Oxidation-enhanced difusion of C atoms on SiC alloy layer/Si(001) surface under oxide growth and etching conditions

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

The oxidation kinetics on the SiC alloy layer has been investigated using the real-time XPS measurement. Experiments were performed at the BL23SU of SPring-8. The SiC alloy layer was formed with exposing a p-type Si(001) surface to ethylene, and the SiC alloy layer was oxidized at Langmuir-type adsorption (773 K) and 2D oxide island growth (933 K), respectively. In case of Langmuir-type adsorption, it is found that no carbon atoms are oxidized and carbon concentration at the SiO/Si interface increases. These results indicate the carbon atom condensation occurs, leading to the SiO/SiC/Si layers formation. On the other hand, the carbon concentration decrease by 20% in spite of the etching of 38 Si layers in the 2D oxide island growth. Based on these results, it is found that the diffusion of carbon atoms is occurred due to not only oxide growth but also Si etching.