ABSTRACTWe have implemented an atomistic simulation of the Ostwald ripening of extrinsic defects (clusters, {113}'s and dislocation loops) which occurs during annealing of ion implanted silicon. Our model describes the concomitant time evolution of the defects and of the supersaturation of Si interstitial atoms in the region. It accounts for the capture and emission of these interstitials to and from extrinsic defects (defined by their formation energy) of sizes up to thousands of atoms and includes a loss term due to the interstitial flux to the surface. This model reproduces well the dissolution of {113} defects in Si implanted wafers. We have subsequently studied the characteristics of TED in the case of B implantation at low and ultra low energy. In such cases, the distance between the defect layer and the surface plays a crucial role in determining the TED decay time. The simulations show that defect dissolution occurs earlier and for smaller sizes in the ultra-low energy regime. Under such conditions, TED is mostly characterized by its “pulse” component which takes place at the very beginning of the anneal, probably during the ramping up. In summary, we have shown that the physical modelling of the formation and of the growth of extrinsic defects leads to a correct prediction of the “source term” of Si interstitials and at the origin of TED.