PDF(Pubmed)
Abstract：
In this study, we investigated the influence of quasi-one-dimensional (Quasi-1D) characteristics on the source and drain contact resistances within vertical nanowire (NW) field-effect transistors (FETs) of diminutive diameter. The top contact of the NW is segregated into two distinct regions: the first encompassing the upper surface, designated as the axial contact, and the second encircling the side surface, known as the radial contact, which is formed during the top-contact metal deposition process. Quantum confinement effects, prominent within Quasi-1D NWs, exert significant constraints on radial transport, consequently inducing a noticeable impact on contact resistance. Notably, in the radial direction, electron tunneling occurs only through quantized, discrete energy levels. Conversely, along the axial direction, electron tunneling freely traverses continuous energy levels. In a meticulous numerical analysis, these disparities in transport mechanisms unveiled that NWs with diameters below 30 nm exhibit a markedly higher radial contact resistance compared to their axial counterparts. Furthermore, an increase in the overlap length (less than 5 nm) contributes to a modest reduction in radial resistance; however, it remains consistently higher than the axial contact resistance.
摘要：
在这项研究中,我们研究了准一维（Quasi-1D）特性对小直径垂直纳米线（NW）场效应晶体管（FET）内源极和漏极接触电阻的影响。NW的顶部触点分为两个不同的区域：第一个包含上表面，指定为轴向接触，第二个环绕侧面，称为径向接触，其在顶部接触金属沉积工艺期间形成。量子限制效应,在准1DNW中突出，对径向运输施加重大限制，因此对接触电阻产生明显的影响。值得注意的是,在径向方向上，电子隧穿仅通过量子化发生，离散能级。相反，沿轴向,电子隧穿自由穿越连续的能级。在细致的数值分析中，运输机制中的这些差异揭示了直径小于30nm的NWs与轴向对应物相比具有明显更高的径向接触电阻。此外，重叠长度的增加（小于5nm）有助于径向电阻的适度降低；然而，它始终高于轴向接触电阻。
