High-rate deposition of nanocrystalline silicon using the expanding thermal plasma technique

Nanocrystalline silicon films have been deposited at very high deposition rates using the expanding thermal plasma technique and their structural properties have been analyzed. The crystallinity and crystallite size and orientation have been determined for various hydrogen-to-silane dilution ratios and it is shown that films with a crystalline fraction of 60–80% can be deposited at deposition rates within the range 1.5–3.0 nm/s. The hydrogen concentration and atomic densities in the film have been investigated by infrared spectroscopy and elastic recoil detection/Rutherford backscattering revealing underestimation of the hydrogen content by infrared spectroscopy as well as a reduced atomic film density for the nanocrystalline silicon films.