Direct evidence for β-hydride elimination on Si (100)

Abstract

The adsorption and decomposition of ethylbromide on Si(100)−(2×1) is investigated as a way of generating surface ethyl groups. The interactions of ethylbromide with Si are explored by a variety of methods including ultraviolet photoelectron spectroscopy, temperature-programmed desorption and high-resolution electron energy loss spectroscopy. Enthylbromide adsorbs molecularly on Si(100) at a surface temperature of 110 K. The CBr bond cleaves by warming the surface to temperatures greater than 200 K. The resulting ethyl groups decompose at surface temperatures greater than 500 K to yield ethylene and molecular hydrogen. Deuterium labelling of the ethyl groups is used to verify that the predominant pathway to ethylene production is through a β-hydride elimination step.