Simulation of 2D ballistic deposition of porous nanostructured thin-films

TL;DR

This paper presents a 2D ballistic deposition simulation code to study how geometric factors like angle, standard deviation, and particle size influence thin-film microstructure, porosity, and roughness, matching experimental results.

Contribution

The paper introduces a novel 2D ballistic deposition simulation code that incorporates shadowing effects and particle size variations to analyze thin-film growth.

Findings

Simulation results match theoretical and experimental data.

Porosity and roughness depend on deposition angle and particle size.

Good qualitative agreement with collimated glancing angle deposition experiments.

Abstract

A "two-dimensional ballistic deposition" (2D-BD) code has been developed to study the geometric effects in ballistic deposition of thin-film growth. Circular discs are used as depositing specie to understand the shadowing effects during the evolution of a thin-film. We carried out the 2D-BD simulations for the angles of deposition $20^0$-$80^0$ in steps of $10^0$. Standard deviations $1^0$, $2^0$, $4^0$, $6^0$ and $10^0$ are used for each angle of deposition with disc size of $1.5 \overset{\circ}{A}$ to understand its effect on the microstructure of the thin-films. Angle of growth, porosity and surface roughness properties have been studied for the afore-mentioned angles of deposition and their standard deviations. Ballistic deposition simulations with the discs of different sizes have been carried out to understand the effect of size in ballistic deposition. The results from this code are compared with the available theoretical and experimental results. The code is used to simulate a collimated glancing angle deposition (C-GLAD) experiment. We obtain a good qualitative match for various features of the deposits.