Responsivity enhancement of CMOS-MEMS thermoelectric infrared sensor by heat transduction absorber design

This study presents a novel heat transduction absorber design to improve the responsivity of thermoelectric infrared sensor with serpentine thermocouple [1] using TSMC 0.18μm 1P6M standard CMOS process. Features of the proposed design (Fig.1a) are: (1) umbrella-like heat transduction structure providing a better heat-flow path, (2) absorber membrane with designed etching release holes to enhance absorption area/efficiency of infrared, and (3) serpentine thermocouple for large thermal resistance [1]. Thus, temperature difference between hot and cold junctions is increased, and the responsivity of IR sensor is significantly improved. Comparing with existing IR sensor [1] (Fig. 1b), the proposed design increases responsivity for 15-fold at 200mtorr.