This paper introduces an analysis on the absorption enhancement in uncooled infrared pixels using resonant plasmon
modes in metal structures, and it reports, for the first time in literature, broad-band absorption enhancement using
integrated plasmonic structures in microbolometers for unpolarized long-wave IR detection. Different plasmonic
structures are designed and simulated on a stack of layers, namely gold, polyimide, and silicon nitride in order to
enhance absorption at the long-wave infrared. The simulated structures are fabricated, and the reflectance measurements
are conducted using an FTIR Ellipsometer in the 8-12 μm wavelength range. Finite difference time domain (FDTD)
simulations are compared to experimental measurement results. Computational and experimental results show similar
spectral reflection trends, verifying broad-band absorption enhancement in the spectral range of interest. Moreover, this
paper computationally investigates pixel-wise absorption enhancement by plasmonic structures integrated with
microbolometer pixels using the FDTD method. Special attention is given during the design to be able to implement the
integrated plasmonic structures with the microbolometers without a need to modify the pre-determined microbolometer
process flow. The optimized structure with plasmonic layer absorbs 84 % of the unpolarized radiation in the 8-12 μm
spectral range on the average, which is a 22 % increase compared to a reference structure with no plasmonic design.
Further improvement may be possible by designing multiply coupled resonant structures.