Room temperature YBaCuO microbolometers

Details of the fabrication process and figures of merit of resistive YBaCuO microbolometers are reported. Thin films of YBaCuO were prepared on Si wafers under conditions that promote formation of the semiconducting phase at room temperatures. Temperature coefficient of resistance with values of up to 0.04 K−1 was uniformly achieved on 10 cm wide wafer. Bulk micromachining was used to create 60×60 μm2 bolometers on Si3N4 bridges with a thermal conductance of ∼7.6×10−7 W/K. The optical responsivity and detectivity of these bolometers were respectively ∼7×104 V/W and 3×109 cm Hz1/2/W at low frequencies. These figures are consistent with those derived from the thermal properties of the bridge and are better than figures of other classes of room temperature bolometer. Good agreement was found between the spectral response of the bolometer and the spectral absorptance of the Si3N4 bridge, confirming the role of the latter as the heat absorber in the device. Under normal operating conditions and assuming F/1 op...