Carbon EUV Pellicle Structure for Hydrogen Radical Resistance
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Solution Overview
Problem
Existing pellicles in EUV lithography are susceptible to damage from hydrogen radicals and have limited mechanical and thermal performance, leading to reduced operational efficiency and pattern contamination on reticles.
Innovation Solution
A pellicle membrane composed of sp2 and sp3 carbon atoms with a carbon-based core layer and a hydrogen-barrier layer made of transition metal oxynitride is used to protect the reticle pattern from particle contamination and extend service life by mitigating the effects of EUV or DUV radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional pellicle is used in EUV lithography, then the reticle pattern is protected from particle contamination, but the pellicle is susceptible to damage from hydrogen radicals and has limited mechanical and thermal performance
Solution Approach 1:
The pellicle membrane is constructed as a composite structure with a core layer containing sp2 and sp3 carbon atoms providing mechanical strength, surrounded by hydrogen-barrier layers made of transition metal oxynitride. This composite design allows each layer to contribute its specific properties: the carbon-based core provides structural integrity while the transition metal oxynitride layers provide resistance to hydrogen radicals, thus resolving the contradiction between mechanical strength and hydrogen radical resistance.
2Duration of action of stationary object
If a pellicle membrane is stretched over a frame to protect the reticle, then particle contamination is prevented, but the pellicle may suffer from thermal expansion issues and reduced service life
Solution Approach 1:
The pellicle membrane is designed with specific material composition parameters - a core layer with sp2 and sp3 carbon atoms providing mechanical strength, surrounded by hydrogen-barrier layers of transition metal oxynitride. The thickness and composition ratios are optimized to achieve low thermal expansion while maintaining high resistance to hydrogen radicals, thus extending service life under EUV lithography conditions.
3Illumination intensity
If the pellicle is made thinner to improve EUV transmittance, then optical performance improves, but mechanical strength and resistance to damage decrease
Solution Approach 1:
The multi-layer composite structure allows the pellicle to achieve high EUV transmittance through optimized thin-layer design while the sp3 carbon-containing core layer provides enhanced mechanical strength. The hydrogen-barrier layers of transition metal oxynitride add protective functionality without significantly increasing thickness, thus maintaining high transmittance while improving both mechanical strength and chemical resistance.
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 carbon-based core layer provides enhanced mechanical and thermal performance, while the hydrogen-barrier layer protects against hydrogen radicals, ensuring high transmittance and reducing pattern defects, thereby extending the pellicle's service life and maintaining pattern integrity.
Implementation Method 1
forming a core layer on the pellicle border, wherein the core layer comprises sp2 and sp3 carbon atoms
Implementation Method 2
forming a hydrogen-barrier layer at least partially covering the core layer so that a pellicle membrane is formed on the pellicle border
Data Source
AI summary
A method of manufacturing an EUV pellicle, includes steps of depositing a first insulating layer on a substrate; partially removing the substrate to form an opening exposing the first insulating layer; partially removing the first insulating layer while leaving a supporting portion in contact with the substrate; forming a core layer on the supporting portion of the insulating layer, wherein the core layer comprises sp2 and sp3 carbon atoms; and forming a hydrogen-barrier layer on the core layer.