Patent ID: 6448157
Filing Date: 2002-09-10
Classification: H01L,Y10S

Abstract:
A fabrication process for a semiconductor device, comprising the steps of:oxidizing surfaces of a substrate at a temperature equal to or higher than 1050Â° C. to form oxide films each of a thickness equal to or more than 1500 nm; removing an oxide film formed on a back surface of the substrate by etching; depositing polysilicon films on both surfaces of the substrate; etching the substrate so as to remove the polysilicon film and the oxide film formed on the surface of the substrate while at least one portion of the oxide film on the surface of the substrate is preserved; further etching the substrate using an etching liquid with which substantially no etching of silicon occurs so as to remove the preserved oxide film on the surface of the substrate; and thereafter, effecting element isolation on the surface of a substrate.