Heat field structure for growth of low-dislocation single crystals by czochralski method and growing process of single crystal

Abstract

The invention discloses a heat field structure for growth of low-dislocation single crystals by a czochralski method and a growing process of the single crystals. The heat field structure comprises a main heater and a bottom heater, the main heater is arranged along the wall of a single crystal furnace, the bottom heater is arranged at the bottom of the single crystal furnace, the main heater is of a gradual cylinder structure, the upper portion of the gradual cylinder structure is thin, and the lower portion of the gradual cylinder structure is thick. The process for growth of the low-dislocation single crystals by the heat field structure at least includes the steps: (1) selecting dislocation-free single crystals as seed crystals, rising temperature, and melting materials to meet target temperature in the growth process of the crystals; (2) stabilizing melts for some time, enabling a heat field to stabilize, searching seeding temperature, performing seeding for 1 hour at a seeding temperature point, and directly crystallizing; (3) automatically controlling equal-diameter growth, closing, and cooling to the indoor temperature to finish growth of the low-dislocation crystals. By the aid of the heat field structure, temperature gradients in a heat field can be reduced, low-temperature gradient areas are enlarged, and the effective length of the low-dislocation crystals can be increased by the aid of the growing process of the crystals in low-temperature gradient heat field.

Description

technical field [0001] The invention relates to a thermal field structure and a growth process for growing a low dislocation single crystal by Czochralski method, and belongs to the technical field of low dislocation single crystal growth. Background technique [0002] The Czochralski method is an important single crystal growth method, which is observable, has a short crystal growth cycle, high efficiency and low cost, and can obtain high-quality single crystals with large diameters. In the Czochralski low dislocation single crystal growth, the temperature gradient is the key factor affecting the dislocation density. Straight single heater structure such as figure 1 As shown, the heater 1 is straight and has the same thickness up and down. In this thermal field, the temperature gradient changes greatly, the temperature gradient at the edge of the heater is large, and the low temperature gradient area is small. Growing low-dislocation single crystals in such a thermal fie...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a thermal field structure for growing low dislocation single crystals by the Czochralski method, so as to solve the problems of large temperature gradient and small range of low temperature gradient regions in the existing low dislocation growth thermal field system

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