Cryogenic NbTiN thin film resistors fabricated by using reactive magnetron sputtering

Reactive magnetron sputtering has been applied for fabrication of NbTiN thin film resistors operating at liquid helium temperature. The resistivity of the NbTiN films at 4 K can be tuned in a wide range from about 100 μΩ cm to 10,000 μΩ cm with sputtering parameters such as discharge current and sputtering pressure. This broad tuning range greatly facilitates the design and fabrication of on-chip lumped-element resistors for millimeter and submillimeter integrated circuits. The NbTiN thin film resistors are found to be nitrogen-deficient, and the resistivity is strongly dependent on the nitrogen atomic ratio. A numerical model of reactive magnetron discharge has been utilized to understand the tuning mechanism, and the simulation results are in qualitative agreement with the measured ones. •Niobium titanium nitride resistors fabricated for superconducting integrated circuits.•Resistivity lies in range from about 100 μΩ cm to 10,000 μΩ cm.•Resistivity tuning with discharge current and sputtering pressure.•Optimization guided by using numerical modeling of reactive magnetron discharge.