Takatoshi Nagoya

Model on transport phenomena and epitaxial growth of silicon thin film in SiHCl3H2 system under atmospheric pressure

Abstract A transport and epitaxy model to describe silicon epitaxial film growth in a SiHCl 3 H 2 system under atmospheric pressure is developed by numerical calculations and comparison with experiments. The rate of epitaxial growth is calculated by computing the transport of momentum, heat and chemical species in a reactor incorporating chemical reactions at a substrate surface described by the Eley-Rideal model. The reaction processes determining the growth rate consist of chemisorption of SiHCl 3 and decomposition by H 2 , rate constants of which are evaluated from the model and measured results. The state of the surface during the epitaxial growth is also discussed considering the intermediate species, elementary reactions and rate-limiting processes. The epitaxial growth rate is able to be predicted by the model in this study over wide growth conditions of the species concentrations and the temperatures.

Modeling of Epitaxial Silicon Thin‐Film Growth on a Rotating Substrate in a Horizontal Single‐Wafer Reactor

The effect of substrate rotation on transport of reactive gases and epitaxial growth rate is investigated for a horizontal single-wafer reactor using a model and experiments. The governing equations for gas velocity, temperature, and chemical species transport are solved for the SiHCl 2 -H 2 system for Si thin-film preparation. The rotating substrate causes a circulating gas flow region above itself in which an asymmetric and nonuniform SiHCl 3 distribution is formed by thermal diffusion and species consumption due to the surface chemical reaction, even when the growth rate profile on the substrate surface is nearly uniform. The thickness of a thin-film grown at any position is obtained by an integral of the local growth rate along a concentric circle on the substrate surface. The good uniformity in the film thickness observed in calculation and measurement is mainly attributed to the averaging effect by integrating the local growth rate, and partially by the species concentration distribution change, both of which are caused by the rotating motion of the substrate.