Pellicle Frame Polymer Coating Stray Light Resistance
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Solution Overview
Problem
Conventional pellicle frames coated with polymers are prone to contamination by particles when exposed to stray light during photolithography, leading to potential interference with the photomask and reduced light resistance, which complicates the production of miniaturized semiconductor and liquid crystal display devices.
Innovation Solution
A pellicle frame with a polymer coating layer comprising multiple layers, where the outermost layer contains no particles or has a lower particle concentration than the inner layers, providing enhanced light resistance and preventing contamination from stray light, allowing increased exposure light energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polymer coating layer with particles is used on the pellicle frame, then the light resistance is improved, but particles may fall off and contaminate the photomask when exposed to stray light
Solution Approach 1:
The polymer coating layer is divided into multiple layers (first polymer layer and second polymer layer) with different particle concentrations. The first layer contains particles for light resistance, while the second outer layer contains substantially no particles to prevent contamination, thus segmenting the functional requirements of light resistance and contamination prevention into separate layers.
Solution Approach 2:
Different regions of the polymer coating layer have different properties: the inner first layer has high particle concentration for light resistance, while the outer second layer has substantially no particles for contamination prevention. This local differentiation of quality allows each layer to perform its specific function optimally.
2Object-affected harmful factors
If the pellicle frame is coated with a polymer containing particles, then stray light resistance is enhanced, but pigment particles or filler particles may fall off and interfere with the photomask
Solution Approach 1:
The coating is segmented into an inner layer containing particles for stray light resistance and an outer particle-free layer that prevents particle fall-off. This segmentation allows the system to maintain stray light resistance while eliminating the harmful effect of particle contamination.
Solution Approach 2:
The second polymer layer acts as an intermediary protective layer between the particle-containing first layer and the external environment. It shields the particles in the first layer from exposure to stray light while preventing particle fall-off, thus mediating between light resistance requirements and contamination prevention.
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 pellicle frame effectively prevents particle contamination on the photomask even when exposed to stray light, enhancing the reliability and precision of photolithography processes for miniaturized pattern formation in semiconductor and liquid crystal display manufacturing.
Implementation Method 1
the current pellicle film for ArF is required to have a light resistance of about 100,000 J, so that the inside face of a pellicle frame is correspondingly required to have a light resistance of about 1,500 J
Implementation Method 2
a matte black electrodeposition coating film prepared by using a matte coating material colored with a black pigment
Data Source
AI summary
There is provided a pellicle frame which prevents particles such as carbon black particles or filler particles from contaminating a photomask even when stray light hits the inside face of the pellicle frame in the exposure step of photolithography. More specifically, provided are a pellicle frame including a frame base, and a polymer coating layer coating at least an inner circumferential surface of the frame base, the polymer coating layer including an outermost polymer layer on a side farthest away from the frame base and one or more inner polymer layers between the frame base and the outermost polymer layer, wherein at least one of the one or more inner polymer layers contains particles, and the outermost polymer layer contains no particles or has a particle concentration lower than a highest particle concentration among the one or more inner polymer layers; and a pellicle including the pellicle frame.