Tunneling spectroscopy of electron subbands in thin silicon-on-insulator metal-oxide-semiconductor field-effect transistors

Abstract

We report the tunneling spectroscopy of thin silicon-on-insulator (SOI) metal-oxide-semiconductor field-effect transistors with tunneling gate oxide. When electrons are injected into a thin SOI well, the gate-tunneling current shows kink structures originating from quantized energy levels in the SOI well. From the theoretical consideration of the energy levels and their density of states, the observed features can be ascribed to electron tunneling into the in-plane fourfold degenerate valley subbands. Furthermore, inhomogeneous peak broadening of the kink structures in the experiment is well explained by the SOI thickness variation.