A method is presented for determining the minority‐carrier diffusion length and surface recombination velocity in passivated, shallow junction semiconductor devices. The method is particularly useful with devices where the minority‐carrier diffusion length is comparable to the diameter of the electron beam interaction volume. A gaussian beam profile is convoluted with a theoretical model for electron‐beam‐induced current and the results used to determine the minority‐carrier diffusion length from measured data. The surface recombination velocity is estimated from the dependence of the measured minority‐carrier diffusion length on the electron beam accelerating voltage. The technique is applied to a photovoltaic infrared sensor device made in mercury‐cadmium‐telluride.