A Study on NbN Thin Films as Resistive Films Prepared via Reactive Magnetron Sputtering

The NbN thin films were deposited onto glass and Al 2 O 3 substrates using reactive magnetron sputtering, employing a niobium target sputtered with a mixture of Ar and N 2 gases. The investigation focused on the phase structures, microstructures, and electrical properties of the NbN thin films under various deposition powers and annealing temperatures. The results indicated the presence of a face-centered cubic (FCC) crystal structure in the as-deposited films at a power of 125 W. Interestingly, the crystallization phase remained unchanged within an annealing temperature range from room temperature to 500 °C. It was observed that the resistivity of the NbN thin films increased with higher nitrogen content, while the temperature coefficient of resistance (TCR) showed a tendency towards more negative values as the nitrogen content rose. Notably, at a nitrogen content of 9%, the film exhibited the lowest resistivity of 273 μΩ-cm with a TCR of -240 ppm/°C.