| 摘要 |
PROBLEM TO BE SOLVED: To provide a silicon carbide epitaxial wafer and a silicon carbide semiconductor element, in which the crystal quality of an epitaxial growth layer is improved, the lowering of the carrier mobility is prevented even when a thick epitaxial growth layer is formed, and an element resistance is low. SOLUTION: The silicon carbide semiconductor element includes: a substrate in which a dopant, causing reduction of the lattice constant when being doped, is doped in a concentration A; an epitaxial growth layer in which the dopant is doped in a concentration B lower than the concentration in the substrate; and a buffer layer formed to have a multilayer structure comprising at least two layers doped with the dopant between the substrate and the epitaxial layer. When the thickness of the buffer layer is defined as d, the average distance from the epitaxial growth layer to each layer is defined as x, and a predefined ratio is defined as P, the doping concentration C of the dopant in each layer of the multilayer structure satisfies the following formula: [B+(A-B)×x/d]×(1-P)≤C≤[B+(A-B)×x/d]×(1+P). COPYRIGHT: (C)2013,JPO&INPIT |
