Metasurface Based Uncooled Microbolometer with High Fill Factor

This paper presents the design, fabrication, characterization, and noise reduction of metasurface integrated uncooled infrared (IR) microbolometers. The metasurface allows the devices to be fabricated with the supporting arms positioned underneath the microbolometer pixel. This permits the use of longer supporting arms without sacrificing the fill factor in a focal plane array. The longer arms reduce the thermal conductance between the microbolometer pixel and the substrate. The metasurface also allows the IR absorption to be engineered to achieve broadband or narrowband response. The inclusion of the metasurface is shown to improve the device performance including, primarily by lowering the electrical resistance of the microbolometer although the temperature coefficient of resistance slightly improved. This reduced the 1/f noise by two orders of magnitude over an identical device with no metasurface.