Evaluation of local valence electron density and dielectric functions in metal interconnects using spatially resolved EELS spectra

Electron energy-loss spectroscopy (EELS) in scanning-TEM with several nanometer spatial resolution, is a powerful technique for the evaluation of the electric properties of metal interconnects. EELS spectra below several tenths eV reflect the dielectric function through electron polarization at local area of interests, which connects with the electric properties such as valence electron density and electrical resistivity.