Vacuum-ultraviolet photopolymerisation of amine-rich thin films

Nitrogen-rich organic thin films were deposited by VUV-assisted photochemical polymerisation of flowing C2H4/NH3 mixtures. The fundamental reaction mechanisms of these binary gas mixtures were investigated as a function of the wavelength of two almost monochromatic VUV sources. Compositions of these “UV-PE:N” films close to the surface were determined by XPS, and the amine concentrations and selectivities were quantified via chemical derivatisation. The UV-PE:N films were compared with plasma polymers deposited using low-pressure glow discharges in similar gas flow mixtures, “L-PPE:N”; it is shown that VUV photochemistry is superior to plasma chemistry in producing almost monofunctional organic thin films.