THERMOELECTRIC INFRARED-SENSORS IN CMOS TECHNOLOGY

We report several integrated thermoelectric infrared sensors on thin silicon oxide/nitride microstructures realized by industrial CMOS IC technology, followed by one compatible maskless anisotropic etching step. No additional material is needed to enhance infrared absorption in the spectral region between 8 and 14 mum, since the passivation layer, as provided by the CMOS process, shows significant absorption bands. We compare aluminium/polysilicon thermopiles with n-poly/p-poly thermopiles. Our sensors show responsivities between 12 and 72 V/W, normalized detectivities between 1.7 x 10(7) and 2.4 x 10(7) cm square-root Hz/W and time constants of 10-20 ms.