| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a highly precise waveguide structure with good control and thereby enable single transverse mode oscillation, by forming a second conductive type first semiconductor layer, whose Al composition ratio is smaller than that of a first conductive type etching stop layer on the etch stopping layer. SOLUTION: Since an etch stopping layer 17 whose Al composition ratio is larger than that of an n-type current blocking layer 12 is formed immediately below the n-type current blocking layer 12, etching of the n-type current blocking layer 12 can be blocked in the etch stopping layer 17. Therefore, it is possible to accurately and uniformly control the etching depth of the n-type current blocking layer 12 and to obtain a waveguide structure which is more precise than a conventional one. A first p-type clad layer 8 whose Al composition ratio is smaller than that of the etch stopping layer 17 is formed immediately below the etching stop layer 17. Since the lower the Al composition ratio is, the is larger the refractive index, therefore, light confinement can be carried out well in this structure. |
