Patent ID: 8889445

Claim:
A method for manufacturing a semiconductor optical device, comprising the steps of: growing a stacked semiconductor layer on a substrate having a cleavage direction in a first direction; forming a first mask having a plurality of openings arranged in the first direction on the stacked semiconductor layer; forming a mark array by etching the stacked semiconductor layer using the first mask, the mark array including a first mark and a second mark; after removing the first mask, forming a second mask having first and second openings extending in a second direction intersecting the first direction, the first opening having a first edge crossing the first mark, the second opening having a second edge crossing the second mark; obtaining a substrate product by forming first and second grooves corresponding to the first and the second openings, respectively, and a waveguide mesa defined by the first and second grooves by etching the stacked semiconductor layer by using the second mask; and producing a laser diode bar by cleaving the substrate product including the first and the second grooves and the waveguide mesa, wherein, in the step of forming the first and second grooves, first and second residual marks are formed on the upper surface of the waveguide mesa, the first and the second residual marks being formed from a part of the first and the second marks, respectively, a first transfer mark is formed on the bottom of the first groove, the first transfer mark being formed by transferring from a part of the first mark, and a second transfer mark is formed on the bottom of the second groove, the second transfer mark being formed by transferring from a part of the second mark.