Method of fabricating buried crescent semiconductor laser device by removing a surface portion of substrate around a groove therein

A method of fabricating a semiconductor laser comprising the steps of:

• preparing a semiconductor wafer composed of a semiconductor substrate of a first conductivity type and a current blocking layer formed on said semiconductor substrate, said current blocking layer comprising at least one semiconductor layer of a second conductivity type, a groove being formed in an upper surface of said wafer having a depth corresponding to at least a thickness of said current blocking layer,
• applying a melt-back etching process to the upper surface of said semiconductor wafer such that both the surface regions of said wafer and the upper sidewall surface regions of said groove are removed, while the lower surface regions of said groove are substantially not removed, and
• growing on said wafer by liquid phase epitaxy, a plurality of semiconductor crystal layers including a layer constituting an active region which is in said groove and is terminated on the etched portions of the side wall of the groove.