Fabrication of a 1024 × 1024 format long wavelength infrared focal plane array based on type-II superlattice and barrier enhanced structure

Abstract 1024 × 1024 format long-wavelength infrared focal plane arrays are realized using type-II superlattice material with a double-barrier enhanced structure grown on 3″ GaSb substrate. The detector structure material exhibits excellent crystalline quality and uniformity. A 100% cutoff wavelength of ~11.8 μm was obtained at 82 K. A dark current density of 1.4 × 10−6 A/cm2 and a differential resistance-area product RA of 4.7 × 104 Ωcm2 at 49 K, 3.6 × 10−5 A/cm2 and 2.8 × 103 Ωcm2 at 70 K, and 2.5 × 10−4 A/cm2 and 5.5 × 102 Ωcm2 at 82 K, at a reverse bias of ~ 50 mV, were obtained, respectively. At zero bias, the R0A was 5.1 × 104 Ωcm2, 290.6 Ωcm2, and 35.6 Ωcm2 at 49 K, 70 K, and 82 K, respectively. Noise equivalent temperature differences of 37.4 mK at 82 K and 31.9 mK at 70 K were achieved with an integration time of 0.12 ms, a 300 K background and f/2.0 optics. The large format FPA also shows excellent imaging.