Study of the localized vibrations of boron in heavily doped Si

Abstract

We have studied the localized vibrational modes of boron in heavily doped Si using Raman scattering for carrier concentrations of 5×${10}^{18}$ to 1.5×${10}^{20}$ ${\mathrm{cm}}^{-3\mathrm{}}$. The line shapes and positions of the local mode and optic-phonon spectra due to interaction with the intervalence band continuum of electronic transitions are studied for different exciting frequencies. The local mode was also examined under uniaxial stress and was found to behave in a fashion similar to that of the optic phonon except for a larger hydrostatic shift, which seems due to the larger local compressibility in the region of the smaller boron atom.