"A SIMPLE HIGH PERFORMANCE AVALANCHE PHOTODIODE FOR LONG-WAVELENGTH OPTICAL COMMUNICATIONS"

FUTURE HIGH SPEED ( 1GBIT) OPTICAL COMMUNICATION SYSTEMS WILL REQUIRE AVALANCHE PHOTODETECTORS (APDS) WHICH OPERATE AT 1300 AND 1550NM WAVELENGTHS. LABORATORY TESTS HAVE SHOWN THAT INGAAS/INP APDS CAN BE MADE WHICH OUTPERFORM BOTH PIN/FET RECEIVERS AND GERMANIUM APDS AT THESE WAVELENGTHS - AT HIGH DATA RATES. HOWEVER THESE DEVICES ARE EXTREMELY DIFFICULT TO MAKE AND ELABORATE CRYSTAL GROWTH AND PROCESSING TECHNIQUES WITH CRITICAL TOLERANCES MUST BE EMPLOYED TO FABRICATE THEM. THIS MAY EXPLAIN WHY ONLY ONE OR TWO JAPANESE MANUFACTURERS OFFER THEM FOR SALE IN LIMITED QUANTITIES WITH THOUSAND DOLLAR PRICE TAGS AND NO AMERICAN MANUFACTURERS SELL THEM TO DATE. EPITAXX, INC. PROPOSES TO DEVELOP A TOTALLY NEW, HIGHLY SIMPLIFIED INGAAS/INP APD STRUCTURE WHICH BYPASSES THESE FABRICATION DIFFICULTIES. THE SIMPLICITY OF THE DEVICE WOULD EVENTUALLY ALLOW FOR A HIGH-YIELD MANUFACTURING PROCESS - WITH DEVICE COSTS COMPARABLE TO PRESENT-DAY SILICON APDS - AND REMOVE ONE OF THE BIGGEST IMPEDIMENTS TO WIDESPREAD USE OF LONG-WAVELENGTH FIBER OPTICS. IN PHASE I OF THIS PROGRAM, TWO-DIMENSIONAL ELECTRIC FIELD MODELING WOULD BE CARRIED OUT IN CONSULTATION WITH PROF. S.R. FORREST OF THE UNIVERSITY OF SOUTHERN CALIFORNIA TO DETERMINE THE OPTIMUM GEOMETRY OF THE DEVICE. A FINAL OPTIMIZED DEVICE STRUCTURE WILL BE PROPOSED ALONG WITHAPPROPRIATE MASKS FOR FABRICATION.