MOCVD GROWN GAAS/ALGAAS AND GAAS/INGAAS STRUCTURES WITH APPLICATION TO HEMTS

UNTIL RECENTLY, NEARLY ALL MAJOR WORK ON HEMTS HAS BEEN PERFORMED BY MBE. WITHIN THE LAST YEAR, SEVERAL JAPANESE COMPANIES, AFTER INTENSIVE RESEARCH EFFORTS, HAVE BEGUN TO OFFER MOCVD-GROWTH HEMT DEVICES FOR SALE. BASED ON OUR EXPERIENCE AND PREVIOUS WORK IN THE GROWTH AND FABRICATION OF MOCVD HEMTS, EMCORE FEELS THAT A CONCERTED EFFORT IN NECESSARY TO PROMOTE AND STIMULATE BOTH THE GROWTH AND FABRICATION OF MOCVD-GROWTH HEMT DEVICES IN THE U.S. MOCVD, BY VIRTUE OF ITS HIGH THROUGHPUT AND GREATER ECONOMY IN A PRODUCTION SETTING, OFFERS THE MOST PROMISING APPROACH TO THE COMMERCIALIZATION OF HIGH SPEED HETEROJUNCTION DEVICES. WE BELIEVE THIS IS THE MOTIVATION BEHIND THE INTENSE CURRENT INTEREST AND SUBSTANTIAL BASIC RESEARCH EFFORT BY THE JAPANESE. HEMT STRUCTURES WILL BE STUDIED WITH RESPECT TO SEVERAL STRUCTURAL PARAMETERS. THE PHASE I STUDY WILL VARY SPACER LAYER THICKNESS AND ALUMINUM CONCENTRATION. THE EFFECTOF THESE VARIATIONS OF 2 DEG MOBILITY AND SHEET CARRIER CONCENTRATION WILL BE DETERMINED BY COMPARISON WITH BASELINE DATA ON A STANDARD HEMT STRUCTURE, PRESENTLY IN PILOT-PRODUCTION. MATERIALS WILL BE CHARACTERIZED FOR TRANSPORT PROPERTIES AND UNIFORMITY.