Strain-induced reaction kinetics of O molecule at SiO/Si interfaces studied by real-time X-ray photoelectron spectroscopy
SiO/Si界面での歪誘起O反応キネティクスのリアルタイムX線光電子分光研究
Tang, J.*; 小川 修一*; 吉越 章隆 ; 石塚 眞治*; 高桑 雄二*
Tang, J.*; Ogawa, Shuichi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; Takakuwa, Yuji*
界面酸化速度(Rint), 酸化状態(Si, Si, Si, Si), 酸化誘起歪(Si, Si)の大きさを酸化中同時モニターするために、O圧力(PO)に依存したOSiO/Si界面でのO反応キネティクスをSPring-8のBL23SUにおいてリアルタイムX線光電子分光を使って調べた。表面酸化後、POを増やすと非線形(Rintは(PO))な振る舞いをした(ここでnはSi(111)およびSi(001)基板に対して概ね0.5)。結果は酸化誘起歪によって生成する欠陥がSiO/Si界面でのOの活性な解離吸着サイトであるという酸化モデルによって解釈できる。さらに、表面酸化中にPOを増やすとSiとSiが界面参加開始時点で大きく変化することもわかった。
The reaction kinetics of O molecule at SiO/Si interfaces were investigated as a function of O pressure (PO) by real-time X-ray photoelectron spectroscopy at BL23SU, SPring-8, to monitor the interfacial oxide growth rate (Rint), the oxidation states (Si, Si, Si and Si, and the magnitude of oxidation-induced strain (Si and Si) at the same time during oxidation. When increasing PO after the surface oxidation, Rint showed a nonlinear power-low function of (PO), where n was almost the same as 0.5 for both Si(111) and Si(001) substrates. The results are interpreted by a Si oxidation model, in which the defect generated by the oxidation-induced strain is an active site for dissociative adsorption of O at SiO/Si interface. Furthermore, when increasing PO during the surface oxidation, Si and Si showed significant changes at the start of interfacial oxidation.