Thermal Evolution of Extrinsic Defects in Ion Implanted Silicon: Current Understanding and Modelling

摘要

In this paper, we present an extensive study of the thermal evolution of the extended defects found in ion implanted Si as a function of annealing conditions. Quantitative analysis of their thermal behaviour has been performed by Transmission Electron Microscopy (TEM). This study shows that the defect kinetics can be described by an Ostwald ripening process whereby the defects exchange Si atoms and evolve in size and type to minimise their formation energy. The relative stability of these different families can be explained considering the Ostwald ripening of 4 main types of defect eventually in presence of strong sinks or sources. Finally, we present a physically based model to predict the evolution of extrinsic defects during annealing. It makes use of the combined physical concepts of non-conservative Ostwald ripening and defect formation energy and calculates the time evolution of defect densities, size distributions, number of clustered interstitials and free-interstitial supersaturation. We have tested our model against some classical experiments concerning the dissolution of {113} defects.