MODULATION DOPED FETS ON HETEROSTRUCTURE LAYERS (SDHT, HEMT, TEGFET, MODFET) ARE OF PRIME INTEREST FOR FUTURE HIGH SPEED CIRCUITS WITH IMPROVED PERFORMANCE CHARACTERISTICS.

MODULATION DOPED FETS ON HETEROSTRUCTURE LAYERS (SDHT, HEMT, TEGFET, MODFET) ARE OF PRIME INTEREST FOR FUTURE HIGH SPEED CIRCUITS WITH IMPROVED PERFORMANCE CHARACTERISTICS. CIRCUITS BASED ON SDHT TECHNOLOGY HAVE DEMONSTRATED SUPERIOR PERFORMANCE IN SPEED AND SPEEDPOWER PRODUCT IN DIGITAL, AS WELL AS, LOW-NOISE MICROWAVE APPLICATIONS. DIGITAL SWITCHING TIMES OF AS SHORT AS 6PS HAVE BEEN REALIZED, THE FASTEST IN ANY SEIMICONDUCTOR TECHNOLOGY AND COMPARABLE TO THE FASTEST RESULTS OBTAINED IN JOSEPHSON JUNCTION CIRCUITS. EXTREMELY LOW NOISE FIGURES AND HIGH CUT-OFF FREQUENCIES INDICATE SUPERIOR ANALOG APPLICATIONS. THE EFFECTS OF RADIATION ON SDHT DEVICES HAS NOT BEEN ADDRESSED THUS FAR. MANY APPLICATIONS FOR WHICH THESE HIGH PERFORMANCE CIRCUITS ARE IDEALLY SUITED FOR, (EARLY WARNING SYSTEMS, SPACE BASED DEFENSIVE SHIELDS FOR EXAMPLE) REQUIRE OPERATION IN RADIATION CONTAMINATED ENVIRONMENTS. IT IS THIS AREA-THE ASSESSMENT OF RADIATION EFFECTS ON SDHT DEVICES AND CIRCUITS-THAT OUR PROPOSAL ADDRESSES.