Quick-cooling induced acceleration of oxidation on Si(001) studied by real-time photoelectron spectroscopy

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

Real-time photoelectron spectroscopy using a He-I resonance line and synchrotron radiation have been carried out to measure oxide thickness, oxidation states and strained Si atoms near the SiO/Si(001) interface during oxidation with varying temperature to clarify the mechanism of interface oxidation. A slight acceleration of oxidation rate also occurred even when substrate temperature was cooled down from 550C to 90C. In this case, the thermal activation effect is ruled out. It was found that the significant increase of Si occurred at the same time of the increase of Si only during cooling. After cooling down to about 90C, both of Si and Si increase very slowly. This good accordance suggests that the increase of interface strain is associated with the increase of active site of O dissociative adsorption at interface as expected in our Si oxidation model.