Variation in optical-absorption edge in SiN x layers with silicon clusters
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Using optical methods, data on optical constants are obtained for silicon nitride films synthesized by plasma-chemical vapor deposition (PCVD). Models for calculating the permittivity in the model of inhomogeneous phase mixture of silicon and silicon nitride are considered. It is found that the optical-absorption edge (E g) and the photoluminescence peak shift to longer wavelengths with increasing nitrogen atomic fraction x in sin x films. When x approaches the value 4/3 characteristic for stoichiometric silicon nitride Si3N4, a nonlinear sharp increase in E g is observed. Using Raman scattering, Si-Si bonds are revealed, which confirms the direct formation of silicon clusters during the film deposition. The relation between the composition of nonstoichiometric silicon nitride films, values of permittivity, and the optical-band width is established for light transmission.
PACS numbers61.43.Dq 64.70.Nd 78.20.Ci 81.05.Ge
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- 1.M. M. Gorshkov, Ellipsometry (Sovetskoe Radio, Moscow, 1974) [in Russian].Google Scholar
- 2.V. N. Novikov, A. P. Sokolov, O. A. Golikova, et al., Fiz. Tverd. Tela (Leningrad) 32, 1515 (1990) [Sov. Phys. Solid State 32, 884 (1990)].Google Scholar
- 3.J. Tauc, in Optical Properties of Solids, Ed. by F. Abeles (North-Holland, Amsterdam, 1972), p. 277.Google Scholar
- 6.V. I. Gavrilenko, A. M. Grekhov, D. V. Korbutyak, and V. G. Litovchenko, Optical Properties of Semiconductors: A Handbook (Naukova Dumka, Kiev, 1987) [in Russian].Google Scholar
- 7.F. Alvarez and A. A. Valladares, Phys. Rev. B 68, 205203 (2003).Google Scholar
- 8.L. D. Landau and E. M. Lifshitz, Course of Theoretical Physics, Vol. 8: Electrodynamics of Continuous Media, 2nd ed. (Nauka, Moscow, 1982; Pergamon, Oxford, 1984), Chap. 9, p. 67.Google Scholar