Effects of ambients on oxygen precipitation in silicon

摘要

We have discovered an ambient effect on the precipitation of oxygen in the bulk of silicon wafers. Oxidizing ambients were found to strongly retard the precipitation, in comparison with various inert ambients. The precipitation process was studied by the methods of infrared spectrophotometry, thermal conversion, and transmission electron microscopy. In oxidizing ambients, oxygen precipitates tended to cluster in colonies. A typical colony consisted of a few to tens of precipitates, webbed in a complex of dislocation loops. In contrast, precipitates formed in inert ambients were usually isolated. Two mechanisms are suggested to explain this effect, both involving oxidationhyphen;generated silicon selfhyphen;interstitials.