The exposure of Ge (001) substrates to atomic oxygen was studied in situ to establish the
stability of the germanium oxide. After preparing chemically clean and atomically flat Ge
(001) surfaces, the Ge samples were exposed to atomic oxygen in a wide temperature range
from room temperature to 400 C⁠. The chemical composition of the so-formed oxides was
studied by means of x-ray photoelectron spectroscopy, while the structure was observed by
reflection high energy electron diffraction. At low substrate temperatures the atomic oxygen …