DEVELOPMENT OF GROWTH APPARATUS FOR THE MICROWAVE PLASMA-ASSISTED DEPOSITION OF DIAMOND-LIKE AND REFRACTORY THIN FILMS

THE TECHNIQUE OF LOW TEMPERATURE FORMATION OF DIAMOND-LIKE AND REFRACTORY THIN FILMS USING PLASMA-ASSISTED CHEMICAL VAPOR DEPOSITION (PA-CVD) IS CRUCIAL FOR MANY DOD APPLICATIONS. THE DEVELOPMENT OF SUCH A PROCESS FILL PERMIT DEPOSITION OF HIGH QUALITY, SMOOTH SURFACE AND HIGH DENISTY, REFRACTORY FILMS ON A VARIETY OF SUBSTRATES. PA-CVD, USING A MICROWAVE PLASMA SOURCE, IS A VERY ATTRACTIVE THIN FILM DEPOSITION PROCESS FOR DIAMOND-LIKE AND REFRACTORY THIN FILMS. THIS NOVEL PROCESS SUBSTITUTES ELECTRON KINETIC ENERGY FOR CONVENTIONAL THERMAL ENERGY AND ENHANCES COMPOUND FORMATION WITH THE PRESENCE OF ATOMIC OR IONIC SPECIES, THUS OFFERING LOWER TEMPERATURE DEPOSITION, THROUGH THE USE OF NON-THERMAL EQUILIBRIUM GROWTH CONDITIONS. IN ADDITION, THE PA-CVD PROCESS OFFERS THE POTENTIAL ADVANTGES OF LOW COST, LARGE SCALE FABRICATION. OUR APPROACH IS BASED ON PRELIMINARY RESULTS DEMONSTRATED AT EMCORE BY DEPOSITING THIN FILMS OF THE SUPERCONDUCTING CERAMIC OXIDE, YBACUO, USING MICROWAVE PA-CVD. TEXTURED, HIGH DENSITY, MIRROR SMOOTH SURFACE YBCO FILMS HAVE BEEN FORMED IN SITU AT A REDUCED SUBSTRATE TEMPERATURE OF 570 DEG C. THIS IS OVER 250 DEG C LOWER THAN FOR A THERMAL EQUILIBRIUM CVD PROCES. OUR RESULTS INDICATE THAT THE PROTOTYPE PA-CVD SYSTEM USED IS A SUITABLE STARTING POINT FOR THE DEVELOPMENT OF A SCALABLE PA-CVD SYTEM DESIGN FOR COMMERCIAL R&D AND PRODUCTION MARKETS.