| 摘要 |
PURPOSE:To control the first clad layer to a fixed film thickness accurately and easily in manufacturing the semiconductor laser of ridge wave guide type by utilizing the characteristic of etching of AlxGa1-xAs with hot hydrochloric acid. CONSTITUTION:The second clad layer 11, an active layer 12, the first clad layer 13, and a P<+> GaAs layer 14 are formed on a substrate 1 by the molecular ray epitaxial growing method and the like. Here, the first clad layer 13 is composed of a P-Alx'Ga1-x'As layer 13 a and a P-Alx''Ga1-x''As layer 13b (where, x'>0.4, X''<0.45). In case of etching the AlxGa1-xAs with dydrochloric acid, it is not etched under the condition of x>0.45, but etched at speeds proportional to the values of x under the condition of x>0.45. Therefore, first on selective removal of a P<+> GaAs layer 14 with a mask 15 put over a stripe region, or on further etching with hot hydrochloric acid after removal to part of the layer 13a, only the layer 13a is removed, and the film thickness of the clad layer 13 becomes the film thickness of the layer 13b. |
