Abstract: A method has been developed for the removal of silicon nitride and silicon dioxide, or other semiconductor materials from a surface of a wafer or CVD reactor. The method uses NF.sub.3, mixed with an electropositive diluent, preferably argon, at a given range of concentration, pressure, flowrate, and power to obtain the fastest possible etch rates. The etch rates of the film being processed can be caused to increase even as the concentration of NF.sub.3 in the diluent is decreased by choosing the proper diluent and operating conditions. Not only does this method increase the etch rate, thereby increasing the throughput of the reactor using this process, it also accomplishes this task at low concentrations of NF3 resulting in a lower cost.