Residual Strains in Phosphorus-Diffused Silicon

Abstract

An x-ray line-broadening method is used to determine the residual strain level in a single-crystal silicon slice diffused with high amounts of phosphorus (surface concentration >1021 atoms/cm3). The strain level was found to be higher than that from the Prussin model. This is shown to be due to insufficient penetration of the diffusion-induced dislocations inside the diffused layers. Moreover, the strains along 〈220〉 directions were found to be considerably higher than those along other directions. This is interpreted as additional broadening along the Burgers vector direction.