INSULATOR-COATED SPUTTER GUN FOR GROWING SUPERCONDUCTING OXIDE-FILMS

Superconducting Y-Ba-Cu-O films have been successfully grown on 2-in.- diam (100) MgO and CeO2-buffered R-plane sapphire substrates using a s imple, inexpensive hot-wall dc sputtering system. The deposition chamb er was made of a quartz tube and heated by a furnace outside the chamb er. A new sputter gun was developed by shielding the surface of a cath ode electrode using an insulating layer of alumina. The spatial variat ions of thickness and composition of films across a 2-in.-diam wafer a re 4.9% and 4.2%, respectively. Superconducting properties of the film s within a 2-in.-diam area are zero-resistance temperature Tc (zero) o f 88-90 K and critical current density Jc (77 K, zero field) of (1.5-3 .5) X 10(6) A/cm(2). (C) 1997 American Vacuum Society.