Semiconductor laser

Abstract

A semiconductor device is formed by sequentially forming a first clad layer, active layer, second clad layer, and cap layer from, for example, an AlGaAs layer with an AlAs mixing ratio of .gtoreq.0.4, on a substrate made of GaAs or the like by MBE, MOCVD or another high precision growth process. Then AlGaAs layer is selectively removed only in the vicinity of formed ridges, and in this part, grooves on two stripes are formed from the cap layer surface, leaving the second clad layer with an intact thickness of, for example, only 3000 .ANG.. An insulation layer made of, for example, SiN is then formed in the groove area and the AlGaAs layer region, thereby creating a current stripe structure, in which only two grooves provide for current passages, that is, the light-emitting regions. In this structure, the thickness of the mesa pattern (ridge part) between the two grooves may be a minimum limit and the processing precision may be improved, while by properly selecting the thickness of the AlGaAs layer, a sufficiently large distance may be set between the mount surface and the active layer, so that the problem of solder climbing-up along the device end surface may be prevented. When the AlAs mixing ratio is controlled at 0.4 in the AlGaAs layer, it is possible to easily remove portions thereof selectively, by using hydrogen fluoride.