Catalyst-enhanced vapor-phase epitaxy of quartz thin films under atmospheric pressure
2002; Royal Society of Chemistry; Volume: 12; Issue: 3 Linguagem: Inglês
10.1039/b108850p
ISSN1364-5501
AutoresNaoyuki Takahashi, Masayuki Hoshogi, Takato Nakumura, Yoshimi Momose, Satoshi Nonaka, Hiromi Yagi, Yoichi Sinriki, Katsumi Tamanuki,
Tópico(s)Aerogels and thermal insulation
ResumoPreparation of quartz (rock crystal) films has been studied by an atmospheric pressure chemical vapor deposition method using Si(OC2H5)4 and O2 as starting materials in the presence of gaseous HCl. The films were deposited onto a sapphire (0001) substrate at 600–850 °C with a growth rate of 0.3–3.0 µm h−1. Their X-ray diffraction profiles showed an intense diffraction peak at 50.6° assigned to the (0003) diffraction of quartz with a hexagonal structure suggesting epitaxial growth. The full-width at half-maximum was 10.0 min for the quartz film prepared at 850 °C. Reflection high-energy electron diffraction measurements showed a diffraction pattern similar to that of a single crystal of quartz. It was found by energy-dispersive analysis of the X-rays that the [O]/[S] ratios of the deposited films were in the range of 1.94–1.97, independent of the growth temperature. Fourier transform infrared spectra exhibited a weak absorption band at 3585 cm−1, suggesting OH radicals to be present as an impurity. The refractive index of the quartz epitaxial films prepared at 850 °C was 1.528.
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