HIGH-RESOLUTION ELECTRON-MICROSCOPY STUDY OF THE ERSI2/SI(111) INTERFACE

High Resolution Transmission Electron Microscopy (HREM) was used to investigate the atomic structure of the ErSi2/Si(111) interface. The samples were grown by solid phase epitaxy from codeposited ErSi films at room temperature, on Si c(7 × 7) surfaces. The disilicide films showed the epitaxial relationship: [1230]ErSi2 {norm of matrix} [022]Si and [1010]ErSi2 {norm of matrix} [422]Si. According to the geometrical theory, eight models are found for the interface structure. By inspection of the interatomic distances, it is shown that only four of them are possible. The HREM images were interpreted by means of simulated images. HREM images allowed us to determine the presence of two types of structure. A single, one atomic plane high, step without associated dislocation, is sufficient to induce a change in the interface structure from one model to another. © 1990.