Structural and Mechanical Properties of Zr-Si-N Thin Films Prepared by Reactive Magnetron Sputtering

Flávio Gustavo Ribeiro Freitas,Gabriel Soares,Edson Reis Vitória,Renata Gomes Carvalho,Roberto Hübler,Amanda Gardênia Santos Conceição,Eduardo Kirinus Tentardini

doi:10.1590/1516-1439.336214

Abstract

Zirconium silicon nitride (ZrSiN) thin films were deposited by reactive magnetron sputtering in order to verify the silicon influence on coating morphology and mechanical properties. The Si/(Zr+Si) ratio was adjusted between 0 to 15% just modifying the power applied on the silicon target. Only peaks associated to ZrN crystalline structure were observed in XRD analysis, since Si3N4 phase was amorphous. All samples have (111) preferred orientation, but there is a peak intensity reduction and a broadening increase for the sample with the highest Si/(Zr+Si) ratio (15%), demonstrating a considerable loss of crystallinity or grain size reduction (about 8 nm calculated by Scherrer). It was also observed that the I(200)/I(111) ratio increases with silicon addition. Chemical composition and thickness of the coatings were determined by RBS analysis. No significant changes in nanohardness with increasing Si content were found. The morphology observed by FEG-SEM presents non columnar characteristics for thin films with silicon addition. The set of results suggests that Si addition is restricting the columnar growth of ZrN thin films. This conclusion is justified by the fact that Si contributes to increase the ZrN grains nucleation during the sputtering process.

Highlights

Nitride transition metal thin films have been used in the last decades due to properties as hardness and wear resistance[1,2,3]
Stoichiometric zirconium nitride thin films has a metallic gold color[18] and the Zirconium nitride (ZrN) coating deposited in this work with Ar/N2 ratio of 19/2 presented this characteristic
A set of Zirconium silicon nitride (ZrSiN) thin films modifying Si concentration were deposited using different powers applied on the silicon target

Summary

Introduction

Nitride transition metal thin films have been used in the last decades due to properties as hardness and wear resistance[1,2,3]. Zirconium nitride (ZrN) is a typical coating used because its tribological properties, besides corrosion and oxidation resistance. ZrN thin films present columnar microstructure, micro-cracks and pores, which are defects associated with transition metals nitrides deposited by PVD and CVD techniques. These coatings characteristics allow direct contact between the external environment and the substrate, compromising the mechanical properties and its applications in high temperature or corrosive environments[4,5,6]. It is important to note that ZrN thin films mechanical properties are associated with a complex state of compression of the crystalline lattice (residual stress). The result is that the crystalline lattice remains in a metastable condition and, the structure can be changed if the necessary activation energy is

Methods

Results

Conclusion