AlGaN/GaN HEMTs on
Silicon Carbide Substrates for Microwave Power Operation
Richard Lossy 1 ,
Nidhi Chaturvedi 1 , Peter Heymann 1 , Klaus Köhler 2 ,
Stefan Müller 2 and
Joachim Würfl 1
1 Ferdinand-Braun-Institut
für Höchstfrequenztechnik, Albert-Einstein-Straße 11, 12489 Berlin, Germany 2
Fraunhofer-Institut für Angewandte Festkörperphysik, Tullastraße 72, 79108
Freiburg, Germany
Phone: +49 30
63922630 Fax: +49 30 63922685 e-mail: lossy@fbh-berlin.de
Keywords: Gallium nitride, HEMT, power semiconductor
Abstract
Results from technology and
microwave characterization of large periphery Al-GaN/ GaN power HEMTs on
insulating SiC substrates are presented. The influence of processing steps on
device performance is discussed. DC characteristics reveal current densities
above 1.2 A/mm and extrinsic trans-conductances of 275 mS/mm. A power density
of 5.2 W/mm @ 2 GHz is obtained for devices up to 2 mm gate width. The maximum
power level achieved on-wafer is 13.8 W @ 2 GHz for 4 mm wide devices. A hybrid
amplifier using packaged 4 mm devices delivers 15.1 W.