Development of a 230-micron array of Dual-Polarization Kinetic Inductance Detectors

Kinetic Inductance Detectors (KIDs) are promising candidates for far-infrared (FIR) astronomical missions due to their high sensitivity and natural multiplexing capability. This work presents two dual-polarization KID absorber designs targeting the 1.3 THz band, based on cross-shaped and mohn-shaped unit-cell geometries. Full-wave electromagnetic simulations predict absorption efficiencies above 90% for both orthogonal polarizations. A prototype array with aluminum (Al) superconducting film was fabricated on high-resistivity silicon using an optimized wet-etching process for submicron aluminum structures. Dark cryogenic characterization at 10 mK demonstrates well-defined resonances and high internal quality factors, validating the low-frequency resonator design. These results support the suitability of the proposed designs for future FIR detector arrays.