Preparation and Raman study of B-doped Si microcrystals

We prepared B-doped Si microcrystals using an r.f. cosputtering method. The samples were investigated by transmission electron microscopy, IR absorption and Raman measurements. The Raman spectra of the samples were found to change depending on the excitation wavelength. The asymmetric spectral shapes observed were very similar to those observed for heavily B-doped bulk Si. The characteristic excitation-wavelength dependence of the spectra can be attributed to discrete-continuum Fano-type interference in the Si microcrystals. The IR absorption spectra showed a broad structure which is considered to arise from resonant excitation of surface plasmons in Si microcrystals. These results clearly suggest that B atoms are efficiently incorporated into Si microcrystals.