Near-infrared, Linear Mode, Photon Counting HgCdTe Focal Plane Arrays

The MDA is developing deployable airborne systems such as the Airborne Laser (ABL) for boost-phase missile defense. The ABL’s mission would significantly benefit from the development of sensors that enhance target detection and ranging capabilities. We propose near-infrared, linear mode, photon counting avalanche photodiode (APD) arrays that are compatible with ABL and based on highly sensitive HgCdTe heterostructure detectors. They offer the advantageous combination of several properties, including staring mode operation, high bandwidth, high quantum efficiencies, low noise, linearity and room temperature operation. The proposed arrays will be fabricated in a lateral current collection device architecture that possesses a larger optical detection area than electrical junction area, and also has the advantages of a reduced dark current and higher resistance than a traditional planar device. In the Phase I effort, we will use a 2D device modeling tool to design, simulate and optimize HgCdTe near-infrared, lateral current collection, photon counting APDs, grow the structures by molecular beam epitaxy, fabricate single element detectors with lithography, perform inductively coupled plasma etching and metal evaporation, and characterize the electrical, optical, gain and noise performance of the sensing detectors.