Method for processing substrate, chemical solution, and method for providing chemical solution

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Solution Overview

Problem

Existing substrate processing methods using fluorine-containing alcohols and isopropyl alcohol (IPA) face challenges in mass production due to high global warming potential, moisture absorption, and potential for pattern collapse from capillary forces during drying.

Innovation Solution

A method involving a rinsing step with water, followed by a chemical solution replacement using an organic solvent with higher specific gravity than water, transitioning to a supercritical state for removal, excluding solvents with fluorine atoms, to suppress pattern collapse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fluorine-containing alcohol is used as a supercritical fluid, then pattern collapse is suppressed, but global warming potential increases and cost increases

Engineering Contradiction:

Improvepattern collapse suppressionVSAvoidglobal warming potential

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces expensive fluorine-containing alcohols with common, inexpensive organic solvents like isopropyl alcohol or acetone that can be easily disposed of after use. These solvents achieve the same supercritical drying function without the environmental persistence and high global warming potential of fluorinated compounds.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical composition parameters of the supercritical fluid from fluorine-containing alcohols to conventional organic solvents. By adjusting the critical temperature and pressure parameters within the processing conditions, the patent achieves effective pattern collapse suppression using environmentally friendly alternatives.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If isopropyl alcohol (IPA) is used as a supercritical fluid, then cost is reduced, but moisture absorption increases leading to pattern collapse

Engineering Contradiction:

Improvecost reductionVSAvoidmoisture absorption resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies a preliminary water removal step using a water-soluble solvent before introducing the organic supercritical fluid. This preliminary action prevents moisture from remaining on the substrate surface, eliminating the source of pattern collapse while allowing the use of cost-effective organic solvents.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces a water-soluble solvent as an intermediary substance that bridges the water-based rinsing solution and the organic supercritical fluid. This intermediary removes water from the substrate surface, preventing moisture absorption issues while enabling the use of inexpensive organic solvents.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If conventional drying methods are used, then process simplicity is maintained, but pattern collapse occurs due to capillary force

Engineering Contradiction:

Improveprocess simplicityVSAvoidpattern collapse

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent utilizes the phase transition of organic solvents to supercritical states by applying heat and pressure. This phase transition eliminates the liquid-gas interface and surface tension, preventing capillary force-induced pattern collapse while maintaining a relatively simple processing flow.

Inventive Principle:

Principle #36Phase transitions

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

Effectively removes residual liquid without forming interfaces, reducing pattern collapse and environmental impact while maintaining cost-effectiveness.

Implementation Method 1

raising the temperature of the substrate wetted with the chemical solution to a temperature equal to or higher than the critical temperature of the chemical solution to allow the chemical solution to reach a supercritical state

Methodology Applied

Scientific EffectSupercritical state transition: Phase Change

Implementation Method 2

removing the chemical solution in the supercritical state from the surface of the substrate... since no gas-liquid interface is formed, the surface of the substrate can be dried without causing the capillary force to act

Methodology Applied

Scientific EffectSupercritical drying: Supercritical Drying

Data Source

PatentUS12593639B2Method for processing substrate, chemical solution, and method for providing chemical solution

Publication Date: 2026.03.31 TOKYO OHKA KOGYO CO LTD

AI summary

A method for processing a substrate, for processing a surface of a substrate having projections/depressions formed on the surface, the method having: a rinsing step S101 of rinsing the surface of the substrate with a rinsing solution containing water; a chemical solution replacement step S102 of bringing a chemical solution into contact with the surface of the substrate that has been rinsed, to replace a liquid adhering to the surface of the substrate from the rinsing solution to the chemical solution; a state change step S103 of raising a temperature of the substrate wetted with the chemical solution to a temperature equal to or higher than the critical temperature of the chemical solution to allow the chemical solution to reach a supercritical state; and a removing step S104 of removing the chemical solution in the supercritical state from the surface of the substrate, in which the chemical solution contains an organic solvent (S1) (excluding, however, organic solvents having a fluorine atom) having a higher specific gravity than water.