The effects of ion irradiation defects on the carrier concentration of 6H-SiC epitaxial layer were studied by current–voltage (I–V), capacitance.-voltage (C–V) measurements, thermally stimulated capacitance and deep-level transient spectroscopy. The defects were produced by irradiation with 10MeV C+ at a fluence of 1011/cm2 and subsequent thermal annealing were carried out in the temperature range 500–1700K under an N2 flux. I–V and C–V measurements reveal the presence of a high defect concentration after irradiation and annealing at temperature lower than 1000K. Thermally stimulated capacitance measurements showed that some of the defects induce a deactivation of the N donor, while some of the generated defects, behaving as donor-like traps, contribute to increase the material free carrier concentration at temperatures above their freezing point. Deep level transient spectroscopy measurements performed at 150 to 450K showed the presence of several overlapping traps after ion irradiation and annealing at 1000K: these traps suffer a recovery and a transformation at higher temperatures. The annealing of all traps at temperatures as high as 1700K allows one to completely restore the n-type conductivity. The defects mainly responsible of the observed change in the carrier concentration were identified.

Effects of Implantation Defects on the Carrier Concentration of 6H-SiC. A.Ruggiero, S.Libertino, F.Roccaforte, F.La Via, L.Calcagno: Applied Physics A, 2006, 82[3], 543-7