Effects of low-energy ion beam action on Ge/Si heteroepitaxy from molecular beam

The evolution of the surface morphology of a pseudomorphic Ge film on Si up on irradiation with its own low-energy (230 eV) ions during heteroepitaxy f rom molecular beam has been studied experimentally by reflection high-energ y electron diffraction. It has been found that irradiation with a continuou s ion beam leads to a decrease in the critical Ge film thickness at which a transition from two-dimensional layer-by-layer to three-dimensional growth takes place. Exposure to pulsed ion irradiation (0.5 s) at instants of tim e that correspond to a fractional surface coverage more than 0.5 enhances t he reflection intensity, which corresponds to a decrease in the roughness o f the growth surface. (C) 2000 MAIK "Nauka/Interperiodica".