Pellicle Adhesive Residue Reduction via Silane Copolymer
Solution Overview
Problem
The challenge is to develop an adhesive for pellicles used in photolithography that minimizes adhesive residue on masks after exposure, particularly when using shorter wavelength excimer lasers, as current adhesives either leave residue or have poor load-bearing capacity.
Innovation Solution
Incorporating a silane compound and/or a radical trapping agent and/or a UV absorbent into the adhesive, which reduces adhesive residue and outgassing, thereby enhancing the pellicle's durability and ease of removal without compromising load-bearing strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a silicone-based adhesive is used for the pellicle, then the adhesive strength is sufficient to prevent pellicle removal during exposure, but adhesive residue remains on the mask after peeling
Solution Approach 1:
The invention changes the chemical composition parameters of the adhesive by incorporating specific additives (silane compound, radical trapping agent, UV absorbent) into the acrylic-based adhesive formulation. This modifies the adhesive's chemical structure and reactivity to reduce residue formation while maintaining bonding strength
Solution Approach 2:
The invention creates a composite adhesive material by combining acrylic-based adhesive with multiple functional additives (silane compound, radical trapping agent, UV absorbent). This composite formulation achieves both strong adhesion and minimal residue by integrating multiple material properties into a single adhesive system
2Manufacturing precision
If exposure light with shorter wavelength is used, then higher resolution lithography is achieved, but adhesive residue increases due to increased contamination
Solution Approach 1:
The invention converts the harmful effect of short-wavelength exposure light (which causes increased contamination and adhesive degradation) into a beneficial outcome by adding UV absorbent and radical trapping agents that specifically counteract the damaging effects of these wavelengths, thereby reducing adhesive residue while maintaining high-resolution capability
Solution Approach 2:
The invention modifies the adhesive's chemical parameters by adding components that are specifically responsive to UV radiation and short-wavelength light, changing how the adhesive behaves under high-resolution lithography conditions to reduce residue formation
3Ease of operation
If pellicle is peeled frequently for cleaning, then contamination is removed, but adhesive residue accumulates on the mask
Solution Approach 1:
The invention changes the adhesive's chemical composition to include silane compounds and radical trapping agents that reduce the adhesive's tendency to leave residue during peeling operations, making frequent pellicle removal feasible without accumulating mask contamination
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 effectively decreases adhesive residue and outgassing, extending the pellicle's lifespan and improving manufacturing efficiency by ensuring stable adhesive strength and easy removal without causing mask contamination.
Implementation Method 1
adhesive residue on a mask after lithographic exposure and outgassing from the adhesive are decreased
Implementation Method 2
the adhesive contains a (meth)acrylic alkyl ester copolymer and a silane compound... adhesive residue on a mask after lithographic exposure and outgassing from the adhesive are decreased
Data Source
AI summary
To provide a pellicle having a an adhesive, wherein adhesive residue is decreased at the time of peeling the pellicle from a mask after lithographic exposure and outgassing from the adhesive is suppressed The pellicle according to the present invention is a pellicle comprising a pellicle frame, a tensioned pellicle film placed on one end surface of the pellicle frame and an adhesive applied to the other end surface thereof, in which the adhesive contains a (meth)acrylic alkyl ester copolymer and a silane compound, and the (meth)acrylic alkyl ester copolymer is a copolymer of a (meth)acrylic alkyl ester having an alkyl group of 4 to 14 carbon atoms and a monomer having a functional group reactive to at least either one of an isocyanate group or an epoxy group.