Thermal system and process for controlling 8-inch zone melting silicon monocrystals

Abstract

The invention relates to a thermal system and a process for controlling 8-inch zone melting silicon monocrystals. The thermal system comprises a coil and a heat insulating bucket; two sides outside a furnace with the same height of the coil 1 are provided with magnetic field generators for generating transverse magnetic fields; and a reflector for reflecting heat of a melting zone is arranged between the coil and the heat insulating bucket. The process comprises the following steps of: when the shoulder expanding diameter reaches 100mm, extending the reflector to form a heat insulating circle at the peripheries of the silicon monocrystals, opening the magnetic field generators, ensuring that the height of the melting area above the silicon monocrystals is 3-5mm in the shoulder expanding process; and when the diameter of the silicon monocrystals reaches 205mm, rotating an arm, wherein the furnace pressure is 4-8bar in the equal diameter keeping process. Because the newly designed zone melting silicon monocrystal thermal system is adopted and process parameters are adjusted, 8-inch zone melting silicon monocrystals are drawn successfully, the problems of temperature fluctuation and fusion flow fluctuation in large-diameter silicon monocrystal forming difficulties are solved, dislocation is avoided and reduced, and the requirement of the market on the 8-inch zone melting silicon monocrystals is met.

Description

technical field [0001] The invention relates to a silicon single crystal drawing method, in particular to a thermal system and process for pulling an 8-inch zone melting silicon single crystal. Background technique [0002] In order to increase productivity, reduce costs, and increase profits, semiconductor device manufacturers are gradually requesting to increase the diameter of silicon wafers. Larger diameters are an eternal topic for the semiconductor device industry and the material industry. However, in the production process of zone-melted silicon single crystals, it becomes more and more difficult to form crystals with the increase of single crystal diameter. Due to problems in equipment, thermal system, process parameters, etc., the prior art The maximum size of the molten silicon single crystal in the lower zone is Φ6 inches. Contents of the invention [0003] The object of the present invention is to provide a thermal system and process for drawing 8-inch zone m...

AI Technical Summary

Problems solved by technology

In this regard, the present invention solves the problem of temperature fluctuation and melt fluctuation by applying a magnetic field and controlling the height of the melting zone above the single crystal, so as to reduce the solidification strain and stress

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