| 摘要 |
PROBLEM TO BE SOLVED: To realize a high yield and a satisfactory repproducibility in a state of excellent crystallinity by deciding the bulk lattice constant of a first growth layer and the bulk lattice constant of a second growth layer of a lamination structure body to satisfy a specific relation. SOLUTION: A thermal expansion coefficient of a sapphire board 10, for example, is larger than a thermal expansion coefficient of a lamination structure body consisting of a III-V nitride single crystal semiconductor layer. In addition, the bulk lattice constant a1 of a first growth layer 12 and the bulk lattice constant a2 of an Si doped n-type GaN second growth layer 13 satisfy the relation a2<a1<=1.005a2. As a result, the first growth layer 12 generates compressive strain on receiving compression stress at a temperature lower than that of crystal growth, thereby making the lattice constant of in-plane direction (a-axial direction) smaller than the bulk lattice constant of the first growth layer 12 and close to the bulk lattice constant of the second growth layer 13. As a result, lattice strain of the second growth layer 13 is reduced and crystallinity of the second growth layer 13 can be improved. |
