Thermal desorption of Ge native oxides and the loss of Ge from the surface

The annealing behavior of Ge native oxides has been studied with x-ray photoemission spectroscopy (XPS). The native oxides were primarily GeO₂ with small amounts of GeO_x (x<2). Annealing was performed using a rapid thermal processor (RTP) with a N₂ purge at atmospheric pressure. Ion-implanted Ge substrates were used to investigate the loss of Ge from the surface due to thermal desorption of Ge oxides. It was found that thermal desorption of volatile Ge oxides and oxidization of Ge take place successively, which results in the loss of Ge from the surface.