A HIGH-T-C SUPERCONDUCTOR BOLOMETER ON A SILICON-NITRIDE MEMBRANE

In this paper, we describe the design, fabrication, and performance of a high-T-c GdBa(2)Cu3O(7-delta) superconductor bolometer positioned o n a 2- x 2-mm(2) 1-mu m-thick silicon nitride membrane, The bolometer structure has an effective area of 0.64 mm(2) and was grown on a speci ally developed silicon-on-nitride (SON) layer, This laver was made by direct bonding of silicon nitride to silicon after chemical mechanical polishing, The operation temperature of the bolometer is 85 K, A ther mal conductance G = 3.3 . 10(-5) W/K with a time constant of 27 ms has been achieved, The electrical noise equivalent power (NEP) at 5 Hz is 3.7 . 10(-12) WHz(-1/2), which is very close to the theoretical phono n noise limit of 3.6 . 10(-12) WHz(-1/2), meaning that the excess nois e of the superconducting film is very low. This bolometer is comparabl e to other bolometers with respect to high electrical performance, Our investigations are now aimed at decreasing the NEP for 84-mu m radiat ion by further reduction of G and adding an absorption layer to the de tector, This bolometer is intended to be used as a detector in a Fabry -Perot (FP)-based satellite instrument designed for remote sensing of atmospheric hydroxyl.