Computational fluid dynamics study of the atomic layer deposition process around cylindrical and planar configurations

Computational fluid dynamics (CFD) simulations were used to model atomic layer deposition (ALD) coating processes in the continuum flow regime. CFD model was validated for non-reactive and reactive flows. In ALD CFD simulations, surfaces in various test cases were considered as non-porous aluminum oxide. The effect of trimethylaluminium precursor partial pressure, initial condition, and Reynolds number (Re) on coating timescale were analyzed. The CFD model accurately captured the surface coverage solution for all cases when the domain was initially filled with the precursor. The absence of initial precursor delayed coating time during the surface concentration level development process. As Re increased, coating time significantly decreased due to reduced diffusion limitations and promoted convection swiftly transporting precursors to the surfaces. The provided example showed that 2D polydisperse fixed cylinder bed is fully coated within approximately one flow time through the bed. The benefits of CFD in understanding ALD processes were discussed.