Residual stress gradient analysis by the GIXRD method on CVD tantalum thin films

Tantalum thin films have been preferred in case of corrosion protection in the chemical industry in high temperature applications because of their long lifetime. Residual stresses could be generated during thin film deposition and have some important influence on the film properties in use. The residual stress gradient and distribution should be correctly determined. Pseudo-grazing incidence X-ray diffraction (GIXRD) can be used to evaluate the residual stress gradient. A modified method sin2ψ* has been developed for GIXRD stress analysis with the calculation of geometry adapted real angles ψ*. This method allows more practically determination of stress gradients near the surface in specific directions. The developed new technique was applied on three tantalum thin film specimens with different thicknesses (from 0.55 to 2.55 μm) obtained with a CVD process.