Inelastic electron tunneling spectrometer to characterize metal–oxide–semiconductor devices with ultrathin oxides

Abstract

We describe an easy to build inelastic electron tunneling spectrometer, controlled by a computer, to analyze and characterize metal–oxide–semiconductor (MOS) devices. The method, material, and circuit are also described. Typical inelastic electron tunneling spectra obtained from a MOS tunnel junction with various degrees of nonlinear conductance–voltage behavior are presented. Our results suggest that such a spectrometer has appropriate resolution (4 mV of full width half maximum) and suitable signal-to-noise ratio to clearly identify the electrode and insulator vibrational modes. Results are reported on aluminum gate 2.1 nm thick oxide devices fabricated on n-type (111) silicon substrates.