Parasitic Surface Reactions in High-Aspect Ratio Via Filling using ALD: A Stochastic Kinetic Model

Abstract

A scalable kinetic Monte-Carlo model (sKMC) of molecular transport for atomic layer deposition (ALD) for high aspect-ratio (AR) features is developed. Surface coverage is a critical parameter studied here in detail. The capabilities of the stochastic model provide insight into challenges in growing ALD films in high-AR via structures faced by the industry, including the effects of parasitic surface reactions resulting in poor coverage. Furthermore, we provide experimental results verifying the model's prediction by growing ALD SiNx, on high-AR via structures. By compensating for the processing errors corroborated by the model, we experimentally improved sidewall coverage from 70% to 92%.