'Real-time' multiwavelength ellipsometry diagnostics for monitoring dry etching of Si and TiNx deposition

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.