BN/Graphene/BN Transistors for RF Applications

TL;DR

This paper presents the first BN/Graphene/BN field effect transistors for RF applications, demonstrating high mobility and promising high-frequency performance suitable for next-generation graphene RF electronics.

Contribution

It introduces a novel BN/Graphene/BN FET structure that preserves graphene's high mobility and demonstrates RF performance metrics for the first time.

Findings

Current density exceeds 1 A/mm

DC transconductance near 250 mS/mm

fT=33 GHz with an fT.LG product of 15 GHz.um

Abstract

In this letter, we demonstrate the first BN/Graphene/BN field effect transistor for RF applications. The BN/Graphene/BN structure can preserve the high mobility of graphene, even when it is sandwiched between a substrate and a gate dielectric. Field effect transistors (FETs) using a bilayer graphene channel have been fabricated with a gate length LG=450 nm. A current density in excess of 1 A/mm and DC transconductance close to 250 mS/mm are achieved for both electron and hole conductions. RF characterization is performed for the first time on this device structure, giving a current-gain cut-off frequency fT=33 GHz and an fT.LG product of 15 GHz.um. The improved performance obtained by the BN/Graphene/BN structure is very promising to enable the next generation of high frequency graphene RF electronics.