Semiconductor laser

Abstract

A method of fabricating a semiconductor laser includes forming a mask having a stripe opening in a <011> direction on a {100} surface of a first conductivity type substrate, and growing a double-heterojunction structure including a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer on the {100} surface using the mask, thereby producing a stripe-shaped ridge in which the active layer and the first conductivity type lower cladding layer are covered with the second conductivity type upper cladding layer. The stripe-shaped ridge has an ordinary mesa-shaped cross-section in a direction perpendicular to the stripe direction and a symmetrical hexagonal cross-section in the stripe direction. In this method, since the conventional selective etching for forming the ridge is dispensed with, the processing precision of the ridge is improved. Further, the second conductivity type cladding layer and the active layer grown on the side surfaces of the first conductivity type cladding layer are very thin and have low dopant incorporating efficiencies, so that portions of the first conductivity type cladding layer grown at the side surfaces of the ridge have high resistivity, and reactive current is blocked by these high-resistance portions.