Abstract
Titanium nitride (TiN) thin films with the thickness of 0.1, 0.2, 0.5, 1.0, 2.0 and 4.0μm were coated on a carbon steel substrate by the ion beam mixing method. The film had a strong fiber texture with ‹001› axis perpendicular to the film surface. The distribution of the residual stress in thin films was measured by the grazing incidence X-ray diffraction (GIXD) and the scattering vector (SV) methods. The in-plane stress measurement by GIXD was applicable to the thickness down to 0.2μm of TiN films. The stress was a compression of around 2 to 3GPa. The compressive stress was found to increase in the very-near surface region of 20 to 30nm in depth. Thinner films had a steeper increase of the compressive stress in the very-near surface region. The strain distribution measured by the SV method using Cr-Kα radiation was nearly constant over the region of the penetration depth between 0.3 and 0.6μm from the surface, and that by using synchrotron X-rays was also constant over the penetration depth from 0.4 to 1μm. The stress distributions measured by the in-plane measurement and the one-tilt method combined with the surface removal method showed a good agreement with each other. The compressive residual stress was uniform within thin films except very near the surface of about 20 to 30nm in depth.
