Embedded gate CVD MoS 2 microwave FETs

Recent studies have increased the cut off frequencies achievable by exfoliated MoS 2 by employing a combination of channel length scaling and geometry modification. However, for industrial scale applications, the mechanical cleavage process is not scalable but, thus far, the same device improvements have not been realized on chemical vapor deposited MoS 2 . Here we use a gate-first process flow with an embedded gate geometry to fabricate short channel chemical vapor deposited MoS 2 radio frequency transistors with a notable f T of 20 GHz and f max of 11.4 GHz, and the largest high-field saturation velocity, v sat = 1.88 × 10 6 cm/s, in MoS 2 reported so far. The gate-first approach, facilitated by cm-scale chemical vapor deposited MoS 2 , offers enhancement mode operation, I ON / I OFF ratio of 10 8 , and a transconductance ( g m ) of 70 μS/μm. The intrinsic f T ( f max ) obtained here is 3X (2X) greater than previously reported top-gated chemical vapor deposited MoS 2 radio frequency field-effect transistors. With as-measured S -parameters, we demonstrate the design of a GHz MoS 2 -based radio frequency amplifier. This amplifier has gain greater then 15 dB at 1.2 GHz, input return loss > 10 dB, bandwidth > 200 MHz, and DC power consumption of ~10 mW.