Uniformity Control in Planetary Chemical Vapor Deposition Reactor Systems

A simplified model of the spatially dependent deposition profile in chemical vapor deposition reactors with planetary wafer rotation is developed. The model focuses on reactors operated in “depletion” mode, a situation where the precursor species have undergone a sequence of gas-phase decomposition reactions leaving only the deposition species to diffuse to and react on the substrate surface, generating the thin film. The model is used to identify the reactor design and operating parameters that influence the shape of the deposition profile. By projecting the deposition profile onto the rotating wafers, the thickness uniformity as a function of reactor system operating parameters also is examined.