Characterization of Different Length Scales and Periodicities inGe/Si Microstructures by Raman Spectroscopy: Theory and Experiment

The Raman spectra of samples of the type [(GenSim)N-1 GenSiM]×pwithn≈m≈5 monolayers,M≈200 monolayers andp≈10–20 were measured in the backscattering configuration in the wavenumber range 2–600 cm−1. The experimental results are discussed by comparison with simulated spectra calculated with a linear chain model with bond polarizabilities for the Raman intensities. Comparison between experimental and theoretical spectra gives insights into the sensitivity of the different Raman peaks as a probe of periodicity and interface roughness length scales.