Deposition of Cr-Si-Ni-Mo films at a low sputtering current and performance of heat and humid resistance

Cr-Si-Ni-Mo resistive films were deposited on columnar alumina substrates at a low sputtering current from mother alloy target. The effects of sputtering currents on the resistance value (R) and temperature coefficient of resistance (TCR) of deposition films were studied. Cr-Si-Ni-Mo films deposited for 2 (Sample 1) and 2.5 h (Sample 2) at a current of 150 mA have a high R (4-20 kΩ without being trimmed) and low TCR ranging from −25 to 2 ppm/°C. Life expectancy and high temperature storage experiments indicate that these two kinds of films have a high thermal stability. In the case of 2.2 MΩ resistors with a tolerance of ±0.5%, the resistance change ratio (ΔR/R) of both Samples 1 and 2 is less than 0.4% in heat and humid experiments with two cycles, and the later has a better heat and humid resistance than the former, showing a less insensitivity to water. XRD and SEM experiments were performed to explore the relations between the microstructure of Cr-Si-Ni-Mo films and their water sensitivity.