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: 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 for producing an SiC volume monocrystal by sublimation growth. Before the beginning of growth, an SiC seed crystal is arranged in a crystal growth region of a growth crucible and powdery SiC source material is introduced into an SiC storage region of the growth crucible. During the growth, by sublimation of the powdery SiC source material and by transport of the sublimated gaseous components into the crystal growth region, an SiC growth gas phase is produced there. The SiC volume monocrystal having a central center longitudinal axis grows by deposition from the SiC growth gas phase on the SiC seed crystal. The SiC seed crystal is heated substantially without bending during a heating phase before the beginning of growth, so that an SiC crystal structure with a substantially homogeneous course of lattice planes is provided in the SiC seed crystal.

Abstract: A method is used for producing an SiC volume monocrystal by sublimation growth. During growth, by sublimation of a powdery SiC source material and by transport of the sublimated gaseous components into the crystal growth region, an SiC growth gas phase is produced there. The SiC volume monocrystal grows by deposition from the SiC growth gas phase on the SiC seed crystal. The SiC seed crystal is bent during a heating phase before such that an SiC crystal structure with a non-homogeneous course of lattice planes is adjusted, the lattice planes at each point have an angle of inclination relative to the direction of the center longitudinal axis and peripheral angles of inclination at a radial edge of the SiC seed crystal differ in terms of amount by at least 0.05° and at most by 0.2° from a central angle of inclination at the site of the center longitudinal axis.

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.

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 silicon carbide bulk single crystal is produced at a growth temperature of up to 2200° C. by sublimation growth and is subjected to thermal aftertreatment after the sublimation growth. The bulk single crystal is brought to an aftertreatment temperature that is higher than a growth temperature. Very low-stress and low-dislocation SiC substrates can be produced from such a SiC bulk single crystal, the substrates additionally having a particularly low electrical resistivity. The SiC bulk single crystal is positioned within an SiC powder before the thermal aftertreatment and it is completely surrounded by the SiC powder during the thermal aftertreatment.

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.

Abstract: A configuration for producing a bulk SiC crystal includes a growing crucible having an electrically conductive crucible wall, an inductive heating device disposed outside the growing crucible for inductively coupling an electric current, which heats the growing crucible, into the crucible wall, and an insulation layer disposed between the crucible wall and the inductive heating device. The insulation layer is formed of a graphite insulation material having short carbon fibers with a fiber length in a range of between 1 mm and 10 mm and a fiber diameter in a range of between 0.1 mm and 1 mm. A method for producing a bulk SiC crystal is also provided.

Abstract: A method is used for producing a bulk SiC crystal having a resistivity of at least 1012 ?cm and a diameter of at least 7.62 cm. An SiC growth gas phase is generated in a crystal growth region. The bulk SiC crystal grows by deposition from the SiC growth gas phase. The SiC growth gas phase is fed from an SiC source material, which is contained in an SiC supply region inside the growing crucible. First dopants which have a flat dopant level at a distance of at most 350 meV from an SiC band edge, and second dopants which have a low-lying dopant level at a distance of at least 500 meV from the SiC band edge, are delivered in gaseous form to the crystal growth region. Bulk SiC crystals are thereby obtained, and large-area SiC substrates obtained therefrom whose resistivity is at least 1012 ?cm everywhere.