Effect of heat treatment on carbon in

zhangcunbiao

Effect of heat treatment on carbon in
multicrystalline silicon
Deren Yanga,
*, H.J. Moeller
b
a
State Key Lab of Silicon Materials, Zhejiang University, 310027 Hangzhou, China
b
Institute for Experimental Physics, Technical University of Freiberg, 09596 Freiberg, Germany
Abstract
Effect of heat treatment on carbon in cast multicrystalline silicon (mc-Si) has been studied
by means of Fourier Transmission Infrared Spectroscopy. Carbon is found to be involved in
the formation of as-grown precipitates in mc-Si with higher oxygen content. The experimental
results reveal that carbon is difficult to precipitate in mc-Si with lower oxygen or higher
nitrogen concentration during annealing in the temperature range from 4501C to 11501C.
Carbon can enhance the nucleation of oxygen precipitates at lower temperature (o8501C).
Although carbon does not affect the amount of oxygen precipitates at higher temperature
(>9501C), it is suggested that carbon diffuses into oxygen precipitates by the enhancement of
silicon self-interstitials. The experiments point out that preannealing at 7501C enhances the
decrease of substitute carbon concentration during subsequent annealing at 10501C.