Silicon dioxide was deposited from tetraethylorthosilicate (TEOS) and remote microwave oxygen plasma on a heated silicon substrate in a cold-wall reactor. The deposition rate and film quality were examined as functions of substrate temperature, total pressure, absorbed plasma power and O2:TEOS flow ratio. The deposition reaction exhibited an activation energy of approximately 10 kJ/mol for substrate temperatures in the range of 323-623 K. The deposition rate reached a maximum with increasing total pressure. The rate was found to be a near-linear function of the absorbed microwave power. At fixed absorbed power the rate reached a maximum with increasing O2:TEOS flow ratio. A one-dimensional mathematical model was developed to predict the oxygen radical concentration at the exit of the afterglow region of the oxygen discharge. Comparisons of the predicted oxygen radical concentrations with the deposition rates at corresponding deposition conditions supports the view that the overall SiO2 deposition reaction is largely controlled by the concentration of oxygen radicals. The average refractive index of the deposited films was 1.466±0.011. Fourier transform infra-red (FTIR) transmission spectra showed significant concentrations of hydroxyls in the deposited films.