Patterned resistive sheets for potential use in 3D stacked multispectral reduced thermal mass microbolometer

Patterned resistive sheets (PRS) are resistive sheets with periodic patterns which provide further advantages to the functionality of the microbolometer. This study examines the potential of both single- and double-layer designs to achieve spectral selectivity in both broadband and narrowband absorption in the microbolometer's application. First, important design parameters, including rules and processes, are established. These include descriptions of sheet resistance, air gap, material refractive index, thicknesses of dielectric and bolometric layers, mirror, pattern shape and size, and unit cell period. Moreover, interactions among these elements are examined. Second, single-layer designs using dipole and slot PRS are introduced as initial designs for the reduced thermal mass design. Applying holes without changing spectral selectivity are investigated for narrowband application. Moreover, the method to tune the change of spectral selectivity is introduced. Third, newly stacked two-color design is suggested. The out-of-band transmission and reflection characteristics of the dipole and slot PRS are investigated to increase the absorption of each layer. Additionally, different pattern shapes, such as the circular patch and square patch, are investigated for easier fabrication.