MANUFACTURE OF VISIBLE SEMICONDUCTOR LASER

PURPOSE:To decrease the ohmic resistance of a P electrode as far as possible by performing Zn diffusion in the atmosphere wherein P is excessive and As is insufficient so as to form a Zn diffusion area. CONSTITUTION:A Zn diffusion area 7b is formed in an atmosphere which is rich in PH3 wherein decomposition of P of AlGaInP4a is suppressed but composition of As of GaAs 6 is easy to occur. The ratio of Zn diffusion speed within AlInP to one within GaAs can be made small since the diffusion within GaAs is accelerated while the diffusion within AlGaInP is suppressed. Accordingly, the diffusion depth t1 within GaAs can be made larger. Hereby, the expansion of currents can be enlarged, and the ohmic resistance of a P electrode 10 can be decreased.