Enhanced switching characteristics of circular-shaped double-gate Si-doped MoS2 TFET for future high-speed applications

Abstract

This study proposes a novel steep subthreshold swing (SS) circular-shaped double gate silicon-doped molybdenum disulfide (MoS₂) TFET. In the proposed device, initially the Si-doped MoS₂ is used in the channel, which is further extended towards the source side to enhance the SS and $I_{ON}/I_{OFF}$. The simulation results show that these modifications improve SS and $I_{ON}/I_{OFF}$ by 1.59 and 85.4 times, respectively. Afterward, rectangular gates are replaced by circular gates removing the edge effect and further improving the SS, and $I_{ON}/I_{OFF}$ ratio to 5.8 mV/dec and $6.6\times 10^{11}$, respectively. The overall simulation results illustrate that the proposed device offers a steep SS with significant electrostatic control, improved tunneling efficiency, and low leakage current, which makes it a potential candidate for low-power and high-speed applications. In addition, analytical modeling is also performed to verify the simulated surface potential, and it is found that the analytical results agree well with the simulated ones. Furthermore, the impact of interface trap charges (ITCs) has also been analyzed to confirm the device’s reliability. The results validate that the proposed device is immune to ITCs.