Characterization of uncooled bolometer with vanadium tungsten oxide infrared active layer

Abstract

A surface micromachining uncooled infrared detector with an optimized vanadium alloy oxide layer is fabricated, based on low temperature annealing of V-W alloy oxide layer. Vanadium oxide is a promising material for an uncooled bolometer, due to its high temperature coefficient of resistance at room temperature. An infrared active layer is needed to be with the reflective layer to enhance its IR absorption. Test bolometers are successfully fabricated and then are radiated by an IR laser source at various power levels with a chopper in a frequency range of 1-500 Hz. The responsivity and the noise of the test bolometer are measured and the detectivity is calculated. From the results, the calculated detectivity is 1.1 x 10(7) cm Hz(1/2) W-1. Bolometer detectivity can be increased further if the noise in the device is reduced. (C) 2005 Elsevier B.V. All rights reserved.