Uncooled infrared microbolometers with low thermal conductance based on shared leg

Abstract

This paper introduces three topologically optimized microbridge architectures for Mn–Co–Ni–O (MCNO)-based uncooled infrared microbolometers, achieving enhanced responsivity via innovative structural designs and advanced thermosensitive materials. One shared-leg topology was chosen for fabrication and experimental testing. This design elevates the fill factor from 44.2% to 74.9% while employing only 0.75 legs and 0.5 anchors per pixel, thereby preserving mechanical stability. Consequently, the normalized voltage responsivity doubles to 9 × 104 V/W at 20 Hz relative to conventional double-leg architectures. Furthermore, the sputtered polycrystalline MCNO films demonstrate a pronounced negative temperature coefficient of resistance (NTCR = −3%/K at 25 °C) with less than 3% variation over thermal cycling from −40 to 140 °C, underscoring their minimal thermal hysteresis.