Abstract
Metallic titanium, in nitrogen atmosphere with specified pressures (pN) ranging from 10-6 to 10-4 Torr, was evaporated on glass substrates heated at temperatures (Ts) between 300 to 500°C. X-ray analysis revealed that the films were composed of α-titanium, distorted titanium phase, amorphous phase, and TiN. The distorted titanium phase was found to extend to a high concentration of nitrogen (x=0.5). In particular, the specimens evaporated at pN=2.0×10-5 Torr and Ts=500°C had maximum resistivity of 270 µΩ-cm and a very small negative value of the temperature coefficient of resistance (0 to -20 ppm/°C) for an extended range of temperatures (-190 to 200°C). The excess resistivity of the distorted titanium phase can be mainly interpreted in terms of two kinds of carrier scattering, one due to nitrogen atoms randomly distributed at vacant interstitials, another attributable to grain boundaries involved.