Fabrication of c-axis oriented YBaCuO trilayer junctions with Ar plasma treatment

We have fabricated c-axis oriented YBaCuO/PrBaCuO/YBaCuO trilayer junctions on a LSAT single crystal substrate. Since the c-axis oriented junctions had a smaller critical current density J/sub c/ compare to [103] oriented YBaCuO trilayer junctions, an Ar plasma treatment was carried out. After base electrode deposition, the film sample was bombarded by Ar plasma generated by a RF signal applying the substrate holder. During the process, only Ar gas was supplied, and a substrate temperature was kept at deposition temperature. A typical junction without Ar plasma treatment had a J/sub c/ of 180 A/cm/sup 2/. The junction with Ar plasma treatment, on the other hand, showed J/sub c/ of 1.6 kA/cm/sup 2/, suggesting that the Ar plasma treatment can be used to improve the junction properties.