Structural and electrical characteristics of microcrystalline silicon prepared by hot-wire chemical vapor deposition using a graphite filament

Intrinsic hydrogenated microcrystalline silicon (mu c-Si:H) films were prepared on Corning glass substrates by hot-wire chemical vapor deposition using a graphite filament. The advantage of the graphite filament is its longer lifetime and greater chemical stability as compared to the commonly used Ta and W wires, particularly at lower filament temperatures at which silicides are known to. form on Ta and W. This study examines the deposition of mu c-Si: H at the lower filament temperature of 1525 degrees C. A low substrate temperature of 210 degrees C was used for all mu c-Si:H depositions with resulting deposition rates of up to 2.0 +/- 0.2 angstrom/s. Raman spectroscopy and electrical conductivity measurements showed that mu c-Si:H growth occurred only for silane concentrations below 1.5% dilution in hydrogen. The average grain size was found to be 25 nm measured by transmission electron microscopy. (C) 2007 American Vacuum Society.