Experimental verification of the unified Si oxidation model, 4; Dependence on surface oxidation reaction manner

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

In this study, real-time XPS observation of Si(001) surface oxidation is employed to investigate the surface oxidation reaction manner dependence of SiO/Si interface and growth rate of the second oxide layer. Oxidation experiments were performed at the surface reaction analysis apparatus placed at BL23SU, SPring-8. A p-type Si(001) surface was oxidized by dry oxygen. In the Langmuir-type adsorption, the amount of strained Si atoms at the end of surface oxidation is 0.46 ML, and then significant interface oxidation can be observed. On the other hand, in the 2D oxide island growth, the amount of strained Si atoms is 0.15 ML and progress of interface oxidation hardly observed. These results indicate that when interface strain is large, the interface oxidation rate also large, and then that strongly depends on Si surface oxidation manner.