IMPROVED PRECURSORS FOR THE METALORGANIC CVD OF YBCO THIN FILMS

THIS PROGRAM WILL DEVELOP SUITABLE PRECURSORS, PARTICULARLY FOR BARIUM WHICH EXHIBIT INCREASED VOLATILITY AND STABILITY IN THE METALORGANIC CHEMICAL VAPOR DEPOSITION (MOCVD) PROCESS OF HTSC FILMS BY PYROLYZING ORGANOMETALLIC PRECURSORS AT THE SUBSTRATE SURFACE. MOCVD OFFERS THE ADVANTAGES OF SCALE-UP CAPABILITY, HIGHLY OXIDIZING DEPOSITION CONDITIONS, LOW-TEMPERATURE DEPOSITION CAPABILITY, AND EXCELLENT COMPOSITIONAL CONTROL. IN CONTRAST TO THE CASE OF III/V COMPOUND SEMICONDUCTORS, THE PRECURSORS COMMONLY AVAILABLE FOR Y, BA AND CU ARE LOW VOLATILITY SOLIDS. WHICH UNFORTUNATELY NEED SUBSTANTIAL HEATING (125-250 DEGREES CELSIUS) TO OBTAIN USEFUL GROWTH RATES. THIS DEMANDS HIGH TEMPERATURE COMPONENTS, HEATED LINES AND A MORE COMPLEX MOCVD SYSTEM DESIGN. THE HIGH TEMPERATURE, THOUGH ENCOURAGE A SIGNIFCANT DEGREE WHICH ADVERSELY AFFECTS THE DEPOSITION PROCESS.