Abstract: A bulk SiC single crystal is produced by placing an SiC seed crystal in a crystal growth region of a growth crucible, and introducing SiC source material into an SiC reservoir region, and the bulk SiC single crystal is grown on from an SiC growth gas phase by deposition. The growth crucible is surrounded by an insulation that extends rotationally symmetrically and axially towards the central middle longitudinal axis. The insulation has mutually concentric insulation cylinder components and the insulation is notionally divided into insulation ring segments that are in turn notionally divided into volume elements. The insulation cylinder components are selected and positioned relative to one another such that every volume element of the insulation ring segment in question has a volume element density varying by not more than 10% from an average insulation ring segment density of the insulation ring segment in question.

Abstract: A silicon-carbide volume monocrystal is produced with a specific electrical resistance of at least 105 ?cm. An SiC growth gas phase is generated in a crystal growing area of a crucible. The SiC volume monocrystal grows by deposition from the SiC growth gas phase. The growth material is transported from a supply area inside the growth crucible to a growth boundary surface of the growing monocrystal. Vanadium is added to the crystal growing area as a doping agent. A temperature at the growth boundary surface is set to at least 2250° C. and the SiC volume monocrystal grows doped with a vanadium doping agent concentration of more than 5·1017 cm?3. The transport of material from the SiC supply area to the growth boundary surface is additionally influenced. The growing temperature at the growth boundary surface and the material transport to the growth boundary surface are influenced largely independently of one another.