Zhejiang University

Xiangyang Ma

Deren Yang

Biao Wang

Ze Xu

An internal gettering process for a Czochralski silicon wafers comprises: (1) heating a Cz silicon wafer to 1200-1250&#xb0; C. at a heating rate of 50-100&#xb0; C./s under a nitrogen atmosphere, maintaining for 30-150 seconds, cooling the Cz silicon wafer to 800-1000&#xb0; C. first at a cooling rate of 5-50&#xb0; C./s, and then cooling the Cz silicon wafer naturally; (2) annealing the Cz silicon wafer obtained in the step (1) at 800-900&#xb0; C. under an argon atmosphere for a period of 8-16 hours. The present invention only involves two heat treatment steps which require lower temperature and shorter time comparing to the conventional processes. The density of the bulk microdefects and the width of the denuded zone can be easily controlled by the temperature, duration and cooling rate of rapid thermal processing in the first step.

Growing community of inventors

Hangzhou, China

Xiangyang Ma