Negative Resist Composition for EUV Lithography

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current negative resist compositions for semiconductor lithography face challenges in achieving high sensitivity and resolution while maintaining low line edge roughness, particularly when exposed to electron beams or EUV, due to the contradictory relationship between sensitivity, resolution, and line edge roughness.

Innovation Solution

A negative resist composition comprising a polyphenol compound with two or more phenolic hydroxyl groups, an acid generator that produces acid upon exposure to active energy rays, and a crosslinking agent with a specific chemical structure, optimizing solubility in alkaline aqueous solutions to enhance pattern formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a chemically amplified photosensitive composition is used to increase sensitivity, then sensitivity is improved, but resolution and line edge roughness deteriorate due to the contradictory relationship between sensitivity, resolution, and LER

Engineering Contradiction:

ImprovesensitivityVSAvoidresolution

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent changes the molecular weight parameter of the polyphenol compound from conventional high molecular weight (10,000 or more) to low molecular weight (300 to 3,000), which fundamentally alters the resist's performance characteristics to achieve both high sensitivity and high resolution simultaneously

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resist system combining low-molecular-weight polyphenol compound with specific crosslinking agents (formula 1) and acid generators, where the synergistic interaction of components achieves the desired balance between sensitivity, resolution, and LER that cannot be obtained by single materials

Inventive Principle:

Principle #40Composite materials

2Strength

If polymer materials with high molecular weight are used, then resist strength is improved, but resolution and line edge roughness deteriorate

Engineering Contradiction:

Improveresist strengthVSAvoidresolution

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent fundamentally changes the molecular weight parameter from high (10,000+) to low (300-3,000), and introduces a specific molecular structure (polyphenol compound with 2-8 phenolic hydroxyl groups) that provides sufficient strength through chemical bonding rather than molecular weight

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent enhances local strength at the crosslinking sites through specific chemical bonds formed between the polyphenol compound and crosslinking agent, creating strong local networks that provide overall resist strength without requiring high molecular weight throughout the entire polymer chain

Inventive Principle:

Principle #3Local quality

3Reliability

If conventional crosslinking agents are used, then crosslinking reaction is achieved, but sensitivity, resolution, and resist shape are not satisfied

Engineering Contradiction:

Improvecrosslinking reactionVSAvoidresolution

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes the chemical structure parameter of the crosslinking agent to formula (1) with specific organic groups (Ra, Rb, Rc) and hydrogen atoms, which optimizes the crosslinking reaction characteristics to achieve high sensitivity and resolution

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces specific functional groups (phenolic hydroxyl groups) at specific positions in the polyphenol compound that locally enhance crosslinking efficiency and pattern shape control, leading to improved resolution and resist morphology

Inventive Principle:

Principle #3Local quality

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 achieves well-shaped patterns with high sensitivity and resolution, preventing pattern collapse and improving adhesion to the substrate, thereby overcoming the limitations of existing resist materials.

Implementation Method 1

an acid generator which directly or indirectly produces acid by exposure to active energy rays having a wavelength of 248 nm or less

Methodology Applied

Scientific EffectPhotochemical reaction: Photopolymerisation

Implementation Method 2

a crosslinking bond is formed between the resin and crosslinking agent by the action of acid produced from the acid generator component by the exposure

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentUS8841059B2Crosslinking agent, negative resist composition, and pattern forming method using the negative resist composition

Publication Date: 2014.09.23 DAI NIPPON PRINTING CO LTD

AI summary

A negative resist composition, which shows excellent sensitivity and resolution in pattern formation by exposure to electron beams or EUV, a novel crosslinking agent suitable for the resist composition, and a pattern forming method using the resist composition are presented. The negative resist composition comprises: (A) a polyphenol compound comprising two or more phenolic hydroxyl groups in a molecule thereof and having a molecular weight of 300 to 3,000, (B) an acid generator which directly or indirectly produces acid by exposure to active energy rays having a wavelength of 248 nm or less, and (C) a crosslinking agent represented by the chemical formula (1).