Crystallization method for improving czochralski monocrystal

Abstract

The invention provides a crystallization method for improving a czochralski monocrystal. The crystallization method comprises the step: sequentially adding a silicon raw material and a barium carbonate powder into a quartz crucible at an initial charging stage of the czochralski monocrystal. The quartz crucible comprises a body; the body comprises a transparent layer and an air bubble layer whichare sequentially arranged from inside to outside; and the outer wall of the body is provided with an outer coating. The invention provides the crystallization method suitable or pulling P-type and N-type silicon single crystal rods, the technical problem that barium carbonate powder is repeatedly added during repeated charging to increase the content of a barium element in a silicon liquid so as to result in low crystallization rate of the czochralski monocrystal is solved, not only can the crystallization rate of monocrystal pulling be increased, but also the content of the barium element inthe silicon liquid can be effectively controlled, the process is simplified, the production efficiency is increased, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of Czochralski silicon single crystal, and in particular relates to an improved crystallization method of Czochralski single crystal. Background technique [0002] The traditionally used quartz crucible is coated on the inner wall. The disadvantage of coated crucible is that it increases the crucible making process, wastes man-hours, increases costs, and the inner coating is easy to fall off with long-term high-temperature operation. With the growth of crystals, There will still be a small amount of Ba element entering the silicon liquid, which will change the structure of the growing crystal, generate dislocations, and cause crystal formation differences. At the same time, the outer wall in contact with the carbon-carbon crucible is easily softened and has a short service life. [0003] Proposed in the open patent CN109267147A that the applicant applied to add barium carbonate powder in the drawing process...

AI Technical Summary

Problems solved by technology

[0004] The problem to be solved by the present invention is to provide a method for improving the crystallization of Czochralski single crystals, especially suitable for the drawing of P-type and N-type single crystal silicon rods, which solves the problem of repeated throwing and charging in the prior art. Repeated sprinkling of barium carbonate powder increases the content of barium in the silicon liquid, resulting in the technical problem of low crystallization rate of Czochralski single crystal. It can not only improve the crystallization rate of single crystal pulling, but also effectively control the barium in the silicon liquid. The content of elements, simplify the process, improve production efficiency and reduce production costs

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