A biaxial rotation for depositing homogeneous large-area double-sided YBa2Cu3O7-x thin films

To deposit homogeneous large-area double-sided YBa2Cu3O7-X thin films simultaneously, a single inverted cylindrical target sputtering system with a simple rotation apparatus and a tubelike heater has been developed. The substrate (2 in. LaAlO3) rotated continuously in the heater so that films can be deposited on both sides simultaneously. Three different rotation modes, which are vertical in-plane rotation, out-of-plane rotation, and biaxial rotation (filed as a Chinese patent). have been tried out. The thickness distributions have been measured and compared with theoretical investigation results. While deposited with the subtle biaxial rotation mode, the film shows a much better thickness homogeneity than that with the other two single-axial rotation modes. The measurement result of critical transition temperature (T-C) gives the demonstration that the biaxial rotation technique effectively improves the homogeneity of large-area thin films deposited by inverted cylindrical sputtering. Microwave surface resistance (R-S), which is the key property for high-temperature superconductivity films used for fabricating microwave devices, ranged from 20 to 50 mOmega (at 75 K, 145 GHz). (C) 2002 American Vacuum Society.