Development of an automated dual ion beam assisted process for superconducting oxide film deposition

An automated dual ion beam sputter deposition system has been developed, in which individual targets of Y, Cu, and BaF2 are sequentially sputtered to produce Y-Ba-Cu-O films with controlled composition. The dwell time of the ion beam on each target is determined by a computer controlled feedback loop using the signal of a quartz crystal resonator. Each individual target is exposed to the ion beam at the same spatial location, which optimizes compositional and thickness homogeneity across the substrate surface. As deposited superconducting Y-Ba-Cu-O films have been successfully grown at temperatures in the range 700-720degC using either an oxygen ion beam or an ozone jet directed at the substrate. Oxygenation effects by the two sources on film stoichiometry and microstructure are discussed. (orig.)