YBa2Cu3O7 SUPERCONDUCTOR MICROBOLOMETER ARRAYS FABRICATED BY SILICON MICROMACHINING

Linear arrays of YBa2Cu3O7 transition edge microbolometers have been fabricated on silicon substrates using silicon micromachining to produce microbolometer structures with good thermal isolation. These bolometers, measuring 85 mu m x 115 mu m x 1 pm, have a noise equivalent power (NEP) of 9 x 10(-13) Watts/Hz(1/2) (neglecting contact noise) and a thermal time constant of 24 msec. With contact noise, the NEP is 9 x 10(-12) Watts/Hz(1/2). This performance indicates that a 2D staring focal plane array of superconductor microbolometers could have a performance comparable to HgCdTe staring arrays without further improvements in the sharpness of the superconducting transition or reductions in the YBa2Cu3O7 electrical noise. The use of silicon processing technology to fabricate the superconductor microbolometers results in a significant cost advantage over HgCdTe, and there is no long wavelength cutoff dependence in the sensitivity of a superconductor microbolometer.