HIGH-ACCURACY RAMAN MEASUREMENTS USING THE STOKES AND ANTI-STOKES LINES

We show that by measuring the separation between the Stokes and anti-S tokes peaks excited by two different laser lines we obtain a very prec ise determination of absolute phonon energies. The method is useful fo r measuring small changes of these energies with strain, temperature, laser power, etc. It doubles the changes and avoids the necessity of u sing the reference lines in the Raman spectra. The method can be appli ed for the determination of phonon deformation potentials, for the cha racterization of strained heteroepitaxial layers, and for micro-Raman analysis of strain in silicon integrated circuits. We give examples of phonon shifts in Si, Ge, GaAs, InAs, and Cap as a function of applied biaxial strain, laser power, and temperature. (C) 1997 American Insti tute of Physics.