高輝度放射光XPSによるSi(001)表面炭化・酸化反応過程のリアルタイム観察

Real-time observation for carbonation and oxidation processes at Si(001) surface by high briliance synchrotron radiation XPS

穂積 英彬*; 小川 修一*; 吉越 章隆 ; 石塚 眞治*; 寺岡 有殿; 高桑 雄二*

Hozumi, Hideaki*; Ogawa, Shuichi*; Yoshigoe, Akitaka; Ishizuka, Shinji*; Teraoka, Yuden; Takakuwa, Yuji*

p型Si(001)表面酸化に対する基板歪みの影響を明らかにするため、エチレンを用いてSiを炭化させてSiC層を形成した。実験はSPring-8のBL23SUの表面化学反応解析装置にて高輝度放射光XPSを用いて行った。酸化速度はSiC層表面の方が清浄面より速かった。また、バルクSiの光電子強度で規格化したC1s強度は表面酸化で一定であり、界面酸化で緩やかに減少するため、C原子の脱離やSiO膜中への取り込みが起こらず、Si基板内部へ拡散していることが示唆された。

We investigated effects of lattice strain due to displacement of hetero atoms on a p-type Si(001) surface during oxidation. Experiments were performed using the surface reaction analysis apparatus placed at the BL23SU of SPring-8. In order to change the lattice strain, an SiC layer was formed by carbonization with CH exposure. Oxidation rate on the carbonized surface was faster than that on a clean surface. C1s photoemission intensity normalized by Si bulk intensity was almost constant during oxidation at the surface and gradually decreased at the interface. It was suggested that C atoms did not exist in the SiO layer and diffused into the Si substrate, and the growth of oxide was related with the normalized C1s intensity.