Deciphering Vacancy Defect Evolution of 2D MoS 2 for Reliable Transistors

• Published in: ACS applied materials & interfaces 2023-08, Vol.15 (32), p.38603-38611
• Main Authors: Gao, Li, Zhang, Xiankun, Yu, Huihui, Hong, Mengyu, Wei, Xiaofu, Chen, Zhangyi, Zhang, Qinghua, Liao, Qingliang, Zhang, Zheng, Zhang, Yue
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.3c07806

Two-dimensional (2D) MoS is an excellent candidate channel material for next-generation integrated circuit (IC) transistors. However, the reliability of MoS is of great concern due to the serious threat of vacancy defects, such as sulfur vacancies (V ). Evaluating the impact of vacancy defects on the service reliability of MoS transistors is crucial, but it has always been limited by the difficulty in systematically tracking and analyzing the changes and effects of vacancy defects in the service environment. Here, a simulated initiator is established for deciphering the evolution of vacancy defects in MoS and their influence on the reliability of transistors. The results indicate that V below 1.3% are isolated by slow enrichment during initiation. Over 1.3% of V tend to enrich in pairs and over 3.5% of the enriched V easily evolve into nanopores. The enriched V with electron doping in the channel cause the threshold voltage (V ) negative drift approaching 6 V, while the expanded nanopores initiate the V roll-off and punch-through of transistors. Finally, sulfur steam deposition has been proposed to constrain V enrichment, and reliable MoS transistors are constructed. Our research provides a new method for deciphering and identifying the impact of defects.