Vibrational Excitation in Gas-Surface Reaction : Abstraction of Hydrogen Chemisorbed on a Silicon Surface by Atomic Oxygen

초록

We have calculated the probability of the OH formation and energy deposit of the reaction exothermicity in the newly formed OH, particularly in its vibrational motion, in the gas-surface reaction O(g)+H(ad)/Si→OH(g)+Si on the basis of the collision-induced Eley-Rideal mechanism. The calculation in extended to O(g)+D(ad)/Si→OD(g)+Si. The translational and vibrational motions share most of the energy when the adatom-surface vibration is initially in the ground state. When the initial excitation increases, the vibrational energy of OH/OD rises accordingly, while the energies shared by other motions vary only slightly. The product vibrational excitation is significant in both OH and OD and the population distribution is strongly inverted, especially in OD. Flow of energy between the reaction zone and the solid has been incorporated in trajectory calculations. The amount of energy propagated into the solid is only a few percent of the available energy in the OH formation, but it roughly doubles in the OD formation.