Silicon epitaxy on hydrogen-terminated Si(001) surfaces using thermal and energetic beams

Silicon epitaxy on hydrogen-terminated Si(001) surfaces has been studied using molecular dynamics simulations. Epitaxy on the dihydride-terminated Si(001)-(1 x 1)surface is inhibited for Si atoms at thermal energies due to strain hindrances created by hydrogen. At greater incident Si atom energies (2-10 eV), epitaxy proceeds primarily through ''subplantation'', i.e. subsurface implantation of the incident Si atom accompanied by segregation of SiH2 during growth. The subplantation probability rises very rapidly with the incident-atom energy, a result which is consistent with the observation of epitaxial film growth on dihyride-terminated Si(001) by sputter deposition when under similar conditions conventional molecular beam epitaxy results in amorphous Si growth. On the hydrogen-terminated Si(001)-(2 x 1) surface, the simulation results suggest that both subplantation and hydrogen atom transfer to the incident Si atom are possible routes to epitaxy. (C) 1997 Elsevier Science B.V.