Low-noise AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor recessed by electron cyclotron resonance plasma etching

GaAs pseudomorphic high electron mobility transistors recessed by electron cyclotron resonance (ECR) plasma etching have been investigated. We used a BCl3/SF6 gas mixture to implement the gate recess process. We obtained a un iformity of the threshold voltage to within 50 mV in 3-inch wafers. The GaA s PHEMTs with a 0.2-mu m gate length recessed by the ECR plasma exhibited a minimum noise figure (NFmin) as low as 0.26 dB with an associated gain (G( a)) of 13 dB at 12 GHz. At 18 GHz, the NFmin was 0.47 dB with a Ga of 11.66 dB. These results suggest that the ECR plasma etching process reported her e is suitable as a manufacturing process for gate recess of a GaAs PHEMT.