Growth of the Ge overlayer on Si(100)-(2 x 1)

The initial stages of the development of a Ge adatom layer on a clean Si(001)-(2 x 1) surface are consistent with random deposition and limited surface mobility. A critical comparison of the rate of attenuation of the Si buckled dimer up-atom signal by Ge deposition with the growth of the two well-resolved features of the Ge adatom spectrum rules out the substitution of Ge into the Si dimers. Instead, Ge is captured by the dangling bonds of the Si dimers and remains on the surface, initially dominantly as isolated Ge atoms, then as dimers, and finally in islands or clusters. (C) 2000 Elsevier Science B.V. All rights reserved.