ELECTRON-BEAM DAMAGE JOSEPHSON-JUNCTIONS - THE RELATION BETWEEN BEAM DAMAGE PROFILE AND ELECTRICAL-PROPERTIES

It has been found that in the production of electron beam damaged junc tions in thin films of the high-Tc superconductor YBa2Cu3O7-delta, usi ng a small condenser aperture results in a narrow damage width of 20nm , compared to over 100nm when a larger aperture is used. Junctions pro duced using the large aperture show a quadratic dependence of the curr ent density on temperature, while the junctions produced using the sma ller aperture have a more unusual cubic temperature dependence. A func tional dependence of the J(C) is given from which the sensitivity of t he current density to the damage can be calculated.