Taper-Etching SiO2 Clad Layers for Near-Field Light Generators
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Solution Overview
Problem
Conventional reactive ion etching methods struggle to form V-shaped grooves with intersecting wall faces at predetermined angles in SiO2 or SiON layers, which are essential for creating effective near-field light generators used in thermally-assisted magnetic recording devices.
Innovation Solution
A taper-etching method using an etching mask made of elemental Al and an etching gas containing N2, which produces a sidewall protective film of AlN, allowing for the formation of grooves with wall faces intersecting at angles between 30° to 65°, enabling the fabrication of clad layers for near-field light generators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional reactive ion etching is used on SiO2 or SiON layers, then etching can be performed, but V-shaped grooves with wall faces intersecting at predetermined angles cannot be formed
Solution Approach 1:
A sidewall protective film made of AlN is introduced as an intermediary layer during the etching process. This film is formed by reacting N2 gas with elemental Al in the etching mask, and it protects the sidewalls of the groove during etching, enabling the formation of V-shaped grooves with wall faces intersecting at predetermined angles (30° to 65°) in SiO2 or SiON layers
Solution Approach 2:
The etching gas composition is changed to include N2 in addition to the main component gas. This parameter change enables the formation of AlN sidewall protective film during etching, which fundamentally alters the etching outcome from conventional vertical or rounded grooves to precise V-shaped grooves with controlled intersection angles
2Illumination intensity
If the angle between wall faces is reduced to increase surface plasmon intensity, then near-field light generation improves, but manufacturing precision of the groove becomes more difficult to achieve
Solution Approach 1:
The AlN sidewall protective film acts as a mediator that enables precise control of the groove geometry during etching. By protecting the sidewalls uniformly, it allows the formation of sharp V-shaped grooves with small intersection angles (30° to 65°) that concentrate surface plasmons effectively while maintaining manufacturing precision through the controlled formation process
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 enables the precise formation of clad layers with desired angle ranges, enhancing the intensity and spot diameter of surface plasmons, thereby improving the performance of near-field light generators in thermally-assisted magnetic recording devices.
Implementation Method 1
an etching mask made of elemental Al and an etching gas containing N2, which produces a sidewall protective film of AlN
Implementation Method 2
enhancing the intensity and spot diameter of surface plasmons
Data Source
AI summary
A method of taper-etching a layer to be etched that is made of SiO2 or SiON and has a top surface. The method includes the step of forming an etching mask with an opening on the top surface of the layer to be etched, and the step of taper-etching a portion of the layer to be etched, the portion being exposed from the opening, by reactive ion etching so that a groove having two wall faces that intersect at a predetermined angle is formed in the layer to be etched. The etching mask is formed of a material containing elemental Al. The step of taper-etching employs an etching gas that contains a main component gas, which contributes to the etching of the layer to be etched, and N2.