Performance of titanium and amorphous germanium microbolometer infrared detectors

Abstract

There is a considerable interest in recent years on microbolometer infrared detectors, due to the possibility of operating them at room temperature and the compatibility with CMOS fabrication process. In this work, we have fabricated bolometers with Ti and a:Ge as the sensing elements using a CMOS compatible process. Noise measurements indicate that detectivity D* of over 1.5×109 cmHz1/2W-1 and 4×109 cmHz1/2W-1 at 30 Hz could be realized for a:Ge and Ti bolometers, respectively. With further improvements in design and processing, it is estimated that bolometer focal plane arrays (FPAs) with noise equivalent temperature difference (NETD) of less than 50 mK are realizable using the above materials.