Self-organization in Si/CoSi2(111) heteroepitaxy

We present a scanning tunneling microscopy study of the initial stages of e pitaxial Si overgrowth of CoSi2(111) films. Under suitable growth condition s the silicon was found to decorate the steps of the silicide. This opens u p the possibility of creating arrays of parallel silicon wires on a CoSi2 s ubstrate. After oxidation of the silicon by exposing it to air the silicide in between the wires can be removed by wet etching, leaving an array of ex pitaxial CoSi2 wires. The mechanism leading to the formation of the silicon wires was identified as strongly enhanced diffusion of adatoms on a silici de surface compared to a silicon surface and preferential nucleation on upw ard steps. (C) 1999 American Vacuum Society. [S0734-211X(99)04804-0].