The inherent asymmetry in area and position of drain/source region in the ring field-effect transistor (Ring-FET) provides a unique channel electrostatic, different from symmetric double-gate FET, which renders it with immunity to short channel effects (SCEs). This electrostatics of ring-FET has the potential to mitigate ambipolarity in tunnel FET (TFET). In this article, using a well-calibrated TCAD simulation and analytical model, we investigate the electrostatics of all-silicon n-type Ring-TFET (R-TFET). The results are compared with conventional all-silicon n-type double gate TFET (DG-TFET). Two possible configurations of R-TFET obtained by interchanging the source and the drain positions are termed as source-inside TFET (SI-TFET) and drain-inside TFET (DI-TFET). We observed that DI-TFET mitigates the ambipolarity by $100 \times$ at $V_{DS}=\text{0.5 V}$ and $2000 \times$ at $V_{DS}=\text{1 V}$ compared to DG-TFET. Besides, the drain induced barrier thinning (DIBT) of DI-TFET is (89 mV/V) less than DG-TFET (108 mV/V), for a channel length of 32 nm, thus the proposed DI-TFET also offers better short channel immunity.

中文翻译：

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研究 Ring-TFET 以实现更好的静电控制和抑制双极性

环形场效应晶体管 (Ring-FET) 中漏极/源极区域的面积和位置固有的不对称性提供了独特的沟道静电，不同于对称双栅极 FET，这使其具有抗短沟道效应 (SCE) 的能力. 环形 FET 的这种静电特性有可能减轻隧道 FET (TFET) 中的双极性。在本文中，我们使用经过良好校准的 TCAD 仿真和分析模型，研究了全硅 n 型环形 TFET (R-TFET) 的静电。结果与传统的全硅 n 型双栅极 TFET (DG-TFET) 进行了比较。通过交换源极和漏极位置获得的 R-TFET 的两种可能配置被称为源极内部 TFET (SI-TFET) 和漏极内部 TFET (DI-TFET)。我们观察到 DI-TFET 通过以下方式减轻双极性$100 \times$ 在 $V_{DS}=\text{0.5 V}$ 和 $2000 \times$ 在 $V_{DS}=\text{1 V}$与 DG-TFET 相比。此外，对于 32 nm 的沟道长度，DI-TFET 的漏极诱导势垒减薄 (DIBT) 比 DG-TFET (108 mV/V) 小 (89 mV/V)，因此所提出的 DI-TFET 也提供了更好的短通道抗扰度。