Short-channel graphene nanoribbon transistors with enhanced symmetry between p- and n-branches

Graphene’s unique symmetry between pand n-branches has enabled several interesting device applications; however, short-channel devices often exhibit degraded symmetry. We examine how graphene nanoribbon geometries can improve transfer characteristics and p–n symmetry, as well as reduce Dirac point shift for highly scaled graphene devices. RF graphene transistors utilizing a multiribbon channel are fabricated with channel length down to 100nm, achieving 4.5-fold improved transconductance, 3-fold improved cutoff frequency, and 2.4-fold improved symmetry compared with sheet devices. The improved performance is linked to reduced contact effects by modeling the extent of charge transfer into the channel as a function of graphene width. © 2014 The Japan Society of Applied Physics