A High-Speed Thermoelectric Infrared Sensor Fabricated by CMOS Technology and Micromachining

Abstract

A high-speed thermoelectric infrared sensor has been fabricated by the CMOS process and micromachining. The time constant of the sensor has been reduced by means of a reduction of sensor size and a thin Si₃N₄ membrane structure. The sensitivity has been improved with a precisely patterned Au black infrared absorption layer formed by a PSG lift-off process. The characteristics of the sensor have been simulated using a thermal equivalent circuit model. A time constant of 270 μsec and sensitivity of 60 V/W at atmospheric pressure have been achieved. This time constant is smaller than any other reported value of thermopiles.