Atomic oxygen interaction with surface materials in oxygen-containing plasmas

Heterogeneous surface kinetics plays a role in most plasma processes, where surfaces interact either with active discharges or their afterglow. It can affect both plasma and surface properties. In this work we employ deterministic and Kinetic Monte Carlo methods to simulate the surface kinetics of oxygen species in oxygen and carbon dioxide glow discharges interacting with silica-based materials. This description includes physisorption and chemisorption of oxygen atoms at the surface, together with their desorption, surface diffusion and recombination back into gaseous molecular oxygen. We further describe the formation of dangling bonds due to the arrival of fast particles to the surface. The simulation results are validated by comparisons with experimental measurements of atomic oxygen loss frequency. The change in the recombination regime experimentally observed at pressures around 1 Torr is well captured by the model.