论文标题
发现金属触点对单层MOS2的影响
Uncovering the Effects of Metal Contacts on Monolayer MoS2
论文作者
论文摘要
金属触点是二维（2D）半导体设备电子性能的关键限制。在这里，我们介绍了七种金属（y，sc，ag，al，ti，au，ni）之间的接触界面的全面研究，其工作函数从3.1到5.2 eV）和通过化学蒸气沉积生长的单层MOS2。我们将薄金属膜蒸发到MOS2上，并通过拉曼光谱，X射线光电子光谱，X射线衍射，透射电子显微镜和电特性来研究界面。我们发现，1）超薄氧化的氧化剂mos2 n型（> 2x10^12 1/cm^2）而不会降解其迁移率，2）AG，AU和Ni沉积会导致MOS2损害不同的损害（从<3 1/cm至> 6 1/cm的峰宽扩大了Raman E'峰，并与SCM 2相反。必须避免与单层MOS2接触时反应性金属，但是对照研究表明，该反应主要限于多层膜的顶层。最后，我们发现4）薄金属不会显着劳累MOS2，正如X射线衍射所证实的那样。这些是与MOS2的金属接触的重要发现，并且广泛适用于许多其他2D半导体。
Metal contacts are a key limiter to the electronic performance of two-dimensional (2D) semiconductor devices. Here we present a comprehensive study of contact interfaces between seven metals (Y, Sc, Ag, Al, Ti, Au, Ni, with work functions from 3.1 to 5.2 eV) and monolayer MoS2 grown by chemical vapor deposition. We evaporate thin metal films onto MoS2 and study the interfaces by Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and electrical characterization. We uncover that, 1) ultrathin oxidized Al dopes MoS2 n-type (> 2x10^12 1/cm^2) without degrading its mobility, 2) Ag, Au, and Ni deposition causes varying levels of damage to MoS2 (broadening Raman E' peak from <3 1/cm to >6 1/cm), and 3) Ti, Sc, and Y react with MoS2. Reactive metals must be avoided in contacts to monolayer MoS2, but control studies reveal the reaction is mostly limited to the top layer of multilayer films. Finally, we find that 4) thin metals do not significantly strain MoS2, as confirmed by X-ray diffraction. These are important findings for metal contacts to MoS2, and broadly applicable to many other 2D semiconductors.
