Impact of ferroelectric on the electrical characteristics of silicon–germanium based heterojunction Schottky barrier FET

Abstract

This work investigates the impact of ferroelectric gate oxide on high-k gate dielectric with low band gap Silicon Germanium ferroelectric Schottky barrier FET (SiGe Fe-SBFET), has been qualitatively simulated. The present research focuses on major improvement over the conventional device in terms of drain current and reduced subthreshold swing and analog performances. The proposed device has been analyzed in terms of numerous device electrostatic parameters such as electric field and energy band diagram using a ferroelectric material. A novel approach of SiGe-Fe-SBFET provides an effective technique helps to increase the performance in terms of on-current and off-state current of the device. The SiGe-Fe-SBFET also provides high Ion/Ioff ratio of 4.188 × 1012 and low Subthreshold swing of 67 mV/dec in comparison with germanium (Ge) and silicon (Si) material based ferroelectric SBFET. Apart from this, the increasing of tunneling width for the drive of carriers in the drain-channel junction, which results in a reduction of ambipolar conduction in off-state with gate drain underlap. Further, the analog performances of proposed and conventional device are evaluated such as transconductance, intrinsic gate delay, output conductance and cut-frequency which is dependent of parasitic gate capacitances are also investigated through a 2D Silvaco Atlas simulator.