Photomask Transparent Planarization Layer for Roll-to-Roll Lithography
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Solution Overview
Problem
The existing photolithography methods face challenges in preventing contamination between the photoresist layer and the shielding pattern layer during the exposure process, and they are not suitable for continuous roll-to-roll processing due to the thickness and surface roughness of the transparent planarization layer.
Innovation Solution
A photomask with a transparent planarization layer of specific thickness (30 µm to 500 µm) and surface roughness (0.1 nm to 20 nm) is used, which covers a shielding mask pattern on a substrate, preventing contamination and enabling roll-to-roll processing by maintaining a flat surface for light transmission and pattern formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a transparent planarization layer is added to prevent contamination between photoresist and shielding pattern, then contamination prevention is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
A transparent planarization layer is introduced as an intermediary component between the shielding mask pattern and the photoresist layer. This intermediate layer physically separates the two components, preventing direct contact and contamination while allowing light transmission for exposure. The planarization layer serves as a mediator that resolves the contamination issue without requiring fundamental changes to the photomask or photoresist structures.
2Object-affected harmful factors
If a thick transparent planarization layer is used to ensure coverage, then contamination prevention is improved, but roll-to-roll processing capability deteriorates
Solution Approach 1:
The thickness of the transparent planarization layer is optimized to a specific range (30-500 µm) that balances two competing requirements: sufficient thickness to ensure complete coverage of the shielding mask pattern and prevent contamination, while maintaining thinness enough to allow flexible roll-to-roll processing. This parameter optimization enables the layer to fulfill its protective function without compromising manufacturing productivity.
3Illumination intensity
If the surface roughness of transparent planarization layer is reduced for flatness, then light scattering is minimized, but manufacturing precision requirements increase
Solution Approach 1:
The surface roughness of the transparent planarization layer is controlled within a specific range (0.1-20 nm) to achieve optimal light transmission. By maintaining the roughness at or below 20 nm, the layer provides sufficiently flat surfaces that minimize light scattering and diffraction effects during exposure, ensuring high-quality pattern formation. This parameter specification balances optical performance with achievable manufacturing precision.
4Productivity
If continuous roll-to-roll exposure is enabled, then productivity is improved, but exposure quality control becomes more difficult
Solution Approach 1:
The transparent planarization layer is prepared in advance with predetermined thickness (30-500 µm) and surface roughness (0.1-20 nm) characteristics before the exposure process. This preliminary preparation ensures that when roll-to-roll exposure occurs, the photomask already has the optimal surface properties needed for high-quality pattern formation. The advance preparation of these critical parameters enables continuous high-speed processing while maintaining consistent exposure quality throughout production.
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 solution allows for continuous exposure in a short period, prevents contamination, and enhances pattern obtainment by maintaining a flat surface and minimizing light scattering, making it suitable for roll-to-roll processing and improving pattern formation.
Implementation Method 1
a transparent planarization layer located on a surface of the substrate provided with the shielding mask pattern
Implementation Method 2
The photolithography method refers to all processes uniformly coating a photoresist on a base plate, exposing a pattern on a photomask using an exposure apparatus and the photomask
Implementation Method 3
making it suitable for roll-to-roll processing and improving pattern formation
Data Source
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AI summary
The present specification relates to a photomask, a laminate including the photomask, a method for manufacturing the photomask, a device for forming a pattern using the photomask, and a method for forming a pattern using the photomask.