Low-cost microbolometer with nano-scaled plasmonic absorbers for far infrared thermal imaging applications

Abstract

We present a scalable low-cost microbolometer technology platform which is based on separate fabrication of MEMS and read-out ASIC CMOS wafers. Mechanical, electrical and hermetical connection is achieved by Cu-based thermocompression bonding. The performance loss due to the resulting backside illumination of the sensor is compensated by an optimized microbolometer design including nano-scaled plasmonic absorbers, a dedicated pixel geometry and the use of highly temperature sensitive devices. The low-cost approach features CMOS compatible MEMS processes, wafer level packaging and uncooled operation of the sensor.