Method and thermal field for growing ingot polycrystal silicon by adopting directional solidification method

Abstract

The invention relates to a method and a thermal field for growing ingot polycrystal silicon by adopting a directional solidification method. The method comprises the following steps of melting, crystallizing, annealing and cooling. The heat insulation cavity in the ingot polycrystal thermal field consists of a top plate, side walls and a bottom plate, wherein the top plate is fixedly positioned; the side walls and the bottom plate can move up and down; and the distance between each side wall and the bottom plate is controlled according to the requirements of different stages in a crystal growth process. The invention has the advantages that: the power consumption in the material meting process is reduced, and the effect of saving power is achieved; and the movement distance of the bottom plate and each side wall of the heat cavity is respectively controlled, the heat dissipation direction of the bottom is controlled in the polycrystal silicon ingot growth process and the growth interface of the crystal is indirectly controlled, so that the flat growth interface is favorable for obtaining high-quality crystal and improving the installing and replacing efficiency of photovoltaic cells.

Description

technical field [0001] The invention relates to a polycrystalline ingot crystal growth process, in particular to a polycrystalline ingot growth method capable of effectively saving energy and controlling the crystal growth interface and its thermal field. Background technique [0002] There are two representative thermal fields for growth of ingot polysilicon by directional solidification. One is represented by GTsolar, which is characterized by opening and closing the bottom of the heat preservation chamber through the movement of the side wall of the heat preservation chamber, realizing the crystallization of materials, Growth, annealing, cooling and other processes. The other is represented by the heat field of Jinggong polycrystalline furnace growth furnace. The characteristics of its growth process are that the bottom plate of the heat preservation chamber is moved to achieve the purpose of opening and closing the bottom of the heat preservation chamber, and realize cry...

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Problems solved by technology

During the crystal growth process of Jinggong Polycrystalline Furnace, the side wall of the heat preservation chamber is fixed, the bottom plate moves down, the distance between the heat dissipation window and the ingot block is relatively large, and the heat dissipation around the opening causes the heat dissipation intensity of the center to be much greater than that of the edge, causing the center of the crystal growth interface to be convex. , the radial temperature gradient in the crystal is large, and the thermal stress will produce too many crystal defects, which will affect the quality of the crystal

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