Mechanism of epitaxial growth of monolayer CaF on Si(111)-(7×7)

Abstract
Using scanning tunneling microscopy, the epitaxial growth of a monolayer of CaF on the Si(111)-7×7) surface has been studied. We observe how the Si atoms of the 7×7 structure rearrange into a bulklike structure and find that four excess Si atoms per 7×7 unit cell are produced in the transition to the bulklike structure. These excess Si atoms seem to remain in the epitaxial CaF layer, creating defects.