Comparison study of tunneling models for Schottky field effect transistors and the effect of Schottky barrier lowering

An Airy function transfer matrix tunneling model and the Wentzel-Kramers-Brillouin (WKB) tunneling model have been compared in the application to Schottky field effect transistors (SFETs) with and without the incorporation of Schottky barrier lowering (SBL). Model calculations have shown that the WKB model can predict tunneling current through a Schottky barrier with reasonable accuracy when SBL is excluded. It is also shown that the WKB model can mimic the total current behavior in an SFET when SBL is included and when thermal current is excluded. In both cases, though, the actual physical behavior of the SFET is misrepresented, and so it is finally shown that in the design cases of interest (low Schottky barrier heights), thermal current dominates the total ON-state current in SFETs.