Thermal Stability and Oxidation of Group IV Terminated (100) Diamond Surfaces

High resolution X-ray photoelectron spectroscopy is used to explore the thermal stability of as-prepared and oxidized silicon and germanium-terminated (100) diamond surfaces which form two domain (3 × 1) surface reconstructions. The as-prepared germanium and silicon-terminated surfaces are stable up to 1200 °C, making them the most thermally stable surface termination for diamond (100). The oxidized forms of these surfaces can be created via exposure to O₂, H₂O or atmospheric conditions and retain the (3 × 1) surface symmetry. The thermal stability of the oxidized surfaces exhibit differing behavior. A 700 °C anneal is sufficient to liberate oxygen from the germanium-oxide-terminated (100) diamond surface, leaving the pristine germanium-terminated surface, while the silicon-oxide-terminated surface is thermally stable up to 1200 °C, at which point both silicon and oxygen are removed.