Investigation of Ion implantation induced electrically active defects in p-type silicon

We investigated ion implantation induced electrically active defects in p-type silicon using deep level transient spectroscopy (DLTS) and photoconductivity spectroscopy at cryogenic temperatures. Implantation related deep traps in H₂, B¹¹, and P³¹ implanted p-type Si and their recovery under isothermal annealing are described. We observed distinct deep trap levels located in the energy range between 0.25 eV up to 0.53 eV away from the valence band edge, which was either suppressed or eliminated upon thermal annealing below 600degC. Supporting the DLTS results, photoconductivity shows strong recovery of a broad absorption band present near the conduction band edge upon thermal annealing. In this paper, we discuss the origin of the broad photoconductivity absorptions and DLTS emission in Si and their relation to the ion implantation induced damage to the lattice structure.