Fabrication and characterization of bolometric oxide thin film based on vanadium-tungsten alloy

Abstract

In this work, we present novel fabrication and characterization of new bolometric material with high temperature coefficient of resistance (TCR) and low resistance for uncooled microbolometers. The new bolometric oxide thin film was fabricated based on vanadium-tungsten alloy and oxidation of the deposited alloy. The vanadium-tungsten alloy was formed by co-sputtering method and in order to improve uniformity of the film, vanadium-tungsten alloy target was used. The deposited vanadium-tungsten metal thin films with various tungsten concentrations were oxidized at 573 K for various times. Finally, for the application of the vanadium-tungsten-oxide to the microbolometer, we also performed some experiments concerning photolithography and etching. Fabricated bolometric film was resolved in water, so very thin SiNx layer, which deposited by plasma enhanced chemical vapor deposition was adopted as protecting layer and we established process condition for the patterning of vanadium-tungsten-oxide. As the results, we characterized material properties and bolometric properties such as TCR and noise. And we could successfully fabricate the new bolometric material with high TCR and good noise properties. So, the performance of a microbolometer may be improved with the use of this material. (C) 2005 Elsevier B.V. All rights reserved.