TECHNIQUES FOR THE PULSED ENERGY DEPOSITION OF PARTICLE-FREE, ULTRA-SMOOTH HIGH CRITICAL TEMPERATURE SUPERCONDUCTING THIN FILMS

APPLICATIONS OF THE NEW HIGH TEMPERATURE SUPERCONDUCTORS IN ELECTRONIC COMPONENTS REQUIRE THE DEVELOPMENT OF WELL-CONTROLLED TECHNIQUES FOR FABRICATING THIN FILMS OF THEMATERIALS. CONSIDERABLE SUCCESS HAS BEEN OBTAINED WITH PULSED EXCIMER LASER DEPOSITION. THIS METHOD HAS DEMONSTRATED EXCELLENT CONTROL OVER CHEMICAL COMPOSITION AND PHASE. HOWEVER, THE FILMS OFTEN CONTAIN UNWANTED PARTICULATE MATERIAL EJECTED FROM THE SOURCE. MINIMIZING THE NUMBER OF PARTICLES IN THE FILMS IS ESSENTIAL FOR PATTERNING SMALL DEVICE FEATURES AND FABRICATING MULTI-LAYER STRUCTURES WITHOUT PINHOLES OR ELECTRICAL SHORTS. SMOOTH, PARTICLE-FREE SURFACES ALSO ARE REQUIRED TOACHIEVE LOW MICROWAVE LOSSES. THE PURPOSE OF THIS STUDY IS TO REDUCE THE INCIDENCE OF THESE PARTICLES BY DESIGNING AND CONSTRUCTING A VELOCITY FILTER OR SHUTTER MECHANISM THAT WILL BLOCK THE PASSAGE OF THE SLOWER MOVING PARTICLES WHILE ALLOWING THE DESIRED FASTER MOVING VAPOR SPECIES OF THE EVAPORANT TO DEPOSIT ON THE SUBSTRATE. THE PARTICLE- TRAPPING TECHNIQUE WILL BE APPLIED TO THE FILM DEPOSITION OF THE YTTRIUM- BARIUM-COPPER-OXIDE SUPERCONDUCTOR ON SUITABLE SUBSTRATES, E.G., STRONTIUM TITANATE OR LANTHANUM ALUMINATE. PROCESSING CONDITIONS WILL BE OPTIMIZED TO ACHIEVE FILMS WITH LOW PARTICLE CONTENT AND GOOD SUPERCONDUCTING PROPERTIES.