Mechanism and Kinetics of Nonequilibrium and Multilayer Adsorption and Desorption of Gases on Solids

A novel approach to the characterization of dynamic interactions of gases with solid surfaces is developed. A model is developed to represent the simultaneous adsorption and desorption processes in these systems. The model can simulate properties of nonequilibrium adsorption and desorption processes as well as the equilibrium state (isotherms and isobars). It also provides information on the distribution of loading of tightly bound molecules as the first layer on the surface as well as loosely bound physisorbed molecules as the upper layers during a transient process and at the equilibrium state. The model is validated and applied to the adsorption of moisture on oxides (ZrO2 and HfO2). Practical application of this work is shown by optimizing the purge recipes for removal of moisture from ZrO2 film. Optimization helps in lowering gas and energy consumption as well as reducing the purge times.