Suppression of ambipolarity in tunnel-FETs using gate oxide as parameter: analysis and investigation

In this study, the authors present a double-gate tunnel field-effect transistor with dual gate oxide thickness (henceforth referred to as DOT-DGTFET) to suppress ambipolar current conduction (Iamb). Conventional n-type DGTFET conducts current for negative VGS also and poses a challenge for circuit design. Conduction current in n-type DGTFET for negative VGS is referred to as ambipolar current (Iamb). In the proposed DOT-DGTFET structure, a thin gate oxide of 3 nm is used towards the source–channel junction and a thick gate oxide is used towards the drain–channel junction. Use of thicker gate oxide towards drain–channel junction suppresses Iamb significantly while only marginally affecting ION. Subsequently, the proposed technique for ambipolarity suppression is compared with some of the existing techniques and they observe that DOT-DGTFET suppresses ambipolarity significantly with minimal effect on the ON state current.