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

A high breakdown voltage and a low gate leakage current Al0.2Ga0.8As/In0.15Ga0.85As 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 Al2O3 layers are used as gate insulator. The fabricated devices achieved peak extrinsic transconductance (gm) value at gate bias (VGS) of 0 V for single power supply amplifier application. The fabricated 2 × 100 μm2 devices exhibited a peak gm of 161 mS/mm, a threshold voltage of −1.2 V, and a drain-to-source current (Ids) of 310 mA/mm. These characteristics demonstrate that the LPD-deposited Al0.2Ga0.8As/In0.15Ga0.85As MOSPHEMTs have potential for microwave power device applications.