Chemically Amplified Resist Polymer for EUV Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current chemically amplified resist compositions face challenges in achieving high sensitivity and reduced line width roughness (LWR) or critical dimension uniformity (CDU) for pattern formation, especially when processed using electron beam (EB) or extreme ultraviolet (EUV) lithography, due to acid diffusion issues.
Innovation Solution
A polymer comprising recurring units with an acid labile group containing a multiple bond, phenolic hydroxyl groups, and units that generate acid upon exposure is formulated, which enhances sensitivity, contrast, and resolution while minimizing acid diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If acetal protective groups requiring small activation energy are used to achieve high sensitivity, then resist sensitivity is improved, but acid diffusion occurs causing degradation of LER and loss of CDU
Solution Approach 1:
The invention changes the chemical structure parameter of the protective group from conventional acetal to a novel group containing a multiple bond (double or triple bond). This structural modification alters the activation energy characteristics and acid diffusion behavior, achieving both high sensitivity and suppressed acid diffusion. The multiple bond introduces unique electronic and steric properties that conventional single-bond protective groups lack.
Solution Approach 2:
The invention uses a composite protective group structure combining multiple functional elements: a multiple bond (double or triple bond), specific substituent patterns (R1-R8 groups), and acid-labile characteristics. This composite structure integrates the benefits of high acid reactivity (for sensitivity) with controlled diffusion properties, which cannot be achieved by conventional single-type protective groups.
2Manufacturing precision
If conventional protective groups are used to control acid diffusion, then LER and CDU are maintained, but resist sensitivity is insufficient
Solution Approach 1:
The invention modifies the protective group structure by introducing a multiple bond, which changes the electronic distribution, bond strength, and spatial configuration. This parameter change enables the protective group to maintain structural integrity during storage and application while providing controlled acid diffusion during exposure, achieving both precision and sensitivity.
Solution Approach 2:
The protective group is segmented into distinct functional regions: the multiple bond region (providing structural rigidity and controlled diffusion), the substituent regions (R1-R8 providing electronic modulation), and the acid-labile region (providing deprotection functionality). This segmentation allows each region to independently optimize its function while working together to achieve overall performance.
3Manufacturing precision
If the diffusion of generated acid is suppressed to improve resolution, then LER and CDU are improved, but deprotection reaction cannot occur efficiently reducing sensitivity
Solution Approach 1:
The invention changes the chemical parameters of the protective group to create an optimized balance: the multiple bond provides structural stability that limits acid diffusion, while the acid-labile bonds within the group maintain high reactivity toward generated acid. This parameter optimization ensures that acid remains localized (improving resolution) while still being able to trigger efficient deprotection where needed.
Solution Approach 2:
The protective group acts as an intermediary between the generated acid and the polymer backbone. It selectively allows acid to penetrate and trigger deprotection at the intended location while preventing acid from diffusing to adjacent unexposed regions. The multiple bond structure serves as a controlled gateway that mediates acid transport, enabling precise spatial control of the deprotection reaction.
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 proposed resist composition exhibits improved sensitivity, high contrast, and wide process margins with reduced LWR and CDU, enabling the formation of fine patterns with enhanced dissolution properties.
Implementation Method 1
recurring units adapted to generate an acid upon exposure
Implementation Method 2
Under the catalysis of an acid generated from the photoacid generator upon exposure to high-energy radiation, the protective group is deprotected
Data Source
AI summary
A polymer comprising recurring units having a multiple bond-containing acid labile group, recurring units having a phenolic hydroxyl group, and recurring units adapted to generate an acid upon exposure is used to formulate a resist composition, which exhibits a high sensitivity, low LWR and improved CDU when processed by lithography using EUV of wavelength 13.5 nm.