This study examined the morphological and compositional changes that occur in oxidized poly-Si1-xGex film during electron-beam irradiation in a transmission electron microscope. Before irradiation, the oxide layer was composed of a mixture of SiO2 and GeO2 phases. However, during electron-beam irradiation, there were significant changes in the microstructure and elemental distribution. For the oxidized poly-Si0.6Ge0.4 films, the agglomeration of GeO2 was observed at the surface region. On the other hand, in the case of the oxidized poly-Si0.4Ge0.6 films, the crystallization of GeO2 occurred in the oxide layer. Ge lattice fringes and twinning were also observed in the oxide layer. (C) 2007 Elsevier B.V. All rights reserved.