Performance Enhancement of Dopingless Tunnel-FET Based on Ge-Source with High-k

In this paper, we have proposed and investigated the performance of a Germanium (Ge) source (GeS) dopingless (DL) tunnel field-effect transistor (DLTFET) with high-k dielectric material. The proposed GeS-DLTFET employes a low bandgap Ge for the source region to improve the ON state current, whereas, Si is used in the drain region to keep the OFF state current low. However, dopingless structure in the proposed device yields immunity towards random dopant fluctuations and simplified fabrication process flow. The proposed device shows significant improvement in the drive current ION, and point subthreshold swing (SS). Simulation results show an enhancement of about 40× in ON current and 9× decrement in SS as compared to conventional DLTFET. The higher values of g_m~1 mS/μm and f_T ~ 400 GHz of GeS-DLTFET makes proposed device suitable for analog and RF applications.