Observation of chemisorbed O molecule at SiO/Si(001) interface during Si dry oxidation

Siドライ酸化におけるSiO/Si(001)界面の化学吸着O分子の観察

津田 泰孝   ; 吉越 章隆 ; 小川 修一*; 坂本 徹哉*; 高桑 雄二*

Tsuda, Yasutaka; Yoshigoe, Akitaka; Ogawa, Shuichi*; Sakamoto, Tetsuya*; Takakuwa, Yuji*

We irradiated n-Si(001) with a 0.06 eV supersonic O molecular beam and characterized the SiO surface and SiO/Si interface using real-time X-ray photoemission spectroscopy. The molecularly-adsorbed O was observed not only during the Si surface oxidation process but also during the SiO/Si interface oxidation process, suggesting that trapping-mediated adsorption occurs at SiO/Si interface as well as on the Si surface. We found a good linear correlation between the SiO/Si interface oxidation rate and the amount of molecularly-adsorbed O, revealing that the double-step oxidation loop exclusively proceeds through P-paul formation and minority carrier trapping at room temperature. The offset of the linear correlation indicates the presence of ins-paul on the SiO surface, which has nothing to do with the double-step oxidation loop because point defect generation is not affected by the volume expansion of ins-paul oxidation in the flexible SiO network.