Plasmon Generator Manufacturing via Multi-Layer Etching Mask

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Solution Overview

Problem

Thermally-assisted magnetic recording heads with plasmon generators face issues such as heat-induced shrinkage and corrosion, leading to reduced lifespan and difficulty in accurately controlling the neck height for optimal performance and recording density.

Innovation Solution

A manufacturing method for a plasmon generator with a narrow and wide portion, where the boundary between the two is accurately controlled using a multi-layer etching mask process, enabling precise formation of the near-field light generating surface and enhancing heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the plasmon generator is used to generate near-field light for thermally-assisted magnetic recording, then the coercivity of the recording medium is lowered and data writing is enabled, but heat is generated causing the plasmon generator to shrink and become distant from the medium facing surface

Engineering Contradiction:

Improvedata writing capabilityVSAvoidposition control of plasmon generator

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The plasmon generator is divided into a head portion and a neck portion with different functions. The head portion generates near-field light while the neck portion serves as a heat dissipation path and positioning structure, allowing the boundary position to be precisely controlled through etching mask design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The boundary position between the head portion and neck portion is predetermined in the initial plasmon generator structure before etching. The etching mask is designed with specific patterns to maintain this predetermined boundary position during the etching process, preventing heat-induced shrinkage from affecting positioning accuracy.

Inventive Principle:

Principle #10Preliminary action

2Loss of energy

If the neck height is reduced to improve heat dissipation, then heat-induced shrinkage is mitigated, but the manufacturing precision of the boundary position becomes difficult to control

Engineering Contradiction:

Improveheat dissipation efficiencyVSAvoidboundary position control

Core Design Contradiction:

Loss of energyVSManufacturing precision

Solution Approach 1:

Different regions of the plasmon generator are given different properties: the head portion is optimized for near-field light generation while the neck portion is optimized for heat dissipation. The neck height and width are specifically designed to provide thermal management without compromising boundary position precision.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The etching mask acts as an intermediary tool to precisely define the boundary between the head portion and neck portion. By carefully designing the mask pattern and etching parameters, the boundary position can be controlled with high precision even when the neck height is reduced for improved heat dissipation.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If the boundary position between narrow and wide portions is not accurately controlled, then manufacturing is simplified, but the near-field light generation efficiency and recording density are reduced

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidrecording density

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The problem of boundary position control is solved by adding dimensional precision through the etching mask design. The mask introduces a new dimensional control layer that defines the boundary position with high precision, transforming a simple manufacturing process into a precisely controlled multi-dimensional process.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method allows for improved control of the plasmon generator's geometry, reducing heat-induced issues and enhancing the efficiency and reliability of near-field light generation, thus extending the lifespan and improving recording density of thermally-assisted magnetic recording heads.

Implementation Method 1

excite surface plasmons on the plasmon generator by using evanescent light which is generated at the surface of the core from the light propagating through the core, and to generate near-field light from the excited surface plasmons at the near-field light generating surface

Methodology Applied

Scientific EffectSurface plasmon excitation:

Implementation Method 2

generate near-field light from the excited surface plasmons at the near-field light generating surface

Methodology Applied

Scientific EffectNear-field light generation:

Implementation Method 3

etching the initial plasmon generator into the plasmon generator by using the etching mask

Methodology Applied

Scientific EffectEtching:

Data Source

PatentUS9958769B1Method of manufacturing a plasmon generator

Publication Date: 2018.05.01 HEADWAY TECHNOLOGIES INC

AI summary

A plasmon generator including a wide portion and a narrow portion is manufactured by etching an initial plasmon generator using an etching mask. The etching mask includes a first mask layer for defining the shape of one of the narrow portion and the wide portion, and a second mask layer for defining the shape of the other of the narrow portion and the wide portion. The etching mask is formed by forming a first hard mask, a second initial mask layer and a second hard mask in this order on a first initial mask layer, and etching the first and second initial mask layers by using the first and second hard masks.