Plasmon Generator Manufacturing via Protruding Dielectric Structure

The patent transitions from planar photolithography to three-dimensional fabrication by forming a protruding part that extends vertically from the substrate. The width of the front end face is defined by the dimensions of this protruding structure rather than by lateral photoresist patterning, thereby bypassing the diffraction limit of photolithography and enabling sub-100nm width control through vertical structure formation and selective removal.

The manufacturing process is divided into distinct stages: forming the protruding part, depositing the metal film, and selectively removing portions. This segmentation allows each step to be optimized independently, with the width control achieved in the protruding part formation stage rather than being constrained by the final patterning step.

The patent achieves high precision width control by forming a protruding part with controlled vertical dimensions. The width of the front end face is determined by the cross-sectional dimensions of this vertical structure, which can be precisely controlled through deposition and etching processes that offer better resolution than photolithography, thereby enabling reduced near-field light spot diameter for higher recording density.

The patent changes the controlling parameter for width from lateral photoresist pattern dimensions to vertical protruding structure dimensions. This parameter change allows the width to be controlled by deposition thickness and etch depth rather than by optical diffraction limits, enabling precision at the sub-100nm scale required for high recording density applications.