Semiconductor laser device and a method of fabricating the same

Abstract

A semiconductor laser device is provided which includes a semiconductor substrate and a multi-layered structure disposed on the substrate, the multi-layered structure containing an Al.sub.x Ga.sub.1-x As (0<x<1) first cladding layer formed on the substrate, an Al.sub.y Ga.sub.1-y As (0<y<1, x>y) active layer for laser oscillation formed on the first cladding layer, an Al.sub.x Ga.sub.1-x As (0<x<1) second cladding layer formed on the active layer, and an Al.sub.z Ga.sub.1-z As (0<z<1) current blocking layer formed above the second cladding layer, the current blocking layer having a striped groove as a current injection path. The method includes the steps of: forming a multi-layered structure on a semiconductor substrate, the multi-layered structure containing in order, an Al.sub.x Ga.sub.1-x As (0<x<1) first cladding layer, an Al.sub.y Ga.sub.1-y As (0<y<1, x>y) active layer for laser oscillation, an AlGaAs (0<x<1) second cladding layer, a GaAs buffer layer, an Al.sub.u Ga.sub.1-u As (0<u<1) etching stopper layer, an Al.sub.z Ga.sub.1-z As (0<z<1, z<u) current blocking layer, and a GaAs protective layer; etching the protective layer and the current blocking layer to form a striped groove as a current injection path; removing the exposed portion of the etching stopper layer on the bottom of the striped groove; removing the portion of the buffer layer on the bottom of the striped groove and at least one part of the protective layer by a melt-back technique; and growing an Al.sub.x Ga.sub.1-x As (0<x<1) third cladding layer so as to bury the striped groove therein and growing a GaAs contact layer on the third cladding layer.