| 摘要 |
To provide an epitaxial substrate for electronic devices which can improve vertical breakdown voltage in a Group III nitride electronic device on a conductive SiC single crystal substrate, and to provide a method of producing the same. The epitaxial substrate for an electronic device comprises a conductive SiC single crystal substrate, a buffer as an insulating layer on the SiC single crystal substrate, and a main laminate formed by epitaxially growing a plurality of Group III nitride layers on the buffer; and a lateral direction is a current flow direction. Further, the buffer includes at least an initial growth layer in contact with the SiC single crystal substrate and a superlattice laminate having a superlattice multi-layer structure on the initial growth layer. The initial growth layer is made of a B a1 Al b1 Ga c1 In d1 N (0 ‰¤ a 1 ‰¤ 1, 0 < b 1 ‰¤ 1, 0 ‰¤ c 1 ‰¤ 1, 0 ‰¤ d 1 ‰¤ 1, a 1 + b 1 + c 1 + d 1 = 1) material. Furthermore, the superlattice laminate is configured by alternately stacking a first layer made of a B a2 Al b2 Ga c2 In d2 N (0 ‰¤ a 2 ‰¤ 1, 0 ‰¤ b 2 ‰¤ 1, 0 ‰¤ c 2 ‰¤ 1, 0 ‰¤ d 2 ‰¤ 1, a 2 + b 2 + c 2 + d 2 = 1) material and a second layer made of a B a3 Al b3 Ga c3 In d3 N (0 ‰¤ a 3 ‰¤ 1, 0 ‰¤ b 3 ‰¤ 1, 0 ‰¤ c 3 ‰¤ 1, 0 ‰¤ d 3 1, a 3 + b 3 + c 3 + d 3 = 1) material having a different band gap from the first layer. Characteristically, at least one of the superlattice laminate and a portion of the main laminate on the buffer side has a C concentration of 1 × 10 18 /cm 3 or more. |
