Fluorine-Modified Resist Composition for Immersion Lithography

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Solution Overview

Problem

Conventional resist compositions for immersion lithography face challenges in reducing substance elution and improving water tracking ability, leading to defects in resist patterns, especially with increased scanning speed in scan-type immersion lithography.

Innovation Solution

A resist composition that includes a base component and a fluorine additive component with a structural unit derived from a specific compound, enhancing the hydrophobicity of the resist film to reduce substance elution and improve water tracking ability, thereby reducing defects and improving lithography properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the hydrophobicity of the resist film is enhanced to reduce substance elution, then the elution of substance into the immersion medium is reduced, but the water tracking ability may be adversely affected

Engineering Contradiction:

Improvesubstance elutionVSAvoidwater tracking ability

Core Design Contradiction:

Loss of substanceVSReliability

Solution Approach 1:

The patent modifies the chemical composition parameters of the resist film by incorporating fluorine-containing compounds with specific molecular structures (formula 1) that have controlled fluorine content (0.1-10 mass%) and specific functional groups. This changes the surface energy and chemical properties of the resist film to achieve optimal balance between hydrophobicity and water tracking ability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resist system by combining the base resist components with fluorine-containing compounds as additives. This composite material approach allows the fluorine-containing compound to provide hydrophobicity while the base resist maintains water tracking ability, achieving synergistic effects that resolve the contradiction

Inventive Principle:

Principle #40Composite materials

2Productivity

If the scanning speed is increased to improve productivity, then the production efficiency is improved, but the water tracking ability deteriorates leading to defects

Engineering Contradiction:

Improvescanning speedVSAvoidwater tracking ability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies fluorine-containing compounds to the resist film before the immersion lithography process to pre-establish enhanced hydrophobicity and water tracking ability. This preliminary modification ensures that when high-speed scanning is performed, the resist film already has the necessary properties to prevent defects, rather than trying to correct issues during the process

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If conventional resist compositions are used in immersion lithography, then the basic lithography properties are maintained, but substance elution occurs and defects are generated

Engineering Contradiction:

Improvelithography propertiesVSAvoidsubstance elution and defects

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The fluorine-containing compound acts as an intermediary substance between the resist film and the immersion medium (water). It modifies the interface properties to reduce substance elution into the water while maintaining the necessary lithography properties, preventing defect generation without compromising manufacturing precision

Inventive Principle:

Principle #24Intermediary (Mediator)

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 water repellency and reduces defect generation, enhancing the productivity and quality of resist patterns in immersion lithography, particularly at higher scanning speeds.

Implementation Method 1

enhancing the hydrophobicity of the resist film to reduce substance elution

Methodology Applied

Scientific EffectHydrophobicity: Hydrophobe

Implementation Method 2

a water tracking ability in which the immersion medium is capable of tracking the movement of the lens

Methodology Applied

Scientific EffectWater tracking: Wetting

Data Source

PatentUS10838301B2Resist composition, method of forming resist pattern, fluorine-containing compound, and compound

Publication Date: 2020.11.17 TOKYO OHKA KOGYO CO LTD

AI summary

A resist composition which generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid, the resist composition including: a base component which exhibits changed solubility in a developing solution under action of acid and a fluorine additive component which exhibits decomposability to an alkali developing solution, the fluorine additive component including a fluorine resist component having a structural unit derived from a compound represented by general formula (f1-1) in which W represents a polymerizable group-containing group; Rf1 and Rf2 each independently represents a hydrogen atom or an electron-withdrawing group; and Rf3 represents a hydrocarbon group