Monolithic Integrated Thermoelectric IR Detector Microsystem by CMOS-MEMS Technology

摘要

In this paper,a monolithic integrated thermoelectric IR detector microsystem consisting of a thermopile IR detector and an amplifier circuit is presented. The IR detector microsystem was fabricated by 0.5 μm single poly, single metal, 2 μm N-well CMOS process and XeF2 post-CMOS maskless dry isotropic etching. N-Poly/Al thermocouple was embedded in 2.4 μm SiO2/Si3N4/SiO2 sandwich membrane and dielectric film was adopted as absorber. For a high temperature difference between the cold junction and the hot junction, etching window in the absorber was designed to avoid cutting off the heat transfer path from absorber to hot junctions. The gain of the amplifier circuit was designed to 1000. The IR detector microsystem was characterized in air at room temperature. A responsivity of 52.1 V W-1 and a specific detectivity of 4.1×107 cm Hz1/2 W-1 were found for the thermoelectric IR detector.