Journal Article

Approaching the quantum limit in two-dimensional semiconductor contacts

Ning, Hongkai, Ma, Liang, Lu, Junpeng, Shi, Yi, Yu, Zhihao, Wang, Wenhui, Nie, Yuefeng, Ni, Zhenhua, Li, Taotao, Gao, Si, Fan, Dongxu, Tu, Xuecou, Xu, Tao, Li, Weisheng, Xu, Yifei, Sun, Litao, Wang, Peng, Wang, Xinran, Wang, Wenfeng, Duan, Xidong, Liu, Lei, Li, Jia, Pop, Eric, Qiu, Hao, Sun, Wenjie, Wang, Jinlan, Köroğlu, Çağıl, Gong, Xiaoshu

2023

Overview

The development of next-generation electronics requires scaling of channel material thickness down to the two-dimensional limit while maintaining ultralow contact resistance 1 , 2 . Transition-metal dichalcogenides can sustain transistor scaling to the end of roadmap, but despite a myriad of efforts, the device performance remains contact-limited 3 – 12 . In particular, the contact resistance has not surpassed that of covalently bonded metal–semiconductor junctions owing to the intrinsic van der Waals gap, and the best contact technologies are facing stability issues 3 , 7 . Here we push the electrical contact of monolayer molybdenum disulfide close to the quantum limit by hybridization of energy bands with semi-metallic antimony ( 01 1 ̅ 2 ) through strong van der Waals interactions. The contacts exhibit a low contact resistance of 42 ohm micrometres and excellent stability at 125 degrees Celsius. Owing to improved contacts, short-channel molybdenum disulfide transistors show current saturation under one-volt drain bias with an on-state current of 1.23 milliamperes per micrometre, an on/off ratio over 10 8 and an intrinsic delay of 74 femtoseconds. These performances outperformed equivalent silicon complementary metal–oxide–semiconductor technologies and satisfied the 2028 roadmap target. We further fabricate large-area device arrays and demonstrate low variability in contact resistance , threshold voltage, subthreshold swing, on/off ratio, on-state current and transconductance 13 . The excellent electrical performance, stability and variability make antimony ( 01 1 ̅ 2 ) a promising contact technology for transition-metal-dichalcogenide-based electronics beyond silicon. The electrical contact of two-dimensional transistors is pushed close to the quantum limit by hybridization of the energy bands with antimony; the contacts have low contact resistance and excellent stability.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: 639/925/357/1018 / 639/925/927/1007 / Antimony / Chalcogenides / Chemical bonds / CMOS / Contact resistance / Electric contacts / Electrical junctions / Electronics / Energy bands / Humanities and Social Sciences / Hybridization / Low dimensional semiconductors / Metals / Molybdenum / Molybdenum disulfide / multidisciplinary / Science / Science (multidisciplinary) / Semiconductor devices / Semiconductor junctions / Silicon / Spectrum analysis / Stability / Threshold voltage / Transistors / Transition metal compounds