MODELING OF HIGH-DOSE ION IMPLANTATION-INDUCED DOPANT TRANSIENT DIFFUSION, AND DOPANT TRANSIENT ACTIVATION IN SILICON (BORON AND ARSENIC DIFFUSION)

A phenomenological model is developed that, through an effective diffusivity, describes implantation-enhanced diffusion (IED) of impurity atoms in Si via a dual vacancy-interstitial mechanism. This is a transient diffusion mechanism that applies to the processes of both rapid thermal annealing and conventional furnace annealing of ion implantation (I/I)-induced structural defects, and dopant diffusion and activation. In addition to the conventional diffusion mechanisms the overall model includes the mechanisms of the vacancy-interstitial pair generation by high dose impurity implantation, which causes diffusion enhancement of dopant in silicon, and a ''transient activation'' mechanism of dopant at the initial stage of the annealing process. The models have been implemented and tested in the SUPREM-III1 process simulation program. In addition, I/I-induced damage effect is taken into account, and an algorithm is introduced that monitors damage evolution during thermal treatments. Activation energies and other model coefficients have been fitted for these models, and the resulting simulations are compared against secondary-ion mass spectroscopy profiles.