MANUFACTURE OF SEMICONDUCTOR LASER

PURPOSE:To obtain a laser having excellent reliability by forming a striped mask on the surface of the center of a superlattice optical guide layer on the upper side of an active layer, forming an organic metal by vapor growth on both sides of the mask and bringing a superlattice except a central region to a disordered state through thermal diffusion. CONSTITUTION:N-AlxGa1-xAs 42 and an active layer 44 including an I-Aly Ga1-yAs barrier layer 44a and an I-GaAs quantum well layer 44b are superposed onto an N- GaAs substrate 40, and oscillation threshold currents are reduced by selecting thickness and an oscillation wavelength is determined by choosing the width of a well. A P- AlyGa1-yAs waveguide layer 46 and a P-superlattice waveguide layer 45 are superposed. A striped mask 50 consisting of Si3N4 is executed, an Si adding layer 52 in high concentration is formed by vapor growth on a side section 48b, the layer 52 is coated with an Si3N4 layer 44 and Si is thermally diffused and a superlattice except a central section 48a is brought to a disordered state, and a current constriction layer 56 is formed. A clad layer 60 and a connecting layer 62 are stacked, and upper and lower electrodes 64, 66 are attached, thus completing a semiconductor laser. According to the constitution, there is no possibility of the deterioration and damage of the quality of a crystal, thus lengthening the lifetime of a laser element and improving reliability thereof.