Thermal behaviour of chromium nitride/titanium–titanium carbonitride multilayers

Chromium nitride/titanium–titanium carbonitride multilayers composed of a 40nm Cr interface followed by a 4.4μm thick Cr2N layer, a 150nm thick Ti layer, and a 1 μm thick TiCxNy top layer were deposited on silicon wafers by magnetron sputtering. The structural changes and the phase content changes of these multilayer samples were studied by means of high-temperature in-situ X-ray diffraction experiments at temperatures up to 550°C. The lattice constants of the Cr phase as well as the Ti phase display an aberrant expansion behaviour during these experiments which is influenced by the defect structure, a nitrogen incorporation, and residual stress in the layers. The results were compared with structural data obtained by ex-situ transmission electron microscopy investigations of pristine and heated material, revealing phase separation and strong diffusion phenomena.