Large-diameter silicon crystal growth device

Abstract

The invention discloses a large-diameter silicon crystal growth device. The device comprises a heat-preserving system, a heating system, a stream guidance system and a supporting device, wherein the upper part of the heat-preserving system is provided with a heat-preserving cover plate and a furnace bottom heat-preserving structure; the heat-preserving cover plate adopts a double-layer structure, namely, an upper heat-preserving cover plate (1) and a lower heat-preserving cover plate (2) superposed on each other; and a clearance between the upper heat-preserving cover plate (1) and the lower heat-preserving cover plate (2) is filled with a graphite carbon felt. The technical scheme is used for controlling silicon monocrystals of 8 inches and more than 8 inches. Compared with the prior art, the device has the advantages of achieving better energy conservation, consumption reduction and inert gas guidance, improving the heat-preserving effect of the heat-preserving system, reducing heat radiation, changing temperature gradient in a melt, reducing the change of transverse temperature gradient, relatively stabilizing the liquid level temperature of the melt, contributing to the growth of silicon monocrystals, improving an air stream guidance device and preventing gas turbulence.

Description

technical field [0001] The invention belongs to the technical field of photoelectric conversion materials, and relates to production process equipment of single crystal silicon, more specifically, the invention relates to a large-diameter silicon crystal growth device. Background technique [0002] Czochralski method CZ Czochralski single crystal method, through resistance heating, the polysilicon in the quartz crucible is melted, and the temperature is kept slightly higher than the melting point of silicon, under the protection of inert gas, after seeding, shouldering , shoulder turning, equal diameter, finishing, crystal removal and other process steps to complete the crystal growth. The larger the size of the growing single crystal, the higher the requirements on the graphite thermal system. [0003] At present, my country is in the leading position in the world in the processing technology and production scale of graphite thermal systems used in silicon single crystal g...

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Problems solved by technology

[0003] At present, my country is in the leading position in the world in the processing technology and production scale of graphite thermal systems used in silicon single crystal growth. However, in the design of graphite thermal systems for growing large-sized single crystals, during the single crystal growth process, There will be many situations such as abnormal growth, broken edges, etc.

Therefore, the large-size silicon single crystal growth technology is still in a blind spot in China. Although there are very few companies that can barely grow it, they cannot be recognized and popularized by the market due to the high operating production costs and the failure to achieve the comprehensive economic benefits of the enterprise; The entire domestic silicon monocrystalline industry is still at the growth level of 6-inch and below 6-inch silicon single crystals. However, the demand for 8-inch and above 8-inch silicon single crystals in foreign markets is increasing day by day. How to design and grow large-diameter silicon The thermal system of single crystal is imminent

[0004] As we all know, the melting point of silicon is 1420°. If it is a 20-inch open thermal field device with a feeding capacity of 75kg, it will consume about 120kw of electric energy per hour to maintain this temperature.

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