D. Davazoglou et al., THERMODYNAMIC STUDY, COMPOSITION, AND MICROSTRUCTURE OF LOW-PRESSURE CHEMICAL-VAPOR-DEPOSITED SILICON DIOXIDE FILMS GROWN FROM TEOS N2O MIXTURES/, Journal of the Electrochemical Society, 145(4), 1998, pp. 1310-1317
Citations number
26
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
A calculational thermodynamic investigation of the chemical vapor depo
sition of SiO2 films from TEOS/N2O mixtures has been performed based o
n the minimization of the Gibbs energy of the Si-O-C-H-N system. The r
esults illustrate the influence of temperature, pressure, and initial
gas composition on the formation of stable phases. SiO2 films have bee
n grown in a conventional horizontal low-pressure chemical vapor depos
ition reactor at 983 and 1093 K and pressure 0.3 Torr. X-ray photoelec
tron spectroscopy measurements have shown that the deposited films con
tained carbon impurities with concentration decreasing with the increa
se of the N2O/TEOS flow ratio, in qualitative agreement with the therm
odynamic calculations. X-ray photoelectron spectroscopy and Rutherford
backscattering spectroscopy measurements have shown that the O/Si rat
io in the films was less than 2 and that it was approaching this value
for high N2O/TEOS flows. Atomic force microscopy measurements have sh
own that the films exhibited a granular morphology with grain size inc
reasing with the deposition temperature and the N2O/TEOS flow ratio. T
he analysis of Fourier transform infrared spectra taken on the films h
as shown that the absorption near 1080 cm(-1) was due to the presence
of more than one oscillator, the positioning of which was related to v
ariations in the O/Si ratio, the interatomic distances, and the bond a
ngles in the films.