Atomic Scale Control of Si(001) Surface by Wet-Chemical Treatment

Abstract

ABSTRACTSTM observation of the wet-chemical treated Si(001) surface was carried out. On the surface treated by 1%-HF solution (pH=2), the STM images were always rough and hardly exhibited the atomic feature. The STM images on the surface treated by HCl:HF=19:1 solution (pH<1) after 1%-HF dipping were also rough in a macroscopic scale but they occasionally shown atomlike corrugation in a magnified scale. The atomlike corrugation tends to align toward [110] directions which may reflect the ordered structure on Si(001) surface. This result indicates that in the case of etching by the HCl:HF=19:1 solution, the microscopic roughness on Si(001) surface tends to decrease, which might be explained by the steric hindrance effect during extremely slow etching.