Kinetics and Mechanism of Nanostructures in Oxidation ofSi_1-xGe_x Alloys

We investigate the oxidation behaviour of Si_1-xGe_x alloys (x= 0.05, 0.15, and 0.25). The oxidation of SiGe films with different compositions was carried out in O₂ (dry) atmosphere at 800 °C , 900 °C, and 1000 °C, respectively, for various lengths of time. The thickness and property of nanoparticle and nanolayer in oxide films and germanium segregation in oxidation of SiGe alloys are measured by using a high precision ellipsometer. The results are in good agreement with the Rutherford backscattering spectrometry, profile dektak instrument and high-resolution scanning transmission electron microscopy. We found that the Ge content in the oxide layer increases with the Ge content in SiGe alloys, the Ge content in the oxide film decreases with the increasing oxidation temperature and time. Rejection of Ge results in piling up of Ge at the interface between the growing SiO₂of nanostructure of oxide and Ge segregation in oxidation of
Si_1-xGe_x alloys.