Defects in Si-Rich SiO2 Films Prepared by Radio-Frequency Magnetron Co-sputtering Using Variable Energy Positron Annihilation Spectroscopy

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2009,（4）
• 页码范围: 156-159
• 页数: 4页
• 语种: 英文

摘要

Si-rich SiO2 films prepared by rf magnetron co-sputtering method are studied by slow positron beams. The nega-tively charge point defects (probably Pb centres or peroxy radicals) at the silicon nanocluster (nc-Si)/SiO2 interface are observed by Doppler broadening spectra. Coincidence Doppler-broadening spectra show that positrons have a higher annihilation probability with core electrons nearby oxygen atoms than silicon atoms. The formation of N-related bonds may be the reason for the prevention of the migration reaction of Si and O atoms, hence nc-Si formation is inhibited by annealing in nitrogen compared to in vacuum.