Effect of double-layers formation on the deposition of microcrystalline silicon films in hydrogen diluted silane discharges

摘要

The effect of the double layers formation on the gas-phase composition of SiH_4/H_2 discharges and the deposition rate of microcrystalline silicon thin films has been investigated by applying mass spectrometric and film growth measurements. Spatially Resolved Optical Emission Spectroscopy has been used for the detection of the appearance of this additional electron heating mechanism that in the present conditions results from the variation of either the discharge power or the total gas pressure. The experimental results have been in all case combined to a gas phase and surface simulator of SiH_4/H_2 discharges allowing thus the discussion for the rather limited effect of this mechanism on the deposition process of μc-Si:H thin films.