Numerical estimation of intrinsic stress in physical vapor deposited thin-films

A method of numerically estimating intrinsic stress has been developed for thin-film coatings of TiSiCN prepared by plasma enhanced magnetron sputtering at 280 °C. A portable optical setup was designed to be used with a commercial lab microscope, for taking measurements of the radii of curvature of the coated samples. The sensitivity of the optical instrument was optimized for taking measurements over a specific range of radii. A finite element model was developed in Abaqus to computationally determine the intrinsic and residual stresses in the thin films, with the help of the optical measurements. The computationally generated stresses and curvatures were found to agree well with previous analytical work. An average intrinsic stress of −2.49 GPa was observed for the thin-film samples. The stress relief in all the samples was calculated to be in the range of (20−30) %. Variations in the intrinsic and residual stress in the coatings indicate the possibility of a non-uniform deposition incidence based on their substrate positions.