Thermally-assisted magnetic recording head having plasmon generator of multiple metal layers

A manufacturing method for a thermally-assisted magnetic recording head,

• the thermally-assisted magnetic recording head including:
• a medium facing surface configured to face a recording medium;
• a main pole configured to produce a write magnetic field for writing data on the recording medium;
• a waveguide including a core configured to allow light to propagate therethrough and a cladding arranged around the core;
• and
• a plasmon generator,
• the plasmon generator including a first metal layer, a second metal layer, and a third metal layer,
• the first metal layer being formed of a first metal material, the first metal layer being located away from the medium facing surface, the first metal layer including a plasmon exciting portion configured to excite a surface plasmon thereon based on the light propagating through the core and a first front end facing the medium facing surface,
• the second metal layer being formed of a second metal material, the second metal layer being located on the first metal layer at a distance from the medium facing surface, the second metal layer including a second front end facing the medium facing surface,
• the third metal layer being formed of the second metal material and located on the second metal layer,
• the third metal layer including a narrow portion located on the second metal layer, the narrow portion including a front end face that is located in the medium facing surface, and a rear end opposite the front end face, the front end face being configured to generate near-field light from the surface plasmon,
• the second metal layer having a maximum width greater than that of the narrow portion of the third metal layer in a track width direction,
• the rear end of the narrow portion of the third metal layer being located farther from the medium facing surface than is the second front end of the second metal layer, and
• at least part of the first front end of the first metal layer being located farther from the medium facing surface than is the second front end of the second metal layer,
• the manufacturing method comprising:
• a step of forming the main pole;
• a step of forming the waveguide;
• and
• a step of forming the plasmon generator, wherein
• the step of forming the plasmon generator includes
• a step of forming the first metal layer and the second metal layer, and
• a step of forming the third metal layer, and
• the step of forming the first metal layer and the second metal layer includes
• a step of forming a first metal film of the first metal material,
• a step of forming a second metal film of the second metal material on the first metal film,
• a first etching step of etching part of the first metal film near a location where the medium facing surface is to be formed, after the formation of the second metal film, and
• a second etching step of etching the first metal film and the second metal film so that the first metal film and the second metal film make the first metal layer and the second metal layer, respectively.