The optimization of contact interface between metal/MoS2 FETs by oxygen plasma treatment

• Published in: Journal of materials science. Materials in electronics Vol. 31; no. 12; pp. 9660 - 9665
• Main Authors: Zhang, Yadong, Jia, Kunpeng, Liu, Jiangtao, Pan, Yu, Luo, Kun, Yu, Jiahan, Zhang, Yongkui, Tian, Hanmin, Wu, Zhenhua, Yin, Huaxiang
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2020; Springer Nature B.V
• Subjects: Atmospheric pressure; Characterization and Evaluation of Materials; Chemistry and Materials Science; Contact resistance; Field effect transistors; Materials Science; Molybdenum disulfide; Molybdenum oxides; Molybdenum trioxide; Optical and Electronic Materials; Optimization; Oxygen plasma; Performance enhancement; Room temperature; Semiconductor devices
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-03511-7

The quality of the contact is key for the performance enhancement of the MoS 2 device. As the oxygen plasma treatment is developed in the fabrication of MoS 2 field effect transistor (FET), we demonstrate that the tunneling layer (MoO 3 ) is formed on the top of the MoS 2 contact region and the process induced organic residues in the source and drain regions is effectively removed. The formation of MoO 3 can degrade the Fermi level pinning effect at the MoS 2 /metal interface and lowering the Schottky barrier height. And the flatness of the interface has been greatly improved, with the roughness reduced from 0.53 to 0.166 nm. In this paper, we improve the device performance with an on-/off-current ratio increase by four orders of magnitude, a mobility increase by 10 times at room temperature and the 33-fold decrease in contact resistance. This research shows that oxygen plasma treatment is a promising method for the integration of MoS 2 FET in the future.