Towards mm-wave nanoelectronics and RF switches using MoS2 2D Semiconductor

Abstract

In this paper, we report state-of-the-art large area CVD monolayer MoS2-based RF transistors and RF switches. An embedded gate structure was used to fabricate short channel CVD Mos2Rf FETs with an intrinsic fT of 20 GHz, intrinsic $\mathbf{f}_{\mathbf{max}}$ of 11.4 GHz, and the high-field saturation velocity Vsat of $\mathbf{1.88}\times \mathbf{10}^{\mathbf{6}}\ \mathbf{cm}/\mathbf{s}$. The gate-first process allows for enhancement mode operation, $\mathbf{I}_{\mathbf{ON}}/\mathbf{I}_{\mathbf{OFF}}$ ratio of $\mathbf{10}^{\mathbf{8}}$, and a transconductance $(\mathbf{g}_{\mathbf{m}})$ of 70 $\pmb{\mu} \mathbf{S}/\pmb{\mu}\mathbf{m}$. Also, we use a vertical MIM structure for a RF switch based on CVD Mos2. The device was programmed with a voltage as low as 1 V, and achieves an ON-state resistance of $\sim \mathbf{5}\ \pmb{\Omega}$ and an OFF-state capacitance of ~6 fF. We measured and simulated the RF performance of the device up to 50 GHz and report 0.5 dB insertion loss, 15 dB isolation (both at 50 GHz), and 5 THz cutoff frequency.