Growth Kinetics of Ion Beam Sputtered Al-thin films by Dynamic Scaling Theory

TL;DR

This study investigates the growth kinetics of ion beam sputtered aluminum thin films using dynamic scaling theory, revealing how surface morphology and roughness evolve with deposition time.

Contribution

It applies dynamic scaling theory to analyze AFM data, providing new insights into the surface growth mechanisms of aluminum thin films over varying deposition durations.

Findings

Surface roughness increases with shorter deposition times.

Surface diffusion dominates at 3 minutes, while bulk diffusion prevails at 15 minutes.

Interfacial width decreases as deposition time increases.

Abstract

This paper reports the study of growth kinetics of ion beam sputtered aluminum thin films. Dynamic scaling theory was used to derive the kinetics from AFM measurements. AFM imaging revealed that surface incorporates distinctly different morphologies. Variation in deposition times resulted in such distinctiveness. The growth governing static (alpha) as well as dynamic (beta) scaling exponents have been determined. The exponent (alpha) decreased as the deposition time increased from 3 to 15 minutes. Consequently, the interfacial width (xi) also decreased with critical length (Lc), accompanied with an increase in surface roughness. Surface diffusion becomes a major surface roughening phenomenon that occurs during deposition carried out over a short period of 3 minutes. Extension of deposition time to 15 minutes brought in bulk diffusion process to dominate which eventually led to smoothening of a continuous film.