Oxygen atoms dissolved near the surface regions in Ge1-xSix alloys were studied by extended energy-loss fine structure analysis using electron energy-loss spectroscopy and the local structures around O were determined. Oxygen preferentially formed Si-O-Si centers, rather than Si-O-Ge or Ge-O-Ge. The O-Si bond length was increased with decreasing Si content, in accordance with the increase in the Si-Si, Si-Ge and Ge-Ge bond lengths. The increase in O-Si bond length was much more significant than that expected from the changes in Si-Si, Si-Ge and Ge-Ge bond lengths. The derived local atomic configuration of the Si-O-Si center changed with increasing Si content, which corresponds well to the surface oxidization process of crystalline Si.

Structure of Oxygen-Related Defect Centers in Ge1-xSix Alloys Studied by Extended Energy-Loss Fine Structure Analysis. S.Muto, H.Sugiyama, I.Yonenaga, T.Tanabe: Japanese Journal of Applied Physics, 2005, 44[4A], 1892-6