On the origin of deep pit formation for gas phase HCl etched (111) silicon wafers

Abstract

A quantitative model is presented in which the formation process of deep etch pits on (111) silicon is described by the instability of hollow cores around dislocations. These dislocations may be grown-in dislocations introduced during CVD heating, or micro-defects in the form of dislocation loops. The critical undersaturation at which the hollow cores open up could be quantitatively compared with the steepness of shallow pits at the same undersaturation.