SiO_2/Si interfaces on high-index surfaces: Re-evaluation of trap densitiesand characterization of bonding structures

摘要

Interface trap densities, D_(it), at the thermally oxidized Si surfaces were investigated for the (001), (111), (110), (120), (331), and (113) orientations. The oxides were formed by dry or wet oxidation in the temperature range of 700-950 ℃. D_(it) took a maximum not only on the (111) surfaces but also on (110). Low D_(it) values were obtained on wet-oxidized high-index surfaces. Correlation between D_(it) and the interface anisotropy observed by reflectance difference spectroscopy suggests preferential oxidation of the Si atoms with the (lll)-like bonding geometry on the (113) surfaces.