Point defect engineering strategies to suppress A-center formation in silicon

We investigate the impact of tin doping on the formation of vacancy-oxygen pairs ( VO or A-centers) and their conversion to VO2 clusters in electron-irradiated silicon. The experimental results are consistent with previous reports that Sn doping suppresses the formation of the A-center. We introduce a model to account for the observed differences under both Sn-poor and Sn-rich doping conditions. Using density functional theory calculations, we propose point defect engineering strategies to reduce the concentration of the deleterious A-centers in silicon. We predict that doping with lead, zirconium, or hafnium will lead to the suppression of the A-centers. (C) 2011 American Institute of Physics. [doi:10.1063/1.3666226]