A novel process of room temperature deposition of thin SiO2 film by laser ablation from a c-Si target in a low pressure ( < 5 mTorr) rf oxygen magnetron plasma background was developed. The gas phase reactions which usually dominate in other high pressure reactive ablation processes are suppressed and the energetic particles from the target have good transport to the substrate in the low pressure background. The surface reactions are continuously enhanced after the arrival of Si particles by the high fluxes of oxygen radicals and ions from the steady state magnetron discharge. The deposition of stoichiometric, less disorder, dense, and water free films are demonstrated.