Ultra-shallow P+/N junctions formed by recoil implantation

The concept of recoil implantation is proposed to facilitate fabrication of ultrashallow p(+)/n junctions. In this method, a thin boron film is first deposited onto the Si wafer surface. Then the boron atoms are knocked into the Si substrate by Ge implantation or Ar plasma source ion implantation. Dopant activation and damage removal are achieved via rapid thermal annealing. Preliminary results show the realization of sub-100 nm deep p(+)/n junctions with this technique. Monte Carlo simulations were performed to predict the recoiled boron profiles, and agree well with the experimental results.