Surface Chemistry on Microclusters: Recent Results from Silicon and Germanium Cluster Beams

Abstract

ABSTRACTSupersonic cluster beam techniques have recently produced some fascinating new information as to the surface chemistry and physics of small (2–100 atom) clusters of various semiconductors. For example, it appears that silicon clusters exhibit a remarkably pronounced alternation in reactivity as a function of cluster size. For ammonia chemisorption certain clusters such as Si33+, Si39+, and Si45+ have been found to be almost completely inert, while neighboring clusters such as Si36 and Si45+ chemisorb ammonia readily. Such sharply patterned reactivity results may provide significant clues as to the detailed nature of semiconductor surface restructuring and the consequent effects of this restructuring upon the surface chemistry.