The formation of B interstitial clusters was a key limiting factor for the fabrication of highly conductive ultra-shallow doped regions in future silicon-based device technology. Optimized vacancy engineering strongly reduces B clustering, enabling low-temperature electrical activation to levels rivalling what could be achieved with conventional pre-amorphization and solid-phase epitaxial regrowth. An optimized 160keV Si implant in a 55/145nm silicon-on-insulator structure enables stable activation of a 500eV B implant to a concentration ~5 x 1020/cm3.

Vacancy-Engineering Implants for High Boron Activation in Silicon-on-Insulator. A.J.Smith, N.E.B.Cowern, R.Gwilliam, B.J.Sealy, B.Colombeau, E.J.H.Collart, S.Gennaro, D.Giubertoni, M.Bersani, M.Barozzi: Applied Physics Letters, 2006, 88[8], 082112 (3pp)