Evaluation of characteristics in VO x microbolometer fabricated by MOD on Si 3 N 4 /SiO 2 membrane

Abstract

VO x thin films were fabricated on Si 3 N 4 /SiO 2 /Si substrates by firing precursor films, which were fabricated by metal-organic decomposition (MOD), with a reduced pressure. Resistance-temperature (R-T) characteristics of the films indicating the phase transition from metal to insulator with about 4 orders of resistance change specified with VO 2 (M) were obtained. Furthermore, the films fabricated with a firing temperature of 580-600°C had temperature coefficient of resistance (TCR) of −2.8 to −2.9 %/K at room temperature. After fabricating VO x microbolometers with 40 × 10 μm 2 using the films on Si 3 N 4 /SiO 2 /Si substrates, Si with a thickness of about 340 μm was etched using Deep-RIE and XeF 2 vapor etching from the backside of the substrate. Then, the VO x microbolometer was completed on Si 3 N 4 /SiO 2 membrane. The VO x microbolometer on Si 3 N 4 /SiO 2 membrane had a high DC sensitivity of 2310 W −1 , which was about 15 times higher than that of the microbolometer on the Si 3 N 4 /SiO 2 /Si substrate.