Impurity–vacancy defects in implanted float-zone and Czochralski-Si

The dual implantation method developed for defect engineering wO.W. Holland, L. Xie, B. Nelson, D.S. Zhou, J. Electron. Mater. 25 1996.99x uses an amorphizing implant in conjunction with high energy Siq-ion implantation to inject vacancies. Following annealing of the implanted samples for 20 min at 6008C and at 8008C, the amorphous layer recrystallizes by solid-phase epitaxial growth SPEG., and the unwanted interstitials are consumed by recombination with vacancies. Doppler broadening of annihilation radiation and beam positron lifetime measurements reveal that there are residual divacancy–impurity complexes formed in the SPEG layer. Since the effect is nearly identical in both float-zone and Czochralski-Si, the source of the impurities is not likely to be residual oxygen in the unimplanted crystals. q1999 Published by Elsevier Science B.V. All rights reserved.