Theoretical Study of Ballistic Transport in Silicon Nanowire and Graphene Nanoribbon Field-Effect Transistors Using Empirical Pseudopotentials
Theoretical Study of Ballistic Transport in Silicon Nanowire and Graphene Nanoribbon Field-Effect Transistors Using Empirical Pseudopotentials
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DOI：
10.1109/ted.2017.2695960
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发表时间：
2017-06-01
影响因子：
3.1
通讯作者：
Fischetti, Massimo V.
中科院分区：
文献类型：
--
作者：
Fang, Jingtian;Chen, Shanmeng;Fischetti, Massimo V.
我们对栅极全能场效应晶体管（fet）的弹道性能进行了理论研究，该晶体管的通道由不同宽度的扶手椅边石墨烯纳米带（aGNRs）和方形截面的硅纳米线（SiNWs）组成。我们应用了一个基于经验伪势的原子量子输运形式。我们的研究结果表明，在短通道长度（例如，3-aGNRs低于10 nm）下，agnfet的关断行为受到源-漏隧穿的严重影响。将阈值电压Vth定义为电流达到给定I-OFF = 0.4 μ a / μ m时的栅极偏置，在栅极超速驱动V- gs -V-th = 0.25 V（对应于假设的V- dd约为0.4 V）时，具有5nm通道长度的器件可以达到的最大电流仅为400 μ a / μ m。相比之下，sinwfet即使在5nm处也不受源极-漏极隧道效应的影响，并且显示出几乎理想的亚阈值摆幅，在相同的栅极过载驱动为0.25 V时具有令人满意的1000 μ a / μ m电流，以及合理的I-ON/I-OFF比约为2 × 10(3)。
We present a theoretical study of the ballistic performance of gate-all-around field-effect transistors (FETs) with channels consisting of armchair-edge graphene nanoribbons (aGNRs) of various widths and silicon nanowires (SiNWs) with square cross sections. We apply an atomistic quantum transport formalism based on empirical pseudopotentials. Our results show that the turn-OFF behavior of aGNRFETs is seriously affected by source-to-drain tunneling at short channel lengths (e.g., below 10 nm for 3-aGNRs). Defining the threshold voltage Vth as the gate bias at which the current reaches a given I-OFF = 0.4 mu A/mu m, devices with a 5-nm channel length can reach a maximum current of only 400 mu A/mu m at a gate overdrive V-GS-V-th = 0.25 V (corresponding to an assumed V-DD of about 0.4 V). In contrast, SiNWFETs remain immune from source-to-drain tunneling even at 5 nm and show an almost ideal subthreshold swing, a satisfactory current of 1000 mu A/mu m at the same gate overdrive of 0.25 V, and a reasonable I-ON/I-OFF ratio around 2 x 10(3).