Patent ID: 8617912

Claim:
A method for manufacturing a semiconductor laser, the method comprising the steps of: preparing a mold having a pattern surface on which a pattern including a plurality of recesses is formed; forming a stacked semiconductor layer on a principal surface of a substrate, the stacked semiconductor layer including an active layer and a grating layer; forming a resin part on the grating layer; forming a resin pattern portion having recesses on the resin part by transferring the pattern formed on the pattern surface of the mold onto the resin part by a nano-imprint technique using the mold; forming a diffraction grating in the grating layer by etching the grating layer using the resin part on which the resin pattern portion is formed as a mask; and forming a mesa-structure on the stacked semiconductor layer by etching the stacked semiconductor layer, wherein the recesses in the mold extend in a first direction that is parallel to the pattern surface and are periodically arranged in a second direction that is orthogonal to the first direction, each of the recesses in the mold including two end portions in the first direction and a middle portion between the two end portions, a depth of at least one of the two end portions from the pattern surface being greater than a depth of the middle portion from the pattern surface, wherein, in the step of forming the resin pattern portion, the recesses formed in the resin part are periodically arranged in a third direction that is parallel to the principal surface of the substrate, wherein, in the step of forming the diffraction grating, the diffraction grating has two end portions in a direction orthogonal to the third direction corresponding to the pattern formed on the pattern surface of the mold, and wherein the step of forming the mesa-structure includes the steps of: covering a part of a top surface of the stacked semiconductor layer with a mask that does not cover the top surface of the stacked semiconductor layer over the end portions of the diffraction grating, the mask extending in the third direction, and etching the stacked semiconductor layer using the mask so as to remove the end portions of the diffraction grating.