Real-time observation of thermal oxidation process on high-index silicon surfaces by means of photoemission spectroscopy with synchrotron radiation

大野 真也*; 安部 壮祐*; 兼村 瑠威*; 吉越 章隆; 寺岡 有殿; 尾形 祥一*; 安田 哲二*; 田中 正俊*

no journal, , 

The initial oxidation on high-index silicon surfaces with (001), (113), (120) and (331) orientations at 340-920 K has been investigated by real-time X-ray photoemission spectroscopy using 687 eV photons. Based on the study of Si(001), it has been shown that O 1s state can be decomposed into two components, low-binding-energy component (LBC) and high-binding-energy component (HBC). Analysis of the O 1s state indicated that the O atom in the strained Si-O-Si structure contributes to LBC, although this state was assigned to the suboxide components. Temperature dependence of the ratio of LBC and HBC indicated that relaxation of the interface strain occurs above a certain critical temperature except Si(113). We observed an abrupt change of the Si intensity above 820 K for Si(120). LEED patterns suggest that no surface reconstruction occurs on this surface, indicating that growth mode changes due to instability of the surface structure.