Simulation of Conformality of ALD Growth Inside Lateral Channels: Comparison Between a Diffusion-Reaction Model and a Ballistic Transport-Reaction Model

21 April 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Atomic layer deposition (ALD) has found significant use in the coating of high-aspect-ratio (HAR) structures. Approaches to model ALD film conformality in HAR structures can generally be classified into diffusion-reaction (DR) models, ballistic transport-reaction (BTR) models and Monte Carlo simulations. This work compares saturation profiles obtained using a DR model and a BTR model. The saturation profiles were compared qualitatively and quantitatively in terms of half-coverage penetration depth, slope at half-coverage penetration depth and adsorption front broadness. The results showed qualitative agreement between the models, except for a section of elevated surface coverage at the end of the structure, `trunk', observed in the BTR model. Quantitatively, the BTR model produced deeper penetration into the structure, lower absolute values of the slope at half-coverage penetration depth and broader adsorption fronts compared to the DR model. These differences affect the values obtained when extracting kinetic parameters from the saturation profiles.


atomic layer deposition
saturation profile
diffusion-reaction model
ballistic transport-reaction model
Knudsen diffusion


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