Low temperature deposition of dielectric thin films is more and more used in very largescale integrated (VLSI) circuits. For this purpose, distributed electron cyclotron resonance (DECR) plasma appears to be a promising tool. The most interesting feature of this recent plasma is the high ion density (≈1011 cm−3) associated with low electronic temperature (2–3eV) and low energy species (20–30 eV). The purpose of this study is to discuss the effects of the reactant gas mixture composition (O2sol;SiH4) and the rf substrate bias power on the physical, chemical and electrical properties of DECR SiO2 films deposited at floating temperature (<100°C). Under optimum deposition conditions, the films show excellent characteristics, comparable to those obtained with thermal oxides grown at 850–1050°C.