Tantalum nitride thin film with a nearly zero temperature coefficient of resistance synthesized by magnetron co-sputtering.

In deposition of nitride films through reactive sputtering, the degree of nitrogen dissociation from N 2 in vacuum chambers is small and difficult to control, while the nitrogen sputtered from a nitride target is in the ionic state, reactive, and tunable through the power of the target. In this study, co-sputtering of TaN target and Ta target is used to prepare tantalum nitride films of Ta 2 N phase with low resistance and low temperature coefficient of resistance (TCR). We investigated effects of the power of the TaN target and annealing temperature on the phase, structure, and electrical properties of the thin films, and obtained an optimal Ta 2 N-phase thin-film with adjustable resistance in the low segment and a TCR of −8 ppm/°C. • The metal Ta atoms from the Ta target easily take over the ion state N component from the TaN target. • Tantalum nitride films with low resistance and low TCR were successfully prepared by co-sputtering Ta and TaN targets. • Vacuum annealing at a medium temperature improves the electrical properties of the film. • The best tantalum nitride film has a square resistance of 2.586 Ω·□−1, a resistivity of 243.084 μΩ·cm, and a TCR of −8 ppm/°C. [ABSTRACT FROM AUTHOR]