Near-Field Light Element Sharp Tip Manufacturing
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Solution Overview
Problem
Existing methods for manufacturing near-field light generating elements for heat-assisted magnetic recording struggle to create a sharply pointed top end face, which is essential for achieving a small spot diameter and sufficient intensity of near-field light, due to the rounding of edges during the etching process.
Innovation Solution
A manufacturing method involving a metal layer with a polishing stopper layer and a non-metallic inorganic coating layer is used, where the coating layer has a lower etching rate than the metal layer, allowing for precise formation of inclined surfaces and a sharply pointed edge through controlled etching steps, preventing edge rounding and enabling the creation of a near-field light generating element with a sharply pointed tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If photoresist etching is used to form the near-field light generating element, then the manufacturing process is simple, but the top end becomes rounded and cannot achieve a sharply pointed shape
Solution Approach 1:
The patent applies preliminary action by forming inclined surfaces on the metal layer before the final etching step. The coating layer is deposited over these pre-formed inclined surfaces, and during subsequent polishing, the coating layer is removed to expose the metal layer with the pre-formed inclined surfaces, which then serve as the basis for the sharply pointed tip.
Solution Approach 2:
The patent uses an intermediary approach by introducing a coating layer made of non-metallic inorganic material as a mediator between the metal layer and the etching process. This coating layer has different etching characteristics than the metal layer, allowing it to protect certain areas during etching while enabling the formation of the sharply pointed tip through selective removal.
2Illumination intensity
If the top end is made more sharply pointed to reduce spot diameter, then near-field light intensity improves, but the etching process causes edge rounding that prevents achieving the desired sharpness
Solution Approach 1:
The patent applies parameter changes by utilizing the different etching rates between the coating layer and the metal layer. By controlling the etching parameters and selecting materials with appropriate etching rate differences, the process achieves selective removal of material to form the sharply pointed tip without edge rounding.
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
This method effectively produces a near-field light generating element with a sharply pointed top end face, allowing for the generation of near-field light with a small spot diameter and sufficient intensity, enhancing the recording density and thermal stability of magnetic recording devices.
Implementation Method 1
the coating layer being made of a non-metallic inorganic material that has an etching rate lower than that of the metal layer in a second etching step
Implementation Method 2
a polishing step of polishing the coating layer until the polishing stopper layer is exposed
Implementation Method 3
A known method for generating near-field light is to apply laser light to a plasmon antenna, which is a small piece of metal, for example. The laser light applied to the plasmon antenna excites surface plasmons on the plasmon antenna, and near-field light is generated based on the surface plasmons.
Data Source
AI summary
A near-field light generating element has an outer surface including first and second inclined surfaces and an edge part that connects the first and second inclined surfaces to each other. In a method of manufacturing the near-field light generating element, a polishing stopper layer is initially formed on a metal layer, and the polishing stopper layer and the metal layer are etched so that the metal layer is provided with the first inclined surface. Next, a coating layer is formed to cover the metal layer and the polishing stopper layer. The coating layer is made of a non-metallic inorganic material that has an etching rate lower than that of the metal layer in a second etching step to be performed later. Next, the coating layer is polished until the polishing stopper layer is exposed. Next, the second etching step is performed to etch the polishing stopper layer and the metal layer using the coating layer as the etching mask. This provides the metal layer with the second inclined surface and the edge part, and thereby makes the metal layer into the near-field light generating element.