DETAILED MODEL OF THE AFTERGLOW REGION OF A MICROWAVE GENERATED OXYGEN PLASMA

A one-dimensional mass continuity equation was used to model a low pressure, high radical concentration, nonisothermal oxygen afterglow reactor. This type of afterglow system has never been modeled despite its broad range of uses: low temperature passivation of polycrystalline silicon thin film transistors, chemical vapor deposition and etching, ceramic superconductor oxidation, growing silicon dioxide surfaces, and surface cleaning including the removal of photoresist films. It was shown that the model, with no adjustable parameters, yielded very good agreement with experimental measures of O-atom flux. The temperature profile and charged particle concentration profile used in the model were measured experimentally. The model was manipulated to study the influence of temperature profile, pressure, homogeneous and heterogeneous kinetics, O-atom generation, and flow rate on the afterglow plasma. Some results were surprising, such as the finding that the value and position of maximum O-atom concentration can be readily manipulated. The model was also used to assess the validity of a frequently used probe of O-atom flux.