Oxidation states of Ge(100)-21 surface formed by supersonic O molecular beam

Yoshigoe, Akitaka ; Teraoka, Yuden; Okada, Ryuta; Yamada, Yoichi*; Sasaki, Masahiro*

Ge has been attracting considerable attention as one of the promising materials for next-generation MOSFET devises because of its high carrier mobility. In the application of Ge, it is important to fabricate well-defined thin oxide layer on the surfaces. Understanding of adsorption process of oxygen molecules on surfaces of Ge is the essential step toward the establishment of the controlled oxide layer. In this research, we studied the oxidation mechanism of the Ge(100) using in-situ SR-XPS (synchrotron radiation X-ray photoelectron spectroscopy). In the oxidation of Ge(100) at room temperature, it was found that the population of the higher oxidation state of Ge became larger with increasing the translational energy of the impinging oxygen beam. This is very essential information that will be important in controlling the oxide layer on Ge substrate.