High quality Yba2Cu3O7-x thin films prepared by plasma-enhanced metalorganic chemical vapor deposition

The authors have grown YBa2Cu3O7-x superconducting thin films epitaxially, in-situ, by a microwave-plasma enhanced metalorganic chemical vapor deposition process. The films had smooth mirror-like surfaces and were deposited at a substrate temperature of 730 degree C in 2 torr of N2O partial pressure. LaAlO3 and SrTiO3 were selected as the substrate materials because of their close lattice match to YBa2Cu3O7-x. Electrical resistance versus temperature measurements of the as deposited films show normal metallic behavior and sharp superconducting transitions with Tc(R = 0) ∼89K. Critical current densities measured on patterned bridges were 5 x 105 A/cm2 at 78K for the films on LaAlO3 and SrTiO3, respectively. X-ray diffraction measurements indicate that films grew epitaxially in the plane of the substrate with c-axis perpendicular to the substrate surface