Patent ID: 6436846
Filing Date: 2002-08-20
Classification: H01L

Abstract:
A combined preanneal/oxidation single rapid thermal process (RTP) to simultaneously obtain a preselected thermal oxide thickness and a corresponding preselected denuded zone depth and bulk micro defect density (BMD) on a silicon wafer, comprising:exposing the wafer to a controlled temperature and a controlled preannealing time in an oxidation ambient selected from 100% oxygen argon with about 5% oxygen, NO and N2O for about 10 seconds at ambient pressure to obtain a preselected target pad thermal oxide thickness about 4 nm to about 8 nm that corresponds to a preselected target denuded zone depth of about 10 &mgr;m and thereby eliminate the need to strip an oxide layer of uncontrollable thickness prior to formation of a pad nitride; said controlled temperature ranging from about 1,150Â° C. to about 1,200Â° C.