; the first boss and the second boss are integrally formed on the outer wall, the effects of improving the structural strength and facilitating clamping are achieved, the damage probability of the crucible is reduced, meanwhile, the anti-sticking layers are arranged on the inner walls of the crucible upper, the crucible bottom and the connecting part, the reaction between the quartz crucible and a carbon-carbon crucible can be blocked, and sticking is avoided.

Description

Technical field:

[0001] The utility model relates to the technical field of single crystal silicon production equipment, in particular to a single crystal silicon leak-proof silicon crucible. Background technology:

[0002] At present, the industrial production of single crystal silicon usually adopts the direct pulling method: the silicon material is heated and melted in the quartz crucible of the single crystal furnace, and then the molten silicon at the pulling position is controlled to near the crystallization temperature, crystallization is carried out using a seed crystal, and then the crystallized single crystal silicon is gradually elongated to form a single crystal silicon rod; the main material of the quartz crucible used is silicon oxide, which will gradually soften during the heating process, which may cause collapse and silicon leakage. Therefore, a crucible made of a carbon-carbon composite material needs to be installed outside the quartz crucible to support the quartz crucible. The quartz crucible is a consumable, and the quartz crucible needs to be separated from the carbon-carbon crucible after the crystal pulling is completed.

[0003] For ease of assembly, a certain gap is left between the quartz crucible and the carbon-carbon crucible so that they can be easily loaded. However, after being heated and softened, they will fit tightly with the external carbon-carbon crucible. After being cooled and hardened, the quartz crucible is not easy to remove. At the same time, in a high temperature environment, the quartz crucible will react with the inner surface of the carbon-carbon crucible, resulting in stickiness. Therefore, the existing solution is to make the carbon-carbon crucible separate from the crucible bottom. After the crystal pulling is completed, the crucible bottom can be removed separately, which is convenient for separating the quartz crucible from the carbon-carbon crucible. However, this design has the risk of silicon leakage. If the quartz crucible breaks during the crystal pulling process, the molten silicon material will quickly leak from the joint between the crucible side and the crucible bottom to the furnace bottom, damaging the single crystal furnace, or even burning through the furnace bottom to cause an accident. In addition, the design of separating the crucible side and the crucible bottom will result in different thermal stresses on the two materials after long-term use, which will easily cause deformation and make them unable to fit together, reducing the service life of the carbon-carbon crucible. Utility model content:

[0004] The utility model aims to provide a single crystal silicon leak-proof silicon crucible to solve the problems existing in the prior art.

[0005] The utility model is implemented by the following technical scheme: a single crystal silicon leak-proof silicon crucible, characterized in that it includes an integrally formed crucible side, a crucible bottom and a connecting portion between the crucible side and the crucible bottom, the crucible side is a structure expanding from the inside to the outside, the crucible bottom is an arc shape, and the wall thickness of the connecting portion is greater than the wall thickness of the crucible side.

[0006] Furthermore, the inclination angle of the crucible side is 2°-5°.

[0007] Furthermore, a circle of first bosses is integrally formed on the upper edge of the crucible side, the top surface of the first bosses is a plane perpendicular to the axis of the crucible side, and a circle of second bosses is integrally formed on the outer wall of the crucible side.

[0008] Furthermore, a cylindrical protrusion is integrally formed at the center of the bottom of the crucible.

[0009] Furthermore, the inner walls of the crucible side and the crucible bottom are covered with an anti-sticking layer, and the material of the anti-sticking layer is silicon carbide.

[0010] The utility model has the advantages that the crucible side and the crucible bottom are integrally formed, which can prevent the leakage of high-temperature molten silicon and cause silicon leakage when the internal quartz crucible is broken. The integrally formed crucible is not easy to deform and has a long service life. The crucible side is expanded from the inside to the outside as a whole, which is convenient for separating the quartz crucible from the carbon-carbon crucible, so that the internal quartz crucible will not be stuck in the external carbon-carbon crucible after being heated and softened, and the internal quartz crucible can be easily taken out after the crystal pulling is completed. The outer wall is integrally formed with a first boss and a second boss to increase the structural strength and facilitate clamping, thereby reducing the probability of crucible breakage. At the same time, an anti-sticking layer is provided on the crucible side, the crucible bottom and the inner wall of the connecting part to block the reaction between the quartz crucible and the carbon-carbon crucible, avoid sticking, and further facilitate the separation of the quartz crucible from the carbon-carbon crucible. Description of the drawings:

[0011] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0012] Figure 2 It is a cross-sectional view of the utility model.

[0013] Figure 3 It is a schematic diagram of the installation of the utility model and the crucible tray.

[0014] In the figure: a crucible side 1, a crucible bottom 2, a connecting portion 3, a first boss 4, a second boss 5, a convex block 6, and a groove 7. Specific implementation method:

[0015] The following will be combined with the drawings of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0016] In the description of the present invention, it should be noted that the terms "center", "up", "down", "front", "back", "top", "bottom", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and 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, and therefore cannot be understood as a limitation on the present invention.

