| 摘要 |
PROBLEM TO BE SOLVED: To reduce cost of a semiconductor laser device and to improve reliability thereof by narrowing the width of a current introduction region formed on a first clad layer in the middle the thickness of the layer, thereby making the current introduction width narrower than the waveguide width of the laser beam. SOLUTION: On a substrate 1 are laminated a clad layer 9, an active layer 8, a first clad layer 7, an etching stop layer 6, an AlGaInP graded second clad layer 5, and a heterobuffer layer 3. An Al composition of the second clad layer 5 is graded in the direction of thickness of the layer, the Al composition increases linearly near the active layer 8 and decreases linearly near the interface of the etching stop layer 6. Next, a SiO2 film 31 laminated on the growth surface is removed, such that a stripe of SiO2 film 31 having 5 μm remains, and the second clad layer 5 is etched with a bromide-based etching liquid with the remaining SiO2 film 31 as a mask. This makes the second clad layer 5 narrow in the middle the width of the second clad layer 5, for example, is 4 μm at the bottom and 2.5 μm at the narrow portion. |
