Patent ID: 7947520

Claim:
A method of making a semiconductor laser, comprising the steps of: growing a semiconductor region of an active layer; etching a part of the semiconductor region to form a ridge structure; forming an insulating film on a top and a side of the ridge structure, the insulating film being made of silicon dioxide; forming a single resin layer of photosensitive material to bury the ridge structure and the insulating film, the single resin layer being made of photosensitive silicon-based resin, single resin layer covering the top and the side of the ridge structure, and a thickness of the resin layer being larger than a height of the ridge structure; forming a cured resin portion and an uncured portion in the single resin layer by performing lithographic exposure of the single resin layer through a photomask, the photomask having a pattern, a width of the pattern being greater than a width of the top of the ridge structure, the single resin layer being expose with light through the photomask, the light being diffracted around an edge of the pattern of the photomask, the single resin layer having a portion behind the pattern of the photomask, the portion of the single resin layer being exposed with the diffracted light, and the uncured resin portion being provided on the top of the ridge structure; removing the uncured resin portion of the single resin layer to form a dent, the dent being provided on the top of the ridge structure; after removing the uncured resin portion, etching an overall surface of the cured resin portion and dent by etchant to form an etched resin layer, an opening being formed in the etched resin layer by thinning the cured resin portion, the etchant including CF 4 and O 2 and a part of the insulating film being exposed in the opening of the etched resin layer; etching the part of the insulating film using the etched resin layer as a mask to form an opening in the insulating film, the insulating film being dry etched by etchant including CF 4 , the etched resin layer including a first portion and a second portion, the first and second portions of the etched resin layer being arranged on the active layer, the first portion of the etched resin layer being adjacent to the ridge structure, the second portion of the etched resin layer being adjacent to the first portion of the etched resin layer, a surface of the first portion of the etched resin layer being convexly curved to an edge of the opening of the insulating film; and forming an electrode over the ridge structure and the etched resin layer, the electrode being in contact with the top of the ridge structure through the opening of the etched resin layer, and the electrode being in direct contact with the etched resin layer.