In this study, we investigate the impact of thermal annealing on the electrical characteristics of epitaxial graphene field effect transistors. Top gated devices were fabricated from graphene obtained on silicon carbide (siC) substrate. Thanks to an annealing at 300 degrees C, the performance of the devices was enhanced by a factor of 90. The maximal transconductance reached significantly high values such as 5300 mu S/mu m at V-D = 3 V. corresponding to a carrier mobility of 2000 cm(2) V-1 s(-1). (C) 2012 Elsevier Ltd. All rights reserved.