Towards mm-Wave Nanoelectronics and RF Switches Using MoS2 2D Semiconductor

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 MoS2 RF FETs with an intrinsic fT of 20 GHz, intrinsic fmax of 11.4 GHz, and the high-field saturation velocity vsat of 1.88×10⁶ cm/s. The gate-first process allows for enhancement mode operation, ION/IOFF ratio of 10⁸, and a transconductance (gm) of 70 µS/µm. 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 ~5 Ω 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.