Surface defect formation in epitaxial Si grown on boron-doped substrates by ultrahigh vacuum chemical vapor deposition

We have investigated the formation mechanism of surface defects in a Si epi taxial layer grown on BF2+-implanted Si(100) substrates by ultrahigh vacuum chemical vapor deposition. The density of surface defects increases linear ly with the BF2+ dose. It is found that surface defects are generated at th e interface, although neither stacking faults nor dislocations are formed i n the epitaxial layer. X-ray photoelectron spectroscopy measurements reveal ed that surface segregation of boron occurs. We propose a model of the defe ct formation in which inhomogeneous distribution of segregated boron across the substrate surface causes the difference in the epitaxial growth rate b etween high and low boron concentration regions.