Edge-enhanced Raman scattering in narrow sGe fin field-effect transistor channels

We report micro-Raman spectroscopy results on strained Ge narrow (20 nm) channels for finFET nanoelectronics technology. It is found that the Raman activity of the structures is strongly dependent on the relative orientation of the excitation laser polarization and the structure geometry. While the observation of the typical Ge Raman signatures is challenging for the antiparallel orientation, a dramatic enhancement of the signal is found for a parallel orientation. Simulations confirm that a significant concentration of the light's electromagnetic field in the vicinity of the edges of the structures is at the origin of the strong Raman enhancement. The edge enhancement of the Raman scattering is a promising tool for the non-destructive characterization of nanometer-scale semiconductor structures and devices. (C) 2015 AIP Publishing LLC.