Abstract
By simply placing a shadow mask between the target material and substrate, the particle (or droplet) problem peculiar to the excimer laser deposition technique was completely eliminated. It is tentatively called the " eclipse method", in which the deposition proceeds through only diffusion. Mirrorlike YBa2Cu3Oy thin films with T c as high as 90–93 K were obtained reproducibly by (eclipse) ArF excimer laser ablation on MgO substrates in 0.3 Torr O2 ambient. The growth rate reduction was only 70% under this ambient condition. Even when the pressed-powder targets were employed for deposition, the metal-insulator-superconductor (MIS) layered structure seldom encountered the pinhole problem.