This article demonstrates the growth of silicon dioxide(SiO2)on a gallium arsenide (GaAs) substrate by use of the liquid phase deposition (LPD) method at extremely low temperature(∼40 °C).This method cannot only growSiO2but it can also obtain good quality and reliability due to the suppression of interdiffusion in such a low temperature process. The deposition rate ofLPD-SiO2on GaAs is up to 1265 Å/h. The refractive index of theLPD-SiO2film on GaAs is about 1.42 with growth at 40 °C. When theLPD-SiO2film on the GaAs substrate is used to fabricate a metal–oxide–semiconductor capacitor with a device area of0.3 cm2,the surface charge density(Qss/q)is about3.7×1011 cm−2and the leakage current is 43.3 pA at−5 V.A proposed mechanism for the LPD ofSiO2on GaAs is also presented. ©1997 American Institute of Physics.