Ion beam induced defects in crystalline silicon

Abstract

A short review of the current understanding and modelling of the formation of ion beam induced defects in crystalline silicon is given in the first part of this article. Some recent experiments on the evolution of {1 1 3} defects formed after Si + implants in CVD grown wafers and on the formation of small clusters in ultra-low energy high-dose B implanted Si are then presented. It is found that, independently of the experimental conditions, {1 1 3} defects evolve in all cases following a non-conservative Ostwald Ripening mechanism. In some cases, {1 1 3} defects have been found to transform into dislocation loops, while in other cases they completely dissolve during annealing. After RTA annealing of ultra-low energy high-dose B + implanted Si, small two-dimensional {1 0 0} loops are formed. Both Si and B atoms are contained in the defects. These results indicate that boron interstitial clusters can be imaged by TEM and thus can be much bigger than generally assumed.