Internal gettering in epi silicon prepared under different conditions

The efficiency of internal gettering in epi-silicon was studied in samples prepared under different conditions as compared to external gettering and p(+) gettering. The parameters changed were substrate resistivity, oxygen content and presence/absence of poly-Si on the tack-side. The efficiency of internal gettering was assessed by measurement of the electron-beam-induced-current contrast versus temperature and applying existing models for interpreting the results, Internal gettering is effective also in p(+) substrates with poly-Si on the back-side when the density of oxygen precipitates is high and their size small. Internal gettering is not effective for low density of oxygen precipitates when either p(+) substrates or poly-Si or both are used.