Tip-induced β -hydrogen dissociation in an alkyl group bound on Si(001)

Atomic-scale chemical modification of surface-adsorbed ethyl groups on Si(001) was induced and studied by means scanning tunneling microscopy. Tunneling at sample bias > +1.5V leads to tip-induced C-H cleavage a $\beta$-hydrogen the covalently bound configuration. The reaction is characterized formation an additional Si-H Si-C bond. probability shows linear dependence current 300 K; largely suppressed 50 K. observed surface room temperature thus attributed one-electron excitation in combination with thermal activation.