A semiconductor YBaCuO microbolometer for room temperature IR imaging

The characteristics of infrared (IR) microbolometer arrays utilizing semiconducting YBaCuO and operating at room temperature are presented. Surface-micromachined structures in the form of 1 x 10 arrays of pixel size 40 mu m x 40 mu m and 60 mu m x 60 mu m as well as single pixels of various geometries were constructed. Using the chopped radiation from a broad-band IR source, the responsivity R-V of the sensor was measured to be as high as 10(4) V/W and detectivity D* to be similar to 2 x 10(7) cm Hz(1/2)/W for a thermal conductance G similar to 10(-5) W/K between the detector and the substrate. The spectral response was found to be uniform over a range of 1-12 mu m. Silicon micromachining and ambient-temperature processing were employed to ensure compatibility and, therefore, potential integration with CMOS-based signal processing circuitry. Methods of enhancing the figures of merit are discussed.