Top-Gated Monolayer MoS₂ Transistors on Growth Substrate by One-Step Integration of High-κ Dielectrics and Low-Resistance Bilayer Contacts.

Abstract

Fabricating top-gated transistors of 2D semiconductors directly on growth substrates holds promise for unlocking their full potential, yet faces challenges in integrating dielectrics and high-quality contacts. Here, we report top-gated monolayer MoS₂ (ML-MoS₂) transistors directly on sapphire growth substrate via plug-and-probe one-step integration of high-κ dielectrics and low-resistance bilayer contacts. Leveraging ML-MoS₂ grown on high-step-density sapphire, contact electrodes, high-κ dielectrics, and gate electrodes are predeposited sequentially. The entire stack is then transferred onto another as-grown ML-MoS₂, yielding top-gated transistors with atomically clean, sharp interfaces. Notably, the strong metal-MoS₂ interfacial interaction drives transfer of the underlying ML-MoS₂ with electrodes, forming low-resistance bilayer contacts. The resulting top-gated ML-MoS₂ transistors show superior performance, including low contact resistance of ∼1.6 kΩ·μm, high on/off ratio of ∼10⁸, mobility of ∼42.9 cm²·V^-1·s^-1, and on-state current of ∼22.4 μA/μm. Furthermore, functional logic gates (inverters, NOR and NAND gates) are constructed, verifying the feasibility of this plug-and-probe approach.