When high energy heavy ions bombard a single crystal, such as MeV Si implantation in Si, the surface region became vacancy-rich, while interstitials were mostly distributed near the range of the implants. It was demonstrated that vacancies retarded, while interstitials enhanced, B thermal diffusion in Si. Experimental results on the modification of B diffusivity by point defect engineering were considered, including its application in ultra-shallow junction (10nm) formation. Cluster ions, such as GeB and SiB, implantation in Si, and 2-stage annealing were used for forming ultra-shallow junction in Si.

The Point Defect Engineering Approaches for Ultra-Shallow Boron Junction Formation in Silicon. W.K.Chu, J.R.Liu, X.Lu, L.Shao, X.Wang, P.Ling: Nuclear Instruments and Methods in Physics Research B, 2002, 190[1-4], 34-9