E ffect of nitrogen doping on the minority carrier lifetime in

zhangcunbiao

E  ffect of nitrogen doping on the minority carrier lifetime in
Czochralski silicon
* Can Cui, Deren Yang , Xuegong Yu, Xiangyang Ma, Liben Li, Duanlin Que
State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou 310027, PR China
Abstract
The effect of nitrogen doping on the minority carrier lifetime in Czochralski silicon (CZ-Si) passivated in dry
O at different temperatures was studied. It was found that the most effective passivation temperature of 2
nitrogen-doped CZ silicon (NCZ-Si) wafers was 1000 8C, the same as that of CZ-Si wafers, but the most
effective passivation time was 0.5 h, which is shorter than that of CZ-Si wafers (1 h). Furthermore, with
increasing anneal time, the minority carrier lifetime of NCZ-Si decreased more quickly than that of CZ-Si, while
interstitial oxygen in NCZ-Si precipitated more heavily. The experiments also showed that, during two-step (650
8C11050 8C) annealing, the minority carrier lifetime of NCZ-Si decreased significantly due to oxygen
precipitation. It can be concluded that the crystal quality of as-grown NCZ-Si is similar to that of as-grown
CZ-Si, however the minority carrier lifetime of NCZ-Si decreased more rapidly than that of CZ-Si during
thermal cycles because of nitrogen enhancing oxygen precipitates.
  2002 Elsevier Science B.V. All rights reserved.
Keywords: Silicon; Lifetime; Passivation; Nitrogen
1   . Introduction