Thermal He desorption spectrometry was used to characterize He implantation-induced defects. Samples of 6H-, 4H- and β–SiC were implanted with He using energies ranging from 100 to 3keV and doses ranging from 1013 to 1015/cm2. They were then subjected to ramp annealing at up to 1800K, with a constant heating rate of 10K/s. Two groups of peaks contributed to the desorption spectrum: a low-temperature group centered at 600K, and a high-temperature group centered at 1200K. The evolution of these desorption peaks, with implantation dose and energy, was studied. The first group (at 600K) could be attributed to interstitial He and to clusters of interstitial He. The second group (at 1200K) could be related to He release from He-vacancy clusters. A shift in the latter group, towards higher temperatures with increasing dose, was attributed to He-vacancy clustering in an Ostwald ripening process.

Helium Implantation Defects in SiC - a Thermal Helium Desorption Spectrometry Investigation. E.Oliviero, M.F.Beaufort, J.F.Barbot, A.van Veen, A.V.Fedorov: Journal of Applied Physics, 2003, 93[1], 231-8