Dopingless Tunnel FET with a Hetero-Material Gate: Design and Analysis

We report a two-dimensional simulation study of a dopingless TFET with a hetero-gate dielectric. The energy band gap on the source side is modulated using a hetero-gate-dielectric in a dopingless TFET to increase the source-side tunneling rate. The use of a hetero-gate-dielectric, only on the source side, will ensure that the ambipolar current is not enhanced due to the drain-side tunneling. We demonstrate that the dopingless TFET with a hetero-gate dielectric exhibits an enhanced ON-state current and a reduced subthreshold swing when compared to a conventional dopingless TFET. Since a low thermal budget is required for fabricating the dopingless TFETs, our results indicate that high performance dopingless TFETs can be realized for low-power and low-cost applications using our approach.