BARC Barrier Layer Isolation for Magnetic Writer Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional perpendicular magnetic recording (PMR) head fabrication methods face issues with reflective seed layers affecting photolithography and resulting in footings that increase trench width and scumming, limiting resolution and process window.
Innovation Solution
A low reflectivity bottom antireflective coating (BARC) with a barrier layer is applied on the seed layer to isolate it from ambient and mask interactions, reducing physical and chemical interactions and stabilizing the BARC, thereby improving lithography stability and reducing footings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional SiN BARC layer is used to reduce reflections from the substrate, then photolithography quality is improved, but footings are formed that increase trench width and scumming, reducing line width resolution
Solution Approach 1:
An organic BARC layer is introduced as an intermediary between the SiN BARC layer and the photoresist. This organic layer acts as a mediator that prevents direct acid-base interaction between the photoresist and SiN BARC, thereby eliminating footing formation while maintaining the optical benefits of the SiN BARC for photolithography
Solution Approach 2:
The patent uses a composite BARC structure consisting of two distinct layers: an inorganic SiN BARC layer for optical performance and an organic BARC layer for chemical compatibility. This composite structure combines the advantages of both materials while mitigating their individual drawbacks
2Ease of manufacture
If the photoresist layer is placed directly on the reflective seed layer, then the fabrication process is simplified, but unwanted optical effects due to reflections adversely affect photolithography
Solution Approach 1:
The SiN BARC layer serves as an intermediary between the reflective seed layer and the photoresist layer. It reduces optical reflections from the seed layer, preventing unwanted optical effects during photolithography while allowing the photoresist to be applied directly over it
3Manufacturing precision
If acid treatment or oxygen plasma treatment is applied to remove footings, then footing reduction is achieved, but the process complexity increases and may not adequately remove footings in head formation
Solution Approach 1:
The organic BARC layer is applied in advance before photolithography to prevent footing formation at the interface between the photoresist and SiN BARC. This preliminary protective action eliminates the need for subsequent footing removal treatments, simplifying the overall 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
The method enhances the stability of the BARC, improving line width resolution, reducing scumming, and increasing the process window, allowing for the fabrication of thinner structures with reduced variations between devices.
Implementation Method 1
A low reflectivity bottom antireflective coating (BARC) with a barrier layer is applied on the seed layer
Implementation Method 2
providing a barrier layer on at least a portion of the BARC... The barrier layer isolates the BARC from the mask
Data Source
AI summary
A method and system for providing a magnetic writer are described. The method and system include providing a bottom antireflective coating (BARC) on a portion of the magnetic writer. The BARC has a low reflectivity. The method and system also include providing a barrier layer on at least a portion of the BAR and providing a mask on at least a portion of the barrier layer. The barrier layer isolates the BARC from the mask.