Linking the Operating Parameters of Chemical Vapor Deposition Reactors with Film Conformality and Surface Nano-Morphology

Abstract

A multiscale modeling framework is used to couple the co-existing scales, i.e., macro-, micro- and nano-scale, in chemical vapor deposition (CVD) processes. The framework consists of a reactor scale model (RSM) for the description of the transport phenomena in the bulk phase (macro-scale) of a CVD reactor and two models for the micro- and nano-scale: (a) A feature scale model (FSM) describing the deposition of a film inside features on a predefined micro-topography on the wafer and (b) a nano-morphology model (NMM) describing the surface morphology evolution during thin film deposition on an initially flat surface. The FSM is deterministic and consists of three sub-models: A ballistic model for the species' transport inside features, a surface chemistry model, and a profile evolution algorithm based on the level set method. The NMM is stochastic and is based on the kinetic Monte Carlo method. The coupling of RSM with FSM is performed through a correction of the species consumption on the wafer. The linking of RSM with NMM is performed through "feeding" of the deposition rate calculated by RSM to the NMM. The case study is CVD of Silicon (Si) from Silane. The effect of the reactor's operating parameters on the Si film conformality inside trenches is investigated by the coupling of RSM with FSM. The formation of dimmers on an initially flat Si (001) surface as well as the periodic change of the surface nano-morphology is predicted.