Raman Spectroscopy of Ion-Implanted Silicon

Abstract

AbstractRaman spectroscopy is used to characterize silicon implanted with boron at a dose of 1014/cm2 or less and thermally annealed. The Raman scattering strengths and band shapes of the first-order optical mode at 520 cm-1 and of the second-order phonon modes are investigated to determine which modes are sensitive to the boron implant. The asimplanted samples show diminishing Raman scattering strength as the boron dose increases when the incident laser beam is 60° with respect to the sample normal. Thermal annealing restores some of the Raman scattering strength. Three excitation wavelengths are used and the shortest, 457.9 nm, yields the greatest spectral differences from unimplanted silicon. The backscattering geometry shows a variety of changes in the Raman spectrum upon boron implantation. These involve band shifts of the first-order optical mode, bandwidth variations of the first-order optical mode, and the intensity of the second-order mode at 620 cm-1.