Laser diode device and method of manufacturing laser diode device

A method of manufacturing a laser diode device, the method comprising:

• preparing a semiconductor substrate including a semi-polar surface, the semiconductor substrate being formed of a hexagonal III-nitride semiconductor;
• forming an epitaxial layer on the semi-polar surface of the semiconductor substrate, the epitaxial layer including a light emitting layer of the laser diode device;
• etching the epitaxial layer to a predetermined depth thereof through a mask, and forming a ridge section in a shape of a stripe;
• forming a first electrode in a region corresponding to the ridge section before the forming of the ridge section, or forming the first electrode on a top surface of the ridge section after the forming of the ridge section;
• forming an insulating material layer on a surface of the epitaxial layer including a top surface of the first electrode;
• etching the insulating material layer, and thereby forming an insulating layer, the insulating layer covering the epitaxial layer in an adjacent region of the ridge section and a side surface of the ridge section, and the insulating layer covering part or all of side surfaces of the first electrode continuously from the epitaxial layer;
• forming a pad electrode, the pad electrode covering a top surface of the first electrode and the insulating layer, the pad electrode being electrically connected to the first electrode;
• and
• forming a second electrode on a surface, of the semiconductor substrate, opposite to the semi-polar surface.