Absorption coefficient of oxide precipitates in silicon wafers after different three-step annealing

Systematic measurements aimed at quantifying the contribution of precipitates to the infrared absorption of silicon are presented here, carried out on wafers with the same initial interstitial oxygen (Oi) concentration subjected to three-step treatments. To precisely determine the intensity of the precipitate-related bands, the measurements were performed at liquid He temperature. The results demonstrate the possibility of accounting for the contribution of precipitates in the standard quantitative determination of Oi in silicon at room temperature.