Patent ID: 8617911

Claim:
A method for forming a coating film on a facet of a semiconductor optical device, the method comprising the steps of: preparing an epitaxial wafer by forming a multilayer semiconductor structure including an active layer on a main surface of a substrate; forming a plurality of stripe electrodes and a plurality of bonding pads on the multilayer semiconductor structure of the epitaxial wafer, the stripe electrodes extending longitudinally in a first direction and being arranged in a second direction that is perpendicular to the first direction, the bonding pads being respectively electrically connected to the stripe electrodes; forming a projection portion on the multilayer semiconductor structure of the epitaxial wafer to have a height measured from the main surface of the substrate that is greater than a height of the stripe electrodes; forming a plurality of laser diode bars by cutting the epitaxial wafer in the second direction; arranging the laser diode bars on a support surface such that a side surface of at least one laser diode bar is oriented in a normal direction of the support surface, and disposing spacers between the laser diode bars; and forming a coating film on the side surface of the at least one laser diode bar, wherein, the at least one laser diode bar has at least one projection portion, and the at least one projection portion is formed a distance from the side surface of the at least one laser diode bar that is shorter than a distance between the side surface and the bonding pad.