Modeling Spray Pyrolysis Deposition

The deposition of a thin tin oxide film allows for the manufacture of modern gas sensors. Spray pyrolysis deposition is used to grow the required thin films, as it can be seamlessly integrated into a standard CMOS processing sequence. A model for spray pyrolysis deposition is developed and implemented within the Level Set framework. Two models for the topography modification due to spray pyrolysis deposition are presented, with an electric and a pressure atomizing nozzle. The resulting film growth is modeled as a layer by layer deposition of the individual droplets which reach the wafer surface or as a CVDlike process, depending on whether the droplets form a vapor near the interface or if they deposit a film only after surface collision.