Robust Array-Composite Micromachined Thermopile IR Detector by CMOS Technology

Abstract

An improvement in mechanical stability and a reduction in time constant have been obtained over a traditional CMOS-compatible micromachined thermopile infrared detector. The single big thermopile (SBT) is replaced with a series-connected small thermopile array (STA). The small thermopile in array-composite structure is scaled down compared with the traditional SBT structure. Compared with SBT, STA shows a better compromise among mechanical stability, time constant, and sensitivity. Because of the small floating structure design, the STA detector only shows a one-fourth deflection as the SBT detector. In addition, the time constant of the STA detector is also much reduced due to the size effect, while sensitivity and detectivity for SBT and STA detectors are nearly the same.