Interface engineering for the suppression of ambipolar behavior in Schottky-barrier MOSFETs

We study the suppression of ambipolar behavior of Schottky-barrier MOSFETs using an interface engineering approach. Inserting a thin silicon nitride layer between the metallic source/drain electrodes and the silicon yields low Schottky barriers and results in unipolar device characteristics demonstrated with pseudo-MOSFETs. Simulations support the observed suppression and show that with appropriate silicon nitride thickness the metal-induced-gap states can be suppressed and hence the properties of the contact can be tuned from metal-semiconductor-like to the behavior of a doped-contact. Furthermore, there is a trade-off between suppression of the ambipolar behavior, contact length and on-state current.