Vg. Kechagias et al., 'Real-time' multiwavelength ellipsometry diagnostics for monitoring dry etching of Si and TiNx deposition, THIN SOL FI, 364(1-2), 2000, pp. 213-219
An Ultra-fast Multiwavelength Ellipsometer with 16 different wavelengths (U
MWE), was used to monitor and study: (i) the ion etching of c-Si substrate,
and the subsequent formation of an amorphous Si(a-Si) overlayer and (ii) t
he TiNx film growth, with a Ti interlayer on Si substrate, during depositio
n. The ellipsometer was adapted on a high vacuum chamber system and the fil
ms were deposited with the unbalanced magnetron sputtering deposition techn
ique. UMWE measurements were performed to study the multi-spectral response
and time dependence of dielectric function epsilon(omega)(= epsilon(1) + i
epsilon(2)) in the energy region 1.54-4.32 eV in terms of process paramete
rs, ion energy (substrate bias V-b) and N-2 content in the plasma. By analy
sing the 'real-time' spectra we estimated the amorphization rate of Si, the
thickness and the structure of alpha-Si overlayer, as well as the TiNx thi
ckness and stoichiometry during deposition. The latter is directly related
to the plasma frequency omega(p), the energy where epsilon(1)(omega(p)) = 0
, that depends on V-b and N-2 content. (C) 2000 Elsevier Science S.A. All r
ights reserved.