Resist Composition Using Aromatic Solvent to Reduce LWR

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Solution Overview

Problem

Conventional resist compositions suffer from line width roughness (LWR) issues, particularly as demands for higher resolution resist patterns increase, limiting the precision of line patterns formed during the development process.

Innovation Solution

A resist composition is developed using a resin component that changes alkali solubility upon acid exposure, combined with an acid generator and an aromatic organic solvent, which reduces LWR by enhancing the solubility and pattern formation accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional resist compositions are used for high resolution lithography, then manufacturing precision requirements increase, but line width roughness (LWR) deteriorates

Engineering Contradiction:

Improveline width uniformityVSAvoidline width roughness

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical parameters of the resist composition by incorporating specific compounds: (1) a resin with carboxyl groups that provides controlled solubility, (2) a sulfonium salt acid generator for precise acid generation, (3) a cyclic carbonate additive that modifies the chemical environment, and (4) an aromatic solvent that enhances uniformity. These parameter changes collectively reduce LWR while maintaining manufacturing precision for high-resolution lithography.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If shorter wavelength light sources are used for miniaturization, then resolution improves, but transparency requirements increase

Engineering Contradiction:

Improvepattern resolutionVSAvoidlight absorption

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the optical parameters of the resist composition by selecting materials with appropriate transparency characteristics. The aromatic solvent and cyclic carbonate additive are specifically chosen to maintain high transparency in the ArF excimer laser wavelength range (193 nm), reducing light absorption while preserving the resolution benefits of the shorter wavelength source.

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 proposed solution effectively minimizes LWR, leading to improved resist pattern uniformity and precision, particularly effective for ArF excimer laser lithography, with enhanced mask linearity and exposure margin.

Implementation Method 1

an acid generator component (B) that generates acid upon exposure

Methodology Applied

Scientific EffectPhotoacid generation: Photoionisation

Implementation Method 2

obtained by dissolving a resin component (A) that displays changed alkali solubility under action of acid and an acid generator component (B) that generates acid upon exposure in an organic solvent (S)

Methodology Applied

Scientific EffectSolvation: Solvation

Data Source

PatentUS8007981B2Resist composition and method of forming resist pattern

Publication Date: 2011.08.30 TOKYO OHKA KOGYO CO LTD

AI summary

A resist composition of the present invention is obtained by dissolving a resin component (A) that displays changed alkali solubility under action of acid and an acid generator component (B) that generates acid upon exposure in an organic solvent (S), wherein the organic solvent (S) includes an aromatic organic solvent (S1). According to the present invention, a resist composition and a method of forming a resist pattern, in which the level of LWR is reduced, can be provided.