Acid-Generating Resin for Lithography Pattern Quality
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Solution Overview
Problem
Current chemically amplified positive resist compositions for semiconductor microfabrication, particularly in ArF excimer laser lithography, extreme ultraviolet (EUV) lithography, and electron lithography, face challenges in achieving high resolution patterns and suppressing the elution of cation and anion components, which affect pattern quality and line edge roughness.
Innovation Solution
A novel resin is developed that generates an acid by irradiation and is a salt of an organic cation and an anionic polymer with no carbon-carbon unsaturated bond, incorporating structural units from optionally substituted acrylic compounds and alicyclic compounds with anionic groups, which improves resist performance and solubility in alkali solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional acid generators (non-polymer compounds) are used in chemically amplified positive resist compositions, then the resist can achieve basic patterning functionality, but the cation and anion components elute in water or high refractive index solvents during liquid immersion lithography, degrading pattern quality and increasing line edge roughness
Solution Approach 1:
The patent combines the acid generator function and the polymer backbone into a single integrated molecule. The onium salt (acid generator) is covalently bonded to the polymer chain, eliminating the need for separate cation/anion pairs. This merging prevents elution of ionic components during liquid immersion lithography while maintaining acid generation capability upon irradiation.
Solution Approach 2:
The acid generator is pre-attached to the polymer backbone before the lithography process. This preliminary bonding ensures that when the resist is exposed to liquid immersion conditions, the ionic components cannot elute because they are already anchored to the polymer structure, thus preventing pattern degradation from the outset.
2Manufacturing precision
If high resolution patterns are pursued in ArF excimer laser lithography, extreme ultraviolet (EUV) lithography, and electron lithography, then manufacturing precision improves, but the elution of ionic components from conventional acid generators increases, harming pattern profile
Solution Approach 1:
The patent merges the acid generator with the polymer backbone through covalent bonding, creating a unified structure where the ionic components cannot separate and elute. This eliminates the harmful elution effect that degrades high-resolution patterns in advanced lithography processes.
Solution Approach 2:
The polymer backbone acts as an intermediary that anchors the acid generator to the resist matrix. This intermediary structure prevents direct contact and potential elution of ionic components while still allowing acid generation to occur upon irradiation, thus protecting pattern quality.
3Ease of manufacture
If conventional acid generators are used, then the resist composition is simpler to manufacture, but the cation and anion components separate and elute in processing solvents, reducing resist performance
Solution Approach 1:
The patent combines multiple functional components (polymer backbone and acid generator) into a single molecular structure. This merging simplifies the overall resist composition by eliminating the need for separate acid generator additives, while simultaneously improving reliability by preventing component elution during processing.
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 resin enhances pattern resolution and line edge roughness, reducing cation and anion component elution, thereby providing excellent resist abilities and improved pattern profiles in advanced lithography processes.
Implementation Method 1
a resin which generates an acid by irradiation and is a salt of an organic cation and an anionic polymer
Data Source
AI summary
The present invention provides a resin which generates an acid by irradiation and is a salt of an organic cation and an anionic polymer wherein the anionic polymer has no carbon-carbon unsaturated bond. The present invention further provides a chemically amplified resist composition comprising the same.