Ab Initio Computational Screening and Performance Assessment of van der Waals and Semimetallic Contacts to Monolayer WSe2 P-Type Field-Effect Transistors
Ab Initio Computational Screening and Performance Assessment of van der Waals and Semimetallic Contacts to Monolayer WSe2 P-Type Field-Effect Transistors
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DOI：
10.1109/ted.2023.3241569
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发表时间：
2023-04
影响因子：
3.1
通讯作者：
Ning Yang;Y. Lin;Chih-Piao Chuu;M. Rahman;Tong Wu;Ang-Sheng Chou;Hung-Yu Chen;W. Woon;S. Liao;Shengxi Huang;Xiaofeng Qian;Jing Guo;I. Radu;H. P. Wong;Han Wang
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文献类型：
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作者：
Ning Yang;Y. Lin;Chih-Piao Chuu;M. Rahman;Tong Wu;Ang-Sheng Chou;Hung-Yu Chen;W. Woon;S. Liao;Shengxi Huang;Xiaofeng Qian;Jing Guo;I. Radu;H. P. Wong;Han Wang
基于二维半导体（如MoS 2、WS 2和WSe 2）的逻辑器件的最新技术发展引发了极大的兴奋，为实际应用铺平了道路。制造低电阻p型接触到2-D半导体仍然是一个关键的挑战。解决这一挑战的关键是找到高功函数的金属材料，同时在金属/半导体界面引入最小的金属诱导能隙态（MIGS）。在这项工作中，我们进行了系统的计算筛选的新的金属材料和它们的异质结与单层WSe 2的基础上从头算密度泛函理论和量子器件模拟。两种接触策略，货车德瓦尔斯（vdW）金属接触和散装半金属接触，被确定为有前途的解决方案，以实现肖特基势垒和低接触电阻的p型接触的WSe 2 p型场效应晶体管（pFET）。根据我们的筛选标准，找到了p型接触材料的良好候选者，包括vdW金属类别中的1H-NbS 2，1H-TaS 2和1 T-TiS 2，以及块状半金属类别中的Co 3Sn 2S 2和TaP。对这些新型p型接触材料的模拟表明，降低了MIGS，更少的费米能级钉扎效应，可以忽略的肖特基势垒高度和小的接触电阻（下降到20 Ω\mu \text{m}$）。
Recent technology development of logic devices based on 2-D semiconductors such as MoS2, WS2, and WSe2 has triggered great excitement, paving the way to practical applications. Making low-resistance p-type contacts to 2-D semiconductors remains a critical challenge. The key to addressing this challenge is to find high-work function metallic materials which also introduce minimal metal-induced gap states (MIGSs) at the metal/semiconductor interface. In this work, we perform a systematic computational screening of novel metallic materials and their heterojunctions with monolayer WSe2 based on ab initio density functional theory and quantum device simulations. Two contact strategies, van der Waals (vdW) metallic contact and bulk semimetallic contact, are identified as promising solutions to achieving Schottky-barrier-free and low-contact-resistance p-type contacts for WSe2 p-type field-effect transistor (pFETs). Good candidates of p-type contact materials are found based on our screening criteria, including 1H-NbS2, 1H-TaS2, and 1T-TiS2 in the vdW metal category, as well as Co3Sn2S2 and TaP in the bulk semimetal category. Simulations of these new p-type contact materials suggest reduced MIGS, less Fermi-level pinning effect, negligible Schottky barrier height and small contact resistance (down to $20~\Omega \mu \text{m}$ ).