Patent ID: 7855093

Claim:
A method of manufacturing semiconductor laser device comprising: a first step of laminating a first clad layer, an active layer, and a diffraction grating layer on a semiconductor substrate through epitaxial growth; a second step of forming a diffraction grating by etching the diffraction grating layer; and a third step of performing burying regrowth of the diffraction grating through epitaxial growth on a second clad layer of different conduction type from the first clad layer, wherein immediately before the third step, halogen-based gas is introduced to a reactor, and etching is performed on the diffraction grating so that each side wall has at least two or more crystal faces and a ratio of length of an upper side in a waveguide direction to a bottom side parallel to a (100) surface is 0 to 0.3, and a reactive product formed on side surfaces of the diffraction grating and in trench portions between stripes of the diffraction grating at an increase in temperature for regrowth is removed.