A novel surface kinetic model using translating mixed-layer representation was proposed and demonstrated. In this model, a translating mixed layer was constructed where the total number of atoms is conserved as the etching or deposition proceeds, to have a convection or movement flux from or to the substrate volume (the volume under the translating mixed layer) that corresponds to the difference between the adsorption flux and removal flux. The model is demonstrated for silicon etching with chlorine chemistry and silicon oxide etching with fluorine chemistry, with results agreeing well with measured data, as well as with previously developed Monte Carlo simulation results. The computation speed of the translating mixed-layer model was 100-10 000 times faster than that of Monte Carlo simulation. (c) 2006 American Vacuum Society.