<title>Semiconducting YBCO bolometers for uncooled IR detection</title>

Abstract

Amorphous semiconducting Y-Ba-Cu-O is attractive as the temperature sensitive element for uncooled IR bolometers and pyroelectric detectors. Thin films can be easily fabricated by RF magnetron sputtering at room temperature from a composite target. It is compatible with micromachining techniques for the fabrication of thermally isolated structures. As a bolometer, Y-Ba-Cu-O possesses a relatively high temperature coefficient of resistance of 3.5% K-1 near room temperature. This paper will present the IR characteristics of 40-micrometer X 40-micrometer microbolometer arrays fabricated in thermal isolation structures. These detectors are aimed at thermal imaging at 10-micrometer wavelength. Recently, self-supporting YBaCuO pixels have been developed. In this case, the Y-Ba-Cu-O thin film pixel requires no underlying bridge material to provide structural support. The Y-Ba-Cu-O thin film is supported solely by the electrode arms. Responsivity and detectivity greater than 4 X 103 V/W and 108 cmHz1/2/W respectively have been measured in these detectors. The development of large area 1.5-mm and 0.4- mm square YBaCuO bolometers for NASA's global warming studies in low-orbiting satellites will also be presented. These large area detectors require large optical bandwidths covering the 0.3-micrometer to 100-micrometer wavelength band.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.