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.

Abstract: The present invention relates to a configuration and in particular a physical vapor transport growth system for simultaneously growing more than one silicon carbide (SiC) bulk crystal. Furthermore, the invention relates to a method for producing such a bulk SiC crystal. A physical vapor transport growth system for simultaneously growing more than one SiC single crystal boule comprises a crucible containing two growth compartments for arranging at least one SiC seed crystal in each of them, and a source material compartment for containing a SiC source material, wherein said source material compartment is arranged symmetrically between said growth compartments and is separated from each of the growth compartments by a gas permeable porous membrane.

Abstract: A method is used to produce a bulk SiC single crystal. A seed crystal is arranged in a crystal growth region of a growing crucible. An SiC growth gas phase is produced in the crystal growth region. The bulk SiC single crystal having a central longitudinal mid-axis grows by deposition from the SiC growth gas phase, the deposition taking place on a growth interface of the growing bulk SiC single crystal. The SiC growth gas phase is at least partially fed from an SiC source material and contains at least one dopant from the group of nitrogen, aluminum, vanadium and boron. At least in a central main growth region of the growth interface arranged about the longitudinal mid-axis, a lateral temperature gradient of at most 2 K/cm measured perpendicular to the longitudinal mid-axis is adjusted and maintained in this range. The bulk SiC single crystal has a large facet region.

Abstract: A bulk AlN single crystal is grown on a monocrystalline AlN seed crystal having a central longitudinal mid-axis and disposed in a crystal growth region of a growing crucible. The bulk AlN single crystal grows parallel to the longitudinal mid-axis by deposition on the AlN seed crystal. The crucible has a lateral crucible inner wall extending in the growth direction. A free space is formed between the AlN crystals and the lateral crucible inner wall. Bulk AlN single crystals and monocrystalline AlN substrates produced therefrom are obtained with only few dislocations, which are substantially distributed homogeneously. Growing crucibles are provided with a crucible lid with a gap formed between an inner growing crucible and the crucible lid through which some of the AlN growth gas phase generated inside the crystal growth region escapes and is deposited on a bottom of an outer growing crucible opposite the lid.

Abstract: A bulk AlN single crystal is grown on a monocrystalline AlN seed crystal having a central longitudinal mid-axis and disposed in a crystal growth region of a growing crucible. The bulk AlN single crystal grows in a growth direction oriented parallel to the longitudinal mid-axis by deposition on the AlN seed crystal. The crucible has a lateral crucible inner wall extending in the growth direction, a free space being provided between the AlN seed crystal and the growing bulk AlN single crystal on the one hand, and the lateral crucible inner wall on the other hand. Bulk AlN single crystals and monocrystalline AlN substrates produced therefrom are therefore obtained with only few dislocations, which furthermore are substantially distributed homogeneously. The growing crucible, inside which the crystal growth region is located, is an inner growing crucible which is arranged in an outer growing crucible.