Semiconductor device and method for manufacturing semiconductor device

A method for manufacturing a semiconductor device comprising:

• a step of forming a semiconductor laser that emits laser light on an upper surface of a substrate;
• a step of forming a waveguide having a first conductive layer provided on the upper surface of the substrate, and a waveguide layer that is provided on the first conductive layer and guides the laser light;
• a step of forming an embedment layer surrounding the semiconductor laser and the waveguide on the upper surface of the substrate;
• a step of removing a part of the embedment layer on both sides of an end part, of the waveguide, connected to the semiconductor laser such that the embedment layer is separated in a waveguide direction of the waveguide to form an exposed part in which the substrate is exposed from the embedment layer;
• a step of covering the semiconductor laser, the waveguide, the embedment layer and the exposed part with an insulating film;
• an opening forming step of providing a plurality of openings on both sides of the waveguide in the insulating film to expose the exposed part;
• and
• an etching step of performing wet etching using etching liquid having a higher etching rate for the first conductive layer than the waveguide layer with the insulating film being as a mask to remove a part of the first conductive layer in the end part, and providing a separation region in which the first conductive layer is separated in the waveguide direction in the end part.