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

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