Fabrication of type-II InAs/GaSb superlattice long-wavelength infrared focal plane arrays

Abstract In this paper, we present an InAs/GaSb type-II superlattice (SL) with the M-structure for the fabrication of a long-wavelength (10 μm range) infrared (LWIR) focal plane arrays (FPA), which are grown by molecular beam epitaxy (MBE). The M-structure is named for the shape of the band alignment while the AlSb layer is inserted into the GaSb layer of InAs/GaSb SL. A 320 × 256 LWIR FPA has been fabricated with low surface leakage and high R 0 A product of FPA pixels by using anodic sulfide and SiO 2 physical passivation. Experiment results show that the devices passivated with anodic sulfide obviously have higher R 0 A than the un-sulphurized one. The 50% cutoff wavelength of the LWIR FPA is 9.1 μm, and the R 0 A is 224 Ω cm 2 with the average detectivity of 2.3 × 10 10  cm Hz 1/2  W −1 .