Microscopic Theory of Oxygen Reaction Mechanisms at SiO_2/Si(100) Interface

摘要

Microscopic mechanisms of reaction of oxygen at SiO2/Si(100) interface are studied based on first-principles calculations. It is found that in the SiO2 region of the interface the most stable configuration of reaction species is molecular-type oxygen which does not form any bonds with SiO2-network forming atoms, while the O2 in the Si substrate dissociates and forms two SiOSi bonds. The calculated energies indicate that the incorporation of O2 molecules into the Si substrate dominates the interfacial reaction of the oxidant. The cooperative reaction of each O atom of the O2 with each Si atoms at the interface leads to the low energy barrier compared with that of the O atom.