Films of YBa2Cu3O7−δ and YBa2Cu3O7−δ/MgO/YBa2Cu3O7−δ layered structures have been synthesized in situ using ion-beam sputter deposition. The surface morphology of the films has been studied by means of both scanning tunneling microscopy (STM) and scanning electron microscopy (SEM). STM analysis of films deposited at 720 and 680 °C reveals the presence of spiral growth columns, indicative of the screw-dislocation growth mode. However, the surface appears much smoother than that reported previously for YBCO films deposited by off-axis sputtering, revealing that particular film growth conditions affect the surface morphology. SEM analysis reveals the presence of copper-rich surface precipitates, the areal density and size of which are a function of the substrate temperature and the film composition, particularly the copper content. The deposition of YBCO/MgO/YBCO sandwich structures has also been investigated. A multilayer structure with an 80-Å-thick MgO layer has been successfully produced, and cross-sectional transmission electron microscopy analysis reveals that although the MgO layer is not epitaxial, c-axis oriented YBa2Cu3O7−δ grew on top. Very thin multilayered structures may be difficult to deposit on film surfaces dominated by the screw-dislocation growth mode, due to the high density of steps.