Study of TCR of TiW alloy films deposited by magnetron sputtering

TiW alloy is not only a excellent infrared radiant material, but also a infrared sensitive material, and was often used as a film in the infrared thermal imaging detectors. The temperature coefficient of resistance (TCR) of TiW alloy film is an important parameter influencing the characteristic, so it is very necessary to study the effect of TiW alloy films deposition parameters on TCR. In this paper, TiW alloy films were deposited by DC magnetron sputtering on ordinary glass, and the target is high pure TiW alloy material ((Ti:W)atom=3:7), the working gas is Ar. The square resistance of TiW alloy films under the different temperature was measured using four-point probe meter, and TCR was calculated according to the measurement curve. The influence of working pressure, Ar flow rate and sputtering current on the TCR of TiW alloy films was investigated. After studying, the best process parameters were obtained, that are, sputtering current 0.32A, working pressure 0.8Pa, and Ar flow rate 60sccm. Under these condition, TCR of TiW alloy films is 2‰/K. The measurement results indicate that the time stability of TiW alloy films is excellent.