Effects of initial in coverage for preparation of InSb bilayer on electrical properties of InSb films grown by surface reconstruction controlled epitaxy

We investigated the effects of initial In coverage for the preparation of InSb bilayer on electrical properties of InSb films grown by surface reconstruction controlled epitaxy. The electron mobility of the InSb films was affected by the initial In coverage of the In-induced surface reconstruction on Si(111) surface. Electron mobility increased with the increase in the initial In coverage up to 1.5 monolayers (ML), and decreased with further increase in In coverage. The InSb film grown with an optimal initial In coverage of 1.5ML has a high electron mobility of about 40,000 cm ²/(V·s) at room temperature. This may be due to the reduction of the 2×1-Sb surface phase or In islands on the surface after the preparation of the InSb bilayer, which cause dislocations in the film. Therefore, the perfectness of the order of atomic planes in Si-Sb-In is very important for a uniform InSb/Si interface formation before the subsequent InSb molecular beam epitaxy (MBE) growth.