On the role of nanocavities in suppressing boron transient enhanced diffusion and deactivation in F+ coimplanted silicon

Abstract

An effective and process optimized method to suppress transient enhanced diffusion is proposed. The method presented consists of designing a vacancy-type defect region which effectively blocks the flux of interstitials from the end of range region towards the surface of the substrate. This band of vacancy-type defects is produced by high dose F+ coimplants. We provide a detailed microstructure study of the vacancy-type defect evolution and demonstrate that under optimum conditions, the vacancy-type defects effectively suppress transient enhanced diffusion, boron deactivation, and end of range defects. We also show the process conditions to obtain an effective interstitial barrier without introducing other detrimental diffusion effects.