Oxidation of silicon with neutral atomic oxygen species generated in a rare gas plasma has recently been shown to produce high-quality thin oxides. It has been speculated that atomic oxygen in the first excited state, O(D-1), is a dominant reactive species in the oxidation mechanism. In this study, we investigate the role of O(D-1) in silicon oxidation in-the-absence of other oxidizing species. The O(D-1) is generated by laser-induced photodissociation of N2O at 193 nm. We find that, at 400degreesC, O(D-1) is effective in the initial stages of oxidation, but the oxide growth rate decreases dramatically past 1.5 nm. Oxide films thicker than 2 nm were not achieved regardless of oxidation time or N2O partial pressure (0.5-90 mTorr), indicating O(D-1) cannot be a dominant reactive species in thicker rapid oxidation mechanisms. We suggest that quenching of O(D-1) to O(P-3) (ground state) during diffusion through thicker oxides results in drastically slower oxidation kinetics. In contrast, oxidation with a vacuum ultraviolet excimer lamp operating at 172 nm resulted in rapid oxide growth up to 4 nm. Thus, other species produced in plasmas and excimer lamps, such as molecular and atomic ions, photons, and free and conduction band electrons, likely play a dominant role in the rapid oxidation mechanism of thicker oxides (>2 nm). (C) 2003 American Vacuum Society. [DOI: 10.1116/1.1563254].