| 摘要 |
PURPOSE:To contrive the improvement in manufacturing yield of the titled element of hetero junction type and in reliability of characteristics by a method wherein a groove is formed in a substrate on which multilayer crystals are laminated. CONSTITUTION:After the grown surface of a crystal layer 8 is flattened by filling the groove 7 formed in the crystal growing substrate 1 with the crystal layer 8 doped with a small amount of Mg (0.2 at % or less), a clad layer 9 doped with a large amount of Mg (0.3 at % or more) is grown. Thereby, a clad layer 9 suitably controlled in carrier concentration and layer thickness is deposited on the substrate 1, and a flat active layer 4 is laminated thereon, resulting in the formation of a multilayer crystal structure for laser oscillation. Since the groove is filled with a crystal layer, the growing speed does not decrease, and the coefficient of As diffusion in the growing solution is kept constant; accordingly, the groove is filled rapidly. As a result, the growing surface of the crystal layer is almost flattened in a relatively short time. Next, a perfect hetero junction which prevents the leakage of carriers from the active layer can be obtained by depositing a flat active layer on the clad layer 9 having a sufficient carrier concentration. |
