1 1 2010 Developing High Performance III V Superlattice IRFPAs for Defense Challenges and Solutions
The antimonide superlattice infrared detector technology program was established to explore new infrared detector materials and technology. The ultimate goal is to enhance the infrared sensor system capability and meet challenging requirements for many applications. Certain applications require large format focal plane arrays (FPAs) for a wide field of view. These FPAs must be able to detect infrared signatures at long wavelengths, at low infrared background radiation, and with minimal spatial cross talk. Other applications require medium format pixel, co registered, dual band capability with minimal spectral cross talk. Under the technology program, three leading research groups have focused on device architecture design, high quality material growth and characterization, detector and detector array processing, hybridization, testing, and modeling. Tremendous progress has been made in the past few years. This is reflected in orders of magnitude reduction in detector dark current density and substantial increase in quantum efficiency, as well as the demonstration of good quality long wavelength infrared FPAs. Many technical challenges must be overcome to realize the theoretical promise of superlattice infrared materials. These include further reduction in dark current density, growth of optically thick materials for high quantum efficiency, and elimination of FPA processing related performance degradation. In addition, challenges in long term research and development cost, superlattice material availability, FPA chip assembly availability, and industry sustainability are also to be met. A new program was established in 2009 with a scope that is different from the existing technology program. Called Fabrication of Superlattice Infrared FPA (FastFPA) this 4 year program sets its goal to establish U.S. industry capability of producing high quality superlattice wafers and fabricating advanced FPAs. It uses horizontal integration strategy by leveraging existing III V industry resources and taking advantage of years of valuable experiences amassed by the HgCdTe FPA industry. By end of the program span, three sets of FPAs will be demonstrated a small format long wave FPA, a large format long wave FPA, and a medium format dual band FPA at long wave and mid wave infrared.