ANTENNA-COUPLED HIGH-TC AIR-BRIDGE MICROBOLOMETER ON SILICON

An antenna-coupled high-T(c) superconducting microbolometer on a silic on substrate, operating at infrared wavelengths, is described. This de tector incorporates a silicon-micromachined yttria-stabilized zirconia air bridge at the feed of a planar lithographic antenna to simultaneo usly minimize the thermal conductance and the heat capacity of the bol ometer. At an operating temperature of 87.4 K, the optical responsivit y measured using a 300-K blackbody source over a 0.2-1.9 THz bandwidth is 2900 V/W, the optical noise-equivalent power (NEp) is 9X10(-12) W/ Hz1/2 and the time constant is < 10 mus. This NEP is nearly a factor o f 2 lower than the previous record for a liquid-nitrogen-cooled therma l detector, and the time constant is several orders of magnitude short er.