Monocrystalline wafers of 6H-type material were bombarded with He+, C+ and Si+ ions, at temperatures of between 160 and 870K, to fluences ranging from 7.5 x 1017 to 1021/m2. Damage accumulation and its subsequent annealing, at temperatures of up to 1170K, were studied by means of in situ 2MeV He+ Rutherford back-scattering spectrometry and channelling. The defect concentration at the damage peak was observed to increase sigmoidally with increasing ion fluence during bombardment at low temperatures. The isochronal recovery of bombardment damage which had been introduced at low temperatures was observed to exhibit an exponential dependence upon temperature. The relative disorder which was accumulated under 550keV C+ ion bombardment, as a function of bombardment temperature, exhibited a significant decrease between 300 and 670K. Bombardment with 550keV Si+ at 180K, to a fluence of 6.0 x 1019/m2, produced an amorphous layer which extended from the surface, to a depth of 0.6µm. The thickness of the amorphous layer decreased linearly, with annealing temperature, up to 870K. At low ion fluences, the defects which were produced by He+ bombardment at 160K were more difficult to anneal out at 300K than those which were produced by Si+ bombardment. This suggested that the trapping of He might inhibit recombination.

Rutherford Backscattering Spectrometry Channelling Study of Ion-Irradiated 6H-SiC. W.Jiang, W.J.Weber, S.Thevuthasan, D.E.McCready: Surface and Interface Analysis, 1999, 27[4], 179-84