THE ANALYSIS OF SURFACE-ADSORBED ORGANIC-MOLECULES BY ALKALI-ASSISTEDMIES COMBINED WITH UPS(HE-I)

Metastable impact electron spectroscopy (MIES) in combination with UPS (HeI) is applied to the study of s-triazine and triethoxytriazine mole cules adsorbed on Si(100) either alone or in combination with cesium a toms. It is demonstrated that the presence of the Cs atoms facilitates the identification of the adsorbed species considerably. It is conclu ded that (i) non-dissociative adsorption of the studied organic molecu les occurs whereby the basal rings of the molecules lie flat on the si licon surface, in accordance with previous studies by Bu and Lin, (ii) the binding of the molecules to the surface is mainly via the lone pa ir orbitals of the nitrogen in the ring, and (iii) s-triazine reacts s trongly with oxygen which bonds to the carbon atoms of the triazine ri ng.