The deposition condition of $YBa_2Cu_3O_{7-x}$ superconducting thin film on MgO substrate has been established by off-axis RF magnetron sputtering method. A C-axis normal film has been obtained at 750 - 780℃ and 580 - 650℃. The critical temperature of thin film deposits at these range is 76-83.5 K. As deposition temperature decreases, the surface of film becomes flat and uniform. The optimum condition is 620℃, 10 mTorr and 3 hours. Using low oxigen pressure, we can obtain superconducting film near 600℃ with high deposition rate.
A possible in-plane orientation on MgO substrate has been investigated by microstructure and θ-scan method. It is possible that $YBa-2Cu_3O_{7-x}$ thin film can be used for natural step edge junction on cleavaged MgO substrate. Using the ion milling method, $YBa_2Cu_3O{7-x}$ bicrystal that have a potential of application in boundary Josephson junction has been manufactured.
