ENERGY CORRECTION BY EVAPORATED GOLD IN X-RAY PHOTOELECTRON-SPECTROSCOPY

This work reports measurements of the binding-energy shift of gold eva porated on several insulating materials including polymers such as pol ytetrafluoroethylene and polyethylene and inorganic materials such as silicon oxide. The Au binding energy showed higher values than that fo r bulk gold in the initial stage of deposition even after correction f or charging effects. The energy shifts seen for the polymer substrates were smaller to those for inorganic materials such as silicon oxide a nd silicon nitride. The thickness of gold necessary to obtain the bulk Au binding energy was small for substrates whose Au binding-energy sh ifts were small. Thus, it was confirmed that it is very important to d eposit an appropriate amount of gold to obtain the correct binding ene rgies. These results can be explained by extra-atomic relaxation, beca use a larger extra-atomic relaxation energy is expected for substrates on which gold atoms or clusters can migrate easily and form larger cl usters. These clusters cause smaller binding-energy shifts and require smaller amounts of evaporated gold. (C) 1996 American Vacuum Society.