Charge-optimized many-body interaction potential for AlN revisited to explore plasma-surface interactions

TL;DR

This paper develops a revised charge-optimized many-body potential for AlN to improve the accuracy of plasma-surface interaction simulations in sputter deposition processes.

Contribution

The authors enhance the COMB3 AlN potential by integrating the QTE$^+$ charge model and reparameterizing it with an adaptive strategy, enabling reliable plasma-surface interaction studies.

Findings

The revised potential accurately models particle emission during ion bombardment.

It effectively captures point defect formation in AlN surfaces.

The new potential is suitable for reactive molecular dynamics simulations.

Abstract

Plasma-surface interactions during AlN thin film sputter deposition could be studied by means of reactive molecular dynamics (RMD) methods. This requires an interaction potential that describes all species as well as wall interactions (e.g., particle emission, damage formation) appropriately. However, previous works focused on the establishment of AlN bulk potentials. Although for the third-generation charge-optimized many-body (COMB3) potential at least a single reference surface was taken into account, surface interactions are subject to limited reliability only. The demand for a revised COMB3 AlN potential is met in two steps: First, the Ziegler-Biersack-Littmark potential is tapered and the variable charge model QTE$^+$ is implemented to account for high-energy collisions and distant charge transport, respectively. Second, the underlying parameterization is reworked by applying a self-adaptive evolution strategy implemented in the GARFfield software. Four wurtzite, three zinc blende and three rock salt surfaces are considered. An example study on the ion bombardment induced particle emission and point defect formation reveals that the revised COMB3 AlN potential is appropriate for the accurate investigation of plasma-surface interactions by means of RMD simulations.