Production method and growth arrangement for producing bulk sic single crystal

A method of producing a bulk SiC single crystal by sublimation growth, the method comprising:

• a) prior to a commencement of a growing process, placing at least one SiC seed crystal in a crystal growth region of a growth crucible, and introducing SiC source material into a SiC reservoir region of the growth crucible,
• b) during the growing process, generating an SiC growth gas phase in the crystal growth region by sublimation of the SiC source material and by transporting sublimed gaseous components into the crystal growth region, and growing the bulk SiC single crystal having a central middle longitudinal axis onto the SiC seed crystal by deposition from an SiC growth gas phase;
• wherein:
• c) the growth crucible, prior to commencement of the growing process, is surrounded by an insulation that extends in a rotationally symmetric manner and axially in a direction of a central middle longitudinal axis and that has at least two insulation cylinder components;
• and wherein:
• c1) the at least two insulation cylinder components are in a mutually concentric arrangement with one inside another, and each of the at least two insulation cylinder components has a wall thickness measured in a radial direction;
• c2) the insulation is notionally divided into multiple insulation ring segments arranged successively and axially in the direction of the central middle longitudinal axis;
• c3) each of the insulation ring segments is in turn notionally divided into multiple volume elements arranged alongside one another in a tangential direction;
• c4) each of the insulation ring segments has an average insulation ring segment density measured over respective wall thicknesses of all of the at least two insulation cylinder components;
• and
• c5) the at least two insulation cylinder components, each of which have variances in density in sub-regions, are selected and positioned relative to one another in such a way that every volume element of the insulation ring segment in question has a volume element density varying by not more than 10% from the average insulation ring segment density of the insulation ring segment in question;
• and
• c6) every volume element extends in axial direction over an axial element length which is equal to an axial segment length of the insulation ring segment and is up to 50 mm, in circumferential direction over an outer tangential element length of up to 50 mm, and in radial direction over a sum of all wall thicknesses of the at least two insulation cylinder components.