Pattern Tone Reversal for High-Throughput HDD Manufacturing
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Solution Overview
Problem
Current hard disk drive (HDD) patterning techniques require breaking vacuum and are not compatible with high-throughput production, especially for bit pattern media (BPM) disk manufacturing, and face challenges in etch selectivity between mask material and underlying layers.
Innovation Solution
The method involves initial resist patterning, collimated deposition of a mask material, and an etch back using reactive ion etching (RIE), which allows for pattern tone reversal without thick material deposition or planarization, and offers etch selectivity through the microloading effect, enabling patterning on both sides of a disk without breaking vacuum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional vacuum-based patterning techniques are used, then manufacturing precision is maintained, but productivity decreases due to vacuum breaking requirements
Solution Approach 1:
The patent changes the fundamental parameter of the patterning process by using reactive ion etching (RIE) instead of traditional vacuum-based techniques. This parameter change enables high-throughput production while maintaining etch selectivity through controlled plasma chemistry and power density adjustments
Solution Approach 2:
The patent replaces mechanical vacuum-based patterning systems with a chemical plasma-based RIE system. This substitution eliminates the need for vacuum breaking while achieving comparable or superior patterning precision through chemical selectivity rather than mechanical control
2Manufacturing precision
If thick mask material is deposited, then etch selectivity is improved, but device complexity and material usage increase
Solution Approach 1:
The patent optimizes the mask layer thickness parameter to a specific range (5-50 nm) that provides sufficient etch selectivity without excessive material usage. The reactive ion etching process parameters are simultaneously adjusted to maintain high selectivity at this reduced thickness
Solution Approach 2:
The patent employs a sacrificial mask layer that is selectively removed after transferring the pattern. The mask material is deposited precisely where needed and then discarded after serving its patterning function, optimizing the balance between selectivity and material consumption
3Manufacturing precision
If planarization is performed, then manufacturing precision is improved, but productivity decreases
Solution Approach 1:
The patent performs preliminary patterning of the mask layer before the etching process, establishing the complete pattern structure in advance. This preliminary action eliminates the need for subsequent planarization steps while maintaining surface flatness through controlled deposition and etching sequences
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 approach enables high-throughput production of HDDs with efficient patterning on both sides of disks, maintaining etch selectivity and compatibility with BPM disk manufacturing, enhancing operational efficiency and reducing manufacturing complexity.
Implementation Method 1
an etch back using reactive ion etching (RIE), which allows for pattern tone reversal without thick material deposition or planarization
Data Source
AI summary
A method for patterning a substrate is disclosed. Depressions are patterned into a resist layer over a substrate. A mask layer is deposited over the resist layer at least partially filling the depressions. The mask layer is etched to expose a top surface of the resist layer and leaving at least a portion of the mask layer in the depressions of the resist layer, wherein the mask layer over said top surface of the resist layer is etched at a faster rate than said mask layer in the depressions of the resist layer. Exposed portions of the resist layer are removed to expose portions of the substrate. Exposed portions of the substrate are etched.