Enhancement of oxidation at Ge(111)-c(28) surface at 300 K by supersonic O molecular beam

Okada, Ryuta; Yoshigoe, Akitaka ; Teraoka, Yuden; 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. Understanding of O adsorption process on Ge substrate with various index planes is the most essential to control the quality of oxide layers for these devices. In this research, we employ SR-XPS (synchrotron radiation X-ray photoelectron spectroscopy) measurement to study the oxidation mechanism of the Ge(111) which is known as one of the low index planes. We found the difference in Ge3d profiles of the Ge oxide formed by between supersonic O molecular beam and back filling O. The difference shows that the kinetic energy of the supersonic O molecular beam caused higher coordination of Ge oxide than that of back filling O. This result suggests the presence of new O adsorption states activated by the supersonic O molecular beam.