Potential energy distribution of interstitial O2 molecule in the vicinity of

SiO2/Si(001) interface was investigated by means of classical molecular

simulation. A 4nm-thick SiO2 film model was built by oxidizing a Si(001)

substrate, and the potential energy of an O2 molecule was calculated at Cartesian

grid points with an interval of 0.05nm in the SiO2 film region. The result showed

that the potential energy of the interstitial site gradually rises with approaching the

interface. The potential gradient was localized in the region within about 1nm from

the interface, which coincides with the experimental thickness of the interfacial

strained layer. The potential energy was increased by about 0.62eV at the SiO2/Si

interface. The result agrees with a recently proposed kinetic model for the dry

oxidation of silicon, which argues that the oxidation rate was fully limited by the

oxidant diffusion.

Potential Energy Landscape of an Interstitial O2 Molecule in a SiO2 Film Near the

SiO2/Si(001) Interface. H.Ohta, T.Watanabe, I.Ohdomari : Physical Review B,

2008, 78[15], 155326