IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Electronics Thursday Sessions
       Session EL-ThA

Paper EL-ThA7
RHEED Intensity Oscillation during Thermal Oxidation on Si(001) Surface with O@sub 2@

Thursday, November 1, 2001, 4:00 pm, Room 124

Session: In-Situ Semiconductor Characterization
Presenter: Y. Takakuwa, Tohoku University, Japan
Authors: Y. Takakuwa, Tohoku University, Japan
F. Ishida, Tohoku University, Japan
Correspondent: Click to Email
Auger electron spectroscopy combined with reflection high energy electron diffraction (RHEED-AES) was applied to investigate the surface reaction dynamics during thermal oxidation on Si(001)2x1 surface with O@sub 2@. In the RHEED-AES measurement, O KLL Auger electrons excited by a grazing-incident electron beam for RHEED observation were detected, enabling to observe simultaneously the SiO@sub 2@ coverage and surface morphology. In the temperature region of two-dimensional growth of SiO@sub 2@ islands at 630~800°C as confirmed by the time evolution of O KLL Auger electron intensity, an oscillatory behavior in RHEED half-order spot intensity was observed, indicating that etching of the surface occured between SiO@sub 2@ islands. The etching rate obtained by the oscillation period was 0.039 ML/s at an O@sub 2@ pressure of 2x10@super -7@ Torr independently of the temperature and SiO@sub 2@ coverage, and increased in proportion to the O@sub 2@ pressure, suggesting that the etching reaction was rate-limited by O@sub 2@ supply. Since part of adsorbed oxygen atoms is consumed for nucleation and two-dimensional growth of SiO@sub 2@ islands in this temperature region, the assigned rate-limiting reaction means that the etching reaction takes place not only through SiO desorption but also through SiO@sub 2@ growth, that is, incorporation of Si atoms into SiO@sub 2@ islands. The fraction of the amount of incorporated Si atoms into SiO@sub 2@ islands to that of etched Si atoms will be discussed against SiO@sub 2@ coverage.