FABRICATION OF LONG WAVELENGTH ARRAY BY IN-SITU MOLECULAR BEAM EPITAXY

BANDGAP ENGINEERING BY MOLECULAR BEAM EPITAXY (MBE) IS NOT ONLY CAPABLE OF PRODUCING A STRAINED SUPERLATTICE (SSL) OF INSB/INAS(1-X)SB(X) FOR LONGWAVELENGTH INFRARED (LWIR, 8-12 MICRON) DETECTORS, BUT IS ALSO CAPABLE OF PROCESSING THE DETECTORS INTO A MONOLITHIC ARRAY. WE WILL DEVELOP THE MBE PROCESS FIRST TO GROW THE SSL ON A BUFFERED SILICON (SI) SUBSTRATE AND THEN DELINATE THE SSL INTO AN ARRAY OF PHOTODIODES WHICH CAN BE INTERFACED DIRECTLY ONTO A READOUT CIRCUITRY PREVIOUSLY FABRICATED ON THE SAME SI SUBSTRATE. THUS, A MONOLITHIC ARRAY IS FABRICATED IN-SITU DURING A SINGLE EPITAXY PROCESS. THE KEY INNOVATION PROPOSED IS THE COMBINING OF THE SSL EPITAXY, PHOTODIODE FORMATION AND READOUT ELECTRONIC INTERFACING AS A SINGLE PROCESS FOR FABRICATING THE MONOLITHIC ARRAY. WHEN SUCCESSFULLY DEVELOPED, THE PROCESS SHOULD BE HIGH YIELD, LOW COST AND CAPABLE OF PRODUCING HIGH-PERFORMANCE LWIR DETECTOR ARRAYS BY ELIMINATING THE USE OF WET CHEMICAL ETCHING.