A Vanadium Dioxide Microbolometer in the Transition Region for Millimeter Wave Imaging

This paper presents the design of a new class of microbolometer that exhibits high responsivity for passive imaging arrays (camera) at millimeter wave (mmW) band. The main objective is to exploit the non-linear behavior of phase-change material (PCM) vanadium dioxide (VO
2
) by biasing the sensor at the transition cliff (~68 °C). Simulated results together with calculations show high responsivity of 7.5×10
³
V/W and low noise equivalent power (NEP) of 6.1 pW/√Hz. The corresponding response time of the proposed microbolometer is 376 µs. Two orders of magnitude improvement in device performance as compared with the state-of-the-art sensors is the direct result of both suspension in air by micro-electro-mechanical systems (MEMS) microfabrication processing as well as the sharp change in resistivity of VO
2
in its transition region.