DOPED POLYCRYSTALLINE SIC WAFER WITH IMPROVED FLATNESS AND ELECTRICAL CONDUCTIVITY, AND METHOD FOR PRODUCING SUCH A WAFER

• Main Authors: FERRATO, Marc, POTIER, Alexandre, BOMMIER, Christophe
• Format: Patent
• Language: English; French
• Published: 29.08.2024
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CRYSTAL GROWTH; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

The invention relates to a wafer made of polycrystalline SiC that has a preferred crystal orientation, this wafer being characterised in that, on each of the faces thereof: (i) the C422 texture coefficient thereof is less than 40%; and (ii) the C220 + C200 + C400 texture coefficient thereof is greater than 50% and preferably greater than 80%. This wafer can be produced by means of a CVD method. The thus-obtained rough blank can be thinned by means of grinding and polishing. The flatness, electrical conductivity and thermal conductivity thereof, which are important properties for a microelectronic substrate, can be improved by heat treatment. Plaque en SiC polycristallin présentant une orientation cristalline préférentielle, ladite plaque étant caractérisée en ce que sur chacune de ses faces : (i) son coefficient de texture C422 est inférieur à 40 %, et 5 (ii) son coefficient de texture C220 + C200 + C400 est supérieur à 50 %, et de préférence supérieur à 80 %. Cette plaque peut être fabriquée par un procédé de CVD. L'ébauche brute ainsi obtenue peut être amincie par rectification et polissage. Sa planéité, sa conductivité électrique et sa conductivité thermique, qui sont des propriétés importantes en vue d'une utilisation comme 10 substrat en microélectronique, peuvent être améliorées par un traitement thermique.