The channel lengths of transistors are now nearing the nanometer, making these devices increasingly prone to direct source-to-drain tunneling (DSDT), a leakage mechanism commonly considered to set the end of Moore’s law. In MOSFETs, the probability for a charge carrier to undergo DSDT decays exponentially with channel length, source depletion length, and drain depletion length. Bound-charge engineering (BCE) is a recently introduced scheme where the depletion lengths of FETs can be controlled through effective doping by surface bound charges residing on the interface between a semiconductor and an adjacent oxide. In this letter, BCE is applied to reduce DSDT leakage current down to acceptable levels in MOSFETs with channels as short as $2.3\mathrm{nm}$; the higher the oxide permittivity, the lower the DSDT leakage. This idea is tested on ultrascaled Si nanowire MOSFETs via atomistic quantum transport simulations based on the nonequilibrium Green’s function (NEGF) formalism and the tight-binding model, as well as on physically larger Si nanosheet MOSFETs via continuum NEGF–$\mathbf{k}·\mathbf{p}$ simulations based on the finite-element method.

晶体管的沟道长度现在接近纳米，使得这些器件越来越容易发生直接源漏隧道 (DSDT)，这是一种通常被认为是摩尔定律终结的泄漏机制。在 MOSFET 中，电荷载流子经历 DSDT 的概率随沟道长度、源极耗尽长度和漏极耗尽长度呈指数衰减。束缚电荷工程 (BCE) 是最近引入的一种方案，其中 FET 的耗尽长度可以通过驻留在半导体和相邻氧化物之间的界面上的表面束缚电荷进行有效掺杂来控制。在这封信中，BCE 用于将 MOSFET 中的 DSDT 漏电流降低到可接受的水平，并且通道短至$2.3\mathrm{纳米}$; 氧化物介电常数越高，DSDT 泄漏越低。通过基于非平衡格林函数 (NEGF) 形式和紧束缚模型的原子量子传输模拟，以及通过连续介质 NEGF 在物理上更大的 Si 纳米片 MOSFET 上测试了这个想法。$\mathbf{ķ}·\mathbf{p}$基于有限元方法的模拟。