In this paper, using device simulations, we investigate electrical characteristics of a tunnel field-effect transistor (TFET) in which band-to-band tunneling (BTBT) occurs dominantly within the channel, rather than at source-channel junction. The within-channel BTBT is enabled by sharp band-bending induced by the dual material gate (DMG). The work-functions of two metal gates are chosen, such that the surface potential profile exhibits a distinct step at the DMG interface. Consequently, even under equilibrium condition, a high lateral electric field and an abrupt tunneling junction exist at the DMG interface. When a small gate voltage is applied, the inherent lateral electric field aids in creating an abrupt band alignment and obtaining a small tunneling width. As a result, an excellent average subthreshold swing is obtained in the proposed device. We have also investigated scaling of channel lengths in the proposed device and have demonstrated that within-channel tunneling can be exploited for channel lengths of 40 nm and above. Furthermore, low drain threshold voltage and suppressed drain-induced barrier lowering can be obtained in the proposed device. Moreover, in contrast to conventional TFETs, electrical characteristics of the proposed device are less susceptible to source doping variations and shift in gate-edge with respect to the source-channel junction.

中文翻译：

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在纳米级隧道场效应晶体管中开发通道内隧道

在本文中，通过使用器件仿真，我们研究了隧道场效应晶体管（TFET）的电特性，其中，带间隧穿（BTBT）主要发生在通道内，而不是在源极-通道结处。通道内BTBT由双材料门（DMG）引起的尖锐的频带弯曲实现。选择两个金属栅极的功函数，以使表面电势轮廓在DMG界面处呈现出明显的台阶。因此，即使在平衡条件下，DMG界面处也存在高的横向电场和陡峭的隧道结。当施加较小的栅极电压时，固有的横向电场有助于产生陡峭的能带对准并获得较小的隧穿宽度。结果，在所提出的装置中获得了极好的平均亚阈值摆幅。 纳米以上。此外，在所提出的器件中可以获得低漏极阈值电压和抑制的漏极引起的势垒降低。而且，与传统的TFET相反，所提出的器件的电特性不易受到源极掺杂变化和相对于源极-沟道结的栅极边缘偏移的影响。