Analysis of oxide layer on Ge(100)-21 formed by supersonic O beam

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

Ge has been attracted considerable attention as a new material of LSI because of its high carrier mobility. The O translational kinetic energy will be essential to understand the formation of oxide layers on Ge substrate for these devices. We previously reported that the high kinetic energy of the supersonic O beam enhances the oxidation on the Ge(100) at room temperature. In this research, we employed SR-XPS to analyze the oxidized Ge(100) surface formed by supersonic O molecular beam and back-filling O. In our experiments, we found the increase in amounts of the Ge oxide formed by supersonic O molecular beam comparing to that formed by back-filling O, although their coordination numbers were same in both cases. This result suggests that new oxygen adsorption states on the Ge(100) surface are activated by the supersonic O molecular beam. Our results give new knowledge concerning mechanisms of the formation of oxide layers on Ge substrate.