HgCdTe 128×128 infrared focal plane arrays on alternative substrates of CdZnTe/GaAs/Si

Abstract
High quality p-on-n heterojunction infrared detectors have been fabricated using controllably doped HgCdTe grown by liquid phase epitaxy on CdZnTe/GaAs/Si alternative substrates grown by metalorganic chemical vapor deposition and used to demonstrate the first 128×128 focal plane array fabricated on these materials. Detectors with a cutoff wavelength of 6.0 μm and a resistance-area product R0 Aj average of 6.0×104 Ω cm2 at 80 K for 16 189 detectors in the array were achieved, and for operating temperatures above approximately 120 K were comparable in performance to detectors co-fabricated on standard lattice-matched bulk CdZnTe substrates. Below 120 K, detector performance was limited by excess generation-recombination current, probably caused by a higher threading dislocation density compared with that for the bulk substrates.