A strong influence of ion implantation flux on the accumulation of radiation damage, the so-called dose rate effect, was observed and systematically studied in SiC. The 100keV Si+ ions were implanted into bulk 4H-SiC wafers by using different ion fluxes (1.9 x 1010–4.9 x 1013/cm2s) and keeping the implantation dose constant at 5 x 1014 Si+/cm2. The implants were performed both at room temperature and at up to 220C. Rutherford back-scattering spectrometry in the channeling mode using 2MeV He+ ions was employed to measure ion implantation damage profiles in the samples. For the flux interval used the most, pronounced dynamic annealing effect was detected at 80–160C, having an activation energy of 1.3eV. For example, at 100C the amount of disordered Si atoms at the projected ion range was reduced by a factor of 4 by decreasing the ion flux from 4.9 x 1013 to 1.9 x 1010/cm2s. The results were discussed in terms of migration and annihilation of intrinsic type defects for both the Si and C sub-lattices. In addition, two regions for the damage accumulation – at the surface and at the damage peak for 100keV Si+ ions – were observed.

Dynamic Annealing in Ion-Implanted SiC - Flux versus Temperature Dependence. A.Y.Kuznetsov, J.Wong-Leung, A.Hallén, C.Jagadish, B.G.Svensson: Journal of Applied Physics, 2003, 94[11], 7112-5