The technique of point-defect engineering, with excess vacancies produced near to the surface region by MeV Si ion implantation, was applied to form ultra-shallow junctions with sub-keV B implants. Point-defect engineering could reduce boride-enhanced diffusion that dominates the enhanced diffusion of ultra-low energy B implants. Point-defect engineering could further sharpen the dopant profile and enhance B activation. For 1015/cm2, 0.5keV B implantation, B solid solubility was enhanced at 750 to 1000C, with an enhancement factor of 2.5 at 900C. These features had enabled a shallower and sharper box-like B junction achievable by point-defect engineering in combination with ultra-low energy 0.5keV B implantation.

Enhancement of Boron Solid Solubility in Si by Point-Defect Engineering. L.Shao, J.Zhang, J.Chen, D.Tang, P.E.Thompson, S.Patel, X.Wang, H.Chen, J.Liu, W.K.Chu: Applied Physics Letters, 2004, 84[17], 3325-7