Patent ID: 8349198

Claim:
A method of manufacturing a near-field light generator, the near-field light generator comprising: a waveguide that propagates light and has a top surface; a clad layer that has a bottom surface in contact with the top surface of the waveguide, a top surface opposite to the bottom surface, and an opening penetrating from the top surface to the bottom surface; a plasmon generator that is accommodated in the opening at least in part; and a dielectric film that is provided in the opening so as to be interposed between the plasmon generator and each of the waveguide and the clad layer, wherein: each of the clad layer and the dielectric film has a refractive index lower than that of the waveguide; the opening has a first opening sidewall and a second opening sidewall that decrease in distance from each other with decreasing distance to the top surface of the waveguide; the plasmon generator has a first inclined surface that is opposed to the first opening sidewall, a second inclined surface that is opposed the second opening sidewall, an edge part that connects the first and second inclined surfaces to each other, and a near-field light generating part that lies at an end of the edge part and generates near-field light; and a surface plasmon is excited on the edge part through coupling with evanescent light that occurs at the top surface of the waveguide based on the light propagated through the waveguide, the surface plasmon is propagated along the edge part to the near-field light generating part, and the near-field light generating part generates near-field light based on the surface plasmon, the method comprising the steps of: forming the waveguide; forming an initial clad layer on the waveguide, the initial clad layer being intended to undergo the formation of the opening therein later to thereby become the clad layer; etching the initial clad layer by reactive ion etching so that a recess that does not reach the top surface of the waveguide is formed in the initial clad layer; etching the recess by wet etching until the top surface of the waveguide is exposed in part, so that the recess becomes the opening and the initial clad layer becomes the clad layer; forming the dielectric film in the opening; and forming the plasmon generator on the dielectric film.