RADIATION MONITORING DEVICES, INC. — Department of Defense SBIR Phase I: MDA14-021

Description

The unique electronic properties of periodically-arranged indium arsenide/gallium antimonide (InAs/GaSb) mesas in the type-II strained layer superlattices (SLS) make them a superior alternative to the conventional HgCdTe sensors for longwave infrared focal plane array (LWIR FPA) detectors. However, despite the highly promising quantum features of SLS, its performance is currently limited by high reverse leakage current, attributed to the discontinuity in the periodic crystal structure caused by mesa delineation. The Phase I efforts will address this challenge by applying a suitable passivation to the complex morphologies of type-II SLS mesas, in order to eliminate the dangling bonds from the surface and provide a robust barrier against the diffusion of chemical species, which could have deleterious effects on the device performance. The proposed idea is built on the foundations of the novel chemical precursors that are proprietary to and available at RMD, Inc. Using these precursors, a passivation technology with appropriate properties such as: band gap, thermal expansion, lattice, adhesion, and surface energy, will be developed. The passivation technology will be optimized to yield uniform, conformal, pinhole-free and stoichiometric composition, processed at low substrate temperatures. Approved for Public Release 14-MDA-8047 (14 Nov 14)