How good is mono-layer transition-metal dichalcogenide tunnel field-effect transistors in sub-10 nm? - An ab initio simulation study

Rigorous ab initio quantum transport simulation based on flexible plane wave method has been presented to predict the performance of mono-layer transition-metal dichalcogenide (TMD) tunnel field-effect transistors (TFETs) at scaling limit. WTe₂-TFET appears as the most promising candidate for both high-performance (HP) and low-operating-power (LOP) transistors with the I_ON as high as 1890 μA/μm, which is very close to the ITRS 2024 requirements for 7nm physical gate length scaling. While other TMD-TFETs are found much less applicable. In addition, performance enhancement based on atomic defect engineering has been proposed. The simulation reveals transition metal vacancy inside the tunneling diode can dramatically increase I_ON while keeping I_OFF unchanged. As an evidence, simulation shows Mo-vacancy engineered mono-layer MoS₂-TFET with 6.3nm physical gate length has 15 times larger I_ON (1324μA/μm) and the same I_OFF (1.2×10-2 μA/μm) compared to the pristine device.