Raman scattering study of Ge dot superlattices

The phonon spectrum of self-organised Ge dot superlattices grown by molecul ar beam epitaxy (MBE) of Ge and Si layers utilising Stranski-Krastanov grow th mode was studied by Raman scattering using macro- and micro-Raman experi mental setup. The strain and interdiffusion of Ge and Si atoms in Ge quantu m dots (QDs) were estimated from the analysis of frequency positions of lon gitudinal and transversal optical phonons observed in the Raman spectra. Ra man scattering by folded longitudinal acoustic phonons in the Ge dot superl attices was observed and explained using elastic continuum theory. An avera ge size of Ge QDs was obtained from transmission electron microscopy measur ements. (C) 2001 Elsevier Science B.V. All rights reserved.