SILICON CARBIDE SEMICONDUCTOR DEVICE

• Main Authors: NISHIGUCHI TARO, WADA KEIJI, HORII TAKU, HIYOSHI TORU, UCHIDA MITSUAKI
• Format: Patent
• Language: English; Japanese
• Published: 26.03.2020
• 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

To provide a silicon carbide semiconductor device having improved long-term reliability.SOLUTION: A silicon carbide semiconductor device includes: a silicon carbide epitaxial layer including a first impurity region of a first conductivity-type; and a gate insulating film. A groove portion is formed in a surface of the first impurity region, the groove portion extending in one direction along the surface, a width of the groove portion in the one direction being twice or more as large as a width of the groove portion in a direction perpendicular to the one direction, and a maximum depth of the groove portion from the surface being 10 nm or less. Pit portions are further formed in the surface. A maximum depth from the surface of the pit portion is greater than a maximum depth from the surface of the groove portion. The width of the groove portion in the one direction is 50 μm or less. The silicon carbide semiconductor device further includes a silicon carbide substrate. The silicon carbide substrate has a diameter of 150 mm or more.SELECTED DRAWING: Figure 1 【課題】長期信頼性が向上した炭化珪素半導体装置を提供する。【解決手段】炭化珪素半導体装置は、第１導電型を有する第１不純物領域を含む炭化珪素エピタキシャル層と、ゲート絶縁膜とを備える。第１不純物領域の表面には、表面に沿って一方向に延びるとともに、一方向における幅が前記一方向に垂直な方向における幅の２倍以上であり、かつ、表面からの最大深さが１０ｎｍ以下である溝部が形成されている。表面にはピット部がさらに形成されている。ピット部の表面からの最大深さは、溝部の表面からの最大深さよりも大きい。一方向における溝部の幅は、５０μｍ以下である。炭化珪素半導体装置は、炭化珪素基板をさらに備える。炭化珪素基板の直径は、１５０ｍｍ以上である。【選択図】図１