The deposition of SiO2 by remote PECVD using microwave activated oxygen species and SiH4 were examined. The deposition rate has been found to be greatly enhanced by reducing the distance between the substrate surface and the end of the supplying nozzle for the plasma excited oxygen species.

The deposition rate decreased with increasing substrate temperature under the condition that the activated oxygen species and SiH4 molecules collide with each other many times. Its activation energy was -0.27 eV.

It has been found that the gas phase reaction caused by the collision is important to obtain high quality films. A SiO2 film with a resistivity larger than 1×1016 Ω·cm was able be obtained with high deposition rates beyond 200 nm/min, at low temperatures below 400°C. The minimum interface state density was 4.3×1010 cm−2eV−1 for a film deposited at 230 nm/min, and 2.0×1010 cm−2eV−1 for a film deposited at 30 nm/min.