Multitarget magnetron sputtering of large area YBa2Cu3O7−δ thin films

One important requirement for large scale applications of high Tc superconducting films as well as for some very interesting experiments in the field of microwave properties is the successful deposition of high quality large area thin films. The utilization of a multitarget magnetron sputtering system, especially designed for preparing film sizes up to two inches in diameter, allows a variety of different film compositions in the YBCO system. To avoid problems arising from the chemical properties of many barium compounds, we used targets of the intermetallic compounds BaCu and YCu, respectively. Argon is used as sputtering gas. Beside this, we let a flow of oxygen direct to the growing film to form the superconducting oxide. The substrate holder can be heated up by quartz lamps over 900 °C. We are using two different ways to prepare thin supercondcuting films. The first way is an ‘ex‐situ’ process. The oxygen partial pressure during depoistion is very low due to the metallic surface of the targets. The su...