FABRICATION OF A DIFFUSION COOLED SUPERCONDUCTING HOT-ELECTRON BOLOMETER FOR THZ MIXING APPLICATIONS

Recent interest in bolometers for heterodyne mixing applications has p rompted development of microbridges which are small enough to allow el ectron diffusion to dominate over electron-phonon interaction as a coo ling mechanism. Prior results at 533 GHz have demonstrated several GHz intermediate frequency (IF) bandwidth. Here we describe our processin g method in which the bolometer element is a 10 nm thin film of niobiu m defined by electron beam lithography down to dimensions of 80 nm. Th is microbridge is embedded in a normal metal (Au) antenna structure fo r 1.2 and 2.5 THz applications.