Inelastic Electron Tunneling Spectroscopy in MIS and MS Tunnel Junctions

Abstract

Calculation of the tunneling conductance for inelastic tunneling process with excitation energy \( \hbar \omega \) are carried out, and it is clarified that inelastic electron tunneling spectroscopy (IETS) can be a useful tool for investigation of electronic states in semiconductors. The electronic states of the semiconductor are related to the inelastic tunneling current in the bias range from \( \hbar \omega/e\) to \( \hbar \omega /e+V_{\text{F}}\). This bias increase of \( \hbar \omega/e\) brings some advantage such as separation of the electronic structure from zero bias anomaly and from other structure due to excitation in the barrier. In experiments for MS contacts of InSrTiO 3- x , concaves appeared in the d V /d J curves via inelastic tunneling process, and they were confirmed to be due to the electronic states of the SrTiO 3- x .