LARGE-AREA DOUBLE-SIDED YBA2CU3O7-DELTA FILMS GROWN BY SINGLE-SOURCE METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION

Thin films of YBa2Cu3O7-delta were sequentially grown on both sides of 3 in, diameter LaAlO3 substrates by a single-source MOCVD technique t o facilitate the fabrication of double-sided high temperature supercon ductor microwave devices. YBCO films on bath sides of the LaAlO3 subst rates had thicknesses greater than 4000 Angstrom, T-c's of 87-88.5 K, and microwave surface resistances as low as 23 m Omega at 94 GHz and 7 7 K (scaling to 260 mu Omega at 10 GHz). It was found that the substra te temperature, brought to the desired value by radiant heating, playe d a critical role in the deposition of very low surface resistance YBC O films. Microwave bandpass filters with a 19-pole forward coupled con figuration were fabricated from these films. The filters showed excell ent performance with dissipation losses as low as 0.5 dB. (C) 1995 Ame rican Institute of Physics.