In this study, chemical dry etching characteristics of silicon oxide layers were investigated in the F-2/N-2/Ar remote plasmas. A toroidal-type remote plasma source was used for the generation of remote plasmas. The effects of additive N-2 gas on the etch rates of various silicon oxide layers deposited using different deposition techniques and precursors were investigated by varying the various process parameters, such as the F-2 flow rate, the additive N-2 flow rate, and the substrate temperature. The etch rates of the various silicon oxide layers at room temperature were initially increased and then decreased with the N-2 flow increased, which indicates an existence of the maximum etch rates. Increase in the oxide etch rates under the decreased optical emission intensity of the F radicals with the N-2 flow increased implies that the chemical etching reaction is in the chemical reaction-limited regime, where the etch rate is governed by the surface chemical reaction rather than the F radical density. The etch rates of the silicon oxide layers were also significantly increased with the substrate temperature increased. In the present experiments, the F-2 gas flow, the additive N-2 flow rate, and the substrate temperature were found to be the critical parameters in determining the etch rate of the silicon oxide layers. (c) 2006 American Vacuum Society.