Microhardness of Nanostructured SixN1-x Thin Films Prepared by Reactive Magnetron Sputtering

Abstract

Nanostructured silicon nitride (SixN1-x) thin films were prepared by reactive magnetron sputtering using Ar/N2 gas mixture of 1:1. The structures and fractional compositions of the prepared samples were determined by x-ray diffraction (XRD) and electron-dispersion x-ray diffraction (EDS) patterns as functions of inter-electrode distance. They showed that the prepared films were polycrystalline and the partial amount of silicon (x) is ranging in 0.825-0.865 as the inter-electrode distance was ranging in 2.5-7.5cm. The particle sizes of the prepared nanostructured were determined by the field-effect scanning electron microscopy (FE-SEM) to be about 38nm. Also, the highest value of the surface roughness of the prepared nanostructures was determined by the atomic force microscopy (AFM) and found to increase with increasing inter-electrode distance to be 29.00nm for the samples prepared at 7.5cm. The measured Vickers microhardness of the prepared films showed relatively high values (570-750) and was decreased with decreasing film thickness, which is inversely proportional to the inter-electrode distance. However, no uniform relation between the microhardness and fractional composition of the prepared sample was observed.