| 摘要 |
PROBLEM TO BE SOLVED: To obtain a semiconductor device by which light can be confined in an active layer, in which cracks are hardly generated by a method, wherein the difference between the composition ratio of Al in a substrate and the compositional ratio of Al in a semiconductor is set at a specific value or lower. SOLUTION: The difference between the composition ratio of an n-type AlxGa1-xN (where 0<x<1) substrate 10 and the composition ratio of an n-type clad layer 11 as a first semiconductor layer is made small as possible, from the viewpoint of preventing the generation of cracks. This difference is sufficient, when it is smaller than 0.15. In addition, for example, the difference in the compositional ratio of Al between the n-type AlGaN substrate 10, the n-type clad layer 11 and a p-type clad layer 13 is set at 0.05. Then, the thickness of the n-type clad layer 11 and that of the p-type clad layer 13 can be set respectively at 1.5 μm or higher, so that cracks can be reduced drastically as compared to conventional cases. As a result, light can be confined fully in an active layer 12, and the characteristics of a nitride gallium-based semiconductor light emitting device can be enhanced more than those in conventional cases. |
