The electrical properties of high-purity 4H–SiC epitaxial layers were investigated. The current density versus applied voltage curves showed that some specimens had space charge limited transport behavior. Lampert–Mark model for trap-controlled electron transport in semi-insulating materials demonstrated the presence of an intra-gap state at 0.26eV below the conduction band. Photo-deep level transient spectroscopy had confirmed the presence of a deep level at about 0.3eV below the conduction band only in samples with non-Ohmic behavior. Cathodoluminescence imaging had revealed the presence of high luminescent areas related to stacking faults under the devices showing non-ohmic behavior. The presence of single-layer stacking faults was detected by cathodoluminescence spectroscopy due to the typical emission at 2.95eV. Thus, it was demonstrated that the stacking faults modified the charge transport from Ohmic conduction to space charge limited conduction of the affected samples.

Effects of Single-Layer Shockley Stacking Faults on the Transport Properties of High-Purity Semi-Insulating 4h–SiC. F.Fabbri, A.Cavallini: Journal of Applied Physics, 2010, 108[1], 013702