During the plasma-enhanced chemical vapor deposition (PECVD) of SiO₂ onto InP, an oxide may grow. This oxide could affect the electrical properties of the SiO₂-InP interface. In this paper we report on the temperature dependence of the growth rate, composition and topography of oxides grown in a PECVD reactor which has a separate plasma chamber. The oxide growth rate in the main chamber was found to be a function of the transfer tube length and was greater than the thermal oxidation rate for T<350°C. The oxide composition was found to be primarily InPO₄ with some In₂O₃ in the thicker layers. The topography varied with processing.