Quantum transport in WSe2/SnSe2 tunneling field effect transistors with high-k gate dielectrics

Abstract

Combining two-dimensional materials and high-k gate dielectrics offers a promising way to enhance the device performance of tunneling field-effect transistor (TFET). In this work, the device performance of WSe2/SnSe2 TFET with various gate dielectric materials is investigated based on quantum transport simulation. Results show that TFETs with high-k gate dielectric materials exhibit improved on-off ratio and enhanced transconductance. The optimized WSe2/SnSe2 TFET with TiO2 gate dielectrics achieves an on-state current of 1560 μA/μm and a subthreshold swing (SS) of 48 mV/dec. The utilization of high-k gate dielectric materials results in shorter tunneling length, higher transmission efficiency, and increased electron tunneling probability. The performance of the WSe2/SnSe2 TFET would be affected by the presence of the underlap region. Moreover, WSe2/SnSe2 TFETs with La2O3 dielectric can be scaled down to 3 nm while meeting high-performance (HP) device requirements according to the International Technology Roadmap for Semiconductors (ITRS). This research presents a practical solution for designing advanced logic devices in the sub-5 nm technology node.