Reaction probabilities of oxygen with heated (110)-germanium and (111) and (100)-silicon single-crystals

Abstract

The reactivity of oxygen with heated (110)-germanium and (111) and (100)-silicon single crystals was investigated using a molecular beam technique. The sticking probability α of oxygen on (110)-oriented germanium crystals increased from less than 10^–3 to 2 × 10^–2 with increasing oxygen exposure. The value of α on silicon was 4 × 10^–2 at a substrate temperature of 1300°K, independent of water orientation or conductivity type. Silicon surfaces were observed to be rendered passive to oxygen attack at 1100–1200°K at an oxygen beam pressure of 5 × 10^–6 torr. Extensive faceting of the original, optically polished (110)-germanium surface characteristic of the crystallographic symmetry was observed.