Top-Gated Epitaxial Graphene FETs on Si-Face SiC Wafers With a Peak Transconductance of 600 mS/mm

In this letter, we present state-of-the-art performance of top-gated graphene n-FETs and p-FETs fabricated with epitaxial graphene layers grown on Si-face 6H-SiC substrates on 50-mm wafers. The current-voltage characteristics of these devices show excellent saturation with on-state current densities (I
_on
) of 0.59 A/mm at V
_ds
= 1 V and 1.65 A/mm at V
_ds
= 3 V. I
_on
/I
_off
ratios of 12 and 19 were measured at V
_ds
= 1 and 0.5 V, respectively. A peak extrinsic g
_m
as high as 600 mS/mm was measured at V
_ds
= 3.05 V, with a gate length of 2.94 ¿m. The field-effect mobility versus effective electric field (E
_eff
) was measured for the first time in epitaxial graphene FETs, where record field-effect mobilities of 6000 cm
²
/V·s for electrons and 3200 cm
²
/V·s for holes were obtained at E
_eff
~ 0.27 MV/cm .