SILICON-BASED HIGH-DENSITY LWIR IMAGING ARRAYS

WE PROPOSE A NEW APPROACH TO LONG WAVELENGTH INFRARED (LWIR) IMAGING ARRAYS USING SUPERLATTICE SCHOTTKY BARRIER (SB) PHOTODIODES GROWN BY MOLECULAR BEAM EPITAXY (MBE) ON SILICON (SI). THESUPERLATTICE SB PHOTODIODES ARE PROCESSED WITH READOUT ELECTRONICS ONTHE SI FORMING A MONOLITHIC ARRAY. WE WILL FIRST PERFORM THE MBE GROWTH OF THE COBALT SILICIDE/SI SUPERLATTICE TO DEMONSTRATE THE FEASIBILITY OF FABRICATING THE SUPERLATTICE SB PHOTODIODES FOR A 12-MICRON WAVELENGTH CUTOFF, FOLLOWED BY DESIGNING AN APPROPRIATE READOUT SCHEME FOR THE PHOTODIODES TO FORM A MONOLITHIC ARRAY. OUR OVERALL GOAL IS TO DEVELOP THE SB ARRAY WITH HIGH DENSITY, AND OPTIMIZE IT FOR A 40% QUANTUM EFFICIENCY, A 1% NON-UNIFORMITY AND A FABRICATION COST COMPARABLE TO THAT OF THE CURRENTLY-AVAILABLE PT-SILICIDE SB ARRAY COVERING THE 3-5 MICRON SPECTRAL BAND. THE RESULTANT LWIR ARRAYS WILL FIND APPLICATIONS IN FLIRS, SPACE-BASED INTERCEPTORS AND EARLY WARNING AND SURVEILLANCE SYSTEMS. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONSINFRARED SURVEILLANCE SYSTEMS, SEEKERS, FLIRS AND SMART MUNITION SYSTEMS, AND IN COMMERCIAL SYSTEMS SUCH AS REMOTE SENSING OF EARTH RESOURCES, ASTRONOMY, MEDICAL IMAGING SYSTEMS AND THERMAL IMAGING SYSTEMS FOR PROCESS CONTROL.