THE ROLE OF ANTIPHASE DOMAIN BOUNDARIES IN SI EPITAXY BY ULTRAHIGH-VACUUM CHEMICAL-VAPOR-DEPOSITION FROM SIH4 OR SIH2CL2 ON SI(100)-(2X1)

The importance of antiphase domain boundaries for epitaxial multilayer growth during ultrahigh vacuum chemical vapor deposition of Si on Si( 100)-(2 x 1) from SiH4 and SiH2Cl2 at intermediate temperatures is ill ustrated. Under these conditions multilayer growth is governed by hete rogeneous nucleation of dimer strings at antiphase domain boundaries o f the underlying layer which represent deep potential minima for diffu sing species. This is in contrast to the formation of the first epitax ial layer, which nucleates homogeneously on the hat substrate terraces .