Scanning tunneling microscopy of semiconductor surfaces

This research program studies the atomic structure of semiconductor surfaces using scanning tunneling microscopy (STM). Extensive work has been carried out on the behavior of both indium and gallium on the (111) and the (100) surfaces of silicon. The STM images provide new structural information on all of the metal-induced surface reconstructions observed in these systems. The STM has been particularly applicable to the study of multi-phase surfaces, localized defects, local metal segregation, all of which arise during the growth of a metal on a semiconductor, and can play an important role in the properties of the surface. Information on such spatially localized features (Sub-100 A) is inaccessible by other means. Some preliminary studies of the InP (110) surface have been done. It is anticipated that the primary thrust of the research will shift to compound semiconductor surfaces during the coming year.