PREPARATION OF HIGH-TC SUPERCONDUCTING BI-SR-CA-CU-O FILMS BY ORGANOMETALLIC CHEMICAL VAPOR-DEPOSITION USING 2ND-GENERATION FLUOROCARBON-BASED PRECURSORS

High-T(c) superconducting Bi-Sr-Ca-Cu-O thin films with good electrical properties and smooth surface morphologies have been prepared by low-pressure organometallic chemical vapor deposition using the new fluorocarbon-based precursors Sr(hexafluoroacetylacetonate)2.tetraglyme and Ca(hexafluoroacetylacetonate)2.triglyme together with Cu(acetylacetonate)2 and triphenylbismuth [Bi(C6H5)3]. The fluorinated precursors are air-stable and exhibit high, stable volatility even after prolonged heating. X-ray diffraction measurements reveal that the films deposited at 650-degrees-C contain some fluoride phases but no high-T(c) phases. However, post-annealing in oxygen produces films composed predominantly of the Bi2Sr2CaCu2O(x) phase with high preferential orientation of the crystallite c axes perpendicular to the substrate surface. Four-probe resistivity measurements indicate the onset of film superconductivity at approximately 100 K and zero resistivity achieved at 73 K.