Silicon Resist Underlayer Composition for Fine EUV Patterning

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Solution Overview

Problem

The challenge in semiconductor manufacturing is to achieve finer patterning with reduced resist film thickness while maintaining good lithography characteristics, particularly in metal oxide resist underlayer films, which are essential for next-generation EUV lithography.

Innovation Solution

A silicon-containing resist underlayer film-forming composition comprising polysiloxane and a solvent, with specific hydrolyzable silane components, is used to form a film that enhances sensitivity without increasing pattern roughness, incorporating organic groups with carbon-carbon double bonds to trap electrons and improve curing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the thickness of the resist film is reduced to achieve finer patterning, then the resolution is improved, but the sensitivity deteriorates

Engineering Contradiction:

Improvepatterning resolutionVSAvoidlithography sensitivity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces a silicon-containing resist underlayer film as an intermediary layer between the photoresist and substrate. This underlayer film contains organic groups with carbon-carbon double bonds that act as electron traps, mediating the interaction between incident electrons and the photoresist to improve sensitivity without compromising patterning resolution

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical composition parameters of the underlayer film by incorporating specific organic groups (vinyl, allyl, propargyl groups) with carbon-carbon double bonds. This parameter change enables electron trapping functionality, which improves lithography sensitivity while maintaining the thin film structure needed for fine patterning

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the resist film is thinned for finer patterning, then the resolution is improved, but the pattern roughness increases

Engineering Contradiction:

Improvepatterning resolutionVSAvoidpattern roughness

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The silicon-containing underlayer film serves as an intermediary that provides a controlled interface between the photoresist and substrate. The organic groups with carbon-carbon double bonds in this layer trap electrons and reduce scattering, thereby suppressing pattern roughness while enabling fine patterning resolution

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite underlayer film combining silicon-containing inorganic components with organic groups (vinyl, allyl, propargyl) containing carbon-carbon double bonds. This composite structure provides both the adhesion benefits of silicon-containing materials and the electron-trapping functionality of organic double bonds, reducing pattern roughness

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If conventional chemically amplified resist underlayer film is used, then the process is simple, but the lithography characteristics are insufficient for metal oxide resist

Engineering Contradiction:

Improveprocess simplicityVSAvoidlithography characteristics

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the chemical composition parameters of the underlayer film by incorporating organic groups with carbon-carbon double bonds (vinyl, allyl, propargyl groups) into the silicon-containing polymer structure. This compositional modification provides electron-trapping functionality that improves lithography characteristics for metal oxide resist while maintaining a relatively simple single-layer structure

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 composition improves sensitivity in fine patterning without reducing the roughness of the pattern, particularly in metal-containing resist films, enabling resolutions below 25 nm.

Implementation Method 1

incorporating organic groups with carbon-carbon double bonds to trap electrons and improve curing efficiency

Methodology Applied

Scientific EffectElectron trapping: Absorption (EM radiation)

Implementation Method 2

the polysiloxane contains a constituent unit derived from a hydrolyzable silane (A)

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP4671866A1Composition for forming silicon-containing resist underlayer film having carbon-carbon double bond

Publication Date: 2025.12.31 NISSAN CHEM CORP

AI summary

A silicon-containing resist underlayer film-forming composition including: component [A]: a polysiloxane; and component [C]: a solvent, in which the polysiloxane contains a constituent unit derived from a hydrolyzable silane (A) represented by the following Formula (A-1), in the Formula (A-1), a and b each independently represent an integer of 1 to 3, c represents an integer of 0 to 2, b+c represents an integer of 1 to 3, R1 represents a group represented by the following Formula (A-1-1), R2 represents a (a+1)-valent group having no ring structure or a (a+1)-valent group having an aromatic hydrocarbon ring, R3 represents a specific group, X represents, for example, an alkoxy group, in the Formula (A-1-1), R11 represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, R12 represents a hydrogen atom, a hydrocarbon group having 1 to 4 carbon atoms, or a halogen atom, and * represents a bonding hand.