Characterization of monolayer oxide formation processes on high-index Si surface by photoelectron spectroscopy with synchrotron radiation

Abe, Sosuke*; Ono, Shinya*; Kanemura, Rui*; Yoshigoe, Akitaka ; Teraoka, Yuden; Ogata, Shoichi*; Yasuda, Tetsuji*; Tanaka, Masatoshi*

Thermal oxidation of high-index silicon surfaces, Si(113), Si(331) and Si(120) in a monolayer regime has been investigated by X-ray photoelectron spectroscopy (XPS) with synchrotron radiation. The oxide thickness, composition and band bending are evaluated by peak deconvolution of the Si 2p core level XPS spectra. We found that changes in the oxide composition correlate with changes in the band bending. This reveals that production of the Si state is associated with the Si ejection process accompanied by the production of vacancies. We found that reactivity of the Si(120) surface in oxidation is drastically reduced at reaction temperatures below 690 K.