Assessment of high-frequency performance limits of graphene field-effect transistors
Field effect transistor (FET), radio frequency (RF), carbon nanotube (CNT), intrinsic cut-off frequency, transconductance
ABSTRACT High frequency performance limits of graphene field-effect transistors (FETs) down to a channel length of 20 nm have been examined by using self-consistent quantum simulations. The results indicate that although Klein band-to-band tunneling is significant for sub-100 nm graphene FETs, it is possible to achieve a good transconductance and ballistic on–off ratio larger than 3 even at a channel length of 20 nm. At a channel length of 20 nm, the intrinsic cut-off frequency remains at a few THz for various gate insulator thickness values, but a thin gate insulator is necessary for a good transconductance and smaller degradation of cut-off frequency in the presence of parasitic capacitance. The intrinsic cut-off frequency is close to the LC characteristic frequency set by graphene kinetic inductance (L) and quantum capacitance (C), which is about 100 GHz•μm divided by the gate length.
Tsinghua University Press
Jyotsna Chauhan,Jing Guo, Assessment of high-frequency performance limits of graphene field-effect transistors. NanoRes.2011, 4(6): 571–579