Substrate Bias and Pressure Effect on Formation of YBaCuO Thin Films in RF Magnetron Sputtering System

Effect of substrate bias on formation of YBaCuO films at various pressures by the rf magnetron sputtering method is studied. It is found that the best films are obtained at the optimum bias voltage with regard to the end point of the critical temperature. The optimum substrate bias lowers the energy of ions which damage YBaCuO films. Furthermore, this optimum bias approaches 0 V when the total pressure becomes higher, where the energy of ions is small.