A Tight Binding Method Study of Optimized $\hbox{Si}{-} \hbox{SiO}_{2}$ System

A mixed method of molecular dynamics and tight binding is applied to a Si-cluster surrounded by SiO
₂
in order to study an influence of interfacial states on the band structure of the Si cluster. As a result, it is found that intrinsic interfacial states invade the band gaps of Si and SiO
₂
from the conduction band, which may suggest that the Si dot surrounded by SiO
₂
sounds metallic due to the interfacial states. This feature occurs while the size of the Si dot is less than at least 4 nm.