The authors have identified oxidation and desorption processes of Ge native oxide by chemical bonding states measured by X-ray photoemission spectroscopy. Ge oxidation occurs at the temperatures of 450500 °C in an oxidizing ambient. Ge desorption in nitrogen ambient is observed at the temperatures of 500550 °C, which is higher than the oxidation temperature by 50 °C. Combined oxidation and desorption processes proceed subsequently and cause a loss of Ge from the surface when Ge is annealed in oxidizing ambient at a temperature higher than desorption temperature. The surface loss is avoided when Ge is annealed with SiO2 cap layer in an identical annealing condition.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering