METHOD FOR FORMING YBCO THIN FILM USING SAPPHIRE SUBSTRATE

摘要

PURPOSE: A method for forming a YBCO(YBa2Cu3O7-delta) thin film using a sapphire substrate is to improve a critical current density and a critical temperature of the YBCO to be formed on an upper part of a CeO2 film by improving a surface roughness of the CeO2 to be used as a buffer film. CONSTITUTION: A method for forming a YBCO thin film comprises the steps of: locating a sapphire substrate(30) on a substrate holder of a resonance chamber in a PLD(Pulsed Laser Deposition) equipment; regulating and maintaining the temperature of the substrate holder in the range of 750 to 850 deg.C; depositing a CeO2 film(32) as a buffer film on the sapphire substrate by scanning a laser beam to a target of the CeO2 material after regulating the inner pressure of the resonance chamber in the range of 45 to 55 mTorr, and an energy density of an excimer laser in the range of 0.8 to 2.0 J/square centimeter; and depositing a YBCO thin film(34) on the CeO2 film by an in-situ within the resonance chamber. The CeO2 is formed at a thickness of 10 to 100 nm.