Wang Jiaxin, Jia Rundong, Huang Qianqian, Pan Chen, Zhu Jiadi, Wang Huimin, Chen Cheng, Zhang Yawen, Yang Yuchao, Song Haisheng, Miao Feng, Huang Ru
Key Laboratory of Microelectronic Devices and Circuits (MOE), Institute of Microelectronics, Peking University, Beijing, 100871, China.
School of Physics, Nanjing University, Nanjing, 210093, China.
Sci Rep. 2018 Dec 10;8(1):17755. doi: 10.1038/s41598-018-35661-4.
Van der Waals heterostructures composed of two-dimensional (2D) transition metal dichalcogenides (TMD) materials have stimulated tremendous research interest in various device applications, especially in energy-efficient future-generation electronics. Such ultra-thin stacks as tunnel junction theoretically present unprecedented possibilities of tunable relative band alignment and pristine interfaces, which enable significant performance enhancement for steep-slope tunneling transistors. In this work, the optimal 2D-2D heterostructure for tunneling transistors is presented and elaborately engineered, taking into consideration both electric properties and material stability. The key challenges, including band alignment and metal-to-2D semiconductor contact resistances, are optimized separately for integration. By using a new dry transfer technique for the vertical stack, the selected WS/SnS heterostructure-based tunneling transistor is fabricated for the first time, and exhibits superior performance with comparable on-state current and steeper subthreshold slope than conventional FET, as well as on-off current ratio over 10 which is among the highest value of 2D-2D tunneling transistors. A visible negative differential resistance feature is also observed. This work shows the great potential of 2D layered semiconductors for new heterostructure devices and can guide possible development of energy-efficient future-generation electronics.
由二维（2D）过渡金属二硫属化物（TMD）材料组成的范德华异质结构激发了人们对各种器件应用的巨大研究兴趣，特别是在节能的下一代电子器件方面。作为隧道结的这种超薄堆叠理论上呈现出可调谐相对能带排列和原始界面的前所未有的可能性，这使得陡坡隧道晶体管的性能得到显著提升。在这项工作中，考虑到电学性质和材料稳定性，提出并精心设计了用于隧道晶体管的最佳二维-二维异质结构。包括能带排列和金属与二维半导体接触电阻在内的关键挑战分别针对集成进行了优化。通过使用一种用于垂直堆叠的新型干法转移技术，首次制造出了基于选定的WS/SnS异质结构的隧道晶体管，该晶体管表现出优异的性能，与传统场效应晶体管相比，具有相当的导通态电流和更陡的亚阈值斜率，以及超过10的开/关电流比，这是二维-二维隧道晶体管中的最高值之一。还观察到明显的负微分电阻特性。这项工作展示了二维层状半导体在新型异质结构器件方面的巨大潜力，并可为节能的下一代电子器件的可能发展提供指导。
