Characteristics of vanadium-tungsten-oxide bolometric thin films for uncooled IR detectors

Abstract

In this paper, we present novel fabrication of new bolometric material with high TCR. and low resistance for uncooled IR detectors. Tungsten was co-sputtered with vanadium by a conventional RF sputter method, and the deposited vanadium-tungsten metal thin films were oxidized at 573 K for various times. Vanadium metal could not be oxidized easily at low temperature, but the tungsten addition gave rise to easy oxidation, even at the low temperature of 573 K. As a result, we could obtain very high TCR., over -3.0 %/K, at relatively low device resistance below 100 kOmega. These are very remarkable results. For the application of fabricated V-W-O film to a microbolometer, we also performed some experiments concerning patterning processes such as photolithography and etching. So, we established process conditions for the patterning of V-W-O film.