ON PICOSTRUCTURAL MODELS OF PHYSICALLY VAPOR-DEPOSITED FILMS OF TITANIUM NITRIDE

The atomistic models of Knotek et al. and of Goldfarb et al. explaining the intrinsic stresses in physically vapor-deposited films by an ion-peening mechanism are tested against X-ray diffraction data from magnetron-sputtered TiN films deposited at different ion current densities. It was found that both models fail to explain the observed data completely. Using additional microstructural information from electron micrographs, new models are presented to account for lattice distortions observed in both the tensile and the compressively stressed films. These models assume the existence of oriented lattice defects. Further experiments which could reveal the actual role of argon entrapment and an origin of intrinsic lattice distortions are suggested.