The process whereby CVD films are etched in acidic fluoride solutions has been investigated at 25° and 60°C by use of a series of well‐characterized etchants. The rate law for the dissolution process has been identified and is found to be linear in both and , but independent of [F−]. Although the exact magnitude of the etch rates of CVD is known to depend on the deposition conditions used, it is thought that the general form of the rate law will remain constant. Comparison between the rate constants for and those previously reported for suggests that the etch rate of can be increased relative to that of by use of elevated temperatures and very low pH solutions, and by adjustment of the nitride deposition parameters so as to increase the ratio in the reaction mixture.