MODELING OF INHOMOGENEOUS FILM DEPOSITION AND TARGET EROSION IN REACTIVE SPUTTERING

Presented is a generalized microphysical model for reactive sputtering, taking into account inhomogeneities of both the target erosion and the deposition of films on condensing surfaces of substrates and chamber walls. The integral quantities, as the total metal ejection rate or the reactive gas consumption, can be treated as if the erosion and deposition were homogeneous but over properly determined effective areas. Conversely, the local quantities, as the target coverage by the compound or the film composition, are strongly influenced by the inhomogeneities. Both chamber wall area Aw and the substrate area As influence the system behavior. An increase of Asand/or decrease of Awleads to higher reactive gas content in films. This effect makes it possible to use a simple flow rate control for a high rate deposition of nearly stoichiometric films, as TiN, in the metallic mode of target operation. © 1990, American Vacuum Society. All rights reserved.