Towards High-Performance Monolayer Semiconductor Transistors with Semimetallic Ohmic Contact
ORAL
Abstract
Atomically thin two-dimensional (2D) semiconductors have great potential for realizing high-performance electronic devices. However, energy barriers at the metal-semiconductor interface, which fundamentally lead to high contact resistances and poor current-delivery capabilities, have restrained the advancement of 2D semiconductor transistors to date. Here, we report a novel ohmic contact technology between semimetallic bismuth and semiconducting monolayer transition metal dichalcogenides (TMDs) where the gap-state pinning is sufficiently suppressed and degenerate states in the TMD are spontaneously formed in contact with bismuth. Through this approach, we achieve zero Schottky barrier height, a record-low contact resistance (RC) of 123 Ω μm, and a record-high on-state current density (ION) of 1135 μA μm-1 on monolayer MoS2. We also demonstrate that excellent ohmic contacts can be formed on various monolayer semiconductors, including MoS2, WS2, and WSe2. Theoretical investigation show that ION is now limited by the self-heating effect and can be further optimized. This technology unveils the full potential of high-performance monolayer transistors that are on par with the state-of-the-art 3D semiconductors, enabling further device down-scaling and extending Moore’s Law.
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Presenters
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Yuxuan Lin
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley
- Massachusetts Institute of Technology MIT