Observation of Oxide-Thickness-Dependent Interface Roughness in Si MOS Structure

Abstract

The relationship between roughness at the Si/SiO 2 interface and the oxide thickness was investigated by means of a nondestructive measuring method, using the Si metal-oxide-semiconductor (MOS) structure. It was demonstrated that the Si/SiO 2 interface roughness recovers during thermal oxidation. This recovery process was also verified by observation with the transmission electron microscope (TEM). It was found that the recovery effect on the roughness at the Si/SiO 2 interface depends on the oxidation process and that it is more significant in wet oxidation than in dry oxidation.