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Because of YBa 2 CH 3 < / sub > O 7 - x (YBCO) high temperature superconducting thin films with excellent electrical properties , with its production of high-temperature superconducting passive microwave devices have the advantage of small size , light weight , low loss , low noise , low dispersion , and good market prospects in the field of microelectronics applications . Microelectronic devices , however , integration and industrialization urgent requirements of the preparation of large area thin film materials , good preparation performance large area YBCO thin films become a research focus of the high-temperature superconducting films . Sol - gel method with low-cost , simple process , in any size and shape of the substrate film-forming characteristics , a method of preparation of large area YBCO film great potential . In this paper, a low fluoride as copper ion complexing agent to the acrylic sol process , to explore the impact of different stoichiometric ratio of the precursor and heat treatment process of the YBCO film microstructure and superconducting phase . By XRD, SEM and superconductivity and other test analysis found : cation precursor stoichiometric ratio of Y: Ba: Cu = 1:2:4 of the YBCO thin film having a preferred c-axis growth orientation , its critical transition temperature T the c is about 90K, the transition width the △ T c < 1K (77K , 0T ) : heat treatment process , pretreatment temperature of 500 ° C , the end of the treatment temperature of 800 ℃ sample of the superconducting transition temperature T c highest transition width △ T c narrowest . The thickness variation of the film morphology are discussed , the study found YBCO thin film on LaAlO 3 (LAO) substrate is the preferred c-axis growth , and with the increase of the film thickness large YBCO thin films by the c-axis growth orientation to the growth of a-axis orientation . Finally, a suitable sol ratio and the heat treatment process, with a preferred c-axis growth orientation and in-plane uniformity YBCO film was prepared on a 3 inch the LAO monocrystalline substrate . The average roughness of the surface of the film was 38nm, and the average thickness of 0.83 μm , and the thickness deviation was 3.71 % , of △ T c distributed in between 0.46-0.92 .
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