Iodine-Containing Polymers for EUV Resist Sensitivity

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Solution Overview

Problem

Current EUV lithography technologies face challenges in resist sensitivity and line edge roughness due to low absorption cross-section of typical resist materials at 13.5 nm, necessitating improved materials with enhanced EUV sensitivity.

Innovation Solution

Development of iodine-containing monomers and polymers with specific structural features to increase absorption cross-section, including a monomer formula (I) and copolymers with acid-deprotectable units, which are incorporated into photoresist compositions to enhance EUV sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If typical resist materials (carbon, oxygen, hydrogen, nitrogen) are used, then the material composition is simple and easy to manufacture, but the absorption cross-section at 13.5 nm is very weak resulting in poor EUV sensitivity

Engineering Contradiction:

ImproveEUV sensitivityVSAvoidmaterial complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the atomic composition parameters of the resist material by incorporating iodine atoms, which have remarkably high absorption cross-section at EUV radiation (13.5 nm). This parameter change directly addresses the weak absorption issue while maintaining polymer structure for manufacturability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates composite polymer materials combining iodine-containing monomers with other functional monomers (acid-deprotectable monomers, solubility-controlled monomers). This composite approach achieves high EUV sensitivity through iodine while incorporating multiple functions (solubility control, acid generation) within a single material system

Inventive Principle:

Principle #40Composite materials

2Reliability

If fluorine atoms are used to increase absorption cross-section, then EUV sensitivity is improved compared to typical atoms, but the absorption is still insufficient compared to iodine

Engineering Contradiction:

ImproveEUV sensitivityVSAvoidabsorption cross-section

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the atomic absorption parameter by selecting iodine instead of fluorine or other light elements. Iodine's atomic structure provides remarkably high absorption cross-section at 13.5 nm, directly resolving the insufficient absorption problem while maintaining reasonable material quantities

Inventive Principle:

Principle #35Parameter changes

3Reliability

If iodine-containing monomers are incorporated into polymers, then EUV sensitivity is improved, but solubility and processability may be compromised

Engineering Contradiction:

ImproveEUV sensitivityVSAvoidsolubility

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent applies local quality by incorporating iodine-containing monomer units at specific positions within the polymer chain, rather than uniformly throughout. The patent specifies that iodine-containing monomers should be present at 0.1-10 mol% of total monomers, creating localized high-absorption regions while maintaining overall polymer solubility and processability

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates composite polymers combining iodine-containing monomers with solubility-controlled monomers (containing polar groups, hydrogen bonding groups, or ionic groups). This composite structure achieves both high EUV sensitivity from iodine and good solubility from the complementary monomer units

Inventive Principle:

Principle #40Composite materials

4Reliability

If extended chain structures are used to improve iodine incorporation, then EUV sensitivity is enhanced, but line edge roughness may increase

Engineering Contradiction:

ImproveEUV sensitivityVSAvoidline edge roughness

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent optimizes the molecular weight and chain length parameters of the polymer to balance iodine incorporation with line edge roughness. By controlling the degree of polymerization and monomer distribution, the patent achieves sufficient iodine content for high sensitivity while maintaining smooth line edges through appropriate chain architecture

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 iodine-containing polymers demonstrate improved EUV sensitivity and reduced line edge roughness, enabling faster exposure and higher resolution in EUV lithography.

Implementation Method 1

Iodine has remarkably high absorption cross-section at EUV radiation

Methodology Applied

Scientific EffectPhotoabsorption: Absorption (EM radiation)

Data Source

PatentUS10901316B2Iodine-containing polymers for chemically amplified resist compositions

Publication Date: 2021.01.26 DUPONT ELECTRONIC MATERIALS INT LLC

AI summary

A monomer having formula (I):wherein in formula (I), groups and variables are the same as described in the specification.