Direct Observation by Transmission Electron Microscopy of the Early Stages of Growth of Superconducting Thin Films

Abstract
The fabrication of high quality thin films often depends on the early stages of the growth process during which epitaxy is established. The substrate surface structure generally plays a critical role at this stage. Many observations of the high‐Tc superconductor film‐substrate interface structure and chemistry have been made by transmission electron microscopy (TEM) of cross‐section samples. Ion‐milling induced damage, however, can be severe in these specimens. In the present study, the early stages of the growth of high Tc superconducting thin films of YBa2Cu3O have been studied by TEM using a technique which requires no post‐deposition specimen preparation.