The defects introduced into 4H–SiC by irradiation with various ions were investigated by means of deep-level transient spectroscopy at 100 to 700K. The defects were generated with 60MeV H+ and with 6.7MeV C+ in the fluence range 3.5 x 1011 to 1.5 x 1012/cm2 and 109 to 1010/cm2, respectively. The ion beam cross the entire epitaxial layer and introduce an almost uniform defect concentration. Deep level transient spectroscopy measurements showed the formation of 3 main traps located Ec–0.68eV, Ec–0.98eV and Ec–1.5eV; independently of the irradiating ion. The trap concentration increased linearly with ion fluence suggesting that these traps were associated to the point defects generated by ion irradiation. Surprisingly the determined values of defect production efficiency (defects/eV) depend on the type of ion and they decreased by increasing the elastic energy loss for all the introduced defects. This behavior could be related to the local point defect (vacancies and self interstitials) recombination which was higher in the denser cascade.

Point Defect Production Efficiency in Ion Irradiated 4H–SiC. L.Calcagno, A.Ruggiero, P.Musumeci, G.Cuttone, F.La Via, G.Foti: Nuclear Instruments and Methods in Physics Research Section B, 2007, 257[1-2], 279-82