Abstract
Nanocrystalline silicon (nc-Si) films were prepared by a plasma-enhanced chemical vapor deposition method at a deposition temperature below 220
°C with different dynamic pressures (
P
g), hydrogen flow rates ([H
2]), and RF powers, using SiH
4/H
2/SiF
4 mixtures. We examined the photo-luminescence (PL) spectra and the structural properties. We observed two stronger and weaker PL spectra with a peak energies around
E
PL
=
1.8 and 2.2–2.3
eV, respectively, suggesting that the first band was related to nanostructure in the films, and another band was associated with SiO-related bonds. The nc-Si films with rather large PL intensity was obtained for high [H
2] and/or low pressure values, However, effects of [H
2] are likely to be different from those of
P
g. The average grain size (
δ) and the crystalline volume fraction (
ρ) at first rapidly increase, and then slowly increase, with increasing
P
g. Other parameters exhibited opposite behaviors from those of
δ or
ρ. These results were discussed in connection with the changes in the PL properties with varying the deposition conditions.