Thermodynamic Theory of Silicon Chemical Vapor Deposition

Abstract

Silicon chemical vapor deposition via silane is determined with classical thermodynamics. Drastic assumptions are used, such as the hydrogen carrier gas does not interact with the silicon thin film growth and the energy of reaction is adjusted to experiments. As a result, a linear function of temperature akin to a Gibbs free energy of reaction is shown to control silicon growth rates, and the characteristic Arrhenius plot is fully determined. The surface response of the growth rate activation energy is neatly mapped, bringing clarity to the parameter space for which a single value is a valid metric. A meta-analysis of growth rates is carried out for a demonstration of the portability of the linear function of temperature across reactors and to mine out reactor scaling factors. A silane heterogeneous decomposition reaction is also a great model chemistry for chlorosilanes. Silicon deposition is notoriously a complex chemical process, but with thermodynamics, the reaction mechanism is successfully reduced to the essentials.