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 illustrated. Under these conditions multilayer growth is governed by heterogeneous nucleation of dimer strings at antiphase domain boundaries of the underlying layer which represent deep potential minima for diffusing species. This is in contrast to the formation of the first epitaxial layer, which nucleates homogeneously on the hat substrate terraces.