LARGE AREA DISTRIBUTED ELECTRONICS ON GLASS BY ION IMPLANTATION OF SILICON-GERMANIUM ALLOYS

THIS PROJECT ADDRESSES THE INTEGRATED PRODUCTION OF DETECTOR AND READOUT ELECTRONICS FOR SUPERCONDUCTING SUPER COLLIDER (SSC) MICROSTRIP DETECTORS. THIN FILM TRANSISTOR (TFT) CIRCUITRY BEING DEVELOPED FOR FLAT PANEL DISPLAYS IS RADIATION RESISTANT, CAN BE USED FOR DIGITAL SIGNAL PROCESSING, AND CAN BE DEPOSITED ON THE SAME SUBSTRATES AS THE MICROSTRIP DETECTORS. HOWEVER, TFT CIRCUITRY DOES NOT YET MEET THE HIGH SPEED AND LOW POWER DISSIPATION REQUIREMENTS OF THE SSC APPLICATION. POLYCRYSTALLINE SILICON-GERMANIUM ALLOYS, WHICH CAN SHOW SELF-PASSIVATION AT GRAIN BOUNDARIES AND CAN BE DEPOSITED AT LOWER TEMPERATURES THAN PURE SILICON, ARE EXPECTED TO BE SUPERIOR TO POLYCRYSTALLINE OR AMORPHOUS SILICON FOR TFTS AND COULD MEET THE SSC REQUIREMENTS. LOW TEMPERATURE CHEMICAL VAPOR DEPOSITION OF THIN FILMS WILL BE FOLLOWED BY ION IMPLANTATION OF GERMANIUM TO CHANGE THE AS-DEPOSITED MICROCRYSTALLINE STRUCTURE TO A PARTIALLY AMORPHOUS MATERIAL. THE AMORPHOUS ALLOY WILL THEN BE RECRYSTALLIZED AT LOW TEMPERATURE TO ATTAIN LARGE GRAIN SIZES. IN PHASE I, MATERIAL PROPERTIES ARE BEING INVESTIGATED AS A FUNCTION OF GERMANIUM CONTENT AND TEMPERATURE-TIME ANNEAL CYCLES. HALL MOBILITY MEASUREMENTS ARE BEING MADE TO DETERMINE THE FEASIBILITY OF FABRICATING HIGH SPEED DEVICES IN THE RESULTING MATERIAL. PHASE II EXPERIMENTS WILL OPTIMIZE PROCESS PARAMETERS AND DEMONSTRATE-THROUGH PROTOTYPE CIRCUITRY ON A MICROSTRIP DETECTOR-DEVICE SPEED, POWER CONSUMPTION, AND RADIATION RESISTANCE.