Experimental results were presented which were related to several different intrinsic defects. These included the so-called D1 defect which was created after irradiation and which was temperature-stable. From the optical measurements, it was possible to identify the D1 bound exciton as being an iso-electronic defect bound at a hole attractive pseudo-donor. It was possible to correlate this with the electrically observed hole trap, HS1, seen in minority carrier transient spectroscopy. Finally, the formation and properties of a

critical generated defect in high-power SiC bipolar devices were described. It was identified as being a stacking fault in the SiC basal plane. It could be seen as a local reduction in the carrier lifetime, in triangular or rectangular shape, which explained the enhanced forward voltage drop in the diodes. The entire stacking faults were also optically active, and could be seen as dark triangles and rectangles in low-temperature cathodoluminescence. The fault and their bounding partial dislocations were seen and identified by using synchrotron topography.

Defects in 4H Silicon Carbide. J.P.Bergman, L.Storasta, F.H.C.Carlsson, S.Sridhara, B.Magnusson, E.Janzen: Physica B, 2001, 308-310, 675-9