SiO2 ultrathin and thin films have been deposited on single-crystal Si substrates by means of nonreactive radio frequency magnetron sputtering. The temperature of the substrate and the deposition times have been varied in the range of 200-500 degrees C and 60-14 400 s, respectively. The average deposition rate has a range of 0.5-5 nm/min and tends to decrease with the increase of the substrate temperature. Two different growth regimes may be observed for ultrathin and thin films, the transition taking place in the range of 5-10 nm depending on the substrate temperature. The roughness of the film surface and the grain dimensions do increase with the substrate temperature for short deposition times (t <= 300 s), whereas their behavior is less defined for intermediate ones (300 s < t < 1800 s). Finally, for long deposition times (t > 1800 s) the roughness increases again with T, and its slope is higher, the higher the substrate temperature is. (C) 2007 American Vacuum Society.