Photoresist Composition for Immersion Lithography
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Solution Overview
Problem
Current photoresist compositions for forming negative photoresist patterns face challenges in achieving optimal resolution and uniformity, particularly in immersion exposure processes, where existing compositions with acid-labile groups may not provide sufficient control over development processes.
Innovation Solution
A photoresist composition comprising a resin with specific structural units represented by formulas (I) and (a4), along with an acid generator, is applied to a substrate, exposed to radiation, baked, and developed to form a pattern, utilizing a process that includes steps of application, drying, exposure, baking, and development to produce a negative photoresist pattern with improved characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a photoresist composition with acid-labile groups is used for negative pattern formation, then development control is improved, but resolution and pattern uniformity deteriorate
Solution Approach 1:
The patent changes the chemical parameter of the resin by introducing fluorinated cyclic carbonates with specific molecular structures (formulas 1-4) and controlling their content ratio (5-50 mol%). This parameter change modifies the resin's interaction with the alkaline developer, achieving both good development control and high pattern uniformity without relying on acid-labile groups.
Solution Approach 2:
The patent creates a composite photoresist system combining the fluorinated cyclic carbonate resin (main resin) with specific additives including base components (formulas 2-1 to 2-4), acid generators, and other functional materials. This composite approach synergistically achieves resolution, uniformity, and development control that cannot be obtained by the main resin alone.
2Manufacturing precision
If conventional photoresist composition is used, then manufacturing process is simple, but CD uniformity and resolution are insufficient
Solution Approach 1:
The patent achieves superior CD uniformity by changing the chemical composition parameters - specifically using fluorinated cyclic carbonates with 5-12 carbon atoms in specific molecular configurations (formulas 1-4) at controlled ratios (5-50 mol%). This precise parameter control enables high-resolution patterning with excellent CD uniformity.
Solution Approach 2:
The patent introduces specific fluorinated cyclic carbonate structures (formulas 1-4) with distinct local molecular characteristics into the resin system. These localized structural features provide specific interactions during exposure and development that enhance CD uniformity and resolution without requiring complete redesign of the entire composition system.
3Productivity
If photoresist composition for immersion exposure is used, then exposure efficiency is improved, but pattern defects increase
Solution Approach 1:
The patent modifies the resin's chemical parameters by incorporating fluorinated cyclic carbonate groups that provide optimal solubility and reactivity characteristics for immersion exposure. The specific fluorine-containing structures (formulas 1-4) at 5-50 mol% content optimize the resin's interaction with immersion liquid and photoacid generator, achieving high exposure efficiency with minimal defects.
Solution Approach 2:
The patent employs a photoresist composition designed for single-use immersion exposure processes, where the fluorinated resin structure is optimized to perform its function during the exposure and development cycle, then can be removed or replaced. This approach enables high-throughput manufacturing with consistent quality.
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 composition achieves enhanced CD uniformity and reduced defects in the photoresist pattern, providing improved resolution and resistance to dry-etching, suitable for advanced lithography techniques like KrF excimer laser and EUV exposure lithography.
Implementation Method 1
a compound which generates an acid by exposure
Data Source
AI summary
A photoresist composition comprisinga resin which has no acid-labile group and which comprises a structural unit represented by formula (I);and a structural unit represented by formula (a4);a resin which has an acid-labile group; andan acid generator.