Patent ID: 8617969

Claim:
A method for producing a semiconductor optical device comprising the steps of: growing a semiconductor stacked layer including an etch stop layer and a plurality of semiconductor layers on a major surface of a substrate; forming a mask layer on a top surface of the semiconductor stacked layer so that a tip portion of each protrusion generated in the step of growing the semiconductor stacked layer is exposed at the top surface; etching each protrusion by wet etching using the mask layer; after etching each protrusion by wet etching, removing the protrusion by dry etching; and removing the mask layer from the top surface, after removing each protrusion by dry etching, wherein the step of forming the mask layer includes the steps of: forming an insulating layer on the tip portion and a side surface of each protrusion and on the top surface of the semiconductor stacked layer; forming a resist layer by applying a resist on the insulating layer so that the tip portion of each protrusion is exposed; and selectively removing the insulating layer from the tip portion and side surface of each protrusion using the resist layer, said step of selectively removing the insulating layer including over-etching the insulating layer below the resist layer at the periphery of each protrusion to form an opening in the insulating layer around each protrusion with the size of the formed opening being larger than a size of the bottom of the protrusion.