Characterization of triazine derivatives on silicon wafers studied by photoelectron spectroscopy (XPS, UPS) and metastable impact electron spectroscopy (MIES)

Thin films of a diandicyanato bisphenol A (DCBA) prepolymer and thin layers of the trimer of the 2,4,6-tris-(2,2-bisphenyl-propane)-1,3,5-triazine (p-CPC trimer), both deposited on silicon wafers covered by their native oxide, have been investigated by x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and metastable impact electron spectroscopy (MIES). MIES as well as angle dependent XPS indicate a preferential orientation of the molecules of the first adlayer on the surface. The adsorption of the first layer is governed by the interaction of the trioxytriazine rings with the substrate surface. This adsorption model is supported by the calculated conformation of the DCBA and p-CPC trimer.