Low temperature grown AlGaAs passivation in GaAs power MESFET

We report on the device performance of a GaAs power MESFET with Low-Temperature-Grown (LTG) Al/sub 0.3/Ga/sub 0.7/As passivation. By combining two technologies, LTG passivation and MOCVD selectively regrown contacts, we were able to fabricate a record performance GaAs power MESFET. On-wafer power measurement of a device yielded a maximum output power of 1 W/mm at 30% power-added-efficiency and a linear gain of 11.5 dB. We have also looked at the current transport across LTG-Al/sub 0.3/Ga/sub 0.7/As as a function of the temperatures to gain insight into its properties.