The kinetics of ion-enhanced etching reactions have been investigated by exposing a silicon sample to coincident beams of Cl2 and modulated Ar+ ions. The distribution and time-dependent emission of neutral products were measured by mass spectrometry for a range of Ar+ bombardment energies (125–800 eV) and Cl2/Ar+ flux ratios (20–200). SiCl2 and SiCl4 are the primary etching products, and the emission of SiCl4 is enhanced relative to SiCl2 as the bombardment energy is reduced. A model for SiCl2 production incorporating a surface residence time and an emission temperature greater than that of the sample is consistent with data acquired for three flight path lengths. SiCl4 is emitted with a thermally equilibrated velocity after a residence time that varies from 180 to 300 μs over the range of ion energies and flux ratios. These results suggest that physical sputtering plays only a minor role in the kinetics of ion-enhanced etching.