Residual stress control in TiN/Si coatings deposited by unbalanced magnetron sputtering

Abstract

TiN coatings deposited by unbalanced magnetron sputtering were used in a case study to determine the relationship between some deposition parameters, such as substrate bias and working gas pressure, and residual stress magnitude in the coatings. The test coatings, ranging in thickness from 1 to 12 μm, were deposited on thin silicon wafers and evaluated for residual stress magnitude and anisotropy, as well as nanohardness. It was found that the properties of TiN coatings could be linked to the stress level, which in turn was strongly affected by the deposition process conditions. The stress–temperature correlations were investigated by subjecting the coatings to a temperature cycle from room temperature to about 100 °C above the maximum deposition temperature. Stress–temperature plots were used to characterize residual stress relaxation in the coatings during post-deposition heat treatment.