화학공학소재연구정보센터
Journal of Vacuum Science & Technology A, Vol.18, No.2, 635-638, 2000
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 X 60 mu m(2) bolometers on Si3N4 bridges with a thermal conductance of similar to 7.6 x 10(-7) W/K. The optical responsivity and detectivity of these bolometers were respectively similar to 7 x 10(4) V/W and 3 x 10(9) cmHz(1/2)/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 optics, the noise equivalent temperature difference of focal planes that make use of YBaCuO microbolometers was estimated to be less than 50 mK in the spectral range of 8-14 mu m.