SiO desorption kinetics of Si(111) surface oxidation studied by real-time photoelectron spectroscopy

Tang, J.*; Nishimoto, Kiwamu*; Ogawa, Shuichi*; Yoshigoe, Akitaka ; Ishizuka, Shinji*; Watanabe, Daiki*; Teraoka, Yuden; Takakuwa, Yuji*

The kinetics of the initial oxide growth on the Si(111) surface have been investigated using real-time photoelectron spectroscopy and density functional theory calculations. Including SiO desorption into the description of the transition from Langmuir-type adsorption to two-dimensional oxide island growth reveals that oxidation at high temperature and low oxygen pressure is not governed by 2D oxide island growth despite sigmoidal oxygen uptake curves. Because SiO desorption during the initial oxide growth depends strongly on temperature and oxide coverage in the transition region, an initial oxidation model for the transition region is proposed. According to O-pressure dependent experimental results and theoretical calculations, the SiO desorption is due to the formation of the transition state tri-ins2 species, SiO desorption during the initial oxidation is suppressed by the most thermally stable oxygen adsorption species tri-ins3 formed on Si(111)77.