Precision Thin Film Resistors Based on Ni–Cr Quinternary Alloy Thin Films Prepared by Magnetron Sputtering Technique

Abstract

Thin film resistor devices were fabricated based on Ni–Cr quinternary alloy thin films deposited by DC magnetron sputtering technique, where four Ni–Cr alloy targets with different composition of Al, Mn, and Si were used. Ni–Cr quinternary alloy thin film properties were investigated regarding the composition of quinternary targets, thin film processing conditions and post-deposition annealing conditions. Temperature coefficient of resistance (TCR) values of the Ni–Cr quinternary alloy thin films were investigated in order to evaluate the performance of the thin film resistor devices. The more the Cr composition in the Ni–Cr alloy target increased, the smaller was the TCR of the resulting thin film. The lower the pressure during the thin film deposition was, the lower was the oxygen content in the resulting thin films, which resulted again in smaller TCR of the thin film. In addition, TCR of the resistor devices increased drastically for samples with thin films annealed at 300 °C caused by formation of NiO layer through oxidation. A good performance of the smallest TCR values within ±10 ppm/°C was achieved for the thin film resistor device by optimized quinternary Ni–Cr alloy target composition [Ni (50 wt %)–Cr (40 wt %)–Al (3 wt %)–Mn (4 wt %)–Si (3 wt %)] combined with magnetron sputtering condition controls.