Aerogel Grid Pellicle for EUV Photolithography

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional pellicles for EUV photolithography systems are prone to mechanical and thermo-mechanical degradation due to high absorption and thermal loading, leading to instability and potential deformation or destruction under EUV radiation, which affects the integrity and longevity of the photolithography process.

Innovation Solution

A pellicle design incorporating an aerogel grid to support a low-absorption membrane, which minimizes light absorption and image degradation, and is constructed to withstand repeated exposures and maintenance procedures, using a process that includes forming a membrane layer on an aerogel grid and mounting it to a frame.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a conventional membrane is used as pellicle support, then the pellicle can be manufactured with simple structure, but the membrane undergoes mechanical and thermo-mechanical degradation due to high absorption and thermal loading under EUV radiation

Engineering Contradiction:

Improvepellicle manufacturing simplicityVSAvoidmembrane stability under EUV radiation

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent employs an aerogel grid structure with highly porous characteristics to support the membrane. The aerogel material's porous nature provides exceptional mechanical strength and thermal stability while maintaining low mass density, preventing the membrane from degrading under EUV radiation thermal loading.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent creates a composite structure combining the aerogel grid with the membrane material. This composite approach leverages the complementary properties of both materials: the aerogel provides structural stability and radiation resistance, while the membrane maintains optical transparency and flexibility, together solving the contradiction between simplicity and reliability.

Inventive Principle:

Principle #40Composite materials

2Strength

If the pellicle uses high-absorption materials for structural support, then the pellicle can withstand mechanical stresses, but light absorption increases causing image degradation

Engineering Contradiction:

Improvepellicle mechanical strengthVSAvoidlight transmission quality

Core Design Contradiction:

StrengthVSIllumination intensity

Solution Approach 1:

The aerogel grid's porous structure provides high strength-to-weight ratio, allowing the pellicle to withstand mechanical stresses from EUV radiation and handling while maintaining minimal light absorption. The porosity enables light to pass through with minimal interference, preserving image quality.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent uses thin-film aerogel structures that provide sufficient mechanical strength while being optically transparent. The thin-film configuration minimizes the total material path length for light, reducing absorption and maintaining high illumination intensity through the pellicle.

Inventive Principle:

Principle #30Flexible shells and thin films

3Device complexity

If conventional pellicles are used without aerogel support, then the structure is simpler and easier to manufacture, but the pellicle deforms or destroys under repeated EUV exposures and maintenance procedures

Engineering Contradiction:

Improvepellicle structure complexityVSAvoidpellicle longevity under repeated use

Core Design Contradiction:

Device complexityVSDuration of action of stationary object

Solution Approach 1:

The aerogel grid provides exceptional durability and resistance to thermal and mechanical stresses from repeated EUV exposures and maintenance procedures. The porous structure's inherent stability prevents deformation and destruction, extending the pellicle's operational lifespan.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent replaces conventional mechanical support structures with an aerogel-based system that uses the material's inherent thermomechanical stability rather than relying on traditional mechanical reinforcement. This substitution provides superior longevity while maintaining acceptable structural complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 aerogel-supported pellicle provides enhanced durability and stability, reducing image quality degradation and allowing for repeated cleaning and reuse, thus improving the robustness and cost-effectiveness of EUV photolithography processes.

Implementation Method 1

an aerogel grid and a membrane formed on the aerogel grid

Methodology Applied

Scientific EffectPorous material structure: Porosity

Implementation Method 2

minimizes light absorption and image degradation

Methodology Applied

Scientific EffectLight absorption: Absorption (EM radiation)

Data Source

PatentUS9547232B2Pellicle with aerogel support frame

Publication Date: 2017.01.17 GLOBALFOUNDRIES US INC

AI summary

Disclosed herein are various pellicles for use during extreme ultraviolet (EUV) photolithography processes. An EUV radiation device disclosed herein includes a reticle, a substrate support stage, a pellicle positioned between the reticle and the substrate support stage, wherein the pellicle includes an aerogel grid and a membrane formed on the aerogel grid, and a radiation source that is adapted to generate radiation at a wavelength of about 20 nm or less that is to be directed through the pellicle toward the reticle.