Method of regenerating semiconductor wafer

Abstract

A method of regenerating a semiconductor wafer which allows a used wafer, even if the wafer contains a crystal defect such as a COP, to be regenerated into a high-quality semiconductor wafer is provided. A used silicon wafer is polished in a step S1. Next, the used silicon wafer is immersed in mixed acids including at least two kinds of acids in a step S2. A surface treatment is performed on the used silicon wafer to planarize the surface of the used silicon wafer in a step S3. Then, a high temperature annealing process is performed in a step S4, to ultimately obtain a regenerate wafer. The high temperature annealing process includes either a first high temperature annealing process which is performed at a high temperature of 1200° C. or higher in an argon atmosphere for 30 to 60 minutes, or a second high temperature annealing process which is performed at a high temperature of 1200° C. or higher in a hydrogen atmosphere for 30 to 60 minutes.

Dependencies are inferred from the claim text.