The adsorption of methylsilane on Cu(111) has been investigated by metastable deexcitation spectroscopy. The deexcitation process for the clean copper and silicide surfaces was demonstrated to occur via resonance ionization followed by Auger neutralization, while upon the adsorption of methylsilane at 295 K it changes to Auger deexcitation. Accompanied by ultraviolet photoelectron spectroscopy, the MD spectrum at 295 K reveals the presence of a methyl group on the surface, supporting the assertion that the majority of the surface is covered with methylsilane fragments. Annealing the surface above 420 K reveals the presence of clean copper sites on a partially silicide surface. (c) 2005 Elsevier B.V. All rights reserved.