Dresden 2003 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Halbleiterphysik
HL 4: GaN: Bauelemente
HL 4.5: Vortrag
Montag, 24. März 2003, 11:30–11:45, BEY/154
Effect of Transistor Geometry on DC and RF Performance of AlGaN/GaN HEMTs on Silicon Substrate — •Peter Javorka1, Assadullah Alam2, Michel Marso1, Mike Wolter1, Juraj Bernát1, Alfred Fox1, Michael Heuken2, Peter Kordoš1, and Hans Lüth1 — 1Institute of Thin Films and Interfaces-1, Forschungszentrum Jülich, Germany — 2Aixtron AG, Aachen, Germany
AlGaN/GaN HEMTs are extensively studied because of their capability for high-frequency, high-power and high-temperature applications. Beneath SiC and sapphire, silicon has gained a lot of interest as substrate for AlGaN/GaN structures. We have studied the influence of device geometry on DC and RF performance. The gate length of the devices was changed in the range of 0.3 to 0.7µm and the gate width in the range of 100 to 400µm, also source-drain spacing was varied from 2 to 5µm. A peak of drain saturation current of ∼0.95A/mm and an extrinsic transconductance of 148mS/mm were obtained for unpassivated devices with a source-drain distance of 2µm and a gate length of 0.3µm. For this device we evaluated a cut-off frequency of 45GHz and a maximum frequency of oscillation of 22GHz. For two finger devices the ratio fmax/fT decreases with increasing gate width, but an enhancement of the fmax/fT ratio was observed for four finger devices.