Silicon-dioxide (SiO2) growth on an indium-phosphide (InP) substrate by use of room-temperature (similar to30degreesC) liquid-phase deposition (LPD) is demonstrated. The produced LPD-SiO2 is of good quality and reliability because of the suppression of interdiffusion by use of relatively low temperatures. Because LPD is difficult without residual OH on the substrate, an InP surface rich in hydroxyls (In-OH) is created by pretreating the wafer substrate in a (29% NH4OH:H2O2 = 1:1) solution. The LPD-SiO2/InP is used to fabricate a metal-oxide semiconductor (MOS) capacitor with a device area of 1.12 X 10(-4) cm(2), yielding a leakage-current density of 8.1 X 10(-8) A/cm(2) at 3 MV/cm. A mechanism for the LPD deposition Of SiO2 on InP is also presented.