Session B37: Focus Session: Graphene Growth, Characterization, and Devices: Devices and Contacts

11:15 AM–2:15 PM, Monday, March 21, 2011
Room: C146

Sponsoring Unit: DMP
Chair: Thomas Seyller, University of Erlanger-Nuernberg

Abstract ID: BAPS.2011.MAR.B37.1

Abstract: B37.00001 : BN / Graphene / BN RF Transistors

11:15 AM–11:27 AM

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  Han Wang

  Thiti Taychatanapat
    (Harvard University)

  Allen Hsu

  Pablo Jarillo-Herrero

  Tomas Palacios

In this work we demonstrate the first BN/graphene/BN transistor for high frequency RF applications. This sandwich structure allows a significant improvement in the mobility of graphene, which reaches more than 18,000 cm$^{2}$/Vs at room temperature. Graphene field effect transistors (GFETs) have been fabricated with L$_{DS}$= 800 nm and L$_{G}$=300 nm. The minimum conduction point of these devices is very close to zero, a result of the negligible substrate doping to the graphene. A current density in excess of 1 A/mm and DC transconductance above 200 mS/mm are achieved for both electron and hole conductions. RF characterization is performed for the first time on this device structure and initial results show a current-gain cut-off frequency $f_{T}$=10 GHz. These experimental results have been combined with simulations of the small-signal model to study the scaling potential of these GFETs for high frequency applications. The impact of the access resistances (R$_{s}$, R$_{d})$, the capacitances (C$_{gs}$, C$_{gd}$, C$_{ds})$, and the transconductance (g$_{m}$) on the frequency performance of the GFETs has also been studied. Finally, the fabricated devices have been compared to GFETs fabricated with SiO$_{2}$ substrate and Al$_{2}$O$_{3}$ gate dielectrics. The improved performance obtained by the BN/graphene/BN structure is very promising to enable the next generation of high frequency RF electronics.

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