Shrink Material for Lithography Pattern Control

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Solution Overview

Problem

Current methods for shrinking hole patterns in photolithography, such as the RELACS method and those using amino-containing polymers or block copolymers, face issues like non-uniform size reduction, shape deformation, and increased dimensional variations, particularly in narrow pitch patterns and trench patterns.

Innovation Solution

A shrink material comprising a polymer with specific recurring units and an anti-vanishing solvent is applied to a resist pattern, forming a negative tone resist pattern through exposure and organic solvent development, allowing for controlled shrinkage of hole and slit sizes without pattern deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the RELACS method or amino-containing polymer method is used to shrink hole patterns, then the resist pattern thickness is increased, but the dimensional variation and edge roughness are worsened

Engineering Contradiction:

Improvedimensional uniformityVSAvoidedge roughness

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention changes the chemical parameters of the shrink material by using a polymer with specific recurring units (formulae 1a and 1b) containing ester groups and hydroxyl groups, combined with a specific solvent system. This parameter change enables controlled shrinkage while maintaining dimensional uniformity and reducing edge roughness, resolving the contradiction between thickness increase and quality maintenance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite shrink material system combining a specific polymer with recurring units of formulae (1a) and (1b) and a solvent containing anti-vanishing solvent. This composite material approach allows simultaneous achievement of pattern thickening, dimensional uniformity, and reduced edge roughness, overcoming the limitations of single-component materials.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If block copolymer direct self-assembly is used to shrink hole patterns, then shrinkage amount is increased and dimensional variation is reduced, but pattern shape deformation occurs

Engineering Contradiction:

Improvedimensional variationVSAvoidpattern shape

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The invention applies local quality by using a shrink material with specific functional groups (ester and hydroxyl) that interact locally with the resist pattern surface. This localized interaction enables uniform shrinkage without causing the shape deformation associated with block copolymer self-assembly, while maintaining dimensional precision.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention replaces the mechanical/physical self-assembly mechanism of block copolymers with a chemical bonding mechanism involving the polymer's recurring units and solvent system. This substitution eliminates the shape deformation caused by DSA while maintaining the benefits of reduced dimensional variation and increased shrinkage control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Length of moving object

If shrink material is applied to narrow pitch patterns, then pattern shrinking is achieved, but dimensional variation increases

Engineering Contradiction:

Improvepattern sizeVSAvoiddimensional variation

Core Design Contradiction:

Length of moving objectVSManufacturing precision

Solution Approach 1:

The invention changes the chemical composition parameters of the shrink material by incorporating specific recurring units with ester and hydroxyl groups, which provide controlled interaction with narrow pitch patterns. This parameter change enables effective shrinking while maintaining dimensional uniformity, resolving the contradiction between size reduction and precision maintenance.

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 process effectively reduces the size of holes and slits in a controlled manner, improving dimensional uniformity and edge roughness of the resist pattern, addressing the limitations of existing methods.

Implementation Method 1

the shrink material comprising an amino-containing polymer or polyamine, which bonds to the resist surface via neutralization reaction with carboxyl groups on the resist surface

Methodology Applied

Scientific EffectNeutralization reaction: Chemical Bonding

Implementation Method 2

a shrink material comprising a polymer and a solvent containing an anti-vanishing solvent which does not cause a resist pattern after development to vanish

Methodology Applied

Scientific EffectAnti-vanishing solvent action:

Implementation Method 3

a base resin having an acid labile group-substituted carboxyl group and an acid generator

Methodology Applied

Scientific EffectAcid-catalyzed reaction: Catalysis

Data Source

PatentUS9904172B2Shrink material and pattern forming process

Publication Date: 2018.02.27 SHIN ETSU CHEMICAL CO LTD

AI summary

A shrink material is provided comprising a specific polymer and a solvent containing an anti-vanishing solvent. A pattern is formed by applying a resist composition comprising a base resin and an acid generator onto a substrate to form a resist film, exposing, developing in an organic solvent developer to form a negative resist pattern, applying the shrink material onto the pattern, and removing the excessive shrink material with an organic solvent for thereby shrinking the size of holes and/or slits in the pattern.