128 × 128 long-wavelength/mid-wavelength two-color HgCdTe infrared focal plane array detector with ultralow spectral cross talk

TLDR

LW/MW two‑color FPA infrared detection provides high‑temporal and spatial coherence and is a leading third‑generation remote‑sensing technology. The study designs and fabricates HgCdTe LW/MW two‑color infrared detectors. The detectors were built by selectively B⁺ implantation of top LW and bottom MW photodiodes using a micro‑mesa array, followed by photo‑lithographic fabrication of a 128×128 array, passivation, metallization, mesa isolation, and flip‑chip hybridization with an ROIC. Experimental and numerical studies demonstrate effective cross‑talk suppression and enhanced photoresponse.

Abstract

High temporal and spatial coherent simultaneous long-wavelength/mid-wavelength (LW/MW) two-color focal plane array (FPA) infrared detection is the cutting-edge technique for third-generation infrared remote sensing. In this Letter, HgCdTe LW/MW two-color infrared detectors were designed and fabricated. The top long-wavelength and bottom mid-wavelength infrared planar photodiodes were processed by selective B(+)-implantation after etching the long-wavelength epilayer into a curvature and exposing the mid-wavelength layers for the implantation of the n region of the MW photodiode by a micro-mesa array technique. A 128×128 MW/LW HgCdTe infrared FPA detector is fabricated photo-lithographically by simultaneous nonplanar B(+)-implantation of the LW and MW photodiodes, passivation and metallization of the sidewalls, mesa isolation, and flip-chip hybridization with a read-out integrated circuit. The inner mechanisms for suppressing the cross talk and improving photoresponse have been carried out by combining experimental work with numerical simulations.