Damage introduced into the Si substrate by ion-implantation can have a profound effect on the diffusion of dopants during rapid thermal annealing (RTA) or low temperature furnace annealing. In this paper defect production models are discussed for three cases: 1) low dose B+ implants, 2) B+ implants into preamorphized Si, and 3) BF2+, As+ and P+ self-amorphizing implants. Enhanced diffusion transients of dopants are related to the annealing of point-defect clusters, end-of-range dislocations and projected range misfit dislocations. Diffusion activation energies are reduced by the formation enthalpies of point defects generated by the annealing of implantation-induced damage. © 1989.