Effect of ramping anneals under inert or oxidizing ambient on the formation of oxygen precipitate denuded zone in nitrogen-doped Czochralski silicon wafers

✍ Scribed by Ma, Xiangyang ;Tian, Daxi ;Gong, Longfei ;Yang, Deren

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 206 KB
• Volume: 203
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.200522115

✦ Synopsis

Abstract

The formation of an oxygen precipitate denuded zone in nitrogen‐doped Czochralski (NCZ) silicon and conventional CZ silicon subjected to ramping anneals under Ar or O~2~ ambient has been investigated. It is revealed that the nitrogen doping is able to homogenize substantially the density of bulk micro‐defects associated with oxygen precipitation in the silicon wafers with different thermal histories and initial oxygen contents. The oxygen precipitate denuded zone is only formed in specimens subjected to the ramping anneal under Ar ambient. It is believed that the ramping anneal under Ar ambient could be an alternative intrinsic gettering process for NCZ silicon wafers, while it is not very appropriate for conventional CZ silicon wafers. Furthermore, it is somewhat unexpected that oxygen precipitation during the ramping anneal under O~2~ ambient is not suppressed but slightly enhanced in comparison with that during the ramping anneal under Ar ambient, the reason for which is tentatively explained. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)