Deposition of SiO2 and TiO2 thin films by plasma enhanced chemical vapor deposition for antireflection coating

doi:10.1016/S0022-3093(97)00175-0

Journal of Non-Crystalline Solids

Volume 216, 1 August 1997, Pages 77-82

https://doi.org/10.1016/S0022-3093(97)00175-0 Get rights and content

Abstract

Silicon dioxide and titanium dioxide films were deposited at low temperature by electron cyclotron resonance (ECR) plasma enhanced chemical vapor deposition (PECVD) using respectively O₂ and tetraethoxysilane (TEOS) or titanium isopropoxide (TIPT) as precursors. To control the thickness and the refractive index during deposition, the plasma reactor was equipped with an in situ spectroscopic ellipsometer. Deposition kinetics and layer properties were investigated by spectroscopic ellipsometry, X-ray photoelectron spectroscopy (XPS) and chemical etch rate. A double film antireflection coating was fabricated and reflectance was measured using a UV-visible near-infrared spectrometer. Results reported demonstrate that deposition of SiO₂ and TiO₂ films at low temperature by PECVD is a promising method to produce antireflection coatings for solar cells.

References (25)

K.L. Jiao et al.
Solar Cells
(1987)
K.S. Yeung et al.
Thin Solid Films
(1983)
J.P. Lu et al.
Thin Solid Films
(1991)
H.J. Frenck et al.
Thin Solid Films
(1991)
W.G. Lee et al.
Thin Solid Films
(1994)
J. Joseph et al.
Thin Solid Films
(1983)
S. Callard et al.
Appl. Phys. Lett.
(1996)
D. Zhang et al.
Appl. Phys. Lett.
(1995)
Z. Chen et al.
IEEE Trans. Electron Dev.
(1993)
S. Matsuo et al.
Jnp. J. Appl. Phys.
(1983)

Handbook of Chemistry and Physics (CRC, Boca Raton,...

D.C. Bradley

Chem. Rev.

(1989)

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Citation Excerpt :
On the other hand, two optical transitions were observed for the rutile phase at room temperature, with two optical gap energies equal to 3.06 eV (for a direct optical transition) and 3.10 eV (for an indirect optical transition) [29]. In order to solve the problem caused by the large optical gap energy, which prevents the use of the TiO2 layers in certain optical applications, the optical gap energy reduced to fit the optical applications requiring a low optical gap [30,31]. This, in turn, promotes the absorption of the light beam in a wide spectral range, rather than being restricted to the ultraviolet region of the spectrum.
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Deposition of SiO2 and TiO2 thin films by plasma enhanced chemical vapor deposition for antireflection coating

Abstract

Solar Cells

Thin Solid Films

Thin Solid Films

Thin Solid Films

Thin Solid Films

Thin Solid Films

Appl. Phys. Lett.

Appl. Phys. Lett.

IEEE Trans. Electron Dev.

Jnp. J. Appl. Phys.

Chem. Rev.

Deposition of SiO₂ and TiO₂ thin films by plasma enhanced chemical vapor deposition for antireflection coating