Acenaphthylene Monomer Resist Composition for Lithography

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Solution Overview

Problem

Existing chemically amplified resist compositions face challenges in achieving high sensitivity, high contrast, and improved lithography properties while minimizing acid diffusion and preventing pattern collapse during fine pattern formation and etching.

Innovation Solution

A monomer with an acenaphthylene structure and an acid labile tertiary ester group is incorporated into a polymer, which forms a chemically amplified resist composition that exhibits high solvent solubility, sensitivity, and contrast, and forms patterns with improved etch resistance and collapse resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If acid diffusion is suppressed by reducing temperature and/or time of post-exposure bake, then resolution is improved, but sensitivity and contrast are drastically reduced

Engineering Contradiction:

ImproveresolutionVSAvoidsensitivity

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The invention changes the chemical parameters of the acid generator by using a polymer-bound acid generator with a specific structure (Formula 1) that generates a bulky acid. This structural modification allows the acid to diffuse less while maintaining sufficient reactivity, thereby improving resolution without sacrificing sensitivity and contrast.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure by incorporating the acid generator functionality directly into the polymer backbone (polymer-bound acid generator). This composite approach combines the benefits of the polymer matrix with the acid generation capability, enabling controlled acid diffusion while maintaining high sensitivity.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If acid diffusion distance is reduced to improve resolution, then manufacturing precision is improved, but sensitivity and contrast are reduced

Engineering Contradiction:

ImproveresolutionVSAvoidcontrast

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention modifies the acid generator structure to produce a bulky acid with controlled diffusion characteristics. The specific structural parameters of the polymer-bound acid generator (Formula 1) are optimized to achieve the right balance between acid diffusion distance and acid strength, maintaining both resolution and contrast.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional resist compositions are used, then ease of manufacture is maintained, but pattern collapse and etch resistance are insufficient for fine patterns

Engineering Contradiction:

Improveease of manufactureVSAvoidpattern collapse resistance

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention uses a composite polymer structure that combines the acenaphthylene backbone (for pattern collapse resistance) with pendant acid labile groups (for etch resistance). This composite approach maintains ease of manufacture through conventional polymerization while achieving the required performance for fine patterns.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention applies local quality by incorporating specific functional groups at different positions: the acenaphthylene structure provides mechanical strength and pattern collapse resistance, while the pendant acid labile groups provide etch resistance. Each part of the polymer molecule is optimized for its specific function.

Inventive Principle:

Principle #3Local 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 high sensitivity, high contrast, and improved lithography properties, forming fine patterns with reduced line width roughness and enhanced etch resistance.

Implementation Method 1

the addition of an acid generator capable of generating a bulky acid is an effective means for suppressing acid diffusion

Methodology Applied

Scientific EffectPhotolysis: Photodissociation

Implementation Method 2

image blurs due to acid diffusion become a problem

Methodology Applied

Scientific EffectAcid diffusion: Diffusion

Implementation Method 3

an attempt to minimize acid diffusion by reducing the temperature and/or time of post-exposure bake (PEB) fails, resulting in drastic reductions of sensitivity and contrast

Methodology Applied

Scientific EffectAcid elimination reaction: Decomposition (biological)

Implementation Method 4

pattern collapse during fine pattern formation and resistance during etching step are important for positive resist compositions

Methodology Applied

Scientific EffectPattern collapse resistance:

Data Source

PatentUS20250110405A1Monomer, polymer, chemically amplified resist composition, and pattern forming process

Publication Date: 2025.04.03 SHIN ETSU CHEMICAL CO LTD

AI summary

A monomer containing as a polymerizable group an acenaphthylene structure having an acid labile group of tertiary ester type attached thereto is provided as well as a polymer comprising repeat units derived from the monomer. A chemically amplified resist composition comprising the polymer has advantages including high sensitivity, high contrast, improved lithography properties, e.g., EL, LWR and profile, collapse resistance during fine pattern formation, and etch resistance after development.