An XPS study on the chemical bond structure at the interface between SiOxNy and N doped polyethylene terephthalate

The super-thin silicon oxynitride (SiOxNy) films were deposited onto the N doped polyethylene terephthalate (PET) surface. Varying the N doping parameters, the different chemical bond structures were obtained at the interface between the SiOxNy film and the PET surface. X-ray photoelectron spectra results showed that at the initial stage of SiOxNy film growth, the C=N bonds could be broken and C–N–Si crosslink bonds could be formed at the interface of SiOxNy/PET, which C=N bonds could be formed onto the PET surface during the N doping process. At these positions, the SiOxNy film could be crosslinked well onto the PET surface. Meanwhile, the doped N could crosslink the [SiO4] and [SiN4] tetrahedrons, which could easily form the dense layer structure at the initial stage of SiOxNy film growth, instead of the ring and/or chain structures of [SiO4] tetrahedrons crosslinked by O. Finally, from the point of applying SiOxNy/PET complex as the substrate, the present work reveals a simple way to crosslink them, as well as the crosslink model and physicochemical mechanism happened at the interface of complex.