A novel ultra-steep subthreshold swing iTFET with control gate and control source biasing

In this paper, we propose a novel structure with Control Source and Control Gate structured tunnel field-effect transistor (CSCG‑iTFET), which achieves an unprecedentedly steep subthreshold swing (SS) while maintaining high ON-state current ([Formula: see text]). In addition, using Schottky contacts at the source without doping reduces leakage current and thermal budget. We compared the performance of four different device structures, including conventional Double Gate TFET with Control Gate, iTFET with Control Gate, iTFET with Charge Enhancement Layer and Control Gate, and our structure. The accumulation layer can be enhanced by using the characteristic of Control Source to modulate the voltage. We performed simulation studies using Sentaurus TCAD. Utilize calibrated models for accurate simulations, exploiting the same referenced processes, demonstrate that the Control Source iTFET exhibits an average subthreshold swing S.S_AVG of 9.69 mV/Dec and a minimum subthreshold swing S.S_MIN of 1.72 mV/Dec, respectively. At V_D = 0.2 V, the I_ON current is 2.95 × 10^- 7 A/µm, and the I_ON/I_OFF ratio is 3.84 × 10⁹. It is believed that the performance can be further improved if the fabrication processes are optimized.