Positron annihilation studies of long range effect in Ar, N and C ion-implanted silicon

The thermal evolution of defects inside and beyond the implantation layer in Si wafer exposed to the irradiation with 25 keV C+, N+ and Ar+ ions with different doses has been investigated by positron beam measurements. Two types of defects were detected: the small cavities and divacancies in the implanted layer which thickness corresponding to the projectile range. Cavities were only present for dose 2*1016 and were not observed for 2*1014 and 2*1015 ions/cm2. For the dose of 2*1016 ions/cm2 the defects were detected also beyond the implantation layer indicating the presence of the long range effect. Obtained results indicate on influence of ion type and dose on defect distribution and its thermal evolution beyond the implanted layer. The recovery process was similar for Ar+ and N+ but differ for C+ ion implantation.