Nanotube Pellicle Coating for EUV Radical Protection

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Solution Overview

Problem

The challenge in semiconductor manufacturing is protecting UV and EUV reflecting components from damage caused by hydrogen and oxygen radicals during EUV processing, while maintaining high transmission levels and heat transfer efficiency.

Innovation Solution

An optical assembly using a matrix of nanotube bundles or individual nanotubes with a core-shell structure and a protective coating layer that shields against hydrogen and oxygen radicals, ensuring high EUV transmittance and heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective coating is applied to shield against hydrogen and oxygen radicals, then reliability is improved, but EUV transmittance may deteriorate

Engineering Contradiction:

Improveprotection from radical damageVSAvoidEUV transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies a composite coating structure consisting of multiple layers with different materials and functions. The inner layer uses silicon nitride or boron nitride for radical protection, while the outer layer uses fluorinated materials for low EUV absorption. This composite structure resolves the contradiction by combining materials with complementary properties to achieve both protection and high transmittance.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The coating is applied with spatial differentiation where the inner layer directly contacts the nanotube surface for radical protection, while the outer layer is optimized for EUV transmission. This local quality differentiation allows each layer to perform its specific function optimally without compromising the other.

Inventive Principle:

Principle #3Local quality

2Duration of action of stationary object

If a protective coating is applied to shield against hydrogen and oxygen radicals, then durability is improved, but heat transfer efficiency may deteriorate

Engineering Contradiction:

Improvemask lifeVSAvoidheat transfer efficiency

Core Design Contradiction:

Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

The patent optimizes the coating thickness parameter to be extremely thin (1-10 nanometers) to minimize thermal resistance while maintaining radical protection. This parameter optimization allows the coating to provide chemical protection without significantly impeding heat transfer from the nanotubes.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The composite coating structure uses materials with different thermal and chemical properties. The inner silicon nitride/boron nitride layer provides chemical stability and radical resistance, while the outer fluorinated layer maintains low thermal resistance and high EUV transmittance, thus preserving heat transfer efficiency.

Inventive Principle:

Principle #40Composite materials

3Strength

If nanotube bundles are used as transparent layer, then mechanical strength is improved, but EUV transmittance may deteriorate

Engineering Contradiction:

Improvestructural integrityVSAvoidEUV transmittance

Core Design Contradiction:

StrengthVSIllumination intensity

Solution Approach 1:

The patent uses individual nanotubes or loosely bundled nanotubes arranged as a mesh or matrix structure rather than dense bundles. This thin-film-like arrangement provides mechanical strength while maintaining high EUV transmittance by minimizing the total material cross-section that EUV photons must traverse.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The nanotube arrangement creates an inherently porous structure with significant open space between tubes. This porosity allows EUV radiation to pass through with minimal interaction while the nanotube framework maintains structural integrity and strength.

Inventive Principle:

Principle #31Porous 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

The solution effectively protects the optical assembly from radical damage, extends the life of EUV masks, and maintains high EUV transmittance and heat transfer efficiency.

Implementation Method 1

The coating layer protects the matrix of nanotubes from damage caused by hydrogen and oxygen radicals that may occur during extreme ultraviolet processing

Methodology Applied

Scientific EffectRadical protection:

Implementation Method 2

generating extreme ultraviolet radiation in an extreme ultraviolet lithography system. The extreme ultraviolet radiation is passed through a coating layer of a pellicle membrane

Methodology Applied

Scientific EffectEUV transmission: Absorption (EM radiation)

Implementation Method 3

maintains high EUV transmittance and heat transfer efficiency

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS12461447B2Optical assembly with coating and methods of use

Publication Date: 2025.11.04 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Coated nanotubes and bundles of nanotubes are formed into membranes useful in optical assemblies in EUV photolithography systems. These optical assemblies are useful in methods for patterning materials on a semiconductor substrate. Such methods involve generating, in a UV lithography system, UV radiation. The UV radiation is passed through a coating layer of the optical assembly, e.g., a pellicle assembly. The UV radiation that has passed through the coating layer is passed through a matrix of individual nanotubes or matrix of nanotube bundles. UV radiation that passes through the matrix of individual nanotubes or matrix of nanotube bundles is reflected from a mask and received at a semiconductor substrate.