<title>Resistive YBaCuO microbolometers for infrared imaging applications</title>

Abstract

Details of the fabrication process and figures of merit of resistive YBaCuO micro bolometers are reported. Thin films of YBaCuO were prepared on Si wafers under conditions that promote formation of the semiconducting phase at room temperatures. Effects of the preparation conditions on activation energy of YBaCuO were studied to obtain films with a large temperature coefficient of resistance (TCR). TCR with values of up to 0.04 K-' was achieved uniformly on 10-cm wide wafer areas. Bulk micromachining was used to create 60 x 60 Iim2 bolometers on Si3N4 bridges with a thermal conductance of 7.6x 10 W I K. The low frequency responsivity and detectivity of the micro bolometers were respectively 7 x 10 V I W and 3 x 10 cm.Hz112 / W at room temperatures. These figures compare favorably with figures of other classes of uncooled micro bolometer and are consistent with those derived from thermal properties of the bridge. Under normal operating conditions and assuming f I 1.0 optics, the NETD of focal planes that make use of these micro bolometers was estimated to be less than 50 mK in the spectral range of 8 to 14 Im.