MONOCRISTAL DE CARBURE DE SILICIUM DE GRANDE PURETÉ ET DE GRANDE TAILLE, SUBSTRAT, PROCÉDÉ DE PRÉPARATION ET DISPOSITIF DE PRÉPARATION ASSOCIÉS

摘要

The present application discloses a large-sized high-purity silicon carbide single crystal, a substrate and a preparation method thereof, and a preparation device thereof, and belongs to the field of silicon carbide single crystals and substrates thereof. In the present application, by changing a thermal field distribution of a PVT method, and changing the conventional method for creating an axial temperature gradient through heat dissipation with an upper thermal insulation hole, into creating the axial temperature gradient by using different wall thicknesses of the crucible and different thicknesses of the thermal insulation structure, and changing a thermal insulation structure on the upper side of the graphite crucible at a same time, a thermal field structure with a uniform radial temperature distribution is created; especially, the radial distribution of the internal thermal field of the large-sized crucible is uniform; since the electroactive impurity element grows into the crystal along with the temperature gradient, such a thermal field structure with a uniform radial temperature distribution will direct the electroactive impurity element to be uniformly distributed in the radial direction, to further prepare the high-purity semi-insulating silicon carbide single crystal and the single crystal substrate having a uniform radial resistivity and a low stress.