Magnetron reactive ion etching of GaAs was investigated for the first time in a SiCl4plasma as a function of process parameters such as pressure and power density. The etch rate of GaAs is found to be much faster than the figures reported for conventional (unmagnetized) reactive ion etching. Vertical sidewalls and smooth surface morphology were obtained under the reported experimental conditions. Schottky diodes were fabricated on etched samples to assess the extent of residual damage. The ideality factor and barrier height of the etched samples were found to be close to those of an unetched control sample. The results indicate that SiCl4magnetron etching has promise for use in GaAs device fabrication.