Optimization of the Deposition Conditions of Titanium Nitride from Ammonia and Titanium Tetrachloride

TiN has been used in numerous technological applications including: cutting or milling tools and inserts, cold extrusion nozzles and punches, forming or stamping tools, and diffusion barrier. It is currently deposited from an initial gas mixture composed of hydrogen, ammonia and titanium tetrachloride. This paper reports on the optimization of its deposition conditions at atmospheric pressure. A complete factorial design with three factors and two levels, thus requiring 2 3 =8 experiments, has been carried out. The following parameters were selected: the deposition temperature, the molar fraction of titanium tetrachloride and the molar fraction of ammonia. The influence of these factors on the deposition rate, the grain size estimated by the Scherrer method and the texture coefficient as determined by X-ray diffraction were studied. The mechanical properties of the coatings (microhardness, Young's modulus) were measured by depth-sensing indentation.