Network Behavior in Thin Film Growth Dynamics

TL;DR

This paper introduces a network modeling approach for thin film growth that captures re-emission dynamics, revealing universal behaviors in network properties across different deposition techniques and conditions.

Contribution

It presents a novel network-based framework for modeling thin film growth, incorporating re-emission effects and uncovering universal network behaviors across various techniques.

Findings

Universal degree distribution patterns observed across techniques.

Network traffic varies with sticking coefficient and growth method.

Re-emission networks reveal consistent behaviors despite morphological differences.

Abstract

We present a new network modeling approach for various thin film growth techniques that incorporates re-emitted particles due to the non-unity sticking coefficients. We model re-emission of a particle from one surface site to another one as a network link, and generate a network model corresponding to the thin film growth. Monte Carlo simulations are used to grow films and dynamically track the trajectories of re-emitted particles. We performed simulations for normal incidence, oblique angle, and chemical vapor deposition (CVD) techniques. Each deposition method leads to a different dynamic evolution of surface morphology due to different sticking coefficients involved and different strength of shadowing effect originating from the obliquely incident particles. Traditional dynamic scaling analysis on surface morphology cannot point to any universal behavior. On the other hand, our detailed network analysis reveals that there exist universal behaviors in degree distributions, weighted average degree versus degree, and distance distributions independent of the sticking coefficient used and sometimes even independent of the growth technique. We also observe that network traffic during high sticking coefficient CVD and oblique angle deposition occurs mainly among edges of the columnar structures formed, while it is more uniform and short-range among hills and valleys of small sticking coefficient CVD and normal angle depositions that produce smoother surfaces.