Effects of two‐step rapid thermal processing in different ambients on denuded zone and oxygen precipitation in Czochralski silicon

The effects of two-step rapid thermal processing (RTP) sequentially in different ambients on the formation of denuded zone (DZ) and oxygen precipitation in the Czochralski (CZ) silicon wafers have been investigated. With the first-step RTP in Ar ambient, no obvious DZ but a high density of bulk micro-defects (BMDs) were formed in the sample with the second-step RTP in N2 ambient, while the BMD density in the sample with the second-step RTP in O2 ambient was remarkably low. With the first-step RTP in N2 ambient, a high density of BMDs and a width of DZ could be formed in either of the samples with the second-step RTP in Ar or O2 ambient, but the DZ width in the two samples differed to a certain extent. With the first-step RTP in O2 ambient, the two samples with the second-step RTP in Ar and N2 ambients respectively possessed reasonably comparable DZ width and BMD density. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)