Résumé
Raman scattering spectra have been collected on p-type 4H-SiC samples doped with aluminum up to 5×10^19 atoms per cubic cm. The distortion and asymmetry of FTA modes which appear in the low frequency range has been probed in great details. We show that, using standard Fano formulae with three parameters per mode, one can successively fit all FTA modes profiles in the concentration range 2×10^16 - 5×10^19 Al.cm-3