Dual-heater mobile-heat-shield type Czochralski crystal growing furnace

Abstract

The invention discloses semiconductor material growing equipment, and in particular relates to a Czochralski crystal growing furnace for semiconductor single crystal growth. In the invention, the downward motion of a heat shield is used to replace the upward motion of a crucible, so that the crucible can only rotate and not ascend any more, thus, one degree of freedom is reduced and the system complexity is decreased; by adopting dual heaters respectively located at the bottom and the side face of the crucible respectively to control the growth of a crystal by aiming at different stages respectively, the temperature gradient control of the crystal and melt is more convenient; the relative positions between the crucible and the heaters are kept parallel and unchanged, and the heat radiation of the heaters is directly used for baking the crucible, so that the heat transfer efficiency is greatly improved in comparison with that in a traditional method in which the crucible in the traditional single crystal furnace is constantly away from a heating zone; and a flow guiding cylinder is used for guiding argon gas to carry out enhanced heat exchange on the crystal, so that an convection vortex of the argon gas above the melt is inhibited, thus, impurities and micro-defects in the crystal are favorably reduced and the consumption level of the argon gas is decreased.

Description

technical field [0001] The invention relates to a device for manufacturing solar-grade and semiconductor-grade single-crystal silicon, in particular to a double-heater moving heat-shield Czochralski single-crystal furnace in which the heat shield moves up and down and the crucible is stationary. technical background [0002] Czochralski (CZ) crystal growth technology is the most important method for growing solar-grade and semiconductor-grade single crystal silicon. The process flow is: first put a certain amount of polysilicon raw material into the crucible, heat it to melt (temperature up to 1600°C), clamp the seed crystal (ie crystal seed) at the lower end of the pull rod, immerse in the molten crystal raw material, pull the rod Slowly pull up and rotate slowly at the same time, and finally grow a cylindrical single crystal silicon rod. The entire single crystal growth process is roughly divided into six stages: (1) charging and melting; (2) welding of seed crystal and m...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to solve the problems that the temperature gradient of the crystal and the melt at the interface in the traditional Czochralski furnace is difficult to control, and the energy utilization rate of the heater is not high.

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