Depth profiling of defects in nitrogen implanted silicon using a slow positron beam

Positron annihilation spectroscopy PAS. has been used to determine the subsurface vacancy profile in Si after implantation with 50 keV nitrogen ions for a range of fluences from 5=1011 to 1=1014 cmy2. The spatial extent of the defect distributions was estimated by employing composite-Gaussian defect profiles in the ROYPROF positron diffusion analysis program. The results are compared with both VEPFIT and TRIM TRansport of Ions in Matter.calculations. q1999 Elsevier Science B.V. All rights reserved