High rate DC-reactive sputter deposition of Y₂O₃ film on the textured metal substrate for the superconducting coated conductor

Y₂O₃ film was directly deposited on Ni-3at%W substrate by DC reactive sputtering. DC reactive sputtering was carried out using metallic Y target and water vapor for oxidizing the elements of metallic target on the substrate. The detailed conditions of DC reactive sputtering for depositions of Y₂O₃ films were investigated. The window of water vapor for proper growth of Y₂O₃ films was determined by sufficient oxidations of the Y₂O₃ films and the non-oxidation of the target surface, which was required for high rate sputtering. The window turned out to be fairly wide in the chamber used. As the sputtering power was raised, the deposition rate increased without narrowing the window. The fabricated Y₂O₃ films showed good texture qualities and surface morphologies. The YBCO film deposited directly on the Y₂O₃ buffered Ni-3at%W substrate showed T_c, I_c (77 K, self field), and J_c (77 K, self field) of 89 K, 64 A/cm and 1.1 MA/cm², respectively.