JPS6473787A - Semiconductor laser and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent a luminous efficiency from decreasing, and to simplify production process, by forming an internal current constriction structure through impurity diffusion utilizing the difference in a thickness of a current blocking layer on the mesa part from that on the other part. CONSTITUTION:A mesa part 22 is formed in a substrate 21 of a p type GaAs into which Zn ions are doped. Then, a current blocking layer 23 of an n type GaAs which has a higher thickness in the part other than the mesa part 22, a clad layer 25 of a p type AlGaAs, an active layer 26 of the p type AlGaAs, a clad layer 27 of an n type AlGaAs, and a gap layer 28 of the n type GaAs are in turn grown in the respective crystals. Subsequently, when heat treatment is performed, the Zn ions are diffused from the substrate 21 into the layer 23 to form a diffusion layer 24 containing Zn. As a result, a current flow path through the substrate 21 and the layers 24-28 is formed on the mesa part 22, while the part other than the mesa part 22 is so biased in the reverse direction owing to the p-n junction between the layer 23 and the layer 25 that current does not flow therethrough, therefore an internal current constriction structure being produced. Accordingly, current flows effectively through the mesa part 22 so that a luminous efficiency can be prevented from decreasing. Moreover, only one crystal growth process is needed using the method in which a V-shaped groove and the like are not formed in the substrate so that the production process can be simplified.