A non-destructive approach for doping profiles characterization by micro-Raman spectroscopy: the case of B-implanted Ge

B-implanted Ge samples have been investigated by micro-Raman spectroscopy under different excitation wavelengths, with the aim of gaining insights about the B distribution at different depths beneath the sample surface. The intensities, observed under the different excitation wavelengths, of the B-Ge Raman peak at about 545 cm-1, which is due to the local vibrational mode of the substitutional B atoms in the Ge matrix, have been used to calibrate the optical absorption lengths in B-implanted Ge. Then, by using these calibrated values, a very sharp correlation between the spectral features of the Ge-Ge Raman peak at ~300 cm-1 and the content of substitutional B atoms has been derived. Accordingly, a non-destructive approach, based on micro-Raman spectroscopy under different excitation wavelengths, is presented to estimate, at least at the lowest depths, the carrier concentration profiles from the spectral features of the Ge-Ge Raman peak.