Surface modification of chalcogenide glasses by N2 plasma treatment

Surface modification of chalcogenide glasses by N2 plasma treatment was investigated in the present paper. Two glasses, Ge30As10Se60 and As2S3, were studied and a microwave plasma apparatus equipped with a high-purity nitrogen gas source was used. The effects of N2 plasma treatment on surface strengthening of chalcogenide glasses were shown by increased microhardness. Explanations are based on a N+ implantation effect and bonding of active neutral N atoms from the plasma with sputtered elements from the glass surface. They also account for the much greater effect of N+ plasma treatment than that of the N+ ions implantation in increasing the microhardness of similar chalcogenide glasses. A comparison of X-ray photoelectron spectrometer (XPS) spectra for the Ge25As15Se60 glass samples before and after N2 plasma treatment provides further support for the mechanism suggested.