APPLICATION OF AUGER-ELECTRON SPECTROSCOPY TO STUDIES OF SILICON-SILICIDE INTERFACE

We discuss the use of Auger electron spectroscopy to obtain chemical state information about the transition-metal/Si and silicide/Si interfaces. Characteristic Si L//2//,//3VV Auger spectra for silicides of nine different transition metals are presented and analyzed in terms of chemical bonding in the compounds. The use of Auger peak shape analysis to obtain depth profiles of chemical state is illustrated by the detection of thin silicide layers at the metal/Si interface in as-deposited samples. The possibility of chemical state changes induced by inert gas ion bombardment is discussed and this effect is proposed to explain almost identical Si LVV peak shapes observed for different silicides of a particular transition metal. Pd//2Si is shown to be stable against bombardment-induced bonding changes, and for this system sequential deposition studies of Pd on Si yield basically the same information as does sputter profiling.