DAMAGE TO YBA2CU3OY SURFACE CAUSED BY AR ION-BEAM ETCHING

We studied transport properties through a YBa2Cu3Oy (YBCO) surface etc hed by exposure of the YBCO surface to an Ar ion beam. In layered junc tions of Au/(100)-oriented YBCO with the etched surface, Poole-Frenkel emission was detected by analyzing current-voltage curves. This sugge sts that a relatively thick insulating layer was formed on the YBCO su rface by damage resulting from the Ar ion beam etching.