MOLECULAR BEAM EPITAXY FOR FABRICATING LONG WAVELENGTH INFRARED DETECTORS USING INASSB ON SI SUBSTRATE

MIDCOURSE SURVEILLANCE AND MISSILE SURVEILLANCE SYSTEMS REQUIRE LONG WAVELENGTH INFRARED (LWIR) AND MEDIUM WAVELENGTH INFRARED (MWIR) DETECTOR ARRAYS, REPECTIVELY. CURRENT IRREPRODUCIBILITY OF HGCDTE TECH-NOLOGY FOR THE LWIR SPECTRAL REGION HAS FORCED A REAPPRAISAL OF DEVELOPING INASSB AS AN ALTERNATE HAVING HIGHER PRODUCIBILITY, STRONG BONDING, AND BETTER UNIFORMITY WHILE PROCESSING HIGHER OR COMPARABLE PERFORMANCE. RECENT PROGRESS MADE IN MOLECULAR BEAM EPITAXY (MBE) OF INASSB AND STRAINED SUPERLATTICE (SSL) OF III-V COMPOUNDS HAS OPENED THE POSSIBILITY OF USING INASSB SSL MATERIAL AS AN ALTERNATIVE TO HGCDTE TECHNOLOGY. ION-BEAM EPITAXY (IBE) AND MBE CONFIGURATIONS AND REQUIREMENTS FOR GROWING INASSB SSL ARE BEING INVESTIGATED AND DESIGNED. A SPECIAL BUFFERED SILICON SUBSTRATE IS BEING USED FOR THE INASSB EPITAXY, AIMED AT ACHIEVING UNIFORM EPILAYER HAVING A CUTOFF WAVELENGTH OF 12 MICRONS AS 77K. THE BUFFERED SUBSTRATE IS FORMED BY AN INNOVATIVE IBE TECHNIQUE. SPECIAL IBE - MBE FIXTURES ARE BEING DESIGNED AND MBE PROCESSES ARE BEING DELINEATED. WHEN SUCCESSFULLY DEMONSTRATED, THIS APPROACH COULD LEAD TO MORE REPRODUCIBLE, UNIFORM AND SENSITIVE DETECTORS THAN THOSE OF LWIR HGCDTE TECHNOLOGY.