IMPROVED MORPHOLOGY AND SURFACE-RESISTANCE OF EUBA2CU3O7-DELTA THIN-FILMS ON MGO SUBSTRATES OBTAINED BY INTERMITTENT MAGNETRON SPUTTER-DEPOSITION

We demonstrate that the surface morphology of off-center magnetron spu ttered EUBa(2)Cu(3)O(7-delta) (EBCO) thin films on MgO (100) substrate s is improved significantly by using the intermittent deposition metho d. This method comprises three steps. First, an initial EBCO layer, 2 to 10 unit cell layers thick, is grown at 630-660 degrees C under a lo w oxygen partial pressure of 0.1 Pa. Then the initial layer is in. sit u. annealed for 30 min under the same conditions used for the depositi on. Finally, another EBCO layer is grown on top of the first layer. An EBCO thin film grown in this way has an extremely smooth surface and the surface resistance at 50 GHz is 3 m Ohm or less at 77 K; which com pares with the best value ever reported.