We demonstrated that formation of sub-10 nm junctions can be realized by the technique of point defect engineering (PDE). The approach was based on the fact that high-energy ion bombardment with silicon can spatially separate the distribution of interstitials and vacancies, with a vacancy-rich region formed near the surface region. Effects of PDE on the boride-enhanced diffusion (BED) were systematically investigated by using boron superlatfices grown by molecular-beam epitaxy. We observed that a high-energy implant provides an effective method to suppress BED. Furthermore, PDE can also (1) increase the stability of highly doped junction, (2) retard boron diffusion to a rate much less than normal diffusion, (3) sharpen the dopant profile, and (4) enhance boron activation. (C) 2004 American Vacuum Society.