Si(001) surface layer-by-layer oxidation studied by real-time photoelectron spectroscopy using synchrotron radiation

Ogawa, Shuichi*; Yoshigoe, Akitaka ; Ishizuka, Shinji*; Teraoka, Yuden; Takakuwa, Yuji*

In this study, layer-by-layer oxidation at Si(001) surface was studied experimentally by real-time photoelectron spectroscopy. Changes of band bending due to oxidation-induced midgap states in connection with the oxygen uptake and changes in oxidation states were observed. Oxidation experiments were performed using the surface reaction analysis apparatus (SUREAC2000) installed at the BL23SU in the SPring-8. O 1s and Si 2p core level photoelectron spectra were measured alternately at acquisition times of 24 and 65 s, respectively. Curve-fitting analyses for them were carried out and two and seven components were found, respectively. On the basis of the observed changes of each oxidation state, the Si emission kinetics during layer-by-layer oxidation is discussed.