Ballistic transport and reaction modeling of atomic layer deposition manufacturing processes

摘要

In this paper we develop a model describing the ballistic transport of chemical precursor species for an atomic layer deposition process (ALD). Because of the large Knudsen number corresponding to ALD over nanoporous materials, the gas-phase transport inside the nanostructures takes place in a purely ballistic manner. Precursor transmission probability functions describing the fluxes between the pore surface features are developed and then are coupled to ALD surface reaction models, spatially discretized, and integrated over each precursor exposure period to determine the pore spatial surface reaction extent profile. Predictions from our dynamic model then are compared to a previously published study of ALD in nanopores to validate our simulator. The utility of physically based models of the type we develop can be exploited to determine optimal precursor exposure levels for ALD based nanomanufacturing operations.