The preparation of two inch double-sided YBCO thin films

The preparation of two inch double-sided YBCO thin films by simultaneous sputtering from a single target is reported. The lateral homogeneity of microwave surface resistance of the YBCO thin films, on both sides of the two inch wafer, is characterized by using a Fabry-Perot resonator at 145 GHz and 75 K. Values of microwave surface resistance R-S (75 K, 145 GHz, 0 T) below 55 mOmega were reached over the whole area of YBCO thin films on two inch LaAlO3 wafers. The majority of the wafer area has R-S (75 K, 145 GHz, 0 T) values in the range of 15 mOmega to 40 mOmega. The uniformity of R-S values in the whole two inch wafer is excellent and the properties of YBCO thin films were found to be very similar on both sides of the wafer.