An experimental procedure has been developed which permits accurate short‐time diffusion anneals for diffusion periods as short as a few seconds. This method is applicable to diffusors which are volatile at the diffusion temperature. It will be illustrated for zinc diffusion into silicon which mainly takes place via the kick‐out mechanism. Previous long‐time diffusion studies have yielded the productCeqIDIof equilibrium concentration and diffusivity of Si self‐interstitials(I) involved in the interstitial‐substitutional exchange of Zn. The present short‐time diffusion method enables us to determineCeqIandDIseparately by comparing measured spreading‐resistance profiles with computer simulations based on the kick‐out model.