Al0.2Ga0.8As/In0.15Ga0.85As MOSPHEMT with low temperature LPD-deposited Al2O3 as gate dielectric

Abstract A high breakdown voltage and a low gate leakage current Al 0.2 Ga 0.8 As/In 0.15 Ga 0.85 As metal–oxide–semiconductor–pseudomorphic high-electron mobility transistor (MOSPHEMT) with low temperature and low-cost liquid-phase-deposition (LPD) process are reported for the first time. The LPD-deposited 15 nm thin Al 2 O 3 layers are used as gate insulator. The fabricated devices achieved peak extrinsic transconductance ( g m ) value at gate bias ( V GS ) of 0 V for single power supply amplifier application. The fabricated 2 × 100 μm 2 devices exhibited a peak g m of 161 mS/mm, a threshold voltage of −1.2 V, and a drain-to-source current ( I ds ) of 310 mA/mm. These characteristics demonstrate that the LPD-deposited Al 0.2 Ga 0.8 As/In 0.15 Ga 0.85 As MOSPHEMTs have potential for microwave power device applications.