Multiparameter and Parallel Optimization of ReaxFF Reactive Force Field for Modeling the Atomic Layer Deposition of Copper

Abstract

In this study, we aim to develop a ReaxFF reactive force field for simulating the reaction mechanism of copper atomic layer deposition (ALD). To achieve this, we optimized the Cu/C, Cu/H, and Cu/N parameters of ReaxFF and extended the existing Cu potential to describe Cu/C/H/O/N interactions involved in Cu ALD. The parametrization procedure was implemented through an efficient multiparameter and parallel optimization scheme based on the Taguchi method. Using the newly developed Cu potential, we performed reactive molecular dynamics (RMD) simulations on an “abbreviated” ALD cycle using a [Cu(iPr-amd)]2 (iPr-amd = N,N′-diisopropylacetamidinate) or Cu(dmap)2 (dmap = dimethylamino-2-propoxide) precursor with the H radical as a coreactant. In the first half-cycle, the [Cu(iPr-amd)]2 precursor is found to adsorb dissociatively on the Cu surface as Cu(iPr-amd) monomers. During the second half-cycle, H radicals partly eliminate precursor fragments to the gas phase, but some intermediates such as C5H12N2 and C2H4N...