Initial stages of Ge and Si growth near SB monoatomic steps on Si(100) -: art. no. 193306

We used ab initio methods, based on density functional theory, to study the interaction of Si and Ge monomers and dimers near monoatomic S-B steps on Si(100). We have obtained that the formation energies of rebonded and nonbonded steps are different, being 0.078 eV/2a and 0.068 eV/2a, respectively. For monomers, the interaction of Si and Ge near the steps is very similar, but for dimers they become different due to the larger bond distance between Ge atoms in the dimer. We have observed that Ge dimers will not bind directly to the step, what we propose can be responsible for the observed reversal of step roughness during Ge growth on Si(100).