In this work, a hetero structure gate-drain underlap (UL) Schottky barrier (SB) Field Effect Transistor (FET) is explored to achieve high device performance compared with high-k and low-k hetero structure SB FET (HSBFET). The effects of gate drain UL junction on the performances of UL-HSBFETs have been studied in terms of electrical characteristics including on-current (Ion), subthreshold swing, Ion/Ioff ratio, ambipolar conduction, and Ioff current. The low on-state current of silicon-based SB FETs can be enhanced by introducing the low bandgap silicon germanium material. Gate-drain UL and silicon germanium channel with low barrier height provides less tunnelling width which enhances the carrier injection at on-state compared with low-k and high-k HSBFET. Further, the proposed UL-HSBFET suppresses the ambipolar conduction due to holes. In contrast to conventional high-k and low-k HSBFET that suffers from severe ambipolar conduction, the UL-HSBFET device reduces the conduction at drain-channel junction with increasing the UL length to 5, 10, 15, and 20 nm. This provides better radio frequency performances with improved carrier capability of the proposed device. Therefore, UL-HSBFET device can be one of the best possible competitor for high-frequency application. The performance comparison of all the devices is carried out using Technology Computer-Aided Design (TCAD) simulator. � The Institution of Engineering and Technology 2018.