Inductive line tunneling FET using epitaxial tunnel layer with Ge-source and charge enhancement insulation

Abstract

Abstract In this paper, we propose an inductive line tunneling FET using Epitaxial Tunnel Layer with Ge-Source and Charge Enhancement Insulation (CEI ETL GS-iTFET). The CEI ETL GS-iTFET allows full overlap between the gate and source regions, thereby enhancing the line tunneling. In addition, a germanium layer is introduced on the source side to form a heterojunction, effectively improving the device's conduction current. An ETL is incorporated to combat point tunneling leakage, resulting in a steeper subthreshold swing. Furthermore, a CEI consisting of Si3N4 is introduced between the germanium source and the Schottky metal, which effectively reduces carrier losses in the inversion layer and improves the overall device performance. This study presents a calibration-based approach to simulations, taking into account practical process considerations. Simulation results show that at V D = 0.2 V, the CEI ETL GS-iTFET achieves an average subthreshold swing (SS avg) of 30.5 mV/dec, an I on of 3.12 × 10–5 A/μm and an I on/I off ratio of 1.81 × 1010. These results demonstrate a significantly low subthreshold swing and a high current ratio of about 1010. In addition, the proposed device eliminates the need for multiple implantation processes, resulting in significant manufacturing cost reductions. As a result, the CEI ETL GS-iTFET shows remarkable potential in future low-power device competition.

Keywords

• Tunneling effect
• Subthreshold swing
• Schottky contact
• Fermi level pinning
• Line tunneling