The TCR of Ni24.9Cr72.5Si2.6 thin films deposited by DC and RF magnetron sputtering**Project supported by the National Natural Science Foundation of China (Nos. 51377025, 61376114)

Abstract

The temperature coefficient of resistance (abbreviated as TCR) of thin film resistors on some sensor chips, such as thermal converters, should be less than several ppm/°C. However, the TCR of reported thin films is larger than 5 ppm/°C. In this paper, Ni24.9Cr72.5Si2.6 films are deposited on silicon dioxide film by DC and RF magnetron sputtering. Then as-deposited films are annealed at 450 °C under different durations in N2 atmosphere. The sheet resistance of thin films with various thickness and annealing time are measured by the four probe resistivity test system at temperature of 20, 50, 100, 150, and 200 °C and then the TCR of thin films are calculated. Experimental results show that the film with the TCR of only –0.86 ppm/°C can be achieved by RF magnetron sputtering and appropriate annealing conditions.