B SI(100) SURFACE - ATOMIC-STRUCTURE AND EPITAXIAL SI OVERGROWTH/

A boron-accumulated Si(100) surface with boron coverage up to 0.1 mono layer has been prepared by high-temperature annealing of B-doped Si sa mples. Scanning tunneling microscopy has been used to monitor the tran sformation in surface morphology and surface atomic structure induced by boron surface accumulation. The specific boron-induced surface feat ures have been elucidated and a model of their atomic structure has be en proposed. On the boron-accumulated surface epitaxial Si films with a thickness of 0.1-3.0 monolayers have been grown using solid phase ep itaxy and molecular beam epitaxy. The results show that under appropri ate growth conditions B surface segregation can be suppressed even on the atomic scale. The effect of boron induced features on the growth p rocess has been discussed. (C) 1996 American Vacuum Society.