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Thermally-stimulated current (TSC) is presented as a powerful technique for investigation of shallow interface traps in metal-insulator-semiconductor (MIS) structures fabricated on wide bandgap semiconductors. This work highlighted often made mistakes during the characterization of MIS structures with this technique which was originally used for the characterization of the structures on silicon. Accuracy of the results can be significantly improved by the implementation of the proposed methods of analysis. Display Omitted Thermally stimulated current (TSC) measurement of the HfO2/SiO2/SiC MOS structureMethodology of the TSC analysis is discussed for wide-bandgap semiconductors and double dielectrics.Analysis of thermally stimulated current line-shape is not useful for complex MOS structure on wide-bandgap semiconductors.The trap profile is discussed taking into account SiO2/SiC and SiO2/HfO2 interfaces.

In this article an additional annealing step was used to increase the quality of gate dielectric layers on silicon carbide obtained by thermal oxidation. The mixture of POCl3, N2 and O2 gases was used within temperature range of 950 °C–1100 °C. Abnormal oxide growth rate was observed during the annealing process. Significant improvement of trap density was achieved however the best results were obtained for lower range of annealing temperatures (950 °C–1000 °C).

Scandium is introduced into bulk SiC during the physical vapor transport (PVT) growth. SiC crystals grown with different Sc contents (from 0.5 wt% up to 2.5 wt%, added to the SiC source material) are studied. Magnetic properties of SiC doped with scandium during the PVT growth are reported for the first time. The presence of antiferromagnetic interactions between magnetic moments of Sc ions is concluded from the temperature dependence of magnetic susceptibility. Detailed PL spectra of 4H-/6H-SiC:B and 4H-/6H-SiC:Sc crystals are presented. A new energy level of 35–37 meV is found on SiC:Sc samples and its possible assignment to a complex defect, consisting of nitrogen donor and scandium acceptor, is proposed.

SiC crystals grown by a Physical Vapor Transport (PVT) method in the presence of varying Ce impurity contents (from 0.1 wt% up to 2.5 wt%) added to SiC source material are investigated. The presence of the cerium vapor in the growth atmosphere is confirmed by X-ray photoelectron spectroscopy measurements. Different electrical properties of SiC crystals are obtained while use was made of non-oxide (CeSi 2 ) or oxide (CeO 2 ) sources of Ce impurity. The impact of cerium on low concentrations of boron atoms in bulk SiC is reported. Presence of Ce in the vapor stabilizes the growth of the 4H-SiC polytype.

The effect of the presence of CeO2 in the source material on the properties of SiC crystals grown by Physical Vapor Transport (PVT) method is investigated. The doping efficiency and, indirectly, the presence of the cerium vapour in the growth atmosphere were examined by study of structural, electrical and optical properties of the crystals. X-ray photoelectron spectroscopy shows that Ce2O3 and CeO2 coexist on the SiC post-growth surfaces. A detectable Ce incorporation is observed only in the last grown part of the crystal.

In this work results of nitrogen doping in the amount of 0 vol.%, 3 vol.% and 10 vol.% on the growth of the 4H polytype on the 6H-SiC seed are presented. SiC crystals grown by PVT method on the (000-1) C-face of 6H seeds using the open seed backside design have been investigated. Structural and electrical properties of the crystals were studied by different experimental methods.

A set of single crystal growth experiments was performed in the new resistively heated two-heater furnace, which plays the role of an induction furnace with a moving coil. In this new experimental setup we are able to control the shape of the crystallization front, from flat to extremely convex. The positive results of the experimental tests differ significantly from prior discouraging interpretation of computational modeling results obtained by a commonly used software, previously presented in the literature. The essence of a new regulation of the temperature field during the crystal growth is a displacement of the maximum of the temperature field, which at the beginning of the growth is located close to the seed and it moves towards the source material as the crystal length increases. In this way, the crystallization front is heated with a similar intensity regardless the increasing crystal length.

In this work we present the growth of 4H-SiC crystals (2 inch in diameter) on the 8° off- axis C-face 6H-SiC seeds, inclined toward [11-20] direction. The growth of crystals by physical vapour transport method (PVT) was realized with the open seed backside in the experimental setup with graphite resistive heater. Some of the crystals were doped with cerium in the purpose of the 4H polytype growth stabilization. For Ce-doped crystals the seed backside carbonization process was decreased in comparison with such effect observed in the undoped SiC crystals.

Results of vanadium doping in PVT SiC bulk growth by the use of the seeding technique with an open seed backside are shown. Structural and electrical properties of 4H and 6H-SiC:V were investigated by a variety of experimental methods. In the crystal studied, the solubility limit of V in SiC was exceeded and structural defects consisting of V-rich precipitates occured. Electrical properties of this crystal were determined by the V3+/V4+ acceptor level. The V3+ charge state of vanadium was formed by compensating shallow donors (mainly nitrogen) and for both 4H and 6H polytypes it was detectable in optical absorption (in the near-IR range) and electron paramagnetic resonance.

4H-SiC single crystals grown by the seeded physical vapour transport method have been investigated. These crystals were grown on 6H-SiC seeds. The influence of the seed temperature, form and granulation of SiC source materials on the stability and efficiency of the 4H polytype growth have been investigated. A new way of the seed mounting - with an open backside - has been used. Crystals obtained were free of structural defects in the form of hexagonal voids. The crystalline structure of SiC crystals was investigated by EBSD (Electron Backscatter Diffraction) and X-Ray diffraction methods. Moreover, defects in crystals and wafers cut from these crystals were examined by optical, scanning electron and atomic force microscopy combined with KOH etching.

n- and p-type 6H-SiC single crystals grown by PVT method using different charge materials – poly-SiC sinter or fresh SiC powder – have been studied. An open or closed seed backside during the growth processes have been applied. In the former, a distinct decrease backside etching of the seed was observed. Crystals have been extensively characterized with respect to their purity, quality and electrical properties using complex experimental methods. For the n-type boule an axially and radially homogeneous resistivity ~0.11 cm at 300 K was observed. Electrical properties of the p-type crystal, i.e., high room-temperature resistivity of 239 cm, were affected by compensation effects between residual donors (nitrogen and oxygen) and acceptors (mainly boron).

An effect of electron irradiation on the concentrations of deep-level centers in C-rich and Si-rich 6H-SiC wafers is investigated. In the former material, the main deep-level centers with activation energies of Ec-0.50, Ec-0.64 and Ec-0.67 eV are found to be related to dicarbon interstitials and CiNC complexes located in hexagonal and quasi-cubic lattice sites, respectively. In the latter material, the dicarbon interstitials are dominant after the irradiation with 1.5-MeV electrons. At the energy of bombarding electrons equal to 0.3 and 0.7 MeV, the activation energies of the dominant deep-level centers are Ec-0.38 and Ec-0.52 eV, respectively. The first center is related to carbon vacancies and the second to silicon interstitials.

The results of investigation of structural and electrical properties of bulk SiC crystals, which were grown by physical vapor transport method with di erent Ce impurity content added to the SiC source material, are presented. The gradual dosage of cerium from the SiC source and continuous presence of the cerium vapor over the SiC crystallization fronts during the crystal growth processes are con rmed. The cerium in uences the overall concentration of structural defects. The increase of the concentration of both, donors and acceptors, and appearance of new shallow donors (15 32 meV) in 4H-SiC crystals are observed.