Pre-Wet Liquid Composition for Uniform Low-Volume Resist Coating

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Solution Overview

Problem

The challenge in semiconductor manufacturing is forming uniform resist films with minimal resist composition while avoiding coating defects, particularly with the demand for thinner films and economic efficiency.

Innovation Solution

A pre-wet liquid with specific surface tension, viscosity, and vapor pressure, composed of single or mixed organic solvents, is applied before resist composition, ensuring uniform spreading and preventing evaporation-related defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a small amount of resist composition is used to reduce cost, then economic efficiency is improved, but coating defects occur and uniformity deteriorates

Engineering Contradiction:

Improveresist composition usageVSAvoidresist film uniformity

Core Design Contradiction:

Loss of substanceVSManufacturing precision

Solution Approach 1:

The pre-wet liquid is applied to the substrate before applying the resist composition. This preliminary action modifies the substrate surface properties, creating optimal conditions for resist spreading and adhesion, thereby enabling uniform resist films even when using minimal amounts of resist composition.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention specifies precise physical parameter ranges for the pre-wet liquid (surface tension: 20-35 mN/m, viscosity: 0.5-2.0 cP, vapor pressure: 0.1-1.0 mmHg) to optimize its performance. By controlling these parameters, the pre-wet liquid achieves optimal wetting and spreading characteristics that enhance resist composition distribution and film uniformity.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If pre-wet liquid with high surface tension is used to prevent coating defects, then film uniformity is improved, but resist composition spreading becomes difficult

Engineering Contradiction:

Improveresist film uniformityVSAvoidresist composition spreading

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The invention optimizes the surface tension of the pre-wet liquid within a specific range (20-35 mN/m). This parameter optimization balances two competing requirements: high enough surface tension to prevent coating defects and maintain film uniformity, but not so high that it hinders the spreading of resist composition. The viscosity (0.5-2.0 cP) and vapor pressure (0.1-1.0 mmHg) parameters are also controlled to achieve optimal spreading characteristics.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If pre-wet liquid with low viscosity is used to improve spreading, then resist composition distribution is enhanced, but liquid control becomes difficult

Engineering Contradiction:

Improveresist composition distributionVSAvoidliquid application control

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention specifies a controlled viscosity range (0.5-2.0 cP) for the pre-wet liquid. This range is low enough to allow good spreading and distribution of the resist composition across the substrate surface, but not so low that the liquid becomes difficult to control during the application process. The balanced viscosity ensures both good distribution and manageable application.

Inventive Principle:

Principle #35Parameter changes

4Manufacturing precision

If pre-wet liquid with high vapor pressure is used to prevent evaporation defects, then coating defects are reduced, but solvent loss increases

Engineering Contradiction:

Improvecoating defect reductionVSAvoidsolvent loss

Core Design Contradiction:

Manufacturing precisionVSLoss of substance

Solution Approach 1:

The invention controls the vapor pressure of the pre-wet liquid within a specific range (0.1-1.0 mmHg). This parameter control prevents excessive evaporation during the coating process, thereby reducing coating defects that would otherwise occur due to solvent loss. The low vapor pressure ensures that the pre-wet liquid remains stable during application and does not evaporate prematurely, maintaining consistent performance.

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 pre-wet liquid enables efficient use of a small amount of resist composition, achieving uniform resist films with reduced defects and improved economic efficiency.

Implementation Method 1

a pre-wet liquid having a surface tension of 29.0 mN/m or more

Methodology Applied

Scientific EffectSurface tension: Surface Tension

Implementation Method 2

a vapor pressure of 2.5 to 5.0 mmHg

Methodology Applied

Scientific EffectVapor pressure: Vapour Pressure

Data Source

PatentUS12474636B2Pre-wet liquid, resist film forming method, pattern forming method, and kit

Publication Date: 2025.11.18 FUJIFILM CORP

AI summary

The pre-wet liquid is provided. The pre-wet liquid has a surface tension of 29.0 mN/m or more, a viscosity of 1.8 cP or less, and a vapor pressure of 2.5 to 5.0 mmHg, in a case of consisting of a single solvent, the pre-wet liquid has an SP value of 25.0 MPa1/2 or less and does not have a benzene ring group, and in a case of consisting of a mixed solvent, the pre-wet liquid satisfies the requirement 1 in which is a mixed solvent consisting of only two or more kinds of organic solvents A having specific SP value and specific surface tension and having no benzene ring group or the requirement 2 in which is a mixed solvent of an organic solvent A and an organic solvent B having specific SP value and specific surface tension.