Recent developments in MEMS-based tunable IR detectors

A hybrid approach to fabrication of single tunable infrared detectors for sensing applications is presented. In this approach the detector and IR Fabry-Perot tunable filter are fabricated separately and then bonded together using a flip-chip technique. This approach allows for less stringent processing conditions for both, detector and filter, resulting in the following advantages: (1) the maximum allowed processing temperature of the MEMS is not limited by the detector material; (2) increased freedom in the design of the actuating structure as there is practically no space limit; (3) good flatness of the silicon substrate on which filter is fabricated (in contrast to the monolithic approach where the filter is fabricated on top of the detector); and (4) the hybrid approach allows use of detectors fabricated with any available technology suitable for detection in IR range.