SIMS SPECTRUM OF O-W(100) CHEMISORPTION SYSTEM

The adsorption of oxygen on clean W(100) has been studied with static mode SIMS. Studies were made at different temperatures and oxygen exposures under stringent vacuum conditions. Both the positive and negative secondary ion spectra were investigated by using low energy (500 eV) and low current density Ne+ primary ions, so that the adsorbed layer was not perturbed. The correlations among the secondary ions O+, O- and various tungsten oxide ions showed qualitative changes at different stages of chemisorption. All these features corresponded very well to the structural and adsorption site changes observed with LEED and other techniques. This work shows that SIMS can give structural and chemical information of chemisorbed layers in the submonolayer range. © 1978.