Current dopant diffusion theory is based on dopant‐point‐defect interaction, and assumes that the number of dopant‐defect pairs is much smaller than the unpaired dopant concentration. In cases where a large number of excess defects are created from implantation damage, this may no longer be a valid assumption. A new derivation of the dopant and defect equations is presented which is valid for any concentration of dopant‐defect pairs.