Carbon Nanotube Pellicle Membrane for EUV Etch Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithographic apparatus pellicles and spectral purity filters face challenges in withstanding harsh EUV environments, leading to rapid degradation, out-of-band radiation exposure, and optical element damage, necessitating improved materials and methods to enhance durability and reduce unwanted radiation exposure.
Innovation Solution
Employing uncapped carbon nanotubes with nanoparticles and optional aerogel layers, and using methods like chemical passivation and biased elements to reduce etching and enhance hydrogen recombination, along with regenerative techniques to repair and extend pellicle lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a pellicle is made thinner to increase EUV transmissivity, then transmissivity is improved, but mechanical strength and reliability deteriorate
Solution Approach 1:
The pellicle uses a composite structure combining silicon oxide layers with aluminum or aluminum oxide layers. The silicon oxide provides mechanical strength and structural integrity, while the aluminum layers provide high EUV reflectivity and durability. This composite approach allows the pellicle to maintain thin dimensions for high transmissivity while incorporating materials that provide the necessary mechanical strength to withstand the harsh EUV environment.
2Illumination intensity
If a pellicle is made thinner to increase EUV transmissivity, then transmissivity is improved, but resistance to degradation in harsh environment worsens
Solution Approach 1:
The pellicle employs a composite structure with alternating layers of silicon oxide and aluminum or aluminum oxide. The silicon oxide layers provide chemical stability and resistance to degradation from hydrogen plasma and other harsh EUV environment factors, while the aluminum layers provide high EUV reflectivity. This multi-layer composite design enables the thin pellicle to maintain both high transmissivity and high resistance to environmental degradation.
Solution Approach 2:
The pellicle is designed to operate in the inert vacuum environment of the EUV lithography system, and the silicon oxide and aluminum materials are specifically chosen for their chemical inertness and stability in this environment. The materials resist degradation from hydrogen plasma, oxygen, and other species present in the harsh EUV environment, maintaining reliability despite the thin dimensions required for high transmissivity.
3Ease of manufacture
If conventional materials are used for pellicles, then ease of manufacture is maintained, but durability and lifespan in EUV environment deteriorate
Solution Approach 1:
The pellicle uses a composite structure of silicon oxide and aluminum layers that can be manufactured using established thin-film deposition techniques such as atomic layer deposition (ALD) and sputtering. These are conventional semiconductor manufacturing processes, making the pellicle compatible with existing fabrication infrastructure. The specific layer thicknesses and material compositions are optimized to provide enhanced durability and lifespan in the harsh EUV environment while maintaining compatibility with standard manufacturing processes.
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 provides enhanced durability and reduced degradation of pellicles and spectral purity filters, minimizing deformation and contamination, while maintaining high EUV transmissivity and extending their operational lifespan.
Implementation Method 1
it is necessary for the pellicle to have high EUV transmissivity. A high EUV transmissivity allows a greater proportion of the incident radiation through the pellicle
Implementation Method 2
using methods like chemical passivation and biased elements to reduce etching and enhance hydrogen recombination
Implementation Method 3
Employing uncapped carbon nanotubes with nanoparticles and optional aerogel layers, and using methods like chemical passivation
Data Source
AI summary
A pellicle membrane for a lithographic apparatus, the membrane including uncapped carbon nanotubes. A method of regenerating a pellicle membrane, the method including decomposing a precursor compound and depositing at least some of the products of decomposition onto the pellicle membrane. A method of reducing the etch rate of a pellicle membrane, the method including providing an electric field in the region of the pellicle membrane to redirect ions from the pellicle, or heating elements to desorb radicals from the pellicle, preferably wherein the pellicle membrane is a carbon nanotube pellicle membrane. An assembly for a lithographic apparatus, the assembly including a biased electrode near or including the pellicle membrane or heating means for the pellicle membrane.