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This paper presents the results of electrical performance studies of the newly developed GaAs pHEMT transistors with Al-based metallization of the ohmic and barrier contacts, and fully copper metallization of interconnects, air bridges, and backside. The transistors exhibited a source-drain saturation current of Idss=280 mA/mm and a maximum transconductance of gm=450 mS/mm at Uds=1.5 V. The current cut off frequency for transistors with 600 μm total gate width was 80 GHz at Uds=1.5 V and Ugs=-0.35 V, and the power gain limiting frequency was 100 GHz. Output power at 1 dB gain compression with matched input and output load an impedance was P1db=26 dBm or 670 mW/mm at an efficiency level of about 28% and the transistor gain G=11 dB. Measurements were performed at Uds=8 V, Ids=1/3 of Idss at 12 GHz. The obtained results demonstrate the promise of Al and Cu metallization in the low cost manufacture of microwave transistors and monolithic integrated circuits based on them.