High performance graphene field effect transistors on an aluminum nitride substrate with high surface phonon energy

We demonstrate top-gate graphene field effect transistors (FETs) on an aluminum nitrite (AlN) substrate with high surface phonon energy. Electrical transport measurements reveal significant improvement of the carrier mobility of graphene FETs on AlN compared to those on SiO₂. This is attributed to the suppression of surface phonon scattering due to the high surface phonon energy of the AlN substrate. The RF cut-off frequency of the graphene FET is also greatly increased when the AlN substrate is used. AlN can easily be formed on a Si or SiO₂ substrate using a standard semiconductor process and thus provides a practical way to improve the performance of graphene FETs.