Preparation and Characterization of High Temperature Superconductor Film Surfaces

Research was conducted on deposition and characterization of high temperature superconductor films. A number of configurations for sputter deposition of films were tested, including three-source co-sputtering with the guns facing, and with the guns off-axis, from the growing film, and single composite-target sputtering. The best film properties were obtained with off- axis, single target sputtering onto a heated substrate. Films were deposited onto heated magnesium oxide substrates using simultaneous sputtering (co- sputtering) from three metal targets: yttrium, copper, and a barium copper alloy. After a significant number of depositions were carried out to optimize film composition and to maximize transition temperature, we began deposition onto substrates of strontium titanate. These substrates allowed higher transition temperatures and films with lower resistivities.