Plastic Crystalline Drying for High-Aspect-Ratio Substrate Patterns

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Solution Overview

Problem

Conventional drying technologies, such as freeze drying and sublimation drying, often result in pattern collapse due to stress caused by crystal grain boundaries formed during the solidification and sublimation of sublimable substances on substrates with fine patterns and high aspect ratios, despite efforts to reduce pattern collapse using materials like cyclohexane.

Innovation Solution

A substrate treating method and apparatus using a substrate treating liquid containing a plastic crystalline material in a molten state, which forms a plastic crystalline layer on the substrate surface, allowing the layer to transition directly from a liquid to a gas state without an intermediate solid phase, thereby reducing stress on the pattern and preventing collapse.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional sublimation drying is used to remove liquid from substrate, then drying efficiency is improved, but pattern collapse occurs due to stress from crystal grain boundaries

Engineering Contradiction:
Improvedrying efficiencyVSAvoidpattern integrity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the physical state parameters of the drying agent by using a plastic crystalline material that transitions from liquid to gas without forming a solid crystal structure. This parameter change eliminates crystal grain boundary formation while maintaining efficient drying through direct liquid-to-gas transition.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes a unique phase transition pathway where the plastic crystalline material transitions directly from liquid state to gas state, bypassing the solid crystal phase entirely. This phase transition approach eliminates the formation of crystal grain boundaries that cause stress and pattern collapse in conventional sublimation drying.

Inventive Principle:
Principle #36Phase transitions

2Manufacturing precision

If freeze drying is used to prevent pattern collapse, then pattern integrity is improved, but stress from solidification and sublimation still causes collapse in fine high aspect ratio patterns

Engineering Contradiction:
Improvepattern integrityVSAvoidstress from crystal grain boundaries
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The invention changes the material parameters by selecting a plastic crystalline substance that does not form rigid crystal structures during phase transition. This parameter change eliminates the stress-generating crystal grain boundaries while maintaining the supportive function during drying.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs a modified phase transition sequence where the drying agent transitions from liquid to gas without passing through a solid phase. This eliminates the solidification and sublimation steps that create stress and crystal grain boundaries in conventional freeze drying methods.

Inventive Principle:
Principle #36Phase transitions

3Productivity

If materials like cyclohexane are used for sublimation drying, then drying efficiency is improved, but pattern collapse still occurs due to crystal grain boundary formation

Engineering Contradiction:
Improvedrying efficiencyVSAvoidstress from crystal grain boundaries
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the fundamental parameter of the drying agent's crystalline structure by using a plastic crystalline material that lacks rigid long-range order. This parameter change allows efficient drying while eliminating the formation of stress-inducing crystal grain boundaries that occur with conventional sublimable materials like cyclohexane.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a plastic crystalline material that combines properties of both liquid and crystalline states, creating a unique material phase that enables efficient drying without forming rigid crystal grain boundaries. This composite material approach merges the benefits of structured materials with the flexibility of liquids.

Inventive Principle:
Principle #40Composite materials

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

This approach effectively minimizes pattern collapse by eliminating the formation of crystal grain boundaries, even on substrates with fine patterns and high aspect ratios, compared to conventional methods using sublimable substances.

Implementation Method 1

the plastic crystalline material in the state of the plastic crystal is changed into a gas state without an intermediate phase of liquid so as to remove the plastic crystalline layer

Methodology Applied
Scientific EffectPhase transition (liquid to gas without intermediate solid phase): Phase Change

Implementation Method 2

cooling the substrate treating liquid supplied to the front surface Wa of the substrate W so as to form a plastic crystalline layer 63 on the front surface Wa of the substrate W

Methodology Applied
Scientific EffectPhase transition (liquid to plastic crystal state): Phase Change

Implementation Method 3

bringing the plastic crystalline material into a state of the plastic crystal so as to form the plastic crystalline layer

Methodology Applied
Scientific EffectPlastic crystalline state formation: Crystallisation

Implementation Method 4

supplying the coolant 64 toward the back surface Wb of the substrate W

Methodology Applied
Scientific EffectHeat removal: Cooling

Data Source

PatentEP3460830B1Substrate treating method, substrate treating liquid and substrate treating apparatus
Publication Date: 2024.11.06 SCREEN HOLDINGS CO LTD
  • EP3460830B1 patent drawingFigure 1~2
  • EP3460830B1 patent drawingFigure 3
  • EP3460830B1 patent drawingFigure 4A~4B

AI summary

Disclosed is a substrate treating method of performing drying treatment on a pattern-formed surface of a substrate, the substrate treating method comprising: a supplying step of supplying a substrate treating liquid containing a plastic crystalline material in a molten state to the pattern-formed surface of the substrate; a plastic crystalline layer forming step of bringing, on the pattern-formed surface, the plastic crystalline material into a state of a plastic crystal so as to form a plastic crystalline layer; and a removing step of changing the plastic crystalline material in the state of the plastic crystal into a gas state without an intermediate phase of liquid so as to remove the plastic crystalline material from the pattern-formed surface.