Low-noise AlN-on-Si resonant infrared detectors using a commercial foundry MEMS fabrication process

This work presents the first measured results for resonant AlN-based infrared (IR) detectors fabricated using a proprietary InvenSense AlN MEMS process. Resonators fabricated in the first fabrication run achieved high electromechanical performance with a Q of ∼1400 at 115 MHz, insertion loss of 17.9 dB, and a motional impedance of 670 Ω. The detectors are coated with an IR absorber layer (SiN
x
), and tested for response to IR radiation using a calibrated, traceable black body source. The estimated responsivity of the device is 210ppb/µW for the longwave-infrared (LWIR) spectrum. The detectors are expected to have low noise, with estimated NEDT and NEP of 51 mK and 52.7 pW/Hz
^0.5
, respectively. The resonators are fabricated in a hybrid MEMS/CMOS wafer level packaged die, allowing for CMOS-based routing and readout.