Liu Maomao, Wei Sichen, Shahi Simran, Jaiswal Hemendra Nath, Paletti Paolo, Fathipour Sara, Remškar Maja, Jiao Jun, Hwang Wansik, Yao Fei, Li Huamin
Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA.
Nanoscale. 2020 Sep 7;12(33):17253-17264. doi: 10.1039/d0nr01573c. Epub 2020 Apr 24.
High contact resistance is one of the primary concerns for electronic device applications of two-dimensional (2D) layered semiconductors. Here, we explore the enhanced carrier transport through metal-semiconductor interfaces in WS field effect transistors (FETs) by introducing a typical transition metal, Cu, with two different doping strategies: (i) a "generalized" Cu doping by using randomly distributed Cu atoms along the channel and (ii) a "localized" Cu doping by adapting an ultrathin Cu layer at the metal-semiconductor interface. Compared to the pristine WS FETs, both the generalized Cu atomic dopant and localized Cu contact decoration can provide a Schottky-to-Ohmic contact transition owing to the reduced contact resistances by 1-3 orders of magnitude, and consequently elevate electron mobilities by 5-7 times. Our work demonstrates that the introduction of transition metal can be an efficient and reliable technique to enhance the carrier transport and device performance in 2D TMD FETs.
高接触电阻是二维（2D）层状半导体在电子器件应用中的主要问题之一。在此，我们通过引入一种典型的过渡金属铜，并采用两种不同的掺杂策略，来探索在WS场效应晶体管（FET）中通过金属-半导体界面增强载流子传输：（i）通过沿沟道随机分布铜原子进行“广义”铜掺杂，以及（ii）通过在金属-半导体界面采用超薄铜层进行“局部”铜掺杂。与原始的WS FET相比，广义的铜原子掺杂剂和局部的铜接触修饰都可以实现从肖特基接触到欧姆接触的转变，这是由于接触电阻降低了1-3个数量级，从而使电子迁移率提高了5-7倍。我们的工作表明，引入过渡金属可以成为一种有效且可靠的技术，以增强二维过渡金属二卤化物场效应晶体管中的载流子传输和器件性能。
