Laser and nitrogen plasma beam induced modifications in amorphous silicon thin films

Amorphous hydrogenated silicon (a-Si:H) thin films deposited on a (100) Si wafer by plasma enhanced chemical vapor deposition (PECVD) were irradiated by KrF (λ=248 nm) excimer laser or treated in a plasma jet generated by a capacity coupled RF discharge in N2, respectively. Various techniques such as X-ray photoelectron spectroscopy (XPS), ellipsometry, optical microscopy and microhardness measurements were used to characterize the laser and nitrogen plasma jet induced composition and crystallinity modifications. Oxidation/reduction effects together with crystallization were evidenced in the case of the laser treatment. The formation of different compounds containing Si, C, N and O was observed as an effect of nitrogen plasma treatment.