Raman spectroscopic study of surface layer in fluorine-implanted Si

Abstract

Raman scattering application was introduced to directly probe the depth profile of structural changes in a very thin surface layer of F+-implanted Si by use of a single Ar+ laser (488 nm) excitation. The results of Raman scattering and sheet resistance measurement showed an unusual annealing behavior of the F+-implanted Si:In the range of annealing temperature Ta from 200 °C to 400 °C, disordering was observed to increase with increasing Ta but a stronger trend of ordering with Ta increasing further above 400 °C. This abnormal behavior could be explained as due to competition between the ordering effect of thermal annealing with increasing Ta and the disordering effect of the implanted fluorine ions randomly breaking the Si–Si crystal bonds in the surface diffusion layer.