| 摘要 |
PROBLEM TO BE SOLVED: To provide a compound semiconductor substrate which enables improvement in voltage withstanding and quality of a crystal.SOLUTION: A compound semiconductor substrate comprises: a Si (silicon) substrate 1; a SiC (silicon carbide) layer 2 formed on a surface of the Si substrate 1; an AlN (aluminum nitride) layer 3 formed on a surface of the SiC layer 2; composite layers 6a, 6b and 6c formed on a surface of the AlN layer 3; and a GaN (gallium nitride) layer 7 on a surface of the composite layer 6c. The composite layers 6a, 6b and 6c include AlN (aluminum nitride) layers 4a, 4b and 4c and GaN layers 5a, 5b and 5c formed on surfaces of the AlN layers 4a, 4b and 4c, respectively. At least in one of the composite layers 6a, 6b and 6c, average densities of C and Fe in the GaN layer 5a, 5b or 5c are higher than average densities of C and Fe in the AlN layer 4a, 4b or 4c, respectively.SELECTED DRAWING: Figure 1 |
