The formation of crystalline silicon nanoparticles was investigated by means
of Raman spectroscopy. SiO
(x = 1 and x = 1.5) films deposited by
electron-gun evaporation onto silica substrates were submitted to
post-deposition thermal treatments at 1000 and 1100 °C for various times.
From lineshape analysis of the Raman band, it appeared that the crystalline
volume fraction never excessed 30% for annealing at 1000 °C, while the
mean diameter remained almost constant. Complete crystallisation was
achieved after annealing at 1100 °C, accompanied by an increase of the
nanoparticle size. Mean diameters of the nanoparticles obtained from Raman
spectra analysis along the two main confinement models, Richter et al., Campbell,
Fauchet model and bond-polarizability model, were discussed and compared to
values deduced from transmission electron microscopy measurements.