RF Performance Projections of Graphene FETs vs. Silicon MOSFETs

A graphene field-effect-transistor (GFET) model calibrated with extracted device parameters and a commercial 65 nm silicon MOSFET model are compared with respect to their radio frequency behavior. GFETs slightly lag behind CMOS in terms of speed despite their higher mobility. This is counterintuitive, but can be explained by the effect of a strongly nonlinear voltage-dependent gate capacitance. GFETs achieve their maximum performance only for narrow ranges of V DS and I DS , which must be carefully considered for circuit design. For our parameter set, GFETs require at least μ = 3000 cm 2 V −1 s −1 to achieve the same performance as 65 nm silicon MOSFETs.