Si(001) dimer structure observed with scanning tunneling microscopy

Scanning tunneling microscopy has been used to determine the atomic structure of the clean Si(001) surface. The basic structural unit of the reconstruction has been resolved with a lateral resolution of 1/4 3. Buckled and nonbuckled dimers appear to be present in roughly equal amounts, indicating that they have nearly the same energy. The presence of atomic-scale defects is discussed. © 1985 The American Physical Society.