HIGH TEMPERATURE BCSCO SUPERCONDUCTING THIN FILMS ON SI SUBSTRATE AT LOW PROCESSING TEMPERATURE FOR POSSIBLE APPLICATIONS IN HYBRID OPTO-ELECTRONICS DEVICES

IN THE PROPOSED PROGRAM, FOR THE FIRST TIME, EPITAXIAL GROWTH OF THIN FILM OF HIGH TEMPERATURE BISMUTH-CALCIUM- STUNTIUM-COPPER-OXIDE SUPERCONDUCTOR ON SILICON SUBSTRATE AT LOW PROCESSING TEMPERATURE BY LASER INDUCED DEPOSITION, IS EXAMINED. THE FIRST MOST IMPORTANT STEP IN SUCCESSFUL APPLICATION OF THESE HIGHLY PROMISING MATERIALS IN MICRO-ELECTRONICS AND HYBRID OPTO-ELECTRONICS, IS THE FABRICATION OF HIGH QUALITY THIN FILMS ON SEMICONDUCTOR SUBSTRATE. IN THIS PROGRAM, THIN FILM WILL BE PREPARED BY PLASMA ASSISTED LASER DEPOSITION TECHNIQUE USING 265 NM UV LASER AT 10 HZ. IN THIS TECHNIQUE, A HIGH FLUX OF UV PHOTONS IS DIRECTED ONTO THE BISMUTH-CALCIUM-STUNTIUM- COPPER-OXIDE SUPERCONDUCTING TARGET WHICH IS IN CLOSE PROXIMITY TO SI SUBSTRATE. THIS TECHNIQUE HAS BEEN SUCCESSFULLY ADOPTED AT EXCEL FOR DEPOSITING THIN FILMS OF HIGH TEMPERATURE SUPERCONDUCTOR ON VARIOUS INSULATING OXIDE SUBSTRATES. ONE ADVANTAGE OF THIS TECHNIQUE IS THAT PRECISELY CONTROLLED THIN FILMS OF DESIRED STOICHIOMETRY CAN BE DEPOSITED AT LOW PROCESSING TEMPERATURE WITHOUT THE NEED OF ANY HIGH TEMPERATURE (900 DEGREES CENTIGRADE) POST ANNEALING. THIS LOW TEMPERATURE PROCESSING HAS IMPLICATIONS RELATING TO HOW THIN (10-20 NM) A FILM CAN BE DEPOSITED ON SI BEFORE INTRODUCING SUBSTRATE-FILM INTERACTION. ONCE A HIGH QUALITY THIN FILM IS PRODUCED, THE NEXT LOGICAL STEP IS TO PRODUCE PATTERNS IN THESE FILMS FOR DEVICE FABRICATION AND ALSO THE MEASUREMENTS OF CRITICALCURRENT DENSITY. TRADITIONAL WET PROCESSING METHODS COMMONLY USED FOR PATTERNING MAY HAVE A DETERIMENTAL EFFECT ON THE PROPERTIES OF THE FILM. THUS IN THE PRESENT WORK, A DRY PROCESSING METHOD, NAMELY LASER INDUCED ETCHING, WILL BEUTILIZED TO FABRICATE 10-MU WIDE LINE USING 532 NM LASER AT KHZ REP. RATE. SUPERCONDUCTIVITY IN THE GROWN FILM WILL BE CONFIRMED BY PERFECT CONDUCTIVITY AT TRANSITION TEMPERATURE. CRITICAL CURRENT DENSITY ACROSS THE MICRO-BRIDGE WILL BE MEASURED BY FOUR PROBE RESISTIVE TECHNIQUE.