Deposition of nanocrystalline silicon films (nc-Si:H) from a pure ECWR-SiH4 plasma

A novel plasma enhanced chemical vapour deposition (PECVD) technique employing electron cyclotron wave resonance (ECWR) for plasma excitation was used for the deposition of hydrogenated nanocrystalline silicon (nc-Si:H) films. nc-Si:H-films could be produced with large deposition rates up to 6.5 Angstrom/s with pure SiH4, as process gas in contrast to conventional glow-discharge technique where the high hydrogen dilution needed for the formation of the crystalline phase leads to considerably lower deposition rates. The basic dependence of the deposition parameters on the nature of the condensing phase was investigated. Besides the substrate temperature dependence the resulting phase deposited from a pure silane plasma is mainly determined by the dissociation degree of the plasma and the generation of atomic hydrogen which can be varied by the high frequency input power and the SiH4-flow.