Large-size High Temperature Superconducting Thin Film by High Power ArF Excimer Laser

Abstract

40mm by 40mm large size YBa₂Cu₃O_7-x high temperature superconducting thin films were fabricated by a pulsed laser deposition. A high energy ArF excimer laser up to 1.2J/pulse and a substrate-rotation deposition technique with substrate off setting to the center of the plume were developed for making large area thin films.The ArF excimer laser has a newly developed back UV-preionization system and a high precision high voltage trigger cirouit and utilizes a LC inversion voltage doubling circuit for high voltage discharge. To improve an energy profile of ArF laser beam, a segment mirror was also developed. Large area superconducting thin films were deposited with the shaped high energy ArF excimer laser of 0.58J on the surface of the target and the substrate rotation technique with off setting distance of40mm. The superconducting thin film has thickness variation less than10% and superconducting transition temperatures between 85K to 90K over the whole substrate.