The equivalence of vacancy-type damage in ion-implanted Si seen by positron annihilation spectroscopy

The response of the Doppler-broadened annihilation linewidth parameter S to ion dose has been measured using a controllable-energy positron beam for n-type Fz–Si(100) implanted with 120 keV Ge+, 400 keV O+, 200 keV He+, and 450 keV H+ ions. For all ions S increases with dose, indicating the presence of vacancy-type defects. It is found that the maximum S values for the Ge+, O+, and H+ implants can be normalized to one well-defined distribution using values of predicted vacancy concentration from the Monte Carlo code TRIM. This result implies that vacancy-type defects from these three implantations are similar in both structure and interstitial recombination rate. The He+ data do not lie perfectly on the universal distribution; it is suggested that this is a result of defect passivation by the implanted He.