Liquid phase deposition (LPD) was performed to fabricate titanium dioxide (TiO2) on AlGaAs by using ammonium sulfide pretreatment In addition, the study investigated how postoxidation rapid thermal annealing (RTA) affected the LPD-TiO2 on (NH4)(2)S-x-treated AlGaAs. The deposition rate of the as-deposited LPD-TiO2 for the 10 min 5% (NH4)(2)S-x-treated AlGaAs was approximately 126 nm/h. Following the 10 min 5% (NH4)(2)S-x pretreatment and a postoxidation RTA at 350 degrees C for 1 mm, the root mean square value, leakage current density at 0 MV/cm, interface trap density, and flat-band voltage shift were improved to 6.20, 5.64 x 10(-8) A/cm(2), 6A8 x 10(11) cm(-2) eV(-1), and 1.5 V, respectively. (C) 2014 Elsevier B.V. All rights reserved.