Getter Sputtering for the Preparation of Thin Films of Superconducting Elements and Compounds

A new sputtering technique which eliminates the need for ultrahigh vacuums in preparing thin films of materials sensitive to gaseous impurities is described. This technique uses the gettering action of part of the sputtered atoms to produce an atmosphere within an anode can very low in reactive gases such as O2 and N2. In consequence, contamination by such interstitial impurities is prevented during deposition. The method has been successfully used for the preparation of superconducting films of materials such as Ta, Nb, V3Si, V3Ge, and V3Ga. This technique in conventional vacuum equipment produces films of pure elements with superconducting properties comparable to those of bulk material. The method should be applicable also to the preparation of magnetic alloy films and epitaxial semiconductor films where contamination by reactive gases has been a problem.