SiC EPITAXIAL WAFER AND SEMICONDUCTOR DEVICE

• Main Authors: NISHIO JOJI, SHIMIZU TATSUO, OTA CHIHARU, SHINOHE TAKASHI
• Format: Patent
• Language: English; Japanese
• Published: 26.04.2018
• 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

PROBLEM TO BE SOLVED: To provide a SiC epitaxial wafer capable of reducing the resistance of an impurity layer.SOLUTION: A SiC epitaxial wafer comprises: a 4H-SiC substrate 100; a first p type SiC epitaxial layer 102 including a p type impurity (an element A) and a n type impurity (an element D) in which a combination of the element A and the element D is Al, Ga or In and at least one of N, B and P and a concentration ratio of the element D to the element A is 0.33-1.0; a second n type SiC epitaxial layer 106 provided between the SiC substrate and the first SiC epitaxial layer; and a third p type SiC epitaxial layer 108 provided between the second and first SiC epitaxial layers and having a p type impurity concentration lower than that of the first SiC epitaxial layer. The SiC substrate is a n type and has a n type impurity concentration higher than that of the second SiC epitaxial layer, and the concentration of the element A is 1×10- 1×10cm.SELECTED DRAWING: Figure 10 【課題】不純物層の抵抗を低減したＳｉＣエピタキシャルウェハの提供。【解決手段】４Ｈ−ＳｉＣ基板１００と、ｐ型不純物（元素Ａ）とｎ型不純物（元素Ｄ）を含有し、元素Ａと元素Ｄが、Ａｌ、Ｇａ又はＩｎとＮ、ＢとＰの少なくとも一方の組み合わせで、元素Ｄの元素Ａに対する濃度比が０．３３〜１．０、ｐ型の第１のＳｉＣエピタキシャル層１０２と、ＳｉＣ基板と第１のＳｉＣエピタキシャル層の間に設けられるｎ型の第２のＳｉＣエピタキシャル層１０６と、第２のＳｉＣエピタキシャル層と第１のＳｉＣエピタキシャル層の間に設けられ、ｐ型不純物濃度が、第１のＳｉＣエピタキシャル層より低いｐ型の第３のＳｉＣエピタキシャル層１０８と、を備え、ＳｉＣ基板がｎ型で、ｎ型不純物濃度が、第２のＳｉＣエピタキシャル層より高く、元素Ａの濃度が１×１０１８〜１×１０２２ｃｍ−３であるＳｉＣエピタキシャルウェハ。【選択図】図１０