Quantitative inelastic tunneling spectroscopy in the silicon metal-oxide-semiconductor system

A dual temperature method has been developed for subtracting the 77 K thermally smoothed background from 4.2 K inelastic electron tunneling spectra of ultrathin dielectric metal-insulator-semiconductor junctions. A mode resolving method applied to the remaining spectrum clearly identifies electrode and insulator vibrational modes. The ability to track these relative mode positions and amplitudes shows promise as a unique interface analysis and process diagnostic method. Results are reported on polycrystalline silicon gate, 1.5-nm-thick oxide devices fabricated on 1–10 Ω cm, N-type, (100) silicon substrates by a standard industrial process sequence.