EXCEPTIONS TO THE MICROSTRUCTURE ZONE MODEL REVEALED BY THE REACTIVE DC MAGNETRON SPUTTER-DEPOSITION OF DELTA-TINX THIN-FILMS

This paper deals with the influence of the nitrogen flow rate on the m icrostructure of delta-TiN(x) films prepared by d.c, magnetron sputter ing. The delta-TiN(x) films were prepared under decreasing nitrogen fl ow rates to obtain nitrogen contents in the films ranging from x = 0.9 9 to 0.95. Ion bombardment of the films was negligible in these experi ments. Some films prepared under deposition conditions which typically result in a fine-grain (about 0.1 mum) transition zone microstructure exhibit a ''large''-grain (about 1 mum) zone III microstructure. It h as been demonstrated that there exists a narrow area of nitrogen flow rate for which the microstructure of the films does not agree with the zone model. The large-grain films are stress free. The nitrogen conte nt in the films containing large grains is x = 0.97. All deposition co nditions except the nitrogen flow rate were kept constant in this expe riment. Chemical energy dissipated during the reactive process can exp lain the observed effects.