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).
