Fabrication of Bi-La-Sr-Mn-O uncooled microbolometer

Since perovskite manganese oxide Bi-La-Sr-Mn-O (BLSMO) has a large temperat ure coefficient of resistance (TCR: defined as 1/R dR/dT) of above 3%/K, it has been considered to be a suitable candidate for use as an uncooled IR b olometer material. We fabricated a single pixel device of the BLSMO microbo lometer and evaluated it. The BLSMO film was deposited by RF magnetron sput tering at ambient temperature in an oxygen atmosphere. The film showed the TCR of 3.1 %/K at room temperature. The size of the single pixel device is 38 x 38 mum(2). To achieve high infrared absorption, the detector contains an infrared absorbing membrane with a high fill factor of 90%. In a vacuum, the detector showed a thermal conductance of 1.3 x 10(-7) W/K and a respon sivity of 4.8 x 10(5) V/W. According to these numerical values, a noise equ ivalent temperature difference (NETD) of the BLSMO microbolometer was estim ated as being about 0.1 K with f/1.0 optics.