Growth Kinetic studies of ion beam sputtered AlN-thin films: Effect of reactive assistance of nitrogen plasma

TL;DR

This study investigates the surface growth dynamics of AlN thin films deposited via reactive dual ion beam sputtering, analyzing how nitrogen plasma assistance influences surface roughness and scaling behavior over time.

Contribution

It introduces a detailed analysis of AlN film growth using Dynamic Scaling Theory, highlighting the effects of nitrogen plasma assistance on surface roughness and diffusion mechanisms.

Findings

Surface roughness increases with deposition time.

Static scaling exponent decreases as surface coverage improves.

Surface diffusion dominates roughening during growth.

Abstract

Reactive dual ion beam sputter deposition of AlN thin films was carried out for the analysis of surface growth characteristics by Atomic Force Microscopy. The variation of roughness as a function of deposition time was analysed by Dynamic Scaling Theory (DST). Two distinct exponents, static and dynamic were used to unravel the film growth characteristics. As the deposition time increased, static scaling exponent decreased gradually and substrate surface coverage was increased which is indicated by a decrease in critical length Lc. The rms roughness of the film was increased from 1.99 to 3.42 nm as the deposition time was increased from 3 minutes to 15 minutes. Dynamic scaling exponent was found to be 0.36. During the growth, surface diffusion (n = 4) becomes the major roughening phenomenon while Bulk diffusion (n = 3) turns into the dominating smoothening phenomenon.