Electron population factor in light enhanced oxidation of silicon

Abstract

Electrons in the electron/hole creation event are shown to be the prime catalytic agent in photon-stimulated oxidation enhancement of silicon. Oxidation enhancement in the 10–50% range occurs at only moderate power density levels of visible wavelength light and increases greatly for photon energies just exceeding the conduction-band edge between SiO2 and Si. ‘‘Hot’’-electron injection into the SiO2 is thought to enhance the oxidation via a process of electron attachment to some of the in-diffusing O2 species, with subsequent dissociation into O and O− species. This injected hot-electron flux reaction with O2 is thought to also occur at a reduced level during standard thermal oxidation.