| 摘要 |
PROBLEM TO BE SOLVED: To prevent n type impurities from diffusing to an active layer and suppress a deterioration of crystallinity of the active layer, by a method wherein carrier concentration on a side of the active layer of an n type clad layer is non-doped or set to a specific value, and the carrier concentration on a reverse side of the active layer is set into a specific range. SOLUTION: The flux of dopant gas introduced during epitaxial growth of an n type layer 3 is lessened gradually. Thus, carrier concentration on a side of a buffer layer 2 of the n type clad layer 3 is set to 7×10<17> -7×10<18> cm<-3> , and the carrier concentration on a side of an active layer 4 is set to 5×10<17> cm<-3> or less. As described above, the carrier concentration on a side of the active layer 4 of the n type clad layer 3 is formed low, so that diffusion of n type dopant in the case where another semiconductor layer is epitaxially grown is prevented, and a deterioration of crystallinity is not caused in the active layer 4 and in an interface between the active layer 4 and the n type clad layer 3. |
