Crucible device for polycrystalline silicon growth process

Abstract

The invention belongs to a crucible device for a process of equipment for growing polycrystalline silicon by utilizing a directional solidification technology. The device is characterized in that a square high-purity graphite crucible is used for replacing the commonly used square high-purity quartz crucible; the square high-purity quartz crucible is formed by processing a whole graphite blank, and is assisted by relevant process designs (see figure); Si3N4, SiO/SiN or other materials are sprayed on the interior surface of the crucible and cured at high temperature. The square high-purity graphite crucible can be repetitively used in the polycrystalline silicon directional growth solidifying furnace, and then the producing cost of polycrystalline silicon ingots is greatly decreased, thereby reducing the silicon sheet price for the development of photovoltaic industry.

Description

technical field [0001] The invention belongs to a process crucible device in polysilicon growth equipment using directional solidification technology. Background technique [0002] The traditional polysilicon directional solidification growth furnace uses a square high-purity quartz crucible as a crucible, which is a consumable part and cannot be used repeatedly. That is, one crucible is required for each furnace of polysilicon. When preparing cast polysilicon, during the melting of raw materials and the crystallization of crystalline silicon, the silicon melt and the quartz crucible are in contact for a long time, which will produce a viscous effect. Due to the different thermal expansion coefficients of the two, it is likely to cause crystalline silicon or quartz crucible to break when the crystal is cooled; and because the silicon melt and the quartz crucible are in contact for a long time, the same as the preparation of Czochralski single crystal silicon, it will cause c...

AI Technical Summary

Problems solved by technology

At present, the above method is adopted for the crucible in the polysilicon ingot casting process, which is a commonly used process. The disadvantage is that one crucible is used for each furnace. The crucible is a pure consumable, and the cost is high, which is not conducive to reducing the cost of silicon wafers.

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