Applied Science and Convergence Technology 1995; 4(2): 172-176
Published online June 1, 1995
Copyright © The Korean Vacuum Society.
Jae Won Han,Jung Rae Park,Mu-yong Choi
YBa₂Cu₃O_(7-y) thin films have been prepared on MgO(100) substrates placed on-axis to the target by de magnetron sputtering in a variety of oxygen/argon gas pressures with different substrate-target distances. We found that films with the c-axis perpendicular to the substrate deposited in an optimally high gas pressure with on-axis substrate-target configuration exhibit such good electrical and structural properties as those deposited with off-axis configuration do. Increasing the substrate-target distance was found to be effective in reducing the resputtering effect and enhancing superconductivity of films, but not so much as increasing the gas pressure was. We also found that high deposition rates may promote mixed α- and c-axis growth of YBCO films on MgO substrates. Dependences of the T_c, the ratio of resistances at 300 K and 100 K, and the X-ray diffraction pattern on the gas pressure and the substrate-target distance are described.