Covalent functionalization of silicon nitride surfaces by semicarbazide group

The paper reports on the covalent attachment of semicarbazide functional groups onto hydrogen-terminated silicon-rich silicon nitride (SixN4; 4 < x < 5) surface under photochemical conditions. UV-irradiation (254 nm) of the surface coated with a thin film of tert-butyl 2-[(allylamino)carbonyl]hydrazine-carboxylate yields an organic monolayer covalently attached to the surface via Si-C bonds and terminated with t-Boc-protected semicarbazide moieties. Removal of the protecting group produces a reactive semicarbazide-terminated monolayer. The photo-induced reaction was investigated by means of X-ray photoelectron spectroscopy (XPS) and contact angle measurements.