SPUTTERING OF YBA2CU3O7-DELTA/NDALO3/YBA2CU3O7-DELTA TRILAYERS

Epitaxial YBa2Cu3O7-delta/NdAlO3/YBa2Cu3O7-delta-trilayers were grown by sputtering from stoichiometric targets. The YBa2Cu3O7-delta (YBCO) films were deposited by dc-magnetron sputtering. For the NdAlO3 films, rf-magnetron sputtering was used. The individual YBCO films revealed critical-current densities up to 3 X 10(6) A/cm2 at 77 K. The bilayer and trilayer structures were characterized by x-ray diffraction, Rutherford backscattering spectroscopy, and transmission electron microscopy (TEM). The channel yield chi(min) of the YBCO film on top was 15% for an in situ deposited trilayer. The epitaxial growth of the subsequent layers was proved by cross-sectional TEM. Although the NdAlO3 layer contained misoriented grains, the top YBCO layer grows in single orientation over these areas Preliminary electrical measurements show that NdAlO3 is a useful insulating dielectric for microelectronic applications.