| 摘要 |
PURPOSE:To make current concentration to an active layer excellent, by providing a block layer, which has a smaller forbidden band width than that of a P- InP light guide layer, different composition from that of the active layer, and a forbidden band width smaller than that of the active layer, as a P-InP block layer. CONSTITUTION:On an N-InP substrate 1, an N-InP light guide layer 2, an undoped or N- or P-In1-xGaxAs1-yPy active layer 3, a P-InP light guide layer 4, and a P-In1-xGaxAs1-yPy cap layer 5 are sequentially laminated. Then, a stripe shaped mask 6 is formed on the layer 5, and etching is performed until the layer 2 is reached. In the removed part, a P-In1-xGaxAs1-yPy block layer 7, an N-InP embedded layer 8, and an N-In1-xGaxAs1-yPy cap layer 9 are sequentially laminated. Those layers have a smaller forbidden band width than that of the layer 4, different compositions of (x) and (y) from those of the layer 3, and a forbidden band width smaller than the layer 3. The mask 6 is removed. Then a mask 10 having a stripe shaped window is provided on the layer 9. A P<+> diffused layer 11, which is broader than the stripe width of the mask 6 and reaches the layer 4, is provided. |
