Amorphous-silicon-based uncooled microbolometer IRFPA

Abstract

LETI LIR has been involved in Amorphous Silicon uncooled microbolometer development for a few years. This paper reports recent progress that have been carried out both in technological and product field. Due to the very particular features of LETI LIR technology, large fill factor, high thermal insulation, associated with small thermal time constant, can be achieved, resulting in a large detector responsivity. In addition, pulsed bias has been introduced showing performance improvement in terms of power consumption, reliability, faster thermal response. A model has been developed which accounts for these improvements. Electro-thermal results obtained from an IRCMOS 256 X 64, 47 micrometers detector sizes, laboratory prototype show that NETD less than 50 mK at f/1 can be obtained even at a high video scanning rate, that is compatible with micro scanning techniques.