The influence of HCl on the oxidation-enhanced diffusion of boron and arsenic in silicon has been studied. Experimental data at 1000, 1100, and 1150 °C were obtained using secondary ion mass spectrometry (SIMS). A previously proposed empirical model was used in analyzing the impurity profiles, and the parameters of this model were determined by matching the computer simulations of dopant diffusion with the SIMS profiles. The dependence of the model parameters on temperature and HCl concentration is discussed.