Effect of Ti interlayer on the residual stress and texture development of TiN thin films deposited by unbalanced magnetron sputtering

Abstract

The purpose of this study is to investigate the effects of Ti interlayer on the texture and residual stress of overlaying titanium nitride (TiN) thin films at a high residual stress state. Films were deposited by unbalanced magnetron (UBM) sputtering methods on substrates with or without a Ti interlayer. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to reveal the microstructure of the thin films. Residual stresses and pole figures of the grown films including Ti interlayer and TiN were measured by X-ray diffraction (XRD) techniques. Thin films with weak fiber texture were produced. The compressive residual stresses in the TiN films of all specimens were higher than −4.5 GPa; in contrast, the stresses in the Ti-interlayers were much lower at less than 0.72 GPa and in the tensile state. Results showed that the Ti interlayer had a relatively weaker effect on the texture of the TiN films prepared by UBM sputtering compared to those deposited by ion beam assisted deposition (IBAD) in the previous study. It was found that about 50% of the residual stress in the TiN film was relieved by the introduction of a Ti interlayer with a thickness of 200 nm.