| 摘要 |
PURPOSE:To control the thickness of a clad layer accurately and to stabilize the lateral mode oscillation conspicuously, by forming a double-heterojunction structure including an upper clad layer by the first crystal growth. CONSTITUTION:On an N-GaAs substrate 1, the following layers are sequentially grown by the first crystal growing: an N-AlGaAs layer 2 as the first clad layer, which forms a double-heterojunction structure; an AlGaAs layer 3; a p-AlGaAs layer 4; and an N-GaAs layer 5 as an intermediate light-absorbing layer. The growing is performed by the liquid phase epitaxial growing method, which can accurately control the film thickness. Etching is performed, and a protruded part 5a having an inverted mesa structure is formed. An N-AlGaAs layer is grown as an upper layer 6. By utilizing the difference in melt-back speed, a groove 9 is formed. A P-AlGaAs layer 7 can be epitaxially grown on the layer 4. The third clad layer 7 and the second clad layer 4 form a unitary body, which operates as the upper clad layer with respect to the active layer 3. A part 5b and a part 6c operate as a current narrowing layer. |
