A method for manufacturing a semiconductor device includes forming a semiconductor laminated structure (12) on an N shaped substrate (10) as a wafer (16) including semiconductor laser structures (14); forming a spaced groove (22) in the separating zone (18) between the semiconductor laser structures on a major surface of the wafer; separating the wafer to laser bars (26) including at least two of the semiconductor laser structures (14) arrayed in a bar shape, after forming the first groove; forming a second groove (30) in the first groove of the laser bars, the second groove having a width no wider than the first groove; and separating one of the laser bars into respective semiconductor lasers along the second groove.