Thin Film Processing for High-Tc Superconductors of Bi-System

Basic thin film deposition processes for the high-Tc superconductors of Bi-systems are described in relation to their structure and superconducting properties. For the rare-earth high-Tc superconductors YBC the thin film deposition processes are clasified into three processes: (i) deposition below crystallizing temperature followed by annealing [process (1)], (ii) deposition above crystallizing temperatme followed by annealing [process (2)], (iii) deposition above crystallizing temperature without postannealing [process (3)]. For the Bi-system there appear several superconducting phases including the low-Tc phase Bi2Sr2Ca2Cu2Ox and the high-Tc phase Bi2Sr2Ca2Cu3Ox. Thin films with these superconducting phases are synthesized by a selection of the substrate temperature Ts during the deposition in the process (1) and/or (2): The high-Tc phase with Tc ≈=110K is synthesized at Ts>800°C; the low-Tc phase with Tc=80K, at Ts