Investigation of TiO2 on AlGaAs prepared by liquid phase deposition and its application

The study explored titanium dioxide (TiO2) on aluminum gallium arsenide (AlGaAs) prepared by liquid phase deposition (LPD) at 40 °C. The leakage current density was about 8.4 × 10−6 A/cm2 at 1 MV/cm. The interface trap density (Dit) and the flat-band voltage shift (ΔVFB) were 2.3 × 1012 cm−2 eV−1 and 1.2 V, respectively. After rapid thermal annealing (RTA) in the ambient N2 at 350 °C for 1 min, the leakage current density, Dit, and ΔVFB were improved to 2.4 × 10−6 A/cm2 at 1 MV/cm, 7.3 × 1011 cm−2 eV−1, and 1.0 V, respectively. Finally, the study demonstrates the application to the AlGaAs/InGaAs metal–oxide–semiconductor pseudomorphic high-electron-mobility transistor (MOS-PHEMT). The results indicate the potential of the proposed device with a LPD-TiO2 gate oxide for power application.

► The paper exhibits the possibility of the TiO2 on AlGaAs prepared by LPD. ► The properties of LPD-TiO2 can be improved after suitable thermal annealing. ► The subthreshold swing and the gate leakage current are improved for the MOS-PHEMT. ► The results indicate the potential of the MOS-PHEMT for power application.