Dissociation reaction kinetics of metastable oxygen molecule on partially oxidized Si(111) surfaces by real-time photoelectron spectroscopy

リアルタイム光電子分光による部分酸化Si(111)面における準安定酸素分子の解離反応速度論

西本 究*; Tang, J.*; 小川 修一*; 吉越 章隆 ; 石塚 眞治*; 渡辺 大輝*; 寺岡 有殿; 高桑 雄二*

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

Metastable oxygen molecule has long lifetime of dissociation on Si(111) surface. We reported that the number of adsorbed oxygen atoms at the completion of Langmuir-type adsorption on Si(111) surface increases about three times with increasing temperature from room temperature to 873 K. In this study to clarify the role of metastable oxygen molecules in the initial oxide growth, real-time photoelectron spectroscopy techniques were used to measure time evolutions of oxygen uptake on partially oxidized Si(111) surface after oxygen supply was stopped. We concluded that the decrease of work function is ascribed to dissociation of metastable oxygen molecules, suggesting metastable oxygen molecules are concerned with the oxide growth until Langmuir-type adsorption is completed.