Study of carrier concentration profiles in Al-implanted Ge by micro-Raman spectroscopy under different excitation wavelengths

The distribution profile of Al implanted in crystalline Ge has been investigated by micro-Raman spectroscopy. Using different excitation laser lines, corresponding to different optical penetration depths, the Al concentration at different depths beneath the sample surface has been studied. We have found a strong correlation between the intensity of the AlGe Raman peak at similar to 370cm1, which is due to the local vibrational mode of substitutional Al atoms, and the carrier concentration profile, obtained by the spreading resistance profiling analysis. A similar connection has been also observed for both shape and position of the GeGe Raman peak at similar to 300cm1. According to these experimental findings, we propose here a fast and nondestructive method, based on micro-Raman spectroscopy under different excitation wavelengths, to estimate the carrier concentration profiles in Al-implanted Ge. Copyright (c) 2013 John Wiley & Sons, Ltd.