RAMAN-SCATTERING IN POLYCRYSTALLINE SILICON DOPED WITH BORON

The Raman spectra of polycrystalline silicon doped with implanted boron were measured before and after thermal annealing. In addition to the peak of the silicon phonon mode at 521 cm-1, a shoulder at about 500 cm-1 was observed. For samples without annealing, this shoulder increased with the increase of the dopant dose. The origin of this shoulder was attributed to the small correlation length due to lattice damage. After thermal annealing, the peak of the silicon phonon mode was greatly broadened. This was best explained by a theoretical model which included both a finite size effect and a Fano effect. The asymmetry factors associated with the Fano effect were obtained as a function of the dopant dose.