Oxidation control of GaAs pHEMTs for high efficiency applications

In this letter, for the first time, an investigation of partially oxidized GaAs-on-insulator (GOI) AlGaAs/InGaAs/GaAs pseudomorphic HEMTs is reported. Fully oxidized pHEMTs demonstrated minimized substrate leakage current and high output impedance, but suffered from 30/spl sim/40% charge loss. Fully oxidized devices also showed transconductance peaking that could be removed by controlled partial oxidation. Partially oxidized pHEMT devices showed improved power added efficiencies (PAEs) at a low supply voltage of 3.0 V compared to fully oxidized or unoxidized devices and negligible charge loss (<10%).