High-performance MoS2 transistors with low-resistance molybdenum contacts
High-performance MoS2 transistors with low-resistance molybdenum contacts
复制标题
DOI：
10.1063/1.4866340
复制
发表时间：
2014-03-03
影响因子：
4
通讯作者：
Banerjee, Kaustav
中科院分区：
文献类型：
--
作者：
Kang, Jiahao;Liu, Wei;Banerjee, Kaustav
本文介绍和评价了钼(Mo)作为原子薄二硫化钼(MoS_2)的替代触头金属，并对高性能场效应管进行了实验验证。为了了解界面的物理性质和各种因素对Mo-MoS_2接触的影响，采用密度泛函理论(DFT)方法模拟了Mo与单层MoS_2形成的高质量接触界面，结果表明，在源漏接触下，Mo与MoS_2形成零隧道势垒和零肖特基势垒的高质量接触界面，并且由于费米能级的钉扎，在源漏-沟道结处形成了极低的肖特基势垒(0.1 eV)。与DFT模拟结果一致的是，在使用Mo接触的单层和多层MoS2晶体管上，实验证明了高迁移率、高导通电流和低接触电阻。所得结果不仅揭示了用Mo作为MoS_2接触金属的优点，而且强调了仅考虑功函数和肖特基理论不能直观地预测与二维材料接触的性质。(C)2014 AIP出版有限责任公司。
In this Letter, molybdenum (Mo) is introduced and evaluated as an alternative contact metal to atomically-thin molybdenum disulphide (MoS2), and high-performance field-effect transistors are experimentally demonstrated. In order to understand the physical nature of the interface and highlight the role of the various factors contributing to the Mo-MoS2 contacts, density functional theory (DFT) simulations are employed, which reveal that Mo can form high quality contact interface with monolayer MoS2 with zero tunnel barrier and zero Schottky barrier under source/drain contact, as well as an ultra-low Schottky barrier (0.1 eV) at source/drain-channel junction due to strong Fermi level pinning. In agreement with the DFT simulations, high mobility, high ON-current, and low contact resistance are experimentally demonstrated on both monolayer and multilayer MoS2 transistors using Mo contacts. The results obtained not only reveal the advantages of using Mo as a contact metal for MoS2 but also highlight the fact that the properties of contacts with 2-dimensional materials cannot be intuitively predicted by solely considering work function values and Schottky theory. (C) 2014 AIP Publishing LLC.