Positron re-emission microscopy in the reflection geometry was used to obtain images of 6H-type materials which had been implanted with 50keV O+ ions, to 1013/cm2, through a micromesh mask. Positrons were re-emitted, from areas which had been exposed to implantation, with an average intensity that was some 85% of that which was characteristic of unimplanted regions. This was a result of trapping by vacancy-type defects which had been created below the surface. The results were consistent with a model which assumed that the positrons were thermalized before re-emission. A comparison with simulations also indicated that post-implantation vacancy migration and coalescence led to a reduction of almost 95% in the open-volume defect concentration in the sub-surface region.

Positron Re-Emission Microscopy of Perfect and O+-Implanted SiC. C.P.Burrows, P.G.Coleman: Journal of Physics - Condensed Matter, 1998, 10[46], 10399-402