MOCVD OF HTSC: PROCESS DEVELOPMENT FOR UNIFORM LARGE AREA GROWTH

SEVERAL METHODS, INCLUDING SPUTTERING, E-BEAM EVAPORATION, LASER ABLATION AND METALORGANIC CHEMICAL VAPOR DEPOSITION (MOCVD), HAVE SUCCEEDED IN DEPOSITING HIGH QUALITY THIN FILMS OF HIGH TEMPERATURE SUPERCONDUCTORS (HTSC) ON 1 CM2 SUBSTRATES. HOWEVER, THE GROWTH OF HIGH QUALITY THIN FILMS OVER LARGE AREAS HAS YET TO BE ACHIEVED AND PROCESS REPRODUCIBILITY IS MARGINAL. THESE TWO SHORTCOMINGS ARE THE MAJOR REMAINING BARRIERS TO THE COMMERCIAL PRODUCTION OF PASSIVE HTSC COMPONENTS. BASED ON WORK DONE IN THE GROWTH OF COMPOUNT SEMICONDUCTORS, MOCVD HAS EMERGED AS THE PREEMINENT DEPOSITION METHOD FOR THE GROWTH OF UNIFORM FILMS OVER LARGE AREAS. THE MOST UNIFORM FILMS GROWN BY MOCVD HAVE BEEN DEPOSITED UNDER STAGNATION POINT FLOW. ATM IS CURRENTLY GROWING STATE-OF-THE-ART TLBACACUO THIN FILMS BY MOCVD IN A STAGNATION POINT FLOW REACTOR WHICH IS CAPABLE OF HANDLING 3 INCH DIAMETER SUBSTRATES. THE GOAL OF PHASE I IS TO USE A COMBINED MODELING/EMPIRAL APPROACH TO DEVELOP CVD HARDWARE AND OPERATING CONDITIONS WHICH GIVE UNIFORM BA(2)CACU(2)O(X) FILMS. IN PHASE II, THE CONCERTED APPROACH WILL BE EXTENDED TO THE CVD OF TL(2)CA(2)CACU(2)O(X) WITH A TARGETED THICKNESS AND COMPOSITIONAL UNIFORMITY MILESTONE OF LESS THAN + OR - 5% OVER 3 INCH DIAMETER SUBSTRATES. A SECONDARY OBJECTIVE IS THAT UNIFORM GROWTH TAKE PLACE UNDER CONDITIONS WHICH ARE HIGHLY TOLERANT OF SMALL FLUCTUATIONS IN THE PROCESS PARAMETERS TO ENSURE A LEVEL OF PROCESS REPRODUCIBILITY TYPICAL OF THE ELECTRONICS INDUSTRY.