[0017] like Figure 1As shown: a single crystal silicon leak-proof silicon crucible, comprising an integrally formed crucible side 1, a crucible bottom 2 and a connecting portion 3 between the crucible side 1 and the crucible bottom 2. When pulling crystals, a quartz crucible is placed inside. When silicon leaks, the molten silicon melt will be retained in the carbon-carbon crucible and will not overflow, thereby avoiding silicon leakage accidents. Figure 2 As shown: the crucible side 1 is a structure that expands from the inside to the outside, and the inclination angle of the crucible side 1 is 2°-5°. After heating, the quartz crucible softens and gradually sticks to the inner wall of the carbon-carbon crucible. For the traditional carbon-carbon crucible without an inclination angle, after the crystal pulling is completed and cooled, the side wall of the quartz crucible will be deformed and stuck in the carbon-carbon crucible, which is not easy to take out. The internal quartz crucible needs to be smashed before it can be taken out; after the crucible side 1 is designed to expand from the inside to the outside, the cross-sectional area of ​​the upper part of the carbon-carbon crucible is larger than the cross-sectional area of ​​the lower part. The carbon-carbon crucible is turned over and inverted with the opening facing downward, and the internal quartz crucible can be poured out. The crucible side 1 that expands outward can prevent the quartz crucible from being stuck in the carbon-carbon crucible. At the same time, because the liquid level will gradually drop during crystal pulling, in order to ensure that the volume of the upper part of the crucible and the volume of the lower part will not differ too much, the inclination angle of the crucible side 1 should not be too large, and can be set to 2°-5°.

[0018] The crucible bottom 2 is arc-shaped, consistent with the shape of the bottom of the quartz crucible contained inside, and can stably support the quartz crucible. The wall thickness of the connecting portion 3 is greater than the wall thickness of the crucible side 1. Since the crucible side 1 and the crucible bottom 2 of the external carbon-carbon crucible need to be gently tapped during the process of taking out the internal quartz crucible, the position where the crucible side 1 and the crucible bottom 2 are connected is subject to greater stress. In order to prevent damage at this position, this position is thickened to increase the strength.

[0019] A circle of first bosses 4 are integrally formed on the upper edge of the crucible side 1, and the top surface of the first boss 4 is a plane perpendicular to the axis of the crucible side 1, and a circle of second bosses 5 are integrally formed on the outer wall of the crucible side 1; the first boss 4 on the upper edge of the crucible serves to strengthen the strength of the upper edge of the crucible. If silicon leakage or furnace stewing occurs, the silicon material and the quartz crucible will stick to the inner wall of the carbon-carbon crucible. At this time, knocking cannot separate the internal furnace material and the quartz crucible. The carbon-carbon crucible needs to be turned 180° as a whole, and freely released downward on a wooden board or other soft plane, and dropped on the wooden board to peel off the internal silicon material and quartz crucible by gravity impact. The first boss 4 on the upper edge of the crucible can prevent the upper edge of the crucible from being damaged when impacting the wooden board, thereby increasing the strength. The upper edge of the first boss 4 is set to a horizontal plane, which can disperse the pressure when impacting the wooden board and avoid the upper edge of the crucible side 1 from breaking. The function of the second boss 5 on the outer wall of the crucible side 1 is to facilitate lifting and clamping. During installation and disassembly, due to the large size and weight of the carbon-carbon crucible, an overhead crane or forklift is required for lifting. However, the traditional crucible is a cylinder as a whole with an arc-shaped bottom, which is not convenient for fixing and clamping. A clamp can be added to the second boss 5 to stably fix the crucible when installing and flipping the crucible.

[0020] like Figure 3 As shown: the crucible is installed on the crucible tray in the single crystal furnace, and a rotating lifting device is connected to the bottom of the crucible tray for driving the crucible to rotate and lift up and down during the crystal pulling process. A cylindrical protrusion 6 is integrally formed at the center position of the crucible bottom 2, and a groove 7 corresponding to the cylindrical protrusion 6 is provided on the crucible tray at the bottom of the crucible. Since the bottom 2 of the crucible is arc-shaped, it may slip during operation and cause tipping. At the same time, in order to ensure that the crucible is placed horizontally during installation, a cylindrical protrusion 6 is provided at the bottom of the crucible. During installation, the cylindrical protrusion 6 is aligned with the groove 7 on the crucible tray, and the protrusion 6 is embedded in the groove 7 to ensure the level of installation. During operation, the protrusion 6 cooperates with the groove 7 to play a limiting role, which can prevent the crucible from tipping over.

[0021] Furthermore, in order to prevent the quartz crucible from reacting with the carbon-carbon crucible and causing sticking, the inner walls of the crucible side 1 and the crucible bottom 2 are covered with an anti-sticking layer, and the material of the anti-sticking layer is silicon carbide; the anti-sticking layer can be covered on the inner wall of the crucible by brushing silicon carbide material or by vapor phase chemical deposition. The silicon carbide material is resistant to high temperatures and can block the quartz crucible from the carbon-carbon crucible to prevent the two from reacting and preventing the quartz crucible from sticking to the carbon-carbon crucible, making it difficult to peel off the quartz crucible.

Claims

1. A single crystal silicon leak-proof silicon crucible, characterized in that: The invention comprises an integrally formed crucible rim (1), a crucible bottom (2) and a connecting portion (3) between the crucible rim (1) and the crucible bottom (2); the crucible rim (1) is a structure expanding from the inside to the outside, the crucible bottom (2) is arc-shaped, and the wall thickness of the connecting portion (3) is greater than the wall thickness of the crucible rim (1).

2. A single crystal silicon leak-proof silicon crucible according to claim 1, characterized in that: The inclination angle of the crucible side (1) is 2°-5°.

3. A single crystal silicon leak-proof silicon crucible according to claim 2, characterized in that: A circle of first bosses (4) is integrally formed on the upper edge of the crucible side (1), the top surface of the first bosses (4) is a plane perpendicular to the axis of the crucible side (1), and a circle of second bosses (5) is integrally formed on the outer wall of the crucible side (1).

4. The single crystal silicon leak-proof silicon crucible according to claim 3, characterized in that: A cylindrical protrusion (6) is integrally formed at the center of the crucible bottom (2).

5. The single crystal silicon leak-proof silicon crucible according to claim 4, characterized in that: The inner walls of the crucible side (1) and the crucible bottom (2) are covered with an anti-sticking layer, and the material of the anti-sticking layer is silicon carbide.

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