Fabrication and characterization of YBa2Cu3O7-delta/SrTiO3/Ag trilayer films on SrTiO3 bicrystal substrates

We have fabricated YBa2Cu3O7-delta/SrTiO3/Ag trilayer thin films on bicrystal SrTiO3 substrates for electric field effect three terminal devices. For the electrical transport measurements the samples were patterned using optical lithography and wet or ion beam etching. The dielectric properties of the SrTiO3 barrier layer were analyzed by measuring the temperature and voltage dependence of the relative dielectric constant epsilon(r) and the resistivity rho(iso). By optimization of the deposition process, rho(iso) = 2 x 10(10)Omega m and a breakdown voltage E-bd = 1 x 10(7)V/m were obtained at 4.2K, For epsilon(r) a maximum value of 460 was observed around 75 M. By the deposition of the trilayer structure on bicrystal substrates, gated grain boundary Josephson junctions (GBJs) were fabricated. High quality GBJs have been obtained covered by a SrTiO3 gate insulator with a maximum change in the polarization of 0.08 C/m(2).