Effects of deposition dynamics on epitaxial growth

TL;DR

This study uses kinetic Monte Carlo and molecular dynamics simulations to investigate how deposition dynamics like steering and screening influence epitaxial growth, revealing characteristic surface morphologies and the dominant role of steering effects.

Contribution

It introduces a combined simulation approach to analyze the impact of deposition dynamics on epitaxial surface morphology, highlighting new insights into facet formation and slope selection.

Findings

Surface roughness is enhanced by grazing angle deposition.

Asymmetric mound structures are formed due to deposition dynamics.

Steering effects are more influential than screening effects in morphology development.

Abstract

The dynamic effects, such as the steering and the screening effects during deposition, on an epitaxial growth (Cu/Cu(001)), is studied by kinetic Monte Carlo simulation that incorporates molecular dynamic simulation to rigorously take the interaction of the deposited atom with the substrate atoms into account. We find three characteristic features of the surface morphology developed by grazing angle deposition: (1) enhanced surface roughness, (2) asymmetric mound, and (3) asymmetric slopes of mound sides. Regarding their dependence on both deposition angle and substrate temperature, a reasonable agreement of the simulated results with the previous experimental ones is found. The characteristic growth features by grazing angle deposition are mainly caused by the inhomogeneous deposition flux due to the steering and screening effects, where the steering effects play the major role rather than the screening effects. Newly observed in the present simulation is that the side of mound in each direction is composed of various facets instead of all being in one selected mound angle even if the slope selection is attained, and that the slope selection does not necessarily mean the facet selection.