High-Performance Edge-Contact Monolayer Molybdenum Disulfide Transistors
Jiankun Xiao, Xiong Xiong, Xinhang Shi, Shiyuan Liu, Shenwu Zhu, Yue Zhang, Ru Huang, Yanqing Wu
Abstract
Edge contact is essential for achieving the ultimate device pitch scaling of stacked nanosheet transistors with monolayer 2-dimensional (2D) channels. However, due to large edge-contact resistance between 2D channels and contact metal, there is currently a lack of high-performance edge-contact device technology for 2D material channels. Here, we report high-performance edge-contact monolayer molybdenum disulfide (MoS 2 ) field-effect transistors (FETs) utilizing well-controlled plasma etching techniques. Plasma etching with pure argon improves the edge dangling bonds and thus improves the edge-contact quality. Edge-contact monolayer MoS 2 FET shows good ohmic contact even at cryogenic temperatures (20 K), achieving a record-low contact resistance ( R c ) of 1.25 kΩ·μm among all edge-contact MoS 2 devices. The record-high on-state current of 436 μA/μm and transconductance of 123 μS/μm at V ds = 1 V are achieved on an edge-contact monolayer MoS 2 FET with L ch = 120 nm. This work highlights the great potential of edge contacts for high-performance monolayer transition metal dichalcogenide (TMD) material electronics.