Resist Composition with Acid Trapping for EUV Patterning

Solution Overview

Problem

Conventional organic solvent development for negative tone resist compositions in microelectronic manufacturing suffers from low dissolution contrast and poor resolution due to high acid diffusion, leading to image blurring and edge roughness issues.

Innovation Solution

A resist composition incorporating a base polymer with specific repeat units, including a carboxy group substituted with an acid labile group and a maleimide group in the side chain, is used to enhance dissolution contrast and suppress acid diffusion, thereby improving resolution and edge roughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional organic solvent development resist composition is used, then the process is simple and cost-effective, but the dissolution contrast is low and resolution is poor due to high acid diffusion

Engineering Contradiction:

ImproveresolutionVSAvoidacid diffusion

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a base polymer with specific local chemical structures (repeat units containing carboxy groups and maleimide groups) that creates localized acid trapping zones. The carboxy groups (—COOH) and maleimide groups (—CO—CH=CH—CO—) are positioned at specific locations within the polymer chain to locally neutralize and trap acid, preventing its diffusion while maintaining overall resist performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The base polymer acts as an intermediary substance between the acid generator and the resist film matrix. It mediates the acid diffusion by providing functional groups that trap and neutralize acid, thereby controlling acid distribution and preventing harmful diffusion effects while allowing the resist to maintain its structural integrity and development characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If crosslinking reaction proceeds by acid in addition to deprotection reaction, then the resist composition can be developed with organic solvent, but the acid diffusion distance becomes long causing image blurring

Engineering Contradiction:

Improveorganic solvent developmentVSAvoidimage sharpness

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent introduces a base polymer with specific local chemical structures (repeat units containing carboxy groups and maleimide groups) that creates localized acid trapping zones. The carboxy groups (—COOH) and maleimide groups (—CO—CH=CH—CO—) are positioned at specific locations within the polymer chain to locally neutralize and trap acid, preventing its diffusion while maintaining overall resist performance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The base polymer acts as an intermediary substance between the acid generator and the resist film matrix. It mediates the acid diffusion by providing functional groups that trap and neutralize acid, thereby controlling acid distribution and preventing harmful diffusion effects while allowing the resist to maintain its structural integrity and development characteristics.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Manufacturing precision

If the dissolution contrast of resist film is increased, then the resolution improves, but the edge roughness increases

Engineering Contradiction:

ImproveresolutionVSAvoidedge roughness

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The patent changes the chemical parameters of the base polymer by introducing specific repeat units with carboxy groups and maleimide groups. These parameter changes in the polymer's chemical structure enable the resist to achieve high dissolution contrast while controlling edge roughness through the specific acid-trapping capability of the functional groups.

Inventive Principle:

Principle #35Parameter changes

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 resist composition achieves high dissolution contrast, improved resolution, and reduced edge roughness, resulting in better pattern profiles and exposure latitude, making it suitable for advanced micropatterning applications such as VLSI fabrication and EUV exposure.

Implementation Method 1

an acid generator (a photoacid generator) capable of generating an acid by photolysis

Methodology Applied

Scientific EffectPhotolysis: Photodissociation

Implementation Method 2

maleimide groups are dimerized by light irradiation

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Implementation Method 3

a polymer including a repeat unit having a carboxy group substituted with an acid labile group and a repeat unit having a maleimide group in a side chain, wherein crosslinking reaction proceeds by an acid

Methodology Applied

Scientific EffectCrosslinking reaction: Chemical Bonding

Data Source

PatentUS20240329529A1Resist composition and pattern forming process

Publication Date: 2024.10.03 SHIN ETSU CHEMICAL CO LTD

AI summary

The resist composition exhibits a higher resolution and smaller edge roughness than those of a conventional organic solvent development type negative resist composition. Provided is a resist composition comprising a base polymer containing a polymer including a repeat unit having a carboxy group substituted with an acid labile group and a repeat unit having a maleimide group in a side chain.