Real-time measurements of chemical bonding states and substrate curvature during initial oxidation of Si(110) surface

Yamamoto, Yoshihisa*; Suzuki, Yasushi*; Miyamoto, Yu*; Bantaculo, R.*; Suemitsu, Maki*; Enta, Yoshiharu*; Teraoka, Yuden; Yoshigoe, Akitaka ; Asaoka, Hidehito  ; Yamazaki, Tatsuya

Time evolution of chemical bonding states and substrate curvature were measured by SR-PES (Synchrotron Radiation Photoemission Spectroscopy) and MOS (Multi-beam Optical Sensor) methods during initial oxidation of Si(110) surface. The SR-PES measurements were performed at the surface chemistry experimental station in the BL23SU of SPring-8. Oxygen uptake was a Langmuir type so that oxygen adsorption took place randomly in the conditions of 1.510 Pa and 873 K. In that case, Although Si and Si increased rapidly in the beginning of oxidation, Si was a minor component. This fact suggests that oxidation rate of inter-plane Si-Si bonds (B-bonds), which make a chain in the (-110) direction, is larger than that of in-plane Si-Si bonds (A-bonds) so that Si is observed strongly. The variation of substrate curvature also indicates that oxidation of B-bonds is faster than that of A-bonds, which makes a strong compression stress in the (-110) direction.