Thermally-Assisted Magnetic Recording Head Plasmon Alignment

The patent applies preliminary action by forming the gap film and surrounding layer before forming the main pole. This sequence allows the main pole to be self-aligned to the plasmon generator through the pre-formed gap film structure, achieving precise alignment without requiring complex post-fabrication adjustment processes. The gap film is deposited and patterned first, creating a template that guides the subsequent main pole formation.

The gap film serves as an intermediary element between the plasmon generator and the main pole. It provides a physical reference structure that mediates the alignment process, allowing both components to be precisely positioned relative to each other. The surrounding layer acts as another intermediary that defines the lateral boundaries and maintains the spatial relationship between the plasmon generator and main pole during fabrication.

The patent applies local quality by creating a non-uniform main pole structure with different width characteristics at different locations. The main pole has a narrower end face width at the medium-facing surface to achieve small track width, while maintaining a larger width at the coil-facing surface to ensure sufficient write magnetic field magnitude. This spatial variation in dimensions allows simultaneous optimization of both recording density and magnetic field strength.

The patent resolves the contradiction by transitioning from a single-dimension solution to a multi-dimensional approach. Instead of uniformly reducing the main pole dimensions, it varies the width in the lateral dimension at different heights, creating a tapered or stepped structure. This dimensional variation allows the end face to be narrow for small track width while the body remains sufficiently wide for strong magnetic field generation.

The patent applies merging by integrating the alignment function into the gap film structure itself rather than treating it as a separate alignment mechanism. The gap film is formed as a continuous layer that simultaneously serves as an insulator, a spacer, and an alignment reference. This consolidation of functions reduces device complexity compared to using separate alignment marks or adjustment mechanisms.

The fabrication process employs self-service through self-aligned formation steps. The main pole is formed using the gap film and surrounding layer as self-aligned masks and templates, eliminating the need for complex external alignment procedures. The structures automatically position themselves relative to each other through the sequential deposition and etching processes, reducing overall device complexity.