Fabrication and modelling of a prototype dual-band HgCdTe infrared detector structure

Abstract

A monolithic HgCdTe photoconductive device structure is presented that is suitable for dual-band optically registered infrared photodetection in the two atmospheric transmission windows of 3-5 /spl mu/m and 8-12 /spl mu/m, which correspond to the mid-wave and long-wave infrared bands; MWIR and LWIR, respectively. The proposed structure employs a wider bandgap isolating layer between the two photosensitive layers such that an effective electrical barrier is formed thus prohibiting carrier transport between the two infrared absorbing layers. A comprehensive device model has been developed and the technology is demonstrated using a mature HgCdTe photoconductive device fabrication process. The fabricated detectors have an MWIR cutoff of 5.0 /spl mu/m, and LWIR cutoff of 10.5 /spl mu/m.