In silicon technology it is thought that an electrically activated, ultra-shallow doping layer will be necessary, and it is predicted to reach 10nm in the year 2014. Ion implantation is a useful method, however, defects are also introduced. High-temperature annealing after ion implantation recovers the crystallization of silicon and activates the implanted dopant. However, it is difficult to keep the ultra-shallow dopant profile because of the diffusion of dopant in Si. In this study, ultra-low-energy ion implantation was examined to reduce the damage during implantation process. The lowest sheet resistance of 2.8 kΩ and the shallow dopant layers below 8 nm were achieved at the ion energy of 300 eV.