Semiconductor laser and method of making the same

Abstract

The present invention relates to a semiconductor laser equipped with a novel window structure, thereby realizing higher output, and a method of making the same. The method is a method of making a semiconductor laser having a window structure transparent to emitted laser light. In particular, into a laminate structure comprising a semiconductor substrate, a lower cladding layer, an active layer, and an upper cladding layer, impurity atoms is implanted to a predetermined region of the upper cladding layer by ion implantation method, thereby forming an impurity implanted region above the active layer. Further, in this method, after the laminate structure is heat-treated to such an extent that the impurity atom fails to reach the active layer, the laminate structure is cleaved in the area where the impurity atom is implanted, thus yielding a semiconductor laser. As a result of such a heat treatment, the vacancies generated upon ion implantation diffuse into the active layer, whereas the impurity atoms themselves do not diffuse into the active layer. This vacancy diffusion forms, in the vicinity of the cleavage plane in the active layer, a window structure in which a well layer and barrier layers which constitute the quantum well structure are selectively interdiffused. This window structure suppresses the catastrophic optical damage during high output operation.