A floated absorbing structure for uncooled microbolometer

Abstract

We propose a versatile infrared (IR) absorbing structure for uncooled infrared detectors. We have designed an infrared absorber consisting of five thin film layers (dielectric layer/protection layer/active layer/supporting layer/reflecting layer) that produce a quarter-wavelength resonance condition. It has excellent thermal properties, which are not influenced by the deformation of the thermal isolation structure. We fabricated a microbolometer with the proposed IR absorption structure by a surface micromachining technology. We estimated an IR absorptance of 80%. This IR absorption structure can be applied to both surface micromachining and bulk micromachining.