The effects of sample temperature and reactant flow rate on aluminum etching in BBr3and BBr3/Br2mixtures were investigated in a parallel‐plate plasma etcher. Etch samples were bonded to the electrode with conductive epoxy to promote thermal equilibrium. Results indicated that the reaction was gas phase controlled between 30 and 140 °C; above 140 °C, the gas phase limitation may be due to reactant adsorption while a product desorption limitation may exist below 30 °C. Transport limitations were encountered at reactant flow rates below 10 sccm.