STRUCTURE OF TITANIUM NITRIDE COATINGS DEPOSITED BY PHYSICAL VAPOR-DEPOSITION - A UNIFIED STRUCTURE MODEL

The results of positron annihilation, X-ray diffraction (on both adherent and free-standing films) and scanning electron microscopy studies, performed both before and after tempering, on titanium nitride film deposited by low rate d.c. sputtering, high rate magnetron sputtering and reactive ion plating have been combined to give a unified structure model. The various contributions to both macrostrain (macrostress) and microstrain (microstress) are discussed as a function of the processing variables (substrate bias, deposition rate etc.) for each of the physical vapor deposition processes. In particular, the model can account for the high lattice parameter of physically vapor-deposited titanium nitride coatings and the variation in unit cell dimension of the nitride with deposition rate and substrate bias voltage.