School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
Nano Lett. 2013 Jun 12;13(6):2640-6. doi: 10.1021/nl400778q. Epub 2013 May 20.
Monolayer molybdenum disulfide (MoS2) with a direct band gap of 1.8 eV is a promising two-dimensional material with a potential to surpass graphene in next generation nanoelectronic applications. In this Letter, we synthesize monolayer MoS2 on Si/SiO2 substrate via chemical vapor deposition (CVD) method and comprehensively study the device performance based on dual-gated MoS2 field-effect transistors. Over 100 devices are studied to obtain a statistical description of device performance in CVD MoS2. We examine and scale down the channel length of the transistors to 100 nm and achieve record high drain current of 62.5 mA/mm in CVD monolayer MoS2 film ever reported. We further extract the intrinsic contact resistance of low work function metal Ti on monolayer CVD MoS2 with an expectation value of 175 Ω·mm, which can be significantly decreased to 10 Ω·mm by appropriate gating. Finally, field-effect mobilities (μFE) of the carriers at various channel lengths are obtained. By taking the impact of contact resistance into account, an average and maximum intrinsic μFE is estimated to be 13.0 and 21.6 cm(2)/(V s) in monolayer CVD MoS2 films, respectively.
单层二硫化钼（MoS2）具有 1.8eV 的直接带隙，是一种很有前途的二维材料，有望在下一代纳米电子应用中超越石墨烯。在这篇快报中，我们通过化学气相沉积（CVD）法在 Si/SiO2 衬底上合成了单层 MoS2，并综合研究了基于双栅 MoS2 场效应晶体管的器件性能。我们研究了超过 100 个器件，以获得 CVD MoS2 器件性能的统计描述。我们检查并将晶体管的沟道长度缩小到 100nm，并在 CVD 单层 MoS2 薄膜中实现了 62.5mA/mm 的创纪录高漏极电流，这是迄今为止报道的最高值。我们进一步提取了低功函数金属 Ti 在单层 CVD MoS2 上的本征接触电阻，其期望值为 175Ω·mm，通过适当的栅极可以显著降低至 10Ω·mm。最后，我们获得了在不同沟道长度下的载流子的场效应迁移率（μFE）。考虑到接触电阻的影响，在单层 CVD MoS2 薄膜中，平均和最大本征μFE 分别估计为 13.0 和 21.6cm2/（Vs）。
