Coincidence Doppler broadening positron annihilation spectroscopy in defects of silicon and iron

Coincidence Doppler broadening (CDB) method in positron annihilation spectroscopy has been applied to chemical state analysis of the defects in silicon and iron implanted with O+ 2 x 10(15)/cm(2) at 180 keV and Cu+ 1 x 10(15)/cm(2) at 140 keV, respectively. Oxygen implantation to Si followed by annealing leads to the formation of vacancy-oxygen complexes. In combination with lifetime measurement, it has been found that V6O2 complexes are formed by annealing at 600degreesC and transformed into V10O6 at 800degreesC. In Cu ion implantation to Fe, it has been directly proved that vacancies and Cu atoms aggregate and our measurements suggest that the inner wall of the grown-up defect is covered with Cu atoms. (C) 2003 Elsevier Science Ltd. All rights reserved.